RESUMO
BACKGROUND: The western Russell's viper (Daboia russelii) is widely distributed in South Asia, and geographical venom variation is anticipated among distant populations. Antivenoms used for Russell's viper envenomation are, however, raised typically against snakes from Southern India. The present study investigated and compared the venom proteomes of D. russelii from Sri Lanka (DrSL) and India (DrI), the immunorecognition of Indian VINS Polyvalent Antivenom (VPAV) and its efficacy in neutralizing the venom toxicity. METHODS: The venoms of DrSL and DrI were decomplexed with C18 high-performance liquid chromatography and SDS-polyacrylamide gel electrophoresis under reducing conditions. The proteins fractionated were identified through nano-ESI-liquid chromatography-tandem mass spectrometry (LCMS/MS). The immunological studies were conducted with enzyme-linked immunosorbent assay. The neutralization of the venom procoagulant effect was evaluated in citrated human plasma. The neutralization of the venom lethality was assessed in vivo in mice adopting the WHO protocol. RESULTS: DrSL and DrI venom proteomes showed comparable major protein families, with phospholipases A2 (PLA2) being the most abundant (> 60% of total venom proteins) and diverse (six protein forms identified). Both venoms were highly procoagulant and lethal (intravenous median lethal dose in mice, LD50 = 0.24 and 0.32 µg/g, for DrSL and DrI, respectively), while lacking hemorrhagic and anticoagulant activities. VPAV was immunoreactive toward DrSL and DrI venoms, indicating conserved protein antigenicity in the venoms. The high molecular weight venom proteins were, however, more effectively immunorecognized than small ones. VPAV was able to neutralize the coagulopathic and lethal effects of the venoms moderately. CONCLUSION: Considering that a large amount of venom can be injected by Russell's viper during envenomation, the potency of antivenom can be further improved for optimal neutralization and effective treatment. Region-specific venoms and key toxins may be incorporated into the immunization procedure during antivenom production.
RESUMO
The western Russell's viper (Daboia russelii) is widely distributed in South Asia, and geographical venom variation is anticipated among distant populations. Antivenoms used for Russell's viper envenomation are, however, raised typically against snakes from Southern India. The present study investigated and compared the venom proteomes of D. russelii from Sri Lanka (DrSL) and India (DrI), the immunorecognition of Indian VINS Polyvalent Antivenom (VPAV) and its efficacy in neutralizing the venom toxicity. Methods: The venoms of DrSL and DrI were decomplexed with C18 high-performance liquid chromatography and SDS-polyacrylamide gel electrophoresis under reducing conditions. The proteins fractionated were identified through nano-ESI-liquid chromatography-tandem mass spectrometry (LCMS/MS). The immunological studies were conducted with enzyme-linked immunosorbent assay. The neutralization of the venom procoagulant effect was evaluated in citrated human plasma. The neutralization of the venom lethality was assessed in vivo in mice adopting the WHO protocol. Results: DrSL and DrI venom proteomes showed comparable major protein families, with phospholipases A2 (PLA2) being the most abundant (> 60% of total venom proteins) and diverse (six protein forms identified). Both venoms were highly procoagulant and lethal (intravenous median lethal dose in mice, LD50 = 0.24 and 0.32 µg/g, for DrSL and DrI, respectively), while lacking hemorrhagic and anticoagulant activities. VPAV was immunoreactive toward DrSL and DrI venoms, indicating conserved protein antigenicity in the venoms. The high molecular weight venom proteins were, however, more effectively immunorecognized than small ones. VPAV was able to neutralize the coagulopathic and lethal effects of the venoms moderately. Conclusion: Considering that a large amount of venom can be injected by Russell's viper during envenomation, the potency of antivenom can be further improved for optimal neutralization and effective treatment. Region-specific venoms and key toxins may be incorporated into the immunization procedure during antivenom production.(AU)
Assuntos
Animais , Venenos/toxicidade , Antivenenos/biossíntese , Daboia , Proteômica , Localizações GeográficasRESUMO
The western Russell's viper (Daboia russelii) is widely distributed in South Asia, and geographical venom variation is anticipated among distant populations. Antivenoms used for Russell's viper envenomation are, however, raised typically against snakes from Southern India. The present study investigated and compared the venom proteomes of D. russelii from Sri Lanka (DrSL) and India (DrI), the immunorecognition of Indian VINS Polyvalent Antivenom (VPAV) and its efficacy in neutralizing the venom toxicity. Methods: The venoms of DrSL and DrI were decomplexed with C18 high-performance liquid chromatography and SDS-polyacrylamide gel electrophoresis under reducing conditions. The proteins fractionated were identified through nano-ESI-liquid chromatography-tandem mass spectrometry (LCMS/MS). The immunological studies were conducted with enzyme-linked immunosorbent assay. The neutralization of the venom procoagulant effect was evaluated in citrated human plasma. The neutralization of the venom lethality