Agradecemos Manel Bolivar por sua ajuda no trabalho de campo. Somos gratos ao &quot;Parc Natural del Montgrí, les Illes Medes i el Baix Ter&quot; por seu apoio às nossas pesquisas e amostragem permissões. O manipulador submarino foi projetado por Ayelet Dadon-Pilosof e fabricado pelo Sr. Pilosof. Este trabalho foi apoiado pelo projecto Governo espanhol CSI-Coral [número de concessão CGL2013-43106-R para RC e MR] e por uma bolsa FPU do &quot;Ministerio de Educación, Cultura y Deporte (MECD)&quot; a TM. Esta é uma contribuição do Biogeoquímica Marinha e grupo Pesquisa em Mudanças Globais financiado pelo Governo Catalão [número de concessão 2014SGR1029] e ISF concessão 1280/13 e BSF concessão 2.012.089 para G. Yahel.

<ol>
	<li>Gili, J. M., Coma, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Benthic+suspension+feeders:+their+paramount+role+in+littoral+marine+food+webs.">Benthic suspension feeders: their paramount role in littoral marine food webs.</a> Trends. Ecol. Evol. 13 (8), 316-321 (1998).</li><li>Reiswig, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+situ+pumping+activities+of+tropical+Demospongiae.">In situ pumping activities of tropical Demospongiae.</a> Mar. 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The authors have nothing to disclose.

etapas preparatórias Frascos de colector para os DOM e análise de nutrientes Uma vez que os navios de colector podem interagir com micro-constituintes dissolvidos e as paredes do amostrador pode ser um substrato para as bactérias de crescimento 30-34, diferentes frascos de DOM e recolha de nutrientes foram testados. Borosilicato não é recomendado para a quantificação de sílica 33,35, uma vez...

