87 research outputs found

    Adubação verde com nabo para soja em sistema de plantio direto no leste paraguaio

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    Um sistema de plantio direto de rotação soja-trigo foi praticado por muitos anos em uma "Terra Roxa" no leste do Paraguai. A compactação do solo e a erosão foram reconhecidas recentemente como problemas potenciais. Este estudo examina o efeito da substituição do trigo antieconômico pela adubação verde com nabo (Raphanus sativus L. var. oleiferus Metzg.) sobre as propriedades do solo e a produção de soja. A fase gasosa, porosidade, densidade do solo, saturação em água, índice de cone, pH, cátions trocáveis, fóforo disponível (P) e distribuição de agregados foram medidos. Ao contrário das expectativas iniciais, o nabo não reduziu a compactação do solo. Ao contrário, ele estabilizou a estrutura dos agregados na superfície do solo. Efeitos positivos do nabo no crescimento e produtividade da soja plantada em seguida, foram detectados em um ano muito seco, mas não em um ano excepcionalmente úmido. Em uma segunda parte desse estudo foram comparados os retornos de nutrientes do nabo e do trigo. O nabo produziu 10.7 t ha-1 de matéria seca da parte aérea e absorveu 294, 27, 302, 175, e 33 kg ha-1 de N, P, K, Ca, e Mg, respectivamente, enquanto o trigo 98, 11, 67, 11, e 7 kg ha-1 de N, P,K,Ca, e Mg, respectivamente. Aproximadamente 75% do N absorvido pelo trigo foi removido do solo por ocasião da colheita, enquanto que a maioria dos nutrientes do resíduo do nabo retornaram ao solo antes do plantio da soja, com efeitos positivos em relação à fertilidade do solo. Benefícios adicionais da adubação verde com nabo, incluem a probabilidade reduzida de erosão através da melhoria da estrutura dos agregados e uma melhor cobertura do solo.A no-tillage soybean-wheat cropping system has been practiced for many years on the "Terra Rossa" soils of eastern Paraguay. Soil compactness and soil erosion have recently been identified as potential problems. This study examines the effect of replacing unprofitable wheat by green-manure turnip (Raphanus sativus L. var. oleiferus Metzg.) on soil properties and soybean production. Gaseous phase, porosity, bulk density, water saturation, cone index, pH, exchangeable-cations, available-phosphorus (P) and aggregate size distribution of the soil were measured. Contrary to initial expectations, turnip did not reduce soil compactness. Instead, turnip stabilized the aggregate structure of the surface soil. Positive effects of turnip on subsequent soybean growth and yield were detected in a rather dry year but not in an exceptionally wet year. In a second part of this study, nutrient return from turnip and wheat residues were compared. Turnip produced 10.7 t ha-1 of shoot dry matter, and absorbed 294, 27, 302, 175, and 33 kg ha-1 of N, P, K, Ca, and Mg, respectively. Wheat absorbed 98, 11, 67, 11, and 7 kg ha-1 of N, P, K, Ca, and Mg, respectively. About 75% of the N absorbed by wheat was removed from the field at harvest whereas most nutrients in the turnip residue were returned to the soil before planting of soybeans with positive effects on soil fertility. Additional benefits of green-manure turnip would include a reduced chance for erosion through improvements in aggregate structure and through a more complete soil cover

    Effect of branched-chain amino acid supplementation on the oxidized/reduced state of plasma albumin in rats with chronic liver disease

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    We examined whether continuous supplementation with branched-chain amino acids phosphorylates ribosomal protein S6, a downstream effector of mammalian target of rapamycin, and improves hypoalbuminemia of rats with chronic liver disease. Sprague-Dawley rats were fed a casein diet (control group) or a branched-chain amino acid-supplemented casein diet (branched-chain amino acid group) for 11 weeks with repeated injections of carbon tetrachloride. Throughout this experimental period, no significant difference in plasma albumin concentration was seen between groups. The percentage of reduced albumin within total plasma albumin gradually decreased in both control and branched-chain amino acid groups. After 11 weeks with supplementation, phosphorylation of ribosomal protein S6 was significantly increased in the liver of rats in the branched-chain amino acid group compared with the control group. Furthermore, the percentage of reduced albumin within total albumin was significantly higher in the branched-chain amino acid group than in the control group. These results indicate that continuous supplementation with branched-chain amino acids in rats with chronic liver disease induces phosphorylation of hepatic ribosomal protein S6 and attenuates decreases in the percentage of reduced albumin, although levels of plasma albumin are not increased