was assessed in vivo in mice adopting the WHO protocol. Results: DrSL and DrI venom proteomes showed comparable major protein families, with phospholipases A2 (PLA2) being the most abundant (> 60% of total venom proteins) and diverse (six protein forms identified). Both venoms were highly procoagulant and lethal (intravenous median lethal dose in mice, LD50 = 0.24 and 0.32 µg/g, for DrSL and DrI, respectively), while lacking hemorrhagic and anticoagulant activities. VPAV was immunoreactive toward DrSL and DrI venoms, indicating conserved protein antigenicity in the venoms. The high molecular weight venom proteins were, however, more effectively immunorecognized than small ones. VPAV was able to neutralize the coagulopathic and lethal effects of the venoms moderately. Conclusion: Considering that a large amount of venom can be injected by Russell's viper during envenomation, the potency of antivenom can be further improved for optimal neutralization and effective treatment. Region-specific venoms and key toxins may be incorporated into the immunization procedure during antivenom production.(AU)
Assuntos
Animais , Venenos/toxicidade , Antivenenos/biossíntese , Daboia , Proteômica , Localizações GeográficasRESUMO
BACKGROUND: Geographic variation in body size and condition can reveal differential local adaptation to resource availability or climatic factors. Body size and condition are related to fitness in garter snakes (Thamnophis), thus good body condition may increase survival, fecundity in females, and mating success in males. Phylogenetically related species in sympatry are predicted to exhibit similar body condition when they experience similar environmental conditions. We focused on interspecific and geographical variation in body size and condition in three sympatric Mexican garter snakes from the highlands of Central Mexico. METHODS: We assessed SVL, mass, and body condition (obtained from Major axis linear regression of ln-transformed body mass on ln-transformed SVL) in adults and juveniles of both sexes of Thamnophis eques, T. melanogaster, and T. scalaris sampled at different locations and ranges from 3-11 years over a 20-year period. RESULTS: We provide a heterogeneous pattern of sexual and ontogenic reproductive status variations of body size and condition among local populations. Each garter snake species shows locations with good and poor body condition; juvenile snakes show similar body condition between populations, adults show varying body condition between populations, and adults also show sex differences in body condition. We discuss variations in body condition as possibly related to the snakes' life cycle differences.
RESUMO
Vocal dialects are fundamental to our understanding of the transmission of social behaviours between individuals and populations, however few accounts trace this phenomenon among mammals over time. Northern elephant seals (Mirounga angustirostris) provide a rare opportunity to examine the trajectory of dialects in a long-lived mammalian species. Dialects were first documented in the temporal patterns of the stereotyped vocal displays produced by breeding males at four sites in the North Pacific in 1968 and 1969, as the population recovered from extreme exploitation. We evaluated the longevity of these geographical differences by comparing these early recordings to calls recently recorded at these same locations. While the presence of vocal dialects in the original recordings was re-confirmed, geographical differences in vocal behaviour were not found at these breeding rookeries nearly 50 years later. Moreover, the calls of contemporary males displayed more structural complexity after approximately four generations, with substantial between-individual variation and call features not present in the historical data. In the absence of measurable genetic variation in this species-owing to an extreme population bottleneck-a combination of migration patterns and cultural mutation are proposed as factors influencing the fall of dialects and the dramatic increase in call diversity.
Assuntos
Migração Animal , Focas Verdadeiras/fisiologia , Vocalização Animal , Animais , California , Cultura , Masculino , MéxicoRESUMO
The total phenolic compounds content, free radical-scavenging capacity and capsaicinoid content in populations of wild Piquin chili (C. annuum) were studied. Aqueous and hydroalcoholic extracts from nine ecotypes were evaluated. High contents of phenolic compounds and free radical-scavenging capacities were observed for both extracts; however, the values that were found for the hydroalcoholic phase were substantially higher. LC-MS analysis allowed for the detection of 32 compounds, where apigenin-8-C-glucoside followed by vanillic acid 1-O-ß-o-glucopyranosylester (Isomer I or II) and 7-ethoxy-4-methylcoumarin were the most widely distributed; they were found in more than 89% of the ecotypes. The diversity of identified phenolic compounds was different among ecotypes, allowing them to be distinguished by chemical diversity, free radical-scavenging capacities and heat Scoville units. The total capsaicinoid content was higher in Population I (23.5 mg/g DW) than in Populations II and III, which had contents of 15.3 and 10.7 mg/g DW, respectively. This variability could lead to phytochemical exploitation and the conservation of the natural populations of wild chili.
