374 research outputs found

    Testing the Benefits of Blended Education: Using Social Technology to Foster Collaboration and Knowledge Sharing in Face-To-Face LIS Courses

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    Blended education, which mixes elements of face-to-face and online educational delivery, can occur at the activity, course, program, or administrative level. This study examined the use of student blogs to test the benefits of course-level blended educational delivery for LIS students enrolled in a face-to-face course. Data collected from students' blogs were also used to assess whether Zach and Agosto's (2009) framework for maximizing student collaboration and knowledge sharing in online courses can be applied to face-to-face courses. The study found that blogs successfully supported collaboration and community building because they were well-suited to sharing course-related knowledge and because students encountered few technical barriers. These findings support Zach and Agosto's proposed criteria for selecting technologies to foster increased collaboration and knowledge sharing, e.g., low learning curves and easily facilitated student interaction. The results suggest that blended education can bring many of the educational benefits of online learning to face-to-face students

    Youth beyond borders: Methodological challenges in youth information interaction

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    The pace of technological change is rapid and the impact of this acceleration on the information behavior of youth from diverse backgrounds is multifaceted. Most young people have online access in some form, but the uses and quality of access vary tremendously (Madden, Lenhart, Duggan, Cortesi & Gasser, 2013). With the growth and variation of information behaviors among youth in social media and the mobile Web, keeping pace with research methods used to capture these behaviors and phenomena continues to be a discussion among scholars. Adding to the complications of research in this area, youth are increasingly using information and communications technologies (ICT) across platforms for a variety of information behaviors, including academic and social reasons (Agosto & Abbas, 2010). It is often not enough to solely examine a young person's Twitter feed-we need to see how that conversation carries from Twitter, to direct messages, to texting, to a Facebook post and so on. This variation suggests a need for greater nuance in research (Madden, Lenhart, Duggan, Cortesi & Gasser, 2013; Gasser, Cortesi, Malik & Lee, 2012). This panel will bring together several researchers experienced in studying youth information practices to discuss their methodologies and strategies in dealing with these intricate issues. This panel will be conducted in a roundtable style-encouraging deep conversation between the researchers and the audience. This will be followed by a small group discussions with the audience and conclude by sharing back best practices uncovered through the group discussions. Through attending this panel, attendees will engage with current developments in diverse youth, ICT and research methodologies, and identify priorities and approaches for future work in these areas

    Genome-wide analysis of core promoter elements from conserved human and mouse orthologous pairs

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    BACKGROUND: The canonical core promoter elements consist of the TATA box, initiator (Inr), downstream core promoter element (DPE), TFIIB recognition element (BRE) and the newly-discovered motif 10 element (MTE). The motifs for these core promoter elements are highly degenerate, which tends to lead to a high false discovery rate when attempting to detect them in promoter sequences. RESULTS: In this study, we have performed the first analysis of these core promoter elements in orthologous mouse and human promoters with experimentally-supported transcription start sites. We have identified these various elements using a combination of positional weight matrices (PWMs) and the degree of conservation of orthologous mouse and human sequences – a procedure that significantly reduces the false positive rate of motif discovery. Our analysis of 9,010 orthologous mouse-human promoter pairs revealed two combinations of three-way synergistic effects, TATA-Inr-MTE and BRE-Inr-MTE. The former has previously been putatively identified in human, but the latter represents a novel synergistic relationship. CONCLUSION: Our results demonstrate that DNA sequence conservation can greatly improve the identification of functional core promoter elements in the human genome. The data also underscores the importance of synergistic occurrence of two or more core promoter elements. Furthermore, the sequence data and results presented here can help build better computational models for predicting the transcription start sites in the promoter regions, which remains one of the most challenging problems

    Large conductance modulation of gold thin films by huge charge injection via electrochemical gating

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    By using an electrochemical gating technique with a new combination of polymer and electrolyte, we were able to inject surface charge densities n 2D as high as 3.5×1015e/cm2 in gold films and to observe large relative variations in the film resistance, ΔR/R ′, up to 10% at low temperature. ΔR/R ′ is a linear function of n 2D-as expected within a free-electron model-if the film is thick enough (25nm); otherwise, a tendency to saturation due to size effects is observed. The application of this technique to 2D materials might allow extending the field-effect experiments to a range of charge doping where large conductance modulations and, in some cases, even the occurrence of superconductivity are expected. © 2012 American Physical Society

