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Size Effects (size + effects)
Kinds of Size Effects Selected AbstractsBEQUEST RECEIPT AND FAMILY SIZE EFFECTSECONOMIC INQUIRY, Issue 1 2010NATHAN D. GRAWE This article tests the connection between credit constraints and negative family size effects on child earnings using bequest receipt to signal access to credit markets. The dominant economic model of fertility predicts a negative relationship between family size and child achievement. In the model, limits on borrowing create this "quality-quantity trade-off." This article tests for the relevance of credit constraints using Panel Study of Income Dynamics data to compare family size effects across groups defined by bequest receipt. Contrary to the credit constraints explanation, those receiving large bequests exhibit large family size effects, while those not receiving bequests show little to no effect. (JEL J13, D1, I2) [source] On a Proper Account of First- and Second-Order Size Effects in Crystal Plasticity,ADVANCED ENGINEERING MATERIALS, Issue 3 2009Marc G. D. Geers This paper addresses engineering size effects in miniaturized metallic components. First, the critical role of processing induced size effects is emphasized. Next, the need for a rigorous strain gradient enrichment in crystal plasticity modelling is advocated, directly resulting from the coarse graining of discrete dislocation interactions. The physical origin of the energetic enrichment is discussed and its deterministic derivation is briefly confronted with analogous statistical mechanics results. [source] Size Effects on Silica PolymorphismJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 10 2002Sheng-Wei Wu In this study, we found that the polymorphism and sintering behavior of silica can be affected by the size of starting particles. The formation of the stable tridymite phase, which is metastable unless a flux or mineralizer is present, is achieved with sintering of very fine silica particles of about 10 nm without the presence of a flux or mineralizer. Cristobalite phase is obtained as an intermediate as the amorphous phase transforms into the stable tridymite phase. [source] Research on Advanced Materials for Li-ion BatteriesADVANCED MATERIALS, Issue 45 2009Hong Li Abstract In order to address power and energy demands of mobile electronics and electric cars, Li-ion technology is urgently being optimized by using alternative materials. This article presents a review of our recent progress dedicated to the anode and cathode materials that have the potential to fulfil the crucial factors of cost, safety, lifetime, durability, power density, and energy density. Nanostructured inorganic compounds have been extensively investigated. Size effects revealed in the storage of lithium through micropores (hard carbon spheres), alloys (Si, SnSb), and conversion reactions (Cr2O3, MnO) are studied. The formation of nano/micro core,shell, dispersed composite, and surface pinning structures can improve their cycling performance. Surface coating on LiCoO2 and LiMn2O4 was found to be an effective way to enhance their thermal and chemical stability and the mechanisms are discussed. Theoretical simulations and experiments on LiFePO4 reveal that alkali metal ions and nitrogen doping into the LiFePO4 lattice are possible approaches to increase its electronic conductivity and does not block transport of lithium ion along the 1D channel. [source] Influence of size on the constitutive equations of concrete or rock dowelsINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 15 2008Letícia Fleck Fadel Miguel Abstract The numerical fracture analysis of non-homogeneous rock or concrete dowels subjected to shear and compression is described in detail. The method of analysis allows the consideration of scale and rate effects due to material non-homogeneity and fracture. The proposed approach is verified by comparing numerical predictions with experimental results reported in the literature for a series of small rock samples, since experimental evidence for large bodies is not yet available (2007). Results generated by Monte Carlo simulation using the so-called discrete element method to model the dowels suggest that a simple three parameters law can be used to predict the relationship between tangential stress at the base and lateral distortion. It is observed that the larger the size of the cubes, the smaller both the peak tangential stress and the rupture distortion. Size effects are also evaluated in samples with vertical restraint. The influence of loading rate is likewise numerically assessed for two sample sizes. The effect is compatible with experimental evidence available for concrete using small samples. Copyright © 2008 John Wiley & Sons, Ltd. [source] Anisotropic contraction in forisomes: Simple models won't fitCYTOSKELETON, Issue 5 2008Winfried S. Peters Abstract Forisomes are ATP-independent, Ca2+ -driven contractile protein bodies acting as reversible valves in the phloem of plants of the legume family. Forisome contraction is anisotropic, as shrinkage in length is associated with radial expansion and vice versa. To test the hypothesis that changes in length and width are causally related, we monitored Ca2+ - and pH-dependent deformations in the exceptionally large forisomes of Canavalia gladiata by high-speed photography, and computed time-courses of derived geometric