Showing papers by "Texas Christian University published in 2016"

The SDSS-IV extended baryon oscillation spectroscopic survey: Overview and early data

Abstract: In a six-year program started in 2014 July, the Extended Baryon Oscillation Spectroscopic Survey (eBOSS) will conduct novel cosmological observations using the BOSS spectrograph at Apache Point Observatory. These observations will be conducted simultaneously with the Time Domain Spectroscopic Survey (TDSS) designed for variability studies and the Spectroscopic Identification of eROSITA Sources (SPIDERS) program designed for studies of X-ray sources. In particular, eBOSS will measure with percent-level precision the distance-redshift relation with baryon acoustic oscillations (BAO) in the clustering of matter. eBOSS will use four different tracers of the underlying matter density field to vastly expand the volume covered by BOSS and map the large-scale-structures over the relatively unconstrained redshift range 0.6 0.6 sample of BOSS galaxies. With ~195,000 new emission line galaxy redshifts, we expect BAO measurements of d_A(z) to an accuracy of 3.1% and H(z) to 4.7% at an effective redshift of z = 0.87. A sample of more than 500,000 spectroscopically confirmed quasars will provide the first BAO distance measurements over the redshift range 0.9 2.1; these new data will enhance the precision of dA(z) and H(z) at z > 2.1 by a factor of 1.44 relative to BOSS. Furthermore, eBOSS will provide improved tests of General Relativity on cosmological scales through redshift-space distortion measurements, improved tests for non-Gaussianity in the primordial density field, and new constraints on the summed mass of all neutrino species. Here, we provide an overview of the cosmological goals, spectroscopic target sample, demonstration of spectral quality from early data, and projected cosmological constraints from eBOSS.

Aspcap: the apogee stellar parameter and chemical abundances pipeline

Abstract: NSF [AST11-09718, AST-907873]; Alfred P. Sloan Foundation; National Science Foundation; U.S. Department of Energy Office of Science; University of Arizona; Brazilian Participation Group; Brookhaven National Laboratory; University of Cambridge; Carnegie Mellon University; University of Florida; French Participation Group; German Participation Group; Harvard University; Instituto de Astrofisica de Canarias; Michigan State/Notre Dame/JINA Participation Group; Johns Hopkins University; Lawrence Berkeley National Laboratory; Max Planck Institute for Astrophysics; Max Planck Institute for Extraterrestrial Physics; New Mexico State University; New York University; Ohio State University; Pennsylvania State University; University of Portsmouth; Princeton University; Spanish Participation Group; University of Tokyo; University of Utah; Vanderbilt University; University of Virginia; University of Washington; Yale University; Spanish Ministry of Economy and Competitiveness (MINECO) [AYA2014-56359-P]; Janos Bolyai Research Scholarship of the Hungarian Academy of Sciences; Spanish Ministry of Economy and Competitiveness [AYA-2011-27754, AYA2014-58082-P]

Value creation through stakeholder synergy

Abstract: Our “stakeholder synergy” perspective identifies new value creation opportunities that are especially effective strategically because a single strategic action (1) increases different types of value for two or more essential stakeholder groups simultaneously, and (2) does not reduce the value already received by any other essential stakeholder group. This result is obtainable because multiple potential sources of value creation exist for each essential stakeholder group. Actions that meet these criteria increase the size of the value “pie” available for essential stakeholder groups, and thereby serve to attract exceptional stakeholders and obtain their increasing effort and commitment. The stakeholder synergy perspective extends stakeholder theory further into the strategy realm, and offers insights for realizing broader value creation that is more likely to produce sustainable competitive advantage. Copyright © 2014 John Wiley & Sons, Ltd.

