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1.
Int J Mol Sci ; 25(8)2024 Apr 09.
Article in English | MEDLINE | ID: mdl-38673723

ABSTRACT

Recent studies have shown that maternal vitamin D deficiency (VDD) causes long-term metabolic changes in offspring. However, little is known about the impact of maternal VDD on offspring endocrine pancreas development and insulin secretion in the adult life of male and female animals. Female rats (Wistar Hannover) were fed either control (1000 IU Vitamin D3/kg), VDD (0 IU Vitamin D3/kg), or a Ca2+-enriched VDD diet (0 IU Vitamin D3/kg + Ca2+ and P/kg) for 6 weeks and during gestation and lactation. At weaning, VDD status was confirmed based on low serum calcidiol levels in dams and pups. Next, male and female offspring were randomly separated and fed a standard diet for up to 90 days. At this age, serum calcidiol levels were restored to normal levels in all groups, but serum insulin levels were decreased in VDD males without affecting glucagon levels, glycemia, or glucose tolerance. Islets isolated from VDD males showed lower insulin secretion in response to different glucose concentrations, but this effect was not observed in VDD females. Furthermore, VDD males, but not females, showed a smaller total pancreatic islet area and lower ß cell mass, an effect that was accompanied by reduced gene expression of Ins1, Ins2, Pdx1, and SLC2A2. The decrease in Pdx1 expression was not related to the methylation profile of the promoter region of this gene. Most of these effects were observed in the male VDD+Ca2+ group, indicating that the effects were not due to alterations in Ca2+ metabolism. These data show that maternal VDD selectively impairs the morphology and function of ß cells in adult male offspring rats and that female offspring are fully protected from these deleterious effects.


Subject(s)
Insulin-Secreting Cells , Insulin , Rats, Wistar , Vitamin D Deficiency , Animals , Female , Insulin-Secreting Cells/metabolism , Male , Vitamin D Deficiency/metabolism , Rats , Pregnancy , Insulin/blood , Insulin/metabolism , Prenatal Exposure Delayed Effects/metabolism , Prenatal Exposure Delayed Effects/etiology , Sex Factors , Insulin Secretion
2.
Nature ; 619(7971): 788-792, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37468625

ABSTRACT

Ecological interactions are one of the main forces that sustain Earth's biodiversity. A major challenge for studies of ecology and evolution is to determine how these interactions affect the fitness of species when we expand from studying isolated, pairwise interactions to include networks of interacting species1-4. In networks, chains of effects caused by a range of species have an indirect effect on other species they do not interact with directly, potentially affecting the fitness outcomes of a variety of ecological interactions (such as mutualism)5-7. Here we apply analytical techniques and numerical simulations to 186 empirical mutualistic networks and show how both direct and indirect effects alter the fitness of species coevolving in these networks. Although the fitness of species usually increased with the number of mutualistic partners, most of the fitness variation across species was driven by indirect effects. We found that these indirect effects prevent coevolving species from adapting to their mutualistic partners and to other sources of selection pressure in the environment, thereby decreasing their fitness. Such decreases are distributed in a predictable way within networks: peripheral species receive more indirect effects and experience higher reductions in fitness than central species. This topological effect was also evident when we analysed an empirical study of an invasion of pollination networks by honeybees. As honeybees became integrated as a central species within networks, they increased the contribution of indirect effects on several other species, reducing their fitness. Our study shows how and why indirect effects can govern the adaptive landscape of species-rich mutualistic assemblages.


Subject(s)
Biodiversity , Biological Evolution , Genetic Fitness , Symbiosis , Animals , Pollination , Symbiosis/physiology , Bees/physiology
4.
Lipids ; 57(6): 313-325, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36098349

