Resumo
The present study aimed to verify whether the inclusion of other ingredients in the diet of laying hens could interfere with the traceability of bovine meat and bone meal (BMBM) in eggs through stable carbon and nitrogen isotope analysis. Two hundred and fifty-six white laying hens were used and randomly distributed into eight treatments composed of: CONTROL: control diet; GLUTEN: control diet + corn gluten; YEAST: control diet + yeast; GLUTEN + YEAST: control diet + corn gluten + yeast; BMBM: control diet + 4.5 % BMBM; BMBM + GLUTEN: control diet + corn gluten + 4.5 % BMBM; BMBM + YEAST: control diet + yeast + 4.5 % BMBM; BMBM + GLUTEN + YEAST: control diet + corn gluten + yeast + 4.5 % BMBM. The isotopic results were subjected to multivariate analysis of variance (MANOVA) and LDA multivariate linear discriminant analysis. At 28 days, the eggs of the birds given diets without the addition of BMBM differed from the CONTROL group. The yolks showed that all treatments were significantly different from the CONTROL, and at 56 days, all eggs and egg yolks were different from the CONTROL. At 28 days, albumen was significantly different for all CONTROL experimental treatments; however, at 56 days, the YEAST treatment showed no difference from the control. Thus, it was concluded that even with the addition of other ingredients, the isotope technique is still able to detect the BMBM in eggs.
Assuntos
Feminino , Animais , Dieta/veterinária , Gema de Ovo , Isótopos de Carbono/análise , Isótopos de Nitrogênio/análiseResumo
ABSTRACT The present study aimed to verify whether the inclusion of other ingredients in the diet of laying hens could interfere with the traceability of bovine meat and bone meal (BMBM) in eggs through stable carbon and nitrogen isotope analysis. Two hundred and fifty-six white laying hens were used and randomly distributed into eight treatments composed of: CONTROL: control diet; GLUTEN: control diet + corn gluten; YEAST: control diet + yeast; GLUTEN + YEAST: control diet + corn gluten + yeast; BMBM: control diet + 4.5 % BMBM; BMBM + GLUTEN: control diet + corn gluten + 4.5 % BMBM; BMBM + YEAST: control diet + yeast + 4.5 % BMBM; BMBM + GLUTEN + YEAST: control diet + corn gluten + yeast + 4.5 % BMBM. The isotopic results were subjected to multivariate analysis of variance (MANOVA) and LDA multivariate linear discriminant analysis. At 28 days, the eggs of the birds given diets without the addition of BMBM differed from the CONTROL group. The yolks showed that all treatments were significantly different from the CONTROL, and at 56 days, all eggs and egg yolks were different from the CONTROL. At 28 days, albumen was significantly different for all CONTROL experimental treatments; however, at 56 days, the YEAST treatment showed no difference from the control. Thus, it was concluded that even with the addition of other ingredients, the isotope technique is still able to detect the BMBM in eggs.
Resumo
Although stable isotopes have been increasingly used in ornithology since 1980 in many places, Brazil has been slow in adopting this methodology, especially when it comes to terrestrial birds. The most common elements in bird ecology studies are carbon, nitrogen, hydrogen, and oxygen stable isotopes, which provide information on diet, trophic interactions, habitat use, migration, geographic patterns, and physiology. It is important that Brazilian ornithologists become aware of the potential of stable isotope analysis in ecological studies, and the shortcomings of this tool. The use of stable isotopes to study bird ecology has great potential in Brazil, since many ecological questions about Neotropical birds can be addressed by it (e.g., resource and habitat use, migratory routes, isotopic niches, anthropogenic impacts, individual specialization). Brazilian museums and other Natural History collections can provide samples to study long-term temporal dynamics in bird ecology. Additionally, the integration of avian tissue sample information into a database may increase the collaboration among researchers and promote sample reuse in a variety of studies. All biomes in Brazil have been under pressure from anthropogenic impacts (e.g., land-use change, habitat loss, fragmentation, intensive agriculture), affecting several taxa, including terrestrial birds. Considering the negative effects of human expansion over natural areas and that stable isotopes provide useful ecological information, ornithologists in Brazil should increase their use of this tool in the future.(AU)
Assuntos
Animais , Aves , Fenômenos Ecológicos e Ambientais , Isótopos , Brasil , EcossistemaResumo
