272 research outputs found
Lidar backscattering measurements of background stratospheric aerosols
A comparative lidar-dustsonde experiment was conducted in San Angelo, Texas, in May 1974 in order to estimate the uncertainties in stratospheric-aerosol backscatter for the NASA Langley 48-inch lidar system. The lidar calibration and data-analysis procedures are discussed. Results from the Texas experiment indicate random and systematic uncertainties of 35 and 63 percent, respectively, in backscatter from a background stratospheric-aerosol layer at 20 km
Langley Mach 4 scramjet test facility
An engine test facility was constructed at the NASA Langley Research Center in support of a supersonic combustion ramjet (scramjet) technology development program. Hydrogen combustion in air with oxygen replenishment provides simulated air at Mach 4 flight velocity, pressure, and true total temperature for an altitude range from 57,000 to 86,000 feet. A facility nozzle with a 13 in square exit produces a Mach 3.5 free jet flow for engine propulsion tests. The facility is described and calibration results are presented which demonstrate the suitability of the test flow for conducting scramjet engine research
Psychosocial Well-Being and Functional Outcomes in Youth With Type 1 Diabetes 12 years After Disease Onset
Sense of coherence moderates job demand‐resources and impact on burnout among nurses and midwives in the context of the COVID ‐19 pandemic: a cross‐sectional survey.
This study aimed to test the propositions using the job demands‐resources (JD‐R) model for main/moderation/mediation effects of a sense of coherence and practice environment support on mental well-being (anxiety, depression and burnout) outcomes in nurses and midwives in Australia during the COVID-19 pandemic. Cross-sectional quantitative survey. The study was a cross-sectional design using self-report questionnaires reported as per the Reporting of Observational Studies in Epidemiology Guidelines. Following human research ethics approval (2020.ETH.00121) participants were recruited to take part in an online anonymous survey using self-report instruments to test the JD-R model in Australia. 156 participant nurses and midwives experienced anxiety, depression and emotional burnout during COVID-19. While a considerable proportion of participants indicated high levels of emotional exhaustion, their responses showed low levels of depersonalization (detached response to other people) and high levels of personal accomplishment (high levels of work performance and competence). A sense of coherence was a significant protective factor for mental health well-being for the participants, which is to say, high levels of sense of coherence were predictive of lower levels of anxiety, depression and burnout in this study sample. It is evident that both nursing and midwifery professions require psychosocial support to preserve their health both in the short and long term. Ensuring individualized tailored support will require a layered response within organizations aimed at individual self-care and collegial peer support. There was no patient or public contribution in this study, as the focus was on nurses and midwives
Space and transatmospheric propulsion technology
This report focuses primarily on Japan's programs in liquid rocket propulsion and propulsion for spaceplane and related transatmospheric areas. It refers briefly to Japan's solid rocket programs and to new supersonic air-breathing propulsion efforts. The panel observed that the Japanese had a carefully thought-out plan, a broad-based program, and an ambitious but achievable schedule for propulsion activity. Japan's overall propulsion program is behind that of the United States at the time of this study, but the Japanese are gaining rapidly. The Japanese are at the forefront in such key areas as advanced materials, enjoying a high level of project continuity and funding. Japan's space program has been evolutionary in nature, while the U.S. program has emphasized revolutionary advances. Projects have typically been smaller in Japan than in the United States, focusing on incremental advances in technology, with an excellent record of applying proven technology to new projects. This evolutionary approach, coupled with an ability to take technology off the shelf from other countries, has resulted in relatively low development costs, rapid progress, and enhanced reliability. Clearly Japan is positioned to be a world leader in space and transatmospheric propulsion technology by the year 2000
Understanding the needs and preferences for cancer care among First Nations people: an integrative review.
This systematic review aimed to identify the needs and preferences for cancer care services among Australian First Nations people. An integrative review was conducted. A wide range of search terms were used to increase the sensitivity and specificity of the searches in electronic databases. Methodological quality assessment, data extraction, was conducted independently by two reviewers, and a narrative synthesis was conducted. Forty‐two studies were included. A total of 2965 Australian First Nations adults, both men and women of various ages across the lifespan, were represented; no First Nations children affected by cancer were represented in the studies. Three themes emerged which included: (1) discrimination, racism and trauma, resulting from colonization, directly impacted First National people's cancer care experience; (2) cultural ways of knowing, being and doing are fundamental to how First Nations people engage with cancer care services; and (3) First Nations people need culturally safe person‐centred cancer care services that address practical needs. Most participants represented in this review experienced discrimination, racism and trauma, resulting from colonization, which directly negatively impacted Aboriginal peoples' cancer care experience. While the Optimal Cancer Pathway (OCP) was launched in Australia several years ago, people with cancer may continue to experience distressing unmet care needs. Our team includes both First Nations people, non‐First Nations researchers and healthcare professionals with expertise in cancer care. The researchers employed decolonizing restorative approaches to ensure voice, respect, accountability and reciprocity in this review work. Members of the multidisciplinary team including nurses and policymakers should reflect on these findings, ensure that they have up‐to‐date cultural safety training and stand together with Indigenous and non‐Indigenous cancer leaders to take proactive steps to stamp out and dismantle oppression in health, and safely implement the OCP
Quantitative EEG in type 1 diabetic adults with childhood exposure to severe hypoglycaemia: a 16 year follow-up study
Assessing the effect of closed-loop insulin delivery from onset of type 1 diabetes in youth on residual beta-cell function compared to standard insulin therapy (CLOuD study): a randomised parallel study protocol.