ABSTRACT

Although it is well established that glucocorticoids inactivate thermogenesis and promote lipid accumulation in interscapular brown adipose tissue (IBAT), the underlying mechanisms remain unknown. We found that dexamethasone treatment (1 mg/kg) for 7 days in rats decreased the IBAT thermogenic activity, evidenced by its lower responsiveness to noradrenaline injection associated with reduced content of mitochondrial proteins, respiratory chain protein complexes, noradrenaline, and the ß3 -adrenergic receptor. In parallel, to understand better how dexamethasone increases IBAT lipid content, we also investigated the activity of the ATP citrate lyase (ACL), a key enzyme of de novo fatty acid synthesis, glucose-6-phosphate dehydrogenase (G6PD), a rate-limiting enzyme of the pentose phosphate pathway, and the three glycerol-3-P generating pathways: (1) glycolysis, estimated by 2-deoxyglucose uptake, (2) glyceroneogenesis, evaluated by phosphoenolpyruvate carboxykinase activity and pyruvate incorporation into triacylglycerol-glycerol, and (3) direct phosphorylation of glycerol, investigated by the content and activity of glycerokinase. Dexamethasone increased the mass and the lipid content of IBAT as well as plasma levels of glucose, insulin, non-esterified fatty acid, and glycerol. Furthermore, dexamethasone increased ACL and G6PD activities (79% and 48%, respectively). Despite promoting a decrease in the incorporation of U-[14 C]-glycerol into triacylglycerol (~54%), dexamethasone increased the content (~55%) and activity (~41%) of glycerokinase without affecting glucose uptake or glyceroneogenesis. Our data suggest that glucocorticoid administration reduces IBAT thermogenesis through sympathetic inactivation and stimulates glycerokinase activity and content, contributing to increased generation of glycerol-3-P, which is mostly used to esterify fatty acid and increase triacylglycerol content promoting IBAT whitening.


Subject(s)
Adipose Tissue, Brown , Glycerol Kinase , Animals , Rats , Adipose Tissue, Brown/metabolism , Glycerol Kinase/metabolism , Glucocorticoids , Glycerol , Rats, Wistar , Thermogenesis , Triglycerides/metabolism , Fatty Acids/metabolism , Dexamethasone/metabolism , Norepinephrine , Adipose Tissue/metabolism
5.
An Acad Bras Cienc ; 94(4): e20200425, 2022.
Article in English | MEDLINE | ID: mdl-35894356

ABSTRACT

This study was conducted to evaluate the effects of replacing forage sorghum for dehydrated cashew bagasse (DCB) in the proportions of 0; 8; 16 and 24%, based on the natural matter at the time of ensiling on the physicochemical parameters of meat from feedlot lambs. None of the physical parameters evaluated showed a significant difference between the substitution levels of sorghum forage for DCB. The final pH obtained in this study showed a value above the recommended for freshly slaughtered meat from animals 24 hours in refrigeration, being considered DFD meat (dark, firm and dry). Regarding the chemical parameters, it was observed that there were no significant differences between the levels of substitution of sorghum forage for DCB to variable moisture and ash was perceived negative linear effect for protein and quadratic effect on lipid levels meat. The replacement of forage sorghum up to 24% of dehydrated bagasse cashew the ensilage does not compromise the quality of the meat, however, the substitution of 8% is to be preferred because it provides meats with lower lipid content.


Subject(s)
Anacardium , Sorghum , Animals , Cellulose , Diet/veterinary , Edible Grain , Lipids , Meat , Sheep , Sheep, Domestic , Silage/analysis
6.
Am Nat ; 199(6): 804-807, 2022 06.
Article in English | MEDLINE | ID: mdl-35580229

ABSTRACT

AbstractA pressing issue is to understand how biological complexity impacts the persistence and adaptation of populations. Natural environments are under unprecedented pressure as a result of climate change and land use change, which makes biological populations and ecological communities vulnerable. Evolution by natural selection-that is, genetic change in response to selection-is one important way species can cope with such changes. Selection often operates on complex traits, and much of selection is due to ecological interactions that, in turn, often form complex networks of species. In this sense, ecological interactions play a dual role: ecological interactions are essential to guarantee the resilience of communities and the functioning of ecosystem services, and they are a source of selection that shapes complex traits. The development of a new integrative framework combining the complexity of selected traits with the complexity of interaction patterns is essential to address potential cascading effects and extinctions. Unfortunately, studies that focus on these two levels of complexity, whether using theoretical or empirical approaches, are still scarce. In this special feature, we bring together articles that contribute to bridging this gap in the study of species coevolution and the evolution of complex traits.


