980 resultados para 630502 Pasture, browse and fodder crops


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Projected change in forage production under a range of climate scenarios is important for the evaluation of the impacts of global climate change on pasture-based livestock production systems in Brazil. We evaluated the effects of regional climate trends on Panicum maximum cv. Tanzânia production, predicted by agro-meteorological model considering the sum of degree days and corrected by a water availa bility index. Data from Brazilian weather stations (1963?2009) were considered as the current climate (baseline), and future scenarios, based on contrasting scenarios interms of increased temperature and atmospheric CO2 concentrations (high and low increases), were determined for 2013?2040 (2025 scenario) and for 2043?2070 (2055 scenario). Predicted baseline scenarios indicated that there are regional and seasonal variations in P. maximum production related to variation intemperature and water availability during the year. Production was lower in the Northeast region and higher in the rainforest area. Total annual productionunder future climate scenarios was predicted toincrease by up to 20% for most of the Brazilian area, mainly due to temperature increase, according to each climate model and scenario evaluated. The highest increase in forage production is expected to be in the South, Southeast and Central-west areas of Brazil. In these regions, future climate scenarios will not lead to changes in the seasonal production, with largerincreases in productivity during the summer. Climate risk is expected to decrease, as the probability of occurrence of low forage productions will be lower. Due to the predicted increase in temperature and decrease in rainfall in the Northeast area, P. maximum production is expected to decrease, mainly when considering scenarios based on the PRECIS model for the 2055 scenario.

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Uncoupling protein one (UCP1) is a mitochondrial inner membrane protein capable of uncoupling the electrochemical gradient from adenosine-5'-triphosphate (ATP) synthesis, dissipating energy as heat. UCP1 plays a central role in nonshivering thermogenesis in the brown adipose tissue (BAT) of hibernating animals and small rodents. A UCP1 ortholog also occurs in plants, and aside from its role in uncoupling respiration from ATP synthesis, thereby wasting energy, it plays a beneficial role in the plant response to several abiotic stresses, possibly by decreasing the production of reactive oxygen species (ROS) and regulating cellular redox homeostasis. However, the molecular mechanisms by which UCP1 is associated with stress tolerance remain unknown. Here, we report that the overexpression of UCP1 increases mitochondrial biogenesis, increases the uncoupled respiration of isolated mitochondria, and decreases cellular ATP concentration. We observed that the overexpression of UCP1 alters mitochondrial bioenergetics and modulates mitochondrial-nuclear communication, inducing the upregulation of hundreds of nuclear- and mitochondrial-encoded mitochondrial proteins. Electron microscopy analysis showed that these metabolic changes were associated with alterations in mitochondrial number, area and morphology. Surprisingly, UCP1 overexpression also induces the upregulation of hundreds of stress-responsive genes, including some involved in the antioxidant defense system, such as superoxide dismutase (SOD), glutathione peroxidase (GPX) and glutathione-S-transferase (GST). As a consequence of the increased UCP1 activity and increased expression of oxidative stress-responsive genes, the UCP1-overexpressing plants showed reduced ROS accumulation. These beneficial metabolic effects may be responsible for the better performance of UCP1-overexpressing lines in low pH, high salt, high osmolarity, low temperature, and oxidative stress conditions. Overexpression of UCP1 in the mitochondrial inner membrane induced increased uncoupling respiration, decreased ROS accumulation under abiotic stresses, and diminished cellular ATP content. These events may have triggered the expression of mitochondrial and stress-responsive genes in a coordinated manner. Because these metabolic alterations did not impair plant growth and development, UCP1 overexpression can potentially be used to create crops better adapted to abiotic stress conditions.