The present study aimed to verify whether the inclusion of other ingredients in the diet of laying hens could interfere with the traceability of bovine meat and bone meal (BMBM) in eggs through stable carbon and nitrogen isotope analysis. Two hundred and fifty-six white laying hens were used and randomly distributed into eight treatments composed of: CONTROL: control diet; GLUTEN: control diet + corn gluten; YEAST: control diet + yeast; GLUTEN + YEAST: control diet + corn gluten + yeast; BMBM: control diet + 4.5 % BMBM; BMBM + GLUTEN: control diet + corn gluten + 4.5 % BMBM; BMBM + YEAST: control diet + yeast + 4.5 % BMBM; BMBM + GLUTEN + YEAST: control diet + corn gluten + yeast + 4.5 % BMBM. The isotopic results were subjected to multivariate analysis of variance (MANOVA) and LDA multivariate linear discriminant analysis. At 28 days, the eggs of the birds given diets without the addition of BMBM differed from the CONTROL group. The yolks showed that all treatments were significantly different from the CONTROL, and at 56 days, all eggs and egg yolks were different from the CONTROL. At 28 days, albumen was significantly different for all CONTROL experimental treatments; however, at 56 days, the YEAST treatment showed no difference from the control. Thus, it was concluded that even with the addition of other ingredients, the isotope technique is still able to detect the BMBM in eggs.(AU)
Assuntos
Animais , Bovinos/fisiologia , Farinha/análise , Isótopos/análise , Programas de Rastreamento/métodosResumo
Cladocerans, an important zooplankton community, are consumers from the base of the food web of aquatic environments. We investigated the contribution of producers (phytoplankton and periphytic biofilm) and particulate organic carbon (POC). Collections were carried out in lakes of the Upper Paraná River Floodplain, the last stretch free of dams in the second-largest South American basin. Isotope ratios (δ13C and δ15N) were measured, besides the contributions of probable food sources to the cladocerans biomass. The phytoplankton constituted the source of carbon for cladocerans, followed by POC. Thus this work, in addition to emphasizing the importance of cladocerans in nutrient cycling, highlighted the need for the conservation of environments surrounding the lakes as they are the sources of organic matter for aquatic communities. Besides, the analyzed zooplanktonic organisms demonstrated their role in the interconnection between the green and brown food webs, which have been studied separately for a long time.
Os cladóceros, importante comunidade zooplanctônica, são consumidores da base da cadeia alimentar dos ambientes aquáticos. O objetivo foi identificar a real contribuição dos produtores (fitoplâncton e biofilme perifítico) e do carbono orgânico particulado (COP) na biomassa dos cladóceros. As coletas foram realizadas em lagoas da planície de inundação do alto rio Paraná, último trecho livre de barragens na segunda maior bacia da América do Sul. As razões isotópicas (δ¹³C e δ15N) e as contribuições de prováveis fontes de alimento para a biomassa de cladóceros foram medidas. Verificou-se valores enriquecidos de δ15N para o fitoplâncton de ambiente sob impacto antrópico, COP com valores de d13C semelhante a plantas C3 e diferenças na assinatura do d13C do fitoplâncton dos ambientes estudados. Ademais, que o fitoplâncton constituiu a maior fonte de carbono para os cladóceros (35% ou mais da biomassa dos cladóceros), seguido pelo COP (30% ou mais). Assim, o presente trabalho, além de enfatizar a importância dos cladóceros na ciclagem de nutrientes, destacou a necessidade de conservação dos ambientes no entorno dos lagos, uma vez que são fontes de matéria orgânica para as comunidades aquáticas. Além disso, os organismos zooplanctônicos analisados demonstraram seu papel na interconexão entre as cadeias alimentares verde e marrom, que há muito vêm sendo estudadas separadamente.
Assuntos
Animais , Fitoplâncton , Cadeia Alimentar , Cladocera , Matéria Orgânica , Zooplâncton , Brasil , LagosResumo
Kajikia audax, Thunnus albacares, Katsuwonus pelamis, and Auxis spp. occupy high and middle-level trophic positions in the food web. They represent important sources for fisheries in Ecuador. Despite their ecological and economic importance, studies on pelagic species in Ecuador are scarce. This study uses stable isotope analysis to assess the trophic ecology of these species, and to determine the contribution of prey to the predator tissue. Isotope data was used to test the hypothesis that medium-sized pelagic fish species have higher δ15N values than those of the prey they consumed, and that there is no overlap between their δ13C and δ15N values. Results showed higher δ15N values for K. audax, followed by T. albacares, Auxis spp. and K. pelamis, which indicates that the highest position in this food web is occupied by K. audax. The stable isotope Bayesian ellipses demonstrated that on a long time-scale, these species do not compete for food sources. Moreover, δ15N values were different between species and they decreased with a decrease in predator size.(AU)
