特别感谢瑞吉莫霍克环保部，国家韦拉卡鱼类孵化场，美国鱼类和野生动物局研究单位，南伊利诺伊大学，美国鱼类和野生动物服务东北渔业中心，英镑鱼子酱，美国加州大学戴维斯分校，加里森坝国家鱼类孵化场，熊崖国家鱼类孵化场和美国鱼类和野生动物服务巴拿马市水产资源局的帮助为这个项目提供的鲟鱼。 本文是美国地质调查局大湖科学中心的贡献2013。

重要提示:由于美国鲟所有物种的保护状态，允许收购和鱼之前，实验室方法得到处理。所有标本均从孵化来源获得验尸由于自然原因和处置下列标准程序。 1.试样制备<ol><li>前的任何切口侧放鲟胎体和用卷尺从鼻子到尾部精确到1mm的前端测量总长度。（图1A） </li><li>在配衡衡称重鲟鱼胴体至最接近克评估任何外部标记或标记和记录胴体。 </li></ol> 2.耳石提取<ol><li>使与颅骨的基极和第一背盾之间的大的圆角刀的垂直切口穿过所述主体的头部从主体（图1B）中分离出来。去除头，涂后氡头部所以口朝上（图1C）。 </li><li>通过使用圆角刀沿头骨（图1D）的腹侧切开取出口的软组织和腮。使从鼻子到颅骨完全平分头（图1E）的底部的前端的电的骨锯的切口。用手分开的两半，以暴露脑腔（图2A）。 </li><li>取下并丢弃用钳子查看半规管脑腔（图2B）内脑质（红色方框左边）（红色框右侧）。 </li><li>脑腔内有镊子（图2C）拆下半规管软骨。小心刺穿半规管软骨与钳子的前端，并删除耳石（图2D）。与来自半规管软骨镊子取出耳石（软骨内硬骨结构）（图2E） </stroNG&gt;。 </li><li>重复步骤2.3 - 2.4从头骨的另一半去除耳石。 </li><li>浸在92％乙醇的耳石，持续5秒，以消除任何软骨。在一个开设25毫升闪烁瓶中的地方耳石干燥24小时。 </li></ol>

<ol>
	<li>Auer, N. A., LeBreton, G. T. O., Beamish, F. W. H., McKinley, R. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Conservation.">Conservation.</a> Sturgeons and Paddlefish of North America. 27, 252-276 (2004).</li><li>Campana, S. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Accuracy,+precision+and+quality+control+in+age+determination,+including+a+review+of+the+use+and+abuse+of+age+validation+methods).">Accuracy, precision and quality control in age determination, including a review of the use and abuse of age validation methods).</a> Journal of Fish Biology. 59, 197-242 (2001).</li><li>Bruch, R. M., Campana, S. E., Davis-Foust, S. L., Hansen, M. J., Janssen, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lake+Sturgeon+age+validation+using+bomb+radiocarbon+and+known-age+fish.">Lake Sturgeon age validation using bomb radiocarbon and known-age fish.</a> Transactions of the American Fisheries Society. 138, 361-372 (2009).</li><li>Baremore, I. E., Rosati, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+validated,+minimally+deleterious+method+for+ageing+sturgeon.">A validated, minimally deleterious method for ageing sturgeon.</a> Fishery Bulletin. 112, 274-282 (2014).</li><li>Stevensen, J. T., Secor, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Age+determination+and+growth+of+Hudson+River+Atlantic+sturgeon,+Acipenser+oxyrhynchus.">Age determination and growth of Hudson River Atlantic sturgeon, Acipenser oxyrhynchus.</a> Fishery Bulletin. 97, 153-166 (1999).</li><li>Brennan, J. S., Cailliet, G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+age-determination+techniques+for+white+sturgeon+in+California.">Comparative age-determination techniques for white sturgeon in California.</a> Transactions of the American Fishery Society. 118, 296-310 (1989).</li><li>Rossiter, A., Noakes, D. L. G., Beamish, F. W. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Validation+of+age+estimation+for+the+lake+sturgeon.">Validation of age estimation for the lake sturgeon.</a> Transactions of the American Fisheries Society. 124, 777-781 (1995).</li><li>Chalupnicki, M. A., Dittman, D. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=North+American+Sturgeon+Otolith+Morphology.">North American Sturgeon Otolith Morphology.</a> Copeia. , 260-266 (2016).</li><li>Secor, D. H., Dean, J. M., Laban, E. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Manual for otolith removal and preparation for microstructural examination. , (1991).</li></ol>

Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

提取鲟尸体耳石的另一种方法的概述已详细说明。要注意，特别注意的是需要在颅骨的中线的横向切口放置以均匀平分颅骨，以确保清扫期间不会伤害耳石是很重要的。如果切口是不够深以完全平分颅骨这将是非常困难的，以暴露脑腔，其中耳石的位置是清晰可见。有经验的，整体的技术是相对简单的，并导致被发现完整耳石的高百分比。这种新方法提供了研究的另一种方法，以提取比鲟可以使?...

