481 research outputs found
UV/Optical/IR Color Sequences Along the Tidal Ring/Arm of Arp 107
We construct UV/optical/IR spectral energy distributions for 29 star forming
regions in the interacting galaxy Arp 107, using GALEX UV, Sloan Digitized Sky
Survey optical, and Spitzer infrared images. In an earlier study utilizing only
the Spitzer data, we found a sequence in the mid-infrared colors of
star-forming knots along the strong tidal arm in this system. In the current
study, we find sequences in the UV/optical colors along the tidal arm that
mirror those in the mid-infrared, with blue UV/optical colors found for regions
that are red in the mid-infrared, and vice versa. With single-burst stellar
population synthesis models, we find a sequence in the average stellar age
along this arm, with younger stars preferentially located further out in the
arm. Models that allow two populations of different ages and dust attenuations
suggest that there may be both a young component and an older population
present in these regions. Thus the observed color sequences may be better
interpreted as a sequence in the relative proportion of young and old stars
along the arm, with a larger fraction of young stars near the end. Comparison
with star forming regions in other interacting galaxies shows that the Arp 107
regions are relatively quiescent, with less intense star formation than in many
other systems.Comment: Astronomical Journal, in pres
Reasonable Double Definitional Instruction Results in Abolishing Exclusion of Outstanding Reasonable Hypothesis as Standard of Review in Circumstantial Evidence Cases.
Abstract Forthcoming
Application of RHIZON samplers to obtain high-resolution pore-fluid records during geochemical investigations of gas hydrate systems
Microfluidic SAXS study of lamellar and multilamellar vesicle phases of linear sodium alkylbenzenesulfonate surfactant with intrinsic isomeric distribution
The structure and flow behaviour of a concentrated aqueous solution (45 w.t. %) of the ubiquitous linear sodium alkylbenzene sulfonate (NaLAS) surfactant is investigated by microfluidic small-angle X-ray scatterong (SAXS) at 70 ⁰C. NaLAS is an intrinsically complex mixture of over 20 surfactant molecules, presenting coexisting micellar (L1) and lamellar (Lα) phases. Novel microfluidic devices were fabricated to ensure pressure and thermal resistance, ability to handle viscous fluids, and low SAXS background. Polarized light optical microscopy showed that the NaLAS solution exhibits wall slip in microchannels, with velocity profiles approaching plug flow. Microfluidic SAXS demonstrated the structural spatial heterogeneity of the system with a characteristic lengthscale of 50 nL. Using a statistical flow-SAXS analysis we identified the micellar phase and multiple coexisting lamellar phases with a continuous distribution of d spacings between 37.5 Å - 39.5 Å. Additionally, we showed that the orientation of NaLAS lamellar phases is strongly affected by a single microfluidic constriction. The bilayers align parallel to the velocity field upon entering a constriction and perpendicular to it upon exiting. On the other hand, multi-lamellar vesicle phases are not affected under the same flow conditions. Our results demonstrate that, despite the compositional complexity inherent to NaLAS, microfluidic SAXS can rigorously elucidate its structure and flow response
La reducción de la fecundidad en un programa de salud materno infantil
Incluye BibliografíaPublicado en Estudios de Planificación Familiar, vol. 6, 197
Binge drinking and perceived ethnic discrimination among Hispanics/Latinos: Results from the Hispanic community health study/study of Latinos sociocultural ancillary study
The study assessed whether overall perceived ethnic discrimination and four unique discrimination types were associated with binge drinking in participants from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) who also completed the HCHS/SOL Sociocultural Ancillary Study (n = 5,313). In unadjusted analyses that were weighted for sampling strategy and design, each unit increase in discrimination type was associated with a 12 - 63% increase in odds of binge drinking; however, after adjusting for important demographic variables including age, sex, heritage group, language, and duration of US residence, there was no longer an association between discrimination and binge drinking. Further research still needs to identify the salient factors that contribute to increased risk for binge drinking among Hispanics/Latinos
The lytic granules of natural killer cells are dual-function organelles combining secretory and pre-lysosomal compartments.
