bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of agitator design and catalyst concentration on partial hydrogenation of sunflower oil
Authors: Maes Jeroen , Houlton David , Himmelsbach Werner , De Greyt Wim
Published: October 2007

In this study, lab‐scale hydrogenation of sunflower oil was conducted at 190 °C and 2 bar using two different catalyst types at varying concentrations and two different agitator designs (surface gassing and hollow shaft) at varying power inputs. At identical power input and reaction conditions, the reaction rate with the hollow‐shaft agitator was 1.68 times higher than with surface gassing agitation. The catalyst concentration had to exceed a certain feedstock‐dependent threshold value of 25 ppm Ni in order to start the reaction. At low catalyst concentration, the reaction rate increased proportionally with increasing catalyst concentration. When hydrogen consumption became higher than the available mass transfer provided by the agitation system, the reaction time became less dependent on the catalyst concentration. For the hollow‐shaft agitator, this situation was observed at a reaction rate of 3.7 ΔIV/min, where trans formation was at its maximum with more than 40% trans fatty acids in partially hydrogenated sunflower oil with IV 65. The region in which hydrogen mass transfer did not limit the reaction rate could be extended by more efficient agitation design or increased agitation power. In this way, productivity can be increased and trans formation can be controlled in a better way when compared to hydrogenation with a less efficient agitator.
Development of HPLC and NACE methods for the simultaneous determination of benzoic and sorbic acids in sour snap beans containing oil
Authors: Han Po , Jia Zhenmin , Liu Mian , Li Yongbo , Liu Hongxia , Yang Hui , Wang Xie , Ban Fuguo , Zhang Shusheng
Published: October 2007

The practical methods were developed for the simultaneous determination of benzoic acid (BA) and sorbic acid (SA) in sour snap bean samples containing oil. BA and SA in the samples were extracted by ultrasonication with water, followed by cleanup procedures with precipitation for removing the potential proteins and with petroleum ether liquid–liquid extraction for removing the edible oil contained in the samples. The HPLC method was developed using Supelco C18 (250 mm×4.6 mm id, 5 μm) as column, MeOH–20 mM NH4Ac (25:75 v/v) at 1.0 mL/min as the mobile phase and 230 nm as the detection wavelength. The optimal NACE method was established with a running buffer of 20.0 mM NH4Ac in 95% MeOH (pH* 10.6), and an applied voltage of −30 kV over a capillary of 50 μm id×48.5 cm (40 cm to the detector window), which gave a baseline separation of BA and SA, and as well as of the blank matrix within ca. 10 min. Both HPLC and NACE methods gave the relatively lower limits of quantification at about 0.01–0.02 and 0.04–0.05 mg/kg, respectively, whereas the overall recoveries were larger than 85.0%. The proposed methods have been successfully applied to measure 15 real sour bean samples and the content profile of BA and SA in sour bean samples was obtained and evaluated.
Comparison of the contents of various antioxidants of sea buckthorn berries using CE
Authors: Gorbatsova Jelena , Lõugas Tiina , Vokk Raivo , Kaljurand Mihkel
Published: October 2007

The increased interest in sea buckthorn (Hippophae rhamnoides L.) made it possible to investigate the antioxidant content in it. To address this issue, the presence of following antioxidant compounds were analyzed: trans‐resveratrol, catechin, myricetin, quercetin, p‐coumaric acid, caffeic acid, L‐ascorbic acid (AA), and gallic acid (linear range of 50–150 μmol/L) in six different varieties of sea buckthorn berries extracts (sea buckthorn varieties: “Trofimovskaja (TR),” “Podarok Sadu (PS),” and “Avgustinka (AV),”) received from two local Estonian companies. Trans‐Resveratrol, catechin, AA, myricetin, and quercetin were found in extracts of sea buckthorn. Moreover, AA, myricetin, and quercetin contents were quantified. The biggest average AA content was found in TR (740 mg/100 g of dried berries, respectively). Furthermore, the same varieties gave the biggest quercetin content 116 mg/100 g of dried berries, respectively. For analysis, CZE was used and the results were partly validated by HPLC. Statistically no big differences in levels of antioxidants were consistently found in different varieties of sea buckthorn extracts investigated in this work.
Analyses of alkaloids in different products by NACE‐MS
Authors: Chiu Chen‐Wen , Liang Hsin‐Hui , Huang Hsi‐Ya
Published: October 2007

A simple method for the separation and characterization of five nicotine‐related alkaloids by NACE employing UV and MS detections is described here for the first time. Several factors, including NACE parameters (compositions of running solution) and MS parameters (such as nature and flow rate of sheath liquid, pressure of nebulization gas, and flow rate of dry gas), were optimized in order to obtain both an adequate CE separation and high MS signals for the alkaloid compounds used in this study. A reliable CE separation of five alkaloids was achieved in 50 mM ammonium formate that was dissolved in an ACN/methanol mixture (50:50, v/v) of pH* 4.0 (apparent pH 4.0). The optimal electrospray MS measurement was carried out in the positive ionization mode using a coaxial sheath liquid composed of isopropyl alcohol and water in the ratio of 80:20 v/v at a flow rate of 180 μL/h. In addition, the proposed NACE method was also applied in the analyses of alkaloids in several products including chewing gums, beverages, and tobaccos. This NACE‐MS method was found to provide a better detection ability and separation resolution for the analysis of nicotine alkaloids when compared to other aqueous CE‐MS reports.
Distortions in Electrochemical Impedance Spectroscopy Measurements Using 3‐Electrode Methods in SOFC. I – Effect of Cell Geometry
Authors: Cimenti M. , Co A. C. , Birss V. I. , Hill J. M.
Published: October 2007

