Cronbach’s Alpha Under Insufficient Effort Responding: An Analytic Approach

Surveys commonly suffer from insufficient effort responding (IER). If not accounted for, IER can cause biases and lead to false conclusions. In particular, Cronbach’s alpha has been empirically observed to either deflate or inflate due to IER. This paper will elucidate how IER impacts Cronbach’s alpha in a variety of situations. Previous results concerning internal consistency under mixture models are extended to obtain a characterization of Cronbach’s alpha in terms of item validities, average variances, and average covariances. The characterization is then applied to contaminating distributions representing various types of IER. The discussion will provide commentary on previous simulation-based investigations, confirming some previous hypotheses for the common types of IER, but also revealing possibilities from newly considered responding patterns. Specifically, it is possible that the bias can change from negative to positive (and vice versa) as the proportion of contamination increases

Individual Difference Correlates of Being Sexually Unrestricted Yet Declining an HIV Test

Which individual differences accurately predict one’s decision to get tested for human immunodeficiency virus (HIV), and do individuals who have regular short-term sex get tested at higher rates? Two studies—one lab study (total valid N = 69, with n = 20 who were tested) and one involving a student health center (valid N = 250, n = 4 who were tested)—involved participants (total valid N = 319, with n = 24 who got tested) taking a number of personality and individual difference measures, including the dark triad (Machiavellianism, narcissism, and psychopathy). Then, in both studies, participants had the opportunity to actually get tested for HIV. After analyzing data from Study 1, for Study 2 we preregistered the prediction that narcissistic participants would tend to (a) show disinclination to get tested for HIV, and (b) show proclivity for unrestricted short-term sexual behavior, manifesting in (c) a significant difference between these two correlations. As predicted, such a difference in correlations was evident for narcissism as well as psychopathy (the latter, however, was not predicted), suggesting that such individuals are not likely to seek HIV diagnostic information, but are taking more sexual risks. A research synthesis was consistent with these ideas (although controlling for demographic factors diminished the effects). Narcissistic and psychopathic individuals may be undetected hubs in the network of sexually active individuals with HIV. These results are silent on whether the typical HIV patient is narcissistic or psychopathic; the results merely implicate narcissistic and psychopathic traits in the spread of the virus

Smaller Is Better: Associations Between Personality and Demographics Are Improved by Examining Narrower Traits and Regions

19 pagesThe personality of individuals is clustered by geographic regions; a resident of a region is more similar to another resident than to a random non-resident. Research in geographical psychology often has focused on this clustering effect in broad regions, such as countries and states, using broad domains of personality, such as the Big Five. We examined the extent to which (a) a narrower geographic unit, the U.S. ZIP Code, accounted for more variance explained in aggregating personality than a broader region, the U.S. state; and (b) progressively narrower personality traits (domains, facets, and nuances, respectively) provided more specificity in describing personality-demographic relationships. Results from this study (nparticipants = 39,886, nzipcodes = 2,074) indicated that the variance explained by aggregating personality was multiple times as large for U.S. ZIP Codes than for states (median = 4.4). At the level of personality domains, ZIP Code population density and income disparity were positively correlated with Openness and negatively correlated with Conscientiousness and Agreeableness. Facets within each domain were differentially correlated with each demographic, which demonstrated that facets added specificity to the personality-demographic relationships beyond that of domains. Item-level analysis revealed the most specific finding: higher population density and income disparity were associated with politically liberal attitudes and beliefs of self-exceptionalism, while lower density and income disparity were associated with authoritarian attitudes and concern for abiding by rules and laws. Findings suggest that future studies in geographical and personality psychology could benefit from using the narrowest feasible unit of analysis.Preparation of this manuscript was funded in part by grant SMA-1419324 from the National Science Foundation

The Peculiar SN 2005hk: Do Some Type Ia Supernovae Explode as Deflagrations?

