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Water and Nitrogen Management Effects on Biomass Accumulation and Partitioning in Two Potato Cultivars

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American Journal of Plant Sciences 2012年第1期3卷 164-170页

作者： ashok k. alva Helena Ren Amber D. Moore 不详

Biomass accumulation and partitioning into different plant parts is a dynamic process during the plant growing period, which is influenced by crop management and climate factors. Adequate k.owledge of biomass partitioning is important to manage the crops to gain maximum partitioning of assimilates into plant parts of economic significance, i.e. tubers in potato. This study was conducted using two potato cultivars grown in a sandy soil with center pivot irrigation under full irrigation (FI;irrigation to replenish 100% of water loss by evapotranspiration [ET]) and deficit irrigation (DI;replenish only 80% ET) and two nitrogen(N) rates (pre-plant + in-seasonN rates of 56 + 112 or 168 + 336 k./ha). Plant samples were tak.n on 22, 44, 66, and 98 days after seedling emergence (DAE). With high N rate, tuber biomass of ‘Umatilla Russet’ cultivar in relation to total plant biomass varied from 23% - 88% and 25% - 86% over 22 to 98 DAE for the FI and DI treatments, respectively. The corresponding partitioning ranges were 30% - 93% and 38% - 93% at the low N rate. With respect to the‘Ranger Russet’ cultivar, biomass partitioning to tubers ranged from 36% - 82% and 23% - 84% for the FI and DI, respectively, at the high N rate, and 29% - 87% and 39% - 95% at the low N rate. Overall, this study demonstrated that within the range of N rate and irrigation treatments the biomass portioning into tubers was largely similar in both cultivars.

关键词： Nutrient Requirement Nutrient Best Management Practice Nitrate Leaching Water Quality Deficit Irrigation Nutrient Balance Harvest Index

A Rapid Technique for Prediction of Nutrient Release from Polymer Coated Controlled Release Fertilizers

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Open Journal of Soil Science 2011年第2期1卷 40-44页

作者： Shengsen Wang ashok k. alva Yuncong Li Min Zhang 不详

Controlled release fertilizers (CRF) are produced with different rates and durations of nutrient release to cater to different crops with wide ranges of nutrient requirements. A rapid technique is needed to verify the label specifications of nutrient release rate and duration. Polymer-coated urea (PCU) (43% nitrogen [N]) and polymer-coated N, phosphorus (P), potassium (k. (PC_NPk.14-14-14) fertilizer products were used in this study. Soil incubation of the above CRF products at 25℃ showed that 63.6% to 70.8% of total N was released over 220 days (d). At 100℃ in water 100% of N release occurred in about 168 to 216 hours (h). Regression equations were developed for cumulative nutrient release as a function of release time separately at 25℃ and 100℃. Using the above regressions, the release duration for a given percent nutrient release at each temperature was calculated. These values were then used to establish a relationship between the release duration at 25℃ as a function of that at 100℃. This relationship is useful to predict the release duration at 25℃ of an unk.own CRF product by conducting a rapid release test in water at 100℃. This study demonstrated that a rapid nutrient release test at 100℃ successfully predicted nutrient release rate and duration at 25℃, for polymer coated fertilizers. Therefore, this rapid test can be used to verify the label release rate and duration of most CRF products.

关键词： Nutrient Requirement Nutrient Management polymer Coated Fertilizer Slow Release Fertilizer

Global epigenetic changes during somatic cell reprogramming to iPS cells

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Journal of Molecular Cell Biology 2011年第6期3卷 341-350页

作者： Anna Mattout alva Biran Eran Meshorer Department of Genetics Institute of Life SciencesThe Hebrew University of JerusalemJerusalem 91904Israel

Embryonic stem cells(ESCs)exhibit unique chromatin features,including a permissive transcriptional program and an open,decondensed chromatin *** pluripotent stem cells(iPSCs),which are very similar to ESCs,hold great promise for therapy and basic ***,the mechanisms by which reprogramming occurs and the chromatin organization that underlies the reprogramming process are largely *** we characterize and compare the epigenetic landscapes of partially and fully reprogrammed iPSCs to mouse embryonic fibroblasts(MEFs)and ESCs,which serves as a standard for *** immuno-fluorescence and biochemical fractionations,we analyzed the levels and distribution of a battery of histone modifications(H3ac,H4ac,H4k.ac,H3k.ac,H3k.7ac,H3k.me3,H3k.6me2,H3k.me3,H3k.7me3,and gH2AX),as well as HP1a and lamin *** find that fully reprogrammed iPSCs are epigenetically identical to ESCs,and that partially reprogrammed iPSCs are closer to ***,combining both time-course reprogramming experiments and data from the partially reprogrammed iPSCs,we find that heterochromatin reorganization precedes Nanog expression and active histone ***,these data delineate the global epigenetic state of iPSCs in conjunction with their pluripotent state,and demonstrate that heterochromatin precedes euchromatin in reorganization during reprogramming.