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Annona dioica St. Hil. is a species that grows to approximately 2 m tall and is very widespread in the cerrados. Individual plants of this androdioecious species produce numerous hermaphroditic or male flowers, but few fruits. The aim of this study was to determine the sex ratio among the plants and to compare the frequency of herbivory between male and hermaphroditic flowers. The fieldwork was done by studying flowering plants in grasslands used as pasture for cattle at Fazenda Nhumirim. One hundred and forty-seven male plants and 71 hermaphroditic plants were examined and produced a total of 194 and 94 flowers, respectively, during the study period. The male:hermaphrodite sex ratio was 2.07:1, and was similar to the male:hermaphrodite flower ratio of 2.06:1. The frequency of florivory rate in hermaphrodites was significantly higher than in male flowers (33.0%, n = 31, and 25.7%, n = 50, respectively; G = 14.83; d.f. = 1; p < 0.001). The mean fresh weights of male and hermaphroditic flowers were significantly different (8.38 ± 2.40 g vs. 6.93 ± 2.68 g, respectively; 0 ± SEM; n = 50 each; t = 2.479; d.f. = 49; p = 0.017). These results indicate that the low fruit set in this species can be explained by the sex ratio, the greater herbivory of hermaphroditic flowers and the probable absence of pollinators.

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Application of calcium silicate (SiCa) as soil acidity corrective was evaluated in a Rhodic Hapludox soil with palisade grass conducted under pasture rotation system with different grazing intensities. Experimental design was complete randomized blocks with four grazing intensities - grazing intensities were imposed by forage supply (50, 100, 150 and 200 kg t-1 of DM per LW) - in experimental plots with four replicates and, in the subplots, with seven doses of calcium silicate combined with lime: 0+0, 2+0, 4+0, 6+0, 2+4, 4+2 and 0+6 t ha-1, respectively. In the soil, it was evaluated the effect of four levels of calcium silicate (0, 2, 4 and 6 t ha-1) at 45, 90, and 365 days at three depths (0-10, 10-20 and 20-40 cm) and at 365 days, it was included one level of lime (6 t ha-1). For determination of leaf chemical composition and silicate content in the soil, four levels of calcium silicate (0, 2, 4 and 6 t ha-1) were evaluated at 45 and 365 days and at 45 days only for leaf silicate, whereas for dry matter production, all corrective treatments applied were evaluated in evaluation seasons. Application of calcium silicate was positive for soil chemical traits related to acidity correction (pH(CaCl2), Ca, Mg, K, H+Al and V), but the limestone promoted better results at 365 days. Leaf mineral contents were not influenced by application of calcium silicate, but there was an increase on silicate contents in leaves and in the soil. Dry matter yield and chemical composition of palisade grass improved with the application of correctives.

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The dispersal and survival of the phlebotomines Nyssomyia intermedia and Nyssomyia neivai (both implicated as vectors of the cutaneous leishmaniasis agent) in an endemic area was investigated using a capture-mark-release technique in five experiments from August-December 2003 in municipality of Iporanga, state of São Paulo, Brazil. A total of 1,749 males and 1,262 females of Ny. intermedia and 915 males and 411 females of Ny. neivai were marked and released during the five experiments. Recapture attempts were made using automatic light traps, aspiration in natural resting places and domestic animal shelters and Shannon traps. A total of 153 specimens (3.48%) were recaptured: 2.59% (78/3,011) for Ny. intermedia and 5.35% (71/1,326) for Ny. neivai. Both species were recaptured up to 144 h post-release, with the larger part of them recaptured within 48 h. The median dispersion distances for Ny. intermedia and Ny. neivai, respectively, were 109 m and 100 m. The greatest dispersal range of Ny. intermedia was 180 m, while for Ny. neivai one female was recaptured in a pasture at 250 m and another in a pigsty at 520 m, showing a tendency to disperse to more open areas. The daily survival rates calculated based on regressions of the numbers of marked insects recaptured on the six successive days after release were 0.746 for males and 0.575 for females of Ny. intermedia and 0.649 for both sexes of Ny. neivai. The size of the populations in the five months ranged from 8,332-725,085 for Ny. intermedia males, 2,193-104,490 for Ny. intermedia females, 1,687-350,122 for Ny. neivai males and 254-49,705 for Ny. neivai females.

