604 research outputs found

    Partisan Asymmetries in Online Political Activity

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    We examine partisan differences in the behavior, communication patterns and social interactions of more than 18,000 politically-active Twitter users to produce evidence that points to changing levels of partisan engagement with the American online political landscape. Analysis of a network defined by the communication activity of these users in proximity to the 2010 midterm congressional elections reveals a highly segregated, well clustered partisan community structure. Using cluster membership as a high-fidelity (87% accuracy) proxy for political affiliation, we characterize a wide range of differences in the behavior, communication and social connectivity of left- and right-leaning Twitter users. We find that in contrast to the online political dynamics of the 2008 campaign, right-leaning Twitter users exhibit greater levels of political activity, a more tightly interconnected social structure, and a communication network topology that facilitates the rapid and broad dissemination of political information.Comment: 17 pages, 10 figures, 6 table

    Hmong Adults Self-Rated Oral Health: A Pilot Study

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    Since 1975, the Hmong refugee population in the U.S. has increased over 200%. However, little is known about their dental needs or self-rated oral health (SROH). The study aims were to: (1) describe the SROH, self-rated general health (SRGH), and use of dental/physician services; and (2) identify the factors associated with SROH among Hmong adults. A cross-sectional study design with locating sampling methodology was used. Oral health questionnaire was administered to assess SROH and SRGH, past dental and physician visits, and language preference. One hundred twenty adults aged 18–50+ were recruited and 118 had useable information. Of these, 49% rated their oral health as poor/fair and 30% rated their general health as poor/fair. Thirty-nine percent reported that they did not have a regular source of dental care, 46% rated their access to dental care as poor/fair, 43% visited a dentist and 66% visited a physician within the past 12 months. Bivariate analyses demonstrated that access to dental care, past dental visits, age and SRGH were significantly associated with SROH (P \u3c 0.05). Multivariate analyses demonstrated a strong association between access to dental care and good/excellent SROH. About half of Hmong adults rated their oral health and access to dental care as poor. Dental insurance, access to dental care, past preventive dental/physician visits and SRGH were associated with SROH

    Analysis of five-year trends in self-reported language preference and issues of item non-response among Hispanic persons in a large cross-sectional health survey: implications for the measurement of an ethnic minority population

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    <p>Abstract</p> <p>Background</p> <p>Significant differences in health outcomes have been documented among Hispanic persons, the fastest-growing demographic segment of the United States. The objective of this study was to examine trends in population growth and the collection of health data among Hispanic persons, including issues of language preference and survey completion using a national health survey to highlight issues of measurement of an increasingly important demographic segment of the United States.</p> <p>Design</p> <p>Data from the 2003-2007 United States Census and the Behavioral Risk Factor Surveillance System were used to compare trends in population growth and survey sample size as well as differences in survey response based on language preference among a Hispanic population. Percentages of item non-response on selected survey questions were compared for Hispanic respondents choosing to complete the survey in Spanish and those choosing to complete the survey in English. The mean number of attempts to complete the survey was also compared based on language preference among Hispanic respondents.</p> <p>Results</p> <p>The sample size of Hispanic persons in the Behavioral Risk Factor Surveillance System saw little growth compared to the actual growth of the Hispanic population in the United States. Significant differences in survey item non-response for nine of 15 survey questions were seen based on language preference. Hispanic respondents choosing to complete the survey in Spanish had a significantly fewer number of call attempts for survey completion compared to their Hispanic counterparts choosing to communicate in English.</p> <p>Conclusions</p> <p>Including additional measures of acculturation and increasing the sample size of Hispanic persons in a national health survey such as the Behavioral Risk Factor Surveillance System may result in more precise findings that could be used to better target prevention and health care needs for an ethnic minority population.</p

    Lysophosphatidic acid enhances survival of human CD34(+) cells in ischemic conditions

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    Several clinical trials are exploring therapeutic effect of human CD34(+) cells in ischemic diseases, including myocardial infarction. Unfortunately, most of the cells die few days after delivery. Herein we show that lysophosphatidic acid (LPA)-treated human umbilical cord blood-derived CD34(+) cells cultured under hypoxic and serum-deprived conditions present 2.2-fold and 1.3-fold higher survival relatively to non-treated cells and prostaglandin E2-treated cells, respectively. The pro-survival effect of LPA is concentration- and time-dependent and it is mediated by the activation of peroxisome proliferator-activator receptor γ (PPARγ) and downstream, by the activation of pro-survival ERK and Akt signaling pathways and the inhibition of mitochondrial apoptotic pathway. In hypoxia and serum-deprived culture conditions, LPA induces CD34(+) cell proliferation without maintaining the their undifferentiating state, and enhances IL-8, IL-6 and G-CSF secretion during the first 12 h compared to non-treated cells. LPA-treated CD34(+) cells delivered in fibrin gels have enhanced survival and improved cardiac fractional shortening at 2 weeks on rat infarcted hearts as compared to hearts treated with placebo. We have developed a new platform to enhance the survival of CD34(+) cells using a natural and cost-effective ligand and demonstrated its utility in the preservation of the functionality of the heart after infarction.info:eu-repo/semantics/publishedVersio

