337 research outputs found
Munchausen by internet: current research and future directions.
The Internet has revolutionized the health world, enabling self-diagnosis and online support to take place irrespective of time or location. Alongside the positive aspects for an individual's health from making use of the Internet, debate has intensified on how the increasing use of Web technology might have a negative impact on patients, caregivers, and practitioners. One such negative health-related behavior is Munchausen by Internet
Konstruktivistische Ansätze in der Erwachsenenbildung und Weiterbildung
Theoretical approaches in the field of further education and advanced vocational training have to face multifaceted demands: the analysis of knowledge aquisition and knowledge transfer and its instructional support as well as the revealment of the mechanisms which influence further education on an organisational level in companies. This article describes, that herefore especially moderate constructivistic approaches are useful. After an introduction to the philosophical tradition of these approaches and important characteristics of adult learning, two examples of constructivistic models are being described particularly: The theory of situated learning environments and career counseling. Concluding it is shown, that a moderate constructive perspective fulfils important criteria for the theoretic modelling of further education processes.Theoretische Ansätze in der Erwachsenen- und insbesondere in der beruflichen Weiterbildung müssen sich vielfältigen Ansprüchen stellen: der Analyse des Wissenserwerbs und Wissenstransfers und seiner instruktionalen Unterstützung ebenso wie der Aufdeckung der Mechanismen, die in den Betrieben auf organisatorischer Ebene die Weiterbildung beeinflussen. In diesem Beitrag wird die Auffassung vertreten, daß dafür insbesondere liberalisierte konstruktivistische Ansätze gut geeignet sind. Nach einer Einführung in die philosophische Tradition dieser Ansätze und wichtiger Merkmale des Lernens im Erwachsenenalter werden zwei Beispiele konstruktivistischer Modelle genauer beschrieben: die Theorie situierter Lernumgebungen und das career counseling. Abschließend wird gezeigt, daß eine liberalisierte konstruktivistische Perspektive wichtige Kriterien für die theoretische Modellierung von Weiterbildungsprozessen erfüllt
Comparison of two independent systematic reviews of trials of recombinant human bone morphogenetic protein-2 (rhBMP-2) : The Yale Open Data Access Medtronic Project
Background: It is uncertain whether the replication of systematic reviews, particularly those with the same objectives and resources, would employ similar methods and/or arrive at identical findings. We compared the results and conclusions of two concurrent systematic reviews undertaken by two independent research teams provided with the same objectives, resources, and individual participant-level data. Methods: Two centers in the USA and UK were each provided with participant-level data on 17 multi-site clinical trials of recombinant human bone morphogenetic protein-2 (rhBMP-2). The teams were blinded to each other's methods and findings until after publication. We conducted a retrospective structured comparison of the results of the two systematic reviews. The main outcome measures included (1) trial inclusion criteria; (2) statistical methods; (3) summary efficacy and risk estimates; and (4) conclusions. Results: The two research teams' meta-analyses inclusion criteria were broadly similar but differed slightly in trial inclusion and research methodology. They obtained similar results in summary estimates of most clinical outcomes and adverse events. Center A incorporated all trials into summary estimates of efficacy and harms, while Center B concentrated on analyses stratified by surgical approach. Center A found a statistically significant, but small, benefit whereas Center B reported no advantage. In the analysis of harms, neither showed an increased cancer risk at 48 months, although Center B reported a significant increase at 24 months. Conclusions reflected these differences in summary estimates of benefit balanced with small but potentially important risk of harm. Conclusions: Two independent groups given the same research objectives, data, resources, funding, and time produced broad general agreement but differed in several areas. These differences, the importance of which is debatable, indicate the value of the availability of data to allow for more than a single approach and a single interpretation of the data. Systematic review registration: PROSPERO CRD42012002040and CRD42012001907
A survey of security issue in multi-agent systems
Multi-agent systems have attracted the attention of researchers because of agents' automatic, pro-active, and dynamic problem solving behaviors. Consequently, there has been a rapid development in agent technology which has enabled us to provide or receive useful and convenient services in a variety of areas such as banking, transportation, e-business, and healthcare. In many of these services, it is, however, necessary that security is guaranteed. Unless we guarantee the security services based on agent-based systems, these services will face significant deployment problems. In this paper, we survey existing work related to security in multi-agent systems, especially focused on access control and trust/reputation, and then present our analyses. We also present existing problems and discuss future research challenges. © Springer Science+Business Media B.V 2011
Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease
Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.
