bluuebunny/crossref_metadata_2025_split huggingface dataset:
Snow accumulation in forests from ground and remote‐sensing data
Authors: Lundberg Angela , Nakai Yuichiro , Thunehed Hans , Halldin Sven 
Published: May 2004

AbstractWinter‐forest processes affect global and local climates. The interception‐sublimation fraction (F) of snowfall in forests is a substantial part of the winter water budget (up to 40%). Climate, weather‐forecast and hydrological modellers incorporate increasingly realistic surface schemes into their models, and algorithms describing snow accumulation and snow‐interception sublimation are now finding their way into these schemes. Spatially variable data for calibration and verification of wintertime dynamics therefore are needed for such modelling schemes. The value of F was determined from snow courses in open and forested areas in Hokkaido, Japan. The value of F was related to species and canopy‐structure measures such as closure, sky‐view fraction (SVF) and leaf‐area index (LAI). Forest structure was deduced from fish‐eye photographs. The value of F showed a strong linear correlation to structure: F = 0·44 − 0·6 × SVF for SVF < 0·72 and F = 0 for SVF > 0·72, and F = 0·11 LAI. These relationships seemed valid for evergreen conifers, larch trees, alder, birch and mixed deciduous stands. Forest snow accumulation (SF) could be estimated from snowfall in open fields (So) and to LAI according to SF = So (1 − 0·11 LAI) as well as from SVF according to SF = So (0·56 + 0·6 SVF) for SVF < 0·72. The value of SF was equal to So for SVF values above 0·72. The value of sky‐view fraction was correlated to the normalized difference snow index (NDSI) using a Landsat‐TM image for observation plots exceeding 1 ha. Variables F and SF were related to NDSI for these plots according to: F = −0·37NDSI + 0·29 and SF = So (0·81 + 0·37NDSI). These relationships are somewhat hypothetical because plot‐size limitation only allowed one sparse‐forest observation of NDSI to be used. There is, therefore, a need to confirm these relationships with further studies. Copyright © 2004 John Wiley & Sons, Ltd.
Multi‐decadal variability of drought risk, eastern Australia
Authors: Kiem Anthony S. , Franks Stewart W. 
Published: May 2004

AbstractA number of previous studies have identified changes in the climate occurring on decadal to multi‐decadal time‐scales. Recent studies also have revealed multi‐decadal variability in the modulation of the magnitude of El Niño–Southern Oscillation (ENSO) impacts on rainfall and stream flow in Australia and other areas. This study investigates multi‐decadal variability of drought risk by analysing the performance of a water storage reservoir in New South Wales, Australia, during different climate epochs defined using the Inter‐decadal Pacific Oscillation (IPO) index. The performance of the reservoir is also analysed under three adaptive management techniques and these are compared with the reservoir performance using the current ‘reactive’ management practices. The results indicate that IPO modulation of both the magnitude and frequency of ENSO events has the effect of reducing and elevating drought risk on multi‐decadal time‐scales. The results also confirm that adaptive reservoir management techniques, based on ENSO forecasts, can improve drought security and become significantly more important during dry climate epochs. These results have marked implications for improving drought security for water storage reservoirs. Copyright © 2004 John Wiley & Sons, Ltd.
A review of models and micrometeorological methods used to estimate wetland evapotranspiration
Authors: Drexler Judy Z. , Snyder Richard L. , Spano Donatella , Paw U Kyaw Tha 
Published: May 2004

