923 resultados para CNPQ::CIENCIAS BIOLOGICAS::MICROBIOLOGIA::BIOLOGIA E FISIOLOGIA DOS MICROORGANISMOS


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This study to aimed investigate the community of ectoparasites associated with birds in the Mata do Olho D água, in the municipality of Macaíba, Rio Grande do Norte (RN), Brazil, its structure and the ambiental and hosts influential variables on it, and to verify microhabitats preferences by species of chewing lice and feather mites. We examined 172 individuals belonging to 38 species of Passeriformes and non-Passeriformes. 12 new geographic records are reported and 11 host-parasite associations not yet known for chewing lice and feather mites species. Significant relationship was found between the abundance of chewing lice and the variables total length (r = 0.29, p <0.05) and exposed culmen (r = 0.38, p <0.05) of the hosts. A principal component (PC1) accounted for 90.1% of the hosts morphological variation was significantly influential on the abundance of chewing lice (p <0.05), indicating that the morphological characteristics of the hosts may be positively influencing the abundance of these ectoparasites. Significantly higher frequency of individuals with high loads of chewing lice was detected during the dry period (x ² = 8.5, p <0.05), corroborating studies that propose that birds of arid environments suffer as much pressure as those of parasitic humid environments. Analyses of null models of co-occurrence and niche overlap showed a high degree of structure in the feather mites and chewing lice assemblies, when compared with other groups, and preferences in the use of microhabitats by taxa identified. These results corroborate ecological theories in host-parasite systems, contribute to the knowledge of ectoparasites associated with neotropical birds, and the need for experimental studies, as well as further deepening the biology of these arthropods

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Many prey organisms change their phenotype to reduce the predation risk. However, such changes are associated with trade-offs, and can have negative effects on prey growth or reproduction. Understand how preys assess the predation risk is essential to evaluate the adaptive value of predator-induced phenotypic and its ecological consequences. In this study, we performed a mesocosm experiment to test: i) if growth and stoichiometry of Lithobates catesbeianus tadpoles is altered in response to giant water bug presence (Belostoma spp.); ii) if these responses depend on tadpoles density in environment. Here, we show that tadpoles growth and stoichiometry are not changed by predator presence, neither in low nor in high densities. Our results suggest that tadpoles exposed to predation risk regulate their physiology to preserve the elemental stoichiometric homeostase of their body and excretion. Further, point out to need for future studies that elucidate under what conditions growth and stoichiometry are changed in response to predation risk

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

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Flowering is a process marked by switch of shoot apical meristem to floral meristem, and it involves a complex regulation by endogenous and environmental factors. Analyses of key flowering genes have been carried out primarily in Arabidopsis thaliana and have provided a foundation for understanding the underlying molecular genetic mechanisms controlling different aspects of floral development. Several homologous have been found in other species, but for crops species such as tomatoes this process is not well known. The aim of this work was to use the genetic natural variation associated to the flowering process and use molecular tools such as subtractive libraries and real time PCR in order to identify and analyze the expression from genes that may be associated to flowering in these two species: L. esculentum cv Micro-Tom and L. pimpinellifolium. Our results showed there were identified many genes related to vegetative and possibly to the flowering process. There were also identified many sequences that were unknown. We ve chosen three genes to analyze the expression by real time PCR. The histone H2A gene gave an expression higher in L. pimpinellifolium, due to this the expression of this gene may be associated to flowering in this specie. It was also analyzed the expression of an unknown gene that might be a key factor of the transition to flowering, also in L. pimpinellifolium. For the elongation factor 1-α expression, the expression results were not informative, so this gene may have a constitutive expression in vegetative and flowering state. The results observed allowed us to identify possible genes that may be related to the flowering process. For further results it will be necessary a better characterization of them.

