137 research outputs found

    Are all cognitive items equally prone to position effects? Exploring the relationships among item features and position effects

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    One type of context effect is a position effect, which implies parameters of an item are influenced by the position of the item on the test. Researchers often discuss two types of position effects: negative position effects and positive position effects (e.g., Albano, 2013; Debeer & Janssen, 2013). Items exhibiting negative position effects become harder when placed later on the test, whereas items exhibiting positive position effects become easier when placed later on the test. Researchers have primarily examined the underlying causes of position effects through an item or person perspective (e.g., Bulut, 2015; Kingston & Dorans, 1984; Qian, 2014). Researchers who adopted an examinee perspective on position effects exclusively studied the relationships among person variables and position effects. Researchers who adopted an item perspective on position effects exclusively studied the relationships among item variables and position effects. These two perspectives are limiting because they do not encourage researchers to consider the potential interactions among person variables, item variables, and position effects. In this dissertation, I examined the underlying causes of position effects through an integrated perspective, where I studied the relationships among person variables, item variables, and position effects simultaneously. I conducted a true experiment in which I administered items from two low-stakes assessments in different order to two groups of examinees, examined the presence of position effects, and evaluated the degree to which position effects were moderated by different item (item length, number of response options, mental taxation, and graphic) and person variables (effort, change in effort, and gender). I modeled position effects and their relationships with item and person variables under the generalized linear mixed modeling (GLMM) framework. On both assessments, I found items exhibited significant negative linear position effects on both assessments, with the magnitude of the position effects varying from item to item. Items became harder when placed later on the assessments but the extent to which they became harder differed slightly across items. Additionally, I found the position effects to be moderated by item difficulty and item length but not number of response options, mental taxation, or graphic. Easier and longer items were more prone to position effects than harder and shorter items; however, items varying in mental taxation, items containing a graphic, and items varying in response options were similarly prone to position effects. More so, I found examinee effort levels, change in effort patterns, and genders did not moderate the relationships among position effects and item features. Based on these findings, testing practitioners should be cautious about administering long or easy items in different order across forms and/or administrations

    EcoCyc: fusing model organism databases with systems biology.

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    EcoCyc (http://EcoCyc.org) is a model organism database built on the genome sequence of Escherichia coli K-12 MG1655. Expert manual curation of the functions of individual E. coli gene products in EcoCyc has been based on information found in the experimental literature for E. coli K-12-derived strains. Updates to EcoCyc content continue to improve the comprehensive picture of E. coli biology. The utility of EcoCyc is enhanced by new tools available on the EcoCyc web site, and the development of EcoCyc as a teaching tool is increasing the impact of the knowledge collected in EcoCyc

    Clinical and Virological Study of Dengue Cases and the Members of Their Households: The Multinational DENFRAME Project

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    Dengue is the most important mosquito-borne viral disease in humans. This disease is now endemic in more than 100 countries and threatens more than 2.5 billion people living in tropical countries. It currently affects about 50 to 100 million people each year. It causes a wide range of symptoms, from an inapparent to mild dengue fever, to severe forms, including dengue hemorrhagic fever. Currently no specific vaccine or antiviral drugs are available. We carried out a prospective clinical study in South-East Asia and Latin America, of virologically confirmed dengue-infected patients attending the hospital, and members of their households. Among 215 febrile dengue subjects, 177 agreed to household investigation. Based on our data, we estimated the proportion of dengue-infected household members to be about 45%. At the time of the home visit, almost three quarters of (29/39) presented an inapparent dengue infection. The proportion of inapparent dengue infection was higher in South-East Asia than in Latin America. These findings confirm the complexity of dengue disease in humans and the need to strengthen multidisciplinary research efforts to improve our understanding of virus transmission and host responses to dengue virus in various human populations

    Validation and utilization of an internally controlled multiplex Real-time RT-PCR assay for simultaneous detection of enteroviruses and enterovirus A71 associated with hand foot and mouth disease