Kajikia audax, Thunnus albacares, Katsuwonus pelamis e Auxis spp. ocupam posições tróficas intermedias e/ou elevadas nas cadeias alimentares. Estas espécies representam um importante recurso pesqueiro no Ecuador. Apesar da sua importância económica e ecológica, estudos nestas espécies pelágicas no Ecuador são raras. Este estudo usa isótopos estáveis para avaliar o seu nível trófico de modo a determinar a contribuição das suas presas para os tecidos destes predadores. Dados dos isótopos foram usados para testar a hipótese de que estas espécies de peixes pelágicos possuem valores mais elevados de δ15N do que daqueles das presas consumidas, e que não existe uma sobreposição entre os valores de δ13C e δ15N. Resultados mostram que valores mais elevados de δ15N para K. audax, seguidos por T. albacares, Auxis spp. e K. pelamis, indicam que a posição mais elevada na cadeia alimentar é ocupada por K. audax. Elipses Bayesianas de isótopos estáveis demonstram que, a uma escala de longo-termo, estas espécies de peixes não competem pelos recursos. Adicionalmente, os valores de δ15N são diferentes entre espécies de peixe estudadas e estes valores decrescem com a diminuição do tamanho do predador.(AU)
Assuntos
Animais , Cadeia Alimentar , Ecologia , Isótopos , PerciformesResumo
Kajikia audax, Thunnus albacares, Katsuwonus pelamis, and Auxis spp. occupy high and middle-level trophic positions in the food web. They represent important sources for fisheries in Ecuador. Despite their ecological and economic importance, studies on pelagic species in Ecuador are scarce. This study uses stable isotope analysis to assess the trophic ecology of these species, and to determine the contribution of prey to the predator tissue. Isotope data was used to test the hypothesis that medium-sized pelagic fish species have higher δ15N values than those of the prey they consumed, and that there is no overlap between their δ13C and δ15N values. Results showed higher δ15N values for K. audax, followed by T. albacares, Auxis spp. and K. pelamis, which indicates that the highest position in this food web is occupied by K. audax. The stable isotope Bayesian ellipses demonstrated that on a long time-scale, these species do not compete for food sources. Moreover, δ15N values were different between species and they decreased with a decrease in predator size.(AU)
Kajikia audax, Thunnus albacares, Katsuwonus pelamis e Auxis spp. ocupam posições tróficas intermedias e/ou elevadas nas cadeias alimentares. Estas espécies representam um importante recurso pesqueiro no Ecuador. Apesar da sua importância económica e ecológica, estudos nestas espécies pelágicas no Ecuador são raras. Este estudo usa isótopos estáveis para avaliar o seu nível trófico de modo a determinar a contribuição das suas presas para os tecidos destes predadores. Dados dos isótopos foram usados para testar a hipótese de que estas espécies de peixes pelágicos possuem valores mais elevados de δ15N do que daqueles das presas consumidas, e que não existe uma sobreposição entre os valores de δ13C e δ15N. Resultados mostram que valores mais elevados de δ15N para K. audax, seguidos por T. albacares, Auxis spp. e K. pelamis, indicam que a posição mais elevada na cadeia alimentar é ocupada por K. audax. Elipses Bayesianas de isótopos estáveis demonstram que, a uma escala de longo-termo, estas espécies de peixes não competem pelos recursos. Adicionalmente, os valores de δ15N são diferentes entre espécies de peixe estudadas e estes valores decrescem com a diminuição do tamanho do predador.(AU)
Assuntos
Animais , Cadeia Alimentar , Ecologia , Isótopos , PerciformesResumo
The objective ofthisstudy was to evaluatethebehavior of carbon incorporation andturnoverin hoof and ribs of pigsat different periodsof development in the search fortissuesthat reflectlongerthe formerdiet.We used132commercial hybrids (barrows and females), weaned atan average age of21 days,distributed ina completely randomized designwithfour treatmentsondifferent daysof substitution of corn(C4cycleplantgrain) dietswithbrokenrice (C3 cycleplantgrain) at 21, 42, 63 and 110 daysof age tochangethe carbon-13 isotope signal.By means ofisotopicdilution curves, we observedthat animalswhose C4dietwasreplaced withC3dietat 21, 42, 63and 110days of age,for hoof and rib,reached anew levelof isotope equilibrium. Bone samplesare better choicesto reflect theformer diet, due to conservation of the isotopic signal for longer.(AU)
Assuntos
Animais , Suínos , Carbono/análise , Carbono/química , Isótopos de Carbono/análise , Casco e Garras , CostelasResumo
The objective ofthisstudy was to evaluatethebehavior of carbon incorporation andturnoverin hoof and ribs of pigsat different periodsof development in the search fortissuesthat reflectlongerthe formerdiet.We used132commercial hybrids (barrows and females), weaned atan average age of21 days,distributed ina completely randomized designwithfour treatmentsondifferent daysof substitution of corn(C4cycleplantgrain) dietswithbrokenrice (C3 cycleplantgrain) at 21, 42, 63 and 110 daysof age tochangethe carbon-13 isotope signal.By means ofisotopicdilution curves, we observedthat animalswhose C4dietwasreplaced withC3dietat 21, 42, 63and 110days of age,for hoof and rib,reached anew levelof isotope equilibrium. Bone samplesare better choicesto reflect theformer diet, due to conservation of the isotopic signal for longer.
