Boston University

About: Boston University is a education organization based out in Boston, Massachusetts, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 48688 authors who have published 119622 publications receiving 6276020 citations. The organization is also known as: BU & Boston U.

Measurement of the negative muon anomalous magnetic moment to 0.7 ppm

Abstract: We present the first results of the Fermilab National Accelerator Laboratory (FNAL) Muon g-2 Experiment for the positive muon magnetic anomaly a_{μ}≡(g_{μ}-2)/2. The anomaly is determined from the precision measurements of two angular frequencies. Intensity variation of high-energy positrons from muon decays directly encodes the difference frequency ω_{a} between the spin-precession and cyclotron frequencies for polarized muons in a magnetic storage ring. The storage ring magnetic field is measured using nuclear magnetic resonance probes calibrated in terms of the equivalent proton spin precession frequency ω[over ˜]_{p}^{'} in a spherical water sample at 34.7 °C. The ratio ω_{a}/ω[over ˜]_{p}^{'}, together with known fundamental constants, determines a_{μ}(FNAL)=116 592 040(54)×10^{-11} (0.46 ppm). The result is 3.3 standard deviations greater than the standard model prediction and is in excellent agreement with the previous Brookhaven National Laboratory (BNL) E821 measurement. After combination with previous measurements of both μ^{+} and μ^{-}, the new experimental average of a_{μ}(Exp)=116 592 061(41)×10^{-11} (0.35 ppm) increases the tension between experiment and theory to 4.2 standard deviations.

Projections on the number of individuals with atrial fibrillation in the European Union, from 2000 to 2060

Abstract: Aims Since atrial fibrillation (AF) is associated with increased risks of cardiovascular and cerebrovascular complications, estimations on the number of individuals with AF are relevant to healthcare planning. We aimed to project the number of individuals with AF in the Netherlands and in the European Union from 2000 to 2060. Methods and results Age- and sex-specific AF prevalence estimates were obtained from the prospective community-based Rotterdam Study. Population projections for the Netherlands and the European Union were obtained from the European Union's statistics office. In the age stratum of 55–59 years, the prevalence of AF was 1.3% in men (95% CI: 0.4–3.6%) and 1.7% in women (95% CI: 0.7–4.0%). The prevalence of AF increased to 24.2% in men (95% CI: 18.5–30.7%), and 16.1% in women (95% CI: 13.1–19.4%), for those >85 years of age. This age- and sex-specific prevalence remained stable during the years of follow-up. Furthermore, we estimate that in the European Union, 8.8 million adults over 55 years had AF in 2010 (95% CI: 6.5–12.3 million). We project that this number will double by 2060 to 17.9 million (95% CI: 13.6–23.7 million) if the age- and sex-specific prevalence remains stable. Conclusion We estimate that from 2010 to 2060, the number of adults 55 years and over with AF in the European Union will more than double. As AF is associated with significant morbidities and mortality, this increasing number of individuals with AF may have major public health implications.

An algorithm for the retrieval of albedo from space using semiempirical BRDF models

Abstract: Spectral albedo may be derived from atmospherically corrected, cloud-cleared multiangular reflectance observations through the inversion of a bidirectional reflectance distribution function (BRDF) model and angular integration. This paper outlines an algorithm suitable for this task that makes use of kernel-based BRDF models. Intrinsic land surface albedos are derived, which may be used to derive actual albedo by taking into account the prevailing distribution of diffuse skylight. Spectral-to-broadband conversion is achieved using band-dependent weighting factors. The validation of a suitable BRDF model, the semiempirical Ross-Li (reciprocal RossThick-LiSparse) model and its performance under conditions of sparse angular sampling and noisy reflectances are discussed, showing that the retrievals obtained are generally reliable. The solar-zenith angle dependence of albedo may be parameterized by a simple polynomial that makes it unnecessary for the user to be familiar with the underlying BRDF model. The algorithm given is that used for the production of a BRDF/albedo standard data product from NASA's EOS-MODIS sensor, for which an at-launch status is provided. Finally, the algorithm is demonstrated on combined AVHRR and GOES observations acquired over New England, from which solar zenith angle-dependent albedo maps with a nominal spatial resolution of 1 km are derived in the visible band. The algorithm presented may be employed to derive albedo from space-based multiangular measurements and also serves as a guide for the use of the MODIS BRDF/albedo product.

Bronchiolitis obliterans organizing pneumonia.

Abstract: In 50 of 94 patients with bronchiolitis obliterans we found no apparent cause or associated disease, and the bronchiolitis obliterans occurred with patchy organizing pneumonia. Histologic characteristics included polypoid masses of granulation tissue in lumens of small airways, alveolar ducts, and some alveoli. The fibrosis was uniform in age, suggesting that all repair had begun at the same time. The distribution was patchy, with preservation of background architecture. Clinically, there was cough or flu-like illness for 4 to 10 weeks, and crackles were heard in the lungs of 68 per cent of the patients. Radiographs showed an unusual pattern of patchy densities with a "ground glass" appearance in 81 per cent. Physiologically, there was restriction in 72 per cent of the patients, and 86 per cent had impaired diffusing capacity. Obstruction was limited to smokers. The mean follow-up period was four years. With corticosteroids, there was complete clinical and physiologic recovery in 65 per cent of the subjects; two died from progressive disease. This disorder differs from bronchiolitis obliterans with irreversible obstruction. It was confused most often with idiopathic pulmonary fibrosis. In view of the benign course and therapeutic response, a histologic distinction is important.

Guidelines of care for the management of acne vulgaris

Abstract: Acne is one of the most common disorders treated by dermatologists and other health care providers. While it most often affects adolescents, it is not uncommon in adults and can also be seen in children. This evidence-based guideline addresses important clinical questions that arise in its management. Issues from grading of acne to the topical and systemic management of the disease are reviewed. Suggestions on use are provided based on available evidence.