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Basic Properties (basic + property)
Selected AbstractsFixed-Reimbursement Insurance: Basic Properties and Comparative StaticsJOURNAL OF RISK AND INSURANCE, Issue 2 2003Louis Eeckhoudt In a number of settings, insurance contracts specify a fixed reimbursement in the event of a loss which is not conditioned on the size of the realized loss. In this article, we explore the theoretical properties of this form of insurance and draw comparisons with other types of insurance policies, such as those based on coinsurance and deductibles. We also examine links between our results and those from the literature on precautionary saving. [source] Selection and Basic Properties of the Buffer Material for High-Level Radioactive Waste Repository in ChinaACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 5 2008WEN Zhijian Abstract Radioactive wastes arising from a wide range of human activities are in many different physical and chemical forms, contaminated with varying radioactivity. Their common features are the potential hazard associated with their radioactivity and the need to manage them in such a way as to protect the human environment. The geological disposal is regarded as the most reasonable and effective way to safely disposing high-level radioactive wastes in the world. The conceptual model of geological disposal in China is based on a multi-barrier system that combines an isolating geological environment with an engineered barrier system. The buffer is one of the main engineered barriers for HLW repository. It is expected to maintain its low water permeability, self-sealing property, radio nuclides adsorption and retardation properties, thermal conductivity, chemical buffering property, canister supporting property, and stress buffering property over a long period of time. Bentonite is selected as the main content of buffer material that can satisfy the above requirements. The Gaomiaozi deposit is selected as the candidate supplier for China's buffer material of high level radioactive waste repository. This paper presents the geological features of the GMZ deposit and basic properties of the GMZ Na-bentonite. It is a super-large deposit with a high content of montmorillonite (about 75%), and GMZ-1, which is Na-bentonite produced from GMZ deposit is selected as the reference material for China's buffer material study. [source] Deficient long-term synaptic depression in the rostral cerebellum correlated with impaired motor learning in phospholipase C ,4 mutant miceEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 10 2001Mariko Miyata Abstract Long-term depression (LTD) at parallel fibre,Purkinje cell synapse of the cerebellum is thought to be a cellular substrate for motor learning. LTD requires activation of metabotropic glutamate receptor subtype 1 (mGluR1) and its downstream signalling pathways, which invariably involves phospholipase C,s (PLC,s). PLC,s consist of four isoforms (PLC,1,4) among which PLC,4 is the major isoform in most Purkinje cells in the rostral cerebellum (lobule 1 to the rostral half of lobule 6). We studied mutant mice deficient in PLC,4, and found that LTD was deficient in the rostral but not in the caudal cerebellum of the mutant. Basic properties of parallel fibre,Purkinje cell synapses and voltage-gated Ca2+ channel currents appeared normal. The mGluR1-mediated Ca2+ release induced by repetitive parallel fibre stimulation was absent in the rostral cerebellum of the mutant, suggesting that their LTD lesion was due to the defect in the mGluR1-mediated signalling in Purkinje cells. Importantly, the eyeblink conditioning, a simple form of discrete motor learning, was severely impaired in PLC,4 mutant mice. Wild-type mice developed the conditioned eyeblink response, when pairs of the conditioned stimulus (tone) and the unconditioned stimulus (periorbital shock) were repeatedly applied. In contrast, PLC,4 mutant mice could not learn the association between the conditioned and unconditioned stimuli, although their behavioural responses to the tone or to the periorbital shock appeared normal. These results strongly suggest that PLC,4 is essential for LTD in the rostral cerebellum, which may be required for the acuisition of the conditioned eyeblink response. [source] The small-angle scattering structure functions of the single tetrahedronJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 3-1 2003W. Gille Basic properties of the SAS correlation function , (r) and related functions are represented for a tetrahedron of edge length a. An interval splitting into four basic r -intervals in a sequence of cases for averaging the intersection volume between two tetrahedrons has been performed. Remarkably simple analytic expressions result in the first r -interval. Indeed, ,(r) is a polynomial of degree three. The coefficients are given explicitly. The asymptotic expansion I(h) is compared with the exact scattering intensity I(h). [source] Growth of tin oxide nanocrystalsCRYSTAL RESEARCH AND TECHNOLOGY, Issue 10-11 2005L. Zanotti Abstract Functional oxides are presently much investigated as regards not only their basic properties, but also their actual and potential applications. Tin oxides appear particularly interesting when grown in nanowire shape (SnO2 -NW) because of their electronic- and sensor-device applications. In this paper the results of a systematic study on nucleation and growth of SnO2 -NWs, when an open-tube vapor-transport technique is employed, are reported and discussed. The vapor transport conditions have been investigated in greater detail and for the first time a growth model is proposed. Functional tests at different temperatures and gaseous compositions have proved that the SnO2 -NW are suitable for the preparation of highly-sensitive and stable gas sensors. