989 resultados para GENETIC EVALUATION
Resumo:
The knowledge of thermochemical parameters such as the enthalpy of formation, gas-phase basicity, and proton affinity may be the key to understanding molecular reactivity. The obtention of these thermochemical parameters by theoretical chemical models may be advantageous when experimental measurements are difficult to accomplish. The development of ab initio composite models represents a major advance in the obtention of these thermochemical parameters,. but these methods do not always lead to accurate values. Aiming at achieving a comparison between the ab initio models and the hybrid models based on the density functional theory (DFT), we have studied gamma-butyrolactone and 2-pyrrolidinone with a goal of obtaining high-quality thermochemical parameters using the composite chemical models G2, G2MP2, MP2, G3, CBS-Q, CBS-4, and CBS-QB3; the DFT methods B3LYP, B3P86, PW91PW91, mPW1PW, and B98; and the basis sets 6-31G(d), 6-31+G(d), 6-31G(d,p), 6-31+G(d,p), 6-31++G(d,p), 6-311G(d), 6-311+G(d), 6-311G(d,p), 6-311+G(d,p), 6-311++G(d,p), aug-cc-pVDZ, and aug-cc-pVTZ. Values obtained for the enthalpies of formation, proton affinity, and gas-phase basicity of the two target molecules were compared to the experimental data reported in the literature. The best results were achieved with the use of DFT models, and the B3LYP method led to the most accurate data.
Resumo:
To study the genetic structure of the Tikuna tribe, four major Native American mitochondrial DNA (mtDNA) founder haplogroups were analyzed in 187 Amerindians from eight Tikuna villages located in the Brazilian Amazon. The central position of these villages in the continent makes them relevant for attempts to reconstruct population movements in South America. In this geographic region, there is particular concern regarding the genetic structure of the Tikuna tribe, formerly designated ""enigmatic"" due to its remarkable degree of intratribal homogeneity and the scarcity of private protein variants. In spite of its large population size and geographic distribution, the Tikuna tribe presents marked genetic and linguistic isolation. All individuals presented indigenous mtDNA haplogroups. An intratribal genetic heterogeneity pattern characterized by two highly homogeneous Tikuna groups that differ considerably from each other was observed. Such a finding was unexpected, since the Tikuna tribe is characterized by a social system that favors intratribal exogamy and patrilocality that would lead to a higher female migration rate and homogenization of the mtDNA gene pool. Demographic explosions and religious events, which significantly changed the sizes and compositions of many Tikuna villages, may be reflected in the genetic results presented here. Am J Phys Anthropol 140:526-531,2009. (C) 2009 Wiley-Liss, Inc
Resumo:
This study investigated the organic and inorganic constituents of healthy leaves and Candidatus Liberibacter asiaticus (CLas)-inoculated leaves of citrus plants. The bacteria CLas are one of the causal agents of citrus greening (or Huanglongbing) and its effect on citrus leaves was investigated using laser-induced breakdown spectroscopy (LIBS) combined with chemometrics. The information obtained from the LIBS spectra profiles with chemometrics analysis was promising for the construction of predictive models to identify healthy and infected plants. The major, macro- and microconstituents were relevant for differentiation of the sample conditions. The models were then applied to different inoculation times (from 1 to 8 months). The models were effective in the classification of 82-97% of the diseased samples with a 95% significance level. The novelty of this method was in the fingerprinting of healthy and diseased plants based on their organic and inorganic contents. (C) 2010 Elsevier B.V. All rights reserved.
Resumo:
Ficus arpazusa Casaretto is a fig tree native to the Atlantic Rain Forest sensu lato. High levels of genetic diversity and no inbreeding were observed in Ficus arpazusa. This genetic pattern is due to the action of its pollinator, Pegoscapus sp., which disperses pollen an estimated distance of 5.6 km, and of Ficus arpazusa`s mating system which, in the study area, is allogamous. This study highlights the importance of adding both ecological and genetic data into population studies, allowing a better understanding of evolutionary processes and in turn increasing the efficacy of forest management and revegetation projects, as well as species conservation.
