Distribution by Scientific Domains

Terms modified by Select

  • select case
  • select committee
  • select compound
  • select demographic
  • select group
  • select patient
  • select population
  • select sample

  • Selected Abstracts

    Local perspective of the impact of the HIPAA privacy rule on research

    CANCER, Issue 2 2006
    M.P.H., Michael S. Wolf Ph.D.
    Abstract BACKGROUND The operational and economic impact of the Health Insurance Portability and Accountability Act (HIPAA) of 1996 was evaluated. The setting was a natural experiment which involved a single-site, clinical research study that was initiated before the enactment of HIPAA and subsequently modified to be compliant with the new policy. METHODS A formative assessment was conducted of the recruitment process to a clinical trial evaluating the efficacy of an educational strategy to inform Veterans about the National Cancer Institute/Department of Veterans Affairs cosponsored Selenium and Vitamin E Cancer Prevention Trial (SELECT). Personnel time and costs were determined based on weekly accrual for study periods before and after the implementation of HIPAA. Root cause analysis was used to assess the recruitment protocol and to identify areas for improvement. RESULTS The implementation of HIPAA resulted in a 72.9% decrease in patient accrual (7.0 patients/wk vs. 1.9 patients/wk, P < 0.001), and a threefold increase in mean personnel time spent recruiting (4.1 hrs/patient vs. 14.1 hrs/patient, P < 0.001) and mean recruitment costs ($49/patient vs. $169/patient, P < 0.001). Upon review of the modified HIPAA-compliant protocol, revisions in the recruitment procedure were adopted. The revised protocol improved weekly accrual by 73% (1.9 patients/wk vs. 7.1 patients/wk, P < 0.001) and resulted in improvements in personnel time (5.4 hrs/patient) and recruitment costs ($65/patient). CONCLUSION Enactment of HIPAA initially placed a considerable burden on research time and costs. Establishing HIPAA-compliant recruitment policies can overcome some of these obstacles, although recruitment costs and time are likely to be greater than those observed before HIPAA. Cancer 2006. © 2005 American Cancer Society. [source]

    Automated, scalable culture of human embryonic stem cells in feeder-free conditions

    Rob J. Thomas
    Abstract Large-scale manufacture of human embryonic stem cells (hESCs) is prerequisite to their widespread use in biomedical applications. However, current hESC culture strategies are labor-intensive and employ highly variable processes, presenting challenges for scaled production and commercial development. Here we demonstrate that passaging of the hESC lines, HUES7, and NOTT1, with trypsin in feeder-free conditions, is compatible with complete automation on the CompacT SelecT, a commercially available and industrially relevant robotic platform. Pluripotency was successfully retained, as evidenced by consistent proliferation during serial passage, expression of stem cell markers (OCT4, NANOG, TRA1-81, and SSEA-4), stable karyotype, and multi-germlayer differentiation in vitro, including to pharmacologically responsive cardiomyocytes. Automation of hESC culture will expedite cell-use in clinical, scientific, and industrial applications. Biotechnol. Bioeng. 2009;102: 1636,1644. © 2008 Wiley Periodicals, Inc. [source]

    Do Biocides Select for Antibiotic Resistance?,

    Some similarities exist between bacterial resistance to antibiotics and to biocides, and gram-negative bacteria that have developed resistance to cationic biocides may also be insusceptible to some antibiotics. Outer membrane changes are believed to be responsible for this non-specific increase in resistance. Efflux, another important resistance mechanism, is associated with the qacA/B gene system in staphylococci that confers low-level resistance to cationic agents including chlorhexidine salts and quaternary ammonium compounds. It has been proposed that the introduction into clinical practice of Chlorhexidine and quaternary ammonium compounds has resulted in the selection of staphylococci containing qacA genes on multiresistance plasmids. A linkage between low-level resistance to triclosan and to antibiotics has recently been claimed to occur in Escherichia coli, with the bisphenol selecting for chromosomally-mediated antibiotic resistance. A key issue in many studies has been the use of biocides at concentrations significantly below those used clinically. It remains to be determined how an increase to low-level resistance to cationic biocides can be held responsible for the selection of antibiotic-resistant bacteria. [source]

    Comparative evaluation of Candi Select test and conventional methods for identification of Candida albicans in routine clinical isolates