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] An answer to an important controversy and the need for caution when using simple models to predict inelastic earthquake response of buildings with torsionEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 5 2010Stavros A. Anagnostopoulos Abstract This paper presents evidence that the extension of conclusions based on the widely used simplified, one story, eccentric systems of the shear-beam type, to actual, nonsymmetric buildings and consequent assessments of the pertinent code provisions, can be quite erroneous, unless special care is taken to match the basic properties of the simplified models to those of the real buildings. The evidence comes from comparisons of results obtained using three variants of simplified models, with results from the inelastic dynamic response of three- and five-story eccentric buildings computed with detailed MDOF systems, where the members are idealized with the well-known plastic hinge model. In addition, a convincing answer is provided on a pertinent hanging controversy: For frame-type buildings, designed in accordance with the dynamic provisions of modern codes (such as EC8 or IBC2000), which allow reduced shears at the stiff edge due to torsion, the frames at the flexible sides are the critical elements in terms of ductility demands. Copyright © 2009 John Wiley & Sons, Ltd. [source] Extracellular signal-regulated kinase activation is required for consolidation and reconsolidation of memory at an early stage of ontogenesisEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 10 2009Solčne Languille Abstract The ability to form long-term memories exists very early during ontogeny; however, the properties of early memory processes, brain structures involved and underlying cellular mechanisms are poorly defined. Here, we examine the role of extracellular signal-regulated kinase (ERK), a member of the mitogen-activated protein kinase/ERK signaling cascade, which is crucial for adult memory, in the consolidation and reconsolidation of an early memory using a conditioned taste aversion paradigm in 3-day-old rat pups. We show that intraperitoneal injection of SL327, the upstream mitogen-activated protein kinase kinase inhibitor, impairs both consolidation and reconsolidation of early memory, leaving short-term memory after acquisition and after reactivation intact. The amnesic effect of SL327 diminishes with increasing delays after acquisition and reactivation. Biochemical analyses revealed ERK hyperphosphorylation in the amygdala but not the hippocampus following acquisition, suggesting functional activation of the amygdala as early as post-natal day 3, although there was no clear evidence for amygdalar ERK activation after reactivation. These results indicate that, despite an immature brain, the basic properties of memory and at least some of the molecular mechanisms and brain structures implicated in aversion memory share a number of similarities with the adult and emerge very early during ontogeny. [source] Tactile responses of hindpaw, forepaw and whisker neurons in the thalamic ventrobasal complex of anesthetized ratsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 2 2008J. Aguilar Abstract The majority of studies investigating responses of thalamocortical neurons to tactile stimuli have focused on the whisker representation of the rat thalamus: the ventral,posterior,medial nucleus (VPM). To test whether the basic properties of thalamocortical responses to tactile stimuli could be extended to the entire ventrobasal complex, we recorded single neurons from the whisker, forepaw and hindpaw thalamic representations. We performed a systematic analysis of responses to stereotyped tactile stimuli , 500 ms pulses (i.e. ON,OFF stimuli) or 1 ms pulses (i.e. impulsive stimuli) , under two different anesthetics (pentobarbital or urethane). We obtained the following main results: (i) the tuning of cells to ON vs. OFF stimuli displayed a gradient across neurons, so that two-thirds of cells responded more to ON stimuli and one-third responded more to OFF stimuli; (ii) on average, response magnitudes did not differ between ON and OFF stimuli, whereas latencies of response to OFF stimuli were a few milliseconds longer; (iii) latencies of response to ON and OFF stimuli were highly correlated; (iv) responses to impulsive stimuli and ON stimuli showed a strong correlation, whereas the relationship