bluuebunny/crossref_metadata_2025_split huggingface dataset:
Resolving barometric pressure waves in seasonal snowpack with a prototype‐embedded wireless sensor network
Authors: Lampkin D. J. 
Published: February 2010

AbstractNetworked micro‐sensors have the capacity to enable improvements in ground‐based data collection at resolutions that are currently unresolved. Crossbow® Environmental Motes (MEP410 models) were embedded in an accumulated snowpack in a meadow at Niwot Ridge long‐term ecological research (LTER) C1 site. Motes were mounted to a custom designed deployment structure that constitutes an adaptive sensor ‘tower’ at a maximum height of 142 with sensors deployed at depths of 122, 71 and 17 cm from the ground. Barometric pressures measured from this embedded wireless network indicate low frequency fluctuations over the study period with higher frequency components varying as a function of depth. Mean pressures measured over the analysis period were 707·82 mb (122 cm), 702·48 mb (71 cm), and 704·09 mb (17 cm). Results indicate filtering of high frequency components of pressure measured at depth with reduced amplitude and time‐lag (phase shift) modulated by changes in snowpack permeability related to density changes. Copyright © 2010 John Wiley & Sons, Ltd.
On the temporal resolution of mass balance models for soluble chemicals in soils
Authors: Pistocchi A. 
Published: February 2010

AbstractA daily step model of chemical mass balance in the topsoil is presented and validated at the three experimental sites in Europe, and subsequently applied to perform two distinct numerical experiments. First, an experiment was run using hypothetic soluble chemicals with half‐lives ranging from 10−1 to 104, with a range of representative European climate and soil properties, assuming uniform constant emissions of the chemicals throughout the year. Chemical mass in soil from the daily step model calculations can be surrogated by the monthly step model consistently parameterized in terms of absolute values, patterns and inter‐monthly variability with decreasing accuracy at higher chemical half‐lives. Leaching fluxes can be also surrogated by the monthly step calculation, although with higher errors. Runoff is correct in the order of magnitude, but it shows only a weak correlation with the monthly mean of the daily model output. For leaching and runoff, the accuracy depends mainly on soil properties. Variability is well reproduced for both leaching and runoff.The second experiment represented a pulse emission of chemicals discharged on a single day in a 12‐month period. Results from the annual average mass of chemicals in the soil, annual runoff and leaching fluxes from the daily step model were compared with the results obtained from the experiment assuming constant‐removal rates for the year. The two values are within a factor of 10 for half‐lives longer than 10 days; therefore, it is possible to emulate the daily step model with a simple constant‐removal rate model for screening‐level assessment. The experiments suggest that simpler schemes may be a practical screening‐level approximation of detailed daily step models for both continuous and pulse emissions, two cases providing extreme bounds of variation to real world emissions. Copyright © 2010 John Wiley & Sons, Ltd.
Isotopic composition (δ18O and δD) of precipitation and groundwater in a semi‐arid, mountainous area (Guadiana Menor basin, Southeast Spain)
Authors: Fernández‐Chacón F. , Benavente J. , Rubio‐Campos J. C. , Kohfahl C. , Jiménez J. , Meyer H. , Hubberten H. , Pekdeger A. 
Published: February 2010