parameters (including volume and surface area). Soybean forisomes, which in the resting state resemble those of Canavalia geometrically but have less than 2% of the volume, were also studied to identify size effects. Calcium induced sixfold volume increases in forisomes of both species; in soybean, responses were completed in 0.15 s, compared to about 0.5 s required for a rapid response in Canavalia followed by slow swelling for several minutes. This size-dependent behavior supports the idea that forisome contractility might rest on similar mechanisms as those of polyelectrolyte gels, a class of artificial "smart" materials. In both species, time-courses of forisome length and diameter were variable and lacked correlation, arguing against a simple causal relationship between changes in length and width. Moreover, changes in the geometry of soybean forisomes differed qualitatively between Ca2+ - and pH-responses, suggesting that divalent cations and protons target different sites on the forisome proteins. Cell Motil. Cytoskeleton 2008. © 2008 Wiley-Liss, Inc. [source] Scale dependence of diversity measures in a leaf-litter ant assemblageECOGRAPHY, Issue 2 2004Maurice Leponce A reliable characterization of community diversity and composition, necessary to allow inter-site comparisons and to monitor changes, is especially difficult to reach in speciose invertebrate communities. Spatial components of the sampling design (sampling interval, extent and grain) as well as temporal variations of species density affect the measures of diversity (species richness S, Buzas and Gibson's evenness E and Shannon's heterogeneity H). Our aim was to document the small-scale spatial distribution of leaf litter ants in a subtropical dry forest of the Argentinian Chaco and analyze how the community characterization was best achieved with a minimal sampling effort. The work was based on the recent standardized protocol for collecting ants of the leaf litter ("A.L.L.": 20 samples at intervals of 10 m). To evaluate the consistency of the sampling method in time and space, the selected site was first subject to a preliminary transect, then submitted after a 9-month interval to an 8-fold oversampling campaign (160 samples at interval of 1.25 m). Leaf litter ants were extracted from elementary 1 m2 quadrats with Winkler apparatus. An increase in the number of samples collected increased S and decreased E but did not affect much H. The sampling interval and extent did not affect S and H beyond a distance of 10 m between samples. An increase of the sampling grain had a similar effect on S than a corresponding increase of the number of samples collected, but caused a proportionaly greater increase of H. The density of species m,2 varied twofold after a 9-month interval; the effect on S could only be partially corrected by rarefaction. The measure of species numerical dominance was little affected by the season. A single standardized A.L.L. transect with Winkler samples collected <45% of the species present in the assemblage. All frequent species were included but their relative frequency was not always representative. A log series distribution of species occurrences was oberved. Fisher's , and Shannon's H were the most appropriate diversity indexes. The former was useful to rarefy or abundify S and the latter was robust against sample size effects. Both parametric and Soberón and Llorente extrapolation methods outperformed non-parametric methods and yielded a fair estimate of total species richness along the transect, a minimum value of S for the habitat sampled. [source] Fitness and body size in mature odonatesECOLOGICAL ENTOMOLOGY, Issue 2 2000Natalia Sokolovska Summary The relationship between body size and fitness components in odonates was examined using a meta-analysis of 33 published studies. There was a positive and significant overall effect of body size on mating rate and lifetime mating success among males. There was also a weaker but still significant positive effect of body size on survivorship of males. The relationship between body size, mating rate, longevity, and lifetime mating success differed significantly between males of territorial and nonterritorial species. The effect of body size was significant for all fitness components in territorial species but significant only for longevity and lifetime mating success in nonterritorial species. Effect sizes appeared to be strongest on longevity in both sexes, and on male mating rate in territorial species. Other effect sizes, even when significant, were small. Despite a much smaller data set, female fitness also increased significantly with body size. Both clutch size and longevity showed a significant positive relationship with body size. These results suggest that there is a general fitness benefit to large size in odonates. Nevertheless, significant heterogeneity is apparent in this effect, which can be attributed to sex, mating system, and fitness component. Finally, these analyses point to inadequacies in the current data that need further study before the potentially rich patterns in size effects on fitness can be explored more thoroughly. [source] BEQUEST RECEIPT AND FAMILY SIZE EFFECTSECONOMIC INQUIRY, Issue 1 2010NATHAN D. GRAWE This article tests the connection between credit constraints and negative family size effects on child earnings using bequest receipt to signal access to credit markets. The