Design Structure Matrix Extensions and Innovations: A Survey and New Opportunities

Abstract: The design structure matrix (DSM), also called the dependency structure matrix, has become a widely used modeling framework across many areas of research and practice. The DSM brings advantages of simplicity and conciseness in representation, and, supported by appropriate analysis, can also highlight important patterns in system architectures (design structures), such as modules and cycles. A literature review in 2001 cited about 100 DSM papers; there have been over 1000 since. Thus, it is useful to survey the latest DSM extensions and innovations to help consolidate progress and identify promising opportunities for further research. This paper surveys the DSM literature, primarily from archival journals, and organizes the developments pertaining to building, displaying, analyzing, and applying product, process, and organization DSMs. It then addresses DSM applications in other domains, as well as recent developments with domain mapping matrices (DMMs) and multidomain matrices (MDMs). Overall, DSM methods are becoming more mainstream, especially in the areas of engineering design, engineering management, management/organization science, and systems engineering. Despite significant research contributions, however, DSM awareness seems to be spreading more slowly in the realm of project management.

Gender stereotypes in advertising: a review of current research

Abstract: The purpose of this paper is to highlight the historical context of gender stereotypes in advertising and then examine the scholarship related to gender stereotypes. Gender portrayals in advertising have been examined extensively in the last five decades and still remain an important topic. Changing role structure in the family and in the labor force has brought significant variation in both male and female roles and subsequently how it is reflected in advertising. It has been noted that there is a culture lag. Sexes for a long period of time were depicted in advertising in more traditional roles. Women were presented in an inferior manner relative to their potential and capabilities, while at the same the data indicated a shift towards more positive role portrayals. The changing role of men is the area that has seen the greatest interest in the past few years. Men are depicted in advertising in ‘softer’ roles, while interacting with their children. Men are also shown in more egalitarian roles. The paper ...

A meta-analysis update on the effects of early family/parent training programs on antisocial behavior and delinquency

Abstract: To update Piquero et al.’s meta-analysis on early family/parent training programs. Screening of eligible studies was carried out for the period between January 2008 and August 2015. An additional 23 studies were identified, which were added to the original database of 55 studies, totaling an overall sample of 78 eligible studies. A random-effects model was used to obtain an overall mean effect size estimate. Additional analyses were performed to assess publication bias and moderation. An overall average, positive, and significant effect size of 0.37 was calculated, which corresponds to 32 out of 100 in a treated group versus 50 out of 100 in a control group who offended. There was some evidence of publication bias and moderation. Early family/parent training programs are an effective evidence-based strategy for preventing antisocial behavior and delinquency.

Theories of the (state-owned) firm

Abstract: State-owned enterprises (SOEs) contribute approximately 10% of the world’s GDP. SOEs at one time were predicted to disappear from the economic landscape of the world, but today SOEs are growing more prevalent in the world economy. The current theories of the firm that form the pillars of the management discipline largely ignore the theoretical differences that SOEs introduce into the conceptualization of the firm. Therefore, we extend four core theories of the firm by incorporating SOEs as a mainstream (not special or marginal) organizational form into these theories. We focus specifically on property rights theory, transaction cost theory, agency theory, and resource-based theory, culminating in a research agenda with 12 testable propositions.

A meta-analysis update on the effectiveness of early self-control improvement programs to improve self-control and reduce delinquency

Abstract: To update Piquero et al.’s (Justice Quarterly 27:803–834, 2010) meta-analysis on early self-control improvement programs. Screening of eligible studies was carried out for the period between January 2010 and September 2015. An additional seven studies were identified, which were added to the original database of 34 studies, totaling an overall sample of 41 eligible studies. A random effects model was used to obtain an overall mean effect size estimate. Additional analyses were performed to assess publication bias and moderation. Overall average, positive, and significant effect sizes were observed for improving self-control (0.32) and reducing delinquency (0.27). There was evidence of publication bias for the self-control improvement outcomes, as well as some evidence of moderation for both self-control improvement and delinquency outcomes. Early self-control improvement programs are an effective evidence-based strategy for improving self-control and reducing delinquency.

Vocabulary Knowledge of Children With Cochlear Implants: A Meta-Analysis.

Abstract: This article employs meta-analysis procedures to evaluate whether children with cochlear implants demonstrate lower spoken-language vocabulary knowledge than peers with normal hearing. Of the 754 articles screened and 52 articles coded, 12 articles met predetermined inclusion criteria (with an additional 5 included for one analysis). Effect sizes were calculated for relevant studies and forest plots were used to compare differences between groups of children with normal hearing and children with cochlear implants. Weighted effect size averages for expressive vocabulary measures (g = -11.99; p < .001) and for receptive vocabulary measures (g = -20.33; p < .001) indicated that children with cochlear implants demonstrate lower vocabulary knowledge than children with normal hearing. Additional analyses confirmed the value of comparing vocabulary knowledge of children with hearing loss to a tightly matched (e.g., socioeconomic status-matched) sample. Age of implantation, duration of implantation, and chronological age at testing were not significantly related to magnitude of weighted effect size. Findings from this analysis represent a first step toward resolving discrepancies in the vocabulary knowledge literature.

