198 research outputs found

    Shuttle landing facility cloud cover study: Climatological analysis and two tenths cloud cover rule evaluation

    Get PDF
    The two-tenths cloud cover rule in effect for all End Of Mission (EOM) STS landings at the Kennedy Space Center (KSC) states: 'for scattered cloud layers below 10,000 feet, cloud cover must be observed to be less than or equal to 0.2 at the de-orbit burn go/no-go decision time (approximately 90 minutes before landing time)'. This rule was designed to protect against a ceiling (below 10,000 feet) developing unexpectedly within the next 90 minutes (i.e., after the de-orbit burn decision and before landing). The Applied Meteorological Unit (AMU) developed and analyzed a database of cloud cover amounts and weather conditions at the Shuttle Landing Facility for a five-year (1986-1990) period. The data indicate the best time to land the shuttle at KSC is during the summer while the worst time is during the winter. The analysis also shows the highest frequency of landing opportunities occurs for the 0100-0600 UTC and 1300-1600 UTC time periods. The worst time of the day to land a shuttle is near sunrise and during the afternoon. An evaluation of the two-tenths cloud cover rule for most data categorizations has shown that there is a significant difference in the proportions of weather violations one and two hours subsequent to initial conditions of 0.2 and 0.3 cloud cover. However, for May, Oct., 700 mb northerly wind category, 1500 UTC category, and 1600 UTC category there is some evidence that the 0.2 cloud cover rule may be overly conservative. This possibility requires further investigation. As a result of these analyses, the AMU developed nomograms to help the Spaceflight Meteorological Group (SMG) and the Cape Canaveral Forecast Facility (CCFF) forecast cloud cover for EOM and Return to Launch Site (RTLS) at KSC. Future work will include updating the two tenths database, further analysis of the data for several categorizations, and developing a proof of concept artificial neural network to provide forecast guidance of weather constraint violations for shuttle landings

    Evaluating the potential risks and benefits of infant rotavirus vaccination in England.

    Get PDF
    Rotarix(Âź), a vaccine for the prevention of gastroenteritis in young children, was introduced in England in July 2013. At around this time, an elevated risk of intussusception (a cause of bowel obstruction) was reported among infants vaccinated in Australia and the USA. A risk-benefit analysis compared potential vaccine-related risks (additional intussusception admissions and deaths) with estimated vaccine benefits (prevented rotavirus general practitioner visits, emergency visits, admissions and deaths) in the 2012 birth cohort. Detailed data from England included the incidence of intussusception events aged <2 years by week of age, the coverage of vaccination aged <2 years by week of age, and the incidence of rotavirus gastroenteritis (RVGE) events aged <5 years by week of age. Recent estimates of vaccine-related risk from Australia were applied during the 1-21 day period after the first and second dose of vaccination. Rotarix(Âź) is estimated to cause one additional intussusception admission in every 18,551 vaccinated English infants (5th and 95th percentiles, 6728-93,952), equivalent to 35 (7-98) additional intussusception admissions each year. The vaccine is estimated to prevent three rotavirus deaths, 13,000 rotavirus admissions, 27,000 rotavirus emergency visits and 74,000 rotavirus GP consultations in children aged <5 years, and lead to annual savings of over ÂŁ11 million, each year. We estimate 375 (136-1900) fewer RVGE admissions for every additional intussusception admission, and 88 (18-852) fewer RVGE deaths for every additional intussusception death. The estimated benefits of Rotarix(Âź) vaccination would greatly exceed the potential risk in England

