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Different States (different + states)
Selected AbstractsTribological Studies of a Zr-Based Glass-Forming Alloy with Different States,ADVANCED ENGINEERING MATERIALS, Issue 11 2009Feng Jiang Abstract The tribological characteristics of a glass-forming alloy, Zr52.5Cu17.9Ni14.6Al10.0Ti5.0, in atomic percent (at.%, Vit 105), with different microstructural states have been investigated. Friction and wear studies were conducted using a ball-on-flat reciprocating sliding apparatus against an AISI E52100 bearing steel under dry condition. The observed wear resistance in an ascending order is: the deformed, creep-tested, and as-cast states. Wear analyses suggested that the wear processes of glass-forming alloys involved abrasion, adhesion, and oxidation. The differences in hardness, free volume, and brittleness in different states significantly affected the friction and wear behaviors of the glass-forming alloys. [source] Deformation by examples: a density flow approachCOMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 2 2007Hoi-Chau Leung Abstract In this article, a shape transformation technique is introduced for deforming objects based on a given deformation example. The example consists of two reference shapes representing two different states of an object. The reference shapes are assumed to morph from one state to the other. The evolution between the two reference shapes determines the shape transformation function. Any given objects can then be deformed by the same transformation. A continuous 4D Radial Basis Function is used to construct a density flow field (an extension of the optical flow in computer vision) representing the shape transformation of the example in 3-space. Objects embedded in the density flow field are deformed by moving vertices of the objects along the density flow vectors. Additional parameters are introduced to control the process of the deformation. This provides explicit control on the shape of the object obtained in the deformation process. Copyright © 2007 John Wiley & Sons, Ltd. [source] Performance analysis and improvement for BitTorrent-like file sharing systemsCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 13 2007Ye Tian Abstract In this paper, we present a simple mathematical model for studying the performance of the BitTorrent (http://www.bittorrent.com) file sharing system. We are especially interested in the distribution of peers in different states of the download job progress. With the model we find that the distribution of the download peers follows an asymmetric U-shaped curve under the stable state, due to BitTorrent's unchoking strategies. In addition, we find that the seeds' departure rate and the download peers' abort rate will influence the peer distribution in different ways notably. We also analyze the content availability under the dying process of the BitTorrent file sharing system. We find that the system's stability deteriorates with decreasing and unevenly distributed online peers, and BitTorrent's built-in ,tit-for-tat' unchoking strategy could not help to preserve the integrity of the file among the download peers. We propose an innovative ,tit-for-tat' unchoking strategy which enables more peers to finish the download job and prolongs the system's lifetime. By playing our innovative strategy, download peers could cooperate to improve the stability of the system by making a trade-off between the current downloading rate and the future service availability. Finally, experimental results are presented to validate our analytical results and support our proposals. Copyright © 2007 John Wiley & Sons, Ltd. [source] Multiple states based temporal consistency for dynamic verification of fixed-time constraints in Grid workflow systemsCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 7 2007Jinjun Chen Abstract To verify fixed-time constraints in Grid workflow systems, consistency and inconsistency conditions have been defined in conventional verification work. However, with a view of the run-time uncertainty of activity completion duration, we argue that, although the conventional consistency condition is feasible, the conventional inconsistency condition is too restrictive and covers several different states. These states, which are handled conventionally by the same exception handling, should be handled differently for the purpose of cost saving. Therefore, in this paper, we divide conventional inconsistency into weak consistency, weak inconsistency and strong inconsistency and treat conventional consistency as strong consistency. Correspondingly, we develop some algorithms on how to verify them. Based on this, for weak consistency we present a method on how to adjust it to strong consistency by using mean activity time redundancy and temporal dependency between fixed-time constraints. For weak inconsistency, we analyse briefly why it can be handled by simpler and more cost-saving exception handling while for strong inconsistency, the conventional exception handling remains deployed. The final quantitative evaluation demonstrates that our research can achieve better cost-effectiveness than the conventional work. Copyright © 2006 John Wiley & Sons, Ltd. [source] Histology, histochemistry and morphometry