8,485 research outputs found
Are there socioeconomic gradients in stage and grade of breast cancer at diagnosis? Cross sectional analysis of UK cancer registry data
Socioeconomic gradients in uptake of breast cancer screening in the United Kingdom should, intuitively, lead to socioeconomic gradients in disease progression at diagnosis. However, studies have found little evidence of such an effect. Although this could be interpreted as evidence that socioeconomic gradients in uptake of screening do not have clinically important consequences, all of the published studies have used data from before (pre-1988) or during the early stages (1988-95) of implementation of the national breast cancer screening programme. We investigated the relation between socioeconomic position and progression of breast cancer at diagnosis by using recent data from the Northern and Yorkshire Cancer Registry and Information Service (NYCRIS), which is estimated to achieve around 93% ascertainment
Microhardness and Scanning Electron Microscopy Analysis of Nd:YAG Laser and Acid Treatment Effects in Dentin
Laser irradiation at and above parameters producing the modification threshold for dentin causes structural changes to the dentin surface. This study determined the microhardness of dentin before and after laser modification and acid treatment using a repeated-measures de-sign. Seven dentin sections (4 mm in thickness) were cut from freshly extracted non-carious third molars using a diamond saw. The middle occlusal third was used as the test dentin surface. One section served as a control (C); three received laser modification (L) and then acid treatment (L + A); and three received acid (A) and then laser treatment (A + L). Laser modification was made using a pulsed (120 ÎŒs) fiber-optic-delivered (500 ÎŒm diameter) Nd:YAG (â= 1.06 ÎŒm) laser at the physical modification threshold of 207 J/cm2. Acid treatment consisted of 10% nitric acid applied for 45 seconds. Twenty Knoop indentation microhardness measurements (KHN) were obtained using 300 g force engaged for 15 seconds for each section before and after each treatment (n = 400). Knoop microhardness values recorded: C = 62 ± 3; L = 149 ± 35; A = 24 ± 5; L + A = 40 ± 16; and A + L = 33 ± 5. Multifactor-repeated measures, with analysis of variance (ANOVA; p †0.05), indicated significant differences between all treatment groups. Scanning electron microscopy analysis of dentin surfaces documented unique surface morphology for all treatment conditions. Laser modification of dentin before or after acid treatment increased dentin microhardness
A Study of Trihalomethane Precursors in Deer Creek Reservoir
Deer Creek Reservoir and tributaries were monitored from May to December 1983 in a study of the occurrence of trihalomethane (THM) precursors in the reservoir and nutrient dynamics of the reservoir system. Microcosms were used to study the effect of the following parameters on THM precursor production in the reservoir system: phosphorus loading, sediment, algal growth, and application of algicide. Additionally, THM precursor concentrations of interstitial water were analyzed in reservoir and microcosm sediment samples. Microcosms treated with ahigh phosphorus loading (70 ug/1) had THM precursor concentrations significantly higher than those measured in microcosms treated with a low phosphorus loading (10 ug/1). The presence of sediment in microcosms did not significantly affect THM precursor concentrations. Algae growth did result in THM production significantly aboce that measured in microcosms without algae growth. No correlation between total organic carbon and terminal total trihalomethane concentrations was found to exist in microcosms. Potassium permanganate and copper sulface were used as algicides. Applications of 0.3 mg/1 potassium permanganate and 50 ug/1 copper sulfate as Cu^+2 did not appear to affect THM precursor, total phosphorus, total suspended solids, or volatile suspended solids concentrations in the microcosms. Anoxic phosphorus release occurred in dark microcosms after the dissolved oxygen concentration dropped below approximately 3.0 mg/1. Considering all data collected, no significant difference in THM precursor concentraion could be detected between tributary and reservoir samples. THM precursor concentrations in tributaries were found to vary significantly be season. Samples collected from three depths within the reservoir were not found to have significantly different mean terminal total trihalomethane concentrations over the sampling period. No correlation between total organic carbon and terminal total trihalomethane concentrations was found to exist. Total phosphorus concentrations in tributaries were quite high, particularly in Main and Daniels Creeks
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What arguments and from whom are most influential in shaping public health policy: thematic content analysis of responses to a public consultation on the regulation of television food advertising to children in the UK.