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    Background: Hand foot and mouth disease (HFMD) is a disease of public health importance across the Asia-Pacific region. The disease is caused by enteroviruses (EVs), in particular enterovirus A71 (EV-A71). In EV-A71-associated HFMD, the infection is sometimes associated with severe manifestations including neurological involvement and fatal outcome. The availability of a robust diagnostic assay to distinguish EV-A71 from other EVs is important for patient management and outbreak response. Methods: We developed and validated an internally controlled one-step single-tube real-time RT-PCR in terms of sensitivity, linearity, precision, and specificity for simultaneous detection of EVs and EV-A71. Subsequently, the assay was then applied on throat and rectal swabs sampled from 434 HFMD patients. Results: The assay was evaluated using both plasmid DNA and viral RNA and has shown to be reproducible with a maximum assay variation of 4.41 % and sensitive with a limit of detection less than 10 copies of target template per reaction, while cross-reactivity with other EV serotypes was not observed. When compared against a published VP1 nested RT-PCR using 112 diagnostic throat and rectal swabs from 112 children with a clinical diagnosis of HFMD during 2014, the multiplex assay had a higher sensitivity and 100 % concordance with sequencing results which showed EVs in 77/112 (68.8 %) and EV-A71 in 7/112 (6.3 %). When applied to clinical diagnostics for 322 children, the assay detected EVs in throat swabs of 257/322 (79.8 %) of which EV-A71 was detected in 36/322 (11.2 %) children. The detection rate increased to 93.5 % (301/322) and 13.4 % (43/322) for EVs and EV-A71, respectively, when rectal swabs from 65 throat-negative children were further analyzed. Conclusion: We have successfully developed and validated a sensitive internally controlled multiplex assay for rapid detection of EVs and EV-A71, which is useful for clinical management and outbreak control of HFMD. Keywords: Hand foot and mouth disease, Enteroviruses, Enterovirus A71, Real-time RT-PCR, Diagnosi

    2021 Asian Pacific Society of Cardiology Consensus Recommendations on the Use of P2Y12 Receptor Antagonists in the Asia-Pacific Region: Special Populations

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    Advanced age, diabetes, and chronic kidney disease not only increase the risk for ischaemic events in chronic coronary syndromes (CCS) but also confer a high bleeding risk during antiplatelet therapy. These special populations may warrant modification of therapy, especially among Asians, who have displayed characteristics that are clinically distinct from Western patients. Previous guidance has been provided regarding the classification of high-risk CCS and the use of newer-generation P2Y12 inhibitors (i.e. ticagrelor and prasugrel) after acute coronary syndromes (ACS) in Asia. The authors summarise evidence on the use of these P2Y12 inhibitors during the transition from ACS to CCS and among special populations. Specifically, they present recommendations on the roles of standard dual antiplatelet therapy, shortened dual antiplatelet therapy and single antiplatelet therapy among patients with coronary artery disease, who are either transitioning from ACS to CCS; elderly; or with chronic kidney disease, diabetes, multivessel coronary artery disease and bleeding events during therapy

    Consensus Recommendations by the Asian Pacific Society of Cardiology: Optimising Cardiovascular Outcomes in Patients with Type 2 Diabetes

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    The Asian Pacific Society of Cardiology convened a consensus statement panel for optimising cardiovascular (CV) outcomes in type 2 diabetes, and reviewed the current literature. Relevant articles were appraised using the Grading of Recommendations, Assessment, Development and Evaluation system, and consensus statements were developed in two meetings and were confirmed through online voting. The consensus statements indicated that lifestyle interventions must be emphasised for patients with prediabetes, and optimal glucose control should be encouraged when possible. Sodium–glucose cotransporter 2 inhibitors (SGLT2i) are recommended for patients with chronic kidney disease with adequate renal function, and for patients with heart failure with reduced ejection fraction. In addition to SGLT2i, glucagon-like peptide-1 receptor agonists are recommended for patients at high risk of CV events. A blood pressure target below 140/90 mmHg is generally recommended for patients with type 2 diabetes. Antiplatelet therapy is recommended for secondary prevention in patients with atherosclerotic CV disease

