What drives Venture Capital Syndication

This paper analyses the syndication behavior of VC organisations and the factors influencing their overall propensity to co-invest. We develop hypothesis concerning the investment behavior of Venture Capitalists in the German market and compare these hypothesis to the actual empirical evidence from a data set including 2,500 VC investments. We find that the underlying theories of financial and resource driven motives can indeed be used to explain the observed behavior for syndicated venture capital investments. We show that mainly Resource driven motives foster the propensity to syndicate an investment. Additionally, we find that Venture Capital Firms tend to diversify their portfolio, such that both motives of venture capital syndication (Finance and Resource driven) seem to be present at the same time and play a significant role simultaneously for the decision to jointly co-invest. We find evidence that a lower level of experience and expertise fosters the need to syndicate an investment.Venture Capital, Syndication

Seismic imaging with generalized Radon transforms: stability of the Bolker condition

Generalized Radon transforms are Fourier integral operators which are used, for instance, as imaging models in geophysical exploration. They appear naturally when linearizing about a known background compression wave speed. In this work we first consider a linearly increasing background velocity in two spatial dimensions. We verify the Bolker condition for the zero-offset scanning geometry and provide meaningful arguments for it to hold even if the common offset is positive. Based on this result we suggest an imaging operator for which we calculate the top order symbol in the zero-offset case to study how it maps singularities. Second, to support the usage of background models obtained from linear regression we present a stability result for the Bolker condition under perturbations of the background velocity and of the offset

Visco-acoustic full waveform seismic inversion: from a DG forward solver to a Newton-CG inverse solver

In this paper we present a holistic framework for full waveform inversion (FWI) in the visco-acoustic regime. FWI entails the reconstruction of material parameters (such as density and sound speed) from measurements of reflected wave fields (seismograms). We derive a discontinuous Galerkin (DG) solver for the visco-acoustic wave equation and incorporate it into an inverse solver. For the DG discretization we provide a block diagonal preconditioner for the efficient computation of the time steps by GMRES which yields a convergence estimate in space and time. Numerical tests illustrate these results. Furthermore, we set up an inverse solver of well established Newton-CG type, and we express the required Fréchet derivative and its adjoint in the DG setting. Reconstructions from simulated cross-well seismograms highlight the challenges of FWI and demonstrate the performance of the scheme. Some of the inversion experiments use seismograms generated by an independent FDTD forward solver to avoid an inverse crime

Imaging with the elliptic Radon transform in 3D from an analytical and numerical perspective

The three-dimensional elliptic Radon transform (eRT) averages distributions over ellipsoids of revolution. It thus serves as a linear model in seismic imaging where one wants to recover the earth’s interior from reflected wave fields. As there is no inversion formula known for the eRT, approximate formulas have to be used. In this paper we suggest several of those, microlocally analyze their properties, provide and implement an adapted algorithm whose performance we test by diverse numerical experiments. Our previous results of [Inverse Problems, 34 (2018), 014002 & 114001] are thus generalized to three space dimensions

Genetic Analysis of White Facial and Leg Markings in the Swiss Franches-Montagnes Horse Breed

White markings and spotting patterns in animal species are thought to be a result of the domestication process. They often serve for the identification of individuals but sometimes are accompanied by complex pathological syndromes. In the Swiss Franches-Montagnes horse population, white markings increased vastly in size and occurrence during the past 30 years, although the breeding goal demands a horse with as little depigmented areas as possible. In order to improve selection and avoid more excessive depigmentation on the population level, we estimated population parameters and breeding values for white head and anterior and posterior leg markings. Heritabilities and genetic correlations for the traits were high (h2 > 0.5). A strong positive correlation was found between the chestnut allele at the melanocortin-1-receptor gene locus and the extent of white markings. Segregation analysis revealed that our data fit best to a model including a polygenic effect and a biallelic locus with a dominant-recessive mode of inheritance. The recessive allele was found to be the white trait-increasing allele. Multilocus linkage disequilibrium analysis allowed the mapping of the putative major locus to a chromosomal region on ECA3q harboring the KIT gen

Theoriepräferenzen von Soziologiestudierenden

Vor kurzem veröffentlichte Jürgen Gerhards einen höchst interessanten Beitrag in dieser Zeitschrift. Die Überlegungen Gerhards nimmt der Artikel zum Anlass, einige ergänzende empirische Befunde aus einem laufenden Forschungsprojekt zum soziologischen Feld in Deutschland zu präsentieren, in dessen Kontext bisher 2.218 Studierende der Sozialwissenschaften zu den Lehrinhalten der Soziologie befragt wurden. Anhand der Ergebnisse dieser Befragung kann ein systematisches Bild über den gegenwärtigen Status Quo der tatsächlich gelesenen Werke in der Soziologie gewonnen werden. Dabei bestätigen die Befunde die von Gerhards diagnostizierte Orientierung an den Klassikern und den geringen Grad der inhaltlichen Paradigmatisierung, weisen jedoch auf eine verstärkte Kanonisierung der deutschsprachigen Soziologie hin. So geben die Befunde erste Hinweise darauf, dass durchaus Standardisierungstendenzen der Lehrinhalte über verschiedene Standorte hinweg zu beobachten sind.   Recently Jürgen Gerhards published a deeply interesting article in this journal. The article at hand will present some supplementary findings from a running research project on the sociological field in Germany. Up to now, 2.218 students of sociology have been surveyed about their sociological preferences and readings. The results confirm the findings of Gerhards that there is a strong alignment to the classic readings in sociology and a low degree of paradigmatization of content. Additionally, the results provide insights into standardization tendencies concerning the contents of sociological teaching across different universities

