Two-dimensional negative donors in magnetic fields

A finite-difference solution of the Schroedinger equation for negative donor centers D^- in two dimensions is presented. Our approach is of exact nature and allows us to resolve a discrepancy in the literature on the ground state of a negative donor. Detailed calculations of the energies for a number of states show that for field strengths less than \gamma=0.117 a.u. the donor possesses one bound state, for 0.117<\gamma<1.68 a.u. there exist two bound states and for field strengths \gamma>1.68 a.u. the system possesses three bound states. Further relevant characteristics of negative donors in magnetic fields are provided.Comment: 7 pages, 1 figur

A Novel Patient-Reported Outcome-Based Evaluation (PROBE) of Quality of Life in Patients with Inflammatory Bowel Disease

OBJECTIVES:There is increased interest in measuring patient-reported outcomes (PROs) such as quality of life (QoL) among patients with inflammatory bowel disease (IBD). We aimed to create and validate a new measure of QoL to assess the psychosocial burden of IBD using publicly available assessment tools.METHODS:Using the Crohn's & Colitis Foundation's IBD Partners cohort, we performed several cross-sectional and longitudinal analyses to create a new PRO-based evaluation (PROBE) of QoL among patients with Crohn's disease (CD) and ulcerative colitis (UC). We used factor analysis and Pearson correlation test to identify candidate questions for inclusion, Wilcoxon rank-sum test to examine responsiveness of the PROBE to changes in disease activity, and test-retest reliability assessments in patients with stable disease activity. We also compared the PROBE to the Short Inflammatory Bowel Disease Questionnaire to assess construct validity.RESULTS:A total of 4,854 patients (64% CD, 36% UC) completed surveys with 6 items included in the final PROBE. Compared with baseline there was a significant decrease in PROBE scores at follow-up among patients who experienced a flare for UC (25.0 vs 22.2, P = 0.001) and CD (23.1 vs 21.0, P < 0.001). Among patients with stable disease activity, Cronbach alpha was 0.87 in CD and 0.82 in UC. The PROBE correlated well with the Short Inflammatory Bowel Disease Questionnaire in CD (r = 0.88) and UC (r = 0.86).DISCUSSION:We created a novel measure to assess QoL in patients with IBD using publicly available survey items. This new PROBE can be used to facilitate clinical care, clinical and epidemiological research, and quality improvement

Predictors of blood volatile organic compound levels in Gulf coast residents article

To address concerns among Gulf Coast residents about ongoing exposures to volatile organic compounds, including benzene, toluene, ethylbenzene, o-xylene, and m-xylene/p-xylene (BTEX), we characterized current blood levels and identified predictors of BTEX among Gulf state residents. We collected questionnaire data on recent exposures and measured blood BTEX levels in a convenience sample of 718 Gulf residents. Because BTEX is rapidly cleared from the body, blood levels represent recent exposures in the past 24 h. We compared participants' levels of blood BTEX to a nationally representative sample. Among nonsmokers we assessed predictors of blood BTEX levels using linear regression, and predicted the risk of elevated BTEX levels using modified Poisson regression. Blood BTEX levels in Gulf residents were similar to national levels. Among nonsmokers, sex and reporting recent smoky/chemical odors predicted blood BTEX. The change in log benzene was -0.26 (95% CI: -0.47, -0.04) and 0.72 (0.02, 1.42) for women and those who reported odors, respectively. Season, time spent away from home, and self-reported residential proximity to Superfund sites (within a half mile) were statistically associated with benzene only, however mean concentration was nearly an order of magnitude below that of cigarette smokers. Among these Gulf residents, smoking was the primary contributor to blood BTEX levels, but other factors were also relevant

Lung function in oil spill responders 4-6 years after the Deepwater Horizon disaster

Oil spill response and clean-up (OSRC) workers were exposed to hazardous airborne chemicals following the 2010 Deepwater Horizon disaster. The aim of this study was to evaluate lung function in workers 4–6 years following the disaster using a prospective cohort. Participants who completed two spirometry test sessions 1–3 years, and 4–6 years after the spill (N = 1,838) were included and forced expiratory volume in 1 s (FEV1; ml), forced vital capacity (FVC; ml), and ratio (FEV1/FVC; %) determined. Linear mixed models were utilized to estimate relationships between OSRC exposures and lung function 4–6 years after the spill and changes since the prior measurement. Despite suggestive reduced lung function at 1–3 years, at the 4–6-year exam workers with total hydrocarbon (THC) exposure 1–2.99 ppm and ≥3 ppm compared to those with ≤0.29 ppm exhibited higher FEV1 (β: 108 ml, 95% CI: 17, 198) and (β: 118 ml, 95% CI: 5, 232), respectively. Compared with support workers, those in higher exposed jobs displayed greater improvement in FEV1 between visits: cleanup on water (β: 143 ml, 95% CI: 35, 250), operations (β: 132 ml, 95% CI: 30, 234) and response (β: 149 ml, 95% CI: 43, 256). Greater FEV1 improvement was also associated with higher versus the lowest level THC exposure: 1–2.99 ppm (β: 134 ml, 95% CI: 57, 210) and ≥3 ppm (β: 205 ml, 95% CI: 109, 301). Lung function decrements seen shortly after the spill were no longer apparent 4–6 years later, with the greatest improvement among those with the highest exposures

What is being done to deter ambush marketing? Are these attempts working?

This paper examines industry responses in Australasia and Europe to the growing practice of ambush marketing, to establish whether the measures that have been put in place to deter the practice have indeed prevented the ‘ambush’ effect, whereby audiences associate non-sponsoring organisations with particular sporting events. Although some of these measures may be more effective than others in blocking ambush attempts, they also come with potentially negative consequences for event sponsors

Tries and conversions: are sports sponsors pursuing the right objectives?

