300 research outputs found

    PlantSimLab - a modeling and simulation web tool for plant biologists.

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    BACKGROUND: At the molecular level, nonlinear networks of heterogeneous molecules control many biological processes, so that systems biology provides a valuable approach in this field, building on the integration of experimental biology with mathematical modeling. One of the biggest challenges to making this integration a reality is that many life scientists do not possess the mathematical expertise needed to build and manipulate mathematical models well enough to use them as tools for hypothesis generation. Available modeling software packages often assume some modeling expertise. There is a need for software tools that are easy to use and intuitive for experimentalists. RESULTS: This paper introduces PlantSimLab, a web-based application developed to allow plant biologists to construct dynamic mathematical models of molecular networks, interrogate them in a manner similar to what is done in the laboratory, and use them as a tool for biological hypothesis generation. It is designed to be used by experimentalists, without direct assistance from mathematical modelers. CONCLUSIONS: Mathematical modeling techniques are a useful tool for analyzing complex biological systems, and there is a need for accessible, efficient analysis tools within the biological community. PlantSimLab enables users to build, validate, and use intuitive qualitative dynamic computer models, with a graphical user interface that does not require mathematical modeling expertise. It makes analysis of complex models accessible to a larger community, as it is platform-independent and does not require extensive mathematical expertise

    A proposed method to investigate reliability throughout a questionnaire

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    <p>Abstract</p> <p>Background</p> <p>Questionnaires are used extensively in medical and health care research and depend on validity and reliability. However, participants may differ in interest and awareness throughout long questionnaires, which can affect reliability of their answers. A method is proposed for "screening" of systematic change in random error, which could assess changed reliability of answers.</p> <p>Methods</p> <p>A simulation study was conducted to explore whether systematic change in reliability, expressed as changed random error, could be assessed using unsupervised classification of subjects by cluster analysis (CA) and estimation of intraclass correlation coefficient (ICC). The method was also applied on a clinical dataset from 753 cardiac patients using the Jalowiec Coping Scale.</p> <p>Results</p> <p>The simulation study showed a relationship between the systematic change in random error throughout a questionnaire and the slope between the estimated ICC for subjects classified by CA and successive items in a questionnaire. This slope was proposed as an awareness measure - to assessing if respondents provide only a random answer or one based on a substantial cognitive effort. Scales from different factor structures of Jalowiec Coping Scale had different effect on this awareness measure.</p> <p>Conclusions</p> <p>Even though assumptions in the simulation study might be limited compared to real datasets, the approach is promising for assessing systematic change in reliability throughout long questionnaires. Results from a clinical dataset indicated that the awareness measure differed between scales.</p

    Simvastatin for patients with Acute Respiratory Distress Syndrome: long term outcomes and cost-effectiveness from a randomised controlled trial

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    Background: Simvastatin therapy for patients with ARDS has been shown to be safe and associated with minimal adverse effects, but it does not improve clinical outcomes. The aim of this research was to report on mortality and cost-effectiveness of simvastatin in patients with ARDS at 12 months. Methods: A cost-utility analysis alongside a multicentre, double-blind, randomised controlled trial carried out in the UK and Ireland. Five hundred and forty intubated and mechanically ventilated patients with acute respiratory distress syndrome were randomly assigned (1:1) to receive once-daily simvastatin (at a dose of 80 mg) or identical placebo tablets enterally for up to 28 days. Results: Mortality was lower in the simvastatin group (31.8%; 95% CI 26.1, 37.5) compared to the placebo group (37.3%; 95% CI 31.6, 43.0) at 12 months although this was not significant. Simvastatin was associated with statistically significant QALY gain (incremental QALYs 0.064, 95% CI 0.002, 0.127) compared to placebo. Simvastatin was also less costly (incremental total costs –£3601, 95% CI –8061, 859). At a willingness-to-pay threshold of £20,000 per QALY the probability of simvastatin being cost-effective was 99%. Sensitivity analyses indicated that the results were robust to changes in methodological assumptions with the probability of cost-effectiveness never dropping below 90%. Conclusion: Simvastatin was found to be cost-effective for the treatment of ARDS, being associated with both a significant QALY gain and a cost saving. There was no significant reduction in mortality at 12 months

    Novel Diagnosis of Lyme Disease: Potential for CAM Intervention

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    Lyme disease (LD) is the most common tick-borne disease in the northern hemisphere, producing a wide range of disabling effects on multiple human targets, including the skin, the nervous system, the joints and the heart. Insufficient clinical diagnostic methods, the necessity for prompt antibiotic treatment along with the pervasive nature of infection impel the development and establishment of new clinical diagnostic tools with increased accuracy, sensitivity and specificity. The goal of this article is 4-fold: (i) to detail LD infection and pathology, (ii) to review prevalent diagnostic methods, emphasizing inherent problems, (iii) to introduce the usage of in vivo induced antigen technology (IVIAT) in clinical diagnostics and (iv) to underscore the relevance of a novel comprehensive LD diagnostic approach to practitioners of Complementary and Alternative Medicine (CAM). Utilization of this analytical method will increase the accuracy of the diagnostic process and abridge the time to treatment, with antibiotics, herbal medicines and nutritional supplements, resulting in improved quality of care and disease prognosis

