552 research outputs found

    Quantification of soil organic matter using mathematical models based on colorimetry in the Munsell color system

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    O presente estudo teve como objetivo desenvolver modelos matemáticos para a quantificação do teor de matéria orgânica, a partir da cor do solo, obtida por aparelho colorímetro no sistema Munsell de cores. Para esse fim, 912 amostras de solo foram coletadas na região de Porto Grande (Amapá) e enviadas para análises química, granulométrica e determinação da cor em amostras secas e úmidas. Os componentes valor e croma da cor do solo no sistema Munsell, obtidos por colorímetro, foram utilizados para quantificar através de regressão múltipla passo a passo (stepwise) o teor de matéria orgânica do solo. O modelo de predição com base em todas as amostras apresentou R² de 0,66 para amostras úmidas e 0,56 para amostras secas, ao serem validados utilizando amostras independentes. Foi possível ainda melhorar os modelos quando as amostras foram separadas por classe de solo ou textura, e os modelos gerados com base em cores de amostras úmidas foram sistematicamente superiores àqueles utilizando amostras secas. Em relação às classes de solo, os melhores resultados foram obtidos para Argissolos e Latossolos, ambos gerando um R² de validação independente de 0,73 (amostra úmida). Para textura, os melhores resultados foram obtidos para solos de textura muito argilosa, com R² de validação de 0,81 (amostra úmida). Os modelos de predição de matéria orgânica em função da cor do solo possuem simplicidade e potencial para serem utilizados no laboratório e no campo, especialmente para Argissolos e Latossolos de textura argilosa, de maneira automática e sem necessidade de uso de produtos ou reagentes.This study aimed to derive mathematical models to predict the soil organic matter content based on soil color obtained by a colorimeter in the Munsell color system. A total of 907 soil samples were collected in the region of Porto Grande (Amapá, Brazil) and analyzed in the laboratory for chemical properties, particle size distribution and color of dry and wet samples. The Munsell color components value and croma obtained using a colorimeter were used to predict soil organic matter content based on stepwise multiple linear regression. Models derived using all samples had R² of 0.66 for wet samples and 0.56 for dry samples, respectively, when validated using independent samples. It was possible to improve the models by separating the samples by soil class or texture. The models derived using colors obtained from wet samples were systematically better than those based on dry samples. Among soil classes, best results were obtained for Argissolos (Ultisols) and Latossolos (Oxisols), both having an R² of independent validation of 0.73 (wet sample). For texture, best results were obtained for very clayey soils, with an R² of validation of 0.81 (wet sample). The soil organic matter prediction models based on soil color have simplicity and potential to be used in the laboratory and in the field with quick and unnecessary chemical products, especially for Ultisols and Oxisols of clayey texture.CNPq/PQ e CNPq/PIBI

    Association of cypermethrin, dichlorvos and piperonyl butoxide against Rhipicephalus (Boophilus) microplus in naturally infested cattle

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    This study evaluated the effectiveness of cypermethrin (5%) associated to dichlorvos (45%) and piperonylbutoxide (25%) against R. (B.) microplus in naturally infested cattle. Forty bovine females were selected,after three consecutive counts (days -3, -2 and -1) of engorged females of R. (B.) microplus, between 4.5and 8.0 mm in length, on the left side of each animal. For the average of these three counts, the animalswere randomized into four groups of 10 bovines each, on day zero, treated with topical administration(Spray) of this compound at a dose of 1:400 and 1:800 and the positive control group (cypermethrin 15% +chlorpirivos 25% + citronella 1%) at the dose of 1:800. To evaluate the treatment effectiveness were realizedfurther tick counts on days 3rd, 7th, 14th, 21st, 28th and 35th day post-treatment (DPT). It was found that thecombination of Cypermethrin, dichlorvos and piperonyl butoxide, for both studied doses, demonstratedeffectiveness with at least 95%, between the 3rd to 21st DPT, reducing significantly (P<0.01) the tick femalesnumber in the groups treated when they were compared to the control group, observed during all bioassay(35 days), representing an effective alternative in the chemotherapy control by the parasitism of thisixodidae.Este estudo avaliou a eficácia antiparasitária da associação de cipermetrina (5%), diclorvos (45%) ebutóxido de piperolina (25%) contra R. (B.) microplus em bovinos naturalmente infestados. Foramselecionadas 40 fêmeas bovinas após três contagens consecutivas (dias -3, -2 e -1) de fêmeasingurgitadas de R. (B.) microplus, entre 4,5 e 8,0 mm de comprimento, presentes no lado esquerdo de cadaanimal. Pela média das três contagens, os animais foram divididos em quatro grupos de 10 animais cada,sendo no dia zero, tratados com a administração tópica (pulverização) deste composto na dose de 1:400 e1:800 e para o grupo controle positivo (cipermetrina 15% + clorpirivos 25%+ citronela 1%) na dose de 1:800.Para avaliação da eficácia antiparasitária foram realizadas novas contagens de R. (B.) microplus nos dias3°, 7°, 14°, 21°, 28° e 35° pós-tratamento (DPT). V erificou-se que a associação de Cipermetrina, Diclorvos eButóxico de Piperolina, nas duas posologias estudadas, demonstrou eficácia mínima de 95% do 3o ao 21°DPT, reduzindo significativamente (P<0,01) o número de fêmeas de R. (B.) microplus nos grupos tratadosem relação ao grupo controle, entre o 3° e 35° DPT, representando uma alternativa eficaz no controlequimioterápico do parasitismo por este ixodídeo

    Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

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    This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good

    Juxtaposing BTE and ATE – on the role of the European insurance industry in funding civil litigation

