bluuebunny/crossref_metadata_2025_split huggingface dataset:
Measurement and analysis of the redistribution of soil moisture and solutes in a maize field in the lower reaches of the Yellow River
Authors: Chen J. Y. , Tang C. Y. , Sakura Y. , Kondoh A. , Shen Y. J. , Song X. F. 
Published: August 2004

AbstractThe lower reaches of the Yellow River are basically a discharge zone with a high salt content, and the study area of Yucheng in Shandong Province became arable only after the water diversion project from the Yellow River was implemented in 1972. The sustainability of agriculture in this area is examined through the redistribution of soil moisture and solutes in the vertical profile based on the measurement of soil moisture, potential and solute content in a maize field at the Yucheng Experimental Station. Diurnal moisture fluctuations appear in the surface layers at 30 and 50 cm depths, and the daily water content at 90 cm depth decreases about a month after planting, due mainly to the effect of root water extraction, even reaching a level lower than that at 70 cm depth. Soil moisture obviously increases for the three layers at 30, 50, 90 cm depth, and the relevant peak‐time shifts from the surface 30 cm depth to the deep layer at 120 cm depth with a varied time lag in response to rainfall events, but there is little or no signal for the other layers due to the effects of soil properties, roots, and soil storage. The existence of a convergent zero flux plane may explain to some extent the accumulation of moisture and solutes in the layer at 120 cm depth. Though the chemical facies along the profile from the unsaturated surface to the deep saturated zone generally evolves in a direction of decreasing SO42 − and Cl−, a strong driving force upward and the accumulation of solute at 120 cm may change the redistribution pattern and three groups of this pattern were classified according to the evolution and concentration distribution profiles. The main factors affecting the moisture, solute and their distributions for the three groups are varied: rainfall, irrigation and evapotranspiration for the surface layer till 70 cm depth, root extraction for the accumulation layer of 70–120 cm depth, and the fluctuation of the groundwater table for the deep layer at 120–200 cm depth. The agriculture appears sustainable as long as diverted water from the Yellow River is available, but the high content of solute accumulation in the layer at about 120 cm depth is a potential risk. Copyright © 2004 John Wiley & Sons, Ltd.
Energy fluxes and the Priestley–Taylor parameter over winter wheat and maize in the North China Plain
Authors: Zhang Yongqiang , Liu Changming , Yu Qiang , Shen Yanjun , Kendy Eloise , Kondoh Akihiko , Tang Changyuan , Sun Hongyong 
Published: August 2004

AbstractSurface energy fluxes above the canopies of well‐irrigated winter wheat and maize in the North China Plain were measured by the Bowen‐ratio energy balance technique in 1999–2000. Seasonal variation of the ratio of latent heat flux λE to available energy Rn − G showed that the ratio of λE to Rn − G exceeded 83% when leaf area index (LAI) varied from 2·0 to 6·0. The seasonal trend of evaporative fraction (EF) for winter wheat was similar to that of LAI before senescence stage, which is a critical factor controlling EF, which itself reflects the partitioning of available energy into λE. The Priestley–Taylor parameter α over the wheat and maize canopies changed greatly over the course of a growing season, and the seasonal average α of winter wheat was 1·17 and 1·26, and that of maize was 1·06 and 1·09 in the two consecutive years. α for winter wheat was exponentially correlated to 0–20 cm surface soil moisture, but not for maize and with the increase of soil depths, the correlation between α and soil moisture was weak. Under different soil moisture conditions, a linear correlation between extractable soil water and leaf water potential ψ for winter wheat was found. Copyright © 2004 John Wiley & Sons, Ltd.
Groundwater recharge from irrigated cropland in the North China Plain: case study of Luancheng County, Hebei Province, 1949–2000
Authors: Kendy Eloise , Zhang Yongqiang , Liu Changming , Wang Jinxia , Steenhuis Tammo 
Published: August 2004