    Endothelial Progenitor Cells influence acute and subacute stroke hemodynamics

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    BACKGROUND: Endothelial Progenitor Cells (EPCs) are a circulating stem cell population with in vivo capacity of promoting angiogenesis after ischemic events. Despite the promising preclinical data, their potential integration with reperfusion therapies and hemodynamic evolution of stroke patients is still unknown. Our aim was to determine the association of EPCs with acute, subacute and chronic hemodynamic features. METHODS: In this prospective study, we included consecutive patients with ages between 18 and 80years and non-lacunar ischemic stroke within the territory of a middle cerebral artery. All patients were subject to hemodynamic evaluation by ultrasound at baseline, seven days and three months. We quantified cerebral blood flow (CBF) and assessed early recanalization and collateral flow. Hemorrhagic transformation was graded in Magnetic Resonance imaging performed at seven days. EPCs were isolated from peripheral venous blood collected in the first 24h and seven days, counted and submitted to functional in vitro tests. RESULTS: We included 45 patients with a median age of 70±10years. The angiogenic and migratory capacities of EPCs were associated with increased collateral flow in the acute stage and day seven CBF, without statistically significant associations with recanalization nor haemorrhagic transformation. The number of EPCs was not associated with any hemodynamic variable. CONCLUSIONS: The functional properties of EPCs are associated with acute and subacute stroke hemodynamics, with no effect on haemorrhagic transformation.info:eu-repo/semantics/publishedVersio

    Redrawing Boundaries: WITNESS and the Politics of Citizen Videos

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    This article engages with several pressing issues revolving around ‘citizen witnessing’, with specific reference to the human rights advocacy group, WITNESS. In the course of tracing WITNESS’ development over the past two decades, it offers an evaluative assessment of the challenges its members have faced in promoting a grassroots, citizen-centred approach to video reportage. More specifically, this advocacy is informed by an ethical commitment to advancing human rights causes by equipping citizens in crisis situations with cameras, and the training to use them, so that they might bear witness to the plight of others. In so doing, this article argues, WITNESS offers a tactical reformulation of the guiding tenets of peace journalism, one with considerable potential for recasting anew its strategic priorities

    Click-chemistry mediated synthesis of OTBN-1,2,3-Triazole derivatives exhibiting STK33 inhibition with diverse anti-cancer activities

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    There is a continuous and pressing need to establish new brain-penetrant bioactive compounds with anti-cancer properties. To this end, a new series of 4′-((4-substituted-4,5-dihydro-1H-1,2,3-triazol-1-yl)methyl)-[1,1′-biphenyl]-2-carbonitrile (OTBN-1,2,3-triazole) derivatives were synthesized by click chemistry. The series of bioactive compounds were designed and synthesized from diverse alkynes and N3-OTBN, using copper (II) acetate monohydrate in aqueous dimethylformamide at room temperature. Besides being highly cost-effective and significantly reducing synthesis, the reaction yielded 91–98 % of the target products without the need of any additional steps or chromatographic techniques. Two analogues exhibit promising anti-cancer biological activities. Analogue 4l shows highly specific cytostatic activity against lung cancer cells, while analogue 4k exhibits pan-cancer anti-growth activity. A kinase screen suggests compound 4k has single-digit micromolar activity against kinase STK33. High STK33 RNA expression correlates strongly with poorer patient outcomes in both adult and pediatric glioma. Compound 4k potently inhibits cell proliferation, invasion, and 3D neurosphere formation in primary patient-derived glioma cell lines. The observed anti-cancer activity is enhanced in combination with specific clinically relevant small molecule inhibitors. Herein we establish a novel biochemical kinase inhibitory function for click-chemistry-derived OTBN-1,2,3-triazole analogues and further report their anti-cancer activity in vitro for the first time

    Click-chemistry mediated synthesis of OTBN-1,2,3-Triazole derivatives exhibiting STK33 inhibition with diverse anti-cancer activities

