247 research outputs found
Early Developmental Processes and the Continuity of Risk for Underage Drinking and Problem Drinking
Developmental pathways to underage drinking emerge before the second decade of
life. Many scientists, however, as well as the general public, continue to focus on
proximal influences surrounding the initiation of drinking in adolescence, such as social, behavioral, and genetic variables related to availability and ease of acquisition of the drug, social reinforcement for its use, and individual differences in drug responses. In the past 20 years, a considerable body of evidence has accumulated on the early (often much earlier than the time of the first drink) predictors and pathways of youthful alcohol use and abuse. These early developmental influences involve numerous risk, vulnerability, promotive, and protective processes. Some of these factors are not related directly to alcohol use, whereas others involve learning and expectancies about later drug use that are shaped by social experience. The salience of these factors (identifiable in early childhood) for understanding the course and development of adult alcohol and other drug use disorders is evident from the large and growing body of findings on their ability to predict adult clinical outcomes. This review summarizes the evidence on early pathways toward and away from underage drinking, with a particular focus on the risk and protective factors and the mediators and moderators of risk for underage drinking that become evident during the preschool and early school years. It is guided by a developmental perspective on the aggregation of risk and protection and examines the contributions of biological, psychological, and social processes within the context of normal development.Implications of this evidence for policy, intervention, and future research are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65125/1/UM 33 Zucker2008_EarlyDevelopmentalProc.Pediatrics_InPress_.pd
A New Giant Stellar Structure in the Outer Halo of M31
The Sloan Digital Sky Survey has revealed an overdensity of luminous red
giant stars ~ 3 degrees (40 projected kpc) to the northeast of M31, which we
have called Andromeda NE. The line-of-sight distance to Andromeda NE is within
approximately 50 kpc of M31; Andromeda NE is not a physically unrelated
projection. Andromeda NE has a g-band absolute magnitude of ~ -11.6 and central
surface brightness of ~ 29 mag/sq.arcsec, making it nearly two orders of
magnitude more diffuse than any known Local Group dwarf galaxy at that
luminosity. Based on its distance and morphology, Andromeda NE is likely
undergoing tidal disruption. Andromeda NE's red giant branch color is unlike
that of M31's present-day outer disk or the stellar stream reported by Ibata et
al. (2001), arguing against a direct link between Andromeda NE and these
structures. However, Andromeda NE has a red giant branch color similar to that
of the G1 clump; it is possible that these structures are both material torn
off of M31's disk in the distant past, or that these are both part of one
ancient stellar stream.Comment: 11 pages, 3 figures; ApJ Letters accepted versio
Extrasolar planets in stellar multiple systems
Analyzing exoplanets detected by radial velocity or transit observations, we
determine the multiplicity of exoplanet host stars in order to study the
influence of a stellar companion on the properties of planet candidates.
Matching the host stars of exoplanet candidates detected by radial velocity or
transit observations with online multiplicity catalogs in addition to a
literature search, 57 exoplanet host stars are identified having a stellar
companion. The resulting multiplicity rate of at least 12 percent for exoplanet
host stars is about four times smaller than the multiplicity of solar like
stars in general. The mass and the number of planets in stellar multiple
systems depend on the separation between their host star and its nearest
stellar companion, e.g. the planetary mass decreases with an increasing stellar
separation. We present an updated overview of exoplanet candidates in stellar
multiple systems, including 15 new systems (compared to the latest summary from
2009).Comment: 11 pages, 4 figures, appendix with 6 tables, accepted for publication
in A&
To B or not to B: a question of resolution?