    MYCOSES, Issue 3-4 2002
    S. Foongladda
    Candida albicans; Identifizierung; Candi Select- Test; Bewertung. Summary. The Candi Select test (Sanofi Diagnostics, Pasteur, Marnes-La-Coquette, France) is a new yeast-selective medium for the identification of Candida albicans in the clinical laboratory. The performance of this test was compared with the conventional methods of chlamydospore formation, germ tube formation and carbohydrate fermentation. Four hundred and twenty clinical yeast isolates from 412 fresh clinical specimens, including 283 C. albicans, 59 C. tropicalis, 39 Trichosporon spp., 19 C. glabrata, 11 Cryptococcus neoformans and 9 other yeasts, were evaluated. Colonies of C. albicans produced a blue-green colour on the Candi Select media which could be distinguished from the other yeasts with the naked eye within 24,48 h. The sensitivity and specificity of the Candi Select test for the identification of C. albicans were 99.65% and 97.08%, respectively. The blue-green colonies of C. albicans were easy to identify and recognize in mixed cultures and did not need detailed microscopic examination. Zusammenfassung., Der Candi Select-Test (Sanofi Diagnostics Pasteur, Marnes-La-Coquette, Frankreich) ist ein neuer selektiver Nährboden für die Identifizierung von Candida albicans im klinischen Labor. Die neue Methode wurde mit den konventionellen Methoden der Chlamydosporenbildung, der Keimschlauchbildung und der Kohlenhydrat-Gärung verglichen. Vierhundertzwanzig Hefeisolate, nämlich 283 C. albicans, 59 Candida tropicalis, 39 Trichosporon spp., 19 Candida glabrata, 11 Cryptococcus neoformans und 9 andere Hefen, isoliert aus 412 frischen klinischen Untersuchungsproben, wurden mit allen Methoden untersucht. Mit blossem Auge erkennbar, unterschieden sich innerhalb von 24,48 Stunden die blau-grünen Farbkolonien von C. albicans von allen anderen Hefen auf dem Candi Select Nährboden. Sensitivität und Spezifizität des Candi Select Tests für die Identifizierung von C. albicans betrugen 99.65% und 97.08%. Die blau-grünen Farbkolonien von C. albicans waren in den Mischkulturen leicht zu identifizieren, eine mikroskopische Untersuchung erübrigt sich daher. [source]


    BIOETHICS, Issue 1 2005
    ABSTRACT In 2001, Julian Savulescu wrote an article entitled ,Procreative Beneficence: Why We Should Select the Best Children', in which he argued for the genetic selection of intelligence in children. That article contributes to a debate on whether genetic research on intelligence should be undertaken at all and, if so, should intelligence selection be available to potential parents. As such, the question of intelligence selection relates to wider issues concerning the genetic determination of behavioural traits, i.e. alcoholism. This article is designed as an engagement in the intelligence selection debate using an analysis of Savulescu's arguments to raise a series of problematic issues in relation to the ethics of parental selection of intelligence. These problematic issues relate to wider assumptions that are made in order to put forward intelligence selection as a viable ethical option. Such assumptions are more generic in character, but still relate to Savulescu's article, concerning issues of genetic determinism, private allocation and inequality, and, finally, individual versus aggregate justice. The conclusion focuses on what the implications are for the question of agency, especially if intelligence selection is allowed. [source]

    Scanning electron microscopic analysis of different drug eluting stents after failed implantation: From nearly undamaged to major damaged polymers,

    Marcus Wiemer MD
    Abstract Background: Implantation of drug eluting stents (DES) in tortuous and/or calcified vessels is much more demanding compared with implantation of bare metal stents (BMS) due to their larger diameters. It is unknown whether drug eluting stent coatings get damaged while crossing these lesions. Methods: In 42 patients (34 male, 68.1 ± 10 years) with 45 calcified lesions (15.9 mm ± 7.9 mm), DES could not be implanted, even after predilatation. Diabetes was present in 19 patients (45 %). Sixty-one stents were used; 19 Cypher selectÔ, 18 Taxus LibertéÔ, 10 CoStarÔ, 5 Endeavor RXÔ, 4 Xience VÔ. 3 Janus CarbostentÔ, 1 Yukon Choice SÔ, and 1 AxxionÔ DES. The entire accessible surface area of these stents, in either the unexpanded and expanded state, were examined with an environmental scanning electron microscope (XL30 ESEM, Philips) to evaluate polymer or surface damage. Results: The polymers of Taxus Liberte, Cypher Select, Xience V, CoStar, and Janus DES were only slightly damaged (less than 3% of surface area), whereas the Endeavor RX Stents showed up to 20% damaged surface area. In DES without a polymer (Yukon and Axxion), it could be shown that most of the stent surface (up to 40%) were without any layer of drug. Conclusion: Placement of drug eluting stents in tortuous vessels and/or calcified lesions could cause major surface damage by scratching and scraping of the polymer or drug by the arterial wall, even before implantation. There were remarkable differences among the stents examined, only minor damage with the Cypher, Taxus Costar, Janus, and Xience V, whereas the Endeavor, the Yukon, and the Janus DES showed large areas of surface injury. © 2009 Wiley-Liss, Inc. [source]

