bluuebunny/crossref_metadata_2025 huggingface dataset:
Explorable three‐dimensional digital model of the female pelvis, pelvic contents, and perineum for anatomical education
Authors: Sergovich Aimée , Johnson Marjorie , Wilson Timothy D.
Published: February 2010

The anatomy of the pelvis is complex, multilayered, and its three‐dimensional organization is conceptually difficult for students to grasp. The aim of this project was to create an explorable and projectable stereoscopic, three‐dimensional (3D) model of the female pelvis and pelvic contents for anatomical education. The model was created using cryosection images obtained from the Visible Human Project, in conjunction with a general‐purpose three‐dimensional segmentation and surface‐rendering program. Anatomical areas of interest were identified and labeled on consecutive images. Each 2D slice was reassembled, forming a three‐dimensional model. The model includes the pelvic girdle, organs of the pelvic cavity, surrounding musculature, the perineum, neurovascular structures, and the peritoneum. Each structure can be controlled separately (e.g. added, subtracted, made transparent) to reveal organization and/or relationships between structures. The model can be manipulated and/or projected stereoscopically to visualize structures and relationships from different angles with excellent spatial perception. Because of its ease of use and versatility, we expect this model may provide a powerful teaching tool for learning in the classroom or in the laboratory. Anat Sci Educ. © 2010 American Association of Anatomists.
Flash Chemistry Extensively Optimized: High‐Temperature Swern–Moffatt Oxidation in an Automated Microreactor Platform
Authors: Nieuwland Pieter J. , Koch Kaspar , van Harskamp Noud , Wehrens Ron , van Hest Jan C. M. , Rutjes Floris P. J. T.
Published: February 2010

The generally accepted benefits of small lateral dimensions of microreactors (1 μm to 1 mm) enable a different way of performing synthetic chemistry: Extremely short contact times in the millisecond range can circumvent the need for performing highly exothermic and fast reactions at very low temperatures. In order to fully exploit this technology, such fast processes need to be redesigned and investigated for optimal reaction conditions, which can differ drastically from the ones traditionally applied. In a comprehensive study, we optimized the selective Swern–Moffatt oxidation of benzyl alcohol to benzaldehyde by varying five experimental parameters, including reaction time and temperature. Employing an ultrashort mixing and reaction time of only 32 ms, the optimal temperature was determined to be 70 °C, approximately 150 °C higher than in the conventional batch conditions. This remarkable difference shows both the potency of continuous‐flow chemistry as well as the urgency of a paradigm shift in reaction design for continuous‐flow conditions.
Wheat flour formulation by mixture design and multivariate study of its technological properties
Authors: Vigni Mario Li , Durante Caterina , Foca Giorgia , Ulrici Alessandro , Jespersen Birthe Pontoppidan Møller , Bro Rasmus , Cocchi Marina
Published: February 2010

Wheat flour plays a pivotal role in determining the overall quality of bread (loaf dimensions, crumb texture and consistency). A precise knowledge of flour chemical and technological properties is of paramount importance for the baking industry, to tune the modifications of the recipe and production parameters. However, it is still common to have to deal with an empirical, ‘trial and error’‐based approach, and generally, time consuming techniques are employed to determine the quality indexes for flour.

In the context of an industrial bread‐making process, this study addresses the evaluation of the effect of a systematic variation in the mixture composition of wheat flours on their properties. The main objective is to offer this field a more rigorous method to evaluate and improve flour properties, by employing experimental design methodologies and interpreting the results in a multivariate way, instead of the common ‘one variable at a time’ approach. The results show that a careful planning of flour mixtures when testing new varieties and formulation helps to obtain meaningful and easy‐to‐understand results as far as their properties are concerned. Copyright © 2010 John Wiley & Sons, Ltd.
Evaluation of model predictive ability by external validation techniques
Authors: Consonni Viviana , Ballabio Davide , Todeschini Roberto
Published: February 2010

This paper deals with the problem of evaluating the predictive ability of regression models. In some cases, model validation by internal cross‐validation technique is not enough and validation by an external test set has been suggested as an effective way of evaluating the model predictive ability. Different functions for calculating the predictive squared correlation coefficient Q2 from an external set were proposed, which lead to occasionally different estimates of the model predictive ability and therefore to contrasting decisions about model adequacy. In this paper, advantages and drawbacks of these functions in estimating model predictive ability from some simulated datasets are discussed by comparison. Copyright © 2010 John Wiley & Sons, Ltd.
Einsatz der Multimodalspektroskopie bei der Kristallisation
Authors: Engler M. , Beinrauch P. , Trefz P. , Boldrini B. , Kessler R. W.
Published: February 2010

Kristallisationen sind wichtige Schlüsselprozesse für eine Vielzahl von Produkten der Chemischen und Pharmazeutischen Industrie. Kenntnisse über die chemische Zusammensetzung (z. B. Polymorphie) und die morphologische Struktur (z. B. Partikelgröße und ‐verteilung) der Substanzen sind während der Reaktion von großer Bedeutung für die Prozesskontrolle. Zudem können die physikochemischen und pharmakologischen Eigenschaften der Kristallisationsprodukte mit Hilfe dieses Wissens online modelliert und gesteuert werden. Das Ziel prozessanalytischer Techniken, wie z. B. der optischen Spektroskopie, ist die simultane Messung der Identität und Konzentration der Edukte und Produkte sowie der Zahl und Größe der Partikel. Im Rahmen dieser Arbeit wird die Kombination verschiedener spektroskopischer online‐Methoden im UV/VIS‐ und NIR‐Bereich, sowie Ramanspektroskopie genutzt, um diese morphologischen und chemischen Informationen simultan zu erhalten und für die Prozesskontrolle zu nutzen.
Analytische Prozesschromatographie – aktuelle Entwicklungen und industrielle Umsetzungen
Authors: Tups H.
Published: February 2010

Die analytische Prozesschromatographie hat sich in den letzten Jahren zu einem unentbehrlichen Werkzeug der Prozessanalytik entwickelt. Aktuelle Entwicklungen wie die Miniaturisierung der Prozesschromatographen durch Komponenten der Mikrosystemtechnik oder die Integration von Probenaufbereitungen in Prozesschromatographiesysteme erschließen der analytischen Prozesschromatographie neue Anwendungsfelder.
Proposing magnetic nanoparticle hyperthermia in low‐field MRI
Authors: Cantillon‐Murphy Pádraig , Wald Lawrence L. , Zahn Markus , Adalsteinsson Elfar
Published: February 2010

This work examines feasibility, practical advantages, and disadvantages of a combined MRI/magnetic particle hyperthermia (MPH) system for cancerous tumor treatment in low perfusion tissue. Although combined MRI/hyperthermia systems have been proposed and constructed, the current proposal differs because the hyperthermia system would be specifically designed to interact with the magnetic nanoparticles injected at the tumor site. The proposal exploits the physical similarities between the magnetic nanoparticles currently employed for MPH and those used as superparamagnetic iron oxide (SPIO) contrast agents in MR imaging. The proposal involves the addition of a rotating magnetic field RF hyperthermia source perpendicular to the MRI B0 field which operates in a similar manner to the MRI RF excitation field, B1, but at significantly higher frequency and field strength such that the magnetic nanoparticles are forced to rotate in its presence. This rotation is the source of increases in temperature which are of therapeutic benefit in cancer therapy. For rotating magnetic fields with amplitudes much smaller than B0, the nanoparticles' suspension magnetization rapidly saturates with increasing B0. Therefore, the proposal is best suited to low‐field MRI systems when magnetic saturation is incomplete. In addition, careful design of the RF hyperthermia source is required to ensure no physical or RF interference with the B1 field used for MRI excitation. Notwithstanding these caveats, the authors have shown that localized steady‐state temperature rises in small spherical tumors of up to 10°C are conceivable with careful selection of the nanoparticle radius and concentration, RF hyperthermia field amplitude and frequency. © 2010 Wiley Periodicals, Inc. Concepts Magn Reson Part A 36A: 36–47, 2010.
MRI‐phased array evaluation using a human body model
Authors: Bulumulla Selaka , Marinelli Luca , Hardy Christopher J.
Published: February 2010

We develop methodology to evaluate MRI‐phased array receivers using an anatomically and electromagnetically accurate human body model. The human body model accurately represents the different permittivity and conductivity values of various tissue types in the human body, at the frequency of interest. The phased array receiver is a posterior array with 16 coils, typically placed on the patient table for imaging. We obtain the electric and magnetic fields associated with each coil using the finite‐difference time‐domain method and estimate a simplified metric to evaluate the receiver array contribution to the signal‐to‐noise ratio (SNR) distribution. The results highlight SNR variation in the left–right direction, an artifact seen in imaging, but not apparent in quasi‐static simulations with uniform phantoms. We use the results to compare two design variations of 16‐coil phased arrays. In addition, we use the results to compare imaging methods that have potential to reduce the computational complexity of high channel count arrays by reducing the number of data streams used in image reconstruction. © 2010 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 37B: 20–28, 2010
A novel target‐field approach to design bi‐planar shim coils for permanent‐magnet MRI
Authors: Liu Wentao , Tang Xin , Zu Donglin
Published: February 2010

A novel target‐field approach for designing bi‐planar gradient and shim coils of restricted radius for use with permanent‐magnet MRI systems is presented in this article. The method is based on identification of the weighting of harmonic components in the current distribution that will generate a magnetic field whose z‐component follows a chosen spherical harmonic function. Mathematical expressions that relate the harmonic terms in the surface current distribution to spherical harmonic terms in the field expansion are established and then used in a simple matrix inversion approach to design a range of shim coils. The expressions providing a spherical harmonic decomposition of the field components produced by a particular current distribution are novel. The results can be used to design bi‐planar shim coils of restricted radius that will generate a field variation that follows a certain spherical harmonic over a reasonably‐sized volume. A stream function was utilized to obtain the discrete wire distribution on the coil plane. This method does not require the setting of the target‐field points. Through an analysis of the matrix equations in terms of condition numbers, we show that this novel approach has no ill‐conditioned problems. © 2010 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 37B: 29–38, 2010
Bold‐fMRI activation from visual stimuli in human amblyopia with independent component analysis
Authors: Zeng Weiming , Jiang Li
Published: February 2010

Amblyopia is common human visual disease. In this article, we use blood oxygenation level dependent functional magnetic resonance imaging to study child amblyopica with independent component analysis method. Comparing the results of amblyopic eye viewing with that of normal eye viewing, we find that, on the one hand, human amblyopia may lead to occipital cortex dysfunction and reduce the activity of primary visual areas; on the other hand, it may extend visual stimuli into other stimulireflection. © 2010 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 37B: 7–12, 2010
Validation and application of a module of the M. D. Anderson Symptom Inventory for measuring multiple symptoms in patients with gastrointestinal cancer (the MDASI‐GI)
Authors: Wang Xin Shelley , Williams Loretta A. , Eng Cathy , Mendoza Tito R. , Shah Nyma A. , Kirkendoll Karyn J. , Shah Pankil K. , Trask Peter C. , Palos Guadalupe R. , Cleeland Charles S.
Published: February 2010

BACKGROUND:

The M. D. Anderson Symptom Inventory (MDASI) was developed as a brief yet comprehensive tool to assess patient‐reported symptom severity and interference in patients with cancer. The authors report the development of an MDASI module for use in patients with gastrointestinal (GI) cancer (the MDASI‐GI).

METHODS:

Patients with GI cancer (N = 184) participated in module development and validation. The process included: 1) generating GI‐specific candidate items with input from GI oncologists and from qualitative interviews with patients and adding those items to the core MDASI for testing; 2) dropping candidate GI items that lacked sensitivity; 3) validating the psychometric properties (validity, reliability, sensitivity) of the resulting MDASI‐GI; and 4) conducting cognitive debriefing interviews with patients to confirm the questionnaire's ease of comprehension, relevance, and acceptability.

RESULTS:

Five GI‐specific symptom items (constipation, diarrhea, difficulty swallowing, change in taste, and feeling bloated) were added to the original 19 MDASI symptom and interference items to form the MDASI‐GI. Sixty‐one percent of the sample had 1 or more moderate‐to‐severe symptom(s) (≥5 on a severity scale from 0 to 10). Cronbach α values were .80 and .87 for symptom severity items and interference items, respectively. Known‐group validity (sensitivity) was supported by the ability of the MDASI‐GI to detect significant differences in symptom and interference levels according to performance status (P < .001). Cognitive debriefing demonstrated that, for patients, the MDASI‐GI was an easy‐to‐use and understandable tool.

CONCLUSIONS:

The current results indicated that the MDASI‐GI is a valid, reliable, and concise tool for measuring symptom severity and interference with function in patients with GI cancer. Cancer 2010.
The role of high‐dose imatinib in the management of patients with gastrointestinal stromal tumor
Authors: Gronchi Alessandro , Blay Jean‐Yves , Trent Jonathan C.
Published: February 2010

After an era of few treatment options for patients with locally advanced or metastatic gastrointestinal stromal tumor (GIST), imatinib has emerged as the standard of care and first‐line treatment for these patients. Although imatinib was initially approved at the doses of 400 and 600 mg daily, results from clinical studies established 400 mg daily as the standard initial dose for the majority of advanced GIST patients. Nevertheless, the use of high‐dose imatinib (800 mg daily) has been shown to benefit patients with advanced or metastatic GIST that progresses on the standard‐dose, and has been recommended in this setting by the major management guidelines in Europe and the United States. Results from the Meta‐GIST meta‐analysis showed that patients whose GIST harbors a KIT exon 9 mutation garner a longer progression‐free survival time when treated initially with high‐dose imatinib (800 mg daily) compared with those patients with KIT exon 11 or no mutations. Thus, the use of high‐dose imatinib is recommended by the clinical practice guidelines in these 2 specific clinical situations. In addition, clinicians should weigh the clinical benefit of administering high‐dose imatinib against the associated toxicities, as well as the proper management of dose‐related side effects. Cancer 2010. © 2010 American Cancer Society.
Patient‐reported acute gastrointestinal symptoms during concurrent chemoradiation treatment for rectal cancer
Authors: Chen Ronald C. , Mamon Harvey J. , Chen Yu‐Hui , Gelman Rebecca S. , Suh W. Warren , Talcott James A. , Clark Jeffrey W. , Hong Theodore S.
Published: February 2010

BACKGROUND:

Although it is known that standard 5‐fluorouracil–based chemoradiation therapy for rectal cancer causes significant acute gastrointestinal (GI) toxicity, research on patient‐reported outcomes (PROs) is limited. The authors undertook the current study to assess the feasibility of incorporating PRO measurement into routine clinical practice and to describe the trajectory of symptom development during treatment.

METHODS:

Seventy‐seven consecutive patients who were treated between 2006 and 2008 were eligible. Patients completed the 7‐item Bowel Problems Scale immediately before weekly physician visits.

RESULTS:

The questionnaire completion rate was 95%. Individual GI symptoms had different trajectories of development. By Week 5, approximately 40% of all patients developed clinically meaningful pain, bowel urgency, or tenesmus that was not present during Week 1; 30% developed diarrhea, abdominal cramping, and passing mucus. However, overall symptom burden was moderate. Seventy‐five percent of patients who presented with rectal bleeding at Week 1 improved by Week 3 of treatment. Within each physician‐assessed grade of diarrhea, patient experience varied widely. For example, of the 50 patients who developed grade 2 diarrhea on the Radiation Therapy Oncology Group Acute Morbidity Scale, the numbers of patients reporting only occasional symptoms versus those reporting frequent or very frequent symptoms were similar.

CONCLUSIONS:

PROs provided information on patient symptoms during chemoradiation treatment for rectal cancer that was not captured otherwise, and it was feasible to incorporate PROs into routine clinical practice. The current results may be used by physicians to counsel their patients before treatment initiation and to provide a benchmark against which trials that use new therapies may be compared. Cancer 2010; 116:1879–86. © 2010 American Cancer Society.
Disrupting established tumor blood vessels
Authors: McKeage Mark J. , Baguley Bruce C.
Published: February 2010

The unique characteristics of tumor vasculature represent an attractive target that may be exploited by vascular‐targeting anticancer agents. A promising strategy involves the selective disruption of established tumor blood vessels by tumor‐vascular disrupting agents (tumor‐VDAs), which exhibit antivascular activity, resulting in inhibition of tumor blood flow and extensive necrosis within the tumor core. The tumor‐VDA class can be subdivided into flavonoid compounds, which are related to flavone acetic acid, and tubulin‐binding compounds. ASA404, of the flavonoid class, is the most advanced tumor‐VDA in clinical development and has been evaluated preclinically and in several phase 1 and phase 2 studies. Preclinical studies have demonstrated the selective apoptosis of tumor endothelial cells and the inhibition of tumor blood flow. Synergistic activity was observed with ASA404 and with several chemotherapeutic agents, particularly taxanes. In clinical trials, compared with chemotherapy alone, ASA404 was tolerated well and produced improved activity in patients with nonsmall cell lung cancer when combined with paclitaxel and carboplatin. Phase 3 clinical trials are ongoing. Selectively targeting established tumor vasculature with tumor‐VDAs represents a promising and innovative approach to improving the efficacy of standard anticancer therapies. Cancer 2010. © 2010 American Cancer Society.
Commercial Runner peanut cultivars in the USA: Fatty acid composition
Authors: Shin Eui‐Cheol , Pegg Ronald B. , Phillips R. Dixon , Eitenmiller Ronald R.
Published: February 2010

Though peanuts are classified as a high‐fat food, they possess good proportions of fatty acids deemed as heart healthy. The fatty acid compositions of Runner peanuts were determined for commercially grown cultivars over two recent crop years. GC‐FID analyses revealed that the fatty acid levels for Runner peanuts were significantly (p <0.05) different among the normal, mid‐, and high‐oleic peanuts investigated. Oleic acid‐to‐linoleic acid (O/L) ratios were found to be 1.93 ± 0.30, 5.25 ± 1.12, and 16.9 ± 5.20 for normal, mid‐, and high‐oleic peanut lipids, respectively. Tamrun OL01 possessed a fatty acid profile characteristic of a mid‐oleic cultivar. From the sample set (n = 151), mean % weights for oleic acid and linoleic acid were 52.09 ± 2.84 and 27.38 ± 2.60 in normal, 69.33 ± 3.18 and 13.66 ± 2.35 in mid‐oleic, and 78.45 ± 2.05 and 5.11 ± 1.67 in high‐oleic peanuts, respectively. Cluster analysis segregated cultivars based on fatty acids into normal, mid‐, and high‐oleic groups. Factorial analysis revealed that cultivar effects were significant (p <0.01) for all fatty acids, except for lignoceric acid. Cultivar effects were also highly significant (p <0.001) for O/L, IV, unsaturated/saturated fatty acid (U/S) ratio, and % saturation. Significant crop year effects were shown for palmitic, oleic, arachidic, gondoic, and lignoceric acids, as well as U/S ratio and % saturation. Healthy unsaturated fats accounted for ˜80% in all crop years and cultivars.
Improved disc SDS‐PAGE for extraction of low molecular weight proteins from serum
Authors: Li Tiechun , Dai Shuping , Wang Ziming , Zhang Hanqi
Published: February 2010

The low molecular weight proteins can provide a lot of valuable information of biomarkers. To study these proteins, the high abundance and high molecular weight proteins must be removed prior to analysis. In this work, a simple and inexpensive disc SDS‐PAGE to extract low molecular weight proteins from human serum and cutoff proteins larger than 30 kDa was developed. Some experimental conditions were examined. The experimental results obtained by plate SDS‐PAGE and MALDI‐TOF MS showed that the molecular weight of extracted proteins was about in the range from 0.3 to 28 kDa. Some experiments, including precipitation of proteins in organic solvents, SPE and cytochrome C test, were carried out and the experimental results demonstrated successful recovery of proteins/peptides with molecular weight from several hundreds of dalton to about 30 kDa. The experimental results obtained by plate SDS‐PAGE indicated the repeatability was satisfactory.
Cadmium biosorption properties of the metal‐resistant Ochrobactrum cytisi Azn6.2
Authors: Rodríguez‐Llorente Ignacio D. , Gamane Djamila , Lafuente Alejandro , Dary Mohammed , El Hamdaoui Abdelaziz , Delgadillo Julián , Doukkali Bouchra , Caviedes Miguel A. , Pajuelo Eloísa
Published: February 2010

The aim of this work was to establish the conditions for using Ochrobactrum cytisi Azn6.2 as a metal biosorbent. Azn6.2 is a novel strain from the legume symbiont O. cytisi that has been isolated from nodules of Medicago polymorpha plants grown on heavy metal‐polluted soils. Compared with the strain ESC1, Azn6.2 showed some biochemical differences, as well as antibiotic susceptibility, Azn6.2 was multi‐resistant to heavy metals, such as Cu, Cd and Zn, and bacterial pellets were able to biosorb high amounts of Cd and Zn. As shown by scanning electron microscopy coupled to energy dispersive X‐ray, most of Cd was attached to the cell surface. Optimal conditions for Cd biosorption were established, being 1 mM Cd ions in solution and 2 h of contact with the biosorbent at room temperature. At these conditions, maximal Cd loading capacity reached 32–34 mg/g. Cd desorption from bacterial pellets was achieved after washing with EDTA or, at higher efficiency, at pH 1.0. These results indicated that biosorption/desorption on O. cytisi Azn6.2 biomass should be a cost‐effective method for Cd recovery from contaminated solutions.
Bioethanol and biodiesel: Alternative liquid fuels for future generations
Authors: Sivakumar Ganapathy , Vail Daniel R. , Xu Jianfeng , Burner David M. , Lay Jackson O. , Ge Xumeng , Weathers Pamela J.
Published: February 2010