The use of a reference electrode (RE) is necessary to independently measure the overpotential of each electrode in solid oxide fuel cells (SOFC). This type of set‐up, known as the 3‐electrode (or 3‐terminal) configuration, can give erroneous results if the RE does not effectively separate the potential of the two active electrodes. In this work, calculations and experiments were performed to verify the effectiveness of the 3‐electrode configuration used in electrochemical impedance spectroscopy (EIS) measurements for studying the kinetics of anodes and cathodes in SOFC. Initially, a theoretical analysis of the impedance distortions in relation to the electrode geometry and configuration is presented and the main causes of distortions are elucidated. Then, this analysis is corroborated by experimental results obtained using two specially designed cells. Calculations and experiments reconfirm that configurations characterised by electrodes of equal area and symmetrical placement do not produce EIS distortions when the electrodes have similar area‐specific polarisation resistances and time constants. Moreover, distortions can be low even in considerably misaligned configurations when electrodes are small and relatively inactive.
Inhibition of injury‐induced glial aromatase reveals a wave of secondary degeneration in the songbird brain
Authors: Wynne Ryan D. , Walters Bradley J. , Bailey David J. , Saldanha Colin J.
Published: October 2007

Mechanical or anoxic/ischemic brain insult results in reactive gliosis and a pronounced wave of apoptotic secondary degeneration (WSD). Reactive glia express aromatase (estrogen synthase) and glial estrogen synthesis decreases apoptosis and the volume of degeneration. Whether aromatization by glia affects gliosis itself or the initiation/maintenance of the WSD remains unknown. Adult male zebra finches (Taeniopygia guttata) were injured with a needle that contained the aromatase inhibitor fadrozole or vehicle into contralateral hemispheres. Birds were killed at 0, 2, 6, 24, 72h, 2 or 6 weeks postinjury. Gliosis and degeneration were measured with vimentin‐ and Fluoro‐Jade B‐expression, respectively. Reactive gliosis was detectable at 6 h, reached asymptote at 72 h, and continued until 6 weeks postinsult. Gliosis extended further around fadrozole‐injury than vehicle, an effect driven by a larger area of gliosis around fadrozole‐ relative to vehicle‐injury at 72 h postinsult. Glial aromatase was inhibited for about 2 weeks postinjury since aromatase relative optical density was higher around fadrozole‐injury relative to vehicle‐injury until this time‐point. Degeneration around vehicle‐injury reached asymptote at 2 h postinsult, but that around fadrozole‐injury peaked 24–72 h postinjury and decreased thereafter. Thus, the injury‐induced WSD as described in mammals is detectable in zebra finches only following glial aromatase inhibition. In the zebra finch, injury‐induced estrogen provision may decrease reactive gliosis and severely dampen the WSD, suggesting that songbirds are powerful models for understanding the role of glial aromatization in secondary brain damage. © 2007 Wiley‐Liss, Inc.
Increased mediastinal fat and impaired left ventricular energy metabolism in young men with newly found fatty liver
Authors: Perseghin Gianluca , Lattuada Guido , De Cobelli Francesco , Esposito Antonio , Belloni Elena , Ntali Georgia , Ragogna Francesca , Canu Tamara , Scifo Paola , Del Maschio Alessandro , Luzi Livio
Published: October 2007

Fatty liver is characterized by metabolic abnormalities at the liver, but also at skeletal muscle and adipose tissue sites. It is hypothesized that the heart may be suffering metabolic alterations, and this study was undertaken to ascertain whether individuals with fatty liver have left ventricular (LV) alterations of energy metabolism, structure, and function and abnormal amounts of epicardial fat as a specific marker of visceral fat accumulation. To this end we studied young, nondiabetic men matched for anthropometric features with (n = 21) or without (n = 21) fatty liver by means of (1) cardiac magnetic resonance imaging (MRI); (2) cardiac 31P-MR spectroscopy (MRS); and (3) hepatic 1H-MRS to assess quantitatively the intrahepatic fat (IHF) content. Insulin sensitivity was determined by the updated HOMA-2 computer model. Individuals with fatty liver showed reduced insulin sensitivity, increased serum free fatty acid (FFA), and E-selectin, abnormal adipokine concentrations, and higher blood pressure. LV morphology and systolic and diastolic functions were not different; however, in the scanned intrathoracic region, the intrapericardial (7.8 ± 3.1 versus 5.9 ± 2.5 cm2;

P

< 0.05) and extrapericardial (11.7 ± 6.1 versus 7.8 ± 3.2 cm2;

P

< 0.03) fat was increased in men with fatty liver compared with those without fatty liver. The phosphocreatine (PCr)/adenosine triphosphate (ATP) ratio, a recognized

in vivo

marker of myocardial energy metabolism, was reduced in men with fatty liver in comparison with normals (1.85 ± 0.35 versus 2.11 ± 0.31;

P

< 0.016). In conclusion, in newly found individuals with fatty liver, fat was accumulated in the epicardial area and despite normal LV morphological features and systolic and diastolic functions, they had abnormal LV energy metabolism. (Hepatology 2008.)
Selenium‐Containing Heterocycles from Isoselenocyanates: Base‐Catalyzed Reaction of Malononitrile with Phenyl Isoselenocyanate and Bromoacetonitrile or α‐Halogenated Ketones
Authors: Sommen Geoffroy L. , Linden Anthony , Heimgartner Heinz
Published: October 2007

