3,441 research outputs found

    Adjustment of the infiltration curve by different empirical models

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    A estimativa de algumas propriedades físico-hídricas do solo, por meio do uso de modelos empíricos, constitui uma excelente alternativa para a redução do tempo e do custo das análises laboratoriais, especialmente para aplicação rápida e precisa desses valores em projetos agrícolas. O objetivo do presente trabalho é estimar a velocidade de infiltração de água no solo por meio de modelos empíricos propostos por Horton, Kostiakov e Kostiakov-Lewis e comparar os resultados com os dados obtidos em campo por meio do infiltrômetro de anel. A pesquisa foi conduzida em solo de textura arenosa da área experimental da Empresa Estadual de Pesquisas Agropecuárias – EMEPA, localizada no município de Lagoa Seca (PB). Foram realizados, ao longo da área experimental, um total de 65 testes de infiltração, por meio do infiltrômetro de anel. Os modelos de Horton, Kostiakov e Kostiakov-Lewis foram ajustados aos dados obtidos em campo com o infiltrômetro de anel. Dentre os modelos testados, o proposto por Horton foi o que apresentou o melhor desempenho. Entretanto, os prognósticos dos modelos de Horton, Kostiakov e Kostiakov-Lewis foram praticamente similares.Conocer las estimativas de algunas propiedades físico hídricas del suelo, através del uso de modelos empíricos constituye una excelente alternativa de reducción de costos y de tiempo para los analisis laboratoriales, en especial pala la aplicación rápida y precisa de esos valores en projectos agrícolas. El objetivo de este trabajo es estimar la velocidad de la infiltración del agua en el suelo usando el méctodo empírico propuesto por Horton Kostiakov y Kostiakov-Lewis y cvomparar los resultados con los datos obtenidos a campo con el uso del infiltrómetro de anillo. La pesquisa se condujo en suelo de textura arenosa del área experimental de la Empresa Estadual de Pesquisas Agropecuárias –EMBRAPA, localizada en la Municipalidad de Lagoa Seca  en el Estado de Pernambuco.  Realizamos aproximadamente 65 experimentos de infiltración con el infiltrómetro de anillo. Los modelos propuestos por Horton Kostiakov y Kostiakov-Lewis fueron ajustados a los datos obtenidos a campo con el infiltrómetro de anillo. Entre todos los modelos testados el de Horton presentó los mejores resultados. Entretanto, los pronósticos de los modelos Horton Kostiakov y Kostiakov – Lewis se mostraron muy similares.The estimation of some hydro-physical properties of soil through the use of empirical models is an excellent alternative for reducing the time and cost of laboratory tests, especially for quick and precise application of those values in agricultural projects. The aim of this study is to estimate the speed of infiltration of water into the soil by means of empirical models proposed by Horton, Kostiakov and Kostiakov-Lewis and comparing the results with data obtained in the field through the ring infiltrometer. The research was conducted in sandy soil texture of the experimental area of the State Enterprise for Agricultural Research - EMEPA, located in Lagoa Seca, PB. A total of 65 tests of infiltration through the ring infiltrometer were performed along the experimental area. The models of Horton, Kostiakov and Kostiakov-Lewis, were fitted to data obtained in the field with the ring infiltrometer. Among the models tested, the one proposed by Horton had the best performance. However, the prognostic models of Horton, Kostiakov and Kostiakov-Lewis were almost similar

    Visceral leishmaniasis in the State of Maranhão, Brazil: evolution of an epidemic

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    The authors provide a brief report on the historical evolution of visceral leishmaniasis in the State of Maranhão, Brazil, evaluating possible factors for growth of the disease in the State and control measures by the Brazilian Ministry of Health to integrate health services finto the maintenance of control programs.Os autores fazem um breve relato da evolução histórica da leishmaniose visceral no Estado do Maranhão, Brasil, avaliando as possíveis causas da expansão da referida doença no Estado, assim como as medidas de controle adotadas pelo Ministério da Saúde objetivando a diminuição da incidência da mesma.Universidade Federal do Maranhão Faculdade de Medicina Departamento de PatologiaEscola Paulista de MedicinaUNIFESP, EPMSciEL

    Oral cleft prevention programa (OCPP)

