103 research outputs found

    Field study of surcharge effects on a steel sheet pile bulkhead

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    This thesis presents the results of a field study conducted to determine surcharge effects on a steel sheet pile bulkhead

    Engaging Teachers in Digital Products and Processes: Interview Feature Articles

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    Students sit in pairs interviewing each other--talking, laughing, taking notes with pen and paper. Computers begin to appear on tables, as students segue into drafting feature articles-- those splash-of-color pieces that go beyond straight news in magazines and news source. Conversation diminishes to a soft hum, as focus shifts to the interplay of thinking, written notes, and the emerging text on the computer screen. Words continue to waft over the room as comments and questions pertaining to content and processes are directed to others. Computer screens are filling up with these words… Thus begins, the first day of writing workshop in our teacher education courses

    “We Do More Than Discuss Good Ideas”: A Close Look at the Development of Professional Capital in an Elementary Education Liaison Group

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    In an era when many news media, policy makers, and professionals in the field may consider teacher education under attack, teacher education programs are being held accountable for increased rigor (Council of Chief of State School Officers, 2012). Teacher educators are in a unique position to examine more closely specific practices and teacher education as a profession to enhance program quality and candidate outcomes. Toward that end, we focused on work within a community of practice (Wenger, 1998) for this inquiry. Faculty who work in elementary school settings at least one day per week, serving as liaisons to partner schools and supervising teacher candidates, made up this community

    The Effect of Travel Burden on Depression and Anxiety in African American Women Living with Systemic Lupus

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    The United States has a deficit of rheumatology specialists. This leads to an increased burden in accessing care for patients requiring specialized care. Given that most rheumatologists are located in urban centers at large hospitals, many lupus patients must travel long distances for routine appointments. The present work aims to determine whether travel burden is associated with increased levels of depression and anxiety among these patients. Data for this study were collected from baseline visits of patients participating in a lupus study at MUSC. A travel/economic burden survey was assessed as well as the 8-item Patient Health Questionnaire (PHQ-8) and the 7-item Generalized Anxiety Disorder (GAD-7) survey as measures of depression and anxiety, respectively. Linear regression models were used to assess the relationship between travel burden and depression and anxiety. Frequency of healthcare visits was significantly associated with increased depression (β = 1.3, p = 0.02). Significant relationships were identified between anxiety and requiring time off from work for healthcare appointments (β = 4, p = 0.02), and anxiety and perceived difficulty in traveling to primary care providers (β = 3.1, p = 0.04). Results from this study provide evidence that travel burden can have an effect on lupus patients’ anxiety and depression levels

    Biophysical and Ultrastructural Characterization of Adeno-Associated Virus Capsid Uncoating and Genome Release

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    We describe biophysical and ultrastructural differences in genome release from adeno-associated virus (AAV) capsids packaging wild-type DNA, recombinant single-stranded DNA (ssDNA), or dimeric, self-complementary DNA (scDNA) genomes. Atomic force microscopy and electron microscopy (EM) revealed that AAV particles release packaged genomes and undergo marked changes in capsid morphology upon heating in physiological buffer (pH 7.2). When different AAV capsids packaging ss/scDNA varying in length from 72 to 123% of wild-type DNA (3.4 to 5.8 kb) were incrementally heated, the proportion of uncoated AAV capsids decreased with genome length as observed by EM. Genome release was further characterized by a fluorimetric assay, which demonstrated that acidic pH and high osmotic pressure suppress genome release from AAV particles. In addition, fluorimetric analysis corroborated an inverse correlation between packaged genome length and the temperature needed to induce uncoating. Surprisingly, scAAV vectors required significantly higher temperatures to uncoat than their ssDNA-packaging counterparts. However, externalization of VP1 N termini appears to be unaffected by packaged genome length or self-complementarity. Further analysis by tungsten-shadowing EM revealed striking differences in the morphologies of ssDNA and scDNA genomes upon release from intact capsids. Computational modeling and molecular dynamics simulations suggest that the unusual thermal stability of scAAV vectors might arise from partial base pairing and optimal organization of packaged scDNA. Our work further defines the biophysical mechanisms underlying adeno-associated virus uncoating and genome release

