bluuebunny/crossref_metadata_2025_split huggingface dataset:
Parental history of myocardial infarction and risk of heart failure in male physicians
Authors: Djoussé L. , Gaziano J. M. 
Published: November 2008

AbstractBackground  Although heart failure (HF) remains a major public health issue, limited data are available on the utility of parental information on the risk of HF in offspring.Materials and methods  We prospectively examined the association between parental history of myocardial infarction (MI) and incident HF among 20 187 offspring in the Physicians’ Health Study I. Parental history and age at MI was assessed by a questionnaire and a Cox regression was used to estimate relative risks of HF.Results  After an average follow‐up of 19·6 years, 1036 new HF cases were documented. Overall, while a history of early parental MI (before age 55) was associated with a 32% increased risk of HF in offspring compared with subjects whose parent did not have MI, parental MI at older ages was not associated with HF risk. However, the relation between parental history of MI and HF was stronger and mainly observed for HF with antecedent MI. Compared with subjects without parental history of MI, multivariable adjusted hazard ratios (95% CI) for HF with antecedent MI were 3·44 (2·15–5·51), 2·24 (1·20–4·21), 1·26 (0·63–2·51), and 1·37 (0·92–2·03) for parental MI occurred at the age of < 55, 55–59, 60–64, and 65 + y, respectively.Conclusions  Our data suggest that parental MI at an early age is a strong and independent predictor of HF with antecedent MI among US male physicians. This information, along with existing tools, may help clinicians identify patients at risk of HF with antecedent MI.
Biocompatibility of haemodialysis membranes determined by gene expression of human leucocytes: a crossover study
Authors: Wilflingseder J. , Perco P. , Kainz A. , Korbély R. , Mayer B. , Oberbauer R. 
Published: November 2008

ABSTRACTBackground  Biocompatibility of haemodialysis membranes is the most important quality criteria to enable long‐term dialysis without major harmful effects. This study sought to evaluate the differences of genomic signatures derived from peripheral blood mononuclear cells (PBMC) in patients undergoing haemodialysis treatment using two different dialyser membranes: one semi‐synthetic and one full‐synthetic membrane.Design  Microarray experiments were conducted in PBMCs of four stable haemodialysis patients before and after dialysis comparing semi‐synthetic (Hemophan® GFS Plus 16) and full‐synthetic (Hemoflow® FX80) dialysis membranes, respectively. Genes differentially expressed when comparing the two different membranes used were analysed in order to elucidate the underlying molecular mechanisms affecting PBMCs in the course of dialysis treatment.Results  One hundred and seventy‐two genes were identified as up‐regulated after treatment with semi‐synthetic membranes when compared to full‐synthetic membranes. These genes could be assigned to processes including immunity and defence, signal transduction, and apoptosis. Dialysis with a full‐synthetic membrane, on the other hand, led to an activation of 72 genes that were mainly involved in cell cycle and cell cycle control.Conclusion  The over‐representation of genes belonging to immunity/defence, signal transduction, and apoptosis as found with semi‐synthetic membranes suggests that full‐synthetic membranes are more biocompatible than semi‐synthetic membranes.
Prostaglandin receptors mediate effects of substances released from ischaemic rat hearts on non‐ischaemic cardiomyocytes
Authors: Birkenmeier K. , Janke I. , Schunck W.‐H. , Trimpert C. , Krieg T. , Landsberger M. , Völker U. , Felix S. B. , Staudt A. 
Published: November 2008