We present extensive u'g'r'i'BVRIYJHKs photometry and optical spectroscopy of SN 2005hk. These data reveal that SN 2005hk was nearly identical in its observed properties to SN 2002cx, which has been called ``the most peculiar known type Ia supernova.'' Both supernovae exhibited high ionization SN 1991T-like pre-maximum spectra, yet low peak luminosities like SN 1991bg. The spectra reveal that SN 2005hk, like SN 2002cx, exhibited expansion velocities that were roughly half those of typical type Ia supernovae. The R and I light curves of both supernovae were also peculiar in not displaying the secondary maximum observed for normal type Ia supernovae. Our YJH photometry of SN 2005hk reveals the same peculiarity in the near-infrared. By combining our optical and near-infrared photometry of SN 2005hk with published ultraviolet light curves obtained with the Swift satellite, we are able to construct a bolometric light curve from ~10 days before to ~60 days after B maximum. The shape and unusually low peak luminosity of this light curve, plus the low expansion velocities and absence of a secondary maximum at red and near-infrared wavelengths, are all in reasonable agreement with model calculations of a 3D deflagration which produces ~0.25 M_sun of 56Ni.Comment: Accepted by PASP, to appear in April 2007 issue, 63 pages, 16 figures, 11 table

Managing Incidental Genomic Findings in Clinical Trials: Fulfillment of the Principle of Justice

<p>Managing Incidental Genomic Findings in Clinical Trials: Fulfillment of the Principle of Justice</p

ASPCAP: THE APOGEE STELLAR PARAMETER AND CHEMICAL ABUNDANCES PIPELINE

The Apache Point Observatory Galactic Evolution Experiment (APOGEE) has built the largest moderately high-resolution (R ≈ 22,500) spectroscopic map of the stars across the Milky Way, and including dust-obscured areas. The APOGEE Stellar Parameter and Chemical Abundances Pipeline (ASPCAP) is the software developed for the automated analysis of these spectra. ASPCAP determines atmospheric parameters and chemical abundances from observed spectra by comparing observed spectra to libraries of theoretical spectra, using χ2 minimization in a multidimensional parameter space. The package consists of a fortran90 code that does the actual minimization and a wrapper IDL code for book-keeping and data handling. This paper explains in detail the ASPCAP components and functionality, and presents results from a number of tests designed to check its performance. ASPCAP provides stellar effective temperatures, surface gravities, and metallicities precise to 2%, 0.1 dex, and 0.05 dex, respectively, for most APOGEE stars, which are predominantly giants. It also provides abundances for up to 15 chemical elements with various levels of precision, typically under 0.1 dex. The final data release (DR12) of the Sloan Digital Sky Survey III contains an APOGEE database of more than 150,000 stars. ASPCAP development continues in the SDSS-IV APOGEE-2 survey

The Eighth Data Release of the Sloan Digital Sky Survey: First Data from SDSS-III

The Sloan Digital Sky Survey (SDSS) started a new phase in August 2008, with new instrumentation and new surveys focused on Galactic structure and chemical evolution, measurements of the baryon oscillation feature in the clustering of galaxies and the quasar Ly alpha forest, and a radial velocity search for planets around ~8000 stars. This paper describes the first data release of SDSS-III (and the eighth counting from the beginning of the SDSS). The release includes five-band imaging of roughly 5200 deg^2 in the Southern Galactic Cap, bringing the total footprint of the SDSS imaging to 14,555 deg^2, or over a third of the Celestial Sphere. All the imaging data have been reprocessed with an improved sky-subtraction algorithm and a final, self-consistent photometric recalibration and flat-field determination. This release also includes all data from the second phase of the Sloan Extension for Galactic Understanding and Evolution (SEGUE-2), consisting of spectroscopy of approximately 118,000 stars at both high and low Galactic latitudes. All the more than half a million stellar spectra obtained with the SDSS spectrograph have been reprocessed through an improved stellar parameters pipeline, which has better determination of metallicity for high metallicity stars.Comment: Astrophysical Journal Supplements, in press (minor updates from submitted version

The Ninth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-III Baryon Oscillation Spectroscopic Survey