The global population is expected to increase by approximately 3 billion people by 2050. With this increase in population, industry, transportation the cost of fossil fuels will grow dramatically. New technologies are needed for fuel extraction using feedstocks that do not threaten food security, cause minimal or no loss of natural habitat and soil carbon. At the same time, waste management has to be improved and environmental pollution should be minimized or eliminated. Liquid biofuels such as lignocellulosic‐based ethanol from plant biomass and algal‐based biodiesel are sustainable, alternative biofuels that could stabilize national security and provide clean energy for future generations. Ideally, the technology should also foster recycling of agricultural feedstocks and improve soil fertility and human health. This article provides updated information on the energy potential and breadth of liquid biofuel biotechnology.
How realistic are outdoor microcosms? A comparison of the biota of microcosms and natural ponds
Authors: Williams Penny , Whitfield Mericia , Biggs Jeremy , Fox Gill , Nicolet Pascale , Shillabeer Nigel , Sherratt Tom , Heneghan Phil , Jepson Paul , Maund Steve
Published: February 2010

This study investigated the extent to which aquatic plant and macroinvertebrate assemblages in small outdoor microcosms (cylinders 1.25-m diameter × 1.25 m deep) resembled assemblages found in natural ponds in Britain. Comparisons were made in terms of community structure, species richness, and numbers of uncommon species. Multivariate analysis indicated that, although the microcosms had no exact natural analogues, their plant and animal assemblages were most like those of deep, circumneutral ponds. Unlike natural ponds, the microcosms supported relatively species-poor invertebrate assemblages, lacking uncommon species. Among individual taxa, microcosms supported similar numbers of species of Gastropoda, Isopoda, Amphipoda, and Odonata as natural ponds but significantly fewer Coleoptera, Hemiptera, and Trichoptera species. This was most likely due to the absence of a shallow littoral area in the microcosms. Because of their vertical sides, the microcosms supported no marginal wetland plants, but submerged and floating-leaved plant assemblages were similar in community type and species richness to natural ponds. Refinements to microcosm and mesocosm designs are identified that would enable experimental systems to more closely replicate the assemblages found in natural ponds. In particular, the incorporation of natural margins would be likely to lead to experimental communities that were closer analogues of natural ponds.
Spatial patterns in benthic biodiversity of Chesapeake Bay, USA (1984–1999): Association with water quality and sediment toxicity
Authors: Preston Benjamin L.
Published: February 2010

Non–point-source pollution is an increasing source of stress to aquatic, estuarine, and marine ecosystems. Such pollution may be of unknown etiology, distributed over extensive spatial scales, and comprised of multiple stressors. Current stressor-based paradigms for ecological risk assessment (ERA) may be insufficient to characterize risk from multiple stressors at regional spatial scales, necessitating the use of effects-based approaches. Historical data (1984–1999) for benthic macroinvertebrate biodiversity in Chesapeake Bay, USA, were incorporated into a geographic information system (GIS) and spatial analysis tools were used to model zones within the bay predicted to be of low or high anthropogenic impact. Data for benthic water quality and sediment toxicant concentrations from each of these zones were subsequently analyzed and compared to identify associations between benthic biodiversity and potential stressors. A number of stressors were significantly associated with high-impact zones, including increased nitrogen and phosphorus concentrations, low dissolved oxygen, heavy metals, pesticides, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls. The spatial autocorrelation among multiple stressors suggests that traditional stressor-based approaches to ERA may result in the a priori exclusion of ecologically relevant stressors. Considering the effects of individual stressors rather than net effects of multiple stressors may result in underestimation of risk. The GISs are a useful tool for integrating multiple data sets in support of comprehensive regional ERA.
Weak coupling of a Reynolds model and a Stokes model for hydrodynamic lubrication
Authors: Nilsson B. , Hansbo P.
Published: February 2010

The Reynolds model is a reduced Stokes model, valid for narrow lubrication regions. In order to be able to handle locally non‐narrow regions such as pits or grooves, often displaying rapid geometrical variations, there is a need to be able to transit to the more accurate Stokes model. A fundamental problem is how to couple the two models in a numerical simulation, preferably allowing for different meshes in the different domains. In this paper, we present a weak coupling method for Reynolds and Stokes models for lubrication computations, including the possibility of cavitation in the different regions. The paper concludes with a numerical example. Copyright © 2010 John Wiley & Sons, Ltd.
A Simple and Accurate Method for High‐Temperature PEM Fuel Cell Characterisation
Authors: Kulikovsky A. A. , Oetjen H.‐F. , Wannek Ch.
Published: February 2010

