CHANDRA Observations of X-ray Jet Structure on kpc to Mpc Scales

With its exquisite spatial resolution of better than 0.5 arcsecond, the Chandra observatory is uniquely capable of resolving and studying the spatial structure of extragalactic X-ray jets on scales of a few to a few hundred kilo-parsec. Our analyses of four recent Chandra images of quasar jets interpret the X-ray emission as inverse Compton scattering of high energy electrons on the cosmic microwave background. We infer that these jets are in bulk relativistic motion, carrying kinetic powers upwards of 10^46 ergs/s to distances of hundreds of kpc, with very high efficiency.Comment: 4 pages, 3 figures, to be published in the proceedings of the Bologna jet workshop, "The Physics of Relativistic Jets in the CHANDRA and XMM Era.

Towards a killer app for the Semantic Web

Killer apps are highly transformative technologies that create new markets and widespread patterns of behaviour. IT generally, and the Web in particular, has benefited from killer apps to create new networks of users and increase its value. The Semantic Web community on the other hand is still awaiting a killer app that proves the superiority of its technologies. There are certain features that distinguish killer apps from other ordinary applications. This paper examines those features in the context of the Semantic Web, in the hope that a better understanding of the characteristics of killer apps might encourage their consideration when developing Semantic Web applications

Access to substance use treatment among young adults who use prescription opioids non-medically

BACKGROUND: Non-medical prescription opioid (NMPO) use is a substantial public health problem in the United States, with 1.5 million new initiates annually. Only 746,000 people received treatment for NMPO use in 2013, demonstrating substantial disparities in access to treatment. This study aimed to assess correlates of accessing substance use treatment among young adult NMPO users in Rhode Island, a state heavily impacted by NMPO use and opioid overdose. METHODS: This analysis uses data from a study of 200 Rhode Island residents aged 18 to 29 who reported NMPO use in the past 30 days. We compared individuals who had ever successfully enrolled in a substance use treatment program without ever facing barriers, individuals who had ever attempted to enroll but were unable, and individuals who never attempted to enroll. We used multinomial logistic regression to determine the independent correlates of never attempting and unsuccessfully attempting to access substance use treatment. RESULTS: Among 200 participants, the mean age was 24.5, 65.5% were male, and 61.5% were white. Nearly half (45.5%) had never attempted to enroll in substance use treatment, while 35.0% had successfully enrolled without ever facing barriers and 19.5% were unsuccessful in at least one attempt to enroll. In multivariable models, non-white participants were more likely to never have attempted to enroll compared to white participants. Previous incarceration, experiencing drug-related discrimination by the medical community, and a monthly income of $501 -$1500 were associated with a decreased likelihood of never attempting to enroll. A history of overdose and a monthly income of $501 -$1500 were associated with an increased likelihood of unsuccessfully accessing treatment. The most commonly reported barriers to accessing treatment were waiting lists (n = 23), health insurance not approving enrollment (n = 20), and inability to pay (n = 16). CONCLUSIONS: This study demonstrates significant disparities in access to treatment among young adults who report NMPO use. A history of overdose was shown to correlate with experiencing barriers to substance use treatment utilization. Interventions are needed to reduce drug-related discrimination in clinical settings and to provide mechanisms that link young adults (particularly with a history of overdose) to evidence-based treatment

The Health Belief Model Applied to Understanding Diabetes Regimen Compliance

Inadequate adherence to prescribed treatment plans is perhaps the most serious obstacle to achieving success ful therapeutic outcomes, and non compliance by diabetic patients is no exception. This is partly based on pa tients' realization that compliance does not necessarily result in lack of illness. A psychosocial framework for under standing patient compliance is the Health Belief Model, which is based upon the value an individual places on the identified goal and the likelihood that compliance will achieve that goal. This Model has been useful to explain noncompliance, to make an "educa tional diagnosis," and for designing compliance-enhancing interventions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68410/2/10.1177_014572178501100108.pd

Determining patterns in the composition of dissolved organic matter in fresh waters according to land use and management