The reaction of phenyl isoselenocyanate (1a) with malononitrile (=propanedinitrile) in DMF in the presence of Et3N leads to the intermediate ketene N,Se‐hemiacetal 6a, which can be trapped with bromoacetonitrile or α‐halogenated ketones 12a and 12b (Scheme 3). The products are [(alkylseleno)(phenylamino)methylene]malononitriles 10 and 13, which are obtained in good yield. In the case of the (2‐oxoalkyl)seleno derivatives 13, they are in equilibrium with the cyclic hemiacetals 14. Chemical and spectroscopic evidence for the structures of the new compounds are described. The structure of 14a was established by X‐ray crystallography.
Affinity and Reaction Rates: Reconsideration of Experimental Data
Authors: Pekař Miloslav
Published: October 2007

Two published experimental confirmations of either the linear relationship between the reaction rate and its affinity, or the ‘thermodynamic coupling’ are revised. It is shown that ‘proved’ results are more consequences of a given experimental arrangement or of methods used for the treatment of experimental concentration data than outcomes of some general thermodynamic law. The affinity should be considered not as a quantity determining the value of the reaction rate but as an alternative quantity for description of the evolution of a reacting system, its distance from equilibrium. The affinity, perhaps, expresses some potential for a reaction, but its manifestation in the reaction rate is controlled by the very kinetics.
Synthesis, Structure, and Conformation of 2′,3′‐Fused Oxathiane and Thiomorpholine Uridines
Authors: Sun Jingbo , Wu Jinchang , Yang Hua
Published: October 2007

The syntheses of two 2′,3′‐fused bicyclic nucleoside analogues, i.e., 1‐[(4aR,5R,7R,7aS)‐hexahydro‐5‐(hydroxymethyl)‐4,4‐dioxidofuro[3,4‐b][1,4]oxathiin‐7‐yl]pyrimidine‐2,4(1H,3H)‐dione (1a) and 1‐[(4aS,5R,7R,7aS)‐hexahydro‐7‐(hydroxymethyl)‐1,1‐dioxido‐2H‐furo[3,4‐b][1,4]thiazin‐5‐yl]pyrimidine‐ 2,4(1H,3H)‐dione (1b), are described, the key step being an intramolecular hetero‐Michael addition. Their structures and conformations, previously solved by X‐ray crystallography, were analyzed in more detail, using 1D‐ and 2D‐NMR as well as HR‐MS analyses.
Synthesis and Structure of O,O‐Diethyl N‐[(trans‐4‐Aryl‐5,5‐dimethyl‐2‐oxido‐2λ5‐1,3,2‐dioxaphosphorinan‐2‐yl)methyl]phosphoramidothioates
Authors: Miao Zhiwei , Zhang Jianfeng , Cui Zhanwei , Wang Bin , Chen Ruyu
Published: October 2007

A study on the synthesis of the novel N‐(cyclic phosphonate)‐substituted phosphoramidothioates, i.e., O,O‐diethyl N‐[(trans‐4‐aryl‐5,5‐dimethyl‐2‐oxido‐2λ5‐1,3,2‐dioxaphosphorinan‐2‐yl)methyl]phosphoramidothioates 4a–l, from O,O‐diethyl phosphoramidothioate (1), a benzaldehyde or ketone 2, and a 1,3,2‐dioxaphosphorinane 2‐oxide 3 was carried out (Scheme 1 and Table 1). Some of their stereoisomers were isolated, and their structure was established. The presence of acetyl chloride was essential for this reaction and accelerated the process of intramolecular dehydration of intermediate 5 forming the corresponding Schiff base 7 (Scheme 2).
Enzymatic Resolution of O‐(Methoxymethyl)‐Protected Tropane‐diols
Authors: Affolter Olena , Baro Angelika , Laschat Sabine , Fischer Peter
Published: October 2007

A convenient synthetic route to enantiomerically pure tropane‐diol building blocks is described. The reaction sequence started from tropenone derivatives 1, which were dihydroxylated to give 6,7‐dihydroxytropanone derivatives 2. After introduction of the methoxymethyl (MOM) protecting group in diol 2a, a lipase‐mediated resolution of the resulting racemic mono‐MOM ether (±)‐5d with vinyl acetate and vinyl trifluoroacetate gave the acetates (−)‐6d and (−)‐6f, respectively, with 96–99% ee, and MOM ether (+)‐5d with up to 89% ee. Deacetylation of (−)‐6d afforded quantitatively MOM ether (−)‐5d with 99% ee, the absolute configuration of which was assigned via the modified Mosher method to be (R) at C(6). Enzymatic treatment of unprotected diol 2a with vinyl trifluoroacetate or alkoxycarbonylation resulted in the formation of Cs‐symmetrical products 9 and 12 rather than the desired desymmetrized derivatives.
Direct Amination of meso‐Tetraarylporphyrin Derivatives – Easy Route to A3B‐, A2BC‐, and A2B2‐Type Porphyrins Bearing Two Nitrogen‐Containing Substituents at the meso‐Positioned Phenyl Groups
Authors: Ostrowski Stanisław , Grzyb Sebastian , Mikus Agnieszka
Published: October 2007

meso‐Tetraarylporphyrinato complexes 1a–g (ZnII, CuII, and NiII) bearing one or two nitro‐substituted aryl moieties react with 1,1,1‐trimethylhydrazinium iodide in the presence of tBuOK in THF at 0–5° or in the presence of KOH in DMSO at 60–70° according to a nucleophilic substitution of an H‐atom, thus affording porphyrins 2a–g and 3f,g with amino‐functionalized meso‐positioned aryl substituents in yields up to 73% (Scheme 1 and Table). The products obtained are attractive intermediates for further derivatization of porphyrins and may be of potential use as sensitizers in photodynamic cancer therapy.
Generation, Spectroscopic Characterization by EPR, and Decay of a Pyranine‐Derived Radical
Authors: Aliaga Carolina , Arenas Andrea , Aspée Alexis , López‐Alarcón Camilo , Lissi Eduardo A.
Published: October 2007