Alimentadores de suspensão bentônicos desempenham um papel essencial no funcionamento dos ecossistemas marinhos 1. Ao filtrar grandes volumes de água 2,3, eles removem e excretar partículas (plâncton e detritos) e compostos dissolvidos 1 (e referências) e são um importante agente de acoplamento de 4,5 bentônica-pelágica e ciclagem de nutrientes 6,7. Com precisão medir a partículas e compostos dissolvidos removidos e excretados pelos alimentadores de suspensão bentônicas (como esponjas, ascídias, poliquetas, e bivalves) é fundamental para compreender a sua fisiologia, metabolismo e ecologia alimentar. Juntamente com bombeamento medições da taxa, ele também permite a quantificação dos fluxos de nutrientes mediadas por estes organismos e seu impacto ecológico na qualidade da água, bem como em processos de escala do ecossistema. Escolhendo o método adequado para medir as taxas de remoção e produção de partículas e com dissolvidalibras por filtradores de suspensão é fundamental para a obtenção de dados fiáveis ​​sobre a sua atividade alimentar 8. Como apontado por Riisgård e outros, inadequadas metodologias viés resultados, distorcer as condições experimentais, produzir estimativas incorretas de ingestão e excreção de certas substâncias, e pode levar à quantificação errônea dos fluxos de nutrientes processados ​​por esses organismos. Os dois métodos mais utilizados para medir partículas e fluxos de nutrientes dissolvidos em alimentadores do filtro envolver a incubação (técnicas indiretas) ou cobrança simultânea de ambiente e água expirado (técnicas diretas). Incubação técnicas baseiam-se na medição da taxa de alteração da concentração de partículas e nutrientes dissolvidos na água incubadas, e estimar as taxas de produção ou remoção comparação com os controlos adequados 8. No entanto, encerrando um organismo em uma câmara de incubação pode alterar a sua feeding e comportamento de bombagem devido a alterações no regime de fluxo natural, devido a uma diminuição em oxigénio e / ou na concentração de alimentos, ou devido à acumulação de compostos excreção na água de incubação 7,9 (e suas referências). Em adição aos efeitos de confinamento e de abastecimento de água modificado, uma grande tendência de técnicas de incubação decorre de efeitos de re-filtração (ver por exemplo 10). Embora alguns destes problemas metodológicos foram superadas, utilizando o volume direito e forma do recipiente de incubação 11 ou com a introdução de um sistema de redoma de recirculação 12 in situ, esta técnica muitas vezes subestima taxas de remoção e de produção. A quantificação do metabolismo de compostos dissolvidos tais como o azoto orgânico dissolvido (DON) e o carbono (DOC) ou nutrientes inorgânicos, tem provado ser especialmente propensos a erros causados ​​por técnicas de incubação 13. No final dos anos 60 e início dos anos 70, Henry Reiswig9,14,15 foi pioneira na aplicação de técnicas diretas para quantificar remoção de partículas por esponjas Caribe gigantes, por amostragem separadamente a água inspirado e expirado pelos organismos in situ. Devido à dificuldade de aplicar a técnica de Reiswig em alimentadores de suspensão menores e em condições submarinas mais desafiadoras, a maior parte da investigação neste campo foi restrito ao laboratório (in vitro) empregando principalmente técnicas de incubação indiretos 16. Yahel e colegas reaparelhado Reiswig do direta técnica in situ a trabalhar em condições de menor escala. Seu método, denominado Inex 16, é baseado em amostragem subaquática simultânea da água inalado (In) e expirado (Ex) por organismos não perturbadas. A concentração diferente de uma substância (por exemplo, bactérias) entre um par de amostras (iNEX) proporciona uma medida da retenção (ou produção) de substância que pelo animal. A técnica Inex emprega tubos abertas ebaseia-se no jacto excurrente produzido pela actividade de bombeamento do organismo estudado para substituir passivamente a água ambiente no tubo de recolha. Enquanto Yahel e colegas aplicaram com sucesso esta técnica no estudo de mais de 15 suspensão alimentadores diferentes taxa (por exemplo, 17), o método é limitado pelo alto nível de prática e experiência necessários, pelo tamanho minúsculo de alguns orifícios excurrentes, e por condições do mar. Para superar esses obstáculos, desenvolvemos uma técnica alternativa baseada na sucção controlada da água amostrada através de tubos hora (diâmetro externo &lt;1,6 mm). Nosso objetivo era criar um dispositivo simples, confiável e de baixo custo que permitiria limpo e controlado de amostragem de água situ a partir de um ponto muito específico, como o orifício excurrent de alimentadores de suspensão bentônicos. Para ser eficaz, o método tem de ser não-intrusivo, de modo a não afectar o regime de fluxo ambiente ou modificar o behavior dos organismos estudados. O dispositivo apresentado aqui é denominado VacuSIP. É uma simplificação do sistema desenvolvido pelo SIP Yahel et ai. (2007) 18 para amostragem por pontos baseado em ROV no fundo do mar. O VacuSIP é consideravelmente mais barato do que a SIP original e foi adaptado para o trabalho baseado em mergulho. O sistema foi projetado de acordo com os princípios apresentados e testados por Wright e Stephens (1978) 19 e Møhlenberg e Riisgård (1978) 20 para ambientes de laboratório. Embora o sistema VacuSIP foi concebido para estudos in situ do