58 resultados para Beak


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This study provides information on the species composition and the number of butterflies in different phases of an ithomiine aggregation during the 2004 dry season in central Brazil, and tests some hypotheses concerning the pocket formation. The results obtained suggest that ithomiine pockets constitute primarily an adaptation of butterflies to the adverse climatic conditions of the dry season, such as high temperatures and low air relative humidity, rather than the occurrence of large concentrations of adult food resources (flowers visited for nectar were not found in the pocket site) or defense against visually hunting predators (contrary to the prediction tested, the frequency of butterflies bearing birds beak marks on the wings significantly increased along the period of pocket formation, especially in the case of Mechanitis polymnia, the most abundant species in the pocket). Other hypotheses concerning the pocket formation are also discussed.

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Stress in local isolation structures is studied by micro‐Raman spectroscopy. The results are correlated with predictions of an analytical model for the stress distribution and with cross‐sectional transmission electron microscopy observations. The measurements are performed on structures on which the Si3N4 oxidation mask is still present. The influence of the pitch of the periodic local isolation pattern, consisting of parallel lines, the thickness of the mask, and the length of the bird"s beak on the stress distribution are studied. It is found that compressive stress is present in the Si substrate under the center of the oxidation mask lines, with a magnitude dependent on the width of the lines. Large tensile stress is concentrated under the bird"s beak and is found to increase with decreasing length of the bird"s beak and with increasing thickness of the Si3N4 film.

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A new subspecies of Pedicularis pyrenaica J. Gay (Scrophulariaceae) in Central Pyrenees. We describe a new subspecies of Pedicularis pyrenaica (P. pyrenaica subsp. praetermissa) from the Central Pyrenees, which differs from the typical in the shape of the upper lip of the corolla (fusiform, attenuated in a conical beak), as for the larger size of the corolla and the whole plant. We add several comments on the morphological characterization and the habitat of the plant in relation to close taxa

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Determining the relative roles of vicariance and selection in restricting gene flow between populations is of central importance to the evolutionary process of population divergence and speciation. Here we use molecular and morphological data to contrast the effect of isolation (by mountains and geographical distance) with that of ecological factors (altitudinal gradients) in promoting differentiation in the wedge-billed woodcreeper, Glyphorynchus spirurus, a tropical forest bird, in Ecuador. Tarsus length and beak size increased relative to body size with altitude on both sides of the Andes, and were correlated with the amount of moss on tree trunks, suggesting the role of selection in driving adaptive divergence. In contrast, molecular data revealed a considerable degree of admixture along these altitudinal gradients, suggesting that adaptive divergence in morphological traits has occurred in the presence of gene flow. As suggested by mitochondrial DNA sequence data, the Andes act as a barrier to gene flow between ancient subspecific lineages. Genome-wide amplified fragment length polymorphism markers reflected more recent patterns of gene flow and revealed fine-scale patterns of population differentiation that were not detectable with mitochondrial DNA, including the differentiation of isolated coastal populations west of the Andes. Our results support the predominant role of geographical isolation in driving genetic differentiation in G. spirurus, yet suggest the role of selection in driving parallel morphological divergence along ecological gradients.

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Ecological network patterns are influenced by diverse processes that operate at different temporal rates. Here we analyzed whether the coupled effect of local abundance variation, seasonally phenotypic plastic responses, and species evolutionary adaptations might act in concert to shape network patterns. We studied the temporal variation in three interaction properties of bird species (number of interactions per species, interaction strength, and interaction asymmetry) in a temporal sequence of 28 plant frugivore interaction networks spanning two years in a Mediterranean shrubland community. Three main hypotheses dealing with the temporal variation of network properties were tested, examining the effects of abundance, switching behavior between alternative food resources, and morphological traits in determining consumer interaction patterns. Our results demonstrate that temporal variation in consumer interaction patterns is explained by short-term variation in resource and bird abundances and seasonal dietary switches between alternative resources (fleshy fruits and insects). Moreover, differences in beak morphology are associated with differences in switching behavior between resources, suggesting an important role of foraging adaptations in determining network patterns. We argue that beak shape adaptations might determine generalist and specialist feeding behaviors and thus the positions of consumer species within the network. Finally, we provide a preliminary framework to interpret phylogenetic signal in plant animal networks. Indeed, we show that the strength of the phylogenetic signal in networks depends on the relative importance of abundance, behavioral, and morphological variables. We show that these variables strongly differ in their phylogenetic signal. Consequently, we suggest that moderate and significant phylogenetic effects should be commonly observed in networks of species interactions. Read More: http://www.esajournals.org/doi/abs/10.1890/07-1939.1