Subject(s)
Ecosystem , Selection, Genetic , Biological Evolution , Biota , Climate Change
7.
Ecol Lett ; 23(12): 1789-1799, 2020 Dec.
Article in English | MEDLINE | ID: mdl-32969577

ABSTRACT

Ecological interactions shape the evolution of multiple species traits in populations. These traits are often linked to each other through genetic correlations, affecting how each trait evolves through selection imposed by interacting partners. Here, we integrate quantitative genetics, coevolutionary theory and network science to explore how trait correlations affect the coevolution of mutualistic species not only in pairs of species but also in species-rich networks across space. We show that genetic correlations may determine the pace of coevolutionary change, affect species abundances and fuel divergence among populations of the same species. However, this trait divergence promoted by genetic correlations is partially buffered by the nested structure of species-rich mutualisms. Our study, therefore, highlights how coevolution and its ecological consequences may result from conflicting processes at different levels of organisation, ranging from genes to communities.


Subject(s)
Biological Evolution , Symbiosis , Phenotype
8.
Geriatr Nurs ; 41(6): 899-904, 2020.
Article in English | MEDLINE | ID: mdl-32653259

ABSTRACT

Institutionalized older adults are at greater risk of malnutrition, which is associated with cognitive impairment. This study investigated the association between nutritional status, advanced activities of daily living (AADL), and cognitive function among Brazilian older adults living in care homes. This cross-sectional study was conducted on 95 older adults (73.3 ± 12.5 years). Socio-demographic variables, cognitive function (measured by Mini Mental State Examination - MMSE), AADL, Mini Nutritional Assessment (MNA), and anthropometric variables were assessed. Regarding MNA, 37.8% were malnourished, 47.3% were at risk of malnutrition, and 14.9% were well-nourished. Malnourished participants (37.8%) and those with fewer number of AADL (82.3%) showed cognitive decline (MMSE < 24) (p = 0.000 and 0.030, respectively). Inadequate waist-hip ratio was associated with cognitive decline (OR 9.3; 95% IC, 9.06 - 9.85; p = 0.03). Nutritional status and AADL were associated with cognitive function. Nutritional assessment helps to early identify malnutrition and possibly to prevent cognitive impairment.


Subject(s)
Activities of Daily Living , Malnutrition , Aged , Cognition , Cross-Sectional Studies , Geriatric Assessment , Humans , Malnutrition/diagnosis , Malnutrition/epidemiology , Nutrition Assessment , Nutritional Status , Prevalence
9.
Preprint in Portuguese | SciELO Preprints | ID: pps-381

ABSTRACT

This is the first report by the COVID19 Observatory - Group: Contagion Networks analyzing mortality data from the city of São Paulo. In this report, we integrated mortality data for the city of São Paulo between 04/02/2020 and 04/28/2020, with information on the flow of victims between hospitals and cemeteries/crematoriums. We included in our analyzes both confirmed and suspected deaths from COVID-19. The main objectives of this report were: (1) to describe the structure of the flow of victims between locations and (2) to suggest changes in the current flow based on geographical distances in order to avoid a potential overload of the mortuary system. We suggest that the city of São Paulo should plan for a potential overload of the mortuary system (that is, the number of burials), based on the presented results. Thus, our results reinforce the need to adopt specific planning for the management of the extraordinary number of victims of this pandemic. Our predictions are based on the structural analysis of the COVID-19 victim flow network, which shows several hotspots with high vulnerability to system overload. These hotspots concentrate with either the greatest number of deaths (hospital) or of burials (cemetery or crematorium), and therefore have high potential to become overwhelmed by receiving many bodies due to the increase in victims of the pandemic. We recommend special attention to be given to localities on the east side of São Paulo, which has both the most vulnerable hospitals in the city, and also houses cemeteries and crematoriums that have a central role in the network and / or are vulnerable. Based on our optimization analysis, we suggest logistical changes in the current flow of bodies from hospitals to cemeteries/crematoriums so as not to overload the funeral system and minimize transportation costs. In this sense, our results are potentially useful for improving the operational planning of the Municipality of São Paulo, ratifying or rectifying actions underway at the municipal level.


