485 research outputs found

    Estimating PM\u3csub\u3e2.5\u3c/sub\u3ein Southern California using satellite data: Factors that affect model performance

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    Background: Studies of PM2.5 health effects are influenced by the spatiotemporal coverage and accuracy of exposure estimates. The use of satellite remote sensing data such as aerosol optical depth (AOD) in PM2.5 exposure modeling has increased recently in the US and elsewhere in the world. However, few studies have addressed this issue in southern California due to challenges with reflective surfaces and complex terrain. Methods: We examined the factors affecting the associations with satellite AOD using a two-stage spatial statistical model. The first stage estimated the temporal PM2.5/AOD relationships using a linear mixed effects model at 1 km resolution. The second stage accounted for spatial variation using geographically weighted regression. Goodness of fit for the final model was evaluated by comparing the daily PM2.5 concentrations generated by cross-validation (CV) with observations. These methods were applied to a region of southern California spanning from Los Angeles to San Diego. Results: Mean predicted PM2.5 concentration for the study domain was 8.84 µg m-3. Linear regression between CV predicted PM2.5 concentrations and observations had an R 2 of 0.80 and RMSE 2.25 µg m-3. The ratio of PM2.5 to PM10 proved an important variable in modifying the AOD/PM2.5 relationship (β = 14.79, p ≤ 0.001). Including this ratio improved model performance significantly (a 0.10 increase in CV R 2 and a 0.56 µg m-3 decrease in CV RMSE). Discussion: Utilizing the high-resolution MAIAC AOD, fine-resolution PM2.5 concentrations can be estimated where measurements are sparse. This study adds to the current literature using remote sensing data to achieve better exposure data in the understudied region of Southern California. Overall, we demonstrate the usefulness of MAIAC AOD and the importance of considering coarser particles in dust prone areas

    Concomitant primary breast carcinoma and primary choroidal melanoma: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Choroidal melanoma and choroidal metastasis are distinct pathological entities with very different treatments and prognoses. They may be difficult to distinguish to the untrained observer.</p> <p>Case presentation</p> <p>A case of concomitant choroidal melanoma in a woman with primary breast carcinoma is described. The choroidal lesion was thought initially to be a metastasis, and treated with external beam radiotherapy. The tumour did not regress but remained stable in size for a period of three years. Following referral to an ophthalmologist, the diagnosis was revised after re-evaluation of the clinical, ultrasonographic and angiographic findings.</p> <p>Conclusion</p> <p>Although metastases are the most common ocular tumour, a differential diagnosis of a concurrent primary ocular malignancy should always be considered, even in patients with known malignant disease. Thorough ophthalmic evaluation is important, as multiple primary malignancies may occur concomitantly. The prognostic and therapeutic implications of accurate diagnosis by an ophthalmologist are of profound significance to affected patients and their families.</p

    Genetic, environmental and stochastic factors in monozygotic twin discordance with a focus on epigenetic differences

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    PMCID: PMC3566971This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

    FDI technology spillovers, geography, and spatial diffusion

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    This paper investigates the geographic extent of FDI technology spillovers and associated spatial diffusion. By adopting a spatiotemporal autoregressive panel model as the platform of our study, the complex impact resulting from FDI penetration is separated into spatial direct and indirect effect while accounting for feedback loops among regions. A set of spatially partitioned summary measures is produced to identify and to quantify FDI spillovers from different channels with distinct geographic scopes. Empirical results based on data from China document that the direct impacts of FDI presence to a specific location itself are likely to be negative. Domestic firms mainly benefit from FDI presence in their neighboring regions through knowledge spillovers that have wider geographic scope. Negative market stealing effect nevertheless has no spatial boundary. Policy implications of these findings are discussed

    Folic acid supplementation in postmenopausal women with hot flushes: phase III randomised double-blind placebo-controlled trial

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    Objective To assess whether folic acid supplementation ameliorates hot flushes. Design Double-blind, placebo-controlled randomised trial. Setting Nine hospitals in England. Population Postmenopausal women experiencing ≥50 hot flushes weekly. Methods Women (n = 164) were randomly assigned in a 1:1 ratio to receive folic acid 5 mg tablet or placebo daily for 12 weeks. Participants recorded frequency and severity of hot flushes in a Sloan Diary daily and completed Greene Climacteric and Utian Quality of Life (UQoL) Scales at 4-week intervals. Main outcome measures The change in daily Hot Flush Score at week 12 from randomisation based on Sloan Diary Composite Score B calculation. Results Data of 143 (87%) women were available for the primary outcome. The mean change (SD) in Hot Flush Score at week 12 was −6.98 (10.30) and −4.57 (9.46) for folic acid and placebo group, respectively. The difference between groups in the mean change was −2.41 (95% CI −5.68 to 0.87) (P = 0.149) and in the adjusted mean change −2.61 (95% CI −5.72 to 0.49) (P = 0.098). Analysis of secondary outcomes indicated an increased benefit in the folic acid group regarding changes in total and emotional UQoL scores at week 8 when compared with placebo. The difference in the mean change from baseline was 5.22 (95% CI 1.16–9.28) and 1.88 (95% CI 0.23–3.52) for total and emotional score, respectively. Conclusions The study was not able to demonstrate that folic acid had a statistically significant greater benefit in reducing Hot Flush Score over 12 weeks in postmenopausal women when compared with placebo. Tweetable abstract Folic acid may ameliorate hot flushes in postmenopausal women but confirmation is required from a larger study

    The effect of TCM acupuncture on hot flushes among menopausal women (ACUFLASH) study: A study protocol of an ongoing multi-centre randomised controlled clinical trial

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    BACKGROUND: After menopause, 10–20% of all women have nearly intolerable hot flushes. Long term use of hormone replacement therapy involves a health risk, and many women seek alternative strategies to relieve climacteric complaints. Acupuncture is one of the most frequently used complementary therapies in Norway. We designed a study to evaluate whether Traditional Chinese Medicine acupuncture-care together with self-care is more effective than self-care alone to relieve climacteric complaints. METHODS/DESIGN: The study is a multi-centre pragmatic randomised controlled trial with two parallel arms. Participants are postmenopausal women who document ≥7 flushes/24 hours and who are not using hormone replacement therapy or other medication that may influence flushes. According to power calculations 200 women are needed to detect a 50% reduction in flushes, and altogether 286 women will be recruited to allow for a 30% dropout rate. The treatment group receives 10 sessions of Traditional Chinese Medicine acupuncture-care and self-care; the control group will engage in self-care only. A team of experienced Traditional Chinese Medicine acupuncturists give acupuncture treatments. DISCUSSION: The study tests acupuncture as a complete treatment package including the therapeutic relationship and expectation. The intervention period lasts for 12 weeks, with follow up at 6 and 12 months. Primary endpoint is change in daily hot flush frequency in the two groups from baseline to 12 weeks; secondary endpoint is health related quality of life, assessed by the Women's Health Questionnaire. We also collect data on Traditional Chinese Medicine diagnoses, and we examine treatment experiences using a qualitative approach. Finally we measure biological variables, to examine potential mechanisms for the effect of acupuncture. The study is funded by The Research Council of Norway
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