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

Training Efficient Controllers via Analytic Policy Gradient

Control design for robotic systems is complex and often requires solving an optimization to follow a trajectory accurately. Online optimization approaches like Model Predictive Control (MPC) have been shown to achieve great tracking performance, but require high computing power. Conversely, learning-based offline optimization approaches, such as Reinforcement Learning (RL), allow fast and efficient execution on the robot but hardly match the accuracy of MPC in trajectory tracking tasks. In systems with limited compute, such as aerial vehicles, an accurate controller that is efficient at execution time is imperative. We propose an Analytic Policy Gradient (APG) method to tackle this problem. APG exploits the availability of differentiable simulators by training a controller offline with gradient descent on the tracking error. We address training instabilities that frequently occur with APG through curriculum learning and experiment on a widely used controls benchmark, the CartPole, and two common aerial robots, a quadrotor and a fixed-wing drone. Our proposed method outperforms both model-based and model-free RL methods in terms of tracking error. Concurrently, it achieves similar performance to MPC while requiring more than an order of magnitude less computation time. Our work provides insights into the potential of APG as a promising control method for robotics. To facilitate the exploration of APG, we open-source our code and make it available atgithub.com/lis-epfl/apg_trajectory_tracking

La mesure de l'impact des clusters: Quelques éléments de réflexion et de bibliographie

--

A experiência do consumidor em festivais de música e o seu impacto na lealdade ao festival e na imagem da marca patrocinadora

The influence of gender on the physical and chemical properties of the M. longissimus dorsi et lumborum of mountain reedbuck (Redunca fulvorufula) was examined. The mean live weights of ten male (28.58 kg) and nineteen female (30.58 kg) mountain reedbuck did not differ (P>0.05), and the mean cold carcass weight was 16.36 kg for both genders. Gender had no influence (P > 0.05) on any of the physical characteristics (pH, drip loss, cooking loss, shear force, colour) investigated. For the proximate chemical analysis of the M. longissimus dorsi et lumborum muscle, the effect of gender was only significant for the protein content, where the females (24.51%) displayed a higher percentage of protein compared to the males (23.68%). Neither the amino acid nor the mineral content differed significantly between the two genders. Glutamic acid (11.35 g/100 g) was the most abundant amino acid, followed by aspartic acid (2.94 9/100 g), glycine (0.86 g/100 g) and serine (0.66 g/100 g). The mineral content of mountain reedbuck indicated that meat derived from this species is high in phosphorus (206.47 mg/100g), high in iron (4.19 mg/100g), a source of zinc (1.80 mg/ 100g), and low in sodium (4.19 mg/100 g). No significant differences between the genders for total saturated fatty acids (38.09%), total mono-unsaturated fatty acids (18.04%) or total polyunsaturated fatty acids (43.74%) were noted. The mean polyunsaturated:saturated fatty acid ratio for mountain reedbuck was 1.15 and the mean n-6:n-3 PUFA ratio 2.08. The extent of the influence of gender on physical and chemical characteristics of meat was found to be of limited practical value

Remanescentes de quilombos na região de Morro Alto - RS: contribuição da geografia física do reconhecimento das áreas ocupadas

O presente artigo tem como objetivo apresentar a contribuição da Geografia Física na elaboração do relatório técnico sobre o reconhecimento da Comunidade Negra de Morro Alto, localizada no Litoral Norte do Estado do Rio Grande do Sul, Brasil. O relatório da comunidade foi realizado por um grupo de pesquisadores através de estudos e levantamentos históricos, antropológicos e geográficos necessários ao cumprimento do disposto constitucional que garante a demarcação e titulação das áreas ocupadas por comunidades remanescentes de quilombo. Com base em relatos da história oral e documental, a equipe reconstruiu a ocupação histórica da comunidade e suas relações com a área ocupada. A contribuição do conhecimento geográfico teve abrangência ampla, atendendo demandas do grupo, tais como: na análise de documentos cartográficos; na interpretação de toponímias e/ou conceitos geográficos emitidos em relatos da história oral; na elaboração da base cartográfica e de mapas temáticos e na delimitação da área pleiteada pela comunidade do Morro Alto. A contribuição mais específica do conhecimento geográfico centrou-se na análise das alterações ambientais diante dos tipos de apropriação da natureza pelos diferentes grupos sociais identificados na área de estudo. A análise dos espaços degradados reflete uma profunda exclusão social e econômica no âmbito local da comunidade negra com a natureza