鲟鱼（ 鲟 ）的人口在世界各地已经超过一个世纪的下降，由于影响，包括栖息地的丧失，人口分散，和过度捕捞，使得许多人口由州和联邦法律的保护1,2。管理机构在整个美国和世界已经确定鲟鱼为修复和恢复1目标物种。多数鲟鱼种群的人口特征（增长，招聘，饮食）进行了研究，以更好地了解基础生物学和生活史特点1。由于多数鲟鱼种群的保护状况，年龄评估是小受威胁居民在没有牺牲或损害个人是必要的困难。 骨结构的年龄估计和生长分析的目的，提取已常用的技术3。使用翅片射线段，以确定斯特奇的年龄上已成为一个实际非致命的方法，但该技术的验证已被限制和年龄可以是非常困难的老年个体（&gt; 15岁）破译4。研究人员评估在验证墨西哥湾鲟鱼（ 尖吻鲟desoti）5，大西洋鲟（A. O操作。oxyrinchus）6，白鲟（A. transmontanus）7，和湖鲟鱼的年龄中华鲟使用多个骨性结构及其使用（A. fluvescens）8总结说，第一边缘胸鳍线提供最准确的年龄，但结束了侵入性操作是有害的个体较大。目前，存在使用耳石形状指标成功9的非常高的速率北美鲟鱼种类区分的发展。与在颅底背横切口取出耳石的工艺细节是一种常见多耳石ction方法发现整个文献和塞科尔等清晰细腻。 （1991）10。然而，这种方法是难以在具有非常厚的头骨与小且脆弱和将趋向于打破耳石鲟实现。文学的进一步审查表明鲟鱼耳石去除过程中没有其他详细的方法。本文的目的是详细地从腹侧进入大脑腔提取鲟耳石的另一种方法。

<table border="0" cellpadding="0" cellspacing="0" width="573">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Measuring Board</td>
			<td style="width:71px;"></td>
			<td style="width:119px;"></td>
			<td style="width:167px;">Metric meter stick is preferred</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Weighing scale</td>
			<td style="width:71px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Filleting Knife</td>
			<td style="width:71px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Scalpel</td>
			<td style="width:71px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Forceps</td>
			<td style="width:71px;"></td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Sample vials</td>
			<td style="width:71px;"></td>
			<td style="width:119px;"></td>
			<td>25 ml scintillation vials work well</td>
		</tr>
	</tbody>
</table>

alternative method of removing otoliths from sturgeon

提取的鱼有很厚的头骨可能是困难和非常耗时的耳石（耳骨）。使得在用一只手或电锯头骨顶部的横纵切口如果操作不当可能损坏耳石的普遍做法。鲟鱼（ 鲟 ）是一个特别的家族，有一个非常大且厚头骨。从鱼揭露耳石的腹侧面进入大脑腔一个新的实验室方法比在文献中发现的其他耳石提取方法更容易。在文献中综述的方法被设计为场，并且在快速处理大量的鱼的更有效。但是，这种新的技术被设计为更适合于实验室环境时的时间并不紧迫，并且从每个试样成功提取是至关重要的。查找和使用这种技术去除耳石的成功是非常高的，且不会影响标tructure以任何方式。这种替代的技术是适用于其它类似的鱼种用于提取耳石。

世界各地的鲟鱼的成人的大小差别很大，但耳石的位置是一致的。使用一把锋利的片刀被发现删除图1D容易证明口腔的软组织。电动锯骨机是横向切口，显露图1E脑腔的首选工具。然而，注意平分头骨的中线需要否则耳石可以在此过程中压碎。如果正确进行该过程然后大脑空腔将均匀地为在图2A所示的耳石无损伤被暴露。脑物质容易与?...

Watch this Scientific Journal Video about Alternative Method of Removing Otoliths from Sturgeon at JoVE.com

Alternative Method of Removing Otoliths from Sturgeon

The goal of the protocol is to show an effective method to extract the otoliths from sturgeon carcasses.

