50 research outputs found
MetaLab and metalabR: Facilitating dynamic meta-analyses in developmental psychology
Background: Developmental psychologists often make statements of the form âbabies learn to do X at age Yâ. Yet summaries made on the basis of one or a few studies can misrepresent a messy and complex evidence base. True results may also not be generalizable outside of the specific testing context for theoretically important reasons including the language or age of the infants. Other factors that are typically considered "noise" might also impede generalizability, including the lab where testing takes place, the type of stimuli, or the methods that were used. Systematic reviews and meta-analyses help bring coherence to a complex evidence base, control for confounds, and increase confidence in results. However, meta-analyses are underused in developmental research. Objective: To facilitate developmental researchersâ access to current meta-analyses, we created MetaLab (metalab.stanford.edu), a platform for open, dynamic meta-analytic datasets. In 6 years, the site has grown to 30 meta-analyses with data from 45,000 infants and children. A key feature is the standardized data storage format, which allows a unified framework for analysis and visualization. This facilitates the addition of new data points, resulting in community-augmented meta-analyses (CAMAs; Tsuji, Bergmann, & Cristia, 2014), which provide the most up-to-date summary of the body of literature. Use of this standardized format is facilitated by tailored documentation and our metalabR package, as follows. Method: The MetaLab website hosts tutorials for conducting a systematic review and quantitative synthesis. In progress are tutorials for researchers who are planning on conducting, or who have conducted, a study on a topic where a MetaLab CAMA already exists. These tutorials will help researchers decide on their methodology and sample size, based on the collated body of evidence, and to add their results to the CAMA when their study is complete. Currently in development, our new R package, metalabR, facilitates and standardizes the process of conducting and integrating meta-analyses with the MetaLab platform. Existing key features focus on ensuring adherence to our data format by providing functions for reading, validating, and cleaning new datasets and added data points, and calculating standardized effect sizes. Multiple datasets can be read into one dataframe to allow for meta-meta-analysis across different topics. MetalabR helps one access existing MetaLab functionalities for quantitative analysis, building on metafor (Viechtbauer, 2007) to run inverse-variance weighted multivariate meta-analytic models with random effects. The package also includes functions for data visualization, building on ggplot2 (Wickham, 2016) to create scatter, forest, funnel and violin plots, all with a standardized theme and colour scheme. In progress is a function for generating a summary report of results of random effects models appropriate for meta-analyses in experimental developmental psychology. In addition to using the metalabR package in R, various shinyapps can be accessed from the MetaLab website, which have a user-friendly interface and require no knowledge of R or coding. These are tools for visualizing MetaLab data, conducting power analyses and power simulations, and data validation tools to ensure a reviewerâs planned meta-analysis fits the MetaLab structure and format, so their data can eventually be integrated into MetaLab. Outlook: MetaLab facilitates the adoption of transparent, reproducible, and dynamic meta-analyses in developmental psychology along multiple dimensions. It contains tools for conducting a new meta-analysis, planning a study, contributing to an existing meta-analysis, and conducting a meta-meta-analysis across multiple meta-analyses. Our functionalities and interfaces are also easily adaptable for use outside of the field of developmental psychology, with one spinoff having been created for evidence synthesis of vocal patterns in neuropsychiatric conditions (Nyholm Jensen & Dwenger, 2020, metavoice.au.dk). We will continue to develop MetaLab and metalabR to accommodate different types of data, and interface with standards such as Brain Imaging Data Structure (BIDS, Gorgolewski et al., 2016) for neuroimaging datasets, thereby further broadening the scope and utility of MetaLab
Cost-Effectiveness of Using HAART in Prevention of Mother-To-Child Transmission in the DREAM-Project Malawi
Introduction: Cost-effectiveness analysis are crucial in the management of the HIV/AIDS epidemic, particularly in resource-limited settings. Such analyses have not been performed in the use of highly active antiretroviral therapy (HAART) for prevention of mother-to-child transmission (PMTCT).
Objective: Cost-effectiveness analysis of HAART approach in Malawi for PMTCT.
Methods: In 2 health centres in Malawi 6500 pregnant women were tested; 1118 pregnant women completed the entire Drug Resource Enhancement against Aids and Malnutrition-Project Malawi (DREAM - PM) PMTCT protocol. The costs of the intervention were calculated using the ingredients method. Outcomes estimated were cost for infection averted and cost for DALY saved compared with no intervention.