OBJECTIVES: We explore one aspect of the decision making process-public consultation on policy proposals by a national regulatory body-aiming to understand how public health policy development is influenced by different stakeholders. DESIGN: We used thematic content analysis to explore responses to a national consultation on the regulation of television advertising of foods high in fat, salt and sugar aimed at children. SETTING: UK. RESULTS: 139 responses from key stakeholder groups were analysed to determine how they influenced the regulator's initial proposals for advertising restrictions. The regulator's priorities were questioned throughout the consultation process by public health stakeholders. The eventual restrictions implemented were less strict in many ways than those originally proposed. These changes appeared to be influenced most by commercial, rather than public health, stakeholders. CONCLUSIONS: Public health policy making appears to be considered as a balance between commercial and public health interests. Tactics such as the questioning and reframing of scientific evidence may be used. In this example, exploring the development of policy regulating television food advertising to children, commercial considerations appear to have led to a watering down of initial regulatory proposals, with proposed packages not including the measures public health advocates considered to be the most effective. This seems likely to have compromised the ultimate public health effectiveness of the regulations eventually implemented.Funding - This work was undertaken by the Centre for Diet and Activity Research (CEDAR), a UKCRC Public Health Research Centre of Excellence. Funding from Cancer Research UK, the British Heart Foundation, the Economic and Social Research Council, the Medical Research Council, the National Institute for Health Research, and the Wellcome Trust, under the auspices of the UK Clinical Research Collaboration, is gratefully acknowledged. The funders had no role in the study design, data collection, analysis, interpretation, or writing, nor in the decision to submit the article for publication
A Theoretical Model for the Relation for Supermassive Black Holes in Galaxies
We construct a model for the formation of black holes within galactic bulges.
The initial state is a slowly rotating isothermal sphere, characterized by
effective transport speed \aeff and rotation rate . The black hole
mass is determined when the centrifugal radius of the collapse flow exceeds the
capture radius of the central black hole. This model reproduces the observed
correlation between black hole masses and galactic velocity dispersions, \mbh
\approx 10^8 M_\odot (\sigma/200 \kms)^4, where \sigma = \sqrt{2} \aeff.
This model also predicts the ratio \mrat of black hole mass to host mass:
\mrat 0.004 (\sigma/200 \kms).Comment: 9 pages, 2 figures, submitted to Astrophysical Journal Letter
Unmanned aerial systems (UAS) operatorsâ accuracy and confidence of decisions: Professional pilots or video game players?
Unmanned Aerial Systems (UAS) operations have outpaced current training regimes resulting in a shortage of qualified UAS pilots. Three potential UAS operator groups were explored for suitability (i.e. video game players [VGP]; private pilots; professional pilots) and examined to assess levels of accuracy, confidence and confidence-accuracy judgements (W-S C-A) during a simulated civilian cargo flight. Sixty participants made 21 decision tasks, which varied across three levels of danger/risk. Scales of Tolerance of Ambiguity, Decision Style and NEO-PIR were also completed. Professional pilots and VGPs exhibited the highest level of decision confidence, with VGPs maintaining a constant and positive W-S C-A relationship across decision danger/risk. As decision danger/risk increased, confidence, accuracy and W-S C-A decreased. Decision danger also had a role to play in the confidence expressed when choosing to intervene or rely on automation. Neuroticism was negatively related, and conscientiousness positively related, to confidence. Intolerance of ambiguity was negatively related to W-S C-A. All groups showed higher levels of decision confidence in decisions controlled by the UAS in comparison to decisions where the operator manually intervened. VGPs display less overconfidence in decision judgements. Findings support the idea that VGPs could be considered a resource in UAS operation
Effect of Restrictions on Television Food Advertising to Children on Exposure to Advertisements for âLess Healthyâ Foods: Repeat Cross-Sectional Study