从鲟鱼去除耳石替代方法

Extracting the otoliths (ear bones) from fish that have very thick skulls can be difficult and very time consuming. The common practice of making a ...

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8.4K 次观看.  Great Lakes Science Center. The goal of the protocol is to show an effective method to extract the otoliths from sturgeon carcasses. 

视频: Alternative Method of Removing Otoliths from Sturgeon

Detection of Foodborne Bacterial Pathogens from Individual Filth Flies

There is unanimous consensus that insects are important vectors of foodborne pathogens. However, linking insects as vectors of the pathogen causing a particular foodborne illness outbreak has been challenging. This is because insects are not being aseptically collected as part of an environmental sampling program during foodborne outbreak investigations and because there is not a standardized method to detect foodborne bacteria from individual insects. To take a step towards solving this problem, we adapted a protocol from a commercially available PCR-based system that detects foodborne pathogens from food and environmental samples, to detect foodborne pathogens from individual flies.Using this standardized protocol, we surveyed 100 wild-caught flies for the presence of Cronobacter spp., Salmonella enterica, and Listeria monocytogenes and demonstrated that it was possible to detect and further isolate these pathogens from the body surface and the alimentary canal of a single fly. Twenty-two percent of the alimentary canals and 8% of the body surfaces from collected wild flies were positive for at least one of the three foodborne pathogens. The prevalence of Cronobacter spp. on either body part of the flies was statistically higher (19%) than the prevalence of S. enterica (7%) and L.monocytogenes (4%). No false positives were observed when detecting S. enterica and L. monocytogenes using this PCR-based system because pure bacterial cultures were obtained from all PCR-positive results. However, pure Cronobacter colonies were not obtained from about 50% of PCR-positive samples, suggesting that the PCR-based detection system for this pathogen cross-reacts with other Enterobacteriaceae present among the highly complex microbiota carried by wild flies. The standardized protocol presented here will allow laboratories to detect bacterial foodborne pathogens from aseptically collected insects, thereby giving public health officials another line of evidence to find out how the food was contaminated when performing foodborne outbreak investigations.

A PCR-based protocol was adapted to detect Cronobacter spp., Salmonella enterica, and Listeria monocytogenes from body surfaces and alimentary canals of individual wild-caught flies. The goal of this protocol is to detect and isolate bacterial pathogens from individual insects collected as part of an environmental sampling program during foodborne outbreak investigations.

从个人污秽苍蝇检测食源性细菌病原体

There is unanimous consensus that insects are important vectors of foodborne pathogens. However, linking insects as vectors of the pathogen causing a ...

科研

环境科学

Vegetated Treatment Systems for Removing Contaminants Associated with Surface Water Toxicity in Agriculture and Urban Runoff

Urban stormwater and agriculture irrigation runoff contain a complex mixture of contaminants that are often toxic to adjacent receiving waters. Runoff may be treated with simple systems designed to promote sorption of contaminants to vegetation and soils and promote infiltration. Two example systems are described: a bioswale treatment system for urban stormwater treatment, and a vegetated drainage ditch for treating agriculture irrigation runoff. Both have similar attributes that reduce contaminant loading in runoff: vegetation that results in sorption of the contaminants to the soil and plant surfaces, and water infiltration. These systems may also include the integration of granulated activated carbon as a polishing step to remove residual contaminants. Implementation of these systems in agriculture and urban watersheds requires system monitoring to verify treatment efficacy. This includes chemical monitoring for specific contaminants responsible for toxicity. The current paper emphasizes monitoring of current use pesticides since these are responsible for surface water toxicity to aquatic invertebrates.

This article summarizes the design attributes and the effectiveness of treatment systems that treat urban stormwater and agriculture irrigation runoff to remove pesticides and other contaminants associated with aquatic toxicity.

用于去除与农业和城市径流中地表水毒性有关的污染物的植被处理系统

Urban stormwater and agriculture irrigation runoff contain a complex mixture of contaminants that are often toxic to adjacent receiving waters. Runoff may ...

Extraction and Characterization of Surfactants from Atmospheric Aerosols

Surface-active compounds, or surfactants, present in atmospheric aerosols are expected to play important roles in the formation of liquid water clouds in the Earth&#39;s atmosphere, a central process in meteorology, hydrology, and for the climate system. But because specific extraction and characterization of these compounds have been lacking for decades, very little is known on their identity, properties, mode of action and origins, thus preventing the full understanding of cloud formation and its potential links with the Earth&#39;s ecosystems.
In this paper we present recently developed methods for 1) the targeted extraction of all the surfactants from atmospheric aerosol samples and for the determination of 2) their absolute concentrations in the aerosol phase and 3) their static surface tension curves in water, including their Critical Micelle Concentration (CMC). These methods have been validated with 9 references surfactants, including anionic, cationic and non-ionic ones. Examples of results are presented for surfactants found in fine aerosol particles (diameter &#60;1 &#956;m) collected at a coastal site in Croatia and suggestions for future improvements and other characterizations than those presented are discussed.

