1,544 research outputs found
Fixed base simulator study of an externally blown flap STOL transport airplane during approach and landing
A fixed-base simulator study was conducted to determine the flight characteristics of a representative STOL transport having a high wing and equipped with an external-flow jet flap in combination with four high-bypass-ratio fan-jet engines during the approach and landing. Real-time digital simulation techniques were used. The computer was programed with equations of motion for six degrees of freedom and the aerodynamic inputs were based on measured wind-tunnel data. A visual display of a STOL airport was provided for simulation of the flare and touchdown characteristics. The primary piloting task was an instrument approach to a breakout at a 200-ft ceiling with a visual landing
Flight evaluation of the effect of winglets on performance and handling qualities of a single-engine general aviation airplane
A flight evaluation was conducted to determine the effects of winglets on the performance and handling qualities of a light, single-engine general aviation airplane. The performance measurements were made with a pace airplane to provide calibrated airspeeds; uncalibrated panel instruments in the test airplane were used to provide additional quantitative performance data. These tests were conducted with winglets on and off during the same day to measure relative performance effects. Handling qualities were evaluated by means of pilot comments. Winglets increased cruise speed 8 knots (5.6 percent) at 3962 m (13,000 ft) density altitude and 51 percent maximum continuous power setting. Maximum speed at 3962 m was virtually unchanged. Rate of climb increased approximately 6 percent, or 0.25 m/sec (50 ft/min), at 1524 m (5000 ft). Stall speed was virtually unchanged. Handling qualities were favorably affected
End-of-life experiences of mothers with advanced cancer: perspectives of widowed fathers
Despite the importance of parenting-related responsibilities for adult patients with terminal illnesses who have dependent children, little is known about the psychological concerns of dying parents and their families at the end of life (EOL). The aim of this study was to elicit widowed fathers’ perspectives on how parental status may have influenced the EOL experiences of mothers with advanced cancer
Exploring the future of tourism and quality of life
Few studies to date have examined the impact of tourism on quality of life (QoL) as conventional research has tended to focus, instead, on resident attitudes towards tourism and tourism ’s impacts in particular (Smith, 1977; 1989). Even
less research has addressed whether tourism can drive or facilitate sustainable development (Miller and Twining-Ward, 2005) or whether tourism can contribute to the subjective wellbeing of those involved in travel and tourism. Impact studies generally ask residents to agree or disagree with statements regarding perceived impacts from tourism on their community. By contrast, QoL research aims to understand how
these impacts are internalised and influence an
individual’s overall life satisfaction (Andereck et al, 2007). With terms used interchangeably QoL, happiness and well-being refer to one’s satisfaction with life, and feelings of contentment or fulfilment with one’s experiences in the world (ibid.). Whether tourism as phenomena and practice may support the growing body of evidence that demonstrates a positive relationship between existential factors such as life purpose / meaning, personal growth and wellbeing (Vella-Brodrick, 2007) was the topic of intense debate during the 2008 Business Enterprises for Sustainable Travel Education Network (BEST EN) Think Tank VIII
Coupling in-depth genome annotations with genome editing technology for harnessing genomic variation to promote precision breeding in tropical soybean.
ABSTRACT: Directional selection during crop domestication and advanced breeding has resulted in significant changes in plant genomes. The extent of intraspecific variation in a crop documents domestication and highlights variants underlying complex traits. Studies demonstrate that most naturally occurring variants in crops are low frequency, and only a small fraction of those might have important functions to trait variation. To understand the inheritance of quantitative traits, diversity panels have become available by crossing inbred lines to produce genomic maps that relate phenotypic variation to recombination and ultimately to genome structure. Using these resources, genomics studies have suggested that selection performs poorly in pericentromeric regions because of reduced recombination frequency (RF). Thus, manipulating RF and meiotic crossover location is an appealing issue to advance crop breeding. In our study, we are using genomic analysis to characterize intragenomic diversity of tropical elite soybean lines in terms of heterozygosity, RF, chromatin structure and accessibility. Our results to date include the generation of draft genome assemblies for two soybean advanced lines using PACBIO long-read sequencing, Chromium Linked-Reads sequencing and an approach rooted in polymer physics that determines the most likely genome structure using chromosomal contact data. In-depth genome-wide characterization is ongoing using ATAC-Seq and Parent-Progeny resequencing. We also present our efforts to apply DNA-free editing tools in implementing genetic alterations that are expected to engineer desirable traits in soybeans by modifying meiotic specific expression. These changes are expected to increase genetic and epigenetic variations with favorable outcomes in seed oil and protein pathway regulation. Financial support: Embrapa-Monsanto Fund/Project:03.17.03.002.00.0
A qualitative study of independent fast food vendors near secondary schools in disadvantaged Scottish neighbourhoods
Background:
Preventing and reducing childhood and adolescent obesity is a growing priority in many countries. Recent UK data suggest that children in more deprived areas have higher rates of obesity and poorer diet quality than those in less deprived areas. As adolescents spend a large proportion of time in school, interventions to improve the food environment in and around schools are being considered. Nutrient standards for school meals are mandatory in the UK, but many secondary pupils purchase foods outside schools at break or lunchtime that may not meet these standards.
Methods:
Qualitative interviews were conducted with fast food shop managers to explore barriers to offering healthier menu options. Recruitment targeted independently-owned shops near secondary schools (pupils aged c.12-17) in low-income areas of three Scottish cities. Ten interviews were completed, recorded, and transcribed for analysis. An inductive qualitative approach was used to analyse the data in NVivo 10.
Results:
Five themes emerged from the data: pride in what is sold; individual autonomy and responsibility; customer demand; profit margin; and neighbourhood context. Interviewees consistently expressed pride in the foods they sold, most of which were homemade. They felt that healthy eating and general wellbeing are the responsibility of the individual and that offering what customers want to eat, not necessarily what they should eat, was the only way to stay in business. Most vendors felt they were struggling to maintain a profit, and that many aspects of the low-income neighbourhood context would make change difficult or impossible.
Conclusions:
Independent food shops in low-income areas face barriers to offering healthy food choices, and interventions and policies that target the food environment around schools should take the neighbourhood context into consideration
Stability of Solid State Reaction Fronts
We analyze the stability of a planar solid-solid interface at which a
chemical reaction occurs. Examples include oxidation, nitridation, or silicide
formation. Using a continuum model, including a general formula for the
stress-dependence of the reaction rate, we show that stress effects can render
a planar interface dynamically unstable with respect to perturbations of
intermediate wavelength
A phase II trial of bendamustine in combination with rituximab in older patients with previously untreated diffuse large B-cell lymphoma
Bendamustine in combination with rituximab (BR) has been associated with high response rates and acceptable toxicity in older patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL). Evaluation of BR is warranted in the front-line setting for DLBCL patients not eligible for anthracyclines or for the elderly. In this phase II study, we enrolled DLBCL patients aged ≥65 years who were poor candidates for R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) to determine the efficacy and safety of BR in previously untreated stage II–IV DLBCL. Twenty-three patients were enrolled with a median age of 80 years. 52% of patients presented with poor functional status (Eastern Cooperative Oncology Group performance score of ≥2). The overall response rate was 78% with 12 complete responses (52%). At a median follow up of 29 months, the median overall survival was 10.2 months and the median progression-free survival was 5.4 months. The most common grade 3/4 adverse events were haematological. Combination therapy with BR demonstrates high response rates as front-line therapy in frail older patients with DLBCL, but survival rates were low. BR should be used with caution in future clinical trials involving older DLBCL patients with poor functional status
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