of the ovary of the adult plains viscacha (Lagostomus maximus) in different reproductive stagesACTA ZOOLOGICA, Issue 4 2009Mirta Alicia Flamini Abstract Lagostomus maximus is a South American Hystricognathi rodent whose reproductive behaviour shows characteristics unusual for mammals, such as polyovulation (200,800 oocytes) and a high rate of embryo mortality. Thirty-six mature females captured in the province of Buenos Aires showed different physiological reproductive stages. Most of them presented a postpartum oestrus in August,September. This characteristic is different from that reported in other geographical areas. The stages considered were: anoestrus, follicular phase, early pregnancy and late pregnancy. The ovaries were light-pink and smooth and presented a tortuous cord-like aspect. Many primordial follicles were found in all the females studied. Follicles in different states of maturation and primary and accessory corpora lutea were observed in the cortex. These structures were smaller than those present in other related species. Follicles did not project into the surface of the organ. Calcified follicles of diverse size were found in all the ovaries. Atretic follicles were found in all the stages analysed. Interstitial tissue surrounding the follicles and the corpora lutea was also observed. The number and proportion of different cortical structures varied in the physiological stages analysed. The ovaries of the viscacha have differential characteristics in comparison to other Hystricognathi, some of them related to polyovulation. [source] Monitoring of protein profiles for the optimization of recombinant fermentation processes using public domain databasesELECTROPHORESIS, Issue 1-2 2003Karin Dürrschmid Abstract The expression of human superoxide dismutase in fed-batch fermentation of E. coli HMS174(DE3)(pET3ahSOD) was studied as model system. Due to the frequently used strong T7 promoter system a high metabolic load is exerted, which triggers stress response mechanisms and finally leads to the differentiation of the host cell. As a consequence, host cell metabolism is partly shifted from growth to survival accompanied by significant alterations of the protein pattern. In terms of process optimization two-dimensional electrophoresis deserves as a powerful tool to monitor these changes on protein level. For the analysis of samples derived from different states of recombinant protein production wide-range Immobiline Dry Strips pH 3,10 were used. In order to establish an efficient procedure for accelerated process optimization and to avoid costly and time-consuming analysis like mass spectrometry (MS), a database approach for the identification of significant changes of the protein pattern was evaluated. On average, 935 spots per gel were detected, whereby 50 are presumably stress-relevant. Out of these, 24 proteins could be identified by using the SWISS-2DPAGE database (www.expasy.ch/ch2d/). The identified proteins are involved in regulatory networks, energy metabolism, purine and pyrimidine nucleotide synthesis and translation. By this database approach, significant fluctuations of individual proteins in relation to recombinant protein production could be identified. Seven proteins show strong alterations (>100%) directly after induction and can therefore be stated as reliable marker proteins for the assessment of stress response. For distinctive interpretation of this highly specific information, a bioinformatic and statistic tool would be essential in order to perceive the role and contribution of individual proteins in stress response. [source] Tribological Studies of a Zr-Based Glass-Forming Alloy with Different States,ADVANCED ENGINEERING MATERIALS, Issue 11 2009Feng Jiang Abstract The tribological characteristics of a glass-forming alloy, Zr52.5Cu17.9Ni14.6Al10.0Ti5.0, in atomic percent (at.%, Vit 105), with different microstructural states have been investigated. Friction and wear studies were conducted using a ball-on-flat reciprocating sliding apparatus against an AISI E52100 bearing steel under dry condition. The observed wear resistance in an ascending order is: the deformed, creep-tested, and as-cast states. Wear analyses suggested that the wear processes of glass-forming alloys involved abrasion, adhesion, and oxidation. The differences in hardness, free volume, and brittleness in different states significantly affected the friction and wear behaviors of the glass-forming alloys. [source] In Situ Observation of Dynamic Recrystallization in the Bulk of Zirconium Alloy (Adv. Eng.ADVANCED ENGINEERING MATERIALS, Issue 8 2009Mater. The cover shows the in-situ diffraction setup. A fine synchrotron beam transmits the sample situated in a (heated) load frame and scatters into Debye-Scherrer cones. Large crystallites map onto spots onto the 2D detector rather than continuous rings. In the background, the intensity distribution of one selected reflection - here beta-Zr 110 - is plotted in color scale as a function of azimuthal angle (horizontal axis) and time (vertical axis) revealing the different states during thermo-mechanical processing. More details can be found in the article by K.