dominant economic model of fertility predicts a negative relationship between family size and child achievement. In the model, limits on borrowing create this "quality-quantity trade-off." This article tests for the relevance of credit constraints using Panel Study of Income Dynamics data to compare family size effects across groups defined by bequest receipt. Contrary to the credit constraints explanation, those receiving large bequests exhibit large family size effects, while those not receiving bequests show little to no effect. (JEL J13, D1, I2) [source] Assessing sediment contamination in estuariesENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 1 2001Peter M. Chapman Abstract Historic and ongoing sediment contamination adversely affects estuaries, among the most productive marine ecosystems in the world. However, all estuaries are not the same, and estuarine sediments cannot be treated as either fresh or marine sediments or properly assessed without understanding both seasonal and spatial estuarine variability and processes, which are reviewed. Estuaries are physicochemically unique, primarily because of their variable salinity but also because of their strong gradients in other parameters, such as temperature, pH, dissolved oxygen, redox potential, and amount and composition of particles. Salinity (overlying and interstitial) varies spatially (laterally, vertically) and temporally and is the controlling factor for partitioning of contaminants between sediments and overlying or interstitial water. Salinity also controls the distribution and types of estuarine biota. Benthic infauna are affected by interstitial salinities that can be very different than overlying salinities, resulting in large-scale seasonal species shifts in salt wedge estuaries. There are fewer estuarine species than fresh or marine species (the paradox of brackish water). Chemical, toxicological, and community-level assessment techniques for estuarine sediment are reviewed and assessed, including chemistry (grain size effects, background enrichment, bioavailability, sediment quality values, interstitial water chemistry), biological surveys, and whole sediment toxicity testing (single-species tests, potential confounding factors, community level tests, laboratory-to-field comparisons). Based on this review, there is a clear need to tailor such assessment techniques specifically for estuarine environments. For instance, bioavailability models including equilibrium partitioning may have little applicability to estuarine sediments, appropriate reference comparisons are difficult in biological surveys, and there are too few full-gradient estuarine sediment toxicity tests available. Specific recommendations are made to address these and other issues. [source] Testing Conditional Asset Pricing Models Using a Markov Chain Monte Carlo ApproachEUROPEAN FINANCIAL MANAGEMENT, Issue 3 2008Manuel Ammann G12 Abstract We use Markov Chain Monte Carlo (MCMC) methods for the parameter estimation and the testing of conditional asset pricing models. In contrast to traditional approaches, it is truly conditional because the assumption that time variation in betas is driven by a set of conditioning variables is not necessary. Moreover, the approach has exact finite sample properties and accounts for errors-in-variables. Using S&P 500 panel data, we analyse the empirical performance of the CAPM and theFama and French (1993)three-factor model. We find that time-variation of betas in the CAPM and the time variation of the coefficients for the size factor (SMB) and the distress factor (HML) in the three-factor model improve the empirical performance. Therefore, our findings are consistent with time variation of firm-specific exposure to market risk, systematic credit risk and systematic size effects. However, a Bayesian model comparison trading off goodness of fit and model complexity indicates that the conditional CAPM performs best, followed by the conditional three-factor model, the unconditional CAPM, and the unconditional three-factor model. [source] Ultrasound-Assisted Synthesis of CuO Nanorods in a Neat Room-Temperature Ionic LiquidEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 19 2009Tarek Alammar Abstract CuO nanorods were prepared via ultrasound-assisted synthesis in the room temperature ionic liquid (RTIL) 1-butyl-3-methylimidazoliumbis(trifluoromethylsulfonyl)imide [C4mim][Tf2N] as a reaction medium. The structure and morphology of CuO nanorods were characterized with X-ray powder diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), vibrational and UV/Vis absorption spectroscopy. The synthesized CuO nanocrystals are of rod like shape with lengths from 30 to 100 nm and diameters of about 10 nm. Quantum size effects were observed as the bandgap of the CuO nanorods was determined to 2.41 eV from UV/Vis absorption measurements, which is significantly larger than the bulk value. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Effect of Grain Size Reduction and Geometrical Confinement in Fine Grained Copper: Potential Applications as a Material for Reversible Electrical Contacts,ADVANCED ENGINEERING MATERIALS, Issue 8 2010Yannick Champion The potential of ultrafine grained copper as a material for reversible electrical contact is investigated. The influence of grain size and sample size on strength and electrical properties is discussed. The existence of an optimal grain size and the relevance of size effects for the mechanical properties are analyzed. [source] Functional Adhesive Surfaces with "Gecko" Effect: The Concept of Contact Splitting,ADVANCED ENGINEERING MATERIALS, Issue 5 2010Marleen Kamperman Abstract Nature has developed reversibly adhesive surfaces whose stickiness has attracted much research attention over the last decade. The central lesson from nature is that "patterned" or "fibrillar" surfaces can produce higher adhesion forces to flat and rough substrates than smooth surfaces. This paper critically examines the principles behind fibrillar adhesion from a contact mechanics perspective, where much progress has been made in recent years. The benefits derived from "contact splitting" into fibrils are separated into extrinsic/intrinsic contributions from fibril deformation, adaptability to rough surfaces, size effects due to surface-to-volume ratio, uniformity of stress distribution, and defect-controlled adhesion. Another section covers essential considerations for reliable and reproducible adhesion testing, where better standardization is still required. It is argued that, in view of the large number of parameters, a thorough understanding of adhesion effects is required to enable the fabrication of reliable adhesive surfaces based on biological examples. [source] When more observations are better than less: a connectionist account of the acquisition of causal strengthEUROPEAN JOURNAL OF SOCIAL PSYCHOLOGY, Issue 2 2001Frank Van Overwalle The statistical law of large numbers prescribes that estimates are more reliable and accurate when based on a larger sample of observations. This effect of sample size was investigated on causal attributions. Subjects received fixed levels of consensus and distinctiveness covariation, and attributions were measured after a varying number of trials. Whereas prominent statistical models of causality (e.g. Cheng & Novick, 1990; Försterling, 1992) predict no effect of sample size, adaptive connectionist models (McClelland & Rumelhart, 1988) predict that subjects will incrementally adjust causal ratings in the direction of the true covariation the more observations are made. In three experiments, sample size effects were found consistent with the connectionist prediction. Possible extensions of statistical models were considered and simulated, but none of them accommodated the data as well as connectionist models. Copyright © 2001 John Wiley & Sons, Ltd. [source] On a Proper Account of First- and Second-Order Size Effects in Crystal Plasticity,ADVANCED ENGINEERING MATERIALS, Issue 3 2009Marc G. D. Geers This paper addresses engineering size effects in miniaturized metallic components. First, the critical role of processing induced size effects is emphasized. Next, the need for a rigorous strain gradient enrichment in crystal plasticity modelling is advocated, directly resulting from the coarse graining of discrete dislocation interactions. The physical origin of the energetic enrichment is discussed and its deterministic derivation is briefly confronted with analogous statistical mechanics results. [source] Multiaxial fatigue of welded joints under constant and variable amplitude loadingsFATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 5 2001C. M. Sonsino Flange-tube joints from fine grained steel StE 460 with unmachined welds were investigated under biaxial constant and variable amplitude loading (bending and torsion) in the range of 103 to 5,×,106 cycles to crack initiation and break-through, respectively. In order not to interfere with residual stresses they were relieved by a heat treatment. In-phase loading can be treated fairly well using the conventional hypotheses (von Mises or Tresca) on the basis of nominal, structural or local strains or stresses. But the influence of out-of-phase loading on fatigue life is severely overestimated if conventional hypotheses are used. However, the hypothesis of the effective equivalent stress that is introduced leads to fairly good predictions for constant as well as for random variable amplitude loads. Therefore, the knowledge of local strains or stresses is necessary. They are determined by boundary element analyses that are dependent on weld geometry. This hypothesis considers the fatigue-life-reducing influence of out-of-phase loading by taking into account the interaction of local shear stresses acting in different surface planes of the material. Further, size effects resulting from weld geometry and loading mode were included. Damage accumulation under a Gaussian spectrum can be assessed for in- and out-of-phase combined bending and torsion using an allowable damage sum of 0.35. [source] Polarizability, Susceptibility, and Dielectric Constant of Nanometer-Scale Molecular Films: A Microscopic ViewADVANCED FUNCTIONAL MATERIALS, Issue 13 2010Amir Natan Abstract The size-dependence of the polarizability, susceptibility, and dielectric constant of nanometer-scale molecular layers is explored theoretically. First-principles calculations based on density functional theory are compared to phenomenological modeling based on polarizable dipolar arrays for a model system of organized monolayers composed of oligophenyl chains. Size trends for all three quantities are primarily governed by a competition between out-of-plane polarization enhancement and in-plane polarization suppression. Molecular