Sports sponsorship is perceived as important in developing relationships with key clients. However, few companies set relationship marketing objectives when sponsoring sports. This paper aims to examine whether sports sponsors are pursuing the right objectives. It concludes that a deeper understanding of the sponsor's relationship marketing objectives could heighten the sponsor's success, thereby reinforcing and sustaining their own relationship with the sponsoring organisation

Physical activity, sedentary time and breast cancer risk: a Mendelian randomisation study

Objectives: Physical inactivity and sedentary behaviour are associated with higher breast cancer risk in observational studies, but ascribing causality is difficult. Mendelian randomisation (MR) assesses causality by simulating randomised trial groups using genotype. We assessed whether lifelong physical activity or sedentary time, assessed using genotype, may be causally associated with breast cancer risk overall, pre/post-menopause, and by case-groups defined by tumour characteristics. Methods: We performed two-sample inverse-variance-weighted MR using individual-level Breast Cancer Association Consortium case-control data from 130 957 European-ancestry women (69 838 invasive cases), and published UK Biobank data (n=91 105–377 234). Genetic instruments were single nucleotide polymorphisms (SNPs) associated in UK Biobank with wrist-worn accelerometer-measured overall physical activity (nsnps=5) or sedentary time (nsnps=6), or accelerometer-measured (nsnps=1) or self-reported (nsnps=5) vigorous physical activity. Results: Greater genetically-predicted overall activity was associated with lower breast cancer overall risk (OR=0.59; 95% confidence interval (CI) 0.42 to 0.83 per-standard deviation (SD;~8 milligravities acceleration)) and for most case-groups. Genetically-predicted vigorous activity was associated with lower risk of pre/perimenopausal breast cancer (OR=0.62; 95% CI 0.45 to 0.87,≥3 vs. 0 self-reported days/week), with consistent estimates for most case-groups. Greater genetically-predicted sedentary time was associated with higher hormone-receptor-negative tumour risk (OR=1.77; 95% CI 1.07 to 2.92 per-SD (~7% time spent sedentary)), with elevated estimates for most case-groups. Results were robust to sensitivity analyses examining pleiotropy (including weighted-median-MR, MR-Egger). Conclusion: Our study provides strong evidence that greater overall physical activity, greater vigorous activity, and lower sedentary time are likely to reduce breast cancer risk. More widespread adoption of active lifestyles may reduce the burden from the most common cancer in women

Associations of obesity and circulating insulin and glucose with breast cancer risk: a Mendelian randomization analysis.

BACKGROUND: In addition to the established association between general obesity and breast cancer risk, central obesity and circulating fasting insulin and glucose have been linked to the development of this common malignancy. Findings from previous studies, however, have been inconsistent, and the nature of the associations is unclear. METHODS: We conducted Mendelian randomization analyses to evaluate the association of breast cancer risk, using genetic instruments, with fasting insulin, fasting glucose, 2-h glucose, body mass index (BMI) and BMI-adjusted waist-hip-ratio (WHRadj BMI). We first confirmed the association of these instruments with type 2 diabetes risk in a large diabetes genome-wide association study consortium. We then investigated their associations with breast cancer risk using individual-level data obtained from 98 842 cases and 83 464 controls of European descent in the Breast Cancer Association Consortium. RESULTS: All sets of instruments were associated with risk of type 2 diabetes. Associations with breast cancer risk were found for genetically predicted fasting insulin [odds ratio (OR) = 1.71 per standard deviation (SD) increase, 95% confidence interval (CI) = 1.26-2.31, p  =  5.09  ×  10-4], 2-h glucose (OR = 1.80 per SD increase, 95% CI = 1.3 0-2.49, p  =  4.02  ×  10-4), BMI (OR = 0.70 per 5-unit increase, 95% CI = 0.65-0.76, p  =  5.05  ×  10-19) and WHRadj BMI (OR = 0.85, 95% CI = 0.79-0.91, p  =  9.22  ×  10-6). Stratified analyses showed that genetically predicted fasting insulin was more closely related to risk of estrogen-receptor [ER]-positive cancer, whereas the associations with instruments of 2-h glucose, BMI and WHRadj BMI were consistent regardless of age, menopausal status, estrogen receptor status and family history of breast cancer. CONCLUSIONS: We confirmed the previously reported inverse association of genetically predicted BMI with breast cancer risk, and showed a positive association of genetically predicted fasting insulin and 2-h glucose and an inverse association of WHRadj BMI with breast cancer risk. Our study suggests that genetically determined obesity and glucose/insulin-related traits have an important role in the aetiology of breast cancer

A case-only study to identify genetic modifiers of breast cancer risk for BRCA1/BRCA2 mutation carriers

Breast cancer (BC) risk for BRCA1 and BRCA2 mutation carriers varies by genetic and familial factors. About 50 common variants have been shown to modify BC risk for mutation carriers. All but three, were identified in general population studies. Other mutation carrier-specific susceptibility variants may exist but studies of mutation carriers have so far been underpowered. We conduct a novel case-only genome-wide association study comparing genotype frequencies between 60,212 general population BC cases and 13,007 cases with BRCA1 or BRCA2 mutations. We identify robust novel associations for 2 variants with BC for BRCA1 and 3 for BRCA2 mutation carriers, P < 10−8, at 5 loci, which are not associated with risk in the general population. They include rs60882887 at 11p11.2 where MADD, SP11 and EIF1, genes previously implicated in BC biology, are predicted as potential targets. These findings will contribute towards customising BC polygenic risk scores for BRCA1 and BRCA2 mutation carriers