Name: a procedure to observe context-induced renewal of pavlovian-conditioned alcohol-seeking behavior in rats
Uploaded: 2014-09-19T14:00:00.000+00:00
Duration: 13 min 24 s
Description: Watch this Scientific Journal Video about A Procedure to Observe Context-induced Renewal of Pavlovian-conditioned Alcohol-seeking Behavior in Rats at JoVE.com

<p class='jove_content'>This work was supported by the National Institute on Alcohol Abuse and Alcoholism (RO1 AA014925 awarded to Dr. Patricia H. Janak at University of California, San Francisco, CA, USA), Fonds de recherche du Quebec &#8211; Sant&#233; (NC) and the Natural Sciences and Engineering Research Council (NC, 387224-2010). The open-access publication of this article was made possible by sponsorship from Med Associates Inc. </p>

<p class="jove_content"> 모든 절차는 콩 코디 아 대학에서 동물 연구 윤리위원회의 승인 및 동물 관리에 캐나다위원회의 추천과 동의합니다. </p><p class="jove_title"> 1 동물 </p><ol><li> (- 도착 240 g을 220) 남성 긴 에반스 쥐를 얻습니다. </li><li> 오전 7:00 조명 12 시간 명암주기에 온도 (21 ° C)와 습도 (44 %) 제어 동물 보호 시설에서 쥐에 유지한다. </li><li> 도착시 페어 - 집 쥐. 삼일 후, 개별적으로 베타 - 칩 침구, 나일론 뼈, 표준 쥐 차우와 물을 무료로 이용할 플라스틱 신발 상자 케이지의 집 쥐. 물병에 더하여, 제 병의 후속 배치를 허용하는 두 고리가 케이지 뚜껑을 사용한다. 참고 : 개별적으로 즉시이 동물 보호 시설에 도착 쥐를 수납 할 수있다. </li><li> 매일 쥐를 처리하기 시작합니다. 참고 : 가이드로 취급 일주는 파이 인에게 적응 충분합니다최대 cked 및 실험자에 의해 처리. </li></ol><p class="jove_title"> 홈 케이지에서 2 간헐적 에탄올 액세스 </p><p class="jove_content"> 참고 : 홈 케이지에서 실시 간헐적 에탄올 접근을 쥐 실험의 행동 훈련 단계는 <sup>17 ~ 19을</sup> 시작하기 전에 에탄올의 생리 학적으로 관련 양을 마실 수 있도록. 이 밝거나 어두운주기 동안 언제든지 초기화 할 수 있지만, 빛 단계에서이 절차를 시작합니다. </p><ol><li> 각 쥐​​에 대한 두 병을 준비합니다. <ol><li> 100 ml의 플라스틱 에탄올 병 473 ㎖의 표준 플라스틱 물병으로 실린더를 졸업 사용합니다. 때문에 누설 및 증발에 에탄올의 손실을 최소화하기 위해, 거의 최대 볼륨 용량을 가득 상대적으로 작은 용량의 에탄올 병을 사용합니다. </li><li> 수돗물에 95 % 에탄올을 희석하여 만든 15 % 에탄올, 한 병을 채 웁니다. NOTE : 다른 에탄올 농도, 예컨대 10 % 또는 20 %로, 15 % 에탄올 대신에 사용될 수도있다. </li><li> 인터넷수돗물 제 병 것이다. </li><li> 각 병에 누설을 최소화하기 위해 볼 베어링을 포함하는 sipper 튜브, 고무 마개를 삽입합니다. </li></ol></li><li> 제어 케이지 쥐 또는 침구 류를 포함하지 않는 제외하고 홈 케이지와 동일하게 취급이 제어 케이지를 설정합니다. <ol><li> 2.1.4 - 2.1.1 단계에 지정된대로 제어 케이지 에탄올과 물을 병을 준비합니다. </li><li> (- 2.8.2 단계 2.8.1에 설명 된대로) 에탄올 액세스 세션의 과정을 통해 발생할 수있는 유출 및 / 또는 증발 제어하는​​ 제어 케이지에서 얻은 방법을 사용하십시오. </li></ol></li><li> 모든 에탄올과 물을 병의 무게를 측정. 모든 무게를 기록한다. </li><li> 모든 쥐의 무게를 측정. 모든 무게를 기록한다. </li><li> 에탄올 병 및 각 가정 케이지의 물 한 병을 놓고 동시에 케이지를 제어 할 수 있습니다. 24 시간 동안 케이지에 두 병을 둡니다. </li><li> 24 시간주기의 끝에서, 두 병에서 제거동시에 케이지. </li><li> 모든 에탄올과 물을 병의 무게를 측정. 모든 무게를 기록한다. </li><li> 이를 24 시간 이전에 각 래트의 홈 케이지에 배치 될 때이 병의 중량으로부터 집 케이지로부터 분리 할 때 24 시간 동안 소비 된 양의 에탄올과 물을 결정하기 위해, 각각의 병의 중량을 뺀다. <ol><li> 이 제어 케이지에 대한 동일한 작업을 수행하고 각 유체에 대한 유출의 평균 금액을 계산합니다. </li><li> 각 쥐​​에 해당하는 에탄올과 물 소비 측정에서 각각 에탄올과 물 유출의 평균 금액을 뺍니다. </li><li> g / kg, 물의 소비 및 에탄올 선호도 에탄올 소비량을 계산하기 위해 이러한 차이 유출 제어 수단을 사용한다. </li></ol></li><li> 에탄올 소비량 (g / kg), 제 전체 용액 (에탄올 + 물 성분)의 농도에 기초하여 부피 (㎖) 에탄올로 소비 된 용액의 중량 (g)으로 변환을 계산하기있어서식 볼륨 (ML) = 무게 (g) / 밀도 (g / ㎖). NOTE : 용액의 에탄올 농도는 농도의 함수로서 변할 것이다. <ol><li> 다음으로, 소비 중량 (g) 에탄올을 수득하기 위해 사용되는 특정 비율 솔루션 스케일링 에탄올의 밀도 (g / ㎖)에 의해 소비 에탄올 용액의 양 (ml)에 곱한다. </li><li> 에탄올 소비량 g / kg 측정 값을 얻기 위해 래트 체중 (kg)에 의해 소비되는 에탄올의 중량 (g)을 나눈다. </li></ol></li><li> 에탄올 선호도를 계산하기 위해, 전체 유체 (에탄올 + 물, ML) 흡기의 비율로 에탄올 섭취 (ml)로 표현한다. </li><li> 쥐의 홈 케이지 만 다시 물병을 돌려줍니다. 다음 24 시간 동안 물에 쥐에 대한 액세스 권한을 부여하지만, 에탄올 없습니다. 대신 에탄올 병의 홈 케이지에 미리 무게 초 물병을 배치합니다. </li><li> 24 시간주기의 끝에서, 동시에 케이지에서 모두 물병을 제거. </li><li> 물 병의 두 세트의 무게를. 녹음 모든 웨이ghts. </li><li> 이 단계 2.8.1에서 설명 된 바와 같이 제어 케이지에서 얻은 평균 유출 측정 값을 감산하는, 24 시간 이전 홈 케이지에 배치 될 때이 병의 중량으로부터 집 케이지로부터 분리 할 때 각각의 병의 중량을 빼기 - 2.8.2. </li><li> 물 소비를 계산하기 위해이 유출 제어 차이 방법을 사용하십시오. </li><li> 2.14 단계 2.1에 기재된 바와 같이, 래트를 에탄올과 물 병 모두를 제공하여 다시 사이클을 시작한다. <ol><li> 에탄올 소비의 높은 안정적인 수준을 유도하는 다수의 (약 12) 세션이주기를 반복합니다. 홈 케이지에서 에탄올 소비의 대표적인 결과 (g / kg)는 <strong>그림 1을</strong> 참조하십시오. </li><li> 사이드 환경의 발달을 방지하기 위해 세션을 통해 케이지 뚜껑에 에탄올과 물을 병의 공간적 위치를 교대. </li><li> 걸쳐 정확하고 안정적​​인 에탄올 농도가되도록 일주일에 한 번씩 신선한 에탄올 용액을 만들기세션. 이 방법을 사용하는 시간의 연장 기간 동안 에탄올을 증발의 영향을 최소화한다. </li></ol></li></ol><p class="jove_title"> 3 장치 </p><ol><li> 통풍, 사운드 감쇠 부스 내부 하우스 각 조절 실. </li><li> 각 조절 스테인레스 스틸 금속 막대 바닥의 실, 명확한 폴리 카보네이트 천장, 명확한 폴리 카보네이트 다시 벽과 현관 문, 알루미늄 금속 패널 측벽을 구축합니다. <ol><li> 중앙에서 오른쪽 금속 측벽의 기지 근처에 유체 포트를 설치합니다. 포트에 항목을 감지하는 적외선 광전지와 유체 포트에 입구를 착용. </li><li> 뭉툭한 팁 바늘을 사용하여 에탄올을 포함하는 20 ML의 주사기에 유체 포트의 뒷면에서 폴리에틸렌 튜브를 연결합니다. 음향 감쇠 부스 밖에있는 주사기 펌프에 주사기를 놓습니다. 파블로프 차별 교육 세션의 경우, 펌프로 배치하기 전에 주사기로 에탄올을로드합니다. 프라임 튜브 나y를 수동으로 펌프를 진행하고 유체 포트에서 초과 에탄올을 닦아. </li><li> 왼쪽 사이드에서 챔버의 천장 근처 중앙 흰색 houselight를 설치합니다. </li><li> 식자 (2 Hz에서 사이클)와 왼쪽 사이드의 왼쪽 상단 모서리에 스피커와 화이트 노이즈 발생기를 설치합니다. </li></ol></li><li> 독특한 상황을 만들 시각, 후각, 촉각 자극의 특정 구성으로 각 조절 챔버 복장. <ol><li> 두 개의 서로 다른 문맥, 상황에 맞는 하나와 문맥이 같은 다른 절반 조절 실의 지정된 컨텍스트 일​​ 및 상황에 맞는 2 구성의 절반을 사용합니다. </li><li> 페트리 접시에 검은 마분지 천장과 전면을 통해 패널과 후면 챔버의 벽 (수돗물에 희석 레몬 오일로 만든 10 % V / V) 스프레이 레몬 냄새를 배치하고 중앙에 배치, 상황에 맞는 하나를 만들려면 챔버의 바닥 아래 금속 폐기 트레이, 그리고 금속 R 위에 투명한 폴리 카보네이트 층 패널을 삽입외경 층. 흡수 종이 타월이나 벤치 라이너 폐기물 트레이 라인. </li><li> 상황이를 만들려면, 그들은 분명 있도록 페트리 접시에 (수돗물 벤즈알데히드를 희석하여 만든 10 % V / V) 아몬드 냄새 스프레이 중앙 배치, 발견 챔버의 천장과 전면 및 후면 벽을두고 챔버의 바닥 아래 금속 폐기 트레이 및에 금속봉 위에 바닥 천공 금속 플로어 패널을 삽입한다. 흡수 종이 타월이나 벤치 라이너 폐기물 트레이 라인. </li></ol></li></ol><p class="jove_title"> 4 습관화 </p><p class="jove_content"> 행동 훈련 방에 쥐 습관화 및 공기 챔버 내에서이 컨텍스트의 각. 실험이 단계의 경우, 20 ml의 주사기로 에탄올을로드하지 않습니다. </p><ol><li> 이 짧은 습관화 세션의 실험실에서 행동 훈련 방에 동물 보호 시설에서 이송되는 과정에 쥐를 길들. <ol><li> 첫 번째 세션에서, 래트를로드 나n은 그들의 집 동물 관리 시설에서 휠 카트 상 케이지, 및 실험실 행동 트레이닝 실에 전송. , 실내 조명을 밝히는 각 사운드 감쇠 부스에서 팬을 켜고 방을 종료하고, 문을 닫고 카트에 자신의 홈 케이지에 남아있는 동안 쥐가 20 분 동안이 새로운 환경에 적응 할 수 있습니다. 이 20 분의 기간이 종료되면, 동물 관리 시설에 쥐를 반환. </li><li> 두 번째 세션에서, 실험실에서 행동 훈련 방에 쥐를 가지고. 이전으로, 객실의 조명과 칸막이 팬을 둡니다. 문이 혼란을 최소화하기 위해 폐쇄와 함께 방에 남아 있고, 처리하고 행동 훈련 방에 각각 쥐의 무게. 무게를 기록하고 동물 보호 시설로 쥐를 반환합니다. </li></ol></li><li> 이 짧은 습관화 세션에서 조절 챔버에 쥐를 길들. <ol><li> , 행동 훈련 방에 쥐를 운반 각 쥐의 체중을 기록,그리고 그 지정 조절 실에 각각 쥐를로드합니다. </li><li> 첫번째 습관화 세션에서 절반 상황 1과 챔버와 문맥이 같은 나머지를 설정합니다. </li><li> 제 습관화 세션에서 이전 세션에서 사용하지 않은 콘텍스트 각 챔버를 설정. </li><li> , 쥐의 이러한 절반은 제 이상적 상황 1이어서 제 문맥이 노출되는 상황이, 다른 절반이어서, 콘텍스트 (1)에 노출되어, 카운터 방식 습관화 세션을 수행 모두 습관화 세션을 수행 필요한 경우가 이일에 분산 될 수 있지만 같은 날. </li><li> 습관화 세션의 경우, 프로그램이 실행 된 후 1 분 houselight을 조명하는 컴퓨터 프로그램을 사용한다. 20 분 세션 중에 유체 포트 항목의 총 수를 기록한다. 세션의 끝에서, 해제 houselight 프로그램. 습관화 세션 중에 에탄올 또는 단서를 제공하지 마십시오. </li></ol></l난&gt; <li> , 챔버에서 쥐를 제거 자신의 홈 케이지에 반환하고, 동물 보호 시설로 다시 운반 할 것. </li><li> 장비 <em>(예를 들면,</em> 플로어 패널, 폐기물 운반, 페트리 접시)를 청소합니다. 자세한 내용은 단계 5.7를 참조하십시오. </li></ol><p class="jove_title"> 5 파블로프 차별 교육 (PDT) </p><p class="jove_content"> 행동면에 기차 쥐 에탄올이 아닌 초 청각 신호와 결합되어 한 청각 신호를 구별합니다. 실험이 단계의 경우, 15 % 에탄올로 20 ml의 주사기를 입력합니다. </p><ol><li> 단계 3.3.2 및 3.3.3에 기술 된 바와 같이, 특유의 콘텍스트를 생성하는 시각적, 후각의 특정 구성, 및 촉각 자극과 각 조절 실을 옷 <ol><li> 에탄올 소비 및 선호도에 따라, 컨텍스트 1과 카운터 방식이 문맥에 나머지 절반에 쥐의 절반이 할당 홈 케이지 에탄올 액세스 과정의 마지막 2 세션에서 평균화. 계속 참조내선 상황에 맞는 A. 참고로 PDT 동안 사용 : 각 쥐은 훈련이 단계에서 하나의 상황을 경험해야합니다. </li><li> 후각 자극이 각 조절 실에 추가 할 수있는 마지막 상황에 맞는 자극이 있는지 확인합니다. 후각 자극을 포함하는 서로 다른 냄새의 comingling을 최소화하기 위해 챔버와 음향 감쇠 부스의 문을 닫습니다. </li></ol></li><li> , 행동 훈련 방으로 쥐를 가져와 각 쥐의 체중을 기록하고 그 지정 조절 실에 각각 쥐를로드합니다. </li><li> 각 PDT 세션 동안 다음과 같은 일련의 이벤트를 제어하는​​ 컴퓨터 프로그램을 시작합니다. <ol><li> 프로그램 후 5 분가 발급 된에서, houselight을 밝히는. </li><li> 백색 잡음 자극을 제시하고 리모콘은 16 회를 자극. CS +로 이러한 청각 자극 중 하나를 지정하고 다른 두 컨텍스트 걸쳐 카운터 방식, CS-한다. </li><li> 각 CS + 및 CS - 시험 리터를 확인대서양 표준시 10 초. </li><li> CS +의 마지막 6 초 동안 유체 포트에 0.2 ㎖의 에탄올을 제공합니다. CS- 중에 에탄올을 제공하지 마십시오. </li><li> 각 PDT 세션 평균 마지막 58 분을합니다. 변수 시간 67 초 일정에 CS + 및 CS - 각을 제시한다. </li><li> 10 초 CS 간격 동안 기록 유체 포트 항목 (CS 프레 젠 테이션 도중 10 초), 10 초 미리 CS 간격 (직전 CS 발병에 10 초), 그리고 10 초 후 CS 간격 (즉시 10 초 다음 CS는 CS + 및 CS - 프리젠 테이션뿐만 아니라, 전체 세션에 대한 총 유체 포트 항목 모두에 대해) 오프셋 (offset). 또한 이러한 간격 중에 각 포트 항목의 지속 시간을 기록한다. </li><li> 세션의 끝에, houselight을 해제. </li></ol></li><li> , 챔버에서 쥐를 제거 자신의 홈 케이지에 반환하고, 동물 보호 시설로 다시 운반 할 것. </li><li> 쥐가 각 PDT의 배달 에탄올 3.2 ml의 소비되도록 유체 포트 확인ession. </li><li> 소량의 물을 함유하는 60 ml의 시린지로 폴리에틸렌 튜브에서 에탄올 세척. 그리고, 건조 있는지 확인하기 위해, 둘째, 빈 주사기를 사용하여 튜브를 통해 공기의 60 ML을 전달합니다. </li><li> 장비를 청소합니다. 매일 청소를 들어, 바닥 패널, 폐기물 트레이 및 배양 접시를 씻으십시오. 주되면 전체 조절 챔버 청소. 실험 장치에 원치 않는 냄새를 도입 피하기 위해 향수 청소 제품을 사용하지 마십시오. </li><li> 쥐 CS- 대 CS +에 자신의 포트 항목 응답 안정적 차별을 표시 할 때까지 매일 PDT 세션을 계속합니다. 참고 : CS-에 대한 응답으로 만든 포트 항목이 낮게 유지해야하는 반면 CS +에 대한 응답으로 만든 포트 항목이 세션을 통해 증가 할 전망이다. 필요한 PDT 세션의 정확한 수는 가이드로에 약 20 세션을 계획 다를 수 있습니다 응답 조건 차별, 그러나 달성하기 위해. </li></ol><p class="jove_title"> 6 소멸 </p><ol><li> 각 조절을 참 복장BER 시각, 후각, 촉각 자극으로 쥐 PDT 세션 동안 경험 한 별개의 컨텍스트를 만들 수 있습니다. 컨텍스트 1 PDT에 사용 된 경우, 예를 들어, 소쇠 세션 문맥이 같은 챔버를 구성. B. 콘텍스트로서 흡광 동안 사용 컨텍스트를 참조 </li><li> 동일 PDT 세션에 멸종 세션을 실시하지만, 연사 + 중에 에탄올을 제공하지 않습니다. <ol><li> CS +와 CS-을 제시 PDT 동안 사용 된 동일한 컴퓨터 프로그램을 사용합니다. </li><li> 실험 단계에 걸쳐 일관성을 유지하기 위해, 주사기 펌프에 빈 주사기를로드하고, 펌프를 온 떠난다. 폴리에틸렌 튜브 멸종 세션 전에 에탄올이 포함되어 있는지 확인합니다. </li></ol></li><li> 쥐가 더 이상 쇼 CS + 및 CS - 사이에 응답 차별까지 매일 멸종 세션을 계속합니다. 참고 : 더 differe이 없을 때까지 CS +에 대한 응답으로 만든 포트 항목은 점차 멸종 세션에 걸쳐 감소 할 전망CS-에 대한 응답으로 만든 CS +에 대한 응답으로 만든 포트 항목 및 포트 항목 사이 후부. 다를 수 있습니다 응답 이었지만, 가이드로에 약 8 세션을 계획 소화 필요한 멸종 세션의 정확한 숫자. </li><li> 단계 14.4에 기재된 바와 같이, 각 세션의 끝에 장비를 청소한다. </li></ol><p class="jove_title"> 7 컨텍스트에 의한 갱신 테스트 </p><ol><li> PDT 세션 동안 경험 한 상황을 만들 시각, 후각, 촉각 자극 각 조절 챔버를 착용. 예를 들어, 주어진 쥐 PDT 세션에서 문맥을 경험 한 경우, 테스트 세션 컨텍스트 한 그의 챔버를 구성. 컨텍스트 A와 갱신 테스트 중에 사용되는 컨텍스트를 참조하십시오 </li><li> 동일 PDT 세션에 상황에 의한 갱신 시험을 실시하지만, 갱신 테스트 중에 에탄올을 제공하지 않습니다. 제시 <br /> 에탄올을 보류 CS +와 PDT 세션 동안 이전과 CS-하지만. <ol><li> 같은 컴퓨터의 홍보를 사용하여CS + 및 CS -을 제시 PDT 동안 사용되었다 ogram. </li><li> , 단계에 걸쳐 일관성을 유지 주사기 펌프에 빈 주사기를로드하고 나가려면 펌프가 켜져. 폴리에틸렌 튜브 테스트 세션 전에 에탄올이 포함되어 있는지 확인합니다. </li></ol></li><li> 파블로프 에어컨 알코올 추구 행동의 맥락에 의한 갱신을 준수하십시오. 주 :이 갱신 효과는 CS + 및 CS- 상대적 CS-에 응답하여 만들어진 포트 엔트리 동작 변경없이, CS +에 응답하여 만들어진 포트 항목의 수를 선택적 증가에 의해 명백 할 것이다는 관찰이 응답 멸종 훈련의 끝. </li><li> 단계 14.4에 기재된 바와 같이, 세션의 끝에서 장비를 청소한다. </li></ol>

