1,035 research outputs found
Impactos Nutricionais E Produção De Pimentão Submetido à Deficiência Hídrica
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The sweet pepper is a solanaceous plant of American origin with large consumption in Brazil. In order to study the effects of water stress on the sweet pepper crop, an experiment was conducted in greenhouse. The treatments consisted of soil water content (100%, 85%, 70% and 55% of moisture in the soil field capacity) in a randomized block design with 6 replicates where the experimental units consisted of 16 plants. During the experiment (47, 62, 77 and 92 days after planting) levels of macronutrients (N, P, K, Ca, Mg and S) and micronutrients (B, Cu, Fe, Mn and Zn) present in each plant fraction and the dry mass of plants for the accumulation of these determination were determined. At harvest the number, width and length of fruits from each plant were obtained. Variables were subjected to Tukey test at 5% probability. The water content in the soil interfered significantly with productive variables. To the accumulation of nutrients in the dry matter (leaf + stem) the elements with higher absorption are ordered as follows: K> N> Ca> Mg> S> P and Fe>Mn> Zn> B> Cu. © 2016, Universidade Estadual Paulista - UNESP. All rights reserved.214724735CNPq, Conselho Nacional de Desenvolvimento Científico e TecnológicoConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
Effect of chronic ethanol exposure on rat ventilatory responses to hypoxia and hypercapnia
OBJECTIVE: The effect of chronic ethanol exposure on chemoreflexes has not been extensively studied in experimental animals. Therefore, this study tested the hypothesis that known ethanol-induced autonomic, neuroendocrine and cardiovascular changes coincide with increased chemoreflex sensitivity, as indicated by increased ventilatory responses to hypoxia and hypercapnia. METHODS: Male Wistar rats were subjected to increasing ethanol concentrations in their drinking water (first week: 5% v/v, second week: 10% v/v, third and fourth weeks: 20% v/v). At the end of each week of ethanol exposure, ventilatory parameters were measured under basal conditions and in response to hypoxia (evaluation of peripheral chemoreflex sensitivity) and hypercapnia (evaluation of central chemoreflex sensitivity). RESULTS: Decreased respiratory frequency was observed in rats exposed to ethanol from the first until the fourth week, whereas minute ventilation remained unchanged. Moreover, we observed an increased tidal volume in the second through the fourth week of exposure. The minute ventilation responses to hypoxia were attenuated in the first through the third week but remained unchanged during the last week. The respiratory frequency responses to hypoxia in ethanol-exposed rats were attenuated in the second through the third week but remained unchanged in the first and fourth weeks. There was no significant change in tidal volume responses to hypoxia. With regard to hypercapnic responses, no significant changes in ventilatory parameters were observed. CONCLUSIONS: Our data are consistent with the notion that chronic ethanol exposure does not increase peripheral or central chemoreflex sensitivity
The Spatial Properties of L- and M-Cone Inputs to Electroretinograms That Reflect Different Types of Post-Receptoral Processing
yesWe studied the spatial arrangement of L- and M-cone driven electroretinograms (ERGs) reflecting
the activity of magno- and parvocellular pathways. L- and M-cone isolating sine
wave stimuli were created with a four primary LED stimulator using triple silent substitution
paradigms. Temporal frequencies were 8 and 12 Hz, to reflect cone opponent activity, and
30, 36 and 48 Hz to reflect luminance activity. The responses were measured for full-field
stimuli and for different circular and annular stimuli. The ERG data confirm the presence of
two different mechanisms at intermediate and high temporal frequencies. The responses
measured at high temporal frequencies strongly depended upon spatial stimulus configuration.