    A generic assay for whole-genome amplification and deep sequencing of enterovirus A71

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    Enterovirus A71 (EV-A71) has emerged as the most important cause of large outbreaks of severe and sometimes fatal hand, foot and mouth disease (HFMD) across the Asia-Pacific region. EV-A71 outbreaks have been associated with (sub)genogroup switches, sometimes accompanied by recombination events. Understanding EV-A71 population dynamics is therefore essential for understanding this emerging infection, and may provide pivotal information for vaccine development. Despite the public health burden of EV-A71, relatively few EV-A71 complete-genome sequences are available for analysis and from limited geographical localities. The availability of an efficient procedure for whole-genome sequencing would stimulate effort to generate more viral sequence data. Herein, we report for the first time the development of a next-generation sequencing based protocol for whole-genome sequencing of EV-A71 directly from clinical specimens. We were able to sequence viruses of subgenogroup C4 and B5, while RNA from culture materials of diverse EV-A71 subgenogroups belonging to both genogroup B and C was successfully amplified. The nature of intra-host genetic diversity was explored in 22 clinical samples, revealing 107 positions carrying minor variants (ranging from 0 to 15 variants per sample). Our analysis of EV-A71 strains sampled in 2013 showed that they all belonged to subgenogroup B5, representing the first report of this subgenogroup in Vietnam. In conclusion, we have successfully developed a high-throughput next-generation sequencing-based assay for whole-genome sequencing of EV-A71 from clinical samples

    Contributions of mean and shape of blood pressure distribution to worldwide trends and variations in raised blood pressure: A pooled analysis of 1018 population-based measurement studies with 88.6 million participants

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    © The Author(s) 2018. Background: Change in the prevalence of raised blood pressure could be due to both shifts in the entire distribution of blood pressure (representing the combined effects of public health interventions and secular trends) and changes in its high-blood-pressure tail (representing successful clinical interventions to control blood pressure in the hypertensive population). Our aim was to quantify the contributions of these two phenomena to the worldwide trends in the prevalence of raised blood pressure. Methods: We pooled 1018 population-based studies with blood pressure measurements on 88.6 million participants from 1985 to 2016. We first calculated mean systolic blood pressure (SBP), mean diastolic blood pressure (DBP) and prevalence of raised blood pressure by sex and 10-year age group from 20-29 years to 70-79 years in each study, taking into account complex survey design and survey sample weights, where relevant. We used a linear mixed effect model to quantify the association between (probittransformed) prevalence of raised blood pressure and age-group- and sex-specific mean blood pressure. We calculated the contributions of change in mean SBP and DBP, and of change in the prevalence-mean association, to the change in prevalence of raised blood pressure. Results: In 2005-16, at the same level of population mean SBP and DBP, men and women in South Asia and in Central Asia, the Middle East and North Africa would have the highest prevalence of raised blood pressure, and men and women in the highincome Asia Pacific and high-income Western regions would have the lowest. In most region-sex-age groups where the prevalence of raised blood pressure declined, one half or more of the decline was due to the decline in mean blood pressure. Where prevalence of raised blood pressure has increased, the change was entirely driven by increasing mean blood pressure, offset partly by the change in the prevalence-mean association. Conclusions: Change in mean blood pressure is the main driver of the worldwide change in the prevalence of raised blood pressure, but change in the high-blood-pressure tail of the distribution has also contributed to the change in prevalence, especially in older age groups

    Rising rural body-mass index is the main driver of the global obesity epidemic in adults

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    Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities(.)(1,2) This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity(3-6). Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55% of the global rise in mean BMI from 1985 to 2017-and more than 80% in some low- and middle-income regions-was due to increases in BMI in rural areas. This large contribution stems from the fact that, with the exception of women in sub-Saharan Africa, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. These trends have in turn resulted in a closing-and in some countries reversal-of the gap in BMI between urban and rural areas in low- and middle-income countries, especially for women. In high-income and industrialized countries, we noted a persistently higher rural BMI, especially for women. There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories.Peer reviewe
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