22 research outputs found
Ontogenetic color changes may strengthen suggestion about systematic affinities between two species of Chironius (Serpentes, Colubridae)
Sexual dimorphism, reproductive cycle, and fecundity of the water snake Ptychophis flavovirgatus (Serpentes, Colubridae)
Reproductive biology and food habits of Pseudoboa nigra (Serpentes: Dipsadidae) from the Brazilian cerrado
Neste trabalho fornecemos informações sobre tamanho corporal, dimorfismo sexual, ciclo reprodutivo e hábitos alimentares da serpente Pseudoboini Pseudoboa nigra, que ocorre no domínio do Cerrado na região central da América do Sul. Com base na dissecção de 147 espécimes preservados, mostramos que as fêmeas são em média maiores e atingem maturidade sexual com maior tamanho corporal que os machos. O dimorfismo sexual não foi significativo para o tamanho da cabeça, mas os machos possuem caudas relativamente mais longas que as fêmeas. A vitelogênese, a postura de ovos e a espermatogênese ocorrem durante todo o ano, e os machos não armazenam esperma no ducto deferente por longos períodos. A principal presa dessa espécie são lagartos; não há evidências de variação ontogenética ou de diferenças relacionadas ao sexo na dieta dessa espécie.Herein we provide data on body size, sexual size dimorphism, reproductive cycle, and food habits of the pseudoboini snake Pseudoboa nigra, which is distributed mainly in central South America throughout the Cerrado domain. Based on dissections of 147 preserved specimens, it is shown that females attain, and mature at, larger body sizes than males. There is no significant sexual dimorphism in head length, but males have longer tails relative to their body sizes. Vitellogenesis, egg-laying, and sperm production occur throughout the year, but males do not exhibit long-term sperm storage. The main prey of P. nigra is lizards; there is no evidence of ontogenetic change or sex differences in the diet of this species
Study protocol for the multicentre cohorts of Zika virus infection in pregnant women, infants, and acute clinical cases in Latin America and the Caribbean: The ZIKAlliance consortium
Background: The European Commission (EC) Horizon 2020 (H2020)-funded ZIKAlliance Consortium designed a multicentre study including pregnant women (PW), children (CH) and natural history (NH) cohorts. Clinical sites were selected over a wide geographic range within Latin America and the Caribbean, taking into account the dynamic course of the ZIKV epidemic. Methods: Recruitment to the PW cohort will take place in antenatal care clinics. PW will be enrolled regardless of symptoms and followed over the course of pregnancy, approximately every 4 weeks. PW will be revisited at delivery (or after miscarriage/abortion) to assess birth outcomes, including microcephaly and other congenital abnormalities according to the evolving definition of congenital Zika syndrome (CZS). After birth, children will be followed for 2 years in the CH cohort. Follow-up visits are scheduled at ages 1-3, 4-6, 12, and 24 months to assess neurocognitive and developmental milestones. In addition, a NH cohort for the characterization of symptomatic rash/fever illness was designed, including follow-up to capture persisting health problems. Blood, urine, and other biological materials will be collected, and tested for ZIKV and other relevant arboviral diseases (dengue, chikungunya, yellow fever) using RT-PCR or serological methods. A virtual, decentralized biobank will be created. Reciprocal clinical monitoring has been established between partner sites. Substudies of ZIKV seroprevalence, transmissio
Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial
Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt
Does gestation or feeding affect the body temperature of the golden lancehead, Bothrops insularis (Squamata: Viperidae) under field conditions?
Temperature affects physiological performance in reptiles and, therefore, body temperature (Tb) control is argued to have an important adaptive value. Alterations in Tb due to transient changes in physiological state, as during digestion or gestation, are often linked to the potential benefits of a more precise Tb regulation. However, such thermoregulatory responses in nature remain controversial, particularly for tropical snakes. Herein, we measured Tb of the golden lanceheads, Bothrops insularis (Amaral, 1921), at Queimada Grande Island, southeastern Brazil, to test for alteration in selected body temperatures associated with feeding or gestation. We found no evidence that postprandial or gravid snakes selected for higher Tb indicating that, under natural conditions, body temperature regulation in B. insularis apparently encompasses other ecological factors beyond physiological state per se
Diversity, natural history, and geographic distribution of snakes in the Caatinga, Northeastern Brazil
Guedes, Thaís B., Nogueira, Cristiano, Marques, Otavio A. V. (2014): Diversity, natural history, and geographic distribution of snakes in the Caatinga, Northeastern Brazil. Zootaxa 3863 (1): 1-93, DOI: 10.11646/zootaxa.3863.1.
When Basking Is Not an Option: Thermoregulation of a Viperid Snake Endemic to a Small Island in the South Atlantic of Brazil
It is broadly accepted that snakes are able to regulate their body temperature (T-b) behaviorally, but fundamental differences in this ability have been suggested to exist between temperate and tropical species. Herein, we examined the thermal ecology of the Golden Lancehead, Bothrops Insular's, a critically endangered Neotropical crotaline snake endemic to Queimada Grande Island (QGI), southeastern Brazil. We sampled T-b's of individual snakes found in the field and tested which proximal factors, biotic and abiotic, were potentially relevant for their thermoregulatory behavior and T-b selection. We verified whether T-b regulation would be compensated, through the day and/or seasons, by adjustments in the thermoregulatory effort. Finally, we hypothesized that for a Neotropical snake, the thermoregulatory effort would be lower because the thermal quality of habitat is higher compared to species inhabiting temperate zones. In general, B. insularis conformed to this hypothesis. However, seasonal declines in the thermal quality of habitat during the colder seasons and during nighttime were compensated by increases in the effectiveness of thermoregulation. Overall, T-b of B. insularis is determined largely by environmental variables, particularly air temperature, with some influence of biotic factors, such as body size. Use of open areas for basking, a common thermoregulatory behavior for squamates, was largely avoided; this may be explained by ecological factors, and may be due to foraging constraints and increased risks of predation and dehydration.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq