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Practical Importance (practical + importance)
Selected AbstractsParallel protein folding with STAPLCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 14 2005Shawna Thomas Abstract The protein-folding problem is a study of how a protein dynamically folds to its so-called native state,an energetically stable, three-dimensional conformation. Understanding this process is of great practical importance since some devastating diseases such as Alzheimer's and bovine spongiform encephalopathy (Mad Cow) are associated with the misfolding of proteins. We have developed a new computational technique for studying protein folding that is based on probabilistic roadmap methods for motion planning. Our technique yields an approximate map of a protein's potential energy landscape that contains thousands of feasible folding pathways. We have validated our method against known experimental results. Other simulation techniques, such as molecular dynamics or Monte Carlo methods, require many orders of magnitude more time to produce a single, partial trajectory. In this paper we report on our experiences parallelizing our method using STAPL (Standard Template Adaptive Parallel Library) that is being developed in the Parasol Lab at Texas A&M. An efficient parallel version will enable us to study larger proteins with increased accuracy. We demonstrate how STAPL enables portable efficiency across multiple platforms, ranging from small Linux clusters to massively parallel machines such as IBM's BlueGene/L, without user code modification. Copyright © 2005 John Wiley & Sons, Ltd. [source] Risk Uncertainty and Supply Chain Decisions: A Real Options PerspectiveDECISION SCIENCES, Issue 3 2010G. Tomas M. Hult ABSTRACT Supply chain risk uncertainty can create severe repercussions, thus it is not surprising that research interest in supply chain risk has been growing. While extant inquiry is informative, there is a lack of investigations that center on supply chain investment decisions when facing high levels of risk uncertainty. Given the potential dollar value involved in these decisions, an understanding of how these supply chain decisions are made is of significant theoretical and practical importance. Real options theory, with its focus on decision making under conditions of uncertainty, is an appealing theoretical lens for this endeavor. In essence, real options theory asserts that managerial decisions center on creating and then exercising or not exercising certain opportunities. To date, theorizing about and investigations of real options have used firms as their focus. Not yet examined are real options within supply chains that cross firm boundaries and drive much of the competitive activity in the modern economy. Accordingly, we extend real options theory to the supply chain context by examining how different types of options are approached relative to supply chain project investments. Specifically, we theorize how the options will be related to perceived value under conditions of high supply chain risk uncertainty. Overall, our investigation builds knowledge by extending real options theory to the supply chain context and by providing evidence suggesting some options operate differently in supply chains than they do in firms. [source] Service Personnel, Technology, and Their Interaction in Influencing Customer Satisfaction,DECISION SCIENCES, Issue 1 2006Craig M. Froehle ABSTRACT Managing both the technologies and the personnel needed for providing high-quality, multichannel customer support creates a complex and persistent operational challenge. Adding to this difficulty, it is still unclear how service personnel and these new communication technologies interact to influence the customer's perceptions of the service being provided. Motivated by both practical importance and inconsistent findings in the academic literature, this exploratory research examines the interaction of media richness, represented by three different technology contexts (telephone, e-mail, and online chat), with six customer service representative (CSR) characteristics and their influences on customer satisfaction. Using a large-sample customer survey data set, the article develops a multigroup structural equation model to analyze these interactions. Results suggest that CSR characteristics influence customer service satisfaction similarly across all three technology-mediated contexts. Of the characteristics studied, service representatives contribute to customer satisfaction more when they exhibit the characteristics of thoroughness, knowledgeableness, and preparedness, regardless of the richness of the medium used. Surprisingly, while three other CSR characteristics studied (courtesy, professionalism, and attentiveness) are traditionally believed to be important in face-to-face encounters, they had no significant impact on customer satisfaction in the technology-mediated contexts studied. Implications for both practitioners and researchers are drawn from the results and future research opportunities are discussed. [source] Bounds on Parameters in Panel Dynamic Discrete Choice ModelsECONOMETRICA, Issue 3 2006Bo E. Honoré Identification of dynamic nonlinear panel data models is an important and delicate problem in econometrics. In this paper we provide insights that shed light on the identification of parameters of some commonly used models. Using these insights, we are able to show through simple calculations that point identification often fails in these models. On the other