Assuntos
Animais , Carbono/análise , Carbono/química , Casco e Garras , Costelas , Isótopos de Carbono/análise , SuínosResumo
In South America, mercury contamination due to gold mining operations is a threat to both biodiversity and human health. We examined mercury (Hg) concentrations in fishes that constitute important subsistence fisheries from mined and non-mined tributaries in the middle Mazaruni River, Guyana. Mercury concentrations and trophic food web structure (based on carbon and nitrogen stable isotopes) were characterized for primary basal sources and 39 fish species representing seven trophic guilds. Fishes collected at mined sites had higher mercury concentrations; piscivores and carnivores had the highest Hg concentrations and exhibited significant Hg biomagnification. Our results showed that medium- to large-bodied fishes commonly eaten by local people contained Hg values that exceed the World Health Organization (WHO) criteria, and pose a health concern for riverine communities along the Mazaruni River that depend on fish as their main source of protein. Further research to determine the sources of Hg contamination and how it affects human health in this neotropical river must become a top priority. In addition, more research on how Hg contamination impacts the fishes themselves and overall aquatic biodiversity is also needed in the Mazaruni River which has both high fish endemism and diversity.(AU)
Na América do Sul, a contaminação por mercúrio devido às operações de mineração de ouro é uma ameaça à biodiversidade e à saúde humana. Nós examinamos as concentrações de mercúrio (Hg) em peixes que constituem importantes pescarias de subsistência em afluentes minerados e não minerados no médio rio Mazaruni, Guiana. As concentrações de mercúrio e a estrutura trófica da teia alimentar (baseada em isótopos estáveis de carbono e nitrogênio) foram caracterizadas para fontes basais primárias e 39 espécies de peixes representando sete guildas tróficas. Os peixes coletados em locais minerados tiveram maiores concentrações de mercúrio; piscívoros e carnívoros tiveram as maiores concentrações de Hg e exibiram biomagnificação significativa de Hg. Nossos resultados mostraram que peixes de corpo médio a grande comumente consumidos pela população local continham valores de Hg que excedem os critérios da Organização Mundial de Saúde (OMS) e representam uma preocupação para a saúde das comunidades ribeirinhas ao longo do rio Mazaruni que dependem dos peixes como sua principal fonte de proteína. Outras pesquisas para determinar as fontes de contaminação por Hg e como isso afeta a saúde humana neste rio neotropical devem se tornar uma prioridade. Além disso, mais pesquisas sobre como a contaminação por Hg impacta os próprios peixes e a biodiversidade aquática em geral também são necessárias no rio Mazaruni, que tem alto endemismo e diversidade de peixes.(AU)
Assuntos
Animais , Contaminação Química , Peixes/fisiologia , Mercúrio/toxicidade , Cadeia Alimentar , Bioacumulação , Isótopos de Mercúrio/químicaResumo
In South America, mercury contamination due to gold mining operations is a threat to both biodiversity and human health. We examined mercury (Hg) concentrations in fishes that constitute important subsistence fisheries from mined and non-mined tributaries in the middle Mazaruni River, Guyana. Mercury concentrations and trophic food web structure (based on carbon and nitrogen stable isotopes) were characterized for primary basal sources and 39 fish species representing seven trophic guilds. Fishes collected at mined sites had higher mercury concentrations; piscivores and carnivores had the highest Hg concentrations and exhibited significant Hg biomagnification. Our results showed that medium- to large-bodied fishes commonly eaten by local people contained Hg values that exceed the World Health Organization (WHO) criteria, and pose a health concern for riverine communities along the Mazaruni River that depend on fish as their main source of protein. Further research to determine the sources of Hg contamination and how it affects human health in this neotropical river must become a top priority. In addition, more research on how Hg contamination impacts the fishes themselves and overall aquatic biodiversity is also needed in the Mazaruni River which has both high fish endemism and diversity.(AU)
Na América do Sul, a contaminação por mercúrio devido às operações de mineração de ouro é uma ameaça à biodiversidade e à saúde humana. Nós examinamos as concentrações de mercúrio (Hg) em peixes que constituem importantes pescarias de subsistência em afluentes minerados e não minerados no médio rio Mazaruni, Guiana. As concentrações de mercúrio e a estrutura trófica da teia alimentar (baseada em isótopos estáveis de carbono e nitrogênio) foram caracterizadas para fontes basais primárias e 39 espécies de peixes representando sete guildas tróficas. Os peixes coletados em locais minerados tiveram maiores concentrações de mercúrio; piscívoros e carnívoros tiveram as maiores concentrações de Hg e exibiram biomagnificação significativa de Hg. Nossos resultados mostraram que peixes de corpo médio a grande comumente consumidos pela população local continham valores de Hg que excedem os critérios da Organização Mundial de Saúde (OMS) e representam uma preocupação para a saúde das comunidades ribeirinhas ao longo do rio Mazaruni que dependem dos peixes como sua principal fonte de proteína. Outras pesquisas para determinar as fontes de contaminação por Hg e como isso afeta a saúde humana neste rio neotropical devem se tornar uma prioridade. Além disso, mais pesquisas sobre como a contaminação por Hg impacta os próprios peixes e a biodiversidade aquática em geral também são necessárias no rio Mazaruni, que tem alto endemismo e diversidade de peixes.(AU)
