bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stabilizing Rainfed Wheat Yields with Supplemental Irrigation and Nitrogen in a Mediterranean Climate
Authors: Oweis Theib , Pala Mustafa , Ryan John 
Published: July 2010

AbstractThe West Asia‐North Africa (WANA) region, with a Mediterranean‐type climate, has an increasing deficit in cereal production, especially bread wheat (Triticum aestivum L.). Rainfed cropping coincides with the relatively cool, rainy winter season, usually from October to May. Cereal yields are low and variable in response to inadequate and erratic seasonal rainfall and associated management factors, such as lack of N and late sowing. In an area where water is limited, small amounts of supplemental irrigation (SI) water can make up for the deficits in seasonal rain and potentially produce satisfactory yields. This field study (1992–1993 to 1995–1996) on a deep clay soil (a Calcixerollic Xerochrept) in northern Syria was conducted for four growing seasons to assess the effects of SI (rainfed, 1/3, 2/3, and full irrigation) combined with N rate (0, 50, 100, and 150 kg ha−1) and sowing date (early, normal, and late) on one traditional (Mexipak 65) and three improved bread wheat cultivars (Cham 4, Cham 6, Gomam). Yields of rainfed wheat varied with seasonal rainfall and its distribution, with all main factors having significant effects. A delay in the sowing date from November to January consistently reduced yields and the response to both SI and N. With irrigation, crop responses were generally significant up to 100 kg N ha−1, while optimum response for rainfed conditions was with 50 kg N ha−1. An addition of only limited irrigation (1/3 full irrigation) significantly increased yields, but near maximum yields were obtained by 2/3 of full irrigation. Responses to N and SI were greatest for the higher‐yielding cultivars. Use efficiency for both water and N was greatly increased by SI. Thus, with minimum irrigation during the winter growing season combined with appropriate management, inputs, and varieties, wheat output could be substantially and consistently increased in the semiarid Mediterranean zone. Production functions developed from this dataset can help predict the effects of changing any of these parameters in other locations in the region.
Background of the MSEA‐RZWQM Modeling Project
Authors: Watts Darrell G. , Fausey Norman R. , Bucks D. A. 
Published: July 2010

AbstractThe Management Systems Evaluation Areas (MSEA) project was established in 1990 as a part of the Midwest Water Quality Initiative to evaluate the effect of agricultural management practices and systems on the quality of water resources, to increase understanding of processes affecting water contamination, and to develop cost‐effective strategies to reduce water contamination from pesticides and plant nutrients. The Midwest was chosen because it produces so much of the country's corn (>80%) and soybean (≈70%) crops, and consumes >50% of the N fertilizer and almost 60% of the herbicides applied. The MSEA project collected a large volume of data across a wide region. Properly calibrated and validated, simulation models could use this database to estimate water quality impacts over much longer periods than the expected life of the MSEA field program and to simulate responses for other combinations of soils, management systems, and weather conditions. The Root Zone Water Quality Model (RZWQM) was chosen for model improvement, calibration, and validation, to be followed by multilocation simulation of several specific management systems used in Midwest corn and corn‐soybean production. Model improvement was an iterative process across multiple locations. The next seven papers in this issue provide an overview of RZWQM Version 3.2, an explanation of the calibration‐validation process, and documentation of that process and the modeling at MSEA locations in Iowa, Minnesota, Missouri, Nebraska, Ohio, and Colorado.
Subsoil Nitrate and Bromide Uptake by Contrasting Alfalfa Entries
Authors: Blumenthal Jürg M. , Russelle Michael P. , Lamb JoAnn F.S. 
Published: July 2010