AbstractEffective management of limited water resources in the North China Plain requires reliable calculation of historical groundwater balances at local, sub‐watershed scales. These calculations typically are hindered by poorly constrained recharge estimates. Using a simple soil‐water balance model, we independently calculated annual recharge from irrigated cropland to unconfined alluvial aquifers underlying Luancheng County, Hebei Province, in the western part of the North China Plain, for 1949–2000. Model inputs include basic soil characteristics and daily precipitation, potential evapotranspiration, irrigation, crop root depth, and leaf‐area index; model outputs include daily actual evapotranspiration and areal groundwater recharge. Results indicate that areal recharge is not a constant fraction of precipitation plus irrigation, as previously assumed, but rather the fraction increases as the water inputs increase. Thus, model‐calculated recharge rates range from 5 to 109 cm year−1, depending on the quantity of precipitation and irrigation applied. The important implication is that, because this drainage recharges the underlying aquifer, improving irrigation efficiency by reducing seepage does not save water. This explains why successful efforts to reduce groundwater pumping for irrigation have had no effect on water‐table declines. So long as crop cover is extensive and all crop‐water requirements are met—which has been the case in Luancheng County since the 1960s—groundwater levels will continue to decline at a steady rate. Potential solutions include reducing the irrigated area, reintroducing fallow periods, and shifting water from agriculture to other, less consumptive uses. Copyright © 2004 John Wiley & Sons, Ltd.
Pre‐processing rainfall data from multiple gauges to improve TOPMODEL simulation results in a large semi‐arid region
Authors: Boston Trevor , Xia Jun , Zhu Yizhong 
Published: August 2004

AbstractModelling of semi‐arid regions presents some complex challenges that must be overcome to produce reliable simulation results. This paper discusses the findings of a calibration and cross‐validation process using TOPMODEL to simulate stream discharge from the semi‐arid Banqiao sub‐catchment located in Gansu Province, China. Rainfall was pre‐processed using two different methods and compared against the use of mean rainfall data from 10 gauging stations. The results indicate that correlating multiple rainfall gauge measurements against stream discharge and weighting the rainfall gauges according to correlation factors can be a useful means of obtaining more representative rainfall input. The second method used a transfer function model (TFM) equipped with a non‐linear rainfall filter function to generate effective rainfall. The TFM was calibrated repeatedly using different degrees of non‐linearity in the rainfall filter function until an optimal model was found. The effective rainfall used to generate the best TFM was applied in TOPMODEL. Applying the TFM effective rainfall to TOPMODEL allowed better simulation of discharge than use of either the correlation‐weighted or mean rainfall input. Although the R2 validation efficiencies or ‘goodness of fit’ generally lagged those seen during calibration, 90% of TOPMODEL validation runs using TFM effective rainfall and 60% of those using correlation‐weighted rainfall exceeded runs using mean rainfall. Copyright © 2004 John Wiley & Sons, Ltd.
Assessment of groundwater contamination by nitrates associated with wastewater irrigation: A case study in Shijiazhuang region, China
Authors: Tang C. , Chen J. , Shindo S. , Sakura Y. , Zhang W. , Shen Y. 
Published: August 2004

AbstractIn arid and semi‐arid regions there is usually a shortage of irrigation water; thus, wastewater water, as well as other low‐quality water resources, may become an important source of water and nutrients. However, (pre)treated wastewater may contain elements and compounds that can damage the environment. It also has the potential to affect water quality adversely in an aquifer that may be the source of drinking water in the area. In order to assess the impacts of wastewater on the environment, groundwater samples were taken and analysed in typical croplands in the North China Plain, where urban wastewater or groundwater have been used for irrigation for several decades. Concentrations of nitrate (NO3−) in groundwater in the study area varied from 50 to 130 mg l−1 in the croplands irrigated by wastewater, but in the croplands irrigated by pumping wells, away from the Dongming Canal, NO3− concentrations are less than 35 mg l−1. It was found that values of δ15N ranged from +5 to +13‰, and dominantly from +7 to +11‰, and the NO3− concentration in most wells with depths of less than 40 m was higher than the drinking water standard set by the WHO. Cluster analysis was used to classify the spatial distribution of nitrates resulting from the wastewater. Identification of chemical patterns is found to be effective for the comprehensive assessment of the spatial distribution of groundwater quality. It is also emphasized that the wastewater in this area controls the NO3− distribution in the groundwater, and should be used carefully to protect both soil and groundwater from NO3− pollution. Copyright © 2004 John Wiley & Sons, Ltd.
The renewability of water resources and its quantification in the Yellow River basin, China
Authors: Xia Jun , Wang Zhonggen , Wang Gangsheng , Tan Ge 
Published: August 2004

