Human capital and entrepreneurial success : a meta-analytical review

The study meta-analytically integrates results from three decades of human capital research in entrepreneurship. Based on 70 independent samples (N = 24,733), we found a significant but small relationship between human capital and success (r(c) = .098). We examined theoretically derived moderators of this relationship referring to conceptualizations of human capital, to context, and to measurement of success. The relationship was higher for outcomes of human capital investments (knowledge/skills) than for human capital investments (education/experience), for human capital with high task-relatedness compared to low task-relatedness, for young businesses compared to old businesses, and for the dependent variable size compared to growth or profitability. Findings are relevant for practitioners (lenders, policy makers, educators) and for future research. Our findings show that future research should pursue moderator approaches to study the effects of human capital on success. Further, human capital is most important if it is task-related and if it consists of outcomes of human capital investments rather than human capital investments; this suggests that research should overcome a static view of human capital and should rather investigate the processes of learning, knowledge acquisition, and the transfer of knowledge to entrepreneurial tasks

Tip–sample interactions: Extraction of single molecular pair potentials from force curves

This article describes a method for extracting the true tip–sample potential from an experimental force curve in atomic force microscopy. This potential is not the negative integral of the force curve. Rather, the potential is a more complicated function of the force curve and cantilever spring constant. If information about the shape of the tip is known, a decorrelation may be performed to extract molecular pair potentials from the total tip–sample potential. Applications and limitations of this method are discussed

Force indeterminacy in the jammed state of hard disks

Granular packings of hard discs are investigated by means of contact dynamics which is an appropriate technique to explore the allowed force-realizations in the space of contact forces. Configurations are generated for given values of the friction coefficient, and then an ensemble of equilibrium forces is found for fixed contacts. We study the force fluctuations within this ensemble. In the limit of zero friction the fluctuations vanish in accordance with the isostaticity of the packing. The magnitude of the fluctuations has a non-monotonous friction dependence. The increase for small friction can be attributed to the opening of the angle of the Coulomb cone, while the decrease as friction increases is due to the reduction of connectivity of the contact-network, leading to local, independent clusters of indeterminacy. We discuss the relevance of indeterminacy to packings of deformable particles and to the mechanical response properties.Comment: 4 pages, 3 figures. Minor changes, journal reference adde

Elizabeth River Tributyltin Monitoring Program 1999-2006 : A Report to the Virginia Department of Environmental Quality Tidewater Regional Office

The purpose of this project was to implement a study in 1999/2000 that would document the current levels of tributyltin (TBT) in the Elizabeth River and provide baseline data for future efforts to determine the trend of TBT concentrations found in the Elizabeth River Watershed. Subsequent years of sampling have documented spatial and temporal trends in TBT and are described in this report

The journey from high school to college: Do collaborative connections improve student transition?

Each year, thousands of students enter postsecondary education unprepared for the many academic, social, and emotional challenges they will face. Collaborative programs between secondary and postsecondary institutions have therefore developed as one way to address these issues. Although numerous studies have focused on quantitative evaluation of collaborative programs, few have included qualitative analysis of the opinions and ideas of those students who were involved in the efforts. The purpose of this study was to gauge the effect of student participation in pre-college collaborative experiences on students\u27 transition from secondary to postsecondary education. Within the context of Schlossberg\u27s Transition Theory, the study attempted to determine the impact of participation in two specific types of collaborative programs, academic alliance and motivational/compensatory, on student awareness of, adjustment to, and commitment to college. Focusing on the four key factors of Schlossberg\u27s Transition Theory—situation, self, support, and strategies—the study employed face-to-face, semi structured interviews with 27 college students who were alumni of the two programs, College Summit and the Writing Coalition, to determine student perceptions of their pre-college and college transition experiences. The qualitative data analysis revealed that all students perceived their collaborative experiences as beneficial and positive, and the majority of the students reported that they were very committed to completing a college education. Finally, study participants candidly shared their suggestions for developing even more successful collaborative programs

Elizabeth River TBT Monitoring Report on TBT Methodology Detection Limit, Precision and Linearity

The purpose of this project was to determine the accuracy, precision, linearity and Method Detection Limit (MDL) for tributyltin (TBT) analytical techniques available at the Virginia Institute of Marine Science prior to implementing an environmental monitoring program in the Elizabeth River, Virginia. This precursory work is to document the ability of analytical techniques to accurately detect TBT in ambient water samples at concentrations of 1 ng/L and greater

A Manual for the Analysis of Butyltins in Environmental Samples

The Virginia Institute of Marine Science (VIMS) has developed methods for the analysis of tributyltin (TBT) in environmental samples. These methods have been published in the scientific literature where they are freely available to the public. When used by skilled analysts and supported by appropriate quality assurance and quality control procedures (QA/QC), we believe these methods, as well as other published analytical methods for TBT, can provide accurate and precise results. As in any environmental analysis, method performance is a function of the sample type, available instrumentation and skill and care taken by laboratory workers. The suitability of the data produced will only be confirmed by proper QA/QC in the laboratory. At the request of the Virginia Department of Environmental Quality (DEQ), the Virginia Institute of Marine Science has prepared this laboratory manual as an advisory to those interested in methods for analysis of TBT in environmental samples. This manual is based on the previously published methods developed at VIMS and describes procedures for the analysis of TBT in water, sediment and biota samples. This effort is not intended to endorse these techniques as the only suitable methods for butyltin analysis, but is intended to provide detailed information on procedures which have been developed and successfully used at VIMS for the past ten years. It contains a higher level of detail than previous publications and also incorporates any recent changes in procedures, as well as listing possible sources for reagents and standards. This manual also contains a bibliography which lists published VIMS methods as well as other literature citations in which alternative techniques for the analysis of TBT may be found