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Most descriptions of the ostrich oropharynx and oesophagus are superficial and supply little meaningful morphological data. The aim of this investigation is describe the ostrich oropharingeal cavity, in order to supply the deficiency of macroscopic data about this important animal. Five heads of 12 to 14-month-old ostriches of either sex were anatomically dissected to expose the oropharynx. The ostrich oropharynx was "bell-shaped" composed by the maxillary and mandibular ramphoteca. The roof and floor presented two distinct regions different in colour of the mucosa. The rostral region was pale pink contrasting to creamy-pink coloured caudal region. The median longitudinal ridge extended rostrally from the apex of the choana to the tip of the beak in the roof and it is clearly more prominent and rigid than the homolog in the floor that appeared thin and stretched rostrally, continuing caudally surrounding the tongue and the laryngeal mound eventually merging with the oesophageal mucosa. The floor was formed by the interramal region, tongue and laryngeal mound containing shield-shaped glottis. It can be concluded that the present study, in addition to confirming the basic features of the oropharynx previously described for the ostrich, clarified the contradictory information presented in the literature and also provided new, unreported morphological data, some of which may be important when studying nutrition and health in these birds.

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A young common barn owl (Tyto alba) was referred to the Núcleo de Reabilitação da Fauna Silvestre (Nurfs), Federal University of Pelotas (UFPel), after been found in a barn of a brick factory in the urban area of Pelotas, Rio Grande do Sul, Brazil. The bird was apathic, weak and with crusty lesions in the featherless areas (eyes, beak, legs), and died soon after arrival at Nurfs. Necropsy and histopathological examination of the lesions were carried out. The hyperplasia and hypertrophy of the cutaneous lesions, several eosinophilic intracyto-plasmic inclusion bodies in epithelial cells (Bollinger bodies), as well as particles characteristic of poxvirus, observed by electronic microscopy, confirmed the infection by avian poxvirus, what highlights the importance of Tyto alba as carrier of the virus in the wild.

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The rhea (Rhea americana americana) is an american bird belonging to Ratite's family. Studies related to its morphology are still scarce. This study aims to describe the macroscopic structures of the oropharyngeal cavity. Five heads (2 to 6 months old) formalin preserved were anatomically dissected to expose the oropharynx. The oropharynx of the rhea was "bell-shaped" composed by the maxillary and mandibular rhamphotheca. The roof and floor presented two distinct regions different in colour of the mucosa. The rostral region was pale pink contrasting to grey coloured caudal region. The median longitudinal ridge extended rostrally from the apex of the choana to the tip of the beak in the roof and it is clearly more prominent and rigid than the homolog in the floor that appeared thin and stretched merely along the rostral portion of the regio interramalis. The floor was formed by the interramal region, (regio interramalis) tongue and laryngeal mound containing glove-shaped glottis. This study confirmed the basic morphology of the oropharinx of the rhea. However, important morphological information not previously described is highlighted and contradictory information present in the literature is clarified.

