On the slow motion of a spheroid in a rotating stratified fluid

We consider the slow motion generated when a body is set into motion relative to an incompressible, inviscid, non-diffusive rotating stratified fluid, showing that there is generated in general a topographic Rossby wave which leads to non-decaying fluctuations in the lift on the obstacle and a fluctuating non-zero drag. The problem is relevant to the flow patterns and forces excited when slow oceanic flows cross bottom topography and suggests a mechanism for slow fluctuations observed in laboratory experiments

Prevalence of beliefs about actual and mythical causes of cancer and their association with socio-demographic and health-related characteristics: findings from a cross-sectional survey in England

Background: Literature on population awareness about actual causes of cancer is growing but comparatively little is known about the prevalence of people’s belief concerning mythical causes of cancer. This study aimed to estimate the prevalence of these beliefs and their association with socio-demographic characteristics and health behaviours. Methods: A survey containing validated measures of beliefs about actual and mythical cancer causes and health behaviours (smoking, alcohol consumption, physical activity, fruit and vegetable consumption, overweight) was administered to a representative English population sample (N=1,330). Results: Awareness of actual causes of cancer (52% accurately identified; 95% Confidence Interval (CI) 51-54) was greater than awareness of mythical cancer causes (36% accurately identified; 95%CI 34-37; P<0.01). The most commonly endorsed mythical cancer causes were exposure to stress (43%; 95%CI 40-45), food additives (42%; 95%CI 39-44) and electromagnetic frequencies (35%; 95%CI 33-38). In adjusted analysis, greater awareness of actual and mythical cancer causes was independently associated with younger age, higher social grade, being white and having post-16 qualifications. Awareness of actual but not mythical cancer causes was associated with not smoking and eating sufficient fruit and vegetables. Conclusions: Awareness of actual and mythical cancer causes is poor in the general population. Only knowledge of established risk factors is associated with adherence to behavioural recommendations for reducing cancer risk

How is cervical cancer screening information communicated in UK websites? A cross-sectional analysis of content and quantitative presentation formats

Objectives: To investigate whether UK websites about cervical cancer screening targeted to the public include (1) information about benefits and risks of screening, possible screening results and cervical cancer statistics, (2) quantitative presentation formats recommended in the risk communication literature and (3) appeals for participation and/or informed decision-making. Design: Cross-sectional analysis of websites using a comprehensive checklist of information items on screening benefits, risks, possible results and cervical cancer statistics. Outcome measures: We recorded the number of websites that contained each of the information items, and the presentation format used for probabilistic information (no quantification provided, verbal quantifiers only, different types of numerical formats and/or graphs). We also recorded the number of websites containing appeals for participation and/or informed decision-making. Setting: Websites were identified through the most common Google search terms used in the UK to find information on cervical screening, according to GoogleTrends and a commercial internet-monitoring programme. Two additional websites were identified by the authors as relevant. Results: After applying exclusion criteria, 14 websites were evaluated, including websites of public and private health service providers, charities, a medical society and a pharmacy. The websites mentioned different benefits, risks of screening and possible results. However, specific content varied between websites. Probabilistic information was often presented using non-recommended formats, including relative risk reductions to express screening benefits, and verbal quantifiers without numbers to express risks. Appeals for participation were present in most websites, with almost half also mentioning informed decision-making. Conclusions: UK websites about cervical cancer screening were generally balanced. However, benefits and risks were presented using different formats, potentially hindering comparisons. Additionally, recommendations from the literature to facilitate understanding of quantitative information and facilitate informed decisions were often not followed. Designing websites that adhere to existing recommendations may support informed screening uptake

Using ‘gist-based’ information to reduce inequalities and improve cancer screening uptake

Colorectal cancer (CRC) is the second most common cause of cancer death in the UK. Screening is key to promoting early diagnosis and thereby improving survival. The English NHS Bowel Cancer Screening Programme (BCSP) invites adults aged 60-69 to complete a home-based Faecal Occult Blood test (FOBt) kit every 2 years. Routinely collected data indicate uptake of only 54% for the first invitation; varying from 35% in the most deprived quintile of residential areas to 61% in the least deprived quintile. Evidently, the full benefits of CRC screening are not being realised and inequalities in CRC outcomes may increase. Evidence from a number of sources indicates less awareness of CRC, and less recognition of the benefits of screening, in lower SES groups. It is therefore crucial that the screening information booklet mailed with the test enables people of all levels of health literacy to make an informed decision about participating in the BCSP. This thesis describes the development and testing of a health communication intervention that aims to reduce inequalities in uptake. Study 1 used the ‘think-aloud’ method to examine responses to the existing information booklet in order to identify barriers to comprehension. The process of designing a supplementary leaflet to facilitate ‘gist-based’ processing is described. Gist is defined as the qualitative representation of concepts, and gist-based processing is the preference for evaluating information in its simplest form. Performance-based user-testing was used to optimise the content, design and layout of the gist leaflet (study 2). The communicative effectiveness of the leaflet was tested in study 3, which was a community-based randomised controlled trial (registration number: ISRCTN62215021) in which adults approaching the screening age were randomised to be sent standard screening information (control) or standard information plus the gist leaflet (intervention). Findings from 964 respondents showed that the gist leaflet was considered to be readable and useful and did not cause additional worry about CRC. Screening intention and perceived risk were unaffected by the gist leaflet, however knowledge was significantly higher among the intervention group. Study 4 was a national, cluster randomised trial (registration number: ISRCTN74121020) nested in the existing NHS BCSP (n=163,566). Adults who were 5 being sent a screening invitation were randomised to receive the standard information or standard information plus the gist leaflet. Randomisation was by day of mailing and stratified by screening hub. The gist leaflet had no effect on the socioeconomic gradient in screening uptake and no effect on screening uptake overall. Among a sub-sample of people being invited for the first time, a small but significant difference in screening uptake was seen in the intervention group. This effect was particularly apparent among men and older people. Despite the small effects of the gist intervention on screening uptake among specific sub-groups, the provision of supplementary gist-based information in this context is unlikely to reduce the socioeconomic gradient in CRC screening uptake. Implications for the NHS BCSP and future research are discussed