metabolismo dos alimentadores de suspensão bentônicos, ele também pode ser usado para os estudos de laboratório e onde é necessária, uma amostra de água de ponto fonte controlada e limpo. O sistema é especialmente útil quando a integração ao longo de períodos prolongados (mínimo de-horas) ou em filtrações in situ são obrigatórios. O VacuSIP tem sido utilizado com sucesso no laboratório Yahel desde 2011, e tem tambémsido empregado em dois estudos recentes de fluxos de nutrientes mediadas por espécies de esponjas das Caraíbas e Mediterrâneo 21 (Morganti et al. apresentado). O uso de samplers específicas, a duração de amostragem prolongada, e as condições de campo, em que VacuSIP é aplicado, implicará alguns desvios protocolos oceanográficos padrão para coletar, filtrar, analisar e armazenar amostras de analitos sensíveis. Para reduzir o risco de contaminação pelo sistema VacuSIP ou o risco de modificação da água amostrada por actividade bacteriana após a recolha, foi testada em vários procedimentos de filtração e de armazenamento in situ. Diferentes dispositivos de filtragem, recipientes de recolha, armazenamento e procedimentos foram examinados a fim de alcançar a técnica mais adequada para a análise de dissolvido inorgânico (PO 4 3-, NO x -, NH 4 +, SiO 4) e orgânico (DOC + DON) compostos e ultra-plâncton (&lt;1081; m) e partículas orgânicas (POC + PON amostragem). Para reduzir ainda mais o risco de contaminação, especialmente em condições de campo, o número de passos de manipulação foi reduzida ao mínimo. O formato visual no qual o método é apresentado é orientada para facilitar a reprodutibilidade e a reduzir o tempo necessário para aplicar a técnica de forma eficiente. Visão geral do sistema Para obter a amostra em água in situ bombeada de alimentadores de suspensão com orifícios exhalant tão pequenas quanto 2 mm, a actividade de bombagem de cada espécime é primeiramente visualizada através da libertação filtrada fluoresceína tingido água do mar junto ao orifício de inalação (s) e observando-se o seu fluxo a partir da abertura excurrente 16 (ver também a Figura 2B em 18). A água inspirado e expirado pelo espécimen do estudo (incurrent e excurrentes) são então amostrados simultaneamente com a utilização de um par de tubos instalados na hora manipulador-construído sob encomenda ou em dois dos &quot;ARMS &quot;de um tripé portátil flexível de cabeça para baixo (Figura 1 e suplementares Vídeo 1). A água inalado pelo organismo estudo é recolhido por posicionando cuidadosamente a extremidade proximal de um tubo no interior ou perto da abertura de inalação do organismo estudo. Um idêntico tubo é então posicionado no interior do orifício excurrente. Esta operação requer o cuidado de evitar o contacto ou perturbação do animal, por exemplo, por ressuspensão do sedimento. para iniciar a amostragem, um mergulhador perfura um septo no recipiente de recolha com uma agulha de seringa ligado à extremidade distal de cada tubo, permitindo que a pressão de água externa para forçar a água amostrada para dentro do recipiente através do tubo de amostragem. a sucção é iniciada pelo vácuo criado previamente nos frascos e pela diferença de pressão entre a água externa e o recipiente da amostra evacuada . Para garantir uma coleção de água limpa exalado e evitar aspiração acidental de ambiágua ent 16, a taxa de amostragem da água deve ser mantida a uma taxa significativamente mais baixa (&lt;10%) do que a taxa de fluxo excurrent. A taxa de sucção é controlada pelo comprimento do tubo e o seu diâmetro interno (ID). O diâmetro interno pequeno também garante um volume morto insignificante (&lt;200 ul por metro de tubo). Recolha de amostras durante períodos prolongados (minutos a horas) faz com que seja possível integrar o patchiness inerente da maioria das substâncias de interesse. Para garantir que as amostras sejam adequadamente preservadas em sessões de amostragem subaquáticas prolongadas, bem como para o transporte para o laboratório, uma filtração em situ é recomendado para analitos sensíveis. A seleção dos vasos de amostragem, montagem de filtração, e tubos são ditadas pelos organismos de estudo e a questão de pesquisa específica. O protocolo descrito abaixo assume que um perfil metabólico completo é de interesse (para um resumo ver Figura 2). No entanto, a natureza modular do protocolo permite Fou modificação fácil para acomodar esquemas de amostragem simples ou até mesmo muito diferentes. Para um perfil metabólico completo, o protocolo de amostragem deve incluir os seguintes passos: (1) A visualização de fluxo; (2) alimentação amostragem ultra-plâncton (plâncton &lt;10 mm); (3) A amostragem absorção de nutrientes inorgânicos e excreção (usando filtros em linha); (4) Amostra dissolvida absorção orgânica e excreção (usando filtros em linha); (5) a alimentação de partículas e excreção (usando filtros em linha); (6) Repita o passo 2 (alimentação ultra-plâncton como verificação de qualidade); (7) O fluxo de visualização. Quando logisticamente viável, recomenda-se que as medições de perfil metabólicas são combinados com a taxa de bombeamento (por exemplo, o método a velocidade da frente de corante, em 16), bem como com as medições de respiração. Estas medições são as melhores tomadas no início e no final da sessão de amostragem. Para a medição da respiração, optodes subaquáticas ou micro-eletrodos são preferíveis.