Resumo:
Evaluation of the aquatic macroinvertebrate community as a tool for monitoring a reservoir in the Pitangui river basin, Parana, Brazil. Benthic and nektonic macroinvertebrates play an important role in the structure and function of aquatic ecosystems and their distribution is influenced by chemical features of the substrate, vegetation composition, and water depth. Knowledge on the fauna contributes to the assessment of water quality and development of biodiversity conservation activities. Different biotic factors affecting the invertebrate community were evaluated in the Alagados reservoir, the main water source of the city of Ponta Grossa, Parana. In five different sampling points, 18,473 specimens of aquatic or semiaquatic macroinvertebrates were collected, belonging to 46 taxa of the phylla Annelida (Hirudinea and Oligochaeta), Mollusca (Gastropoda), Platyhelminthes (Turbellaria), Nematoda and Arthropoda (Arachnida, Crustacea and Insecta). This community was composed mainly of predators (45.7% of the taxa sampled), collectors and/or filterers (23.9%), scrapers (15.2%), shredders (13.0%) and detritivores (2.2%). Diversity (H`) and evenness (J) indices were significantly low for the sites examined, and H` ranged between 0.3301 and 1.0396. Regarding tolerance of organisms to organic pollution, more sensitive taxa were very rare (Plecoptera) or unusual (Trichoptera and Ephemeroptera). Among the more resistant groups are Chironomidae and Hirudinea, both fairly common in the samples. This study corroborates the importance of bioindicators as a tool to assess water quality for human consumption and for the conservation of aquatic environments, integrating physical, chemical and biological factors in monitoring programs.
Resumo:
This article reviews the literature to provide the current state of the genetic critic in Brazil. It lists the currently available books and periodicals, annals of congresses or symposia published by members of the Association of Researchers in Genetic Critic (APCG), showing the tendencies that guide the research in the endless universe of human creation. It also highlights the object of study of the genetic critic, which is not necessarily the one that precedes the word but the processes of creation. Finally, it shows the essential role of genetic critic even in the computer era, since the hard disk maintains all the changes made in the text by obliterations and substitutions if the adequate software is installed.
Resumo:
There is a widely held paradigm that mangroves are critical for sustaining production in coastal fisheries through their role as important nursery areas for fisheries species. This paradigm frequently forms the basis for important management decisions on habitat conservation and restoration of mangroves and other coastal wetlands. This paper reviews the current status of the paradigm and synthesises the information on the processes underlying these potential links. In the past, the paradigm has been supported by studies identifying correlations between the areal and linear extent of mangroves and fisheries catch. This paper goes beyond the correlative approach to develop a new framework on which future evaluations can be based. First, the review identifies what type of marine animals are using mangroves and at what life stages. These species can be categorised as estuarine residents, marine-estuarine species and marine stragglers. The marine-estuarine category includes many commercial species that use mangrove habitats as nurseries. The second stage is to determine why these species are using mangroves as nurseries. The three main proposals are that mangroves provide a refuge from predators, high levels of nutrients and shelter from physical disturbances. The recognition of the important attributes of mangrove nurseries then allows an evaluation of how changes in mangroves will affect the associated fauna. Surprisingly few studies have addressed this question. Consequently, it is difficult to predict how changes in any of these mangrove attributes would affect the faunal communities within them and, ultimately, influence the fisheries associated with them. From the information available, it seems likely that reductions in mangrove habitat complexity would reduce the biodiversity and abundance of the associated fauna, and these changes have the potential to cause cascading effects at higher trophic levels with possible consequences for fisheries. Finally, there is a discussion of the data that are currently available on mangrove distribution and fisheries catch, the limitations of these data and how best to use the data to understand mangrove-fisheries links and, ultimately, to optimise habitat and fisheries management. Examples are drawn from two relatively data-rich regions, Moreton Bay (Australia) and Western Peninsular Malaysia, to illustrate the data needs and research requirements for investigating the mangrove-fisheries paradigm. Having reliable and accurate data at appropriate spatial and temporal scales is crucial for mangrove-fisheries investigations. Recommendations are made for improvements to data collection methods that would meet these important criteria. This review provides a framework on which to base future investigations of mangrove-fisheries links, based on an understanding of the underlying processes and the need for rigorous data collection. Without this information, the understanding of the relationship between mangroves and fisheries will remain limited. Future investigations of mangrove-fisheries links must take this into account in order to have a good ecological basis and to provide better information and understanding to both fisheries and conservation managers.