-D. Liss on page 637. [source] A Framework for Valuing Derivative SecuritiesFINANCIAL MARKETS, INSTITUTIONS & INSTRUMENTS, Issue 5 2001Philip Gray This paper develops a general framework for valuing a wide range of derivative securities. Rather than focusing on the stochastic process of the underlying security and developing an instantaneously-riskless hedge portfolio, we focus on the terminal distribution of the underlying security. This enables the derivative security to be valued as the weighted sum of a number of component pieces. The component pieces are simply the different payoffs that the security generates in different states of the world, and they are weighted by the probability of the particular state of the world occurring. A full set of derivations is provided. To illustrate its use, the valuation framework is applied to plain-vanilla call and put options, as well as a range of derivatives including caps, floors, collars, supershares, and digital options. [source] From unambiguous quantum state discrimination to quantum state filteringFORTSCHRITTE DER PHYSIK/PROGRESS OF PHYSICS, Issue 2-3 2003J.A. Bergou Unambiguous discrimination among nonorthogonal but linearly independent quantum states is possible with a certain probability of success. Here, we consider a new variant of that problem. Instead of discriminating among all of the N different states, we now ask for less. We want to unambiguously assign the state to one of two complementary subsets of the set of N given non-orthogonal quantum states, each occurring with given a priori probabilities. We refer to the special case when one subset contains only one state and the other contains the remaining N -1 states as unambiguous quantum state filtering. We present an optimal analytical solution for the special case of N=3, and discuss the optimal strategy to unambiguously distinguish |,1, from the set {|,2,,|,3,}. For unambiguous filtering the subsets need not be linearly independent. We briefly discuss how to construct generalized interferometers (multiports) which provide a fully linear optical implementation of the optimal strategy. [source] Self-Assembling Peptide as a Potential Carrier for Hydrophobic Anticancer Drug Ellipticine: Complexation, Release and In Vitro DeliveryADVANCED FUNCTIONAL MATERIALS, Issue 1 2009Shan Yu Fung Abstract The self-assembling peptide EAK16-II is capable of stabilizing hydrophobic compounds to form microcrystal suspensions in aqueous solution. Here, the ability of this peptide to stabilize the hydrophobic anticancer agent ellipticine is investigated. The formation of peptide-ellipticine suspensions is monitored with time until equilibrium is reached. The equilibration time is found to be dependent on the peptide concentration. When the peptide concentration is close to its critical aggregation concentration, the equilibration time is minimal at 5,h. With different combinations of EAK16-II and ellipticine concentrations, two molecular states (protonated or cyrstalline) of ellipticine could be stabilized. These different states of ellipticine significantly affect the release kinetics of ellipticine from the peptide-ellipticine complex into the egg phosphatidylcholine vesicles, which are used to mimic cell membranes. The transfer rate of protonated ellipticine from the complex to the vesicles is much faster than that of crystalline ellipticine. This observation may also be related to the size of the resulting complexes as revealed from the scanning electron micrographs. In addition, the complexes with protonated ellipticine are found to have a better anticancer activity against two cancer cell lines, A549 and MCF-7. This work forms the basis for studies of the peptide-ellipticine suspensions in vitro and in vivo leading to future development of self-assembling peptide-based delivery of hydrophobic anticancer drugs. [source] Exploiting Chemical Switching in a Diels,Alder Polymer for Nanoscale Probe Lithography and Data Storage,ADVANCED FUNCTIONAL MATERIALS, Issue 11 2006B. Gotsmann Abstract Reversibly crosslinked polymer films have properties that are beneficial to scanned-probe data storage and lithographic applications that use thermomechanical nanoindentation as a write or expose mechanism. The novel polymer under study contains linkages based on thermally reversible Diels,Alder crosslinking. Thermomechanical properties on the nanometer scale are analyzed by indentation experiments on polymer thin films using heated tips. The underlying indentation mechanism is studied at varying tip temperatures and indentation times, revealing Arrhenius kinetics. This is in contrast to the Williams,Landau,Ferry kinetics usually observed for polymer systems. The discrepancy is explained by the reversible crosslinking incorporated into the structure of the polymer that allows switching between two different states: a rigid, highly crosslinked, low-temperature state, and a deformable, fragmented, high-temperature state. An individual indentation volume of less than 10,20,L (10,000,molecule pairs) is estimated. These kinetics experiments demonstrate that a chemical reaction of only a few thousand molecules can be transduced into a mechanically measurable action. The ability to cycle between two sets of properties in these materials opens up new perspectives in lithography and data storage. Examples of data storage with densities up to 1,Tb,in.,2 