The pyraninoxyl radical is readily formed from the MnO2‐promoted oxidation of pyranine. The free radical can be formed in high concentrations (mM), and presents a characteristic EPR spectrum that indicates a high spin‐density delocalization. It is relatively stable under nitrogen (half‐life ca. 50 min) but readily decays in presence of O2. In spite of its high stability, the radical readily reacts with antioxidants (phenols and ascorbic acid) with a partial recovery of the parent pyranine. High concentrations of the pyraninoxyl radical (ca. 9 μM) are present when pyranine is exposed to a free radical source (10 mM 2,2′‐azobis[2‐amidinopropane], 37°). The fact that these radicals readily react with antioxidants (ascorbic acid and caffeic acid) supports the proposal that protection by antioxidants of peroxyl radical‐promoted pyranine bleaching is mainly due to the occurrence of a repair mechanism.
Four New Podocarpane‐Type Trinorditerpenes from Aleurites moluccana
Authors: Liu Hai‐Yang , Li Shi‐Jin , Zhao Yi , Ni Wei , Hao Xiao‐Jiang , Li Jun‐Zhu , Hua Yan , Xie Bai‐Bo , Qing Chen , Chen Chang‐Xiang
Published: October 2007

Four new podocarpane‐type trinorditerpenenes, (5β,10α)‐12,13‐dihydroxypodocarpa‐8,11,13‐trien‐3‐one (1), (5β,10α)‐12‐hydroxy‐13‐methoxypodocarpa‐8,11,13‐trien‐3‐one (2), (5β,10α)‐13‐hydroxy‐12‐methoxypodocarpa‐8,11,13‐trien‐3‐one (3), and (3α,5β,10α)‐13‐methoxypodocarpa‐8,11,13‐triene‐3,12‐diol (4), together with four known diterpenes, 12‐hydroxy‐13‐methylpodocarpa‐8,11,13‐trien‐3‐one (5), spruceanol (6), ent‐3α‐hydroxypimara‐8(14),15‐dien‐12‐one (7), and ent‐3β,14α‐hydroxypimara‐7,9(11),15‐triene‐12‐one (8), were isolated from the twigs and leaves of Aleurites moluccana. Their structures were elucidated by means of comprehensive spectroscopic analyses, including NMR and MS. Except 8, all compounds were evaluated for their cytotoxicity; compound 4 exhibited moderate inhibitory activity against Raji cells with an IC50 value of 4.24 μg/ml.
Reactions of Dimethoxycarbene with N‐Tosylated Imines
Authors: Mlostoń Grzegorz , Warkentin John , Linden Anthony , Heimgartner Heinz
Published: October 2007

The reactions of dimethoxycarbene (DMC; 2), which was generated in situ by thermal decomposition of 2,5‐dihydro‐2,2‐dimethoxy‐5,5‐dimethyl‐1,3,4‐oxadiazole (1), with N‐tosylated imines of xanthone and 2,3 : 6,7‐dibenzosuberenone, 3a and 3d, respectively, led to different adducts with rearranged skeletons. In the case of 3a, the 1 : 1 adduct 5 as well as the 2 : 1 adduct 6 were obtained (Scheme 2). The formation of both products can be explained by a migration of a MeO group of the DMC fragment in a zwitterionic intermediate. On the other hand, migration of a Me group of DMC is necessary for the formation of the two 1 : 1 adducts 13 and 14 of 2 and 3d (Scheme 5). The structures of all products have been established by X‐ray crystallography.
A Mild and Efficient Method for Chlorination of Baylis–Hillman Adducts Using PPh3/Cl3CCONH2
Authors: Das Biswanath , Chowdhury Nikhil , Damodar Kongara , Ravikanth Bommena
Published: October 2007

A new and convenient stereoselective synthesis of (Z)‐2‐(chloromethyl)alk‐2‐enoates has been achieved from Baylis–Hillman adducts by treatment with PPh3/Cl3CCONH2 at room temperature. The synthesis can proceed under mild and acid‐free conditions to form the products in high yields.
Diterpenoids of Isodon macrophylla
Authors: Qin Song , Chen Si‐Han , Guo Yue‐Wei , Gu Yu‐Cheng
Published: October 2007

Two new ent‐abietane diterpenoids, macrophynin E (1) and macrophynin F (2), and a known related ent‐abietanoid (−)‐lambertic acid (3), together with four known ent‐kauranoids, were isolated from the roots and aerial parts of Isodon macrophylla, respectively. The structures of the new compounds were elucidated on the basis of spectroscopic‐data analysis and chemical correlations.
Changes in flow conveyance and implication for flood protection, Sava River, Zagreb
Authors: Bonacci Ognjen , Ljubenkov Igor
Published: October 2007

