bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vegetated filter effects on sedimentological connectivity of agricultural catchments in erosion modelling: a review
Authors: Gumiere Silvio Jose , Le Bissonnais Yves , Raclot Damien , Cheviron Bruno 
Published: July 2010

AbstractThe sedimentological connectivity of agricultural catchments may be affected by anthropogenic structures (land management practices) established to reduce sediment exportation from agricultural plots to water streams. Distributed erosion models may in theory provide information about where and how these structures should be installed in catchments to reduce sediment exportation. The interaction between sediment exportation and land management practices is very complex from both theoretical and experimental points of view. Vegetated filters are a widely used land management practice. They interact with water flow, change turbulence conditions, and ultimately affect sediment transport and deposition processes. Experimental results have shown that the efficiency of sediment trapping in vegetated filters is influenced by flow characteristics, sediment size, and vegetation type, as well as by the slope and width of the filter in the streamwise direction. At the catchment scale, the spatial organisation of management practices is crucial for the global sedimentological connectivity. Present‐day erosion models propose different approaches to simulate the influence of management practices on soil loss and sediment export for agricultural catchments. Some of them use the Sediment Delivery Ratio (SDR) or P‐factor to describe sediment transport from source to sink areas. Others, such as in the TRAVA and VSFMOD, rely on process‐based descriptions involving changes in roughness and infiltrability along flow paths to study the effect of management practices. From the literature review conducted herein, we identified the lack of an approach of intermediate complexity, that would be more physically relevant than SDR and P‐factor approaches, but simpler and easier to spatialise than TRAVA and VSFMOD‐type models. Copyright © 2010 John Wiley and Sons, Ltd.
Poultry litter–induced endocrine disruption in fathead minnow, sheepshead minnow, and mummichog laboratory exposures
Authors: Yonkos Lance T. , Fisher Daniel J. , Van Veld Peter A. , Kane Andrew S. , McGee Beth L. , Staver Kenneth W. 
Published: July 2010

AbstractAnimal feeding operations in the United States produce more than 500 million tons of manure annually. Disposal of poultry waste via application as fertilizer results in substantial runoff of poultry litter–associated contaminants (PLAC). Of particular concern are sex steroids, 17β-estradiol, estrone and testosterone, responsible for sex differentiation and development of reproductive structures. In a series of laboratory assays, mature male and mixed-sex larval/juvenile fish were continuously exposed to environmentally relevant PLAC solutions. Effects on gonads were assessed histologically, and vitellogenin (VTG) induction was measured as a gauge of estrogenicity. Twenty-one-day exposures to laboratory-generated PLAC solutions routinely induced VTG in mature male Pimephales promelas. Vitellogenesis in Fundulus heteroclitus only occurred at the highest tested PLAC concentration, and Cyprinodon variegatus were unresponsive at any tested concentration. All species produced considerable VTG in response to a 17β-estradiol–positive control. A pronounced feminization was seen in P. promelas when exposed to PLAC as larvae but not when exposed as juveniles. Runoff from a poultry litter–amended field cropped under standard agronomic practices induced significant VTG in male P. promelas. Results indicate that environmentally relevant PLAC concentrations exhibit endocrine activity sufficient to induce VTG production in male fish and possibly affect sex ratios in resident fish populations. Environ. Toxicol. Chem. 2010;29:2328–2340. © 2010 SETAC
Modeling the effect of water chemistry on the bioaccumulation of waterborne cadmium in zebra mussels
Authors: Bourgeault Adeline , Gourlay-Francé Catherine , Tusseau-Vuillemin Marie-Hélène 
Published: July 2010

AbstractThe present study aims at investigating the effects of Zn, Ca, and dissolved organic carbon (DOC) on the waterborne Cd bioaccumulation of a freshwater bivalve (Dreissena polymorpha). Mussels were exposed for 48 h at 3 µg/L of Cd in different media. Their physiological activities were assessed by separately measuring the filtration rate in the same exposure water. Increased Zn (from 3 to 89 µg/L) and Ca (from 37 to 131 mg/L) concentrations in water led to a threefold and sevenfold reduction of Cd bioaccumulation, whereas the effect of DOC varied greatly depending on its concentration. At low DOC concentrations (from 0.2 to 1.1 mg/L), the uptake of Cd increased, whereas at higher concentrations (from 1.1 to 17.1 mg/L), the uptake decreased. The filtration activity was not strongly influenced by either Zn or Ca concentration, whereas it was modified in enriched DOC media in the same manner as Cd uptake. A competitive model was built to predict the waterborne uptake rate constant of Cd (k u) as a function of Zn and Ca concentrations in the water. Over the range of DOC concentrations we tested, organic matter was shown to influence Cd bioaccumulation in two ways: by modifying Cd speciation and thus its bioavailability and its interaction with the biological membrane, and by affecting the mussel's physiology and therefore its sensitivity to metal. The present study provides a useful means of adjusting the toxicokinetic constant to the water's physicochemical characteristics and proposes a unifying model that takes into account the different geochemical and biological influences on bioaccumulation. Environ. Toxicol. Chem. 2010;29:2182–2189. © 2010 SETAC
Study of pyrolysis and upward flame spread on charring materials—Part I: Experimental study
Authors: Wasan S. R. , Van Hees P. , Merci B. 
Published: July 2010

