Organelle-Specific Single-Molecule Imaging of \u3cem\u3eα\u3c/em\u3e4\u3cem\u3eβ\u3c/em\u3e2 Nicotinic Receptors Reveals the Effect of Nicotine on Receptor Assembly and Cell-Surface Trafficking

Nicotinic acetylcholine receptors (nAChRs) assemble in the endoplasmic reticulum (ER) and traffic to the cell surface as pentamers composed of α and β subunits. Many nAChR subtypes can assemble with varying subunit ratios, giving rise to multiple stoichiometries exhibiting different subcellular localization and functional properties. In addition to the endogenous neurotransmitter acetylcholine, nicotine also binds and activates nAChRs and influences their trafficking and expression on the cell surface. Currently, no available technique can specifically elucidate the stoichiometry of nAChRs in the ER versus those in the plasma membrane. Here, we report a method involving single-molecule fluorescence measurements to determine the structural properties of these membrane proteins after isolation in nanoscale vesicles derived from specific organelles. These cell-derived nanovesicles allowed us to separate single membrane receptors while maintaining them in their physiological environment. Sorting the vesicles according to the organelle of origin enabled us to determine localized differences in receptor structural properties, structural influence on transport between organelles, and changes in receptor assembly within intracellular organelles. These organelle-specific nanovesicles revealed that one structural isoform of the α4β2 nAChR was preferentially trafficked to the cell surface. Moreover, nicotine altered nAChR assembly in the ER, resulting in increased production of the receptor isoform that traffics more efficiently to the cell surface. We conclude that the combined effects of the increased assembly of one nAChR stoichiometry and its preferential trafficking likely drive the up-regulation of nAChRs on the cell surface upon nicotine exposure

Neighborhood Safety and Attractiveness Influence Physical Activity among African American and Hispanic or Latina Women

Introduction: Although the benefits of adopting physical activity (PA) are well publicized, physical inactivity rates remain high, and African American and Hispanic or Latina women do less PA compared to white women. Many interventions have begun to focus on conveniently performed lifestyle PA, such as walking. The purpose of this study was to investigate the relationship between neighborhood safety and attractiveness and PA in a sample of African American (AA) and Hispanic or Latina (HL) women participating in Health Is Power (1R01CA109403). Method: Women (AA N=202 and HL N=107) who enrolled in the study were middle-aged (M=45.8 years), overweight (M BMI=34.2 kg/m2) and largely sedentary (M accelerometer measured PA=19.6 min/day). Self-reported PA was measured by the International Physical Activity Questionnaire (IPAQ) long form and objectively measured PA was collected using an accelerometer at baseline (T1) and post intervention (T2). Neighborhood safety and attractiveness were measured by trained observers using the Pedestrian Environment Data Scan (PEDS). Results: At T1, African American women did more moderate intensity PA (M=24.3 vs. 10.9 minutes of moderate PA per day) and reported doing more walking (M=867.7 vs. 432.2 MET-minutes per day) than Hispanic or Latina women. At T2, African American still did more PA than Hispanic or Latina women (M=25.0 vs. 11.7 minutes of moderate PA per day), but there were no differences in self-reported PA. Bivariate associations showed that as safety (r=-0.144) and attractiveness (r=-0.149) for bicycling increased, self-reported walking decreased (ps\u3c0.05). Linear regression analyses indicated attractiveness for bicycling predicted increased T2 accelerometer measured PA (p=0.025), after adjusting for ethnicity, site, socioeconomic status (SES) and age. Conclusions: Neighborhood safety and attractiveness may influence PA. Community leaders and policy makers should consider the relationship between the built environment, PA and obesity in communities where African American and Hispanic or Latina reside when passing and/or enforcing public policies and amendments

Measured and Self-reported Neighborhood Characteristics and Physical Activity Among African American Women

African American women are vulnerable to physical inactivity compared to white women. Measured and self-reported neighborhood characteristics may be associated with physical activity (PA), yet few studies have examined these factors among minority women. The purpose of this study was to investigate the associations of measured and self-reported neighborhood characteristics with individual PA. The Pedestrian Environment Data Scan was completed for 25% of randomly selected residential street segments within a 400 meter radius of each participants’ address. African American women (N=262, M age=44.4 yrs) completed interviewer administered questionnaires assessing self-reported neighborhood characteristics. PA was measured using the International Physical Activity Questionnaire (IPAQ) long (M MET minutes/week=2519) and accelerometry (M MVPA=19.0 min/day). Most women were obese (N=176, 67.2%; M BMI= 34.0). IPAQ PA was not associated with accelerometer PA. Bivariate correlations suggested relationships between greater measured pedestrian facility density and more IPAQ transportation PA , greater reported pedestrian facility density and more IPAQ leisure time PA, greater reported bicycle facility density and more IPAQ moderate PA and IPAQ total PA (ps\u3c.05). Simultaneous ecological multiple regression models demonstrated that reported pedestrian facility density (Beta=.138, t=2.181) and body fat percentage (Beta= -.089, t= -1.398) were associated with IPAQ leisure time PA (R²=.027; p=.04), reported bicycle facility density (Beta=.138, t=2.161) was associated with IPAQ moderate PA (R²=.019; p=.03), and reported bicycle facility density (Beta=.130, t=2.041) was associated with IPAQ total PA (R²= .017; p=.04). No measured or reported neighborhood characteristics were associated with accelerometer measured PA. Measured and reported built environment attributes are significantly associated with self-reported PA but may be mediated by weight status