Clinical validation of an AI-based pathology tool for scoring of metabolic dysfunction-associated steatohepatitis
\ua9 The Author(s) 2024.Metabolic dysfunction-associated steatohepatitis (MASH) is a major cause of liver-related morbidity and mortality, yet treatment options are limited. Manual scoring of liver biopsies, currently the gold standard for clinical trial enrollment and endpoint assessment, suffers from high reader variability. This study represents the most comprehensive multisite analytical and clinical validation of an artificial intelligence (AI)-based pathology system, AI-based measurement of metabolic dysfunction-associated steatohepatitis (AIM-MASH), to assist pathologists in MASH trial histology scoring. AIM-MASH demonstrated high repeatability and reproducibility compared to manual scoring. AIM-MASH-assisted reads by expert MASH pathologists were superior to unassisted reads in accurately assessing inflammation, ballooning, MAS ≥ 4 with ≥1 in each score category and MASH resolution, while maintaining non-inferiority in steatosis and fibrosis assessment. These findings suggest that AIM-MASH could mitigate reader variability, providing a more reliable assessment of therapeutics in MASH clinical trials
AI-based automation of enrollment criteria and endpoint assessment in clinical trials in liver diseases
\ua9 The Author(s) 2024.Clinical trials in metabolic dysfunction-associated steatohepatitis (MASH, formerly known as nonalcoholic steatohepatitis) require histologic scoring for assessment of inclusion criteria and endpoints. However, variability in interpretation has impacted clinical trial outcomes. We developed an artificial intelligence-based measurement (AIM) tool for scoring MASH histology (AIM-MASH). AIM-MASH predictions for MASH Clinical Research Network necroinflammation grades and fibrosis stages were reproducible (κ = 1) and aligned with expert pathologist consensus scores (κ = 0.62–0.74). The AIM-MASH versus consensus agreements were comparable to average pathologists for MASH Clinical Research Network scores (82% versus 81%) and fibrosis (97% versus 96%). Continuous scores produced by AIM-MASH for key histological features of MASH correlated with mean pathologist scores and noninvasive biomarkers and strongly predicted progression-free survival in patients with stage 3 (P < 0.0001) and stage 4 (P = 0.03) fibrosis. In a retrospective analysis of the ATLAS trial (NCT03449446), responders receiving study treatment showed a greater continuous change in fibrosis compared with placebo (P = 0.02). Overall, these results suggest that AIM-MASH may assist pathologists in histologic review of MASH clinical trials, reducing inter-rater variability on trial outcomes and offering a more sensitive and reproducible measure of patient responses
Maximum (prior) brain size, not atrophy, correlates with cognition in community-dwelling older people: a cross-sectional neuroimaging study
<p>Abstract</p> <p>Background</p> <p>Brain size is associated with cognitive ability in adulthood (correlation ~ .3), but few studies have investigated the relationship in normal ageing, particularly beyond age 75 years. With age both brain size and fluid-type intelligence decline, and regional atrophy is often suggested as causing decline in specific cognitive abilities. However, an association between brain size and intelligence may be due to the persistence of this relationship from earlier life.</p> <p>Methods</p> <p>We recruited 107 community-dwelling volunteers (29% male) aged 75–81 years for cognitive testing and neuroimaging. We used principal components analysis to derived a 'general cognitive factor' (g) from tests of fluid-type ability. Using semi-automated analysis, we measured whole brain volume, intracranial area (ICA) (an estimate of maximal brain volume), and volume of frontal and temporal lobes, amygdalo-hippocampal complex, and ventricles. Brain atrophy was estimated by correcting WBV for ICA.