and maskless lithography with resolution below 20,nm are demonstrated at writing times of 10,,s per bit/pixel. [source] Health Care and Pension Benefits for Construction Workers: TheRole of Prevailing Wage Laws Health Care and Pension Benefits for Construction WorkersINDUSTRIAL RELATIONS, Issue 2 2000Jeffrey S. Petersen This article examines the affect of state prevailing wage laws (PWLs) on the amount and mix of wages and benefits paid to construction workers. PWLs require contractors who win bids on state-financed construction projects to pay compensation rates equivalent to those prevailing in local construction markets. During 1982-1992, 6 states repealed their PWLs, 9 states who never had a PWL did not enact one, and 32 states kept their PWLs. Data from the Form 5500 series, the Census of Construction Industries, the Current Employment Statistics, and the Current Population Survey are combined to evaluate the effects of PWL repeals on compensation. When comparing the experiences of different states, PWLs enhance both wages and benefits, with the largest percentage increase going toward employer pension contributions. PWLs appear to create an incentive for both employers to pay and workers to accept a larger percentage of their total compensation in the form of benefits. [source] Bayesian estimation of traffic lane stateINTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING, Issue 1 2003Ivan Nagy Abstract Modelling of large transportation systems requires a reliable description of its elements that can be easily adapted to the specific situation. This paper offers mixture model as a flexible candidate for modelling of such element. The mixture model describes particular and possibly very different states of a specific system by its individual components. A hierarchical model built on such elements can describe complexes of big city communications as well as railway or highway networks. Bayesian paradigm is adopted for estimation of parameters and the actual component label of the mixture model as it serves well for the subsequent decision making. As a straightforward application of Bayesian method to mixture models leads to infeasible computations, an approximation is applied. For normal stochastic variations, the resulting estimation algorithm reduces to a simple recursive weighted least squares. The elementary modelling is demonstrated on a model of traffic flow state in a single point of a roadway. The examples for simulated as well as real data show excellent properties of the suggested model. They represent much wider set of extensive tests made. Copyright © 2003 John Wiley & Sons, Ltd. [source] Telomere Higher-Order Structure and Genomic InstabilityIUBMB LIFE, Issue 8 2003Terace Fletcher Abstract Telomeres, nucleoprotein complexes at the end of eukaryotic chromosomes, have vital roles in chromosome integrity. Telomere chromatin structure is both intricate and dynamic allowing for a variety of responses to several stimuli. A critical determinant in telomere structure is the G-strand overhang. Facilitated by telomeric proteins, the G-strand overhang stabilizes telomere higher-order assemblies most likely by adopting unusual DNA structures. These structures influence activities that occur at the chromosome end. Dysfunctional telomeres induce signals resulting in cell growth arrest or death. To overcome telomere dysfunction, cancer cells activate the DNA polymerase, telomerase. The presence of telomerase at the telomere may establish a particular telomeric state. If the chromosome ends of cancer and normal cells exist in different states, cancer-specific telomere structures would offer a unique chemotherapeutic target. IUBMB Life, 55: 443-449, 2003 [source] Implementing bedside handover: strategies for change managementJOURNAL OF CLINICAL NURSING, Issue 17-18 2010Anne McMurray Aims and objectives., To identify factors influencing change in two hospitals that moved from taped and verbal nursing handover to bedside handover. Background., Bedside handover is based on patient-centred care, where patients participate in communicating relevant and timely information for care planning. Patient input reduces care fragmentation, miscommunication-related adverse events, readmissions, duplication of services and enhances satisfaction and continuity of care. Design., Analysing change management was a component of a study aimed at developing a standard operating protocol for bedside handover communication. The research was undertaken in two regional acute care hospitals in two different states of Australia. Method., Data collection included 532 semi-structured observations in six wards in the two hospitals and 34 in-depth interviews conducted with a purposive sample of nursing staff involved in the handovers. Observation and interview data were analysed separately then combined to generate thematic analysis of factors influencing the change process in the transition to bedside handover. Results and conclusion., Themes included embedding the change as part of the big picture, the need to link the project to standardisation initiatives, providing reassurance on safety and quality, smoothing out logistical difficulties and learning to listen. We conclude that change is more likely to be successful when it is part of a broader initiative such as a quality improvement strategy. Relevance to clinical practice., Nurses are generally supportive of quality improvement initiatives, particularly those aimed at standardising care. For successful implementation, change managers should be mindful of clinicians' attitudes, motivation and concerns and their need for reassurance when changing their practice. This is particularly important when change is dramatic, as in moving from verbal handover, conducted in the safety of the nursing office, to bedside handover where there is greater transparency and accountability for the accuracy and appropriateness of communication content and processes. [source] Basic ingredients of free energy calculations: A reviewJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 8 2010Clara D. Christ Abstract Methods to compute free energy differences between different states of a molecular system are reviewed with the aim of identifying their basic ingredients and their utility when applied in practice to biomolecular systems. A free energy calculation is comprised of three basic components: (i) a suitable model or Hamiltonian, (ii) a sampling protocol with which one can generate a representative ensemble of molecular configurations, and (iii) an estimator of the free energy difference itself. Alternative sampling protocols can be distinguished according to whether one or more states are to be sampled. In cases where only a single state is considered, six alternative techniques could be distinguished: (i) changing the dynamics, (ii) deforming the energy surface, (iii) extending the dimensionality, (iv) perturbing the forces, (v) reducing the number of degrees of freedom, and (vi) multi-copy approaches. In cases where multiple states are to be sampled, the three primary techniques are staging, importance sampling, and adiabatic decoupling. Estimators of the free energy can be classified as global methods that either count the number of times a given state is sampled or use energy differences. Or, they can be classified as local methods that either make use of the force or are based on transition probabilities. Finally, this overview of the available techniques and how they can be best used in a practical context is aimed at helping the reader choose the most appropriate combination of approaches for the biomolecular system, Hamiltonian and free energy difference of interest. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010 [source] The influence of drug kinetics in blood on the calculation of oral bioavailability in linear pharmacokinetics: The traditional equation may considerably overestimate the true value,JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 4 2006Leonid M. Berezhkovskiy Abstract A common calculation of oral bioavailability is based on the comparison of the areas under the concentration-time curves after intravenous and oral drug administration. It does not take into account that after the oral dosing a drug enters the systemic circulation in different states, that is, as free fraction, protein bound and partitioned into blood cells, and plasma lipids, while after intravenous input it is introduced into the systemic circulation only as a free fraction. Consideration of this difference leads to a novel equation for the oral bioavailability. In general, the traditional calculation overestimates the oral bioavailability. For a widely applied model of a linear pharmacokinetic system with central (plasma) drug elimination it is shown that the traditional calculation of the oral bioavailability could substantially overestimate the true value. If the existence of an immediate equilibrium between different drug fractions in blood is assumed, the obtained equation becomes identical to the traditional one. Thus the deviation of oral bioavailability from the value given by a common calculation appears to be a kinetic phenomenon. The difference could be significant for the drugs with the rate constant of elimination from plasma of the same order of magnitude or greater than the dissociation rate constant of drug,protein complexes, or the off-rate constant of partitioning from the blood cells, if the blood concentration profiles were used to calculate the oral bioavailability. © 2006 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 95:834,848, 2006 [source] Drama activities as ideational resources for primary-grade children in urban science classroomsJOURNAL OF RESEARCH IN SCIENCE TEACHING, Issue 3 2010Maria Varelas Abstract In this study we explored how dramatic enactments of scientific phenomena and concepts mediate children's learning of scientific meanings along material, social, and representational dimensions. These drama activities were part of two integrated science-literacy units, Matter and Forest, which we developed and implemented in six urban primary-school (grades 1st,3rd) classrooms. We examine and discuss the possibilities and challenges that arise as children and teachers engaged in scientific knowing through such experiences. We use Halliday's (1978. Language as social semiotic: The social interpretation of language and meaning. Baltimore, MD: University Park Press) three metafunctions of communicative activity,ideational, interpersonal, and textual,to map out the place