AbstractAlfalfa (Medicago sativa L.) is a deeply rooted perennial legume that can protect the environment by absorbing nitrate (NO−3) both better than annual crops and from deeper in the soil. Our objectives were to characterize subsoil NO−3 removal by eight alfalfa entries differing in symbiotic efficiency, root system architecture, forage quality, and leaf morphology, and to evaluate Br− as an alternative tracer to 15N for monitoring NO−3 uptake. Low (=0.3 mM) or high (20 mM) NO−3‐N concentrations were supplied through a subsoil irrigation system installed in a Hubbard loamy sand soil (sandy, mixed Udorthentic Haploboroll) at Becker, MN. Nitrate uptake and N2 fixation were evaluated during two regrowth periods using 15N. We also added small concentrations of Br− to the subsoil NO−3 during three regrowth periods. Subsoil NO−3‐N removal was similar for the seven N2‐fixing entries, suggesting that selection for traits such as root system architecture, high forage quality, or multiple (>3) leaflets does not necessarily confer an advantage in NO−3 absorption. Even though ‘Ineffective Agate’ yielded less herbage than the N2‐fixing entries, this non‐N2 fixing cultivar removed about 38% more subsoil NO−3 than N2‐fixing entries over the growing season. These results confirm our earlier findings that non‐N2‐fixing alfalfa cultivars are likely to be more effective in phytoremediation of NO−3‐contaminated sites than are standard cultivars. It also confirms our earlier conclusion that the simple difference technique may underestimate rates of symbiotic N2 fixation when inorganic N supply is large. A strong correlation between 15N and Br− uptake in the herbage (mg excess Br− = 25.2 × mg excess 15N, r2 = 0.97) led us to conclude that Br‐ can be used as a tracer of NO−3 absorption by alfalfa in the field. This provides a new, dual‐tracer approach for such studies.
Yield and Mineral Composition of Alfalfa and Sunflowers as Influenced by the Degree of Reaction of Calcium Carbonate with Two Acid Soils
Authors: Baker Aaron , Brady N. C. 
Published: July 2010

AbstractThe comparative effects of reacted and unreacted CaCO3 in two acid soils on the growth and nutrient uptake of alfalfa and sunflowers were determined. The soils, both Mardin silt loams, had pH values of 4.6 and 5.5 respectively, and CaCO3 was applied at the rate of 1.35 tons per 2 × 106 lbs.Reaction of CaCO3 with the more acid soil increased the yields and calcium contents of both alfalfa and sunflowers. On the less acid soil, reaction of the CaCO3 with the soil was not effective in increasing the yield of either plant, although the calcium content of both plants was higher where CaCO3 had been allowed to react with the soil before planting.Plant analyses showed a better relationship between manganese content and yield than that of any other element investigated.
Available Soil Nitrogen Measurements by Microbiological Techniques and Chemical Methods
Authors: Boswell Fred C. , Richer A. C. , Casida L. E. 
Published: July 2010

AbstractMicrobiological and chemical techniques for assaying available soil nitrogen were evaluated using 30 soil samples selected from Georgia, Iowa, New Jersey, and Pennsylvania. The nitrifying capacity of these soils, as measured by incubation under controlled conditions, was used as the standard for comparison.A microbiological techniques was devised, using a strain of the proteinaceous bacterium Pseudomonas aeruginosa. Production of a pigment, pyocyanin, by this organism during growth in a medium in which soil served as the nitrogen source was used as the criterion for measuring available soil nitrogen. With this technique, a highly significant negative correlation was obtained between pigment production and nitrifying capacity for the 30 soil samples studied. The method has the advantage that only 4 days are required for the assay, in contrast to 2 to 8 weeks for the determination of nitrifying capacity.The microbiological technique was compared with the chemical methods of Truog and Purvis. In the Truog procedure, ammonia is distilled from soils in the presence of alkaline permanganate. The Purvis method involves hydrolysis and mild oxidation with dilute H2SO4 followed by ammonium ion determination by Nesslerization. Both chemical methods yielded highly significant correlation with nitrifying capacity. The correlation between the two chemical methods also was highly significant. The Truog method and the microbiological technique exhibited a negative correlation of high significance.
Measuring Horizontal and Vertical Hydraulic Conductivity of Soil With the Double‐Tube Method
Authors: Bouwer Herman 
Published: July 2010

AbstractHorizontal and vertical hydraulic conductivity, symbols Kh and Kv, respectively, of anisotropic soils in which the principal conductivity components are in the horizontal and vertical directions, can be measured with the double‐tube method. The principle is based on manipulation of flow direction in the artificially saturated soil region below the auger hole. As with the original double‐tube method, the presence of a water table is not required.If the water levels in the inner and the outer tube differ, the streamlines in the resulting flow system below the auger hole have both horizontal and vertical portions. Thus, the hydraulic conductivity measured with the conventional double‐tube method from this flow system on the basis of assumed isotropy, symbol Kdt, is some resultant of Kh and Kv. If the water levels in the inner and the outer tube are the same, the flow in the soil below the inner tube is, initially, vertically downward. Piezometers are used to measure the vertical hydraulic gradient and knowing the intake rate, Kv can be computed. By transformation to equivalent isotropic systems, the relationship between Kdt/Kv and Kh/Kv can be determined and expressed in the form of a graph. Thus, knowing Kdt and Kv, the conductivity Kh can be evaluated from that graph.Laboratory studies on artificial anisotropic soil consisting of alternating 0.5‐cm. layers of coarse and fine soil were performed to verify and exemplify the method.
Water and Chloride Movement Through Soil Columns Simulating Pedal Soils
Authors: Bouma J. , Anderson J. L. 
Published: July 2010

