7,567 research outputs found
Predicting the subcellular localization of viral proteins within a mammalian host cell
BACKGROUND: The bioinformatic prediction of protein subcellular localization has been extensively studied for prokaryotic and eukaryotic organisms. However, this is not the case for viruses whose proteins are often involved in extensive interactions at various subcellular localizations with host proteins. RESULTS: Here, we investigate the extent of utilization of human cellular localization mechanisms by viral proteins and we demonstrate that appropriate eukaryotic subcellular localization predictors can be used to predict viral protein localization within the host cell. CONCLUSION: Such predictions provide a method to rapidly annotate viral proteomes with subcellular localization information. They are likely to have widespread applications both in the study of the functions of viral proteins in the host cell and in the design of antiviral drugs
An International Study of the Ability and Cost-Effectiveness of Advertising Methods to Facilitate Study Participant Self-Enrolment Into a Pilot Pharmacovigilance Study During Early Pregnancy
Knowledge of the fetal effects of maternal medication use in pregnancy is often inadequate and current pregnancy pharmacovigilance (PV) surveillance methods have important limitations. Patient self-reporting may be able to mitigate some of these limitations, providing an adequately sized study sample can be recruited.To compare the ability and cost-effectiveness of several direct-to-participant advertising methods for the recruitment of pregnant participants into a study of self-reported gestational exposures and pregnancy outcomes.The Pharmacoepidemiological Research on Outcomes of Therapeutics by a European Consortium (PROTECT) pregnancy study is a non-interventional, prospective pilot study of self-reported medication use and obstetric outcomes provided by a cohort of pregnant women that was conducted in Denmark, the Netherlands, Poland, and the United Kingdom. Direct-to-participant advertisements were provided via websites, emails, leaflets, television, and social media platforms.Over a 70-week recruitment period direct-to-participant advertisements engaged 43,234 individuals with the study website or telephone system; 4.78% (2065/43,234) of which were successfully enrolled and provided study data. Of these 90.4% (1867/2065) were recruited via paid advertising methods, 23.0% (475/2065) of whom were in the first trimester of pregnancy. The overall costs per active recruited participant were lowest for email (€23.24) and website (€24.41) advertisements and highest for leaflet (€83.14) and television (€100.89). Website adverts were substantially superior in their ability to recruit participants during their first trimester of pregnancy (317/668, 47.5%) in comparison with other advertising methods (P<.001). However, we identified international variations in both the cost-effectiveness of the various advertisement methods used and in their ability to recruit participants in early pregnancy.Recruitment of a pregnant cohort using direct-to-participant advertisement methods is feasible, but the total costs incurred are not insubstantial. Future research is needed to identify advertising strategies capable of recruiting large numbers of demographically representative pregnant women, preferentially in early pregnancy
Active-duty military service members’ visual representations of PTSD and TBI in masks
Active-dutymilitary service members have a significant risk of sustaining physical and psychological trauma resulting in traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD). Within an interdisciplinary treatment approach at the National Intrepid Center of Excellence, servicemembers participated in mask making during art therapy sessions. This study presents an analysis of the mask-making experiences of service members (n = 370) with persistent symptoms from combatand mission-related TBI, PTSD, and other concurrent mood issues. Data sources included mask images and therapist notes collected over a five-year period. The data were coded and analyzed using grounded theory methods. Findings indicated that mask making offered visual representations of the self related to individual personhood, relationships, community, and society. Imagery themes referenced the injury, relational supports/losses, identity transitions/questions, cultural metaphors, existential reflections, and conflicted sense of self. These visual insights provided an increased understanding of the experiences of service members, facilitating their recovery
Carboxyhaemoglobin levels and their determinants in older British men
Background: Although there has been concern about the levels of carbon monoxide exposure, particularly among older people, little is known about COHb levels and their determinants in the general population. We examined these issues in a study of older British men.Methods: Cross-sectional study of 4252 men aged 60-79 years selected from one socially representative general practice in each of 24 British towns and who attended for examination between 1998 and 2000. Blood samples were measured for COHb and information on social, household and individual factors assessed by questionnaire. Analyses were based on 3603 men measured in or close to (< 10 miles) their place of residence.Results: The COHb distribution was positively skewed. Geometric mean COHb level was 0.46% and the median 0.50%; 9.2% of men had a COHb level of 2.5% or more and 0.1% of subjects had a level of 7.5% or more. Factors which were independently related to mean COHb level included season (highest in autumn and winter), region (highest in Northern England), gas cooking (slight increase) and central heating (slight decrease) and active smoking, the strongest determinant. Mean COHb levels were more than ten times greater in men smoking more than 20 cigarettes a day (3.29%) compared with non-smokers (0.32%); almost all subjects with COHb levels of 2.5% and above were smokers (93%). Pipe and cigar smoking was associated with more modest increases in COHb level. Passive cigarette smoking exposure had no independent association with COHb after adjustment for other factors. Active smoking accounted for 41% of variance in COHb level and all factors together for 47%.Conclusion: An appreciable proportion of men have COHb levels of 2.5% or more at which symptomatic effects may occur, though very high levels are uncommon. The results confirm that smoking (particularly cigarette smoking) is the dominant influence on COHb levels
A Quantum Scattering Interferometer
The collision of two ultra-cold atoms results in a quantum-mechanical
superposition of two outcomes: each atom continues without scattering and each
atom scatters as a spherically outgoing wave with an s-wave phase shift. The
magnitude of the s-wave phase shift depends very sensitively on the interaction
between the atoms. Quantum scattering and the underlying phase shifts are
vitally important in many areas of contemporary atomic physics, including
Bose-Einstein condensates, degenerate Fermi gases, frequency shifts in atomic
clocks, and magnetically-tuned Feshbach resonances. Precise measurements of
quantum scattering phase shifts have not been possible until now because, in
scattering experiments, the number of scattered atoms depends on the s-wave
phase shifts as well as the atomic density, which cannot be measured precisely.