Coinfections of the Respiratory Tract: Viral Competition for Resources.

Abstract: Studies have shown that simultaneous infection of the respiratory tract with at least two viruses is common in hospitalized patients, although it is not clear whether these infections are more or less severe than single virus infections. We use a mathematical model to study the dynamics of viral coinfection of the respiratory tract in an effort to understand the kinetics of these infections. Specifically, we use our model to investigate coinfections of influenza, respiratory syncytial virus, rhinovirus, parainfluenza virus, and human metapneumovirus. Our study shows that during coinfections, one virus can block another simply by being the first to infect the available host cells; there is no need for viral interference through immune response interactions. We use the model to calculate the duration of detectable coinfection and examine how it varies as initial viral dose and time of infection are varied. We find that rhinovirus, the fastest-growing virus, reduces replication of the remaining viruses during a coinfection, while parainfluenza virus, the slowest-growing virus is suppressed in the presence of other viruses.

Customer-Base Concentration, Profitability, and the Relationship Life Cycle

Abstract: Using a recently expanded dataset on supplier-customer links, we introduce a dynamic relationship life-cycle hypothesis. We hypothesize that the relation between customer-base concentration and profitability is significantly negative in the early years of the relationship, but becomes positive as the relationship matures. The key driver of this dynamic is the customer-specific investments that the relationship entails. These investments result in larger fixed costs, greater operating leverage, and a higher probability of losses early in the relationship, but can significantly benefit the firm as the relationship matures. Although many of these money-losing firms in early-stage relationships were not studied in Patatoukas (2012), we find a market reaction to increases in customer concentration similar to that in his paper. This result provides powerful confirmatory evidence of the value of customer concentration. We document one of the intangible benefits of customer concentration, technology sha...

Performance-Vesting Provisions in Executive Compensation

Abstract: The usage of performance vesting (p-v) equity awards to top executives in large US companies has grown from 20 to 70 percent from 1998 to 2012. We assess the implications of these increasingly complex awards by examining the accuracy of and biases in disclosure and the connection between the structure of executive pay, risk-taking incentives, and firm risk. To do so, we develop and implement new methods that empirically quantify the significant effects of p-v provisions on the value, delta, and vega of equity-based compensation. We find large biases in the value of executive compensation reported in company disclosures. The elasticity of reported value in economic value is far less than one, with additional bias downward (upward) for large institutional ownership (when the firm uses a high-market-share compensation consultant). Our analysis empirically reaffirms the presence of a causal relation in both the time series and cross section between compensation convexity and firm risk.

Differences in predictions of ODE models of tumor growth: a cautionary example

Abstract: While mathematical models are often used to predict progression of cancer and treatment outcomes, there is still uncertainty over how to best model tumor growth. Seven ordinary differential equation (ODE) models of tumor growth (exponential, Mendelsohn, logistic, linear, surface, Gompertz, and Bertalanffy) have been proposed, but there is no clear guidance on how to choose the most appropriate model for a particular cancer. We examined all seven of the previously proposed ODE models in the presence and absence of chemotherapy. We derived equations for the maximum tumor size, doubling time, and the minimum amount of chemotherapy needed to suppress the tumor and used a sample data set to compare how these quantities differ based on choice of growth model. We find that there is a 12-fold difference in predicting doubling times and a 6-fold difference in the predicted amount of chemotherapy needed for suppression depending on which growth model was used. Our results highlight the need for careful consideration of model assumptions when developing mathematical models for use in cancer treatment planning.