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			<td>1/16&#34; in Blue/pk</td>
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			<td>Pall&#160;</td>
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			<td>binder-free glass fiber filters, 13mm of diameter,&#160; pore size 0.7&#181;m</td>
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			<td>13mm of diameter, pore size 0.2 &#181;m&#160;</td>
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			<td>highly soluble basic mix of anionic and non-ionic surfactant solution&#160;</td>
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			<td>VWR International Eurolab S.L.</td>
			<td>514-0061P</td>
			<td>25mm of diameter , pore size 0.2 &#181;m&#160;</td>
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			<td>IcoGammaPlus</td>
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			<td>Nalgene</td>
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			<td>B&#252;rkle&#160;</td>
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vacusip, an improved inex method for in situ measurement of particulate and dissolved compounds processed by active suspension feeders

Benthic suspension feeders play essential roles in the functioning of marine ecosystems. By filtering large volumes of water, removing plankton and detritus, and excreting particulate and dissolved compounds, they serve as important agents for benthic-pelagic coupling. Accurately measuring the compounds removed and excreted by suspension feeders (such as sponges, ascidians, polychaetes, bivalves) is crucial for the study of their physiology, metabolism, and feeding ecology, and is fundamental to determine the ecological relevance of the nutrient fluxes mediated by these organisms. However, the assessment of the rate by which suspension feeders process particulate and dissolved compounds in nature is restricted by the limitations of the currently available methodologies. Our goal was to develop a simple, reliable, and non-intrusive method that would allow clean and controlled water sampling from a specific point, such as the excurrent aperture of benthic suspension feeders, in situ. Our method allows simultaneous sampling of inhaled and exhaled water of the studied organism by using minute tubes installed on a custom-built manipulator device and carefully positioned inside the exhalant orifice of the sampled organism. Piercing a septum on the collecting vessel with a syringe needle attached to the distal end of each tube allows the external pressure to slowly force the sampled water into the vessel through the sampling tube. The slow and controlled sampling rate allows integrating the inherent patchiness in the water while ensuring contamination free sampling. We provide recommendations for the most suitable filtering devices, collection vessel, and storing procedures for the analyses of different particulate and dissolved compounds. The VacuSIP system offers a reliable method for the quantification of undisturbed suspension feeder metabolism in natural conditions that is cheap and easy to learn and apply to assess the physiology and functional role of filter feeders in different ecosystems.

Otimização dos métodos de coleta de água do mar Seleção de frascos de coletor e procedimento de limpeza vasos de coleta VacuSIP compatíveis devem ter um septo que permite amostragem a ser iniciada por perfuração com uma agulha de seringa. Eles devem suportar a pressão debaixo d&#39;água elevada (2-3 bares no scub...

Watch this Scientific Journal Video about VacuSIP, an Improved InEx Method for In Situ Measurement of Particulate and Dissolved Compounds Processed by Active Suspension Feeders at JoVE.com

VacuSIP, an Improved InEx Method for In Situ Measurement of Particulate and Dissolved Compounds Processed by Active Suspension Feeders

We introduce the VacuSIP, a simple, non-intrusive, and reliable method for clean and accurate point sampling of water. The system was developed and evaluated for the simultaneous collection of the water inhaled and exhaled by benthic suspension feeders in situ, to cleanly measure removal and excretion of particulate and dissolved compounds.

VacuSIP, um método melhorado para Inex<em&gt; In Situ</em&gt; Medição de partículas e dissolvidos compostos Processado por alimentadores de suspensão ativa

Benthic suspension feeders play essential roles in the functioning of marine ecosystems. By filtering large volumes of water, removing plankton and ...

vacusip-an-improved-inex-method-for-situ-measurement-particulate

Research

JoVE Journal

Environment

VacuSIP, an Improved InEx Method for In Situ Measurement of Particulate and Dissolved Compounds Processed by Active Suspension Feeders

10.8K visualizações.  Centre d’Estudis Avançats de Blanes (CEAB-CSIC). We introduce the VacuSIP, a simple, non-intrusive, and reliable method for clean and accurate point sampling of water. The system was developed and evaluated for the simultaneous collection of the water inhaled and exhaled by benthic suspension feeders in situ, to cleanly measure removal and excretion of particulate and dissolved compounds.