    殻状吸水モデルに基づくクッキング速度式に関する研究

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    大量連続の炊飯装置など各種食品のクッキング装置を設計し,制御化などを行なっていくためには,クッキング速度式を設定し,それに含まれている速度パラメータを求めていくことが必要である。 一般に食品のクッキング現象は複雑で,厳密な意味でのクッキング速度式を得ることは困難である。しかし,例えば炊飯などのように,クッキング現象を殻状吸水現象などによって近似的に置きかえができるような場合には,概括的にはなるがクッキング速度式を設定することが可能である。 本研究は,当面する炊飯装置設計などに対応するために,殻状吸水モデルに基づいたクッキング速度式を設定する研究を行ない,米飯などの実験データを例として,シミュレーションを行なった結果を示した。 (1) クッキング速度が,水の吸水殻状部拡散律速と水と固体食品との反応律速とによって支配されるものと考えて,クッキング速度式を球,長い円柱および薄い平板形について設定した。 (2) クッキング速度式に含まれる速度パラメータを求めるための非線形最小二乗法を使用した電子計算機プログラムを作成した。また,この計算のパラメータ初期値を求めるために,何れか一つの律速を仮定して,速度パラメータを陽関数的に求める積分式を誘導した。 (3) 米,うどんおよびきしめんを,近似的に殻状吸水モデルが適用できる球,長い円柱および薄い平板形の食品例として考えて,速度パラメータの算出例を示した。理論的により意味のある速度パラメータを得て検討していくためには,未吸水核の消失現象を仔細に研究する実験などを行なっていくことが必要である。 本研究で示したクッキング速度式は,吸水殻と未吸水核が現われる食品に適用できる。速度パラメータの意味が究明されない限り半理論式的なものであるが,当面する各種のクッキング装置の設計などに対しては簡単な取り扱いをしており有用なものである。In order to design and to control automatically various cooking apparatuses, it is necessary to determine the cooking-rate equations and to obtain the rate parameters for the equations. In this study, we postulated the cooking-rate equations based on the water-soaking-shell models, and reported on the calculation methods of the rate parameters using a non-linear least square method. The rate parameters in the cooking-rate equations of rice, udon and kishimen (round and flat noodles of wheat flour, respectively) were determined at 92.5 °C, assuming the sphere, the long-cylinder and the infinite-slab. The lengths of udon and kishimen increased by the cooking, then the calculated values of these rate parameters did not give the exact theoretical values. The rate parameters in this paper are semi-theoretical or merely experimental ones, but may be adopted with satisfaction for the design of various cooking apparatuses

    Interleukin-4 downregulates the cyclic tensile stress-induced matrix metalloproteinases-13 and cathepsin b expression by rat normal chondrocytes

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    Mechanical stress plays a key role in the pathogenesis of cartilage destruction seen in osteoarthritis (OA). We investigated the effect of cyclic tensile stress (CTS) on the anabolic and catabolic gene expression of rat cultured normal chondrocytes using the Flexercell strain unit. The effects of interleukin (IL)-4, a chondroprotective cytokine, on the changes in gene expression induced by CTS were also investigated. CTS (7% elongation at 0.5 Hz) for 24 h did not affect the expression of aggrecan and type II collagen, whereas CTS significantly upregulated matrix metalloproteinase (MMP)-13 and cathepsin B mRNA expression by chondrocytes. IL-1beta expression was also signifi cantly upregulated by CTS up to 12 h. The upregulation of MMP-13 was observed at 3 h, which was earlier than that of IL-1beta. Furthermore, pre-treatment with IL-4 (10 ng/ml) suppressed both MMP-13 and cathepsin B induction by mechanical stress, as well as CTS-induced IL-1beta expression. Our results suggest that IL-4 might have a therapeutic value in the treatment of OA by downregulation of mechanical stress-induced MMP-13 and cathepsin B expression by chondrocytes.</p

    〈Research Reports〉Continuous soil moisture monitoring under high salinity conditions by dielectric sensors: a reliability test

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    Generalized screening theorem for Higgs decay processes in the two-doublet model

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    The radiative corrections to the decay processes of the neutral (CPCP-even) Higgs boson (HH) into a longitudinal gauge boson pair, {\it i.e.}, HZLZLH \rightarrow Z_{L}Z_{L} and HWL+WLH \rightarrow W_{L}^{+}W_{L}^{-} are analyzed in the two-Higgs doublet model by assuming that all of the Higgs boson masses are much greater than the WW and ZZ bosons'. These calculations are motivated to see if one could see potentially large virtual effects to these decay rates due to the charged and CPCP-odd neutral Higgs boson masses (mGm_{G} and mAm_{A}, respectively) which are supposed to be larger than mHm_{H}. It is pointed out that, although the radiative corrections to the decay width Γ(HWL+WL)\Gamma (H\rightarrow W_{L}^{+}W_{L}^{-}) depend sensitively in general on mGm_{G} and mAm_{A}, there occurs a screening effect, {\it i.e.,} cancellation in leading terms once we set mG=mAm_{G}=m_{A}, so that the radiative corrections tend to be minimized. It is also pointed out that the decay rate Γ(HZLZL)\Gamma (H\rightarrow Z_{L}Z_{L}) is fairly insensitive to the other heavier Higgs masses and is possibly a good measuring tool of the Higgs mixing angle. The mechanism of these screening phenomena in the Higgs decays is explained on the basis of a new screening theorem, which we postulate with reference to the custodial symmetry in the Higgs potential.Comment: 42 pages, latex, 9 figure

