1,202 research outputs found
B0 -> D*- a1+: Chirality tests and resolving an ambiguity in 2\beta+\gamma
We point out that the decays of B mesons into a vector meson and an
axial-vector meson can distinguish between left and right-handed polarized
mesons, in contrast to decays into two vector mesons. Measurements in B0 ->
D*-a1+ are proposed for testing factorization and the V-A structure of the weak
b -> c current, and for resolving a discrete ambiguity in 2\beta + \gamma.Comment: 4 page
Cardiology providersâ recommendations for treatments and use of patient decision aids for multivessel coronary artery disease
Background: Rates of recommending percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) vary across clinicians. Whether clinicians agree on preferred treatment options for multivessel coronary artery disease patients has not been well studied. Methods and results: We distributed a survey to 104 clinicians from the Northern New England Cardiovascular Study Group through email and at a regional meeting with 88 (84.6%) responses. The survey described three clinical vignettes of multivessel coronary artery disease patients. For each patient vignette participants selected appropriate treatment options and whether they would use a patient decision aid. The likelihood of choosing PCI only or PCI/CABG over CABG only was modeled using a multinomial regression. Across all vignettes, participants selected CABG only as an appropriate treatment option 24.2% of the time, PCI only 25.4% of the time, and both CABG or PCI as appropriate treatment options 50.4% of the time. Surgeons were less likely to choose PCI over CABG (RR 0.14, 95% CI 0.03, 0.59) or both treatments over CABG only (RR 0.10, 95% CI 0.03, 0.34) relative to cardiologists. Overall, 65% of participants responded they would use a patient decision aid with each vignette. Conclusions: There is a lack of consensus on the appropriate treatment options across cardiologists and surgeons for patients with multivessel coronary artery disease. Treatment choice is influenced by both patient characteristics and clinician specialty
Ultra-Processed Food Intake Is Associated with Non-Alcoholic Fatty Liver Disease in Adults: A Systematic Review and Meta-Analysis
Non-alcoholic fatty liver disease (NAFLD) is associated with overweight/obesity, metabolic syndrome and type 2 diabetes (T2D) due to chronic caloric excess and physical inactivity. Previous meta-analyses have confirmed associations between ultra-processed food (UPF) intake and obesity and T2D. We aim to ascertain the contribution of UPF consumption to the risk of developing NAFLD. We performed a systematic review and meta-analysis (PROSPERO (CRD42022368763)). All records registered on Ovid Medline and Web of Science were searched from inception until December 2022. Studies that assessed UPF consumption in adults, determined according to the NOVA food classification system, and that reported NAFLD determined by surrogate (steatosis) scores, imaging or liver biopsy were included. The association between UPF consumption and NAFLD was assessed using random-effects meta-analysis methods. Study quality was assessed, and evidence credibility evaluated, using the Newcastle Ottawa Scale and NutriGrade systems, respectively. A total of 5454 records were screened, and 112 records underwent full text review. From these, 9 studies (3 cross-sectional, 3 case-control and 3 cohort), analysing 60,961 individuals, were included in the current review. Both moderate (vs. low) (pooled relative risk 1.03 (1.00â1.07) (p = 0.04) (I2 = 0%)) and high (vs. low) (1.42 (1.16â1.75) (<0.01) (I2 = 89%)) intake of UPF significantly increased the risk of NAFLD. Funnel plots demonstrate low risk of publication bias. Consumption of UPF is associated with NAFLD with a doseâresponse effect. Public health measures to reduce overconsumption of UPF are imperative to reduce the burden of NAFLD, and the related conditions, obesity and T2D.</jats:p
Optical pumping of electronic quantum Hall states with vortex light
A fundamental requirement for quantum technologies is the ability to
coherently control the interaction between electrons and photons. However, in
many scenarios involving the interaction between light and matter, the exchange
of linear or angular momentum between electrons and photons is not feasible, a
condition known as the dipole-approximation limit. An example of a case beyond
this limit that has remained experimentally elusive is when the interplay
between chiral electrons and vortex light is considered, where the orbital
angular momentum of light can be transferred to electrons. Here, we present a
novel mechanism for such an orbital angular momentum transfer from optical
vortex beams to electronic quantum Hall states. Specifically, we identify a
