280 research outputs found
Flight service evaluation of composite components on the Bell Helicopter model 206L: Design, fabrication and testing
The design, fabrication, and testing phases of a program to obtain long term flight service experience on representative helicopter airframe structural components operating in typical commercial environments are described. The aircraft chosen is the Bell Helicopter Model 206L. The structural components are the forward fairing, litter door, baggage door, and vertical fin. The advanced composite components were designed to replace the production parts in the field and were certified by the FAA to be operable through the full flight envelope of the 206L. A description of the fabrication process that was used for each of the components is given. Static failing load tests on all components were done. In addition fatigue tests were run on four specimens that simulated the attachment of the vertical fin to the helicopter's tail boom
Potentially important periods of change in the development of social and role functioning in youth at clinical high risk for psychosis
Sourcing illegal drugs as a hidden older user: the ideal of ‘social supply’
Aims: At a time of growing awareness regarding the non-commercial supply of illegal drugs between friends, this article explores the significance of so-called ‘social supply’ for a group of ‘hidden’ users of illegal drugs aged 40 and over.
Methodology: Semi-structured interviews were conducted with 30 users of illegal drugs aged 40 and over who were not in contact with the criminal justice system or treatment agencies regarding their use. Participants were recruited using snowball sampling.
Findings: Accessing drugs through the commercial market was considered as a less attractive proposition than social supply by the participants. The majority used only socially supplied drugs, with some engaging commercial dealers when socially supplied product was unavailable. A handful sourced drugs exclusively through the commercial market. Some were home growers of cannabis, and a small number had drifted into social supply themselves.
Conclusions: Social supply was seen in a far more favourable light than commercial transactions by our participants, and acted as an ideal against which all other acts of sourcing were compared. Moreover, social supply was often an integral facet of the drug using experience and served to validate and enhance that experience. The relatively benign, non-predatory nature of the social supply engaged in by the participants lends support to calls for some reform of the offence of supply in UK law
Neurobehavioral risk factors influence prevalence and severity of hazardous substance use in youth at genetic and clinical high risk for psychosis
BackgroundElevated rates of alcohol, tobacco, and cannabis use are observed in both patients with psychotic disorders and individuals at clinical high risk for psychosis (CHR-P), and strong genetic associations exist between substance use disorders and schizophrenia. While individuals with 22q11.2 deletion syndrome (22qDel) are at increased genetic risk for psychosis, initial evidence suggests that they have strikingly low rates of substance use. In the current study, we aimed to directly compare substance use patterns and their neurobehavioral correlates in genetic and clinical high-risk cohorts.MethodsData on substance use frequency and severity, clinical symptoms, and neurobehavioral measures were collected at baseline and at 12-month follow-up visits in two prospective longitudinal cohorts: participants included 89 22qDel carriers and 65 age and sex-matched typically developing (TD) controls (40.67% male, Mage = 19.26 ± 7.84 years) and 1,288 CHR-P youth and 371 matched TD controls from the North American Prodrome Longitudinal Study-2 and 3 (55.74% male; Mage = 18.71 ± 4.27 years). Data were analyzed both cross-sectionally and longitudinally using linear mixed effects models.ResultsControlling for age, sex, and site, CHR-P individuals had significantly elevated rates of tobacco, alcohol, and cannabis use relative to TD controls, whereas 22qDel had significantly lower rates. Increased substance use in CHR-P individuals was associated with increased psychosis symptom severity, dysphoric mood, social functioning, and IQ, while higher social anhedonia was associated with lower substance use across all domains at baseline. These patterns persisted when we investigated these relationships longitudinally over one-year. CHR-P youth exhibited significantly increased positive psychosis symptoms, dysphoric mood, social functioning, social anhedonia, and IQ compared to 22qDel carriers, and lower rates of autism spectrum disorder (ASD) compared to 22qDel carriers, both at baseline and at 1 year follow-up.ConclusionIndividuals at genetic and CHR-P have strikingly different patterns of substance use. Factors such as increased neurodevelopmental symptoms (lower IQ, higher rates of ASD) and poorer social functioning in 22qDel may help explain this distinction from substance use patterns observed in CHR-P individuals
Free vibration analysis of an embarked rotating composite shaft using the hp-version of the FEM
‘Because it’s fun’: English and American girls’ counter-hegemonic stories of alcohol and marijuana use
Girls’ alcohol and other drug (AOD) use are depicted culturally as problematic. In this comparative, qualitative, study the voices of 59 English and American justice-involved girls give a counter-hegemonic portrayal of their alcohol and marijuana use. In their stories we see how their AOD use is pleasurable and boundaried. AOD use involves negotiated risk within the situated context of shared experience and friendship networks that heighten and promote pleasure and fun. The findings offer the opportunity to address the ‘credibility gap’ (Measham 2006) in international health promotion policy. Our aim is to promote the adoption of policy approaches that recognize the complexity of girls’ lives and draw on strategies they have devised
Reporting bias in medical research - a narrative review
Reporting bias represents a major problem in the assessment of health care interventions. Several prominent cases have been described in the literature, for example, in the reporting of trials of antidepressants, Class I anti-arrhythmic drugs, and selective COX-2 inhibitors. The aim of this narrative review is to gain an overview of reporting bias in the medical literature, focussing on publication bias and selective outcome reporting. We explore whether these types of bias have been shown in areas beyond the well-known cases noted above, in order to gain an impression of how widespread the problem is. For this purpose, we screened relevant articles on reporting bias that had previously been obtained by the German Institute for Quality and Efficiency in Health Care in the context of its health technology assessment reports and other research work, together with the reference lists of these articles
Cholecystectomy during ceftriaxone therapy. A translational study with a new rabbit model
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