Results: From a private perspective cost for HIV infection averted was US 35.36. From a public perspective, the result became negative as follows: â261 and â16.55, respectively (lower cost than the cost of the therapy for an HIV+ child). The univariate sensitivity analysis showed that the cost for DALY saved always remained under the threshold of US 667 PPD).
Conclusions: Administration of HAART in a PMTCT programme in resource-limited settings is cost-effective. Drugs and laboratory tests are the most significant costs, but further reduction of these expenses is possible
Shaking table tests and numerical analyses on a scaled dry-joint arch undergoing windowed sine pulses
The damages occurred during recent seismic events have emphasised the vulnerability of vaulted masonry structures, one of the most representative elements of worldwide cultural heritage. Although a certain consensus has been reached regarding the static behaviour of masonry arches, still more efforts are requested to investigate their dynamic behaviour. In this regard, the present paper aims to investigate the performance of a scaled dry-joint arch undergoing windowed sine pulses. A feature tracking based measuring technique was employed to evaluate the displacement of selected points, shading light on the failure mechanisms and gathering data for the calibration of the numerical model. This was built according to a micro-modelling approach of the finite element method, with voussoirs assumed very stiff and friction interface elements. Comparisons with existing literature are also stressed, together with comments about scale effects.This work was partly financed by FEDER funds through the Competitivity Factors Operational Programme-COMPETE and by national funds through FCT-Foundation for Science and Technology within the scope of the Project POCI-01-0145-FEDER-007633.info:eu-repo/semantics/publishedVersio
Gastric and intestinal barrier impairment in tropical enteropathy and HIV: limited impact of micronutrient supplementation during a randomised controlled trial
<p>Abstract</p> <p>Background</p> <p>Although micronutrient supplementation can reduce morbidity and mortality due to diarrhoea, nutritional influences on intestinal host defence are poorly understood. We tested the hypothesis that micronutrient supplementation can enhance barrier function of the gut.</p> <p>Methods</p> <p>We carried out two sub-studies nested within a randomised, double-blind placebo-controlled trial of daily micronutrient supplementation in an urban community in Lusaka, Zambia. In the first sub-study, gastric pH was measured in 203 participants. In the second sub-study, mucosal permeability, lipopolysaccharide (LPS) and anti-LPS antibodies, and serum soluble tumour necrosis factor receptor p55 (sTNFR55) concentrations were measured in 87 participants. Up to three stool samples were also analysed microbiologically for detection of asymptomatic intestinal infection. Gastric histology was subsequently analysed in a third subset (n = 37) to assist in interpretation of the pH data. Informed consent was obtained from all participants after a three-stage information and consent process.</p> <p>Results</p> <p>Hypochlorhydria (fasting gastric pH > 4.0) was present in 75 (37%) of participants. In multivariate analysis, HIV infection (OR 4.1; 95%CI 2.2-7.8; <it>P </it>< 0.001) was associated with hypochlorhydria, but taking anti-retroviral treatment (OR 0.16; 0.04-0.67; <it>P </it>= 0.01) and allocation to micronutrient supplementation (OR 0.53; 0.28-0.99; <it>P </it>< 0.05) were protective. Hypochlorhydria was associated with increased risk of salmonellosis. Mild (grade 1) gastric atrophy was found in 5 participants, irrespective of <it>Helicobacter pylori </it>or HIV status. Intestinal permeability, LPS concentrations in serum, anti-LPS IgG, and sTNFR55 concentrations did not differ significantly between micronutrient and placebo groups. Anti-LPS IgM was reduced in the micronutrient recipients (<it>P <</it>0.05).</p> <p>Conclusions</p> <p>We found evidence of a specific effect of HIV on gastric pH which was readily reversed by anti-retroviral therapy and not mediated by gastric atrophy. Micronutrients had a modest impact on gastric pH and one marker of bacterial translocation.</p> <p>Trial Registration</p> <p>Current Controlled Trials ISRCTN31173864</p
How students perceive medical competences: a cross-cultural study between the Medical Course in Portugal and African Portuguese Speaking Countries
<p>Abstract</p> <p>Background</p> <p>A global effort has been made in the last years to establish a set of core competences that define the essential professional competence of a physician. Regardless of the environment, culture or medical education conditions, a set of core competences is required for medical practice worldwide. Evaluation of educational program is always needed to assure the best training for medical students and ultimately best care for patients. The aim of this study was to determine in what extent medical students in Portugal and Portuguese speaking African countries, felt they have acquired the core competences to start their clinical practice. For this reason, it was created a measurement tool to evaluate self-perceived competences, in different domains, across Portuguese and Portuguese-speaking African medical schools.