packing density is the single most important factor controlling this competition and it strongly affects the bulk limit of the dielectric constant as well as the rate at which it is approached. Finally, the polarization does not reach its "bulk" limit, as determined from the Clausius,Mossotti model, but the susceptibility and dielectric constant do converge to the correct bulk limit. However, whereas the Clausius,Mossotti model describes the dielectric constant well at low lateral densities, finite size effects of the monomer units cause it to be increasingly inaccurate at high lateral densities. [source] Arbitrage, Liquidity, and the Valuation of Exchange Traded FundsFINANCIAL MARKETS, INSTITUTIONS & INSTRUMENTS, Issue 5 2008Lucy F. Ackert This paper investigates the performance of U.S. and country exchange traded funds currently traded in the United States and provides new insight into their pricing. While the U.S. funds are priced closely to their net asset values, the country funds are not and can exhibit large, positive autocorrelations in fund premium. The mispricing of country funds is related to momentum, illiquidity, and size effects. We also find an inverted U-shaped relationship between fund premium and market liquidity, which suggests that more active trading does lead to lower mispricing but only after a certain level of liquidity is reached. [source] Cross-generation effects due to cold exposure in Drosophila serrataFUNCTIONAL ECOLOGY, Issue 5 2003A. Magiafoglou Summary 1Environmental variation experienced in the parental and grandparental generation can affect progeny phenotype, performance and response to selection. Here the effects of parental and grandparental exposure to a non-lethal cold shock are considered in Drosophila serrata Malloch. Development time, viability and early age productivity were measured in flies originating from border and central locations in the distribution of this species that had been held under two separate laboratory maintenance schedules. 2Cross-generation effects were detected for several traits. Development time usually decreased following maternal and/or grandmaternal cold exposure. Parental cold exposure negatively influenced viability while grandparental effects on viability were negligible. Early female productivity showed opposing responses depending on generation; maternal cold exposure increased progeny productivity while grandmaternal exposure decreased it. Male parental and grandparental exposure to cold shock decreased male productivity, although this pattern may have been partly confounded by size effects. 3Population effects, reflecting geographical origin, were limited to development time, while selective background effects were demonstrated for most traits. The influence these factors had on the expression of cross-generation effects was negligible, given interactions with treatment were not evident. These responses suggest that environmental variation experienced in preceding generations can influence progeny phenotype in a manner that is complex and difficult to predict. [source] A second-order homogenization procedure for multi-scale analysis based on micropolar kinematicsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 12 2007Ragnar Larsson Abstract The paper presents a higher order homogenization scheme based on non-linear micropolar kinematics representing the macroscopic variation within a representative volume element (RVE) of the material. On the microstructural level the micro,macro kinematical coupling is introduced as a second-order Taylor series expansion of the macro displacement field, and the microstructural displacement variation is gathered in a fluctuation term. This approach relates strongly to second gradient continuum formulations, presented by, e.g. Kouznetsova et al. (Int. J. Numer. Meth. Engng 2002; 54:1235,1260), thus establishing a link between second gradient and micropolar theories. The major difference of the present approach as compared to second gradient formulations is that an additional constraint is placed on the higher order deformation gradient in terms of the micropolar stretch. The driving vehicle for the derivation of the homogenized macroscopic stress measures is the Hill,Mandel condition, postulating the equivalence of microscopic and macroscopic (homogenized) virtual work. Thereby, the resulting homogenization procedure yields not only a stress tensor, conjugated to the micropolar stretch tensor, but also the couple stress tensor, conjugated to the micropolar curvature tensor. The paper is concluded by a couple of numerical examples demonstrating the size effects imposed by the homogenization of stresses based on the micropolar kinematics. Copyright © 2006 John Wiley & Sons, Ltd. [source] Theory and numerics of geometrically non-linear open system mechanicsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 11 2003E. Kuhl Abstract The present contribution aims at deriving a general theoretical and numerical framework for open system thermodynamics. The balance equations for open systems differ from the classical balance equations by additional terms arising from possible local changes in mass. In contrast to existing formulations, these changes not only originate from additional mass sources or sinks but also from a possible in- or outflux of matter. Constitutive equations for the mass source and the mass flux are discussed