Methods are presented for the targeted extraction of surfactants present in atmospheric aerosols and the determination of their absolute concentrations and surface tension curves in water, including their Critical Micelle Concentration (CMC).

提取和表面活性剂的特性，从大气气溶胶

Surface-active compounds, or surfactants, present in atmospheric aerosols are expected to play important roles in the formation of liquid water clouds in ...

Metal Corrosion and the Efficiency of Corrosion Inhibitors in Less Conductive Media

Material corrosion can be a limiting factor for different materials in many applications. Thus, it is necessary to better understand corrosion processes, prevent them and minimize the damages associated with them. One of the most important characteristics of corrosion processes is the corrosion rate. The measurement of corrosion rates is often very difficult or even impossible especially in less conductive, non-aqueous environments such as biofuels. Here, we present five different methods for the determination of corrosion rates and the efficiency of anti-corrosion protection in biofuels: (i) a static test, (ii) a dynamic test, (iii) a static test with a reflux cooler and electrochemical measurements (iv) in a two-electrode arrangement and (v) in a three-electrode arrangement. The static test is advantageous due to its low demands on material and instrumental equipment. The dynamic test allows for the testing of corrosion rates of metallic materials at more severe conditions. The static test with a reflux cooler allows for the testing in environments with higher viscosity (e.g., engine oils) at higher temperatures in the presence of oxidation or an inert atmosphere. The electrochemical measurements provide a more comprehensive view on corrosion processes. The presented cell geometries and arrangements (the two-electrode and three-electrode systems) make it possible to perform measurements in biofuel environments without base electrolytes that could have a negative impact on the results and load them with measurement errors. The presented methods make it possible to study the corrosion aggressiveness of an environment, the corrosion resistance of metallic materials, and the efficiency of corrosion inhibitors with representative and reproducible results. The results obtained using these methods can help to understand corrosion processes in more detail to minimize the damages caused by corrosion.

The testing of processes associated with material corrosion can often be difficult especially in non-aqueous environments. Here, we present different methods for short-term and long-term testing of corrosion behavior of non-aqueous environments such as biofuels, especially those containing bioethanol.

金属腐蚀与腐蚀抑制剂在低导电介质中的效率

Material corrosion can be a limiting factor for different materials in many applications. Thus, it is necessary to better understand corrosion processes, ...

Detection of Viruses from Bioaerosols Using Anion Exchange Resin

This protocol demonstrates a customized bioaerosol sampling method for viruses. In this system, anion exchange resin is coupled with liquid impingement-based air sampling devices for efficacious concentration of negatively-charged viruses from bioaerosols. Thus, the resin serves as an additional concentration step in the bioaerosol sampling workflow. Nucleic acid extraction of the viral particles is then performed directly from the anion exchange resin, with the resulting sample suitable for molecular analyses. Further, this protocol describes a custom-built bioaerosol chamber capable of generating virus-laden bioaerosols under a variety of environmental conditions and allowing for continuous monitoring of environmental variables such as temperature, humidity, wind speed, and aerosol mass concentration. The main advantage of using this protocol is increased sensitivity of viral detection, as assessed via direct comparison to an unmodified conventional liquid impinger. Other advantages include the potential to concentrate diverse negatively-charged viruses, the low cost of anion exchange resin (~$0.14 per sample), and ease of use. Disadvantages include the inability of this protocol to assess infectivity of resin-adsorbed viral particles, and potentially the need for the optimization of the liquid sampling buffer used within the impinger.

An anion exchange resin-based method, adapted to liquid impingement-based bioaerosol sampling of viruses is demonstrated. When coupled with downstream molecular detection, the method allows for facile and sensitive detection of viruses from bioaerosols.

用阴离子交换树脂检测 Bioaerosols 病毒

This protocol demonstrates a customized bioaerosol sampling method for viruses. In this system, anion exchange resin is coupled with liquid ...