Assuntos
Capsicum/química , Sequestradores de Radicais Livres/isolamento & purificação , Fenóis/isolamento & purificação , Capsaicina , Cromatografia Líquida , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/farmacologia , Espectrometria de Massas , Estrutura Molecular , Fenóis/química , Fenóis/farmacologia , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologiaRESUMO
Dendroctonus bark beetles are a worldwide significant pest of conifers. This genus comprises 20 species found in North and Central America, and Eurasia. Several studies have documented the microbiota associated with these bark beetles, but little is known regarding how the gut bacterial communities change across host range distribution. We use pyrosequencing to characterize the gut bacterial communities associated with six populations of Dendroctonus valens and D. mexicanus each across Mexico, determine the core bacteriome of both insects and infer the metabolic pathways of these communities with Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) to evaluate whether these routes are conserved across geographical locations. Our results show that the ß-diversity with UniFrac unweighted varies among locations of both bark beetles mainly due to absence/presence of some rare taxa. No association is found between the pairwise phylogenetic distance of bacterial communities and geographic distance. A strict intraspecific core bacteriome is determined for each bark beetle species, but these cores are different in composition and abundance. However, both bark beetles share the interspecific core bacteriome recorded previously for the Dendroctonus genus consisting of Enterobacter, Pantoea, Providencia, Pseudomonas, Rahnella, and Serratia. The predictions of metabolic pathways are the same in the different localities, suggesting that they are conserved through the geographical locations.
Assuntos
Bactérias/classificação , Metagenômica/métodos , Análise de Sequência de DNA/métodos , Gorgulhos/microbiologia , Animais , Bactérias/genética , DNA Bacteriano/análise , Trato Gastrointestinal/microbiologia , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Redes e Vias Metabólicas , México , FilogeniaRESUMO
The calling behavior, mating time, and the reproductive compatibility of virgin adults of fall armyworms, Spodoptera frugiperda (J. E. Smith), were studied in this work. Larvae were collected on maize (Zea mays L.) from six states located on the Pacific coast (Chiapas, Michoacán, and Sinaloa), on the Gulf of Mexico (Veracruz and Yucatan), and in central Mexico (Morelos). Before the experiments, insects were reared under laboratory conditions for one generation. We recorded the age at which females called for the first time, the onset time of calling, the duration of calling, the onset time of copulation, and the duration of copulation. The calling rhythms of the six populations were dissimilar. Females from all populations began to call in the second or third scotophase. The time for onset of calling and the duration of calling were significantly different among the S. frugiperda populations studied. Spodoptera frugiperda pairs from Sinaloa, Veracruz, Yucatan, and Morelos started to copulate earlier than the pairs from Chiapas and Michoacán. Pairs from Veracruz and Yucatan copulated longer than those from Michoacán, Morelos, Chiapas, and Sinaloa. Our crossing experiment using females and males from the six populations showed that individuals from different populations could copulate and produce fertile offspring. Thus, although the S. frugiperda populations showed variability in the timing of reproduction, the populations were not reproductively incompatible, which indicated that geographic distance has not led to reproductive isolation in corn-strain populations of S. frugiperda in Mexico.
Assuntos
Comunicação Animal , Isolamento Reprodutivo , Comportamento Sexual Animal , Spodoptera/fisiologia , Animais , Copulação , Feminino , Larva/crescimento & desenvolvimento , Masculino , México , Spodoptera/crescimento & desenvolvimento , Zea mays/crescimento & desenvolvimentoRESUMO
Vibrio parahaemolyticus is a pathogenic bacteria which has been associated to the early mortality syndrome (EMS) also known as hepatopancreatic necrosis disease (AHPND) causing high mortality in shrimp farms. Pathogenic strains contain two homologous genes related to insecticidal toxin genes, PirA and PirB, these toxin genes are located on a plasmid contained within the bacteria. Genomic sequences have allowed the finding of two strains with a divergent structure related to the geographic region from where they were found. The isolates from the geographic collection of Southeast Asia and Mexico show variable regions on the plasmid genome, indicating that even though they are not alike they still conserve the toxin genes. In this paper, we report for the first time, a pathogenic V. parahaemolyticus strain in shrimp from South America that showed symptoms of AHPND. The genomic analysis revealed that this strain of V. parahaemolyticus found in South America appears to be more related to the Southeast Asia as compared to the Mexican strains. This finding is of major importance for the shrimp industry, especially in regards to the urgent need for disease control strategies to avoid large EMS outbreaks and economic loss, and to determine its dispersion in South America. The whole-genome shotgun project of V. parahaemolyticus strain Ba94C2 have been deposited at DDBJ/EMBL/GenBank under the accession PRJNA335761.
RESUMO
There is growing interest in latitudinal effects on animal behaviour and life history. One recent focus is on birdsong, which is hypothesized to be more elaborated or complex in the north temperate zone compared with the tropics. Current evidence is mixed and based on cross-species comparisons, or single species with restricted distributions. We circumvent these limitations using a transcontinental sample of 358 songs from house wrens (Troglodytes aedon) at 281 locations spanning more than 100° of latitude (52° N-55° S) across the Americas. We found a significant latitudinal gradient in several basic elements of song performance and complexity between north temperate and tropical populations. Furthermore, we document convergence in song patterns between populations at higher latitudes in the Northern and Southern Hemispheres. Effects were strongest for the number of elements in a song, and the rate of element production, both increasing towards the poles, with similar but weaker effects for other song dimensions (e.g. number of unique elements, trills and trill rate). We consider possible causes related to variable habitats and morphology, concluding that the shorter breeding seasons at higher latitudes in both hemispheres may favour greater song elaboration to mediate territory competition and mate choice.