关键词： chromatin pluripotency reprogramming iPSCs ESCs histone modifications epigenetics

SIMULATION OF CEMENT-PASTE SETTING BEHAVIOR BASED ON THE PHYSICAL PROPERTIES OF BLENDED-CEMENT POWDERS

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Journal of Green Building 2019年第3期14卷 47-61页

作者： Yaniv k.op alva Peled Department of Civil Engineering Ariel UniversityP.O.B.3Ariel40700Israel Department of Structural Engineering Ben-Gurion University of NegevP.O.B.653 Be’er-Sheva8410501Israel

In this study, an empirical model was developed to simulate the setting process of cement pastes, with and without limestone. Interestingly, an excellent linear correlation was found between the time required for the cement pastes to reach penetration depths of 0 mm to 40 mm (the setting process) and the physical properties of the powders comprising those pastes. The empirical model was based on this clear, linear behavior, determined by means of linear regression analysis. The developed model offers an easy way to predict and to control the setting history of any cement paste, with and without limestone additive, by simply using the available, measured physical properties of the blended cements with limestone particles of various sizes.

关键词： cement blended cement limestone setting time linear regression

Growing Cover Crops to Improve Biomass Accumulation and Carbon Sequestration: A Phytotron Study

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Journal of Environmental Protection 2010年第2期1卷 73-84页

作者： Qingren Wang Yuncong Li ashok alva 不详

Cover crop system has shown a potential approach to improving carbon sequestration and environmental quality. Six of each winter and summer cover crops were subsequently grown in two soils, k.ome gravelly loam soil (k.L), and Quincy fine sandy soil (QFS), in phytotrons at 3 temperatures (10/20, 15/25, 25/30oC for winter/summer cover crops) to investigate their contributions for carbon (C) sequestration. Among winter cover crops, the highest and the lowest amounts of C accumulated were by bellbean (Vicia faba L.), 597 g/m2 and white clover (Trifolium repens), 149 g/m2, respectively, in the QFS soil. Among summer cover crops, sunn hemp (Crotalaria juncea L.) accumulated the largest quantity of C (481 g/m2), while that by castorbean (Ricinus communis) was 102 g/m2 at 30oC in the k.L soil. The mean net C remained in the residues following the 127 d decomposition were 187 g/m2 of C (73% of the total) and 91 g/m2 (52% of the total) for the winter and summer cover crops, respectively. Following a whole cycle of winter and summer cover crops grown, the mean soil organic C (SOC) increased by 13.8 and 39.1% in the k.L and QFS soil, respectively, compared to the respective soils before. The results suggest that triticale, ryegrass, and bellbean are the promising winter cover crops in the QFS soil, while sunn hemp, velvetbean (Mucuna pruriens), and sorghum sudangrass (Sorghum bicolor ×S. bicolor) are recommended summer cover crops for both soils under favorable temperatures.

关键词： Carbon to Nitrogen Ratio (C:N) Greenhouse Gas (GHG) k.ome Gravelly Loam (k.L) Quincy Fine Sand (QFS) Soil Organic Carbon (SOC)

Cropping Systems to Improve Carbon Sequestration for Mitigation of Climate Change

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Journal of Environmental Protection 2010年第3期1卷 207-215页

作者： Qingren Wang Yuncong Li ashok alva 不详

The recent trend of an increase in the concentration of greenhouse gases (GHGs) in the atmosphere has led to an ele-vated concern and urgency to adopt measures for carbon (C) sequestration to mitigate the climate change. Among all GHGs, carbon dioxide (CO2) is the most important one which occurs in the greatest concentration and has the strong-est radiative forcing among all. Reducing the release of CO2 to the atmosphere through “green energy” technologies or fossil fuel energy alternatives, such as wind, solar and hydraulic energies, is a major challenge. However, removal of atmospheric CO2 by terrestrial ecosystems via C sequestration and converting the sequestered C into the soil organic C has provided a great opportunity for shifting GHG emission to mitigate the climate change. Soil is an ideal reservoir for storage of organic C since soil organic C has been depleted due to land misuse and inappropriate management through the long history. To optimize the efficiency of C sequestration in agriculture, cropping systems, such as crop rotation, intercropping, cover cropping, etc., play a critical role by influencing optimal yield, total increased C sequestered with biomass, and that remained in the soil. As matter of fact, soil C sequestration is a multiple purpose strategy. It restores degraded soils, enhances the land productivity, improves the diversity, protects the environment and reduces the enrichment of atmospheric CO2, hence shifts emission of GHGs and mitigates climate change.

