322 research outputs found

    Modelling Illegal Drug Participation

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    We contribute to the small, but important, literature exploring the incidence and implications of misreporting in survey data. Specifically, when modelling ‘social bads’, such as illegal drug consumption, researchers are often faced with exceptionally low reported participation rates. We propose a modelling framework where firstly an individual decides whether to participate or not and, secondly, for participants there is a subsequent decision to misreport or not. We explore misreporting in the context of the consumption of a system of drugs and specify a multivariate inflated probit model. Compared with observed participation rates of 12.2%, 3.2% and 1.3% (for use of marijuana, speed and cocaine respectively) the true participation rates are estimated to be almost double for marijuana (23%), and more than double for speed (8%) and cocaine (5%). The estimated chances that a user would misreport their participation is a staggering 65% for a hard drug like cocaine, and still about 31% and 17%, for the softer drugs of marijuana and speed

    Long-term Safety of Epoetin Alfa-epbx for the Treatment of Anemia in ESKD: Pooled Analyses of Randomized and Open-label Studies

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    Rationale & Objective Epoetin alfa-epbx is a biosimilar to the reference product, epoetin alfa. We compare the safety of epoetin alfa-epbx versus epoetin alfa based on a pooled analysis of findings from 2 randomized, double-blind, comparative clinical studies, and report new data for the long-term safety of epoetin alfa-epbx. Study Design Pooled analyses of previously conducted studies. Setting & Participants Hemodialysis patients with anemia. Interventions Data from patients who received 1 or more subcutaneous or intravenous doses of study drug were integrated across route of administration in combined randomized groups (epoetin alfa-epbx, n = 423; epoetin alfa, n = 426). Data from patients who received 1 or more doses of epoetin alfa-epbx in either open-label extension trial were integrated across route of administration in a combined long-term safety studies group (n = 576). Outcomes Adverse events (AEs), immunogenicity, and other outcomes were assessed. Results Incidences of treatment-emergent AEs, serious AEs, and discontinuation of study drug treatment because of treatment-emergent AEs were similar between combined randomized epoetin alfa-epbx and epoetin alfa, which had mean treatment durations of 18.1 and 17.7 weeks, respectively. Incidences of treatment-emergent AEs, serious AEs, and discontinuation of study drug treatment because of treatment-emergent AEs were 86.5%, 39.4%, and 6.6%, respectively, for the combined long-term safety studies group, which had a mean treatment duration of 40.0 weeks. In total, 12 patients across the combined randomized groups (epoetin alfa-epbx, n = 5; epoetin alfa, n = 7) and 9 patients in the combined long-term safety studies group tested anti-recombinant human erythropoietin antibody positive in 1 or more visits during study conduct. No patient in any group developed neutralizing antibodies or pure red blood cell aplasia. Limitations Epoetin alfa comparator not included in the long-term safety studies, greater cumulative exposure to study drug for epoetin alfa-epbx, shorter follow-up in the randomized studies, and potential for selection bias among patients in the open-label long-term safety studies. Conclusions This analysis reinforces previous conclusions of similar safety profiles between epoetin alfa-epbx and epoetin alfa. Furthermore, epoetin alfa-epbx had no unexpected safety signals during long-term treatment

    Towards an understanding of contextual features that influence the linguistic formality of British Sign Language users

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    This paper seeks to understand linguistic formality through the identification and measurement of contextual features. Using an adapted sociometric methodology to combine systemic functional linguistics and sign linguistics, a survey identifies the elements of context that have an effect upon the level of linguistic formality employed by British Sign Language users. The responses of 51 participants are analysed in order to ascertain (i) the level of linguistic formality that would be employed in certain communicative scenarios, and (ii) the contextual features of these scenarios that have an influence on linguistic formality. The results obtained from this study posit that there is an overall agreement shared between British Sign Language users when choosing levels of linguistic formality based on broad contextual description alone. The people involved in the communication and their interpersonal relationships tend to be the biggest influence on the level of formality employed, whereas the topic of the interaction appears to show no significant influence upon linguistic formality on its own. This work contributes further evidence to the importance of studying language within communicative contexts and the importance of formality as an influential factor in linguistic production. It is hoped that this will encourage future studies to derive linguistic data of British Sign Language users, or indee

    High school drinking mediates the relationship between parental monitoring and college drinking: A longitudinal analysis

