995 resultados para Cut levels


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We evaluated the effectiveness of supplementation with high dose of oral vitamin D3 to correct vitamin D insufficiency. We have shown that one or two oral bolus of 300,000 IU of vitamin D3 can correct vitamin D insufficiency in 50% of patients and that the patients who benefited more from supplementation were those with the lowest baseline levels. INTRODUCTION: Adherence with daily oral supplements of vitamin D3 is suboptimal. We evaluated the effectiveness of a single high dose of oral vitamin D3 (300,000 IU) to correct vitamin D insufficiency in a rheumatologic population. METHODS: Over 1 month, 292 patients had levels of 25-OH vitamin D determined. Results were classified as: deficiency <10 ng/ml, insufficiency ≥10 to 30 ng/ml, and normal ≥30 ng/ml. We added a category using the IOM recommended cut-off of 20 ng/ml. Patients with deficient or normal levels were excluded, as well as patients already supplemented with vitamin D3. Selected patients (141) with vitamin D insufficiency (18.5 ng/ml (10.2-29.1) received a prescription for 300,000 IU of oral vitamin D3 and were asked to return after 3 (M3) and 6 months (M6). Patients still insufficient at M3 received a second prescription for 300,000 IU of oral vitamin D3. Relation between changes in 25-OH vitamin D between M3 and M0 and baseline values were assessed. RESULTS: Patients (124) had a blood test at M3. Two (2%) had deficiency (8.1 ng/ml (7.5-8.7)) and 50 (40%) normal results (36.7 ng/ml (30.5-5.5)). Seventy-two (58%) were insufficient (23.6 ng/ml (13.8-29.8)) and received a second prescription for 300,000 IU of oral vitamin D3. Of the 50/124 patients who had normal results at M3 and did not receive a second prescription, 36 (72%) had a test at M6. Seventeen (47%) had normal results (34.8 ng/ml (30.3-42.8)) and 19 (53%) were insufficient (25.6 ng/ml (15.2-29.9)). Of the 72/124 patients who receive a second prescription, 54 (75%) had a test at M6. Twenty-eight (52%) had insufficiency (23.2 ng/ml (12.8-28.7)) and 26 (48%) had normal results (33.8 ng/ml (30.0-43.7)). At M3, 84% patients achieved a 25-OH vitamin D level >20 ng/ml. The lowest the baseline value, the highest the change after 3 months (negative relation with a correlation coefficient r = -0.3, p = 0.0007). CONCLUSIONS: We have shown that one or two oral bolus of 300,000 IU of vitamin D3 can correct vitamin D insufficiency in 50% of patients.

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Glucocorticoids affect physiology and behaviour, reproduction and potentially sexual selection as well. Shortterm and moderate glucocorticoid elevations are suggested to be adaptive, and prolonged and high elevations may be extremely harmful. This suggests that optimal reproductive strategies, and thus sexual selection, may be dose dependent. Here, we investigate effects of moderate and high elevations of blood corticosterone levels on intra- and intersexual behaviour and mating success of male common lizards Lacerta vivipara. Females showed less interest and more aggressive behaviour towards high corticosterone males and blood corticosterone levels affected male reproductive strategy. Males of moderate and high corticosterone elevations, compared with Control males, showed increased interest (i.e., higher number of chases, tongue extrusions, and approaches) towards females and high corticosterone males initiated more copulation attempts. However, neither increased male interest nor increased copulation attempts resulted in more copulations. This provides evidence for a best-of-a-bad-job strategy, where males with higher corticosterone levels compensated for reduced female interest and increased aggressive female behaviour directed towards them, by showing higher interest and by conducting more copulation attempts. Blood corticosterone levels affected intrasexual selection as well since moderate corticosterone levels positively affected male dominance, but dominance did not affect mating success. These findings underline the importance of female mate choice and are in line with adaptive compensatory behaviours of males. They further show that glucocorticoid effects on behaviour are dose dependent and that they have important implications for sexual selection and social interactions, and might potentially affect Darwinian fitness.