AbstractInterpretation of dispersion phenomena in soils is complicated by many complex interactions within the highly heterogeneous pore system. Model experiments were therefore designed to investigate the specific effects on hydrodynamic dispersion of (i) vertically continuous macropores in different types of microstructure and (ii) different flow regimes. Two homogeneous microstructures were formed by mixing, puddling, and drying of sand and silty clay loam materials to sandy loam and clay loam textures. Small vertically continuous cylindrical pores were made in 30‐cm long columns that had a diameter of 10 cm to simulate macropores. Breakthrough curves, following a daily 0.5‐cm application of chloride solution, showed that identical macropores have different hydraulic functions in different soil materials. This intermittent flow resulted in much better displacement of untraced water in the more permeable sandy loam columns, but “immobile” water remained in both soils. Dispersion phenomena in both microstructures (which represented two “ideal” textural porosities) differed significantly when saturated flow was compared with flow through a crust. Implications for the physical interpretation of soil structure descriptions are discussed.
Biotite Kaolinization in Virginia Piedmont Soils: II. Zonation in Single Grains
Authors: Harris W. G. , Zelazny L. W. , Bloss F. D. 
Published: July 2010

AbstractKaolinized zones in soil biotite grains were investigated by x‐ray diffraction (XRD), microprobe, and optical methods. These zones displayed microcrenulations and thus a dulled luster on (001) cleavage surfaces. Compared to unaltered biotite, kaolinized zones were lighter in reflected light but darker in transmitted light, probably because the crenulated (001) surfaces diffuse light. Kaolinized/unkaolinized interfaces in some grains were roughly perpendicular to (001) cleavage. This suggests that kaolinization proceeds inward from the grain edge along a multilayered front by a topotaxial rather than epitaxial reaction. Kaolinized zones contained islands of residual biotite and had an optic axial angle (2V) and dispersion more consistent with biotite than kaolinite. Biotite‐derived kaolinite grains contained Fe, which was either structural or occluded, and had Si/(Al + Fe + Mg + Ti) ratios >1.0. A significant vermiculite intermediate phase is not essential for kaolinization, as indicated by the lack of XRD evidence of vermiculite as well as by the simultaneous loss of K and divalent octahedral cations in examined biotite/kaolinite grains.
Preparing Soil Cores Collected by a Sampling Probe for Laboratory Analysis of Soil Hydraulic Properties
Authors: Amoozegar A. 
Published: July 2010

AbstractCollection of intact soil samples from below the surface by handdriven devices is difficult and time consuming. A simple technique is presented to prepare unencased‐intact soil cores collected with a hydraulic sampling probe for laboratory physical analyses. The methodology has been used to determine the hydraulic properties of samples collected as deep as 6 m in the Piedmont region of North Carolina. The hydraulic conductivity results and dye leaching tests have indicated that boundary flow does not occur at the interface of the soil and paraffin coating. The procedure has many advantages over sampling by hammer‐driven devices. It is fast and economical, and can be used to obtain high quality samples from the B and C horizons.
Comparison of Three Field Methods to Characterize Apparent Macropore Conductivity
Authors: Timlin D. J. , Ahuja L. R. , Ankeny M. D. 
Published: July 2010