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<p class="jove_content"> 모든 실험 절차는 콩 코디 아 대학 (Concordia University) 동물 연구 윤리위원회의 승인 및 동물 관리에 캐나다 협의회 지침에 따라 <span style="font-size: 14px; line-height: 28px;">아르되었다.이 기사의 오픈 액세스 출판은 메드 어소 시에이 츠 주식 회사에서 후원에 의해 가능하게되었다</span> </p>

<p class="jove_content"> 이 절차의 결과는 정기적으로 알코올 배달을 함께 분리 된 환경 자극은 알코올 추구 행동을 구동 할 수있는 능력을 획득 할 수 있음을 알 수있다. 그들은 또한 유용성 또는 알코올의 부재와 관련된 문맥 자극 이산 알코올 예측 신호에 행동 반응을 조절 안내 할 수 있음을 보여줍니다. </p><p class="jove_step"> 프로토콜 내에서 중요한 단계 </p><p class="jove_content"> 본 작업의 컨텍스트는 쥐 외부의 자극을 통합합니다. 그러나 시험에서 쥐의 interoceptive 상태도 갱신 <sup>(20)에 영향을</sup> 미칠 수있는 &#39;맥락&#39;을 구성 할 수있다. 그것은 두개 내 미세 주입하거나 전신 주사처럼, 갱신 시험 전에 발생과 interoceptive 상태를 변경할 수있는 절차에 쥐 습관화하는 것이 중요하다. 또한, 미세 주입하거나 전신 주사에 습관화 멸종와 PDT의 모두 이전에 수행되어야한다essions는 실험의 하나의 특정 단계와 연관되는 것을 같은 절차를 방지합니다. </p><p class="jove_content"> 이러한 CS 기간, CS-US 간격 및 intertrial 간격 (ITI)와 같은 시간적 매개 변수는, 긴 에어컨 패러다임 <sup>21-26의</sup> 다양한 반응 조절에 영향을 미칠 것으로 알려져있다. 마찬가지로, 시간 매개 변수는 우리의 절차의 갱신 효과의 관찰에 영향을 미칠 수있다. 계획서에 명시되지 않은 매개 변수의 세트는 실험적으로 더 큰 수사를 고용하기 전에 파일럿 연구에서 검증해야합니다. </p><p class="jove_step"> 수정 및 문제 해결 </p><p class="jove_content"> 이전 연구는 쥐 홈 케이지 소비 에탄올의 양은 <sup>17,27 쥐를</sup> 구입하는 보조 장비의 기능에 따라 달라질 수 있다는 것을 발견했다. 공급자는 따라서이 단계의 연구를위한 중요한 고려 사항이다. 유사하게, 랫트 균주의 선택은 협력해야에탄올 소비 <sup>28 ~ 31의</sup> 변형 차이의 수많은 보고서가있는 한,주의 깊게 nsidered. </p><p class="jove_content"> 혐오 에어컨 패러다임의 이전 작업은 쥐의 발달 연령은 파블로프 조건화 된 공포 반응 <sup>(32)의</sup> 갱신의 관찰에 영향을 미치는 것으로 나타났습니다. (생후 20 일 미만) 아주 어린 쥐의 갱신 효과의 부족으로 인해 문맥 정보 <sup>(33)의</sup> 장애인 인코딩으로 제시되고있다. 본 절차에 사용되는 래트의 발달 나이 따라서 고려해야한다. </p><p class="jove_content"> 10 % <sup>9,16,</sup> 15 % <sup>14,</sup> 또는 20 ~ <sup>15</sup> % 에탄올 솔루션은 홈 케이지 에탄올 접근과 실험의 PDT 단계 동안 사용했을 때 파블로프의 조건화 알코올 추구 행동의 연장이 관찰되었다. 연구자들은 실험 실용에서이 절차를 확립 할 목적으로 이러한 에탄올 농도 중 하나를 사용할 수도이거 야. </p><p class="jove_content"> 파블로프 차별 교육의 취득시는 전달 된 모든 에탄올 소비되었는지 확인하기 위해 각 세션 후에 유체 포트를 확인하는 것이 중요합니다. 추가로 10에 대한 조절 챔버에서 쥐를 떠나 - 각 세션 후 15 분은 세션 동안 소비되지 않은 모든 에탄올의 소비를 장려하기 위해 초기 PDT에서 수행 할 수 있습니다. PDT이 진행됨에 따라 사용되지 않은 포트에 에탄올을 떠나는 쥐의 수는 감소한다. PDT 쥐의 말에 어느 경우 () 모든 에탄올을 소비하지 및 / 또는 (b)는이 주제는 연구에서 제외해야 다음 CS +에 응답하지 않습니다. 대부분의 쥐 안정적으로 CS-보다 연사 +에 더 반응한다. 그러나 일부 쥐함으로써 차별의 증거를 보여주는하지, 두 신호에 높은 수준에 응답 할 수 있습니다. 높은 PDT 동안 CS + 및 CS - 모두에 반응 보여 쥐 연구에서 제외되지 않습니다. 우리의 경험에 의하면,이 주제는 현저한 차별을 보여PDT시 CS- 응답의 높은 수준의 유체 포트에서 에탄올의 존재에 의해 구동되는 것을 시사 에탄올의 부재하에 제 소등 세션 동안. 이 과목은 강력한 재생 효과를 표시하는 경향이있다. </p><p class="jove_step"> 절차의 한계 </p><p class="jove_content"> 내구성 시험은 에탄올의 부재하에 수행되기 때문에, CS +에 의해 유도 된 조건 포트 항목 서서히 테스트 세션에 걸쳐 감소. 따라서, 행동의 전체 양이 실험적으로 유발 된 변화가 평가 될 수있는에 대해 테스트에서 생성 상당히 낮습니다. 응답이 태스크에 테스트 세션의 단부 대 시작에서 높게되는 경향이 있기 때문에 시험 별 시험 기초 응답 조건화 실험 조작에의 영향을 조사하는 것이 중요하다. </p><p class="jove_content"> 유체 콘센트에 항목이 작업의 주요 종속 측정을 제공합니다. 그러나, 잘못된 포트 항목은 REGI 수 있습니다동물의 수염이 유체 개항에 걸쳐 적외선 빔을 깰 유체 용기에 충분히 가까운 경우 st​​ered. 자주, 잘못된 응답이 분명하지만 전체 포트의 극적인 증가는 이전 세션에서 피사체의 동작을 기준으로 항목으로. 동물을 동영상으로 녹화하는 것은 가능합니다 잘못된 응답의 검출을 용이하게하고, 교육 및 테스트를 통해 쥐에 의해 전시 된 행동의보다 세분화 된 분석을 허용합니다. </p><p class="jove_step"> 기존의 / 대안적인 방법에 대한 기술의 중요성 </p><p class="jove_content"> 약물 추구 행동의 상황에 의한 갱신은 대부분 이러한 레버를 눌러 <sup>8,34</sup> 또는 <sup>12 코를</sup> 찌를으로 차 종속 변수가 조작 적 반응 인 수단 조절 작업을 사용하여 연구되고있다. 본 절차에서, 약물 - 추구 응답의 프레젠테이션에 의해 유도되는 유체 포트 &#39;방식은 에어컨&#39;이다CS의 +. 이 응답은 가능성이 환경 자극과 인간의 남용 약물의 약리 효과 사이의 연결의 형성을 매개하는 학습 과정이다 파블로프 학습을 통해 획득된다. </p><p class="jove_step"> 미래의 응용 프로그램 </p><p class="jove_content"> 이 작업은 파블로프 에어컨 알코올 추구 행동 <sup>16의</sup> 상황에 의한 재생에 관여하는 신경 메커니즘을 연구하는 신경 약리학, optogenetics 및 신경 화학과 함께 사용할 수 있습니다. 또한, 파블로프 에어컨 알코올 추구 행동의 수집 및 멸종을 조절 행동 및 신경 메커니즘을 조사 할 수 있습니다. 마지막으로,이 작업은 인간의 ADDI의 큐 노출 치료 후 약물 예측 신호에 반응에 환경 상황을 관련 약물의 영향을 감소하기위한 중개 연구를위한 중요한 방향을 갱신하지 못할 수 있습니다 멸종의 조작을 탐구하는 데 사용할 수 있습니다CTS. </p>

<p class="jove_content"> 깨어 남은 알코올 남용 장애로 고통 개인이 직면 상당한 도전이다. 금욕은 파블로프 조절을 통해 취하게 <sup>1, 2와</sup> 관련 될 수있는 일상적으로 음주를 함께 환경 적 자극의 행동 심리학 적 및 생리 학적 영향에 대한 취약성의 시간입니다. 알코올 예측 단서에 노출되면 재발 <sup>3,4을</sup> 촉진 알코올을 추구하는 행동을 촉진 할 수 있습니다 알코올 갈망과 같은 조건 반응을 유도 할 수 있습니다. </p><p class="jove_content"> 알코올 소비로 이어질 행동의 틀에 박힌 순서는 자극의 특정 유형의 일상적 알코올 섭취의 약리 효과되기 직전에 발생 될 수 있습니다. 예를 들어, 시각, 냄새와 알코올의 맛이 확실하게 중독 앞에 알코올의 감각 속성입니다. &#39;불연속&#39;또는 &#39;PROXIMA로 지칭되는 이러한 신호 이외에리터 &#39;큐, 마약 정기적으로 또한 갈망 <sup>5,6을</sup> 자극 할 수 있습니다 사용되는 환경 상황. 약이 이전에 따라서 재발 <sup>칠위한</sup> 중요한 트리거 될 수 있습니다 사용되어왔다있는 물리적 위치에 노출. </p><p class="jove_content"> 동물 모델은 약물 - 추구 행동 <sup>8-13</sup> 약물에 관련된 컨텍스트의 영향을 중재 신경 기전을 연구하기 위해 개발되었다. 여기에 설명 된 절차는 알코올 소비와 관련된 상황은 이산, 알코올 예측 파블로프 큐에 의해 유발되는 알코올 추구 행동을 조절하는 방법의 조사를 할 수 있습니다. </p><p class="jove_content"> 파블로프 차별 교육은 쥐가 행동면이 청각 조건 자극, 알코올과 짝을 이루는 CS의 +, 그리고 아닌 CS-을 구별하는 훈련 특정 환경 컨텍스트에서 수행된다. 멸종 세션은 다음 CS에 응답하는 다른 문맥에서 실시하고 있습니다알코올의 결과 보류 된 것으로 +는 줄어든다. 그 후, 알코올 관련, 파블로프 교육 컨텍스트에 재 노출은 CS-에 응답에 변화와 CS +에 의해 유도 된 알코올 추구 행동의 선택적 증가를 트리거합니다. 우리는 지속적으로 <sup>9,14-16를</sup> 복제 한이 결과는, 약물 컨텍스트 약물 전달 <sup>10,13와</sup> 관련된 조작 적 반응의 재생을 촉진하는 것으로 밝혀졌다있는 수단이 조절 절차에서 연구 결과를 확장합니다. </p>