Assuntos
Animais , Contaminação Química , Peixes/fisiologia , Mercúrio/toxicidade , Cadeia Alimentar , Bioacumulação , Isótopos de Mercúrio/químicaResumo
This study aimed to evaluate if the presence of pollutants promotes changes in feeding habits of fish species from different trophic guilds: the detritivorous species, Hypostomus francisci, and the piscivorous, Hoplias intermedius. Both species were sampled at 12 sites (with different degrees of pollution) in the Rio das Velhas basin, which is heavily polluted by domestic and industrial sewage from the Metropolitan Region of Belo Horizonte (MRBH). Stable isotope analyses of carbon (δ13C) and nitrogen (δ15N) of fish tissue and the main food resources were performed. Fishes from both trophic guilds altered their diets in degraded environments, but the detritivorous species showed greater trophic plasticity. The isotopic niche of both trophic guilds was broadest in unpolluted sites and more δ15N enriched in polluted regions. The detritivorous species presented high niche-breadth in unpolluted sites, probably due to the greater variety of resources consumed. In addition, the δ15N of the detritivorous was more enriched than the piscivorous species in polluted sites. In conclusion, fishes from both trophic guilds presented similar isotopic responses to environmental pollution. However, the detritivorous species was more sensitive to these alterations and therefore, is likely a better indicator of environmental condition than the piscivorous.(AU)
Este estudo teve como objetivo avaliar se a presença de poluentes promove mudanças nos hábitos alimentares de espécies de peixes de diferentes guildas tróficas: a espécie detritívora, Hypostomus francisci, e a piscívora, Hoplias intermedius. Ambas espécies foram amostradas em 12 locais (com diferentes níveis de poluição) na bacia do Rio das Velhas, que é altamente poluída por esgoto doméstico e industrial da Região Metropolitana de Belo Horizonte (RMBH). Foram realizadas análises de isótopos estáveis de carbono (δ13C) e nitrogênio (δ15N) dos tecidos dos peixes e dos principais recursos alimentares. Espécies de ambas guildas tróficas alteraram suas dietas em ambientes degradados, mas a espécie detritívora apresentou maior plasticidade trófica. O nicho isotópico de ambas as espécies foi mais amplo em locais menos perturbados e mais enriquecido em δ15N em regiões poluídas. A espécie detritívora apresentou grande amplitude em seu nicho isotópico em locais menos perturbados, provavelmente devido à maior variedade de recursos consumidos. Além disso, o δ15N da espécie detritívora foi mais enriquecido que a espécie piscívora em locais poluídos. Em conclusão, ambas as espécies apresentaram respostas isotópicas semelhantes à poluição ambiental. No entanto, a espécie detritívora foi mais sensível a essas alterações e, portanto, é provavelmente uma melhor indicadora de condição ambiental do que a espécie piscívora.(AU)
Assuntos
Animais , Comportamento Alimentar/classificação , Marcação por Isótopo/veterinária , Ração Animal/toxicidade , Esgotos DomésticosResumo
This study aimed to evaluate if the presence of pollutants promotes changes in feeding habits of fish species from different trophic guilds: the detritivorous species, Hypostomus francisci, and the piscivorous, Hoplias intermedius. Both species were sampled at 12 sites (with different degrees of pollution) in the Rio das Velhas basin, which is heavily polluted by domestic and industrial sewage from the Metropolitan Region of Belo Horizonte (MRBH). Stable isotope analyses of carbon (δ13C) and nitrogen (δ15N) of fish tissue and the main food resources were performed. Fishes from both trophic guilds altered their diets in degraded environments, but the detritivorous species showed greater trophic plasticity. The isotopic niche of both trophic guilds was broadest in unpolluted sites and more δ15N enriched in polluted regions. The detritivorous species presented high niche-breadth in unpolluted sites, probably due to the greater variety of resources consumed. In addition, the δ15N of the detritivorous was more enriched than the piscivorous species in polluted sites. In conclusion, fishes from both trophic guilds presented similar isotopic responses to environmental pollution. However, the detritivorous species was more sensitive to these alterations and therefore, is likely a better indicator of environmental condition than the piscivorous.(AU)
Este estudo teve como objetivo avaliar se a presença de poluentes promove mudanças nos hábitos alimentares de espécies de peixes de diferentes guildas tróficas: a espécie detritívora, Hypostomus francisci, e a piscívora, Hoplias intermedius. Ambas espécies foram amostradas em 12 locais (com diferentes níveis de poluição) na bacia do Rio das Velhas, que é altamente poluída por esgoto doméstico e industrial da Região Metropolitana de Belo Horizonte (RMBH). Foram realizadas análises de isótopos estáveis de carbono (δ13C) e nitrogênio (δ15N) dos tecidos dos peixes e dos principais recursos alimentares. Espécies de ambas guildas tróficas alteraram suas dietas em ambientes degradados, mas a espécie detritívora apresentou maior plasticidade trófica. O nicho isotópico de ambas as espécies foi mais amplo em locais menos perturbados e mais enriquecido em δ15N em regiões poluídas. A espécie detritívora apresentou grande amplitude em seu nicho isotópico em locais menos perturbados, provavelmente devido à maior variedade de recursos consumidos. Além disso, o δ15N da espécie detritívora foi mais enriquecido que a espécie piscívora em locais poluídos. Em conclusão, ambas as espécies apresentaram respostas isotópicas semelhantes à poluição ambiental. No entanto, a espécie detritívora foi mais sensível a essas alterações e, portanto, é provavelmente uma melhor indicadora de condição ambiental do que a espécie piscívora.(AU)