AbstractWe characterize the precipitation and groundwater in a mountainous (peaks slightly above 3000 m a.s.l.), semi‐arid river basin in SE Spain in terms of the isotopes18O and2H. This basin, with an extension of about 7000 km2, is an ideal site for such a study because fronts from the Atlantic and the Mediterranean converge here. Much of the land is farmed and irrigated both by groundwater and runoff water collected in reservoirs. A total of approximately 100 water samples from precipitation and 300 from groundwater have been analysed. To sample precipitation we set up a network of 39 stations at different altitudes (800–1700 m a.s.l.), with which we were able to collect the rain and snowfall from 29 separate events between July 2005 and April 2007 and take monthly samples during the periods of maximum recharge of the aquifers. To characterize the groundwater we set up a control network of 43 points (23 springs and 20 wells) to sample every 3 months the main aquifers and both the thermal and non‐thermal groundwater. We also sampled two shallow‐water sites (a reservoir and a river). The isotope composition of the precipitation forms a local meteoric water line (LMWL) characterized by the equation δD = 7·72δ18O + 9·90, with mean values for δ18O and δD of − 10·28‰ and − 69·33‰, respectively, and 12·9‰ for thed‐excess value. To correlate the isotope composition of the rainfall water with groundwater we calculated the weighted local meteoric water line (WLMWL), characterized by the equation δD = 7·40δ18O + 7·24, which takes into account the quantity of water precipitated during each event. These values of (dδD/dδ18O)< 8 andd‐excess (δD–8δ18O)< 10 in each curve bear witness to the ‘amount effect’, an effect which is more manifest between May and September, when the ground temperature is higher. Other effects noted in the basin were those of altitude and the continental influence. The isotopic compositions of the groundwater are represented by the equation δD = 4·79δ18O − 18·64. The groundwater is richer in heavy isotopes than the rainfall, with mean values of − 8·48‰ for δ18O and − 59·27‰ for δD. The isotope enrichment processes detected include a higher rate of evaporation from detrital aquifers than from carbonate ones, the effects of recharging aquifers from irrigation return flow and/or from reservoirs' leakage and enrichment in δ18O from thermal water. Copyright © 2010 John Wiley & Sons, Ltd.
Sensitivity of streamflow from a Himalayan catchment to plausible changes in land cover and climate
Authors: Ma Xing , Xu Jianchu , van Noordwijk Meine 
Published: February 2010

AbstractGlobal climate change will likely increase temperature and variation in precipitation in the Himalayas, modifying both supply of and demand for water. This study assesses combined impacts of land‐cover and climate changes on hydrological processes and a rainfall‐to‐streamflow buffer indicator of watershed function using the Soil Water Assessment Tool (SWAT) in Kejie watershed in the eastern Himalayas. The Hadley Centre Coupled Model Version 3 (HadCM3) was used for two Intergovernmental Panel on Climate Change (IPCC) emission scenarios (A2 and B2), for 2010–2099. Four land‐cover change scenarios increase forest, grassland, crops, or urban land use, respectively, reducing degraded land. The SWAT model predicted that downstream water resources will decrease in the short term but increase in the long term. Afforestation and expansion in cropland will probably increase actual evapotranspiration (ET) and reduce annual streamflow but will also, through increased infiltration, reduce the overland flow component of streamflow and increase groundwater release. An expansion in grassland will decrease actual ET, increase annual streamflow and groundwater release, while decreasing overland flow. Urbanization will result in increases in streamflow and overland flow and reductions in groundwater release and actual ET. Land‐cover change dominated over effects on streamflow of climate change in the short and middle terms. The predicted changes in buffer indicator for land‐use plus climate‐change scenarios reach up to 50% of the current (and future) range of inter‐annual variability. Copyright © 2010 John Wiley & Sons, Ltd.
Unstructured grid generation using LiDAR data for urban flood inundation modelling
Authors: Tsubaki Ryota , Fujita Ichiro 
Published: February 2010

AbstractInundation disasters, caused by sudden water level rise or rapid flow, occur frequently in various parts of the world. Such catastrophes strike not only in thinly populated flood plains or farmland but also in highly populated villages or urban areas. Inundation of the populated areas causes severe damage to the economy, injury, and loss of life; therefore, a proper management scheme for the disaster has to be developed. To predict and manage such adversity, an understanding of the dynamic processes of inundation flow is necessary because risk estimation is performed based on inundation flow information. In this study, we developed a comprehensive method to conduct detailed inundation flow simulations for a populated area with quite complex topographical features using LiDAR (Light Detection and Ranging) data. Detailed geospatial information including the location and shape of each building was extracted from the LiDAR data and used for the grid generation. The developed approach can distinguish buildings from vegetation and treat them differently in the flow model. With this method, a fine unstructured grid can be generated representing the complicated urban land features precisely without exhausting labour for data preparation. The accuracy of the generated grid with different grid spacing and grid type is discussed and the optimal range of grid spacing for direct representation of urban topography is investigated. The developed method is applied to the estimation of inundation flows, which occurred in the basin of the Shin‐minato River. A detailed inundation flow structure is represented by the flow model, and the flow characteristics with respect to topographic features are discussed. Copyright © 2010 John Wiley & Sons, Ltd.
Impacts of climate change and human activities on surface runoff in the Dongjiang River basin of China
Authors: Liu Dedi , Chen Xiaohong , Lian Yanqing , Lou Zhanghua 
Published: February 2010