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High rates of phosphate fertilizers are applied to potato (Solanum tuberosum L.), which may cause antagonistic interactions with other nutrients and limit crop yields when over-supplied. The purpose of this study was to evaluate the influence of phosphorus (P) levels in nutrient solution on P use efficiency, nutritional status and dry matter (DM) accumulation and partitioning of potato plants cv. Ágata. The experiment was carried out in a greenhouse, arranged in a completely randomized block design with four replications. Treatments consisted of seven P levels in nutrient solution (0, 2, 4, 8, 16, 31, and 48 mg L-1). Plants were harvested after 28 days of growth in nutrient solution, and separated in roots, stems and leaves for evaluations. The treatment effects were analyzed by regression analysis. Phosphorus levels of up to 8 mg L-1 increased the root and shoot DM accumulation, but drastically decreased the root/shoot ratio of potato cv. Ágata. Higher P availability increased P concentration, accumulation and absorption efficiency, but decreased P use efficiency. Higher P levels increased the N, P, Mg, Fe, and Mn concentrations in roots considerably and decreased K, S, Cu, and Zn concentrations. In shoot biomass, N, P, K, and Ca concentrations were significantly increased by P applied in solution, unlike Mg and Cu concentrations. Although higher P levels (> 8 mg L-1) in nutrient solution increased P concentration, accumulation and absorption efficiency, the DM accumulation and partitioning of potato cv. Ágata were not affected.

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Selostus: Koejärjestelyt kohonneen lämpötilan ja CO2-tason vaikutusten simuloimiseksi peltokasveilla Suomessa

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The use of cultivars with a higher yield potential and the adoption of new technology have achieved high grain yields in common bean, which probably changed the demand for nutrients in this crop. However, there is almost no information about the periods of the cycle in which nutrients are most demanded at which quantities by the main cultivars. The objective of this study was to evaluate the macronutrient extraction and exportation by the common bean cultivars Pérola and IAC Alvorada, under different levels of NPK fertilization, on a dystroferric Red Nitosol, in Botucatu, São Paulo State, Brazil. The experiment was arranged in a randomized complete block (split plot) design with four replications. The plots consisted of six treatments based on a 2 x 3 factorial model, represented by two cultivars and three NPK levels (PD0 - 'Pérola' without fertilization, PD1 - 'Pérola' with 50 % of recommended fertilization, PD2 - 'Pérola' with 100 % of recommended fertilization, AD0 - 'IAC Alvorada' without fertilization, AD1 - 'IAC Alvorada' with 50 % of recommended fertilization, and AD2 - 'IAC Alvorada' with 100 % of recommended fertilization) and subplots sampled seven times during the cycle. At higher levels of NPK fertilization, the grain yield and macronutrient extraction and exportation of both cultivars were higher, but without statistical differences. Macronutrient absorption was higher in the treatments with 100 % of recommended NPK fertilization (average amounts per hectare: 140 kg N, 16.5 kg P, 120 kg K, 69 kg Ca, 17.9 kg Mg, and 16.3 kg S). Regardless of the treatment, the demand for N, P, K, Ca, and Mg was highest from 45 to 55 days after emergence (DAE), i.e., in the R7 stage (pod formation), while the highest S absorption rates were concentrated between 55 and 65 DAE. More than 70 % of P, between 58 and 69 % of N, 40 and 52 % of S, 40 and 48 % of K, and 35 and 45 % of Mg absorbed during the cycle was exported with grains, whereas less than 15 % of Ca was exported.

