257 research outputs found

    Phenotypic and Genetic Comparison of a Plant‐Internalized and an Animal‐Isolated Salmonella Choleraesuis Strain

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    Contamination of fresh produce with human pathogens poses an important risk for con‐ sumers, especially after raw consumption. Moreover, if microorganisms are internalized, no re‐ moval by means of further hygienic measures would be possible. Human pathogenic bacteria iden‐ tified in these food items are mostly of human or animal origin and an adaptation to this new niche and particularly for internalization would be presumed. This study compares a plant‐internalized and an animal‐borne Salmonella enterica subsp. enterica serovar Choleraesuis aiming at the identifi‐ cation of adaptation of the plant‐internalized strain to its original environment. For this purpose, a phenotypical characterization by means of growth curves under conditions resembling the indige‐ nous environment from the plant‐internalized strain and further analyses using Pulsed‐field gel electrophoresis and Matrix‐assisted laser desorption ionization time of flight spectrometry were as‐ sessed. Furthermore, comparative genomic analyses by means of single nucleotide polymorphisms and identification of present/absent genes were performed. Although some phenotypical and ge‐ netic differences could be found, no signs of a specific adaptation for colonization and internaliza‐ tion in plants could be clearly identified. This could suggest that any Salmonella strain could directly settle in this niche without any evolutionary process being necessary. Further comparative analysis including internalized strains would be necessary to assess this question. However, these kinds of strains are not easily available

    Early development of accelerated graft coronary artery disease: Risk factors and course

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    AbstractObjectives. This study assessed the time of first appearance of angiographic graft coronary artery disease in relation to clinical and laboratory variables and clinical events in heart transplant recipients.Background. Graft coronary artery disease is the main factor limiting long-term survival after heart transplantation, and it is important to understand its natural history.Methods. One hundred thirty-nine consecutive patients who developed angiographic coronary artery disease after heart transplantation were classified according to early (≀2 years) versus late (>2 years) posttransplantation initial detection of coronary artery disease. These subgroups were analyzed for differences in clinical and laboratory demographics, incidence of progression to ischemic events and incidence of antecedent cytomegalovirus infection.Results. The early-onset group (64 patients) had more rapid progression to ischemic events than the late-onset group (75 patients), with 59% of the late group and only 35% of the early group free from ischemic events by 5 years after initial detection (p = 0.02), but there were no significantly correlated clinical or laboratory predictors of ischemic events. The early group had a significantly higher incidence of antecedent cytomegalovirus infection.Conclusions. We conclude that 1) accelerated graft coronary artery disease develops at variable times after heart transplantation; 2) the early appearance of graft coronary artery disease may be a marker of intrinsically more aggressive disease; 3) cytomegalovirus infection is associated with earlier onset of graft coronary artery disease. Patients with early development of graft coronary artery disease should potentially be given priority for interventional strategies as they are developed

    Advanced EFL learners' beliefs about language learning and teaching: a comparison between grammar, pronunciation, and vocabulary

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    This paper reports on the results of a study exploring learners’ beliefs on the learning and teaching of English grammar, pronunciation and vocabulary at tertiary level. While the importance of learners’ beliefs on the acquisition process is generally recognized, few studies have focussed on and compared learners’ views on different components of the language system. A questionnaire containing semantic scale and Likert scale items probing learners’ views on grammar, pronunciation and vocabulary was designed and completed by 117 native speakers of Dutch in Flanders, who were studying English at university. The analysis of the responses revealed that (i) vocabulary was considered to be different from grammar and pronunciation, both in the extent to which an incorrect use could lead to communication breakdown and with respect to the learners’ language learning strategies, (ii) learners believed in the feasibility of achieving a native-like proficiency in all three components, and (iii) in-class grammar, pronunciation and vocabulary exercises were considered to be useful, even at tertiary level. The results are discussed in light of pedagogical approaches to language teaching

    Social research on neglected diseases of poverty: Continuing and emerging themes

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    Copyright: © 2009 Manderson et al.Neglected tropical diseases (NTDs) exist and persist for social and economic reasons that enable the vectors and pathogens to take advantage of changes in the behavioral and physical environment. Persistent poverty at household, community, and national levels, and inequalities within and between sectors, contribute to the perpetuation and re-emergence of NTDs. Changes in production and habitat affect the physical environment, so that agricultural development, mining and forestry, rapid industrialization, and urbanization all result in changes in human uses of the environment, exposure to vectors, and vulnerability to infection. Concurrently, political instability and lack of resources limit the capacity of governments to manage environments, control disease transmission, and ensure an effective health system. Social, cultural, economic, and political factors interact and influence government capacity and individual willingness to reduce the risks of infection and transmission, and to recognize and treat disease. Understanding the dynamic interaction of diverse factors in varying contexts is a complex task, yet critical for successful health promotion, disease prevention, and disease control. Many of the research techniques and tools needed for this purpose are available in the applied social sciences. In this article we use this term broadly, and so include behavioral, population and economic social sciences, social and cultural epidemiology, and the multiple disciplines of public health, health services, and health policy and planning. These latter fields, informed by foundational social science theory and methods, include health promotion, health communication, and heath education

    Towards local electromechanical probing of cellular and biomolecular systems in a liquid environment

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    Electromechanical coupling is ubiquitous in biological systems with examples ranging from simple piezoelectricity in calcified and connective tissues to voltage-gated ion channels, energy storage in mitochondria, and electromechanical activity in cardiac myocytes and outer hair cell stereocilia. Piezoresponse force microscopy (PFM) has originally emerged as a technique to study electromechanical phenomena in ferroelectric materials, and in recent years, has been employed to study a broad range of non-ferroelectric polar materials, including piezoelectric biomaterials. At the same time, the technique has been extended from ambient to liquid imaging on model ferroelectric systems. Here, we present results on local electromechanical probing of several model cellular and biomolecular systems, including insulin and lysozyme amyloid fibrils, breast adenocarcinoma cells, and bacteriorhodopsin in a liquid environment. The specific features of SPM operation in liquid are delineated and bottlenecks on the route towards nanometer-resolution electromechanical imaging of biological systems are identified.Comment: 37 pages (including refs), 8 figure

    Is the qualitative research interview an acceptable medium for research with palliative care patients and carers?

