1,875 research outputs found

    To use or be used? The role of agency in social media use and well-being

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    In this paper, we develop the concept of agentic social media use: a way of engaging with social media that emphasizes having the beliefs, knowledge, and practices to use it intentionally. In comparison to instances of “mindless” social media use, people who use social media agentically do so with a purpose in mind: they leverage the affordances of social media to do things that are meaningful, useful, or satisfying for them. For example, people can use social media to intentionally build or manage their relationships, to seek out and learn new information about their interests, or to craft a positive image of themselves through the content they post. Crucially, however, there are many other valuable uses of social media that may not be considered conventionally productive but are nonetheless deliberate and useful, such as using social media intentionally to relax, unwind, and entertain themselves in an effort to modulate their emotions. To use social media agentically means to (1) hold an agentic mindset about one's relationship with social media, (2) have the knowledge and literacy to understand how to navigate social media effectively, and (3) enact practices that assert control over specific elements of social media use, such as curating content and refining algorithmic recommendation. Approaching social media use from the perspective of agency and intentionality allows us to better understand heterogeneous social media effects and to identify new ways of helping people benefit from these technologies

    XMM-Newton and optical follow-up observations of three new polars from the Sloan Digital Sky Survey

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    We report follow-up XMM-Newton and optical observations of three new polars found in the Sloan Digital Sky Survey. Simple modeling of the X-ray spectra, and consideration of the details of the X-ray and optical lightcurves corroborate the polar nature of these three systems and provide further insights into their accretion characteristics. During the XMM-Newton observation of SDSS J072910.68+365838.3, X-rays are undetected apart from a probable flare event, during which we find both the typical hard X-ray bremsstrahlung component and a very strong line O VII (E=0.57 keV), but no evidence of a soft blackbody contribution. In SDSS J075240.45+362823.2 we identify an X-ray eclipse at the beginning of the observation, roughly in phase with the primary minimum of the optical broad band curve. The X-ray spectra require the presence of both hard and soft X-ray components, with their luminosity ratio consistent with that found in other recent XMM-Newton results on polars. Lastly, SDSS J170053.30+400357.6 appears optically as a very typical polar, however its large amplitude optical modulation is 180 degrees out of phase with the variation in our short X-ray lightcurve.Comment: 9 pages, 9 figures, accepted for publication in the ApJ (January 2005

    Projections of Ebola outbreak size and duration with and without vaccine use in Équateur, Democratic Republic of Congo, as of May 27, 2018.

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    As of May 27, 2018, 6 suspected, 13 probable and 35 confirmed cases of Ebola virus disease (EVD) had been reported in Équateur Province, Democratic Republic of Congo. We used reported case counts and time series from prior outbreaks to estimate the total outbreak size and duration with and without vaccine use. We modeled Ebola virus transmission using a stochastic branching process model that included reproduction numbers from past Ebola outbreaks and a particle filtering method to generate a probabilistic projection of the outbreak size and duration conditioned on its reported trajectory to date; modeled using high (62%), low (44%), and zero (0%) estimates of vaccination coverage (after deployment). Additionally, we used the time series for 18 prior Ebola outbreaks from 1976 to 2016 to parameterize the Thiel-Sen regression model predicting the outbreak size from the number of observed cases from April 4 to May 27. We used these techniques on probable and confirmed case counts with and without inclusion of suspected cases. Probabilistic projections were scored against the actual outbreak size of 54 EVD cases, using a log-likelihood score. With the stochastic model, using high, low, and zero estimates of vaccination coverage, the median outbreak sizes for probable and confirmed cases were 82 cases (95% prediction interval [PI]: 55, 156), 104 cases (95% PI: 58, 271), and 213 cases (95% PI: 64, 1450), respectively. With the Thiel-Sen regression model, the median outbreak size was estimated to be 65.0 probable and confirmed cases (95% PI: 48.8, 119.7). Among our three mathematical models, the stochastic model with suspected cases and high vaccine coverage predicted total outbreak sizes closest to the true outcome. Relatively simple mathematical models updated in real time may inform outbreak response teams with projections of total outbreak size and duration

    Patient and provider‐level barriers to hepatitis C screening and linkage to care: A mixed‐methods evaluation

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    Achieving practice change can be challenging when guidelines shift from a selective risk‐based strategy to a broader population health strategy, as occurred for hepatitis C (HCV) screening (2012‐2013). We aimed to evaluate patient and provider barriers that contributed to suboptimal HCV screening and linkage‐to‐care rates after implementation of an intervention to improve HCV screening and linkage‐to‐care processes in a large, public integrated healthcare system following the guidelines change. As part of a mixed‐methods study, we collected data through patient surveys (n = 159), focus groups (n = 9) and structured observation of providers and staff (n = 9). We used these findings to then inform domains for the second phase, which consisted of semi‐structured interviews with patients across the screening‐treatment continuum (n = 24) and providers and staff at primary care and hepatology clinics (n = 21). We transcribed and thematically analysed interviews using an integrated inductive and deductive framework. We identified lack of clarity about treatment cost, treatment complications and likelihood of cure as ongoing patient‐level barriers to screening and linkage to care. Provider‐level barriers included scepticism about establishing HCV screening as a quality metric given competing clinical priorities, particularly for patients with multiple comorbidities. However, most felt positively about adding HCV as a quality metric to enhance HCV screening and linkage to care. Provider engagement yielded suggestions for process improvements that resulted in increased stakeholder buy‐in and real‐time enhancements to the HCV screening process intervention. Systematic data collection at baseline and during practice change implementation may facilitate adoption and adaptation to improve HCV screening guideline implementation. Findings identified several key opportunities and lessons to enhance the impact of practice change interventions to improve HCV screening and treatment delivery.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155892/1/jvh13278.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155892/2/jvh13278_am.pd