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    Background: Oral clefts are one of the most common birth defects with significant medical, psychosocial, and economic ramifications. Oral clefts have a complex etiology with genetic and environmental risk factors. There are suggestive results for decreased risks of cleft occurrence and recurrence with folic acid supplements taken at preconception and during pregnancy with a stronger evidence for higher than lower doses in preventing recurrence. Yet previous studies have suffered from considerable design limitations particularly non-randomization into treatment. There is also well-documented effectiveness for folic acid in preventing neural tube defect occurrence at 0.4 mg and recurrence with 4 mg. Given the substantial burden of clefting on the individual and the family and the supportive data for the effectiveness of folic acid supplementation as well as its low cost, a randomized clinical trial of the effectiveness of high versus low dose folic acid for prevention of cleft recurrence is warranted. Methods/design: This study will assess the effect of 4 mg and 0.4 mg doses of folic acid, taken on a daily basis during preconception and up to 3 months of pregnancy by women who are at risk of having a child with nonsyndromic cleft lip with/without palate (NSCL/P), on the recurrence of NSCL/P. The total sample will include about 6,000 women (that either have NSCL/P or that have at least one child with NSCL/P) randomly assigned to the 4 mg and the 0.4 mg folic acid study groups. The study will also compare the recurrence rates of NSCL/P in the total sample of subjects, as well as the two study groups (4mg, 0.4 mg) to that of a historical control group. The study has been approved by IRBs (ethics committees) of all involved sites. Results will be disseminated through publications and presentations at scientific meetings. Discussion: The costs related to oral clefts are high, including long term psychological and socio-economic effects. This study provides an opportunity for huge savings in not only money but the overall quality of life. This may help establish more specific clinical guidelines for oral cleft prevention so that the intervention can be better tailored for at-risk women

    Stand dynamics modulate water cycling and mortality risk in droughted tropical forest

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    Transpiration from the Amazon rainforest generates an essential water source at a global and local scale. However, changes in rainforest function with climate change can disrupt this process, causing significant reductions in precipitation across Amazonia, and potentially at a global scale. We report the only study of forest transpiration following a long-term (>10 year) experimental drought treatment in Amazonian forest. After 15 years of receiving half the normal rainfall, drought-related tree mortality caused total forest transpiration to decrease by 30%. However, the surviving droughted trees maintained or increased transpiration because of reduced competition for water and increased light availability, which is consistent with increased growth rates. Consequently, the amount of water supplied as rainfall reaching the soil and directly recycled as transpiration increased to 100%. This value was 25% greater than for adjacent nondroughted forest. If these drought conditions were accompanied by a modest increase in temperature (e.g., 1.5°C), water demand would exceed supply, making the forest more prone to increased tree mortality.Peer reviewe

    Influência da temperatura na germinação de Brassica napus L. var. oleífera.

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    O objetivo deste trabalho foi descrever a influência da variação de temperatura na germinação de quatro híbridos de canola indicados para cultivo no Brasil. O estudo foi realizado no ano de 2016, na Universidade Federal de Pelotas, – RS. O delineamento experimental utilizado foi o DIC, dispostos em esquema fatorial, 4 Híbridos x 3 temperaturas de geminação, com 4 repetições. Os híbridos utilizados foram o Hyola 50, Hyola 61, Hyola 571CL e Hyola 575CL e as temperaturas testadas foram 10, 20 e 30°C. A temperatura influenciou diretamente a germinação dos híbridos de canola. As temperaturas de 20° a 30°C foram as que promoveram maior incremento nas variáveis: primeira contagem, percentual de sementes germinadas, índice de velocidade de germinação, comprimento de radícula, comprimento de parte aérea, massa seca de plântula e redução no tempo médio de germinação. Os híbridos Hyola 61 e Hyola 571CL apresentaram melhor germinação quando expostos a temperatura de 10°C

    Ameliorating Systematic Uncertainties in the Angular Clustering of Galaxies: A Study using SDSS-III

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    We investigate the effects of potential sources of systematic error on the angular and photometric redshift, z_phot, distributions of a sample of redshift 0.4 < z < 0.7 massive galaxies whose selection matches that of the Baryon Oscillation Spectroscopic Survey (BOSS) constant mass sample. Utilizing over 112,778 BOSS spectra as a training sample, we produce a photometric redshift catalog for the galaxies in the SDSS DR8 imaging area that, after masking, covers nearly one quarter of the sky (9,913 square degrees). We investigate fluctuations in the number density of objects in this sample as a function of Galactic extinction, seeing, stellar density, sky background, airmass, photometric offset, and North/South Galactic hemisphere. We find that the presence of stars of comparable magnitudes to our galaxies (which are not traditionally masked) effectively remove area. Failing to correct for such stars can produce systematic errors on the measured angular auto-correlation function, w, that are larger than its statistical uncertainty. We describe how one can effectively mask for the presence of the stars, without removing any galaxies from the sample, and minimize the systematic error. Additionally, we apply two separate methods that can be used to correct the systematic errors imparted by any parameter that can be turned into a map on the sky. We find that failing to properly account for varying sky background introduces a systematic error on w. We measure w, in four z_phot slices of width 0.05 between 0.45 < z_phot < 0.65 and find that the measurements, after correcting for the systematic effects of stars and sky background, are generally consistent with a generic LambdaCDM model, at scales up to 60 degrees. At scales greater than 3 degrees and z_phot > 0.5, the magnitude of the corrections we apply are greater than the statistical uncertainty in w.Comment: Accepted by MNRA