Este é o primeiro relatório do Observatório COVID19 - Grupo: Redes de Contágio analisando os dados de óbitos da cidade de São Paulo. Neste relatório, integramos os dados de óbitos da cidade de São Paulo entre os dias 02/04/2020 e 28/04/2020 com informações sobre o fluxo de vítimas entre os hospitais e os cemitérios e crematórios da cidade de São Paulo. Incluímos em nossas análises óbitos confirmados e óbitos suspeitos de COVID-19. Os principais objetivos deste relatório são: (1) descrever a estrutura do fluxo de vítimas entre localidades e (2) sugerir mudanças no fluxo com base em distâncias geográficas de maneira a evitar uma potencial sobrecarga do sistema funerário. Sugere-se à prefeitura da cidade de São Paulo que seja realizado um planejamento para uma potencial sobrecarga do sistema funerário (isto é, número de sepultamentos) da cidade de São Paulo com base nos resultados apresentados. Desta forma, nossos resultados reforçam a necessidade de ser adotado planejamento específico para a gestão dos casos extraordinários visualizados no contexto da pandemia. Esta previsão está baseada na análise estrutural da rede de fluxos de vítimas da COVID-19, que indica a concentração de vários locais com alta vulnerabilidade à sobrecarga do sistema. Tais locais concentram a maior quantidade de óbitos (hospitais) ou a maior concentração de sepultamentos (cemitérios ou crematórios) e tem portanto alto potencial de tornarem-se sobrecarregados por receberem muitos corpos devido ao aumento de vítimas da pandemia. Recomenda-se especial atenção à localidades da zona leste de São Paulo, que apresenta os hospitais mais vulneráveis da cidade e abriga cemitérios e crematórios que possuem papel central na rede e/ou encontram-se vulneráveis. Com base em nossa análise de otimização, sugerimos mudanças logísticas no atual fluxo de corpos de hospitais para cemitérios/crematórios de modo a não sobrecarregar o sistema funerário e minimizar os custos de transporte. Neste sentido, nossos resultados são potencialmente úteis ao aperfeiçoamento do planejamento operacional da Prefeitura Municipal de São Paulo, ratificando ou retificando ações em curso no âmbito municipal.

10.
Preprint in Portuguese | SciELO Preprints | ID: pps-35

ABSTRACT

Report from "Observatório COVID19 - Grupo: Redes de Contágio ­ Laboratório de Estudos de Defesa" for the Northeast Region of Brazil. We combined data on confirmed cases of the new coronavirus (SARS-CoV-2) as reported by public authorities by 02/04 and structural analyses of road transport networks within and between the nine States of Northeast Brazil to predict the potential influence of the 187 micro-regions on the geographic propagation of the pandemic.  


Este é o primeiro relatório do Observatório COVID1920 - Grupo: Redes de Contágio ­ Laboratório de Estudos de Defesa para a região Nordeste do Brasil. Combinamos dados de casos confirmados do novo coronavírus (SARS-CoV-2) para o Nordeste, conforme disponível até o dia 02/04, com análises estruturais da rede de rotas rodoviárias intra e interestaduais para estimarmos a vulnerabilidade e potencial influência das microrregiões nordestinas na propagação da doença.

