337 research outputs found

    Effects of humidity on tests of tear production

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    An efficient method for decoding the honey bee waggle dance and its use in determining the effects of hive relocation on foraging efficiency

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    Our understanding and uses of the honey bee waggle dance have come a long way since its discovery by Karl von Frisch in the 1940s. It is now used as a powerful research tool for investigating various features of honey bee biology. Manual dance decoding is time-consuming. It is impractical to decode all circuits of a dance to determine foraging location; however, intra-dance waggle runs vary, so it is important to decode enough to obtain a good average. In chapter 2 I examine the variation among waggle runs made by foraging bees to devise a method of dance decoding. The first and last waggle runs within a dance are significantly more variable than any waggle run in between. We recommend that any four consecutive waggle runs, not including the first and last runs, may be decoded. This thesis also examines how artificially moving hives affects the foraging efficiency of colonies that are moved and whether it has any effect on resident colonies (Chapter 3). We moved three colonies (in observation hives) onto the University of Sussex campus from a site more than 20km away and compared their foraging efficiency to three similarly sized resident colonies. Foraging distance, forager effort, nectar concentration, percentage of successful nectar foragers were the factors used to quantify foraging efficiency. We found that bringing new hives onto the apiary site had no effect on the foraging efficiency of the resident colonies that moved colonies were able to match the foraging efficiency of resident colonies immediately after the move

    Research into gang-associated sexual exploitation and sexual violence : interim report

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    The research has been commissioned by the Office of the Children’s Commissioner for England (OCC) as part of their Inquiry into Child Sexual Exploitation in Gangs and Groups (CSEGG).This report presents the interim findings of a two year study into gang-associated sexual exploitation and violenc

    "It's wrong - but you get used to it" : a qualitative study of gang-associated sexual violence towards, and exploitation of, young people in England

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    A report commissioned by the Office of the Children’s Commissioner’s Inquiry into Child Sexual Exploitation in Gangs and GroupsThe research was commissioned by the Office of the Children’s Commissioner for England as part of its Inquiry into Child Sexual Exploitation in Gangs and Groups. The research aimed to consider: the scale and nature of gang-associated sexual violence and exploitation in six areas of England; the main pathways into gang-related sexual violence and exploitation for young people living in these neighbourhoods; and potential models for an effective multi-agency response to the issue

    Characterisation of the first p-type Segmented Inverted-coaxial Germanium Detector, SIGMA

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    The Segmented Inverted-coaxial GerMAnium (SIGMA) detector is a large volume High Purity Germanium (HPGe) gamma-ray detector that aims to demonstrate superior en- ergy and position resolution over other large volume segmented germanium detectors. The SIGMA prototype detector is the first p-type detector of its kind to be produced. Due to the low noise of the point contact, the SIGMA detector can provide excellent energy resolution and, through the use of Pulse Shape Analysis (PSA), excellent po- sition resolution. Accurate and precise energy and position determination are the key factors in effective gamma-ray tracking making SIGMA particularly suited for use at Radioactive Ion Beam (RIB) experiments such as DESPEC. The SIGMA prototype detector has been characterised and tested at the Univer- sity of Liverpool. SIGMA showed excellent energy resolution with the point contact achieving 0.89 keV at 122 keV and 2.21 keV at 1332 keV and a relative efficiency of 40.9%. A collimated beam of 241Am and 137Cs gamma rays were scanned across the detector in 1 mm steps to investigate the crystal size, structure and position and the active area of the individual segments. The 241Am data was used to produce a risetime matrix displaying the change in drift time across the front face of the crystal. The detector was also operated alongside BGO detectors in coincidence mode and data acquired using the 137Cs beam to investigate pulse shape behaviour in the crystal at a range of positions. The pulses from all functioning segments were collected, includ- ing both real charge and image charge pulses, and used to produce an average response from each segment for individual x-y-z locations in the crystal. The average pulses were compared to investigate the position response of the detector. A measurable difference in pulse shape was seen in multiple segments for a separation of as little as 2 mm in one dimension

    The epidemiology and natural history of ANCA-associated vasculitis in the UK: a response to The UK Strategy for Rare Diseases