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    <p>Abstract</p> <p>Background</p> <p>Contradictory evidence exists about the emotional burden of participating in qualitative research for palliative care patients and carers and this raises questions about whether this type of research is ethically justified in a vulnerable population. This study aimed to investigate palliative care patients' and carers' perceptions of the benefits and problems associated with open interviews and to understand what causes distress and what is helpful about participation in a research interview.</p> <p>Methods</p> <p>A descriptive qualitative study. The data were collected in the context of two studies exploring the experiences of care of palliative care patients and carers. The interviews ended with questions about patients' and carers' thoughts on participating in the studies and whether this had been a distressing or helpful event. We used a qualitative descriptive analysis strategy generated from the interviews and the observational and interactional data obtained in the course of the study.</p> <p>Results</p> <p>The interviews were considered helpful: sharing problems was therapeutic and being able to contribute to research was empowering. However, thinking about the future was reported to be the most challenging. Consent forms were sometimes read with apprehension and being physically unable to sign was experienced as upsetting. Interviewing patients and carers separately was sometimes difficult and not always possible.</p> <p>Conclusion</p> <p>The open interview enables the perspectives of patients and carers to be heard, unfettered from the structure of closed questions. It also enables those patients or carers to take part who would be unable to participate in other study designs. The context is at least as important as the format of the research interview taking into account the relational circumstances with carers and appropriate ways of obtaining informed consent. Retrospective consent could be a solution to enhancing participants control over the interview.</p

    Randomised controlled trial of topical kanuka honey for the treatment of rosacea

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    OBJECTIVE: To investigate the efficacy of topical 90% medical-grade kanuka honey and 10% glycerine (Honevo) as a treatment for rosacea. DESIGN: Randomised controlled trial with blinded assessment of primary outcome variable. SETTING: Outpatient primary healthcare population from 5 New Zealand sites. PARTICIPANTS: 138 adults aged ≄16, with a diagnosis of rosacea, and a baseline blinded Investigator Global Assessment of Rosacea Severity Score (IGA-RSS) of ≄2. 69 participants were randomised to each treatment arm. 1 participant was excluded from the Honevo group, and 7 and 15 participants withdrew from the Honevo and control groups, respectively. INTERVENTIONS: Participants were randomly allocated 1:1 to Honevo or control cream (Cetomacrogol), applied twice daily for 8 weeks. MAIN OUTCOME MEASURES: The primary outcome measure was the proportion of participants who had a ≄2 improvement in the 7-point IGA-RSS at week 8 compared to baseline. Secondary outcomes included change in IGA-RSS and subject-rated visual analogue score of change in severity (VAS-CS) on a 100 mm scale (0 mm 'much worse', 100 mm 'much improved') at weeks 2 and 8. RESULTS: 24/68 (34.3%) in the Honevo group and 12/69 (17.4%) in the control group had a ≄2 improvement in IGA-RSS at week 8 compared to baseline (relative risk 2.03; 95% CI 1.11 to 3.72, p=0.020). The change in IGA-RSS for Honevo compared to control at week 2 minus baseline was -1 (Hodges-Lehman estimate, 95% CI -1 to 0, p=0.03), and at week 8 minus baseline was -1 (Hodges-Lehman estimate, 95% CI -1 to 0, p=0.005). The VAS-CS at week 2 was 9.1 (95% CI 3.5 to 14.7), p=0.002, and at week 8 was 12.3 (95% CI 5.7 to 18.9)ž p<0.001 for Honevo compared to control. CONCLUSIONS: Honevo is an effective treatment for rosacea. TRIAL REGISTRATION NUMBER: This trial was registered in the Australian and New Zealand Clinical Trials Registry ACTRN12614000004662

    The relationship among geometry, working memory, and intelligence in children.

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    Although geometry is one of the main areas of mathematical learning, the cognitive processes underlying geometry-related academic achievement have not been studied in detail. This study explored the relationship among working memory (WM), intelligence (g factor), and geometry in 176 typically developing children attending school in their fourth and fifth grades. Structural equation modeling showed that approximately 40% of the variance in academic achievement and in intuitive geometry (which is assumed to be independent of a person's cultural background) was explained by WM and the g factor. After taking intelligence and WM into account, intuitive geometry was no longer significantly related to academic achievement in geometry. We also found intuitive geometry to be closely related to fluid intelligence (as measured by Raven's colored progressive matrices) and reasoning ability, whereas academic achievement in geometry depended largely on WM. These results were confirmed by a series of regressions in which we estimated the contributions of WM, intelligence, and intuitive geometry to the unique and shared variance explaining academic achievement in geometry. Theoretical and educational implications of the relationship among WM, intelligence, and academic achievement in geometry are discussed
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