bluuebunny/crossref_metadata_2025_split huggingface dataset:
Water balance of tropical rainforest canopies in north Queensland, Australia
Authors: McJannet David , Wallace Jim , Fitch Peter , Disher Mark , Reddell Paul 
Published: August 2007

AbstractThe water balance of four different rainforest types in the Wet Tropics region of north Queensland is inferred from measurements of canopy hydrological components undertaken for periods between 391 to 657 days. These measurements of rainfall, cloud interception, stem‐flow, throughfall, canopy interception and transpiration have revealed considerable differences in the canopy water balance of different locations as a result of forest structural differences, altitude, exposure and climate. Cloud interception is a significant extra input of water to forests at high altitude sites (>1000 m) and varies between 7 and 29% of the total water input. At coastal and lower montane rainforests annual total evaporation is consistently around 50% of the total water input, but in upper montane cloud forest this drops dramatically to only 13% of the water input. At all sites actual evaporation is greater than potential evaporation for most of the year and on an annual basis exceeds potential by between 2 and 53%. The source of this additional energy is uncertain, but is likely to come from advection. Annual interception at all the rainforest sites was greater than annual transpiration, with transpiration dominating in the dry season and interception dominating in the wet season. All of the rainforests have a large annual net water balance to sustain runoff and recharge. Towards the end of the dry season runoff and recharge can cease in coastal lowland and lower mountain forests and they may have to draw on soil moisture and/or ground water at this time. In contrast, upper montane cloud forests have a positive net water balance throughout the year and are therefore an important source of dry season river flows. Furthermore, their exceptionally large annual runoff (∼6500 mm year−1) is a major source of downstream water. Copyright © 2007 John Wiley & Sons, Ltd.
The influence of climate change on suspended sediment transport in Danish rivers
Authors: Thodsen H. , Hasholt B. , Kjærsgaard J. H. 
Published: August 2007

AbstractThe HIRHAM regional climate model suggests an increase in temperature in Denmark of about 3 °C and an increase in mean annual precipitation of 6–7%, with a larger increase during winter and a decrease during summer between a control period 1961–1990 and scenario period 2071–2100. This change of climate will affect the suspended sediment transport in rivers, directly through erosion processes and increased river discharges and indirectly through changes in land use and land cover. Climate‐change‐induced changes in suspended sediment transport are modelled for five scenarios on the basis of modelled changes in land use/land cover for two Danish river catchments: the alluvial River Ansager and the non‐alluvial River Odense. Mean annual suspended sediment transport is modelled to increase by 17% in the alluvial river and by 27% in the non‐alluvial for steady‐state scenarios. Increases by about 9% in the alluvial river and 24% in the non‐alluvial river were determined for scenarios incorporating a prolonged growing season for catchment vegetation. Shortening of the growing season is found to have little influence on mean annual sediment transport. Mean monthly changes in suspended sediment transport between − 26% and + 68% are found for comparable suspended sediment transport scenarios between the control and the scenario periods. The suspended sediment transport increases during winter months as a result of the increase in river discharge caused by the increase in precipitation, and decreases during summer and early autumn months. Copyright © 2007 John Wiley & Sons, Ltd.
Using stochastic state‐space modelling to specify and reduce hydrograph error
Authors: Collier C. G. , Robbins G. L. 
Published: August 2007

AbstractA Bayesian post‐processor is used to generate a representation of the likely hydrograph forecast flow error distribution using raingauge and radar input to a stochastic catchment model and its deterministic equivalent. A hydrograph ensemble is so constructed. Experiments are analysed using the model applied to the River Croal in north‐west England. It is found that for rainfall input to the model having errors less than 3mm h−1, corresponding to about a 15% error in peak flow, the stochastic model outperforms the deterministic model. The range of hydrographs associated with the different model simulations and the measured hydrographs are compared. The significant improvement possible using a stochastic approach is demonstrated for a specific case study, although the mean hydrograph derived using the stochastic model has an error range associated with it. Copyright © 2007 John Wiley & Sons, Ltd.
Hydrologic comparison between a forested and a wetland/lake dominated watershed using SWAT
Authors: Wu Kangsheng , A. Johnston Carol 
Published: August 2007

