Publications by authors named "Murrell S"

Cave Automatic Virtual Environment (CAVE) is a virtual reality (VR) environment that has not been fully studied due to its high cost and complexity in system integration. Previous CAVE-related studies mainly focused on comparing its effectiveness with other learning media, such as textbooks, desktop VR, or head-mounted display (HMD) VR. In this study, through the utilization of CAVE in a meteorology class, we concentrated on CAVE itself, measured how CAVE impacted learners' learning outcomes before and after using CAVE in an actual ongoing undergraduate-level class, and investigated how learners perceived their learning experiences.

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Vaccination strategies aimed at maturing broadly neutralizing antibodies (bnAbs) from naïve precursors are hindered by unusual features that characterize these Abs, including insertions and deletions (indels). Longitudinal studies of natural HIV infection cases shed light on the complex processes underlying bnAb development and have suggested a role for superinfection as a potential enhancer of neutralization breadth. Here we describe the development of a potent bnAb lineage that was elicited by two founder viruses to inform vaccine design.

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The Dempster-Shafer (DS) belief theory constitutes a powerful framework for modeling and reasoning with a wide variety of uncertainties due to its greater expressiveness and flexibility. As in the Bayesian probability theory, the DS theoretic (DST) conditional plays a pivotal role in DST strategies for evidence updating and fusion. However, a major limitation in employing the DST framework in practical implementations is the absence of an efficient and feasible computational framework to overcome the prohibitive computational burden DST operations entail.

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Objectives: Cancer costs have increased substantially in the past decades, prompting specialty societies to urge oncologists to consider value in clinical decision making. Despite oncologists' crucial role in guiding cancer care, current literature is sparse with respect to the oncologists' views on value. Here, we evaluated oncologists perceptions of the use and measurement of value in cancer care.

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Broadly neutralizing antibodies (bnAbs) targeting the HIV envelope glycoprotein (Env) typically take years to develop. Longitudinal analyses of both neutralizing antibody lineages and viruses at serial time points during infection provide a basis for understanding the co-evolutionary contest between HIV and the humoral immune system. Here, we describe the structural characterization of an apex-targeting antibody lineage and autologous clade A viral Env from a donor in the Protocol C cohort.

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Congressional and Veterans Affairs (VA) leaders have recommended the VA become more of a purchaser than a provider of health care. Fee-for-service Medicare provides an example of how purchased care differs from the VA's directly provided care. Using established indicators of overly intensive end-of-life care, we compared the quality of care provided through the two systems to veterans dying of cancer in fiscal years 2010-14.

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Understanding how broadly neutralizing antibodies (bnAbs) to HIV envelope (Env) develop during natural infection can help guide the rational design of an HIV vaccine. Here, we described a bnAb lineage targeting the Env V2 apex and the Ab-Env co-evolution that led to development of neutralization breadth. The lineage Abs bore an anionic heavy chain complementarity-determining region 3 (CDRH3) of 25 amino acids, among the shortest known for this class of Abs, and achieved breadth with only 10% nucleotide somatic hypermutation and no insertions or deletions.

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Oligomannose-type glycans are among the major targets on the gp120 component of the HIV envelope protein (Env) for broadly neutralizing antibodies (bnAbs). However, attempts to elicit oligomannose-specific nAbs by immunizing with natural or synthetic oligomannose have so far not been successful, possibly due to B cell tolerance checkpoints. Here we design and synthesize oligomannose mimetics, based on the unique chemical structure of a recently identified bacterial lipooligosaccharide, to appear foreign to the immune system.

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Background: The Veterans Choice Program (VCP), enacted by Congress after concerns surfaced about access, enables veterans to receive care outside Veterans Health Administration (VHA) facilities. Veterans who face long wait times, large driving distances, or particular hardships are eligible for VCP. Prior purchased care programs were comparatively limited in scope.

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Endogenous viral sequences are essentially 'fossil records' that can sometimes reveal the genomic features of long extinct virus species. Although numerous known instances exist of single-stranded DNA (ssDNA) genomes becoming stably integrated within the genomes of bacteria and animals, there remain very few examples of such integration events in plants. The best studied of these events are those which yielded the geminivirus-related DNA elements found within the nuclear genomes of various species.

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Several HIV envelope-targeting (Env-targeting) antibodies with broad and potent neutralizing activity have been identified and shown to have unusual features. Of these, the PG9 antibody has a long heavy chain complementarity determining region 3 (HCDR3) and possesses unique structural elements that interact with protein and glycan features of the HIV Env glycoprotein. Here, we used the Rosetta software suite to design variants of the PG9 antibody HCDR3 loop with the goal of identifying variants with increased potency and breadth of neutralization for diverse HIV strains.