Assuntos
Distribuição Animal , Aves Canoras/fisiologia , Vocalização Animal , Animais , América Central , Masculino , América do Norte , América do Sul , TerritorialidadeRESUMO
Decoupling between floral and leaf traits is expected in plants with specialized pollination systems to assure a precise flower-pollinator fit, irrespective of leaf variation associated with environmental heterogeneity (functional modularity). Nonetheless, developmental interactions among floral traits also decouple flowers from leaves regardless of selection pressures (developmental modularity). We tested functional modularity in the hummingbird-pollinated flowers of the Ameroglossum pernambucense complex while controlling for developmental modularity. Using two functional traits responsible for flower-pollinator fit [floral tube length (TL) and anther-nectary distance (AN)], one floral trait not linked to pollination [sepal length (SL), control for developmental modularity] and one leaf trait [leaf length (LL)], we found evidence of flower functional modularity. Covariation between TL and AN was ca. two-fold higher than the covariation of either of these traits with sepal and leaf lengths, and variations in TL and AN, important for a precise flower-pollinator fit, were smaller than SL and LL variations. Furthermore, we show that previously reported among-population variation of flowers associated with local pollinator phenotypes was independent from SL and LL variations. These results suggest that TL and AN are functionally linked to fit pollinators and sufficiently decoupled from developmentally related floral traits (SL) and vegetative traits (LL). These results support previous evidences of population differentiation due to local adaptation in the A. pernambucense complex and shed light on the role of flower-leaf decoupling for local adaptation in species distributed across biotic and abiotic heterogeneous landscapes.
Assuntos
Adaptação Fisiológica , Flores/fisiologia , Lamiales/fisiologia , Folhas de Planta/fisiologia , Animais , Aves , PolinizaçãoRESUMO
ABSTRACT The population dynamics of a species tends to change from the core to the periphery of its distribution. Therefore, one could expect peripheral populations to be subject to a higher level of stress than more central populations (the center–periphery hypothesis) and consequently should present a higher level of fluctuating asymmetry. To test these predictions we study asymmetry in wing shape of five populations of Drosophila antonietae collected throughout the distribution of the species using fluctuating asymmetry as a proxy for developmental instability. More specifically, we addressed the following questions: (1) what types of asymmetry occur in populations of D. antonietae? (2) Does the level of fluctuating asymmetry vary among populations? (3) Does peripheral populations have a higher fluctuating asymmetry level than central populations? We used 12 anatomical landmarks to quantify patterns of asymmetry in wing shape in five populations of D. antonietae within the framework of geometric morphometrics. Net asymmetry – a composite measure of directional asymmetry + fluctuating asymmetry – varied significantly among populations. However, once net asymmetry of each population is decomposed into directional asymmetry and fluctuating asymmetry, most of the variation in asymmetry was explained by directional asymmetry alone, suggesting that populations of D. antonietae have the same magnitude of fluctuating asymmetry throughout the geographical distribution of the species. We hypothesize that larval development in rotting cladodes might play an important role in explaining our results. In addition, our study underscores the importance of understanding the interplay between the biology of a species and its geographical patterns of asymmetry.
RESUMO
AIM: To determine the current prevalence and control of major cardiovascular risk factors in stable CAD outpatients worldwide. METHODS: We analysed variations in cardiovascular risk factors in stable CAD outpatients from CLARIFY, a 5-year observational longitudinal cohort study, in seven geographical zones (Western/Central Europe; Canada/South Africa/Australia/UK; Eastern Europe; Central/South America; Middle East; East Asia; and India). RESULTS: Patient presentation (N=32,954, mean age 64.2 years, 78% male) varied between zones, as did prevalence of risk factors (all p < 0.0001). Obesity ranged from 20% (East Asia) to 42% (Middle East), raised blood pressure from 28% (Central/South America and East Asia) to 48% (Eastern Europe), raised LDL cholesterol from 24% (Canada/South Africa/Australia/UK) to 65% (Eastern Europe), elevated heart rate (≥70 bpm) from 38% (Western/Central Europe) to 78% (India), diabetes from 17% (Eastern Europe) to 60% (Middle East), and smoking from 6% (Central/South America) to 19% (Eastern Europe). Aspirin and lipid-lowering drugs were widely used everywhere (≥84% and ≥88%, respectively). Rates of risk factor control varied geographically (all p < 0.0001). Rate of controlled blood pressure in hypertension varied from 47% (Eastern Europe) to 66% (Central/South America), glucose control in diabetes from 23% (India) to 51% (Western/Central Europe and East Asia), controlled LDL cholesterol and dyslipidaemia from 32% (Eastern Europe) to 75% (Canada/South Africa/Australia/UK), heart rate <70 bpm from 22% (India) to 62% (Western/Central Europe), and heart rate ≤60 bpm in angina patients from 2% (India) to 29% (Canada/South Africa/Australia/UK and Central/South America). CONCLUSION: Prevalence and control of major cardiovascular risk factors in stable CAD vary markedly worldwide. Many stable CAD outpatients are being treated suboptimally.