The Dark Triad and Nascent Entrepreneurship: An Examination of Unproductive versus Productive Entrepreneurial Motives

Abstract: This study examined relationships of the dark triad personality characteristics (ie, narcissism, psychopathy, and Machiavellianism) with entrepreneurial intentions and motives Results from samples of business undergraduates (N = 508) and MBA students (N = 234) found narcissism to be positively related to entrepreneurial intentions In addition, results from subgroups of business undergraduates and MBA students high in entrepreneurial intentions (ie, early-stage nascent entrepreneurs) indicated differences in motives for engaging in the startup process Specifically, we found all facets of the dark triad to be positively associated with unproductive entrepreneurial motives, and observed differential associations of the dark triad characteristics with productive entrepreneurial motives

Serum Neurofilament Light in American Football Athletes over the Course of a Season

Abstract: Despite being underreported, American football boasts the highest incidence of concussion among all team sports, likely due to exposure to head impacts that vary in number and magnitude over the season. This study compared a biological marker of head trauma in American football athletes with non-contact sport athletes and examined changes over the course of a season. Baseline serum neurofilament light polypeptide (NFL) was measured after 9 weeks of no contact and compared with a non-contact sport. Serum NFL was then measured over the course of the entire season at eight time-points coincident with expected changes in likelihood of increased head impacts. Data were compared between starters (n = 11) and non-starters (n = 9). Compared with non-starters (mean ± standard deviation) (7.30 ± 3.57 pg•mL−1) and controls (6.75 ± 1.68 pg•mL−1), serum NFL in starters (8.45 ± 5.90 pg•mL−1) was higher at baseline (mean difference; ±90% confidence interval) (1.69; ± 1.96 pg•mL−1 and 1.15; ± 1.4 pg•mL−1, resp...

Low Childhood Socioeconomic Status Promotes Eating in the Absence of Energy Need

Abstract: Life-history theory predicts that exposure to conditions typical of low socioeconomic status (SES) during childhood will calibrate development in ways that promote survival in harsh and unpredictable ecologies. Guided by this insight, the current research tested the hypothesis that low childhood SES will predict eating in the absence of energy need. Across three studies, we measured (Study 1) or manipulated (Studies 2 and 3) participants' energy need and gave them the opportunity to eat provided snacks. Participants also reported their SES during childhood and their current SES. Results revealed that people who grew up in high-SES environments regulated their food intake on the basis of their immediate energy need; they ate more when their need was high than when their need was low. This relationship was not observed among people who grew up in low-SES environments. These individuals consumed comparably high amounts of food when their current energy need was high and when it was low. Childhood SES may have a lasting impact on food regulation.

Spectro-photometric distances to stars: a general-purpose Bayesian approach

Abstract: We developed a code that estimates distances to stars using measured spectroscopic and photometric quantities. We employ a Bayesian approach to build the probability distribution function over stellar evolutionary models given these data, delivering estimates of model parameters for each star individually. The code was first tested on simulations, successfully recovering input distances to mock stars with <1% bias.The method-intrinsic random distance uncertainties for typical spectroscopic survey measurements amount to around 10% for dwarf stars and 20\% for giants, and are most sensitive to the quality of $\log g$ measurements. The code was validated by comparing our distance estimates to parallax measurements from the Hipparcos mission for nearby stars (< 300 pc), to asteroseismic distances of CoRoT red giant stars, and to known distances of well-studied open and globular clusters. The external comparisons confirm that our distances are subject to very small systematic biases with respect to the fundamental Hipparcos scale (+0.4 % for dwarfs, and +1.6% for giants). The typical random distance scatter is 18% for dwarfs, and 26% for giants. For the CoRoT-APOGEE sample, the typical random distance scatter is ~15%, both for the nearby and farther data. Our distances are systematically larger than the CoRoT ones by about +9%, which can mostly be attributed to the different choice of priors. The comparison to known distances of star clusters from SEGUE and APOGEE has led to significant systematic differences for many cluster stars, but with opposite signs, and with substantial scatter. Finally, we tested our distances against those previously determined for a high-quality sample of giant stars from the RAVE survey, again finding a small systematic trend of +5% and an rms scatter of 30%.