<div><h3>Background</h3><p>In 2007, new scheduling restrictions on television food advertising to children in the UK were announced. The aim of the restrictions was to âreduce significantly the exposure of children under 16 to high fat, salt or sugar (HFSS) advertisingâ. We explored the impact of the restrictions on relative exposure to HFSS food advertising among all viewers and among child television viewers, as well as adherence to the restrictions.</p> <h3>Methods</h3><p>We conducted two cross-sectional studies of all advertisements broadcast in one region of the UK over one week periods â the first (week 1) six months before the restrictions were introduced, and the second (week 2) six months after. Data on what products were advertised were linked to data on how many people watched each advertisement. Nutritional content of foods advertised was added to the dataset and used to calculate HFSS status. Relative exposure was calculated as the proportion of all advertising person-minute-views (PMVs) that were for HFSS foods.</p> <h3>Results</h3><p>1,672,417 advertising PMV were included. 14.6% of advertising PMV were for food and 51.1% of these were for HFSS food. Relative exposure of all viewers to HFSS food advertising increased between study weeks 1 and 2 (odds ratio (99% confidence intervals)â=â1·54 (1·51 to 1·57)). Exposure of children to HFSS food advertising did not change between study weeks 1 and 2 (odds ratio (99% confidence intervals)â=â1·05 (0·99 to 1·12)). There was almost universal adherence to the restrictions.</p> <h3>Conclusions</h3><p>Despite good adherence to the restrictions, they did not change relative exposure of children to HFSS advertising and were associated with an increase in relative exposure of all viewers to HFSS advertising. Stronger restrictions targeting a wider range of advertisements are necessary to reduce exposure of children to marketing of less healthful foods.</p> </div
Building consensus on interactions between population health researchers and the food industry: two-stage, online, international Delphi study and stakeholder survey
Abstract
Key to scientific integrity is ensuring that research findings are considered credible by scientific peers, practitioners, policymakers and the public. Industry sponsorship of nutritional research can result in bias and raises significant professional, public and media concern. Yet, there is no international consensus on how to prevent or manage conflicts of interest for researchers considering engaging with the food industry. This study aimed to determine internationally agreed principles to guide interactions between population health researchers and the food industry to prevent or manage conflicts of interest. We used a two-stage, online Delphi study for researchers (n=100 in 28 countries), and an online survey for stakeholders (n=84 in 26 countries). Levels of agreement were sought with 56 principles derived from a systematic review. Respondent comments were analysed using qualitative content analysis. High levels of agreement on principles were achieved for both groups (researchers 68%; stakeholders 65%). Highest levels of agreement were with principles concerning research methods and governance. More contentious were principles that required values-based decision-making, such as determining which elements of the commercial sector are acceptable to interact with. These results provide the basis for developing internationally-agreed guidelines for population health researchers governing interactions with the food industry.The work was undertaken under the auspices of the Centre for Diet and Activity Research (CEDAR), a UKCRC Public Health Research Centre of Excellence which is funded by the British Heart Foundation, Cancer Research UK, Economic and Social Research Council, Medical Research Council, the National Institute for Health Research, and the Wellcome Trust
Making integration foundational in population health intervention research: why we need 'Work Package Zero'
Objectives:Â We aimed to identify when and how integration should take place within evaluations of complex population health interventions (PHIs).
Study design:Â Descriptive analytical approach.
Methods:Â We draw on conceptual insights that emerged through (1) a working group on integration and (2) a diverse range of literature on case studies, small-n evaluations and mixed methods evaluation studies.
Results:Â We initially sought techniques to integrate analyses at the end of a complex PHI evaluation. However, this conceptualization of integration proved limiting. Instead, we found value in conceptualizing integration as a process that commences at the beginning of an evaluation and continues throughout. Many methods can be used for this type of integration, including process tracing, realist evaluation, congruence analysis, general elimination methodology/modus operandi, pattern matching and contribution analysis. Clearly signposting when integrative methods should commence within an evaluation should be of value to the PHI evaluation community, as well as to funders and related stakeholders.
Conclusions:Â Rather than being a tool used at the end of an evaluation, we propose that integration is more usefully conceived as a process that commences at the start of an evaluation and continues throughout. To emphasize the importance of this timing, integration can be described as comprising âWork Package Zeroâ within evaluations of complex PHIs
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