257 research outputs found

    Flight assessment of a large supersonic drone aircraft for research use

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    An assessment is made of the capabilities of the BQM-34E supersonic drone aircraft as a test bed research vehicle. This assessment is made based on a flight conducted for the purpose of obtaining flight test measurements of wing loads at various maneuver flight conditions. Flight plan preparation, flight simulation, and conduct of the flight test are discussed along with a presentation of the test data obtained and an evaluation of how closely the flight test followed the test plan

    Strain-gage bridge calibration and flight loads measurements on a low-aspect-ratio thin wing

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    Strain-gage bridges were used to make in-flight measurements of bending moment, shear, and torque loads on a low-aspect-ratio, thin, swept wing having a full depth honeycomb sandwich type structure. Standard regression analysis techniques were employed in the calibration of the strain bridges. Comparison of the measured loads with theoretical loads are included

    A Digital Program for Calculating the Interaction Between Flexible Structures, Unsteady Aerodynamics and Active Controls

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    A computer program, ISAC, is described which calculates the stability and response of a flexible airplane equipped with active controls. The equations of motion relative to a fixed inertial coordinate system are formulated in terms of the airplane's rigid body motion and its unrestrained normal vibration modes. Unsteady aerodynamic forces are derived from a doublet lattice lifting surface theory. The theoretical basis for the program is briefly explained together with a description of input data and output results

    Parkinson\u27s Disease in Louisiana, 1999-2012: Based on Hospital Primary Discharge Diagnoses, Incidence, and Risk in Relation to Local Agricultural Crops, Pesticides, and Aquifer Recharge

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    The two major causes of Parkinson\u27s disease (PD) are genetic susceptibility and exposure to agricultural pesticides. Access to 23,224 individuals\u27 hospital primary discharge diagnoses of PD allowed the mapping of cases against known crop distributions and pesticides. Our main objective was to map PD risks (cases per 10,000 people) against crops and their pesticides. The ZIP Code address locations, and the 2000 and 2010 census data, were used to map the risks of PD throughout Louisiana and in relation to United States Department of Agriculture (USDA)-recorded crops. The introduction of glyphosate-resistant crops appears to have initiated the PD disappearance from northeastern parishes on the west bank of the Mississippi river. Rice and sugar cane are seemingly unassociated with PD, as is the Mississippi itself, except for Jefferson and St. Charles Parishes, which are essentially urban or industrial. The present major PD-affected areas are associated with commercial forests, woodlands, and pastures, and thus with certain arbor-pastoral pesticides, 2,4-D, chlorpyrifos, and paraquat. Human populations at maximum risk are those living in areas of moderate and high aquifer-recharge potential. The levels of estimated pesticide exposure in these recharge areas we were able to access were of variable use, but significant amounts of 2,4-D were being used

    STABCAR: A program for finding characteristic root systems having transcendental stability matrices

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    STABCAR can be used to determine the characteristic roots of flexible, actively controlled aircraft, including the effects of unsteady aerodynamics. A modal formulation and a transfer-matrix representation of the control system are employed. Operable in either a batch or an interactive mode, STABCAR can provide graphical or tabular output of the variation of the roots with velocity, density, altitude, dynamic pressure or feedback gains. Herein the mathematical model, program structure, input requirements, output capabilities, and a series of sample cases are detailed. STABCAR was written for use on CDC CYBER 175 equipment; modification would be required for operation on other machines

    Trends in Chondrichthyan Research: An Analysis of Three Decades of Conference Abstracts

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    Given the conservation status and ecological, cultural, and commercial importance of chondrichthyan fishes, it is valuable to evaluate the extent to which research attention is spread across taxa and geographic locations and to assess the degree to which scientific research is appropriately addressing the challenges they face. Here we review trends in research effort over three decades (1985–2016) through content analysis of every abstract (n = 2,701) presented at the annual conference of the American Elasmobranch Society (AES), the oldest and largest professional society focused on the scientific study and management of these fishes. The most common research areas of AES abstracts were reproductive biology, movement/telemetry, age and growth, population genetics, and diet/feeding ecology, with different areas of focus for different study species or families. The most commonly studied species were large and charismatic (e.g., White Shark, Carcharodon carcharias), easily accessible to long-term established field research programs (e.g., Lemon Shark, Negaprion brevirostris, and Sandbar Shark, Carcharhinus plumbeus), or easily kept in aquaria for lab-based research (e.g., Bonnethead Shark, Sphyrna tiburo). Nearly 90% of all described chondrichthyan species have never been mentioned in an AES abstract, including some of the most threatened species in the Americas. The proportion of female* first authors has increased over time, though many current female* Society members are graduate students. Nearly half of all research presented at AES occurred in the waters of the United States rather than in the waters of developing nations where there are more threatened species and few resources for research or management. Presentations based on research areas such as paleontology and aquarium-based research have declined in frequency over time, and identified research priorities such as social science and interdisciplinary research are poorly represented. Possible research gaps and future research priorities for the study of chondrichthyan fishes are also discussed

    Alcohol consumption after health deterioration in older adults: a mixed-methods study

