961 resultados para Curson, Jon: New World warblers


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In New World primates, mixed-species troops have been reported. Here, we analysed the performance of affiliative and agonistic behaviours of Callithrix jacchus and Callithrix penicillata living in mixed groups. For this purpose, we recorded the interaction of the individuals from two groups located in Bauru city, in the state of Sao Paulo (Brazil). Our data show that in both groups, affiliative behaviours appeared more frequently than agonistic ones. We concluded that there is cohesion inside the mixed-species troops observed. We suggest that a deeper knowledge about the social behaviour of mixed-species troop species certainly may be useful in projects linked with the management of the impact caused by them.

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The slick hair coat (SLICK) is a dominantly inherited trait typically associated with tropically adapted cattle that are from Criollo descent through Spanish colonization of cattle into the New World. The trait is of interest relative to climate change, due to its association with improved thermo-tolerance and subsequent increased productivity. Previous studies localized the SLICK locus to a 4 cM region on chromosome (BTA) 20 and identified signatures of selection in this region derived from Senepol cattle. The current study compares three slick-haired Criollo-derived breeds including Senepol, Carora, and Romosinuano and three additional slick-haired cross-bred lineages to non-slick ancestral breeds. Genome-wide association (GWA), haplotype analysis, signatures of selection, runs of homozygosity (ROH), and identity by state (IBS) calculations were used to identify a 0.8 Mb (37.7-38.5 Mb) consensus region for the SLICK locus on BTA20 in which contains SKP2 and SPEF2 as possible candidate genes. Three specific haplotype patterns are identified in slick individuals, all with zero frequency in non-slick individuals. Admixture analysis identified common genetic patterns between the three slick breeds at the SLICK locus. Principal component analysis (PCA) and admixture results show Senepol and Romosinuano sharing a higher degree of genetic similarity to one another with a much lesser degree of similarity to Carora. Variation in GWA, haplotype analysis, and IBS calculations with accompanying population structure information supports potentially two mutations, one common to Senepol and Romosinuano and another in Carora, effecting genes contained within our refined location for the SLICK locus.

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Leishmania is a protozoan belonging to the family Trypanosomatidae, obligate intracellular parasite cells of the mononuclear phagocyte system. In the New and Old World several orders of wild mammals (natural reservoirs) and various species of sandflies (vectors) are involved in the transmission of leishmaniasis. The new settlements in rural areas, changes in the environment and unplanned urbanization increased human contact with vector and interaction with the animal reservoir. A simple prophylactic measure seems to be the vector control as well as disease reservoir. With the goal of raising the prophylactic measures that are being used in vector control, the reservoir of the disease and what the infrastructure accordingly. We conducted a literature review in July 2011 in the electronic databases of Bireme, Medline, CancerLit, Portal Capes, SciELO, PubMed and Medscape, the main texts on the subject. Thus, the development of a vaccine that is effective against various forms of leishmaniasis in the old and new world, it is necessary and has been recommended by WHO as a possible tool for effective eradication of the disease.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Applying ecological studies to the adaptations of prehistoric human hunter-gatherer groups has greatly increased our abilities to interpret effects of an ever-changing environment and our access to critical resources on these populations. The Pleistocene/Holocene transition, its climate and human genesis in the new world, draws intensive interest from a number of scientific communities. In Twilight of the Mammoths, Paul Martin adds his views, which are of no surprise, on the megafaunal extirpations during a cultural period referred to in North America as Clovis.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Chimpanzees have been the traditional referential models for investigating human evolution and stone tool use by hominins. We enlarge this comparative scenario by describing normative use of hammer stones and anvils in two wild groups of bearded capuchin monkeys (Cebus libidinosus) over one year. We found that most of the individuals habitually use stones and anvils to crack nuts and other encased food items. Further, we found that in adults (1) males use stone tools more frequently than females, (2) males crack high resistance nuts more frequently than females, (3) efficiency at opening a food by percussive tool use varies according to the resistance of the encased food, (4) heavier individuals are more efficient at cracking high resistant nuts than smaller individuals, and (5) to crack open encased foods, both sexes select hammer stones on the basis of material and weight. These findings confirm and extend previous experimental evidence concerning tool selectivity in wild capuchin monkeys (Visalberghi et al., 2009b; Fragaszy et al., 2010b). Male capuchins use tools more frequently than females and body mass is the best predictor of efficiency, but the sexes do not differ in terms of efficiency. We argue that the contrasting pattern of sex differences in capuchins compared with chimpanzees, in which females use tools more frequently and more skillfully than males, may have arisen from the degree of sexual dimorphism in body size of the two species, which is larger in capuchins than in chimpanzees. Our findings show the importance of taking sex and body mass into account as separate variables to assess their role in tool use. (C) 2011 Elsevier Ltd. All rights reserved.

