Texas Christian University

About: Texas Christian University is a education organization based out in Fort Worth, Texas, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 3245 authors who have published 8258 publications receiving 282216 citations. The organization is also known as: TCU & Texas Christian University, TCU.

Power to the Principals! An Experimental Look at Shareholder Say-On-Pay Voting

Abstract: With recent legislation mandating that publicly traded corporations submit their CEOs' compensation for a nonbinding shareholder vote, a systematic understanding of shareholder preferences has neve

Brazilian peppertree ( Schinus terebinthifolius ) in Florida and South America: evidence of a possible niche shift driven by hybridization

Abstract: Brazilian peppertree (Schinus terebinthifolius Raddi, Anacardiaceae) was introduced into Florida from South America in the 1800s and commercialized as an ornamental plant. Based on herbaria records and available literature, it began to escape cultivation and invade ruderal and natural habitats in the 1950s, and is now considered to be one of Florida’s most widespread and damaging invasive plants. Historical records and molecular evidence indicate that two genetic lineages of Brazilian peppertree were established in Florida, one in Miami on the east coast and a second near Punta Gorda on the west coast. Since arriving, the distributions of these two types have greatly expanded, and they have extensively hybridized. Principal component analysis and reciprocal niche fitting were used to test the equivalency of climatic niches of the Florida populations with the climatic niches of the two South American chloroplast haplotype groups which established in Florida. Both approaches indicated a significant shift in niches between the parental populations in the native range and the invasive populations in Florida. The models, however, closely predicted the areas of initial establishment. We hypothesize that (1) Brazilian peppertree was able to gain an initial foothold in Florida due to niche similarity and (2) the current dissimilarity in native and exotic niches is due to hybridization followed by rapid selection of genotypes adapted to Florida’s climate. In addition, to examine the potential consequence of the introduction of additional genetic diversity from the native range on invasion success, a niche model constructed with occurrences of all native genotypes was projected onto the continental United States. The result of this test indicated that under such an event, the potential invasive range would greatly expand to cover most of the southeastern USA. Our study suggests that multiple introductions from disjunct regions in the native range can facilitate invasion success.

In-sync. iii. the dynamical state of ic 348—a super-virial velocity dispersion and a puzzling sign of convergence

Abstract: Most field stars will have encountered the highest stellar density and hence the largest number of interactions in their birth environment. Yet the stellar dynamics during this crucial phase are poorly understood. Here we analyze the radial velocities measured for 152 out of 380 observed stars in the 2?6 Myr old star cluster IC 348 as part of the SDSS-III APOGEE. The radial velocity distribution of these stars is fitted with one or two Gaussians, convolved with the measurement uncertainties including binary orbital motions. Including a second Gaussian improves the fit; the high-velocity outliers that are best fit by this second component may either (1) be contaminants from the nearby Perseus OB2 association, (2) be a halo of ejected or dispersing stars from IC 348, or (3) reflect that IC 348 has not relaxed to a Gaussian velocity distribution. We measure a velocity dispersion for IC 348 of 0.72 ? 0.07 km s?1 (or 0.64 ? 0.08 km s?1 if two Gaussians are fitted), which implies a supervirial state, unless the gas contributes more to the gravitational potential than expected. No evidence is found for a dependence of this velocity dispersion on distance from the cluster center or stellar mass. We also find that stars with lower extinction (in the front of the cloud) tend to be redshifted compared with stars with somewhat higher extinction (toward the back of the cloud). This data suggest that the stars in IC 348 are converging along the line of sight. We show that this correlation between radial velocity and extinction is unlikely to be spuriously caused by the small cluster rotation of 0.024 ? 0.013 km s?1 arcmin?1 or by correlations between the radial velocities of neighboring stars. This signature, if confirmed, will be the first detection of line of sight convergence in a star cluster. Possible scenarios for reconciling this convergence with IC 348's observed supervirial state include: (a) the cluster is fluctuating around a new virial equilibrium after a recent disruption due to gas expulsion or a merger event, or (b) the population we identify as IC 348 results from the chance alignment of two sub-clusters converging along the line of sight. Additional measurements of tangential and radial velocities in IC 348 will be important for clarifying the dynamics of this region and informing models of the formation and evolution of star clusters. The radial velocities analyzed in this paper have been made available online.

Founder/Chief Executive Officer Exit: A Social Capital Perspective of New Ventures

Abstract: The founder/chief executive officer (CEO) exit is a significant event for all business organizations However, a social capital perspective suggests that the exit of the founder/CEO may be more disruptive for new start-ups due to the critical role the founder/CEO plays in the new organization and the heightened potential chance for failure of a new venture A social capital perspective suggests that the ability of the entrepreneurial firm to perform better is affiliated with the social capital within the organization This study supports a social capital perspective of CEO exit and social capital's impact on performance It helps establish a foundation of study of CEO exit and new ventures from this perspective Introduction There has been a wide variety of research that has examined the impact of the departure of a chief executive officer (CEO) on firm performance (Jayaraman et al 2000; Begley 1995; Daily and Dalton 1992) The evidence from these various streams of research has not provided a consistent set of findings (Jayaraman et al 2000) Entrepreneurial start-ups present the opportunity to provide fresh insight on CEO turnaround by examining a setting where the performance impact of CEO exit is particularly profound; the impact of CEO exit is enhanced because there is a general absence of slack resources to help the organization overcome the CEO exit However, to date, the impact of CEO exit from the perspective of entrepreneurial new ventures has not been extensively examined This paper will examine such ventures, and how new ventures are able to respond to the loss of the CEO, from a social capital perspective, to understand how new ventures can successfully navigate such issues A founder/CEO of a new venture is critical to that venture not only for their leadership but also for the web of relationships that they build Such relationships form a critical part of the organization's social capital Such social capital can be important in dealing with suppliers, obtaining new customers or employees, and navigating regulation relevant to the new venture In a large mature organization, there are a variety of individuals throughout the organization that can do such activities However, in a new venture due to its less intense staffing, the focus of such activities is on the founder/CEO and other top managers The importance of social capital in new ventures to perform such activities has been discussed as part of the ability of the new firm to overcome its liability of newness (Li and Guisinger 1991; Freeman, Carroll, and Hannan 1983) Thus, when a founder/CEO leaves the new venture, the impact can be particularly dramatic because it directly impacts the social capital of the organization To date, however, there has not been an extensive empirical effort to understand the role of social capital in CEO exit for either mature or new ventures New ventures, in the same way as more mature businesses, have the potential to respond and seek to compensate for the loss of the CEO In a new venture, however, the response to such a loss can also more immediately be examined because the new venture has less slack in the organization, which can be redirected to cover such a loss Thus, it is more directly discernable when the new venture seeks to aid individuals with social capital to offset that lost when the founder/CEO left the organization It could be expected from a social capital perspective that those organizations that are able to mitigate the loss of social capital will outperform those firms that are unable to do so Therefore, this study also examines the mitigating factors available to the new venture to offset the loss of social capital associated with the loss of the founder/CEO This empirical study will make three contributions to the literature First, the paper provides fresh insights on the impact of the loss of a CEO in an environment where such an activity is particularly critical …

Contextual Model of Leadership Influence in Hospital Units

Abstract: Using Kerr and Jermier's (1978) taxonomy of substitute and neutralizer variables, the contextual model indicates that the staff nurse's education, group cohesion, and work technology substitute for...