2,648 research outputs found

    A Framework for Assessment of Aviation Safety Technology Portfolios

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    The programs within NASA's Aeronautics Research Mission Directorate (ARMD) conduct research and development to improve the national air transportation system so that Americans can travel as safely as possible. NASA aviation safety systems analysis personnel support various levels of ARMD management in their fulfillment of system analysis and technology prioritization as defined in the agency's program and project requirements. This paper provides a framework for the assessment of aviation safety research and technology portfolios that includes metrics such as projected impact on current and future safety, technical development risk and implementation risk. The paper also contains methods for presenting portfolio analysis and aviation safety Bayesian Belief Network (BBN) output results to management using bubble charts and quantitative decision analysis techniques

    Object-Oriented Bayesian Networks (OOBN) for Aviation Accident Modeling and Technology Portfolio Impact Assessment

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    The concern for reducing aviation safety risk is rising as the National Airspace System in the United States transforms to the Next Generation Air Transportation System (NextGen). The NASA Aviation Safety Program is committed to developing an effective aviation safety technology portfolio to meet the challenges of this transformation and to mitigate relevant safety risks. The paper focuses on the reasoning of selecting Object-Oriented Bayesian Networks (OOBN) as the technique and commercial software for the accident modeling and portfolio assessment. To illustrate the benefits of OOBN in a large and complex aviation accident model, the in-flight Loss-of-Control Accident Framework (LOCAF) constructed as an influence diagram is presented. An OOBN approach not only simplifies construction and maintenance of complex causal networks for the modelers, but also offers a well-organized hierarchical network that is easier for decision makers to exploit the model examining the effectiveness of risk mitigation strategies through technology insertions

    The Development of Trust in the Nurse-Patient Relationship with Hospitalized Mexican American Patients

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    The Hispanic population in the United States is growing and this population experiences health care disparities compared to non-Hispanic Whites. Mexican Americans are the largest sub-group of Hispanics and providing nursing care that is patient-centered and culturally competent is important when caring for this population. Trust is an important component of patient-centered care and culturally competent care as well as a major element , (confianza) in the Hispanic culture. Although nursing researchers have identified the need for trust in culturally competent care with Mexican American patients, none have explored how trust develops between the nurse and the Mexican American patient. The classical grounded theory methodology was used to explore the process of the development of interpersonal trust between the nurse and the hospitalized Mexican American patient. Twenty-two English-speaking Mexican American patients hospitalized at least two days on an obstetric or medical-surgical unit in a hospital in the Midwestern United States were interviewed using a semi-structured interview guide. Through data analysis using constant comparison, a model emerged that explained the development of trust. The core category was Making Me Feel Comfortable and the model had eight categories. These categories reflected stages in the model. The beginning stages of the model included the categories Having Needs and Relying on the Nurse. The middle stages of the model reflecting interaction between the nurse and patient included the categories Coming Across to Me, Taking Care of Me, and Connecting. The final stages were the category Feeling Confianza (Trust) with the outcome categories Confiding in the Nurse and Taking Away the Negative. Of particular importance, anytime there was a negative element while interacting with the nurse during the middle stages, this element halted any further development of trust. Establishment of trust for the hospitalized patient with the nurse was a cyclical process, beginning again with the nurse on the next shift. Hispanic cultural values of personalismo (friendly relations) and familism impacted the development of trust and contributed to the unique findings in this study. The findings of this study have implications for nursing care with Mexican American patients that may impact patient safety and quality care

    Dual Goals of Trunk Restriction and Stability are Prioritized by Individuals with Chronic Low Back Pain During a Volitional Movement