AbstractBackground After ischaemia and during reperfusion, rat hearts release cardiodepressive substances that are putatively cyclooxygenase‐2‐dependent. The present study analyses the mechanisms by which these substances mediate their effect downstream of cyclooxygenase‐2.Materials and methods After 10 min of global stop‐flow ischaemia, isolated rat hearts were reperfused and post‐ischaemic coronary effluent was collected over a period of 30 s. Non‐ischaemic effluent collected before ischaemia was used as a control. We investigated the effect of the effluents on cell shortening and Ca++‐metabolism, by application of fluorescence microscopy of field‐stimulated adult rat cardiomyocytes incubated with fura‐2. Cells were pre‐incubated with inhibitors of protein kinase A and C and with antagonists of protein kinase A‐dependent prostaglandin receptors. We examined the expression of prostaglandin receptors in cardiomyocytes by Western blotting.Results In contrast to non‐ischaemic effluent, post‐ischaemic effluent induced reduction of Ca++transient and cell shortening in the cardiomyocytes. In contrast to protein kinase C inhibitor Myr‐PKC [19–27], the protein kinase A inhibitor Rp‐cAMPS completely blocked the effect of post‐ischaemic effluent. Furthermore, we determined a cyclic adenosine monophosphate increase in cardiomyocytes that were pre‐incubated with post‐ischaemic effluent. The antagonist of prostaglandin E‐receptor EP2 AH6809 and the antagonist of receptor subtype EP4 AH23848 attenuated the effect of post‐ischaemic effluent in contrast to other antagonists of prostaglandin D and I receptors, which did not influence the effect. In lysates of adherend cardiomyocytes, expression of prostaglandin D, E and I receptors was detected by Western blotting.Conclusions The effect of post‐ischaemic effluent is mediated by the protein kinase A‐dependent prostaglandin‐receptor subtypes EP2 and EP4 downstream of cyclooxygenase‐2.
Modelling the effects of ageing on Cd, Zn, Ni and Cu solubility in soils using an assemblage model
Authors: Buekers J. , Degryse F. , Maes A. , Smolders E. 
Published: November 2008

SummaryAgeing reactions can reduce trace metal solubility and can explain natural attenuation of contaminated soils. We modelled ageing reactions in soil with an assemblage model that considers slow reactions in Fe‐oxyhydroxides and reversible sorption on organic matter and clay minerals. Metal adsorption kinetics on Fe‐oxyhydroxides was obtained from data with synthetic oxyhydroxides. Metal solubility and isotopic exchangeability data were obtained from 28 soils amended with Ni, Zn, Cu and Cd metal salts and monitored for 850 days. The assemblage model was constructed in WHAM 6.0 and used soil properties and dissolved organic matter as input data. The model was first validated to predict dissolved metal concentrations, based on the concentration of isotopic exchangeable metals. The model overestimated metal solubility without parameter adjustment by mean factors of 4–7, and successful fits were obtained by increasing the specific surface area of Fe‐oxyhydroxides from measured values of synthetic systems to a value of 600 m2 g−1 recommended by other authors. The effect of ageing on the isotopic exchangeable metal fraction was subsequently modelled starting from the predicted fraction of metals present on Fe‐oxyhydroxides immediately after soil spiking. The observed isotopic exchangeable metal fractions of Ni, Zn and Cd agreed reasonably well with predicted values. The model predicts that ageing reactions are more pronounced at higher pH because metal sorption is increasingly directed to oxyhydroxide surfaces with increasing soil pH. Modelling fixation of Cu requires more information on fixation of that metal in organic matter.
Free‐Form estimation of soil hydraulic properties using Wind’s method
Authors: Iden S. C. , Durner W. 
Published: November 2008

SummaryTransient evaporation experiments offer the potential to determine simultaneously the soil hydraulic properties necessary to simulate water flow in unsaturated soils. We present a new algorithm for determining the retention and conductivity curve from evaporation experiments which uses Wind’s method with a free‐form soil water retention function. Our algorithm estimates nodal values of volumetric water content and derives a smooth and monotone retention curve by cubic Hermite interpolation. A multilevel routine increases the number of nodes and their adequate number is identified by a performance criterion which balances goodness of fit, the cross correlation between the estimated water contents and the number of degrees of freedom. We calculate point values of unsaturated hydraulic conductivity by the instantaneous profile method and discard unreliable conductivity estimates by a statistical filter criterion. Results for three synthetic data sets including an uncertainty analysis of the estimated retention curves show that the algorithm is suitable to identify, both correctly and precisely, the soil hydraulic properties. An application to a real data set confirms these results. In order to enable the free‐form functions to be used in numerical flow simulations, we extrapolate the retention function to the dry range and compute a coupled conductivity function based on the Mualem model. Major advantages of the proposed method are the enormous flexibility provided by the free‐form functions, the low level of parameter cross‐correlation in comparison with classic parametric functions, and the possibility of assessing the uncertainty of the retention curve individually in different ranges of pressure head.
The PESERA coarse scale erosion model for Europe. I. – Model rationale and implementation
Authors: Kirkby M. J. , Irvine B. J. , Jones R. J. A. , Govers G. ,   PESERA team
Published: November 2008