AbstractWithin the past decade or so, the accuracy of evapotranspiration (ET) estimates has improved due to new and increasingly sophisticated methods. Yet despite a plethora of choices concerning methods, estimation of wetland ET remains insufficiently characterized due to the complexity of surface characteristics and the diversity of wetland types. In this review, we present models and micrometeorological methods that have been used to estimate wetland ET and discuss their suitability for particular wetland types. Hydrological, soil monitoring and lysimetric methods to determine ET are not discussed.Our review shows that, due to the variability and complexity of wetlands, there is no single approach that is the best for estimating wetland ET. Furthermore, there is no single foolproof method to obtain an accurate, independent measure of wetland ET. Because all of the methods reviewed, with the exception of eddy covariance and LIDAR, require measurements of net radiation (Rn) and soil heat flux (G), highly accurate measurements of these energy components are key to improving measurements of wetland ET.Many of the major methods used to determine ET can be applied successfully to wetlands of uniform vegetation and adequate fetch, however, certain caveats apply. For example, with accurate Rn and G data and small Bowen ratio (β) values, the Bowen ratio energy balance method can give accurate estimates of wetland ET. However, large errors in latent heat flux density can occur near sunrise and sunset when the Bowen ratio β ≈ −1·0. The eddy covariance method provides a direct measurement of latent heat flux density (λE) and sensible heat flux density (H), yet this method requires considerable expertise and expensive instrumentation to implement. A clear advantage of using the eddy covariance method is that λE can be compared with Rn–G–H, thereby allowing for an independent test of accuracy. The surface renewal method is inexpensive to replicate and, therefore, shows particular promise for characterizing variability in ET as a result of spatial heterogeneity. LIDAR is another method that has special utility in a heterogeneous wetland environment, because it provides an integrated value for ET from a surface. The main drawback of LIDAR is the high cost of equipment and the need for an independent ET measure to assess accuracy. If Rn and G are measured accurately, the Priestley–Taylor equation can be used successfully with site‐specific calibration factors to estimate wetland ET. The ‘crop’ cover coefficient (Kc) method can provide accurate wetland ET estimates if calibrated for the environmental and climatic characteristics of a particular area. More complicated equations such as the Penman and Penman–Monteith equations also can be used to estimate wetland ET, but surface variability and lack of information on aerodynamic and surface resistances make use of such equations somewhat questionable. Copyright © 2004 John Wiley & Sons, Ltd.
Intra‐annual variability in the non‐advective heat energy budget of Devon streams and rivers
Authors: Webb B. W. , Zhang Y. 
Published: May 2004

AbstractThe nature of intra‐annual variability in the non‐advective heat fluxes affecting streams and rivers in Devon, UK was investigated through detailed monitoring of study reaches in an upland moorland catchment, below a regulating reservoir, and flowing through deciduous woodland and coniferous forest during the period May 1995 to April 1996. A clear pattern of seasonal variation was evident, whereby net radiation provided a heat source during the summer but a heat sink in the winter, as incoming short‐wave radiation declined and outgoing long‐wave radiation increased. Sensible transfer added heat to the study reaches in the summer but removed it during the winter, and bed conduction acted as a heat sink in the summer period but as a heat source in the winter months. Friction and evaporation added and removed heat, respectively, from the study reaches throughout the year, but the magnitude of these fluxes reflected seasonal variations in discharge and in wind speed. Water temperature generally followed the net non‐advective heat energy budget, which was positive in summer but negative in winter. Although a general pattern of seasonal variability in the non‐advective heat energy budget was evident, detailed differences in the nature and extent of intra‐annual variability were apparent between the study reaches and particularly between forested and non‐forested sites. Copyright © 2004 John Wiley & Sons, Ltd.
Regional daily baseflow prediction
Authors: Tung Ching‐pin , Hong Nien‐ming , Chen Chu‐hui , Tan Yih‐chi 
Published: May 2004

AbstractThe purposes of this study are to identify the bias of applying the analysis of a log–log plot of baseflow and to derive an equation to describe successive regional mean baseflow. The function −dQ/dt = a Qb has been used to describe baseflow in many studies that obtain the values of a and b from the log–log plot. According to analysis in this study, the value of 1 can be assigned to b in two boundary conditions, but the parameter a is proved to be related to the depth of water table and starting time of recession and thus different values of a may be found for different recession events. This paper points out that no single regression line can be obtained by plotting all baseflow data on a log–log diagram. Instead, there should be parallel lines, and each for a recession event. It implies that no single set of parameters a and b can be applied to predict baseflow. Thus, a new equation describing the relationship between three successive mean baseflows was derived in this study. The bias in the analysis of the log–log plot and the ability of the derived equation to predict baseflow were verified for five watersheds in Taiwan. Results indicate that the formula of mean baseflow prediction can provide reasonable estimates of flows with a leading time of 6 days. Furthermore, stream flows of the Tonkawa creek watershed in USA were used to verify that using average flows can result in better predictions than using instantaneous flows. Copyright © 2004 John Wiley & Sons, Ltd.
Experimental study of consolidation properties of unsaturated soils during draining
Authors: Ke Kai‐Yuan , Tan Yih‐Chi , Chen Chu‐Hui , Chim Kin‐Sang , Yeh Tian‐Chyi J. 
Published: May 2004

