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Different Systems (different + system)
Terms modified by Different Systems Selected AbstractsCorrelations among Extinction Risks Assessed by Different Systems of Threatened Species CategorizationCONSERVATION BIOLOGY, Issue 6 2004JULIAN J. O'GRADY análisis de viabilidad poblacional; categorías de amenaza; especies en peligro; riesgo de extinción Abstract:,Many different systems are used to assess levels of threat faced by species. Prominent ones are those used by the World Conservation Union, NatureServe, and the Florida Game and Freshwater Fish Commission (now the Florida Fish and Wildlife Conservation Commission). These systems assign taxa a threat ranking by assessing their demographic and ecological characteristics. These threat rankings support the legislative protection of species and guide the placement of conservation programs in order of priority. It is not known, however, whether these assessment systems rank species in a similar order. To resolve this issue, we assessed 55 mainly vertebrate taxa with widely differing life histories under each of these systems and determined the rank correlations among them. Moderate, significant positive correlations were seen among the threat rankings provided by the three systems (correlations 0.58,0.69). Further, the threat rankings for taxa obtained using these systems were significantly correlated to their rankings based on predicted probability of extinction within 100 years as determined by population viability analysis (correlations 0.28,0.37). The different categorization systems, then, yield related but not identical threat rankings, and these rankings are associated with predicted extinction risk. Resumen:,Se utilizan muchos sistemas diferentes para evaluar los niveles de amenaza que enfrentan las especies. Son prominentes los utilizados por World Conservation Union, NatureServe Heritage y Florida Game and Freshwater Fish Commission (ahora Florida Fish and Wildlife Conservation Commission). Estos sistemas asignan una categoría de amenaza a los taxa mediante la evaluación de sus características demográficas y ecológicas. Estas categorías de amenaza sustentan a la protección legislativa de especies y guían la definición de prioridades en programas de conservación. Sin embargo, se desconoce si estos sistemas de evaluación categorizan a las especies en orden similar. Para resolver este tema, evaluamos 55 taxa, principalmente de vertebrados, con historias de vidas muy diferentes con cada uno de estos sistemas y determinamos las correlaciones entre las categorías. Hubo correlaciones positivas moderadas entre las categorías de amenaza proporcionadas por los tres sistemas (correlaciones 0.58-0.69). Más aun, las categorías de amenaza proporcionados por estos sistemas estuvieron correlacionadas significativamente con las categorías definidas con base en la probabilidad de extinción pronosticada en 100 años determinada por análisis de viabilidad poblacional (correlaciones 0.28-0.37). Por lo tanto, los diferentes sistemas de categorización están proporcionando categorías de amenazas relacionadas pero no idénticas, y estas categorías están relacionadas con el riesgo de extinción pronosticado. [source] Fabry Disease: Treatment and diagnosisIUBMB LIFE, Issue 11 2009Paula A. Rozenfeld Abstract Fabry disease is an X-linked lysosomal disorder that results from a deficiency of the lysosomal enzyme ,-galactosidase A leading to accumulation of glycolipids, mainly globotriaosylceramide in the cells from different tissues. Classical Fabry disease affects various organs. Clinical manifestations start at early age and include angiokeratoma, acroparesthesia, hypohydrosis, heat/exercise intolerance, gastrointestinal pain, diarrhea, and fever. The main complications of Fabry disease are more prominent after the age of 30 when kidney, heart, and/or cerebrovascular disorders appear. Most of the heterozygous females are symptomatic. Enzyme replacement therapy (ERT) is the only specific treatment for Fabry disease. The beneficial effect of ERT on different organs/systems has been extensively evaluated. Quality of life of patients receiving ERT is improved. Enzyme replacement stabilizes or slows the decline in renal function and reduces left ventricular hypertrophy. Fabry disease may be underdiagnosed because of nonspecific and multiorgan symptoms. Different screening strategies have been carried out in different at-risk populations in order to detect undiagnosed Fabry patients. An increasing knowledge about Fabry disease within the medical community increases the chances of patients to receive a timely diagnosis and, consequently, to access the appropriate therapy. © 2009 IUBMB IUBMB Life, 61(11): 1043,1050, 2009 [source] A 2-year-old child's memory of hospitalization during early infancyINFANT AND CHILD DEVELOPMENT, Issue 6 2008Aletha Solter Abstract A child who had had surgery at 5 months of age, and who had been treated at the time for post-traumatic symptoms (reported in a previous paper by the author), was interviewed 2 years later and almost 3 years later to test for possible verbal recall of his hospitalization. He appeared to have some memories of the experience at 29 months of age, and he was able to superimpose verbal labels onto the preverbal memories. At 40 months of age, however, the memories were no longer verbally accessible. The results are discussed in the context of different theories of encoding, storage, retrieval, and loss of early memories. The findings from this study support other findings indicating that there appears to be some form of long-term memory in place early in life, at least for highly salient, traumatic events. There may be one memory system for traumatic memories, fully functional at birth, and a later developing, different system for neutral memories. It is further hypothesized that there may be a sensitive period around 