    Enhancing Delphi research: methods and results

    Holly Powell Kennedy PhD CNM FACNM
    Background., The Delphi method provides an opportunity for experts (panelists) to communicate their opinions and knowledge anonymously about a complex problem, to see how their evaluation of the issue aligns with others, and to change their opinions, if desired, after reconsideration of the findings of the group's work. Delphi studies have the potential to provide valuable information, yet few researchers have taken further steps to support or refine their findings. Without this step there is a potential threat to the applicability, or external validity, of the results. Aims., The purpose of this article is to present an argument for further inquiry to enhance and support Delphi findings, and specific approaches to this will be considered. Methods., Methods to enhance, expand, or refine Delphi study findings are described. Mixed method design within a Delphi study on midwifery practice is described, and a follow-up narrative study to examine the findings is presented. Findings., Selected results from the follow up narrative study are presented to convey how the narrative data clarified the Delphi findings. Together, the studies provide a more robust depiction of midwifery practice, process, and outcomes. Although there were similarities to the dimensions identified previously, there was a more dynamic focus and explanation of the interaction between the midwife, the woman who had received midwifery care, and the health care system. Study limitations., Lack of diversity in the sample and the midwives' familiarity with the author's past research represent a potential threat to the findings. Prolonged interviews and multiple narratives were gathered in an effort to control for this. Conclusion., Delphi studies are research exercises conducted by a panel of experts. Designing studies to further enhance, clarify, or refine their findings from the context of practice holds promise for their ability to influence clinical care. [source]

    Differential Appetite-Related Responses to Central Neuropeptide S in Lines of Chickens Divergently Selected for Low or High Body Weight

    M. A. Cline
    The anorexigenic 20 amino acid neuropeptide S (NPS) has not been studied in an animal model of hypo- or hyperphagia. The present study aimed to elucidate whether central NPS appetite-related effects are different in lines of chickens that had undergone long-term divergent selection for low (LWS) or high (HWS) body weight and that were hypo- and hyperphagic, respectively. It took a longer time for food intake to be reduced in LWS than HWS chicks administered the lowest dose of NPS tested (0.14 nmol) and, at the highest dose tested (0.56 nmol), they had a greater reduction in food intake than did HWS chicks. HWS chicks responded with a similar magnitude of food intake reduction that was independent of NPS dose. Although water intake was reduced concurrently with food intake after central NPS in both lines, blood glucose concentrations were not affected. Hypothalamic signalling was different between the lines. Although both lines respond to central NPS with decreased c-Fos immunoreactivity in the lateral hypothalamus, the periventricular nucleus had increased c-Fos immunoreactivity in LWS but not HWS chicks. After central NPS treatment, there was increased c-Fos immunoreactivity in the paraventricular nucleus in HWS but not LWS chicks. These data support the notion of differences in the central NPS system between the LWS and HWS lines and infer that central NPS may differentially affect appetite-related processes in other species that contain hypo- and hyperphagic individuals. [source]

    Lazy Solid Texture Synthesis

    Yue Dong
    Abstract Existing solid texture synthesis algorithms generate a full volume of color content from a set of 2D example images. We introduce a new algorithm with the unique ability to restrict synthesis to a subset of the voxels, while enforcing spatial determinism. This is especially useful when texturing objects, since only a thick layer around the surface needs to be synthesized. A major difficulty lies in reducing the dependency chain of neighborhood matching, so that each voxel only depends on a small number of other voxels. Our key idea is to synthesize a volume from a set of pre-computed 3D candidates, each being a triple of interleaved 2D neighborhoods. We present an efficient algorithm to carefully select in a pre-process only those candidates forming consistent triples. This significantly reduces the search space during subsequent synthesis. The result is a new parallel, spatially deterministic solid texture synthesis algorithm which runs efficiently on the GPU. Our approach generates high resolution solid textures on surfaces within seconds. Memory usage and synthesis time only depend on the output textured surface area. The GPU implementation of our method rapidly synthesizes new textures for the surfaces appearing when interactively breaking or cutting objects. [source]

    The neurologic manifestations of mitochondrial disease

    Sumit Parikh
    Abstract The nervous system contains some of the body's most metabolically demanding cells that are highly dependent on ATP produced via mitochondrial oxidative phosphorylation. Thus, the neurological system is consistently involved in patients with mitochondrial disease. Symptoms differ depending on the part of the nervous system affected. Although almost any neurological symptom can be due to mitochondrial disease, there are select symptoms that are more suggestive of a mitochondrial problem. Certain symptoms that have become sine qua non with underlying mitochondrial cytopathies can serve as diagnostic "red-flags." Here, the typical and atypical presentations of mitochondrial disease in the nervous system are reviewed, focusing on "red flag" neurological symptoms as well as associated symptoms that can occur in, but are not specific to, mitochondrial disease. The multitudes of mitochondrial syndromes are not reviewed in-depth, though a select few are discussed in some detail. © 2010 Wiley-Liss, Inc. Dev Disabil Res Rev 2010;16:120,128. [source]

    Keeping the herds healthy and alert: implications of predator control for infectious disease

    ECOLOGY LETTERS, Issue 9 2003
    Craig Packer
    Abstract Predator control programmes are generally implemented in an attempt to increase prey population sizes. However, predator removal could prove harmful to prey populations that are regulated primarily by parasitic infections rather than by predation. We develop models for microparasitic and macroparasitic infection that specify the conditions where predator removal will (a) increase the incidence of parasitic infection, (b) reduce the number of healthy individuals in the prey population and (c) decrease the overall size of the prey population. In general, predator removal is more likely to be harmful when the parasite is highly virulent, macroparasites are highly aggregated in their prey, hosts are long-lived and the predators select infected prey. [source]

    The antibiotic ADEP reprogrammes ClpP, switching it from a regulated to an uncontrolled protease