AbstractChanges in groundwater elevation may cause a change in the net normal stress and matric potential within the soil mass, which results in volume changes of unsaturated soil. This research investigated the relationship between the drawdown of groundwater and the characteristics of volumetric compressibility of unsaturated soil. Sand column experiments were designed and conducted to measure the volume changes of coarse and fine sands under different types of drainage conditions at fast and slow drainage rates. The finite element programFEMWATERwas calibrated and used to simulate the distributions of stress, tension and moisture content within the sands. Finally, based on the changes of net normal stress and matric potential and the observed volume change of the sands, a least‐square method was applied to determine the volumetric consolidation parameters of the unsaturated soils. Copyright © 2004 John Wiley & Sons, Ltd.
The stemflow of trees in a Bornean lowland tropical forest
Authors: Manfroi Odair J. , Koichiro Kuraji , Nobuaki Tanaka , Masakazu Suzuki , Nakagawa Michiko , Nakashizuka Tohru , Chong Lucy 
Published: May 2004

AbstractStemflow volume generation in lowland tropical forests was measured over a 1‐year period in the Malaysian state of Sarawak. The stemflow volume generated by 66 free‐standing trees with a diameter at breast height (DBH) over 1 cm and a tree height over 1 m were measured daily in a representative 10 m × 10 m plot of the forest. Throughfall in the plot was also measured using 20 gauges in a fixed position. Of the 2292 mm of total rainfall observed during the year‐long period, stemflow accounted for 3·5%, throughfall for 82% and there was an interception loss of 14·5%. Understory trees (DBH < 10 cm) played an important role in stemflow generation, producing 77% of the overall stemflow volume and 90% during storms with less than 20 mm of rainfall. Also, owing to their efficiency at funneling rainfall or throughfall water received by their crowns, some understory trees noticeably reduced the catches of the throughfall gauges situated under the reach of their crown areas. During storms producing greater than 20 mm of rainfall, 80% of the total stemflow occurred; trees with a large DBH or height and for which the ratio between crown's diameter and depth is less than 1, tended to generate more stemflow volume in these storms. Mean areal stemflow as a fraction of rainfall in this lowland tropical forest was 3·4%, but may range from 1–10% depending upon the proportion of trees that are high or poor stemflow yielders. Trees with DBH greater than 10 cm were likely to contribute less than 1% of the 3·4% mean areal stemflow in the forest. Copyright © 2004 John Wiley & Sons, Ltd.
Polyethylene glycol–grafted polystyrene particles
Authors: Meng Fenghua , Engbers Gerard H. M. , Feijen Jan 
Published: May 2004

AbstractDensely pegylated particles that can serve as a model system for artificial cells were prepared by covalently grafting amino polyethylene glycol (PEG, molecular weight 3400 or 5000) onto carboxyl polystyrene particles (PS–COOH) using carbodiimide chemistry. PEG‐modified particles (PS–PEG) were characterized by determination of the PEG surface concentration, ζ‐potential, size, and morphology. Under optimized grafting conditions, a dense “brush‐like” PEG layer was formed. A PEG surface concentration of approximately 60 pmol/cm2, corresponding with an average distance between grafted PEG chains of ∼17 Å can be realized. It was shown that grafting of PEG onto PS–COOH reduced the adsorption of proteins from human plasma (85 vol %) in phosphate‐buffered saline up to 90%. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 70A: 49–58, 2004
Evaluation of a resorbable, in situ setting bone substitute in a sheep model
Authors: Niedhart Christopher , Maus Uwe , Piroth Werner , Miltner Oliver , Schmidt‐Rohlfing Bernhard , Siebert Christian H. 
Published: May 2004