A Loop-mediated Isothermal Amplification (LAMP) Assay for Rapid Identification of Bemisia tabaci

The whitefly Bemisia tabaci (Gennadius) is an invasive pest of considerable importance, affecting the production of vegetable and ornamental crops in many countries around the world. Severe yield losses are caused by direct feeding, and even more importantly, also by the transmission of more than 100 harmful plant pathogenic viruses. As for other invasive pests, increased international trade facilitates the dispersal of B. tabaci to areas beyond its native range. Inspections of plant import products at points of entry such as seaports and airports are, therefore, seen as an important prevention measure. However, this last line of defense against pest invasions is only effective if rapid identification methods for suspicious insect specimens are readily available. Because the morphological differentiation between the regulated B. tabaci and close relatives without quarantine status is difficult for non-taxonomists, a rapid molecular identification assay based on the loop-mediated isothermal amplification (LAMP) technology has been developed. This publication reports the detailed protocol of the novel assay describing rapid DNA extraction, set-up of the LAMP reaction, as well as interpretation of its read-out, which allows identifying B. tabaci specimens within one hour. Compared to existing protocols for the detection of specific B. tabaci biotypes, the developed method targets the whole B. tabaci species complex in one assay. Moreover the assay is designed to be applied on-site by plant health inspectors with minimal laboratory training directly at points of entry. Thorough validation performed under laboratory and on-site conditions demonstrates that the reported LAMP assay is a rapid and reliable identification tool, improving the management of B. tabaci.

A Loop-mediated Isothermal Amplification LAMP Assay for Rapid Identification of Bemisia tabaci

This paper reports the protocol for a rapid identification assay for Bemisia tabaci based on loop-mediated isothermal amplification (LAMP) technology. The protocol requires minimal laboratory training and can, therefore, be implemented on-site at points of entry for plant imports such as seaports and airports.

循环介导等温扩增 (灯管) 法快速识别烟粉虱

The whitefly Bemisia tabaci (Gennadius) is an invasive pest of considerable importance, affecting the production of vegetable and ornamental crops in many ...

Sample Preparation Method of Scanning and Transmission Electron Microscope for the Appendages of Woodboring Beetle

This report described sample preparation methods that scanning and transmission electron microscope observations, demonstrated by preparing appendages of the woodboring beetle, Chlorophorus caragana Xie &#38; Wang (2012), for both types of electron microscopy. The scanning electron microscopy (SEM) sample preparation protocol was based on sample chemical fixation, dehydration in a series of ethanol baths, drying, and sputter-coating. By adding Tween 20 (Polyoxyethylene sorbitan laurate) to the fixative and the wash solution, the insect body surface of woodboring beetle was washed more cleanly in SEM. This study&#39;s transmission electron microscopy (TEM) sample preparation involved a series of steps including fixation, ethanol dehydration, embedding in resin, positioning using fluorescence microscopy, sectioning, and staining. Fixative with Tween 20 enabled penetrate the insect body wall of woodboring beetle more easily than it would had been without Tween 20, and subsequently better fixed tissues and organs in the body, thus yielded clear transmission electron microscope observations of insect sensilla ultrastructures. The next step of this preparation was determining the positions of insect sensilla in the sample embedded in the resin block by using fluorescence microscopy to increase the precision of target sensilla positioning. This improved slicing accuracy.

In order to observe ultrastructure of insect sensilla, scanning and transmission electron microscopy (SEM and TEM, respectively) sample preparation protocol were presented in the study. Tween 20 was added into the fixative to avoid sample deformation in SEM. Fluorescence microscopy was helpful for improving slicing accuracy in TEM.

木钻甲虫附着物扫描和透射电子显微镜的样品制备方法

This report described sample preparation methods that scanning and transmission electron microscope observations, demonstrated by preparing appendages of ...