    Janine Kirstein
    Abstract A novel class of antibiotic acyldepsipeptides (designated ADEPs) exerts its unique antibacterial activity by targeting the peptidase caseinolytic protease P (ClpP). ClpP forms proteolytic complexes with heat shock proteins (Hsp100) that select and process substrate proteins for ClpP-mediated degradation. Here, we analyse the molecular mechanism of ADEP action and demonstrate that ADEPs abrogate ClpP interaction with cooperating Hsp100 adenosine triphosphatases (ATPases). Consequently, ADEP treated bacteria are affected in ClpP-dependent general and regulatory proteolysis. At the same time, ADEPs also activate ClpP by converting it from a tightly regulated peptidase, which can only degrade short peptides, into a proteolytic machinery that recognizes and degrades unfolded polypeptides. In vivo nascent polypeptide chains represent the putative primary target of ADEP-activated ClpP, providing a rationale for the antibacterial activity of the ADEPs. Thus, ADEPs cause a complete functional reprogramming of the Clp,protease complex. [source]

    Multiple myeloma: chemotherapy or transplantation in the era of new drugs

    Antonio Palumbo
    Abstract Objective:,To review the current results of studies incorporating novel agents in multiple myeloma (MM) and discuss the role of autologous stem-cell transplantation (ASCT) in the era of new active drugs for the treatment of this disease. The outlook for patients with symptomatic MM is changing with the introduction of bortezomib, thalidomide, and lenalidomide into the repertoire of available chemotherapeutic agents. Compared with standard chemotherapy, a survival benefit has been reported for the first time in 30 yrs. Methods: Articles published in English between 1969 and 2008 were identified by searching PubMed for ,myeloma', ,diagnosis', ,thalidomide', ,bortezomib', ,lenalidomide', ,dexamethasone', ,prednisone', ,doxorubicin', ,cyclophosphamide', ,melphalan', ,combination chemotherapy', and ,autologous transplantation'. Results: In randomized studies, bortezomib, thalidomide, and lenalidomide have each been combined with dexamethasone, alkylating agents, or doxorubicin, and such combinations resulted in significant improvement in progression-free survival. Conclusions: The incorporation of new drugs as induction therapy along with ASCT appears to produce very good partial response rates, slightly superior to those achieved by conventional chemotherapy with new drugs. How to best optimize induction, consolidation, and maintenance therapy and how to best select and prepare patients for ASCT are still to be determined. Randomized trials are needed to directly compare the current best chemotherapeutic approach with best ASCT strategies and to guide clinical practice for patients with MM. [source]

    Antisense oligodeoxynucleotide-induced suppression of basal forebrain NMDA-NR1 subunits selectively impairs visual attentional performance in rats

    Janita Turchi
    Abstract It is generally agreed that basal forebrain neuronal circuits contribute to the mediation of the ability to detect, select and discriminate signals, to suppress the processing of irrelevant information, and to allocate processing resources to competing tasks. Rats were trained in a task designed to assess sustained attention, or in a cued discrimination task that did not tax attentional processes. Animals were equipped with guide cannula to infuse bilaterally antisense oligodeoxynucleotides (ODNs) against the N -methyl- d -aspartate (NMDA) NR1 subunits, or missense ODNs, into the substantia innominata of the basal forebrain. Infusions of antisense or missense ODNs did not affect cued visual discrimination performance. Infusions of antisense ODNs dose-dependently impaired sustained attention performance by selectively decreasing the animals' ability to detect signals while their ability to reject nonsignal trials remained unchanged. The detrimental attentional effects of antisense infusions were maximal 24 h after the third and final infusion, and performance returned to baseline 24 h later. Missense infusions did not affect attentional performance. Separate experiments demonstrated extensive suppression of NR1 subunit immunoreactivity in the substantia innominata. Furthermore, infusions of antisense did not produce neurotoxic effects in that region as demonstrated by the Fluoro-Jade method. The present data support the hypothesis that NMDA receptor (NMDAR) stimulation in the basal forebrain, largely via glutamatergic inputs originating in the prefrontal cortex, represents a necessary mechanism to activate the basal forebrain corticopetal system for mediation of attentional performance. [source]

    Identification and typing of Malassezia yeasts using amplified fragment length polymorphism (AFLPTm), random amplified polymorphic DNA (RAPD) and denaturing gradient gel electrophoresis (DGGE)

    FEMS YEAST RESEARCH, Issue 2 2001
    Bart Theelen
    Abstract Three molecular tools, amplified fragment length polymorphism (AFLPTm), denaturing gradient gel electrophoresis (DGGE) and random amplified polymorphic DNA (RAPD) analysis, were explored for their usefulness to identify isolates of Malassezia yeasts. All seven species could be separated by AFLP and DGGE. Using AFLP, four genotypes could be distinguished within M. furfur. AFLP genotype 4 contained only isolates from deep human sources, and ca. 80% of these isolates were from patients with systemic disease. Most of the systemic isolates belonged to a single RAPD genotype. This suggests that systemic conditions strongly select for a particular genotype. Although the clinical use of DGGE may be limited due to technical demands, it remains a powerful tool for the analysis of complex clinical samples. [source]

