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991.
Ludy Keino Frederick Baijukya Wilson Ng’etich Abigael N. Otinga John R. Okalebo Ruth Njoroge John Mukalama 《PloS one》2015,10(12)
Low soybean yields in western Kenya have been attributed to low soil fertility despite much work done on nitrogen (N) and phosphorus (P) nutrition leading to suspicion of other nutrient limitations. To investigate this, a nutrient omission trial was set up in the greenhouse at the University of Eldoret-Kenya to diagnose the nutrients limiting soybean production in Acrisols from Masaba central and Butere sub-Counties, and Ferralsols from Kakamega (Shikhulu and Khwisero sub-locations) and Butula sub-Counties and to assess the effect of liming on soil pH and soybean growth. The experiment was laid out in a completely randomized design with ten treatments viz; positive control (complete), negative control (distilled water), complete with lime, complete with N, minus macronutrients P, potassium (K), calcium (Ca), magnesium (Mg) and sulphur (S) and with, micro-nutrients boron (B), molybdenum (Mo), manganese (Mn), copper (Cu) and zinc (Zn) omitted. Visual deficiency symptoms observed included interveinal leaf yellowing in Mg omission and N addition and dark green leaves in P omission. Nutrients omission resulted in their significantly low concentration in plant tissues than the complete treatment. Significantly (P≤ 0.05) lower shoot dry weights (SDWs) than the complete treatment were obtained in different treatments; omission of K and Mg in Masaba and Shikhulu, Mg in Khwisero, K in Butere and, P, Mg and K in Butula. Nitrogen significantly improved SDWs in soils from Kakamega and Butula. Liming significantly raised soil pH by 9, 13 and 11% from 4.65, 4.91 and 4.99 in soils from Masaba, Butere and Butula respectively and soybean SDWs in soils from Butere. The results show that, poor soybean growth was due to K, Mg and P limitation and low pH in some soils. The results also signify necessity of application of small quantities of N for initial soybean use. 相似文献
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Frederick J. Schnell Sarah Sundholm Stacy Crumley Patrick L. Iversen Dan V. Mourich 《PLoS pathogens》2012,8(12)
The viral family Arenaviridae includes a number of viruses that can cause hemorrhagic fever in humans. Arenavirus infection often involves multiple organs and can lead to capillary instability, impaired hemostasis, and death. Preclinical testing for development of antiviral or therapeutics is in part hampered due to a lack of an immunologically well-defined rodent model that exhibits similar acute hemorrhagic illness or sequelae compared to the human disease. We have identified the FVB mouse strain, which succumbs to a hemorrhagic fever-like illness when infected with lymphocytic choriomeningitis virus (LCMV). FVB mice infected with LCMV demonstrate high mortality associated with thrombocytopenia, hepatocellular and splenic necrosis, and cutaneous hemorrhage. Investigation of inflammatory mediators revealed increased IFN-γ, IL-6 and IL-17, along with increased chemokine production, at early times after LCMV infection, which suggests that a viral-induced host immune response is the cause of the pathology. Depletion of T cells at time of infection prevented mortality in all treated animals. Antisense-targeted reduction of IL-17 cytokine responsiveness provided significant protection from hemorrhagic pathology. F1 mice derived from FVB×C57BL/6 mating exhibit disease signs and mortality concomitant with the FVB challenged mice, extending this model to more widely available immunological tools. This report offers a novel animal model for arenavirus research and pre-clinical therapeutic testing. 相似文献
994.
In order to study the effect of temperature on the growth of individual fruits in cucumber (cucumis sativus L. cv. Corona), fruits were grown at 17. 5. 20,25 and 30°C continuously or the fruit temperature was changed from 17. 5 to 27.5°C or vice versa. Fruit development appeared to be closely related to the temperature sum. When the growth of a fruit was not constrained by assimilate supply, a decrease in growing period with increasing temperature was more than compensated for by a strong increase in growth rate, resulting in an increase in final fruit weight. However, when the growth of a fruit was constrained by assimilate supply, the increase in growth rate with increasing temperature was small and did not compensate for the decrease in growing period, resulting in a decrease in final fruit weight. Determinations of cell number and size showed that the effect of temperature on fruit growth was due to effects on cell expansion rather than on cell division. When growth was not constrained by assimilate supply. However, when assimilate supply did constrain fruit growth the number of cells per fruit decreased with increasing temperature, while the effect on cell size was negligible. In all stages of fruit development, the growth rate of a cucumber fruit responded within one day to a change in temperature. It was not irreversibly impaired by a low temperature (17. 5°C) during the early development of a fruit. A high temperature treatment (27. 5°C), however, had a great effect on the growth rate of a fruit after the temperature treatment had terminated. At all stages of fruit development (even before anthesis) a period of four days at 27. 5°C resulted in a pronounced stimulation of the growth rate afterwards at 17. 5°C. 相似文献
995.
Frederick Ronald Hayes 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1930,13(1):214-222
Summary The physiological significance of changes in the sailinity of the outer medium on aquatic life is discussed.There is reason to believe that Paramaecium reacts to changes in salinity in at least 4 ways: 1, an alteration in body shape; 2, a change in volume; 3, a variation in the proportion of water; 4, a deviation from the normal rate of respiration.There is a decrease in the rate of oxygen consumption with increasing salinity up to approximately the point where the inner outer media are isotonic. Higher salinities cause the breathing to increase in intensity.The curve representing this process is thus U shaped.It is a pleasure to express my thanks to Professor W. v. Budden-Brock both for the suggestion of this problem and for constant help through the work. Certain tests were carried out in the Physiologisches Institut, Kiel, through the kind permission of Professor R. Höber. 相似文献
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999.
Thioridazine (Mellaril®) was given to 104 psychiatric patients with a variety of illnesses, chiefly schizophrenic reactions. Of 14 patients treated in a double-blind study with successive one-month courses of drug or placebo, nine improved most on the drug and only one on placebo. These results, although limited, confirm a definite therapeutic action for this compound.Nine of 24 patients were significantly improved after treatment with thioridazine for an average of four months following previous treatwith other phenothiazine tranquilizers. Of ten patients treated intensively with thioridazine after they had not responded to other phenothiazine drugs, two were definitely improved and three were slightly improved. Twenty-eight of 56 patients treated from the outset with thioridazine were significantly improved after an average of six months. Most patients received from 100 to 400 mg. daily. These results were comparable to those obtained from other potent phenothiazine tranquilizers. The drug is particularly advantageous for a group of schizophrenic patients who are sometimes made worse by other phenothiazine derivatives or rauwolfia alkaloids. It should also be suitable for treating patients with psychoneuroses and chronic brain syndromes.Only minimal side reactions were observed, chiefly drowsiness, dizziness and nasal stuffiness. Weight gain occurred frequently during treatment. 相似文献
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