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The fauna of Brazilian reef fishes comprises approximately 320 species distributed along the coast of the mainland and islands ocean. Little is known about the levels of connectivity between their populations, but has been given the interest in the relations between the offshore and the islands of the Brazil, in a biogeographical perspective. The oceanic islands Brazilian hosting a considerable number of endemic species, which are locally abundant, and divide a substantial portion of its reef fish fauna with the Western Atlantic. Among the richest families of reef fish in species are Pomacentridae. This study analyzed through analysis of sequences of the mitochondrial DNA control region (D-loop), the standards-breeding population of C. Multilineata in different areas of the NE coast of Brazil, involving both oceanic islands (Fernando de Noronha Archipelago and of St. Peter and St. Paul) and continental shelf (RN and BA). To this aim, partial sequences were used in the region HVR1 of mtDNA (312pb). The population structure and parameters for the estimates of genetic variability, molecular variance (AMOVA), estimation of the index for fixing (FST) and number of migrants were determined. The phylogenetic relationships between the populations were estimated using neighbor-joining (NJ) method. A group of Bayesian analysis was used to verify population structure, according to haplotype frequency of each individual. The genetic variability of populations was extremely high. The populations sampled show moderate genetic structure, with a higher degree of genetic divergence being observed for the sample of the Archipelago of St. Peter and St. Paul. At smaller geographical scale, the sample of Rio Grande do Norte and the Archipelago of Fernando de Noronha do not have genetic differentiation. Three moderately differentiated population groups were identified: a population group (I), formed by the Rio Grande do Norte (I') and the archipelago of Fernando de Noronha (I''), and two other different groups formed by the island population of the archipelago of Saint Peter and St. Paul (II) and Bahia (III). The genetic patterns found suggest that the species has suffered a relatively recent radiation favoring the absence of shared haplotypes. C. multilineata seems to constitute a relatively homogenous population along the West Atlantic coast, with evidence of a moderate population genetic structure in relation to the Archipelago of St. Peter and St. Paul. These data supports the importance of the dispersal larvae by marine current and the interpopulation similarity this species.

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The contamination of the waters resources for wastewater from industrial, agricultural, and domestic sources is a serious environment problem, compromising its use for human consumption and agriculture. The Extremoz-RN Lake is an important freshwater source for the supply of the city of Natal, supplying a population of approximately 160,000 habitants. This aquatic body is located near an industrial pole which can be a serious risk factor for quality of its waters. The objectives of this study were examined the genotoxicity of Extremoz Lake between September of 2006 and January of 2008, by a combination of the Allium micronucleus test, piscine micronucleus test and the comet assay in erythrocytes from peripheral blood of Oreochromis niloticus. Additionally, the level of eight different heavy metals was quantified through spectrometry of atomic absorption of flame. The Allium test did not detect increase in the frequencies of micronucleus in none of the analyzed periods, however a strong cytotoxic activity was demonstrated for decrease in mitotic index in the analyses carried in April and July of 2007. Negative results had been detected in the frequencies of micronucleus in O. niloticus. A statistic significant increase was observed in the levels of DNA damage in comet assay carried in July of 2007. The results of the chemical analysis had detected increase in the levels of cadmium, chromium, copper, nickel, lead and zinc in different periods. These results demonstrated an alteration of the water s quality of the Extremoz Lake caused for the contamination for heavy metals and increase of DNA strand breaks. The use of biomonitoring program of the heavy metal and other pollutants with genotoxic potential combinated with genotoxicity assays is recommends.

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Despite advances in vaccine development and therapy, bacterial meningitis (BM) remains a major cause of death and long-term neurological disabilities. As part of the host inflammatory response to the invading pathogen, factors such as reactive oxygen species are generated, which may damage DNA and trigger the overactivation of DNA repair mechanisms. It is conceivable that the individual susceptibility and outcome of BM may be in part determined by non synonymous polymorphisms that may alter the function of crucial BER DNA repair enzymes as PARP-1, OGG-1 and APE-1. These enzymes, in addition to their important DNA repair function, also perform role of inflammatory regulators. In this work was investigated the non synonymous SNPs APE-1 Asn148Glu, OGG-1 Ser326Cys,PARP-1 Val762Ala, PARP-1 Pro882Leu and PARP-1 Cys908Tyr in patients with bacterial meningitis (BM), chronic meningitis (CM), aseptic meningitis (AM) and not infected (controls). As results we found increased frequency of variant alleles of PARP-1 Val762Ala (P = 0.005) and APE-1 Asn148Glu (P=0.018) in BM patients, APE-1 Asn148Glu in AM patients (P = 0.012) and decrease in the frequency of the variant allele OGG-1 Ser326Cys in patients with CM (P = 0.013), regarding the allelic frequencies in the controls. A major incidence of individuals heterozygous and/ or polymorphic homozygous in BM for PARP-1 Val762Ala (P= 0.0399, OD 4.2, 95% IC 1.213 -14.545) and PARP-1 Val762Ala/ APE-1 Asn148Glu (P = 0.0238, OD 11.111, 95% IC 1.274 - 96.914) was observed related to what was expected in a not infected population. It was also observed a major incidence of combined SNPs in the BM patients compared with the control group (P=0.0281), giving evidences that SNPs can cause some susceptibility to the disease. This combined effect of SNPs seems to regulate the principal cytokines and other factors related to BM inflammatory response and point the importance of DNA repair not only to repair activity when DNA is damaged, but to others essential functions to human organism balance.