AbstractIn this paper, we describe the results from an experimental campaign, focused on vertical upward flame spread over a charring material. First, for validation purposes of simulation tools, we report on cone calorimeter results for square (9.8cm×9.8cm), 1.65 cm thick, medium density fibre samples, mounted horizontally. Temperature is shown at the surface and at different depths. The mass of the sample is continuously measured. From the raw data, we derive the temporal evolution of the mass loss rate due to pyrolysis. Different externally imposed heat fluxes are investigated (20, 30 and 50kW/m2), onto dry and wet material. Afterwards, for the configuration of two particle board plates (0.025 m thick, 0.4 m wide and 2.5 m high), vertically mounted face to face is considered. Two different horizontal spacing distances between the two plates are studied (30.5 and 10.5 cm). The purpose of this set‐up is to investigate the vertical upward flame spread with strong radiative heat feedback. To that purpose, the temporal evolution of surface temperature is measured over the height of the plates. The measurement data are used to test a pyrolysis model in numerical simulations. Copyright © 2010 John Wiley & Sons, Ltd.
Multi‐dimensional wave‐oriented upwind schemes with reduced cross‐wind diffusion for flow in porous media
Authors: Edwards Michael G. 
Published: July 2010

AbstractSingle‐point upstream weighting schemes remain the reservoir simulation standard for integrating the convective components of the subsurface flow equations. While single‐point upstream weighting is attractive due to simplicity and small stencil, the accompanying first‐order error can contribute to a large amount of grid‐dependent numerical diffusion which smooths the numerical solution. New upwind schemes are introduced for reservoir simulation that significantly reduce cross‐wind diffusion, retain a local flux approximation with local conservation, and are free of spurious oscillations. Copyright © 2010 John Wiley & Sons, Ltd.
Decentralization and health care prioritization process in Tanzania: from national rhetoric to local reality
Authors: Maluka Stephen Oswald , Hurtig Anna‐Karin , Sebastián Miguel San , Shayo Elizabeth , Byskov Jens , Kamuzora Peter 
Published: July 2010

AbstractDuring the 1990s, Tanzania like many other developing countries adopted health sector reforms. The most common policy change under the health sector reforms has been decentralization, which involves the transfer of power and authority from the central level to local authorities. Based on the case study of Mbarali district in Tanzania, this paper uses a policy analysis approach to analyse the implementation of decentralized health care priority setting. Specifically, the paper examines the process, actors and contextual factors shaping decentralized health care priority setting processes. The analysis and conclusion are based on a review of documents, key informant interviews, focus group discussion, and notes from non‐participant observation. The findings of the study indicate that local institutional contexts and power asymmetries among actors have a greater influence on the prioritization process at the local level than expected and intended. The paper underlines the essentially political character of the decentralization process and reiterates the need for policy analysts to pay attention to processes, institutional contexts, and the role of policy actors in shaping the implementation of the decentralization process at the district level. Copyright © 2010 John Wiley & Sons, Ltd.
Hydrodynamic and isotopic investigations for evaluating the mechanisms and amount of groundwater seepage through a rockslide dam
Authors: Petitta Marco , Scarascia Mugnozza Gabriele , Barbieri Maurizio , Bianchi Fasani Gianluca , Esposito Carlo 
Published: July 2010

AbstractThis study addresses the influence of landslide dams on surface water drainage and groundwater flow. In the study area of Scanno Lake and Sagittario River (Central Italy), a limestone rockslide‐avalanche formed a lake, which has an outlet that is occasionally active, showing infiltration into the rockslide dam. Several springs are present at the lake's base and are partly fed by seepage through the rockslide debris. Piezometric surveys, discharge measurements, pumping tests and chemical analyses are tools used to build a conceptual model of the groundwater flow and to evaluate the flow through the rockslide debris. Seasonal water isotopic signatures validate the assumed model, showing a mixing of infiltration recharge and groundwater seepage throughout the rockslide debris. Various recharge areas have been found for springs, pointing out those directly fed by the rockslide debris aquifer. Hypotheses about seasonal groundwater mixing between the regional carbonate aquifer and the rockslide debris aquifer are supported by isotope results. Seasonal changes in groundwater table level due to recharge and surface losses from seasonal outlet have been correlated with isotopic groundwater composition from the rockslide debris aquifer and the downstream springs; this relationship highlights the role of the rockslide dam body on the hydrodynamics of the studied area. Relationships between surface waters and groundwater in the area have been completely understood on the basis of water isotopic fingerprinting, finally obtaining a complete evaluation of groundwater renewable resources and its regimen. Copyright © 2010 John Wiley & Sons, Ltd.
Creating conductive structures for cell growth: Growth and alignment of myogenic cell types on polythiophenes
Authors: Breukers R. D. , Gilmore K. J. , Kita M. , Wagner K. K. , Higgins M. J. , Moulton S. E. , Clark G. M. , Officer D. L. , Kapsa R. M. I. , Wallace G. G. 
Published: July 2010