hand, these calculations also suggest that the model restricts the parameter to lie in a region that is very small in many cases, and the failure of point identification may, therefore, be of little practical importance in those cases. Although the emphasis is on identification, our techniques are constructive in that they can easily form the basis for consistent estimates of the identified sets. [source] Mortgage Terminations, Heterogeneity and the Exercise of Mortgage OptionsECONOMETRICA, Issue 2 2000Yongheng Deng As applied to the behavior of homeowners with mortgages, option theory predicts that mortgage prepayment or default will be exercised if the call or put option is ,in the money' by some specific amount. Our analysis: tests the extent to which the option approach can explain default and prepayment behavior; evaluates the practical importance of modeling both options simultaneously; and models the unobserved heterogeneity of borrowers in the home mortgage market. The paper presents a unified model of the competing risks of mortgage termination by prepayment and default, considering the two hazards as dependent competing risks that are estimated jointly. It also accounts for the unobserved heterogeneity among borrowers, and estimates the unobserved heterogeneity simultaneously with the parameters and baseline hazards associated with prepayment and default functions. Our results show that the option model, in its most straightforward version, does a good job of explaining default and prepayment, but it is not enough by itself. The simultaneity of the options is very important empirically in explaining behavior. The results also show that there exists significant heterogeneity among mortgage borrowers. Ignoring this heterogeneity results in serious errors in estimating the prepayment behavior of homeowners. [source] Formation of an Olfactory Search Image for Explosives Odours in Sniffer Dogs,ETHOLOGY, Issue 7 2005Irit Gazit The term ,search image' refers to an animal's heightened ability to detect a specific cryptic prey, after experience with that prey. Formulated in 1960 by Tinbergen (Archives Neerlandaises de zoologie, vol. 13, pp. 265,343), the search image concept has been the subject of much research, albeit almost entirely based on visual search cues in birds of prey. Given the theoretical and practical importance of this concept for foraging or searching in general, we set out to investigate whether dogs could form olfactory search images for explosive odours. Seven experienced explosives detector dogs were first tested for their ability to detect 30 g of the explosives 2,4,6-trinitrotoluene (TNT), RDX + polyisobutylene + di(2-ethylhexyl)sebacate + fuel oil (C4) or pentaerythritol tetranitrate (PETN) placed in various containers randomly distributed along a 300-m limestone track. In consecutive stages of the experiment, we altered the relative percentages of the three explosives. The results showed that the percentage of TNT containers detected by the dogs increased in trials that followed placing of a high percentage of TNT relative to other explosives and decreased in trials that follwed placing of a relatively low percentage of TNT containers. The percentage detection of C4 and PETN was not influenced by their relative abundance at any stage. Overall, these results suggest that dogs can form an olfactory search image that might aid in prey/target detection. [source] Bivariate association analyses for the mixture of continuous and binary traits with the use of extended generalized estimating equationsGENETIC EPIDEMIOLOGY, Issue 3 2009Jianfeng Liu Abstract Genome-wide association (GWA) study is becoming a powerful tool in deciphering genetic basis of complex human diseases/traits. Currently, the univariate analysis is the most commonly used method to identify genes associated with a certain disease/phenotype under study. A major limitation with the univariate analysis is that it may not make use of the information of multiple correlated phenotypes, which are usually measured and collected in practical studies. The multivariate analysis has proven to be a powerful approach in linkage studies of complex diseases/traits, but it has received little attention in GWA. In this study, we aim to develop a bivariate analytical method for GWA study, which can be used for a complex situation in which continuous trait and a binary trait are measured under study. Based on the modified extended generalized estimating equation (EGEE) method we proposed herein, we assessed the performance of our bivariate analyses through extensive simulations as well as real data analyses. In the study, to develop an EGEE approach for bivariate genetic analyses, we combined two different generalized linear models corresponding to phenotypic variables using a seemingly unrelated regression model. The simulation results demonstrated that our EGEE-based bivariate analytical method outperforms univariate analyses in increasing statistical power under a variety of simulation scenarios. Notably, EGEE-based bivariate analyses have consistent advantages over univariate analyses whether or not there exists a phenotypic correlation between the two traits. Our study has practical importance, as one can always use multivariate analyses as a screening tool when multiple phenotypes are available, without extra costs of statistical power and false-positive rate. Analyses on empirical GWA data further affirm the advantages of our bivariate analytical method. Genet. Epidemiol. 