between the responses to impulsive stimuli and OFF stimuli was subtler; (v) unlike ON responses, OFF responses did not decrease when stimuli were moved from the receptive field center to a close location in the excitatory surround. We obtained the same results for hindpaw, forepaw and whisker neurons. Our results support the view of a neurophysiologically homogeneous ventrobasal complex, in which OFF responses participate in the structure of the spatiotemporal receptive field of thalamocortical neurons for tactile stimuli. [source] The Causal Exclusion PuzzleEUROPEAN JOURNAL OF PHILOSOPHY, Issue 1 2002David Pineda The article is divided into two parts. The first part offers a careful reconstruction and detailed discussion of the argument of causal exclusion, as well as of the implications it has for physicalism. In its second part the article examines two important objections to the causal exclusion argument: the generalization objection, which holds that the argument is unacceptable since it confers causal efficacy only to ultimate basic properties, which arguably might not exist; and Yablo's objection, according to which underlying the argument of causal exclusion there is a principle of causal parsimony which leads to strong counterintuitive results and should therefore be abandoned. The article offers grounds for rejecting both objections as well as a new diagnosis of the problem for mental causation generated by the causal exclusion argument. [source] Breath-holding and its breakpointEXPERIMENTAL PHYSIOLOGY, Issue 1 2006M. J. Parkes This article reviews the basic properties of breath-holding in humans and the possible causes of the breath at breakpoint. The simplest objective measure of breath-holding is its duration, but even this is highly variable. Breath-holding is a voluntary act, but normal subjects appear unable to breath-hold to unconsciousness. A powerful involuntary mechanism normally overrides voluntary breath-holding and causes the breath that defines the breakpoint. The occurrence of the breakpoint breath does not appear to be caused solely by a mechanism involving lung or chest shrinkage, partial pressures of blood gases or the carotid arterial chemoreceptors. This is despite the well-known properties of breath-hold duration being prolonged by large lung inflations, hyperoxia and hypocapnia and being shortened by the converse manoeuvres and by increased metabolic rate. Breath-holding has, however, two much less well-known but important properties. First, the central respiratory rhythm appears to continue throughout breath-holding. Humans cannot therefore stop their central respiratory rhythm voluntarily. Instead, they merely suppress expression of their central respiratory rhythm and voluntarily ,hold' the chest at a chosen volume, possibly assisted by some tonic diaphragm activity. Second, breath-hold duration is prolonged by bilateral paralysis of the phrenic or vagus nerves. Possibly the contribution to the breakpoint from stimulation of diaphragm muscle chemoreceptors is greater than has previously been considered. At present there is no simple explanation for the breakpoint that encompasses all these properties. [source] Studies on structural and functional divergence among seven WhiB proteins of Mycobacterium tuberculosis H37RvFEBS JOURNAL, Issue 1 2009Md. Suhail Alam The whiB -like genes (1-7) of Mycobacterium tuberculosis are involved in cell division, nutrient starvation, pathogenesis, antibiotic resistance and stress sensing. Although the biochemical properties of WhiB1, WhiB3 and WhiB4 are known, there is no information about the other proteins. Here, we elucidate in detail the biochemical and biophysical properties of WhiB2, WhiB5, WhiB6 and WhiB7 of M. tuberculosis and present a comprehensive comparative study on the molecular properties of all WhiB proteins. UV,Vis spectroscopy has suggested the presence of a redox-sensitive [2Fe,2S] cluster in each of the WhiB proteins, which remains stably bound to the proteins in the presence of 8 m urea. The [2Fe,2S] cluster of each protein was oxidation labile but the rate of cluster loss decreased under reducing environments. The [2Fe,2S] cluster of each WhiB protein responded differently to the oxidative effect of air and oxidized glutathione. In all cases, disassembly of the [2Fe,2S] cluster was coupled with the oxidation of cysteine-thiols and the formation of two intramolecular disulfide bonds. Both CD and fluorescence spectroscopy revealed that WhiB proteins are structurally divergent members of the same family. Similar to WhiB1, WhiB3 and WhiB4, apo WhiB5, WhiB6 and WhiB7 also reduced the disulfide of insulin, a model substrate. However, the reduction efficiency varied significantly. Surprisingly, WhiB2 did not reduce the insulin disulfide, even though its basic properties were similar to those of others. The structural and functional divergence among WhiB proteins indicated that each WhiB protein is a distinguished member of the same family and together they may represent a novel redox system for M. tuberculosis. [source] DNA-binding and transcription characteristics of three cloned sigma factors from mustard (Sinapis alba L.) suggest overlapping and distinct roles in plastid gene expressionFEBS JOURNAL, Issue 6 2003Anke Homann We have isolated and studied the cloned sigma factors SASIG1-3 from mustard (Sinapis alba). In functional analyses using both promoter and factor mutants, the three recombinant proteins all had similar basic properties but also revealed differences in promoter preference and requirements for single nucleotide positions. Directed muta- genesis of SASIG1 identified critical residues within the conserved regions 2.4 and 4.2 necessary for binding of the ,10 and ,35 promoter elements, respectively. SASIG1 and 2, but not SASIG3, each have a typical region 2.5 for binding of the extended ,10 promoter element. SASIG3 has a pro-sequence reminiscent of ,K from Bacillus subtilis, suggesting that proteolytic cleavage from an inactive precursor is involved in the regulation of plastid transcription. In addition, SASIG2 was found to be more abundant in light-grown as compared to dark-grown mustard seedlings, while the converse was true for SASIG3. [source] The neuronal ceroid lipofuscinosis protein CLN5: new insights into cellular maturation, transport, and consequences of mutations,HUMAN MUTATION, Issue 3 2010Mia-Lisa Schmiedt Abstract Neuronal ceroid lipofuscinoses (NCLs) represent a group of children's inherited neurodegenerative disorders caused by mutations in at least eight different genes. Mutations in the CLN5 gene result in the Finnish variant late infantile NCL characterized by gradual loss of vision, epileptic seizures, and mental deterioration. The CLN5 gene encodes a lysosomal glycoprotein of unidentified function. In this study, we have used both transient and stable expression systems for the characterization of CLN5, focusing on the localization, processing, and intracellular trafficking. We show that CLN5 is proteolytically cleaved, and that the mature polypeptide is transported to the lysosomes. Our data provide the first evidence that soluble CLN5 protein can also undergo mannose-6-phosphate receptor-independent trafficking to the lysosomes. We studied the localization and maturation of the CLN5 carrying the previously uncharacterized vLINCL disease causing mutations in HeLa cells. All analyzed disease mutations disturb the lysosomal trafficking of the mutated CLN5 proteins. The level of lysosomal targeting does not correlate, however, to disease onset, indicating that CLN5 may also function outside lysosomes. This study furthers our understanding of the basic properties of the CLN5 protein, necessary for the characterization of the consequences of disease mutations and for the planning of future therapies for vLINCL. Hum Mutat 31:356,365, 2010. © 2010 Wiley-Liss, Inc. [source] Circuits, computers, and beyond Boolean logic,INTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS, Issue 5-6 2007Tamás Roska Abstract Historically, the invention of the stored programmable computer architecture, introduced by John Von Neumann, was also influenced by electrical circuit implementation aspects, as well as tied to fundamental insight of logic reasoning. It can also be considered as a mind-inspired machine. Since then, the implementation of logic gates, control and memories has developed independently of the architecture. The Cellular Wave Computer architecture (IEEE Trans. Circuits Syst. II 1993; 40:163,173; Electron. Lett. 2007; 43:427,449; J. Circuits Syst. Comput. 2003; 5(2):539,562) as a spatial,temporal universal machine on flows has also been influenced by circuit aspects of very large-scale integration (VLSI) technology, as well as some motivating living neural circuits, via the cellular nonlinear (neural) network (CNN). It might be considered as a brain-inspired machine. In this paper, after summarizing the main properties of the Cellular Wave Computer, we highlight a few basic properties of this new kind of computer and computing. In particular, phenomena related to (i) the one-pass solution of a set of implicit equations due to real-time spatial array feedback, (ii) the true random signal array generation via the insertion of the continuous physical noise signals, (iii) the finite synchrony radius due to the functional delay of wires, as well as to (iv) biology relevance. We also show that the Cellular Wave Computer is performing spatial,temporal inference that goes beyond Boolean logic, a characteristic of living neural circuits. Copyright © 2007 John Wiley & Sons, Ltd. [source] Semiempirical electronic structure calculation on Ca and Pb apatitesINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 4 2009Maria Matos Abstract A systematic study is made on the electronic structure of stoichiometric calcium and lead apatites, using the tight binding extended Hückel method (eHT). The aim is to investigate the applicability of the semiempirical theory to study this family of compounds. A10(BO4)6X2 (A = Ca, Pb) apatites, differing by substitutions in the BO4 tetrahedral unit (B = P, As, and V) and X-channel ion (X = OH, Cl), are considered. The calculations show that eHT is suitable to describe basic properties especially