AbstractConducting polymers provide suitable substrates for the in vitro study of excitable cells, including skeletal muscle cells, due to their inherent conductivity and electroactivity. The thiophene family of conducting polymers offers unique flexibility for tailoring of polymer properties as a result of the ease of functionalization of the parent monomer. This article describes the preparation of films and electrospun fibers from an ester‐functionalized organic solvent‐soluble polythiophene (poly‐octanoic acid 2‐thiophen‐3‐yl‐ethyl ester) and details the changes in properties that result from post‐polymerization hydrolysis of the ester linkage. The polymer films supported the proliferation and differentiation of both primary and transformed skeletal muscle myoblasts. In addition, aligned electrospun fibers formed from the polymers provided scaffolds for the guided differentiation of linearly aligned primary myotubes, suggesting their suitability as three‐dimensional substrates for the in vitro engineering of skeletal muscle tissue. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.
Identifying and reducing error in cluster‐expansion approximations of protein energies
Authors: Hahn Seungsoo , Ashenberg Orr , Grigoryan Gevorg , Keating Amy E. 
Published: July 2010

AbstractProtein design involves searching a vast space for sequences that are compatible with a defined structure. This can pose significant computational challenges. Cluster expansion is a technique that can accelerate the evaluation of protein energies by generating a simple functional relationship between sequence and energy. The method consists of several steps. First, for a given protein structure, a training set of sequences with known energies is generated. Next, this training set is used to expand energy as a function of clusters consisting of single residues, residue pairs, and higher order terms, if required. The accuracy of the sequence‐based expansion is monitored and improved using cross‐validation testing and iterative inclusion of additional clusters. As a trade‐off for evaluation speed, the cluster‐expansion approximation causes prediction errors, which can be reduced by including more training sequences, including higher order terms in the expansion, and/or reducing the sequence space described by thecluster expansion. This article analyzes the sources of error and introduces a method whereby accuracy can be improved by judiciously reducing the described sequence space. The method is applied to describe the sequence–stability relationship for several protein structures: coiled‐coil dimers and trimers, a PDZ domain, and T4 lysozyme as examples with computationally derived energies, and SH3 domains in amphiphysin‐1 and endophilin‐1 as examples where the expanded pseudo‐energies are obtained from experiments. Our open‐source software package Cluster Expansion Version 1.0 allows users to expand their own energy function of interest and thereby apply cluster expansion to custom problems in protein design. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010
Operational stability of cutinase in organic solvent system: model esterification of alkyl esters
Authors: de Barros Dragana P. C. , Fernandes Pedro , Cabral Joaquim M. S. , Fonseca Luís P. 
Published: July 2010

AbstractBACKGROUND: The present work aims to gain further insight on the use of Fusarium solani pisi cutinase from a Saccharomyces cerevisiae strain for the synthesis of short chain ethyl esters, a group of important fruit flavor compounds, in a non‐conventional environment. Synthesis is promoted by cutinase in organic media, in particular, in iso‐octane, an organic solvent recognized as a safe ingredient in food and beverage industrial processes.RESULTS: The effect of solvent and substrate components of the reaction mixture on the enzyme stability was measured separately. Focus was given to the effect of reaction medium on the operational stability of cutinase and on the esterification yield after 24h. The feasibility of the operation in fed batch mode was successfully evaluated. The effect of the addition of substrate in consecutive pulses in the activity and stability of the biocatalyst was again assessed.CONCLUSIONS: The bioconversion system used in this work allowed for the sustained production of short chain alkyl esters for more than 45 days, which is suggestive of the stability of cutinase in the organic environment evaluated. Copyright © 2010 Society of Chemical Industry
The measurement of ionic activities in solution with electrodes containing ion‐exchange‐resin membranes
Authors: Kressman T. R. E. 
Published: July 2010