A simple rule of thumb based on resolution is not adequate to identify the best treatment of atomic displacements in macromolecular structural models. The choice to use isotropic B factors, anisotropic B factors, TLS models or some combination of the three should be validated through statistical analysis of the model refinement
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Cumulative incidence and diagnosis of SARS-CoV-2 infection in New York
Purpose New York State (NYS) is an epicenter of the SARS-CoV-2 pandemic in the United States. Reliable estimates of cumulative incidence in the population are critical to tracking the extent of transmission and informing policies. Methods We conducted a statewide seroprevalence study in a 15,101 patron convenience sample at 99 grocery stores in 26 counties throughout NYS. SARS-CoV-2 cumulative incidence was estimated from antibody reactivity by first poststratification weighting and then adjusting by antibody test characteristics. The percent diagnosed was estimated by dividing the number of diagnoses by the number of estimated infection-experienced adults. Results Based on 1887 of 15,101 (12.5%) reactive results, estimated cumulative incidence through March 29 was 14.0% (95% confidence interval [CI]: 13.3%–14.7%), corresponding to 2,139,300 (95% CI: 2,035,800–2,242,800) infection-experienced adults. Cumulative incidence was highest in New York City 22.7% (95% CI: 21.5%–24.0%) and higher among Hispanic/Latino (29.2%), non-Hispanic black/African American (20.2%), and non-Hispanic Asian (12.4%) than non-Hispanic white adults (8.1%, P \u3c .0001). An estimated 8.9% (95% CI: 8.4%–9.3%) of infections in NYS were diagnosed, with diagnosis highest among adults aged 55 years or older (11.3%, 95% CI: 10.4%–12.2%). Conclusions From the largest U.S. serosurvey to date, we estimated \u3e2 million adult New York residents were infected through late March, with substantial disparities, although cumulative incidence remained less than herd immunity thresholds. Monitoring, testing, and contact tracing remain essential public health strategies
KIC 8164262: a heartbeat star showing tidally induced pulsations with resonant locking
We present the analysis of KIC 8164262, a heartbeat star with a high-amplitude (∼1 mmag), tidally resonant pulsation (a mode in resonance with the orbit) at 229 times the orbital frequency and a plethora of tidally induced g-mode pulsations (modes excited by the orbit). The analysis combines Kepler light curves with follow-up spectroscopic data from the Keck telescope, KPNO (Kitt Peak National Observatory) 4-m Mayall telescope and the 2.7-m telescope at the McDonald observatory. We apply the binary modelling software, phoebe, to the Kepler light curve and radial velocity data to determine a detailed binary star model that includes the prominent pulsation and Doppler boosting, alongside the usual attributes of a binary star model (including tidal distortion and reflection). The results show that the system contains a slightly evolved F star with an M secondary companion in a highly eccentric orbit (e = 0.886). We use the results of the binary star model in a companion paper (Fuller) where we show that the prominent pulsation can be explained by a tidally excited oscillation mode held near resonance by a resonance locking mechanism
Photometric transit search for planets around cool stars from the western Italian Alps: A pilot study
[ABRIDGED] In this study, we set out to a) demonstrate the sensitivity to <4
R_E transiting planets with periods of a few days around our program stars, and
b) improve our knowledge of some astrophysical properties(e.g., activity,
rotation) of our targets by combining spectroscopic information and our
differential photometric measurements. We achieve a typical nightly RMS
photometric precision of ~5 mmag, with little or no dependence on the
instrumentation used or on the details of the adopted methods for differential
photometry. The presence of correlated (red) noise in our data degrades the
precision by a factor ~1.3 with respect to a pure white noise regime. Based on
a detailed stellar variability analysis, a) we detected no transit-like events;
b) we determined photometric rotation periods of ~0.47 days and ~0.22 days for
LHS 3445 and GJ 1167A, respectively; c) these values agree with the large
projected rotational velocities (~25 km/s and ~33 km/s, respectively) inferred
for both stars based on the analysis of archival spectra; d) the estimated
inclinations of the stellar rotation axes for LHS 3445 and GJ 1167A are
consistent with those derived using a simple spot model; e) short-term,
low-amplitude flaring events were recorded for LHS 3445 and LHS 2686. Finally,
based on simulations of transit signals of given period and amplitude injected
in the actual (nightly reduced) photometric data for our sample, we derive a
relationship between transit detection probability and phase coverage. We find
that, using the BLS search algorithm, even when phase coverage approaches 100%,