In fresh waters, the origins of dissolved organic matter (DOM) have been found to exert a fundamental control on its reactivity, and ultimately, its ecosystem functional role. A detailed understanding of landscape scale factors that control the export of DOM to aquatic ecosystems is, therefore, pivotal if the effects of DOM flux to fresh waters are to be fully understood. In this study we present data from a national sampling campaign across the United Kingdom in which we explore the variability in DOM composition in three broad landscape types defined by similar precipitation, geology, land use and management, hydrology, and nutrient enrichment status. We characterised samples from fifty-one sites, grouping them into one of three major underlying classifications: circumneutral streams underlain by clay and mudstone (referred to as ‘clay’), alkaline streams underlain by Cretaceous Chalk or by Carboniferous or Jurassic Limestone (‘limestone’), and acidic streams in peatland catchments underlain by a range of low permeability lithologies (‘peat’). DOM composition was assessed through organic matter stoichiometry (organic carbon: organic nitrogen; organic carbon: organic phosphorus; C/N(P)DOM) and metrics derived from ultra-violet (UV)/visible spectroscopic analysis of DOM such as specific UV absorption (a254 nm; SUVA254). We found similar SUVA254, C/NDOM and DOM/a254 relationships within classifications, demonstrating that despite a large degree of heterogeneity within environments, catchments with shared environmental character and anthropogenic disturbance export DOM with a similar composition and character. Improving our understanding of DOM characterisation is important to help predict shifts in stream ecosystem function, and ecological responses to enrichment or mitigation efforts and how these may result in species composition shifts and biodiversity loss in freshwater ecosystems

The Muonium Atom as a Probe of Physics beyond the Standard Model

The observed interactions between particles are not fully explained in the successful theoretical description of the standard model to date. Due to the close confinement of the bound state muonium ($M = \mu^+ e^-$) can be used as an ideal probe of quantum electrodynamics and weak interaction and also for a search for additional interactions between leptons. Of special interest is the lepton number violating process of sponteanous conversion of muonium to antimuonium.Comment: 15 pages,6 figure

Disseminated Effects in Agent Based Models: A Potential Outcomes Framework and Application to Inform Pre-Exposure Prophylaxis Coverage Levels for HIV Prevention

Pre-exposure prophylaxis (PrEP) for HIV prevention may not only benefit the individual who uses it, but also their uninfected sexual risk contacts. We developed an agent-based model using a novel trial emulation approach to quantify disseminated effects of PrEP use among men who have sex with men in Atlanta, USA from 2015 to 2017. Components (subsets of agents connected through partnerships in a sexual network, but not sharing partnerships with any other agents) were first randomized to an intervention coverage level or control, then within intervention components, eligible agents were randomized to PrEP. We estimated direct and disseminated (indirect) effects using randomization-based estimators and reported corresponding 95% simulation intervals across scenarios ranging from 10% to 90% coverage in the intervention components. A population of 11,245 agents was simulated with an average of 1,551 components identified. Comparing agents randomized to PrEP in 70% coverage components to control agents, there was a 15% disseminated risk reduction in HIV incidence (95% simulation intervals = 0.65, 1.05). Individuals not on PrEP may receive a protective benefit by being in a sexual network with higher PrEP coverage. Agent-based models are useful to evaluate possible direct and disseminated effects of HIV prevention modalities in sexual networks

HIV-Related Stigma Among Healthcare Providers in Different Healthcare Settings: A Cross-Sectional Study in Kerman, Iran

Background: Stigmatizing attitudes among healthcare providers are an important barrier to accessing services among people living with HIV (PLHIV). This cross-sectional study aimed to assess the status and correlates of HIV-related stigma among healthcare providers in Kerman, Iran.Methods: Using a validated and pilot-tested stigma scale questionnaire, we measured HIV-related stigma among 400 healthcare providers recruited from three teaching hospitals (n = 363), private sectors (n = 28), and the only voluntary counseling and testing (VCT) center (n = 9) in Kerman city. Data were gathered using self-administered questionnaires at participants’ workplace during Fall 2016. To examine the correlates of stigmatizing attitudes, we constructed bivariable and multivariable linear regression models. Results: The mean ± standard deviation (SD) of stigma score was 25.95 ± 7.20 out of the possible 50, with higher scores reflecting more stigmatizing attitudes. Paramedics, nurses’ aides, and housekeeping staff had the highest, and VCT personnel had the lowest average stigma scores, respectively. Multivariable regression analyses showed that prior experience of working with PLHIV (β = -2.48; P = .03), exposure to HIV-related educational courses (β = -2.03; P = .02), and <10 years of work experience (β = -2.70; P < .001) were associated with lower stigma scores.Conclusion: Our findings highlight the need for health managers to provide training opportunities for healthcare providers, including programs that focus on improving HIV-related knowledge for healthcare providers. Enforcing policies that aim to reduce HIV-related stigma and discrimination among healthcare providers in Iran are urgently needed