11.
J Appl Physiol (1985) ; 128(4): 855-871, 2020 04 01.
Article in English | MEDLINE | ID: mdl-32027543

ABSTRACT

The sympathetic nervous system (SNS) activates cAMP signaling and promotes trophic effects on brown adipose tissue (BAT) through poorly understood mechanisms. Because norepinephrine has been found to induce antiproteolytic effects on muscle and heart, we hypothesized that the SNS could inhibit autophagy in interscapular BAT (IBAT). Here, we describe that selective sympathetic denervation of rat IBAT kept at 25°C induced atrophy, and in parallel dephosphorylated forkhead box class O (FoxO), and increased cathepsin activity, autophagic flux, autophagosome formation, and expression of autophagy-related genes. Conversely, cold stimulus (4°C) for up to 72 h induced thermogenesis and IBAT hypertrophy, an anabolic effect that was associated with inhibition of cathepsin activity, autophagic flux, and autophagosome formation. These effects were abrogated by sympathetic denervation, which also upregulated Gabarapl1 mRNA. In addition, the cold-driven sympathetic activation stimulated the mechanistic target of rapamycin (mTOR) pathway, leading to the enhancement of protein synthesis, evaluated in vivo by puromycin incorporation, and to the inhibitory phosphorylation of Unc51-like kinase-1, a key protein in the initiation of autophagy. This coincided with a higher content of exchange protein-1 directly activated by cAMP (Epac1), a cAMP effector, and phosphorylation of Akt at Thr308, all these effects being abolished by denervation. Systemic treatment with norepinephrine for 72 h mimicked most of the cold effects on IBAT. These data suggest that the noradrenergic sympathetic inputs to IBAT restrain basal autophagy via suppression of FoxO and, in the setting of cold, stimulate protein synthesis via the Epac/Akt/mTOR-dependent pathway and suppress the autophagosome formation, probably through posttranscriptional mechanisms.NEW & NOTEWORTHY The underlying mechanisms related to the anabolic role of sympathetic innervation on brown adipose tissue (BAT) are unclear. We show that sympathetic denervation activates autophagic-lysosomal degradation, leading to a loss of mitochondrial proteins and BAT atrophy. Conversely, cold-driven sympathetic activation suppresses autophagy and stimulates protein synthesis, leading to BAT hypertrophy. Given its high-potential capacity for heat production, understanding the mechanisms that contribute to BAT mass is important to optimize chances of survival for endotherms in cold ambients.


Subject(s)
Adipose Tissue, Brown , Thermogenesis , Animals , Autophagy , Cold Temperature , Lysosomes , Rats , Sympathetic Nervous System
12.
Proc Biol Sci ; 286(1908): 20191114, 2019 08 14.
Article in English | MEDLINE | ID: mdl-31409249

ABSTRACT

Wildlife disease dynamics are strongly influenced by the structure of host communities and their symbiotic microbiota. Conspicuous amphibian declines associated with the waterborne fungal pathogen Batrachochytrium dendrobatidis (Bd) have been observed in aquatic-breeding frogs globally. However, less attention has been given to cryptic terrestrial-breeding amphibians that have also been declining in tropical regions. By experimentally manipulating multiple tropical amphibian assemblages harbouring natural microbial communities, we tested whether Bd spillover from naturally infected aquatic-breeding frogs could lead to Bd amplification and mortality in our focal terrestrial-breeding host: the pumpkin toadlet Brachycephalus pitanga. We also tested whether the strength of spillover could vary depending on skin bacterial transmission within host assemblages. Terrestrial-breeding toadlets acquired lethal spillover infections from neighbouring aquatic hosts and experienced dramatic but generally non-protective shifts in skin bacterial composition primarily attributable to their Bd infections. By contrast, aquatic-breeding amphibians maintained mild Bd infections and higher survival, with shifts in bacterial microbiomes that were unrelated to Bd infections. Our results indicate that Bd spillover from even mildly infected aquatic-breeding hosts may lead to dysbiosis and mortality in terrestrial-breeding species, underscoring the need to further investigate recent population declines of terrestrial-breeding amphibians in the tropics.


Subject(s)
Anura/microbiology , Chytridiomycota/physiology , Longevity , Microbiota , Mycoses/veterinary , Animals , Brazil , Mycoses/microbiology , Skin/microbiology
13.
Front Genet ; 10: 1344, 2019.
Article in English | MEDLINE | ID: mdl-32010196

ABSTRACT

Studies in microbiology have long been mostly restricted to small spatial scales. However, recent technological advances, such as new sequencing methodologies, have ushered an era of large-scale sequencing of environmental DNA data from multiple biomes worldwide. These global datasets can now be used to explore long standing questions of microbial ecology. New methodological approaches and concepts are being developed to study such large-scale patterns in microbial communities, resulting in new perspectives that represent a significant advances for both microbiology and macroecology. Here, we identify and review important conceptual, computational, and methodological challenges and opportunities in microbial macroecology. Specifically, we discuss the challenges of handling and analyzing large amounts of microbiome data to understand taxa distribution and co-occurrence patterns. We also discuss approaches for modeling microbial communities based on environmental data, including information on biological interactions to make full use of available Big Data. Finally, we summarize the methods presented in a general approach aimed to aid microbiologists in addressing fundamental questions in microbial macroecology, including classical propositions (such as "everything is everywhere, but the environment selects") as well as applied ecological problems, such as those posed by human induced global environmental changes.