Cortisol Extraction from Sturgeon Fin and Jawbone Matrices

The aims of this study were to develop a technique for the extraction of cortisol from sturgeon fins using two washing solvents (water and isopropanol) and quantify any differences in fin cortisol levels among three main sturgeon species. Fins were harvested from 19 sacrificed sturgeons including seven beluga (Huso huso), seven Siberian (Acipenser baerii), and five sevruga (A. stellatus). The sturgeons were raised in Iranian farms for 2 years (2017-2018), and cortisol extraction analysis was conducted in South Korea (January-February 2019). Jawbones from five H. huso were also used for cortisol extraction. Data were analyzed using the general linear model (GLM) procedure in the SAS environment. The intra- and inter-assay coefficients of variation were 14.15 and 7.70, respectively. Briefly, the cortisol extraction technique involved washing the samples (300 &#177; 10 mg) with 3 mL of solvent (ultrapure water and isopropanol) twice, rotation at 80&#160;rpm for 2.5 min, air-drying the washed samples at room temperature (22-28 &#176;C) for 7 days, further drying the samples using a bead beater at 50 Hz for 32 min and grinding them into powder, applying 1.5 mL methanol to the dried powder (75 &#177; 5 mg), and slow rotation (40 rpm) for 18 h at room temperature with continuous mixing. Following extraction, samples were centrifuged (9,500 x g for 10 min), and 1 mL supernatant was transferred into a new microcentrifuge tube (1.5 mL), incubated at 38 &#176;C to evaporate the methanol, and analyzed via enzyme-linked immunosorbent assay (ELISA). No differences were observed in fin cortisol levels among species or in fin and jawbone cortisol levels between washing solvents. The results of this study demonstrate that the sturgeon jawbone matrix is a promising alternative stress indicator to solid matrices.

In this study, we present a protocol for cortisol extraction from the fin and jawbone of sturgeon species. Fin and jawbone cortisol levels were further examined by comparing two washing solvents followed by ELISA assays. This study piloted the feasibility of jawbone cortisol as a novel stress indicator.

皮质醇从鱼翅和爪骨基质提取

The aims of this study were to develop a technique for the extraction of cortisol from sturgeon fins using two washing solvents (water and isopropanol) ...

A Method for Quantifying Foliage-Dwelling Arthropods

Terrestrial arthropods play an important role in our environment. Quantifying arthropods in a way that allows for a precise index or estimates of density requires a method with high detection probability and a known sampling area. While most described methods provide a qualitative or semi-quantitative estimate adequate for describing species presence, richness, and diversity, few provide an adequately consistent detection probability and known or consistent sampling areas to provide an index or estimate with adequate precision to detect differences in abundance across environmental, spatial, or temporal variables. We describe how to quantify leaf-dwelling arthropods by sealing the leaves and end of branches in a bag, clipping and freezing the bagged material, and rinsing the previously frozen material in water to separate arthropods from the substrate and quantify them. As we demonstrate, this method can be used at a landscape scale to quantify leaf-dwelling arthropods with adequate precision to test for and describe how spatial, temporal, environmental, and ecological variables influence arthropod richness and abundance. This method allowed us to detect differences in density, richness, and diversity of leaf-dwelling arthropods among 5 genera of trees commonly found in southeastern deciduous forests.

We describe how to quantify leaf dwelling arthropods by sealing the leaves and end of branches in a bag, clipping and freezing the bagged material, and rinsing the previously frozen material in water to separate arthropods from the substrate for quantification.

定量叶类节肢动物的方法

Terrestrial arthropods play an important role in our environment. Quantifying arthropods in a way that allows for a precise index or estimates of density ...

Electrostatic Method to Remove Particulate Organic Matter from Soil

Estimations of soil organic carbon are dependent on soil processing methods including removal of undecomposed plant material. Inadequate separation of roots and plant material from soil can result in highly variable carbon measurements. Methods to remove the plant material are often limited to the largest, most visible plant materials. In this manuscript we describe how electrostatic attraction can be used to remove plant material from a soil sample. An electrostatically charged surface passed close to dry soil naturally attracts both undecomposed and partially decomposed plant particles, along with a small quantity of mineral and aggregated soil. The soil sample is spread in a thin layer on a flat surface or a soil sieve. A plastic or glass Petri dish is electrostatically charged by rubbing with polystyrene foam or nylon or cotton cloth. The charged dish is passed repeatedly over the soil. The dish is then brushed clean and recharged. Re-spreading the soil and repeating the procedure eventually results in a diminishing yield of particulates. The process removes about 1 to 5% of the soil sample, and about 2 to 3 times that proportion in organic carbon. Like other particulate removal methods, the endpoint is arbitrary and not all free particulates are removed. The process takes approximately 5 min and does not require a chemical process as do density flotation methods. Electrostatic attraction consistently removes material with higher than average C concentration and C:N ratio, and much of the material can be visually identified as plant or faunal material under a microscope.

Removing recently deposited and incompletely decomposed plant material from soil samples reduces the influence of temporary seasonal inputs on soil organic carbon measurements. Attraction to an electrostatically charged surface can be used to quickly remove a substantial amount of particulate organic matter.

从土壤中去除颗粒有机物的静电方法

Estimations of soil organic carbon are dependent on soil processing methods including removal of undecomposed plant material. Inadequate separation of ...