<table><tbody><tr><td>Heavy-duty utility cart</td><td>Rubbermaid</td><td>#4520-88</td><td>Used to transport rats in their home cage from the colony room to the behavior room or other facilities</td></tr><tr><td>Rats, Long-Evans</td><td>Harlan</td><td></td><td>Rats weighed 220-240 g on arrival</td></tr><tr><td>Ohaus scale</td><td>Fisher</td><td>#S402421</td><td>For weighing rats; tare the bottom of a plastic container first, then put the rat in it to weigh it</td></tr><tr><td>Beta-chips, aspen</td><td>Harlan</td><td>#7090A</td><td>Bedding for home cage</td></tr><tr><td>Nylabone</td><td>Bio-Serv</td><td>#K3580</td><td>Enrichment provided in the home cage</td></tr><tr><td>Autoclavable rodent chow</td><td>Agribrands, Charles River</td><td>#5075</td><td>For feeding rats</td></tr><tr><td>Wire bar cage lid</td><td>Ancare</td><td>#R20SS2B</td><td>Custom made with two slots for&amp;nbsp; bottles</td></tr><tr><td>Cage bottom</td><td>Ancare</td><td>#R20PC</td><td>To house rats</td></tr><tr><td>Stoppers</td><td>Ancare</td><td>#8.5</td><td>Rubber stoppers to occlude opening in water bottles &amp;amp; graduated cylinders; goes with ball point sipper tubes&amp;nbsp;</td></tr><tr><td>Ball point tubes, 1.5&quot; length</td><td>Ancare</td><td>#TD-99</td><td>Inserted in stoppers, enables rats to drink from water bottles and graduated cylinders</td></tr><tr><td>Water bottles</td><td>Ancare</td><td>#FSPC8HT</td><td>473 ml (16 oz) capacity, needs to be occluded with stopper</td></tr><tr><td>Graduated cylinders, 100 ml</td><td>Fisher</td><td>#0300741</td><td>To contain ethanol during alcohol exposure in the home cage; spouted end needs to be cut off to enable occlusion with stoppers</td></tr><tr><td>Mettler scale</td><td>Mettler Toledo</td><td>#MS6001S</td><td>For weighing water bottles and ethanol cylinders</td></tr><tr><td>Polyethylene tubing, 1/32&quot; inner diameter,&amp;nbsp; 1/32&quot; wall thickness, 3/32&quot; outside diameter</td><td>Fisher</td><td>#14-169-1A</td><td>To connect 20 ml ethanol syringe to fluid port</td></tr><tr><td>Needle, 18 g, 1.5&quot; length</td><td>Fisher</td><td>#B305199</td><td>To connect polyethylene tubing to ethanol syringes; needs to be filed</td></tr><tr><td>Syringes, 20 ml, Luer-Lok non-sterile</td><td>Fisher</td><td>#1482316J</td><td>To contain ethanol on the fluid pumps; needs to be connected to the polyethylene tubing by a 18 G 1 1/2 needle</td></tr><tr><td>Syringes, 60 ml, Luer-Lok non-sterile</td><td>Fisher</td><td>#14-820-11</td><td>To flush polyethylene tubing after PDT sessions</td></tr><tr><td>Single speed syringe pump, 3.33 rpm</td><td>Med Associates Inc.</td><td>#ENV-018MD</td><td>To hold 20 ml ethanol syringes and deliver ethanol</td></tr><tr><td>Fluid port</td><td>Med Associates Inc.</td><td>#ENV-254-CB</td><td>To enable ethanol delivery during PDT sessions; connected to ethanol syringes with polyethylene tubing</td></tr><tr><td>Port entry infrared detector</td><td>Med Associates Inc.</td><td>#ENV-215M</td><td>Fixed on both sides of&amp;nbsp; fluid port; need 2 per fluid port</td></tr><tr><td>Houselight, 28 V, 100 mA</td><td>Med Associates Inc.</td><td>#ENV-135M</td><td>Provides general lighting in conditioning chamber</td></tr><tr><td>Clicker module</td><td>Med Associates Inc.</td><td>#ENV-225SM</td><td>Auditory stimulus for conditioning chamber</td></tr><tr><td>White noise generator with speaker</td><td>Med Associates Inc.</td><td>#PHM-100</td><td>Auditory stimulus for conditioning chamber</td></tr><tr><td>Bar floor</td><td>Med Associates Inc.</td><td>#ENV-009A-GF</td><td>To go with modular test chamber</td></tr><tr><td>Bench coat, absorbent</td><td>VWR</td><td>#89126-790</td><td>Absorbent paper to put in metal tray, needs to be cut to fit the metal tray</td></tr><tr><td>Polycarbonate sheet, 1/8&quot; thick, 12-5/8&quot; x 10&quot;</td><td>Johnston Plastics</td><td>#30102515</td><td>To make smooth transparent floor insert used for context 1. Needs to be cut in 11.5&quot; x 12.25&quot; pieces</td></tr><tr><td>Aluminium sheet perforated, 0.063&quot; thick, 48&quot; x 96&quot;, 0.250&quot; holes x 0.375&quot; centers</td><td>Anica Steel</td><td></td><td>To make perforated floor insert used for context 2. Needs to be cut in 11.5&quot; x 12.25&quot; pieces</td></tr><tr><td>Black cardboard, 0.053&quot; thick, 28&quot; x 44&quot;</td><td>Omer DeSerres</td><td>#P1909</td><td>To construct panels covering the ceiling, door and back wall of the conditioning chamber in context 1. Needs to be cut to size. Each chamber needs three panels measuring approximately 11.5&quot; x 13.25&quot;. The panels can be joined by the narrower side using duct tape.</td></tr><tr><td>All-purpose strength duct tape, 1.88&quot; x 45 yd.</td><td>Duck Tape</td><td></td><td>Adhesive material to connect the black cardboard panels used to cover the back wall, ceiling and door in context 1.</td></tr><tr><td>Modular test chamber</td><td>Med Associates Inc.</td><td>#ENV-009A</td><td>Conditioning chamber</td></tr><tr><td>Sound attenuating cubicles</td><td>Med Associates Inc.</td><td>#ENV-200R3AM</td><td>Comes with installed 28 V DC fan (#ENV-025F)</td></tr><tr><td>Petri dish</td><td>Fisher</td><td>#08748B</td><td>Bottom only, to contain the sprayed solution that provides the odor stimulus; needs to be centered in the metal tray in conditioning chambers</td></tr><tr><td>PCI interface package</td><td>Med Associates Inc.</td><td>#DIG-700P2-R2</td><td>Connects tabletop interface cabinet to computer; includes 1 interface card, 1 Decode card, 1 ribbon cable and 1 28 V DC power cable</td></tr><tr><td>Large tabletop cabinet and power supply</td><td>Med Associates Inc.</td><td>#SG-6510D</td><td>Used to contain the 12 cards included in the SmartCrtrl 8 Input, 16 Output package</td></tr><tr><td>SmartCtrl 8 Input, 16 Output package</td><td>Med Associates Inc.</td><td>#DIG-716P2</td><td>Used to connect and control the devices in the conditioning chamber. The package includes all the cables, the interface module and the connection panel.</td></tr><tr><td>Med PC IV software</td><td>Med Associates Inc.</td><td>#SOF-735</td><td>Software to run programs. Needs to be installed on the computer.</td></tr><tr><td>Monitor LG, 19&quot; LCD</td><td>Concordia computer store</td><td>#W1942TQ-BF</td><td>Computer monitor; to go with computer running Med PC IV</td></tr><tr><td>HP Z200 tower workstation</td><td>Concordia computer store</td><td>#BZ788US#ABA</td><td>Computer on which Med PC IV is run</td></tr><tr><td>Benzaldehyde, &amp;ge;99%</td><td>Les produits chimiques OMEGA Chemical Company Inc.</td><td>#B37-50</td><td>Dilute in tap water for almond context odor</td></tr><tr><td>Lemon oil, cold pressed, California</td><td>Sigma Aldrich</td><td>#W262528-1KG-K</td><td>Dilute in tap water for lemon context odor</td></tr><tr><td>Ethyl alcohol, 95%</td><td>Commercial Alcohols</td><td></td><td>Dilute in tap water to desired concentration</td></tr></tbody></table>

a procedure to observe context-induced renewal of pavlovian-conditioned alcohol-seeking behavior in rats

<p class="jove_content"> 환경 상황은 학대의 약물 갈망, 절제 약물 사용자의 약물 추구 행동과 프롬프트 재발을 촉진 할 수있는 주관적인 파블로프 에어컨 반응을 일으킬 수 있습니다 소비된다. 우리는 쥐에서 알코올을 추구하는 행동의 내용이 영향을 중재하는 행동 및 신경 프로세스를 연구하기위한 절차를 개발했다. 맛에 순응하고 홈 케이지에서 15 % 에탄올의 약리학 적 효과에 따라, 남성 롱 에반스 쥐 조절 챔버에서 파블로프 차별 교육 (PDT)를받을 수 있습니다. 각 매일 (월 - 금) PDT 세션에서 16 시험이 다른 10 초 청각 조건 자극의 각이 발생합니다. 한 자극 중에 + CS는, 15 % 에탄올 0.2 ㎖를 경구 섭취 유체 포트에 전달된다. 두 번째 자극, CS-에탄올와 연결되어 있지 않습니다. 세션에 걸쳐, CS- 동안 항목 반면 CS + 증가하는 동안 유체 포트에 항목, predi 것을 나타내는 낮은 수준에서 안정CS + 에탄올 간의 연관은, 중지 취득한다. PDT 동안 각 챔버는, 시각 후각 및 촉각 상황에 맞는 자극의 특정 구성을 갖추고있다. PDT에 따라, 멸종 훈련은 지금 상황에 맞는 자극의 다른 구성을 갖추고 동일한 챔버 내에서 수행된다. CS + 및 CS -는 이전과 같이 제시되어 있지만, 에탄올은 CS +시 포트 항목의 점진적인 감소가 발생하는 원천 징수된다. 시험에서 쥐 PDT 컨텍스트에 다시 배치됩니다 및 이전과 CS + 및 CS - 제시하지만, 에탄올없이. 이 조작은 CS- 동안 응답에 변화와 예측 CS + 알코올 중에 포트 항목의 수를 강력하고 선택적 증가를 트리거합니다. 문맥 유도 갱신이라고도이 효과는, 파블로프 알코올 큐에 응답하여 알코올 추구 행동을 자극하는 알코올 섭취와 관련된 컨텍스트의 강력한 능력을 나타낸다. </p>

<p class="jove_content"> 홈 케이지에서 간헐적 에탄올 액세스 : - 12 회 <strong>(그림 1)</strong> 에탄올 소비 (g / kg) 및 홈 케이지에서 간헐적 인 에탄올 액세스 세션에서 에탄올 선호도 증가는 일반적으로 8 내에서 안정적인 수준에 도달. <strong>도 1에</strong> 도시 된 데이터 세트의 안정된 에탄올 소비량 홈 케이지 에탄올 액세스의 마지막 세션에 걸쳐 평균이 1.33에서 ranged - 개별 쥐 6.44 g / kg을. g / kg 소비 plateaued 일단 실험의 홈 케이지 에탄올 소비 단계는 중단 될 수 있고, 쥐의 세션 수를 마시는이 안정된 수준으로 유지된다. </p><p class="jove_content"> 이 단계에서 데이터를 분석하기 위해, 에탄올 소비 (g / kg)과 에탄올 기본 설정에 대한 세션의 피험자 내 요인에 걸쳐 분산 (ANOVA)의 별도의 회 반복 측정 분석을 실시하고 있습니다. </p><p class="jove_content"> 문맥 유도 갱신 절차의 개략도 : 각 위상실험 절차 (PDT, 소멸, 갱신 시험) <strong>그림 2에</strong> 도시되어있다. 자세한 내용은 그림 캡션을 참조하십시오. </p><p class="jove_content"> 응답 방법 및 데이터 분석 : 아래 설명 된 모든 행동 단계에서는 CS + 및 CS- 중에 포트 엔트리 응답은 기준선 입항 응답-CS 사전을 참조하여 정규화된다. 정규화 된 CS 조치를 만들려면 사전 CS 기준 간격 중에 포트 항목의 수를 CS +와 CS-의 프리젠 테이션 중에 포트 항목의 수와 (CS 발병 직전 10 초)을 뺍니다. 행동의 지표가 기준선 수준 이상으로 상승 CS 프레 젠 테이션에 의해 구체적으로 도출으로 표준화 된 CS + 및 표준화 CS- 조치는 역할을한다. </p><p class="jove_content"> 별도의 회 반복 측정 ANOVA는 PDT 멸종 단계에 대한 세션 및 CS 유형 (CS-대 CS +)의 반복 피험자 내 요인으로 실시한다. 단계에 걸쳐 비교를 들어 (PDT는 멸종 갱신알 검사) 사용 데이터 PDT 및 소등의 마지막 두 세션 및 회 반복 측정 ANOVA의 내구성 테스트 데이터 중 하나의 세션에 걸쳐 평균화. 다중 비교를 위해 보정 독립적이거나 쌍 샘플에 대한 중요한 주 효과 및 상호 작용, 사용 <em>후 임시의</em> t-테스트를 ​​추적합니다. 중요성에 대한 기준은 α = 0.05로 설정된다. </p><p class="jove_content"> PDT : PDT 세션에서 CS + 증가 포트 항목의 응답은, CS-포트 항목 응답은 전반적으로 낮고 안정적​​으로 유지하는 반면. PDT 훈련의 초기 세션에서 약간 증가 할 수 CS-에 해당 포트 항목의 응답을 참고; 그러나 CS-에 응답하여 만들어진 항목은 포트의 CS +에 응답하여 만들어진 것보다 더 낮은 수준에서 안정화. 성공적인 차별 CS 동안 포트 항목에서 통계적으로 유의 한 상승에 의해 입증 + CS- <strong>(그림 3)에</strong> 비교된다. 이 결과는 파블로프 에어컨 알코올을 추구하는 행위가 될 수 있음을 나타냅니다엉 CS-을 CS +에 설립 있지만. </p><p class="jove_content"> 멸종 : CS + 포트 항목의 응답이 점차 멸종 세션에서 거절합니다. CS-포트 항목의 응답은 멸종 세션에서 낮고 안정적​​으로 유지. 이상적으로, CS + 및 CS -에 포트 항목 사이에 통계적으로 유의 한 차이의 부족에 의해 입증, 멸종 훈련의 말에 폐지 응답 차별. 그러나, 심지어 흡광 트레이닝의 끝에서, 남아 응답 판별 어느 정도 드문 일이 아니다. 이 경우,이 소등 훈련, 소등의 시작에서 CS + 포트 엔트리 응답에 비해 통계적으로 더 낮뿐만 아니라 PDT의 끝의 끝에서 CS + 해당 포트 엔트리 응답을 확인하는 것이 중요하다 <strong>(도 3)</strong> . 결과의이 패턴은-파블로프 조절 알코올 추구 행동이 크게 소멸되었음을 나타냅니다. </p><p class="jove_content"> 상황에 의한 갱신 시험 : 포트흡광 트레이닝의 끝에서 관찰 CS + 포트 항목에 대하여 컨텍스트 유도 내구성 시험에서 CS + 증가에 진입 응답. CS-에 포트 항목이 변경되지 않고 남아있는이 증가는 CS +에 선택적이다. 또한, CS +에 포트 항목은 상황에 의한 갱신 시험에서 CS-에 포트 항목 <strong>(그림 4)에</strong> 비해 통계적으로 상승합니다. CS + 포트 멸종 및 테스트 사이의 항목뿐만 아니라 CS + 및 테스트 내 CS- 포트 항목의 비교 비교의 통계 확인이 테스트에서 알코올 관련 상황에 의해 유도 파블로프 에어컨 알코올 추구 행동의 선택 갱신을 나타냅니다. </p><p class="jove_content" fo:keep-together.within-page="always"><img alt="그림 1" fo:content-width="4in" src="/files/ftp_upload/51898/51898fig1highres.jpg" width="400" /><br /> <strong>에탄올 소비와 홈 케이지에서 간헐적 인 에탄올 액세스에 의해 유도 선호도 1 에스컬레이션 그림.</strong> 및 평균# 177; SEM <strong>(A)</strong> 에탄올 소비 (g / kg) 및 홈 케이지에서 간헐적 인 에탄올 액세스의 12 회에 걸쳐 <strong>(B)</strong> 에탄올 환경. 두 조치는 일반적으로 세션에 걸쳐 증가하고 안정. 개별 쥐 6.44 g / kg - 안정 에탄올 소비량은 1.33에서 원거리 홈 케이지 에탄올 액세스의 마지막 두 세션에 걸쳐 평균. 이 데이터는 15 % (v / v)로 에탄올을 마시는 남성 긴 에반스 쥐를 사용하여 얻을 수 있었다. </p><p class="jove_content" fo:keep-together.within-page="always"><img alt="그림이" fo:content-width="4in" src="/files/ftp_upload/51898/51898fig2highres.jpg" width="400" /><br /> <strong>. 그림 2 실험 절차의 개략적 인</strong> 절차는 세 단계로 구성 파블로프 차별 훈련 (PDT), 멸종 및 상황에 유도 갱신 시험. 각 PDT 세션 동안 쥐 에탄올의 제공 및 16 시련의 신호를 하나의 청각 조건 자극 (CS +)의 16 시련을받을에탄올 전달과 관련되지 않은 초 청각 자극 (CS-). PDT 세션은 시각, 후각의 특정 구성, 및 촉각 자극 이루어지는 문맥에서 일어난다. 시각 후각, 촉각 자극의 다른 세트로 구성 컨텍스트 B에서 수행되는 소등 세션 동안, CS + 및 CS- 제시되지만 에탄올을 보류한다. 상황에 의한 갱신 테스트를 위해 쥐 상황에 반환하고, CS + 및 CS - 에탄올을받지 않고있다. <a href="https://www.jove.com/files/ftp_upload/51898/51898fig2highres.jpg" target="_blank">이 그림의 더 큰 버전을 보려면 여기를 클릭하십시오.</a> </p><p class="jove_content" fo:keep-together.within-page="always"><img alt="그림 3" fo:content-width="4in" src="/files/ftp_upload/51898/51898fig3highres.jpg" width="400" /><br /> <strong>그림 3 수집 및 차별 파블로프 에어컨 에탄올에 대한 응답.</strong> 평균 ± SEM 표준화 된 포트 항목의 <strong>m의 멸종</strong>컨텍스트 및 멸종 (세션 19-26) - PDT에서 CS + 및 CS - 동안 (18 세션 1) 에이드 컨텍스트 B의 이러한 데이터는 10 % 훈련, 남성 롱 에반스 쥐를 사용하여 얻을 수 있었다 (v / v)로 PDT 동안 CS의 +와 관련하여 제시 하였다 무조건 자극 (US) 에탄올. * p &lt;0.05, CS- 대 CS +. 그림은 원래 Chaudhri, Sahuque, 및 JANAK (2008)에서 출판. 엘스 비어의 허가와 함께 사용됩니다. </p><p class="jove_content" fo:keep-together.within-page="always"><img alt="그림 4" fo:content-width="5in" src="/files/ftp_upload/51898/51898fig4highres.jpg" width="500" /><br /> <strong>그림 4 컨텍스트에 의한</strong> 문맥 A. 데이터에 <strong>파블로프 에어컨 에탄올에 대한 응답.</strong> 평균 컨텍스트에서 PDT 세션에서 CS + 및 CS - 중에 ± SEM 표준화 된 포트 항목, 컨텍스트 B에서 멸종 세션 및 갱신 <strong>시험의 갱신</strong> 아르 PDT와 멸종에 대해 마지막 두 세션에 걸쳐 평균; 내구성 시험은 단일 세션이다. 이데이터 PDT 동안 CS +와 관련하여 제시 하였다 무조건 자극 (US)로서 10 % (v / v) 에탄올로 훈련 수컷 롱 - 에반스 래트를 사용하여 수득 하였다. * p &lt;0.05; ** P &lt;0.001, CS- 대 CS +. #p를 &lt;0.05, CS + 멸종 대 CS + PDT. ^ P &lt;0.05, CS + 시험 대 CS + 멸종. 그림은 원래 Chaudhri, Sahuque, 및 JANAK (2008)에서 출판. 엘스 비어의 허가와 함께 사용됩니다. </p>

Watch this Scientific Journal Video about A Procedure to Observe Context-induced Renewal of Pavlovian-conditioned Alcohol-seeking Behavior in Rats at JoVE.com

A Procedure to Observe Context-induced Renewal of Pavlovian-conditioned Alcohol-seeking Behavior in Rats

<p class="jove_content"> 절차는 쥐에서 알코올 추구 행동의 갱신을 설명한다 트리거 알코올 연관된 환경 콘텍스트의 용량을 연구. </p>

절차 흰쥐의 파블로프 에어컨 알코올 추구 행동의 상황에 의한 갱신을 준수합니다

Environmental contexts in which drugs of abuse are consumed can trigger craving, a subjective Pavlovian-conditioned response that can facilitate ...