2,3 years of age for the recall of early traumatic memories, and that verbal recall is more likely to be present in verbally precocious children during that period. Copyright © 2008 John Wiley & Sons, Ltd. [source] Correlations among Extinction Risks Assessed by Different Systems of Threatened Species CategorizationCONSERVATION BIOLOGY, Issue 6 2004JULIAN J. O'GRADY análisis de viabilidad poblacional; categorías de amenaza; especies en peligro; riesgo de extinción Abstract:,Many different systems are used to assess levels of threat faced by species. Prominent ones are those used by the World Conservation Union, NatureServe, and the Florida Game and Freshwater Fish Commission (now the Florida Fish and Wildlife Conservation Commission). These systems assign taxa a threat ranking by assessing their demographic and ecological characteristics. These threat rankings support the legislative protection of species and guide the placement of conservation programs in order of priority. It is not known, however, whether these assessment systems rank species in a similar order. To resolve this issue, we assessed 55 mainly vertebrate taxa with widely differing life histories under each of these systems and determined the rank correlations among them. Moderate, significant positive correlations were seen among the threat rankings provided by the three systems (correlations 0.58,0.69). Further, the threat rankings for taxa obtained using these systems were significantly correlated to their rankings based on predicted probability of extinction within 100 years as determined by population viability analysis (correlations 0.28,0.37). The different categorization systems, then, yield related but not identical threat rankings, and these rankings are associated with predicted extinction risk. Resumen:,Se utilizan muchos sistemas diferentes para evaluar los niveles de amenaza que enfrentan las especies. Son prominentes los utilizados por World Conservation Union, NatureServe Heritage y Florida Game and Freshwater Fish Commission (ahora Florida Fish and Wildlife Conservation Commission). Estos sistemas asignan una categoría de amenaza a los taxa mediante la evaluación de sus características demográficas y ecológicas. Estas categorías de amenaza sustentan a la protección legislativa de especies y guían la definición de prioridades en programas de conservación. Sin embargo, se desconoce si estos sistemas de evaluación categorizan a las especies en orden similar. Para resolver este tema, evaluamos 55 taxa, principalmente de vertebrados, con historias de vidas muy diferentes con cada uno de estos sistemas y determinamos las correlaciones entre las categorías. Hubo correlaciones positivas moderadas entre las categorías de amenaza proporcionadas por los tres sistemas (correlaciones 0.58-0.69). Más aun, las categorías de amenaza proporcionados por estos sistemas estuvieron correlacionadas significativamente con las categorías definidas con base en la probabilidad de extinción pronosticada en 100 años determinada por análisis de viabilidad poblacional (correlaciones 0.28-0.37). Por lo tanto, los diferentes sistemas de categorización están proporcionando categorías de amenazas relacionadas pero no idénticas, y estas categorías están relacionadas con el riesgo de extinción pronosticado. [source] Defining Political Community and Rights to Natural Resources in BotswanaDEVELOPMENT AND CHANGE, Issue 2 2009Amy R. Poteete ABSTRACT Community-Based Natural Resource Management (CBNRM), once presented as the best way to protect common pool natural resources, now attracts a growing chorus of critiques that either question its underlying assumptions or emphasize problems related to institutional design. These critiques overlook connections between the definition of rights to natural resources and membership in political communities. The potential for competing definitions of political identity and rights across natural resources arises when property rights regimes differ across natural resources and these different systems of rights appeal to alternative definitions of community. In Botswana, the entangling of natural resource policy with identity politics contributed to a partial recentralization of CBNRM in 2007. [source] A cross-system synthesis of consumer and nutrient resource control on producer biomassECOLOGY LETTERS, Issue 7 2008Daniel S. Gruner Abstract Nutrient availability and herbivory control the biomass of primary producer communities to varying degrees across ecosystems. Ecological theory, individual experiments in many different systems, and system-specific quantitative reviews have suggested that (i) bottom,up control is pervasive but top,down control is more influential in aquatic habitats relative to terrestrial systems and (ii) bottom,up and top,down forces are interdependent, with statistical interactions that synergize or dampen relative influences on producer biomass. We used simple dynamic models to review ecological mechanisms that generate independent vs. interactive responses of community-level biomass. We calibrated these mechanistic predictions with the metrics of factorial meta-analysis and tested their prevalence across freshwater, marine and terrestrial ecosystems with a comprehensive meta-analysis of 191 factorial manipulations of herbivores and nutrients. Our analysis showed that producer community biomass increased with fertilization across all systems, although increases were greatest in freshwater habitats. Herbivore removal generally increased producer biomass in both freshwater and marine systems, but effects were inconsistent on land. With the exception of marine temperate rocky reef systems that showed positive synergism of nutrient enrichment and herbivore removal, experimental studies showed limited support for statistical interactions between nutrient and herbivory treatments on producer biomass. Top,down control of herbivores, compensatory