AbstractThe gold standard for bone substitution is the autologous bone graft, but because of its limited supply and the associated morbidity, the search for synthetic alternatives is necessary. A new in situ setting tricalcium phosphate cement was implanted in a trepanation defect (9.4 mm diameter, 10 mm depth) in the distal femoral epiphysis of sheep. Empty cavities and autologous bone graft were used as controls. Histologic and histomorphometric examinations were carried out after 12 weeks. Nearly 90% of the implanted cement was resorbed and replaced by ingrown bone with close contact between surrounding bone, new bone, and remaining cement particles. The amount of bone in the defect area was significantly higher in defects filled with cement relative to defects filled with autologous bone graft (mean 27 vs. 21%, 95% confidence intervals 23 to 31 and 18 to 23, p = 0.026). In conclusion, this new in situ setting cement is bioactive, resorbable, and osteoconductive. It will be useful as an alternative to autologous bone graft to fill stable defects. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 71B: 123–129, 2004
Effect of filler content on bending properties of dental composites: Numerical simulation with the use of the finite‐element method
Authors: Tanimoto Yasuhiro , Nishiwaki Tsuyoshi , Nemoto Kimiya , Ben Goichi 
Published: May 2004

AbstractThe purpose of this work is to investigate the influence of filler content on the bending properties of dental composites by use of the finite‐element method (FEM). The proposed numerical model was constructed from isotropic shell elements representing silica filler, and isotropic beam elements representing the remaining matrix resin. The proposed model was applied to failure analysis under three‐point bending conditions. The validity of applying the numerical model to the failure progression analysis of composites was checked through comparison with experimental results. The results show that, in both the analytical and experimental results, the bending properties, such as maximum bending stress and bending modulus, increase with filler content. Also, the proposed method of failure progression analysis could better simulate the failure process of composites under three‐point bending conditions. In addition, close agreement between the analytical and experimental results was confirmed. The above results indicate that the proposed numerical model is effective for evaluating the bending properties of dental filler composites of any content range. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 71B: 188–195, 2004
The scientifically‐minded psychologist: Science as a core competency
Authors: Bieschke Kathleen J. , Fouad Nadya A. , Collins Frank L. , Halonen Jane S. 
Published: May 2004

AbstractAt the Competencies Conference: Future Directions in Education and Credentialing in Professional Psychology, the Scientific Foundations and Research Competencies Work Group focused on identifying how psychologists practice scientifically. This article presents the subcomponents associated with the core competency of scientific practice. The subcomponents include: 1) access and apply current scientific knowledge habitually and appropriately; 2) contribute to knowledge; 3) critically evaluate interventions and their outcomes; 4) practice vigilance about how sociocultural variables influence scientific practice; and 5) routinely subject work to the scrutiny of colleagues, stakeholders, and the public. In addition, the article briefly discusses how the depth of training for and assessment of each subcomponent will vary by training model. Implications and future directions for individual psychologists, training programs, and the profession are discussed. This is one of a series of articles published in this issue of the Journal of Clinical Psychology. Several other articles that resulted from the Competencies Conference will appear in Professional Psychology: Research and Practice and The Counseling Psychologist. © 2004 Wiley Periodicals, Inc. J Clin Psychol.
Individual and cultural‐diversity competency: Focus on the therapist
Authors: Daniel Jessica Henderson , Roysircar Gargi , Abeles Norman , Boyd Cyndy 
Published: May 2004

AbstractThe Competencies Conference: Future Directions in Education and Credentialing in Professional Psychology was held in Arizona in November 2002. One of the workshops, Individual and Cultural Differences (ICD), focused on racism, homophobia, and ageism. The consensus was that self‐awareness and knowledge about the three “isms” are critical components in the education and training of psychologists. This article, authored by four of the workshop attendees, is a review of the current research and theoretical literature. Implications that address both content and context in graduate programs and training sites are presented. This is one of a series of articles published in this issue of the Journal of Clinical Psychology. Several other articles that resulted from the Competencies Conference will appear in Professional Psychology: Research and Practice and The Counseling Psychologist. © 2004 Wiley Periodicals, Inc. J Clin Psychol.
Competencies Conference: Future Directions in Education and Credentialing in Professional Psychology
Authors: Kaslow Nadine J. , Borden Kathi A. , Collins Frank L. , Forrest Linda , Illfelder‐Kaye Joyce , Nelson Paul D. , Rallo Joseph S. , Vasquez Melba J.T. , Willmuth Mary E. 
Published: May 2004