Resumo:
The aim of this study was to verify the efficacy of a programme for dental plaque control in autistics. Patients were evaluated on five occasions over a period of 180 days using the following instruments: OHI-S, DMF-T, the Fonnes brushing technique and diet questionnaire. Participants were divided into two groups according to level of co-operation on the programme: Group A (co-operative) and Group B (non-cooperative). A statistically significant improvement (p < 0.001) in Oral Hygiene was attained, with 84.2% showing regular or satisfactory hygiene at study end-point. Conclusion: Groups A and B both showed improvement in hygiene (p < 0.001 and p = 0.004), but improvement was significantly higher among co-operative patients (p < 0.001 at 180 days), who also had a higher mean age (p = 0.02).
Resumo:
Background: Condition-dependence is a ubiquitous feature of animal life histories and has important implications for both natural and sexual selection. Mate choice, for instance, is typically based on condition-dependent signals. Theory predicts that one reason why condition-dependent signals may be special is that they allow females to scan for genes that confer high parasite resistance. Such explanations require a genetic link between immunocompetence and body condition, but existing evidence is limited to phenotypic associations. It remains unknown, therefore, whether females selecting males with good body condition simply obtain a healthy mate, or if they acquire genes for their offspring that confer high immunocompetence. Results: Here we use a cross-foster experimental design to partition the phenotypic covariance in indices of body condition and immunocompetence into genetic, maternal and environmental effects in a passerine bird, the zebra finch Taeniopygia guttata. We show that there is significant positive additive genetic covariance between an index of body condition and an index of cell-mediated immune response. In this case, genetic variance in the index of immune response explained 56% of the additive genetic variance in the index of body condition. Conclusion: Our results suggest that, in the context of sexual selection, females that assess males on the basis of condition-dependent signals may gain genes that confer high immunocompetence for their offspring. More generally, a genetic correlation between indices of body condition and imuunocompetence supports the hypothesis that parasite resistance may be an important target of natural selection. Additional work is now required to test whether genetic covariance exists among other aspects of both condition and immunocompetence.
Resumo:
The inflammasome is an inducible cytoplasmic structure that is responsible for production and release of biologically active interleukin-1 (IL-1). A polymorphism in the inflammasome component NALP3 has been associated with decreased IL-1 levels and increased occurrence of vaginal Candida infection. We hypothesized that this polymorphism-induced variation would influence susceptibility to infertility. DNA was obtained from 243 women who were undergoing in vitro fertilization (IVF) and tested for a length polymorphism in intron 2 of the gene coding for NALP3 (gene symbol CIAS1). At the conclusion of testing the findings were analyzed in relation to clinical parameters and IVF outcome. The frequency of the 12 unit repeat allele, associated with maximal inflammasome activity, was 62.3% in cases of female infertility vs. 75.6% in cases where only the male partner had a detectable fertility problem (p = 0.0095). Conversely, the frequency of the 7 unit repeat allele was 28.9% in those with a female fertility problem, 17.0% in women with infertile males and 18.4% in idiopathic infertility (p = 0.0124). Among the women who were cervical culture-positive for mycoplasma the frequency of the 7 unit repeat was 53.7% as opposed to 19.5% in those negative for this infection (p < 0.0001). We conclude that the CIAS1 7 unit repeat polymorphism increases the likelihood of mycoplasma infection-associated female infertility. (C) 2009 Elsevier Ireland Ltd. All rights reserved.
