3,263 research outputs found

    The unseen and unacceptable face of digital libraries

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    The social and organizational aspects of digital libraries are often overlooked but this paper reviews how they can affect users' awareness and acceptance of digital libraries. An analysis of research conducted within two contrasting domains (Clinical and Academic) is presented which highlights issues of user interactions, work practices and the organizational social structures. The combined study comprises an analysis of 98 in-depth interviews and focus groups with lecturers, librarians and hospital clinicians. The importance of current and past roles of the library, and how users interacted with it, are revealed. Web-based digital libraries, while alleviating most library resource and interaction problems, require a change in librarians' and DL designers' roles and interaction patterns if they are to be implemented acceptably and effectively. Without this role change, users will at best be unaware of these digital resources and at worst feel threatened by them. The findings of this paper highlight the importance on DL design and implementation of the social context and supporting user communication (i.e. collaboration and consultation) in their information search and usage activities

    The influence of droplet size and biodegradation on the transport of subsurface oil droplets during the Deepwater Horizon: a model sensitivity study

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    A better understanding of oil droplet formation, degradation, and dispersal in deep waters is needed to enhance prediction of the fate and transport of subsurface oil spills. This research evaluates the influence of initial droplet size and rates of biodegradation on the subsurface transport of oil droplets, specifically those from the Deepwater Horizon oil spill. A three-dimensional coupled model was employed with components that included analytical multiphase plume, hydrodynamic and Lagrangian models. Oil droplet biodegradation was simulated based on first order decay rates of alkanes. The initial diameter of droplets (10–300 μm) spanned a range of sizes expected from dispersant-treated oil. Results indicate that model predictions are sensitive to biodegradation processes, with depth distributions deepening by hundreds of meters, horizontal distributions decreasing by hundreds to thousands of kilometers, and mass decreasing by 92–99% when biodegradation is applied compared to simulations without biodegradation. In addition, there are two- to four-fold changes in the area of the seafloor contacted by oil droplets among scenarios with different biodegradation rates. The spatial distributions of hydrocarbons predicted by the model with biodegradation are similar to those observed in the sediment and water column, although the model predicts hydrocarbons to the northeast and east of the well where no observations were made. This study indicates that improvement in knowledge of droplet sizes and biodegradation processes is important for accurate prediction of subsurface oil spills.National Science Foundation (U.S.) (RAPID: Deepwater Horizon Grant OCE-1048630)National Science Foundation (U.S.) (RAPID: Deepwater Horizon Grant OCE-1044573)National Science Foundation (U.S.) (RAPID: Deepwater Horizon Grant CBET-1045831)Gulf of Mexico Research Initiativ

    Combination of Isosorbide Dinitrate and Hydralazine in Blacks with Heart Failure

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    BACKGROUND We examined whether a fixed dose of both isosorbide dinitrate and hydralazine provides additional benefit in blacks with advanced heart failure, a subgroup previously noted to have a favorable response to this therapy. METHODS A total of 1050 black patients who had New York Heart Association class III or IV heart failure with dilated ventricles were randomly assigned to receive a fixed dose ofisosorbide dinitrate plus hydralazine or placebo in addition to standard therapy for heart failure. The primary end point was a composite score made up of weighted values for death from any cause, a first hospitalization for heart failure, and change in the quality of life. RESULTS The study was terminated early owing to a significantly higher mortality rate in the placebo group than in the group given isosorbide dinitrate plus hydralazine (10.2 percent vs. 6.2 percent, P=0.02). The mean primary composite score was significantly better in the group given isosorbide dinitrate plus hydralazine than in the placebo group (-0.1±1.9 vs. -0.5±2.0, P=0.01; range of possible values, -6 to + 2), as were its individual components (43 percent reduction in the rate of death from any cause [hazard ratio, 0.57; P=0.01] 33 percent relative reduction in the rate of first hospitalization for heart failure [16.4 percent vs. 22.4 percent, P=0.001], and an improvement in the quality of life [change in score, -5.6±20.6 vs. -2.7±21.2, with lower scores indicating better quality of life; P=0.02; range of possible values, 0 to 105]). CONCLUSIONS The addition ofa fixed dose of isosorbide dinitrate plus hydralazine to standard therapy for heart failure including neurohormonal blockers is efficacious and increases survival among black patients with advanced heart failure

    Passive dust collectors for assessing airborne microbial material

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    BackgroundSettled airborne dust is used as a surrogate for airborne exposure in studies that explore indoor microbes. In order to determine whether detecting differences in dust environments would depend on the sampler type, we compared different passive, settled dust sampling approaches with respect to displaying qualitative and quantitative aspects of the bacterial and fungal indoor microbiota.ResultsSettled dust sampling approaches-utilizing plastic petri dishes, TefTex material, and electrostatic dustfall collectors (EDCs)-were evaluated in indoor spaces in the USA and Finland and in an experimental chamber study. The microbial content was analyzed with quantitative PCR (qPCR) to quantify total bacterial and fungal biomass and through high-throughput sequencing to examine bacterial community composition. Bacterial composition and diversity were similar within a sampling environment regardless of the sampler type. The sampling environment was the single largest predictor of microbial community composition within a study, while sampler type was found to have much less predictive power. Quantitative analyses in indoor spaces indicated highest yields using a petri dish approach, followed by sampling with EDCs and TefTex. The highest correlations between duplicate samples were observed for EDC and petri dish approaches, indicating greater experimental repeatability for these sampler types. For the EDC samples, it became apparent that, due to the fibrous nature of the material, a rigorous extraction protocol is crucial to obtain optimal yields and stable, repeatable results.ConclusionsCorrelations between sampler types were strong both in compositional and quantitative terms, and thus, the particular choice of passive settled dust sampler is not likely to strongly alter the overall conclusion of a study that aims to characterize dust across different environments. Microbial cell abundances determined from settled dust varied with the use of different sampling approaches, and thus, consistency in the method is necessary to allow for absolute comparisons within and among studies. Considering practical aspects, petri dishes were found to be an inexpensive, simple, and feasible approach that showed the highest quantitative determinations under typical building conditions, though the choice of sampler will ultimately depend on study logistics and characteristics such as low- or high-exposure settings

