A Longitudinal Analysis of the Effects of News Media Messages on Health Behaviors

Two primary research hypotheses were tested concerning aggregate effects of news media on aggregated health behaviors over time for four health behaviors: marijuana use, seatbelt use, beef consumption, fruit consumption. Several measures of seatbelt use and fruit consumption were used. The first primary hypothesis sought to establish any evidence of news media impact on behavior, and tested for effects using two different operationalizations of media coverage. The first operationalization distinguished between PRO and CON coverage. PRO coverage consisted of stories emphasizing positive aspects of performing the healthy behavior, while CON coverage consisted of stories emphasizing negative aspects of performing the healthy behavior. The second operationalization measured any media stories containing references to performing the behavior (the general behavioral media measure, or GBM). The second hypothesis proposed that media messages emphasizing the positive (PRO) and negative (CON) aspects of performing the healthy behavior would be more strongly associated with behavior change than would the more general behavioral media coverage measure (GBM) (Hypothesis 2A). It was further proposed that if there were very low levels of CON media, the PRO measure should still offer greater prediction than the general measure (Hypothesis 2B). Two methods, distributed lagged regression analysis and ideodynamic models, were used to test hypotheses. iii In sum, there was substantial support for Research Hypothesis 1, that trends in media coverage could explain a significant portion of the variation in trends in behavioral outcomes. Considering any measure of media coverage, any measure of behavior, and any method of analysis, there was at least one significant media/behavior association for each behavior. The conviction with which claims of causal inference could be made was varied. There was less convincing evidence supporting the second set of research hypotheses, that PRO/CON (or PRO only in the absence of CON) coverage would better predict behavior change than the GBM measure. These hypotheses could only be considered if there was any evidence of an association between media coverage and the behavioral measure. Of the five significant media/behavior relationships, four of them provided support (in varying degrees) for the superiority of the more refined media measure(s)

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<p>Total Sample Size (2009–2015) N = 9023.</p

Burst-Time-Dependent Plasticity Robustly Guides ON/OFF Segregation in the Lateral Geniculate Nucleus

Spontaneous retinal activity (known as “waves”) remodels synaptic connectivity to the lateral geniculate nucleus (LGN) during development. Analysis of retinal waves recorded with multielectrode arrays in mouse suggested that a cue for the segregation of functionally distinct (ON and OFF) retinal ganglion cells (RGCs) in the LGN may be a desynchronization in their firing, where ON cells precede OFF cells by one second. Using the recorded retinal waves as input, with two different modeling approaches we explore timing-based plasticity rules for the evolution of synaptic weights to identify key features underlying ON/OFF segregation. First, we analytically derive a linear model for the evolution of ON and OFF weights, to understand how synaptic plasticity rules extract input firing properties to guide segregation. Second, we simulate postsynaptic activity with a nonlinear integrate-and-fire model to compare findings with the linear model. We find that spike-time-dependent plasticity, which modifies synaptic weights based on millisecond-long timing and order of pre- and postsynaptic spikes, fails to segregate ON and OFF retinal inputs in the absence of normalization. Implementing homeostatic mechanisms results in segregation, but only with carefully-tuned parameters. Furthermore, extending spike integration timescales to match the second-long input correlation timescales always leads to ON segregation because ON cells fire before OFF cells. We show that burst-time-dependent plasticity can robustly guide ON/OFF segregation in the LGN without normalization, by integrating pre- and postsynaptic bursts irrespective of their firing order and over second-long timescales. We predict that an LGN neuron will become ON- or OFF-responsive based on a local competition of the firing patterns of neighboring RGCs connecting to it. Finally, we demonstrate consistency with ON/OFF segregation in ferret, despite differences in the firing properties of retinal waves. Our model suggests that diverse input statistics of retinal waves can be robustly interpreted by a burst-based rule, which underlies retinogeniculate plasticity across different species

PrEP Awareness and Attitudes in a National Survey of Primary Care Clinicians in the United States, 2009-2015.

OBJECTIVES:As trials were assessing the safety and efficacy of daily oral antiretroviral preexposure prophylaxis (PrEP) for the prevention of HIV infection, there was a clear need to understand the evolution of knowledge of, and attitudes toward, PrEP among primary care clinicians. METHODS:Physicians and nurse practitioners were surveyed in 2009 (n = 1500), 2010 (n = 1504), 2012 (n = 1503), 2013 (n = 1507), 2014 (n = 1508) and 2015 (n = 1501) to assess their awareness of PrEP, willingness to prescribe PrEP, and whether they support use of public funds to pay for PrEP. Pharmacists (n = 251) were surveyed about PrEP in 2012 only. Descriptive statistics were computed for physician demographics and PrEP-related questions. Prevalence ratios for willingness to prescribe PrEP were computed using Poisson regression analysis. RESULTS:Awareness of PrEP was low among clinicians (2009: 24%, 2010: 29%) but increased after trials reported effectiveness (2012: 49%, 2013: 51%, 2014: 61%, 2015: 66%). Following a description of PrEP with an estimated effectiveness of 75%, across 6 of the study years 91% of clinicians indicated a willingness to prescribe PrEP to at least one group at high risk of HIV acquisition. A smaller majority of clinicians indicated support for public funding of PrEP in 2009: 59%, 2010: 53%, and 2013: 63%. CONCLUSIONS:In surveys conducted before and after the release of PrEP trial results, primary care clinicians were largely unaware of PrEP. They indicated high levels of willingness to prescribe it for patients at high risk of HIV acquisition and expressed interest in education about how to deliver this new clinical HIV prevention method. It will be important to continue monitoring clinician knowledge, attitudes, and practices as the use of PrEP increases in the US

Awareness of PrEP and Willingness to Prescribe PrEP to Persons with Selected Risks for HIV Acquisition by Provider Type, DocStyles, 2009–2015, United States.

<p>Awareness of PrEP and Willingness to Prescribe PrEP to Persons with Selected Risks for HIV Acquisition by Provider Type, DocStyles, 2009–2015, United States.</p

Awareness of PrEP and Willingness to Prescribe PrEP to Persons with Selected Risks for HIV Acquisition by Survey Year, DocStyles, 2009–2015, United States.

<p>Awareness of PrEP and Willingness to Prescribe PrEP to Persons with Selected Risks for HIV Acquisition by Survey Year, DocStyles, 2009–2015, United States.</p

Association of Clinician Characteristics with Willingness to Prescribe PrEP: DocStyles 2009–2015, United States.

<p>Association of Clinician Characteristics with Willingness to Prescribe PrEP: DocStyles 2009–2015, United States.</p