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Where the level of agricultural technology is higher, common bean cultivars with a higher yield potential possibly require greater amounts of micronutrients. In Brazil however, there is a lack of information about the micronutrient extraction and exportation by the main grown cultivars. The objective of this study was to evaluate micronutrient (B, Cu, Fe, Mn, and Zn) extraction and exportation by common bean cultivars Pérola and IAC Alvorada, under different levels of NPK fertilization, on a dystroferric Red Nitosol, in Botucatu, São Paulo State, Brazil. The experiment was arranged in a randomized complete block (split plot) design with four replications. The plots consisted of six treatments based on a 2 x 3 factorial model, represented by two cultivars and three NPK levels (PD0 - 'Pérola' without fertilization, PD1 - 'Pérola' with 50 % of recommended fertilization, PD2 - 'Pérola' with 100 % of recommended fertilization, AD0 - 'IAC Alvorada' without fertilization, AD1 - 'IAC Alvorada' with 50 % of recommended fertilization, and AD2 - 'IAC Alvorada' with 100 % of recommended fertilization) and subplots sampled seven times during the cycle. Higher levels of NPK fertilization increased micronutrient extraction by both cultivars, and treatments with 100 % of recommended NPK fertilization extracted on average 167 g B, 58 g Cu, 1,405 g Fe, 1,213 g Mn and 211 g Zn per hectare. Regardless of the treatment, the highest demand period for B, Cu, Fe, Mn and Zn in both cultivars occurred at the R7 stage (pod formation), i.e. 42 to 55 days after emergence (DAE). The amount of B, Cu, Fe, Mn and Zn exported depended mainly on the level of NPK fertilization used, with values per hectare ranging from 38 to 90 g of B, 12 to 26 g of Cu, 222 to 568 g of Fe 234 to 467 g of Mn, and 40 to 96 g of Zn.

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Summary

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BACKGROUND: Influenza vaccination remains below the federally targeted levels outlined in Healthy People 2020. Compared to non-Hispanic whites, racial and ethnic minorities are less likely to be vaccinated for influenza, despite being at increased risk for influenza-related complications and death. Also, vaccinated minorities are more likely to receive influenza vaccinations in office-based settings and less likely to use non-medical vaccination locations compared to non-Hispanic white vaccine users. OBJECTIVE: To assess the number of "missed opportunities" for influenza vaccination in office-based settings by race and ethnicity and the magnitude of potential vaccine uptake and reductions in racial and ethnic disparities in influenza vaccination if these "missed opportunities" were eliminated. DESIGN: National cross-sectional Internet survey administered between March 4 and March 14, 2010 in the United States. PARTICIPANTS: Non-Hispanic black, Hispanic and non-Hispanic white adults living in the United States (N = 3,418). MAIN MEASURES: We collected data on influenza vaccination, frequency and timing of healthcare visits, and self-reported compliance with a potential provider recommendation for vaccination during the 2009-2010 influenza season. "Missed opportunities" for seasonal influenza vaccination in office-based settings were defined as the number of unvaccinated respondents who reported at least one healthcare visit in the Fall and Winter of 2009-2010 and indicated their willingness to get vaccinated if a healthcare provider strongly recommended it. "Potential vaccine uptake" was defined as the sum of actual vaccine uptake and "missed opportunities." KEY RESULTS: The frequency of "missed opportunities" for influenza vaccination in office-based settings was significantly higher among racial and ethnic minorities than non-Hispanic whites. Eliminating these "missed opportunities" could have cut racial and ethnic disparities in influenza vaccination by roughly one half. CONCLUSIONS: Improved office-based practices regarding influenza vaccination could significantly impact Healthy People 2020 goals by increasing influenza vaccine uptake and reducing corresponding racial and ethnic disparities.