of the multimodal drama genre in elementary urban school science classrooms of young children. As the children talked, moved, gestured, and positioned themselves in space, they constructed and shared meanings with their peers and their teachers as they enacted their roles. Through their bodies they negotiated ambiguity and re-articulated understandings, thus marking this embodied meaning making as a powerful way to engage with science. Furthermore, children's whole bodies became central, explicit tools used to accomplish the goal of representing this imaginary scientific world, as their teachers helped them differentiate it from the real world of the model they were enacting. Their bodies operated on multiple mediated levels: as material objects that moved through space, as social objects that negotiated classroom relationships and rules, and as metaphorical entities that stood for water molecules in different states of matter or for plants, animals, or non-living entities in a forest food web. Children simultaneously negotiated meanings across all of these levels, and in doing so, acted out improvisational drama as they thought and talked science. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 47: 302,325, 2010 [source] Experimental Study on Phase Transformation Between MgB2 and MgB4JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 7 2007S. C. Yan Using X-ray diffraction (XRD), scanning electron microscope (SEM), and differential scanning calorimetry (DSC), we have investigated the reaction between MgB4 and Mg in its solid, liquid, and gas physical states. The XRD results indicate that the reaction of MgB4+Mg=2MgB2 always occurs independently of the different states of Mg. DSC measurements show that the solid,solid reaction MgB4(s)+Mg(s)=2MgB2(s), the Mg melting Mg(s),Mg(l), and the Mg volatilization occur in turn with increasing temperature for mixed (MgB4+Mg) powder with a nominal stoichiometry of MgB2. SEM observations indicate that the resulting synthesized MgB2 samples, obtained from the MgB4+Mg mixtures, have a denser microstructure than those obtained directly from Mg+B mixtures. On the basis of XRD, DSC, and SEM results, a kinetic model for the reaction between MgB4 and Mg is proposed. [source] Holistic trajectories: a study of combined employment, housing and family careers by using multiple-sequence analysisJOURNAL OF THE ROYAL STATISTICAL SOCIETY: SERIES A (STATISTICS IN SOCIETY), Issue 1 2007Gary Pollock Summary., Social science applications of sequence analysis have thus far involved the development of a typology on the basis of an analysis of one or two variables which have had a relatively low number of different states. There is a yet unexplored potential for sequence analysis to be applied to a greater number of variables and thereby a much larger state space. The development of a typology of employment experiences, for example, without reference to data on changes in housing, marital and family status is arguably inadequate. The paper demonstrates the use of sequence analysis in the examination of multivariable combinations of status as they change over time and shows that this method can provide insights that are difficult to achieve through other analytic methods. The data that are examined here provide support to intuitive understandings of clusters of common experiences which are both life course specific and related to socio-economic factors. Housing tenure is found to be of key importance in understanding the holistic trajectories that are examined. This suggests that life course trajectories are sharply differentiated by experience of social housing. [source] Quantitative detection of hepatitis B virus DNA in serum by a new rapid real-time fluorescence PCR assayJOURNAL OF VIRAL HEPATITIS, Issue 6 2001R. Jardi A sensitive and accurate HBV DNA quantification assay is essential for monitoring hepatitis B virus (HBV) replication. This study evaluated a real-time PCR method performed in the LightCyclerTM analyser for quantitative HBV DNA assay. HBV DNA results with this method were compared with those obtained using a branched-chain DNA (bDNA) solution hybridization assay. Real-time PCR was performed using two adjacent fluorescently labelled probes and primers corresponding to the HBV core gene. The same standard employed in the bDNA assay was used for calibration. Serum samples came from 193 HBV surface antigen (HBsAg)-positive patients (34 HBV e antigen (HBeAg)-positive and 93 with antibody to HBeAg (anti-HBe)), and 66 asymptomatic HBV carriers. In addition, we analysed serum samples from 8 anti-HBe-positive patients who had been receiving lamivudine treatment for more than three years. A linear standard curve was seen in the range from 103 to 108 copies/mL. In the reproducibility analysis, intra-assay coefficient of variation (CVs) at two known HBV DNA concentrations were 4% and 2% and interassay CVs were 6% and 4%. The median of serum HBV DNA by real-time PCR was 9.2 × 108 copies/mL in HBeAg-positive patients with persistently elevated alanine aminotransferase (ALT) levels, 1.3 × 107 copies/mL in anti-HBe-positive cases with persistently elevated ALT levels, 3.7 × 104 copies/mL in anti-HBe-positive patients with fluctuating ALT levels and 104 copies/mL in asymptomatic HBV