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    One of the ways in which legal services are financed, and indeed shaped, is through private insurance arrangement. Two contrasting types of legal expenses insurance contracts (LEI) seem to dominate in Europe: before the event (BTE) and after the event (ATE) legal expenses insurance. Notwithstanding institutional differences between different legal systems, BTE and ATE insurance arrangements may be instrumental if government policy is geared towards strengthening a market-oriented system of financing access to justice for individuals and business. At the same time, emphasizing the role of a private industry as a keeper of the gates to justice raises issues of accountability and transparency, not readily reconcilable with demands of competition. Moreover, multiple actors (clients, lawyers, courts, insurers) are involved, causing behavioural dynamics which are not easily predicted or influenced. Against this background, this paper looks into BTE and ATE arrangements by analysing the particularities of BTE and ATE arrangements currently available in some European jurisdictions and by painting a picture of their respective markets and legal contexts. This allows for some reflection on the performance of BTE and ATE providers as both financiers and keepers. Two issues emerge from the analysis that are worthy of some further reflection. Firstly, there is the problematic long-term sustainability of some ATE products. Secondly, the challenges faced by policymakers that would like to nudge consumers into voluntarily taking out BTE LEI

    Severe early onset preeclampsia: short and long term clinical, psychosocial and biochemical aspects

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    Preeclampsia is a pregnancy specific disorder commonly defined as de novo hypertension and proteinuria after 20 weeks gestational age. It occurs in approximately 3-5% of pregnancies and it is still a major cause of both foetal and maternal morbidity and mortality worldwide1. As extensive research has not yet elucidated the aetiology of preeclampsia, there are no rational preventive or therapeutic interventions available. The only rational treatment is delivery, which benefits the mother but is not in the interest of the foetus, if remote from term. Early onset preeclampsia (<32 weeks’ gestational age) occurs in less than 1% of pregnancies. It is, however often associated with maternal morbidity as the risk of progression to severe maternal disease is inversely related with gestational age at onset2. Resulting prematurity is therefore the main cause of neonatal mortality and morbidity in patients with severe preeclampsia3. Although the discussion is ongoing, perinatal survival is suggested to be increased in patients with preterm preeclampsia by expectant, non-interventional management. This temporising treatment option to lengthen pregnancy includes the use of antihypertensive medication to control hypertension, magnesium sulphate to prevent eclampsia and corticosteroids to enhance foetal lung maturity4. With optimal maternal haemodynamic status and reassuring foetal condition this results on average in an extension of 2 weeks. Prolongation of these pregnancies is a great challenge for clinicians to balance between potential maternal risks on one the eve hand and possible foetal benefits on the other. Clinical controversies regarding prolongation of preterm preeclamptic pregnancies still exist – also taking into account that preeclampsia is the leading cause of maternal mortality in the Netherlands5 - a debate which is even more pronounced in very preterm pregnancies with questionable foetal viability6-9. Do maternal risks of prolongation of these very early pregnancies outweigh the chances of neonatal survival? Counselling of women with very early onset preeclampsia not only comprises of knowledge of the outcome of those particular pregnancies, but also knowledge of outcomes of future pregnancies of these women is of major clinical importance. This thesis opens with a review of the literature on identifiable risk factors of preeclampsia

    Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

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    Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

    Search for stop and higgsino production using diphoton Higgs boson decays

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    Results are presented of a search for a "natural" supersymmetry scenario with gauge mediated symmetry breaking. It is assumed that only the supersymmetric partners of the top-quark (stop) and the Higgs boson (higgsino) are accessible. Events are examined in which there are two photons forming a Higgs boson candidate, and at least two b-quark jets. In 19.7 inverse femtobarns of proton-proton collision data at sqrt(s) = 8 TeV, recorded in the CMS experiment, no evidence of a signal is found and lower limits at the 95% confidence level are set, excluding the stop mass below 360 to 410 GeV, depending on the higgsino mass

    Impacts of the Tropical Pacific/Indian Oceans on the Seasonal Cycle of the West African Monsoon

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    The current consensus is that drought has developed in the Sahel during the second half of the twentieth century as a result of remote effects of oceanic anomalies amplified by local land–atmosphere interactions. This paper focuses on the impacts of oceanic anomalies upon West African climate and specifically aims to identify those from SST anomalies in the Pacific/Indian Oceans during spring and summer seasons, when they were significant. Idealized sensitivity experiments are performed with four atmospheric general circulation models (AGCMs). The prescribed SST patterns used in the AGCMs are based on the leading mode of covariability between SST anomalies over the Pacific/Indian Oceans and summer rainfall over West Africa. The results show that such oceanic anomalies in the Pacific/Indian Ocean lead to a northward shift of an anomalous dry belt from the Gulf of Guinea to the Sahel as the season advances. In the Sahel, the magnitude of rainfall anomalies is comparable to that obtained by other authors using SST anomalies confined to the proximity of the Atlantic Ocean. The mechanism connecting the Pacific/Indian SST anomalies with West African rainfall has a strong seasonal cycle. In spring (May and June), anomalous subsidence develops over both the Maritime Continent and the equatorial Atlantic in response to the enhanced equatorial heating. Precipitation increases over continental West Africa in association with stronger zonal convergence of moisture. In addition, precipitation decreases over the Gulf of Guinea. During the monsoon peak (July and August), the SST anomalies move westward over the equatorial Pacific and the two regions where subsidence occurred earlier in the seasons merge over West Africa. The monsoon weakens and rainfall decreases over the Sahel, especially in August.Peer reviewe

    Measurement of associated W plus charm production in pp collisions at √s=7 TeV

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    Peer reviewe
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