    The MITRE trial protocol: a study to evaluate the microbiome as a biomarker of efficacy and toxicity in cancer patients receiving immune checkpoint inhibitor therapy.

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    BACKGROUND: The gut microbiome is implicated as a marker of response to  immune checkpoint inhibitors (ICI) based on preclinical mouse models and preliminary observations in limited patient series. Furthermore, early studies suggest faecal microbial transfer may have therapeutic potential, converting ICI non-responders into responders. So far, identification of specific responsible bacterial taxa has been inconsistent, which limits future application. The MITRE study will explore and validate a microbiome signature in a larger scale prospective study across several different cancer types. METHODS: Melanoma, renal cancer and non-small cell lung cancer patients who are planned to receive standard immune checkpoint inhibitors are being recruited to the MITRE study. Longitudinal stool samples are collected prior to treatment, then at 6 weeks, 3, 6 and 12 months during treatment, or at disease progression/recurrence (whichever is sooner), as well as after a severe (≥grade 3 CTCAE v5.0) immune-related adverse event. Additionally, whole blood, plasma, buffy coat, RNA and peripheral blood mononuclear cells (PBMCs) is collected at similar time points and will be used for exploratory analyses. Archival tumour tissue, tumour biopsies at progression/relapse, as well as any biopsies from body organs collected after a severe toxicity are collected. The primary outcome measure is the ability of the microbiome signature to predict 1 year progression-free survival (PFS) in patients with advanced disease. Secondary outcomes include microbiome correlations with toxicity and other efficacy end-points. Biosamples will be used to explore immunological and genomic correlates. A sub-study will evaluate both COVID-19 antigen and antibody associations with the microbiome. DISCUSSION: There is an urgent need to identify biomarkers that are predictive of treatment response, resistance and toxicity to immunotherapy. The data generated from this study will both help inform patient selection for these drugs and provide information that may allow therapeutic manipulation of the microbiome to improve future patient outcomes. TRIAL REGISTRATION: NCT04107168 , ClinicalTrials.gov, registered 09/27/2019. Protocol V3.2 (16/04/2021)

    Assessing the User Experience of Password Reset Policies in a University

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    Organisations may secure system access through use of passwords that comply with defined complexity rules. It may be required that passwords be changed regularly, using an in-person or online helpdesk. Helpdesk logs record password change events and support requests, but overlook the impact of compliance upon end-user productivity. System managers are not incentivised to investigate these impacts, so productivity costs remain with the end-user. We investigate how helpdesk log data can be analysed and augmented to expose the personal costs. Here we describe exploratory analysis of a university’s helpdesk log data, spanning 30 months and 500,000 system events for approximately 10,000 staff and 20,000-plus students. End-user costs were identified, where follow-on interviews and NASA-RTLX assessments with 20 students informed issues which log data did not adequately describe. The majority of users reset passwords before expiration (75% of log events). Log analysis indicated that the online self-service system was vastly preferred to the helpdesk, but that there was a 4:1 ratio of failed to successful attempts to recover account access. Log data did not describe the effort in managing passwords, where interviews exposed points of frustration. Participants saw the need for security but voiced a lack of understanding of the numerous restrictions on passwords. Frustrations led to adoption of diverse coping strategies. We propose ways to improve support, including real-time communication of reasons for failed password creation attempts, and measurement of timing for both successful and failed login attempts

    Student engagement with feedback and attainment: the role of academic self-efficacy

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    Academic self-efficacy, the belief that one can achieve desired academic goals plays an important role in learning. This study aimed to determine the extent to which academic self-efficacy mediates relationships between students’ perceptions of feedback and their academic attainment. An opportunity sample of 232 students (123 female) in their first year of higher education reported their academic self-efficacy and evaluated their assessment experience, including the perceived quantity and quality of feedback and the extent to which this feedback elicited an active response. Positive associations were observed between academic attainment and students’ confidence that they could achieve their desired grades and adopt appropriate study behaviours. A negative association was identified between attainment and confidence to talk about their studies. Attainment was not related to the perceived quantity or quality of feedback, but did bear a significant association with the reported use to which feedback was put. Positive associations were generally identified between academic self-efficacy and perceptions of feedback. Path models revealed that inter-relationships were best represented by a model wherein academic self-efficacy mediated links between students’ perceptions of feedback and academic attainment. The findings highlight the need to incorporate characteristics of the individual into an understanding of student engagement with feedback
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