Vídeo: VacuSIP, an Improved InEx Method for In Situ Measurement of Particulate and Dissolved Compounds Processed by Active Suspension Feeders

A Noninvasive Method For In situ Determination of Mating Success in Female American Lobsters (Homarus americanus)

Despite being one of the most productive fisheries in the Northwest Atlantic, much remains unknown about the natural reproductive dynamics of American lobsters. Recent work in exploited crustacean populations (crabs and lobsters) suggests that there are circumstances where mature females are unable to achieve their full reproductive potential due to sperm limitation. To examine this possibility in different regions of the American lobster fishery, a reliable and noninvasive method was developed for sampling large numbers of female lobsters at sea. This method involves inserting a blunt-tipped needle into the female&#39;s seminal receptacle to determine the presence or absence of a sperm plug and to withdraw a sample that can be examined for the presence of sperm. A series of control studies were conducted at the dock and in the laboratory to test the reliability of this technique. These efforts entailed sampling 294 female lobsters to confirm that the presence of a sperm plug was a reliable indicator of sperm within the receptacle and thus, mating. This paper details the methodology and the results obtained from a subset of the total females sampled. Of the 230 female lobsters sampled from George&#39;s Bank and Cape Ann, MA (size range = 71-145 mm in carapace length), 90.3% were positive for sperm. Potential explanations for the absence of sperm in some females include: immaturity (lack of physiological maturity), breakdown of the sperm plug after being used to fertilize a clutch of eggs, and lack of mating activity. The surveys indicate that this technique for examining the mating success of female lobsters is a reliable proxy that can be used in the field to document reproductive activity in natural populations.

A Noninvasive Method For In situ Determination of Mating Success in Female American Lobsters Homarus americanus

Fishery-induced changes to exploited crustacean fisheries, such as the American lobster fishery, could potentially influence their reproductive dynamics, leading to a reduction in mating success. This study&#39;s goal was to develop a noninvasive method for ascertaining the mating success of female lobsters that may be physiologically or functionally mature.

Um método não invasivo para<em&gt; Em situ</em&gt; Determinação do sucesso de acasalamento em fêmeas lagostas americanas (<em&gt; Homarus americanus</em&gt;)

Despite being one of the most productive fisheries in the Northwest Atlantic, much remains unknown about the natural reproductive dynamics of American ...

Ambiente

EPA Method 1615. Measurement of Enterovirus and Norovirus Occurrence in Water by Culture and RT-qPCR. I. Collection of Virus Samples

EPA Method 1615 was developed with a goal of providing a standard method for measuring enteroviruses and noroviruses in environmental and drinking waters. The standardized sampling component of the method concentrates viruses that may be present in water by passage of a minimum specified volume of water through an electropositive cartridge filter. The minimum specified volumes for surface and finished/ground water are 300 L and 1,500 L, respectively. A major method limitation is the tendency for the filters to clog before meeting the sample volume requirement. Studies using two different, but equivalent, cartridge filter options showed that filter clogging was a problem with 10% of the samples with one of the filter types compared to 6% with the other filter type. Clogging tends to increase with turbidity, but cannot be predicted based on turbidity measurements only. From a cost standpoint one of the filter options is preferable over the other, but the water quality and experience with the water system to be sampled should be taken into consideration in making filter selections.

EPA Method 1615 uses an electropositive filter to concentrate enteroviruses and noroviruses in environmental and drinking waters. This manuscript describes the procedure for collecting samples for Method 1615 analyses.

EPA Método 1615. Medição de Enterovirus e Norovirus Ocorrência na água pela cultura e RT-qPCR. I. Recolha de amostras de vírus

EPA Method 1615 was developed with a goal of providing a standard method for measuring enteroviruses and noroviruses in environmental and drinking waters. ...

EPA Method 1615. Measurement of Enterovirus and Norovirus Occurrence in Water by Culture and RT-qPCR. II. Total Culturable Virus Assay

A standardized method is required when national studies on virus occurrence in environmental and drinking waters utilize multiple analytical laboratories. The U.S Environmental Protection Agency&#8217;s (USEPA) Method 1615 was developed with the goal of providing such a standard for measuring Enterovirus and Norovirus in these waters. Virus is concentrated from water using an electropositive filter, eluted from the filter surface with beef extract, and then concentrated further using organic flocculation. Herein we present the protocol from Method 1615 for filter elution, secondary concentration, and measurement of total culturable viruses. A portion of the concentrated eluate from each sample is inoculated onto ten replicate flasks of Buffalo Green Monkey kidney cells. The number of flasks demonstrating cytopathic effects is used to quantify the most probable number (MPN) of infectious units per liter. The method uses a number of quality controls to increase data quality and to reduce interlaboratory and intralaboratory variation. Laboratories must meet defined performance standards. Method 1615 was evaluated by examining virus recovery from reagent-grade and ground waters seeded with Sabin poliovirus type 3. Mean poliovirus recoveries with the total culturable assay were 111% in reagent grade water and 58% in groundwaters.