In the full-field conditions, the L-cone driven responses were substantially larger than
the full-field M-cone driven responses and also than the L-cone driven responses with
smaller stimuli. The M-cone driven responses at full-field and with 70° diameter stimuli displayed
similar amplitudes. The L- and M-cone driven responses measured at 8 and 12 Hz
were of similar amplitude and approximately in counter-phase. The amplitudes were constant
for most stimulus configurations. The results indicate that, when the ERG reflects luminance
activity, it is positively correlated with stimulus size. Beyond 35° retinal eccentricity,
the retina mainly contains L-cones. Small stimuli are sufficient to obtain maximal ERGs at
low temporal frequencies where the ERGs are also sensitive to cone-opponent processin
Predição De Classes De Solo Por Mineração De Dados Em área Da Bacia Sedimentar Do São Francisco
The objective of this work was to evaluate different strategies for the prediction of soil class distribution on digital soil maps of areas without reference data, in the sedimentary basin of San Francisco, in the north of the state of Minas Gerais, Brazil. The strategies included: Taxonomic generalization, training by field observations, training set expansion, and the use of different data mining algorithms. Four matrices were developed, differentiated by the volume of data for machine learning and by soil taxonomic levels to be predicted. The performance of the machine learning algorithms-Random Forest, J48, and MLP-, associated with discretization, class balancing, variable selection, and expansion of the training set was evaluated. Class balancing, variable discretization by equal frequencies, and the Random Forest algorithm showed the best performances. The representativeness extension of field observations, that assumes a larger training area, brought no predictive gain. Soil taxonomic generalization to the suborder level reduces the fragmentation of mapped polygons and improves the accuracy of digital soil maps. When generated by training on in situ soil observations at the mapping area, digital soil maps are as accurate as those trained on preexistent maps.5191396140
Correlation of serum leptin and insulin levels of pregnant protein-restricted rats with predictive obesity variables
During pregnancy and protein restriction, changes in serum insulin and leptin levels, food intake and several metabolic parameters normally result in enhanced adiposity. We evaluated serum leptin and insulin levels and their correlations with some predictive obesity variables in Wistar rats (90 days), up to the 14th day of pregnancy: control non-pregnant (N = 5) and pregnant (N = 7) groups (control diet: 17% protein), and low-protein non-pregnant (N = 5) and pregnant (N = 6) groups (low-protein diet: 6%). Independent of the protein content of the diet, pregnancy increased total (F1,19 = 22.28, P < 0.001) and relative (F1,19 = 5.57, P < 0.03) food intake, the variation of weight (F1,19 = 49.79, P < 0.000) and final body weight (F1,19 = 19.52, P < 0.001), but glycemia (F1,19 = 9.02, P = 0.01) and the relative weight of gonadal adipose tissue (F1,19 = 17.11, P < 0.001) were decreased. Pregnancy (F1,19 = 18.13, P < 0.001) and low-protein diet (F1,19 = 20.35, P < 0.001) increased the absolute weight of brown adipose tissue. However, the relative weight of this tissue was increased only by protein restriction (F1,19 = 15.20, P < 0.001) and the relative lipid in carcass was decreased in low-protein groups (F1,19 = 4.34, P = 0.05). Serum insulin and leptin levels were similar among groups and did not correlate with food intake. However, there was a positive relationship between serum insulin levels and carcass fat depots in low-protein groups (r = 0.37, P < 0.05), while in pregnancy serum leptin correlated with weight of gonadal (r = 0.39, P < 0.02) and retroperitoneal (r = 0.41, P < 0.01) adipose tissues. Unexpectedly, protein restriction during 14 days of pregnancy did not alter the serum profile of adiposity signals and their effects on food intake and adiposity, probably due to the short term of exposure to low-protein diet.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Brazilian Foundations FAPEMATUniversidade Federal de Mato Grosso Faculdade de Ciências MédicasUniversidade Federal de Mato Grosso Faculdade de Nutrição Departamento de Alimentos e NutriçãoUniversidade Estadual de Campinas Instituto de Biologia Departamento de Fisiologia e BiofísicaUniversidade Federal de São Paulo (UNIFESP) Departamento de Fisiologia da NutriçãoUNIFESP, Depto. de Fisiologia da NutriçãoBrazilian Foundations FAPEMAT: 175/04CNPq: 479138/2003-6SciEL
Impactos ambientais do manejo agroecológico da caatinga no Rio Grande do Norte.