SummaryThe principles and theoretical background are presented for a new process‐based model (PESERA) that is designed to estimate long‐term average erosion rates at 1 km resolution and has, to date, been applied to most of Europe. The model is built around a partition of precipitation into components for overland flow (infiltration excess, saturation excess and snowmelt), evapo‐transpiration and changes in soil moisture storage. Transpiration is used to drive a generic plant growth model for biomass, constrained as necessary by land use decisions, primarily on a monthly time step. Leaf fall, with corrections for cropping, grazing, etc., also drives a simple model for soil organic matter. The runoff threshold for infiltration excess overland flow depends dynamically on vegetation cover, organic matter and soil properties, varying over the year. The distribution of daily rainfall totals has been fitted to a Gamma distribution for each month, and drives overland flow and sediment transport (proportional to the sum of overland flow squared) by summing over this distribution. Total erosion is driven by erodibility, derived from soil properties, squared overland flow discharge and gradient; it is assessed at the slope base to estimate total loss from the land, and delivered to stream channels.
Modified technique to assess the wettability of soil aggregates: comparison with contact angles measured on crushed aggregates and bulk soil
Authors: Goebel M.‐O. , Bachmann J. , Woche S. K. 
Published: November 2008

SummaryWettability parameters determined for individual soils often show a considerable variation depending on the kind of sample (aggregated or homogeneous material) and the method used. To investigate the causes of this variation, we assessed wettability of both intact and crushed aggregates and bulk soil using different methods. Wettability of intact aggregates was characterized by a modified technique where the specific infiltration rates of water and a completely wetting liquid were used to define a repellency index. Contact angles were determined on crushed aggregates and bulk soil using the Wilhelmy plate and capillary rise methods. The repellency index was found to be sensitive to slight differences in wettability and was in good agreement with Wilhelmy plate contact angles. Contact angles measured with the capillary rise method showed a strong deviation from those determined with the Wilhelmy plate method. This can be ascribed to the underlying assumptions of the capillary rise method (i.e. cylindrical and parallel capillaries) resulting in an over‐estimation of contact angle, particularly for the small‐sized particle fraction because of the impact of inertia and pore structure. No significant differences were found between intact and crushed aggregates whereas the bulk soil was slightly more water‐repellent, probably because of a somewhat larger organic carbon content. We conclude that the contact angle determined by the Wilhelmy plate method and the repellency index are appropriate parameters for characterizing soil water repellency because they detected small changes in wettability over a wide range extending from subcritical water repellency to hydrophobicity.
Effect of organic amendment on amount and chemical characteristics of humic acids in upland field soils
Authors: Kawasaki S. , Maie N. , Kitamura S. , Watanabe A. 
Published: November 2008