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    Background Individuals with chronic low back pain demonstrate impaired responses to volitional and externally-generated postural perturbations that may impact stability whilst performing activities of daily living. Understanding how balance may be impaired by strategy selection is an important consideration during rehabilitation from low back pain to prevent future injurious balance loss. Research question This cross-sectional study explored the influence of an active pain episode on volitional movement patterns and stability during a sit-to-stand task in individuals with chronic low back pain compared to those with no low back pain history. Methods Thirteen participants with low back pain who were in an active flare-up and 13 without pain sat on a height-adjusted chair and performed 5 sit-to-stand movements. Sagittal plane kinematics, kinetics, and surface electromyography were used to compute neuromuscular variables across Acceleration, Transition and Deceleration phases. Stability was assessed using times to contact of body centers of mass and pressure to base of support boundaries. Independent samples t-tests were used to examine group effects, and repeated measures analyses of variance assessed within-subjects effects across movement phases. Results Individuals with low back pain tended to restrict proximal joint motions through heightened muscle activity while increasing distal joint movement and distal muscle contributions. Individuals with low back pain used a greater driving force, indicated by a longer time to contact of the center of pressure, to achieve comparable center of mass stability. Individuals with low back pain may prioritize trunk restriction and stability through the sit-to-stand movement, possibly related to fear of pain or movement. Significance The tendency for individuals with active low back pain to restrict trunk movements may require additional effort to maintain stability. Further research should examine whether trunk restriction is related to pain-related fear of movement and whether additional cognitive resources are required to maintain movement stability

    Some approximation problems in the theory of stationary processes

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    AbstractIn this paper, necessary and sufficient conditions for the regularity of a general (multivariate) stationary process are obtained. These subsume all the known criteria of regularity for such processes

    Projected Impact of Compositional Verification on Current and Future Aviation Safety Risk

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    The projected impact of compositional verification research conducted by the National Aeronautic and Space Administration System-Wide Safety and Assurance Technologies on aviation safety risk was assessed. Software and compositional verification was described. Traditional verification techniques have two major problems: testing at the prototype stage where error discovery can be quite costly and the inability to test for all potential interactions leaving some errors undetected until used by the end user. Increasingly complex and nondeterministic aviation systems are becoming too large for these tools to check and verify. Compositional verification is a "divide and conquer" solution to addressing increasingly larger and more complex systems. A review of compositional verification research being conducted by academia, industry, and Government agencies is provided. Forty-four aviation safety risks in the Biennial NextGen Safety Issues Survey were identified that could be impacted by compositional verification and grouped into five categories: automation design; system complexity; software, flight control, or equipment failure or malfunction; new technology or operations; and verification and validation. One capability, 1 research action, 5 operational improvements, and 13 enablers within the Federal Aviation Administration Joint Planning and Development Office Integrated Work Plan that could be addressed by compositional verification were identified

    Cost-effectiveness findings from the Agewell pilot study of behaviour change to promote health and wellbeing in later life

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    Background: Participation in cognitive and physical activities may help to maintain health and wellbeing in older people. The Agewell study explored the feasibility of increasing cognitive and physical activity in older people through a goal-setting approach. This paper describes the findings of the cost-effectiveness analysis.Method: Individuals over the age of 50 and attending an Agewell centre in North Wales were randomised to one of three conditions: control (IC), goal-setting (GS), or goal-setting with mentoring (GM). We undertook a cost-effectiveness analysis comparing GS vs. IC, GM vs. IC and GM vs. GS. The primary outcome measure for this analysis was the QALY, calculated using the EQ-5D. Participants’ health and social care contacts were recorded and costed using national unit costs.Results: Seventy participants were followed-up at 12 months. Intervention set up and delivery costs were £252 per participant in the GS arm and £269 per participant in the GM arm. Mean health and social care costs over 12 months were £1,240 (s.d. £3,496) per participant in the IC arm, £1,259 (s.d. £3,826) per participant in the GS arm and £1,164 (s.d. £2,312) per participant in the GM arm. At a willingness to pay threshold of £20,000 per QALY there was a 65% probability that GS was cost-effective compared to IC (ICER of £1,070). However, there was only a 41% probability that GM was cost-effective compared to IC (ICER of £2,830) at a threshold of £20,000 per QALY.Conclusion: Setting up and running the community based intervention was feasible. Due to the small sample size it is not possible to draw a firm conclusion about cost-effectiveness; however, our preliminary results suggest that goalsetting is likely to be cost-effective compared to the control condition of no goal-setting, the addition of mentoring was effective but not cost-effective