A set of basic parameters for any polymer electrolyte membrane fuel cell (PEMFC) includes the Tafel slope b and the exchange current density j* of the cathode catalyst, the oxygen diffusion coefficient Db in the cathode gas‐diffusion layer and the cell resistivity Rcell. Based on the analytical model of a PEMFC [A. A. Kulikovsky, Electrochim. Acta (2004) 617], we propose a two‐step procedure allowing to evaluate these parameters for a high‐temperature PEMFC. The procedure requires two polarisation curves measured at different oxygen (air) stoichiometries. The method is validated using the experimental data obtained with the in‐house designed cell. High quality of fitting confirms validity and accuracy of this approach. The physical background of the method is discussed.
Rapid Microwave‐Assisted Solvothermal Synthesis of Methanol Tolerant Pt–Pd–Co Nanoalloy Electrocatalysts
Authors: Sarkar A. , Vadivel Murugan A. , Manthiram A.
Published: February 2010

We report here a microwave‐assisted solvothermal (MW‐ST) method to synthesise carbon‐supported multimetallic nanostructured alloys of Pt, Pd and Co with high crystallinity and homogeneity for electrocatalytic application in fuel cells. Multimetallic nanoalloy electrocatalysts have been synthesised by a one‐pot, rapid MW‐ST method within 15 min at <300 °C without any post‐annealing in reducing gas atmospheres. For a comparison, same multimetallic alloys were also synthesised by heat treatment of co‐precipitated metals. Significant differences were observed in the phase structure and surface composition of the alloys synthesised by the two methods, which were rationalised based on the synthesis procedures adopted. Further, the multimetallic alloys were also explored for their electrocatalytic applications as cathode catalysts for oxygen reduction reaction (ORR). The multimetallic alloys, synthesised by the MW‐ST method, show much higher ORR activity compared to their counterparts synthesised by the conventional borohydride reduction method. While the ORR activity of Pt70Pd20Co10 is comparable to that of commercial Pt, the ORR activity of Pt50Pd30Co20 in direct methanol fuel cells (DMFC) is superior to that of commercial Pt at high methanol concentrations due to its high tolerance to methanol that may crossover from the anode to the cathode.
Improving the Performance of Platinum Nanocrystal Catalysts by Square‐wave Potential Electrochemical Pretreatment
Authors: Zheng L. , Sun J. , Xiong L. , Jin R. , Li J. , Li X. , Zheng D. , Liu Q. , Niu L. , Yang S. , Xia J.
Published: February 2010

Cube‐shaped Pt nanocrystals (with the size of about 160 nm) are prepared by a square‐wave potential electrochemical pretreatment at the expense of Pt nanospheres. A cyclic voltammogram of Pt nanospheres in sulphuric acid shows two pairs of hydrogen adsorption/desorption peaks, which corresponds to the characteristics of a Pt polyoriented surface. However, a cyclic voltammogram of cubic Pt nanocrystals in sulphuric acid shows another pair of hydrogen adsorption/desorption peak at 0.22 V (vs. NHE), which corresponds to the characteristics of Pt (100) surface orientation. Cubic Pt nanocrystals show enhanced electrocatalytic activity over Pt nanospheres for methanol oxidation. The peak current density of cubic Pt nanocrystals is 1.39 mA cm–2Pt, which is 1.48 times that of Pt nanospheres. The poison resistant and oxygen reduction reaction (ORR) activity of cubic Pt nanocrystals are also enhanced compared with those of Pt nanospheres.
Evaluation of the Performance of Carbon Supported Pt–Ru–Ni–P as Anode Catalyst for Methanol Electrooxidation
Authors: Shao A.‐F. , Wang Z.‐B. , Chu Y.‐Y. , Jiang Z.‐Z. , Yin G.‐P. , Liu Y.
Published: February 2010

This research is aimed to improve the activity and stability of ternary alloy Pt–Ru–Ni/C catalyst. A novel anodic catalyst for direct methanol fuel cell (DMFC), carbon supported Pt–Ru–Ni–P nanoparticles, has been prepared by chemical reduction method by using NaH2PO2 as a reducing agent. One glassy carbon disc working electrode is used to test the catalytic performances of the homemade catalysts by cyclic voltammetric (CV), chronoamperometric (CA) and amperometric i–t measurements in a solution of 0.5 mol L–1 H2SO4 and 0.5 mol L–1 CH3OH. The compositions, particle sizes and morphology of home‐made catalysts are evaluated by means of energy dispersive analysis of X‐ray (EDAX), X‐ray diffraction (XRD) and transmission electron micrographs (TEM), respectively. TEM images show that Pt–Ru–Ni–P nanoparticles have an even size distribution with an average diameter of less than 2 nm. The results of CV, CA and i–t curves indicate that the Pt–Ru–Ni–P/C catalyst shows significantly higher activity and stability for methanol electrooxidation due to the presence of non‐metal phosphorus in comparison to Pt–Ru–Ni/C one. All experimental results indicate that the addition of non‐metallic phosphorus into the Pt–Ru–Ni/C catalyst has definite value of research and practical application for enhancing the performance of DMFC.
Temporal variation of over‐bank flooding of Wei River and its impact on a riparian wetland in Xi'an, China
Authors: Tian Shiying , Luo Wan , Jia Zhonghua , Butalia Rajpreet Singh
Published: February 2010