A low‐lying part of the Croatian capital, Zagreb, is exposed to flood risk from the Sava River. The biggest flood to data, with catastrophic consequences, occurred on 26 November 1964. To protect Zagreb from the Sava River floods, a flood control system was built and set in operation at the end of 1978. The Sava River's flood response changed over time as a result of this constructed system, as well as other anthropogenic and natural influences. The series of maximum annual Sava River stages and discharges measured at the Zagreb gauging station from 1926 to 2004 were analysed. Hydrological methods were used in order to assess Zagreb safety from the Sava River floods in the new conditions. This paper detects changes in high water occurrence in the Sava River near Zagreb. Long‐term stages and linear trends in discharges were examined. A simple technique for the conversion of stages to actual river channel morphology conditions was used. The technique presented in this paper enabled the recalculation of flood probabilities. It is stressed that for a complete understanding of floods, an examination should include the study of parameters of both maximum stages and maximum discharges. Copyright © 2007 John Wiley & Sons, Ltd.
Development of a continuous soil moisture accounting procedure for curve number methodology and its behaviour with different evapotranspiration methods
Authors: Kannan N. , Santhi C. , Williams J. R. , Arnold J. G.
Published: October 2007

The curve number (CN) method is widely used for rainfall–runoff modelling in continuous hydrologic simulation models. A sound continuous soil moisture accounting procedure is necessary for models using the CN method. For shallow soils and soils with low storage, the existing methods have limitations in their ability to reproduce the observed runoff. Therefore, a simple one‐parameter model based on the Soil Conservation Society CN procedure is developed for use in continuous hydrologic simulation. The sensitivity of the model parameter to runoff predictions was also analysed. In addition, the behaviour of the procedure developed and the existing continuous soil moisture accounting procedure used in hydrologic models, in combination with Penman–Monteith and Hargreaves evapotranspiration (ET) methods was also analysed. The new CN methodology, its behaviour and the sensitivity of the depletion coefficient (model parameter) were tested in four United States Geological Survey defined eight‐digit watersheds in different water resources regions of the USA using the SWAT model. In addition to easy parameterization for calibration, the one‐parameter model developed performed adequately in predicting runoff. When tested for shallow soils, the parameter is found to be very sensitive to surface runoff and subsurface flow and less sensitive to ET. Copyright © 2007 John Wiley & Sons, Ltd.
Estimating snow distribution over a large area and its application for water resources
Authors: Kazama So , Izumi Hirokazu , Sarukkalige Priyantha Ranjan , Nasu Takayuki , Sawamoto Masaki
Published: October 2007

The spatial and temporal distribution of the snow water equivalent (SWE), snow density and snow depth were estimated by a method combining remote sensing technology and degree‐day techniques over a study area of 370 000 km2. The advantages of this simulation model are its simplicity and the availability of degree‐day parameters, which can be successively evaluated by referring to snow area maps created from satellite images. This simulation worked very well for estimating SWE and helped to separate the areas of thin snow cover from heavier snowfall. However, shallow snow in warm regions led to some misjudgments in the snow area maps because of the time lag between when the satellite image was acquired and the simulation itself. Vulnerable areas, where a large variation in the amount of snow affects people's life, could be identified from the differences between heavy and light snow years. This vulnerability stems from a predicted lack of irrigation water for rice production caused by future climate change. The model developed in this study has the potential to contribute to water management activities and decision‐making processes when considering necessary adaptations to future climate change. Copyright © 2007 John Wiley & Sons, Ltd.
Modelling hydrological response to different land‐use and climate change scenarios in the Zamu River basin of northwest China
Authors: Wang Sufen , Kang Shaozhong , Zhang Lu , Li Fusheng
Published: October 2007

Changes in climate and land use can significantly influence the hydrological cycle and hence affect water resources. Understanding the impacts of climate and land‐use changes on streamflow can facilitate development of sustainable water resources strategies. This study investigates the flow variation of the Zamu River, an inland river in the arid area of northwest China, using the Soil and Water Assessment Tool distributed hydrological model. Three different land‐use and climate‐change scenarios were considered on the basis of measured climate data and land‐use cover, and then these data were input into the hydrological model. Based on the sensitivity analysis, model calibration and verification, the hydrological response to different land‐use and climate‐change scenarios was simulated. The results indicate that the runoff varied with different land‐use type, and the runoff of the mountain reaches of the catchment increased when grassland area increased and forestland decreased. The simulated runoff increased with increased precipitation, but the mean temperature increase decreased the runoff under the same precipitation condition. Application of grey correlation analysis showed that precipitation and temperature play a critical role in the runoff of the Zamu River basin. Sensitivity analysis of runoff to precipitation and temperature by considering the 1990s land use and climate conditions was also undertaken. Copyright © 2007 John Wiley & Sons, Ltd.
Simulating the surface waters of the Amazon River basin: impacts of new river geomorphic and flow parameterizations
Authors: Coe Michael T. , Costa Marcos H. , Howard Erica A.
Published: October 2007

This paper describes the impacts of new river geomorphic and flow parameterizations on the simulated surface waters dynamics of the Amazon River basin. Three major improvements to a hydrologic model are presented: (1) the river flow velocity equation is expanded to be dependent on river sinuosity and friction in addition to gradient forces; (2) equations defining the morphological characteristics of the river, such as river height, width and bankfull volume, are derived from 31 622 measurements of river morphology and applied within the model; (3) 1 km resolution topographic data from the Shuttle Radar Topography Mission (SRTM) are used to provide physically based fractional flooding of grid cells from a statistical representation of sub‐grid‐scale floodplain morphology. The discharge and floodplain inundation of the Amazon River is simulated for the period 1968–1998, validated against observations, and compared with results from a previous version of the model. These modifications result in considerable improvement in the simulations of the hydrological features of the Amazon River system. The major impact is that the average wet‐season flooded area on the Amazon mainstem for the period 1983–1988 is now within 5% of satellite‐derived estimates of flooded area, whereas the previous model overestimates the flooded area by about 80%. The improvements are a consequence of the new empirical river geomorphologic functions and the SRTM topography. The new formulation of the flow velocity equation results in increased river velocity on the mainstem and major tributaries and a better correlation between the mean monthly simulated and observed discharge. Copyright © 2007 John Wiley & Sons, Ltd.
Analysis of infiltration of 2D trickle irrigation under multiple‐line sources
Authors: Chen Jiann‐Mou , Tan Yih‐Chi , Wu Yu‐Zhang
Published: October 2007