AbstractThe drying‐up events in the lower reaches of the Yellow River during the 1990s, which were the most serious problem of water resources issues in China, initiated this study of the concept of water resources renewability in the Yellow River basin. The problem of renewability linked with hydrological process impacted by climate change and human activity is addressed. A quantitative method was developed to analyse causes and propose countermeasures to improve renewability of water resources. The magnitude of renewability change in time and space within the river system can be represented using this method. According to the analysis using an observation data set, it is shown that the renewability of water resources of the Yellow Rive basin has had a significant declining trend since the 1950s. In particular, the renewability indicator in the downstream reaches was reduced to 0·2 during a bad situation during the 1990s. Using the renewability assessment, feasible strategies can be analysed and suggested. Copyright © 2004 John Wiley & Sons, Ltd.
Seasonal variation of energy partitioning in irrigated lands
Authors: Shen Yanjun , Zhang Yongqiang , Kondoh Akihiko , Tang Changyuan , Chen Jianyao , Xiao Jieying , Sakura Yasuo , Liu Changming , Sun Hongyong 
Published: August 2004

AbstractThe energy balance components were measured above the surface of an irrigated wheat and maize field over three successive years using the Bowen ratio technique. The experiments were carried out at Luancheng Experimental Station of Agro‐ecosystem (LESA), Heibei, China, from December 1999 through to September 2001. The seasonal course of energy balance over an irrigated field, the diurnal Bowen ratio patterns in different seasons, and the effect of leaf‐area index (LAI) and soil moisture on the energy balance are discussed. Over 3 years, the net radiation Rn varied from 31·6 to 668 · 1 W m−2, and the soil heat flux G varied from −12 · 7 to 170 · 9 W m−2. The latent heat flux LE also shows apparent correspondence with the development of phenology, e.g. LAI. The diurnal course of the Bowen ratio in different seasons can be categorized into three typical patterns: (1) a ‘wheat pattern’, characterized by a steep morning peak followed by a decrease with the daytime mean value of around 0·30; (2) a ‘maize pattern’, which is a relatively flat course with a daytime mean β of around 0·20–0·25; and (3) a ‘winter pattern’, with a near‐noon high peak with a daytime mean β of more than 10 times that those for wheat or maize. There are linear correlations between evaporative fraction (EF) and LAI for both wheat and maize before senescence seasons. The correspondence of EF appears more dependent on LAI for maize than for wheat. The EF does not appear correlated to soil water status, whereas the Bowen ratio is affected by extractable soil water content for wheat to some extent. No correlation for maize is found. Copyright © 2004 John Wiley & Sons, Ltd.
The dynamics of health in the British Household Panel Survey
Authors: Contoyannis Paul , Jones Andrew M. , Rice Nigel 
Published: August 2004

AbstractThis paper considers the dynamics of a categorical indicator of self‐assessed health using eight waves (1991–1998) of the British Household Panel Survey (BHPS). Our analysis has three focal points: the relative contributions of state dependence and heterogeneity in explaining the dynamics of health, the existence and consequences of health‐related sample attrition, and the investigation of the effects of measures of socioeconomic status, with a particular focus on educational attainment and income. To investigate these issues we use dynamic panel ordered probit models. There is clear evidence of health‐related attrition in the data but this does not distort the estimates of state dependence and of the socioeconomic gradient in health. The models show strong positive state dependence and heterogeneity accounts for around 30% of the unexplained variation in health. Copyright © 2004 John Wiley & Sons, Ltd.
Health care reform and the number of doctor visits—an econometric analysis
Authors: Winkelmann Rainer 
Published: August 2004