robust contribution to the radial photocurrent, in an annular graphene sample
within the quantum Hall regime, that depends on the vorticity of light. This
phenomenon can be interpreted as an optical pumping scheme, where the angular
momentum of photons is transferred to electrons, generating a radial current,
and the current's direction is determined by the light's vorticity. Our
findings offer fundamental insights into the optical probing and manipulation
of quantum coherence, with wide-ranging implications for advancing quantum
coherent optoelectronics
Ultraâprocessed food and nonâcommunicable diseases in the United Kingdom: A narrative review and thematic synthesis of literature
SummaryThe social and economic constructs of the United Kingdom (UK) provide a fertile food environment for the dramatic expansion in the ultraâprocessed food (UPF) market, driving increased UPF consumption. This has coincided with the significant increase in the incidence and prevalence of nonâcommunicable diseases (NCDs) such as obesity, type 2 diabetes, cardiovascular disease, and cancer, with an inherent impact on morbidity and mortality. Our review aims to assess the current epidemiological and public health trends in the United Kingdom, specifically examining consumption of UPFs and subsequent development of NCDs, summarizing existing metaâanalytical and experimental approaches. First, we address important socioeconomic and psychosocial domains that may contribute to increased availability and consumption of UPF. Additionally, we explore the putative mechanistic basis for the association between UPFs and NCDs: partly attributable to their energy density, the macroâ and micronutrient composition (including high refined carbohydrate, saturated, and trans fats composition, in addition to low fiber and protein content), and artificially engineered additives and other compounds that adversely affect health in inadequately researched pathophysiological pathways. This review highlights the importance of promoting minimally processed diets to both clinical and political decision makers.</jats:p
Acetyl-CoA synthetase 2 promotes acetate utilization and maintains cancer cell growth under metabolic stress
A functional genomics study revealed that the activity of acetyl-CoA synthetase 2 (ACSS2) contributes to cancer cell growth under low-oxygen and lipid-depleted conditions. Comparative metabolomics and lipidomics demonstrated that acetate is used as a nutritional source by cancer cells in an ACSS2-dependent manner, and supplied a significant fraction of the carbon within the fatty acid and phospholipid pools. ACSS2 expression is upregulated under metabolically stressed conditions and ACSS2 silencing reduced the growth of tumor xenografts. ACSS2 exhibits copy-number gain in human breast tumors, and ACSS2 expression correlates with disease progression. These results signify a critical role for acetate consumption in the production of lipid biomass within the harsh tumor microenvironment
Multi-hazard Earthquake-Tsunami Structural Fragility Assessment Framework
A probabilistic multi-hazard earthquake-tsunami fragility assessment framework is presented, which accounts for the effect of accumulated damage on the structure due to earthquake loading on its subsequent tsunami response. The fragility assessment framework involves simulating structural response using advanced three dimensional (3D) nonlinear finite-element structural model subjected to sequential earthquake-tsunami loading at multiple seismic and tsunami intensity levels, using back to back nonlinear response history analyses (NRHA) and nonlinear static pushover (NSP) analyses. A modern earthquake-tsunami code designed four story reinforced concrete (RC) special moment resisting frame (SMRF) building is used as an application example to illustrate the proposed framework. Results indicate that the effect of accumulated damage due to earthquake loading is more pronounced in reducing the stiffness of the structure compared to the reduction in structural capacity. Moreover, the tsunami structural capacity required to achieve a given probability of damage exceedance decreases with increasing seismic intensity, especially at lower damage states.Funding for this study was provided as part of the cooperative agreement 70NANB15H044 between the National Institute of Standards and Technology (NIST) and Colorado State University through a subaward to Oregon State University. The content expressed in this paper are the views of the authors and do not necessarily represent the opinions or views of NIST or the US Department of Commerce
Galaxy Zoo: Dust in Spirals
We investigate the effect of dust on spiral galaxies by measuring the
inclination-dependence of optical colours for 24,276 well-resolved SDSS