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    Introduction: Rare diseases have gained recognition over the past decade as an important area for health service improvement. They affect 1 in 17 people over a lifetime, consume 14% of the NHS budget, and are an important cause of illness and death[1]. In 2013, the Department of Health published for the first time a “UK Strategy for Rare Diseases” which identified 5 key recommendations for improving the lives of people with rare diseases, and included the need for epidemiological studies. 75% of rare diseases are genetic in origin, and have onset in childhood. However, rheumatologists provide care for people with a number of rare diseases, amounting to an important component of the 25% of rare diseases which are believed to be non-genetic and present in adulthood. One of the main challenges in studying rare disease, is the difficulty in finding enough people with the disease to study. Recent linkage of databases of primary and secondary care health records in the UK provide an opportunity to study representative samples, large numbers of people, and the breadth of healthcare provision. In this thesis, I report 4 epidemiological studies in routinely collected healthcare data, conducted in an exemplar rheumatic disease, ANCA-associated vasculitis. Methods: I used routinely collected healthcare data from local hospitals, a large database of UK general practice records, and linked hospital episode statistics to identify cases of ANCA-associated vasculitis. The specific questions addressed in the studies were: 1. What are the current incidence, prevalence and mortality of ANCA-associated vasculitis in the UK, stratified by age, sex and ethnic group? I addressed this question in a local hospital cohort, and then in linked primary and secondary care records in England. I used projections of the population structure in 20 years’ time to predict the expected number of incident and prevalent cases. 2. What is the natural history of the most common type of ANCA-associated vasculitis (granulomatosis with polyangiitis) prior to diagnosis, and are there opportunities to diagnose it sooner in primary or secondary care? I conducted a case-control study in a large database of primary care records, and attempted to develop a model for GPs that predicted the risk of a person having granulomatosis with polyangiitis, such as is advocated by the UK Strategy for Rare Diseases. 3. What are the strongest aetiological factors in granulomatosis with polyangiitis in the UK? I compared the frequency of possible aetiological exposures between cases and population-based controls in a large database of prospectively collected primary care data. Results: 1. There were about 1300 new cases of ANCA-associated vasculitis in the UK in 2015, more than previously thought. The incidence has been stable since 2000, however the disease is more common in older people, therefore due to predicted aging of the UK population there will be 34% more cases in 2035. We are not able to detect any differences in incidence rates between people from different ethnic groups, but our studies lacked power for this question. 2. People with granulomatosis with polyangiitis consulted their GP more than healthy people prior to their diagnosis. However, they consulted with a wide variety of symptoms, and none were highly predictive of the diagnosis. In addition, the lower the prevalence of the disease, the lower the positive predictive value of a diagnostic model. Granulomatosis with polyangiitis is rare, so even with an exceptionally well-performing model (with a sensitivity of 100% and a specificity of 90%) only 2 of every 10,000 people flagged as ‘at risk’ would have granulomatosis with polyangiitis, and the rest would have false positive results. 3. People with granulomatosis with polyangiitis were 5 times more likely than population-based controls to have a previous diagnosis of bronchiectasis, and 2-3 times more likely to have a previous diagnosis of an autoimmune disease or chronic renal impairment. Conclusions: 1. Although incidence appears stable, commissioners need to expand services to diagnose and treat people with GPA, and other adult-onset rare diseases, over the next 20 years due to the predicted increase in the proportion of the population in the age-groups at highest risk. 2. In particular, over the next 20 years, the age structure of the Black and Minority ethnic population in the UK is predicted to change to have many more people in older age-groups, and the UK medical community need to be alert to an expected emergence of significant numbers of Black and Minority ethnic people with ANCA-associated vasculitis. 3. Computerised prompts to alert GPs to consider a diagnosis of rare disease are unlikely to work. Resources to improve early diagnosis and treatment of ANCA-associated vasculitis would be better targeted at secondary care where the majority of cases have contact in the year before diagnosis. 4. The novel association of bronchiectasis with developing granulomatosis with polyangiitis raises a new hypothesis for bronchiectasis as a possible aetiological factor in granulomatosis with polyangiitis

    Simulating the density reduction and equity-impact of potential tobacco retail control policies.