O objetivo deste trabalho foi avaliar os impactos ambientais do manejo agroecológico da caatinga, em unidades de produção familiar no Rio Grande do Norte, pelo método Ambitec de produção animal - dimensão ambiental, desenvolvido pela Embrapa Meio Ambiente. Foram avaliadas sete unidades de produção familiar, em quatro projetos de assentamentos de reforma agrária do Município de Apodi, RN. Os dados para o levantamento foram obtidos por meio de questionários aplicados aos representantes das unidades produtivas familiares, que atribuíram, a cada variável estudada, um valor que representou a alteração proporcionada pela implementação da tecnologia. Após a inserção dos coeficientes de alteração de cada variável dos indicadores por unidade de produção, o coeficiente de impacto foi automaticamente calculado por meio da planilha Ambitec. O manejo agroecológico da caatinga resultou num impacto ambiental positivo, e suas maiores contribuições foram relacionadas aos efeitos positivos dos seguintes indicadores: capacidade produtiva do solo, uso de insumos materiais, qualidade do produto e diminuição da emissão de poluentes à atmosfera. Dois indicadores geraram efeitos negativos: o uso de energia e o uso de recursos naturais. Pela superioridade dos benefícios gerados, o manejo agroecológico da caatinga é uma inovação tecnológica geradora de impactos ambientais positivos
Testing the self-cleaning properties of a coordination polymer surface
It is well established that self-cleaning can be related to the hydrophobic or hydrophilic nature of a surface. Using adsorption chromatography, molecular simulations and wetting dynamics measurements, the self-cleaning properties of a new, strongly water resistant and hydrophilic cystine-containing coordination polymer (CP) were tested. Adsorption isotherms of n-octane and methanol were determined in the range of 313–343 K. Next the isosteric enthalpy of adsorption and the change in adsorption entropy were calculated to explain higher adsorption of methanol than n-butane. Performed chromatographic tests, molecular dynamics simulations and wetting dynamics experiments additionally prove that the Zn(Cys)2 CP is a promising material for the application in the preperation of self-cleaning surfaces or coatings
Physical activity: a strategy to improve antibody response to a SARS-CoV-2 vaccine booster dose in patients with autoimmune rheumatic diseases.
Physical activity associates with improved immunogenicity following a 2-dose schedule of CoronaVac (Sinovac's inactivated SARS-CoV-2 vaccine) in patients with autoimmune rheumatic diseases (ARD). This study evaluates whether physical activity impacts vaccine-induced antibody responses to a booster dose in this population. This was a phase-4 trial conducted in Sao Paulo, Brazil. Patients with ARD underwent a 3-dose schedule of CoronaVac. One month after the booster, we assessed seroconversion rates of anti-SARS-CoV-2 S1/S2 IgG, geometric mean titers of anti-S1/S2 IgG, frequency of positive neutralizing antibodies, and neutralizing activity. Physical activity was assessed through questionnaire. Physically active (n = 362) and inactive (n = 278) patients were comparable for most characteristics; however, physically active patients were younger (P<.01) and had a lower frequency of chronic inflammatory arthritis (P<.01). Adjusted models showed that physically active patients had -2 times odds of seroconversion rates (OR: 2.09; 95% confidence interval, 1.22 to 3.61), -22% greater geometric mean titers of anti-S1/S2 IgG (22.09%; 95% confidence interval, 3.91 to 65.60), and -7% greater neutralizing activity (6.76%; 95% confidence interval, 2.80 to 10.72) than inactive patients. Patients with ARD who are physically active have greater odds of experiencing better immunogenicity to a booster dose of CoronaVac. These results support the recommendation of physical activity to improve vaccination responses, particularly for immunocompromised individuals
Explaining the Higgs Decays at the LHC with an Extended Electroweak Model
We show that the recent discovery of a new boson at the LHC, which we assume
to be a Higgs boson, and the observed enhancement in its diphoton decays
compared to the SM prediction, can be explained by a new doublet of charged
vector bosons from an extended electroweak gauge sector model with
SU(3)_C\otimesSU(3)_L\otimesU(1)_X symmetry. Our results show a good
agreement between our theoretical expected sensitivity to a 126--125 GeV Higgs
boson and the experimental significance observed in the diphoton channel at the
8 TeV LHC. Effects of an invisible decay channel for the Higgs boson are also
taken into account, in order to anticipate a possible confirmation of deficits
in the branching ratios into , , bottom quarks, and tau leptons.Comment: 16 pages, 5 figure
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