    The Politics of Land Ownership in NSW: A Case Study

    Get PDF
    From 1885 to 1965, successive New South Wales governments made repeated attempts to break up large pastoral estates into family farms. This policy, which became known as closer settlement, was expected to address a range of pressing social and economic problems. This thesis takes a case study approach to assess the impact of this policy in a specific area, the county of Sandon on the NSW northern tablelands. It tests, at the local level, current theory and models of the land question, with the aim of furthering comprehension of this central issue in the development of New South Wales. From the passing of the Crown Lands Act 1884, the NSW government was increasingly intrusive in determining where land settlement should take place, who was permitted to acquire Crown land, and how large their farms should be. By the turn of the century, the attention of both the government and the community at large became focussed on the need to buy back land locked up in the large pastoral estates to create family farms for those who did not already own land. Under legislation passed from 1901 onwards, across the state many thousands of acres of freehold and leasehold land were compulsorily and voluntarily resumed for this purpose. In the county of Sandon, this resulted in some private subdivisions in response to the threat of compulsory resumption, a voluntary resumption in the late 1930s, and both voluntary and compulsory resumptions to provide farms for returned servicemen and women after the two world wars. The impact of closer settlement in the county of Sandon was marginal, in terms of the expected outcomes. A First World War soldier settlement at Kentucky in the south of the county resulted in an increase in the production of stone and pome fruit and a modest increase in population, with many of the soldier settlers being attracted from outside the district. A modest number of settlers came from outside the district to take farms created by the voluntary and compulsory resumptions in the late 1930s and following the Second World War, but otherwise there was no significant population increase. Over time successful farmers bought out their neighbours, and by 1965 most were engaged in the enterprise which had characterised the district in the first half of the nineteenth century, the grazing of sheep and cattle. Thus, there was no long-term change in agricultural output in the county. Based on this evidence, a new model of land settlement is proposed, that there are three forces which interact to determine the size of rural properties: ∙ Government policy which was aimed at creating family farms of what was known as ‘a home maintenance area’, that is, just large enough to support a family in average conditions, undertaking an enterprise best suited to their land; ∙ A tendency for more successful farmers to purchase additional land and so increase the size of their holdings, or to eventually provide farms for their children; and, ∙ A tendency for farms, over time, to either enlarge or contract to a size which is the most efficient. While it would seem that the first force would be the most powerful, since governments had the power to legislate a maximum farm size, the experience in the county of Sandon demonstrated that this was not the case, as there was a marked trend towards properties of an efficient size. Thus, this study has demonstrated that the policy of closer settlement had little impact on the pattern of land settlement

    STS-48 case study, 17-18 September 1991

    Get PDF
    Weather conditions are documented prior to and during the STS-48 attempted landing at the Shuttle Landing Facility at KSC on 18 Sep. 1991. Trends in meteorological data during 17 and 18 Sep. are examined along with their relationship to the overall weather pattern observed over the KSC region. The primary weather problems during the landing were the formation of showers within 10 nautical miles of the SLF and any ceiling less than 10,000 ft. The controlling factor of the weather was a high pressure ridge that was gradually weakening and moving off the northeast. As this occurred, the low level flow was switching from a easterly to a southeasterly direction. This change in wind direction was reflected by shower movement on the McGill radar and by trends in rawinsondes launched from the Cape. These rawinsondes also indicated that the boundary layers was becoming slightly more unstable several hours prior to the attempted landing which may have aided in the development of clouds and small isolated showers. Also, analyses of Doppler wind profiler and rawinsondes indicated a possible midlevel disturbance in the easterly flow pattern near 700 mb. This weak disturbance may have made the atmosphere a little more unstable early on 18 Sep. Finally, embedded within the southeasterly flow were several bands of low clouds. These clouds were rather difficult to see in unenhanced IR satellite imagery available to forecasters in real time. However, post analyses using several different enhancement curves, adapted from NESDIS, clearly reveals the presence of these clouds

    Barriers and facilitators to HIV Pre-Exposure Prophylaxis (PrEP) in Specialist Sexual Health Services in the United Kingdom: A systematic review using the PrEP Care Continuum

    Get PDF
    OBJECTIVES: HIV pre-exposure prophylaxis (PrEP) delivery in the UK is inequitable; over 95% of PrEP users were men who have sex with men (MSM) despite making up less than 50% of new HIV diagnoses. We conducted a systematic review to identify modifiable barriers and facilitators to PrEP delivery in the UK among underserved populations. METHODS: We searched bibliographic/conference databases using the terms HIV, PrEP, barriers, facilitators, underserved populations, and UK. Modifiable factors were mapped along the PrEP Care Continuum (PCC) to identify targets for interventions. RESULTS: In total, 44 studies were eligible: 29 quantitative, 12 qualitative and three mixed-methods studies. Over half (n = 24 [54.5%]) exclusively recruited MSM, whereas 11 were in mixed populations (all included MSM as a sub-population) and the other nine were in other underserved populations (gender and ethnicity minorities, women, and people who inject drugs). Of the 15 modifiable factors identified, two-thirds were at the PrEP contemplation and PrEParation steps of the PCC. The most reported barriers were lack of PrEP awareness (n = 16), knowledge (n = 19), willingness (n = 16), and access to a PrEP provider (n = 16), whereas the more reported facilitators were prior HIV testing (n = 8), agency and self-care (n = 8). All but three identified factors were at the patient rather than provider or structural level. CONCLUSIONS: This review highlights that the bulk of the scientific literature focuses on MSM and on patient-level factors. Future research needs to ensure underserved populations are included and prioritized (e.g. ethnicity and gender minorities, people who inject drugs) and provider and structural factors are investigated