Over‐bank flooding is one of the driving forces controlling ecological integrity of riparian wetlands. Indentifying natural over‐bank flooding regime and its temporal variations is crucial for developing conservation and restoration plans and making water resources management policies for these ecosystems. Along the midstream of the Wei River in Xi'an, China lies the Jingwei riparian wetland, which was well preserved until the 1970s. Based on historical record of hydrological and morphological data of the Wei River from 1951 to 2000, we analysed temporal variations of over‐bank flooding frequency, duration, and timing in this paper. The natural annual over‐bank flooding regime was identified as having an occurrence frequency of 2·2 times a year and average duration of 5·3 days; these flooding events typically occur between June and September with occasional occurrence in late spring and late autumn. Over‐bank flooding occurrence frequency and duration decreased significantly during the 1990s, seasonal events of over‐bank floods were changed through reduced flooding frequency during summer and disappearing flooding events in late spring and late autumn. Further investigations showed that reduced discharge in the Wei River was the principal cause for these changes in over‐bank flooding dynamics. Our analysis also showed that decreased discharge of the Wei River during the 1990s was attributed near equally to disturbances from human activities and decreased regional precipitation. Results from this study may help reestablish natural over‐bank flooding dynamics in order to ensure successful restoration of Jingwei riparian wetland. Copyright © 2010 John Wiley & Sons, Ltd.
Assessment of intermediate fine sediment storage in a braided river reach (southern French Prealps)
Authors: Navratil O. , Legout C. , Gateuille D. , Esteves M. , Liebault F.
Published: February 2010

This paper presents a field investigation on river channel storage of fine sediments in an unglaciated braided river, the Bès River, located in a mountainous region in the southern French Prealps. Braided rivers transport a very large quantity of bedload and suspended sediment load because they are generally located in the vicinity of highly erosive hillslopes. Consequently, these rivers play an important role because they supply and control the sediment load of the entire downstream fluvial network. Field measurements and aerial photograph analyses were considered together to evaluate the variability of fine sediment quantity stored in a 2·5‐km‐long river reach. This study found very large quantities of fine sediment stored in this reach: 1100 t per unit depth (1 dm). Given that this reach accounts for 17% of the braided channel surface area of the river basin, the quantities of fine sediment stored in the river network were found to be approximately 80% of the mean annual suspended sediment yields (SSYs) (66 200 t year−1), comparable to the SSYs at the flood event scale: from 1000 t to 12 000 t depending on the flood event magnitude. These results could explain the clockwise hysteretic relationships between suspended sediment concentrations and discharges for 80% of floods. This pattern is associated with the rapid availability of the fine sediments stored in the river channel. This study shows the need to focus on not only the mechanisms of fine sediment production from hillslope erosion but also the spatiotemporal dynamics of fine sediment transfer in braided rivers. Copyright © 2010 John Wiley & Sons, Ltd.
Changing properties of hydrological extremes in south China: natural variations or human influences?
Authors: Zhang Qiang , Jiang Tao , Chen Yongqin David , Chen Xiaohong
Published: February 2010

Extreme events are drawing increasing concerns in recent decades due to their catastrophic nature. In this case, we thoroughly analysed the statistical behaviours of hydrological extremes in the south China by taking Guangdong province as a case study because of its unshakable position in the economic development in China. Our results further corroborated the fact that the hydrological changes are the integrated consequences of various external factors, basically the human activities and climate changes. Generally, decreasing annual maximum water (AMW) level was observed mainly in the seaward regions characterized by decreasing occurrence frequency of higher AMW level. Streamflow variations are influenced mainly by precipitation changes. Increasing annual maximum streamflow (AMS) can be attributed to the increasing precipitation intensity in recent years. However, in the East River basin, hydrological regulation function of the water reservoirs greatly reduced the AMS. In the lower East River, however, downcutting river channel and notable increases in the cross‐section area caused larger magnitude of decrease in AMW level when compared to AMS. The time when the relations between AMW level and streamflow start to change matches well the time when massive in‐channel sand dredging occurred, showing tremendous influences of human activities on hydrological processes in the lower Pearl River basin. This study will be of great scientific and practical merits in better understanding the statistical behaviours of hydrological extremes under the changing environment and also help to improve human mitigation to natural hazards in south China. Copyright © 2010 John Wiley & Sons, Ltd.
Field estimation of specific yield in a central Iowa crop field
Authors: Logsdon S. D. , Schilling K. E. , Hernandez‐Ramirez G. , Prueger J. H. , Hatfield J. L. , Sauer T. J.
Published: February 2010

The specific yield (Sy) is the gain or loss of water associated with a corresponding amount of water table rise or fall. Rain may be intercepted by the canopy, refill the soil pore system, taken up by plant roots or drained. Transpired soil water may be replenished from a shallow water table, so water table loss is indirectly tied to evapotranspiration (ET). The purpose of this study was to use continuous data for the different components of the water cycle to back‐calculate Sy for both wetting and drying conditions. Two time periods were considered for a toeslope site in an Iowa corn (Zea mays L.) field: growing season from 22 June to 10 July 2007, and post‐growing season 13–30 October 2007. The field was instrumented with eddy covariance instrumentation for ET estimates, tipping bucket raingage for precipitation, automated well‐depth recorder for water table depth and water content reflectometers (CS616s) for soil water content. During drying in the growing season, mean Sy was 0·19, but drying Sy could not be determined post‐growing season because of no net upward water movement at this time. During wetting, estimates of Sy were improved when soil water increase was subtracted from total rainfall; then the mean wetting Sy was 0·052 versus 0·31–0·46 without this correction. Large differences between seasonal and post‐growing season data reflected the seasonal strong upward gradient created by soil dried from water uptake. Post‐growing season data was dominated by drainage, but seasonal root water uptake intercepted drainage water. Published in 2010 by John Wiley & Sons, Ltd.
Suspended‐sediment sources in an urban watershed, Northeast Branch Anacostia River, Maryland
Authors: Devereux Olivia H. , Prestegaard Karen L. , Needelman Brian A. , Gellis Allen C.
Published: February 2010