The analysis of infiltration of 2D trickle irrigation under multiple‐line sources, governed by the celebrated Richards equation, is performed, aiming at determining the efficiency of trickle irrigation so as to reduce the water demand. A closed‐form solution is explicitly obtained by utilizing the Fourier integral transformation, and this serves as a means to compute the distribution of volumetric water content during trickle irrigation. Results for the infiltration of 2D trickle irrigation under single line and multiple‐line sources are presented, which illustrate the distribution of infiltration water that diffuses into the soil, and make it possible to calculate the period of time required for trickle irrigation for different plants. The results can be applied to verify complicated solutions from other numerical models. Copyright © 2007 John Wiley & Sons, Ltd.
Increased flexibility in base flow modelling using a power law transmissivity profile
Authors: Rupp David E. , Woods Ross A.
Published: October 2007

The hydrological catchment model known as TOPMODEL, in its original and most widely‐used form, assumed that subsurface transmissivity decreases exponentially as subsurface water storage decreases. It has been shown that this leads to recession curves of discharge Q that take the form − dQ/dt = aQb, where a is a constant and b = 2. In order to reproduce a wider range of recession, or base flow, behaviour, a power function for transmissivity was subsequently incorporated into TOPMODEL as an alternative to the exponential function. This was claimed to extend the realistic values of b to range from 1 to 2, inclusive. We show here that the power transmissivity function can also generate values of b > 2 without making unrealistic assumptions (beyond those arguably made in the original TOPMODEL), thus generating recession curves consistent with catchments showing prolonged base flow. Furthermore, the power transmissivity function can generate recession curves that steepen with time (b < 1). Copyright © 2007 John Wiley & Sons, Ltd.
Changes in rainfall and relative humidity in river basins in northwest and central India
Authors: Singh Pratap , Kumar Vijay , Thomas T. , Arora Manohar
Published: October 2007

Seasonal and annual trends of changes in rainfall, rainy days, heaviest rain and relative humidity have been studied over the last century for nine different river basins in northwest and central India. The majority of river basins have shown increasing trends both in annual rainfall and relative humidity. The magnitude of increased rainfall for considered river basins varied from 2–19% of mean per 100 years. The maximum increase in rainfall is observed in the Indus (lower) followed by the Tapi river basin. Seasonal analysis shows maximum increase in rainfall in the post‐monsoon season followed by the pre‐monsoon season. There were least variations in the monsoon rainfall during the last century and winter rainfall has shown a decreasing trend. Most of the river basins have experienced decreasing trends in annual rainy days with a maximum decrease in the Mahanadi basin. The heaviest rain of the year has increased from 9–27 mm per 100 years over different river basins with a maximum of 27 mm for the Brahamani and Subaranrekha river basins. A combination of increase in heaviest rainfall and reduction in the number of rainy days suggest the possibility of increasing severity of floods. Such information is useful in the planning, development and management of water resources in the study area. Further, the majority of river basins have also experienced an increasing trend in relative humidity both on seasonal and annual scales. An increase in annual mean relative humidity for six river basins has been found in the range of 1–18% of mean per 100 years, while a decrease for three river basins from − 1 to − 13% of mean per 100 years was observed, providing a net increase in the study area by 2·4% of mean per 100 years. It is understood that an increase in areal extent of vegetation cover as well as rainfall over the last century has increased the moisture in the atmosphere through enhanced evapotranspiration, which in turn has increased the relative humidity. Copyright © 2007 John Wiley & Sons, Ltd.
Automatic mapping of snow cover depletion curves using optical remote sensing data under conditions of frequent cloud cover and temporary snow
Authors: Li Baolin , Zhu A‐Xing , Zhou Chenghu , Zhang Yichi , Pei Tao , Qin Chengzhi
Published: October 2007

Snow cover depletion curves are required for several water management applications of snow hydrology and are often difficult to obtain automatically using optical remote sensing data owing to both frequent cloud cover and temporary snow cover. This study develops a methodology to produce accurate snow cover depletion curves automatically using high temporal resolution optical remote sensing data (e.g. Terra Moderate Resolution Imaging Spectroradiometer (MODIS), Aqua MODIS or National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR)) by snow cover change trajectory analysis. The method consists of four major steps. The first is to reclassify both cloud‐obscured land and snow into more distinct subclasses and to determine their snow cover status (seasonal snow cover or not) based on the snow cover change trajectories over the whole snowmelt season. The second step is to derive rules based on the analysis of snow cover change trajectories. These rules are subsequently used to determine for a given date, the snow cover status of a pixel based on snow cover maps from the beginning of the snowmelt season to that given date. The third step is to apply a decision‐tree‐like processing flow based on these rules to determine the snow cover status of a pixel for a given date and to create daily seasonal snow cover maps. The final step is to produce snow cover depletion curves using these maps. A case study using this method based on Terra MODIS snow cover map products (MOD10A1) was conducted in the lower and middle reaches of the Kaidu River Watershed (19 000 km2) in the Chinese Tien Shan, Xinjiang Uygur Autonomous Region, China. High resolution remote sensing data (charge coupled device (CCD) camera data with 19·5 m resolution of the China and Brazil Environmental and Resources Satellite (CBERS) data (19·5 m resolution), and the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data with 15 m resolution of the Terra) were used to validate the results. The study shows that the seasonal snow cover classification was consistent with that determined using a high spatial resolution dataset, with an accuracy of 87–91%. The snow cover depletion curves clearly reflected the impact of the variation of temperature and the appearance of temporary snow cover on seasonal snow cover. The findings from this case study suggest that the approach is successful in generating accurate snow cover depletion curves automatically under conditions of frequent cloud cover and temporary snow cover using high temporal resolution optical remote sensing data. Copyright © 2007 John Wiley & Sons, Ltd.
Decadal trend of climate in the Tibetan Plateau—regional temperature and precipitation
Authors: Xu Z. X. , Gong T. L. , Li J. Y.
Published: October 2007