2009. © 2008 Wiley-Liss, Inc. [source] Defect Tolerance and Nanomechanics in Transistors that Use Semiconductor Nanomaterials and Ultrathin Dielectrics,ADVANCED FUNCTIONAL MATERIALS, Issue 17 2008Jong-Hyun Ahn Abstract This paper describes experimental and theoretical studies of the mechanics of free-standing nanoribbons and membranes of single-crystalline silicon transfer printed onto patterned dielectric layers. The results show that analytical descriptions of the mechanics agree well with experimental data, and they explicitly reveal how the geometry of dielectric layers (i.e., the width and depth of the features of relief) and the silicon (i.e., the thickness and widths of the ribbons) affect mechanical bowing (i.e., "sagging") in the suspended regions of the silicon. This system is of practical importance in the use of semiconductor nanomaterials for electronic devices, because incomplete sagging near defects in gate dielectrics provides a level of robustness against electrical shorting in those regions which exceeds that associated with conventional deposition techniques for thin films. Field effect transistors formed using silicon nanoribbons transferred onto a range of ultrathin gate dielectrics, including patterned epoxy, organic self-assembled monolayers, and HfO2, demonstrate these concepts. [source] Numerical stability of unsteady stream-function vorticity calculationsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING, Issue 6 2003E. Sousa Abstract The stability of a numerical solution of the Navier,Stokes equations is usually approached by con- sidering the numerical stability of a discretized advection,diffusion equation for either a velocity component, or in the case of two-dimensional flow, the vorticity. Stability restrictions for discretized advection,diffusion equations are a very serious constraint, particularly when a mesh is refined in an explicit scheme, so an accurate understanding of the numerical stability of a discretization procedure is often of equal or greater practical importance than concerns with accuracy. The stream-function vorticity formulation provides two equations, one an advection,diffusion equation for vorticity and the other a Poisson equation between the vorticity and the stream-function. These two equations are usually not coupled when considering numerical stability. The relation between the stream-function and the vorticity is linear and so has, in principle, an exact inverse. This allows an algebraic method to link the interior and the boundary vorticity into a single iteration scheme. In this work, we derive a global time-iteration matrix for the combined system. When applied to a model problem, this matrix formulation shows differences between the numerical stability of the full system equations and that of the discretized advection,diffusion equation alone. It also gives an indication of how the wall vorticity discretization affects stability. Despite the added algebraic complexity, it is straightforward to use MATLAB to carry out all the matrix operations. Copyright © 2003 John Wiley & Sons, Ltd. [source] Design of a composite beam using the failure probability-safety factor methodINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 9 2005E. Castillo Abstract The paper shows the practical importance of the failure probability-safety factor method for designing engineering works. The method provides an automatic design tool by optimizing an objective function subject to the standard geometric and code constraints, and two more sets of constraints, that guarantee some given safety factors and failure probability bounds, associated with a given set of failure modes. Since a direct solution of the optimization problem is not possible, the method proceeds as a sequence of three steps: (a) an optimal classical design, based on given safety factors, is done, (b) failure probabilities or bounds of all failure modes are calculated, and (c) safety factors bounds are adjusted. This implies a double safety check that leads to safer structures and designs less prone to wrong or unrealistic probability assumptions, and to excessively small (unsafe) or large (costly) safety factors. Finally, the actual global or combined probabilities of the different failure modes and their correlation are calculated using a Monte Carlo simulation. In addition, a sensitivity analysis is performed. To this end, the optimization problems are transformed into another equivalent ones, in which the data parameters are converted into artificial variables. In this way, some variables of the dual associated problems become the desired sensitivities. The method is illustrated by its application to the design of a composite beam. Copyright 2004 © John Wiley & Sons, Ltd. [source] On singularities in the solution of three-dimensional Stokes flow and incompressible elasticity problems with cornersINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 4 2004A. Dimitrov Abstract In this paper, a numerical procedure is presented for the computation of corner singularities in the solution of three-dimensional Stokes flow and incompressible elasticity problems near corners of various shape. For obtaining the order and mode of singularity, a neighbourhood of the singular point is considered with only local boundary conditions. The weak formulation of this problem is approximated using a mixed u, p Galerkin,Petrov finite element method. Additionally, a separation of variables is used to reduce the dimension of the original problem. As a result, the quadratic eigenvalue problem (P+,Q+,2R)d=0 is obtained, where