    Antiparasitic Activity of Natural and Semi-Synthetic Tirucallane Triterpenoids from Schinus terebinthifolius (Anacardiaceae): Structure/Activity Relationships

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    Leishmaniasis and Chagas are diseases caused by parasitic protozoans that affect the poorest population in the World, causing a high mortality and morbidity. As a result of highly toxic and long-term treatments, the discovery of novel, safe and more efficacious drugs is essential. in this work, the in vitro antiparasitic activity and mammalian cytotoxicity of three natural tirucallane triterpenoids, isolated from leaves of Schinus terebinthifolius (Anacardiaceae), and nine semi-synthetic derivatives were investigated against Leishmania (L.) infantum and Trypanosoma cruzi. Trypomastigotes of T. cruzi were the most susceptible parasites and seven compounds demonstrated a trypanocidal activity with IC50 values in the range between 15 and 58 mu g/mL. Four compounds demonstrated selectivity towards the intracellular amastigotes of Leishmania, with IC50 values in the range between 28 and 97 mu g/mL. the complete characterization of triterpenoids was afforded after thorough analysis of nuclear magnetic resonance (NMR) data as well as electrospray ionization mass spectrometry (ESI-MS). Additionally, structure-activity relationships were performed using Decision Trees.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Universidade Federal de São Paulo, Inst Ciencias Ambientais Quim & Farmaceut, BR-09972270 Diadema, SP, BrazilAdolfo Lutz Inst, Ctr Parasitol, BR-01246902 São Paulo, BrazilUniv Fed Paraiba, Ctr Ciencias Aplicadas & Educ, BR-58297000 Rio Tinto, BrazilUniv Fed Uberlandia, Inst Quim, BR-38400902 Uberlandia, MG, BrazilUniversidade Federal de São Paulo, Inst Ciencias Ambientais Quim & Farmaceut, BR-09972270 Diadema, SP, BrazilCNPq: 300546/2012-2CNPq: 471458/2012-0FAPESP: 2011/51739-0FAPESP: 2012/18756-1FAPESP: 2013/16320-4Web of Scienc

    Genetic control of quality melon traits.

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    This research studied the genetic control of the traits related to melon fruit quality. The F1, F2, BC1, BC2 generations from the OL x A-16 and OL x PV crossings were evaluated in two separate trials conducted in randomized blocks with three replications. The evaluated traits were: average fruit weight, shape index, pulp thickness, pulp firmness, soluble solids content and cracking rate. The analyses were accomplished through a classic study of generations involving mixed models. The parameters on heritability and number of loci controlling the traits were evaluated in a broad and narrow sense. The inheritance of the evaluated traits is complex, presenting one gene of greater effect and polygenes with additive and dominant effects

    High dosage folic acid supplementation, oral cleft recurrence and fetal growth

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    Objectives: To evaluate the effects of folic acid supplementation on isolated oral cleft recurrence and fetal growth. Patients and Methods: The study included 2,508 women who were at-risk for oral cleft recurrence and randomized into two folic acid supplementation groups: 0.4 and 4 mg per day before pregnancy and throughout the first trimester. The infant outcome data were based on 234 live births. In addition to oral cleft recurrence, several secondary outcomes were compared between the two folic acid groups. Cleft recurrence rates were also compared to historic recurrence rates. Results: The oral cleft recurrence rates were 2.9% and 2.5% in the 0.4 and 4 mg groups, respectively. The recurrence rates in the two folic acid groups both separately and combined were significantly different from the 6.3% historic recurrence rate post the folic acid fortification program for this population (p = 0.0009 when combining the two folic acid groups). The rate of cleft lip with palate recurrence was 2.9% in the 0.4 mg group and 0.8% in the 4 mg group. There were no elevated fetal growth complications in the 4 mg group compared to the 0.4 mg group. Conclusions: The study is the first double-blinded randomized clinical trial (RCT) to study the effect of high dosage folic acid supplementation on isolated oral cleft recurrence. The recurrence rates were similar between the two folic acid groups. However, the results are suggestive of a decrease in oral cleft recurrence compared to the historic recurrence rate. A RCT is still needed to identify the effect of folic acid on oral cleft recurrence given these suggestive results and the supportive results from previous interventional and observational studies, and the study offers suggestions for such future studies. The results also suggest that high dosage folic acid does not compromise fetal growt
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