AbstractThe Soil and Water Assessment Tool (SWAT) is a physically‐based hydrologic model developed for agricultural watersheds, which has been infrequently validated for forested watersheds, particularly those with deep overwinter snow accumulation and abundant lakes and wetlands. The goal of this study was to determine the applicability of SWAT for modelling streamflow in two watersheds of the Ontonagon River basin of northern Michigan which differ in proportion of wetland and lake area. The forest‐dominated East Branch watershed contains 17% wetland and lake area, whereas the wetland/lake‐dominated Middle Branch watershed contains 26% wetland and lake area. The specific objectives were to: (1) calibrate and validate SWAT models for the East Branch and Middle Branch watersheds to simulate monthly stream flow, and (2) compare the effects of wetland and lake abundance on the magnitude and timing of streamflow. Model calibration and validation was satisfactory, as determined by deviation of discharge D and Nash and Sutcliffe coefficient values E that compared simulated monthly mean discharge versus measured monthly mean discharge. Streamflow simulation discrepancies occurred during summer and fall months and dry years. Several snow melting parameters were found to be critical for the SWAT simulation: TIMP (snow temperature lag factor) and SMFMX and SMFMN (melting factors). Snow melting parameters were not transferable between adjacent watersheds. Differences in seasonal pattern of long‐term monthly streamflow were found, with the forest‐dominated watershed having a higher peak flow during April but a lower flow during the remainder of the year in comparison to the wetland and lake‐dominated watershed. The results suggested that a greater proportion of wetland and lake area increases the capacity of a watershed to impound surface runoff and to delay storm and snow melting events. Representation of wetlands and lakes in a watershed model is required to simulate monthly stream flow in a wetland/lake‐dominated watershed. Copyright © 2007 John Wiley & Sons, Ltd.
Estimating suspended sediment concentrations from turbidity measurements and the calibration problem
Authors: Minella Jean P. G. , Merten Gustavo H. , Reichert José M. , Clarke Robin T. 
Published: August 2007

AbstractIn situ turbidity meters are being increasingly used to generate continuous records of suspended sediment concentration in rivers. However, the usefulness of the information obtained depends heavily on the existence of a close relationship between fluctuations in suspended sediment concentration and turbidity and the calibration procedure that relates suspended sediment concentration to the turbidity meter's signal. This study assesses the relationship between suspended sediment concentration and turbidity for a small (1·19 km2) rural catchment in southern Brazil and evaluates two calibration methods by comparing the estimates of suspended sediment concentration obtained from the calibrated turbidity readings with direct measurements obtained using a USDH 48 suspended sediment sampler. With the first calibration method, the calibration relationship is derived by relating the turbidity readings to simultaneous measurements of concentration obtained from suspended sediment samples collected from the vicinity of the turbidity probe during flood events. With the second method, the calibration is based on the readings obtained from the turbidity meter when the probe immersed in samples of known concentration prepared using soils collected from the catchment. Overall, there was a close link between fluctuations in suspended sediment concentration and turbidity in the stream at the outlet of the catchment, and the estimates of sediment concentration obtained using the first calibration method corresponded closely with the conventionally measured sediment concentrations. However, use of the second calibration method introduced appreciable errors. When the estimated sediment concentrations were compared with the measured values, the mean errors were ± 122 mg l−1 and + 601 mg l−1 for the first and second calibration procedures respectively. Copyright © 2007 John Wiley & Sons, Ltd.
Modelling study on the impact of deep building foundations on the groundwater system
Authors: Ding Guoping , Jiao Jiu J. , Zhang Dongxiao 
Published: August 2007

AbstractCoastal areas are usually the preferred place of habitation for human beings. Anthropogenic activities such as the construction of high‐rise buildings and underground transport systems usually require extensive deep foundations and ground engineering works, which may unintentionally modify the coastal groundwater system because the construction materials of foundations are usually of low hydraulic conductivity. In this paper, the impact of these building foundations on the groundwater regime is studied using hypothetical flow and transport models. Various possible realizations of foundation distributions are generated using stochastic parameters derived from a topographical map of an actual coastal area in Hong Kong. The effective hydraulic conductivity is first calculated for different realizations and the results show that the effective hydraulic conductivity can be reduced significantly. Then a hypothetical numerical model based on FEFLOW is set up to study the change of hydraulic head, groundwater discharge, and saltwater‐fresh water interface. The groundwater level and flow are modified to various degrees, depending on the foundations percentage and the distribution pattern of the buildings. When the foundations percentage is high and the building foundations are aggregated, the hydraulic head is raised significantly and the originally one‐dimensional groundwater flow field becomes complicated. Seaward groundwater discharge will be reduced and some groundwater may become seepage through the ground surface. The transport model shows that, after foundations are added, overall the seawater and fresh groundwater interface moves landward, so extensive foundations may induce seawater intrusion. It is believed that the modification of the coastal groundwater system by building foundations may have engineering and environmental implications, such as submarine groundwater discharge, foundation corrosion, and slope stability. Copyright © 2007 John Wiley & Sons, Ltd.
Climatic control on river discharge simulations, Zackenberg River drainage basin, northeast Greenland
Authors: Mernild Sebastian H. , Hasholt Bent , Liston Glen E. 
Published: August 2007

