183 resultados para cephalic amplexus
Geographic call variation and further notes on habitat of Ameerega flavopicta (Anura, Dendrobatidae)
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We describe habitat and inter-populational call variation of the dendrobatid frog Ameerega flavopicta. Data were collected in the Brazilian states ofminas Gerais and Goias. Principal component analysis separated the Goias population from others because of its higher call rates and shorter calls. The Paranaiba Rivermay represent themajor geographic barrier. We recognize the cephalic amplexus as themain type for the species. Although habitat disturbances increased since 1990, we did not notice differences in the density of callingmales at Serra do Cipo. Ameerega flavopicta appears to be quite resistant to alterations in its natural habitats caused by human activities.
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The known diversity of dart-poison frog species has grown from 70 in the 1960s to 247 at present, with no sign that the discovery of new species will wane in the foreseeable future. Although this growth in knowledge of the diversity of this group has been accompanied by detailed investigations of many aspects of the biology of dendrobatids, their phylogenetic relationships remain poorly understood. This study was designed to test hypotheses of dendrobatid diversification by combining new and prior genotypic and phenotypic evidence in a total evidence analysis. DNA sequences were sampled for five mitochondrial and six nuclear loci (approximately 6,100 base pairs [bp]; x=3,740 bp per terminal; total dataset composed of approximately 1.55 million bp), and 174 phenotypic characters were scored from adult and larval morphology, alkaloid profiles, and behavior. These data were combined with relevant published DNA sequences. Ingroup sampling targeted several previously unsampled species, including Aromobates nocturnus, which was hypothesized previously to be the sister of all other dendrobatids. Undescribed and problematic species were sampled from multiple localities when possible. The final dataset consisted of 414 terminals: 367 ingroup terminals of 156 species and 47 outgroup terminals of 46 species. Direct optimization parsimony analysis of the equally weighted evidence resulted in 25,872 optimal trees. Forty nodes collapse in the strict consensus, with all conflict restricted to conspecific terminals. Dendrobatids were recovered as monophyletic, and their sister group consisted of Crossodactylus, Hylodes, and Megaelosia, recognized herein as Hylodidae. Among outgroup taxa, Centrolenidae was found to be the sister group of all athesphatanurans except Hylidae, Leptodactyidae was polyphyletic, Thoropa was nested within Cycloramphidae, and Ceratophryinae was paraphyletic with respect to Telmatobiinae. Among dendrobatids, the monophyly and content of Mannophryne and Phyllobates were corroborated. Aromobates nocturnus and Colostethus saltuensis were found to be nested within Nephelobates, and Minyobates was paraphyletic and nested within Dendrobates. Colostethus was shown to be rampantly nonmonophyletic, with most species falling into two unrelated cis- and trans-Andean clades. A morphologically and behaviorally diverse clade of median lingual process-possessing species was discovered. In light of these findings and the growth in knowledge of the diversity of this large clade over the past 40 years, we propose a new, monophyletic taxonomy for dendrobatids, recognizing the inclusive clade as a superfamily (Dendrobatoidea) composed of two families (one of which is new), six subfamilies (three new), and 16 genera (four new). Although poisonous frogs did not form a monophyletic group, the three poisonous lineages are all confined to the revised family Dendrobatidae, in keeping with the traditional application of this name. We also propose changes to achieve a monophyletic higher-level taxonomy for the athesphatanuran outgroup taxa. Analysis of character evolution revealed multiple origins of phytotelm-breeding, parental provisioning of nutritive oocytes for larval consumption (larval oophagy), and endotrophy. Available evidence indicates that transport of tadpoles on the dorsum of parent nurse frogs-a dendrobatid synapomorphy-is carried out primitively by male nurse frogs, with three independent origins of female transport and five independent origins of biparental transport. Reproductive amplexus is optimally explained as having been lost in the most recent common ancestor of Dendrobatoidea, with cephalic amplexus arising independently three times. © American Museum of Natural History 2006.
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v.59:no.2(1971)
The central projection of cephalic mechanosensory axons in the haematophagous bug Triatoma infestans
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The projections of mechanosensory hairs located on the dorsal and lateral head of the adult haematophagous bug Triatoma infestans were analyzed by means of cobalt filling. Axons run into the anterior and posterior tegumentary nerve and project through the brain to the ventral nerve cord. The fibres are small in diameter and run as a fascicle. Some branches run into suboesophageal and prothoracic centres; others run as far as to the mesothoracic ganglion. These sensory projections resemble that of wind-sensitive head hairs of the locust. The functional role of this sensory system in this species is discussed.