    Vertical distribution and behaviour of shrimp Pandalus borealis larval stages in thermally stratified water columns: laboratory experiment and field observations

    Abstract By combining field data and laboratory observations of larvae in a simulated thermal gradient, we described the ontogenetic changes in vertical distribution and behaviour of early stages of shrimp Pandalus borealis in thermally stratified water columns. Both in the laboratory and at stations in the north-western Gulf of St Lawrence, the first two larval stages appear to actively select and maintain a position in the upper layer of warmer temperatures, within the thermocline and above the cold (<1°C) intermediate layer. Stage III larvae were distributed deeper in the water column and in colder waters than the previous two stages. Stage IV and V larvae showed the highest degree of swimming activity in the laboratory and a much wider range (from surface to ,200 m) in vertical distribution in the field. The shift to deeper waters and settlement to the bottom habitat appears to happen after the fifth moult, at stage VI. We propose that the pattern of vertical distribution in the field reflects the adjustment of the different developmental stages to the distribution of preferred prey. The description of the ontogenetic change in the vertical distributions and movements of early stages of P. borealis should be valuable information for future attempts to model larval transport and dispersion, and for detecting settlement/recruitment areas using 3D ocean circulation models. The identification of the thermal habitat of the different larval stages and the timing for settlement at the bottom also provides important information for the development of temperature-dependent growth models up to the first juvenile stages. [source]

    The evolution of floral scent: the influence of olfactory learning by insect pollinators on the honest signalling of floral rewards

    FUNCTIONAL ECOLOGY, Issue 5 2009
    Geraldine A. Wright
    Summary 1.,The evolution of flowering plants has undoubtedly been influenced by a pollinator's ability to learn to associate floral signals with food. Here, we address the question of ,why' flowers produce scent by examining the ways in which olfactory learning by insect pollinators could influence how floral scent emission evolves in plant populations. 2.,Being provided with a floral scent signal allows pollinators to learn to be specific in their foraging habits, which could, in turn, produce a selective advantage for plants if sexual reproduction is limited by the income of compatible gametes. Learning studies with honeybees predict that pollinator-mediated selection for floral scent production should favour signals which are distinctive and exhibit low variation within species because these signals are learned faster. Social bees quickly learn to associate scent with the presence of nectar, and their ability to do this is generally faster and more reliable than their ability to learn visual cues. 3.,Pollinators rely on floral scent as a means of distinguishing honestly signalling flowers from deceptive ones. Furthermore, a pollinator's sensitivity to differences in nectar rewards can bias the way that it responds to floral scent. This mechanism may select for flowers that provide olfactory signals as an honest indicator of the presence of nectar or which select against the production of a detectable scent signal when no nectar is present. 4.,We expect that an important yet commonly overlooked function of floral scent is an improvement in short-term pollinator specificity which provides an advantage to both pollinator and plant over the use of a visual signal alone. This, in turn, impacts the evolution of plant mating systems via its influence on the species-specific patterns of floral visitation by pollinators. [source]

    Competitive relationships of Andropogon gerardii (Big Bluestem) from remnant and restored native populations and select cultivated varieties

    FUNCTIONAL ECOLOGY, Issue 3 2004
    Summary 1Although genetic differentiation among plant populations is well known, its relevance for preserving the integrity of native ecosystems has received little attention. In a series of competition experiments with Andropogon gerardii Vitman, a dominant species of the North American Tallgrass Prairie, plant performance was related to seed provenance and restoration activities. 2Glasshouse experiments showed plant performance to be a function of seed source. Differential target plant performance relative to competitor identity was observed when plant performance was assessed across a range of competitor densities. Local and non-local plants were larger when competing against non-local plants relative to the local and cultivar plants, while cultivar plants were consistently larger than local and non-local plants regardless of competitor identity or density. The consistency of cultivar performance could reflect directional selection during cultivar development for consistently high fecundity, vigorous vegetative growth and resistance to pathogens. 3In a field experiment, non-local plants were half the size of local and cultivar plants, supporting recognition of seed provenances of A. gerardii based on differences in plant performance among source populations observed in the glasshouse study, and previous genetic analyses of the same populations. 4This study establishes that seed provenance and restoration activities influence the competitive ability of a dominant species which, in turn, may affect plant community structure and potential ecosystem function. [source]

    Genome-wide association analyses of expression phenotypes

    Gary K. Chen
    Abstract A number of issues arise when analyzing the large amount of data from high-throughput genotype and expression microarray experiments, including design and interpretation of genome-wide association studies of expression phenotypes. These issues were considered by contributions submitted to Group 1 of the Genetic Analysis Workshop 15 (GAW15), which focused on the association of quantitative expression data. These contributions evaluated diverse hypotheses, including those relevant to cancer and obesity research, and used various analytic techniques, many of which were derived from information theory. Several observations from these reports stand out. First, one needs to consider the genetic model of the trait of interest and carefully select which single nucleotide polymorphisms and individuals are included early in the design stage of a study. Second, by targeting specific pathways when analyzing genome-wide data, one can generate more interpretable results than agnostic approaches. Finally, for datasets with small sample sizes but a large number of features like the Genetic Analysis Workshop 15 dataset, machine learning approaches may be more practical than traditional parametric approaches. Genet Epidemiol 31 (Suppl. 1): S7,S11, 2007. © 2007 Wiley-Liss, Inc. [source]