the saddle-point-type matrices P, Q, R are defined explicitly. For a numerical solution of the algebraic eigenvalue problem an iterative technique based on the Arnoldi method in combination with an Uzawa-like scheme is used. This technique needs only one direct matrix factorization as well as few matrix,vector products for finding all eigenvalues in the interval ,,(,) , (,0.5, 1.0), as well as the corresponding eigenvectors. Some benchmark tests show that this technique is robust and very accurate. Problems from practical importance are also analysed, for instance the surface-breaking crack in an incompressible elastic material and the three-dimensional viscous flow of a Newtonian fluid past a trihedral corner. Copyright © 2004 John Wiley & Sons, Ltd. [source] Three-dimensional viscous flow over rotating periodic structuresINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 5 2003Kyu-Tae Kim Abstract The three-dimensional Stokes flow in a periodic domain is examined in this study. The problem corresponds closely to the flow inside internal mixers, where the flow is driven by the movement of a rotating screw; the outer barrel remaining at rest. A hybrid spectral/finite-difference approach is proposed for the general expansion of the flow field and the solution of the expansion coefficients. The method is used to determine the flow field between the screw and barrel. The regions of elongation and shear are closely examined. These are the two mechanisms responsible for mixing. Besides its practical importance, the study also allows the assessment of the validity of the various assumptions usually adopted in mixing and lubrication problems. Copyright © 2003 John Wiley & Sons, Ltd. [source] On the practical importance of the SSP property for Runge,Kutta time integrators for some common Godunov-type schemesINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 3 2005David I. Ketcheson Abstract We investigate through analysis and computational experiment explicit second and third-order strong-stability preserving (SSP) Runge,Kutta time discretization methods in order to gain perspective on the practical necessity of the SSP property. We consider general theoretical SSP limits for these schemes and present a new optimal third-order low-storage SSP method that is SSP at a CFL number of 0.838. We compare results of practical preservation of the TVD property using SSP and non-SSP time integrators to integrate a class of semi-discrete Godunov-type spatial discretizations. Our examples involve numerical solutions to Burgers' equation and the Euler equations. We observe that ,well-designed' non-SSP and non-optimal SSP schemes with SSP coefficients less than one provide comparable stability when used with time steps below the standard CFL limit. Results using a third-order non-TVD CWENO scheme are also presented. We verify that the documented SSP methods with the number of stages greater than the order provide a useful enhanced stability region. We show by analysis and by numerical experiment that the non-oscillatory third-order reconstructions used in (Liu and Tadmor Numer. Math. 1998; 79:397,425, Kurganov and Petrova Numer. Math. 2001; 88:683,729) are in general only second- and first-order accurate, respectively. Copyright © 2005 John Wiley & Sons, Ltd. [source] Consistency with continuity in conservative advection schemes for free-surface modelsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 4 2002Edward S. Gross Abstract The consistency of the discretization of the scalar advection equation with the discretization of the continuity equation is studied for conservative advection schemes coupled to three-dimensional flows with a free-surface. Consistency between the discretized free-surface equation and the discretized scalar transport equation is shown to be necessary for preservation of constants. In addition, this property is shown to hold for a general formulation of conservative schemes. A discrete maximum principle is proven for consistent upwind schemes. Various numerical examples in idealized and realistic test cases demonstrate the practical importance of the consistency with the discretization of the continuity equation. Copyright © 2002 John Wiley & Sons, Ltd. [source] They Don't Do It Often, But They Do It Well: Exploring the relationship between applicant mental abilities and fakingINTERNATIONAL JOURNAL OF SELECTION AND ASSESSMENT, Issue 3 2009Julia Levashina Despite its scientific and practical importance, relatively few studies have been conducted to investigate the relationship between job applicant mental abilities and faking. Some studies suggest that more intelligent people fake less because they do not have to. Other studies suggest that more intelligent people fake more because they have increased capacity to fake. Based on a model of faking likelihood, we predicted that job candidates with a high level of mental abilities would be less likely to fake a biodata measure. However, for candidates who did exhibit faking on the biodata measure, we expected there would be a strong positive relationship between mental abilities and faking, because mental abilities increase their capacity to fake. We found considerable support for hypotheses on a large sample of job candidates (N=17,368), using the bogus item technique to detect faking. [source] Volume recovery, surface properties and membrane integrity of Lactobacillus delbrueckii subsp. bulgaricus dehydrated in the presence of trehalose or sucroseJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2007E.E. Tymczyszyn