Fine sediment sources were characterized by chemical composition in an urban watershed, the Northeast Branch Anacostia River, which drains to the Chesapeake Bay. Concentrations of 63 elements and two radionuclides were measured in possible land‐based sediment sources and suspended sediment collected from the water column at the watershed outlet during storm events. These tracer concentrations were used to determine the relative quantity of suspended sediment contributed by each source. Although this is an urbanized watershed, there was not a distinct urban signature that can be evaluated except for the contributions from road surfaces. We identified the sources of fine sediment by both physiographic province (Piedmont and Coastal Plain) and source locale (streambanks, upland and street residue) by using different sets of elemental tracers. The Piedmont contributed the majority of the fine sediment for seven of the eight measured storms. The streambanks contributed the greatest quantity of fine sediment when evaluated by source locale. Street residue contributed 13% of the total suspended sediment on average and was the source most concentrated in anthropogenically enriched elements. Combining results from the source locale and physiographic province analyses, most fine sediment in the Northeast Branch watershed is derived from streambanks that contain sediment eroded from the Piedmont physiographic province of the watershed. Sediment fingerprinting analyses are most useful when longer term evaluations of sediment erosion and storage are also available from streambank‐erosion measurements, sediment budget and other methods. Copyright © 2010 John Wiley & Sons, Ltd.
Incorporating landscape depressions and tile drainages of a northern German lowland catchment into a semi‐distributed model
Authors: Kiesel J. , Fohrer N. , Schmalz B. , White M. J.
Published: February 2010

Hydrological models need to be adapted to specific hydrological characteristics of the catchment in which they are applied. In the lowland region of northern Germany, tile drains and depressions are prominent features of the landscape though are often neglected in hydrological modelling on the catchment scale. It is shown how these lowland features can be implemented into the Soil and Water Assessment Tool (SWAT). For obtaining the necessary input data, results from a GIS method to derive the location of artificial drainage areas have been used. Another GIS method has been developed to evaluate the spatial distribution and characteristics of landscape depressions. In the study catchment, 31% of the watershed area is artificially drained, which heavily influences groundwater processes. Landscape depressions are common over the 50‐km2 study area and have considerable retention potential with an estimated surface area of 582 ha. It was the scope of this work to evaluate the extent by which these two processes affect model performance. Accordingly, three hypotheses have been formulated and tested through a stepwise incorporation of drainage and depression processes into an auto calibrated default setup: (1) integration of artificial drainage alone; (2) integration of depressions alone and (3) integration of both processes combined. The results show a strong improvement of model performance for including artificial drainage while the depression setup only induces a slight improvement. The incorporation of the two landscape characteristics combined led to an overall enhancement of model performance and the strongest improvement in r2, root mean square error (RMSE) and Nash–Sutcliffe efficiency (NSE) of all setups. In particular, summer rainfall events with high intensity, winter flows and the hydrograph's recession limbs are depicted more realistically. Copyright © 2010 John Wiley & Sons, Ltd.
Osteoblastic induction on calcium phosphate cement–chitosan constructs for bone tissue engineering
Authors: Weir Michael D. , Xu Hockin H. K.
Published: February 2010

Calcium phosphate cement (CPC) is osteoconductive and moldable, and it can conform to complex cavity shapes and set in situ to form hydroxyapatite. Chitosan could increase the strength and toughness of CPC, but there has been no investigation on recombinant human bone morphogenic protein‐2 (rhBMP‐2) delivery via CPC–chitosan composite and its effect on osteogenic induction of cells. The objective of this research was to investigate the mechanical properties and osteoblastic induction of MC3T3‐E1 cells cultured on CPC‐containing chitosan and rhBMP‐2. Cell viability for CPC with chitosan and rhBMP‐2 was comparable with that of control CPC, whereas the CPC–chitosan composite was stronger and tougher than CPC control. After 14 days, osteoblastic induction was quantified by measuring alkaline phosphatase (ALP) activity. ALP (mean ± SD; n = 6) of cells seeded on conventional CPC without rhBMP‐2 was (143 ± 19) (mM pNpp/min)/(μg DNA). The addition of chitosan resulted in an ALP of 161 ± 27. Further addition of rhBMP‐2 to the CPC–chitosan composite increased the ALP to 305 ± 111 (p < 0.05). All ALP activity on CPC composites was significantly higher when compared with the 10.0 ± 3.3 of tissue culture polystyrene (p < 0.05). Flexural strength of CPC containing 15% (mass fraction) chitosan was 19.8 ± 1.4 MPa, which is more than double the 8.0 ± 1.4 MPa of conventional CPC (p < 0.05). The addition of chitosan to CPC increased the fracture toughness from 0.18 ± 0.01 MPa·m1/2 to 0.23 ± 0.02 MPa·m1/2 (p < 0.05). The relatively high strength, self‐hardening CPC–chitosan composite scaffold is promising as a moderate load‐bearing matrix for bone repair, with potential to serve as an injectable delivery vehicle for osteoinductive growth factors to promote osteoblastic induction and bone regeneration. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res, 2010