183 research outputs found
Simulators' validation study: Problem solution logic
A study was conducted to validate the ground based simulators used for aircraft environment in ride-quality research. The logic to the approach for solving this problem is developed. The overall problem solution flow chart is presented. The factors which could influence the human response to the environment on board the aircraft are analyzed. The mathematical models used in the study are explained. The steps which were followed in conducting the validation tests are outlined
Effect of motion frequency spectrum on subjective comfort response
In order to model passenger reaction to present and future aircraft environments, it is necessary to obtain data in several ways. First, of course, is the gathering of environmental and passenger reaction data on commercial aircraft flights. In addition, detailed analyses of particular aspects of human reaction to the environment are best studied in a controllable experimental situation. Thus the use of simulators, both flight and ground based, is suggested. It is shown that there is a reasonably high probability that the low frequency end of the spectrum will not be necessary for simulation purposes. That is, the fidelity of any simulation which omits the very low frequency content will not yield results which differ significantly from the real environment. In addition, there does not appear to be significant differences between the responses obtained in the airborne simulator environment versus those obtained on commercial flights
Development of a research project selection model: Application to a civil helicopter research program
A model is described for planning and decision making in research project selection. Evaluations of each project's direct and indirect benefits, uncertainty in achieving these benefits, and schedule priority with resource budget and program balance constraints are considered. The combination of the interactive effect of project selection, resource allocation and scheduling considerations into one model permits tradeoff alternatives to be studied. Clients' value judgments are used in evaluating the benefits from each proposed project. The model is applied to the NASA Civil Helicopter Technology Program. Research project priorities for this program are established, strengths and weaknesses of the model are discussed, and areas of future development are recommended
Chromosome evolution in Neotropical Danainae and Ithomiinae (Lepidoptera)
Chromosome numbers are given for 1011 populations of 242 species, representing the full range of taxa (49 of the about 52 presently recognized genera) in the Neotropical Nymphalid butterfly subfamily Ithorminae (prime movers for mimicry rings), including many additional geographical subspecies from 47 regions from Mexico and the Caribbean islands throughout all tropical South American countries to southern Brazil. Twelve Neotropical Danainae (in 3 genera), all but one with n = 29 -31, and the Australian Tellervo (n = 32) served as sister groups for comparison. The numbers range near-continuously from n = 5 to n = 120 with modal values (33-84 counts) at n = 12-18, and only 16 and 26 counts at the usual modal number of all butterfly groups, n =30-31. Superimposition of these changes in karyotype on a cladistic phylogeny of the subfamily indicates possible early halving of the complement to n about 14-15, followed by much variation in each genus and tribe. While at least 17 species in 15 genera show stable karyotypes over much of the Nectropics, at least 40 species show large geographical variation in number of chromosomes, rarely accompanied by any evidence for reduction in fertility or incipient speciation. The evolutionary opportunism of the members of this subfamily probably accompanies their known population biology and community ecology: they are common, shade-loving, highly gregarious (occurring in small multispecies "pockets" in deep forest) and often migratory as a community when the environment becomes unfavorable (too hot or dry).141321623
Chromosomal evolution in the South American nymphalidae
We give the chromosome numbers of about 80 species or subspecies of Biblidinae as well as of numbers of neotropical Libytheinae (one species), Cyrestinae (4) Apaturinae (7), Nymphalinae (about 40), Limenitidinae (16) and Heliconiinae (11). Libytheana has about n=32, the Biblidinae, Apaturinae and Nymphalinae have in general n=31, the Limenitidinae have n=30, the few Argynnini n=31 and the few species of Acraeni studied have also mostly n=31. The results agree with earlier data from the Afrotropical species of these taxa. We supplement these data with our earlier observations on Heliconiini, Danainae and the Neotropical Satyroid taxa. The lepidopteran modal n=29-31 represents clearly the ancestral condition among the Nymphalidae, from which taxa with various chromosome numbers have differentiated. The overall results show that Neotropical taxa have a tendency to evolve karyotype instability, which is in stark contrast to the otherwise stable chromosome numbers that characterize both Lepidoptera and Trichoptera.144413714
Quality culture at Nordic Universities
This study aimed to investigate common features and ways of understanding quality culture (QC) within higher education institutions (HEIs) in Nordic countries. While the concept of QC is commonly accepted and often used, its meaning is not always clear. This paper focuses on how Nordic universities frame QC in their internal documentation. The Nordic context was chosen due to the close cooperation on quality issues that characterise HEIs within the Nordic region. The discussion section of this paper outlines QC in relation to quality assurance (QA) among HEIs within the European and Nordic regions. Sixteen universities participated in the study by sharing documents describing their QCs. The data were analysed using qualitative content analysis and discussed from different perspectives, such as regarding how the universities use the concept of QC and how QC is created. Based on the results, a model was created that provides an overview of how QC emerges and how the concept is implemented in documentation. It is hoped that the results will both contribute useful input to the ongoing collaboration on quality issues among HEIs in the Nordic region and will also be useful in enhancing QC at universities in other regions.</p
Co-designing inflammatory bowel disease (Ibd) services in Scotland : findings from a nationwide survey
Background: The Scottish Government’s ambition is to ensure that health services are co-designed with the
communities they serve. Crohn’s and Colitis UK and the Scottish Government acknowledged the need to review
and update the current IBD care model. An online survey was conducted asking IBD patients about their
experiences of the NHS care they receive. This survey was the first step of co-designing and developing a national
strategy for IBD service improvement in Scotland.
Aim: To explore IBD patients’ experiences of current services and make recommendations for future service
development.
Methods: This study was part of a wider cross-sectional on-line survey. Participants were patients with IBD across
Scotland. 777 people with IBD took part in the survey. Thematic analysis of all data was conducted independently
by two researchers.
Results: Three key themes emerged:
Quality of life: Participants highlighted the impact the disease has on quality of life and the desperate need for IBD
services to address this more holistically.
IBD clinicians and access: Participants recognised the need for more IBD nurses and gastroenterologists along with
better access to them. Those with a named IBD nurse reported to be more satisfied with their care.
An explicit IBD care pathway: Patients with IBD identified the need of making the IBD care pathway more explicit to
service users.
Conclusions: Participants expressed the need for a more holistic approach to their IBD care. This includes
integrating psychological, counselling and dietetic services into IBD care with better access to IBD clinicians and a
more explicit IBD care pathway.
Keywords: Inflammatory bowel disease, Co-designing, Qualitative study, Patient survey, Crohn’s disease, Ulcerative coliti
Peak bone mineral density in Vietnamese women
While the prevalence of osteoporosis and risk factors for low bone mineral density (BMD) has been well documented in Caucasian populations, there is a lack of data from Asia. This work was designed to clarify to what extent osteoporosis could be regarded as a major public health problem in Vietnam. Furthermore, to elucidate the prevalence of certain risk factors, such as vitamin D deficiency and other determinants of bone mass as a basis to indentify high-risk individuals among the Vietnamese women and men.
The clinical studies were designed as cross-sectional investigations using a multistage sampling scheme. Within the setting of northern Vietnam (latitude 21°N), districts were selected to represent urban and rural areas. In total 612 healthy women and 222 men aged 13-83 years were investigated. BMD was measured at the lumbar spine, femoral neck and total hip in all qualified subjects with dual energy X-ray absortiometry. Serum concentrations of 25(OH)D, parathyroid hormone, estrogen and testosterone were quantified by electrochemiluminescence immunoassay. Data on clinical history and lifestyle were collected by individual face-to-face interviews.
Reference values for peak BMD were defined. These data allowed the calculation of T-scores and thus for the first time, an accurate identification of osteoporosis in a Vietnamese population. As determined at the femoral neck, the prevalence of osteoporosis was 17-23% in women and 9% in men. The results clearly suggest that osteoporosis is an important public health problem. Postmenopausal women living in urban areas experienced osteoporosis more than rural residents. Serum levels of 25(OH)D and estrogen were significantly associated with bone mass in both women and men. The prevalence of vitamin D deficiency (<20 ng/mL) was very high, 30% in women and 16% in men.
An experimental study on the isoflavone content of different soymilk preparations was performed by HPLC (high pressure liquid chromatography). Values of isoflavones were very low, around 60-80 mg/L, and there were only 10-20% of bioactive aglycones. This is far below the reported threshold levels to exert significant effects on bone.
In the future these data will be useful as a valuable reference base to diagnose osteoporosis and for the clinical management of its consequences. The high prevalence of vitamin D deficiency should raise the awareness of potentially important health issues such as osteoporosis but also about other serious diseases within the Vietnamese society
Parenteral oestrogen in the treatment of prostate cancer: a systematic review
The objectives of this study were to assess the effectiveness and safety of parenteral oestrogen in the treatment of prostate cancer, and to examine any dose relationship. A systematic review was undertaken. Electronic databases, published paper and internet resources were searched to locate published and unpublished studies with no restriction by language or publication date. Studies included were randomised controlled trials of parenteral oestrogen in patients with prostate cancer; other study designs were also included to examine dose–response. Study selection, appraisal, data extraction and quality assessment were performed by one reviewer and independently checked by another. Twenty trials were included in the review. The trials differed with regard to the included patients, formulation and dose of parenteral oestrogen, comparator used, outcome measures reported and the duration of follow-up. The results provide no evidence to suggest that parenteral oestrogen, in doses sufficient to produce castrate levels of testosterone, is less effective than luteinising hormone-releasing hormone (LHRH) or orchidectomy in controlling prostate cancer, or that it is consistently associated with an increase in cardiovascular mortality. Further well-conducted trials of parenteral oestrogen are required. A pilot randomised controlled trial comparing transdermal oestrogen to LHRH analogues in men with locally advanced or metastatic prostate cancer is underway in the United Kingdom
- …