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JoVE Journal

Behavior

12.8K 조회수.  Concordia University.  절차는 쥐에서 알코올 추구 행동의 갱신을 설명한다 트리거 알코올 연관된 환경 콘텍스트의 용량을 연구. 

비디오: A Procedure to Observe Context-induced Renewal of Pavlovian-conditioned Alcohol-seeking Behavior in Rats

Esterification

<p>Source: Lara Al Hariri at the University of Massachusetts Amherst, MA, USA</p>
<ol class="note-items">
	<li data-note-item="1" data-parent-collapse="">Preparation of the Laboratory<button class="expand">Expand</button>
	<p><em>Here, we show the laboratory preparation for 10 students working in pairs, with some excess. Please adjust quantities as needed.</em></p>
	<ul class="lab-items">
		<li data-sub-note-item="1-2">
		<div class="lab-step">First, put on a lab coat, safety glasses, and nitrile gloves.<strong> Note:</strong> Some of the reagents are volatile or have unpleasant odors, so you will handle them in a fume hood.</div>
		</li>
		<li data-sub-note-item="1-3">
		<div class="lab-step">Ensure that you have glass and organic waste containers and that each sink has paper towels.</div>
		</li>
		<li data-sub-note-item="1-4">
		<div class="lab-step">Follow the table to designate codes for the carboxylic acids and alcohols used in this lab. The carboxylic acids are coded A through C, and the alcohols are coded D through I. The students will use a 3:1 molar ratio of alcohol to carboxylic acid in the reaction.
		<table align="center" height="224" style="border-collapse: collapse; font-size: 17px; line-height: 24px;">
			<tbody>
				<tr>
					<td style="border: 1px solid; padding: 0px; text-align: center;"><strong>Code</strong></td>
					<td style="border: 1px solid; padding: 0px; text-align: center;"><strong>Compound</strong></td>
					<td style="border: 1px solid; padding: 0px; text-align: center;"><strong>MW<br />
					(g/mol) </strong></td>
					<td style="border: 1px solid; padding: 0px; text-align: center;"><strong>Density at RT (g/cm<sup>3</sup>)</strong></td>
					<td style="border: 1px solid; padding: 0px; text-align: center;"><strong>Moles per vial</strong></td>
					<td style="border: 1px solid; padding: 0px; text-align: center;"><strong>Grams per vial</strong></td>
					<td style="border: 1px solid; padding: 0px; text-align: center;"><strong>cm<sup>3</sup> per vial </strong></td>
					<td style="border: 1px solid; padding: 0px; text-align: center;"><strong>Number of vials</strong></td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px; text-align: center;">A</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Acetic acid</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">60.05</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">1.049</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">0.07</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">4.2035</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">4.0</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">3</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px; text-align: center;">B</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Butyric acid</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">88.11</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">0.953</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">0.07</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">6.1677</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">6.5</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">3</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px; text-align: center;">C</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Anthranilic acid</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">137.14</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">-</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">0.07</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">9.5998</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">-</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">1</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px; text-align: center;">D</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">1-Propanol</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">60.10</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">0.803</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">0.21</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">12.6210</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">15.7</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">1</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px; text-align: center;">E</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Isoamyl alcohol</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">88.15</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">0.810</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">0.21</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">18.512</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">22.8</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">1</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px; text-align: center;">F</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">1-Butanol</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">74.12</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">0.810</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">0.21</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">15.565</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">19.2</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">1</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px; text-align: center;">G</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Ethanol</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">46.07</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">0.789</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">0.21</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">9.6747</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">12.3</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">1</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px; text-align: center;">H</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Methanol</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">32.04</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">0.791</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">0.21</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">6.7284</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">8.5</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">2</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px; text-align: center;">I</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">1-Octanol</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">130.23</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">0.830</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">0.21</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">27.348</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">32.9</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">1</td>
				</tr>
			</tbody>
		</table>
		</div>
		</li>
		<li data-sub-note-item="1-5">
		<div class="lab-step">Prepare the three carboxylic acids: acetic acid, butyric acid, and anthranilic acid. Each group will need 0.07 moles of their assigned carboxylic acid in a vial.</div>
		</li>
		<li data-sub-note-item="1-6">
		<div class="lab-step">Tare a 10-mL glass vial on an analytical balance in a fume hood. Use a Pasteur pipette to measure 4.2035 g of acetic acid, which will be about 4 mL. Cap the vial and label it &#8216;A&#8217;. Prepare two more labeled vials of acetic acid in the same way.</div>
		</li>
		<li data-sub-note-item="1-7">
		<div class="lab-step">Weigh 6.1677 g of butyric acid, which will be about 6.5 mL, in a tared 10-mL vial. Cap the vial and label it &#8216;B&#8217;. Prepare two more vials of butyric acid in the same way.</div>
		</li>
		<li data-sub-note-item="1-8">
		<div class="lab-step">Use a small spatula to weigh 9.5998 g of solid anthranilic acid in a tared 10-mL vial. Cap the vial and label it &#8216;C&#8217;. You should now have a total of seven vials of carboxylic acid.</div>
		</li>
		<li data-sub-note-item="1-9">
		<div class="lab-step">Prepare the 7 alcohols. Each group will need 0.21 moles of their assigned alcohol in a vial. Use the table as a guide to prepare and label one vial of each alcohol. Prepare and label two vials of methanol.</div>
		</li>
		<li data-sub-note-item="1-10">
		<div class="lab-step">You should now have a total of seven vials of alcohol. Keep the reagent vials in the instructor&#39;s hood for now and put away the stock bottles of the carboxylic acids and alcohols.</div>
		</li>
		<li data-sub-note-item="1-11">
		<div class="lab-step">Assign each student group one of these seven combinations of reagents.
		<table align="center" height="224" style="border-collapse: collapse; font-size: 17px; line-height: 24px;">
			<tbody>
				<tr>
					<td style="border: 1px solid; padding: 0px; text-align: center;"><strong>Ester code</strong></td>
					<td style="border: 1px solid; padding: 0px; text-align: center;"><strong>Carboxylic acid </strong></td>
					<td style="border: 1px solid; padding: 0px; text-align: center;"><strong>Alcohol</strong></td>
					<td style="border: 1px solid; padding: 0px; text-align: center;"><strong>Ester product</strong></td>
					<td style="border: 1px solid; padding: 0px; text-align: center;"><strong>Scent</strong></td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px; text-align: center;">AD</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Acetic acid</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">1-Propanol</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Propyl acetate</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Pear</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px; text-align: center;">AE</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Acetic acid</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Isoamyl alcohol</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Isoamyl acetate</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Banana</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px; text-align: center;">AI</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Acetic acid</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">1-Octanol</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Octyl acetate</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Orange</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px; text-align: center;">BF</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Butyric acid</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">1-Butanol</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Butyl butyrate</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Pineapple</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px; text-align: center;">BG</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Butyric acid</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Ethanol</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Ethyl butyrate</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Strawberry</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px; text-align: center;">BH</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Butyric acid</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Methanol</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Methyl butyrate</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Apple</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px; text-align: center;">CH</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Anthranilic acid</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Methanol</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Methyl anthranilate</td>
					<td style="border: 1px solid; padding: 0px; text-align: center;">Grape</td>
				</tr>
			</tbody>
		</table>
		</div>
		</li>
		<li data-sub-note-item="1-12">
		<div class="lab-step">Prepare or obtain seven vials of the fruit scents and label them with the fruit names as references.</div>
		</li>
		<li data-sub-note-item="1-13">
		<div class="lab-step">Set out the following glassware and equipment at each student lab station (we suggest that students work in pairs):</div>
		</li>
		<li data-sub-note-item="1-14">
		<div class="lab-step">Put bottles of saturated sodium bicarbonate and 3 M sulfuric acid in a dedicated fume hood, along with a roll of plastic paraffin film and scissors.</div>
		</li>
		<li data-sub-note-item="1-15">
		<div class="lab-step">Set out filter paper and Pasteur pipettes in a central area so that every student group can easily access them.
		<table align="center" height="224" style="border-collapse: collapse; font-size: 17px; line-height: 24px;">
			<tbody>
				<tr>
					<td style="border: 1px solid; padding: 0px;">&#160;1&#160;&#160;&#160;&#160;Lab stand</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px;">&#160;2&#160;&#160;&#160;&#160;3-prong clamps</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px;">&#160;1&#160;&#160;&#160;&#160;Stir plate</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px;">&#160;1&#160;&#160;&#160;&#160;Lab jack</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px;">&#160;1&#160;&#160;&#160;&#160;Heating mantle</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px;">&#160;1&#160;&#160;&#160;&#160;Temperature controller</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px;">&#160;2&#160;&#160;&#160;&#160;Pieces of tubing (for condenser)</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px;">&#160;1&#160;&#160;&#160;&#160;Joint clip</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px;">&#160;1&#160;&#160;&#160;&#160;Tube of vacuum grease</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px;">&#160;1&#160;&#160;&#160;&#160;Box of laboratory wipes</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px;">&#160;1&#160;&#160;&#160;&#160;10-mL graduated cylinder</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px;">&#160;1&#160;&#160;&#160;&#160;600-mL beaker</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px;">&#160;1&#160;&#160;&#160;&#160;50-mL round-bottom flask and flask stand</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px;">&#160;1&#160;&#160;&#160;&#160;Standard condenser</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px;">&#160;1&#160;&#160;&#160;&#160;Small stir bar</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px;">&#160;1&#160;&#160;&#160;&#160;Glass rod</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px;">&#160;1&#160;&#160;&#160;&#160;Package of pH paper</td>
				</tr>
				<tr>
					<td style="border: 1px solid; padding: 0px;">&#160;2&#160;&#160;&#160;&#160;Pasteur pipette bulbs</td>
				</tr>
			</tbody>
		</table>
		</div>
		</li>
		<li data-sub-note-item="1-16">
		<div class="lab-step">Just before the lab, fill a large insulated cooler with crushed ice. Place the cooler and an ice scoop in a central area in the lab.</div>
		</li>
		<li data-sub-note-item="1-17">
		<div class="lab-step">When the students arrive, show them how to safely waft vapors before giving them their assigned reagents.</div>
		</li>
	</ul>
	</li>
</ol>

Esterification: Synthesis of Ester by Fischer Esterification - Prep

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Source: Lara Al Hariri at the University of Massachusetts Amherst, MA, USA

	Preparation of the LaboratoryExpand
	Here, we show the laboratory preparation ...