Resumo:
Background: Obesity is a serious chronic disease and the prevalence of this condition is increasing among the elderly. Although the benefits of weight loss to improve control of associated diseases are well known in young adults, they are not in older patients. The use of anti-obesity drugs to promote weight loss is widespread in Brazil and other countries, and obesity specialists frequently prescribe medicines in doses and for durations previously unreported in the literature. Sibutramine, orlistat and amfepramone (diethylpropion) have been evaluated in clinical trials of more than 2 years` duration in adults, demonstrating safety and efficacy, but long-term studies in obesity treatment are absent for other drugs. The efficacy and safety of obesity pharmacotherapy among the elderly is unknown. Objective: To describe the experience of obesity pharmacotherapy in the elderly in a specialized obesity care setting in Brazil, with a focus on efficacy and safety. Methods: A retrospective evaluation was conducted on medical charts from an outpatient clinic of a specialized tertiary centre for the treatment of obesity. We included patients who had had at least one consultation between January and December 2007, were aged >= 60 years at the beginning of the treatment, had had at least 6 months of follow-up and had received a prescription of at least one potential weight-loss drug. Diagnoses reported on medical records were documented. Age, weight, height and body mass index (BMI) were recorded at admission, after 6, 12, 18 and 24 months, and at the last available visit. The medicines prescribed, together with the dose, duration of use, adverse effects and reasons for discontinuation, were documented. Results: The group consisted of 44 women (86%) and 7 men (14%), with a mean +/- SD age of 65.2 +/- 4.5 years, weight of 95.3 +/- 12.5 kg and BMI of 38.5 +/- 4.3 kg/m(2). The mean +/- SD time of follow-up was 39.3 +/- 26.4 months, and the mean weight loss was 6.65 kg (p < 0.01). After the first 6 months, the mean +/- SD weight loss was 5.7 +/- 3.8 kg (p < 0.0001). A smaller weight loss was seen between the 6th and 12th months, with no statistically significant change in weight thereafter. A weight loss of >= 5% was achieved by 64.71%, 63.64%, 62.16% and 69.70% in the 6th, 12th, 18th and 24th months, respectively, and a weight loss of >= 10% was achieved by 17.65%, 34.09%, 32.43% and 39.39% in the 6th, 12th, 18th and 24th months, respectively. The medicines prescribed were sibutramine, orlistat, fluoxetine, sertraline, topiramate, fenproporex, mazindol and amfepramone, alone or in combinations, concomitantly or sequentially. The reasons for discontinuation were lack of response (n = 13), loss of response (development of tolerance) [n= 11], lack of adherence (n = 14) and adverse effects (n= 14). One episode of atrial flutter occurred in a patient taking fenproporex. The weight-loss medications were generally well tolerated, and only transient adverse events were reported. Conclusions: Long-term pharmacotherapy for obesity was effective and well tolerated by this group of elderly patients.
Resumo:
Objectives: We tested two novel drug-eluting stents (DES), covered with a biodegradable-polymer carrier and releasing paclitaxel or sirolimus, which were compared against a bare metal stent (primary objective). The DES differed by the drug, but were identical otherwise, allowing to compare the anti-restenosis effects of sirolimus versus paclitaxel (secondary objective). Background: The efficacy of novel DES with biodegradable polymers should be tested in the context of randomized trials, even when using drugs known to be effective, such as sirolimus and paclitaxel. Methods: Overall, 274 patients with de novo coronary lesions in native vessels scheduled for stent implantation were randomly assigned (2:21 ratio) for the paclitaxel (n = 111), sirolimus (n = 106), or bare metal stent (n = 57) groups. Angiographic follow-up was obtained at 9 months and major cardiac adverse events up to 12 months. Results: Both paclitaxel and sirolimus stents reduced the 9-month in-stent late loss (0.54-0.44 mm, 0.32-0.43 mm, vs. 0.90-0.45 mm respectively), and 1-year risk of target vessel revascularization and combined major adverse cardiac events (P < 0.05 for both, in all comparisons), compared with controls. Sirolimus stents had lower late loss than paclitaxel stents (P < 0.01), but similar 1-year clinical outcomes. There were no differences in the risk of death, infarction, or stent thrombosis among the study groups. Conclusion: Both novel DES were effective in reducing neointimal hyperplasia and 1-year re-intervention, compared to bare metal stents. Our findings also suggest that sirolimus is more effective than paclitaxel in reducing angiographic neointima, although this effect was not associated with better clinical outcomes. (C) 2009 Wiley-Liss, Inc.