37 research outputs found
Patterns of genetic diversity in southern and southeastern Araucaria angustifolia (Bert.) O. Kuntze relict populations
Habitat fragmentation and a decrease in population size may lead to a loss in population genetic diversity. For the first time, the reduction in genetic diversity in the northernmost limit of natural occurence (southeastern Brazil) of Araucaria angustifolia in comparison with populations in the main area of the species continuous natural distribution (southern Brazil), was tested. The 673 AFLPs markers revealed a high level of genetic diversity for the species (Ht = 0.27), despite anthropogenic influence throughout the last century, and a decrease of H in isolated populations of southeastern Brazil (H = 0.16), thereby indicating the tendency for higher genetic diversity in remnant populations of continuous forests in southern Brazil, when compared to natural isolated populations in the southeastern region. A strong differentiation among southern and southeastern populations was detected (AMOVA variance ranged from 10%-15%). From Bayesian analysis, it is suggested that the nine populations tested form five “genetic clusters” (K = 5). Five of these populations, located in the northernmost limit of distribution of the species, represent three “genetic clusters”. These results are in agreement with the pattern of geographic distribution of the studied populations
The Oldest Case of Decapitation in the New World (Lapa do Santo, East-Central Brazil)
We present here evidence for an early Holocene case of decapitation in the New World (Burial 26), found in the rock shelter of Lapa do Santo in 2007. Lapa do Santo is an archaeological site located in the Lagoa Santa karst in east-central Brazil with evidence of human occupation dating as far back as 11.7-12.7 cal kyBP (95.4% interval). An ultra-filtered AMS age determination on a fragment of the sphenoid provided an age range of 9.1-9.4 cal kyBP (95.4% interval) for Burial 26. The interment was composed of an articulated cranium, mandible and first six cervical vertebrae. Cut marks with a v-shaped profile were observed in the mandible and sixth cervical vertebra. The right hand was amputated and laid over the left side of the face with distal phalanges pointing to the chin and the left hand was amputated and laid over the right side of the face with distal phalanges pointing to the forehead. Strontium analysis comparing Burial 26's isotopic signature to other specimens from Lapa do Santo suggests this was a local member of the group. Therefore, we suggest a ritualized decapitation instead of trophy-taking, testifying for the sophistication of mortuary rituals among hunter-gatherers in the Americas during the early Archaic period. In the apparent absence of wealth goods or elaborated architecture, Lapa do Santo's inhabitants seemed to use the human body to express their cosmological principles regarding death
Clinical recommendations for postoperative care after heart transplantation in children: 21 years of a single-center experience
Heart transplantation is an option for children with complex congenital heart disease and cardiomyopathies. A patient's quality of life and long-term survival depend on successful management of the surgical complications and adverse side effects of immunosuppression. The purpose of this review was to summarize the practical management of postoperative care in this patient population and to make recommendations for the future
High levels of B-type natriuretic peptide predict weaning failure from mechanical ventilation in adult patients after cardiac surgery
OBJECTIVE: The failure to wean from mechanical ventilation is related to worse outcomes after cardiac surgery. The aim of this study was to evaluate whether the serum level of B-type natriuretic peptide is a predictor of weaning failure from mechanical ventilation after cardiac surgery. METHODS: We conducted a prospective, observational cohort study of 101 patients who underwent on-pump coronary artery bypass grafting. B-type natriuretic peptide was measured postoperatively after intensive care unit admission and at the end of a 60-min spontaneous breathing test. The demographic data, hemodynamic and respiratory parameters, fluid balance, need for vasopressor or inotropic support, and length of the intensive care unit and hospital stays were recorded. Weaning failure was considered as either the inability to sustain spontaneous breathing after 60 min or the need for reintubation within 48 h. RESULTS: Of the 101 patients studied, 12 patients failed the weaning trial. There were no differences between the groups in the baseline or intraoperative characteristics, including left ventricular function, EuroSCORE and lengths of the cardiac procedure and cardiopulmonary bypass. The B-type natriuretic peptide levels were significantly higher at intensive care unit admission and at the end of the breathing test in the patients with weaning failure compared with the patients who were successfully weaned. In a multivariate model, a high B-type natriuretic peptide level at the end of a spontaneous breathing trial was the only independent predictor of weaning failure from mechanical ventilation. CONCLUSIONS: A high B-type natriuretic peptide level is a predictive factor for the failure to wean from mechanical ventilation after cardiac surgery. These findings suggest that optimizing ventricular function should be a goal during the perioperative period
The genetics and conservation of Araucaria angustifolia: I. Genetic structure and diversity of natural populations by means of non-adaptive variation in the state of Santa Catarina, Brazil
The objective of this study was to generate information relative to the allele distribution and dynamics within and among populations of Araucaria angustifolia, a naturally-occurring conifer in the south of Brazil, being known popularly as "pinheiro-do-Paraná", "araucaria" or pine tree. In order to elucidate the levels and the distribution of the genetic variability, the population's genetic structure and the genetic distance among natural populations of this species with different levels of disturbance in different geographical areas were studied in detail. For this, samples of leaf tissue were collected from 328 adult individuals in nine natural populations in Santa Catarina State. To analyze the samples, the allozyme technique was applied in starch gel electrophoresis (penetrose 13%), with citrate/morfholine buffer. Nine enzymatic systems (PGM, PGI MDH, PRX, SKDH, 6PGDH, ACP, IDH and G6PDH) revealed 15 loci. The analysis provided values for He and Ho of 0.084 and 0.072, respectively. The general average of polymorphic loci was 73% in the species and 26.6% in the studied populations and the allele number per locus was 1.6. Wright's F-statistical estimates indicated the existence of inbreeding in populations (F IS= 0.148) and a low divergence among populations (F ST = 0.044). However, the inbreeding values were variable in different populations. Taken together, the results indicated that the greater part of the genetic variability is contained within populations. The working hypothesis that originally there was greater genetic diversity can be supported by these results which indicate that in the degraded populations the diversity indexes are lower in the degraded populations than those found in better-conserved populations. Thus the fragmentation of the forest followed by "araucaria" exploitation could have contributed to the genetic differentiation expressed through the allele frequency of the studied population