AbstractThis paper evaluates the German health care reform of 1997, using the individual number of doctor visits as outcome measure and data from the German Socio‐Economic Panel for the years 1995–1999. A number of modified count data models allow us to estimate the effect of the reform in different parts of the distribution. The overall effect of the reform was a 10% reduction in the number of doctor visits. The effect was much larger in the lower part of the distribution than in the upper part. Copyright © 2004 John Wiley & Sons, Ltd.
Architecture control of three‐dimensional polymeric scaffolds for soft tissue engineering. I. Establishment and validation of numerical models
Authors: Cao Yang , Davidson Malcolm R. , O'Connor Andrea J. , Stevens Geoffrey W. , Cooper‐White Justin J. 
Published: August 2004

AbstractOne of the most important functions of artificial three‐dimensional (3D) polymeric scaffolds is to serve as a physical support to provide tissues with an appropriate architecture for in vitro cell culture as well as in vivo tissue regeneration. The production of three‐dimensional (3D) polymeric scaffolds with tailored macroporous architecture is thus a crucial step in promoting controlled vascularization and tissue growth within host environments. In this study, 3D poly(lactic‐co‐glycolic acid) (PLGA) scaffolds were manufactured by a thermally induced phase‐separation (TIPS) technique. By controlling the quenching strategy, 3D interconnected PLGA scaffolds with tunable pore size and alignment were obtained and characterized with the use of scanning electron microscopy (SEM). A series of numerical heat‐transfer models were established in an effort to describe the cooling process within the PLGA freezing regime. Among them, a two‐dimensional (2D) solidification model has proved to be the most successful in describing the quenching of the polymer solution and has the potential to be used to infer the various 3D macroporous architectures created from different quenching conditions. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 71A: 81–89, 2004
Exchange transfusion with entirely synthetic red‐cell substitute albumin‐heme into rats: Physiological responses and blood biochemical tests
Authors: Huang Yubin , Komatsu Teruyuki , Yamamoto Hisashi , Horinouchi Hirohisa , Kobayashi Koichi , Tsuchida Eishun 
Published: August 2004

AbstractRecombinant human serum albumin (rHSA) incorporating 2‐[8‐{N‐(2‐methylimidazolyl)}octanoyloxymethyl]‐5,10,15,20‐[tetrakis{α,α,α,α‐o‐(1‐methylcyclohexanoyl)amino}phenyl]porphinatoiron(II) [albumin‐heme (rHSA‐heme)] is an artificial hemoprotein which has the capability to transport O2 in vitro and in vivo. A 20% exchange transfusion with rHSA‐heme into anesthetized rats has been performed to evaluate its clinical safety by monitoring the circulation parameters and blood parameters for 6 h after the infusion. Time course changes in all parameters essentially showed the same features as those of the control group (without infusion) and rHSA group (with administration of the same amount of rHSA). Blood biochemical tests of the withdrawn plasma at 6 h after the exchange transfusion have also been carried out. No significant difference was found between the rHSA‐heme and rHSA groups, suggesting the initial clinical safety of this entirely synthetic O2‐carrier as a red‐cell substitute. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 71A: 63–69, 2004
Proteomic profiling of platelet proteins by trypsin immobilized self‐assembled monolayers digestion chip and protein identification using electrospray ionization tandem mass spectrometry
Authors: Tyan Yu‐Chang , Liao Jiunn‐Der , Jong Shiang‐Bin , Liao Pao‐Chi , Yang Ming‐Hui , Chang Yin‐Wei , Klauser Ruth , Himmelhaus Michael , Grunze Michael 
Published: August 2004