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    <p>Abstract</p> <p>Background</p> <p>College drinking is a significant public health problem. Although parental monitoring and supervision reduces the risk for alcohol consumption among younger adolescents, few studies have investigated the impact of earlier parental monitoring on later college drinking. This study examined whether parental monitoring indirectly exerts a protective effect on college drinking by reducing high school alcohol consumption.</p> <p>Methods</p> <p>A longitudinal cohort of 1,253 male and female students, ages 17 to 19, attending a large, public, mid-Atlantic university was studied at two time points. First, data on high school parental monitoring and alcohol consumption were gathered via questionnaire during the summer prior to college entry. Second, during the first year of college, past-year alcohol consumption was measured via a personal interview. Multiple regression models tested the relationship between parental monitoring and past year alcohol use (i.e., number of drinks per drinking day).</p> <p>Results</p> <p>Holding constant demographics, SAT score, and religiosity, parental monitoring had a significant protective effect on both high school and college drinking level. However, the association between parental monitoring and college drinking level became non-significant once high school drinking level was held constant.</p> <p>Conclusion</p> <p>While parental monitoring did not directly influence college alcohol consumption, evidence for mediation was observed, whereby parental monitoring had an indirect influence on college drinking through reductions in high school drinking. Initiatives that promote effective parenting might be an important strategy to curb high-risk drinking among older adolescents. More research is needed to understand the nature and degree of parent-child communication that is necessary to extend the protective influence of parents into the college years.</p

    Maternal substance use and integrated treatment programs for women with substance abuse issues and their children: a meta-analysis

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    <p>Abstract</p> <p>Background</p> <p>The rate of women with substance abuse issues is increasing. Women present with a unique constellation of risk factors and presenting needs, which may include specific needs in their role as mothers. Numerous integrated programs (those with substance use treatment and pregnancy, parenting, or child services) have been developed to specifically meet the needs of pregnant and parenting women with substance abuse issues. This synthesis and meta-analysis reviews research in this important and growing area of treatment.</p> <p>Methods</p> <p>We searched PsycINFO, MedLine, PubMed, Web of Science, EMBASE, Proquest Dissertations, Sociological Abstracts, and CINAHL and compiled a database of 21 studies (2 randomized trials, 9 quasi-experimental studies, 10 cohort studies) of integrated programs published between 1990 and 2007 with outcome data on maternal substance use. Data were summarized and where possible, meta-analyses were performed, using standardized mean differences (<it>d</it>) effect size estimates.</p> <p>Results</p> <p>In the two studies comparing integrated programs to no treatment, effect sizes for urine toxicology and percent using substances significantly favored integrated programs and ranged from 0.18 to 1.41. Studies examining changes in maternal substance use from beginning to end of treatment were statistically significant and medium sized. More specifically, in the five studies measuring severity of drug and alcohol use, the average effect sizes were 0.64 and 0.40, respectively. In the four cohort studies of days of use, the average effect size was 0.52. Of studies comparing integrated to non-integrated programs, four studies assessed urine toxicology and two assessed self-reported abstinence. Overall effect sizes for each measure were not statistically significant (<it>d </it>= -0.09 and 0.22, respectively).</p> <p>Conclusions</p> <p>Findings suggest that integrated programs are effective in reducing maternal substance use. However, integrated programs were not significantly more effective than non-integrated programs. Policy implications are discussed with specific attention to the need for funding of high quality randomized control trials and improved reporting practices.</p

    Evaluation and Treatment of Iron Deficiency Anemia: A Gastroenterological Perspective

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    A substantial volume of the consultations requested of gastroenterologists are directed towards the evaluation of anemia. Since iron deficiency anemia often arises from bleeding gastrointestinal lesions, many of which are malignant, establishment of a firm diagnosis usually obligates an endoscopic evaluation. Although the laboratory tests used to make the diagnosis have not changed in many decades, their interpretation has, and this is possibly due to the availability of extensive testing in key populations. We provide data supporting the use of the serum ferritin as the sole useful measure of iron stores, setting the lower limit at 100 μg/l for some populations in order to increase the sensitivity of the test. Trends of the commonly obtained red cell indices, mean corpuscular volume, and the red cell distribution width can provide valuable diagnostic information. Once the diagnosis is established, upper and lower gastrointestinal endoscopy is usually indicated. Nevertheless, in many cases a gastrointestinal source is not found after routine evaluation. Additional studies, including repeat upper and lower endoscopy and often investigation of the small intestine may thus be required. Although oral iron is inexpensive and usually effective, there are many gastrointestinal conditions that warrant treatment of iron deficiency with intravenous iron