Assuntos
Animais , Comportamento Alimentar/classificação , Marcação por Isótopo/veterinária , Ração Animal/toxicidade , Esgotos DomésticosResumo
The aim of this study was to determine the food webs structure of a large Patagonian river in two river sections (Upstream and Midstream) and to evaluate isotopic overlap between native and introduced species. We used stable isotope analyses of δ15N and δ13C and stomach content. The Upstream section had a more complex food webs structure with a greater richness of macroinvertebrates and fish species than Midstream. Upstream basal resources were dominated by filamentous algae. Lake Trout were found to have a higher trophic position than all other fish species in that area although, the most abundant fish species, were Rainbow Trout. Depending on the life stage, Rainbow Trout shifted from prey to competitor/predator. In the Midstream section, the base of the food webs was dominated by coarse particulate organic matter, and adult Rainbow Trout had the highest trophic level. Isotopic values changed among macroinvertebrates and fish for both areas. The two most abundant native and invasive species Puyen and Rainbow Trout showed an isotopic separation in Midstream but did not in Upstream areas. The presence of invasive fish that occupy top trophic levels can have a significant impact on native fish populations that have great ecological importance in the region.(AU)
El objetivo de este estudio fue determinar la estructura trófica de un gran río de la Patagonia en dos secciones (río arriba y medio) y evaluar la superposición isotópica entre especies nativas e introducidas. Utilizamos análisis de isótopos estables δ15N y δ13C y contenido estomacal. La sección río arriba tuvo una estructura de trama trófica más compleja, con mayor riqueza de macroinvertebrados y peces respecto de la sección media. Los recursos basales dominantes río arriba fueron las algas filamentosas. En esta área, la trucha de lago tuvo la posición trófica más alta entre los peces, aunque, las especies de peces más abundantes fueron las truchas arcoiris. Dependiendo del estadio, la trucha arcoiris cambió su rol de presa a competidor/depredador. En la sección media del río, la base de la trama trófica estuvo dominada por materia orgánica particulada gruesa y la trucha arcoíris adulta fue el depredador tope. Los valores isotópicos variaron entre zonas para invetebrados y peces. Las dos especies nativas e invasoras más abundantes, Puyen y trucha arcoiris, mostraron una separación isotópica en la sección media, pero no en secciones de río arriba. La presencia de peces invasores que ocupan una posición tope en los niveles tróficos puede tener un impacto significativo sobre las poblaciones de peces nativos de gran importancia ecológica en la región.(AU)
Assuntos
Animais , Truta , Cadeia Alimentar , Corrente MontanteResumo
The aim of this study was to determine the food webs structure of a large Patagonian river in two river sections (Upstream and Midstream) and to evaluate isotopic overlap between native and introduced species. We used stable isotope analyses of δ15N and δ13C and stomach content. The Upstream section had a more complex food webs structure with a greater richness of macroinvertebrates and fish species than Midstream. Upstream basal resources were dominated by filamentous algae. Lake Trout were found to have a higher trophic position than all other fish species in that area although, the most abundant fish species, were Rainbow Trout. Depending on the life stage, Rainbow Trout shifted from prey to competitor/predator. In the Midstream section, the base of the food webs was dominated by coarse particulate organic matter, and adult Rainbow Trout had the highest trophic level. Isotopic values changed among macroinvertebrates and fish for both areas. The two most abundant native and invasive species — Puyen and Rainbow Trout — showed an isotopic separation in Midstream but did not in Upstream areas. The presence of invasive fish that occupy top trophic levels can have a significant impact on native fish populations that have great ecological importance in the region.(AU)
El objetivo de este estudio fue determinar la estructura trófica de un gran río de la Patagonia en dos secciones (río arriba y medio) y evaluar la superposición isotópica entre especies nativas e introducidas. Utilizamos análisis de isótopos estables δ15N y δ13C y contenido estomacal. La sección río arriba tuvo una estructura de trama trófica más compleja, con mayor riqueza de macroinvertebrados y peces respecto de la sección media. Los recursos basales dominantes río arriba fueron las algas filamentosas. En esta área, la trucha de lago tuvo la posición trófica más alta entre los peces, aunque, las especies de peces más abundantes fueron las truchas arcoiris. Dependiendo del estadio, la trucha arcoiris cambió su rol de presa a competidor/depredador. En la sección media del río, la base de la trama trófica estuvo dominada por materia orgánica particulada gruesa y la trucha arcoíris adulta fue el depredador tope. Los valores isotópicos variaron entre zonas para invetebrados y peces. Las dos especies nativas e invasoras más abundantes, Puyen y trucha arcoiris, mostraron una separación isotópica en la sección media, pero no en secciones de río arriba. La presencia de peces invasores que ocupan una posición tope en los niveles tróficos puede tener un impacto significativo sobre las poblaciones de peces nativos de gran importancia ecológica en la región.(AU)