concerning trends with atomic substitution and geometry changes. Band structure, Mulliken charge distribution, and bond orders are in good agreement with results of ab initio density functional theory (DFT) found in the literature. Large variations in the optical gap due to vanadium and lead substitutions are newly found. Changes in the anion X-channel affect the optical gap, which is in close agreement with DFT results. Analysis involving subnets are performed to determine the role of halogenic orbitals in the electronic structure of chloroapatites, showing evidence of covalent Cl bonding. It was also found that PbOH bonding in hydroxy-vanadinite Pb10(VO4)6(OH)2, recently synthesized, is weaker than that of CaOH in vanadate Ca10(VO4)6(OH)2. Arsenium is found to be more weakely bound to the O-tetrahedron than phosphorous, although CaO bond is increased with the substitution. We investigate, in addition, the electronic structure of a model system Ca10(AsO4)6(OH)2, obtained from direct As substitution in the vanadate Ca10(VO4)6(OH)2. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009 [source] Lyapunov-Krasovskii functionals for additional dynamicsINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 9 2003Vladimir L. Kharitonov Abstract A class of Lyapunov,Krasovskii functionals for the additional dynamics introduced by special transformation of time delay systems is given in the paper. Some basic properties of the functionals are also discussed. Copyright © 2003 John Wiley & Sons, Ltd. [source] Comparative study of nine Lactobacillus fermentum bacteriophagesJOURNAL OF APPLIED MICROBIOLOGY, Issue 3 2001R. Foschino Aims:,To investigate the basic properties of six temperate and three virulent phages, active on Lactobacillus fermentum, on the basis of morphology, host ranges, protein composition and genome characterization. Methods and Results:,All phages belonged to the Siphoviridae family; two of them showed prolate heads. The host ranges of seven phages contained a common group of strains. SDS-PAGE protein profiles, restriction analysis of DNA and Southern blot hybridization revealed a high degree of homology between four temperate phages; partial homologies were also detected among virulent and temperate phages. Clustering derived from host range analysis was not related to the results of the DNA hybridizations. Conclusions:,The phages investigated have common characteristics with other known phages active on the genus Lactobacillus. Sensitivity to viral infection is apparently enhanced by the presence of a resident prophage. Significance and Impact of the Study:,These relationships contribute to the explanation for the origin of phage infection in food processes where Lact. fermentum is involved, such as sourdough fermentation. [source] Kinetics of graft copolymerization of poly(hexanedioic acid ethylene glycol) and methyl acrylate initiated by potassium diperiodatocuprate(III)JOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2007Libin Bai Abstract A redox system, potassium diperiodatocuprate(III) [DPC]/poly(hexanedioic acid ethylene glycol) (PEA) system, was employed to initiate graft copolymers of methyl acrylate (MA) and PEA in alkaline medium. The results indicate that the equation of the polymerization rate (Rp) is as follows: Rp = k [MA]1.62[Cu(III)]0.69, and that the overall activation energy of graft polymerization is 42.5 kJ/mol. The total conversion at different conditions (concentration of reactants, temperature, concentration of the DPC, and reaction time) was also investigated. The infrared spectra proved that the graft copolymers were synthesized successfully. Some basic properties of the graft copolymer were studied by instrumental analyses, including thermogravimetry and scanning electron microscope. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2376,2381, 2007 [source] Supercritical fluids in medical radioisotope processing and chemistry, Part II: Applications , real and demonstratedJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 10 2003Richard A. Ferrieri Abstract In Part I of this review series, an overview was presented on what the basic properties of supercritical fluids are and how they can, and are being used in many of today's industries as solvents for extraction, chromatography and reaction. A good part of this overview detailed the kinds of equipment needed, and techniques on how to use them for optimal performance. Part II of this series will delve into specific applications of supercritical fluid technology as it relates to aspects of medical isotope processing. The reader will note that very few applications of this technology to Nuclear Medicine have been published. Many potential applications cited within the context of this review derive from preliminary studies carried out in the author's laboratory. These examples are presented to spark interest in future developments of this nature. Copyright © 2003 John Wiley & Sons, Ltd. [source] A new method for the derivation of the closed nets in the phase diagram space of multisystems.JOURNAL OF METAMORPHIC GEOLOGY, Issue 5 2004Abstract A new convenient