66 research outputs found

    Managing Information Systems Development Projects: What’s on Your Mind?

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    Drawing on a mental model perspective, we investigate information systems (IS) project members’ knowledge and beliefs about how to manage information systems development (ISD) projects. A new construct – ISD mental models – is proposed and defined as the knowledge and belief structures that help IS project members to understand, conduct, and manage ISD projects. Literature reviews and cognitive interviews using the repertory grid technique are used to identify the fundamental concepts that are in project members’ mental models. This study further proposes that the structure of mental models is organized into four ISD project-related areas: product, process, people, and organization. This proposition will be tested by a survey with ISD project members using the pairwise comparison technique. Expected contributions and implications are discussed

    Further development of the Children’s Mathematics Anxiety Scale UK (CMAS-UK) for ages 4–7 years

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    There are currently many mathematics anxiety rating scales designed typically for adult and older children populations, yet there remains a lack of assessment tools for younger children ( 0.45) and high internal consistency (α = 0.88). A single factor model of Online Mathematics Anxiety was related to the experience of an entire mathematics lesson, from first entering the classroom to completing a task. A significant negative correlation was observed between the CMAS-UK and mathematics performance scores, suggesting that children who score high for mathematics anxiety tend to score to perform less well on a mathematics task. Subsequent confirmatory factor analysis was conducted to test a range of module structures; the shortened 19-item CMAS-UK was found to have similar model indices as the 26-item model, resulting in the maintenance of the revised scale. To conclude, the 19-item CMAS-UK provides a reliable assessment of children’s mathematics anxiety and has been shown to predict mathematics performance. This research points towards the origins of mathematics anxiety occurring when number is first encountered and supports the utility of the CMAS-UK. Subsequent research in the area should consider and appropriately define an affective component that may underlie mathematics anxiety at older ages. Mathematics anxiety relates to more complex procedures that elude the experiences of younger children and may instead be the result of number-based experiences in the early years of education.N/

    Development of a highly protective combination monoclonal antibody therapy against Chikungunya virus

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    Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus that causes global epidemics of a debilitating polyarthritis in humans. As there is a pressing need for the development of therapeutic agents, we screened 230 new mouse anti-CHIKV monoclonal antibodies (MAbs) for their ability to inhibit infection of all three CHIKV genotypes. Four of 36 neutralizing MAbs (CHK-102, CHK-152, CHK-166, and CHK-263) provided complete protection against lethality as prophylaxis in highly susceptible immunocompromised mice lacking the type I IFN receptor (Ifnar−/−) and mapped to distinct epitopes on the E1 and E2 structural proteins. CHK-152, the most protective MAb, was humanized, shown to block viral fusion, and require Fc effector function for optimal activity in vivo. In post-exposure therapeutic trials, administration of a single dose of a combination of two neutralizing MAbs (CHK-102+CHK-152 or CHK-166+CHK-152) limited the development of resistance and protected immunocompromised mice against disease when given 24 to 36 hours before CHIKV-induced death. Selected pairs of highly neutralizing MAbs may be a promising treatment option for CHIKV in humans

    Removal of the endocrine disrupter butyl benzyl phthalate from the environment

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    Butyl benzyl phthalate (BBP), an aryl alkyl ester of 1,2-benzene dicarboxylic acid, is extensively used in vinyl tiles and as a plasticizer in PVC in many commonly used products. BBP, which readily leaches from these products, is one of the most important environmental contaminants, and the increased awareness of its adverse effects on human health has led to a dramatic increase in research aimed at removing BBP from the environment via bioremediation. This review highlights recent progress in the degradation of BBP by pure and mixed bacterial cultures, fungi, and in sludge, sediment, and wastewater. Sonochemical degradation, a unique abiotic remediation technique, and photocatalytic degradation are also discussed. The degradation pathways for BBP are described, and future research directions are considered

    Measuring the burden of arboviral diseases: the spectrum of morbidity and mortality from four prevalent infections