Clinical validation of a targeted methylation-based multi-cancer early detection test using an independent validation set
BACKGROUND: A multi-cancer early detection (MCED) test used to complement existing screening could increase the number of cancers detected through population screening, potentially improving clinical outcomes. The Circulating Cell-free Genome Atlas study (CCGA; NCT02889978) was a prospective, case-controlled, observational study and demonstrated that a blood-based MCED test utilizing cell-free DNA (cfDNA) sequencing in combination with machine learning could detect cancer signals across multiple cancer types and predict cancer signal origin (CSO) with high accuracy. The objective of this third and final CCGA substudy was to validate an MCED test version further refined for use as a screening tool. PATIENTS AND METHODS: This pre-specified substudy included 4077 participants in an independent validation set (cancer: n = 2823; non-cancer: n = 1254, non-cancer status confirmed at year-one follow-up). Specificity, sensitivity, and CSO prediction accuracy were measured. RESULTS: Specificity for cancer signal detection was 99.5% [95% confidence interval (CI): 99.0% to 99.8%]. Overall sensitivity for cancer signal detection was 51.5% (49.6% to 53.3%); sensitivity increased with stage [stage I: 16.8% (14.5% to 19.5%), stage II: 40.4% (36.8% to 44.1%), stage III: 77.0% (73.4% to 80.3%), stage IV: 90.1% (87.5% to 92.2%)]. Stage I-III sensitivity was 67.6% (64.4% to 70.6%) in 12 pre-specified cancers that account for approximately two-thirds of annual USA cancer deaths and was 40.7% (38.7% to 42.9%) in all cancers. Cancer signals were detected across >50 cancer types. Overall accuracy of CSO prediction in true positives was 88.7% (87.0% to 90.2%). CONCLUSION: In this pre-specified, large-scale, clinical validation substudy, the MCED test demonstrated high specificity and accuracy of CSO prediction and detected cancer signals across a wide diversity of cancers. These results support the feasibility of this blood-based MCED test as a complement to existing single-cancer screening tests. CLINICAL TRIAL NUMBER: NCT02889978
Measurements of light-absorbing particles on the glaciers in the Cordillera Blanca, Peru
Glaciers in the tropical Andes have been rapidly losing mass since the 1970s.
In addition to the documented increase in temperature, increases in light-absorbing particles deposited on glaciers could be contributing to the
observed glacier loss. Here we report on measurements of light-absorbing
particles sampled from glaciers during three surveys in the Cordillera Blanca
Mountains in Peru. During three research expeditions in the dry seasons
(May–August) of 2011, 2012 and 2013, 240 snow samples were
collected from 15 mountain peaks over altitudes ranging from 4800 to
nearly 6800 m. Several mountains were sampled each of the 3 years and
some mountains were sampled multiple times during the same year. Collected
snow samples were melted and filtered in the field then later analyzed using
the Light Absorption Heating Method (LAHM), a new technique that measures the
ability of particles on filters to absorb visible light. LAHM results have
been calibrated using filters with known amounts of fullerene soot, a common
industrial surrogate for black carbon (BC). As sample filters often contain
dust in addition to BC, results are presented in terms of effective black
carbon (eBC). During the 2013 survey, snow samples were collected and kept
frozen for analysis with a Single Particle Soot Photometer (SP2). Calculated
eBC mass from the LAHM analysis and the SP2 refractory black carbon (rBC)
results were well correlated (r2 = 0.92). These results indicate that a
substantial portion of the light-absorbing particles in the more polluted
regions were likely BC. The 3 years of data show that glaciers in the
Cordillera Blanca Mountains close to human population centers have
substantially higher levels of eBC (as high as 70 ng g−1) than remote
glaciers (as low as 2.0 ng g−1 eBC), indicating that population
centers can influence local glaciers by sourcing BC
High School Quality is Associated with Cognition 58 Years Later
We leveraged a unique school-based longitudinal cohort—the Project Talent Aging Study—to examine whether attending higher quality schools is associated with cognitive performance among older adults in the United States (mean age = 74.8). Participants (n = 2,289) completed telephone neurocognitive testing. Six indicators of high school quality, reported by principals at the time of schooling, were predictors of respondents’ cognitive function 58 years later. To account for school-clustering, multilevel linear and logistic models were applied. We found that attending schools with a higher number of teachers with graduate training was the clearest predictor of later-life cognition, and school quality mattered especially for language abilities. Importantly, Black respondents (n = 239; 10.5 percentage) were disproportionately exposed to low quality high schools. Therefore, increased investment in schools, especially those that serve Black children, could be a powerful strategy to improve later life cognitive health among older adults in the United States
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