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JoVE Lab Manual

화학

Lab Manual Sub Articles

Identifying Alcohols

<p>Source: Lara Al Hariri and Ahmed Basabrain at the University of Massachusetts Amherst, MA, USA</p>
<ol class="note-items">
	<li data-note-item="1" data-parent-collapse="">Ferric Chloride Test for Phenols<button class="expand">Expand</button>
	<p>In this lab, you will identify an unknown alcohol using the ferric chloride test, the Jones test, and the Lucas test. You&#39;ll test known alcohols alongside the unknown alcohol as examples of positive and negative results for each test.</p>
	<p>The four known alcohols are 1-butanol, a primary alcohol, 2-butanol, a secondary alcohol, 2-methyl-2-propanol, a tertiary alcohol, and phenol. The four possible unknown alcohols are 1-propanol, 2-propanol, 2-methyl-2-butanol, and para-chlorophenol.</p>
	<p>You&#39;ll start with the ferric chloride test for the presence of phenols. Iron(III) chloride, or ferric chloride, forms a brown complex when it&#39;s dissolved in water. If you add a phenol to this solution, a purple iron(III)-phenol complex will form instead. This effect is not observed with non-aromatic or aliphatic alcohols.</p>
	<ul class="lab-items">
		<li data-sub-note-item="1-4">
		<div class="lab-step">Put on a lab coat, safety glasses, and gloves before you begin. <strong>Note:</strong> The alcohols that you will test are toxic and flammable, and the reagents that you will use are toxic and corrosive, so you will perform this lab in a fume hood.</div>
		</li>
		<li data-sub-note-item="1-5">
		<div class="lab-step">Now, get your assigned unknown alcohol from your instructor and bring it to your fume hood. Label a 250-mL beaker &#8216;aqueous metal waste&#8217;.</div>
		</li>
		<li data-sub-note-item="1-6">
		<div class="lab-step">Next, put five small test tubes in a rack and label them &#8216;1-butanol&#8217;, &#8216;2-butanol&#8217;, &#8216;2-methyl-2-propanol&#8217;, &#8216;phenol&#8217;, and &#8216;unknown&#8217;. Bring the rack to the analytical balance to obtain phenol.</div>
		</li>
		<li data-sub-note-item="1-7">
		<div class="lab-step">If your unknown is a solid, bring it with you. Weigh about 0.2 g of phenol and pour it into the corresponding tube. Do the same for your unknown if it is a solid and then return to your hood.</div>
		</li>
		<li data-sub-note-item="1-8">
		<div class="lab-step">Now label three small vials &#8216;1-butanol&#8217;, &#8216;2-butanol&#8217;, and &#8216;2-methyl-2-propanol&#8217;.</div>
		</li>
		<li data-sub-note-item="1-9">
		<div class="lab-step">Bring the vials to the solvent hood and use clean Pasteur pipettes to fill each vial with about 1 mL of the matching alcohol.<strong> Note: </strong>Do not reuse pipettes.</div>
		</li>
		<li data-sub-note-item="1-10">
		<div class="lab-step">Next, obtain at least four Pasteur pipettes and a 250-mL beaker. Get more pipettes whenever you need them, and don&#39;t put used pipettes back in the beaker.</div>
		</li>
		<li data-sub-note-item="1-11">
		<div class="lab-step">In your fume hood, pipette 3 &#8211; 4 drops of 1-butanol, 2-butanol, and 2-methyl-2-propanol into the corresponding tubes.</div>
		</li>
		<li data-sub-note-item="1-12">
		<div class="lab-step">To the phenol tube, add several drops of deionized water and shake to mix. This will provide better visual results for the ferric test.</div>
		</li>
		<li data-sub-note-item="1-13">
		<div class="lab-step">If your unknown alcohol is a liquid, use a clean pipette to place 3 &#8211; 4 drops of it in the unknown test tube.</div>
		</li>
		<li data-sub-note-item="1-14">
		<div class="lab-step">Now, obtain the bottle of iron(III) chloride solution and add 2 &#8211; 3 drops to each test tube.</div>
		</li>
		<li data-sub-note-item="1-15">
		<div class="lab-step">Stir each mixture well with a glass rod. Use deionized water to rinse off residual alcohol before mixing the contents of the next tube. Make sure that the phenol dissolves completely along with the unknown if it is a solid.</div>
		</li>
		<li data-sub-note-item="1-16">
		<div class="lab-step">Wait 5 min before comparing your unknown to the known solutions. <strong>Note:</strong> If your unknown solution is purple, like the phenol solution, then your unknown is a phenol derivative. If it looks like the other three tubes, it is not a phenol derivative. Record the results of the test in your lab notebook.
		<h4><strong>Table 1: Identifying Unknown Alcohol</strong></h4>
		<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
			<tbody>
				<tr>
					<td style="text-align: center;"><strong>Alcohol</strong></td>
					<td style="text-align: center;"><strong>Ferric Chloride Test</strong></td>
					<td style="text-align: center;"><strong>Jones Test</strong></td>
					<td style="text-align: center;"><strong>Lucas Test</strong></td>
				</tr>
				<tr>
					<td>1-butanol</td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
				</tr>
				<tr>
					<td>2-butanol</td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
				</tr>
				<tr>
					<td>2-methyl-2-propanol</td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
				</tr>
				<tr>
					<td>Phenol</td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
				</tr>
				<tr>
					<td>Unknown</td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
				</tr>
			</tbody>
		</table>
		<a href="https://www.jove.com/CDNSource/lm/labs/71/Table_1._Identifying_unknown_alcohol.xlsx" target="_blank">Click Here to download Table 1</a></div>
		</li>
		<li data-sub-note-item="1-17">
		<div class="lab-step">The next tests don&#39;t work with phenols, so you&#39;ll only test aliphatic alcohols for the rest of the lab. If your unknown is a phenol derivative, skip the instructions for the unknown and test only the three known aliphatic alcohols.</div>
		</li>
	</ul>
	</li>
	<li data-note-item="2" data-parent-collapse="">The Jones Test for Aliphatic Primary and Secondary Alcohols<button class="expand">Expand</button>
	<p>In this section, you&#39;ll perform the Jones test for primary and secondary alcohols. Jones&#39; reagent is made with chromium trioxide and sulfuric acid in water, which forms chromic acid (H<sub>2</sub>CrO<sub>4</sub>)<em> in situ</em>. This powerful reagent oxidizes secondary alcohols to ketones, primary alcohols to aldehydes, which after forming an aldehyde hydrate, are further reduced to carboxylic acids.</p>
	<p>The oxidation state of chromium is the key to this test. Chromium is in the +6 oxidation state in the Jones&#39; reagent. The Cr(VI) complexes in the reagent give it its bright reddish, orange color.</p>
	<p>When Cr(VI) oxidizes an alcohol, chromium is reduced to the +3 oxidation state. First, the alcohol and chromic acid form a chromate ester. Then, a base (H<sub>2</sub>O) cleaves the C-H bond of the alcohol, forming the carbonyl group while reducing Cr(VI) to Cr(IV). Because the carbon of the alcohol undergoes a 2-electron oxidation, and Cr(VI) a 2-electron reduction, this step is a reduction-oxidation step. Cr(IV) participates in further oxidation steps and is eventually reduced to Cr(III). Cr(III) is often present as hexaaquachromium(III) ions&#160;&#8212; [Cr(H<sub>2</sub>O)<sub>6</sub>]<sup>3+</sup> &#8212; and Cr(III) complexes, where H<sub>2</sub>O molecules are replaced by one or more sulphate ions, [Cr(H<sub>2</sub>O)<sub>5</sub>(SO<sub>4</sub>)]<sup>+</sup>. These complexes give Cr(III) the characteristic green color. So, when you mix Jones&#39; reagent with a primary or secondary alcohol in acetone, the orange solution will turn green.</p>
	<p>Jones oxidation of alcohols doesn&#39;t work with tertiary alcohols because the -OH group is already bonded to three carbon atoms and cannot form an extra C-O bond. Thus, you won&#39;t see a color change if you combine Jones&#39; reagent with a tertiary alcohol because chromium isn&#39;t reduced.</p>
	<ul class="lab-items">
		<li data-sub-note-item="2-5">
		<div class="lab-step">Label four clean test tubes &#8216;1-butanol&#8217;, &#8216;2-butanol&#8217;, &#8216;2-methyl-2-propanol&#8217;, and &#8216;unknown&#8217; and place 10 drops of acetone in each. Acetone is the preferred solvent for Jones oxidation.</div>
		</li>
		<li data-sub-note-item="2-6">
		<div class="lab-step">Then, use clean pipettes to add 3 &#8211; 4 drops of the known aliphatic alcohols and your unknown alcohol to the corresponding tubes.</div>
		</li>
		<li data-sub-note-item="2-7">
		<div class="lab-step">Stir each solution well with the glass rod and rinse the rod with water after mixing each one.</div>
		</li>
		<li data-sub-note-item="2-8">
		<div class="lab-step">Now, obtain the bottle of Jones&#39; reagent and carefully add 2 &#8211; 3 drops to each tube. The reagent is strongly acidic and corrosive, so be careful with it and tightly cap the bottle when you&#39;re done. Then, mix each solution well, cleaning the glass rod after each one.</div>
		</li>
		<li data-sub-note-item="2-9">
		<div class="lab-step">Let the solutions react for 10 min, and then compare your unknown to the knowns. <strong>Note:</strong> If the unknown solution turned green, like 1-butanol and 2-butanol, the test is positive for a primary or secondary alcohol. If it stayed orange, like 2-methyl-2-propanol, the test is negative.</div>
		</li>
		<li data-sub-note-item="2-10">
		<div class="lab-step">Record the results in your lab notebook.</div>
		</li>
	</ul>
	</li>
	<li data-note-item="3" data-parent-collapse="">The Lucas Test for Classifying Small Saturated Alcohols<button class="expand">Expand</button>
	<p>The Jones test doesn&#39;t distinguish between primary and secondary alcohols, so you&#39;ll use the Lucas test to identify which is which.</p>
	<p>Lucas&#39; reagent, which is a mixture of zinc chloride and hydrochloric acid, converts secondary and tertiary alcohols to chloroalkanes at room temperature. Chloroalkanes are nearly insoluble in water, so a positive result appears as the mixture separates into a cloudy chloroalkane-containing layer over a clear layer.</p>
	<p>The rate-determining step of the reaction involves converting the alcohol to a carbocation, so the speed of the reaction depends on how stable the carbocation is.</p>
	<p>Tertiary carbocations are very stable, so tertiary alcohols give a positive reaction almost immediately. Secondary carbocations are less stable, so secondary alcohols give a positive result after a few seconds to a few minutes. Primary carbocations are too unstable for this reaction, so primary alcohols give a negative result.</p>
	<ul class="lab-items">
		<li data-sub-note-item="3-5">
		<div class="lab-step">Now, label for clean test tubes as &#8216;1-butanol&#8217;, &#8216;2-butanol&#8217;, &#8216;2-methyl-2-propanol&#8217;, and &#8216;unknown&#8217;.</div>
		</li>
		<li data-sub-note-item="3-6">
		<div class="lab-step">Obtain the bottle of Lucas&#39; reagent and use a graduated cylinder to measure 2 mL of the reagent for each tube.</div>
		</li>
		<li data-sub-note-item="3-7">
		<div class="lab-step">Next, add 2 drops of 2-methyl-2-propanol to the appropriate tube. Immediately, stir the mixture for a few seconds and place it in the rack. The mixture will promptly separate into a clear lower layer and a cloudy upper layer.</div>
		</li>
		<li data-sub-note-item="3-8">
		<div class="lab-step">Thoroughly rinse the glass rod and record the immediate positive result in your lab notebook.</div>
		</li>
		<li data-sub-note-item="3-9">
		<div class="lab-step">Mix the remaining alcohols with Lucas&#39; reagent in the same way, using a fresh pipette for each alcohol and rinsing the glass rod each time. <strong>Note:</strong> Don&#39;t add too much alcohol or jostle the tubes because that can slow down the reaction.</div>
		</li>
		<li data-sub-note-item="3-10">
		<div class="lab-step">Watch carefully after mixing the unknown alcohol with Lucas&#39; reagent to ensure that you can distinguish an immediate positive result from a positive result after a brief delay.</div>
		</li>
		<li data-sub-note-item="3-11">
		<div class="lab-step">Check on the tubes every few minutes and record positive results as you see them. Note approximately how long it took for delayed positive results to appear.</div>
		</li>
		<li data-sub-note-item="3-12">
		<div class="lab-step">Once the tubes have sat for at least 15 min, you can assume that the results are final. Record the results for 1-butanol, 2-butanol, and for your unknown if applicable.</div>
		</li>
		<li data-sub-note-item="3-13">
		<div class="lab-step">Now, let&#39;s clean up. Your instructor will collect the Cr(VI) solutions, so leave any tubes of orange solution from the Jones test in your hood.</div>
		</li>
		<li data-sub-note-item="3-14">
		<div class="lab-step">Empty the other test tubes into the waste beaker and rinse them with deionized water. Pour the waste into the aqueous metal waste container using a funnel and rinse the beaker with deionized water.</div>
		</li>
		<li data-sub-note-item="3-15">
		<div class="lab-step">Now, wash your glassware as usual and dispose of used pipettes in the glass waste. Lastly, clean your hood and throw out any trash in the lab trash container.</div>
		</li>
	</ul>
	</li>
	<li data-note-item="4" data-parent-collapse="">Results<button class="expand">Expand</button>
	<p>Identify your unknown alcohol. The four possibilities are 1-propanol, 2-propanol, 2-methyl-2-butanol, and para-chlorophenol.</p>
	<ul class="lab-items">
		<li data-sub-note-item="4-2">
		<div class="lab-step">Consider the results of the ferric chloride test first. If the mixture with your unknown alcohol turned purple, like phenol did, your alcohol must be para-chlorophenol. If you saw a negative result, your unknown is one of the three aliphatic alcohols.</div>
		</li>
		<li data-sub-note-item="4-3">
		<div class="lab-step">Look at the results of the Jones test. If the mixture with the unknown alcohol turned green, the unknown could be primary or secondary. If the mixture with your unknown alcohol stayed orange, your unknown alcohol is tertiary. Therefore, a negative Jones result means that your alcohol must be 2-methyl-2-butanol.</div>
		</li>
		<li data-sub-note-item="4-4">
		<div class="lab-step">Lastly, look at the results of the Lucas test. If you had a negative result in the Jones test, you should also have seen an immediate positive result in the Lucas test. This confirms that your alcohol was tertiary. If your unknown had a positive result after a short delay, then your unknown alcohol is secondary, and therefore, must be 2-propanol. Finally, if your unknown had a negative result in the Lucas test, your alcohol is primary, and therefore, must be 1-propanol.</div>
		</li>
	</ul>
	</li>
</ol>

Identifying Alcohols: Ferric Chloride Test, Jones Test, and Lucas Test - Procedure

알코올 식별

Source: Lara Al Hariri and Ahmed Basabrain at the University of Massachusetts Amherst, MA, USA

	Ferric Chloride Test for PhenolsExpand
	In this lab, you ...

Beer's Law

Beer-Lambert Law and Equilibrium Constant Determination - Procedure

맥주의 법칙

Source: Smaa Koraym at Johns Hopkins University, MD, USA

	Lab Setup for Beer&#8217;s LawExpand
	In this lab, you will combine aqueous solutions of FeCl3 ...