Assuntos
Animais , Truta , Cadeia Alimentar , Corrente MontanteResumo
The objective of this study was to determine if lipid extraction processes alter the isotopic value of 13C and 15N of tissues (pectoral muscle, thigh and liver) and eggs and if the use of anticoagulants interferes with blood and plasma 13C and 15N isotopic values. Samples were acquired from the same flock of birds. The 32 egg samples were randomly divided into four treatments (liquid, dehydrated, and fat-extracted with ether or chloroform + methanol) with eight replicates each. The 24 samples of pectoral muscle, thigh muscle and liver of broilers were randomly divided into three treatments (dehydrated, fat-extracted with ether and chloroform + methanol) with eight replicates each. Blood samples were divided into a 3x3 factorial arrangement with three physical forms (liquid, oven-dried or freeze-dried) and three collection methods (with no anticoagulant, with EDTA or heparin). Plasma samples were distributed in a 3x2 factorial arrangement, with three physical forms (liquid, oven-dried, or freeze-dried) and two anticoagulants (EDTA or heparin). The obtained isotopic results were submitted to the multivariate analysis of variance (MANOVA) and univariate (ANOVA, complemented by Tukey test), using the GLM procedure of the statistical program SAS (1996) or Minitab 16. The results show that it is possible to use the evaluated methods of fat extraction, drying and anticoagulants in the isotopic analyses of carbon-13 and nitrogen-15 in chicken tissues.(AU)
Assuntos
Animais , Aves , Marcação por Isótopo/métodos , Marcação por Isótopo/veterinária , CarbonoResumo
The objective of this study was to determine if lipid extraction processes alter the isotopic value of 13C and 15N of tissues (pectoral muscle, thigh and liver) and eggs and if the use of anticoagulants interferes with blood and plasma 13C and 15N isotopic values. Samples were acquired from the same flock of birds. The 32 egg samples were randomly divided into four treatments (liquid, dehydrated, and fat-extracted with ether or chloroform + methanol) with eight replicates each. The 24 samples of pectoral muscle, thigh muscle and liver of broilers were randomly divided into three treatments (dehydrated, fat-extracted with ether and chloroform + methanol) with eight replicates each. Blood samples were divided into a 3x3 factorial arrangement with three physical forms (liquid, oven-dried or freeze-dried) and three collection methods (with no anticoagulant, with EDTA or heparin). Plasma samples were distributed in a 3x2 factorial arrangement, with three physical forms (liquid, oven-dried, or freeze-dried) and two anticoagulants (EDTA or heparin). The obtained isotopic results were submitted to the multivariate analysis of variance (MANOVA) and univariate (ANOVA, complemented by Tukey test), using the GLM procedure of the statistical program SAS (1996) or Minitab 16. The results show that it is possible to use the evaluated methods of fat extraction, drying and anticoagulants in the isotopic analyses of carbon-13 and nitrogen-15 in chicken tissues.
Assuntos
Animais , Aves , Marcação por Isótopo/métodos , Marcação por Isótopo/veterinária , CarbonoResumo
Background:Cutaneous leishmaniasis (CL) is a parasitic disease caused by the protozoan Leishmania spp. Pentavalent antimonial agents have been used as an effective therapy, despite their side effects and resistant cases. Their pharmacokinetics remain largely unexplored. This study aimed to investigate the pharmacokinetic profile of meglumine antimoniate in a murine model of cutaneous leishmaniasis using a radiotracer approach.Methods:Meglumine antimoniate was neutron-irradiated inside a nuclear reactor and was administered once intraperitoneally to uninfected and L. amazonensis-infected BALB/c mice. Different organs and tissues were collected and the total antimony was measured.Results:Higher antimony levels were found in infected than uninfected footpad (0.29% IA vs. 0.14% IA, p = 0.0057) and maintained the concentration. The animals accumulated and retained antimony in the liver, which cleared slowly. The kidney and intestinal uptake data support the hypothesis that antimony has two elimination pathways, first through renal excretion, followed by biliary excretion. Both processes demonstrated a biphasic elimination profile classified as fast and slow. In the blood, antimony followed a biexponential open model. Infected mice showed a lower maximum concentration (6.2% IA/mL vs. 11.8% IA/mL, p = 0.0001), a 2.5-fold smaller area under the curve, a 2.7-fold reduction in the mean residence time, and a 2.5-fold higher clearance rate when compared to the uninfected mice.Conclusions:neutron-irradiated meglumine antimoniate concentrates in infected footpad, while the infection affects antimony pharmacokinetics.(AU)
Assuntos
Animais , Camundongos , Leishmania , Meglumina/farmacocinética , Nêutrons , Leishmaniose Cutânea , Antimônio/farmacocinética , Camundongos Endogâmicos BALB C , RadioisótoposResumo