Here we demonstrate a fundamentally new type of scattering experiment that
interferometrically detects the quantum scattering phase shifts of individual
atoms. By performing an atomic clock measurement using only the scattered part
of each atom, we directly and precisely measure the difference of the s-wave
phase shifts for the two clock states in a density independent manner. Our
method will give the most direct and precise measurements of ultracold
atom-atom interactions and will place stringent limits on the time variations
of fundamental constants.Comment: Corrected formatting and typo
Flow through a circular tube with a permeable Navier slip boundary
For Newtonian fluid flow in a right circular tube, with a linear Navier slip boundary, we show that a second flow field arises which is different to conventional Poiseuille flow in the sense that the corresponding pressure is quadratic in its dependence on the length along the tube, rather than a linear dependence which applies for conventional Poiseuille flow. However, assuming that the quadratic pressure is determined, say from known experimental data, then the new solution only exists for a precisely prescribed permeability along the boundary. While this cannot occur for conventional pipe flow, for fluid flow through carbon nanotubes embedded in a porous matrix, it may well be an entirely realistic possibility, and could well explain some of the high flow rates which have been reported in the literature. Alternatively, if the radial boundary flow is prescribed, then the new flow field exists only for a given quadratic pressure. Our primary purpose here is to demonstrate the existence of a new pipe flow field for a permeable Navier slip boundary and to present a numerical solution and two approximate analytical solutions. The maximum flow rate possible for the new solution is precisely twice that for the conventional Poiseuille flow, which occurs for constant inward directed flow across the boundary
On reminder effects, drop-outs and dominance: evidence from an online experiment on charitable giving
We present the results of an experiment that (a) shows the usefulness of screening out drop-outs and (b) tests whether different methods of payment and reminder intervals affect charitable giving. Following a lab session, participants could make online donations to charity for a total duration of three months. Our procedure justifying the exclusion of drop-outs consists in requiring participants to collect payments in person flexibly and as known in advance and as highlighted to them later. Our interpretation is that participants who failed to collect their positive payments under these circumstances are likely not to satisfy dominance. If we restrict the sample to subjects who did not drop out, but not otherwise, reminders significantly increase the overall amount of charitable giving. We also find that weekly reminders are no more effective than monthly reminders in increasing charitable giving, and that, in our three months duration experiment, standing orders do not increase giving relative to one-off donations
A report on the piloting of a novel computer-based medical case simulation for teaching and formative assessment of diagnostic laboratory testing
Objectives: Insufficient attention has been given to how information from computer-based clinical case simulations is presented, collected, and scored. Research is needed on how best to design such simulations to acquire valid performance assessment data that can act as useful feedback for educational applications. This report describes a study of a new simulation format with design features aimed at improving both its formative assessment feedback and educational function. Methods: Case simulation software (LabCAPS) was developed to target a highly focused and well-defined measurement goal with a response format that allowed objective scoring. Data from an eight-case computer-based performance assessment administered in a pilot study to 13 second-year medical students was analyzed using classical test theory and generalizability analysis. In addition, a similar analysis was conducted on an administration in a less controlled setting, but to a much large sample (n=143), within a clinical course that utilized two random case subsets from a library of 18 cases. Results: Classical test theory case-level item analysis of the pilot assessment yielded an average case discrimination of 0.37, and all eight cases were positively discriminating (range=0.11–0.56). Classical test theory coefficient alpha and the decision study showed the eight-case performance assessment to have an observed reliability of σ=G=0.70. The decision study further demonstrated that a G=0.80 could be attained with approximately 3 h and 15 min of testing. The less-controlled educational application within a large medical class produced a somewhat lower reliability for eight cases (G=0.53). Students gave high ratings to the logic of the simulation interface, its educational value, and to the fidelity of the tasks. Conclusions: LabCAPS software shows the potential to provide formative assessment of medical students’ skill at diagnostic test ordering and to provide valid feedback to learners. The perceived fidelity of the performance tasks and the statistical reliability findings support the validity of using the automated scores for formative assessment and learning. LabCAPS cases appear well designed for use as a scored assignment, for stimulating discussions in small group educational settings, for self-assessment, and for independent learning. Extension of the more highly controlled pilot assessment study with a larger sample will be needed to confirm its reliability in other assessment applications
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