for the particular model problem of bone remodelling in hard tissue mechanics. Particular emphasis is dedicated to the spatial discretization of the coupled system of the balance of mass and momentum. To this end we suggest a geometrically non-linear monolithic finite element based solution technique introducing the density and the deformation map as primary unknowns. It is supplemented by the consistent linearization of the governing equations. The resulting algorithm is validated qualitatively for classical examples from structural mechanics as well as for biomechanical applications with particular focus on the functional adaption of bones. It turns out that, owing to the additional incorporation of the mass flux, the proposed model is able to simulate size effects typically encountered in microstructural materials such as open-pored cellular solids, e.g. bones. Copyright © 2003 John Wiley & Sons, Ltd. [source] ZnS Nanowires with Wurtzite Polytype Modulated Structure,ADVANCED MATERIALS, Issue 14 2003Y. Jiang A novel polytype modulated 1D structure has been grown in ZnS nanowires via intermittent laser ablation,catalytic growth. The polytype modulated ZnS nanowires show a strong blue-shifted bandgap emission centered at 338.2 nm due to quantum size effects. The Figure shows a dark-field image of one of the nanowires (top) and the corresponding electron diffraction patterns (bottom). [source] Small-angle X-ray scattering study of intramuscular fish bone: collagen fibril superstructure determined from equidistant meridional reflectionsJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 2 2008Christian Burger New insights into the bone collagen fibril superstructure have been obtained by novel small-angle X-ray scattering analysis. The analysis was carried out on the small-angle equidistant meridional reflections resulting from the periodic structure of collagen fibrils in their axial direction. Conventional two-dimensional analysis is difficult because of the large discrepancy of longitudinal and lateral length scales for individual fibrils, as well as their preferred orientation. The new approach represents an unapproximated analysis of the equidistant meridional reflections, which takes the exact separation of preferred orientation and fibril size effects into account. The analytical results (e.g. axial period, fibril diameter etc.) agree well with the parameters obtained from transmission electron microscopy. [source] Corrections for surface X-ray diffraction measurements using the Z -axis geometry: finite size effects in direct and reciprocal spaceJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 4 2000O. Robach X-ray diffraction data have to be corrected by geometrical correction factors prior to any quantitative analysis. Here the case of grazing incidence X-ray diffraction measurements is considered, including the case of high exit angles. First, an approach taking into account the evolution of the diffracting area during an , scan is presented. From the calculation of the effective part of the sample surface that participates in the diffraction phenomena at each step of the scan, a more accurate correction factor than those commonly used is derived and the evolution of the line shape along a zero-width rod is explained. Secondly, the case of finite-width rods, under the point-like sample approximation, is considered: the influence of the partial integration, as a result of the detector in-plane acceptance, of a rod with an anisotropic in-plane shape, is studied and leads to an analytical expression for the corresponding correction factor. Finally, a full numerical simulation is presented, which provides an alternative method for correcting the experimental intensities and shows in which conditions the previous formulae are no longer valid. [source] Viscosity and starch particle size effects on rehydration of freeze-dried carrots Alejandro Marabi and I Sam Saguy.JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 4 2005706 (2005), Agriculture85(4):700, Journal of the Science of Food The original article to which this Erratum refers was published in Journal of the Science of Food and Agriculture 85(4):700,706 (2005). Copyright © 2005 Society of Chemical Industry [source] Evidence for quorum sensing in Clostridium botulinum 56ALETTERS IN APPLIED MICROBIOLOGY, Issue 1 2006L. Zhao Abstract Aims:, Experiments were designed to detect quorum-sensing signals produced by Clostridium botulinum. Methods and Results:,Clostridium botulinum 56A cell-free supernatants obtained at the end of lag phase, the mid-exponential phase and early stationary phase of growth were assayed for bioluminescence in the Vibrio harveyi quorum-sensing assay system. Twelve and 16-h culture supernatants induced bioluminescence in the auto-inducer 2 (AI-2) but not the auto-inducer 1 (AI-1) assay. Intra-species quorum sensing was also assayed as the ability of the supernatants to promote spore germination and outgrowth in a microtitre plate system. Spore populations exposed to C. botulinum supernatant from the end of lag phase became positive for growth sooner than controls. Conclusions:, The influence of cell-free supernatant on ungerminated spores and detection of bioluminescence in the AI-2 assay are evidence for a signalling molecule(s) and provide a first step in characterizing C. botulinum quorum sensing. Significance and Impact of the Study:, This study