El cáncer es una neoplasia que afecta a los seres humanos y animales, lo que representa el mayor número de muertes. La radioterapia es una práctica médica, que utiliza radiación ionizante para eliminar o prevenir la multiplicación de las células cancerosas. La radioterapia se divide en dos modalidades, llamadas braquiterapia y teleterapia. Este último ha adquirido espacio dentro de la medicina veterinaria, principalmente para el tratamiento de tumores de cabeza y cuello. Sin embargo, este trabajo propone recopilar y describir los principales casos de teleterapia aplicada a tumores de cabeza y cuello en animales pequeños a través de la literatura. Tras una breve revisión de la literatura elaborada en este estudio, fue posible identificar las principales aplicaciones de la teleterapia en tumores de cabeza y cuello en animales pequeños y destacar la eficacia de esta modalidad de tratamiento en la supervivencia de los animales involucrados.(AU)
The cancer is a neoplasm that affects humans and animals, accounting for the highest number of deaths. Radiation therapy is a medical practice, which uses ionizing radiation to eliminate or prevent the multiplication of cancer cells. Radiotherapy is divided into two modalities, called brachytherapy and teletherapy. This last one has acquired space within the veterinary medicine, mainly for treatment of tumors of head and neck. However, this paper proposes to compile and describe the main cases of teletherapy applied to head and neck tumors in small animals through the literature. After a brief review of the literature elaborated in this study, it was possible to identify the main applications of teletherapy in tumors of the head and neck in small animals and to highlight the efficacy of this therapeutic modality in the survival of the animals involved.(AU)
O câncer é uma neoplasia que acomete seres humanos e animais, sendo responsável pelo maior número de mortalidade. A radioterapia é uma prática médica, que utiliza radiação ionizante para eliminar ou impedir a multiplicação das células cancerígenas. A radioterapia divide-se em duas modalidades, denominadas de braquiterapia e teleterapia. Essa última vem adquirindo espaço dentro da medicina veterinária, principalmente para tratamento de tumores de cabeça e pescoço. Contudo esse trabalho propôs copilar e descrever os principais casos de teleterapia aplicada em tumores de cabeça e pescoço em pequenos animais por meio da literatura. Após uma breve revisão de literatura elaborada nesse estudo, foi possível identificar as principais aplicações da teleterapia nos tumores de cabeça e pescoço em pequenos animais e destacar eficácia dessa modalidade terapêutica na sobrevida dos animais envolvidos.(AU)
Assuntos
Animais , Gatos , Cães , Teleterapia por Radioisótopo/métodos , Teleterapia por Radioisótopo , Teleterapia por Radioisótopo/veterinária , Neoplasias de Cabeça e Pescoço/radioterapia , Neoplasias de Cabeça e Pescoço/veterinária , Radioterapia/veterináriaResumo
El cáncer es una neoplasia que afecta a los seres humanos y animales, lo que representa el mayor número de muertes. La radioterapia es una práctica médica, que utiliza radiación ionizante para eliminar o prevenir la multiplicación de las células cancerosas. La radioterapia se divide en dos modalidades, llamadas braquiterapia y teleterapia. Este último ha adquirido espacio dentro de la medicina veterinaria, principalmente para el tratamiento de tumores de cabeza y cuello. Sin embargo, este trabajo propone recopilar y describir los principales casos de teleterapia aplicada a tumores de cabeza y cuello en animales pequeños a través de la literatura. Tras una breve revisión de la literatura elaborada en este estudio, fue posible identificar las principales aplicaciones de la teleterapia en tumores de cabeza y cuello en animales pequeños y destacar la eficacia de esta modalidad de tratamiento en la supervivencia de los animales involucrados.
The cancer is a neoplasm that affects humans and animals, accounting for the highest number of deaths. Radiation therapy is a medical practice, which uses ionizing radiation to eliminate or prevent the multiplication of cancer cells. Radiotherapy is divided into two modalities, called brachytherapy and teletherapy. This last one has acquired space within the veterinary medicine, mainly for treatment of tumors of head and neck. However, this paper proposes to compile and describe the main cases of teletherapy applied to head and neck tumors in small animals through the literature. After a brief review of the literature elaborated in this study, it was possible to identify the main applications of teletherapy in tumors of the head and neck in small animals and to highlight the efficacy of this therapeutic modality in the survival of the animals involved.
O câncer é uma neoplasia que acomete seres humanos e animais, sendo responsável pelo maior número de mortalidade. A radioterapia é uma prática médica, que utiliza radiação ionizante para eliminar ou impedir a multiplicação das células cancerígenas. A radioterapia divide-se em duas modalidades, denominadas de braquiterapia e teleterapia. Essa última vem adquirindo espaço dentro da medicina veterinária, principalmente para tratamento de tumores de cabeça e pescoço. Contudo esse trabalho propôs copilar e descrever os principais casos de teleterapia aplicada em tumores de cabeça e pescoço em pequenos animais por meio da literatura. Após uma breve revisão de literatura elaborada nesse estudo, foi possível identificar as principais aplicações da teleterapia nos tumores de cabeça e pescoço em pequenos animais e destacar eficácia dessa modalidade terapêutica na sobrevida dos animais envolvidos.