Assuntos
Doença da Artéria Coronariana/epidemiologia , Doença da Artéria Coronariana/terapia , Disparidades em Assistência à Saúde/tendências , Pacientes Ambulatoriais , Padrões de Prática Médica/tendências , Características de Residência , Comportamento de Redução do Risco , África/epidemiologia , Idoso , Ásia/epidemiologia , Austrália/epidemiologia , Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/mortalidade , Estudos Transversais , Europa (Continente)/epidemiologia , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Prevalência , Sistema de Registros , Medição de Risco , Fatores de Risco , América do Sul/epidemiologia , Resultado do TratamentoRESUMO
Lepidocolaptes angustirostris is a South American woodcreeper that inhabits predominantly open lowlands such as the Cerrado, Chaco and Caatinga. Eight subspecies are currently recognized based on plumage patterns and geographical distribution. However, a more detailed morphological analysis and taxonomic revision have not been done in this species. The objective of this study was to conduct a taxonomic revision of L. angustirostris using morphometrical and plumage character, and a Generalized Linear Models analyzes (GLM) were elaborated to identify environmental variables that could account for this variation. We found a high level of intergradation among all named populations. The principal component analyzes show certain levels of morphological differentiation among the taxa, with a first component formed by bill characters (bill length, exposed and total culmen), and a second one that includes the bill width and the tarsus-metatarsus length. In the GLM analyzes, two climatic variables explain the geographical variation in the taxon, temperature seasonality and precipitation of warmest quarter. The ecogeographic rules of Bergmann and Gloger can be applied to this variation, and, more narrowly, the Allen's rule. Thus, the populations of the Narrow-billed Woodcreeper tend to be larger to the south of the distribution. We propose here that L. angustirostris is a single species, with no subordinate taxa. Any evidence analyzed here did not support the taxonomic validity of the proposed subspecies in the taxon. Despite colour-polymorphism identified in the plumage patterns, the high level of intergradation and the poor resolution of geographical boundaries did not support the splitting of this species.(AU)
Lepidocolaptes angustirostris habita principalmente regiões abertas como a Caatinga, o Cerrado e o Chaco. Oito subespécies são atualmente reconhecidas, baseadas em padrões da plumagem e distribuição geográfica. Uma análise morfológica e uma revisão taxonômica nunca foram realizadas nesta espécie. O objetivo deste estudo é desenvolver uma revisão taxonômica de L. angustirostris utiliazndo caracteres morfométricos e de plumagem, e análises de modelagem (GLM) foram feitas para identificar variáveis ambientais que possam explicar esta variação. Os resultados indicam que as diferentes populações de L. angustirostris que habitam as áreas abertas da Caatinga, Cerrado e Chaco (mais as populações amazônicas) não têm um nível significativo de diferenciação mofológica e nem de plumagem para serem consideradas como táxons válidos. Nas análises do GLM, duas variáveis climáticas explicaram a variação geográfica no táxon, a sazonalidade térmica e a precipitação no trimestre mais quente. As leis ecogeográficas de Bergmann e Gloger podem ser aplicadas para explicar esta variação, assim como a lei de Allen, esta de forma mais restrita. Assim, as populações do arapaçu-do-cerrado tendem a ser maiores ao sul da distribuição. A proposta apresentada aqui é de manter o status taxonômico de L. angustirostris como uma espécie única, sem qualquer outro táxon subordinado. Apesar do polimorfismo identificado nos padrões da plumagem, o elevado nível de intergradação e a baixa resolução dos limites geográficos entre as populações não suportam a divisão deste táxon.(AU)
Assuntos
Animais , Passeriformes/anatomia & histologia , Passeriformes/classificação , Classificação , Distribuição Animal , América do SulRESUMO
Lepidocolaptes angustirostris is a South American woodcreeper that inhabits predominantly open lowlands such as the Cerrado, Chaco and Caatinga. Eight subspecies are currently recognized based on plumage patterns and geographical distribution. However, a more detailed morphological analysis and taxonomic revision have not been done in this species. The objective of this study was to conduct a taxonomic revision of L. angustirostris using morphometrical and plumage character, and a Generalized Linear Models analyzes (GLM) were elaborated to identify environmental variables that could account for this variation. We found a high level of intergradation among all named populations. The principal component analyzes show certain levels of morphological differentiation among the taxa, with a first component formed by bill characters (bill length, exposed and total culmen), and a second one that includes the bill width and the tarsus-metatarsus length. In the GLM analyzes, two climatic variables explain the geographical variation in the taxon, temperature seasonality and precipitation of warmest quarter. The ecogeographic rules of Bergmann and Gloger can be applied to this variation, and, more narrowly, the Allen's rule. Thus, the populations of the Narrow-billed Woodcreeper tend to be larger to the south of the distribution. We propose here that L. angustirostris is a single species, with no subordinate taxa. Any evidence analyzed here did not support the taxonomic validity of the proposed subspecies in the taxon. Despite colour-polymorphism identified in the plumage patterns, the high level of intergradation and the poor resolution of geographical boundaries did not support the splitting of this species.
