Does venture capital pay off? a meta-analysis on the relationship between venture capital involvement and firm performance

Venture capital (VC) as an alternative to mainstream corporate finance (Wright and Robbie, 1998) has attracted a large amount of interest in academic research and among practitioners. On e of the main questions is whether VC adds value to firms. Yet, empirical research results are highly inconsistent. Venture capitalists do not only provide capital and monitoring, but also actively assist firms with industry-specific knowledge and skills (MacMillan et al., 1989). Furthermore, they increase the legitimacy of entrepreneurial firms (Zimmerman & Zeitz, 2002). On the other hand, venture capitalists may pressure firms to an initial public offering (IPO) in a premature stage of their life cycle (Gompers, 1996). High costs associated with an IPO may, in turn, decrease profitability and even endanger the survival of firms. Whether venture capital really pays off, thus, largely depends on contextual factors. The aim of this study is to provide a review and synthesis of existing empirical research on the relationship between VC and firm performance. Specifically, we intend to answer two research questions: (1) Does VC increase the performance of firms? (2) Which variables moderate this relationship

Is innovation always beneficial? A meta-analysis of the relationship between innovation and performance in SMEs

The performance implications of innovation in small and medium-sized enterprises (SMEs) have attracted considerable interest among academics and practitioners. However, empirical research on the innovation–performance relationship in SMEs shows controversial results. This meta-analysis synthesizes empirical findings in order to obtain evidence whether and especially under which circumstances smaller, resource-scarce firms benefit from innovation. We find that innovation–performance relationship is context dependent. Factors such as the age of the firm, the type of innovation, and the cultural context affect the impact of innovation on firm performance to a large extent

Neutrality in the balance. Spanish-German relations during the First World War, 1914-1918

There is no abstract for this thesis

Neutrality in the balance. Spanish-German relations during the First World War, 1914-1918

There is no abstract for this thesis

Stability of a trapped atom clock on a chip

We present a compact atomic clock interrogating ultracold 87Rb magnetically trapped on an atom chip. Very long coherence times sustained by spin self-rephasing allow us to interrogate the atomic transition with 85% contrast at 5 s Ramsey time. The clock exhibits a fractional frequency stability of $5.8\times 10^{-13}$ at 1 s and is likely to integrate into the $1\times10^{-15}$ range in less than a day. A detailed analysis of 7 noise sources explains the measured frequency stability. Fluctuations in the atom temperature (0.4 nK shot-to-shot) and in the offset magnetic field ($5\times10^{-6}$ relative fluctuations shot-to-shot) are the main noise sources together with the local oscillator, which is degraded by the 30% duty cycle. The analysis suggests technical improvements to be implemented in a future second generation set-up. The results demonstrate the remarkable degree of technical control that can be reached in an atom chip experiment.Comment: 12 pages, 11 figure

Spin waves and Collisional Frequency Shifts of a Trapped-Atom Clock

We excite spin-waves with spatially inhomogeneous pulses and study the resulting frequency shifts of a chip-scale atomic clock of trapped $^{87}$Rb. The density-dependent frequency shifts of the hyperfine transition simulate the s-wave collisional frequency shifts of fermions, including those of optical lattice clocks. As the spin polarizations oscillate in the trap, the frequency shift reverses and it depends on the area of the second Ramsey pulse, exhibiting a predicted beyond mean-field frequency shift. Numerical and analytic models illustrate the observed behaviors.Comment: Will appear soon in Physical Review Letters - Typos correcte

Improved tests of Local Position Invariance using 87Rb and 133Cs fountains

We report tests of local position invariance based on measurements of the ratio of the ground state hyperfine frequencies of 133Cs and 87Rb in laser-cooled atomic fountain clocks. Measurements extending over 14 years set a stringent limit to a possible variation with time of this ratio: d ln(nu_Rb/nu_Cs)/dt=(-1.39 +/- 0.91)x 10-16 yr-1. This improves by a factor of 7.7 over our previous report (H. Marion et al., Phys. Rev. Lett. 90, 150801 (2003)). Our measurements also set the first limit to a fractional variation of the Rb/Cs ratio with gravitational potential at the level of c^2 d ln(nu_Rb/nu_Cs)/dU=(0.11 +/- 1.04)x 10^-6, providing a new stringent differential redshift test. The above limits equivalently apply to the fractional variation of the quantity alpha^{-0.49}x(g_Rb/g_Cs), which involves the fine structure constant alpha and the ratio of the nuclear g-factors of the two alkalis. The link with variations of the light quark mass is also presented together with a global analysis combining with other available highly accurate clock comparisons.Comment: 5 pages, 3 figures, 3 tables, 34 reference

Second language learning in young children

The interrelationships among selected variables and second language learning were examined in 52 children, three through five years-old. An experimenter-designed curriculum based on active, concrete experiences was used to teach Spanish in a small-group setting;Immediately following the six-month instructional period, children participated in a Spanish posttest which was videotaped and viewed by two university Spanish faculty members who independently rated the children on the criterion variables: vocabulary, listening comprehension, oral production, and pronunciation. Moderator variables included intelligence (Stanford Binet, Form L-M, 1972 Norms), parent attitude toward bilingualism (Mosley, 1969), child\u27s motivation to learn Spanish (experimenter-developed instrument), age in months, and sex;A multiple classification analysis of variance procedure revealed that highly motivated subjects performed better on vocabulary and oral production, but not on listening comprehension. A significant interaction was observed between motivation and age for pronunciation which suggested that high motivation compensated for the neurological immaturity of the younger children. The lack of an observed relationship between intelligence, sex, and age and second language learning suggests the appropriateness of this curriculum for children of normal intelligence and above, regardless of sex, within this age range. The lack of variability in parent attitude may explain the unexpected finding in this study of no significant relationship between parent attitude and children\u27s second language learning;Reference. Mosley, R. T. (1969). Development and application of a Spanish-English bilingualism attitude scale. Unpublished doctoral dissertation, Texas A&M University, College Station, TX