SummaryTo assess the effect of continuous organic material (OM) application on soil humic acids, the amount and chemical characteristics of humic acids in various types of soils (n = 10) were compared between plots treated with farmyard manure (FYM) or rice straw compost (RSC) plus chemical fertilizer (CF) and plots treated with CF alone. The degree of humification (degree of darkening), molecular size distribution and 13C cross polarization/magic angle spinning nuclear magnetic resonance spectra of humic acids from CF‐treated soils showed wide variation among the soils. Humic acid content was generally larger in OM + CF soils than in corresponding CF soils, and the stable C isotopic ratio suggested partial replacement of indigenous humic acids with OM‐derived ones even where no apparent increase in humic acid content was observed. The rate of OM application and the indigenous humic acid content were related positively and negatively, respectively, to the apparent accumulation rate of humic acids among soils. The degree of humification of humic acids was generally smaller in OM + CF soils than in CF soils. Humic acids extracted from FYM and RSC exhibited chemical characteristics typical of humic acids having a smaller degree of humification, which suggested the contribution of OM‐derived humic acids to the differences between OM + CF and CF soil humic acids, such as larger average molecular sizes and smaller and larger proportions of aromatic C and O‐alkyl C, respectively, relative to total C in the OM + CF soil humic acids. Little change was observed in the chemical characteristics of humic acids when the degree of humification of indigenous humic acids was small. The effect of OM application on the chemical characteristics of humic acids was most conspicuous in soils containing humic acids having an intermediate degree of humification, possibly resulting from the combination of accelerated degradation of indigenous humic acids and the accumulation of OM‐derived humic acids.
The UV‐absorbance of dissolved organic matter predicts the fivefold variation in its affinity for mobilizing Cu in an agricultural soil horizon
Authors: Amery F. , Degryse F. , Cheyns K. , De Troyer I. , Mertens J. , Merckx R. , Smolders E. 
Published: November 2008

SummaryIt is well established that dissolved organic matter (DOM) mobilizes copper (Cu) in soils but it is unknown to what extent variable DOM quality affects this. During a 5 month period, 250 leachates of an uncontaminated agricultural soil were sampled at 45 cm depth using passive capillary wick samplers. The dissolved Cu and organic carbon (DOC) concentrations varied sevenfold and were weakly correlated (r = 0.56). The [Cu] : [DOC] ratio varied fivefold and exhibited a significant positive correlation (r = 0.77) with the specific UV‐absorbance of DOM at 254 nm (SUVA), indicating that the more aromatic DOM had higher Cu affinity. The dissolved Cu concentrations were predicted by an assemblage model in WHAM6 using the composition of the solid phase above the wick samplers and that of the solution, including DOC. The predicted [Cu] : [DOC] ratio was almost constant when assuming default DOM properties with 65% of all DOM active as fulvic acid (%AFA). The %AFA was subsequently varied proportionally to the SUVA of DOM and using the SUVA of pure FA (SUVAFA) as a fitting parameter. In that case, the variation in the predicted [Cu] : [DOC] ratio was much larger and the predicted Cu concentrations were within a factor of 1.4 of the measured values for 90% of the samples. The fitted SUVAFA was 38 l g−1 cm−1, in excellent agreement with that of Suwannee River FA (SUVAFA = 37 l g−1 cm−1). It is concluded that the DOM quality, e.g. the aromaticity, should be taken into account when estimating Cu mobility in soils.
Long‐term carbon loss and CO2‐C release of drained peatland soils in northeast Germany
Authors: Kluge B. , Wessolek G. , Facklam M. , Lorenz M. , Schwärzel K. 
Published: November 2008