AbstractObserved rainfall and flow data from the Dongjiang River basin in humid southern China were used to investigate runoff changes during low‐flow and flooding periods and in annual flows over the past 45 years. We first applied the non‐parametric Mann–Kendall rank statistic method to analyze the change trend in precipitation, surface runoff and pan evaporation in those three periods. Findings showed that only the surface runoff in the low‐flow period increased significantly, which was due to a combination of increased precipitation and decreased pan evaporation. The Pettitt–Mann–Whitney statistical test results showed that 1973 and 1978 were the change points for the low‐flow period runoff in the Boluo sub‐catchment and in the Qilinzui sub‐catchment, respectively. Most importantly, we have developed a framework to separate the effects of climate change and human activities on the changes in surface runoff based on the back‐propagation artificial neural network (BP‐ANN) method from this research. Analyses from this study indicated that climate variabilities such as changes in precipitation and evaporation, and human activities such as reservoir operations, each accounted for about 50% of the runoff change in the low‐flow period in the study basin. Copyright © 2010 John Wiley & Sons, Ltd.
Effects of fire and vegetation cover on hydrological characteristics of a Mediterranean shrubland soil
Authors: González‐Pelayo O. , Andreu V. , Gimeno‐García E. , Campo J. , Rubio J. L. 
Published: February 2010

AbstractAn experimental study based on the effects of fire on soil hydrology was developed at the Experimental Station of ‘La Concordia’ (Valencia, Spain). It is located on a calcareous hillside facing SSE and composed of nine erosion plots (4 × 20 m). In summer 2003, after eight years of soil and vegetation recovery from previous fires in 1995 (with three fire treatments: T1 high‐intensity fire, T2 moderate intensity, and T3 not burnt), experimental fires of low intensity were again conducted on the plots already burnt, to study the effects of repeated fires on the soil water infiltration, soil water content and runoff.Infiltration rates and capacities were measured by the mini‐disk infiltrometer method (MDI), assessing the effects of vegetation cover by comparing the under‐canopy microenvironment (UC) and its absence on bare soil (BS), immediately before and after the fire experiments. Soil properties like water retention capacity (SWRC) and water content (SWC) were also determined for the different fire treatments (T1, T2 and T3) and microsites (UC and BS). Hydrological parameters, such as runoff and infiltration rate, were monitored at plot scale from July 2002 to July 2004. In the post‐fire period, data displayed a 20% runoff increase and a decrease in infiltration (18%).Differences in the steady‐state infiltration rate (SSI) and infiltration capacity (IC) were tested with the MDI on the different treatments (T1, T2 and T3), and between the UC and BS microsites of each treatment. After fire, the SSI of the UC soil declined from 16 mm h−1 to 12 mm h−1 on T1, and from 24 mm h−1 to 19 mm h−1 on T2. The IC was reduced by 2/3 in the T1 UC soil, and by half on T2 UC soil. On the BS of T1 and T2, the fire effect was minimal, and higher infiltration rates and capacities were reached. Therefore, the presence/absence of vegetation when burnt influenced the post‐burnt infiltration patterns at soil microscale. On the T3, different rates and capacities were obtained depending on the microsites (UC and BS), with higher SSI (25 mm h−1) and IC (226 mm h−1) on BS than on UC (SSI of 18 mm h−1 and IC of 136 mm h−1).The SWRC and SWC were recovered from 1995 to 2003 (prior to the fires). The 2003 fire promoted high variability on the SWC at pF 0·1, 2 and 2·5, and the SWRC on burnt soils were reduced. To summarize, the IC and SSI post‐fire decreases were related to the lower infiltration rate at plot scale, the significant differences in the SWRC between burnt and control treatments, and the increase in the runoff yield (20%).According to the results, the MDI was a useful tool to characterize the soil infiltration on the vegetation patches of the Mediterranean maquia, and contrary to other studies, on the UC soil, the infiltration rate and IC, when soil was dry, were lower than that obtained on BS. Once the soil gets wet, similar values were found on both microenvironments. Copyright © 2010 John Wiley & Sons, Ltd.
Polycaprolactone/hydroxyapatite composite scaffolds: Preparation, characterization, and in vitro and in vivo biological responses of human primary bone cells
Authors: Chuenjitkuntaworn Boontharika , Inrung Wipawan , Damrongsri Damrong , Mekaapiruk Kongkwan , Supaphol Pitt , Pavasant Prasit 
Published: February 2010