Populationsstruktur und genetische Diversität von Schweizer Schafrassen

Das Jahr 2010 wurde von den Vereinten Nationen zum Jahr der Biodiversität erklärt. Der Schweizerische Schafzuchtverband stellte in diesem Kontext Herdebuchdaten der vier grössten Schweizer Schafrassen zur Analyse der genetischen Diversität zur Verfügung. Untersucht wur-den das Braunköpfige Fleischschaf (BFS; n=10 858), das Schwarzbraune Bergschaf (SBS; n=10 964), das Walliser Schwarznasenschaf (SN; n=14 371) und das Weisse Alpenschaf (WAS; n=32 169). Die Analysen beruhen auf allen Herdebuchtieren der Geburtsjahre 1996–2008 und ihren Ahnen bis und mit Geburtsjahr 1970. Ausgewertet wurden die Daten mit gängiger Software für populationsgenetische Fragestellungen. Die grösste Zunahme beim mittleren Inzuchtkoeffizienten konnte im untersuchten Zeitraum bei der Rasse SN (5,9 → 9,3 %) gefolgt von denRassen BFS (2,4 → 4,3 %), SBS (2,4 → 3,8 %) und WAS (1,4 → 2,5 %) beobachtet werden. Obwohl die Inzuchtraten im Zeitraum 1996 bis 2008 teilweise starke Schwankungen aufwiesen, zeigte sich bei allen vier Rassen grundsätzlich ein steigender Trend. Damit einher ging ein sinkender Trend bei der effektiven Populationsgrösse. Die grösste Anzahl an effektiven Gründertieren, Ahnen und Gründergenomen fanden sich beim weissen Alpenschaf. Bei allen vier Rassen war bei diesen drei Parametern im Laufe der Jahre eine sinkende Tendenz erkennbar, wobei die Abnahme bei der Rasse WAS im Vergleich mit den anderen Rassen viel ausgeprägter war. Ein weiterer Indikator für eine abnehmende genetische Vielfalt von 1996 bis 2008 ist der marginale Genanteil des wichtigsten Ahnen. Dieser ist bei allen vier Rassen angestiegen (SN 11,05 → 19,79 %; BFS 7,67 →11,27 %; SBS 4,45 → 5,19 %; WAS 2,84 →4,69 %).Aufgrund der Ergebnisse stellt sich die Frage nach gezielten Managementmassnahmen nur bei der SN-Population. Bei den anderen drei Rassen sollten die Trends der genetischen Diversitäts-parameter jedoch regelmässig überprüft werden

Identifying Relationships between Physiological Measures and Evaluation Metrics for 3D Interaction Techniques

Abstract. This project aims to present a methodology to study the relationships between physiological measures and evaluation metrics for 3D interaction techniques using methods for multivariate data analysis. Physiological responses, such as heart rate and skin conductance, offer objective data about the user stress during interaction. This could be useful, for instance, to evaluate qualitative aspects of interaction techniques without relying on solely subjective data. Moreover, these data could contribute to improve task performance analysis by measuring different responses to 3D interaction techniques. With this in mind, we propose a methodology that defines a testing protocol, a normalization procedure and statistical techniques, considering the use of physiological measures during the evaluation process. A case study comparison between two 3D interaction techniques (ray-casting and HOMER) shows promising results, pointing to heart rate variability, as measured by the NN50 parameter, as a potential index of task performance. Further studies are needed in order to establish guidelines for evaluation processes based on welldefined associations between human behaviors and human actions realized in 3D user interfaces

Instrument-mounted displays for reducing cognitive load during surgical navigation

Purpose Surgical navigation systems rely on a monitor placed in the operating room to relay information. Optimal monitor placement can be challenging in crowded rooms, and it is often not possible to place the monitor directly beside the situs. The operator must split attention between the navigation system and the situs. We present an approach for needle-based interventions to provide navigational feedback directly on the instrument and close to the situs by mounting a small display onto the needle. Methods By mounting a small and lightweight smartwatch display directly onto the instrument, we are able to provide navigational guidance close to the situs and directly in the operator’s field of view, thereby reducing the need to switch the focus of view between the situs and the navigation system. We devise a specific variant of the established crosshair metaphor suitable for the very limited screen space. We conduct an empirical user study comparing our approach to using a monitor and a combination of both. Results Results from the empirical user study show significant benefits for cognitive load, user preference, and general usability for the instrument-mounted display, while achieving the same level of performance in terms of time and accuracy compared to using a monitor. Conclusion We successfully demonstrate the feasibility of our approach and potential benefits. With ongoing technological advancements, instrument-mounted displays might complement standard monitor setups for surgical navigation in order to lower cognitive demands and for improved usability of such systems