A comparison in species distribution model performance of succulents using key species and subsets of environmental predictors

Identifying the environmental drivers of the global distribution of succulent plants using the Crassulacean acid metabolism pathway of photosynthesis has previously been investigated through ensemble-modeling of species delimiting the realized niche of the natural succulent biome. An alternative approach, which may provide further insight into the fundamental niche of succulent plants in the absence of dispersal limitation, is to model the distribution of selected species that are globally widespread and have become naturalized far beyond their native habitats. This could be of interest, for example, in defining areas that may be suitable for cultivation of alternative crops resilient to future climate change. We therefore explored the performance of climate-only species distribution models (SDMs) in predicting the drivers and distribution of two widespread CAM plants, Opuntia ficus-indica and Euphorbia tirucalli. Using two different algorithms and five predictor sets, we created distribution models for these exemplar species and produced an updated map of global inter-annual rainfall predictability. No single predictor set produced markedly more accurate models, with the basic bioclim-only predictor set marginally out-performing combinations with additional predictors. Minimum temperature of the coldest month was the single most important variable in determining spatial distribution, but additional predictors such as precipitation and inter-annual precipitation variability were also important in explaining the differences in spatial predictions between SDMs. When compared against previous projections, an a posteriori approach correctly does not predict distributions in areas of ecophysiological tolerance yet known absence (e.g., due to biotic competition). An updated map of inter-annual rainfall predictability has successfully identified regions known to be depauperate in succulent plants. High model performance metrics suggest that the majority of potentially suitable regions for these species are predicted by these models with a limited number of climate predictors, and there is no benefit in expanding model complexity and increasing the potential for overfitting

Acceptability of the Cytosponge procedure for detecting Barrett’s oesophagus: A qualitative study

Objective: To investigate the acceptability of the Cytosponge, a novel sampling device to detect Barrett's oesophagus (BE), a precursor to oesophageal adenocarcinoma (EAC), among people with risk factors for this condition. Design: A qualitative study using semistructured interviews and focus group discussions. Data were explored by three researchers using thematic analysis. Setting: Community setting in London, UK. Participants: A recruitment company identified 33 adults (17 men, 16 women) aged 50–69 years with gastro-oesophageal reflux disease (GERD), a risk factor for BE. The majority of participants were white British (73%). The focus groups were stratified by gender and education. 10 individuals were interviewed and 23 participated in four focus groups. Results: 3 key themes emerged from the data: the anticipated physical experience, preferences for the content of information materials and comparisons with the current gold-standard test. Overall acceptability was high, but there was initial concern about the physical experience of taking the test, including swallowing and extracting the Cytosponge. These worries were reduced after handling the device and a video demonstration of the procedure. Knowledge of the relationship between GERD, BE and EAC was poor, and some suggested they would prefer not to know about the link when being offered the Cytosponge. Participants perceived the Cytosponge to be more comfortable, practical and economical than endoscopy. Conclusions: These qualitative data suggest the Cytosponge was acceptable to the majority of participants with risk factors for BE, and could be used as a first-line test to investigate GERD symptoms. Concerns about the physical experience of the test were alleviated through multimedia resources. The development of patient information materials is an important next step to ensuring patients are adequately informed and reassured about the procedure. Patient stakeholders should be involved in this process to ensure their concerns and preferences are considered

Participant-Reported Symptoms and Their Effect on Long-Term Adherence in the International Breast Cancer Intervention Study I (IBIS I)

Purpose: To assess the role of participant-reported symptoms on long-term adherence to preventive therapy in the United Kingdom sample of the International Breast Cancer Intervention Study (IBIS-I). IBIS-I was a randomized controlled trial that investigated the effectiveness of tamoxifen in reducing the risk of breast cancer among women at increased risk of the disease. Participants and Methods: Women were randomly assigned to tamoxifen versus placebo (20 mg/day; n = 4,279). After 456 exclusions, 3,823 women were included in this analysis. Adherence (< 4.5 years or ≥ 4.5 years) was calculated using data from six monthly clinical visits. Analyses were adjusted for age, Tyrer-Cuzick risk, smoking, use of hormone replacement therapy, menopausal status, baseline menopausal symptoms, and treatment. Results: Overall, 69.7% of women were adherent for at least 4.5 years (tamoxifen: 65.2% v placebo: 74.0%; P .05). In both treatment arms, we observed significant trends for lower adherence with increasing severity for all symptoms (P < .01) except headaches (P = .054). Conclusion: In the IBIS-I trial, experiencing predefined symptoms in the first 6 months reduced long-term adherence. Effects were similar between treatment arms, suggesting that women were attributing age-related symptoms to preventive therapy. Interventions were required to support symptom management