INTRODUCTION:Management of newly diagnosed type 1 diabetes (T1D) in children and adolescents is challenging for patients, families and healthcare professionals. The objective of this study is to determine whether continued intensive metabolic control using hybrid closed-loop (CL) insulin delivery following diagnosis of T1D can preserve C-peptide secretion, a marker of residual beta-cell function, compared with standard multiple daily injections (MDI) therapy. METHODS AND ANALYSIS:The study adopts an open-label, multicentre, randomised, parallel design, and aims to randomise 96 participants aged 10-16.9 years, recruited within 21 days of diagnosis with T1D. Following a baseline mixed meal tolerance test (MMTT), participants will be randomised to receive 24 months treatment with conventional MDI therapy or with CL insulin delivery. A further 24-month optional extension phase will be offered to all participants to continue with the allocated treatment. The primary outcome is the between group difference in area under the stimulated C-peptide curve (AUC) of the MMTT at 12 months post diagnosis. Analyses will be conducted on an intention-to-treat basis. Key secondary outcomes are between group differences in time spent in target glucose range (3.9-10 mmol/L), glycated haemoglobin (HbA1c) and time spent in hypoglycaemia (<3.9 mmol/L) at 12 months. Secondary efficacy outcomes include between group differences in stimulated C-peptide AUC at 24 months, time spent in target glucose range, glucose variability, hypoglycaemia and hyperglycaemia as recorded by periodically applied masked continuous glucose monitoring devices, total, basal and bolus insulin dose, and change in body weight. Cognitive, emotional and behavioural characteristics of participants and parents will be evaluated, and a cost-utility analysis performed to support adoption of CL as a standard treatment modality following diagnosis of T1D. ETHICS AND DISSEMINATION:Ethics approval has been obtained from Cambridge East Research Ethics Committee. The results will be disseminated by peer-reviewed publications and conference presentations. TRIAL REGISTRATION NUMBER:NCT02871089; Pre-results
Parental and infant characteristics and childhood leukemia in Minnesota
<p>Abstract</p> <p>Background</p> <p>Leukemia is the most common childhood cancer. With the exception of Down syndrome, prenatal radiation exposure, and higher birth weight, particularly for acute lymphoid leukemia (ALL), few risk factors have been firmly established. Translocations present in neonatal blood spots and the young age peak of diagnosis suggest that early-life factors are involved in childhood leukemia etiology.</p> <p>Methods</p> <p>We investigated the association between birth characteristics and childhood leukemia through linkage of the Minnesota birth and cancer registries using a case-cohort study design. Cases included 560 children with ALL and 87 with acute myeloid leukemia (AML) diagnoses from 28 days to 14 years. The comparison group was comprised of 8,750 individuals selected through random sampling of the birth cohort from 1976–2004. Cox proportional hazards regression specific for case-cohort studies was used to compute hazard ratios (HR) and 95% confidence intervals (CIs).</p> <p>Results</p> <p>Male sex (HR = 1.41, 95% CI 1.16–1.70), white race (HR = 2.32, 95% CI 1.13–4.76), and maternal birth interval ≥ 3 years (HR = 1.31, 95% CI 1.01–1.70) increased ALL risk, while maternal age increased AML risk (HR = 1.21/5 year age increase, 95% CI 1.0–1.47). Higher birth weights (>3798 grams) (HRALL = 1.46, 1.08–1.98; HRAML = 1.97, 95% CI 1.07–3.65), and one minute Apgar scores ≤ 7 (HRALL = 1.30, 95% CI 1.05–1.61; HRAML = 1.62, 95% CI 1.01–2.60) increased risk for both types of leukemia. Sex was not a significant modifier of the association between ALL and other covariates, with the exception of maternal education.</p> <p>Conclusion</p> <p>We confirmed known risk factors for ALL: male sex, high birth weight, and white race. We have also provided data that supports an increased risk for AML following higher birth weights, and demonstrated an association with low Apgar scores.</p
Validity of Recall of Tobacco Use in Two Prospective Cohorts
This project studied the convergent validity of current recall of tobacco-related health behaviors, compared with prospective self-report collected earlier at two sites. Cohorts were from the Oregon Research Institute at Eugene (N = 346, collected 19.5 years earlier) and the University of Pittsburgh, Pennsylvania (N = 294, collected 3.9 years earlier). Current recall was examined through computer-assisted interviews with the Lifetime Tobacco Use Questionnaire from 2005 through 2008. Convergent validity estimates demonstrated variability. Validity estimates of some tobacco use measures were significant for Oregon subjects (age at first cigarette, number of cigarettes/day, quit attempts yes/no and number of attempts, and abstinence symptoms at quitting; all P < 0.03). Validity estimates of Pittsburgh subjects’ self-reports of tobacco use and abstinence symptoms were significant (P < 0.001) for all tobacco use and abstinence symptoms and for responses to initial use of tobacco. These findings support the utility of collecting recalled self-report information for reconstructing salient lifetime health behaviors and underscore the need for careful interpretation
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