behaviour of multiple herbivore guilds, spatial and temporal heterogeneity of interactions, and herbivore-mediated nutrient recycling may lower the probability of consistent interactive effects on producer biomass. Continuing studies should expand the temporal and spatial scales of experiments, particularly in understudied terrestrial systems; broaden factorial designs to manipulate independently multiple producer resources (e.g. nitrogen, phosphorus, light), multiple herbivore taxa or guilds (e.g. vertebrates and invertebrates) and multiple trophic levels; and , in addition to measuring producer biomass , assess the responses of species diversity, community composition and nutrient status. [source] Determination of enantiomeric purity of a novel COX-2 anti-inflammatory drug by capillary electrophoresis using single and dual cyclodextrin systemsELECTROPHORESIS, Issue 9 2003Carlos Pérez-Maseda Abstract E-6087 is the most advanced compound among the cyclooxygenase-2 (COX-2) inhibitor drugs developed in our company. Its activity is mainly associated with the S(,)-enantiomer (E-6232), whereas the R(,)-enantiomer (E-6231) becomes an impurity whose content should be determined. Five main impurities and degradation products of E-6232 have been found (E-6144, E-6024, E-6072, E-6397 and E-6132), and some of them co-elute with the distomer when using a chiral high-performance liquid chromatography (HPLC) method. Consequently, we have optimized the separation of all the impurities from the two enantiomers of E-6087 by capillary electrophoresis (CE), in order to use the method for the enantiomeric purity determination of E-6232. The effect of the methanol (MeOH) content in the background electrolyte (BGE), the sulfobutyl ether-,-cyclodextrin (SBE-,-CD) and heptakis-(2,6-di- O -methyl)-,-cyclodextrin (DM-,-CD) concentration, and the capillary temperature have been studied. Separation of all compounds could be achieved in different systems, either in a single CD-system (with SBE-,-CD) or in a dual CD-system (with DM-,-CD as a neutral CD). By using the dual CD system a limit of detection (LOD) and a limit of quantitation (LOQ) of 0.03% and 0.1% of distomer, respectively, were achieved*. [source] Development and application of a fatty acid based microbial community structure similarity indexENVIRONMETRICS, Issue 4 2002Alan Werker Abstract This article presents an index of similarity that has application in monitoring relative changes of complex microbial communities for the purpose of understanding the impact of community instability in biological wastewater treatment systems. Gas chromatographic data quantifying microbial fatty acid esters extracted from biosolids samples can be used to infer the occurrence of changes in mixed culture community structure. One approach to rapidly assess the relative dissimilarity between samples is to calculate a similarity index scaled between 0 and 1. The many arbitrary scales that are associated with the available calculation methods for similarity indices limits the extent of application. Therefore, a specialized index of similarity was derived from consideration of the measurement errors associated with the chromatographic data. The resultant calculation method provides a clear mechanism for calibrating the sensitivity of the similarity index, such that inherent measurement variability is accommodated and standardization of scaling is achieved. The similarity index sensitivity was calibrated with respect to an effective gas chromatographic peak coefficient of variation, and this calibration was particularly important for facilitating comparisons made between different systems or experiments. The proposed index of similarity was tested with data acquired from a recently completed study of contaminant removal from pulp mill wastewater. The results suggest that this index can be used as a screening tool to rapidly process microbial fatty acid (MFA) compositional data, with the objective of making preliminary identification of underlying trends in (MFA) community structure, over time or between experimental conditions. Copyright © 2002 John Wiley & Sons, Ltd. [source] Phase Diagrams and Glass Formation in Metallic Systems,ADVANCED ENGINEERING MATERIALS, Issue 6 2007M. Baricco Abstract The basic thermodynamic aspects of glass-formation in metallic systems are reviewed. In particular, the specific features of a phase diagram with respect to glass-formation are evidenced. On the basis of the regular solution model, the effect of various thermodynamic quantities on the free energy difference between undercooled liquid and crystal phases are outlined. In order to describe the amorphous phase, a specific heat difference between liquid and solid phases in the undercooling regime is introduced in the CALPHAD assessment of various binary systems. The glass-transition is described as a second order transition. Examples are given for different systems, including Fe-B and Cu-Mg. From the description of the free energy of various phases as a function of composition and temperature, the driving forces for nucleation of crystal phases and the T0 curves are estimated. [source] Tunable Colors in Opals and Inverse Opal Photonic CrystalsADVANCED FUNCTIONAL MATERIALS, Issue 16 2010Carlos I. Aguirre Abstract Colloidal photonic crystals and materials derived from colloidal crystals can exhibit distinct structural colors that result from incomplete photonic band gaps. Through rational materials design, the colors of such photonic crystals can be tuned reversibly by external physical and chemical stimuli. Such stimuli include solvent and dye infiltration, applied electric or magnetic fields, mechanical deformation, light irradiation, temperature changes, changes in pH, and specific molecular interactions. Reversible color changes result from alterations in lattice spacings, filling fractions, and refractive index of system