The Sloan Digital Sky Survey III (SDSS-III) presents the first spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS). This ninth data release (DR9) of the SDSS project includes 535,995 new galaxy spectra (median z=0.52), 102,100 new quasar spectra (median z=2.32), and 90,897 new stellar spectra, along with the data presented in previous data releases. These spectra were obtained with the new BOSS spectrograph and were taken between 2009 December and 2011 July. In addition, the stellar parameters pipeline, which determines radial velocities, surface temperatures, surface gravities, and metallicities of stars, has been updated and refined with improvements in temperature estimates for stars with T_eff<5000 K and in metallicity estimates for stars with [Fe/H]>-0.5. DR9 includes new stellar parameters for all stars presented in DR8, including stars from SDSS-I and II, as well as those observed as part of the SDSS-III Sloan Extension for Galactic Understanding and Exploration-2 (SEGUE-2). The astrometry error introduced in the DR8 imaging catalogs has been corrected in the DR9 data products. The next data release for SDSS-III will be in Summer 2013, which will present the first data from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) along with another year of data from BOSS, followed by the final SDSS-III data release in December 2014.Comment: 9 figures; 2 tables. Submitted to ApJS. DR9 is available at http://www.sdss3.org/dr

EXPLORING ANTICORRELATIONS AND LIGHT ELEMENT VARIATIONS IN NORTHERN GLOBULAR CLUSTERS OBSERVED BY THE APOGEE SURVEY

We investigate the light-element behavior of red giant stars in northern globular clusters (GCs) observed by the SDSS-III Apache Point Observatory Galactic Evolution Experiment. We derive abundances of 9 elements (Fe, C, N, O, Mg, Al, Si, Ca, and Ti) for 428 red giant stars in 10 GCs. The intrinsic abundance range relative to measurement errors is examined, and the well-known C–N and Mg–Al anticorrelations are explored using an extreme-deconvolution code for the first time in a consistent way. We find that Mg and Al drive the population membership in most clusters, except in M107 and M71, the two most metal-rich clusters in our study, where the grouping is most sensitive to N. We also find a diversity in the abundance distributions, with some clusters exhibiting clear abundance bimodalities (for example M3 and M53) while others show extended distributions. The spread of Al abundances increases significantly as cluster average metallicity decreases as previously found by other works, which we take as evidence that low metallicity, intermediate mass AGB polluters were more common in the more metal-poor clusters. The statistically significant correlation of [Al/Fe] with [Si/Fe] in M15 suggests that 28Si leakage has occurred in this cluster. We also present C, N, and O abundances for stars cooler than 4500 K and examine the behavior of A(C+N+O) in each cluster as a function of temperature and [Al/Fe]. The scatter of A(C+N +O) is close to its estimated uncertainty in all clusters and independent of stellar temperature. A(C+N+O) exhibits small correlations and anticorrelations with [Al/Fe] in M3 and M13, but we cannot be certain about these relations given the size of our abundance uncertainties. Star-to-star variations of a-element (Si, Ca, Ti) abundances are comparable to our estimated errors in all clusters

The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment

The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since July 2014. This paper describes the second data release from this phase, and the fourteenth from SDSS overall (making this, Data Release Fourteen or DR14). This release makes public data taken by SDSS-IV in its first two years of operation (July 2014-2016). Like all previous SDSS releases, DR14 is cumulative, including the most recent reductions and calibrations of all data taken by SDSS since the first phase began operations in 2000. New in DR14 is the first public release of data from the extended Baryon Oscillation Spectroscopic Survey (eBOSS); the first data from the second phase of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2), including stellar parameter estimates from an innovative data driven machine learning algorithm known as "The Cannon"; and almost twice as many data cubes from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous release (N = 2812 in total). This paper describes the location and format of the publicly available data from SDSS-IV surveys. We provide references to the important technical papers describing how these data have been taken (both targeting and observation details) and processed for scientific use. The SDSS website (www.sdss.org) has been updated for this release, and provides links to data downloads, as well as tutorials and examples of data use. SDSS-IV is planning to continue to collect astronomical data until 2020, and will be followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14 happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov 2017 (this is the "post-print" and "post-proofs" version; minor corrections only from v1, and most of errors found in proofs corrected