galaxies visually classified in Galaxy Zoo. We find clear trends of reddening
with inclination which imply a total extinction from face-on to edge-on of 0.7,
0.6, 0.5 and 0.4 magnitudes for the ugri passbands. We split the sample into
"bulgy" (early-type) and "disky" (late-type) spirals using the SDSS fracdeV (or
f_DeV) parameter and show that the average face-on colour of "bulgy" spirals is
redder than the average edge-on colour of "disky" spirals. This shows that the
observed optical colour of a spiral galaxy is determined almost equally by the
spiral type (via the bulge-disk ratio and stellar populations), and reddening
due to dust. We find that both luminosity and spiral type affect the total
amount of extinction, with "disky" spirals at M_r ~ -21.5 mags having the most
reddening. This decrease of reddening for the most luminous spirals has not
been observed before and may be related to their lower levels of recent star
formation. We compare our results with the latest dust attenuation models of
Tuffs et al. We find that the model reproduces the observed trends reasonably
well but overpredicts the amount of u-band attenuation in edge-on galaxies. We
end by discussing the effects of dust on large galaxy surveys and emphasize
that these effects will become important as we push to higher precision
measurements of galaxy properties and their clustering.Comment: MNRAS in press. 25 pages, 22 figures (including an abstract comparing
GZ classifications with common automated methods for selecting disk/early
type galaxies in SDSS data). v2 corrects typos found in proof
The Sloan Digital Sky Survey Reverberation Mapping Project: Rapid CIV Broad Absorption Line Variability
We report the discovery of rapid variations of a high-velocity CIV broad
absorption line trough in the quasar SDSS J141007.74+541203.3. This object was
intensively observed in 2014 as a part of the Sloan Digital Sky Survey
Reverberation Mapping Project, during which 32 epochs of spectroscopy were
obtained with the Baryon Oscillation Spectroscopic Survey spectrograph. We
observe significant (>4sigma) variability in the equivalent width of the broad
(~4000 km/s wide) CIV trough on rest-frame timescales as short as 1.20 days
(~29 hours), the shortest broad absorption line variability timescale yet
reported. The equivalent width varied by ~10% on these short timescales, and by
about a factor of two over the duration of the campaign. We evaluate several
potential causes of the variability, concluding that the most likely cause is a
rapid response to changes in the incident ionizing continuum. If the outflow is
at a radius where the recombination rate is higher than the ionization rate,
the timescale of variability places a lower limit on the density of the
absorbing gas of n_e > 3.9 x 10^5 cm^-3. The broad absorption line variability
characteristics of this quasar are consistent with those observed in previous
studies of quasars, indicating that such short-term variability may in fact be
common and thus can be used to learn about outflow characteristics and
contributions to quasar/host-galaxy feedback scenarios.Comment: 15 pages, 14 figures. Accepted for publication in the Astrophysical
Journa
E-commerce adoption by SMEs in developing countries: evidence from Indonesia
This study aims to provide an overview of e-commerce adoption by SMEs in developing countries and, in particular, the extent of the adoption of e-commerce by Indonesian SMEs. It identifies the e-commerce benefits realized by these SMEs and investigates the relationship between the levels of e-commerce adoption and the benefits thus realized. The study was motivated by the limited studies related to e-commerce adoption by SMEs, especially in developing countries. In addition, it seems that most e-commerce studies are focused more on upstream issues: to see the factors that facilitate, or barriers faced regarding e-commerce adoption, rather than downstream issues: to see post-adoption benefits. This certainly limits our understanding about e-commerce adoption by SMEs in developing countries, as well as the post-adoption benefits of e-commerce. Indonesia was chosen as the place in which to conduct the study. A survey of 292 SMEs shows that the majority of them are still at an early stage in their adoption of e-commerce. Their use of e-commerce is dominated by marketing and purchasing and procurement activities. âExtending market reachâ, âincreased salesâ, âimproved external communicationâ, âimproved company imageâ, âimproved speed of processingâ, and âincreased employee productivityâ are reported as the top six e-commerce benefits perceived by these SMEs. This study also shows that SMEs at the higher level of e-commerce adoption experience greater e-commerce benefits than those at other levels of adoption
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