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Activation of the kynurenine (KYN) pathway (KP) by modulators of immune system has been observed during several neurological diseases. Here we assessed the association of chemo-/cytokine levels with the concentration of KP metabolites in cerebrospinal fluid (CSF) and plasma samples from patients with bacterial meningitis (BM). All samples were collected from 42 patients diagnosed with acute bacterial meningitis (ABM), aseptic meningitis, tuberculous meningitis and patients without infection neurological disorders. CSF and plasma concentration of metabolites from the KP was assessed by high pressure liquid chromatography (HPLC) and cytokines and chemokines by Bio-plex 200 suspension array system. Concentrations of the KP metabolites KYN and kynurenic acid (KYNA) were significantly higher in CSF of patients with ABM compared to other groups. Tryptophan (TRP), anthranilic acid (AA), 3-hydroxykynurenine (3HK) and 3-hydroxyanthranilic acid (3HAA) did not show statistical significance, although some of them presented a good accumulation during ABM. The expression of TNF-alpha, IL-6, IL-1beta, IFN-gamma, IL-10, IL-1 receptor antagonist (IL-1Ra), MIP-1alpha, MIP-1beta, MCP-1 and G-CSF was about 100-fold higher in CSF from ABM patients than other infected groups. In all CSF and plasma samples, the concentration of IL-2, IL-12(p70), IL-4, IL-8 and GM-CSF was not significant. ABM still showed significant concentrations of IL-6, IL-10, IL-1Ra and MCP-1 in plasma samples. Based on the comparison of KP metabolites concentrations between plasma and CSF samples we conclude that the activation of the tryptophan pathway upon BM occurs within the brain. This increase in KP metabolites is most due to activation of the KP by molecules as IFN-gamma and TNF-alpha in response to infection.

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The phylogeny is one of the main activities of the modern taxonomists and a way to reconstruct the history of the life through comparative analysis of these sequences stored in their genomes aimed find any justification for the origin or evolution of them. Among the sequences with a high level of conservation are the genes of repair because it is important for the conservation and maintenance of genetic stability. Hence, variations in repair genes, as the genes of the nucleotide excision repair (NER), may indicate a possible gene transfer between species. This study aimed to examine the evolutionary history of the components of the NER. For this, sequences of UVRA, UVRB, UVRC and XPB were obtained from GenBank by Blast-p, considering 10-15 as cutoff to create a database. Phylogenetic studies were done using algorithms in PAUP programs, BAYES and PHYLIP package. Phylogenetic trees were build with protein sequences and with sequences of 16S ribosomal RNA for comparative analysis by the methods of parsimony, likelihood and Bayesian. The XPB tree shows that archaeal´s XPB helicases are similar to eukaryotic helicases. According to this data, we infer that the eukaryote nucleotide excision repair system had appeared in Archaea. At UVRA, UVRB and UVRC trees was found a monophyletic group formed by three species of epsilonproteobacterias class, three species of mollicutes class and archaeabacterias of Methanobacteria and Methanococci classes. This information is supported by a tree obtained with the proteins, UVRA, UVRB and UVRC concatenated. Thus, although there are arguments in the literature defending the horizontal transfer of the system uvrABC of bacteria to archaeabacterias, the analysis made in this study suggests that occurred a vertical transfer, from archaeabacteria, of both the NER genes: uvrABC and XPs. According the parsimony, this is the best way because of the occurrence of monophyletic groups, the time of divergence of classes and number of archaeabacterias species with uvrABC system