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We investigated the color vision pattern in Cebus apella monkeys by means of electroretinogram measurements (ERG) and genetic analysis. Based on ERG we could discriminate among three types of dichromatic males. Among females, this classification is more complex and requires additional genetic analysis. We found five among 10 possible different phenotypes, two trichromats and three dichromats. We also found that Cebus present a new allele with spectral peak near 552 nm, with the amino acid combination SFT at positions 180, 277 and 285 of the opsin gene, in addition to the previously described SYT, AFT and AFA alleles. (C) 2009 Elsevier Ltd. All rights reserved.

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The color vision of most platyrrhine primates is determined by alleles at the polymorphic X-linked locus coding for the opsin responsible for the middle- to long-wavelength (M/L) cone photopigment. Females who are heterozygous at the locus have trichromatic vision, whereas homozygous females and all males are dichromatic. This study characterized the opsin alleles in a wild population of the socially monogamous platyrrhine monkey Callicebus brunneus (the brown titi monkey), a primate that an earlier study suggests may possess an unusual number of alleles at this locus and thus may be a subject of special interest in the study of primate color vision. Direct sequencing of regions of the M/L opsin gene using feces-, blood-, and saliva-derived DNA obtained from 14 individuals yielded evidence for the presence of three functionally distinct alleles, corresponding to the most common M/L photopigment variants inferred from a physiological study of cone spectral sensitivity in captive Callicebus. Am. J. Primatol. 73:189-196, 2011. (C) 2010 Wiley-Liss, Inc.

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Background: Over the last century the incidence of cutaneous melanoma has increased worldwide, a trend that has also been observed in Brazil. The identified risk factors for melanoma include the pattern of sun exposure, family history, and certain phenotypic features. In addition, the incidence of melanoma might be influenced by ethnicity. Like many countries, Brazil has high immigration rates and consequently a heterogenous population. However, Brazil is unique among such countries in that the ethnic heterogeneity of its population is primarily attributable to admixture. This study aimed to evaluate the contribution of European ethnicity to the risk of cutaneous melanoma in Brazil. Methodology/Principal Findings: We carried out a hospital-based case-control study in the metropolitan area of Sao Paulo, Brazil. We evaluated 424 hospitalized patients (202 melanoma patients and 222 control patients) regarding phenotypic features, sun exposure, and number of grandparents born in Europe. Through multivariate logistic regression analysis, we found the following variables to be independently associated with melanoma: grandparents born in Europe-Spain (OR = 3.01, 95% CI: 1.03-8.77), Italy (OR = 3.47, 95% CI: 1.41-8.57), a Germanic/Slavic country (OR = 3.06, 95% CI: 1.05-8.93), or >= 2 European countries (OR = 2.82, 95% CI: 1.06-7.47); eye color-light brown (OR = 1.99, 95% CI: 1.14-3.84) and green/blue (OR = 4.62; 95% CI 2.22-9.58); pigmented lesion removal (OR = 3.78; 95% CI: 2.21-6.49); no lifetime sunscreen use (OR = 3.08; 95% CI: 1.03-9.22); and lifetime severe sunburn (OR = 1.81; 95% CI: 1.03-3.19). Conclusions: Our results indicate that European ancestry is a risk factor for cutaneous melanoma. Such risk appears to be related not only to skin type, eye color, and tanning capacity but also to others specific characteristics of European populations introduced in the New World by European immigrants.