14.
Ciênc. rural (Online) ; 49(9): e20190308, 2019. tab
Article in English | LILACS | ID: biblio-1045433

ABSTRACT

ABSTRACT: This study aimed to evaluate whether cheese whey associated with transitional milk or not, could serve as a suitable alternative to whole milk for calf rearing. For this, twenty-four male calves of crossbred Holstein-Zebu, were distributed in a completely randomized design with three treatments (8 calves per treatment) and fed for 60 days with one of the following liquid diets: i) 100% whole milk, ii) 50% whole milk and 50% cheese whey, and iii) 30% transitional milk and 70% cheese whey. There was no difference in food intake between treatments. The analysis showed that whole milk replacement did not alter the stomach weight or the ruminal cell proliferation when compared to treatment using 100% whole milk; however, the transitional milk/cheese whey group showed larger ruminal papillae. These results suggested that a transitional milk-cheese whey diet associated with solid food and proper nutrient complements might enhance the post-natal development of rumen papillae in calves, which might contribute to prepare them for weaning.


RESUMO: Objetivou-se avaliar se o soro de queijo associado ou não ao leite de transição poderia servir como uma alternativa adequada ao leite integral para a criação de bezerros. Para isso, 24 bezerros machos, mestiços Holandês-Zebu, foram distribuídos em delineamento inteiramente casualizado com três tratamentos (oito bezerros por tratamento) e alimentados por 60 dias com uma das seguintes dietas líquidas: i) 100% leite integral; ii) 50% de leite integral e 50% de soro de queijo, e iii) 30% de leite de transição e 70% de soro de queijo. Não houve diferença na ingestão de alimentos entre os tratamentos. A análise mostrou que a substituição do leite integral não alterou o peso do estômago ou a proliferação das células ruminais quando comparado ao tratamento com 100% de leite integral. No entanto, o grupo de soro de queijo/leite de transição mostrou papilas ruminais maiores. Esses resultados sugerem que uma dieta de soro de queijo com leite de transição associada a alimentos sólidos e a complementos nutricionais apropriados pode aumentar o desenvolvimento pós-natal de papilas no rúmen de bezerros, o que pode contribuir para prepará-los para o desmame.

15.
Sci Rep ; 7(1): 11076, 2017 09 11.
Article in English | MEDLINE | ID: mdl-28894101

ABSTRACT

The family Phyllostomidae, which evolved in the New World during the last 30 million years, represents one of the largest and most morphologically diverse mammal families. Due to its uniquely diverse functional morphology, the phyllostomid skull is presumed to have evolved under strong directional selection; however, quantitative estimation of the strength of selection in this extraordinary lineage has not been reported. Here, we used comparative quantitative genetics approaches to elucidate the processes that drove cranial evolution in phyllostomids. We also quantified the strength of selection and explored its association with dietary transitions and specialization along the phyllostomid phylogeny. Our results suggest that natural selection was the evolutionary process responsible for cranial diversification in phyllostomid bats. Remarkably, the strongest selection in the phyllostomid phylogeny was associated with dietary specialization and the origination of novel feeding habits, suggesting that the adaptive diversification of phyllostomid bats was triggered by ecological opportunities. These findings are consistent with Simpson's quantum evolutionary model of transitions between adaptive zones. The multivariate analyses used in this study provides a powerful tool for understanding the role of evolutionary processes in shaping phenotypic diversity in any group on both micro- and macroevolutionary scales.


Subject(s)
Biological Evolution , Chiroptera , Radiation , Selection, Genetic , Animals , Biodiversity , Chiroptera/anatomy & histology , Chiroptera/classification , Cluster Analysis , Environment
16.
Evolution ; 71(3): 595-609, 2017 03.
Article in English | MEDLINE | ID: mdl-27917480

ABSTRACT

The importance of the environment in shaping phenotypic evolution lies at the core of evolutionary biology. Chipmunks of the genus Tamias (subgenus Neotamias) are part of a very recent radiation, occupying a wide range of environments with marked niche partitioning among species. One open question is if and how those differences in environments affected phenotypic evolution in this lineage. Herein we examine the relative importance of genetic drift versus natural selection in the origin of cranial diversity exhibited by clade members. We also explore the degree to which variation in potential selective agents (environmental variables) are correlated with the patterns of morphological variation presented. We found that genetic drift cannot explain morphological diversification in the group, thus supporting the potential role of natural selection as the predominant evolutionary force during Neotamias cranial diversification, although the strength of selection varied greatly among species. This morphological diversification, in turn, was correlated with environmental conditions, suggesting a possible causal relationship. These results underscore that extant Neotamias represent a radiation in which aspects of the environment might have acted as the selective force driving species' divergence.