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The objective of this study was to identify DNA polymorphisms at the genes leptin, β-lactoglobulin and pituitary-specific transcription factor in three genetic groups of Holstein x Guzerat dairy cows and investigate the relationship between their genotypes and the composition and quality of milk of dairy cows. Samples were collected in August 2009, being 113 blood samples from lactating crossbred cows and 58 milk samples. For analysis of DNA polymorphisms blood samples were collected, analyzed later in the Genetic Laboratory affiliated to the Zootechny Institute of São Paulo and individual milk samples were collected according to standards established by the laboratory of Management Program of Northeast Dairy Herds (PROGEN), at Federal Rural University of Pernambuco (UFRPE) for analysis of milk composition and quality. The characterization of genotypes was performed by PCR-RFLP, for which were designed specific primers for each studied gene and restriction enzymes Kpn2I, HaeIII and HinfI that cut the DNA of the following genes: leptin, β-lactoglobulin and a PIT, respectively. The leptin estimate genotypic frequence were CC 0.112, TT 0.225 and CT 0.661, for β-lactoglobulin were AA 0.136, AB 0.323 and BB 0.539, and for PIT were ++ 0.655, -- 0.311 and +- 0.032. The results show that the population is in Hardy-Weinberg disequilibrium for leptin, β-lactoglobulin and a PIT due to excess of heterozygotes in the population, however, as these genes are associated with the milk production it is considered that the animals have genetic potential for milk production in the Brazilian semi-arid conditions. Through the characterization of the studied herd there were not found implications of the polymorphism of leptin, β-lactoglobulin and PIT in the composition and quality of milk from cows in the different genetic groups 1/2, 3/4 and 7/8 Holstein x Guzerat. Key words: β-lactoglobulin, crossbred cows, leptin, PCR-RFLP, PIT1, semi-arid.

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Abstract: Several factors can affect the development of the broiler, among them we can highlight nutrition and management. In the context nutritional, mineral supplementation is a necessary practice because, in general, the diets did not contain these elements in sufficient quantity to meet the needs of poultry. Zinc is a trace mineral essential to life, participating in several important functions in the body. Generally zinc is added to diets of birds in inorganic forms (oxides, carbonates or sufatos), however in its organic form or chelated presents more bioavailable. The objective of this study was to evaluate the effect of levels of organic zinc (ZnO) in the diet of broilers from 1 to 42 days, housed in new or reused litter. The experiment was conducted in the poultry sector of the Special Unit for Agricultural Sciences EAJ / UFRN. 576 chicks were used 1 day of commercial strain Cobb, distributed in a completely randomized in a 4x2 factorial arrangement with four levels of ZnO 0, 40, 80 and 120 ppm and two environments, new bed (COn) and reused litter (CRE) resulting in eight treatments with six replications of 12 birds. In the pre-initial responses were linearly increasing levels of ZnO on feed intake and quadratic effect on body weight and weight gain. The levels of 72.41 and 70.05 ppm of ZnO in the diet of chicks improved body weight and weight gain, respectively. There was interaction between ZnO and the type of bedding used. The ZnO did not affect broiler performance in the growing phase. There was an interaction between levels of ZnO and type of bed used. The levels of 61.50 and 85.30 ppm organic zinc improves immunity and increases the deposition of zinc in tibia of broilers at 42 days, respectively. ZnO also increases the resistance of the skin of broilers at 42 days of age. Using Cre improves performance of broilers from 1 to 42 days old

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The objective of this study was to evaluate the quality of housing and the physical and chemical characteristics of meat from sheep raised on pasture Brachiaria brizantha and Panicum maximum. The experiment was conducted in the physical area of the Study Group on Forage (GEFOR), located in the Academic Unit Specialized in Agricultural Sciences - Federal University of Rio Grande do Norte - UFRN in Macaíba, RN, Brazil. We used 32 lambs SPRD, obtained from herds in the state, with liveweight (LW) of 24.5 kg were assigned randomly to four treatments consisting of tropical grasses, two cultivars of Brachiaria brizantha, Marandu and Piatã, and two of Panicum maximum, Aruana and Massai. The experimental area was 2.88 ha, divided into 4 paddocks of 0.72 ha, where each picket consisted of a farm and was divided into six plots of 0.12 ha, where the animals remained under rotational grazing. The period of adaptation to the pickets was seven days. At the beginning of the experiment the animals were weighed, identified with plastic earrings and necklaces colored according to the treatment, and treated against. The lambs were loose in the paddock at 8 am and collected at 16 hours, which returned to collective pens. During the time of grazing animals had free access to mineral supplement with monensin Ovinofós ® and water. Before entering the paddocks of pasture were sampled to characterize the chemical composition. Every seven days occurred at weighing, with fasting, to monitor the weight development. Cultivars Marandu, Aruana, Piatã and Massai were grazed for 133, 129, 143 and 142 days, respectively, until the lambs reach slaughter weight. Arriving at 32 kg lambs were evaluated subjectively for body condition score by, passed through fasting period, diet and water for 16 hours were slaughtered. Measurements were made in the inner and outer casings in addition to subjective evaluations regarding muscling, finish and quantity of pelvic-renal fat, then each was divided longitudinally into two half-carcases and cuts were made in the commercial left half, and after heavy calculated their income. Between the 12th and 13th thoracic vertebrae, was performed a cut to expose the cross section of the Longissimus dorsi, which was drawn on the rib eye area (REA) in transparent film. Fat thickness and extent of AOL GR were determined using a caliper. A tissue composition was determined by dissection of the legs. Analyzes were performed physical (color, cooking loss and shear force) and chemical composition of meat (moisture, ash, protein and lipids) in Longissimus dorsi muscle. Grazing tropical grass Brachiaria brizantha cvs. Marandu and Piatã and Panicum maximum cvs. Aruana and Massai can be used for lambs SRPD in the rainy season, because not alter the physico-chemical and chemical composition of meat