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BACKGROUND Non cephalic presentation in childbirth involves various risks to both the mother and the foetus. The incidence in Spain is 3.8% of all full-term pregnancies. The most common technique used to end the gestation in cases of non cephalic presentation is that of caesarian section, and although it provokes a lower rate of morbi-mortality than does vaginal delivery in such situations, there remains the possibility of traumatic injury to the foetal head and neck, while maternal morbidity is also increased. The application of heat (moxibustion) to an acupuncture point, in order to correct non cephalic presentation, has been practised in China since ancient times, but as yet there is insufficient evidence of its real effectiveness. METHODS/DESIGN The experimental design consists of a multi-centre randomised controlled trial with three parallel arms, used to compare real moxibustion, sham moxibustion and the natural course of events, among pregnant women with a non cephalic presentation and a gestational duration of 33-35 weeks (estimated by echography). The participants in the trial will be blinded to both interventions. The results obtained will be analyzed by professionals, blinded with respect to the allocation to the different types of intervention. In addition, we intend to carry out a economic analysis. DISCUSSION This trial will contribute to the development of evidence concerning moxibustion in the correction of non cephalic presentations. The primary outcome variable is the proportion of cephalic presentations at term. As secondary outcomes, we will evaluate the proportion of cephalic presentations at week 38 of gestation, determined by echography, together with the safety of the technique, the specificity of moxibustion and the control of the blinding process. This study has been funded by the Health Ministry of the Andalusian Regional Government. TRIAL REGISTRATION Current Controlled Trials ISRCTN10634508.
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The glandular system is crucially involved in main aspects of ant social life. The function of glands has been primarily studied in the workers (the non-reproductive individuals in a colony). In contrast, little information is available on queens (the reproductive females in a colony) or males in spite of the obvious functional differences between these castes. Here we report a comparison of the general morphology of the mandibular, propharyngeal and postpharyngeal glands between the three castes of the black ant Lasius niger. The analysis clearly shows that all these cephalic glands differ in relative size between castes and suggests a link between gland structure and its behavioral role in queens, workers and males. In particular, males present a hypertrophied mandibular gland. This is consistent with the fact that these glands might be the source of the sex pheromone in this caste. By contrast, queens exhibited the most developed postpharyngeal glands. This is consistent with the production of particular cues by queens for workers to help them to distinguish between reproductive and non-reproductive females. Finally, the propharyngeal glands were most developed in the worker caste and of similar relative size in males and queens. Their function is still enigmatic.
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Phylogeny and revision of the bee genus Rhinocorynura Schrottky (Hymenoptera, Apidae, Augochlorini), with comments on its female cephalic polymorphism. A taxonomic revision and a phylogeny for the species of Rhinocorynura are provided. Six species are recognized: R. briseis, R. crotonis, R. inflaticeps and R. vernoniae stat. nov., the latter removed from synonymy with R. inflaticeps, in addition to two newly described species, R. brunnea sp. nov. and R. viridis sp. nov. Lectotypes for Halictus crotonis Ducke, 1906 and Halictus inflaticeps Ducke, 1906 are hereby designated. Another available name included in Rhinocorynura, Corynuropsis ashmeadi Schrottky, 1909, is removed from the genus and treated as species inquerenda in Augochlorini. Rhinocorynura is monophyletic in the phylogenetic analysis and the following relationships were found among its species: (R. crotonis (R. briseis ((R. brunnea sp. nov. + R. viridis sp. nov.) (R. inflaticeps + R. vernoniae)))). Biogeographic relationships within the genus and comparisons with related taxa are presented. Females of all species exhibit pronounced variation in body size, in two of them, R. inflaticeps and R. vernoniae, with structural modifications possibly linked to division of labor. Identification key and illustrations for the species are provided.
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Miogryllus muranyi n. sp. is described from the Andean Acacia-Cactaceae semi-desert bush in the Chama Valley of Venezuela. The species is characterized by the unusual shape of the male head, which makes it readily distinguishable from any other congener known to date.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Most advanced eusocial bees recruit their nestmates to food resources. Recently, studies in Meliponini species showed that the cephalic salivary (labial) glands (CSGs) are responsible for the production of scent-trail pheromones. Studies on CSGs have shown changes in glandular cell morphology since the worker emerges from brood combs (newly emerged) till forager phase, which may be correlated to changes in the composition of secretion produced. However, no study has been made till now regarding to the composition of CSGs secretion of Scaptotrigona postica and the chemical changes that occur in this secretion according to the worker's life phase or tasks performed. In this study, the chemical profile of CSG secretion in S. postica workers was studied. Glands were taken from specimens newly emerged (NE), working in the brood combs area (CA) and forager (FO) and were analyzed by gas chromatography-mass spectrometry. The results showed that glandular secretion consists of oxygenated compounds of middle volatility (acids, alcohols, aldehydes, ketones, esters and ether), and their quantity varies among the different phases of life, increasing as the individual undergoes from intra- to extra-colonial activities. The NE phase contained the smallest variety and quantity of compounds. Due to the variability of compounds, the CA workers were separated into 3 groups according to the chemical constitution of their secretion. Forager workers showed the largest quantity and variety of chemical compounds. The major compounds in forager gland secretion are 7-hexadecen-1-yl acetate and 5-tetradecen-1-yl acetate. Statistical analysis indicates that the chemical composition of glandular secretion is task-related.
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Treatment of dialysis access-related hand ischaemia with preservation of the access remains an issue. We report the case of a patient presenting critical hand ischaemia 2 years after proximalisation of a distal radio-cephalic fistula with preservation of the original access. After valvulotomy, the distal cephalic vein was used as in situ bypass and directly anastomosed to the distal brachial artery, providing a direct flow to the hand. This procedure relieved the hand ischaemia without sacrificing the functioning fistula. Six months later, the fistula and bypass were still patent, showing that flow reversal of a previous fistula can be an efficient strategy to correct dialysis access-related hand ischaemia in selected cases.