</p> <p>Results</p> <p>Whole brain volume (WBV) correlated with general cognitive ability (g) (r = .21, P < .05). Statistically significant associations between brain areas and specific cognitive abilities became non-significant when corrected for maximal brain volume (estimated using ICA), i.e. there were no statistically significant associations between atrophy and cognitive ability. The association between WBV and g was largely attenuated (from .21 to .03: i.e. attenuating the variance by 98%) by correcting for ICA. ICA accounted for 6.2% of the variance in g in old age, whereas atrophy accounted for < 1%.</p> <p>Conclusion</p> <p>The association between brain regions and specific cognitive abilities in community dwelling people of older age is due to the life-long association between whole brain size and general cognitive ability, rather than atrophy of specific regions. Researchers and clinicians should therefore be cautious of interpreting global or regional brain atrophy on neuroimaging as contributing to cognitive status in older age without taking into account prior mental ability and brain size.</p
Temperature-Dependent Modulation of Chromosome Segregation in msh4 Mutants of Budding Yeast
BACKGROUND:In many organisms, homologous chromosomes rely upon recombination-mediated linkages, termed crossovers, to promote their accurate segregation at meiosis I. In budding yeast, the evolutionarily conserved mismatch-repair paralogues, Msh4 and Msh5, promote crossover formation in conjunction with several other proteins, collectively termed the Synapsis Initiation Complex (SIC) proteins or 'ZMM's (Zip1-Zip2-Zip3-Zip4-Spo16, Msh4-Msh5, Mer3). zmm mutants show decreased levels of crossovers and increased chromosome missegregation, which is thought to cause decreased spore viability. PRINCIPAL FINDINGS:In contrast to other ZMM mutants, msh4 and msh5 mutants show improved spore viability and chromosome segregation in response to elevated temperature (23 degrees C versus 33 degrees C). Crossover frequencies in the population of viable spores in msh4 and msh5 mutants are similar at both temperatures, suggesting that temperature-mediated chromosome segregation does not occur by increasing crossover frequencies. Furthermore, meiotic progression defects at elevated temperature do not select for a subpopulation of cells with improved segregation. Instead, another ZMM protein, Zip1, is important for the temperature-dependent improvement in spore viability. CONCLUSIONS:Our data demonstrate interactions between genetic (zmm status) and environmental factors in determining chromosome segregation
Sustainability of an HIV PEP Program for Sexual Assault Survivors: “Lessons Learned” from Health Care Providers
This study explored challenges to continuing an HIV post-exposure prophylaxis (PEP) program of care provided to sexual assault survivors in the province of Ontario, Canada. Data were collected as part of an implementation and evaluation of a universal offering of HIV PEP (known as the HIV PEP Program) at 24 of 34 provincial hospital-based sexual assault treatment centres. Experienced health care providers were surveyed (n = 132) and interviewed in four focus groups (n = 26) about their perceptions of what, if any, factors threatened their ability to maintain the HIV PEP Program. All focus groups were audio-recorded and the recordings transcribed. The transcriptions and open-ended survey responses were analyzed using content analysis. Administrator, nurse, physician, social worker, and pharmacist respondents perceived important barriers to sustainability of the HIV PEP Program. Eight constructs were identified within four broad themes: resources (inadequate funds, overworked and unacknowledged staff), expertise (insufficient external supports, insufficiently trained and knowledgeable staff), commitment (lack of institutional support, physician resistance to offering HIV PEP), and accommodation (lack of flexibility in addressing specific client and community needs, inaccessibility and lack of clarity of tools). We discuss the implications of these findings and the actions that were taken to address the challenges
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