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The objective of this study was to characterize the socioeconomic profile of the family farmers who live and work in Brazilian rural space and highlight the importance of family agribusiness through the significant relation between some variables as the value of the total production, GDP share in total area of the establishments, agricultural production and farmer income, that show the important participation of these farmers in agricultural productivity and consequently on the economy of country. Therefore, this sector deserves a greater attention and more investment in the development of public policies that lead to a quality education in rural areas, availability of technical courses for farmers, technical assistance more efficient and effective, as well as funding more readily available

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The objectives of this research were characterizing the dairy goat production systems and model it using linear program. On the first step of this research, the model was developed using data from farms that was affiliated in the ACCOMIG/Caprileite, used a similar dairy goat production systems and have a partnership program with Universidade Federal de Minas Gerais . The data of research were from a structured questionnaire applied with farmers and monitoring of production systems during a guided visit on their farms. The results permitted identify that all farms were classified as a small and have a intensive production system. The average herd size had 63.75 dairy goats on lactation; it permits a production of 153, 38 kg of goat milk per day. It was observed that existing more than one channel of commercialization for the goat milk and their derivative products. The data obtained, on the first step of this research, was used to develop a linear program model. It was evaluated in two goat production systems, called P1 and P2. The results showed that the P1 system, with an annual birth and lactation during approximately 300 days was the best alternative for business. These results were compared with a mixed (beef and dairy) goat system in the semiarid region, which indicated merged with both systems. Therefore, to achieve profits and sustainability of the system, in all simulations it was necessary a minimum limit of funding of U.S. $ 10,000.00; this value permit earning of U.S. $ 792.00 per month and pay the investment within 5 years

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The use of non-human primates in scientific research has contributed significantly to the biomedical area and, in the case of Callithrix jacchus, has provided important evidence on physiological mechanisms that help explain its biology, making the species a valuable experimental model in different pathologies. However, raising non-human primates in captivity for long periods of time is accompanied by behavioral disorders and chronic diseases, as well as progressive weight loss in most of the animals. The Primatology Center of the Universidade Federal do Rio Grande do Norte (UFRN) has housed a colony of C. jacchus for nearly 30 years and during this period these animals have been weighed systematically to detect possible alterations in their clinical conditions. This procedure has generated a volume of data on the weight of animals at different age ranges. These data are of great importance in the study of this variable from different perspectives. Accordingly, this paper presents three studies using weight data collected over 15 years (1985-2000) as a way of verifying the health status and development of the animals. The first study produced the first article, which describes the histopathological findings of animals with probable diagnosis of permanent wasting marmoset syndrome (WMS). All the animals were carriers of trematode parasites (Platynosomum spp) and had obstruction in the hepatobiliary system; it is suggested that this agent is one of the etiological factors of the syndrome. In the second article, the analysis focused on comparing environmental profile and cortisol levels between the animals with normal weight curve evolution and those with WMS. We observed a marked decrease in locomotion, increased use of lower cage extracts and hypocortisolemia. The latter is likely associated to an adaptation of the mechanisms that make up the hypothalamus-hypophysis-adrenal axis, as observed in other mammals under conditions of chronic malnutrition. Finally, in the third study, the animals with weight alterations were excluded from the sample and, using computational tools (K-means and SOM) in a non-supervised way, we suggest found new ontogenetic development classes for C. jacchus. These were redimensioned from five to eight classes: infant I, infant II, infant III, juvenile I, juvenile II, sub-adult, young adult and elderly adult, in order to provide a more suitable classification for more detailed studies that require better control over the animal development