Here we present a procedure to measure total culturable viruses using the Buffalo Green Monkey kidney cell line. The procedure provides a standardized tool for measuring the occurrence of infectious viruses in environmental and drinking waters.

EPA Método 1615. A medição do Enterovirus e Norovirus Ocorrência na água por cultura e RT-qPCR. II. De ensaio total de Vírus cultiváveis

A standardized method is required when national studies on virus occurrence in environmental and drinking waters utilize multiple analytical laboratories. ...

EPA Method 1615. Measurement of Enterovirus and Norovirus Occurrence in Water by Culture and RT-qPCR. Part III. Virus Detection by RT-qPCR

EPA Method 1615 measures enteroviruses and noroviruses present in environmental and drinking waters. This method was developed with the goal of having a standardized method for use in multiple analytical laboratories during monitoring period 3 of the Unregulated Contaminant Monitoring Rule. Herein we present the protocol for extraction of viral ribonucleic acid (RNA) from water sample concentrates and for quantitatively measuring enterovirus and norovirus concentrations using reverse transcription-quantitative PCR (RT-qPCR). Virus concentrations for the molecular assay are calculated in terms of genomic copies of viral RNA per liter based upon a standard curve. The method uses a number of quality controls to increase data quality and to reduce interlaboratory and intralaboratory variation. The method has been evaluated by examining virus recovery from ground and reagent grade waters seeded with poliovirus type 3 and murine norovirus as a surrogate for human noroviruses. Mean poliovirus recoveries were 20% in groundwaters and 44% in reagent grade water. Mean murine norovirus recoveries with the RT-qPCR assay were 30% in groundwaters and 4% in reagent grade water.

Here we present a procedure to quantify enterovirus and norovirus in environmental and drinking waters using reverse transcription-quantitative PCR. Mean virus recovery from groundwater with this standardized procedure from EPA Method 1615 was 20% for poliovirus and 30% for murine norovirus.

EPA Método 1615. Medição de Enterovirus e Norovirus Ocorrência na água por cultura e RT-qPCR. Parte III. Detecção de vírus por RT-qPCR

EPA Method 1615 measures enteroviruses and noroviruses present in environmental and drinking waters. This method was developed with the goal of having a ...

Spotting Cheetahs: Identifying Individuals by Their Footprints

The cheetah (Acinonyx jubatus) is Africa's most endangered large felid and listed as Vulnerable with a declining population trend by the IUCN1. It ranges widely over sub-Saharan Africa and in parts of the Middle East. Cheetah conservationists face two major challenges, conflict with landowners over the killing of domestic livestock, and concern over range contraction. Understanding of the latter remains particularly poor2. Namibia is believed to support the largest number of cheetahs of any range country, around 30%, but estimates range from 2,9053 to 13,5204. The disparity is likely a result of the different techniques used in monitoring.
Current techniques, including invasive tagging with VHF or satellite/GPS collars, can be costly and unreliable. The footprint identification technique5 is a new tool accessible to both field scientists and also citizens with smartphones, who could potentially augment data collection. The footprint identification technique analyzes digital images of footprints captured according to a standardized protocol. Images are optimized and measured in data visualization software. Measurements of distances, angles, and areas of the footprint images are analyzed using a robust cross-validated pairwise discriminant analysis based on a customized model. The final output is in the form of a Ward's cluster dendrogram. A user-friendly graphic user interface (GUI) allows the user immediate access and clear interpretation of classification results.
The footprint identification technique algorithms are species specific because each species has a unique anatomy. The technique runs in a data visualization software, using its own scripting language (jsl) that can be customized for the footprint anatomy of any species. An initial classification algorithm is built from a training database of footprints from that species, collected from individuals of known identity. An algorithm derived from a cheetah of known identity is then able to classify free-ranging cheetahs of unknown identity. The footprint identification technique predicts individual cheetah identity with an accuracy of &gt;90%.

The cheetah (Acinonyx jubatus) is an iconic, endangered species, but conservation efforts are challenged by habitat shrinkage and conflict with commercial farmers. The footprint identification technique, a robust, accurate and cost-effective image classification system, is a new approach to monitoring cheetahs.