AbstractSelf‐assembled monolayers (SAMs) on coinage metal provide versatile modeling systems for studies of interfacial electron transfer, biological interactions, molecular recognition, and other interfacial phenomena. Recently, the bonding of enzyme to SAMs of alkanethiols onto Au electrode surfaces was exploited to produce a bio‐sensing system. In this work, the attachment of trypsin to a SAMs surface of 11‐mercaptoundecanoic acid was achieved using water soluble 1‐ethyl‐3‐(3‐dimethylaminopropyl) carbodiimide and N‐hydroxysulfosuccinimide as coupling agent. Experimental results have revealed that the X‐ray Photoelectron Spectroscopy (XPS) C1s core levels at 286.3 and 286.5 eV (C with N), 288.1 eV (amide bond), and 289.3 eV (carboxyl) illustrate the immobilization of trypsin. These data were also in good agreement with Fourier‐Transformed Infrared Reflection‐Attenuated Total Reflection (FTIR‐ATR) spectra for the peaks valued at 1659.4 cm−1 (amide I) and 1546.6 cm−1 (amide II). Using electrospray ionization tandem mass spectrometry (ESI‐MS/MS) observations, analytical results have demonstrated the platelet proteins digestion of the immobilized trypsin on the functionalized SAMs surface. For such surfaces, platelet proteins were digested on the trypsin‐immobilized SAMs surface, which shows the enzyme digestion ability of the immobilized trypsin. The terminal groups of the SAMs structure can be further functionalized with biomolecules or antibodies to develop surface‐base diagnostics, biosensors, or biomaterials. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 71A: 90–97, 2004
The effect of different titanium and hydroxyapatite‐coated dental implant surfaces on phenotypic expression of human bone‐derived cells
Authors: Knabe Christine , Howlett Cameron Rolfe , Klar Falk , Zreiqat Hala 
Published: August 2004

AbstractRoughened titanium (Ti) surfaces have been widely used for dental implants. In recent years, there has been the tendency to replace Ti plasma‐sprayed surfaces by sandblasted and acid‐etched surfaces in order to enhance osseous apposition. Another approach has been the utilization of hydroxyapatite (HA)‐coated implants. This study examines the effect of two roughened Ti dental implant surfaces on the osteoblastic phenotype of human bone–derived cells (HBDC) and compares this behavior to that for cells on an HA‐coated surface. Test materials were an acid‐etched and sandblasted Ti surface (Ti‐DPS), a porous Ti plasma‐sprayed coating (Ti‐TPS), and a plasma‐sprayed porous HA coating (HA). Smooth Ti machined surfaces served as control (Ti‐ma). HBDC were grown on the substrata for 3, 7, 14, and 21 days, counted and probed for various bone‐related mRNAs and proteins (type I collagen, osteocalcin, osteopontin, osteonectin, alkaline phosphatase, and bone sialoprotein). All dental implant surfaces significantly affected cellular growth and the temporal expression of an array of bone‐related genes and proteins. HA‐coated Ti had the most effect on osteoblastic differentiation inducing a greater expression of an array of osteogenic markers than recorded for cells grown on Ti‐DPS and Ti‐TPS, thus suggesting that the HA‐coated surface may possess a higher potency to enhance osteogenesis. Furthermore, Ti‐DPS surfaces induced greater osteoblast proliferation and differentiation than Ti‐TPS. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 71A: 98–107, 2004
Biodegradable poly(ether‐ester) multiblock copolymers for controlled release applications: An in vivo evaluation
Authors: van Dijkhuizen‐Radersma R. , Roosma J. R. , Sohier J. , Péters F. L. A. M. A. , van den Doel M. , van Blitterswijk C. A. , de Groot K. , Bezemer J. M. 
Published: August 2004

AbstractMultiblock poly(ether‐ester)s based on poly(ethylene glycol), butylene terephthalate, and butylene succinate segments were evaluated for their in vivo degradation and biocompatibility in order to establish a correlation with previously reported in vitro results. Porous polymer sheets were implanted subcutaneously for 32 weeks in rats. The degradation was monitored visually (histology), by molecular weight (GPC), and by copolymer composition (NMR). Substitution of the aromatic terephthalate units by aliphatic succinate units was shown to accelerate the degradation rate of the copolymers. Direct correlation of the in vivo and in vitro degradation of the porous implants showed a slightly faster initial molecular weight decrease in vivo. Besides hydrolysis, oxidation occurs in vivo due to the presence of radicals produced by inflammatory cells. In addition, the higher molecular weight plateau of the residue found in vivo indicated a higher solubility of the oligomers in the extracellular fluid compared to a phosphate buffer. Minor changes in the poly(ether‐ester) compositions were noted due to degradation. Microscopically, fragmentation of the porous implants was observed in time. At later stages of degradation, macrophages were observed phagocytozing small polymer particles. Both in vitro cytotoxicity studies and histology on in vivo samples proved the biocompatibility of the poly(ether‐ester)s. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 71A: 118–127, 2004