    A new multimarker test for family-based association studies

    Cyril S. Rakovski
    Abstract We propose a new multimarker test for family-based studies in candidate genes. We use simulations under different genetic models to assess the performance of competing testing strategies, characterized in this study as combinations of the following important factors: genes, statistical tests, tag single nucleotide polymorphisms (SNP) methods, number of tag SNPs and family designs. An ANOVA model is employed to provide descriptive summaries of the effects on power of the above-mentioned factors. We find that tag SNP methods, gene characteristics and family designs have minimal impact on the best testing strategy. The familywise error rate (FWER) controlling multiple comparison procedure and the new multimarker test offer the highest power followed by the asymptotic global haplotype test. Both the FWER and the multimarker test are invariant to family designs and gain power as we increase the number of tag SNPs. However, the performance of the global haplotype test is slightly degraded when analyzing larger numbers of tag SNPs. Within the framework of our study, the best strategy for family-based studies in candidate genes that emerged from our analysis is to use the FWER or the multimarker test and select 6,10 tag SNPs using any of the tag SNP methods considered. We confirm the conclusions of our study with an application to Alzheimer's disease data. Genet. Epidemiol. © 2006 Wiley-Liss, Inc. [source]

    Analysis of the current methods used to size a wind/hydrogen/fuel cell-integrated system: A new perspective

    H. G. Geovanni
    Abstract As an alternative to the production and storage of intermittent renewable energy sources, it has been suggested that one can combine several renewable energy technologies in one system, known as integrated or hybrid system, that integrate wind technology with hydrogen production unit and fuel cells. This work assesses the various methods used in sizing such systems. Most of the published papers relate the use of simulation tools such as HOMER, HYBRID2 and TRNSYS, to simulate the operation of different configurations for a given application in order to select the best economic option. But, with these methods one may not accurately determine certain characteristics of the energy resources available on a particular site, the profiles of estimated consumption and the demand for hydrogen, among other factors, which will be the optimal parameters of each subsystem. For example, velocity design, power required for the wind turbine, power required for the fuel cell and electrolyzer and the storage capacity needed for the system. Moreover, usually one makes excessive use of bi-parametric Weibull distribution function to approximate the histogram of the observed wind to the theoretical, which is not appropriate when there are bimodal frequency distributions of wind, as is the case in several places in the world. A new perspective is addressed in this paper, based on general system theory, modeling and simulation with a systematic approach and the use of exergoeconomic analysis. There are some general ideas on the advantages offered in this method, which is meant for the implementation of wind/hydrogen/fuel cell-integrated systems and in-situ clean hydrogen production. Copyright © 2009 John Wiley & Sons, Ltd. [source]

    Prediction rules for computed tomography in the dementia assessment: do they predict clinical utility of CT?

    Kelly A. Condefer
    Abstract Neuroimaging is widely employed in the dementia assessment in refining clinical decision-making. However, with rising interest in cost-effective medical practice, efforts have been made in the literature to define clinical prediction rules that select for a subgroup of patients who would most likely benefit from neuroimaging. This short study examined the ability of a group of published clinical predictors to identify patients whose diagnoses or management would be influenced by CT scan results. The study finds that none of the published predictors bears a significant relationship to actual influence of CT scans in a group of memory clinic patients, highlighting the need for the development of clinical predictors for neuroimaging that will impact patient care. Copyright © 2003 John Wiley & Sons, Ltd. [source]

    Efficacy of Beauveria bassiana (Bals.) Vuill. against the tarnished plant bug, Lygus lineolaris L., in strawberries

    R. Sabbahi
    Abstract Beauveria bassiana has a high insecticidal potential to control the tarnished plant bug, Lygus lineolaris, a significant pest of strawberries. Screening experiments showed that L. lineolaris adults were susceptible to several B. bassiana isolates. Another screening test with Coleomegilla maculata, a natural enemy found in strawberries, was also performed in order to select the isolate having lower entomopathogenic impact on this insect. Based on data obtained from both insect species and on the ecozone origin of the B. bassiana isolates, INRS-IP and INRS-CFL isolates were selected for further experiments. The LC50 values of these two isolates against L. lineolaris adults were 7.8 × 105 and 5.3 × 105 conidia/ml, and average survival time (AST) values were 4.46 and 4.37 days at a concentration of 1 × 108 conidia/ml respectively. Results also indicated that L. lineolaris nymphs are susceptible to the selected isolates. During field experiments, using a randomized block design with four replicates, INRS-IP and INRS-CFL isolates were applied at two rates (1 × 1011 and 1 × 1013 conidia/ha) weekly during a period of 4 weeks. These multiple applications triggered a significant reduction of L. lineolaris nymphal populations in strawberries. Twenty-four days after the first application, a significant difference was observed between the mean population densities of surviving nymphs in all B. bassiana -treated plots (less than one insect per five plants) compared with those in control plots (four insects per five plants). During the field experiment, persistence of insecticidal activity and viability of B. bassiana conidia were also monitored. The results showed the presence of viable and infective conidia up to 6 days after each application on strawberry foliage. Moreover, the multiple applications of B. bassiana at the rate of 1 × 1013 conidia/ha triggered a significant reduction in strawberry fruit injuries induced by L. lineolaris feeding behaviour compared with the control plots. [source]