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To identify natural infections by Leishmania spp. in insect vectors of cutaneous and visceral leishmaniasis, we performed field studies in natural and anthropic environments in the Guaicurus Settlement (Bodoquena Range) of the Bonito municipality, Mato Grosso do Sul state, Brazil. From October 2002 to October 2003, a total of 1395 sandfly females were captured with Shannon and light traps and dissected in search of flagellates. The sample is composed of a total of 13 species, with Lutzomyia almerioi (59.9%) and Lutzomyia longipalpis (31.4%) predominant. Infections by flagellates were directly observed in three of the dissected of Lu. almerioi females (0.36%). To increase the sensitivity of detection, DNA extracted from pools of the 1220 dissected females (Lu. almerioi 808, Lu. longipalpis 399 and Nyssomyia whitmani 13) was subjected to small subunit rRNA-based polymerase chain reactions (SSU-PCR). DNA from Leishmania (L.) infantum chagasi was detected in at least 0.37% of Lu. almerioi females and in 0.25% of Lu. longipalpis females. The DNA of the Leishmania (Viannia) sp. was detected in 0.12% of Lu. almerioi and in 0.70% of Lu. longipalpis. Leishmania (L.) amazonensis was found in 1.25% of Lu. longipalpis. Mixed infections of L. (Leishmania) sp. and L. (Viannia) sp. were found in 0.50% of Lu. longipalpis. When considering that each positive pool contained at least a single infected specimen, we found a 1.23% rate of Leishmania spp. infection among the total population of dissected female sand flies as determined by PCR. This is the first report of natural infection by L. (L.) infantum chagasi and L. (Viannia) sp. in Lu. almerioi. It is also the first report of infection by L. (Viannia) sp. in Lu. longipalpis. The observation that Lu. longipalpis and Lu. almerioi are naturally infected by agents of both cutaneous and visceral leishmaniases suggests that these two species play a role in the transmission (continua) (continuação) of these diseases within the study area. Furthermore, the finding that Lu. longipalpis has been naturally infected by L. (L.) amazonensis and L. (Viannia) sp., and Lu. almerioi by L. (L.) infantum chagasi and L. (Viannia), suggests their participation as permissive vectors

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OBJECTIVE: We evaluated the relation between overweight and calcium intake in adults living in the municipality of São Paulo, Brazil. METHODS: This was a cross-sectional population-based study on a sample of 1459 adults that was obtained by multistage cluster sampling. Dietary intake was measured by the 24-h recall method. Poisson's and linear regression analyses were performed to evaluate the relation between overweight and quartiles of calcium intake adjusted for energy. RESULTS: The prevalence of overweight was 43.1% and the average adjusted calcium intake was 448.6 mg. In the linear regression analyses, the regression coefficient for adjusted calcium was significant and negative (P = 0.019, beta(1) = -0.0001). Although evaluated by quartiles, the prevalence ratio for overweight in the first quartile of calcium intake was 1.24 (95% confidence interval 1.00-1.54) and that in the second quartile was 1.24 (95% confidence interval 1.03-1.49). CONCLUSION: In the present study, calcium intake showed a significant negative association with body mass index

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Lead poisoning has been reportedly linked to a high risk of learning disabilities, aggression and criminal offenses. To study the association between lead exposure and antisocial/delinquent behavior, a cross-sectional study was conducted with 173 Brazilian youths aged 14\201318 and their parents (n = 93), living in impoverished neighborhoods of Bauru-SP, with high criminality indices. Self-Reported Delinquency (SRD) and Child Behavior Checklist (CBCL) questionnaires were used to evaluate delinquent/antisocial behavior. Body lead burdens were evaluated in surface dental enamel acid microbiopsies. The dental enamel lead levels (DELL) were quantified by graphite furnace atomic absorption spectrometry (GFAAS) and phosphorus content was measured using inductively coupled plasma optical emission spectrometry (ICP-OES). Logistic regression was used to identify associations between DELL and each scale defined by CBCL and SRD scores. Odd ratios adjusted for familial and social covariates, considering a group of youths exposed to high lead levels (\2265 75 percentile), indicated that high DELL is associated with increased risk of exceeding the clinical score for somatic complaints, social problems, rule-breaking behavior and externalizing problems (CI 95 per cent). High DELL was not found to be associated with elevated SRD scores. In conclusion, our data support the hypothesis that high-level lead exposure can trigger antisocial behavior, which calls for public policies to prevent lead poisoning