carriers. The differences in HBV DNA levels among the various groups studied were statistically significant (P < 0.05). The cut-off between chronic hepatitis patients and asymptomatic carriers was found to be at a serum HBV DNA concentration of 5 × 104 copies/mL. Of the 109 serum samples with a viral load < 7.5 × 105 (negative by bDNA assay) 44 (40%) were positive by real-time PCR: 24 (56%) chronic hepatitis and 20 (33%) asymptomatic carriers. There was a positive association between HBV DNA levels determined by real-time PCR and ALT levels (P < 0.05), which was not observed with the bDNA assay for HBV DNA quantification. At 12 months of lamivudine treatment, 6 patients (75%) showed HBV DNA levels < 5 × 104 copies/mL (range < 103,2 × 103), significantly lower than at baseline. At 36 months, 2 of 8 (25%) showed HBV DNA levels persistently lower than 5 × 104 copies/mL (1.7 × 103, 6 × 103). The LightCycler quantitative real-time PCR is a practical, sensitive, reproducible single-tube assay with a wide dynamic range of detection. The assay is automatic except for DNA extraction and the running time is only 70 min. The LightCycler real-time PCR is useful for identifying different states of HBV infection and for evaluating the efficacy of viral therapy. [source] Probing the Contraction and Association of Polystyrene Chains in Semidilute Solution by Non-Radiative Energy TransferMACROMOLECULAR RAPID COMMUNICATIONS, Issue 2 2008Fangfang Tao Abstract The interchain contraction and association of polystyrene in semidilute solution near the , temperature are studies using NET. The results reveal that during a drop of temperature, polystyrene chains pass through different states: a smooth change of conformation at temperatures above the , temperature, an accelerated contraction and association, aggregation of polymer chains, and then further continuous contraction below the , temperature. A pronounced hysteresis is observed during repeated heating. A viscosity study of the same solution was compared with the NET results. It indicates that NET can effectively be used to study conformational changes like contraction and association of polymer chains in a semidilute solution. [source] On the Scaling Behavior of the Force/Extension Relation of a ChainMACROMOLECULAR THEORY AND SIMULATIONS, Issue 7 2010Marios K. Kosmas Abstract Applying an extending force F along the end-to-end vector r of a chain enlarges the initial size ,i , |ri| leading to a final state with ,f larger than ,i. Assuming a power law dependence of the size , , N, of the chain on its length N, at the two different states with different exponents ,i and ,f, a scaling relationship is derived between the measure of the extending force F and the extension , of the chain. The exponent , of the force/extension relation, , , F,, depends on both exponents ,i and ,f of the initial and the final states. A relation between , and the exponents ,i and ,f is derived which permits the explanation of previous results and predicts some more. The scaling behavior is checked with the exactly soluble model of a random walk under a force. [source] Conformational states of human H-Ras detected by high-field EPR, ENDOR, and 31P NMR spectroscopy ,MAGNETIC RESONANCE IN CHEMISTRY, Issue S1 2005Michael Spoerner Abstract Ras is a central constituent of the intracellular signal transduction that switches between its inactive state with GDP bound and its active state with GTP bound. A number of different X-ray structures are available. Different magnetic resonance techniques were used to characterise the conformational states of the protein and are summarised here. 31P NMR spectroscopy was used as probe for the environment of the phosphate groups of the bound nucleotide. It shows that in liquid solution additional conformational states in the GDP as well as in the GTP forms coexist which are not detected by X-ray crystallography. Some of them can also be detected by solid-state NMR in the micro crystalline state. EPR and ENDOR spectroscopy were used to probe the environment of the divalent metal ion (Mg2+ was replaced by Mn2+) bound to the nucleotide in the protein. Here again different states could be observed. Substitution of normal water by 17O-enriched water allowed the determination of the number of water molecules in the first coordination sphere of the metal ion. In liquid solution, they indicate again the existence of different conformational states. At low temperatures in the frozen state ENDOR spectroscopy suggests that only one state exists for the GDP- and GTP-bound form of Ras, respectively. Copyright © 2005 John Wiley & Sons, Ltd. [source] Internal WWAN antenna for the clamshell mobile phone with various chassis shapesMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 9 2010Kin-Lu Wong Abstract Stable performances of an internal WWAN antenna applied in the clamshell mobile phone with various chassis shapes are obtained. Six different states including five possible operating states and one closed state (idle condition) of the clamshell mobile phone, wherein the chassis shapes (main ground and upper ground) vary greatly, are studied. The WWAN antenna is mounted at the bottom of the main ground, and there are three connecting positions between the main ground and the upper ground. For