components. This review article highlights the different systems and mechanisms for achieving tunable color based on opaline materials with close-packed or non-close-packed structural elements and inverse opal photonic crystals. Inorganic and polymeric systems, such as hydrogels, metallopolymers, and elastomers are discussed. [source] Insights into the design of a hybrid system between Anabaena ferredoxin-NADP+ reductase and bovine adrenodoxinFEBS JOURNAL, Issue 4 2003Merche Faro The opportunity to design enzymatic systems is becoming more feasible due to detailed knowledge of the structure of many proteins. As a first step, investigations have aimed to redesign already existing systems, so that they can perform a function different from the one for which they were synthesized. We have investigated the interaction of electron transfer proteins from different systems in order to check the possibility of heterologous reconstitution among members of different chains. Here, it is shown that ferredoxin-NADP+ reductase from Anabaena and adrenodoxin from bovine adrenal glands are able to form optimal complexes for thermodynamically favoured electron transfer reactions. Thus, electron transfer from ferredoxin-NADP+ reductase to adrenodoxin seems to proceed through the formation of at least two different complexes, whereas electron transfer from adrenodoxin to ferredoxin-NADP+ reductase does not take place due because it is a thermodynamically nonfavoured process. Moreover, by using a truncated adrenodoxin form (with decreased reduction potential as compared with the wild-type) ferredoxin-NADP+ reductase is reduced. Finally, these reactions have also been studied using several ferredoxin-NADP+ reductase mutants at positions crucial for interaction with its physiological partner, ferredoxin. The effects observed in their reactions with adrenodoxin do not correlate with those reported for their reactions with ferredoxin. In summary, our data indicate that although electron transfer can be achieved in this hybrid system, the electron transfer processes observed are much slower than within the physiological partners, pointing to a low specificity in the interaction surfaces of the proteins in the hybrid complexes. [source] A polyploid population of Saccharomyces cerevisiae with separate sexes (dioecy)FEMS YEAST RESEARCH, Issue 6 2010Rim Al Safadi Abstract Saccharomyces cerevisiae has proved to be an interesting model for studies of evolution, with whole-genome duplication shown to have played an important role in the evolution of this species. This phenomenon depends on the formation of a transient stable polyploid state. Previous studies have reported polyploidy to be an unstable state in yeast, but here, we describe a polyploid population of S. cerevisiae. The evolution of higher eukaryotes has also involved the development of different systems of sexual reproduction, the choice between self-fertilization and out-crossing becoming a key issue. Saccharomyces cerevisiae is a hermaphrodite eukaryote, despite the theoretical genetic disadvantages of this strategy, in which self-fertilization occurs. We describe, for the first time, a near-dioecious (with separate sexes) population in this species. Mating type and the MAT locus display complex segregations. Essentially, each strain produces, by meiosis, spores of only one mating type: mata or mat,. Moreover, strains are heterothallic, and diploid nonmating clones generated from a single spore do not sporulate. These three properties limit self-fertilization and strongly favour out-crossing. We suggest that the shift in sexual strategy, from hermaphroditism to dioecy, is specific to the brewing process, which overcomes the sexual isolation probably found in natural biotopes. [source] Supramolecular Crystal Engineering at the Solid,Liquid Interface from First Principles: Toward Unraveling the Thermodynamics of 2D Self-AssemblyADVANCED MATERIALS, Issue 13 2009Carlos-Andres Palma Abstract The formation of highly ordered 2D supramolecular architectures self-assembled at the solid,solution interfaces is subject to complex interactions between the analytes, the solvent, and the substrate. These forces have to be mastered in order to regard self-assembly as an effective bottom-up approach for functional-device engineering. At such interfaces, prediction of the thermodynamics governing the formation of spatially ordered 2D arrangements is far from being fully understood, even for the physisorption of a single molecular component on the basal plane of a flat surface. Two recent contributions on controlled polymorphism and nanopattern formation render it possible to gain semi-quantitative insight into the thermodynamics of physisorption at interfaces, paving the way towards 2D supramolecular crystal engineering. Although in these two works different systems have been chosen to tackle such a complex task, authors showed that the chemical design of molecular building blocks is not the only requirement to fulfill when trying to preprogram self-assembled patterns at the solid,liquid interface. [source] Fuzzy controlled central heating systemINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 15 2002Faruk Mendi Abstract In this paper a comparison study was carried out in order to understand how two different systems, classical and fuzzy logic control of central heating affect the economy and comfort of private homes or offices. Also a literature review was done to help decide which one of these systems is more effective. The objective of the fuzzy controller heating system is to estimate the actual heat requirement of the house. It uses a total of five inputs, four of which are derived from energy consumption curve, using conventional digital filtering techniques; the fifth is the average outdoor temperature, whereas, the classical control system burns diesel type fuel in its furnace to heat the water supply (boiler). From the boiler, the hot water is distributed by a pipe system to the individual radiators in the house. Thereby, it is shown that the fuzzy controlled heating system is more effective, also it maximizes the economy and the comfort of the consumer. Copyright © 2002 John Wiley & Sons, Ltd. [source] The public pension system in Taiwan: Equity issues within and between systemsINTERNATIONAL SOCIAL SECURITY REVIEW, Issue 1 2010Ai Ju Shao Abstract This article analyses the challenges facing the New Public Service Pension Fund System in Taiwan, China. After less than two decades of operation, this young system is facing financial imbalance and is embroiled in controversy regarding the generosity of its benefits provisions. The article first introduces Taiwan's different systems for old-age security, with a focus on that for general public-sector employees. It then addresses the financial challenges facing the general public-sector pension system, including the rising cost of its benefits for all taxpayers. Finally, a number of possible reform directions are suggested, including lowering benefit levels, making qualifying criteria more stringent, or establishing a new system. With regards to the latter, any proposed new system must seek to satisfy the goal of longer-term financial soundness while realizing optimal fairness among all stakeholders including taxpayers. [source] Reforming pensions: Principles, analytical errors and policy directionsINTERNATIONAL SOCIAL SECURITY REVIEW, Issue 2 2009Nicholas Barr Abstract This article, sets out a series of principles for pension design rooted in economic theory: pension systems have multiple objectives, analysis should consider the pension system as a whole, analysis should be framed in a second-best context, different systems share risks differently, and systems have different effects by generation and by gender. That discussion is reinforced by identification of a series of widespread analytical errors , errors that appear in World Bank work, but by no means only in World Bank work: tunnel vision, improper use of first-best analysis, improper use of steady-state analysis, incomplete analysis of implicit pension debt, incomplete analysis of the impact of funding (including excessive focus on financial flows, failure to consider how funding is generated, and improper focus on the type of asset in trust funds), and ignoring distributional effects. The second part of the article considers implications for policy: there is no single best pension design, earlier retirement does little or nothing to reduce unemployment, unsustainable pension promises need to be addressed directly, a move from pay-as-you-go towards funding in a mandatory system may or may not be welfare improving, and implementation matters , policy design that exceeds a country's capacity to implement it is bad policy design. We illustrate the ranges of designs of pension systems that fit the fiscal and institutional capacity constraints typical at different levels of economic development. The potential gains from simplicity imply that a country capable of implementing an administratively demanding plan does not necessarily gain from doing so. New Zealand has a simple pension system through choice, not constraint. [source] Influence of fillers on the properties of a phenolic resin cured in acidic mediumJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008J. M. Laza Abstract The curing behavior of a phenolic resol resin in the presence of p -toluensulphonic acid is reported herein. The gel time of different systems has been determined by thermal scanning rheometry. Thermal and mechanical properties of the resin have been modified by the addition of varying amounts of fillers, talc, and kaolin. dynamic mechanical thermal analysis is used to determine the mechanical properties of the systems and the influence of the fillers and the postcuring. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Neurons bearing presenilins: weapons for defense or suicide?JOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 4 2000B.O. Popescu Abstract Apoptotic machinery designed for cell's organized self-destruction involve different systems of proteases which cleave vital proteins and disassemble nuclear and cytoplasmic structures, committing the cell to death. The most studied apoptotic proteolytic system is the caspase family, but calpains and the proteasome could play important roles as well. Alzheimer's disease associated presenilins showed to be a substrate for such proteolytic systems, being processed early in several apoptotic models, and recent data suggest that alternative presenilin fragments could regulate cell survival. Mutations in genes encoding presenilins proved to sensitize neurons to apoptosis by different mechanisms e.g. increased caspase-3 activation, oxyradicals production and calcium signaling dysregulation. Here we review the data involving presenilins in apoptosis and discuss a possible role of presenilins in the regulation of apoptotic biochemical machinery. [source] Removal of anionic pollutants from groundwaters using Alamine 336: chemical equilibrium modellingJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 11 2006Eugenio Bringas Abstract This work reports the study of the chemical equilibrium of the extraction of chromium(VI) anions from groundwaters where other anionic species are present, mainly sulfate and chloride anions, using Alamine 336 as extractant. The analysis was performed working with two different systems: (i) a binary system (sulfate and chloride anions) and, (ii) a tertiary system (chromium, sulfate and chloride anions) with a composition of 9.6,15.4 mol Cr6+ m,3, 5.2,16.7 mol SO42, m,3 and 4.2,13.5 mol Cl, m,3 respectively. A careful experimental design was performed and the data were correlated to the mathematical models obtaining the equilibrium parameters of the extraction reactions in both systems. Copyright © 2006 Society of Chemical Industry [source] Desert shrubs have negative or neutral effects on annuals at two levels of water availability in arid lands of South AustraliaJOURNAL OF ECOLOGY, Issue 6 2008James T. Weedon Abstract 1Perennial plants have been shown to facilitate understorey annual plant species in arid lands through the modification of spatial patterns of resources and conditions. This effect can result from a balance between simultaneously positive and negative interactions, both direct and indirect. This balance may shift with temporal variability in water availability. 