71 research outputs found

    SAME‐SEX MOUNTING BEHAVIOR BETWEEN JUVENILES AND ADULT MALES OF THE WHITE‐BEARDED MANAKIN (MANACUS MANACUS)

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    Abstract ∙ Adult males of lekking species compete with each other during sexual displays to attract females. Juvenile males usually are inexperienced in displays and they have minimal chances of attracting females that visit adults. Despite this supposed lack of competition between adults and juveniles, inexperienced juveniles of the White‐bearded Manakin (Manacus manacus) that try to rehearse displays in lek areas may be chased aggressively by adult males. Here, I describe same‐sex mounting behavior between M. manacus adults and juveniles. Two juvenile males entered the arenas of two high‐ranking adults and rehearsed jump‐snap display soon after they were mounted by adults. Adults did not chase the juveniles, showing no immediate competition or aggressiveness. Four years later, the same (individually‐marked) juveniles had become established adults on the same lek areas where the same‐sex mounting behavior was recorded. For juveniles, the same‐sex mounting behavior may facilitate their approach to arenas of adults and acquisition of display experience. For adults, benefits derived from such behavior may include social hierarchy imposition and avoidance of conflicts with potentially future newcomer juvenile males in lek areas. However, alternative explanations, such as mistaking juvenile males for females by adult males, cannot be ruled out. Resumo ∙ O comportamento de montar entre jovens e adultos machos da rendeira (Manacus manacus)   Machos adultos que possuem o sistema reprodutivo de lek competem intensamente durante exibições sexuais para atraírem fêmeas. Machos juvenis geralmente possuem pouca experiência em exibições e portanto, eles possuem pou‐ cas chances de atraírem as fêmeas que visitam machos adultos. Apesar desta suposta falta de competição entre machos adultos e jovens, alguns jovens inexperientes de rendeiras (Manacus manacus) que tentam praticar exibições podem ser perseguidos por adultos agressivos. No presente estudo, eu descrevo o comportamento de montar, característico da cópula entre machos e fêmeas, entre machos adultos e machos jovens da rendeira . Dois machos jovens praticaram manobras de exibição em duas arenas de machos adultos logo depois que foram montados pelos mesmos adultos. Os adultos não perseguiram estes machos jovens, evidenciando nenhuma competição ou agressividade. Quatro anos depois, os mesmos jovens (individualmente marcados) se estabeleceram nas mesmas áreas de lek onde o comportamento de montar foi registrado. Para os jovens, o comportamento de montar pode facilitar a aproximação em arenas de adultos e a aquisição de experiência em exibições. Para os adultos, os benefícios derivados do comportamento de montar podem incluir imposição de hierarquia social sobre outros machos jovens e eliminação de futuros conflitos com potenciais machos jovens que queiram se estabelecer nas áreas de lek. Apesar dos resultados, um possível erro de identificação de sexo entre machos jovens e fêmeas por machos adultos não é descartado.

    Uso de riacho costeiro da Mata Atlântica pelo limpa-fundo Scleromystax barbatus (Quoy & Gaimard, 1824)