    Water in star-forming regions: physics and chemistry from clouds to disks as probed by Herschel spectroscopy

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    Context. Water is a key molecule in the physics and chemistry of star and planet formation, but it is difficult to observe from Earth. The Herschel Space Observatory provided unprecedented sensitivity as well as spatial and spectral resolution to study water. The Water In Star-forming regions with Herschel (WISH) key program was designed to observe water in a wide range of environments and provide a legacy data set to address its physics and chemistry. Aims. The aim of WISH is to determine which physical components are traced by the gas-phase water lines observed with Herschel and to quantify the excitation conditions and water abundances in each of these components. This then provides insight into how and where the bulk of the water is formed in space and how it is transported from clouds to disks, and ultimately comets and planets. Methods. Data and results from WISH are summarized together with those from related open time programs. WISH targeted ~80 sources along the two axes of luminosity and evolutionary stage: from low- to high-mass protostars (luminosities from 10^5 L⊙) and from pre-stellar cores to protoplanetary disks. Lines of H2O and its isotopologs, HDO, OH, CO, and [O I], were observed with the HIFI and PACS instruments, complemented by other chemically-related molecules that are probes of ultraviolet, X-ray, or grain chemistry. The analysis consists of coupling the physical structure of the sources with simple chemical networks and using non-LTE radiative transfer calculations to directly compare models and observations. Results. Most of the far-infrared water emission observed with Herschel in star-forming regions originates from warm outflowing and shocked gas at a high density and temperature (> 10^5 cm−3, 300–1000 K, v ~ 25 km s−1), heated by kinetic energy dissipation. This gas is not probed by single-dish low-J CO lines, but only by CO lines with Jup > 14. The emission is compact, with at least two different types of velocity components seen. Water is a significant, but not dominant, coolant of warm gas in the earliest protostellar stages. The warm gas water abundance is universally low: orders of magnitude below the H2O/H2 abundance of 4 × 10^−4 expected if all volatile oxygen is locked in water. In cold pre-stellar cores and outer protostellar envelopes, the water abundance structure is uniquely probed on scales much smaller than the beam through velocity-resolved line profiles. The inferred gaseous water abundance decreases with depth into the cloud with an enhanced layer at the edge due to photodesorption of water ice. All of these conclusions hold irrespective of protostellar luminosity. For low-mass protostars, a constant gaseous HDO/H2O ratio of ~0.025 with position into the cold envelope is found. This value is representative of the outermost photodesorbed ice layers and cold gas-phase chemistry, and much higher than that of bulk ice. In contrast, the gas-phase NH3 abundance stays constant as a function of position in low-mass pre- and protostellar cores. Water abundances in the inner hot cores are high, but with variations from 5 × 10^−6 to a few × 10^−4 for low- and high-mass sources. Water vapor emission from both young and mature disks is weak. Conclusions. The main chemical pathways of water at each of the star-formation stages have been identified and quantified. Low warm water abundances can be explained with shock models that include UV radiation to dissociate water and modify the shock structure. UV fields up to 10^2−10^3 times the general interstellar radiation field are inferred in the outflow cavity walls on scales of the Herschel beam from various hydrides. Both high temperature chemistry and ice sputtering contribute to the gaseous water abundance at low velocities, with only gas-phase (re-)formation producing water at high velocities. Combined analyses of water gas and ice show that up to 50% of the oxygen budget may be missing. In cold clouds, an elegant solution is that this apparently missing oxygen is locked up in larger μm-sized grains that do not contribute to infrared ice absorption. The fact that even warm outflows and hot cores do not show H2O at full oxygen abundance points to an unidentified refractory component, which is also found in diffuse clouds. The weak water vapor emission from disks indicates that water ice is locked up in larger pebbles early on in the embedded Class I stage and that these pebbles have settled and drifted inward by the Class II stage. Water is transported from clouds to disks mostly as ice, with no evidence for strong accretion shocks. Even at abundances that are somewhat lower than expected, many oceans of water are likely present in planet-forming regions. Based on the lessons for galactic protostars, the low-J H2O line emission (Eup < 300 K) observed in extragalactic sources is inferred to be predominantly collisionally excited and to originate mostly from compact regions of current star formation activity. Recommendations for future mid- to far-infrared missions are made
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