Concentration Dependence

<p>Source: Smaa Koraym at Johns Hopkins University, MD, USA</p>
<ol class="note-items">
	<li data-note-item="1" data-parent-collapse="">Concentration Dependence<button class="expand">Expand</button>
	<p>In this experiment, you will combine varying concentrations of aqueous HCl and sodium thiosulfate to make solid sulfur, which rapidly gathers into opaque yellow particles at a certain sulfur concentration. Since the reaction solution starts clear and colorless, you can easily tell when it reaches that concentration.</p>
	<p>You&#39;ll use the same test tube and total volume each time, so it will take the same amount of sulfur to make each solution completely opaque. Thus, you&#39;ll measure the reaction progress by timing how long that takes. You&#39;ll then use that data to estimate the reaction orders of the individual reactants and of the overall reaction.</p>
	<p>Before starting the lab, make a table listing the reactant concentrations, the time to solution opacity, and the solution temperature for the trials.</p>
	<h4><strong>Table 1: Reaction progress</strong></h4>
	<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
		<tbody>
			<tr>
				<td><strong>Trial</strong></td>
				<td><strong>[Na<sub>2</sub>S<sub>2</sub>O<sub>3</sub>] (M)</strong></td>
				<td><strong>[HCl] (M)</strong></td>
				<td><strong>Time (s)</strong></td>
				<td><strong>Temp (&#176;C)</strong></td>
			</tr>
			<tr>
				<td style="text-align: center;">1</td>
				<td style="text-align: center;">0.1 M</td>
				<td style="text-align: center;">3.0 M</td>
				<td></td>
				<td></td>
			</tr>
			<tr>
				<td style="text-align: center;">2</td>
				<td style="text-align: center;">0.1 M</td>
				<td style="text-align: center;">3.0 M</td>
				<td></td>
				<td></td>
			</tr>
			<tr>
				<td style="text-align: center;">3</td>
				<td style="text-align: center;">0.2 M</td>
				<td style="text-align: center;">3.0 M</td>
				<td></td>
				<td></td>
			</tr>
			<tr>
				<td style="text-align: center;">4</td>
				<td style="text-align: center;">0.15 M</td>
				<td style="text-align: center;">3.0 M</td>
				<td></td>
				<td></td>
			</tr>
			<tr>
				<td style="text-align: center;">5</td>
				<td style="text-align: center;">0.05 M</td>
				<td style="text-align: center;">3.0 M</td>
				<td></td>
				<td></td>
			</tr>
			<tr>
				<td style="text-align: center;">6</td>
				<td style="text-align: center;">0.1 M</td>
				<td style="text-align: center;">6.0 M</td>
				<td></td>
				<td></td>
			</tr>
			<tr>
				<td style="text-align: center;">7</td>
				<td style="text-align: center;">0.1 M</td>
				<td style="text-align: center;">4.5 M</td>
				<td></td>
				<td></td>
			</tr>
			<tr>
				<td style="text-align: center;">8</td>
				<td style="text-align: center;">0.1 M</td>
				<td style="text-align: center;">1.5 M</td>
				<td></td>
				<td></td>
			</tr>
		</tbody>
	</table>
	<p><a href="https://www.jove.com/CDNSource/lm/labs/50/Table_1._Reaction_progress.xlsx" target="_blank">Click Here to download Table 1</a></p>
	<p>We want to make sure that the reactions are all taking place at room temperature. You&#39;ll perform two benchmark trials, three trials with different sodium thiosulfate concentrations, and three trials with different HCl concentrations. You will vary the concentrations by diluting stock solutions of sodium thiosulfate and HCl, as shown in the following tables.</p>
	<h4><strong>Table 2: Sodium thiosulfate dilutions</strong></h4>
	<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
		<tbody>
			<tr>
				<td style="text-align: center;"><strong>Target Concentration</strong></td>
				<td style="text-align: center;"><strong>Volume of 0.2 M sodium thiosulfate</strong></td>
				<td style="text-align: center;"><strong>Volume of DI water</strong></td>
			</tr>
			<tr>
				<td style="text-align: center;">0.05 M</td>
				<td style="text-align: center;">5 mL</td>
				<td style="text-align: center;">15 mL</td>
			</tr>
			<tr>
				<td style="text-align: center;">0.10 M</td>
				<td style="text-align: center;">10 mL</td>
				<td style="text-align: center;">10 mL</td>
			</tr>
			<tr>
				<td style="text-align: center;">0.15 M</td>
				<td style="text-align: center;">15 mL</td>
				<td style="text-align: center;">5 mL</td>
			</tr>
			<tr>
				<td style="text-align: center;">0.20 M</td>
				<td style="text-align: center;">20 mL</td>
				<td style="text-align: center;">0 mL</td>
			</tr>
		</tbody>
	</table>
	<p><a href="https://www.jove.com/CDNSource/lm/labs/50/Table_2._Sodium_thiosulfate_dilutions.xlsx" target="_blank">Click Here to download Table 2</a></p>
	<h4><strong>Table 3: HCl Dilutions</strong></h4>
	<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
		<tbody>
			<tr>
				<td style="text-align: center;"><strong>Target Concentration</strong></td>
				<td style="text-align: center;"><strong>Volume of 6.0 M HCl</strong></td>
				<td style="text-align: center;"><strong>Volume of DI water</strong></td>
			</tr>
			<tr>
				<td style="text-align: center;">1.5 M</td>
				<td style="text-align: center;">2.5 mL</td>
				<td style="text-align: center;">7.5 mL</td>
			</tr>
			<tr>
				<td style="text-align: center;">3.0 M</td>
				<td style="text-align: center;">5.0 mL</td>
				<td style="text-align: center;">5.0 mL</td>
			</tr>
			<tr>
				<td style="text-align: center;">4.5 M</td>
				<td style="text-align: center;">7.5 mL</td>
				<td style="text-align: center;">2.5 mL</td>
			</tr>
			<tr>
				<td style="text-align: center;">6.0 M</td>
				<td style="text-align: center;">10 mL</td>
				<td style="text-align: center;">0 mL</td>
			</tr>
		</tbody>
	</table>
	<p><a href="https://www.jove.com/CDNSource/lm/labs/50/Table_3._HCl_Dilutions.xlsx" target="_blank">Click Here to download Table 3</a></p>
	<p>Remember to use caution when handling HCl, which is toxic and highly corrosive. Sulfur dioxide, which is a gaseous product of this reaction, is also toxic. You will leave the reaction waste in the fume hood overnight to let the sulfur dioxide escape harmlessly.</p>
	<ul class="lab-items">
		<li data-sub-note-item="1-6">
		<div class="lab-step">First, put on a lab coat, splash-proof safety glasses, and nitrile gloves.</div>
		</li>
		<li data-sub-note-item="1-7">
		<div class="lab-step">Fill a plastic wash bottle with deionized water and get a test tube marked with an X.</div>
		</li>
		<li data-sub-note-item="1-8">
		<div class="lab-step">Clamp the test tube over the center of a small stir plate. The label must be on the opposite side from you. Make sure that you can clearly see the X. Place a small magnetic stir bar in the test tube.</div>
		</li>
		<li data-sub-note-item="1-9">
		<div class="lab-step">Use a thermometer clamp to secure a glass thermometer in the lower third of the tube, keeping it clear of the X and the stir bar.</div>
		</li>
		<li data-sub-note-item="1-10">
		<div class="lab-step">Cut a sheet of about 20 squares of plastic paraffin film from a roll and bring the sheet back to your hood.</div>
		</li>
		<li data-sub-note-item="1-11">
		<div class="lab-step">Lay paper towels in the fume hood as a clean surface for labware to be reused.</div>
		</li>
		<li data-sub-note-item="1-12">
		<div class="lab-step">Label a 600-mL beaker as &#8216;waste&#8217; for the reaction, a 100-mL beaker as &#8216;0.2 M sodium thiosulfate&#8217;, and a 50-mL beaker as &#8216;6 M HCl&#8217;.</div>
		</li>
		<li data-sub-note-item="1-13">
		<div class="lab-step">Fill the 100-mL beaker with 0.2 M sodium thiosulfate from the stock bottle in the dispensing hood.</div>
		</li>
		<li data-sub-note-item="1-14">
		<div class="lab-step">After that, bring the 50-mL beaker and a watch glass to the acid-dispensing hood to obtain 50 mL of 6 M HCl. Cover the filled beaker with the watch glass and bring your portion of HCl back to your hood.</div>
		</li>
		<li data-sub-note-item="1-15">
		<div class="lab-step">Prepare 20 mL of 0.1 M sodium thiosulfate for the first benchmark trial. Use a 10-mL volumetric pipette to measure 10 mL of 0.2 M sodium thiosulfate and dispense it into a 20-mL volumetric flask. Fill the 20-mL volumetric flask with deionized water to the mark.</div>
		</li>
		<li data-sub-note-item="1-16">
		<div class="lab-step">Then, cut a square of plastic paraffin film, seal the flask, and invert it several times to thoroughly mix the solution.</div>
		</li>
		<li data-sub-note-item="1-17">
		<div class="lab-step">Remove the film and pour the solution into the test tube.</div>
		</li>
		<li data-sub-note-item="1-18">
		<div class="lab-step">Prepare 10 mL of 3 M HCl. Pipette 5 mL of 6 M HCl into a 10-mL graduated cylinder. Add deionized water to fill the graduated cylinder to the 10-mL line.</div>
		</li>
		<li data-sub-note-item="1-19">
		<div class="lab-step">Seal the top of the graduated cylinder with plastic paraffin film and thoroughly mix the HCl solution by inverting it several times.</div>
		</li>
		<li data-sub-note-item="1-20">
		<div class="lab-step">Now, start the stir motor and get a reset stopwatch. Confirm that you can see the X through the solution in the test tube.</div>
		</li>
		<li data-sub-note-item="1-21">
		<div class="lab-step">Simultaneously start the stopwatch and pour the 3 M HCl into the test tube.</div>
		</li>
		<li data-sub-note-item="1-22">
		<div class="lab-step">Watch the X through the solution, which will start becoming cloudy when enough sulfur has been produced to saturate it. Stop the stopwatch exactly when the solution becomes so opaque that the X disappears.</div>
		</li>
		<li data-sub-note-item="1-23">
		<div class="lab-step">Record the time in your lab notebook for benchmark trial 1 and then reset the stopwatch. Also, record the temperature of the solution.</div>
		</li>
		<li data-sub-note-item="1-24">
		<div class="lab-step">Now, turn off the stir motor, remove the thermometer, and rinse it with deionized water into the waste beaker.</div>
		</li>
		<li data-sub-note-item="1-25">
		<div class="lab-step">Then, empty the test tube into the waste beaker, retrieve the stir bar with long forceps, and rinse the test tube and stir bar with deionized water.</div>
		</li>
		<li data-sub-note-item="1-26">
		<div class="lab-step">Thoroughly clean the test tube with a test tube brush. Briefly rinse the volumetric flask and graduated cylinder with deionized water as well. Dry everything with paper towels.</div>
		</li>
		<li data-sub-note-item="1-27">
		<div class="lab-step">Repeat the trial in the exact same way for the second benchmark time. If the time is not within 3 - 5 s of the first trial, repeat the benchmark trial until you have two consistent trials.</div>
		</li>
		<li data-sub-note-item="1-28">
		<div class="lab-step">Follow the same overall procedure for each subsequent trial, changing the dilutions as indicated in your table and cleaning your glassware between each trial. Use a 5-mL volumetric pipette as needed when measuring the sodium thiosulfate stock solution in trials four and five.</div>
		</li>
		<li data-sub-note-item="1-29">
		<div class="lab-step">Once you have performed all eight trials, rinse your glassware and tools one last time and neutralize the reaction waste with baking soda. Use caution because sulfur dioxide is one of the reaction products.</div>
		</li>
		<li data-sub-note-item="1-30">
		<div class="lab-step">Transfer the neutralized reaction waste to the designated waste container. Then, pour any remaining sodium thiosulfate solution into its labeled waste container and rinse the beaker with deionized water.</div>
		</li>
		<li data-sub-note-item="1-31">
		<div class="lab-step">Neutralize any remaining HCl with baking soda before flushing it down the drain with tap water.</div>
		</li>
		<li data-sub-note-item="1-32">
		<div class="lab-step">Finally, clean and put away your labware according to your standard practices and throw out any trash remaining in your hood. Your instructor will dispose of the reaction waste later.</div>
		</li>
	</ul>
	</li>
	<li data-note-item="2" data-parent-collapse="">Results<button class="expand">Expand</button>
	<ul class="lab-items">
		<li data-sub-note-item="2-1">
		<div class="lab-step">Now, estimate the reaction order of sodium thiosulfate and HCl. Calculate the starting concentration of sodium thiosulfate in the reaction mixture for trials 1 through 5. Looking at the concentration of sodium thiosulfate and the reaction times, we see that as the concentration doubles, the time to opacity is halved.
		<h4><strong>Table 4: Estimating reaction order sodium thiosulfate</strong></h4>
		<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
			<tbody>
				<tr>
					<td style="text-align: center;"><strong>Trial</strong></td>
					<td style="text-align: center;"><strong>[Na<sub>2</sub>S<sub>2</sub>O<sub>3</sub>] added</strong></td>
					<td style="text-align: center;"><strong>Na<sub>2</sub>S<sub>2</sub>O<sub>3</sub> volume (mL)</strong></td>
					<td style="text-align: center;"><strong>Total volume (mL)</strong></td>
					<td style="text-align: center;"><strong>[Na<sub>2</sub>S<sub>2</sub>O<sub>3</sub>] in mixture </strong></td>
					<td style="text-align: center;"><strong>Time (s)</strong></td>
					<td style="text-align: center;"><strong>Inverse time (s<sup>-1</sup>)</strong></td>
				</tr>
				<tr>
					<td style="text-align: center;">1, 2</td>
					<td style="text-align: center;">0.1</td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
				</tr>
				<tr>
					<td style="text-align: center;">3</td>
					<td style="text-align: center;">0.2</td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
				</tr>
				<tr>
					<td style="text-align: center;">4</td>
					<td style="text-align: center;">0.15</td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
				</tr>
				<tr>
					<td style="text-align: center;">5</td>
					<td style="text-align: center;">0.05</td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
				</tr>
			</tbody>
		</table>
		<a href="https://www.jove.com/CDNSource/lm/labs/50/Table_4._Estimating_reaction_order_sodium_thiosulfate.xlsx" target="_blank">Click Here to download Table 4</a></div>
		</li>
		<li data-sub-note-item="2-2">
		<div class="lab-step">Remember that each trial used the same volume, so it took the same amount of sulfur to make each solution opaque. Thus, the reaction is twice as fast when the sodium thiosulfate concentration is doubled.</div>
		</li>
		<li data-sub-note-item="2-3">
		<div class="lab-step">When the concentration increases by a factor of 4, the reaction rate also increases by a factor of 4. This one-to-one relationship suggests that the reaction was first order for sodium thiosulfate. If so, we would expect a plot of rate versus sodium thiosulfate concentration to be linear.</div>
		</li>
		<li data-sub-note-item="2-4">
		<div class="lab-step">We didn&#39;t measure how much sulfur it took to turn the solution opaque, but we assume that it was the same for each trial. This lets us use the inverse of time to opacity as a stand-in for the rate. The slope won&#39;t be equal to k, but that&#39;s OK for this lab.</div>
		</li>
		<li data-sub-note-item="2-5">
		<div class="lab-step">Plot inverse reaction time as a function of sodium thiosulfate concentration. This confirms the linear relationship between sulfur production and thiosulfate concentration. Thus, the reaction seems to be first order with respect to thiosulfate.</div>
		</li>
		<li data-sub-note-item="2-6">
		<div class="lab-step">Use the same method to estimate the reaction order of HCl. First, calculate the starting concentration of HCl in the benchmark trials and in trials 6 through 8.
		<h4><strong>Table 5: Estimating reaction order HCl</strong></h4>
		<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
			<tbody>
				<tr>
					<td style="text-align: center;"><strong>Trial</strong></td>
					<td style="text-align: center;"><strong>[HCl] added</strong></td>
					<td style="text-align: center;"><strong>HCl volume (mL) </strong></td>
					<td style="text-align: center;"><strong>Total volume (mL) </strong></td>
					<td style="text-align: center;"><strong>[HCl] in mixture </strong></td>
					<td style="text-align: center;"><strong>Time (s)</strong></td>
				</tr>
				<tr>
					<td style="text-align: center;">1, 2</td>
					<td style="text-align: center;">0.1</td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
				</tr>
				<tr>
					<td style="text-align: center;">3</td>
					<td style="text-align: center;">0.2</td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
				</tr>
				<tr>
					<td style="text-align: center;">4</td>
					<td style="text-align: center;">0.15</td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
				</tr>
				<tr>
					<td style="text-align: center;">5</td>
					<td style="text-align: center;">0.05</td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
					<td style="text-align: center;"></td>
				</tr>
			</tbody>
		</table>
		<a href="https://www.jove.com/CDNSource/lm/labs/50/Table_5._Estimating_reaction_order_HCl.xlsx" target="_blank">Click Here to download Table 5</a></div>
		</li>
		<li data-sub-note-item="2-7">
		<div class="lab-step">Then, look at the concentration of HCl and the reaction times for these trials. The reaction times are nearly identical, so the HCl concentration has no effect on the reaction rate. This means that HCl seems to be zeroth order for this reaction.</div>
		</li>
		<li data-sub-note-item="2-8">
		<div class="lab-step">Lastly, add up the reaction orders of the reactants to get the overall reaction order.</div>
		</li>
	</ul>
	</li>
</ol>

Concentration Dependence and Reaction Order - Procedure

집중 의존성

Source: Smaa Koraym at Johns Hopkins University, MD, USA

	Concentration DependenceExpand
	In this experiment, you will combine varying concentrations of ...

Optimal Foraging

<ol class="note-items"><li data-note-item="1" data-parent-collapse="">Simulating Foraging with Artificial Habitats and Prey
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="1-1"><div class="lab-step">NOTE: The foragers will hunt for prey represented by pinto beans in four buckets of rice with varying prey densities. Without knowing what these densities are, foragers must obtain as many prey items as possible in as little time as possible. 
</div></li><li data-sub-note-item="1-2"><div class="lab-step">HYPOTHESES: In this experiment, the experimental hypothesis could be that foragers will catch the most prey in the higher prey density bucket and also spend the most time foraging there.  The null hypothesis would then be that foragers will catch an equal number of prey in each bucket and that foragers will spend an equal amount of time foraging in each patch. 
</div></li><li data-sub-note-item="1-3"><div class="lab-step">To begin the foraging activity, record the names and role of each participant at the top of the student data collection sheet.  NOTE: Before starting the experiment, the forager is allowed to become familiar with the foraging process &#8211; the following steps are a practice round. 
</div></li><li data-sub-note-item="1-4"><div class="lab-step">The forager should kneel or sit in front of the average density bucket. 
</div></li><li data-sub-note-item="1-5"><div class="lab-step">Once the timer says start, the forager may begin looking for the pinto beans representing the prey. The forager can spend as much time as they like foraging in this bucket. 
</div></li><li data-sub-note-item="1-6"><div class="lab-step">Once a prey item is located, the forager must signal that one has been found and place the prey in the cup next to the bucket.
</div></li><li data-sub-note-item="1-7"><div class="lab-step">Once they believe they have acquired most of the prey in the patch, they should tell the timer to stop the time and the practice round is over. 
</div></li><li data-sub-note-item="1-8"><div class="lab-step">To begin the simulation proper, the forager should sit or kneel in front of bucket A. 
</div></li><li data-sub-note-item="1-9"><div class="lab-step">The timer must be ready to start the stopwatch. 
</div></li><li data-sub-note-item="1-10"><div class="lab-step">The recorder should be ready to record the time each prey item is located, in addition to the time that the forager arrived at and left each bucket. 
</div></li><li data-sub-note-item="1-11"><div class="lab-step">When all parties are ready, the timer should start the stopwatch and say &#8220;start&#8221;,  and the forager should begin foraging. NOTE: The stopwatch will run through the rest of the round for buckets B and C.
</div></li><li data-sub-note-item="1-12"><div class="lab-step">As the forager signals finding pinto beans and places them in the cup next to the bucket, the timer should tell the recorder the time.
</div></li><li data-sub-note-item="1-13"><div class="lab-step">The recorder should then write the time in the student data collection sheet.  <a href="https://www.jove.com/CDNSource/lm/labs/34/Table_1_Optimal_foraging.xlsx" style="display:block;margin:20px;" target="_blank">Click Here to download Table 1</a>
</div></li><li data-sub-note-item="1-14"><div class="lab-step">Once the forager has decided to move on to the next bucket, they should tell the timer &#8220;done&#8221;, and begin moving to the next patch. 
</div></li><li data-sub-note-item="1-15"><div class="lab-step">The recorder should record the time the forager left and the time they arrived at bucket B in the student data collection sheet.
</div></li><li data-sub-note-item="1-16"><div class="lab-step">Repeat the same procedure for buckets B and C. Once the forager has completed the activity, it is time for the next forager to begin using the same procedure. 
</div></li></ul></li><li data-note-item="2" data-parent-collapse="">Results
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="2-1"><div class="lab-step">Before performing any data analysis, review the data collection sheet and compile your individual data for captured prey, foraging time, and travel time for each bucket in your student calculations table. <a href="https://www.jove.com/CDNSource/lm/labs/34/Table_2_Optimal_foraging.xlsx" style="display:block;margin:20px;" target="_blank">Click Here to download Table 2</a>
</div></li><li data-sub-note-item="2-2"><div class="lab-step">After this, calculate your individual capture rate for each bucket by dividing the number of prey captured by the sum of the foraging time and travel time and record these values in your table. Individual capture rate =  Number of prey captured / (foraging time + travel time)
</div></li><li data-sub-note-item="2-3"><div class="lab-step">To calculate your Giving-Up-Time or a GUT for each bucket, subtract the time that the last prey item was acquired from the time you left the bucket.  GUT = time forager left bucket  -  time last prey item acquired
</div></li><li data-sub-note-item="2-4"><div class="lab-step">Next, calculate the mean GUT for your foraging group and record the values in your table.
</div></li><li data-sub-note-item="2-5"><div class="lab-step">Finally, calculate your scaled GUT for each bucket by dividing the bucket GUT by your group&#39;s mean GUT. Scaled GUT =  Bucket GUT / Group mean GUT NOTE: The scaled GUT will allow class data to be pooled later on without differences in individual foragers skewing the data. 
</div></li><li data-sub-note-item="2-6"><div class="lab-step">The instructor should now compile the data into the classroom spreadsheet.  <a href="https://www.jove.com/CDNSource/lm/labs/34/Table_3_Optimal_foraging.xlsx" style="display:block;margin:20px;" target="_blank">Click Here to download Table 3</a>
</div></li><li data-sub-note-item="2-7"><div class="lab-step">Plot a bar graph of the average number of prey collected in each bucket. On the x-axis, A should represent the low prey density bucket, B should represent the medium prey density bucket, and C the high prey density bucket. Plot the y-axis as the number of prey items caught. 
</div></li><li data-sub-note-item="2-8"><div class="lab-step">Next, plot the graph of the class average scaled GUT, where the x-axis represents the buckets with varying levels of prey density and the y-axis shows the values for the average scaled GUT. 
</div></li><li data-sub-note-item="2-9"><div class="lab-step">Plot a third graph of the average time spent foraging in each bucket. 
</div></li><li data-sub-note-item="2-10"><div class="lab-step">Now review the Marginal Value Theorem (MVT) from the concepts video and examine the three graphs that you generated from your class data. Take note of whether the graphs conform to the predictions of MVT. 
</div></li></ul></li></ol>

Optimal Foraging: Foraging with Artificial Habitats and Prey - Procedure

최적의 채집

Simulating Foraging with Artificial Habitats and Prey
ExpandNOTE: The foragers will hunt for prey represented by pinto beans in four buckets of rice with ...