    Get PDF
    There is a continuous and pressing need to establish new brain-penetrant bioactive compounds with anti-cancer properties. To this end, a new series of 4′-((4-substituted-4,5-dihydro-1H-1,2,3-triazol-1-yl)methyl)-[1,1′-biphenyl]-2-carbonitrile (OTBN-1,2,3-triazole) derivatives were synthesized by click chemistry. The series of bioactive compounds were designed and synthesized from diverse alkynes and N3-OTBN, using copper (II) acetate monohydrate in aqueous dimethylformamide at room temperature. Besides being highly cost-effective and significantly reducing synthesis, the reaction yielded 91–98 % of the target products without the need of any additional steps or chromatographic techniques. Two analogues exhibit promising anti-cancer biological activities. Analogue 4l shows highly specific cytostatic activity against lung cancer cells, while analogue 4k exhibits pan-cancer anti-growth activity. A kinase screen suggests compound 4k has single-digit micromolar activity against kinase STK33. High STK33 RNA expression correlates strongly with poorer patient outcomes in both adult and pediatric glioma. Compound 4k potently inhibits cell proliferation, invasion, and 3D neurosphere formation in primary patient-derived glioma cell lines. The observed anti-cancer activity is enhanced in combination with specific clinically relevant small molecule inhibitors. Herein we establish a novel biochemical kinase inhibitory function for click-chemistry-derived OTBN-1,2,3-triazole analogues and further report their anti-cancer activity in vitro for the first time

    Rising tides or rising stars?: Dynamics of shared attention on twitter during media events

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    "Media events" generate conditions of shared attention as many users simultaneously tune in with the dual screens of broadcast and social media to view and participate. We examine how collective patterns of user behavior under conditions of shared attention are distinct from other "bursts" of activity like breaking news events. Using 290 million tweets from a panel of 193,532 politically active Twitter users, we compare features of their behavior during eight major events during the 2012 U.S. presidential election to examine how patterns of social media use change during these media events compared to "typical" time and whether these changes are attributable to shifts in the behavior of the population as a whole or shifts from particular segments such as elites. Compared to baseline time periods, our findings reveal that media events not only generate large volumes of tweets, but they are also associated with (1) substantial declines in interpersonal communication, (2) more highly concentrated attention by replying to and retweeting particular users, and (3) elite users predominantly benefiting from this attention. These findings empirically demonstrate how bursts of activity on Twitter during media events significantly alter underlying social processes of interpersonal communication and social interaction. Because the behavior of large populations within socio-technical systems can change so dramatically, our findings suggest the need for further research about how social media responses to media events can be used to support collective sensemaking, to promote informed deliberation, and to remain resilient in the face of misinformation. © 2014 Lin et al

    Prioritizing the Role of Major Lipoproteins and Subfractions as Risk Factors for Peripheral Artery Disease.

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    BACKGROUND: Lipoprotein-related traits have been consistently identified as risk factors for atherosclerotic cardiovascular disease, largely on the basis of studies of coronary artery disease (CAD). The relative contributions of specific lipoproteins to the risk of peripheral artery disease (PAD) have not been well defined. We leveraged large-scale genetic association data to investigate the effects of circulating lipoprotein-related traits on PAD risk. METHODS: Genome-wide association study summary statistics for circulating lipoprotein-related traits were used in the mendelian randomization bayesian model averaging framework to prioritize the most likely causal major lipoprotein and subfraction risk factors for PAD and CAD. Mendelian randomization was used to estimate the effect of apolipoprotein B (ApoB) lowering on PAD risk using gene regions proxying lipid-lowering drug targets. Genes relevant to prioritized lipoprotein subfractions were identified with transcriptome-wide association studies. RESULTS: ApoB was identified as the most likely causal lipoprotein-related risk factor for both PAD (marginal inclusion probability, 0.86; P=0.003) and CAD (marginal inclusion probability, 0.92; P=0.005). Genetic proxies for ApoB-lowering medications were associated with reduced risk of both PAD (odds ratio,0.87 per 1-SD decrease in ApoB [95% CI, 0.84-0.91]; P=9×10-10) and CAD (odds ratio,0.66 [95% CI, 0.63-0.69]; P=4×10-73), with a stronger predicted effect of ApoB lowering on CAD (ratio of effects, 3.09 [95% CI, 2.29-4.60]; P<1×10-6). Extra-small very-low-density lipoprotein particle concentration was identified as the most likely subfraction associated with PAD risk (marginal inclusion probability, 0.91; P=2.3×10-4), whereas large low-density lipoprotein particle concentration was the most likely subfraction associated with CAD risk (marginal inclusion probability, 0.95; P=0.011). Genes associated with extra-small very-low-density lipoprotein particle and large low-density lipoprotein particle concentration included canonical ApoB pathway components, although gene-specific effects were variable. Lipoprotein(a) was associated with increased risk of PAD independently of ApoB (odds ratio, 1.04 [95% CI, 1.03-1.04]; P=1.0×10-33). CONCLUSIONS: ApoB was prioritized as the major lipoprotein fraction causally responsible for both PAD and CAD risk. However, ApoB-lowering drug targets and ApoB-containing lipoprotein subfractions had diverse associations with atherosclerotic cardiovascular disease, and distinct subfraction-associated genes suggest possible differences in the role of lipoproteins in the pathogenesis of PAD and CAD
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