AbstractThe Competencies Conference: Future Directions in Education and Credentialing in Professional Psychology was organized around eight competency‐focused work groups, as well as work groups on specialties and the assessment of competence. A diverse group of psychologists participated in this multisponsored conference. After describing the background and structure of the conference, this article reviews the common themes that surfaced across work groups, with attention paid to the identification, training, and assessment of competencies and competence. Recommendations to advance competency‐based education, training, and credentialing in professional psychology are discussed. This is one of a series of articles published together in this issue of the Journal of Clinical Psychology. Several other articles that resulted from the Competencies Conference will appear in Professional Psychology: Research and Practice and The Counseling Psychologist. © 2004 Wiley Periodicals, Inc. J Clin Psychol.
Collagen containing neonatal astrocytes stimulates regrowth of injured fibers and promotes modest locomotor recovery after spinal cord injury
Authors: Joosten E.A.J. , Veldhuis W.B. , Hamers F.P.T. 
Published: May 2004

AbstractThe use of collagen as a vehicle to transplant neonatal astroglial cells into the lesioned spinal cord of the adult rat allows a precise application of these cells into the lesion gap and minimizes the migration of the transplanted cells. This approach might lead to anatomical and functional recovery. In the present study, 20 adult female Wistar rats were subjected to a dorsal hemisection at thoracic spinal cord levels. Cultured cortical neonatal rat astrocytes were transplanted into the lesion with collagen as a vehicle (N = 10). Prior to transplantation, the cultured astroglial cells were labelled with fast blue. Control rats received collagen implants only (N = 10). During 1 month of survival time, functional recovery of all rats was continuously monitored. Histological data showed that the prelabelled astroglial cells survived transplantation and were localized predominantly in the collagen implant. Virtually no fast blue‐labelled GFAP‐positive astroglial cells migrated out of the implant into the adjacent host spinal cord. The presence of transplanted neonatal astroglial cells resulted in a significant increase in the number of ingrowing neurofilament‐positive fibers (including anterogradely labeled corticospinal axons) into the implant. Ingrowing fibers were closely associated with the transplanted astroglial cells. The implantation of neonatal astroglial cells did result in modest temporary improvements of locomotor recovery as observed during open‐field locomotion analysis (BBB subscore) or during crossing of a walkway (catwalk). © 2004 Wiley‐Liss, Inc.
Optimization of a solid‐phase microextraction procedure for the determination of herbicides by micellar electrokinetic chromatography
Authors: Frías‐García Sergio , Sánchez M. J. , Rodríguez‐Delgado Miguel Á. 
Published: May 2004

AbstractThe use of a different optimization procedure that involves Experimental Design (ED) and Artificial Neural Networks (ANN) for the off‐line coupling solid‐phase microextraction‐micellar electokinetic chomatography (SPME‐MEKC) is presented. This combination of ED and ANN, mathematical tools not previously used in SPME‐MEKC optimization, allowed us to obtain good extraction efficiencies in the SPME procedure for the determination of a group of eleven triazine herbicides in groundwater samples. Both extraction and desorption steps were carried out by solution stirring at 900 rpm. Optimal conditions for the off‐line SPME procedure were: extraction with a poly(dimethylsiloxane)/divinylbenzene SPME fiber for 120 min, 10% (w/v) NaCl, desorption time 40 min, and 70% (v/v) of methanol/buffer as desorption mixture. Detection limits lay between 0.80 μg L–1 and 4.89 μg L–1. Finally, the optimized method was applied to the determination of these compounds in spiked and non‐spiked groundwater samples using a previously optimized MEKC separation.