</p> <p>Methods</p> <p>The information was collected through a questionnaire that defines the knowledge, attitudes and skills that future doctors should acquire. The Cronbach's Alpha and Principal Components Analysis (PCA) were used to evaluate the reliability of the questionnaire. In order to remove possible confounding effect, individual scores were standardized by country.</p> <p>Results</p> <p>The order of the domain's scores was similar between countries. After standardization, Personal Attitudes and Professional Behavior showed median scores above the country global median and Knowledge alone showed median score below the country global median. In Portugal, Clinical Skills showed score below the global median. In Angola, Clinical Skills and General Skills showed a similar result. There were only significant differences between countries in Personal Attitudes (p < 0.001) and Professional Behavior (p = 0.043).</p> <p>Conclusions</p> <p>The reliability of the instrument in Portuguese and Portuguese-speaking African medical schools was confirmed. Students have perceived their level of competence in personal attitudes in a high level and in opposite, knowledge and clinical skills with some weaknesses.</p
Seismic vulnerability and risk assessment of historic masonry buildings
Seismic risk evaluation of built-up areas involves analysis of the level of earthquake hazard of the region, building vulnerability and exposure. Within this approach that defines seismic risk, building vulnerability assessment assumes great importance, not only because of the obvious physical consequences in the eventual occurrence of a seismic event, but also because it is the one of the few potential aspects in which engineering research can intervene. In fact, rigorous vulnerability assessment of existing buildings and the implementation of appropriate retrofitting solutions can help to reduce the levels of physical damage, loss of life and the economic impact of future seismic events. Vulnerability studies of urban centresshould be developed with the aim of identifying building fragilities and reducing seismic risk. As part of the rehabilitation of the historic city centre of Coimbra, a complete identification and inspection survey of old masonry buildings has been carried out. The main purpose of this research is to discuss vulnerability assessment methodologies, particularly those of the first level, through the proposal and development of a method previously used to determine the level of vulnerability, in the assessment of physical damage and its relationship with seismic intensity
Lymphatic filariasis in Peninsular Malaysia: a cross-sectional survey of the knowledge, attitudes, and practices of residents
A global research priority agenda to advance public health responses to fatty liver disease
Background & aims
An estimated 38% of adults worldwide have non-alcoholic fatty liver disease (NAFLD). From individual impacts to widespread public health and economic consequences, the implications of this disease are profound. This study aimed to develop an aligned, prioritised fatty liver disease research agenda for the global health community.
Methods
Nine co-chairs drafted initial research priorities, subsequently reviewed by 40 core authors and debated during a three-day in-person meeting. Following a Delphi methodology, over two rounds, a large panel (R1 n = 344, R2 n = 288) reviewed the priorities, via Qualtrics XM, indicating agreement using a four-point Likert-scale and providing written feedback. The core group revised the draft priorities between rounds. In R2, panellists also ranked the priorities within six domains: epidemiology, models of care, treatment and care, education and awareness, patient and community perspectives, and leadership and public health policy.
Results
The consensus-built fatty liver disease research agenda encompasses 28 priorities. The mean percentage of âagreeâ responses increased from 78.3 in R1 to 81.1 in R2. Five priorities received unanimous combined agreement (âagreeâ + âsomewhat agreeâ); the remaining 23 priorities had >90% combined agreement. While all but one of the priorities exhibited at least a super-majority of agreement (>66.7% âagreeâ), 13 priorities had 90% combined agreement.
Conclusions
Adopting this multidisciplinary consensus-built research priorities agenda can deliver a step-change in addressing fatty liver disease, mitigating against its individual and societal harms and proactively altering its natural history through prevention, identification, treatment, and care. This agenda should catalyse the global health communityâs efforts to advance and accelerate responses to this widespread and fast-growing public health threat.
Impact and implications
An estimated 38% of adults and 13% of children and adolescents worldwide have fatty liver disease, making it the most prevalent liver disease in history. Despite substantial scientific progress in the past three decades, the burden continues to grow, with an urgent need to advance understanding of how to prevent, manage, and treat the disease. Through a global consensus process, a multidisciplinary group agreed on 28 research priorities covering a broad range of themes, from disease burden, treatment, and health system responses to awareness and policy. The findings have relevance for clinical and non-clinical researchers as well as funders working on fatty liver disease and non-communicable diseases more broadly, setting out a prioritised, ranked research agenda for turning the tide on this fast-growing public health threat