Lepidocolaptes angustirostris habita principalmente regiões abertas como a Caatinga, o Cerrado e o Chaco. Oito subespécies são atualmente reconhecidas, baseadas em padrões da plumagem e distribuição geográfica. Uma análise morfológica e uma revisão taxonômica nunca foram realizadas nesta espécie. O objetivo deste estudo é desenvolver uma revisão taxonômica de L. angustirostris utiliazndo caracteres morfométricos e de plumagem, e análises de modelagem (GLM) foram feitas para identificar variáveis ambientais que possam explicar esta variação. Os resultados indicam que as diferentes populações de L. angustirostris que habitam as áreas abertas da Caatinga, Cerrado e Chaco (mais as populações amazônicas) não têm um nível significativo de diferenciação mofológica e nem de plumagem para serem consideradas como táxons válidos. Nas análises do GLM, duas variáveis climáticas explicaram a variação geográfica no táxon, a sazonalidade térmica e a precipitação no trimestre mais quente. As leis ecogeográficas de Bergmann e Gloger podem ser aplicadas para explicar esta variação, assim como a lei de Allen, esta de forma mais restrita. Assim, as populações do arapaçu-do-cerrado tendem a ser maiores ao sul da distribuição. A proposta apresentada aqui é de manter o status taxonômico de L. angustirostris como uma espécie única, sem qualquer outro táxon subordinado. Apesar do polimorfismo identificado nos padrões da plumagem, o elevado nível de intergradação e a baixa resolução dos limites geográficos entre as populações não suportam a divisão deste táxon.
Assuntos
Animais , Classificação , Distribuição Animal , Passeriformes/anatomia & histologia , Passeriformes/classificação , América do SulRESUMO
BCG protection varies and in some places (nearest the equator) is low or absent. Understanding this variation can inform the efforts to develop new vaccines against tuberculosis. Two main hypotheses are used to explain this variation: under masking, new vaccines are unlikely to increase protection; under blocking new vaccines have a greater potential to be effective when BCG is not. We conducted a cluster randomized trial to explored the masking and blocking hypotheses by studying BCG vaccine efficacy of neonatal vaccination and when administered for the first or a second (revaccination) time at school age in two sites (Manaus close and Salvador further south from the equator). Seven hundred and sixty three state schools were matched on socio economic characteristics of the neighborhood and 239,934 children were randomized to vaccine (BCG vaccination at school age) or control group. Protection by first BCG vaccination at school age was high in Salvador (34%, 95% CI 7-53%, p=0.017) but low in Manaus (8%, 95% CI t0 39-40%, p=0.686). For revaccination at school age, protection was modest in Salvador (19%, 95% CI 3-33%, p=0.022) and absent in Manaus (1%, 95% CI to 27-23%, p=0.932). Vaccine efficacy for neonatal vaccination was similar in Salvador (40%, 95% CI 22-54%, p<0.001) and Manaus (36%, 95% CI 11-53%, p=0.008). Variation in BCG efficacy was marked when vaccine was given at school age but absent at birth, which points towards blocking as the dominant mechanism. New tuberculosis vaccines that overcome or by pass this blocking effect could confer protection in situations where BCG is not protective.
Assuntos
Vacina BCG/imunologia , Imunização Secundária , Tuberculose/prevenção & controle , Adolescente , Vacina BCG/uso terapêutico , Brasil/epidemiologia , Criança , Feminino , Geografia , Humanos , Recém-Nascido , Masculino , Classe Social , Tuberculose/epidemiologiaRESUMO
A variação de cunho geográfico nas populações naturais está intimamente ligada às características ecológicas do ambiente como também aos processos históricos que resultaram no estabelecimento de linhagens distintas. Poucas espécies de serpentes têm sido estudadas adequadamente para determinar se existe variação geográfica na morfologia associada ao seu ciclo reprodutivo e dieta. As serpentes do gênero Crotalus são consideradas um bom modelo para estudos relacionados à variação geográfica devido à sua ampla distribuição, que abrange diversos tipos de hábitats. A cascavel C. durissus está restrita a América do Sul. No Brasil ocorre em todos os estados, exceto no Acre e Espírito Santo. São reconhecidas algumas populações isoladas na Floresta Amazônica. Algumas das suas populações exibem um nível considerável de variação morfológica e ecológica, sendo que populações adjacentes podem diferir drasticamente. De um modo geral, são escassos os estudos com esta espécie no Brasil, requerendo urgentes investigações para estabelecer se a variabilidade observada está associada a algum fenômeno específico. Neste estudo, foi examinado um total de 870 exemplares de C. durissus no Brasil. Em termos gerais, de acordo com o dimorfismo sexual, os resultados indicaram que as fêmeas apresentaram um maior número de escamas no ventre, enquanto que os machos apresentaram um número maior de escamas associadas à cauda e de losângulos. Em poucos casos as fêmeas exibiram comprimentos rostro-cloacais maiores, no entanto os maiores tamanhos da cabeça foram evidenciados neste sexo. Por outro lado, na maioria dos casos, os machos foram mais compridos do que as fêmeas, apresentando caudas mais longas. Similarmente as listras