AbstractA spatially distributed, physically based, hydrologic modeling system (MIKE SHE) was applied to quantify intra‐ and inter‐annual discharge from the snow and glacierized Zackenberg River drainage basin (512 km2; 20% glacier cover) in northeast Greenland. Evolution of snow accumulation, distribution by wind‐blown snow, blowing‐snow sublimation, and snow and ice surface melt were simulated by a spatially distributed, physically based, snow‐evolution modelling system (SnowModel) and used as input to MIKE SHE. Discharge simulations were performed for three periods 1997–2001 (calibration period), 2001–2005 (validation period), and 2071–2100 (scenario period). The combination of SnowModel and MIKE SHE shows promising results; the timing and magnitude of simulated discharge were generally in accordance with observations (R2 = 0·58); however, discrepancies between simulated and observed discharge hydrographs do occur (maximum daily difference up to 44·6 m3 s−1 and up to 9% difference between observed and simulated cumulative discharge). The model does not perform well when a sudden outburst of glacial dammed water occurs, like the 2005 extreme flood event. The modelling study showed that soil processes related to yearly change in active layer depth and glacial processes (such as changes in yearly glacier area, seasonal changes in the internal glacier drainage system, and the sudden release of glacial bulk water storage) need to be determined, for example, from field studies and incorporated in the models before basin runoff can be quantified more precisely. The SnowModel and MIKE SHE model only include first‐order effects of climate change. For the period 2071–2100, future IPCC A2 and B2 climate scenarios based on the HIRHAM regional climate model and HadCM3 atmosphere–ocean general circulation model simulations indicated a mean annual Zackenberg runoff about 1·5 orders of magnitude greater (around 650 mmWE year−1) than from today 1997–2005 (around 430 mmWE year−1), mainly based on changes in negative glacier net mass balance. Copyright © 2007 John Wiley & Sons, Ltd.
Electrospun‐modified nanofibrous scaffolds for the mineralization of osteoblast cells
Authors: Venugopal J. , Low Sharon , Choon Aw Tar , Kumar A. Bharath , Ramakrishna S. 
Published: August 2007

AbstractBiocompatible polycaprolactone (PCL) and hydroxyapatite (HA) were fabricated into nanofibrous scaffolds for the mineralization of osteoblasts in bone tissue engineering. PCL and PCL/HA nanofibrous surface were modified using oxygen plasma treatment and showing 0° contact angle for the adhesion and mineralization of osteoblast cells. The fiber diameter, pore size and porosity of nanofibrous scaffolds were estimated to be 220–625 nm, 3–20 μm, and 87–92% respectively. The ultimate tensile strength of PCL was about 3.37 MPa and PCL/HA was 1.07 MPa to withstand the long term culture of osteoblasts on nanofibrous scaffolds. Human fetal osteoblast cells (hFOB) were cultured on PCL and PCL/HA surface modified and unmodified nanofibrous scaffolds. The osteoblast proliferation rate was significantly (p < 0.001) increased in surface‐modified nanofibrous scaffolds. FESEM showed normal phenotypic cell morphology and mineralization occurred in PCL/HA nanofibrous scaffolds, HA acting as a chelating agent for the mineralization of osteoblast to form bone like apatite for bone tissue engineering. EDX and Alizarin Red‐S staining indicated mineral Ca2+ and phosphorous deposited on the surface of osteoblast cells. The mineralization was significantly increased in PCL/HA‐modified nanofibrous scaffolds and appeared as a mineral nodule synthesized by osteoblasts similar to apatite of the natural bone. The present study indicated that the PCL/HA surface‐modified nanofibrous scaffolds are potential for the mineralization of osteoblast for bone tissue engineering. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
The formation of tertiary dentin after pulp capping with a calcium phosphate cement, loaded with PLGA microparticles containing TGF‐β1
Authors: Zhang Weibo , Walboomers X. Frank , Jansen John A. 
Published: August 2007