Subject(s)
Biological Evolution , Environment , Sciuridae/anatomy & histology , Selection, Genetic , Animals , Canada , Genetic Drift , Sciuridae/genetics , Skull/anatomy & histology , United States
17.
Glob Chang Biol ; 22(9): 3233-52, 2016 09.
Article in English | MEDLINE | ID: mdl-26732228

ABSTRACT

Predicting how individual taxa will respond to climatic change is challenging, in part because the impacts of environmental conditions can vary markedly, even among closely related species. Studies of chipmunks (Tamias spp.) in Yosemite National Park provide an important opportunity to explore the reasons for this variation in response. While the alpine chipmunk (T. alpinus) has undergone a significant elevational range contraction over the past century, the congeneric and partially sympatric lodgepole chipmunk (T. speciosus) has not experienced an elevational range shift during this period. As a first step toward identifying the factors underlying this difference in response, we examined evidence for dietary changes and changes in cranial morphology in these species over the past century. Stable isotope analyses of fur samples from modern and historical museum specimens of these species collected at the same localities indicated that signatures of dietary change were more pronounced in T. alpinus, although diet breadth did not differ consistently between the study species. Morphometric analyses of crania from these specimens revealed significant changes in cranial shape for T. alpinus, with less pronounced changes in shape for T. speciosus; evidence of selection on skull morphology was detected for T. alpinus, but not for T. speciosus. These results are consistent with growing evidence that T. alpinus is generally more responsive to environmental change than T. speciosus, but emphasize the complex and often geographically variable nature of such responses. Accordingly, future studies that make use of the taxonomically and spatially integrative approach employed here may prove particularly informative regarding relationships between environmental conditions, range changes, and patterns of phenotypic variation.


Subject(s)
Climate Change , Diet , Sciuridae , Animals , Environment , Feeding Behavior
18.
Rev. Inst. Adolfo Lutz (Online) ; 74(3): 207-215, jul.-set. 2015. tab, graf
Article in Portuguese | LILACS, Sec. Est. Saúde SP, SESSP-CTDPROD, Sec. Est. Saúde SP, SESSP-ACVSES, SESSP-IALPROD, Sec. Est. Saúde SP, SESSP-IALACERVO | ID: lil-786796

ABSTRACT

Este estudo avaliou as características físico-químicas e a qualidade sanitária da carne ovina comercializada em supermercados e mercados públicos no semiárido potiguar. Foram adquiridas amostras de carne ovina em supermercados locais e em boxes de mercados públicos da região citada. Nos pontos de comercialização, foi aplicado um checklist referente às condições higiênico-sanitárias do ambiente, equipamentos e manipuladores. As amostras foram avaliadas quanto à presença de coliformes a 35 ºC e a 45 ºC, enterobactérias, Staphylococcus spp. e Salmonella sp., além dos parâmetros físico-químicos de pH, cor, perda de peso por cocção, capacidade de retenção de água e força de cisalhamento. Os mercados públicos analisados apresentaram 93,34 % de não conformidade na aplicação do checklist. Quanto aos aspectos microbiológicos, 5 % das amostras apresentaram-se impróprias para o consumo, com contaminação por Salmonella sp. Os resultados encontrados nas análises físico-químicas estavam dentro dos padrões estabelecidos para carne ovina. Não houve diferença significativa entre os espécimes dos dois grupos avaliados, exceto para o parâmetro a* da análise de cor nas amostras de mercado público que apresentaram maior teor de vermelho em relação às amostras de supermercados. Portanto, apesar de apresentarem características físico-químicas satisfatórias, esses produtos são vendidos em condições higiênico-sanitárias precárias, que podem representar risco ao consumidor.