Associations between Fall Distance, Age, and Trauma Outcomes in Older Adult Patients

Introduction. Falls are the leading cause of injury death amongolder adults. This study sought to determine if there are differencesbetween fall distance (ground level vs greater than groundlevel) and age (old vs very old) in terms of in-hospital mortality,orthopedic consultations, and neurological consultations. Methods. A retrospective trauma registry review was conductedof older adult patients (aged > 65 years), admitted to aMidwestern Level I trauma facility (2005 - 2010) due to a fall.Results. Of the 1,064 patients analyzed, the majority fell fromground level compared to greater than ground level (64% and36%, respectively). Median age was 80 years. Fall distance wasnot associated significantly with in-hospital mortality (OR0.88; CI 0.50 - 1.54) or neurological consultations (OR 1.02; CI0.72 - 1.43), but was associated with orthopedic consultations(OR 1.49; CI 1.09 - 2.04). Age was not associated with in-hospitalmortality or neurological or orthopedic consultations. Conclusions. Fall distance was not associated with in-hospitalmortality or receiving a neurological consultation.However, older adults who fell from greater than groundlevel were more likely to receive orthopedic consultations.There were no differences in in-hospital mortality or receivinga neurological or orthopedic consultation based onage. These findings indicated that as the older adult populationincreases, burden of care will increase for trauma centersand neurological services. KS J Med 2016;9(3):54-57

Experiences in deploying metadata analysis tools for institutional repositories

Current institutional repository software provides few tools to help metadata librarians understand and analyze their collections. In this article, we compare and contrast metadata analysis tools that were developed simultaneously, but independently, at two New Zealand institutions during a period of national investment in research repositories: the Metadata Analysis Tool (MAT) at The University of Waikato, and the Kiwi Research Information Service (KRIS) at the National Library of New Zealand. The tools have many similarities: they are convenient, online, on-demand services that harvest metadata using OAI-PMH; they were developed in response to feedback from repository administrators; and they both help pinpoint specific metadata errors as well as generating summary statistics. They also have significant differences: one is a dedicated tool wheres the other is part of a wider access tool; one gives a holistic view of the metadata whereas the other looks for specific problems; one seeks patterns in the data values whereas the other checks that those values conform to metadata standards. Both tools work in a complementary manner to existing Web-based administration tools. We have observed that discovery and correction of metadata errors can be quickly achieved by switching Web browser views from the analysis tool to the repository interface, and back. We summarize the findings from both tools' deployment into a checklist of requirements for metadata analysis tools

Evaluating Spillover Effects in Network-Based Studies In the Presence of Missing Outcomes

Estimating causal effects in the presence of spillover among individuals embedded within a social network is often challenging with missing information. The spillover effect is the effect of an intervention if a participant is not exposed to the intervention themselves but is connected to intervention recipients in the network. In network-based studies, outcomes may be missing due to the administrative end of a study or participants being lost to follow-up due to study dropout, also known as censoring. We propose an inverse probability censoring weighted (IPCW) estimator, which is an extension of an IPW estimator for network-based observational studies to settings where the outcome is subject to possible censoring. We demonstrated that the proposed estimator was consistent and asymptotically normal. We also derived a closed-form estimator of the asymptotic variance estimator. We used the IPCW estimator to quantify the spillover effects in a network-based study of a nonrandomized intervention with censoring of the outcome. A simulation study was conducted to evaluate the finite-sample performance of the IPCW estimators. The simulation study demonstrated that the estimator performed well in finite samples when the sample size and number of connected subnetworks (components) were fairly large. We then employed the method to evaluate the spillover effects of community alerts on self-reported HIV risk behavior among people who inject drugs and their contacts in the Transmission Reduction Intervention Project (TRIP), 2013 to 2015, Athens, Greece. Community alerts were protective not only for the person who received the alert from the study but also among others in the network likely through information shared between participants. In this study, we found that the risk of HIV behavior was reduced by increasing the proportion of a participant's immediate contacts exposed to community alerts