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We estimated the sensitivity, i.e., the proportion of all cases of adverse events following immunization (AEFIs) reported to the Brazilian passive surveillance for adverse events following immunization (PSAEFI) with the diphtheria-tetanus-whole-cell pertussis-Haemophilus influenzae type b (DTwP-Hib) vaccine, as well as investigating factors associated with AEFIs reporting. During 2003–2004, 8303 AEFIs associated with DTwP-Hib were reported; hypotonic-hyporesponsive episodes (HHEs), fever and convulsions being the most common. Cure without sequel was achieved in 98.4 per cent of the cases. The mean sensitivity of the PSAEFI was 22.3 per cent and 31.6 per cent, respectively, for HHE and convulsions, varying widely among states. Reporting rates correlated positively with the Human Development Index and coverage of adequate prenatal care, correlating negatively with infant mortality rates. Quality of life indicators and the degree of organization of health services are associated with greater PSAEFI sensitivity. In addition to consistently describing the principal AEFIs, PSAEFI showed the DTwP/Hib vaccine to be safe and allayed public fears related to its use

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OBJECTIVE: To review the effectiveness of school food and nutrition policies world wide in improving the school food environment, student's dietary intake, and decreasing overweight and obesity. METHODS: Systematic review of published and unpublished literature up to November 2007 of three categories of nutrition policy; nutrition guidelines, regulation of food and/or beverage availability, and price interventions applied in preschools, primary and secondary schools. RESULTS: 18 studies met the inclusion criteria. Most evidence of effectiveness was found for the impact of both nutrition guidelines and price interventions on intake and availability of food and drinks, with less conclusive research on product regulation. Despite the introduction of school food policies worldwide few large scale or national policies have been evaluated, and all included studies were from the USA and Europe. CONCLUSION: Some current school policies have been effective in improving the food environment and dietary intake in schools, but there is little evaluation of their impact on BMI. As schools have been proposed worldwide as a major setting for tackling childhood obesity it is essential that future policy evaluations measure the long term effectiveness of a range of school food policies in tackling both dietary intake and overweight and obesity.

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The present study sought to assess the impact of an intervention to reduce weight and control risk factors of noncommunicable chronic diseases in overweight or obese adults who are users of primary and secondary healthcare units of the public health system of Pelotas, Brazil. We hypothesized that individuals who received an educational intervention regarding how to lose weight and prevent other noncommunicable chronic disease risk factors through nutrition would lose weight and acquire active habits during leisure time more frequently than individuals under regular care. Two hundred forty-one participants from the Nutrition Outpatient Clinic of the Medical Teaching Hospital of the Federal University of Pelotas, Brazil, aged 20 years or older and classified as overweight or obese were randomly allocated to either the intervention group (IG; n = 120) or control group (CG; n = 121). The IG received individualized nutritional care for 6 months, and the CG received individualized usual care of the health services. Intention-to-treat analyses showed that at 6 months, mean fasting glycemia and daily consumption of sweet foods and sodium were reduced, and the time spent on physical leisure activity was increased in IG. Analysis of adherence to the protocol of the study revealed that individuals from IG had lost more in body weight, waist circumference, and fasting glucose compared to the CG. Leisure time physical activity increased in IG. Individuals adhered equally to the dietetic recommendations, irrespective of the nutrition approach that was used

