Calibration of the HSPF model with a new coupled FTABLE generation method

The hydrological simulation program FORTRAN (HSPF) is a comprehensive watershed model designed to simulate water quantity and quality processes.It is used widely throughout the world.Calculating discharge from a stream reach by HSPF is based mainly on function tables (FTABLEs),which describe the relationship between surface area,stream stage,volume,and discharge.The traditional method of FTABLE generation (using general stream cross-sections and the Manning equation or other discharge relationships) can be time-consuming and inaccurate when there are limited calibration stations and survey data.Recent insights into generalized coupled stage/storage and stage/discharge relationships,however,offer the potential to improve both the speed and accuracy of compiling FTABLEs and thus HSPF models.This study tested the application of these insights in generating FTABLEs.The study domain included 18 gauging stations in a coastal plain environment on the Peace River watershed in West-Central Florida.In the calibration of this model,wetlands were treated as reaches in HSPF with storage-attenuation characteristics.Over the simulation period,the modeled daily flow and stage correlated well with observed data at all ganging stations along the Peace River.The Nash-Sutcliffe efficiency and correlation coefficient computed using observed and simulated daily flows were 0.90 and 0.91,respectively,at the Peace River outlet.Rigorous testing found that the new system for calibrating the FTABLEs improved the model predictive ability and efficiency.Uncertainty in un-calibrated station performance was also reduced.The model parameters obtained in this study could potentially serve as reference values for model application in similar climatic regions.They may also have particular relevance in disaster management,as the simulation period extended over the hurricane season of 2004,and the model domain was within a high hurricane impact zone.The possible effects of hurricanes on discharge are also briefly discussed.     

Combining multivariate volatility forecasts using weighted losses

The ability to improve out-of-sample forecasting performance by combining forecasts is well established in the literature. This paper advances this literature in the area of multivariate volatility forecasts by developing two combination weighting schemes that exploit volatility persistence to emphasise certain losses within the combination estimation period. A comprehensive empirical analysis of the out-of-sample forecast performance across varying dimensions, loss functions, sub-samples and forecast horizons show that new approaches significantly outperform their counterparts in terms of statistical accuracy. Within the financial applications considered, significant benefits from combination forecasts relative to the individual candidate models are observed. Although the more sophisticated combination approaches consistently rank higher relative to the equally weighted approach, their performance is statistically indistinguishable given the relatively low power of these loss functions. Finally, within the applications, further analysis highlights how combination forecasts dramatically reduce the variability in the parameter of interest, namely the portfolio weight or beta.     

Phospholipid flippases attenuate LPS-induced TLR4 signaling by mediating endocytic retrieval of Toll-like receptor 4

P4-ATPases are lipid flippases that catalyze the transport of phospholipids to create membrane phospholipid asymmetry and to initiate the biogenesis of transport vesicles. Here we show, for the first time, that lipid flippases are essential to dampen the inflammatory response and to mediate the endotoxin-induced endocytic retrieval of Toll-like receptor 4 (TLR4) in human macrophages. Depletion of CDC50A, the β-subunit that is crucial for the activity of multiple P4-ATPases, resulted in endotoxin-induced hypersecretion of proinflammatory cytokines, enhanced MAP kinase signaling and constitutive NF-κB activation. In addition, CDC50A-depleted THP-1 macrophages displayed reduced tolerance to endotoxin. Moreover, endotoxin-induced internalization of TLR4 was strongly reduced and coincided with impaired endosomal MyD88-independent signaling. The phenotype of CDC50A-depleted cells was also induced by separate knockdown of two P4-ATPases, namely ATP8B1 and ATP11A. We conclude that lipid flippases are novel elements of the innate immune response that are essential to attenuate the inflammatory response, possibly by mediating endotoxin-induced internalization of TLR4.     

Review

In this paper we study some methodological problems associated with the development of one of the major theories in low temperature physics, that of superconductivity. The first experimental results of 1911 were interpreted within a framework that hindered the paradoxical aspects of the new phenomenon. Various research programmes degenerated until new experimental results forced a reappraisal of the existing theoretical framework making possible a different formulation of the problem that had to be solved. This led to a progressive research programme, whose positive heuristic we also study.     

Sir William Hamilton (1730–1803): His work and influence in geology

In the formative period of London's scientific instrument industry membership of a guild was a necessary step towards owning a business in the City. Through the guilds' formal system of apprenticeship, boys received first-class training in a skilled trade, and learned essential marketing and managerial techniques. By analysing the guilds' records of apprenticeship and subsequent guild life it is possible to determine chains of masters and apprentices by which the knowledge passed from generation to generation. At the same time, dates can be established for the training and subsequent working life of many known makers. The chains of knowledge reveal new and often important masters who were previously unknown because, by chance, their instruments or advertisements have not survived to the present day. Two guilds have been used to illustrate the chains: Broderers' Company and Joiners' Company.     

Applicability of the universal soil loss equation for southeastern Idaho wildlands

Soil physical and chemical properties were studied to identify habitat differences among 15 sagebrush dominated plant community types of the Great Basin. The sagebrush taxa studied followed an apparent gradient of increasing soil fertility, with Artemisia nova commonly occupying the lowest fertility sites. Sites of moderate soil fertility tended to support A. arbuscula , A. longiloba , and A. tridentata ssp. Wyomingensis . Artemisia tridentata ssp. Tridentata and A. tridentata ssp. Vaseyana were commonly found on sites with the highest soil fertility levels as indicated by maximum organic carbon, nitrogen, and phosphorus levels within such soils. Mollic epipedon depth, total depth, and water-holding capacity of the soil also increased as the dominant sagebrush taxon of a community type changed from A. nova to A. tridentata ssp. Vaseyana . Data from this study provide information concerning soil relationships within relatively undisturbed rangeland communities. Such data are required if future soil sampling efforts within the Great Basin are to have a basis for comparison.     

Fall diet of blue grouse in Oregon

The early fall diet of Oregon blue grouse ( Dendragapus obscurus pallidus ) from Wallowa County, Oregon, was determined from 145 crops obtained during 1981 and 1982. Of more than 50 plant and animal foods in the diet, short-horned grasshoppers ( Acrididae ), prickly lettuce ( Lactuca serriola ), yellow salsify ( Tragopogon dubius ), wild buck-wheat ( Eriogonum spp.), and snowberry ( Symphoricarpos albus ) occurred in 30% or more of the crops and collectively amounted to 68% of the diet by weight. Seven of the 12 most common foods were consumed differentially by the four sex and age classes of birds. Results indicated that blue grouse foraged in forest and grassland habitats.     

Effects of watershed alteration on the brook trout population of a small Black Hills stream

The impacts of adjacent landscaping activity and livestock presence on the brook trout ( Salvelinus fontinalis ) population of a small Black Hills stream were evaluated. Moderate changes in temperature, turbidity, and fecal coliform numbers did not influence brook trout densities. Stream morphometry, particularly factors affecting stream cover, appeared to have the greatest impact on numbers of trout. Brook trout were poor indicators of moderate changes in water quality, but they were adequate indicators of the physical perturbations within the stream.