This study evaluated the sanitary and the physicochemical qualities of lamb meat sold in supermarkets and public markets in the semiarid Rio Grande do Norte. Ten samples of lamb meat were obtained in the local supermarketsand ten specimens in the public market food-stalls. These sale points were evaluated by using a checklist concerning the hygiene and sanitary conditions of environment, equipment and handlers. The collected samples were analyzed for detecting coliforms at 35 °C and 45 °C, enterobacteria, Staphylococcus and Salmonella spp., and the physicochemical parameters (pH, color, weight loss by cooking, water retention capacity and shear strength) were assessed. The food-stalls of public market showed 93.34 % of non-compliance to the checklist items. Concerningthe microbiological aspects, 5 % of the samples were unsuitable for consumption, being contaminated with Salmonella spp. The results found in the physicochemical analyzes complied with the standards established forlamb meat. No significant difference among the samples of the both groups was found, except for the a* color parameter in specimens from the public market food-stalls, which showed a higher red color contents.Despite evidencing satisfactory physicochemical characteristics, these products are sold under poor sanitary conditions, which might pose a risk to the consumer.


Subject(s)
Chemical Phenomena , Meat , Food Hygiene , Food Inspection , Sheep , Food Quality
19.
F1000Res ; 4: 925, 2015.
Article in English | MEDLINE | ID: mdl-27785352

ABSTRACT

We present an open source package for performing evolutionary quantitative genetics analyses in the R environment for statistical computing. Evolutionary theory shows that evolution depends critically on the available variation in a given population. When dealing with many quantitative traits this variation is expressed in the form of a covariance matrix, particularly the additive genetic covariance matrix or sometimes the phenotypic matrix, when the genetic matrix is unavailable and there is evidence the phenotypic matrix is sufficiently similar to the genetic matrix. Given this mathematical representation of available variation, the \textbf{EvolQG} package provides functions for calculation of relevant evolutionary statistics; estimation of sampling error; corrections for this error; matrix comparison via correlations, distances and matrix decomposition; analysis of modularity patterns; and functions for testing evolutionary hypotheses on taxa diversification.

20.
Ciênc. rural ; 43(4): 716-721, abr. 2013. tab
Article in Portuguese | LILACS | ID: lil-669364

ABSTRACT

Este estudo teve como objetivo avaliar o desenvolvimento dos compartimentos estomacais de bezerros mestiços submetidos a diferentes dietas líquidas. Foram utilizados 24 bezerros mestiços, distribuídos em um delineamento inteiramente casualizado com quatro tratamentos e seis repetições: Leite integral; 50% Leite integral + 50% de Soro de queijo; 50% Leite integral + 50% de Soro de queijo adicionado de um ovo integral; e 50% Leite integral + 50% de Soro de queijo adicionado de um ovo integral adicionado de biotina. Foram avaliados o consumo de matéria seca, o ganho de peso, o peso absoluto e relativo (ao peso do corpo vazio e peso do estômago completo) dos quatro compartimentos estomacais, além da altura das papilas de quatro regiões do rúmen. As dietas testadas não afetaram nenhuma das características avaliadas, ficando evidenciada uma relação entre o desempenho dos animais e o desenvolvimento dos compartimentos gástricos. O desenvolvimento dos estômagos de bezerros não foi afetado pelas dietas líquidas testadas, sendo, portanto, possível a substituição de 50% do leite integral por soro de queijo.


This research evaluated the influence of different liquid diets on development of the stomach compartments of crossbred calves. It was used 24 crossbred calves distributed in a completely randomized design with four treatments and six replications: whole milk, 50% whole milk + 50% of cheese whey, 50% whole milk + 50% cheese whey supplemented with a whole egg; whole milk and 50% + 50% of cheese whey a supplemented with a egg added with biotin. I was evaluated the dry matter intake, weight gain, absolute and relative weight (weight of the empty body and weight stomach full) of the four stomach compartments, and papillae height of four rumen regions. The experimental diets did not affect any of the traits, being shown a relationship between animal performance and development of gastric compartments. The development of calf stomachs was not affected by the tested liquid diets, therefore enabling the replacement of 50% of milk for cheese whey.

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