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Induction of apoptosis by tumor necrosis factor (TNF) is modulated by changes in the expression and activity of several cell cycle regulatory proteins. We examined the effects of TNF (1-100 ng/ml) and butyrolactone I (100 µM), a specific inhibitor of cyclin-dependent kinases (CDK) with high selectivity for CDK-1 and CDK-2, on three different cancer cell lines: WEHI, L929 and HeLa S3. Both compounds blocked cell growth, but only TNF induced the common events of apoptosis, i.e., chromatin condensation and ladder pattern of DNA fragmentation in these cell lines. The TNF-induced apoptosis events were increased in the presence of butyrolactone. In vitro phosphorylation assays for exogenous histone H1 and endogenous retinoblastoma protein (pRb) in the total cell lysates showed that treatment with both TNF and butyrolactone inhibited the histone H1 kinase (WEHI, L929 and HeLa) and pRb kinase (WEHI) activities of CDKs, as compared with the controls. The role of proteases in the TNF and butyrolactone-induced apoptosis was evaluated by comparing the number and expression of polypeptides in the cell lysates by gel electrophoresis. TNF and butyrolactone treatment caused the disappearance of several cellular protein bands in the region between 40-200 kDa, and the 110- 90- and 50-kDa proteins were identified as the major substrates, whose degradation was remarkably increased by the treatments. Interestingly, the loss of several cellular protein bands was associated with the marked accumulation of two proteins apparently of 60 and 70 kDa, which may be cleavage products of one or more proteins. These findings link the decrease of cyclin-dependent kinase activities to the increase of protease activities within the growth arrest and apoptosis pathways induced by TNF.

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Human papillomavirus (HPV) infection is the most common sexually transmitted disease in the world and is related to the etiology of cervical cancer. The most common high-risk HPV types are 16 and 18; however, the second most prevalent type in the Midwestern region of Brazil is HPV-33. New vaccine strategies against HPV have shown that virus-like particles (VLP) of the major capsid protein (L1) induce efficient production of antibodies, which confer protection against the same viral type. The methylotrophic yeast Pichia pastoris is an efficient and inexpensive expression system for the production of high levels of heterologous proteins stably using a wild-type gene in combination with an integrative vector. It was recently demonstrated that P. pastoris can produce the HPV-16 L1 protein by using an episomal vector associated with the optimized L1 gene. However, the use of an episomal vector is not appropriate for protein production on an industrial scale. In the present study, the vectors were integrated into the Pichia genome and the results were positive for L1 gene transcription and protein production, both intracellularly and in the extracellular environment. Despite the great potential for expression by the P. pastoris system, our results suggest a low yield of L1 recombinant protein, which, however, does not make this system unworkable. The achievement of stable clones containing the expression cassettes integrated in the genome may permit optimizations that could enable the establishment of a platform for the production of VLP-based vaccines.

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Antecedentes El desarrollo de la hipertensión pulmonar en el recién nacido es una condición grave que supone un peligro para su vida. Se ha propuesto el uso del sildenafil como tratamiento para esta enfermedad, sin embargo no ha sido evaluada su eficacia a través de una revisión sistemática. Objetivos Determinar el efecto del sildenafil en el manejo de recién nacidos con diagnóstico de hipertensión pulmonar a través de la realización de una revisión sistemática de la literatura. Metodología Se planteó la realización de una revisión sistemática de la literatura. La búsqueda fue realizada a través de las bases de datos: Pubmed, Embase, LiLaCS y Cochrane library. Se incluyeron ensayos clínicos controlados y estudios de cohortes publicados en los idiomas inglés y español. Las variables cualitativas fueron estimadas como riesgos relativos o odds ratios con sus IC95%, las variables cualitativas como diferencias de promedios con sus IC95%. Resultados Se incluyeron 4 estudios en la revisión sistemática. Dos estudios compararon el sildenafil contra el placebo. El uso del sildenafil se relacionó con una menor mortalidad y mejoría en los parámetros ventilatorios. Conclusión: Es aconsejable el uso del sildenafil en el manejo de la hipertensión pulmonar en niños.

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Free range egg producers face continuing problems from injurious pecking (IP) which has financial consequences for farmers and poor welfare implications for birds. Beak trimming has been practised for many years to limit the damage caused by IP, but with the UK Government giving notification that they intend to ban beak trimming in 2016, considerable efforts have been made to devise feasible housing, range and management strategies to reduce IP. A recent research project investigated the efficacy of a range of IP reducing management strategies, the mean costs of which came to around 5 pence per bird. Here, the results of the above project’s consumer survey are presented: consumers’ attitudes to free range egg production are detailed showing that, whilst consumers had a very positive attitude towards free range eggs, they were especially uninformed about some aspects of free range egg production. The contingent valuation technique was used to estimate the price premium consumers would be prepared to pay to ensure that hens do not suffer from IP: this was calculated as just over 3% on top of the prevailing retail price of free range eggs. These findings reinforce other studies that have found that whilst consumers are not generally well-informed about certain specific welfare problems faced by animals under free range conditions, they are prepared to pay to improve animal welfare. Indeed, the study findings suggest that producers could obtain an additional price premium if they demonstrate the welfare provenance of their eggs, perhaps through marketing the eggs as coming from birds with intact beaks. This welfare provenance issue could usefully be assured to consumers by the introduction of a mandatory, single, accredited EU-wide welfare-standards labelling scheme.