combinatorial method is developed here to derive the invariant points in multisystem closed nets , the absent phase substitution (APS) method. It substantially simplifies the derivation of the closed nets in multisystems with many components and phases. For the multisystems whose total phase number (NPS) , twice the number of the absent phases (m) in an invariant assemblage, the method can yield regular closed nets with or without globally absent phases; for other multisystems, the method can yield the regular closed nets with globally absent phases. As examples, the APS method was used to predict: (1) the regular closed nets of unary to quinary n + 4-phase multisystems, unary 6-phase multisystem and ternary 8-phase multisystem; (2) the basic properties of the regular closed nets of the quaternary and quinary multisystems with n + 4 and n + 5 phases. Two multisystems were chosen to demonstrate how to select a realistic closed net from the numerous possible closed nets of a complex multisystem, and how to derive a realistic partially closed-net, closed-net-diagram and the related realistic straight-line-net-diagram. Comparisons of our APS method for the derivation of complicated closed nets with other methods indicate that this method is much simpler and more efficient. [source] The glutamate/GABA-glutamine cycle: aspects of transport, neurotransmitter homeostasis and ammonia transferJOURNAL OF NEUROCHEMISTRY, Issue 3 2006Lasse K. Bak Abstract Neurons are metabolically handicapped in the sense that they are not able to perform de novo synthesis of neurotransmitter glutamate and ,-aminobutyric acid (GABA) from glucose. A metabolite shuttle known as the glutamate/GABA-glutamine cycle describes the release of neurotransmitter glutamate or GABA from neurons and subsequent uptake into astrocytes. In return, astrocytes release glutamine to be taken up into neurons for use as neurotransmitter precursor. In this review, the basic properties of the glutamate/GABA-glutamine cycle will be discussed, including aspects of transport and metabolism. Discussions of stoichiometry, the relative role of glutamate vs. GABA and pathological conditions affecting the glutamate/GABA-glutamine cycling are presented. Furthermore, a section is devoted to the accompanying ammonia homeostasis of the glutamate/GABA-glutamine cycle, examining the possible means of intercellular transfer of ammonia produced in neurons (when glutamine is deamidated to glutamate) and utilized in astrocytes (for amidation of glutamate) when the glutamate/GABA-glutamine cycle is operating. A main objective of this review is to endorse the view that the glutamate/GABA-glutamine cycle must be seen as a bi-directional transfer of not only carbon units but also nitrogen units. [source] Estimation of global structural and transport properties of peptides through the modeling of their CZE mobility dataJOURNAL OF SEPARATION SCIENCE, JSS, Issue 16 2010Maria V. Piaggio Abstract Peptide electrophoretic mobility data are interpreted through a physicochemical CZE model, providing estimates of the equivalent hydrodynamic radius, hydration, effective and total charge numbers, actual ionizing pK, pH-near molecule and electrical permittivity of peptide domain, among other basic properties. In this study, they are used to estimate some peptide global structural properties proposed, providing thus a distinction among different peptides. Therefore, the solvent drag on the peptide is obtained through a characteristic friction power coefficient of the number of amino acid residues, defined from the global chain conformation in solution. As modeling of the effective electrophoretic mobility of peptides is carried out in terms of particle hydrodynamic size and shape coupled to hydration and effective charge, a packing dimension related to chain conformation within the peptide domain may be defined. In addition, the effective and total charge number fractions of peptides provide some clues on the interpretation of chain conformations within the framework of scaling laws. Furthermore, the model estimates transport properties, such as sedimentation, friction and diffusion coefficients. As the relative numbers of ionizing, polar and non-polar amino acid residues vary in peptides, their global structural properties defined here change appreciably. Needs for further research are also discussed. [source] High-energy X-ray diffraction using the Pixium 4700 flat-panel detectorJOURNAL OF SYNCHROTRON RADIATION, Issue 4 2009J. E. Daniels The Pixium 4700 detector represents a significant step forward in detector technology for high-energy X-ray diffraction. The detector design is based on digital flat-panel technology, combining an amorphous Si panel with a CsI scintillator. The detector has a useful pixel array of 1910 × 2480 pixels with a pixel size of 154,µm × 154,µm, and thus it covers an effective area of 294,mm × 379,mm. Designed for medical imaging, the detector has good efficiency at high X-ray energies. Furthermore, it is capable of acquiring sequences of images at 7.5 frames per second in full image mode, and up to 60 frames per second in binned