AbstractIt is shown that an electrode made from a membrane (actually a short length of 2‐mm.‐diameter rod) of a cation‐exchange resin of the sulphonated‐phenol type and containing a reference electrolyte of fixed concentration, gives steady and reproducible e.m.f. values when immersed in solutions of the same electrolyte of other concentrations. Between certain limits of concentration, different for every electrolyte, the e.m.f. values are those predicted by the Nernst equation when the activity functions are put equal to the mean ionic activities of cation and anion in the electrolyte solution.The upper limit of conformity with the Nernst equation is determined, at least qualitatively, by the ratio of the mobilities of cation and anion within the resin phase, as predicted by the Meyer & Sievers and the Teorell equations. With some limitations the electrode can be used to measure unknown ionic activities in solution in a manner similar to that of the glass electrode, and the activity coefficients of potassium ferrocyanide in solutions of 0·02–0·001M are measured in this way.Unlike the glass electrode for the hydrogen ion, the resin electrode is not specific for any one ion, and measurements with solutions containing two cationic species show the effect of the contributions from both species to the total e.m.f.
The correlation of the mechanical properties and petrography of a series of quartz‐dolerite roadstones
Authors: Sabine P. A. , Morey June E. , Shergold F. A. 
Published: July 2010

AbstractFifty‐five samples of British rocks of restricted petrological type, namely quartz‐dolerite, were examined petrographically and by mechanical testing. No general correlation was found between mineral content or grain‐size and test results. Considerable correlation exists, however, between the test values and geological occurrence; the specimens from the Whin Sill generally yield test results superior to those from Scottish Permo‐Carboniferous sills, whereas samples from Scottish dykes of Permo‐Carboniferous and Tertiary age respectively form intermediate groups.
Factors limiting general application of the Mackey test for spontaneous heating and ignition
Authors: Bowes P. C. 
Published: July 2010

AbstractThe Mackey test has been considered from the point of view of its suitability as a general method for assessing the spontaneous heating and ignition hazards of materials that are subject to atmospheric oxidation at ordinary temperatures.An experimental study has shown that there is an optimum packing density for self‐heating in specimens of oiled fibre in the Mackey tester.It is considered that the test may, to a limited extent, be adapted to give an indication of relative hazard for a wider range of materials than the textile oils for which it was originally designed. But materials must be compared under the optimum test conditions for spontaneous heating in each, and the extent of the investigation involved in satisfying this requirement reduces the practical value of such an application of the test. Nevertheless the test is of value in that it can be expected to show whether spontaneous heating is at all possible in any solid material.
The free energy of formation of the amide bond in polyamides
Authors: Meggy A. B. 
Published: July 2010

AbstractThe degree of polymerization of a polyamide is determined by the equilibrium between carboxyl, amino, and amide groups, and water molecules. Equations are deduced for the relationship between the equilibrium constant k1, the number‐average chain length n and the partial pressure of water. Allowance is made for the presence of a cyclic monomer, whose amount is determined by a second equilibrium constant k2. For monomers capable of forming 8‐membered or larger rings k2 approaches 0, and for those capable of forming 5‐ or 6‐membered rings k2 approaches 1, and no polymer is formed. For 7‐membered rings k2 has such a value that cyclic monomer and polymer can exist together. When the cyclic monomer is not miscible with the polymer, polymer formation is possible from 5‐ and 6‐membered rings, e.g. diketopiperazine (dioxopiperazine), which polymerizes to polyglycine.From data on polymers of <‐caprolactam equations have been deduced giving the relationship between k1 and k2 and the temperature T, and from these the heat of formation Δk, the entropy ΔS, and the free energy ΔF for the polyamide bond in polyaminocaproic acid have been calculated. Assuming that the values for nylon 66 (produced from hexamethylenediamine and adipic acid) are not greatly different, equations are obtained for the chain length n of nylon 66 in terms of the temperature T and the partial pressure of water, and also for n as a function of T in the presence of an aqueous phase.The reaction between carbon dioxide and a diamine is discussed, and it is shown that for the formation of a polymethyleneurea by this reaction k1 is probably much smaller than for the polyamides, so that conditions are less favourable to the formation of high polymers.It is shown that the inability of α‐amino‐acids to polymerize directly is due to the large amount of ionic work that has to be done in adding a single amino‐acid to a peptide chain. Tripeptides and higher peptides should be able to polymerize.A comparison is made between polyesters and polyamides. The formation of the amide group is accompanied by a large increase in entropy, 20–30 cal./mole degree, which is probably due mainly to the release of oriented water molecules held by the charged carboxyl and amino groups. Polyesters are formed by interaction between uncharged groups, so that the increase in entropy will be much smaller, and the conditions less favourable to polymer formation.
Some instruments for quality control in petroleum refineries
Authors: Eltenton G. C. 
Published: July 2010

AbstractBrief descriptions are given of an automatic distillation apparatus for performing Engler distillations, a recording viscometer for oils and grease, a flash‐point recorder, a recording colorimeter, a detector for water in acetone, and a tester for indicating inhomogeneity in blending vessels. The use of such instruments in petroleum refineries illustrates the growing need for faster and more accurate measurement of product quality.