AbstractThe objective of this study was to investigate some field‐oriented methods designed to characterize the flow rates of both the soil matrix and macropores near saturation. An apparent macropore conductivity was obtained by the difference between saturated and unsaturated hydraulic conductivities at −0.6 kPa of soil water pressure. Saturated conductivities were measured in double‐ring infiltrometers with tensiometers. Soil matrix conductivities were calculated from measurements of soil water pressures and drainage rate during redistribution and were also measured with a thin sand‐cement crust. Another set of data for saturated and unsaturated conductivities was obtained from unconfined ponded measurements in 76.2‐mm‐diam. rings and a tension infiltrometer. Unsaturated conductivities and calculated apparent macropore conductivities from the crust and redistribution methods were comparable. Unsaturated conductivities and apparent macropore conductivities from the tension infiltrometer and unconfined ponded measurements were greater than those from the infiltration‐redistribution method. We concluded that apparent macropore conductivity for the profile can be characterized by using ponded infiltration rates and matrix conductivities near saturation determined from redistribution data. This method accounts for the continuity of the macropore flow system in subsurface layers and involves a larger area for macropore infiltration measurement.
Influence of Oxalate and Soil Organic Matter on Sorption and Desorption of Phosphate onto a Spodic Horizon
Authors: Bhatti J. S. , Comerford N. B. , Johnston C. T. 
Published: July 2010

AbstractPhosphate (PO4) availability limits the productivity of pine plantations growing on Spodosols of the southeastern USA. Oxalate has been shown to interact with both the sorption and desorption PO4 onto soil mineral surfaces. In addition, organic matter, a crucial component of many soil surfaces, affects the adsorption of PO4. We studied the effects of oxalate and organic matter on PO4 sorption and desorption onto the whole soil and clay‐sized fraction of a spodic horizon from a poorly drained Spodosol of the flatwoods region of the lower Coastal Plain of the southeastern USA. Common batch studies and mass balance of OH‐ production and consumption were used to interpret the processes. Maximum reduction in PO4 sorption was observed in samples where organic matter and oxalate were present. The molar ratio of OH‐ ions released to PO4 sorbed supports the idea of a ligand‐exchange mechanism dominating the PO4 sorption process. Some of the sorption sites appear to be common sites for PO4, oxalate, and organic matter. Phosphorus desorption from the spodic horizon by the action of oxalate was through ligand exchange of oxalate for PO4. The presence of soil organic matter increased the amount of PO4 desorbed by oxalate. Oxalate appeared to form stable soluble complexes with Al in solution, thus inhibiting its reprecipitation.
Stakeholder involvement in water management: the role of the stakeholder analysis within participatory processes
Authors: Stanghellini Paola Sabina Lupo 
Published: July 2010

Water is a central resource supporting human activities and ecosystems and it is required for different purposes and uses that are often conflicting. Existing water-related problems are expected to increase and conventional water resource management systems are not likely to be able to face future challenges. There is the need for an integrated water resources management, which should be participatory, technically and scientific informed and which should be based on bottom-up approach.
The Directive 2000/60/EC is based on principles of integrated planning and calls for stakeholder involvement in water management. Involving stakeholders is an important step to ensure that catchment management plans take into consideration local needs, experiences and interests. This paper presents a stakeholder analysis methodology that was developed to support stakeholder participation in water management. The methodology was implemented as a preliminary step in a stakeholder participation project in an alpine sub-catchment in Northern Italy.
Confronting and Resolving an Ethical Dilemma Associated with a Practice Based Evaluation Using Observational Methodology of Health Information Technology
Authors: Taylor H.A. , Sockolow P.S. 
Published: July 2010

SummaryAs the adoption of health information technology (HIT) has escalated, efforts to evaluate its uptake have increased. The evaluation of HIT often requires direct observation of health care practitioners interacting with the system. When in the field, the evaluator who is not a trained health care provider may observe suboptimal use of the technology. If evaluators have plans to share the results of the evaluation at the conclusion of the study, they face a decision point about whether to disclose interim results and the implications of doing so. To provide HIT evaluators with guidance about what issues to weigh when observing the implementation of HIT, this paper presents a study of an actual case and discusses the following considerations: (1) whether the evaluation of HIT is considered to be human subject research; (2) if the evaluation is human subject research, whether the Institutional Review Board will consider it exempt from review or subjected to expedited or full review; and (3) how interim disclosure to the clinic management impacts the research study. The recommendations to evaluators include use of a protocol for interim disclosures to patients, clinicians, and/or clinical management for both quality assurance initiatives and human subjects research.
A Facile Route to Polysubstituted Naphthalenes and Benzofluorenols via Scandium Triflate‐ and Triflic Acid‐ Catalyzed Benzannulation of 2‐(2‐Alkynylarylidene)‐ 1,3‐Dicarbonyl Compounds
Authors: Liu Lu , Wei Lai , Zhang Junliang 
Published: July 2010