SummaryPeatlands are common in many parts of the world. Draining and other changes in the use of peatlands increase atmospheric CO2 concentration. If we are to make reliable quantitative predictions of that effect, we need good information on the CO2 emission rates from peatlands. The present study uses two different methods for predicting CO2‐C release of peatland soils: (i) a 40‐year field investigation of balancing organic carbon stocks and (ii) short‐term CO2‐C release rates from laboratory experiments. To estimate long‐term losses of peat, and its resulting C input to the atmosphere, we combined highly detailed maps of surface topography and its changes, and the organic C contents and bulk densities of a drained peatland from different years. Short‐term CO2‐C release rates were measured in the laboratory by incubating soil samples from several soil horizons at various temperatures and soil moistures. We then derived nonlinear CO2‐C production functions, which we incorporated into a numerical simulation model (HYDRUS). Using HYDRUS, we calculated daily soil water components and CO2‐release for (i) real‐climate data from 1950 to 2003 and (ii) a climate scenario extending to 2050, including an increase in temperature of 2°C and 20% less rainfall during the summer half year, i.e. from April to September inclusive. From our field measurements, we found a mean annual decrease of 0.7 cm in the thickness of the peat. Large losses (> 1.5 cm year−1) occurred only during periods when groundwater levels were low (i.e. a deep water‐table). The annual CO2‐C release results in a mean loss from the peat of about 700 g CO2‐C m−2, mostly as a direct contribution to the atmosphere. Both methods produced very similar results. The model scenarios demonstrated that CO2‐C loss is mainly controlled by the groundwater (i.e. water‐table) depth, which controls subsurface aeration. A local climate scenario estimated a c. 5% increase of CO2‐C losses within the next 50 years.
Fine‐scale genetic structure of Atlantic salmon (Salmo salar) using microsatellite markers: effects of restocking and natural recolonization
Authors: GRANDJEAN FRÉDÉRIC , VERNE SEBASTIEN , CHERBONNEL CORINNE , RICHARD ARNAUD 
Published: November 2008

Summary1. An important goal of conservation biology is to preserve the evolutionary potential of a species by maintaining natural levels of genetic diversity. Here, we assess the population differentiation in the Atlantic salmon, Salmo salar, listed in Annex II of the European Habitats Directive, to provide valuable information for its conservation in Normandy (France).2. Samples collected from 10 natural sites revealed that 13 of 14 microsatellite loci were polymorphic. Significant differentiation among populations was detected (FST = 0.054, P < 0.001), and all FST pairwise comparisons except one were significant. A genetic split was observed between populations inhabiting streams with limestone geology compared to those inhabiting streams with siliceous geology, which could reflect adaptative differences.3. Hatchery stocks used for the restocking of two rivers were genetically distinct from native stocks.4. Analysis of three stream habitats restored in 1995 showed that all were recolonized naturally by wild salmon from geographically close populations and no founder effects were detected. Allelic richness was similar between recolonized and wild populations.5. From a management perspective, our study revealed that restoration of habitat is very effective to recreate new populations in rivers from which salmon have disappeared and that natural recolonization can be fast and effective in terms of genetic diversity.
Trophic relationships in a tropical stream food web assessed by stable isotope analysis
Authors: COAT SOPHIE , MONTI DOMINIQUE , BOUCHON CLAUDE , LEPOINT GILLES 
Published: November 2008

Summary1. Stable isotope analysis, coupled with dietary data from the literature, was used to investigate trophic patterns of freshwater fauna in a tropical stream food web (Guadeloupe, French West Indies).2. Primary producers (biofilm, algae and plant detritus of terrestrial origin) showed distinct δ13C signatures, which allowed for a powerful discrimination of carbon sources. Both autochthonous (13C‐enriched signatures) and allochthonous (13C‐depleted signatures) resources enter the food web. The migrating behaviour of fishes and shrimps between marine and freshwater during their life cycles can be followed by carbon isotopes. Here, shrimp δ13C signatures were shown to shift from −16‰ (for juveniles under marine influence) to −24.7‰ (for adults in freshwater habitats). For resident species, δ13C values partly reflected the species’ habitat preferences along the river continuum: species living in river mouths were 13C‐enriched in comparison with those collected upstream.3. Nitrogen isotopic ratios were also discriminating and defined three main trophic guilds among consumers. The δ15N values of herbivores/detritivores were 5.0–8.4‰, omnivores 8.8–10.2‰ and carnivores 11–12.7‰.4. Mixing model equations were employed to calculate the possible range of contribution made by respective food sources to the diet of each species. The results revealed the importance of omnivorous species and the dependence of riverine biota on terrestrial subsidies, such as leaf detritus and fruits. Finally, the abundance of shrimps and their feeding habits placed in relief their key role in tropical freshwater food webs. Isotopic analysis provides a useful tool for assessing animal feeding patterns.