    A preliminary proposal of policy for dairy herd health management from the viewpoints of culling in the Hiroshima University Farm

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    近年日本の乳牛の平均除籍産次数が3.4産程度に低下しており,対策が必要な現状にある.本研究の目的は,本学農場の乳牛除籍の傾向を把握して,対策について考察することである.2000~2015年度の本農場の記録をもとに解析した.本農場では常時20~25頭程度の搾乳牛が飼養され,2011年3月までは1日2回のパーラー搾乳,それ以降は24時間自動搾乳が行われた.期間内に83頭の乳牛が除籍になり,うち67頭が肉畜として出荷され,16頭が農場内で死亡した.除籍頭数割合は産次とともに増加し,6産時が最も多かった.除籍率は,初産時が最も低く,徐々に増加して4産,5産時に40%を超え,6産時に急激に増加して77.8%となった.除籍理由として,繁殖障害,乳房炎等の疾病が推察された.一般的な繁殖成績改善と疾病予防を進めるとともに,6産以降は繁殖と疾病の履歴に基づき,飼養継続の判断基準確立が必要と考えられた.In Japan, mean value for parity of dairy cows at culling has decreased to 3.4; measures to improve this are required. The aim of the present study is to understand the trends of culling of dairy cows at the Hiroshima University Farm. For that purpose, the farm’s records for dairy cow culling during the period of 2000–2015 were analyzed. At the farm, 20–27 dairy cows are regularly being milked. In March 2011, the milking system at the farm was changed from a milking parlor system to an automatic milking system. During the 16 years analyzed, 67 cows sold for meat and 16 cows that died at the farm totaled to 83 culled cows. The proportion of culled cows for each parity to total culled cows increased with increasing parity, and the number of cows culled at their 6th parity was the highest. The proportion of culled cows to cows that delivered at each parity gradually increased to more than 40% at the 5th parity, and drastically increased to more than 77.8% at the 6th parity. The reasons for culling were reproductive difficulty and diseases, such as mastitis. Therefore, general measures for improving reproductive performance and disease prevention should be taken for the cows at the 4th or lower parity. In addition, for dairy cows at the 5th or higher parity, a diagnostic decision on whether they are artificially inseminated for further delivery or not might be required depending on the individual cow’s record of reproduction and diseases

    Farnesyl pyrophosphate regulates adipocyte functions as an endogenous PPARγ agonist

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    The cholesterol biosynthetic pathway produces not only sterols but also non-sterol mevalonate metabolites involved in isoprenoid synthesis. Mevalonate metabolites affect transcriptional and post-transcriptional events that in turn affect various biological processes including energy metabolism. In the present study, we examine whether mevalonate metabolites activate PPARγ (peroxisome-proliferator-activated receptor γ), a ligand-dependent transcription factor playing a central role in adipocyte differentiation. In the luciferase reporter assay using both GAL4 chimaera and full-length PPARγ systems, a mevalonate metabolite, FPP (farnesyl pyrophosphate), which is the precursor of almost all isoprenoids and is positioned at branch points leading to the synthesis of other longer-chain isoprenoids, activated PPARγ in a dose-dependent manner. FPP induced the in vitro binding of a co-activator, SRC-1 (steroid receptor co-activator-1), to GST (glutathione transferase)–PPARγ. Direct binding of FPP to PPARγ was also indicated by docking simulation studies. Moreover, the addition of FPP up-regulated the mRNA expression levels of PPARγ target genes during adipocyte differentiation induction. In the presence of lovastatin, an HMG-CoA (3-hydroxy-3-methylglutaryl-CoA) reductase inhibitor, both intracellular FPP levels and PPARγ-target gene expressions were decreased. In contrast, the increase in intracellular FPP level after the addition of zaragozic acid, a squalene synthase inhibitor, induced PPARγ-target gene expression. The addition of FPP and zaragozic acid promotes lipid accumulation during adipocyte differentiation. These findings indicated that FPP might function as an endogenous PPARγ agonist and regulate gene expression in adipocytes
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