    Small-Molecule Inhibition of Human Immunodeficiency Virus Type 1 Replication by Specific Targeting of the Final Step of Virion Maturation

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    Despite the effectiveness of currently available human immunodeficiency virus type 1 (HIV-1) therapies, a continuing need exists for new drugs to treat HIV-1 infection. We investigated the mechanism by which 3-O-{3′,3′-dimethylsuccinyl}-betulinic acid (DSB) inhibits HIV-1 replication. DSB functions at a late stage of the virus life cycle but does not inhibit the HIV-1 protease in vitro or interfere with virus assembly or release. DSB specifically delays the cleavage of Gag between the capsid (CA) and p2, resulting in delayed formation of the mature viral core and reduced HIV-1 infectivity. Replication of simian immunodeficiency virus (SIV) was resistant to DSB; however, a chimeric SIV carrying CA-p2 sequences from HIV-1 was inhibited by the drug, indicating that susceptibility to DSB maps to the CA-p2 region of the HIV-1 Gag protein. A single point mutation at the CA-p2 cleavage site of HIV-1 conferred strong resistance to DSB, confirming the target of the drug. HIV-1 strains that are resistant to a variety of protease inhibitors were sensitive to DSB. These findings indicate that DSB specifically protects the CA-p2 cleavage site from processing by the viral protease during virion maturation, thereby revealing a novel mechanism for pharmacologic inhibition of HIV-1 replication

    Lentiviral-Mediated Transgene Expression Can Potentiate Intestinal Mesenchymal-Epithelial Signaling

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    Mesenchymal-epithelial signaling is essential for the development of many organs and is often disrupted in disease. In this study, we demonstrate the use of lentiviral-mediated transgene delivery as an effective approach for ectopic transgene expression and an alternative to generation of transgenic animals. One benefit to this approach is that it can be used independently or in conjunction with established transgenic or knockout animals for studying modulation of mesenchymal-epithelial interactions. To display the power of this approach, we explored ectopic expression of a Wnt ligand in the mouse intestinal mesenchyme and demonstrate its functional influence on the adjacent epithelium. Our findings highlight the efficient use of lentiviral-mediated transgene expression for modulating mesenchymal-epithelial interactions in vivo

    How do validated measures of functional outcome compare with commonly used outcomes in administrative database research for lumbar spinal surgery?

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    Clinical interpretation of health services research based on administrative databases is limited by the lack of patient-reported functional outcome measures. Reoperation, as a surrogate measure for poor outcome, may be biased by preferences of patients and surgeons and may even be planned a priori. Other available administrative data outcomes, such as postoperative cross sectional imaging (PCSI), may better reflect changes in functional outcome. The purpose was to determine if postoperative events captured from administrative databases, namely reoperation and PCSI, reflect outcomes as derived by validated functional outcome measures (short form 36 scores, Oswestry disability index) for patients who underwent discretionary surgery for specific degenerative conditions of the lumbar spine such as disc herniation, spinal stenosis, degenerative spondylolisthesis, and isthmic spondylolisthesis. After reviewing the records of all patients surgically treated for disc herniation, spinal stenosis, degenerative spondylolisthesis, and isthmic spondylolisthesis at our institution, we recorded the occurrence of PCSI (MRI or CT-myelograms) and reoperations, as well as demographic, surgical, and functional outcome data. We determined how early (within 6 months) and intermediate (within 18 months) term events (PCSI and reoperations) were associated with changes in intermediate (minimum 1 year) and late (minimum 2 years) term functional outcome, respectively. We further evaluated how early (6–12 months) and intermediate (12–24 months) term changes in functional outcome were associated with the subsequent occurrence of intermediate (12–24 months) and late (beyond 24 months) term adverse events, respectively. From 148 surgically treated patients, we found no significant relationship between the occurrence of PCSI or reoperation and subsequent changes in functional outcome at intermediate or late term. Similarly, earlier changes in functional outcome did not have any significant relationship with subsequent occurrences of adverse events at intermediate or late term. Although it may be tempting to consider administrative database outcome measures as proxies for poor functional outcome, we cannot conclude that a significant relationship exists between the occurrence of PCSI or reoperation and changes in functional outcome
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