Chirality Inversion of CdSe and CdS Quantum Dots without Changing the Stereochemistry of the Capping Ligand

Abstract: L-cysteine derivatives induce and modulate the optical activity of achiral cadmium selenide (CdSe) and cadmium sulfide (CdS) quantum dots (QDs). Remarkably, N-acetyl-L-cysteine-CdSe and L-homocysteine-CdSe as well as N-acetyl-L-cysteine-CdS and L-cysteine-CdS showed "mirror-image" circular dichroism (CD) spectra regardless of the diameter of the QDs. This is an example of the inversion of the CD signal of QDs by alteration of the ligand's structure, rather than inversion of the ligand's absolute configuration. Non-empirical quantum chemical simulations of the CD spectra were able to reproduce the experimentally observed sign patterns and demonstrate that the inversion of chirality originated from different binding arrangements of N-acetyl-L-cysteine and L-homocysteine-CdSe to the QD surface. These efforts may allow the prediction of the ligand-induced chiroptical activity of QDs by calculating the specific binding modes of the chiral capping ligands. Combined with the large pool of available chiral ligands, our work opens a robust approach to the rational design of chiral semiconducting nanomaterials.

Predictors of Sustained Implementation of School-Wide Positive Behavioral Interventions and Supports.

Abstract: In this analysis of extant data from 3,011 schools implementing school-wide positive behavioral interventions and supports (SWPBIS) across multiple years, we assessed the predictive power of various school characteristics and speed of initial implementation on sustained fidelity of implementation of SWPBIS at 1, 3, and 5 years. In addition, we partitioned variance in whether schools sustained SWPBIS at the school, district, and state levels. Results showed that the largest differences in fidelity were at the state level. In addition, school characteristics (particularly grade levels served) and speed of initial implementation were significant but small predictors of sustained implementation. Results are discussed in terms of effective supports at the state and district levels, as well as addressing types of schools at greater risk of abandonment, such as high schools.

APOGEE KINEMATICS. I. OVERVIEW of the KINEMATICS of the GALACTIC BULGE AS MAPPED by APOGEE

Abstract: We present the stellar kinematics across the Galactic bulge and into the disk at positive longitudes from the SDSS-III APOGEE spectroscopic survey of the Milky Way. APOGEE includes extensive coverage of the stellar populations of the bulge along the mid-plane and near-plane regions. From these data, we have produced kinematic maps of 10,000 stars across longitudes 0 deg -0.5 have dispersion and rotation profiles that are similar to that of N-body models of boxy/peanut bulges. There is a smooth kinematic transition from the thin bar and boxy bulge (l,|b|) -1.0, and the chemodynamics across (l,b) suggests the stars in the inner Galaxy with [Fe/H] > -1.0 have an origin in the disk.

COMPANIONS to APOGEE STARS. I. A MILKY WAY-SPANNING CATALOG of STELLAR and SUBSTELLAR COMPANION CANDIDATES and THEIR DIVERSE HOSTS

Abstract: In its three years of operation, the Sloan Digital Sky Survey Apache Point Observatory Galactic Evolution Experiment (APOGEE-1) observed >14,000 stars with enough epochs over a sufficient temporal baseline for the fitting of Keplerian orbits. We present the custom orbit-fitting pipeline used to create this catalog, which includes novel quality metrics that account for the phase and velocity coverage of a fitted Keplerian orbit. With a typical radial velocity precision of ∼100–200 m s−1, APOGEE can probe systems with small separation companions down to a few Jupiter masses. Here we present initial results from a catalog of 382 of the most compelling stellar and substellar companion candidates detected by APOGEE, which orbit a variety of host stars in diverse Galactic environments. Of these, 376 have no previously known small separation companion. The distribution of companion candidates in this catalog shows evidence for an extremely truncated brown dwarf (BD) desert with a paucity of BD companions only for systems with a < 0.1–0.2 AU, with no indication of a desert at larger orbital separation. We propose a few potential explanations of this result, some which invoke this catalog’s many small separation companion candidates found orbiting evolved stars. Furthermore, 16 BD and planet candidates have been identified around metal-poor ([Fe/H] < −0.5) stars in this catalog, which may challenge the core accretion model for companions >10MJup. Finally, we find all types of companions are ubiquitous throughout the Galactic disk with candidate planetary-mass and BD companions to distances of ∼6 and ∼16 kpc, respectively.