    Reduction in adolescent depression after contact with mental health services: a longitudinal cohort study in the UK

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    Background: Evidence regarding the association between service contact and subsequent mental health in adolescents is scarce, and previous findings are mixed. We aimed to longitudinally assess the extent to which depressive symptoms in adolescents change after contact with mental health services. Methods: As part of a longitudinal cohort study, between April 28, 2005, and March 17, 2010, we recruited 1238 14-year-old adolescents and their primary caregivers from 18 secondary schools in Cambridgeshire, UK. Participants underwent follow-up assessment at months 18 and 36. Trained researchers assessed the adolescents for current mental disorder using the Schedule for Affective Disorders and Schizophrenia for School-Age Children Present and Lifetime version (K-SADS-PL). Caregivers and adolescents reported contact with mental health services in the year before baseline. Adolescents self-reported depressive symptoms (Mood and Feelings Questionnaire [MFQ]) at each timepoint. We assessed change in MFQ sum scores from baseline contact with mental health services using multilevel mixed-effects regression adjusted for sociodemographic, environmental, individual, and mental health confounders, with multiple imputation of missing data. We used propensity score weighting to balance confounders between treatment (users of mental health services) and control (non-users of mental health services) groups. We implemented an MFQ clinical cutoff following the results of receiver operating characteristic analysis. Findings: 14-year-old adolescents who had contact with mental health services in the past year had a greater decrease in depressive symptoms than those without contact (adjusted coefficient −1·68, 95% CI −3·22 to −0·14; p=0·033). By age 17 years, the odds of reporting clinical depression were higher in individuals without contact than in service users who had been similarly depressed at baseline (adjusted odds ratio 7·38, 1·73–31·50; p=0·0069). Interpretation: Our findings show that contact with mental health services at age 14 years by adolescents with a mental disorder reduced the likelihood of depression by age 17 years. This finding supports the improvement of access to adolescent mental health services.This study was funded by The Wellcome Trust (grant number 074296), and the National Institute for Health Research Collaboration for Leadership in Applied Health Research & Care for Cambridgeshire and Peterborough

    Promotion of healthy aging within a community center through behavior change: health and fitness findings from the AgeWell pilot randomized controlled trial

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    The purpose of this randomized controlled trial was to determine if behavior change through individual goal setting (GS) could promote healthy aging, including health and fitness benefits in older adults who attended a community “AgeWell” Center for 12 months. Seventy-five older adults were randomly allocated to either a control or a GS group. Health outcomes were measured at baseline and after 12 months of the participants’ having access to the exception of Agewell Center facilities. The findings demonstrate that participation in the Center in itself was beneficial, with improved body composition and reduced cardiovascular risk in both groups (p < .05), and that this kind of community-based resource offers valuable potential for promoting protective behaviors and reducing health risk. However, a specific focus on identifying individual behavior change goals was required in order to achieve increased activity engagement (p < .05) and to bring about more substantial improvements in a range of health, diet, and physical function measures (p < .05)

    Whole exome and targeted deep sequencing identify genome-wide allelic loss and frequent SETDB1 mutations in malignant pleural mesotheliomas.

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    Malignant pleural mesothelioma (MPM), a rare malignancy with a poor prognosis, is mainly caused by exposure to asbestos or other organic fibers, but the underlying genetic mechanism is not fully understood. Genetic alterations and causes for multiple primary cancer development including MPM are unknown. We used whole exome sequencing to identify somatic mutations in a patient with MPM and two additional primary cancers who had no evidence of venous, arterial, lymphovascular, or perineural invasion indicating dissemination of a primary lung cancer to the pleura. We found that the MPM had R282W, a key TP53 mutation, and genome-wide allelic loss or loss of heterozygosity, a distinct genomic alteration not previously described in MPM. We identified frequent inactivating SETDB1 mutations in this patient and in 68 additional MPM patients (mutation frequency: 10%, 7/69) by targeted deep sequencing. Our observations suggest the possibility of a new genetic mechanism in the development of either MPM or multiple primary cancers. The frequent SETDB1 inactivating mutations suggest there could be new diagnostic or therapeutic options for MPM
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