2We conducted a field experiment in a chenopod shrubland in South Australia to separate the effects of shade, below-ground competition, and soil modification by shrubs on the performance of annual plants, and to determine if the strength and direction of the interaction shifted with changes in water availability. 3Annual plant diversity and seedling density was highest in plots established in open sites away from the dominant shrubs (Maireana sedifolia). Experimental removal of M. sedifolia increased seedling density compared to plots under undisturbed shrubs and plots where the removed shrub was replaced with artificial shade. Shading of open plots also reduced seedling density. Annual plant biomass was highest in areas where shrubs had been removed and was reduced by artificial shading. Biomass was higher in open plots than under intact shrubs. Experimental water addition did not alter plant density, but increased biomass across all treatments, particularly in artificially shaded bush plots. 4Synthesis. Our results show that the overall effect of shrubs on the annual plant community in the system is negative under the range of water availabilities experienced during the experiment. This negative net-effect results from a combination of simultaneous facilitation via soil modification, and above- and below-ground competition. Assessment in different systems of different combinations of mechanisms that have simultaneously positive and negative effects will allow us to refine hypotheses seeking to explain the relative importance of facilitation across spatial and temporal gradients. [source] Capacity development for agricultural biotechnology in developing countries: an innovation systems view of what it is and how to develop itJOURNAL OF INTERNATIONAL DEVELOPMENT, Issue 5 2005Andy Hall There are divergent views on what capacity development might mean in relation to agricultural biotechnology. The core of this debate is whether this should involve the development of human capital and research infrastructure, or whether it should encompass a wider range of activities which also include developing the capacity to use knowledge productively. This paper uses the innovation systems concept to shed light on this discussion, arguing that it is innovation capacity rather than science and technology capacity that has to be developed. It then presents six examples of different capacity development approaches. It concludes by suggesting that policy needs to take a multidimensional approach to capacity development in line with innovation systems perspective. But it also argues that policy needs to recognise the need to develop the capacity of diversity of innovation systems and that a key part of the capacity development task is to bring about the integration of these different systems at strategic points in time. Copyright © 2005 John Wiley & Sons, Ltd. [source] Evaluation of hepatitis C antibody testing in saliva specimens collected by two different systems in comparison with HCV antibody and HCV rna in serum,JOURNAL OF MEDICAL VIROLOGY, Issue 1 2001G.J.J. van Doornum Abstract Two different ELISA assays, the Ortho HCV 3.0 ELISA (Ortho Diagnostics Systems) and the Mono-Lisa anti-HCV Plus (Sanofi Diagnostics Pasteur) were evaluated for the detection of hepatitis C virus (HCV) antibody in saliva samples. Specimens were collected from 152 individuals who participated in a longitudinal cohort study on HIV infection, and who used illicit drugs. Saliva specimens were collected using two different systems: Salivette (Sarstedt) and Omni-Sal (Saliva Diagnostic Systems). Saliva specimens were tested following modified protocols by both ELISAs, and the results were compared with serum specimens that were tested according to the instructions of the manufacturer. Serum samples of 102 (67%) participants were positive by both assays, and 50 persons were negative for HCV antibody. A total of 99 of the 102 serum specimens were confirmed as positive using Ortho Riba HCV 3.0 (Ortho Diagnostics System) and Deciscan HCV (Sanofi Diagnostics Pasteur), and 3 yielded discrepant results. As no cut-off level is known for testing saliva samples by ELISA, 3 different levels were chosen: mean (M),+,1 standard deviation (SD), M,+,2 SD, and M,+,3 SD of the optical densities of saliva tests of the 50 HCV serum antibody negative persons. At a level of M,+,1 SD and M,+,2 SD the Salivette/Mono-Lisa combination gave the greatest proportion of HCV antibody positive saliva specimens obtained from the 102 HCV serum antibody positive participants, 88% and 79%, respectively. Differences between the various collection systems and assay combinations were not significant statistically. In 76 of the 102 persons with HCV antibodies in serum, HCV RNA was detected in serum. Salivary presence of HCV RNA, however, could not be demonstrated. The results show that the assays compared are unsuitable for diagnostic use, but the sensitivities of the assays are acceptable for use in epidemiological studies. J. Med. Virol. 