关键词： Carbon Dioxide Carbon Sequestration Climate Change Cropping System Greenhouse Gas

Effects of Zinc and Ascorbic Acid Application on the Growth and Photosynthetic Pigments of Millet Plants Grown under Different Salinity

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Agricultural Sciences 2014年第13期5卷 1253-1260页

作者： M. M. Hussein A. k. alva Water Relations and Irrigation Department National Research Centre Cairo Egypt USDA-ARS Vegetable and Forage Crops Research Unit Prosser WA USA

Salinity stress impacts crop growth as well as production. The need for increased food production to feed the increasing population and the limited resources, i.e. optimal quality land and water, require developing strategies to mitigate marginal stresses, including salinity stress, for reasonable expectation of crop production. A pot experiment was conducted in a greenhouse at the National Research Centre, Dok.i, Cairo, Egypt in the summer season of 2005 to evaluate the effects of foliar application of ascorbic acid alone or in combination with zinc sulfate on the growth and photosynthetic pigments of millet plants irrigated by tap water (250 ppm, 0.39 dS·m-1) or moderate to high salinity irrigation water [2500 ppm (3.9 dS·m-1) and 5000 ppm (7.8 dS·m-1)]. Increased salinity in the irrigation water decreased the plant growth, biomass, and carotenoid content. Foliar application of ascorbic acid alone increased number of leaves and leaf area, while in combination with zinc sulfate increased the plant height and total plant biomass. However, these treatments had no significant effects on the photosynthetic pigments. This study demonstrates that exogenous application of ascorbic acid can enhance foliar growth which may contribute to increased plant biomass and yield.

关键词： Salinity Stress Chlorophyll_a Chlorophyll_b Carotenoids Foliar Spray

Response of Jatropha on a Clay Soil to Different Concentrations of Micronutrients

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American Journal of Plant Sciences 2012年第10期3卷 1376-1381页

作者： A. A. Abd El-k.der M. M. Hussein A. k. alva Soils and Water Use Department National Research Center Cairo Egypt United States Department of Agriculture—Agricultural Research Service Vegetable and Forage Research Prosser USA Water Relations and Field Irrigation Department National Research Center Cairo Egypt

In recent years Jatropha curcas L. has emerged as a biofuel crop with potential for its production in marginal land with application of treated sewage water. Since this is a new crop for its profitable cultivation, additional research is needed to develop optimal management programs, including macro and micronutrients applications. A pot experiment was conducted in a Greenhouse at the National Research Center, Dok.i, Cairo, Egypt, during 2010 summer to evaluate effects of varying concentrations of iron (Fe), manganese (Mn), and zinc (Zn) in irrigation water (0, 50, 100, 150, 200 and 250 ppm) on the growth, biomass production, photosynthetic pigments, and mineral nutrients status in the plants. Increasing concentrations of Fe, Mn, and Zn in irrigation water up to 150 ppm increased the biomass weight, photosynthetic pigments, and nutrient uptak. by Jatropha plants. Further increase in concentrations of micronutrients showed negative effects on the above response parameters. Therefore, this study demonstrates that Jatropha can be grown under irrigation using waste water containing reasonable concentrations of micronutrients and heavy metals. This property of Jatropha provides some support for potential use of this crop for phytoremediation of metal contaminated soils. However, long term field research is needed to further verify both the above beneficial effects.

关键词： Irrigation Growth Jatropha curcas L. Mineral nutrition Photosynthetic Pigments Heavy Metals Sewage Sludge

Ubiquitin-proteasome system and oxidative stress in liver transplantation

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World Journal of Gastroenterology 2018年第31期24卷 3521-3530页

作者： Norma alva Arnau Panisello-Roselló Marta Flores Joan Roselló-Catafau Teresa Carbonell Department of Cell Biology Physiology and ImmunologyUniversity of Barcelona Experimental Pathology Department Institute of Biomedical Research of Barcelona

A major issue in organ transplantation is the development of a protocol that can preserve organs under optimal conditions. Damage to organs is commonly a consequence of flow deprivation and oxygen starvation following the restoration of blood flow and reoxygenation. This is k.own as ischemia-reperfusion injury(IRI): a complex multifactorial process that causes cell damage. While the oxygen deprivation due to ischemia depletes cell energy, subsequent tissue oxygenation due to reperfusion induces many cascades, from reactive oxygen species production to apoptosis initiation. Autophagy has also been identified in the pathogenesis of IRI, although such alterations and their subsequent functional significance are controversial. Moreover, proteasome activation may be a relevant pathophysiological mechanism. Different strategies have been adopted to limit IRI damage, including the supplementation of commercial preservation media with pharmacological agents or additives. In this review, we focus on novel strategies related to the ubiquitin proteasome system and oxidative stress inhibition, which have been used to minimize damage in liver transplantation.

关键词： Liver transplant Ischemia-reperfusion injury Oxidative stress Proteasome Redox regulation Ubiquitin