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O experimento foi realizado com o objetivo de comparar o desempenho produtivo de duas linhagens comerciais de poedeiras debicadas em diferentes idades na fase de recria. Foram utilizadas 250 aves da linhagem Lohmann (LSL) e 250 aves da linhagem Isa Babcock (IB), debicadas em diferentes idades. A primeira debicagem foi realizada no 8º dia de idade e a segunda na 8ª, 10ª, 12ª ou 14ª semana de idade. Um grupo de 32 aves permaneceu com o bico intacto e outro não foi submetido à segunda debicagem. O delineamento utilizado foi em blocos ao acaso, em esquema fatorial 2x6 (linhagens x idade de debicagem). Não foi verificado efeito significativo da idade de debicagem sobre os parâmetros produtivos analisados, exceto a melhoria significativa na produção de ovos. As aves da linhagem LSL apresentaram melhores resultados para maturidade sexual, peso médio dos ovos, produção de ovos/ave dia, porcentagem de ovos quebrados e conversão alimentar, quando comparadas às aves da linhagem IB. Embora a prática da debicagem tenha melhorado a porcentagem de postura, os resultados evidenciaram que os parâmetros produtivos analisados foram mais influenciados pela linhagem do que pela idade de debicagem.

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Foram utilizadas 288 aves da linhagem Isa Babcock avaliando o efeito da debicagem leve, severa e da não debicagem sobre o desempenho de poedeiras, distribuídas em delineamento inteiramente casualizado em esquema fatorial 3x3 (primeira debicagem x segunda debicagem), com quatro repetições de oito aves cada. A primeira debicagem foi realizada aos nove dias e a segunda debicagem às 12 semanas. Avaliou-se consumo de ração, peso das aves, percentagem de postura e conversão alimentar em quatro períodos de 28 dias cada. de acordo com os resultados, aves com debicagem severa apresentaram menor consumo de ração e menor percentagem de postura(P<0,05).

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To obtain a process stability and a quality weld bead it is necessary an adequate parameters set: base current and time, pulse current and pulse time, because these influence the mode of metal transfer and the weld quality in the MIG-P, sometimes requiring special sources with synergistic modes with external control for this stability. This work aims to analyze and compare the effects of pulse parameters and droplet size in arc stability in MIG-P, four packets of pulse parameters were analysed: Ip = 160 A, tp = 5.7 ms; Ip = 300 A and tp = 2 ms, Ip = 350 A, tp = 1.2 ms and Ip = 350 A, tp = 0.8 ms. Each was analyzed with three different drop diameters: drop with the same diameter of the wire electrode; droplet diameter larger drop smaller than the diameter of the wire electrode. For purposes of comparison the same was determined relation between the average current and welding speed was determined generating a constant (Im / Vs = K) for all parameters. Welding in flat plate by simple deposition for the MIG-P with a distance beak contact number (DBCP) constant was perfomed subsequently making up welding in flat plate by simple deposition with an inclination of 10 degrees to vary the DBCP, where by assessment on how the MIG-P behaved in such a situation was possible, in addition to evaluating the MIG-P with adaptive control, in order to maintain a constant arc stability. Also high speed recording synchronized with acquiring current x voltage (oscillogram) was executed for better interpretation of the transfer mechanism and better evaluation in regard to the study of the stability of the process. It is concluded that parameters 3 and 4 exhibited greater versatility; diameters drop equal to or slightly less than the diameter of the wire exhibited better stability due to their higher frequency of detachment, and the detachment of the drop base does not harm the maintenance the height of the arc