    Women, Witchcraft and the Law in Early Modern Wales (1536-1736): A Continuation of Customary Practice

    Get PDF
    Documentary evidence from the records of the Courts of Great Sessions for Wales1 provides a framework for analysing witchcraft in early modem Wales, specifically from 1536 to 1736. Wales has two distinct types of witchcraft cases: witchcraft as words or slander cases, and witchcraft as 'malefice' cases in which a woman was aocused of practising 'malefice' or premeditated harming. The outcomes in both types of cases before the criminal courts of Wales were almost always the same, the survival of the aocused witch and the woman slandered as a witch. In other words, execution for charges associated with witchcraft was extremely rare in early modern Wales

    The analysis of rapidly developing fog at the Kennedy Space Center

    Get PDF
    This report documents fog precursors and fog climatology at Kennedy Space Center (KSC) Florida from 1986 to 1990. The major emphasis of this report focuses on rapidly developing fog events that would affect the less than 7-statute mile visibility rule for End-Of-Mission (EOM) Shuttle landing at KSC (Rule 4-64(A)). The Applied Meteorology Unit's (AMU's) work is to: develop a data base for study of fog associated weather conditions relating to violations of this landing constraint; develop forecast techniques or rules-of-thumb to determine whether or not current conditions are likely to result in an acceptable condition at landing; validate the forecast techniques; and transition techniques to operational use. As part of the analysis the fog events were categorized as either advection, pre-frontal or radiation. As a result of these analyses, the AMU developed a fog climatological data base, identified fog precursors and developed forecaster tools and decision trees. The fog climatological analysis indicates that during the fog season (October to April) there is a higher risk for a visibility violation at KSC during the early morning hours (0700 to 1200 UTC), while 95 percent of all fog events have dissipated by 1600 UTC. A high number of fog events are characterized by a westerly component to the surface wind at KSC (92 percent) and 83 percent of the fog events had fog develop west of KSC first (up to 2 hours). The AMU developed fog decision trees and forecaster tools that would help the forecaster identify fog precursors up to 12 hours in advance. Using the decision trees as process tools ensures the important meteorological data are not overlooked in the forecast process. With these tools and a better understanding of fog formation in the local KSC area, the Shuttle weather support forecaster should be able to give the Launch and Flight Directors a better KSC fog forecast with more confidence

    Iodinated Cyanine Dyes: A New Class of Sensitisers for use in NIR Activated Photodynamic Therapy (PDT)

    Get PDF
    Iodinated cyanine dye 6a has been developed for use as a NIR excited photosensitiser in photodynamic therapy.</p

    Trends in Self‐Reported Oral Health of US Adults: National Health and Nutrition Examination Survey 1999‐2014

    Get PDF
    Objective Single‐item self‐reported oral health (SROH) is a convenient and reliable measure for the assessment of population‐based oral health. However, little is known about trends and its associations among US adults. This study investigated trends in SROH (aged 20+ years) and the associated factors among adults living in the United States. Methods Self‐reported oral health data for 41 621 adults aged 20+ years from the National Health and Nutrition Examination Survey (NHANES) 1999 to 2014 were analysed. Survey‐weighted descriptive statistics were computed to provide nationally representative estimates. Multivariable logistic regression was performed separately for each survey period with SROH as the primary outcome. Independent variables included were age, gender, race/ethnicity, education level and family poverty income ratio or PIR. Pooled survey‐weighted multivariable logistic regression was also performed to consider possible time‐changing effects. Results The survey‐weighted proportions of “excellent or very good” in SROH increased from 27% in 1999‐2000 (n = 4873) to 38% in 2013‐2014 (n = 5765). Separate multivariable logistic analyses for each survey period suggested that females, Whites (vs Mexican and Black Americans) as well as respondents from high family PIR had higher odds of reporting their oral health as “excellent or very good” (P \u3c .05). The pooled multivariable logistic model confirmed results in the separate logistic regression, and respondents in the more recent survey periods had higher probabilities of reporting “excellent or very good” oral health. Respondents aged 50‐59 years were found to have relatively lower probabilities of reporting “excellent or very good” oral health, while people aged 20‐29 years had higher probabilities than those aged 30‐39 years. Compared to respondents with lower education, those with higher education were more likely to report their oral health as excellent or very good. Conclusions Self‐reported oral health improved from 1999 to 2014. In general, respondents who were young, female, White, had higher education or higher income or were surveyed in more recent years reported excellent or very good oral health
    • 

    corecore