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Garlic contains polyphenol and sulphur compounds, which are responsible for its antioxidant activity (AA). This study aimed at evaluating the AA of fresh garlic and its commercialised products and their shelf life. Fresh garlic (FG) and its products, i.e. chopped with salt (CGS), chopped without salt (CG), fried (FRG) and mixed garlic (FG with dehydrated garlic; MG) antioxidant activity was evaluated by three different methods: DPPH (1,1-diphenyl-2-picrylhydrazyl) assay, ß-carotene/linoleic acid assay and Rancimat® method. Amongst all the analysed products, fried garlic presented the highest antioxidant activity. The free radical-scavenging activity decreased during the shelf life of all analysed products that correlated with the decrease in the total polyphenol content. Our findings suggest that some compounds other than phenol may have contributed towards this outcome

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Bovine rumen protein with two levels of residual lipids (1.9 per cent or 3.8 per cent) was subjected to thermoplastic extrusion under different temperatures and moisture contents. Protein solubility in different buffers, disulphide cross-linking and molecular weight distribution were determined on the extrudates. After extrusion, samples with 1.9 per cent residual lipids content had a higher concentration of protein insoluble by undetermined forces, irrespective of feed moisture and processing temperature used. Lipid content of 3.8 per cent in the feed material resulted in more protein participating in the extrudate network through non-covalent interactions (hydrophobic and electrostatic) and disulphide bonds. A small dependency of the extrusion process on moisture and temperature and a marked dependency on lipid content, especially phospholipid, was observed, Electrophoresis under non-reducing conditions showed that protein extrusion with low feed moisture promoted high molecular breakdown inside the barrel, probably due to intense shear force, and further protein aggregation at the die end

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Objective. To assess the relationship between cortisol concentrations in the last trimester of pregnancy and systemic vascular resistance — SVR in childhood. Materials and methods. This study is part of a cohort involving 130 Brazilian pregnant women and their children, ages 5 to 7 years. Maternal cortisol was determined in saliva by an enzyme immunoassay utilizing the mean concentration of 9 samples of saliva (3 in each different day), collected at the same time, early in the morning. SVR was assessed by the HDI/PulseWave CR-2000 Cardiovascular Profiling System®. Socioeconomic and demographic characteristics and life style factors were determined by a questionnaire. The nutritional status of the women and children was assessed by the body mass index — BMI. The association between maternal cortisol and SVR in childhood was calculated by multivariate linear regression analysis. Results.There were statistically significant associations between maternal cortisol and SVR (p = 0.043) and BMI-z score of the children (p = 0.027), controlling for maternal BMI, birth weight, age, and gender of the children. Conclusion. As far as we know this is the first study in the literature assessing the association between cortisol concentrations in pregnancy and SVR in childhood. Overall, the data suggest that exposure to excess glucocorticoid in the prenatal period is associated to vascular complications in childhood, predisposing to cardiovascular diseases in later life

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Background & aims. This study aimed to determine the relationship between blood lead concentrations and calcium, iron and vitamin C dietary intakes of pregnant women. Methods. Included in the study were 55 women admitted to a hospital, for delivery, from June to August 2002. A food frequency questionnaire was applied to determine calcium, iron and vitamin C intakes, and a general questionnaire to obtain data on demographic-socioeconomic condition, obstetric history, smoking habit, and alcohol intake. Blood lead and haemoglobin were determined, respectively, by atomic absorption spectrometry and by the haemoglobinometer HemoCue®. Multiple linear regression models were used to determine the relationship between blood lead and calcium, iron and vitamin C intakes, and haemoglobin levels, controlling for confounders. Results. The final model of the regression analysis detected an inverse relationship between blood lead and age of the women (p=0.011), haemoglobin (p=0.001), vitamin C (p=0.012), and calcium intake (p<0.001) (R2=0.952). One hundred percent, 98.2% and 43.6% of the women were below the adequate intake (AI) for calcium, and below the recommended dietary allowances (RDA) for iron, and vitamin C, respectively. Conclusion. Despite the small sample size, the results of this study suggest that maternal age, haemoglobin, vitamin C intake, and calcium intake may interfere with blood concentrations of lead