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We present BUSTED, a new approach to identifying gene-wide evidence of episodic positive selection, where the non-synonymous substitution rate is transiently greater than the synonymous rate. BUSTED can be used either on an entire phylogeny (without requiring an a priori hypothesis regarding which branches are under positive selection) or on a pre-specified subset of foreground lineages (if a suitable a priori hypothesis is available). Selection is modeled as varying stochastically over branches and sites, and we propose a computationally inexpensive evidence metric for identifying sites subject to episodic positive selection on any foreground branches.

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Background: Residents of public housing have poorer health indicators than comparably resourced individuals from the larger community.

Objectives: To identify major health concerns, issues, and barriers to health of community members living in public housing developments, especially as related to cardiovascular disease prevention. To identify similarities and differences between data collected using two methods to inform future health promotion programs and policies.

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Background: Despite close proximity to community health centers, public housing residents are at increased risk of uncontrolled chronic disease, in part because of underutilization of routine health care.

Objectives: To assist in program planning, the Partners in Health and Housing Prevention Research Center (PHH-PRC) used the Community Readiness Model to compare readiness of public housing developments and community health centers to address community-identified health priorities. The model assumes that program success to affect change depends on matching the community's level of readiness to address the issue.

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Objectives: To explore whether a ratio of positive to negative affect, from the work of Fredricksen and Losada, could predict high levels of well-being in elderly samples and especially in nursing home residents despite multiple chronic health conditions, consonant with Ryff and Singer's notion of "flourishing under fire."

Method: We used two samples: a probability sample of community-residing elders and a sample from nursing homes. We calculated ratios of positive to negative affect in each sample and measured well-being with social interaction, mental health, life satisfaction, and general well-being.

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The purpose of this study was to evaluate the feasibility of incorporating chronic disease navigation using lay health care workers trained in motivational interviewing (MI) into an existing mammography navigation program. Primary-care patient navigators implemented MI-based telephone conversations around mammography, smoking, depression, and obesity. We conducted a small-scale demonstration, using mixed methods to assess patient outcomes and provider satisfaction.

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Article Synopsis
  • The lack of standard metrics for evaluating cancer prevention and early detection programs makes it hard to identify effective practices.
  • The Prevention and Early Detection Workgroup created recommendations based on reviewing existing literature to establish common clinical metrics.
  • Key recommendations include documenting program characteristics, using core data elements for metrics, and prioritizing unbiased data collection methods to allow for meaningful comparisons across navigation programs.
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Dengue viral infection has become an increasing global health concern with over two-fifths of the world's population at risk of infection. It is the most rapidly spreading vector borne disease, attributed to changing demographics, urbanization, environment, and global travel. It continues to be a threat in over 100 tropical and sub-tropical countries, affecting predominantly children.

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Objective: Our objective was to compare the physiochemical properties and erosion potentials between beverages available in the UK and the US.

Methods: The physiochemical properties (pH, titratable acidity and fluoride concentration) and erosion potential on enamel surfaces of beverages available in the UK were compared to similar beverages from the US. Enamel windows were exposed to beverages for 25h.

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Objective: The objective of this study was to examine two competing hypotheses as they relate to the relationship between vascular and psychosocial risk factors for late-life depression. The stress-vulnerability hypothesis predicts that the depressogenic effect of psychosocial risk is stronger in the presence of cardiovascular risk factors (CVRFs). The other predicts that psychosocial risk factors and vascular risk factors are independent pathways to depression and that there is no combined effect of vascular risk factors and life stress.

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Abstract Data were collected on interpersonal functioning that could be used to evaluate therapeutic outcome for individual clients. The Inventory of Interpersonal Problems (IIP) was administered three times over five weeks to undergraduates, none of whom were currently in therapy. Based on selection using an accepted measure of psychological distress (Outcome Questionnaire-45.

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Objective: Authors examined racial differences in cerebrovascular risk factors (CVRFs) and overall depressive symptomatology.

Methods: The authors applied a correlational design using a depression inventory, the Center for Epidemiological Studies Depression scale (CES-D) and self-report CVRF data from black and white community-dwelling elderly subjects (N=362).

Results: Black subjects were more likely than whites to screen positive for depression, but there were no race differences in CVRFs.

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The current study examined the moderating effect of age on the relationship between cerebrovascular risk factors (CVRF's) and depressive symptoms. Consistent with the broader vascular depression model, it was hypothesized that CVRF's would demonstrate a stronger link to depressive symptoms in the older age groups than among the younger age groups. Data from 2916 adults from the Resources, Stress, and Older Persons Panel Study were utilized.

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