    Antenatal corticosteroids and cardio-metabolic outcomes in adolescents born with very low birth weight

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    Exposure to antenatal corticosteroids (ANCS) is associated with adverse cardio-metabolic outcomes in animal models; however long-term outcomes in clinical studies are not well characterized. We hypothesized that exposure to ANCS would be associated with markers of increased cardio-metabolic risk in adolescents born with very low birth weight (VLBW)

    Writing materiality into management and organization studies through and with Luce Irigaray

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    YesThere is increasing recognition in management and organization studies of the importance of materiality as an aspect of discourse, while the neglect of materiality in post-structuralist management and organization theory is currently the subject of much discussion. This article argues that this turn to materiality may further embed gender discrimination. We draw on Luce Irigaray’s work to highlight the dangers inherent in masculine discourses of materiality. We discuss Irigaray’s identification of how language and discourse elevate the masculine over the feminine so as to offer insights into ways of changing organizational language and discourses so that more beneficial, ethicallyfounded identities, relationships and practices can emerge. We thus stress a political intent that aims to liberate women and men from phallogocentrism. We finally take forward Irigaray’s ideas to develop a feminist écriture of/for organization studies that points towards ways of writing from the body. The article thus not only discusses how inequalities may be embedded within the material turn, but it also provides a strategy that enriches the possibilities of overcoming them from within

    Association of adiposity and mental health functioning across the lifespan:Findings from understanding society (The UK household longitudinal study)

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    Background: Evidence on the adiposity-mental health associations is mixed, with studies finding positive, negative or no associations, and less is known about how these associations may vary by age. Objective: To examine the association of adiposity -body mass index (BMI), waist circumference (WC) and percentage body fat (BF%)- with mental health functioning across the adult lifespan. Methods: Data from 11,257 participants (aged 18+) of Understanding Society: the UK Household Longitudinal Study (waves 2 and 3, 5/2010-7/2013) were employed. Regressions of mental health functioning, assessed by the Mental Component Summary (MCS-12) and the General Health Questionnaire (GHQ-12), on adiposity measures (continuous or dichotomous indicators) were estimated adjusted for covariates. Polynomial age-adiposity interactions were estimated. Results: Higher adiposity was associated with poorer mental health functioning. This emerged in the 30s, increased up to mid-40s (all central adiposity and obesity-BF% measures) or early 50s (all BMI measures) and then decreased with age. Underlying physical health generally accounted for these associations except for central adiposity, where associations remained statistically significant from the mid-30s to50s. Cardiovascular, followed by arthritis and endocrine, conditions played the greatest role in attenuating the associations under investigation. Conclusions: We found strong age-specific patterns in the adiposity-mental health functioning association that varied across adiposity measures. Underlying physical health had the dominant role in attenuating these associations. Policy makers and health professionals should target increased adiposity, mainly central adiposity, as it is a risk factor for poor mental health functioning in those aged between mid-30s to 50 years

    Influence of an outpatient multidisciplinary pain management program on the health-related quality of life and the physical fitness of chronic pain patients

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    BACKGROUND: Approximately 10 to 20 percent of the population is suffering from chronic pain. Since this represents a major contribution to the costs of the health care system, more efficient measures and interventions to treat these patients are sought. RESULTS: The development of general health and physical activity of patients with chronic pain was assessed in an interdisciplinary outpatient pain management program (IOPP). 36 patients with an average age of 48 years were included in the IOPP. Subjective assessment of well-being was performed at five time points (baseline, post intervention and 3, 6, and 12 months thereafter) by using standardized questionnaires. The study focused on the quality of life survey Medical Outcomes Study Short Form-36, which is a validated instrument with established reliability and sensitivity. In addition, the patients participated in physical assessment testing strength, power, endurance, and mobility. Prior to therapy a substantial impairment was found on different levels. Marked improvements in the psychological parameters were obtained by the end of the program. No success was achieved with regard to the physical assessments. CONCLUSION: Although many different studies have evaluated similar programs, only few of them have attained positive results such as improvements of general quality of life or of physical strength. Often no difference from the control group could be detected only some months after the intervention. In the present study no significant persistent improvement of well-being occurred. Possible reasons are either wrong instruments, wrong selection of patients or wrong interventions
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