    The induction of macrophage gene expression by LPS predominantly utilizes Myd88-independent signaling cascades

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    Myeloid differentiation protein-88 (MyD88) is a signal adaptor protein required for cytokine production following engagement of Toll-like receptors (TLRs) by their cognate ligands. Activation of both TLR-3 and TLR-4, however, can engage signaling events independent of MyD88 expression. The relative importance of these MyD88-dependent and -independent signaling pathways in the macrophage response to lipopolysaccharide (LPS) is unknown. Here we define these events using microarray expression profiling of LPS-stimulated macrophages taken from MyD88-null and wild-type mice. Of the 1,055 genes found to be LPS responsive, only 21.5% were dependent on MyD88 expression, with MyD88-independent genes constituting 74.7% of the genetic response. This MyD88-independent gene expression was predominantly transcriptionally regulated, as it was unaffected by cycloheximide blockade of new protein synthesis. A previously undescribed group of LPS-regulated genes (3.8%), whose induction or repression was significantly greater in the absence of MyD88, was also identified by these studies. The regulation of these genes suggested that MyD88 could serve as a molecular brake, constraining gene activity in a subset of LPS-responsive genes. The findings generated with LPS stimulation were recapitulated by exposure of macrophages to live Escherichia coli. These expression-profiling studies redefine the current dogma of TLR-4 signaling and establish that MyD88, although essential for some of the best-characterized macrophage responses to LPS, is not required for the regulation of the majority of genes engaged by macrophage exposure to endotoxin or live bacteria

    Cerebrospinal fluid biomarkers of Alzheimer\u27s disease in a cohort of adults with Down syndrome

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    Introduction: Virtually all individuals with Down syndrome (DS) will develop Alzheimer\u27s disease (AD) pathology by age 40. Cerebrospinal fluid (CSF) biomarkers have characterized AD pathology in cohorts of late-onset AD (LOAD) and autosomal-dominant AD (ADAD). Few studies have evaluated such biomarkers in adults with DS. Methods: CSF concentrations of amyloid beta (AÎČ)40, AÎČ42, tau, phospho-tau181 (p-tau), neurofilament light chain (NfL), soluble triggering receptor expressed on myeloid cells 2 (sTREM2), chitinase-3-like protein 1 (YKL-40), alpha synuclein (αSyn), neurogranin (Ng), synaptosomal-associated protein 25 (SNAP-25), and visinin-like protein 1 (VILIP-1) were assessed in CSF from 44 adults with DS from the Alzheimer\u27s Biomarker Consortium-Down Syndrome study. Biomarker levels were evaluated by cognitive status, age, and apolipoprotein E gene ( Results: Biomarker abnormalities indicative of amyloid deposition, tauopathy, neurodegeneration, synaptic dysfunction, and neuroinflammation were associated with increased cognitive impairment. Age and Discussion: The profile of many established and emerging CSF biomarkers of AD in a cohort of adults with DS was similar to that reported in LOAD and ADAD, while some differences were observed

    Mutations impairing GSK3-mediated MAF phosphorylation cause cataract, deafness, intellectual disability, seizures, and a down syndrome-like facies

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    Transcription factors operate in developmental processes to mediate inductive events and cell competence, and perturbation of their function or regulation can dramatically affect morphogenesis, organogenesis, and growth. We report that a narrow spectrum of amino-acid substitutions within the transactivation domain of the v-maf avian musculoaponeurotic fibrosarcoma oncogene homolog (MAF), a leucine zipper-containing transcription factor of the AP1 superfamily, profoundly affect development. Seven different de novo missense mutations involving conserved residues of the four GSK3 phosphorylation motifs were identified in eight unrelated individuals. The distinctive clinical phenotype, for which we propose the eponym Aymé-Gripp syndrome, is not limited to lens and eye defects as previously reported for MAF/Maf loss of function but includes sensorineural deafness, intellectual disability, seizures, brachycephaly, distinctive flat facial appearance, skeletal anomalies, mammary gland hypoplasia, and reduced growth. Disease-causing mutations were demonstrated to impair proper MAF phosphorylation, ubiquitination and proteasomal degradation, perturbed gene expression in primary skin fibroblasts, and induced neurodevelopmental defects in an in vivo model. Our findings nosologically and clinically delineate a previously poorly understood recognizable multisystem disorder, provide evidence for MAF governing a wider range of developmental programs than previously appreciated, and describe a novel instance of protein dosage effect severely perturbing developmen

    A database of microRNA expression patterns in Xenopus laevis

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    MicroRNAs (miRNAs) are short, non-coding RNAs around 22 nucleotides long. They inhibit gene expression either by translational repression or by causing the degradation of the mRNAs they bind to. Many are highly conserved amongst diverse organisms and have restricted spatio-temporal expression patterns during embryonic development where they are thought to be involved in generating accuracy of developmental timing and in supporting cell fate decisions and tissue identity. We determined the expression patterns of 180 miRNAs in Xenopus laevis embryos using LNA oligonucleotides. In addition we carried out small RNA-seq on different stages of early Xenopus development, identified 44 miRNAs belonging to 29 new families and characterized the expression of 5 of these. Our analyses identified miRNA expression in many organs of the developing embryo. In particular a large number were expressed in neural tissue and in the somites. Surprisingly none of the miRNAs we have looked at show expression in the heart. Our results have been made freely available as a resource in both XenMARK and Xenbase
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