64:13,20, 2001. © 2001 Wiley-Liss, Inc. [source] Molecular interactions of the neuronal GPI-anchored lipocalin LazarilloJOURNAL OF MOLECULAR RECOGNITION, Issue 5 2008Diego Sanchez Abstract Lazarillo, a glycoprotein involved in axon growth and guidance in the grasshopper embryo, is the only member of the lipocalin family that is attached to the cell surface by a GPI anchor. Recently, the study of Lazarillo homologous genes in Drosophila and mouse has revealed new functions in the regulation of lifespan, stress resistance and neurodegeneration. Here we report an analysis of biochemical properties of Lazarillo to gain insight into the molecular basis of its physiological function. Recombinant forms of the grasshopper protein were expressed in two different systems to test: (1) potential binding of several hydrophobic ligands; (2) protein,protein homophilic interactions; and (3) whether interaction with the function-blocking mAb 10E6 interferes with ligand binding. We tested 10 candidate ligands (retinoic acid, heme, bilirubin, biliverdin, ecdysterone, juvenile hormone, farnesol, arachidonic acid, linoleic acid and palmitic acid), and monitored binding using electrophoretic mobility shift, absorbance spectrum, and fluorimetry assays. Our work indicates binding to heme and retinoic acid, resulting in increased electrophoretic mobility, as well as to fatty acids, resulting in multimerization. Retinoic acid and fatty acids binding were confirmed by fluorescence titration, and heme binding was confirmed with absorbance spectrum assays. We demonstrate that Lazarillo oligomerizes in solution and can form clusters in the plasma membrane when expressed and GPI-anchored to the cell surface, however it is unable to mediate cell,cell adhesion. Finally, by ligand-mAb competition experiments we show that ligand-binding alone cannot be the key factor for Lazarillo to perform its function during axonal growth in the grasshopper embryo. Copyright © 2008 John Wiley & Sons, Ltd. [source] Thermodynamic modeling of hydrotrope solutionsAICHE JOURNAL, Issue 1 2006Mandana Akia Abstract A new model for the excess Gibbs energy of hydrotrope solutions is presented. This model is based on the local composition model by Chen et al. Hydrotropes are usually organic salts that can increase the solubility of organic and inorganic compounds in water. The proposed model has five adjustable parameters; one of them is related to long-range forces, and four of them are related to short-range forces. Long-range forces are modeled by the Pitzer-Debye-Huckel equation. However, in our model, the effect of the molecular solute on the dielectric constant of water has also been considered. Modeling of short-range forces is based on local composition concepts. The model parameters are obtained using experimental data for six hydrotropes with four solutes at different temperatures. The water solubility of molecular solutes in the presence of hydrotropes has been calculated for different systems. Accurate results are obtained. © 2005 American Institute of Chemical Engineers AIChE J, 2006 [source] Alternative drug delivery approaches for the therapy of inflammatory bowel diseaseJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 8 2008Yvette Meissner Abstract This article shall give an overview on drug delivery systems for new therapeutic strategies in the treatment of inflammatory bowel disease. The various features of the different approaches allowing locally restricted drug delivery to the inflamed colon are discussed including the main physiological and pathophysiological limitations for the different systems. Conventional drug delivery systems are tightly adapted from developments for colonic delivery by oral administration triggered by release mechanisms owing to the physiological environment that these systems encounter in the colonic region. The newer developments in this context aim for an increased selectivity of drug delivery by targeting mechanisms which have a closer relation to pathophysiological particularities of the disease. Therefore, we were focused especially on new strategies for such treatment including liposomal formulations, cyclodextrins, micro- or nanoparticles, viral gene therapy approaches, and others. Effective and selective delivery even of an otherwise nonspecifically acting drug could provide new therapeutic pathways in the treatment of inflammatory bowel disease. © 2007 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 97: 2878,2891, 2008 [source] Synthesis and characterization of secondary-amine-functional microparticlesJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 15 2004E. Banu Altinta Abstract Secondary-amine-functional microparticles were prepared in the range of 50,250 ,m through the suspension polymerization of styrene, divinylbenzene (DVB), and 2-(tert -butylamino)ethyl methacrylate (tBAEMA). This study focused on the effects of the DVB, tBAEMA, initiator, and stabilizer concentrations and shaking rate on the experimental amine content, swelling ratio, average particle size, and particle size distribution. The suspension polymerization experiments were carried out in two different systems. In the first system, an organic phase, including the monomers and initiator, was dispersed in an aqueous medium in the presence of Al2(SO4)3. Al2(SO4)3, in the presence of an amine monomer (pH , 10), formed colloidal Al(OH)3, which built a nonsticky layer on the surface of the polymerizing droplets that prevented them from coalescing and aggregating. Individual and spherical particles within the range of 50,200 ,m were obtained by this polymerization method. The second method was similar to the first polymerization protocol, except that a certain amount of sodium dodecyl sulfate was added as a costabilizer in the presence of Al2(SO4)3. In these experiments, individual and spherical particles were obtained within the range of 130,250 ,m. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem: 3708,3719, 2004 [source] Mechanical Properties of Magnetic Attachments for Removable Prostheses on Teeth and ImplantsJOURNAL OF PROSTHODONTICS, Issue 8 2008Arne F. Boeckler DMD Abstract Purpose: Magnetic attachments on teeth and implants may be used to improve stability, support, and retention of removable prostheses. Various forms of magnetic attachments are available, divided according to the design, the mechanical properties of the attachments, and the clinical indication. Recently developed attachment systems are small and promise improved retentive capacity, while existing magnetic attachments continue to be technologically modified and improved. This investigation reviewed and compared maximum retentive forces and characteristic curves for magnetic attachments indicated for use as root anchors and on implants. Materials and Methods: Twenty-four samarium-cobalt (SmCo) and neodym-iron-boron (NeFeB) magnetic attachments (12 tooth- and 12 implant-borne) were evaluated. Specimens were delivered by the manufacturers or fabricated according to their instructions. Five magnet pairs of each product and each combination were tested 10 times in a calibrated universal testing machine using a nonmagnetic test device (s = 40 mm, v = 20 mm/min). Results were recorded electronically and compared to manufacturers' details. Results: Maximum retentive forces for root keepers ranged from 1.4 to 6.6 N. Maximum retentive forces for magnetic attachments on implants ranged from 0.7 to 5.8 N. After a distance of 0.1 mm, a complete reversed distribution of the different systems became obvious. The retentive force provided by the manufacturer was achieved in one implant abutment, with retentive force (as compared to those provided by the manufacturers) for root keepers ranging between 42.5% and 92.9% and for implant abutments between 43.0% and 99.4%. Conclusion: There were differences between magnetic attachments for both the initial retentive capabilities and the characteristic curves. Recently introduced products provided relatively high initial retentive forces despite their small size. The measured retentive forces and the manufacturer's information differed in the majority of magnetic systems evaluated. [source] Recommending change clusters to support software investigation: an empirical studyJOURNAL OF SOFTWARE MAINTENANCE AND EVOLUTION: RESEARCH AND PRACTICE, Issue 3 2010Martin P. Robillard Abstract During software maintenance tasks, developers often spend a valuable amount of effort investigating source code. This effort can be reduced if tools are available to help developers navigate the source code effectively. We studied to what extent developers can benefit from information contained in clusters of change sets to guide their investigation of a software system. We defined change clusters as groups of change sets that have a certain amount of elements in common. Our analysis of 4200 change sets for seven different systems and covering a cumulative time span of over 17 years of development showed that less than one in five tasks overlapped with change clusters. Furthermore, a detailed qualitative analysis of the results revealed that only 13% of the clusters associated with applicable change tasks were likely to be useful. We conclude that change clusters can only support a minority of change tasks, and should only be recommended if it is possible to do so at minimal cost to the developers. Copyright © 2009 John Wiley & Sons, Ltd. [source] The communication of meaning and the structuration of expectations: Giddens' "structuration theory" and Luhmann's "self-organization"JOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 10 2010Loet Leydesdorff The communication of meaning as distinct from (Shannon-type) information is central to Luhmann's social systems theory and Giddens' structuration theory of action. These theories share an emphasis on reflexivity, but focus on meaning along a divide between interhuman communication and intentful action as two different systems of reference. Recombining these two theories into a theory about the structuration of expectations, interactions, organization, and self-organization of intentional communications can be simulated based on algorithms from the computation of anticipatory systems. The self-organizing and organizing layers remain rooted in the double contingency of the human encounter, which provides the variation. Organization and self-organization of communication are reflexive upon and therefore reconstructive of each other. Using mutual information in three dimensions, the imprint of meaning processing in the modeling system on the historical organization of uncertainty in the modeled system can be measured. This is shown empirically in the case of intellectual organization as "structurating" structure in the textual domain of scientific articles. [source] A model for quantitative evaluation of an end-to-end question-answering systemJOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 8 2007Nina Wacholder We describe a procedure for quantitative evaluation of interactive question-answering systems and illustrate it with application to the High-Quality Interactive Question-Answering (HITIQA) system. Our objectives were (a) to design a method to realistically and reliably assess interactive question-answering systems by comparing the quality of reports produced using different systems, (b) to conduct a pilot test of this method, and (c) to perform a formative evaluation of the HITIQA system. Far more important than the specific information gathered from this pilot evaluation is the development of (a) a protocol for evaluating an emerging technology, (b) reusable assessment instruments, and (c) the knowledge gained in conducting the evaluation. We conclude that this method, which uses a surprisingly small number of subjects and does not rely on predetermined relevance judgments, measures the impact of system change on work produced by users. Therefore this method can be used to compare the product of interactive systems that use different underlying technologies. [source] | |||||||||||||||||||||||||||||||||||||