suggests that spores do not behave independently of each other and may explain the inocula size effects observed in challenge studies. Whether AI-2 production in C. botulinum serves as an inter-species signal or as a detoxification mechanism remains to be determined. [source] Nanoscale lead and noble gas inclusions in aluminum: Structures and propertiesMICROSCOPY RESEARCH AND TECHNIQUE, Issue 5-6 2004Erik Johnson Abstract Transmission electron microscopy has been used for structural and physical characterization of nanoscale inclusions of lead and noble gases in aluminum. When the inclusion sizes approach nanoscale dimensions, many of their properties are seen to deviate from similar properties in bulk and in most cases the deviations will increase as the inclusion sizes decrease. Binary alloys of lead and noble gases with aluminum are characterized by extremely low mutual solubilities and inclusions will, therefore, exist as practically pure components embedded in the aluminum matrix. Furthermore, the thermal vacancy mobility in aluminum at and above room temperature is sufficiently high to accommodate volume strains associated with the inclusions thus leading to virtually strain free crystals. The inclusions grow in parallel cube alignment with the aluminum matrix and have a cuboctahedral shape, which reflects directly the anisotropy of the interfacial energies. Inclusions in grain boundaries can have single crystalline or bicrystalline morphology that can be explained from a generalized Wulff analysis such as the ,-vector construction. The inclusions have been found to display a variety of nanoscale features such as high Laplace pressure, size-dependent superheating during melting, deviations from the Wulff shape displaying magic size effects, a shape dependence of edge energy, and so on. All these effects have been observed and monitored by TEM using conventional imaging conditions and high-resolution conditions in combination with in-situ analysis at elevated temperatures. Microsc. Res. Tech. 64:356,372, 2004. © 2004 Wiley-Liss, Inc. [source] The impact of personality disorders on treatment outcome in bipolar disorder: A reviewPERSONALITY AND MENTAL HEALTH, Issue 1 2007Peter J. Bieling Bipolar disorder (BD) is a chronic psychiatric illness for which there are a number of efficacious and effective treatments. However, for many sufferers recovery is incomplete or tenuous. Factors associated with poor outcomes in the disorder are of special interest, and comorbidity of BD with personality disorder (PD) has been proposed as a possible predictor of poor outcome. We reviewed available studies (n = 12) in the literature that specifically assessed the impact of personality psychopathology on illness outcomes in BD including functioning, response to treatment and suicidality. Quality of methodology, assessment methods and number of participants in studies were highly variable. Despite these variations in study quality, the presence of a PD was robustly associated (usually medium size effects) with a worse outcome in BD. Patients with BD and a diagnosis of PD are more likely to be hospitalized, require more time to achieve symptom stabilization, have more chronic impairments in occupational and social functioning, are less compliant to medication, have greater levels of suicidality and utilize more psychiatric services than patients with BD alone. The implications of these findings for further research and clinical care in BD are discussed. Copyright © 2007 John Wiley & Sons, Ltd. [source] Biases affecting the proportional reporting ratio (PRR) in spontaneous reports pharmacovigilance databases: the example of sertindolePHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Issue 4 2003Nicholas Moore Abstract Background Automated measures of reporting disproportionality in databases of spontaneous reports of adverse drug reactions are an emerging tool to identify drug-related alerts. Sertindole, a new atypical neuroleptic known to prolong the QT interval, was suspended in November 1998 because the proportion of reports of fatal reactions suggesting arrhythmia among all reports with sertindole was almost ten times higher than that for other atypical neuroleptics in the UK. This excess risk was not predicted in preclinical data and had not been found in premarketing trials. Method Reporting patterns over time were analysed. Prescription Event Monitoring (PEM) studies and a large retrospective cohort allowed for the comparison of actual death rates with atypical neuroleptics, and to assess which proportion of the deaths that occurred were reported. Results There were indications of possible skewing of reporting related to notoriety, surveillance and market size effects. Death rates in PEM studies were essentially similar between sertindole and other neuroleptics. Cardiac deaths had been two to three times more often reported than other causes of death. Conclusion Proportional reporting ratios indicate differential reporting of possible reactions, not necessarily differential occurrence. There was no indication of an actual increase of risk of all causes or cardiac deaths during sertindole treatment, but only an increased risk of its being reported. The suspension of sertindole was rescinded by Committee on Proprietary Medicinal Products (CPMP) in October 2001. Copyright © 2003 John Wiley & Sons, Ltd. [source] | |||||||||||||||||||||||||||||||