    Identification of the clonal complexes of Staphylococcus aureus strains by determination of the conservation patterns of small genomic islets

    M. Suzuki
    Abstract Aims:, To investigate the clonality of Staphylococcus aureus isolates, it is important to identify their clonal complexes (CCs) with multilocus sequence typing (MLST). However, it is expensive to carry out MLST analyses for many isolates. The aim of this study, therefore, was to develop a cost-effective method to identify CCs by determining the conservation pattern of ,small genomic islets' (SGIs). SGIs are nonconserved regions between strains and have single or multiple open-reading frames (ORFs). Methods and Results:, The whole-genome sequences of nine strains were compared in order to select 16 SGIs. The conservation patterns of the 16 SGIs (islet patterns) were investigated in 136 S. aureus isolates, which were classified into 21 CCs. The islet patterns (IPs) exhibited a one-to-one correspondence with the CCs, except for isolates belonging to CC1, CC5 and CC8. The IPs typical of strains belonging to CC1, CC5 and CC8 differed between those of sequence type 1 (ST1) and ST188 (CC1), ST5 and ST6 (CC5) and ST8 and ST239 (CC8). Significance and Impact of the Study:, The CCs of many isolates can be identified in an easy and inexpensive manner by detecting these 16 SGIs. Emergent clones, particularly methicillin-resistant ones, can be identified by examining numerous islets by IP analysis. [source]

    Isolation and selection of Bacillus spp. as potential biological agents for enhancement of water quality in culture of ornamental fish

    R. Lalloo
    Abstract Aims:, To isolate, select and evaluate Bacillus spp. as potential biological agents for enhancement of water quality in culture of ornamental fish. Methods and Results:, Natural isolates obtained from mud sediment and Cyprinus carpio were purified and assessed in vitro for efficacy based on the inhibition of growth of pathogenic Aeromonas hydrophila and the decrease in concentrations of ammonium, nitrite, nitrate and phosphate ions. Based on suitability to predefined characteristics, the isolates B001, B002 and B003 were selected and evaluated in vitro in the presence of Aer. hydrophila and in a preliminary in vivo trial with C. carpio. The inhibitory effect on pathogen growth and the decrease in concentrations of waste ions was demonstrated. Based on 16S RNA sequence homology, the isolates were identified as Bacillus subtilis, Bacillus cereus and Bacillus licheniformis, respectively. Isolate B002 did not contain the anthrax virulence plasmids pOX1, pOX2 or the B. cereus enterotoxin. Conclusions:, Selected isolates effected synergistic reduction in pathogen load and the concentrations of waste ions in vitro and in vivo and are safe for use in ornamental aquaculture. Significance and Impact of the Study:, A new approach for assessment of biological agents was demonstrated and has yielded putative isolates for development into aquaculture products. [source]

    Failure of the ammonia oxidation process in two pharmaceutical wastewater treatment plants is linked to shifts in the bacterial communities

    L. Wittebolle
    Abstract Aims:, To investigate whether two different wastewater treatment plants (WWTPs) , treating the same pharmaceutical influent , select for a different bacterial and/or ammonia oxidizing bacterial (AOB) community. Methods and Results:, Molecular fingerprinting demonstrated that each WWTP had its own total bacterial and AOB community structure, but Nitrosomonas eutropha and N. europea were dominant in both WWTP A and B. The DNA and RNA analysis of the AOB communities revealed different patterns; so the most abundant species may not necessarily be the most active ones. Nitritation failures, monitored by chemical parameter analysis, were reflected as AOB community shifts and visualized by denaturing gradient gel electrophoresis (DGGE)-based moving window analysis. Conclusions:, This research demonstrated the link between functional performance (nitritation parameters) and the presence and activity of a specific microbial ecology (AOB). Clustering and moving window analysis based on DGGE showed to be valuable to monitor community shifts in both WWTPs. Significance and Impact of the Study:, This study of specific community shifts together with functional parameter analysis has potential as a tool for relating functional instability (such as operational failures) to specific-bacterial community shifts. [source]

    Do pipits use experimentally supplemented rich sources of calcium more often in an acidified area?