생물학

생태학

Animal Behavior

<ol class="note-items"><li data-note-item="1" data-parent-collapse="">Making Choice Chambers
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="1-1"><div class="lab-step">Before beginning the experiments, use one of the Sharpies from the lab table to trace a line around the circumference of the bottom of both bottles. One line should be 1 cm from the base of the bottle and the other should be 1.5 cm from the base of the bottle.
</div></li><li data-sub-note-item="1-2"><div class="lab-step">Use a razor blade to make a small cut in each bottle at the mark. 
</div></li><li data-sub-note-item="1-3"><div class="lab-step">Then, insert the scissors and carefully cut along the line until the bottoms of the bottles are removed completely.
</div></li><li data-sub-note-item="1-4"><div class="lab-step">Fit one bottle bottom into the other.
</div></li><li data-sub-note-item="1-5"><div class="lab-step">Tape the bottles together to make a secure chamber.
</div></li><li data-sub-note-item="1-6"><div class="lab-step">Use the razor blade and scissors to poke a hole into the center of the chamber. 
</div></li><li data-sub-note-item="1-7"><div class="lab-step">Take a piece of tape and fold the edge onto itself to make a tab and place the tape over the hole.  Note: The tab helps with easy removal and reattachment of the tape to the chamber.
</div></li><li data-sub-note-item="1-8"><div class="lab-step">Use the Sharpie to label one side of the chamber A and the other side B.
</div></li><li data-sub-note-item="1-9"><div class="lab-step">Upon receiving the colony of <em>Drosophila</em>, perform a count to make sure there are 40 living individuals in the vial.
</div></li></ul></li><li data-note-item="2" data-parent-collapse="">Geotaxis
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="2-1"><div class="lab-step">To perform a geotaxis assay, first attach a clean, empty bottle cap to each end of the choice chamber and turn the fly vial upside down onto its lid.
</div></li><li data-sub-note-item="2-2"><div class="lab-step">Open the tape flap in the center of the choice chamber.
</div></li><li data-sub-note-item="2-3"><div class="lab-step">Insert the funnel into the hole and tap all of the flies into the chamber. HYPOTHESES: The alternate hypothesis is that more flies will be moving against gravity, or up, regardless of the orientation of the choice chamber. Alternatively, if the flies are positively geotactic, then more flies will move down, or with gravity. The null hypothesis is that the flies will have no preference with regard to gravity and will move randomly within the chamber. 
</div></li><li data-sub-note-item="2-4"><div class="lab-step">Once the <em>Drosophila</em> are in the chamber, close the tape flap, rotate the chamber so that it stands vertically with side A on the bottom, and start the timer.
</div></li><li data-sub-note-item="2-5"><div class="lab-step">Immediately, count the number of <em>Drosophila</em> that are moving up and the number that are moving down. Record these data for time point 0 in the table. 
</div></li><li data-sub-note-item="2-6"><div class="lab-step">After 30 seconds, rotate the chamber so that side B is on the bottom and count the number of <em>Drosophila</em> that are moving up or down. Record these data for time point 30 in the table.
</div></li><li data-sub-note-item="2-7"><div class="lab-step">After 60 seconds, rotate the chamber so that side A is on the bottom again and record the number of moving flies for time point 60.  <a href="https://www.jove.com/CDNSource/lm/labs/15/Table_1_Animal_behavior.xlsx" style="display:block;margin:20px;" target="__blank">Click Here to download Table 1</a>
</div></li><li data-sub-note-item="2-8"><div class="lab-step">Hold the chamber over the fly vial and carefully open the cap to return all of the <em>Drosophila</em> back to their empty vial. 
</div></li></ul></li><li data-note-item="3" data-parent-collapse="">Phototaxis
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="3-1"><div class="lab-step">To perform a phototaxis analysis, first cover side A of the choice chamber with tin foil, taking care that the foil reaches to the exact center between the two sides. 
</div></li><li data-sub-note-item="3-2"><div class="lab-step">Ensure the caps are secured on both ends of the chamber.  HYPOTHESES: In this exercise, the alternative hypothesis is that more flies will be found in the light side of the choice chamber, if the flues are attracted to light, or on the dark side if they are repelled by light. The null hypothesis is that <em>Drosophila</em> will have no preference with regard to either stimulus. Therefore, equal numbers of flies will be found on either side of the choice chamber.
</div></li><li data-sub-note-item="3-3"><div class="lab-step">Open the tape flap in the center of the choice chamber, insert the funnel into the hole, and tap all 40 flies into the chamber as previously described.
</div></li><li data-sub-note-item="3-4"><div class="lab-step">Set the timer to sound an alarm at 10 minutes.
</div></li><li data-sub-note-item="3-5"><div class="lab-step">When the alarm sounds, stop the timer, and count the number of flies in the open side B of the chamber.
</div></li><li data-sub-note-item="3-6"><div class="lab-step">Subtract that number from the total number of flies added to the choice chamber to calculate the number of flies in the covered side A.
</div></li><li data-sub-note-item="3-7"><div class="lab-step">Record these data in the table for time point 10.  <a href="https://www.jove.com/CDNSource/lm/labs/15/Table_2_Animal_behavior.xlsx" style="display:block;margin:20px;" target="__blank">Click Here to download Table 2</a>
</div></li><li data-sub-note-item="3-8"><div class="lab-step">Carefully, return all of the flies back to their empty vial.
</div></li></ul></li><li data-note-item="4" data-parent-collapse="">Chemotaxis
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="4-1"><div class="lab-step">HYPOTHESES: In this exercise, the alternative hypothesis is that more flies will be found on the side of the chamber with the apple cider vinegar if the flies are attracted to the odor. Or, if the flies are repelled by the vinegar, then more of them will be found on the side of the chamber presenting the odorless water. The null hypothesis is that <em>Drosophila</em> will have no preference with regard to either stimulus and will move randomly in the chamber.  Use an individual disposable plastic pipette to dispense two drops of the apple cider vinegar onto one cotton ball for side A of the chamber. 
</div></li><li data-sub-note-item="4-2"><div class="lab-step">Use an individual disposable plastic pipette to dispense two drops of the distilled water onto a cotton ball for side B of the chamber. 
</div></li><li data-sub-note-item="4-3"><div class="lab-step">Fold two pieces of tape over themselves to create individual pieces of double-sided tape and use the tape to attach each cotton ball to the inside of the single bottle cap.
</div></li><li data-sub-note-item="4-4"><div class="lab-step">Screw the bottle caps with the cotton balls onto their corresponding sides of the chamber.
</div></li><li data-sub-note-item="4-5"><div class="lab-step">Transfer all of the flies into the chamber and set the timer to sound an alarm after 10 minutes. 
</div></li><li data-sub-note-item="4-6"><div class="lab-step">When the alarm sounds, stop the timer and record the number of flies in each side of the chamber. <a href="https://www.jove.com/CDNSource/lm/labs/15/Table_3_Animal_behavior.xlsx" style="display:block;margin:20px;" target="__blank">Click Here to download Table 3</a>
</div></li><li data-sub-note-item="4-7"><div class="lab-step">At the end of the final experiment, funnel the flies into a morgue tube containing 70% ethanol. 
</div></li><li data-sub-note-item="4-8"><div class="lab-step">Dismantle the choice chambers for recycling.  NOTE: Since all of the chemicals used in these experiments are lab safe, the liquids can be disposed of down the sink, the chambers rinsed, and the solids can be thrown away in the trash. 
</div></li></ul></li><li data-note-item="5" data-parent-collapse="">Results
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="5-1"><div class="lab-step">Gather all of the data collected for the geotaxis, phototaxis, and chemotaxis experiments.
</div></li><li data-sub-note-item="5-2"><div class="lab-step">Plot these values as bar graphs for different conditions and different time points.
</div></li><li data-sub-note-item="5-3"><div class="lab-step">Use these data to draw inferences about the behavior of <em>drosophila melanogaster</em>. 
</div></li></ul></li></ol>

Animal Behavior: Studying Taxis Behavior of Drosophila - Procedure

동물 행동

Making Choice Chambers
ExpandBefore beginning the experiments, use one of the Sharpies from the lab table to trace a line around the circumference of the ...

Extinction

<ol class="note-items"><li data-note-item="1" data-parent-collapse="">Diversity and Extinction during the Paleogene Epoch
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="1-1"><div class="lab-step">Begin this procedure by reading the extinction reading supplement that has been printed out for you. <br /><strong>NOTE:</strong> Alternatively, you may download the reading supplement at the link below.&nbsp; <a href="https://www.jove.com/CDNSource/lm/labs/24/Lab_20_Reading Supplement.docx" style="display:block;margin:20px;" target="_blank">Click here to download the extinction reading supplement</a>
</div></li><li data-sub-note-item="1-2"><div class="lab-step">Using the information contained in the extinction reading supplements pertaining to the taxa of interest and the Chicxulub impact event, make predictions for each taxon listed in Table 1. Consider whether diversity in each taxon increased, decreased, or stayed the same immediately following the Cretaceous-Paleogene boundary and later on in the Paleogene epoch. <a href="https://www.jove.com/CDNSource/lm/labs/24/Table_1_Extinction.xlsx" style="display:block;margin:20px;" target="_blank">Click Here to download Table 1</a>
</div></li><li data-sub-note-item="1-3"><div class="lab-step">Then, fill out the reasons for each of your predictions in the Contributing Factors column. HYPOTHESES: The experimental hypothesis is that many of the different taxa will show changes in diversity after the Cretaceous-Paleogene event, and again at the end of the Paleogene, with some increasing in diversity, while others decrease. The null hypothesis is that there will be no changes in diversity between taxa following the Cretaceous-Paleogene event, or at the end of the Paleogene.
</div></li><li data-sub-note-item="1-4"><div class="lab-step">Gather diversity data by going to the Paleobiology Database: <a href="http://www.paleobiodb.org" target="_blank">www.paleobiodb.org</a>.
</div></li><li data-sub-note-item="1-5"><div class="lab-step">In the center of the screen, click the yellow box labeled Download Data. Under the italicized heading, &#8220;What do you want to download?&#8221;, select Diversity over time on the left side and Comma-separated values on the right side.
</div></li><li data-sub-note-item="1-6"><div class="lab-step">Scroll down to the heading &#8220;Select by taxonomy&#8221;.
</div></li><li data-sub-note-item="1-7"><div class="lab-step">In the first box labeled 'Taxon or taxa to include', type in the name of the taxon that data is being gathered on.  NOTE: Ensure the spelling is correct.
</div></li><li data-sub-note-item="1-8"><div class="lab-step">Now, go to the dropdown menu right below that box labeled &#8220;Taxonomic resolution&#8221;, and select genera.
</div></li><li data-sub-note-item="1-9"><div class="lab-step">Under the next heading, Select by time, type Maastrichtian into the first box and Chattian in the box directly below. Make sure the dropdown menu labeled Time rule is set to major and the Temporal resolution is set to stage.
</div></li><li data-sub-note-item="1-10"><div class="lab-step">Select &#8220;Assume extant taxa range through to present&#8221;. Scroll back up to the middle of the page and click download. A save window will open.
</div></li><li data-sub-note-item="1-11"><div class="lab-step">Save the .csv file to a safe and accessible place and rename it to make it easy to identify.
</div></li><li data-sub-note-item="1-12"><div class="lab-step">Open the file and scroll down to the main dataset under Records.  NOTE: The data are arranged in reverse time order by geological stage. The second column, interval_name, gives the accepted name of the stage in question. The next two columns give the appropriate dates of the stage in millions of years before the present. The final column, number of occurrences, gives a total count of the genera extant during that geological stage as determined from occurrence of fossils.
</div></li><li data-sub-note-item="1-13"><div class="lab-step">To more easily work with this data, copy and paste each column into a new sheet. Be sure to label this sheet with the taxon in question, the data and time the data were obtained, and the data source.
</div></li><li data-sub-note-item="1-14"><div class="lab-step">Repeat this process for each of the taxa in Table 1 (steps 4 &#8211; 12). NOTE: Data from multiple taxa can be kept on the same sheet, so long as they are kept distinct and labeled appropriately.
</div></li><li data-sub-note-item="1-15"><div class="lab-step">To create line plots for each of the taxa showing the change in diversity over time, select the max_ma column and the number of occurrences column simultaneously.
</div></li><li data-sub-note-item="1-16"><div class="lab-step">In Excel, select Insert from the top toolbar and find the section labeled Charts. Select the bottom center icon, Insert Scatter Chart.
</div></li><li data-sub-note-item="1-17"><div class="lab-step">Then, select the Scatter with Straight Lines and Markers and a graph should appear. NOTE: Since the axis of this graph is in units of millions of years ago, the axis is in the reverse direction of time when put in numerical order.
</div></li><li data-sub-note-item="1-18"><div class="lab-step">To fix this, click on the green plus sign in the top-right corner of the graph and hover over Axes. This should reveal a small black arrow. Click the arrow to open up a small menu and select More Options.
</div></li><li data-sub-note-item="1-19"><div class="lab-step">This will open the Axis Options menu. Under Axis Options, click the box next to Values in reverse order. NOTE: It is also possible to change the axis scales from this menu, which can be used to eliminate the excess time that is not being analyzed in this lab. Keep any changes consistent between different graphs.
</div></li><li data-sub-note-item="1-20"><div class="lab-step">Double-click on the title at the top of the graph and change it to the taxon being represented.
</div></li><li data-sub-note-item="1-21"><div class="lab-step">Make a separate graph for each of the taxa in Table 1. Keep them organized and in one location. A separate sheet for graphs is recommended.
</div></li></ul></li><li data-note-item="2" data-parent-collapse="">Results
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="2-1"><div class="lab-step">For each graph, identify the location of the Cretaceous-Paleogene boundary and draw a vertical line through the graph at this point.
</div></li><li data-sub-note-item="2-2"><div class="lab-step">Using the information from the graphs, fill out Table 2. In some cases, it may be helpful to go back to the original dataset and compare actual values, particularly when they are small. <a href="https://www.jove.com/CDNSource/lm/labs/24/Table_2_Extinction.xlsx" style="display:block;margin:20px;" target="_blank">Click Here to download Table 2</a>
</div></li><li data-sub-note-item="2-3"><div class="lab-step">Compare these values to the predictions made in Table 1 and discuss if the original contributing factors are still likely candidates.
</div></li><li data-sub-note-item="2-4"><div class="lab-step">Using the dataset, calculate the percentage of total taxa that went extinct over the Cretaceous-Paleogene boundary using this equation.
</div></li><li data-sub-note-item="2-5"><div class="lab-step">There is an event in the middle of the Paleogene known as the Paleocene-Eocene Thermal Maximum about 55.5 million years ago. This represents a high point in temperature during the Paleogene epoch at approximately 8 &#176;C higher than today&#39;s average temperature. Does this point seem to have an effect on diversity for any of the taxa? If yes, then which ones?
</div></li></ul></li></ol>

Extinction: Diversity and Extinction during the Paleogene Epoch - Procedure

소멸

Diversity and Extinction during the Paleogene Epoch
ExpandBegin this procedure by reading the extinction reading supplement that has been printed out for ...

Group Behavior

<ol class="note-items"><li data-note-item="1" data-parent-collapse="">The Hawk-Dove Game
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="1-1"><div class="lab-step">NOTE: In this activity, you will play the hawk and dove game with a single partner and then with multiple partners to observe hypothetical costs and benefits of the antagonist or cooperative behavior respectively. 
</div></li><li data-sub-note-item="1-2"><div class="lab-step">Before the activity starts, review the cost-benefit table so that you understand how to score the game. <a href="https://www.jove.com/CDNSource/lm/labs/33/Table_1_Group_behavior.xlsx" style="display:block;margin:20px;" target="_blank">Click Here to download Table 1</a>
</div></li><li data-sub-note-item="1-3"><div class="lab-step">HYPOTHESES: The experimental hypothesis for this exercise could be that the dove strategy will become more frequent between repeated partners, and the hawk strategy will become more frequent when interactions are with a variety of partners. The null hypothesis could be that there will be no change in strategy over time with repeat or different partner combinations. NOTE: Benefit can be determined by looking at the left column and choosing the row that corresponds to the card you played. The box that corresponds to the choice of your partner can be found in the top row. For the purposes of this game, B equals four and C equals three. So depending on the cards played, player one here, which is you, would gain a score of two, four, zero or one half. 
</div></li><li data-sub-note-item="1-4"><div class="lab-step">Collect a set of two game cards. 
</div></li><li data-sub-note-item="1-5"><div class="lab-step">Take out the cards labeled hawk and dove and place them face down on the table or conceal them in your hands. 
</div></li><li data-sub-note-item="1-6"><div class="lab-step">When the instructor gives the signal show either of the two cards to the student sitting across from you. Try to strategize how to receive the highest benefit from every interaction on your own but do not communicate with your partner. 
</div></li><li data-sub-note-item="1-7"><div class="lab-step">In the Single Partner Recording Table (Table 2) provided by your instructor, note the cards played as well as the benefit you received for that round.
</div></li><li data-sub-note-item="1-8"><div class="lab-step">Repeat showing cards to the same partner and determining benefit on your instructor&#39;s signal for a total of 15 rounds.
</div></li><li data-sub-note-item="1-9"><div class="lab-step">At the end of those rounds, the student with the highest total benefit value was determined to be the &#8220;winner&#8221;, or the most fit.
</div></li><li data-sub-note-item="1-10"><div class="lab-step">As a class, determine the percentages of hawks and doves played as well as the average benefit received for each round, using this formula: Class average benefit=(sum total benefit)/(number of players)
</div></li><li data-sub-note-item="1-11"><div class="lab-step">For the second game, and then for each round of play, one row of students should rotate to their right, leaving all players with a new partner.
</div></li><li data-sub-note-item="1-12"><div class="lab-step">Continue playing for 15 rounds or until students end up back in their starting positions, recording the data in the Multiple Partner Recording Table (Table 3) given to you by your instructor.
</div></li><li data-sub-note-item="1-13"><div class="lab-step">For each round, determine the percentages of hawks and doves played that round, as well as the average benefit received.
</div></li></ul></li><li data-note-item="2" data-parent-collapse="">Cheating and Cooperation Exercise
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="2-1"><div class="lab-step">NOTE: In this activity, you will exchange benefits, represented by colored or similar items, with your classmates. In this simulation, a cheater is defined as a person who gives fewer benefits than they receive. During this activity, you will observe the frequency of cheating behavior over time. 
</div></li><li data-sub-note-item="2-2"><div class="lab-step">HYPOTHESES: The experimental hypothesis is that cheaters will receive fewer benefits over time and cooperators will continue to provide equal benefits to one another. The null hypothesis is that the frequency of cheaters and cooperators does not change over time. 
</div></li><li data-sub-note-item="2-3"><div class="lab-step">Each person should collect beads of one color to represent a tangible benefit, as well as one paper bag and a three-ring binder.
</div></li><li data-sub-note-item="2-4"><div class="lab-step">Get into a group of three so that all members have objects of the same color.
</div></li><li data-sub-note-item="2-5"><div class="lab-step">Now find another group with a different color to pair with. In each round, partners will exchange benefits without knowing what they are receiving from their partner and without discussion within their group.  NOTE: Benefits of a different color from your starting color are worth twice as much.
</div></li><li data-sub-note-item="2-6"><div class="lab-step">Turn face to face with a member from the other group while still being able to conceal the objects in your possession.  TIP:<strong> </strong>Setting up a screen using a notebook or sitting behind a desk can be helpful here.
</div></li><li data-sub-note-item="2-7"><div class="lab-step">When given a signal from the instructor, place zero to two benefits into the paper bag and pass it to your partner.
</div></li><li data-sub-note-item="2-8"><div class="lab-step">Simultaneously, receive the bag from your partner and then remove the benefits from the bag.
</div></li><li data-sub-note-item="2-9"><div class="lab-step">Make a note of how many benefits you gave away and how many you received in the Cheating and Cooperation Table (Table 4) provided by your instructor.
</div></li><li data-sub-note-item="2-10"><div class="lab-step">Turn to a new member from the other group and repeat the exchange.
</div></li><li data-sub-note-item="2-11"><div class="lab-step">Rotate through all of the members of the other group for as many rounds as the instructor determines - which will not be revealed until the game ends so as not to alter player behavior.
</div></li><li data-sub-note-item="2-12"><div class="lab-step">Once the game has ended, note for each round in the cheating and cooperation table whether you gave more than your partner, received more from them or if you gave the same amount.
</div></li><li data-sub-note-item="2-13"><div class="lab-step">Now total up all of the benefits in your possession, with benefits you&#39;ve received from the other group being worth twice as much.
</div></li><li data-sub-note-item="2-14"><div class="lab-step">For each round, the whole class should total up the number of cheaters - with cheaters defined as those who gave less than they received.
</div></li></ul></li><li data-note-item="3" data-parent-collapse="">Results
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="3-1"><div class="lab-step">For both the single partner hawk-dove game and the multiple partners hawk-dove game, use the whole class data to plot the percentages as two separate lines - one for the percentage of hawks, and one for the percentage of doves, for each of the 15 rounds.
</div></li><li data-sub-note-item="3-2"><div class="lab-step">Take note of whether the cards played changed as more rounds were played.
</div></li><li data-sub-note-item="3-3"><div class="lab-step">Manipulate the values for B and C to see if you can find the point at which values of B and C would render the hawk strategy no longer effective (this would be the point when there is no benefit to choosing the hawk strategy over always choosing the dove strategy).
</div></li><li data-sub-note-item="3-4"><div class="lab-step">As a class, use the data from the cheating and cooperation activity to make a graph showing the percentage of rounds each individual player cheated versus the amount of benefits they ended with.
</div></li><li data-sub-note-item="3-5"><div class="lab-step">Consider whether it is better to be a cheater or a cooperator in this scenario and discuss as a class what makes this scenario different from the hawk-dove game.
</div></li><li data-sub-note-item="3-6"><div class="lab-step">Now, use the class data to graph the percentage of cheaters against the number of rounds, and look for any trends over time.
</div></li><li data-sub-note-item="3-7"><div class="lab-step">Consider which type of strategy would most likely evolve in a setting where partners interact repeatedly.
</div></li><li data-sub-note-item="3-8"><div class="lab-step">Then, note which tactic might be beneficial for a species that relies on cooperation. 
</div></li><li data-sub-note-item="3-9"><div class="lab-step">Discuss as a class what would likely happen if you increased or decreased the relative value of the benefits you receive.
</div></li></ul></li></ol>