paravertebrais foram significativamente maiores nos machos. As análises discriminantes indicaram que as populações apresentaram padrões de variabilidade morfológica altamente complexos, ainda que a segregação de algumas das populações possa refletir fortes tendências evolutivas próprias dentro de algumas linhagens. A análise de variação geográfica indicou que variáveis ambientais influenciaram parcialmente a variabilidade morfológica nas populações de acordo com a sua distribuição. De acordo com os parâmetros relacionados a historia natural, o ciclo reprodutivo das fêmeas foi bem conservador, refletindo um padrão bienal e sazonal. Nos machos o ciclo espermatogênico mostra também um padrão sazonal exibindo variações anuais entre as populações. A associação entre os processos históricos, aspectos fisiológicos e condições climáticas são provavelmente os principais fatores que influenciaram as mudanças nestes padrões reprodutivos em fêmeas e machos. A dieta foi constituída principalmente por roedores, fato possivelmente associado à maior abundância e disponibilidade deste tipo de presa ao longo do ano nas áreas de ocorrência da espécie. No entanto, lagartos do grupo dos teiídeos podem ser considerados como itens alimentares eventualmente importantes na dieta de C. durissus do Brasil
The geographical variation is intimately associated to the ecological characteristics such as the historical process of a species. A few species of snakes have been studied adequately to determine an existence of geographical variation in morphology, reproduction and diet. Rattlesnakes (Crotalus) are considered a good model for geographical variation studies, due to their wide distribution that include several habitat types. The rattlesnake, Crotalus durissus is restricted to South America. In Brazil, this group is present throughout the country, except in states of Acre and Espírito Santo. In addition, there are isolated populations in open areas in Amazonia, in the Amazonian savannas in the states of Amazonas, Roraima, Pará and Amapá. Some populations of C. durissus show considerable variation in the morphology, reproduction and diet composition even with neighboring populations differing drastically from each other. Generally, there has been little research conducted of C. durissus in Brazil needing urgent investigation to this respect. A total of 870 specimens of C. durissus were examined. In general, according to the sexual dimorphism, the results indicated that the females have a higher number of ventral scales, while the males showed a greater number of scales associated to the tail and the lozanges. In a few cases, the females exhibited larger snout-vent length but larger head sizes were shown in this sex. Overall, males were longer than females, exhibiting tails and paravertebral stripes which were relatively longer. The discriminant analysis showed in general populations with patterns of highly complex morphological variability, even though the segregation of some populations may reflect strong evolutionary tendencies of their own within some groups. The analysis of geographic variation indicated that environmental variables partially influenced the morphological variability in populations according to their distribution. In accordance with parameters related to natural history, the reproductive cycle of females, was extremely conservative, reflecting a biennial seasonal pattern. In males, the spermatogenic cycle also shows a seasonal pattern, which demonstrated annual variations between populations. The association between the historical processes, physiological aspects and climatic conditions is probably the main factors that influenced these reproductive patterns in females and males. The diet was composed mainly of rodents, habit related to the abundance and availability of the prey, however teid lizards can also be considered as an important food item of the diet of C. durissus from Brazil
Assuntos
Animais , Crotalus/anatomia & histologia , Crotalus/crescimento & desenvolvimentoRESUMO
Geographic variation of the fox Lycalopex culpaeus (Mammalia, Canidae) in Chile: taxonomic implications. We studied the geographic variation of skulls of Lycalopex culpaeus using qualitative and quantative analyses. The sampling area covered Chile, from its northern portion, to Tierra del Fuego and the neighbouring Hoste island, as well as part of Argentina. Five subespecies are currently recognized from this large area. We found two morphotypes that are segregated geographically. Both groups mostly differ by morphometric attributes, followed by qualitative features. Specimens from northern Chile (Tarapacá and Antofagasta) have small skulls, short rostrum, a liriform sagital zone, and lack the interparietal crest. The second group is formed by specimens from north-western and central Argentina, central-south Chile, Patagonia, and the austral islands of Tierra del Fuego and Hoste. This group presents a strong sagital crest, large rostrum, and a large skull. Our results agree with observed patterns of mitochondrial DNA variation. We propose to retain the name L. c. andinus for the populations of northern Chile and to synonymize L. c. magellanicus, L. c. lycoides, and L. c. smithersi under L. c. culpaeus. Rev. Biol. Trop. 57 (1-2): 421-432. Epub 2009 June 30.