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    <p>Abstract</p> <p>Background</p> <p>Globally, arthropod-borne virus infections are increasingly common causes of severe febrile disease that can progress to long-term physical or cognitive impairment or result in early death. Because of the large populations at risk, it has been suggested that these outcomes represent a substantial health deficit not captured by current global disease burden assessments.</p> <p>Methods</p> <p>We reviewed newly available data on disease incidence and outcomes to critically evaluate the disease burden (as measured by disability-adjusted life years, or DALYs) caused by yellow fever virus (YFV), Japanese encephalitis virus (JEV), chikungunya virus (CHIKV), and Rift Valley fever virus (RVFV). We searched available literature and official reports on these viruses combined with the terms "outbreak(s)," "complication(s)," "disability," "quality of life," "DALY," and "QALY," focusing on reports since 2000. We screened 210 published studies, with 38 selected for inclusion. Data on average incidence, duration, age at onset, mortality, and severity of acute and chronic outcomes were used to create DALY estimates for 2005, using the approach of the current Global Burden of Disease framework.</p> <p>Results</p> <p>Given the limitations of available data, nondiscounted, unweighted DALYs attributable to YFV, JEV, CHIKV, and RVFV were estimated to fall between 300,000 and 5,000,000 for 2005. YFV was the most prevalent infection of the four viruses evaluated, although a higher proportion of the world's population lives in countries at risk for CHIKV and JEV. Early mortality and long-term, related chronic conditions provided the largest DALY components for each disease. The better known, short-term viral febrile syndromes caused by these viruses contributed relatively lower proportions of the overall DALY scores.</p> <p>Conclusions</p> <p>Limitations in health systems in endemic areas undoubtedly lead to underestimation of arbovirus incidence and related complications. However, improving diagnostics and better understanding of the late secondary results of infection now give a first approximation of the current disease burden from these widespread serious infections. Arbovirus control and prevention remains a high priority, both because of the current disease burden and the significant threat of the re-emergence of these viruses among much larger groups of susceptible populations.</p

    Wetting considerations in capillary rise and imbibition in closed square tubes and open rectangular cross-section channels

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    The spontaneous capillary-driven filling of microchannels is important for a wide range of applications. These channels are often rectangular in cross-section, can be closed or open, and horizontal or vertically orientated. In this work, we develop the theory for capillary imbibition and rise in channels of rectangular cross-section, taking into account rigidified and non-rigidified boundary conditions for the liquid–air interfaces and the effects of surface topography assuming Wenzel or Cassie-Baxter states. We provide simple interpolation formulae for the viscous friction associated with flow through rectangular cross-section channels as a function of aspect ratio. We derive a dimensionless cross-over time, Tc, below which the exact numerical solution can be approximated by the Bousanquet solution and above which by the visco-gravitational solution. For capillary rise heights significantly below the equilibrium height, this cross-over time is Tc ≈ (3Xe/2)^(2/3) and has an associated dimensionless cross-over rise height Xc ≈ (3Xe/2)^(1/3), where Xe = 1/G is the dimensionless equilibrium rise height and G is a dimensionless form of the acceleration due to gravity. We also show from wetting considerations that for rectangular channels, fingers of a wetting liquid can be expected to imbibe in advance of the main meniscus along the corners of the channel walls. We test the theory via capillary rise experiments using polydimethylsiloxane oils of viscosity 96.0, 48.0, 19.2 and 4.8 mPa s within a range of closed square tubes and open rectangular cross-section channels with SU-8 walls. We show that the capillary rise heights can be fitted using the exact numerical solution and that these are similar to fits using the analytical visco-gravitational solution. The viscous friction contribution was found to be slightly higher than predicted by theory assuming a non-rigidified liquid–air boundary, but far below that for a rigidified boundary, which was recently reported for imbibition into horizontally mounted open microchannels. In these experiments we also observed fingers of liquid spreading along the internal edges of the channels in advance of the main body of liquid consistent with wetting expectations. We briefly discuss the implications of these observations for the design of microfluidic systems
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