AbstractThe aim of the current study was to evaluate the effect of a calcium phosphate material equipped with poly (lactic‐co‐glycolic acid) microspheres for pulp capping, and to measure the dentin bridge formation, when using various concentrations of transforming growth factor (TGF) β1. Preset samples were made (2 mm diameter; 2 mm height), containing 0 (controls), 20, or 400 ng TGF‐β1. These were placed in goat incisors. Incisors capped with glass‐ionomer cement only were used as negative controls. Twelve weeks after pulp capping, the incisors were retrieved, processed for histology, and graded on basis of tertiary dentin formation. The results showed that new dentin formation was seen in all samples, except the negative controls. The histological grading indicated significant differences between the samples loaded with high amount of TGF‐β1 versus the three other groups (p < 0.05). In conclusion, our study demonstrated that the composite with 400 ng TGF‐β1 was able to trigger resident stem cells in the pulp to differentiate into odontoblast‐like cells and to induce the formation of tertiary dentin. The material might be a good candidate for vital pulp therapy. Production and manipulation methods could be improved for follow‐up studies. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Fabricate coaxial stacked nerve conduits through soft lithography and molding processes
Authors: Wang De‐Yao , Huang Yi‐You 
Published: August 2007

AbstractIn this article we present a new way to fabricate nerve conduits with various multi‐channels patterns by microfabrication. Soft lithography was used to manufacture silicon‐based structures and replicate them with PDMS for producing nerve conduit subunit molds. After that, 3% chitosan/acetic acid solution was filled into PDMS molds and then hardened and peeled off. Nerve conduit subunits were fabricated repeatedly by a set of methods for mass production. Afterward, a plurality of conduit subunits stacked coaxially and coated with outer membrane to form the whole nerve conduit. Because of the precise capability of soft lithography, it is well‐suited for nerve conduits with complex designs, such as a combination of multiple degradation control and drug delivery system. Besides, the miniaturization and batch processes are serviceable to the economic effect and the utilization in industry. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Association of ambulatory use of statins and beta‐blockers with long‐term mortality after vascular surgery
Authors: Barrett Thomas W. , Mori Motomi , De Boer David 
Published: August 2007

AbstractBACKGROUNDThe use of drugs to improve postoperative outcomes has focused on short‐term end points and centered on beta‐blockers. Emerging evidence suggests statins may also improve postoperative outcomes.OBJECTIVEWe sought to ascertain if the ambulatory use of statins and/or beta‐blockers was associated with a reduction in long‐term mortality after vascular surgery.DESIGNRetrospective cohort study with a median follow‐up of 2.7 years.SETTINGRegional multicenter study at Veterans Affairs medical centers.PATIENTSThree thousand and sixty‐two patients presenting for vascular surgery.MEASUREMENTSPatients were categorized as using statins or beta‐blockers if they filled a prescription for the study drug within 30 days of surgery. Survival analyses, propensity score methods, and stratifications by the revised cardiac risk index (RCRI) were performed.RESULTSPropensity‐adjusted ambulatory use of statins and beta‐blockers was associated with a reduction in mortality over the study period compared with nonuse of these medications hazard ratio [HR] = 0.78 [95% CI: 0.67–0.92], P = .0021, and number needed to treat (NNT) = 22 for statins; HR = 0.84 [95% CI: 0.73–0.96], P = .0106, and NNT = 30 for beta‐blockers. In addition, for propensity‐adjusted use of both statins and beta‐blockers compared with neither the HR was 0.56 [95% CI: 0.42–0.74] P < .0001, and NNT was 9. The RCRI confirmed combination statin and beta‐blocker use was beneficial at all levels of risk. Use of the combination study drugs by the highest‐risk patients was associated with a 33% decrease in mortality after 2 years (P = .0106).CONCLUSIONSThe use of ambulatory statins alone or in combination with beta‐blockers is associated with a reduction in long‐term mortality after vascular surgery, and combination use benefits patients at all levels of risk. Journal of Hospital Medicine 2007;2:241–252. © 2007 Society of Hospital Medicine.
Synthesis of tritium‐labeled puerarin—a potential antidipsotropic agent
Authors: Lee D. Y. W. , Ji X. S. , Zhang X. 
Published: August 2007