Group Behavior: Hawk-Dove Game and Trading Exercise - Procedure

집단 행동

The Hawk-Dove Game
ExpandNOTE: In this activity, you will play the hawk and dove game with a single partner and then with multiple partners to observe ...

Artificial Selection

<ol class="note-items"><li data-note-item="1" data-parent-collapse="">Observing Artificial Selection in Plants 
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="1-1"><div class="lab-step">To begin the experiment, collect five two-week old grown plants from the generation one population that appear healthy. Note: Plants should appear green, not wilted, and not have damaged leaves. Experimental Hypothesis: The experimental hypothesis for this lab might be that the number of lead trichomes varies naturally, but the average number will increase over generations if only plants with the highest number of trichomes are interbred or decrease if those with the least are interbred. Null Hypothesis: The null hypothesis might be that the average number of trichomes will not change over subsequent generations after artificial selection.
</div></li><li data-sub-note-item="1-2"><div class="lab-step">Label each plant with a letter from A to E and with both partners&#8217; names.
</div></li><li data-sub-note-item="1-3"><div class="lab-step">Record any natural differences you see between your plant samples. Note: All of the plants are the same age, so any observed variation is due to expressed phenotype, not development.
</div></li><li data-sub-note-item="1-4"><div class="lab-step">Use a hand lens to count the number of trichomes found on the petiole of the lowest leaf, not including the round, first-grown cotyledons for each plant. Note: It can be helpful to shine a light onto the plant and to hold it against a dark background, such as a lab bench, during the trichome analysis. 
</div></li><li data-sub-note-item="1-5"><div class="lab-step">Both partners will conduct counts on each plant independently and compare answers. If the counts are different, enlist a third counter or take the average of the two results.
</div></li><li data-sub-note-item="1-6"><div class="lab-step">After this, determine the median number of trichomes for the entire class.  <a target="__blank" style="display:block;padding:20px;" href="https://www.jove.com/CDNSource/lm/labs/2/Lab_2_Table_A.xlsx">Click Here to download Table A</a>
</div></li><li data-sub-note-item="1-7"><div class="lab-step">Determine the top and bottom 10% of the plants from the class trichome count. These groups will make up the two artificially selected lines: high hairiness and low hairiness, respectively.
</div></li><li data-sub-note-item="1-8"><div class="lab-step">If more than 10% of the plants have no trichomes, select 10% of those plants randomly for the low hairiness plant line.
</div></li><li data-sub-note-item="1-9"><div class="lab-step">Separate the two groups of selected plants and label them clearly.
</div></li><li data-sub-note-item="1-10"><div class="lab-step">Move the plants to a well-lit area and keep them well watered until they develop flowers. Note: Flowers typically develop around 14 days.
</div></li><li data-sub-note-item="1-11"><div class="lab-step">When the flowers are fully developed, use a pollination wand or paintbrush to rub the stigma and anther of one plant&#8217;s flowers for a few seconds.
</div></li><li data-sub-note-item="1-12"><div class="lab-step">Using the same wand or brush, rub the inside of each flower of every other plant in the same selection line.
</div></li><li data-sub-note-item="1-13"><div class="lab-step">Using a different wand or brush, repeat steps 11 through 12 on the other line. Note: Take care not to cross the lines. Spread the pollen only among the appropriately selected plants.
</div></li><li data-sub-note-item="1-14"><div class="lab-step">Return the generation one plants to the growing areas. When the plants reach approximately 1 month old, they should produce mature seed pods.
</div></li><li data-sub-note-item="1-15"><div class="lab-step">Allow the plants to dry out once the seed pods turn yellow.
</div></li><li data-sub-note-item="1-16"><div class="lab-step">Break the seed pods open and collect the seeds.
</div></li><li data-sub-note-item="1-17"><div class="lab-step">Obtain new pots for the generation two seeds.
</div></li><li data-sub-note-item="1-18"><div class="lab-step">Fill the pots with moist potting soil about halfway and add a fertilizer pellet to each pot.
</div></li><li data-sub-note-item="1-19"><div class="lab-step">Fill the pots with more soil to fill just below the lip.
</div></li><li data-sub-note-item="1-20"><div class="lab-step">Make a shallow depression in the soil of each pot with a probe.
</div></li><li data-sub-note-item="1-21"><div class="lab-step">Touch a clean toothpick to a gluestick and use the toothpick to transplant the seeds into the soil one by one.
</div></li><li data-sub-note-item="1-22"><div class="lab-step">Cover the seeds with a thin layer of soil.
</div></li><li data-sub-note-item="1-23"><div class="lab-step">Label the pots with their hairiness line and place them in the designated growing area.
</div></li><li data-sub-note-item="1-24"><div class="lab-step">Use a plastic dropper to water the plants as needed to ensure they do not dry out.
</div></li><li data-sub-note-item="1-25"><div class="lab-step">When the plants are two weeks old, collect five plants from each line and label them A to E.
</div></li><li data-sub-note-item="1-26"><div class="lab-step">Then, count the trichomes on these plants as previously described (steps 4- 5).
<a target="__blank" style="display:block;padding:20px;" href="https://www.jove.com/CDNSource/lm/labs/2/Lab_2_Table_B.xlsx">Click Here to download Table B</a>
</div></li></ul></li><li data-note-item="2" data-parent-collapse="">Data Analysis
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="2-1"><div class="lab-step">Create a frequency graph based on the generation one class data with the trichome count on the x axis and the number of plants on the y axis. Label the mean. 
</div></li><li data-sub-note-item="2-2"><div class="lab-step">Then, create frequency graphs for both of the selected hairiness lines.
</div></li><li data-sub-note-item="2-3"><div class="lab-step">Compare the frequency graphs for generation one and both hairiness lines.
</div></li><li data-sub-note-item="2-4"><div class="lab-step">Take note of phenotypic shifts observed in the selected hairiness lines.
</div></li></ul></li></ol>

Artificial Selection: Visualization in Plants and Data Analysis - Procedure

인위적 선택

Observing Artificial Selection in Plants 
ExpandTo begin the experiment, collect five two-week old grown plants from the generation one population that ...

진화

Natural Selection

<ol class="note-items"><li data-note-item="1" data-parent-collapse="">Simulating Natural Selection
<button class="expand">Expand</button><ul class="lab-items"><li data-sub-note-item="1-1"><div class="lab-step">To begin, cut the white, black, and gray pipe cleaners into quarters, which should produce a total of 100 pieces that are 3 inches long.
</div></li><li data-sub-note-item="1-2"><div class="lab-step">Then, cut the green pipe cleaners in the quantities and lengths specified in the video, taking care to minimize waste. This approximates a normal distribution of lengths and should result in an additional 100 pieces total. NOTE: One 12-inch pipe cleaner should yield multiple lengths, for example, a 5-inch piece and a 7-inch piece. Use this advantage to reduce waste.
</div></li><li data-sub-note-item="1-3"><div class="lab-step">Now, cut one sheet of black and one sheet of white construction paper into approximately 3-inch strips measured along the long edge of the paper.
</div></li><li data-sub-note-item="1-4"><div class="lab-step">Tape these strips down to cover the base of a dissecting tray to create an alternating pattern of black and white strips. NOTE: In the first simulation, you will use the white, gray, and black pipe cleaner segments against a black and white background to simulate different selection pressures due to predation on a population. You will select your prey using two different strategies, eyes-open and eyes-closed. For each of these strategies, you will perform four rounds consisting of 25 selections, alternating between two partners. After each round you will restore the population back to its original size using the proportions of phenotypes present after selection.
</div></li><li data-sub-note-item="1-5"><div class="lab-step">To begin the first scenario, count out 12 white, 12 black, and 26 gray pipe cleaner segments with your partner. Hypotheses: Here the experimental hypothesis might be that different predation strategies, such as having the eyes open or closed, will result in distinct selection pressures on the populations. Further, different phenotypes may be positively selected in the alternate scenarios. The null hypothesis might be that different predation strategies will have no effect on the populations or phenotypes.
</div></li><li data-sub-note-item="1-6"><div class="lab-step">Mix the pipe cleaner segments together as best as possible. Then, sprinkle them into the papered tray. NOTE: Ideally, the pipe cleaners will be spread out. However, this may not occur due to their self-adhering nature.
</div></li><li data-sub-note-item="1-7"><div class="lab-step">Once the segments are in the tray, separate them as best as possible without moving them too far from where they landed. As few segments as possible should be touching.
</div></li><li data-sub-note-item="1-8"><div class="lab-step">Have the first partner close their eyes. When given an audible signal by the second partner, the first should open their eyes and grab the first pipe cleaner they see from the tray as quickly as possible.
</div></li><li data-sub-note-item="1-9"><div class="lab-step">Set the removed pipe cleaner to the side.
</div></li><li data-sub-note-item="1-10"><div class="lab-step">Alternating partners, repeat this process a total of 25 times (steps 8 &#8211; 9).
</div></li><li data-sub-note-item="1-11"><div class="lab-step">Count the remaining pipe cleaners by color and record this in the data collection table for Scenario 1. <a href="https://www.jove.com/CDNSource/lm/labs/23/Lab_23_Tables_1_and_2.xlsx" style="display:block;margin:20px;" target="__blank">Click Here to download Tables 1 and 2</a>
</div></li><li data-sub-note-item="1-12"><div class="lab-step">Then, restore the population to 50 by adding one pipe cleaner of the same color for each of the remaining pipe cleaners. Hold these to the side until they are all gathered.
</div></li><li data-sub-note-item="1-13"><div class="lab-step">Then, sprinkle the pipe cleaners into the tray as previously described (steps 6-7). Repeat this process for three more rounds consisting of 25 selections each and record the counts for each of the rounds in the data collection table for Scenario 1.
</div></li><li data-sub-note-item="1-14"><div class="lab-step">Remove all pipe cleaners from the tray after the fourth round.
</div></li><li data-sub-note-item="1-15"><div class="lab-step">For Scenario 2, again count out 12 white, 12 black, and 26 gray pipe cleaner segments and sprinkle them randomly into the tray.
</div></li><li data-sub-note-item="1-16"><div class="lab-step">Follow the same protocol as in Scenario 1. However, when given the signal, the grabbing partner should keep their eyes closed. To aid in accuracy, it may help to position the hand near to the tray before grabbing.
</div></li><li data-sub-note-item="1-17"><div class="lab-step">Repeat this process 25 times, switching partner roles, and record the remaining pipe cleaner amounts in the data collection table for Scenario 2.
</div></li><li data-sub-note-item="1-18"><div class="lab-step">Then, restore the population to 50 based on that count. Do this for all four rounds. NOTE: In the second simulation, you will be using the eyes-open and eyes-closed predation strategies as previously described to select pipe cleaners of various lengths.
</div></li><li data-sub-note-item="1-19"><div class="lab-step">For Scenario 3, gather all 100 of the pipe cleaners that have been cut to varying lengths to represent different phenotypes.
</div></li><li data-sub-note-item="1-20"><div class="lab-step">One partner should hold all the pipe cleaners upright and loosely in one hand resting on the tabletop, such that the bottom end of each pipe cleaner rests against the tabletop.
</div></li><li data-sub-note-item="1-21"><div class="lab-step">Now, the partner that is not holding the pipe cleaners should close their eyes. When given an audible signal, the partner should open their eyes and grab the first pipe cleaner they see from their partner&#39;s hand.
</div></li><li data-sub-note-item="1-22"><div class="lab-step">Repeat this process 50 times (step 21). However, the partners should not switch roles during the round this time. The partner holding the pipe cleaners should always be the one giving the signal and never grabbing from the bunch.
</div></li><li data-sub-note-item="1-23"><div class="lab-step">After the first round consisting of 50 selections, count the remaining pipe cleaners by length. Then, record this information in the data collection table for scenario three. <a href="https://www.jove.com/CDNSource/lm/labs/23/Lab_23_Tables_3_and_4.xlsx" style="display:block;margin:20px;" target="__blank">Click Here to download Tables 3 and 4</a>
</div></li><li data-sub-note-item="1-24"><div class="lab-step">Add one pipe cleaner of the same length as each of the remaining ones to restore the population to 100. This will likely require more pipe cleaners than were originally cut. Try to use scraps from the class to reduce waste.
</div></li><li data-sub-note-item="1-25"><div class="lab-step">Repeat this for three more rounds, alternating which partner holds or grabs each round.
</div></li><li data-sub-note-item="1-26"><div class="lab-step">To perform Scenario 4, gather the varied-length pipe cleaners in their original proportions.
</div></li><li data-sub-note-item="1-27"><div class="lab-step">Now repeat the grabbing process, as described in Scenario 3. However, only remove 30 pipe cleaners instead of 50.
</div></li><li data-sub-note-item="1-28"><div class="lab-step">Divide the count at the end of each round by two for each phenotype 4 inches or below, rounding fractions down.
</div></li><li data-sub-note-item="1-29"><div class="lab-step">Then, record these values in the data recording table for Scenario 4.
</div></li><li data-sub-note-item="1-30"><div class="lab-step">Use the relative proportions of the phenotypes in the final population to restore the population to 100. When restoring the population to 100, it may be necessary to calculate relative proportions of phenotypes.
</div></li><li data-sub-note-item="1-31"><div class="lab-step">Repeat this for three more rounds, again alternating holding and grabbing the pipe cleaners.
</div></li><li data-sub-note-item="1-32"><div class="lab-step">For each scenario calculate the survival for each phenotype, that is the proportion of the phenotype surviving.
</div></li><li data-sub-note-item="1-33"><div class="lab-step">Then, calculate the relative fitness, or w, between each round. As reproductive rate does not vary in this simulation, this should always be considered equal, or 1.
</div></li><li data-sub-note-item="1-34"><div class="lab-step">Also, calculate the selection coefficients for each phenotype.
</div></li><li data-sub-note-item="1-35"><div class="lab-step">Now, use the relative frequencies of each phenotype to create histograms with appropriately labeled axes for each scenario showing the population before any selection took place and then alongside these in a different color after four rounds of selection.
</div></li><li data-sub-note-item="1-36"><div class="lab-step">Identify the type of selection taking place in each scenario and label the graphs. 
</div></li><li data-sub-note-item="1-37"><div class="lab-step">Develop a hypothesis to explain your observations. 
</div></li></ul></li></ol>

Natural Selection: Calculating Fitness and Selection - Procedure

자연도태

Simulating Natural Selection
ExpandTo begin, cut the white, black, and gray pipe cleaners into quarters, which should produce a total of 100 pieces that ...