AbstractPolycaprolactone (PCL) is a synthetic biodegradable polymer that has been approved for use as bone graft substitutes. In this study, PCL scaffolds incorporating hydroxyapatite (HAp) particles were fabricated by combined solvent casting and particulate leaching techniques. The average pore dimension was in the range of about 480–500 μm. The porosity, water absorption, and compressive modulus of the scaffold were evaluated. The responses of primary bone cells cultured on the PCL and PCL/HAp scaffolds were examined both in vitro and invivo. In comparison with the cells grown on the PCL scaffold, those cultured on the PCL/HAp counterpart positively expressed the markers of osteogenic differentiation. Cells increased the mRNA expressions of type I collagen and osteocalcin on day 10 and demonstrated a significant increase in calcium deposition. In coherence with the in vitro appearance, histomorphometric analysis in a mouse calvarial model showed a significantly greater amount of new bone formation. The results demonstrated that the prepared PCL/HAp scaffold could be a good candidate as synthetic substitute for bone tissue engineering. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Effects of cyclic flexural fatigue on porcine bioprosthetic heart valve heterograft biomaterials
Authors: Mirnajafi Ali , Zubiate Brett , Sacks Michael S. 
Published: February 2010

AbstractAlthough bioprosthetic heart valves (BHV) remain the primary treatment modality for adult heart valve replacement, continued problems with durability remain. Several studies have implicated flexure as a major damage mode in porcine‐derived heterograft biomaterials used in BHV fabrication. Although conventional accelerated wear testing can provide valuable insights into BHV damage phenomena, the constituent tissues are subjected to complex, time‐varying deformation modes (i.e., tension and flexure) that do not allow for the control of the amount, direction, and location of flexure. Thus, in this study, customized fatigue testing devices were developed to subject circumferentially oriented porcine BHV tissue strips to controlled cyclic flexural loading. By using this approach, we were able to study layer‐specific structural damage induced by cyclic flexural tensile and compressive stresses alone. Cycle levels of 10 × 106, 25 × 106, and 50 × 106 were used, with resulting changes in flexural stiffness and collagen structure assessed. Results indicated that flexural rigidity was markedly reduced after only 10 × 106 cycles, and progressively decayed at a lower rate with cycle number thereafter. Moreover, the against‐curvature fatigue direction induced the most damage, suggesting that the ventricularis and fibrosa layers have low resistance to cyclic flexural compressive and tensile loads, respectively. The histological analyses indicated progressive collagen fiber delamination as early as 10 × 106 cycles but otherwise no change in gross collagen orientation. Our results underscore that porcine‐derived heterograft biomaterials are very sensitive to flexural fatigue, with delamination of the tissue layers the primary underlying mechanism. This appears to be in contrast to pericardial BHV, wherein high tensile stresses are considered to be the major cause of structural failure. These findings point toward the need for the development of chemical fixation technologies that minimize flexure‐induced damage to extend porcine heterograft biomaterial durability. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Investigation of the binding of Cr(III) complexes to bovine and human serum proteins: A proteomic approach
Authors: Tkaczyk Cathy , Huk Olga L. , Mwale Fackson , Antoniou John , Zukor David J. , Petit Alain , Tabrizian Maryam 
Published: February 2010