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The Neotropical evaniid genus Evaniscus Szepligeti currently includes six species. Two new species are described, Evaniscus lansdownei Mullins, sp. n. from Colombia and Brazil and E. rafaeli Kawada, sp. n. from Brazil. Evaniscus sulcigenis Roman, syn. n., is synonymized under E. rufithorax Enderlein. An identification key to species of Evaniscus is provided. Thirty-five parsimony informative morphological characters are analyzed for six ingroup and four outgroup taxa. A topology resulting in a monophyletic Evaniscus is presented with E. tibialis and E. rafaeli as sister to the remaining Evaniscus species. The Hymenoptera Anatomy Ontology and other relevant biomedical ontologies are employed to create semantic phenotype statements in Entity-Quality (EQ) format for species descriptions. This approach is an early effort to formalize species descriptions and to make descriptive data available to other domains.

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O músculo diafragma, encontrado apenas nos mamíferos, é o principal músculo no processo respiratório, servindo de fronteira entre as cavidades torácica e abdominal. Sua importância também ganha destaque em pesquisas realizadas no âmbito dos enxertos, empregando-se diversos tipos de membranas biológicas para o reparo de defeitos diafragmáticos, os quais podem gerar hérnias diafragmáticas. Apesar de muitos estudos já conduzidos para com os primatas não humanos, especialmente no que tange a espécie do novo mundo Callithrix jacchus (Sagui-de-tufo-branco), oriundo do nordeste brasileiro, as pesquisas envolvendo o uso do diafragma em tal espécie é inexistente. Deste modo objetivou-se caracterizar a morfologia e a biometria do diafragma na espécie Callithrix jacchus de ambos os sexos, analisando possíveis divergências estruturais entre machos e fêmeas. Para tal foram utilizados quatros animais, 2 machos e 2 fêmeas, adultos, que vieram a óbito por causas naturais, provenientes de um criadouro comercial. Após fixação em solução de formaldeído 10% os animais foram devidamente dissecados para fotodocumentação e em seguida o diafragma coletado para efetuação da biometria (comprimento e largura) com o uso de um paquímetro e para o processamento histológico por meio da coloração de hematoxilina-eosina e tricrômio de masson, da porção muscular. As mensurações feitas permitiram concluir que não houve diferenças signifcativas entre machos e femeas. A topografia e a presença de três aberturas (forame da veia cava caudal, hiato aórtico e esofágico) na extensão do diafragma corroboram com descrições na literatura classica para outros mamíferos. A presença de um centro tendíneo em "V" difere do encontrado para animais como o peixe-boi e porquinho-da-india, mas é similar ao encontrado para o gambá-de-orelhas-brancas e rato albino. No que diz respeito aos achados histológicos conclui-se que as fibras musculares estão dispostas de forma organizada, apresentam diâmetro grande e núcleos basais, tendo, portanto, características similares do músculo estriado esquelético tanto nos animais machos como nas fêmeas.

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The screwworm, Cochliomyia hominivorax (Coquerel), remains one of the most damaging parasites of livestock in South America, causing millions of dollars in annual losses to producers. Recently, South American countries demonstrated interest in controlling this pest using the Sterile Insect Technique, and a pilot-project was conducted near the Brazil-Uruguay border in 2009. Since molecular studies have suggested the existence of C. hominivorax regional groups, crossing tests were conducted to evaluate mating competitiveness, mating preference and reproductive compatibility between a C. hominivorax strain from the Caribbean (Jamaica-06) and one from Brazil. Mating rates between Jamaican males and Brazilian females ranged between 82 and 100%, and each male inseminated from 3.3 to 3.95 females. Sterile males, regardless of the strain, competed equally against the fertile males for Brazilian females. Jamaican sterile males and Brazilian fertile males mated randomly with fertile or sterile females. No evidence of genetic incompatibility or hybrid dysgenesis was found in the hybridization crosses. Mating barriers should not compromise the use of Jamaican sterile males for Sterile Insect Technique campaigns in Brazil.