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    Habitat used by fish is often related with the requirements of the species, according to their morphological characteristics, feeding, and reproductive strategies. We describe the habitat preference, foraging behavior, and camouflage strategy of Scleromystax barbatus (Callichthyidae: Corydoradinae), an endemic catfish from coastal streams in the Atlantic Forest. The movement and foraging behavior of 11 individuals were observed using focalfish method, and the habitat structure availability (i.e., depth, bottom type, and mesohabitat) was measured in a clearwater stream stretch with 40 m length and 2.8 m width (± 1.5 sd) in southeastern Brazil. In addition, six individuals were captured to verify stomach contents. Habitat selectivity of the species was assessed using the Ivlev electivity index that considers the frequency of occurrence of each habitat variable used by fish in relation to its environmental availability. Scleromystax barbatus selected pools and runs with sandy bottom in depths between 21 cm and 40 cm, and avoided gravel in shallower riffles (up to 10 cm). Individuals foraged close to the bottom in a head-down posture, speculating and revolving the substrate composed by sand, fallen leaves, and twigs. Their long snout and small barbels were used to dislodge the food items of the substrate, which were quickly sucked by the mouth. Aquatic immature insects (mainly trichopterans) were predominant in the stomach contents. Three fish species, Deuterodon iguape Eigenmann, 1907, Mimagoniates microlepis Steindachner, 1877, and Geophagus brasiliensis (Quoy & Gaimard, 1824), were firstly registered following S. barbatus during its foraging activity. The brilliant golden body color with darkish spots of S. barbatus strongly resembles the stream bottom, which indicates disruptive camouflage.Key words: Corydoradinae, habitat use, feeding behavior, disruptive camouflage.O hábitat usado por peixes é frequentemente relacionado com as necessidades das espécies, de acordo com suas características morfológicas e estratégias alimentares e reprodutivas. Descrevemos a preferência de hábitat, forrageamento e a estratégia de camuflagem de Scleromystax barbatus (Callichthyidae: Corydoradinae), um bagre endêmico de riachos costeiros da Mata Atlântica. O deslocamento e o comportamento de forragear de 11 indivíduos foram observados pelo método animal-focal, e a disponibilidade da estrutura de hábitat (i.e., profundidade, tipo de substrato, e meso-hábitat) foi mensurada em um trecho de 40 m de comprimento por 2,8 m de largura (±1,5 dp) em um riacho de água clara no sudeste do Brasil. Além disso, seis indivíduos foram capturados para verificar seus conteúdos estomacais. A seletividade de hábitats por S. barbatus foi avaliada pelo índice de eletividade de Ivlev, que considera a frequência de ocorrência de cada variável do hábitat utilizada pelos peixes em relação à sua disponibilidade total no ambiente. Scleromystax barbatus selecionou poções e rápidos com fundo de areia e profundidades entre 21 cm e 40 cm, e evitou cascalhos em ambientes rasos com menos de 10 cm de profundidade em corredeiras. Os indivíduos forragearam próximos do fundo com a cabeça inclinada em direção ao chão, especulando e revolvendo o substrato composto por areia, folhas e galhos caídos. O focinho longo e os pequenos barbilhões dos indivíduos foram usados para desalojar os itens alimentares do substrato, que eram rapidamente sugados pela boca. Insetos aquáticos imaturos (principalmente tricópteros) foram predominantes nos conteúdos estomacais. Três espécies de peixes, Deuterodon iguape Eigenmann, 1907, Mimagoniates microlepis Steindachner, 1877 e Geophagus brasiliensis (Quoy & Gaimard, 1824), foram registradas pela primeira vez seguindo S. barbatus durante sua atividade de forrageamento. A coloração dourado-brilhante com manchas escuras de S. barbatus se assemelha fortemente à cor do fundo do riacho e indica camuflagem disruptiva.Palavras-chave: Corydoradinae, uso do hábitat, comportamento alimentar, camuflagem disruptiva

    Aves, Emberizidae, Coryphospingus pileatus (Wied, 1821): a new gathered bird species to São Paulo state and evidences of southern geographic expansion in Brazil

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    The Pileated Finch Coryphospingus pileatus has an extensive geographic range that encompasses northeast to central, east and part of southeastern regions in Brazil. In southeastern region, Rio de Janeiro and Minas Gerais states were treated as southern limit of the species distribution. In the present note, we firstly documented the species to São Paulo state, extending to southern its old-believed geographic distribution. We argued several records of C. pileatus in Vale do Paraíba region since 40 years ago. We also hypothesized the future geographic expansion of the species in São Paulo state

    THE DEGREE OF FRUGIVORY OF BIRDS AS ESTIMATED FROM GASTRIC AND FECAL SAMPLES

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    The degree of frugivory (DF) has long been used to characterize the relative importance of fruits to the diet of a bird and, more recently, as a functional trait related to the role of birds in seed dispersal networks. Although quantitative estimations of DF are desirable, general, categorical classifications or coarse estimations of diet composition based in qualitative information are often used. Data on stomach, fecal and regurgitation contents scattered in the literature or easily obtained in the field could be used to provide a quantitative, potentially more reliable assessment of DF. We compiled such data from the literature and our own fieldwork to obtain 12,576 samples for 985 Neotropical bird species, of which 489 species (49.6%) from 61 families had at least one fruit-containing sample. Gastric (i.e. stomach plus regurgitation) and fecal samples provided similar estimates of DF, despite potential differences in the degree of food digestion. The DF we obtained were higher than those presented in the most frequently used source of quantitative DF estimates in the literature (the Elton Traits database). We further explored with a few study cases the utility of stomach, fecal and regurgitation samples to evaluate intraspecific geographic, sexual, and ontogenetic variations in DF, topics rarely investigated so far. We argued that stomach, fecal and regurgitation sample data abundantly available in the literature or obtained from mist-netted birds may be used to produce quantitative assessments of DF likely more reliable than the estimates used so far and useful for a plethora of ecological studies

    Spontaneous Periodontitis Development in Diabetic Rats Involves an Unrestricted Expression of Inflammatory Cytokines and Tissue Destructive Factors in the Absence of Major Changes in Commensal Oral Microbiota