The Tibetan Plateau has one of the most complex climates in the world. Analysis of the climate in this region is important for understanding the climate change worldwide. In this study, climate patterns and trends in the Tibetan Plateau were analysed for the period from 1961 to 2001. Air temperature and precipitation were analysed on monthly and annual time scales using data collected from the National Meteorological Centre, China Meteorological Administration. Nonlinear slopes were estimated and analysed to investigate the spatial and temporal trends of air temperature and precipitation in the Tibetan Plateau using a Mann–Kendall method. Spatial analysis of air temperature and precipitation variability across the Tibetan Plateau was undertaken. While most trends are local in nature, there are general basinwide patterns. Temperature during the last several decades showed a long‐term warmer trend, especially the areas around Dingri and Zogong stations, which formed two increasing centres. Only one of the stations investigated exhibited decreasing trend, and this was not significant. Precipitation in the Tibetan Plateau has increased in most regions of the study area over the past several decades, especially in the eastern and central part, while the western Tibetan Region exhibited a decreased trend over the same period. Copyright © 2007 John Wiley & Sons, Ltd.
Groundwater quality in the semi‐arid region of the Chahardouly basin, West Iran
Authors: Tizro A. Taheri , Voudouris K.S.
Published: October 2007

Chahardouly basin is located in the western part of Iran and is characterized by semi‐arid climatic conditions and scarcity in water resources. The main aquifer systems are developed within alluvial deposits. The availability of groundwater is rather erratic owing to the occurrence of hard rock formation and a saline zone in some parts of the area. The aquifer systems of the area show signs of depletion, which have taken place in recent years due to a decline in water levels. Groundwater samples collected from shallow and deep wells were analysed to examine the quality characteristics of groundwater. The major ion chemistry of groundwater is dominated by Ca2+ and HCO3−, while higher values of total dissolved solids (TDS) in groundwater are associated with high concentrations of all major ions. An increase in salinity is recorded in the down‐gradient part of the basin. The occurrence of saline groundwater, as witnessed by the high electrical conductivity (EC), may be attributed to the long residence time of water and the dissolution of minerals, as well as evaporation of rainfall and irrigation return flow. Based on SAR values and sodium content (%Na), salinity appears to be responsible for the poor groundwater quality, rendering most of the samples not suitable for irrigation use. Copyright © 2007 John Wiley & Sons, Ltd.
Factors controlling specific sediment yield in the upper Indus River basin, northern Pakistan
Authors: Faran Ali Khawaja , de Boer Dirk H.
Published: October 2007

Estimates of sediment yield are essential in water resources analysis, modelling and engineering, in investigations of continental denudation rates, and in studies of drainage basin response to changes in climate and land use. The availability of high resolution, global environmental datasets offers an opportunity to examine the relationships between specific sediment yield (SYsp) and drainage basin attributes in a geographical information system (GIS) environment. This study examines SYsp at 14 long‐term gauging stations within the upper Indus River basin. Twenty‐nine environmental variables were derived from global datasets, the majority with a 1 × 1 km resolution. The SYsp ranges from 194 to 1302 t km−2 yr−1 for sub‐basins ranging from 567 to 212 447 km2. The high degree of scatter in SYsp is greatly reduced when the stations are divided into three groups: upper, glacierized sub‐basins; lower, monsoon sub‐basins; and the main Indus River. Percentage snow/ice cover (LCs) emerges as the single major land cover control for SYsp in the high mountainous upper Indus River basin. A regression model with percentage snow/ice cover (LCs) as the single independent variable explains 73·4% of the variance in SYsp for the whole Indus basin. A combination of percentage snow/ice cover (LCs), relief and climate variables explains 98·5% of the variance for the upper, glacierized sub‐basins. For the lower monsoon region, a regression model with only mean annual precipitation (P) explains 99·4% of the variance. Along the main Indus River, a regression model including just basin relief (R) explains 92·4% of the variance in SYsp. Based on the R2adj and P‐value statistics, the variables used are capable of explaining the majority of variance in the upper Indus River basin. Copyright © 2007 John Wiley & Sons, Ltd.
p‐Dodecylaminophenol derived from the synthetic retinoid, fenretinide: Antitumor efficacy in vitro and in vivo against human prostate cancer and mechanism of action
Authors: Takahashi Noriko , Watanabe Yusuke , Maitani Yoshie , Yamauchi Takayasu , Higashiyama Kimio , Ohba Toshihiro
Published: October 2007