Mediante análisis cualitativos y cuantitativos, se estudió la variación geográfica del cráneo de Lycalopex culpaeus en Chile (desde Tarapacá a la islas australes), y de algunas poblaciones argentinas. En dicha distribución se reconocen cinco de las seis subespecies del culpeo. Los resultados muestran dos grupos morfológicos geográficamente segregados; los mismos se diferencian principalmente por atributos morfométricos, y secundariamente por caracteres cualitativos. individuos del norte chileno (Tarapacá y Antofagasta) presentan cráneos pequeños, poco desarrollados, hocico levemente corto, ausencia de cresta interparietal y una tenue zona sagital "liriforme". Por otra parte, los individuos del noroeste y centro argentino, centro sur chileno, Patagonia e islas australes (islas de Tierra del Fuego y Hoste) (grupo B), no muestran diferencias significativas en su morfometría dento-craneal. En el grupo B destacó una fuerte cresta interparietal y zona sagital, hocicos prolongados y cráneos de mayor tamaño que los del norte chileno. Nuestros resultados coinciden con estudios de patrones de variación en el ADN mitocondrial de cánidos de Chile. Por lo tanto, se propone mantener el nombre L. c. andinus para las poblaciones del norte de Chile y sinonimizar los taxones L. c. magellanicus, L. c. lycoides y L. c. smithersi bajo la forma L. c. culpaeus.
Assuntos
Animais , Raposas/classificação , Crânio/anatomia & histologia , Argentina , Cefalometria , Chile , DNA Mitocondrial/genética , Raposas/anatomia & histologia , Raposas/genética , GeografiaRESUMO
Rapid bird inventoires made in the Caatinga of southern Ceará and west Pernambuco in July and September 2004 found a total of 209 species. Birds characteristic of the different Caatinga habitats (from dense scrub to arboreal-arbustive forations) accounted for 99 species, followed by open habitats or generalist species (65) and waterbirds (45). We found no geographic pattern in area similarity. Numerically dominant species tend to be small insectivores feeding amid the lower vegetation and granivores such as Columbidae and Coryphospingus pileatus. Generalists such as Cyanocorax cyanopogon were also dominant in some áreas. The very disturbed scrub caatinga around temporary lagoons near Petrolina (Pernambuco) had the most species. The regional avifauna show few larger species such as Cracidae and Psitacidae, while birds associated to more arboreal, structured habitats such as the larger Dendrocolaptidae are also scarce or absent, refecting both direct human exploitation and the replacement of forest-like habitats by lower, less diverse scrub habitat.
Inventários rápidos realizados em diferentes pontos no sul do Ceará e oeste de Pernambuco em julho e setembro de 2004 encontraram um total de 209 espécies de aves. A maior riqueza foi de espécies características das várias formações da Caatinga (99 espécies), seguidas por espécies de áreas abertas ou generalistas (65) e aves aquáticas (45). Não foi encontrado um padrão que associasse a similaridade entre áreas a um padrão geográfico. As espécies numericamente dominantes tendem a ser pequenos insetívoros que se alimentam em meio à vegetação baixa e granívoros como Columbidae e Coryphospingus pileatus. Generalistas como Cyanocorax cyanopogon também foram dominantes em alguns pontos. As caatingas muito alteradas ao redor de lagoas temporárias de Petrolina mostraram maior riqueza de espécies. De maneira geral a avifauna regional mostra poucas espécies de maior porte, como Cracidae e Psitacidae maiores, e aquelas dependentes de habitats mais estruturados, como grandes Dendrocolaptidae, refletindo tanto a exploração humana direta como a substituição de habitats de estrutura florestal por formações mais baixas e simples.
RESUMO
Rapid bird inventoires made in the Caatinga of southern Ceará and west Pernambuco in July and September 2004 found a total of 209 species. Birds characteristic of the different Caatinga habitats (from dense scrub to arboreal-arbustive forations) accounted for 99 species, followed by open habitats or generalist species (65) and waterbirds (45). We found no geographic pattern in area similarity. Numerically dominant species tend to be small insectivores feeding amid the lower vegetation and granivores such as Columbidae and Coryphospingus pileatus. Generalists such as Cyanocorax cyanopogon were also dominant in some áreas. The very disturbed scrub caatinga around temporary lagoons near Petrolina (Pernambuco) had the most species. The regional avifauna show few larger species such as Cracidae and Psitacidae, while birds associated to more arboreal, structured habitats such as the larger Dendrocolaptidae are also scarce or absent, refecting both direct human exploitation and the replacement of forest-like habitats by lower, less diverse scrub habitat.
Inventários rápidos realizados em diferentes pontos no sul do Ceará e oeste de Pernambuco em julho e setembro de 2004 encontraram um total de 209 espécies de aves. A maior riqueza foi de espécies características das várias formações da Caatinga (99 espécies), seguidas por espécies de áreas abertas ou generalistas (65) e aves aquáticas (45). Não foi encontrado um padrão que associasse a similaridade entre áreas a um padrão geográfico. As espécies numericamente dominantes tendem a ser pequenos insetívoros que se alimentam em meio à vegetação baixa e granívoros como Columbidae e Coryphospingus pileatus. Generalistas como Cyanocorax cyanopogon também foram dominantes em alguns pontos. As caatingas muito alteradas ao redor de lagoas temporárias de Petrolina mostraram maior riqueza de espécies. De maneira geral a avifauna regional mostra poucas espécies de maior porte, como Cracidae e Psitacidae maiores, e aquelas dependentes de habitats mais estruturados, como grandes Dendrocolaptidae, refletindo tanto a exploração humana direta como a substituição de habitats de estrutura florestal por formações mais baixas e simples.