region of interest modes. Here, the basic properties of this detector applied to high-energy X-ray diffraction are presented. Quantitative comparisons with a widespread high-energy detector, the MAR345 image plate scanner, are shown. Other properties of the Pixium 4700 detector, including a narrow point-spread function and distortion-free image, allows for the acquisition of high-quality diffraction data at high X-ray energies. In addition, high frame rates and shutterless operation open new experimental possibilities. Also provided are the necessary data for the correction of images collected using the Pixium 4700 for diffraction purposes. [source] COMPARISON OF PHYSICAL PROPERTIES OF AGAR, LOW GEL STRENGTH AGAR AND GELATIN, AS SUPPLEMENTARY FOOD FOR PEOPLE WITH SWALLOWING DIFFICULTYJOURNAL OF TEXTURE STUDIES, Issue 4 2002ATSUKO IGARASHI ABSTRACT Low gel strength agar (LGSA), recently developed as a supplementary food for swallowing was compared with ordinary agar and gelatin. LGSA was developed to have physical properties close to that of gelatin, while keeping one property of agar, i. e. its setting temperature which can be controlled comparatively easier than gelatin. Each specimen was prepared with and without orange flavor. After determination of their basic properties, i. e. hardness, adhesiveness, cohesiveness and gumminess, three samples of two flavors, six in all, were studied for ease of swallowing using electromyography and sensory evaluation, on middle age (40 to 60 years old) and senior age (60 to 70 years old) subjects. Those experiments revealed nearly the same results with all samples, except for a slight difference in gumminess in LGSA and gelatin. No significant difference in electromyograms were noted in six samples or with age of subjects. It is feasible to employ agar materials together with gelatin in institutions whose members have swallowing disorders. [source] Mass and lifetime measurements of exotic nuclei in storage ringsMASS SPECTROMETRY REVIEWS, Issue 5 2008Bernhard Franzke Abstract Mass and lifetime measurements lead to the discovery and understanding of basic properties of matter. The isotopic nature of the chemical elements, nuclear binding, and the location and strength of nuclear shells are the most outstanding examples leading to the development of the first nuclear models. More recent are the discoveries of new structures of nuclides far from the valley of stability. A new generation of direct mass measurements which allows the exploration of extended areas of the nuclear mass surface with high accuracy has been opened up with the combination of the Experimental Storage Ring ESR and the FRragment Separator FRS at GSI Darmstadt. In-flight separated nuclei are stored in the ring. Their masses are directly determined from the revolution frequency. Dependent on the half-life two complementary methods are applied. Schottky Mass Spectrometry SMS relies on the measurement of the revolution frequency of electron cooled stored ions. The cooling time determines the lower half-life limit to the order of seconds. For Isochronous Mass Spectrometry IMS the ring is operated in an isochronous ion-optical mode. The revolution frequency of the individual ions coasting in the ring is measured using a time-of-flight method. Nuclides with lifetimes down to microseconds become accessible. With SMS masses of several hundreds nuclides have been measured simultaneously with an accuracy in the 2,×,10,7 -range. This high accuracy and the ability to study large areas of the mass surface are ideal tools to discover new nuclear structure properties and to guide improvements for theoretical mass models. In addition, nuclear half-lives of stored bare and highly charged ions have been measured. This new experimental development is a significant progress since nuclear decay characteristics are mostly known for neutral atoms. For bare and highly charged ions new nuclear decay modes become possible, such as bound-state beta decay. Dramatic changes in the nuclear lifetime have been observed in highly charged ions compared to neutral atoms due to blocking of nuclear decay channels caused by the modified atomic interaction. High ionization degrees prevail in hot stellar matter and thus these experiments have great relevance for the understanding of the synthesis of elements in the universe and astrophysical scenarios in general. © 2008 Wiley Periodicals, Inc., Mass Spec Rev 27: 428,469, 2008 [source] A one-parameter calculus for symmetric domainsMATHEMATISCHE NACHRICHTEN, Issue 9-10 2007Jonathan Arazy Abstract We introduce a parameter dependent operator calculus on hermitian symmetric domains, interpolating the Toeplitz and Weyl calculus, and establish its basic properties including the Berezin transform for rank 1 domains. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Metamaterial inclusions based on grid-graph Hamiltonian pathsMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 12 2006Vincenzo Pierro Abstract This article deals with a study of novel classes of metamaterial inclusions based on space-filling curves. The graph,theoretic Hamiltonian-path (HP) concept is exploited to construct a fairly broad class of space-filling curve geometries that include as special cases the well-known Hilbert an Peano curves whose application to metamaterial inclusions has recently been proposed. In this framework, the basic properties of HP are briefly reviewed, and a full-wave study of the electromagnetic properties of representative grid-graph HP geometries is carried out. Applications to metamaterial inclusions are explored, with focus on artificial magnetic conductors with reduced polarization-sensitivity. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48:2520,2524, 2006; Published online in Wiley InterScience (www.interscience.wiley.com).DOI 10.1002/mop.21982 [source] On the convergence of Fourier series of computable Lebesgue integrable functionsMLQ- MATHEMATICAL LOGIC QUARTERLY, Issue 5 2010Philippe Moser Abstract This paper studies how well computable functions can be approximated by their Fourier series. To this end, we equip the space of Lp -computable functions (computable Lebesgue integrable functions) with a size notion, by introducing Lp -computable Baire categories. We show that Lp -computable Baire categories satisfy the following three basic properties. Singleton sets {f } (where f is Lp -computable) are meager, suitable infinite unions of meager sets are meager, and the whole space of Lp -computable functions is not meager. We give an alternative characterization of meager sets via Banach-Mazur games. We study the convergence of Fourier series for Lp -computable functions and show that whereas for every p > 1, the Fourier series of every Lp -computable function f converges to f in the Lp norm, the set of L1 -computable functions whose Fourier series does not diverge almost everywhere is meager (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Radiative torques: analytical model and basic propertiesMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 3 2007A. Lazarian ABSTRACT We attempt to get a physical insight into grain alignment processes by studying basic properties of radiative torques (RATs). For this purpose we consider a simple toy model of a helical grain that reproduces well the basic features of RATs. The model grain consists of a spheroidal body with a mirror attached at an angle to it. Being very simple, the model allows analytical description of RATs that act upon it. We show a good correspondence of RATs obtained for this model and those of irregular grains calculated by ddscat. Our analysis of the role of different torque components for grain alignment reveals that one of the three RAT components does not affect the alignment, but induces only for grain precession. The other two components provide a generic alignment with grain long axes perpendicular to the radiation direction, if the radiation dominates the grain precession, and perpendicular to magnetic field, otherwise. The latter coincides with the famous predictions of the Davis,Greenstein process, but our model does not invoke paramagnetic relaxation. In fact, we identify a narrow range of angles between the radiation beam and the magnetic field, for which the alignment is opposite to the Davis,Greenstein predictions. This range is likely to vanish, however, in the presence of thermal wobbling of grains. In addition, we find that a substantial part of grains subjected to RATs gets aligned with low angular momentum, which testifies that most of the grains in diffuse interstellar medium do not rotate fast, that is, rotate with thermal or even subthermal velocities. This tendency of RATs to decrease grain angular velocity as a result of the RAT alignment decreases the degree of polarization, by decreasing the degree of internal alignment, that is, the alignment of angular momentum with the grain axes. For the radiation-dominated environments, we find that the alignment can take place on the time-scale much shorter than the time of gaseous damping of grain rotation. This effect makes grains a more reliable tracer of magnetic fields. In addition, we study a self-similar scaling of RATs as a function of ,/aeff. We show that the self-similarity is useful for studying grain alignment by a broad spectrum of radiation, that is, interstellar radiation field. [source] Properties of some stochastic orders: A unified studyNAVAL RESEARCH LOGISTICS: AN INTERNATIONAL JOURNAL, Issue 2 2004Taizhong Hu Abstract The notions of the likelihood ratio order of degree s (s , 0) are introduced for both continuous and discrete integer-valued random variables. The new orders for s = 0, 1, and 2 correspond to the likelihood ratio, hazard rate, and mean residual life orders. We obtain some basic properties of the new orders and their up shifted stochastic orders, and derive some closure properties of them. Such a study is meaningful because it throws an important light on the understanding of the properties of the likelihood ratio, hazard rate, and mean residual life orders. On the other hand, the properties of the new orders have potential applications. © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2004. [source] | ||||||||||||||||||||||||||||||||||