Abstract Aims:, Although the practical importance of adding sugars before drying is well known, the mechanism of protection of bacteria by sugars is not clear. The response of the dehydrated micro-organisms to rehydration is analysed in terms of structural and functional changes, and correlated with their potentiality to grow in rich media. These aspects are related with the membrane integrity and the metabolic state of the rehydrated bacteria, measured by means of surface properties and permeability. To attain this objective, Lactobacillus delbrueckii subsp. bulgaricus was dehydrated in the presence and in the absence of sucrose and trehalose. The bacterial response upon rehydration was investigated by determining: (i) the lag time of the bacterial growing in rich media, (ii) the restoration of the surface properties and the cellular volume and (iii) the membrane integrity. Methods and Results:,Lactobacillus delbrueckii subsp. bulgaricus was grown in MRS at 37°C overnight [De Man et al. (1960)J Appl Bacteriol 23, 130] and then dehydrated for 10, 20 and 30 min at 70°C in a vacuum centrifuge. The lag time of micro-organisms was determined by optical density changes after rehydration. The surface properties were determined by measuring the zeta potential of the bacteria suspended in aqueous solution. The cellular volume recovery was measured, after stabilization in saline solution, by light scattering and by the haematocrit method [Alemohammad and Knowles (1974)J Gen Microbiol 82, 125]. Finally, the membrane integrity has been determined by using specific fluorescent probes [SYTO 9 and propidium iodide, (PI)] that bind differentially depending on the integrity of the bacterial membrane. The lag time of Lact. delbrueckii subsp bulgaricus, dehydrated by heat in the presence of sucrose or trehalose and after that rehydrated, was significantly shortened, when compared with that obtained for bacteria dried in the absence of sugars. In these conditions, trehalose and sucrose maintained the zeta potential and the cell volume close to the control (nondried) cells. However, the membrane integrity, measured with fluorescent probes, was maintained only when cells were dehydrated for 10 min in the presence of sugars. For larger times of dehydration, the membrane integrity was not preserved, even in the presence of sugars. Conclusions:, When the micro-organisms are dehydrated in the absence of protectants, the membrane damage occurs with a decrease in the absolute value of the zeta potential and a decrease in the cellular volume recovered after rehydration. In contrast, when the zeta potential and the cellular volume are restored after rehydration to that corresponding to nondried cells, the micro-organisms are able to recover and grow with a reduced lag time. This can only be achieved when the dehydration is carried out in the presence of sugars. At short dehydration times, the response is associated with the preservation of the membrane integrity. However, for longer times of dehydration the zeta potential and volume recovery occurs in the presence of sugars in spite of a severe damage at membrane level. In this condition, cells are also recovered. In conclusion, to predict the ability of growing after dehydration, other bacterial structural parameters besides membrane integrity, such as zeta potential and cellular volume, should be taken into account. Significance and Impact of the Study:, The correlation of the lag time with the surface and permeability properties is of practical importance because the correlation of these two parameters with cell viability, allow to determine the potential bacterial capacity to grow in a rich medium after the preservation procedure, without necessity of performing a kinetic curve of growth, which is certainly time-consuming. [source] New sets of solubility parameters of linear and crosslinked aromatic polyamidesJOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2010Stefano Fiori Abstract As generally accepted, also in the case of polyamides linear and crosslinked polymeric materials are believed to be characterized by the same solution properties and, consequently, by the same solubility parameters. However, despite their great practical importance, a thorough study aimed to determine the best solvent media able to dissolve linear aromatic polyamides has not been performed yet or, at least, has not been published. In this study, we report on our study on the solubility parameters of linear and crosslinked aromatic polyamides. We demonstrate that the assumption of considering these two classes as having the same solubility properties can lead to dramatically erroneous results. Two new different sets for linear and crosslinked aromatic polyamides are proposed. Namely, linear poly(p -phenylene terephthalamide) is characterized by ,p, ,d, and ,H equal to 8.6, 18.4, and 11.3, respectively; by contrast, the corresponding values of the crosslinked aromatic polyamides taken into consideration are: 11.5, 16.8, and 10.2. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Cell-penetrating peptide TAT-mediated delivery of acidic FGF to retina and protection against ischemia,reperfusion injury in ratsJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 7 2010Yi Wang Abstract The development of non-invasive ocular drug delivery systems is of practical importance in the treatment of retinal disease. In this study, we evaluated the efficacy of transactivator of transcription protein transduction domain (TAT-PTD, TAT49,57) as a vehicle to deliver acidic FGF (aFGF) to retina in rats. TAT-conjugated aFGF-His (TAT-aFGF-His) exhibited efficient penetration into the retina following topical administration to the ocular surface. Immunochemical staining with anti-His revealed that TAT-aFGF-His proteins were readily found in the retina (mainly in the ganglion cell layer) at 30 min. and remained detectable for at least 8 hrs after administration. In contrast, His+ proteins were undetectable in the retina after topical administration of aFGF-His, indicating that aFGF-His cannot penetrate the ocular barrier. Furthermore, TAT-aFGF-His, but not aFGF-His, mediated significant protection against retinal ischemia,reperfusion (IR) injury. After IR injury, retina from TAT-aFGF-His-treated rats showed better-maintained inner retinal layer structure, reduced apoptosis of retinal ganglion cells and improved retinal function compared to those treated with aFGF-His or PBS. These results indicate that conjugation of TAT to aFGF-His can markedly improve the ability of aFGF-His to penetrate the ocular barrier without impairing its biological function. Thus, TAT49,57 provides a potential vehicle for efficient drug delivery in the treatment of retinal disease. [source] Microbial metagenomes: moving forward industrial biotechnologyJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 5 2007Manuel Ferrer Abstract Biotechnology, in terms of exploitation of catalytic activities for industrial applications, is increasingly recognized as one of the pillars of the knowledge-based economy that we are heading for. Comprehensive knowledge of enzymology should be of practical importance for effective intervention on whole cell processes and enzymatic networks. Over the last decade metagenome-based technologies have been developed to take us farther and deeper into the enzyme universe from uncultivable microbes. This sophisticated platform, which identifies new enzymes from vast genetic pools available, and assesses their potential for novel chemical applications, should be increasingly important in the discovery of advanced biotechnological resources. Copyright © 2007 Society of Chemical Industry [source] An evaluation of the hand and nasal flora of Turkish nursing students after clinical practiceJOURNAL OF CLINICAL NURSING, Issue 3 2009Reva Balc Aim., The purpose of this study was to evaluate and compare the hand and nasal flora of nursing students before and after the clinical practice. Background., Hospitals are places where infective agents abound. Healthcare workers, relatives of patients and students practising in the hospital medium are often exposed to these infective agents. Although the role of the hand and nasal flora of healthcare workers in the development of nosocomial infections has been emphasised by earlier studies, there are a limited number of studies which investigate the hand and nasal flora of nursing students. Design., Descriptive. Methods., This descriptive study involved 66 volunteer nursing students. Two samples of flora from both hands and nose of each student were obtained. The inoculated samples were then evaluated through routine bacteriological study methods. Chi-square and percentage calculations were used in comparisons. Results., None of the students had methicillin-resistant Staphylococcus aureus or methicillin-resistant coagulase-negative Staphylococcus colonisation in the hand samples before clinical practice, 6·1% of the students had methicillin-resistant Staphylococcus aureus and 4·5% had methicillin-resistant coagulase-negative Staphylococcus colonisation after the practice. Although the differences between the rates of contamination with pathogen micro-organisms in the hand and nasal flora of the student nurses before and after clinical practice were not significant, the rate of colonisation after clinical practice was higher. Conclusions., In this study, the rate of colonisation after clinical practice was higher. These findings indicate that students might have been contaminated with bacteria during clinical practice. Relevance to clinical practice., The results of this study have practical importance in clinical practice. The role of the hand and nasal flora of nursing students in the development of nosocomial infections is significant. For this reason, some precautions, such as using gloves and handwashing with special solutions when needed, should be taken to prevent nosocomial infections and protect students against associated risks. [source] Rethinking NIMBYism: The role of place attachment and place identity in explaining place-protective actionJOURNAL OF COMMUNITY & APPLIED SOCIAL PSYCHOLOGY, Issue 6 2009Patrick Devine-Wright Abstract The ,NIMBY' (Not In My Back Yard) concept is commonly used to explain public opposition to new developments near homes and communities, particularly arising from energy technologies such as wind farms or electricity pylons. Despite its common use, the concept has been extensively critiqued by social scientists as a useful concept for research and practice. Given European policy goals to increase sustainable energy supply by 2020, deepening understanding of local opposition is of both conceptual and practical importance. This paper reviews NIMBY literature and proposes an alternative framework to explain local opposition, drawing upon social and environmental psychological theory on place. Local opposition is conceived as a form of place-protective action, which arises when new developments disrupt pre-existing emotional attachments and threaten place-related identity processes. Adopting a social