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    Objective To examine if and how older adults modify their drinking after health deterioration, and the factors that motivate changing or maintaining stable drinking behaviour. Study design Explanatory follow-up mixed-methods research. Methods The association between health deterioration and changes in alcohol consumption was examined using secondary data from the English Longitudinal Study of Ageing, a biennial prospective cohort study of a random sample of adults aged 50 years and older living in England. Data were collected through a personal interview and self-completion questionnaire across three waves between 2004 and 2009. The sample size (response rate) across the three waves was 8781 (49.9%), 7168 (40.3%) and 6623 (37.3%). The Chi-squared test was used to examine associations between diagnosis with a long-term condition or a worsening of self-rated health (e.g. from good to fair or fair to poor) and changes in drinking frequency (e.g. everyday, 5–6 days per week, etc.) and volume (ethanol consumed on a drinking day) between successive waves. In-depth interviews with 19 older adults recently diagnosed with a long-term condition were used to explore the factors that influenced change or maintenance in alcohol consumption over time. A purposive sampling strategy was used to recruit a diverse sample of current and former drinkers from voluntary and community organizations in the north of England. An inductive approach was used to analyze the data, facilitating the development of an a posteriori framework for understanding drinking change. Results There was no significant relationship between health deterioration and changes in drinking volume over time. There was however a significant association between health deterioration and changes in drinking frequency between successive waves (χ2 = 15.24, P < 0.001 and χ2 = 17.28, P < 0.001). For example, of participants reporting health deterioration between the first two waves, 47.6% had stable drinking frequency, 23.4% increased their drinking frequency and 29% reported decreased drinking frequency. In comparison, of participants reporting no health deterioration, 52.7% reported stable frequency, 20.8% increased frequency and 26.4% decreased frequency. In qualitative interviews, older adults described a wide range of factors that influence changes in drinking behaviour: knowledge gained from talking to healthcare professionals, online and in the media; tangible negative experiences that were attributed to drinking; mood and emotions (e.g. joy); the cost of alcohol; pub closures; and changes in social roles and activities. Health was just one part of a complex mix of factors that influenced drinking among older adults. Conclusion Patterns of drinking change after health deterioration in older adults are diverse, including stable, increasing and decreasing alcohol consumption over time. Although health motivations to change drinking influence behaviour in some older adults, social and financial motivations to drink are also important in later life and thus a holistic approach is required to influence behaviour

    Parent-reported health care expenditures associated with autism spectrum disorders in Heilongjiang province, China

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    <p>Abstract</p> <p>Background</p> <p>The aim of this study was to determine the health expenses incurred by families with children with autism spectrum disorder (ASD) and those expenses' relation to total household income and expenditures.</p> <p>Methods</p> <p>In this cross-sectional study, health care expenditure data were collected through face-to-face interviews. Expenses included annual costs for clinic visits, medication, behavioral therapy, transportation, and accommodations. Health care costs as a percentage of total household income and expenditures were also determined. The participants included 290 families with ASD children who were treated at the Children Development and Behavior Research Center, Harbin Medical University, China.</p> <p>Results</p> <p>Families with ASD children from urban and rural areas had higher per-capita household expenditures by 60.8% and 74.7%, respectively, compared with provincial statistics for 2007. Behavioral therapy accounted for the largest proportion of health expenses (54.3%) for ASD children. In 19.9% of urban and 38.2% of rural families, health care costs exceeded the total annual household income. Most families (89.3% of urban families; 88.1% of rural families) in that province reported higher health care expenditures than the provincial household average.</p> <p>Conclusion</p> <p>For families with ASD children, the economic burden of health care is substantially higher than the provincial average.</p

    MAKING ANIMALS ALCOHOLIC: SHIFTING LABORATORY MODELS OF ADDICTION

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    The use of animals as experimental organisms has been critical to the development of addiction research from the nineteenth century. They have been used as a means of generating reliable data regarding the processes of addiction that was not available from the study of human subjects. Their use, however, has been far from straightforward. Through focusing on the study of alcoholism, where the nonhuman animal proved a most reluctant collaborator, this paper will analyze the ways in which scientists attempted to deal with its determined sobriety and account for their consistent failure to replicate the volitional consumption of ethanol to the point of physical dependency. In doing so, we will see how the animal model not only served as a means of interrogating a complex pathology, but also came to embody competing definitions of alcoholism as a disease process, and alternative visions for the very structure and purpose of a research field

    The Impact of Thyroid Cancer and Post-Surgical Radioactive Iodine Treatment on the Lives of Thyroid Cancer Survivors: A Qualitative Study

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    BACKGROUND: Adjuvant treatment with radioactive iodine (RAI) is often considered in the treatment of well-differentiated thyroid carcinoma (WDTC). We explored the recollections of thyroid cancer survivors on the diagnosis of WDTC, adjuvant radioactive iodine (RAI) treatment, and decision-making related to RAI treatment. Participants provided recommendations for healthcare providers on counseling future patients on adjuvant RAI treatment. METHODS: We conducted three focus group sessions, including WDTC survivors recruited from two Canadian academic hospitals. Participants had a prior history of WDTC that was completely resected at primary surgery and had been offered adjuvant RAI treatment. Open-ended questions were used to generate discussion in the groups. Saturation of major themes was achieved among the groups. FINDINGS: There were 16 participants in the study, twelve of whom were women (75%). All but one participant had received RAI treatment (94%). Participants reported that a thyroid cancer diagnosis was life-changing, resulting in feelings of fear and uncertainty. Some participants felt dismissed as not having a serious disease. Some participants reported receiving conflicting messages from healthcare providers on the appropriateness of adjuvant RAI treatment or insufficient information. If RAI-related side effects occurred, their presence was not legitimized by some healthcare providers. CONCLUSIONS: The diagnosis and treatment of thyroid cancer significantly impacts the lives of survivors. Fear and uncertainty related to a cancer diagnosis, feelings of the diagnosis being dismissed as not serious, conflicting messages about adjuvant RAI treatment, and treatment-related side effects, have been raised as important concerns by thyroid cancer survivors
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