AbstractPuerarin 1 (8‐β‐D‐Glucopyranosyl‐4′‐7‐dihydroxyisoflavone, NPI‐031G) is the major isoflavone C‐glycoside isolated from Pueraria lobata, a traditional Chinese medicine widely used for the treatment of alcohol intoxication. In order to understand the mode of action of puerarin in the reward pathway of the central nervous system and to study its bioavailability and pharmacokinetics, we developed a synthetic route for the preparation of tritium‐labeled puerarin. The key intermediate 4 was obtained by trimethylsilyl protection of all hydroxyl groups followed by selective deprotection. The corresponding aldehyde 5 was obtained through the subsequent oxidation of the primary alcohol. Standard NaB[3H]4 reduction and hydrolysis produced the tritium‐labeled puerarin 6. Copyright © 2007 John Wiley & Sons, Ltd.
Synthesis of [2,3,4,5,6‐2H5]phenyl glucosinolate
Authors: Bialecki Jason B. , Ruzicka Josef , Attygalle Athula B. 
Published: August 2007

AbstractStarting from commercially available [2,3,4,5,6‐2H5]benzoic acid, [2,3,4,5,6‐2H5]phenyl glucosinolate was synthesized. Under negative‐ion electrospray‐ionization mass spectrometric conditions, this compound affords a peak at m/z 399. Since this m/z value is not known from the ions derived from natural glucosinolates, the [2,3,4,5,6‐2H5]phenyl glucosinolate reported here is useful as an internal standard for the quantification of glucosinolates by negative‐ion mass spectrometry (MS) and liquid chromatography (LC)/MS techniques. Copyright © 2007 John Wiley & Sons, Ltd.
One‐step radiosynthesis of [18F]LBT‐999: a selective radioligand for the visualization of the dopamine transporter with PET
Authors: Dollé Frédéric , Helfenbein Julie , Hinnen Françoise , Mavel Sylvie , Mincheva Zoïa , Saba Wadad , Schöllhorn‐Peyronneau Marie‐Anne , Valette Heric , Garreau Lucette , Chalon Sylvie , Halldin Christer , Madelmont Jean‐Claude , Deloye Jean‐Bernard , Bottlaender Michel , Le Gailliard Joël , Guilloteau Denis , Emond Patrick 
Published: August 2007

AbstractLBT‐999 (8‐((E)‐4‐fluoro‐but‐2‐enyl)‐3‐beta‐p‐tolyl‐8‐aza‐bicyclo[3.2.1]octane‐2‐beta‐carboxylicacid methyl ester) is a recently developed cocaine derivative belonging to a new generation of highly selective dopamine transporter (DAT) ligands (KD: 9 nM for the DAT and IC50 > 1000 nM for the serotonin and norepinephrine transporter). Initial fluorine‐18‐labelling of LBT‐999 was based on the robust and reliable two‐step radiochemical pathway often reported for such tropane derivatives, involving first the preparation of (E)‐1‐[18F]fluoro‐4‐tosyloxybut‐2‐ene followed by a N‐alkylation reaction with the appropriate nor‐tropane moiety. In the present work, a simple one‐step fluorine‐18‐labelling of LBT‐999 is reported, based on a chlorine‐for‐fluorine nucleophilic aliphatic substitution, facilitating as expected both automation and final high‐performance liquid chromatography (HPLC) purification. The process involves: (A) reaction of K[18F]F–Kryptofix®222 with the chlorinated precursor (3.5–4.5 mg) at 165°C for 10 min in DMSO (0.6 mL) followed by (B) C‐18 PrepSep cartridge pre‐purification and finally (C) semi‐preparative HPLC purification on a Waters Symmetry® C‐18. Typically, 3.70–5.92 GBq of [18F]LBT‐999 (> 95% chemically and radiochemically pure) could be obtained with specific radioactivities ranging from 37 to 111 GBq/µmol within 85–90 min (HPLC purification and Sep‐Pak‐based formulation included), starting from a 37.0 GBq [18F]fluoride batch (overall radiochemical yields: 10–16%, non‐decay‐corrected). Copyright © 2007 John Wiley & Sons, Ltd.