255 research outputs found

    Effectiveness of airport screening at detecting travellers infected with novel coronavirus (2019-nCoV).

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    We evaluated effectiveness of thermal passenger screening for 2019-nCoV infection at airport exit and entry to inform public health decision-making. In our baseline scenario, we estimated that 46% (95% confidence interval: 36 to 58) of infected travellers would not be detected, depending on incubation period, sensitivity of exit and entry screening, and proportion of asymptomatic cases. Airport screening is unlikely to detect a sufficient proportion of 2019-nCoV infected travellers to avoid entry of infected travellers

    A population of bang-bang switches of defective interfering particles makes within-host dynamics of dengue virus controllable.

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    The titre of virus in a dengue patient and the duration of this viraemia has a profound effect on whether or not a mosquito will become infected when it feeds on the patient and this, in turn, is a key driver of the magnitude of a dengue outbreak. The assessment of the heterogeneity of viral dynamics in dengue-infected patients and its precise treatment are still uncertain. Infection onset, patient physiology and immune response are thought to play major roles in the development of the viral load. Research has explored the interference and spontaneous generation of defective virus particles, but have not examined both the antibody and defective particles during natural infection. We explore the intrinsic variability in the within-host dynamics of viraemias for a population of patients using the method of population of models (POMs). A dataset from 208 patients is used to initially calibrate 20,000 models for the infection kinetics for each of the four dengue virus serotypes. The calibrated POMs suggests that naturally generated defective particles may interfere with the viraemia, but the generated defective virus particles are not adequate to reduce high fever and viraemia duration. The effect of adding excess defective dengue virus interfering particles to patients as a therapeutic is evaluated using the calibrated POMs in a bang-bang (on-off or two-step) optimal control setting. Bang-bang control is a class of binary feedback control that turns either 'ON' or 'OFF' at different time points, determined by the system feedback. Here, the bang-bang control estimates the mathematically optimal dose and duration of the intervention for each model in the POM set

    A blended learning model for first year science student engagement with mathematics and statistics

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    With the rapid decline of the enrolments in the conventional, campus-based courses, many higher education (HE) institutions around the world opt for provision of dual learning and teaching modes, most often offering fully online experiences in off-campus courses (distance education), and hybrid/ blended learning experiences in on-campus courses. This raises questions related to the quality of technology-enhanced learning (TEL) and teaching experiences (Laurillard, 2009; Kirkwood, 2014). TEL is maturing and entering a normalization phase, with modes such as blended learning expected to become the “new traditional model” or “the new normal” of course delivery mode (Porter et al., 2016) within one or two years (Johnson, Adams Becker, Estrada & Freeman, 2015). This normalisation shifts research paradigm from investigation of the ways the ICTs are used within educational settings to more focused analysis of pedagogical aspects impacting the design and implementation of the integrated ICTs. A rigorous, research-informed investigation is needed to scrutinise factors influencing effective integration of ICTs in the curricula, impact the integrated ICTs have on both teaching and learning, their effectiveness within current environment and the transferability/ adaptability of developed model(s) to other contexts (Kirkwood, 2014). This presentation reports on an informed inquiry investigating the effectiveness of the redesigned technology-enhanced learning and teaching environment in promoting student engagement in a compulsory quantitative methods unit for first year science undergraduates offered at a large, metropolitan university. A blended learning model was adopted including pre-lecture readings, didactic lectures, self-paced computer labs with demonstration videos, collaborative workshops, fortnightly online quizzes, and problem solving tasks based on realistic quantitative analysis. Teaching resources were highly structured and made available to students using Adaptive Release feature, a part of the University’s Blackboard Learning Management System. The Adaptive Release was introduced to foster students’ engagement and encourage students’ self-regulated learning, with focus on assisting students with resource development of management strategies. Quantitative data was collected through access logs on the Blackboard Learning Management System, social media activity within closed groups, an investigation of mathematical background at admission, workshop attendance and unit assessment results. The data analysis used statistical modelling which allowed researchers to demonstrate correlations between student’s preparedness level, engagement and success

    Endotoxin levels and contribution factors of endotoxins in resident, school, and office environments - A review

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    As endotoxin exposure has known effects on human health, it is important to know the generally existing levels of endotoxins as well as their contributing factors. This work reviews current knowledge on the endotoxin loads in settled floor dust, concentrations of endotoxins in indoor air, and different environmental factors potentially affecting endotoxin levels. The literature review consists of peer-reviewed manuscripts located using Google and PubMed, with search terms based on individual words and combinations. References from relevant articles have also been searched. Analysis of the data showed that in residential, school, and office environments, the mean endotoxin loads in settled floor dust varied between 660 and 107,000 EU/m(2), 2180 and 48,000 EU/m(2), and 2700 and 12,890 EU/m(2), respectively. Correspondingly, the mean endotoxin concentrations in indoor air varied between 0.04 and 1610 EU/m(3) in residences, and 0.07 and 9.30 EU/m(3) in schools and offices. There is strong scientific evidence indicating that age of houses (or housing unit year category), cleaning, farm or rural living, flooring materials (the presence of carpets), number of occupants, the presence of dogs or cats indoors, and relative humidity affect endotoxin loads in settled floor dust. The presence of pets (especially dogs) was extremely strongly associated with endotoxin concentrations in indoor air. However, as reviewed articles show inconsistency, additional studies on these and other possible predicting factors are needed. (C) 2016 Elsevier Ltd. All rights reserved.Peer reviewe

    Pre-vaccination testing could expand coverage of two-dose COVID vaccines

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    Recent evidence indicates that a single dose of mRNA-based vaccines produce similar immune responses in people with evidence of past infection compared with two doses in immunologically naive individuals. For COVID-19 vaccines with two dose regimens, point-of-care antibody testing for prior infection when administering the first dose could enable expanded vaccine access in a cost-effective manner. Generally, antibody tests with sensitivity and specificity well below that typically accepted for product licensure would still enable expanded vaccine coverage, though to be cost-beneficial total test cost (i.e. procurement and administration) needs to be less than roughly a third of total vaccine dose cost. For highly sensitive (90%) and specific (99%) tests, coverage could be expanded by more than 33%. Tests with the appropriate performance characteristics are plausible, though likely need setting specific tailoring.</ns3:p

    Estimation of country-level incidence of early-onset invasive Group B Streptococcus disease in infants using Bayesian methods.

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    Neonatal invasive disease caused by Group B Streptococcus (GBS) is responsible for much acute mortality and long-term morbidity. To guide development of better prevention strategies, including maternal vaccines that protect neonates against GBS, it is necessary to estimate the burden of this condition globally and in different regions. Here, we present a Bayesian model that estimates country-specific invasive GBS (iGBS) disease incidence in children aged 0 to 6 days. The model combines different types of epidemiological data, each of which has its own limitations: GBS colonization prevalence in pregnant women, risk of iGBS disease in children born to GBS-colonized mothers and direct estimates of iGBS disease incidence where available. In our analysis, we present country-specific maternal GBS colonization prevalence after adjustment for GBS detection assay used in epidemiological studies. We then integrate these results with other epidemiological data and estimate country-level incidence of iGBS disease including in countries with no studies that directly estimate incidence. We are able to simultaneously estimate two key epidemiological quantities: the country-specific incidence of early-onset iGBS disease, and the risk of iGBS disease in babies born to GBS-colonized women. Overall, we believe our method will contribute to a more comprehensive quantification of the global burden of this disease, inform cost-effectiveness assessments of potential maternal GBS vaccines and identify key areas where data are necessary
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