each operating states, the upper ground is connected to the main ground at one of the three connecting positions. At each position, a band-stop circuit formed by two parallel LC chip elements is embedded, which is designed to excite a parallel resonance at around 900 MHz and hence leads to very high impedance seen into the upper ground in the 900 MHz band. This greatly decreases the excited surface currents on the upper ground, making the presence of the upper ground to have very small effects on the performances of the WWAN antenna mounted at the bottom of the main ground. At around 1900 MHz, owing to its shorter wavelength, the surface currents on the upper ground excited by the WWAN antenna on the main ground are small. Thus, over both the 900- and 1900-MHz bands, the various orientations of the upper ground to the main ground cause small effects on the WWAN antenna embedded therein. Details of the obtained results are presented. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 2148,2154, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25413 [source] The Stepparent Relationship Index: Development, validation, and associations with stepchildren's perceptions of stepparent communication competence and closenessPERSONAL RELATIONSHIPS, Issue 2 2006PAUL SCHRODT There is a growing consensus among family researchers that many of the challenges facing members of stepfamilies revolve around the role of the stepparent. Using schema theory, this study extends recent research on the stepparent role by developing an empirically reliable measure for the primary dimensions that stepchildren identify as part of their stepparent relationship schemas. Participants included 522 young adult stepchildren from 4 different states who completed an inventory assessing key dimensions of the stepparent-stepchild relationship, as well as stepchildren's perceptions of stepparents' communication competence and closeness. The results produced a new multidimensional measure, the Stepparent Relationship Index, as three dimensions of the stepparent-stepchild relationship emerged from factor analytic techniques: positive regard, (step)parental authority, and affective certainty. Each subscale produced acceptable reliability estimates, and initial evidence of concurrent validity was obtained. [source] In-situ IR synchrotron mapping ellipsometry on stimuli-responsive PAA-b-PS/PEG mixed polymer brushesPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 2 2010Dennis Aulich Abstract A binary polymer brush consisting of weak polyelectrolytes was investigated with infrared synchrotron mapping ellipsometry in-situ under the influence of different aqueous solutions. Thickness of the brush layer in dry state was ,15 nm. The brush, consisting of poly(ethylene glycol) and poly(acrylic acid)-b-poly(styrene) in a 50/50 composition was switched between two different states by changing the pH of the solution. An IR mapping ellipsometer at the IRIS beamline located at the BESSY II synchrotron facility in Berlin, Germany, was used for high lateral resolution in-situ measurements. The results show strong chemical changes in the brush layer due to COOH , COO, conversion of the PAA's carboxylic groups. Measurements with spot sizes of ,1 mm on different positions on the samples proved good homogeneity of the brush layer and the qualification of this method for investigation of ultrathin organic films in aqueous solutions in-situ with IR ellipsometry. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Nondestructive testing of polyaramide cables by longitudinal wave propagation: Study of the dynamic modulusPOLYMER ENGINEERING & SCIENCE, Issue 7 2000M. Ferreira It has been observed that cables at different states of fatigue had their own speed of longitudinal propagation of acoustic waves (1). This speed can be measured with piezoelectric captors and is proportional to the square root of the sonic modulus. Our experiments, which have been carried out on Technora cables of diameter 2 mm, show that the modulus obtained from the wave speed has the same behavior in fatigue as the modulus obtained from tensile tests. Furthermore, our experiments also show that the residual strength in the cable is proportional to the modulus. A nondestructive control of cables can hence be made from these sonic modulus measurements. [source] Who Learns from What in Policy Diffusion Processes?AMERICAN JOURNAL OF POLITICAL SCIENCE, Issue 3 2010Fabrizio Gilardi The idea that policy makers in different states or countries may learn from one another has fascinated scholars for a long time, but little systematic evidence has been produced so far. This article improves our understanding of this elusive argument by distinguishing between the,policy,and,political,consequences of reforms and by emphasizing the conditional nature of learning processes. Using a directed dyadic approach and multilevel methods, the analysis of unemployment benefits retrenchment in OECD countries demonstrates that policy makers learn selectively from the experience of others. Right governments tend to be more sensitive to information on the electoral consequences of reforms, while left governments are more likely to be influenced by their policy effects. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||