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    Background: Reducing the provision of tobacco is important for decreasing inequalities in smoking and smoking-related harm. Various policies have been proposed to achieve this, but their impacts—particularly on equity—are often unknown. Here, using national-level data, we simulate the impacts of potential policies designed to reduce tobacco outlet density (TOD). Methods: Tobacco retailer locations (n=9030) were geocoded from Scotland’s national register, forming a baseline. Twelve policies were developed in three types: (1) regulating type of retailer selling tobacco, (2) regulating location of tobacco sales, and (3) area-based TOD caps. Density reduction was measured as mean percentage reduction in TOD across data zones and number of retailers nationally. Equity impact was measured using regression-based Relative Index of Inequality (RII) across income deprivation quintiles. Results: Policies restricting tobacco sales to a single outlet type (‘Supermarket’; ‘Liquor store’; ‘Pharmacy’) caused >80% TOD reduction and >90% reduction in the number of tobacco outlets nationally. However, RIIs indicated that two of these policies (‘Liquor store’, ‘Pharmacy’) increased socioeconomic inequalities in TOD. Equity-promoting policies included ‘Minimum spacing’ and exclusion zones around ‘Child spaces’. The only policy to remove statistically significant TOD inequalities was the one deliberately targeted to do so (‘Reduce clusters’). Conclusions: Using spatial simulations, we show that all selected policies reduced provision of tobacco retailing to varying degrees. However, the most ‘successful’ at doing so also increased inequalities. Consequently, policy-makers should consider how the methods by which tobacco retail density is reduced, and success measured, align with policy aims

    Healthy lifestyle and risk of breast cancer for indigenous and non-indigenous women in New Zealand: a case control study.

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    BACKGROUND: The reasons for the increasing breast cancer incidence in indigenous Māori compared to non-Māori New Zealand women are unknown. The aim of this study was to assess the association of an index of combined healthy lifestyle behaviours with the risk of breast cancer in Māori and non-Māori women. METHODS: A population-based case-control study was conducted, including breast cancer cases registered in New Zealand from 2005-2007. Controls were matched by ethnicity and 5-year age bands. A healthy lifestyle index score (HLIS) was generated for 1093 cases and 2118 controls, based on public health and cancer prevention recommendations. The HLIS was constructed from eleven factors (limiting red meat, cream, and cheese; consuming more white meat, fish, fruit and vegetables; lower alcohol consumption; not smoking; higher exercise levels; lower body mass index; and longer cumulative duration of breastfeeding). Equal weight was given to each factor. Logistic regression was used to estimate the associations between breast cancer and the HLIS for each ethnic group stratified by menopausal status. RESULTS: Among Māori, the mean HLIS was 5.00 (range 1-9); among non-Māori the mean was 5.43 (range 1.5-10.5). There was little evidence of an association between the HLIS and breast cancer for non-Māori women. Among postmenopausal Māori, those in the top HLIS tertile had a significantly lower odds of breast cancer (Odds Ratio 0.47, 95% confidence interval 0.23-0.94) compared to those in the bottom tertile. CONCLUSION: These findings suggest that healthy lifestyle recommendations could be important for reducing breast cancer risk in postmenopausal Māori women

    Intra-dance variation among waggle runs and the design of efficient protocols for honey bee dance decoding

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    Noise is universal in information transfer. In animal communication, this presents a challenge not only for intended signal receivers, but also to biologists studying the system. In honey bees, a forager communicates to nestmates the location of an important resource via the waggle dance. This vibrational signal is composed of repeating units (waggle runs) that are then averaged by nestmates to derive a single vector. Manual dance decoding is a powerful tool for studying bee foraging ecology, although the process is time-consuming: a forager may repeat the waggle run 1- >100 times within a dance. It is impractical to decode all of these to obtain the vector; however, intra-dance waggle runs vary, so it is important to decode enough to obtain a good average. Here we examine the variation among waggle runs made by foraging bees to devise a method of dance decoding. The first and last waggle runs within a dance are significantly more variable than the middle run. There was no trend in variation for the middle waggle runs. We recommend that any four consecutive waggle runs, not including the first and last runs, may be decoded, and we show that this methodology is suitable by demonstrating the goodness-of-fit between the decoded vectors from our subsamples with the vectors from the entire dances
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