AbstractThis paper describes an efficient scandium triflate‐ and triflic acid‐catalyzed benzannulation of 2‐(2‐alkynylarylidene)‐1,3‐dicarbonyl compounds to afford polysubstituted naphthalenes and benzo[a]fluorenols. The product selectivity could be tuned by subtle choice of the catalyst. An unprecedented process between alkynes and ketones is also explored.
DNA – eine vielseitige chemische Verbindung für die Katalyse, zur Kodierung und zur Stereokontrolle
Authors: Silverman Scott K. 
Published: July 2010

AbstractDie DNA (Desoxyribonukleinsäure) ist das genetische Material, das allen Organismen der Erde gemeinsam ist. Unser biologisches Verständnis der DNA ist umfangreich und wird weitreichend genutzt. In den letzten Jahren nun begannen Chemiker, die DNA auch für nicht‐biologische Anwendungen in der Katalyse, der Kodierung und zur Stereokontrolle zu erschließen. Dieser Aufsatz fasst die wichtigsten Fortschritte auf diesen drei spannenden Forschungsfeldern zusammen, von denen sich jedes einen anderen bestimmten Aspekt der chemischen Eigenschaften der DNA zu Nutze macht.
Impaired insulin sensitivity and secretion in normoglycemic patients with spinocerebellar ataxia type 1
Authors: Lalić Nebojša M. , Dragašević NatašA , Stefanova Elka , Jotić Aleksandra , Lalić Katarina , Miličić Tanja , Petrović Igor , Maćešić Marija , Kostić Vladimir S. 
Published: July 2010

AbstractWe have recently shown an impairment in insulin sensitivity and insulin secretion in normoglycemic patients with Huntington disease (HD). To investigate whether such observations are HD‐specific or may be common to other polyglutamine diseases, glucose homeostasis was studied in 12 unrelated, untreated normoglycemic patients with spinocerebellar ataxia type 1 (SCA1), another entity from the family of polyglutamine diseases, and 24 healthy, matched controls. Metabolic investigations included (a) glucose tolerance assessment on the basis of glucose curve during oral glucose challenge; (b) insulin sensitivity assessment by the homeostasis model assessment (HOMA) and the euglycemic insulin clamp (M value); and (c) insulin secretion by acute insulin response (AIR) and insulinogenic index. The evaluation of insulin sensitivity demonstrated higher HOMA‐insulin resistance indices, and lower M values (P < 0.001 and P < 0.05, respectively), while both the AIR and the insulinogenic index were lower in patients with SCA1 compared to controls (P < 0.001 and P < 0.05, respectively). Our data suggested an impairment in insulin secretion capacity, as well as simultaneous decrease in insulin sensitivity, with an increase in insulin resistance level in patients with SCA1. © 2010 Movement Disorder Society
Protective effects of bovine colostrum acid proteins on bone loss of ovariectomized rats and the ingredients identification
Authors: Du Ming , Xu Weili , Yi Huaxi , Han Xue , Wang Cong , Zhang Lanwei 
Published: July 2010

AbstractScope: Milk basic proteins and bovine colostrum extracts have preventive effects on osteoporosis. However, the effects of bovine colostrum acidic proteins (BCAP) on properties of bone have not been reported. This study investigated the effect of BCAP on the prevention of bone loss in ovariectomized (OVX) rats. Methods and results: Forty‐eight 3‐month old female Sprague–Dawley rats were OVX and another 12 rats underwent a sham operation (Sham). The OVX rats were randomly separated into four groups, i.e. OVX control, OVX plus 2 mg/day BCAP, OVX plus 10 mg/day BCAP, and OVX plus 50 mg/day BCAP, and were gavaged once per day for 12 wk. The effects on bone mineral content, bone mineral density, microarchitecture and biomechanical properties were determined. The bioactive ingredients in BCAP were isolated and identified. Results showed that BCAP increased the bone mineral content and bone mineral density of the femur in a dose‐dependent manner. Scanning electron microscope observation and mechanical testing further confirmed the positive effects of BCAP. These positive effects attribute to the fact that osteopontin, lactoferrin, epidermal growth factor and insulin‐like growth factor‐2 are the dominant proteins in BCAP. Conclusions: BCAP (2–50 mg/day) could prevent osteoporosis caused by bone loss in OVX rats.