Spotting Cheetahs: Indivíduos Identificação por suas pegadas

The cheetah (Acinonyx jubatus) is Africa's most endangered large felid and listed as Vulnerable with a declining population trend by the IUCN1. It ranges ...

The Benthic Exchange of O2, N2 and Dissolved Nutrients Using Small Core Incubations

The measurement of sediment-water exchange of gases and solutes in aquatic sediments provides data valuable for understanding the role of sediments in nutrient and gas cycles. After cores with intact sediment-water interfaces are collected, they are submerged in incubation tanks and kept under aerobic conditions at in situ temperatures. To initiate a time course of overlying water chemistry, cores are sealed without bubbles using a top cap with a suspended stirrer. Time courses of 4-7 sample points are used to determine the rate of sediment water exchange. Artificial illumination simulates day-time conditions for shallow photosynthetic sediments, and in conjunction with dark incubations can provide net exchanges on a daily basis. The net measurement of N2 is made possible by sampling a time course of dissolved gas concentrations, with high precision mass spectrometric analysis of N2:Ar ratios providing a means to measure N2 concentrations. We have successfully applied this approach to lakes, reservoirs, estuaries, wetlands and storm water ponds, and with care, this approach provides valuable information on biogeochemical balances in aquatic ecosystems.

The Benthic Exchange of O2, N2 and Dissolved Nutrients Using Small Core Incubations

Here, we present small core incubations for the measurement of sediment-water gas and solute exchange. These will provide reliable measurements of sediment-water exchange that assess the role of sediment in influencing biological and biogeochemical processes in aquatic ecosystems.

A Bolsa Benthic de O<sub&gt; 2</sub&gt;, N<sub&gt; 2</sub&gt; e nutrientes dissolvidos Usando pequeno núcleo incubações

The measurement of sediment-water exchange of gases and solutes in aquatic sediments provides data valuable for understanding the role of sediments in ...

A Simple Approach to Manipulate Dissolved Oxygen for Animal Behavior Observations

The ability to manipulate dissolved oxygen (DO) in a laboratory setting has significant application to investigate a number of ecological and organismal behavior questions. The protocol described here provides a simple, reproducible, and controlled method to manipulate DO to study behavioral response in aquatic organisms resulting from hypoxic and anoxic conditions. While performing degasification of water with nitrogen is commonly used in laboratory settings, no explicit method for ecological (aquatic) application exists in the literature, and this protocol is the first to describe a protocol to degasify water to observe organismal response. This technique and protocol were developed for direct application for aquatic macroinvertebrates; however, small fish, amphibians, and other aquatic vertebrates could be easily substituted. It allows for easy manipulation of DO levels ranging from 2 mg/L to 11 mg/L with stability for up to a 5 min animal-observation period. Beyond a 5 min observation period water temperatures began to rise, and at 10 min DO levels became too unstable to maintain. The protocol is scalable to the study organism, reproducible, and reliable, allowing for rapid implementation into introductory teaching labs and high-level research applications. The expected results of this technique should relate dissolved oxygen changes to behavioral responses of organisms.

This article describes a simple and reproducible protocol to manipulate dissolved oxygen conditions in a laboratory setting for animal behavior studies. This protocol may be used in both teaching and research laboratory settings to evaluate organismal response of macroinvertebrates, fishes, or amphibians to changes in dissolved oxygen concentration.

Uma abordagem simples para manipular oxigênio dissolvido para o comportamento animal Observações

The ability to manipulate dissolved oxygen (DO) in a laboratory setting has significant application to investigate a number of ecological and organismal ...

Understanding Dissolved Organic Matter Biogeochemistry Through In Situ Nutrient Manipulations in Stream Ecosystems

Dissolved organic matter (DOM) is a highly diverse mixture of molecules providing one of the largest sources of energy and nutrients to stream ecosystems. Yet the in situ study of DOM is difficult as the molecular complexity of the DOM pool cannot be easily reproduced for experimental purposes. Nutrient additions to streams however, have been shown to repeatedly alter the in situ and ambient DOM pool. Here we demonstrate an easily replicable field-based method for manipulating the ambient pool of DOM at the ecosystem scale. During nutrient pulse experiments changes in the concentration of both dissolved organic carbon and dissolved organic nitrogen can be examined across a wide-range of nutrient concentrations. This method allows researchers to examine the controls on the DOM pool and make inferences regarding the role and function that certain fractions of the DOM pool play within ecosystems. We advocate the use of this method as a technique to help develop a deeper understanding of DOM biogeochemistry and how it interacts with nutrients. With further development this method may help elucidate the dynamics of DOM in other ecosystems.