    Virion-Associated Vpr Alleviates a Postintegration Block to HIV-1 Infection of Dendritic Cells

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    ABSTRACT Viral protein R (Vpr) is an HIV-1 accessory protein whose function remains poorly understood. In this report, we sought to determine the requirement of Vpr for facilitating HIV-1 infection of monocyte-derived dendritic cells (MDDCs), one of the first cell types to encounter virus in the peripheral mucosal tissues. In this report, we characterize a significant restriction of Vpr-deficient virus replication and spread in MDDCs alone and in cell-to-cell spread in MDDC-CD4 + T cell cocultures. This restriction of HIV-1 replication in MDDCs was observed in a single round of virus replication and was rescued by the expression of Vpr in trans in the incoming virion. Interestingly, infections of MDDCs with viruses that encode Vpr mutants unable to interact with either the DCAF1/DDB1 E3 ubiquitin ligase complex or a host factor hypothesized to be targeted for degradation by Vpr also displayed a significant replication defect. While the extent of proviral integration in HIV-1-infected MDDCs was unaffected by the absence of Vpr, the transcriptional activity of the viral long terminal repeat (LTR) from Vpr-deficient proviruses was significantly reduced. Together, these results characterize a novel postintegration restriction of HIV-1 replication in MDDCs and show that the interaction of Vpr with the DCAF1/DDB1 E3 ubiquitin ligase complex and the yet-to-be-identified host factor might alleviate this restriction by inducing transcription from the viral LTR. Taken together, these findings identify a robust in vitro cell culture system that is amenable to addressing mechanisms underlying Vpr-mediated enhancement of HIV-1 replication. IMPORTANCE Despite decades of work, the function of the HIV-1 protein Vpr remains poorly understood, primarily due to the lack of an in vitro cell culture system that demonstrates a deficit in replication upon infection with viruses in the absence of Vpr. In this report, we describe a novel cell infection system that utilizes primary human dendritic cells, which display a robust decrease in viral replication upon infection with Vpr-deficient HIV-1. We show that this replication difference occurs in a single round of infection and is due to decreased transcriptional output from the integrated viral genome. Viral transcription could be rescued by virion-associated Vpr. Using mutational analysis, we show that domains of Vpr involved in binding to the DCAF1/DDB1/E3 ubiquitin ligase complex and prevention of cell cycle progression into mitosis are required for LTR-mediated viral expression, suggesting that the evolutionarily conserved G 2 cell cycle arrest function of Vpr is essential for HIV-1 replication

    SARS-CoV-2 Vaccination in the Context of Ongoing HIV Cure-Related Research Studies

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    To the Editors: The SARS-CoV-2 pandemic has affected research efforts worldwide. Previously, we described our strategy to mitigate COVID-19 transmission risk during an ongoing HIV cure-related clinical trial. SARS-CoV-2 vaccines recently have been authorized for emergency use and will become available to people with HIV imminently. As a result, researchers must determine how to adjust study protocols to incorporate the likelihood that participants may be vaccinated

    Image Tracking Study on Courtship Behavior of Drosophila

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    Background: In recent years, there have been extensive studies aimed at decoding the DNA. Identifying the genetic cause of specific changes in a simple organism like Drosophila may help scientists recognize how multiple gene interactions may make some people more susceptible to heart disease or cancer. Investigators have devised experiments to observe changes in the gene networks in mutant Drosophila that responds differently to light, or have lower or higher locomotor activity. However, these studies focused on the behavior of the individual fly or on pair-wise interactions in the study of aggression or courtship. The behavior of these activities has been captured on film and inspected by a well-trained researcher after repeatedly watching the recorded film. Some studies also focused on ways to reduce the inspection time and increase the accuracy of the behavior experiment. Methodology: In this study, the behavior of drosophila during courtship was analyzed automatically by machine vision. We investigated the position and behavior discrimination during courtship using the captured images. Identification of the characteristics of drosophila, including sex, size, heading direction, and wing angles, can be computed using image analysis techniques that employ the Gaussian mixture model. The behavior of multiple drosophilae can also be analyzed simultaneously using the motion-prediction model and the variation constraint of heading direction. Conclusions: The overlapped fruit flies can be identified based on the relationship between body centers. Moreover, th
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