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In addition to differences in protein-coding gene sequences, changes in expression resulting from mutations in regulatory sequences have long been hypothesized to be responsible for phenotypic differences between species. However, unlike comparison of genome sequences, few studies, generally restricted to pairwise comparisons of closely related mammalian species, have assessed between-species differences at the transcriptome level. They reported that gene expression evolves at different rates in various organs and in a pattern that is overall consistent with neutral models of evolution. In the first part of my thesis, I investigated the evolution of gene expression in therian mammals (i.e.7 placental and marsupials), based on microarray data from human, mouse and the gray short-tailed opossum (Monodelphis domestica). In addition to autosomal genes, a special focus was given to the evolution of X-linked genes. The therian X chromosome was recently shown to be younger than previously thought and to harbor a specific gene content (e.g., genes involved in brain or reproductive functions) that is thought to have been shaped by specific sex-related evolutionary forces. Sex chromosomes derive from ordinary autosomes and their differentiation led to the degeneration of the Y chromosome (in mammals) or W chromosome (in birds). Consequently, X- or Z-linked genes differ in gene dose between males and females such that the heterogametic sex has half the X/Z gene dose compared to the ancestral state. To cope with this dosage imbalance, mammals have been reported to have evolved mechanisms of dosage compensation.¦In the first project, I could first show that transcriptomes evolve at different rates in different organs. Out of the five tissues I investigated, the testis is the most rapidly evolving organ at the gene expression level while the brain has the most conserved transcriptome. Second, my analyses revealed that mammalian gene expression evolution is compatible with a neutral model, where the rates of change in gene expression levels is linked to the efficiency of purifying selection in a given lineage, which, in turn, is determined by the long-term effective population size in that lineage. Thus, the rate of DNA sequence evolution, which could be expected to determine the rate of regulatory sequence change, does not seem to be a major determinant of the rate of gene expression evolution. Thus, most gene expression changes seem to be (slightly) deleterious. Finally, X-linked genes seem to have experienced elevated rates of gene expression change during the early stage of X evolution. To further investigate the evolution of mammalian gene expression, we generated an extensive RNA-Seq gene expression dataset for nine mammalian species and a bird. The analyses of this dataset confirmed the patterns previously observed with microarrays and helped to significantly deepen our view on gene expression evolution.¦In a specific project based on these data, I sought to assess in detail patterns of evolution of dosage compensation in amniotes. My analyses revealed the absence of male to female dosage compensation in monotremes and its presence in marsupials and, in addition, confirmed patterns previously described for placental mammals and birds. I then assessed the global level of expression of X/Z chromosomes and contrasted this with its ancestral gene expression levels estimated from orthologous autosomal genes in species with non-homologous sex chromosomes. This analysis revealed a lack of up-regulation for placental mammals, the level of expression of X-linked genes being proportional to gene dose. Interestingly, the ancestral gene expression level was at least partially restored in marsupials as well as in the heterogametic sex of monotremes and birds. Finally, I investigated alternative mechanisms of dosage compensation and found that gene duplication did not seem to be a widespread mechanism to restore the ancestral gene dose. However, I could show that placental mammals have preferentially down-regulated autosomal genes interacting with X-linked genes which underwent gene expression decrease, and thus identified a novel alternative mechanism of dosage compensation.

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BACKGROUND: Deep hypothermia has been associated with an increased incidence of postoperative neurologic dysfunction after cardiac surgery in children. Recent studies suggest an excitotoxic mechanism involving overstimulation of glutamate receptors. Extracellular glutamate uptake occurs primarily by astrocytes. Astrocytes also store glycogen, which may be used to sustain the energy-consuming glutamate uptake. Extracellular glutamate and glycogen content were studied during temperature changes mimicking cardiopulmonary bypass in vivo. METHODS: Primary cultures of cerebral cortical astrocytes were used in a specially designed incubator allowing continuous changes of temperature and ambient gas concentrations. The sequence of events was as follows: normothermia, rapid cooling (2.8 degrees C/min) followed by 60 min of deep hypothermia (15 degrees C), followed by rewarming (3.0 degrees C/min) and subsequent 5 h of mild hyperthermia (38.5 degrees C). Two different conditions of oxygenation were studied: (1) normoxia (25% O2, 70% N2, 5% CO2); or (2) hyperoxia (95% O2, 5% CO2). The extracellular glutamate concentrations and intracellular glycogen levels were measured at nine time points. RESULTS: One hundred sixty-two cultures were studied in four independent experiments. The extracellular concentration of glutamate in the normoxic group increased significantly from 35+/-10 nM/mg protein at baseline up to 100+/-15 nM/mg protein at the end of 5 h of mild hyperthermia (P < 0.05). In contrast, extracellular glutamate levels did not vary from control in the hyperoxic group. Glycogen levels decreased significantly from 260+/-85 nM/mg protein at baseline to < 25+/-5 nM/mg protein at the end of 5 h in the normoxic group (P < 0.05) but returned to control levels after rewarming in the hyperoxic group. No morphologic changes were observed in either group. CONCLUSION: The extracellular concentration of glutamate increases, whereas the intracellular glycogen content decreases when astrocytes are exposed to a sequence of deep hypothermia and rewarming. This effect of hypothermia is prevented when astrocytes are exposed to hyperoxic conditions.