AbstractChromium (Cr) compounds are widely used in alloys manufacturing and forming processes. One of the main concerns in the use of cobalt‐chromium (Co‐Cr) alloy‐based implants is the long‐term fate of Co and Cr ions in the blood, organs, and urine of patients. Our previous studies have shown that Cr(III) forms complexes in different cell culture media, whereas Cr(VI) does not form any detectable structure under the same conditions. Because Cr(VI) is known to be more toxic than Cr(III), we hypothesized that the presence of serum proteins in the molecular structure of Cr(III) may be responsible for the difference in toxicity. We investigated the interaction of the Cr(III) complexes with serum proteins and their internalization by U937 macrophage‐like cells. By using a proteomic approach, we showed that in the presence of fetal bovine serum, Cr(III) complexes interacted only with albumin, whereas they interacted mainly with albumin, transferrin, and immunoglobulins (Ig) in the presence of human serum (HS). Cr(III) complexes were more easily engulfed by U937 macrophage‐like cells when they were formed with HS. To the best of our knowledge, this is the first report on the formation of Cr(III) complexes in the presence of serum proteins and the interaction of these complexes with U937 macrophage‐like cells. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res, 2010
Cellular inhibition produced by dental curing lights is a heating artifact
Authors: Blay Jonathan , Price Richard B. 
Published: February 2010

AbstractDental curing lights deliver energy in the 380–520 nm wavelength range. It has been reported that irradiation in these wavelengths may have a negative effect on cell function. We examined the effect of three dental curing lights on the viability of mouse (NIH3T3, Balb/c3T3) and human (HGF‐1) fibroblastic cells, and epithelial (HT‐29) cells grown in culture. Cell inhibition was observed using the MTT assay of mitochondrial function and measures of DNA fragmentation and DNA synthesis. Analyzing the experimental method and careful measurement of the temperature adjacent to the cell monolayer during irradiation showed that damage to the cells was not due to cumulative light exposure, but instead occurred when the temperature of the culture medium rose above 42°C. We conclude that dental curing lights do not cause cell damage as a direct result of the light irradiation. Instead it is caused by the local temperature increase in the cells. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010
Fabrication and characterization of a porous multidomain hydroxyapatite scaffold for bone tissue engineering investigations
Authors: Buckley Conor Timothy , O'Kelly Kevin Unai 
Published: February 2010

AbstractTissue‐engineering scaffold‐based strategies have suffered from limited cell depth viability when cultured in vitro, with viable cells existing within the outer periphery of the fluid–scaffold interface. This is primarily believed to be due to the lack of nutrient delivery into and waste removal from the inner regions of the scaffold construct. This work develops a hydroxyapatite trimodal porous scaffold architecture (i.e., a scaffold providing a discrete domain for cell occupancy and a separate domain for nutrient delivery) through a freeze drying process. Unidirectional channels (500 μm diameter) were incorporated through CNC machining with total combined apparent porosities of 85.1% ± 0.22%. Effective diffusion coefficients for the bimodal phase (consisting of micro‐ and meso‐pores, without channels) were also determined (7.9 × 10−10 m2 s−1). Trimodal scaffolds also demonstrated enhanced permeability values (∼18‐fold increase) compared with bimodal scaffold architectures. In vitro experiments were used to assess initial seeding efficiency and distribution as well as cell viability. The presence of unidirectional channels significantly enhanced initial cell seeding distribution throughout the scaffold depth, while maintaining relatively high seeding efficiencies (67.7% ± 2.2% for trimodal, 79.1% ± 2.1% for bimodal scaffolds). Numerical models demonstrated the effectiveness and efficacy of incorporating channels to increase the core oxygen concentration, with the accuracy of these models improved by using experimentally measured cellular oxygen consumption rates and effective diffusion coefficients. The presence of channels had a positive influence in minimizing the concentration gradients compared with bimodal scaffolds for the same cell density distributions. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010