constructivist perspective and drawing on social representation theory, a framework of place change is proposed encompassing stages of becoming aware, interpreting, evaluating, coping and acting, with each stage conceived at multiple levels of analysis, from intrapersonal to socio-cultural. Directions for future research and potential implications of the place-based approach for public engagement by energy policy-makers and practitioners are discussed. Copyright © 2009 John Wiley & Sons, Ltd. [source] EVALUATION OF CELLS OF LACTOBACILLUS DELBRUECKII SPP.JOURNAL OF FOOD QUALITY, Issue 6 20035 AND PEDIOCOCCUS ACIDILACTICI D3 SUSPENDED IN LACTIC OR ACETIC ACID AS BIOPRESERVATIVES ON FRESH CUT CANTALOUPE AT 7C, LACTIS RM A small although statistically significant (P < 0.05) inactivation of S. choleraesuis was observed when cantaloupe cubes were additionally inoculated with cells P. acidilactici suspended in 5.5 mM lactic acid or 5.5 mM glacial acetic acid solutions. However, the numbers of S. choleraesuis were not significantly lower than in the control on day 10. The amount of inactivation likely would have no practical importance. No significant decline in numbers of S. choleraesuis was attained when the cells of L. delbrueckii spp. lactis were suspended in 5.5 mM lactic acid. None of the treatments contributed to an effective (P > 0.05) inhibition of the spoilage flora on the melons. [source] The deinstitutionalization of American marriageJOURNAL OF MARRIAGE AND FAMILY, Issue 4 2004Andrew J. Cherlin This article argues that marriage has undergone a process of deinstitutionalization,a weakening of the social norms that define partners' behavior,over the past few decades. Examples are presented involving the increasing number and complexity of cohabiting unions and the emergence of same-sex marriage. Two transitions in the meaning of marriage that occurred in the United States during the 20th century have created the social context for deinstitutionalization. The first transition, noted by Ernest Burgess, was from the institutional marriage to the companionate marriage. The second transition was to the individualized marriage in which the emphasis on personal choice and self-development expanded. Although the practical importance of marriage has declined, its symbolic significance has remained high and may even have increased. It has become a marker of prestige and personal achievement. Examples of its symbolic significance are presented. The implications for the current state of marriage and its future direction are discussed. [source] Dryout phenomena in a three-phase fixed-bed reactorAICHE JOURNAL, Issue 1 2003Zhen-Min Cheng Understanding the mechanism of liquid-phase evaporation in a three-phase fixed-bed reactor is of practical importance, because the reaction heat is usually 7,10 times the vaporization heat of the liquid components. Evaporation, especially the liquid dryout, can largely influence the reactor performance and even safety. To predict the vanishing condition of the liquid phase, Raoult's law was applied as a preliminary approach, with the liquid vanishing temperature defined based on a liquid flow rate of zero. While providing correct trends, Raoult's law exhibits some limitation in explaining the temperature profile in the reactor. To comprehensively understand the whole process of liquid evaporation, a set of experiments on inlet temperature, catalyst activity, liquid flow rate, gas flow rate, and operation pressure were carried out. A liquid-region length-predicting equation is suggested based on these experiments and the principle of heat balance. [source] Hamiltonian view on process systemsAICHE JOURNAL, Issue 8 2001Katalin M. Hangos The thermodynamic approach of analyzing structural stability of process plants was extended to construct the simple Hamiltonian model of lumped process systems. This type of model enables us to design a nonlinear PD feedback controller for passivation and loop shaping. This approach is applicable for lumped process systems where Kirchhoff convective transport takes place together with the transfer and sources of various types, and the manipulable input variables are the flow rates. Systems with constant mass holdup and uniform pressure in every balance volume satisfy these conditions. General results are shown by simple examples of practical importance: on a bilinear heat exchanger cell and on an isotherm CSTR with nonlinear reaction. [source] Thermal expansion of organic crystals and precision of calculated crystal density: A survey of Cambridge Crystal DatabaseJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 5 2007Changquan Calvin Sun Abstract True density is a physical property of both fundamental and practical importance to the study of pharmaceutical powders. True density may be calculated from crystal structure. However, precision of such calculated density is not well understood. Furthermore, thermal expansion properties of organic crystals have rarely been characterized. A survey of Cambridge Crystal Database is conducted to assess (1) precision of calculated crystal density from crystal structure; (2) thermal expansion properties of organic crystals. It is shown that calculated crystal density exhibits, on average, a relative standard deviation (RSD) of ,0.4%. It is found that crystal density generally increases linearly with decreasing temperature provided no phase change occurs. Slope of the line, termed thermal density gradient, of organic crystals ranges between 0.04 and 1.74 mg,cm,3,K,1 with an average of ,0.2 