Fenretinide, N‐(4‐hydroxyphenyl)retinamide (4‐HPR) is an aminophenol‐containing synthetic retinoid derivative of all‐trans‐retinoic acid, which is a potent chemopreventive and antiproliferative agent against various cancers. Clinical studies of 4‐HPR have shown side effects consisting of night blindness and ocular toxicity. To maintain potent anticancer activity without side effects, p‐dodecylaminophenol (p‐DDAP) was designed based on structure–activity relationships of 4‐HPR. In our study, we investigate whether p‐DDAP shows anticancer activity against human prostate cancer cell line PC‐3 when compared with 4‐HPR. p‐DDAP inhibited PC‐3 cell growth progressively from low to high concentration in a dose‐dependent manner. p‐DDAP was the most potent antiproliferative agent in vitro among 6 p‐alkylaminophenols and 3 4‐hydroxyphenyl analogs examined including 4‐HPR. Cells treated with p‐DDAP were shown to undergo apoptosis, based on condensation nuclei, cytofluorimetric analysis, propidium iodide staining and the expression of bcl‐2 and caspase 3. p‐DDAP arrested the S phase of the cell cycle, while 4‐HPR arrested the G0/G1 phase. In addition, both the i.v. and i.p. administration of p‐DDAP suppressed tumor growth in PC‐3‐implanted mice in vivo. p‐DDAP showed no effects on blood retinol concentrations, in contrast to reductions after 4‐HPR administration. These results indicate that p‐DDAP exhibits excellent anticancer efficacy against hormonal independent prostate cancer in vitro and in vivo, and it may have great potential for clinical use in the treatment of prostate cancer with reduced side effects. © 2007 Wiley‐Liss, Inc.
Reactive oxygen species‐dependent EndoG release mediates cisplatin‐induced caspase‐independent apoptosis in human head and neck squamous carcinoma cells
Authors: Kim Jong Soo , Lee Ji Hae , Jeong Won Wook , Choi Dae Hwa , Cha Hee Jeong , Kim Do Ha , Kwon Joong Keun , Park Soon Eun , Park Jae Hoo , Cho Hong Rae , Lee Seon Ho , Park Sang Kyu , Lee Byung Ju , Min Young Joo , Park Jeong Woo
Published: October 2007

Cisplatin is a chemotherapeutic agent that is widely used to treat cancers such as head and neck squamous cell carcinoma (HNSCC). Previously, we have reported that cisplatin induced an early caspase‐dependent apoptosis (8 hr) in a HNSCC cell, HN4. In this study, we examined a late caspase‐independent apoptosis as well as an early caspase‐dependent apoptosis in cisplatin‐treated HN4 cells. While z‐VAD‐fmk, a pan‐caspase inhibitor, blocked the caspase activities and protected cells from the early apoptosis, it did not provide protection against delayed apoptosis occurring after extended exposure (16 hr) to cisplatin, suggesting that the delayed apoptotic response in the presence of z‐VAD‐fmk was caspase‐independent. Cisplatin treatment induced reactive oxygen species (ROS) generation, loss of the mitochondrial membrane potential (MMP) and nuclear translocation of endonuclease G (EndoG). Small interfering RNA mediated‐knockdown of EndoG significantly protected cells from the delayed apoptosis induced by cisplatin in the presence of z‐VAD‐fmk. Overexpression of Bcl‐2 in HN4 cells prevented loss of MMP, nuclear translocation of EndoG and protected cells from the delayed apoptosis induced by cisplatin in the presence of z‐VAD‐fmk. Pretreatment with N‐acetyl‐L‐cysteine (NAC), a ROS scavenger, prevented both ROS generation, loss of the MMP and nuclear translocation of EndoG. Together, our data indicate that cisplatin treatment induced ROS‐mediated loss of the MMP, and, then, the nuclear translocation of EndoG, which played a crucial role in caspase‐independent apoptosis of HN4 cells in the presence of z‐VAD‐fmk. This is the first report about the involvement of EndoG in cisplatin‐induced caspase‐independent apoptosis of cells. © 2007 Wiley‐Liss, Inc.
Cigarette smoking, alcohol drinking and the risk of gallbladder cancer death: A prospective cohort study in Japan
Authors: Yagyu Kiyoko , Kikuchi Shogo , Obata Yuki , Lin Yingsong , Ishibashi Teruo , Kurosawa Michiko , Inaba Yutaka , Tamakoshi Akiko
Published: October 2007

Gallbladder cancer is a rare cancer with a poor prognosis, and few risk factors have been identified to date. This prospective study was conducted to evaluate the association of cigarette smoking and alcohol consumption with the risk of gallbladder cancer death. A baseline survey in 45 areas throughout Japan was conducted from 1988 to 1990 using a self‐administered questionnaire, and a total of 113,496 participants (65,740 women) aged 40–89 years at entry were followed for 15 years. During the follow‐up period, 165 gallbladder cancer deaths (95 women) were observed. Among women, the hazard ratio (HR) [95 percent confidence interval: 95% CI] of current smoker was 2.00 [0.91–4.42], when adjusted for age and drinking. There was no clear association between alcohol consumption and the risk. Among men, HR of current smoker was 2.27 [1.05–4.90]. HRs of those who smoked 21 cigarettes or more per day and those with 801–1,000 cigarette‐years were 3.18 [1.18–8.53] and 3.44 [1.40–8.45], respectively, and positive linear associations were observed between that risk and the number of cigarettes per day (p for trend = 0.007) or “cigarette‐years” (p for trend = 0.012). The alcohol dose was linearly associated with risk (p for trend = 0.004), where the HR among those who consumed 72.0 g or more of alcohol per day was 3.60 [1.29–9.85]. Among both men and women, cigarette smoking may elevate the risk of death from gallbladder cancer. Drinking may pose an elevated risk among men, but that seems to be less true among women. © 2007 Wiley‐Liss, Inc.