there is a limit to the detection probability of ~90%. Around program stars
with phase coverage >50% we would have had >80% chances of detecting planets
with P0.5%, corresponding to minimum
detectable radii in the range 1.0-2.2 R_E. [ABRIDGED]Comment: 23 pages, 17 figures, 7 tables. Accepted for publication in MNRA
The magnetic field in the Milky Way filamentary bone G47
Funding: R.J.S. acknowledges funding from an STFC ERF (grant ST/N00485X/1).Star formation primarily occurs in filaments where magnetic fields are expected to be dynamically important. The largest and densest filaments trace the spiral structure within galaxies. Over a dozen of these dense (∼104 cm−3) and long (>10 pc) filaments have been found within the Milky Way, and they are often referred to as "bones." Until now, none of these bones has had its magnetic field resolved and mapped in its entirety. We introduce the SOFIA legacy project FIELDMAPS which has begun mapping ∼10 of these Milky Way bones using the HAWC+ instrument at 214 μm and 18′′.2 resolution. Here we present a first result from this survey on the ∼60 pc long bone G47. Contrary to some studies of dense filaments in the Galactic plane, we find that the magnetic field is often not perpendicular to the spine (i.e., the center line of the bone). Fields tend to be perpendicular in the densest areas of active star formation and more parallel or random in other areas. The average field is neither parallel nor perpendicular to the Galactic plane or the bone. The magnetic field strengths along the spine typically vary from ∼20 to ∼100 μG. Magnetic fields tend to be strong enough to suppress collapse along much of the bone, but for areas that are most active in star formation, the fields are notably less able to resist gravitational collapse.Peer reviewe
The Fifth Data Release of the Sloan Digital Sky Survey
This paper describes the Fifth Data Release (DR5) of the Sloan Digital Sky
Survey (SDSS). DR5 includes all survey quality data taken through June 2005 and
represents the completion of the SDSS-I project (whose successor, SDSS-II will
continue through mid-2008). It includes five-band photometric data for 217
million objects selected over 8000 square degrees, and 1,048,960 spectra of
galaxies, quasars, and stars selected from 5713 square degrees of that imaging
data. These numbers represent a roughly 20% increment over those of the Fourth
Data Release; all the data from previous data releases are included in the
present release. In addition to "standard" SDSS observations, DR5 includes
repeat scans of the southern equatorial stripe, imaging scans across M31 and
the core of the Perseus cluster of galaxies, and the first spectroscopic data
from SEGUE, a survey to explore the kinematics and chemical evolution of the
Galaxy. The catalog database incorporates several new features, including
photometric redshifts of galaxies, tables of matched objects in overlap regions
of the imaging survey, and tools that allow precise computations of survey
geometry for statistical investigations.Comment: ApJ Supp, in press, October 2007. This paper describes DR5. The SDSS
Sixth Data Release (DR6) is now public, available from http://www.sdss.or
The Seventh Data Release of the Sloan Digital Sky Survey
This paper describes the Seventh Data Release of the Sloan Digital Sky Survey
(SDSS), marking the completion of the original goals of the SDSS and the end of
the phase known as SDSS-II. It includes 11663 deg^2 of imaging data, with most
of the roughly 2000 deg^2 increment over the previous data release lying in
regions of low Galactic latitude. The catalog contains five-band photometry for
357 million distinct objects. The survey also includes repeat photometry over
250 deg^2 along the Celestial Equator in the Southern Galactic Cap. A
coaddition of these data goes roughly two magnitudes fainter than the main
survey. The spectroscopy is now complete over a contiguous area of 7500 deg^2
in the Northern Galactic Cap, closing the gap that was present in previous data
releases. There are over 1.6 million spectra in total, including 930,000
galaxies, 120,000 quasars, and 460,000 stars. The data release includes
improved stellar photometry at low Galactic latitude. The astrometry has all
been recalibrated with the second version of the USNO CCD Astrograph Catalog
(UCAC-2), reducing the rms statistical errors at the bright end to 45
milli-arcseconds per coordinate. A systematic error in bright galaxy photometr
is less severe than previously reported for the majority of galaxies. Finally,
we describe a series of improvements to the spectroscopic reductions, including
better flat-fielding and improved wavelength calibration at the blue end,
better processing of objects with extremely strong narrow emission lines, and
an improved determination of stellar metallicities. (Abridged)Comment: 20 pages, 10 embedded figures. Accepted to ApJS after minor
correction
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