mg,cm,3,K,1. It is shown that majority polymorph pairs exhibit significantly different thermal expansion behavior and their density,temperature lines can cross. This likely contributes to the less than perfect prediction of relative stability of polymorphs at ambient temperature using the density rule. © 2007 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 96: 1043,1052, 2007 [source] An analysis of all the relevant facts and arguments indicates that enzyme catalysis does not involve large contributions from nuclear tunnelingJOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 7 2010Shina C. L. Kamerlin Abstract Enzymatic reactions are crucial toward controlling and performing most life processes, and, as such, understanding how they really work has both fundamental and practical importance. Thus, one of the major current challenges of biophysics involves understanding the origin of the enormous catalytic power of enzymes, an issue that is still not widely understood and remains controversial within the scientific community. Several proposals have been put forth to try to explain the origin of enzyme catalysis, one of which is the idea that enzyme catalysis involves special factors such as nuclear quantum mechanical (NQM) effects, and, in particular, nuclear tunneling. Here, we will discuss both the factors for and against this proposition, and demonstrate that an analysis of all the relevant facts and arguments seems to establish that enzyme catalysis does not involve large contributions from nuclear tunneling. Copyright © 2010 John Wiley & Sons, Ltd. [source] Decreased Detectability of Grapevine Leafroll-associated virus 3 in Sakasly Grapevines Cultivated Under the Sahara ConditionsJOURNAL OF PHYTOPATHOLOGY, Issue 9 2006A. Ben salem-Fnayou Abstract The detectability of grapevine-leafroll-associated virus 3 (GLRaV-3) was investigated by enzyme-linked immunosorbent assay (ELISA) and reverse-transcriptase polymerase chain reaction (RT,PCR) in the domestic grapevine cultivar Sakasly, grown over two successive years in the Sahara, at Rjim-Mâatoug in Tunisia. Self-rooted cuttings, infected with GLRaV-3 were cultivated and the presence of the virus was checked over 2 years and compared with controls. During the first year, 80% of the originally infected vines were negative for GLRaV-3 using ELISA. After the second year, 93% and 95% of these plants were negative for GLRaV-3 using ELISA and RT,PCR, respectively. Furthermore, rooted cuttings derived from GLRaV-3-negative plants and grown under controlled conditions in a greenhouse (at 16,20°C) were ELISA-negative in most cases (84%). In addition, biological indexing on Vitis vinifera cv. Gamay Rouge de la Loire showed no leafroll symptoms on this indicator in 92% of the grafted vines. These results suggest a naturally occurring heat therapy in the Tunisian Sahara, which could be of practical importance for the production of GLRaV-3-free grapevine cuttings, especially as scale insect and mealybug vectors have not been observed in this area. [source] Phase Composition and Vaporization Study of LaGa1,xAlxO3, 0 ,x, 1, and La0.9Sr0.1Ga0.8,xAlxMg0.2O2.85, x= 0.1, 0.2, 0.3JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 11 2003Aleksandra Matraszek The vaporization of the LaGa1,xAlxO3 solid solution, 0 ,x, 1, of the perovskite structure, was investigated using Knudsen effusion mass spectrometry in the temperature range of 1623,1928 K. The partial pressures of the gaseous species O2, Ga, GaO, Ga2O, and LaO were determined for the samples investigated. The equilibrium partial pressures were used for the computation of thermodynamic activities of Ga2O3 and La2O3 at 1800 K. Thermodynamic activities of Al2O3 were obtained using Gibbs,Duhem integration. Gibbs energies of formation of the solid-solution LaGa1,xAlxO3 resulted from the thermodynamic activities of the oxide components. Samples of the chemical composition La0.9Sr0.1Ga0.8,xAlxMg0.2O2.85, x= 0.1, 0.2, 0.3, were of practical importance in solid oxide fuel cell (SOFC) technology and also were investigated. The influence of the aluminum concentration in the perovskite phase on the thermodynamic activity and volatility of Ga2O3 is presented and implications for the potential use of this material in SOFC technology are discussed. [source] Inference in molecular population geneticsJOURNAL OF THE ROYAL STATISTICAL SOCIETY: SERIES B (STATISTICAL METHODOLOGY), Issue 4 2000Matthew Stephens Full likelihood-based inference for modern population genetics data presents methodological and computational challenges. The problem is of considerable practical importance and has attracted recent attention, with the development of algorithms based on importance sampling (IS) and Markov chain Monte Carlo (MCMC) sampling. Here we introduce a new IS algorithm. The optimal proposal distribution for these problems can be characterized, and we exploit a detailed analysis of genealogical processes to develop a practicable approximation to it. We compare the new method with existing algorithms on a variety of genetic examples. Our approach substantially outperforms existing IS algorithms, with efficiency typically improved by several orders of magnitude. The new method also compares favourably with existing MCMC methods in some problems, and less favourably in others, suggesting that both IS and MCMC methods have a continuing role to play in this area. We offer insights into the relative advantages of each approach, and we discuss diagnostics in the IS framework. [source] | |||||||||||||||||||||||||||||||