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Selection of common bean (Phaseolus vulgaris L.) cultivars with enhanced root growth would be a strategy for increasing P uptake and grain yield in tropical soils, but the strong plasticity of root traits may compromise their inclusion in breeding programs. The aim of this study was to evaluate the magnitude of the genotypic variability of root traits in common bean plants at two ontogenetic stages and two soil P levels. Twenty-four common bean genotypes, comprising the four growth habits that exist in the species and two wild genotypes, were grown in 4 kg pots at two levels of applied P (20 and 80 mg kg-1) and harvested at the stages of pod setting and early pod filling. Root area and root length were measured by digital image analysis. Significant genotype × P level and genotype × harvest interactions in analysis of variance indicate that the genotypic variation of root traits depended on soil nutrient availability and the stage at which evaluation was made. Genotypes differed for taproot mass, basal and lateral root mass, root area and root length at both P levels and growth stages; differences in specific root area and length were small. Genotypes with growth habits II (upright indeterminate) and III (prostrate indeterminate) showed better adaptation to limited P supply than genotypes of groups I (determinate) and IV (indeterminate climbing). Between the two harvests, genotypes of groups II and III increased the mass of basal and lateral roots by 40 and 50 %, respectively, whereas genotypes of groups I and IV by only 7 and 19 %. Values of the genotypic coefficient of determination, which estimates the proportion of phenotypic variance resulting from genetic effects, were higher at early pod filling than at pod setting. Correlations between shoot mass and root mass, which could indicate indirect selection of root systems via aboveground biomass, were higher at early pod filling than at pod setting. The results indicate that selection for root traits in common bean genotypes should preferentially be performed at the early pod-filling stage.

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Visible and near infrared (vis-NIR) spectroscopy is widely used to detect soil properties. The objective of this study is to evaluate the combined effect of moisture content (MC) and the modeling algorithm on prediction of soil organic carbon (SOC) and pH. Partial least squares (PLS) and the Artificial neural network (ANN) for modeling of SOC and pH at different MC levels were compared in terms of efficiency in prediction of regression. A total of 270 soil samples were used. Before spectral measurement, dry soil samples were weighed to determine the amount of water to be added by weight to achieve the specified gravimetric MC levels of 5, 10, 15, 20, and 25 %. A fiber-optic vis-NIR spectrophotometer (350-2500 nm) was used to measure spectra of soil samples in the diffuse reflectance mode. Spectra preprocessing and PLS regression were carried using Unscrambler® software. Statistica® software was used for ANN modeling. The best prediction result for SOC was obtained using the ANN (RMSEP = 0.82 % and RPD = 4.23) for soil samples with 25 % MC. The best prediction results for pH were obtained with PLS for dry soil samples (RMSEP = 0.65 % and RPD = 1.68) and soil samples with 10 % MC (RMSEP = 0.61 % and RPD = 1.71). Whereas the ANN showed better performance for SOC prediction at all MC levels, PLS showed better predictive accuracy of pH at all MC levels except for 25 % MC. Therefore, based on the data set used in the current study, the ANN is recommended for the analyses of SOC at all MC levels, whereas PLS is recommended for the analysis of pH at MC levels below 20 %.