Understanding Dissolved Organic Matter Biogeochemistry Through In Situ Nutrient Manipulations in Stream Ecosystems

Dissolved organic matter provides an important source of energy and nutrients to stream ecosystems. Here we demonstrate a field-based method to manipulate the ambient pool of dissolved organic matter in situ through easily replicable nutrient pulses.

Compreender orgânico dissolvido Matéria Biogeoquímica Através<em&gt; In Situ</em&gt; Nutrientes Manipulações no córrego Ecossistemas

Dissolved organic matter (DOM) is a highly diverse mixture of molecules providing one of the largest sources of energy and nutrients to stream ecosystems. ...

Production and Measurement of Organic Particulate Matter in a Flow Tube Reactor

Organic particulate matter (PM) is increasingly recognized as important to the Earth's climate system as well as public health in urban regions, and the production of synthetic PM for laboratory studies have become a widespread necessity. Herein, experimental protocols demonstrate approaches to produce aerosolized organic PM by &#945;-pinene ozonolysis in a flow tube reactor. Methods are described for measuring the size distributions and morphology of the aerosol particles. The video demonstrates basic operations of the flow tube reactor and related instrumentation. The first part of the video shows the procedure for preparing gas-phase reactants, ozonolysis, and production of organic PM. The second part of the video shows the procedures for determining the properties of the produced particle population. The particle number-diameter distributions show different stages of particle growth, namely condensation, coagulation, or a combination of both, depending on reaction conditions. The particle morphology is characterized by an aerosol particle mass analyzer (APM) and a scanning electron microscope (SEM). The results confirm the existence of non-spherical particles that have grown from coagulation for specific reaction conditions. The experimental results also indicate that the flow tube reactor can be used to study the physical and chemical properties of organic PM for relatively high concentrations and short time frames.

This paper describes the operation procedure for the flow tube reactor and related data collection. It shows the protocols for setting the experiments, recording data and generating the number-diameter distribution as well as the particle mass information, which gives useful information about chemical and physical properties of the organic aerosols.

Produção e medição de partículas orgânicas em um reator de tubo de fluxo

Organic particulate matter (PM) is increasingly recognized as important to the Earth's climate system as well as public health in urban regions, and the ...

Production and Measurement of Organic Particulate Matter in the Harvard Environmental Chamber

The production and the evolution of atmospheric organic particulate matter (PM) are insufficiently understood for accurate simulations of atmospheric chemistry and climate. The complex production mechanisms and reaction pathways make this a challenging research topic. To address these issues, an environmental chamber, providing enough residence time and close-to-ambient concentrations of precursors for secondary organic materials, is needed. The Harvard Environmental Chamber (HEC) was built to serve this need, simulating the production of gas and particle phase species from volatile organic compounds (VOCs). The HEC has a volume of 4.7 m3 and a mean residence time of 3.4 h under typical operating conditions. It is operated as a completely mixed flow reactor (CMFR), providing the possibility of indefinite steady-state operation across days for sample collection and data analysis. The operation procedures are described in detail in this article. Several types of instrumentation are used to characterize the produced gas and particles. A High-Resolution Time-of-Fight Aerosol Mass Spectrometer (HR-ToF-AMS) is used to characterize particles. A Proton-Transfer-Reaction Mass Spectrometer (PTR-MS) is used for gaseous analysis. Example results are presented to show the use of the environmental chamber in a wide variety of applications related to the physicochemical properties and reaction mechanisms of organic atmospheric particulate matter.

This paper describes operation procedures for the Harvard Environmental Chamber (HEC) and related instrumentation for measuring gaseous and particle species. The environmental chamber is used to produce and study secondary organic species produced from the organic precursors, especially related to atmospheric organic particulate matter.

Produção e medição de partículas orgânicas na câmara ambiental de Harvard

The production and the evolution of atmospheric organic particulate matter (PM) are insufficiently understood for accurate simulations of atmospheric ...