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    Diabetes mellitus is a heterogeneous group of disorders, in which hyperglycemia is a main feature. The objective was to evaluate the involvement of RAGE, inflammatory cytokines, and metalloproteinases in spontaneous periodontitis triggered by diabetes induction. Immunohistochemical procedures for MMP-2, MMP-9, TNF-α, IL-1β, IL-6, RANKL, and RAGE were performed in rats after 1, 3, 6, 9, and 12 months of diabetes induction. Total DNA was extracted from paraffin-embedded tissues and evaluated by Real-TimePCR for 16S total bacterial load and specific periodontopathogens. Our data did not demonstrate differences in microbiological patterns between groups. In diabetic groups, an increase in RAGE-positive cells was detected at 6, 9, and 12 months, while TNF-alpha-stained cells were more prevalent at 6 and 12 months. In experimental groups, IL-β-positive cells were increased after 12 months, IL-6 stained cells were increased at 9 and 12 months, and RANKL-positive cells at 9 months. Diabetes resulted in widespread expression of RAGE, followed by expression of proinflammatory mediators, without major alterations in oral microbial profile. The pervasive expression of cytokines suggests that spontaneous periodontitis development may be independent of microbial stimulation and may be triggered by diabetes-driven imbalance of homeostasis

    Spontaneous Periodontitis Development in Diabetic Rats Involves an Unrestricted Expression of Inflammatory Cytokines and Tissue Destructive Factors in the Absence of Major Changes in Commensal Oral Microbiota

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    Diabetes mellitus is a heterogeneous group of disorders, in which hyperglycemia is a main feature. The objective was to evaluate the involvement of RAGE, inflammatory cytokines, and metalloproteinases in spontaneous periodontitis triggered by diabetes induction. Immunohistochemical procedures for MMP-2, MMP-9, TNF-α, IL-1β, IL-6, RANKL, and RAGE were performed in rats after 1, 3, 6, 9, and 12 months of diabetes induction. Total DNA was extracted from paraffin-embedded tissues and evaluated by Real-TimePCR for 16S total bacterial load and specific periodontopathogens. Our data did not demonstrate differences in microbiological patterns between groups. In diabetic groups, an increase in RAGE-positive cells was detected at 6, 9, and 12 months, while TNF-alpha-stained cells were more prevalent at 6 and 12 months. In experimental groups, IL-β-positive cells were increased after 12 months, IL-6 stained cells were increased at 9 and 12 months, and RANKL-positive cells at 9 months. Diabetes resulted in widespread expression of RAGE, followed by expression of proinflammatory mediators, without major alterations in oral microbial profile. The pervasive expression of cytokines suggests that spontaneous periodontitis development may be independent of microbial stimulation and may be triggered by diabetes-driven imbalance of homeostasis

    Influence of daily usage times on patients’ compliance during at-home bleaching : a randomized clinical trial

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    The effectiveness of at-home dental bleaching treatments depends on the time that bleaching products are in contact with the teeth surface and, consequently, on the adequate use of associated custom acetate trays. Objective: This randomized single-blinded trial aimed to analyze if the daily usage time of these products influences the patient’s compliance behavior when submitted to monitored at-home dental bleaching. Secondary outcomes were color change and tooth sensitivity. Methodology: Sixty-six volunteers were randomly distributed into three groups (n=22): patients were instructed to use the trays for 2 (G2), 4 (G4), and 8 (G8) hours daily. The daily dental bleaching compliance behavior was measured using a microsensor inserted into the trays. Subjective and objective color evaluation assessments were adopted at baseline (T0), one (T1), two (T2), and three weeks (T3) after the beginning of the bleaching treatment, as well as two weeks after the treatment (T4). Tooth sensitivity was analyzed using the VAS scale, ranging from T1 to T4. Results: G2 showed a greater degree of cooperation than G8 and cooperation was inversely proportional to the recommended usage time. Significantly higher color change was observed in the upper arch for G8 when compared to G2 in subjective analysis, from T1 to T4. There were no statistical differences between the groups in objective analysis. Conclusion: Shorter recommended usage time of the bleaching product may improve the patient's compliance with at-home dental bleaching treatments. However, increased daily usage time may promote better subjective color change. Bleaching sensitivity was more significant in the first week for a longer time of use

    Audit du compte spécial. Un mecanisme de controle important dans les cours des comptes

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    Visa o presente trabalho a demonstrar as vantagens da utilização da Tomada de Contas Especial (TCE) como forma de apuração eficiente e célere de irregularidades cometidas por aplicadores de recursos públicos.Cette étude vise à démontrer les avantages de l’utilisation de la Audit du Compte Spécial comme un moyen d’enquête efficace et rapide des irrégularités commises par des applicateurs de ressources publiques.This paper intends to set forth the advantages of using the Special Account Audit as an efficient and expeditious instrument of investigation of irregularities committed by public resources agents
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