    S. Bure
    How birds respond to the recent phenomenon of calcium deficiency in acidified areas is still poorly known. This study, carried out in the Jeseníky Mountains (heavily polluted, acidified area in the Czech Republic), in alpine ecosystems of central Norway, and in the limestone part of the Malá Fatra Mountains (Slovak Republic), provides the first experimental evidence that birds select and bring supplemented calcium-rich items to their nestlings more often in an acidified area. Meadow Pipits Anthus pratensis and Water Pipits A. spinoletta selected calcium-rich items (mainly snail shells) from various materials placed near their nests and this selectivity did not differ between areas or species. Thinning of egg shells (8% at blunt pole, 5% at egg side) suggests that Meadow Pipits in the Jeseníky Mountains were negatively influenced by the low calcium availability, in spite of their ability to adjust foraging behaviour. [source]

    Retroviral vector silencing during iPS cell induction: An epigenetic beacon that signals distinct pluripotent states

    Akitsu Hotta
    Abstract Retroviral vectors are transcriptionally silent in pluripotent stem cells. This feature has been potently applied in studies that reprogram somatic cells into induced pluripotent stem (iPS) cells. By delivering the four Yamanaka factors in retroviral vectors, high expression is obtained in fibroblasts to induce the pluripotent state. Partial reprogramming generates Class I iPS cells that express the viral transgenes and endogenous pluripotency genes. Full-reprogramming in Class II iPS cells silences the vectors as the endogenous genes maintain the pluripotent state. Thus, retroviral vector silencing serves as a beacon marking the fully reprogrammed pluripotent state. Here we review known silencer elements, and the histone modifying and DNA methylation pathways, that silence retroviral and lentiviral vectors in pluripotent stem cells. Both retroviral and lentiviral vectors are influenced by position effects and often exhibit variegated expression. The best vector designs facilitate full-reprogramming and subsequent retroviral silencing, which is required for directed-differentiation. Current retroviral reprogramming methods can be immediately applied to create patient-specific iPS cell models of human disease, however, future clinical applications will require novel chemical or other reprogramming methods that reduce or eliminate the integrated vector copy number load. Nevertheless, retroviral vectors will continue to play an important role in genetically correcting patient iPS cell models. We anticipate that novel pluripotent-specific reporter vectors will select for isolation of high quality human iPS cell lines, and select against undifferentiated pluripotent cells during regenerative medicine to prevent teratoma formation after transplantation. J. Cell. Biochem. 105: 940,948, 2008. © 2008 Wiley-Liss, Inc. [source]

    Duplex Doppler sonography of transplant renal artery stenosis

    Ruth Helena de Morais MD
    Abstract Purpose The aim of this study was to evaluate the accuracy of duplex Doppler sonography in diagnosing transplant renal artery stenosis (TRAS) and to determine which parameter is the most reliable for making that diagnosis. Methods Over a 3-year period, we sonographically evaluated patients who were referred for investigation of possible TRAS. We investigated the following parameters: peak systolic velocity (PSV) in the external iliac and renal arteries, acceleration time and acceleration in the intrarenal arteries, acceleration time in the renal artery, resistance index, and the ratio of the PSVs in the renal and external iliac arteries. We also used MR angiography and digital subtraction arteriography to verify the degree of stenosis. After the evaluations, the patients were classified into 2 groups, 1 with and the other without significant stenosis (> 50% narrowing of the lumen) on digital subtraction arteriography. We also included a control group of patients who had undergone renal transplantation at least 6 months before, had had a good course after transplantation, had a diastolic blood pressure of 90 mm Hg or less, and were taking a maximum of 1 antihypertensive drug. Results Our study population consisted of 22 patients suspected to have TRAS (10 without and 12 with confirmed significant stenosis) and 19 control patients. We found statistically significant differences between the mean values of these 3 groups except for the PSV in the iliac artery and the resistance index in the intrarenal arteries. The most accurate parameters to use in diagnosing TRAS were an acceleration time of 0.1 second or higher in the renal and intrarenal arteries, a PSV of greater than 200 cm/second in the renal artery, and a ratio of PSVs in the renal and external iliac arteries of greater than 1.8. Conclusions Duplex Doppler sonography is an excellent method for screening patients suspected to have TRAS and can help select which of those patients should undergo digital subtraction arteriography. © 2003 Wiley Periodicals, Inc. J Clin Ultrasound 31:135,141, 2003 [source]

    The Effects of Negativity and Motivated Information Processing During a Political Campaign

    Michael F. Meffert
    This research investigated how voters select, process, are affected by, and recall political information in a dynamic campaign environment. It was hypothesized that voters' information selection, processing, and recall are subject to a negativity bias (i.e., negative information dominates over positive information), a congruency bias (i.e., positive information about the preferred candidate and negative information about the opponent candidate dominate over negative information about the preferred candidate and positive information about the opponent), and a candidate bias (i.e., information about the preferred candidate dominates over information about the opponent). Motivated by an initial candidate preference, participants were also expected to develop more polarized candidate evaluations over time. Participants were exposed to quickly changing information in the form of newspaper-style headlines on a dynamic, computer-based information board. The results generally supported negativity bias and candidate bias, whereas congruency bias was only found during information recall. At the information selection and processing stages, participants with a strong initial candidate preference showed a disproportionate preference for negative information about the preferred candidate. However, they developed more positive attitudes at the evaluation and recall stage. This finding suggests that participants were engaged in motivated information processing by counterarguing negative information about their preferred candidate. [source]