Hepatitis B virus in the Lao People’s Democratic Republic: a cross sectional serosurvey in different cohorts

Background Despite hepatitis B vaccination at birth and at 6, 10 and 14 weeks of age, hepatitis B virus (HBV) infection continues to be endemic in the Lao People’s Democratic Republic (PDR). We carried out a cross-sectional serological study in infants, pre-school children, school pupils and pregnant women to determine their burden of disease, risk of infection and vaccination status. Methods A total of 2471 participants between 9 months and 46 years old were recruited from urban (Vientiane Capital, Luang Prabang), semi-urban (Boulhikhamxai and Savannakhet) and remote rural areas (Huaphan). All sera were tested for anti-HBs and anti-HBc. Sera testing positive for anti-HBc alone were further tested for the presence of HBsAg. Results A low prevalence of HBsAg (0.5%) was detected among infants from Vientiane and Luang Prabang, indicating some success of the vaccination policy. However, only 65.6% had protective anti-HBs antibodies, suggesting that vaccination coverage or responses remain sub-optimal, even in these urban populations. In pre-school children from remote areas in Huaphan, 21.2% were positive for anti-HBc antibodies, and 4.6% were for HBsAg positive, showing that a significant proportion of children in these rural regions have early exposure to HBV. In pre-school children with 3 documented HBV vaccinations, only 17.0% (15/55) were serologically protected. Among school-children from semi-urban regions of Luang Prabang, Boulhikhamxai and Savannakhet provinces, those below the age of 9 who were born after HBV vaccine introduction had anti-HBc and HBsAg prevalence of 11.7% and 4.1%, respectively. The prevalence increased to 19.4% and 7.8% of 10–14 year olds and to 27% and 10.2% of 15–19 year olds. Pregnant women from Luang Prabang and Vientiane had very high anti-HBc and HBsAg prevalence (49.5% and 8.2%), indicating high exposure and risk of onward vertical transmission to the unborn infant. Conclusions Overall, the results demonstrate a dramatic deficiency in vaccination coverage and vaccine responses and/or documentation within the regions of Lao PDR studied, which included urbanized areas with better health care access. Timely and effective hepatitis B vaccination coverage is needed in Lao PDR

Procjena probiotičkih svojstava bakterije Enterococcus mundtii, njezino preživljavanje u bozi i proizvodnja bakteriocina in situ

Boza is a low-pH and low-alcohol cereal-based beverage produced in the Balkan Peninsula. Barley was cooked and prepared according to a traditional recipe and inoculated with Enterococcus mundtii ST4V (a potential probiotic and bacteriocin-producing strain), commercially produced boza, Saccharomyces cerevisiae, and a combination of strain E. mundtii ST4V and Saccharomyces cerevisiae. Fermentation was carried out at 37 °C for 3 h. The organoleptic properties of fermented products were evaluated by a qualified taste panel. No significant differences in rheological properties were observed, suggesting that E. mundtii ST4V had no effect on the quality of the final product. Microbial cell numbers remained relatively unchanged during one week of storage. The preservative properties of bacteriocin ST4V were evaluated by contaminating boza with Lactobacillus sakei DSM 20017. Changes in microbial populations were monitored by using classical microbiological methods, PCR with species-specific primers and denaturing gradient gel electrophoresis (DGGE). Adsorption of bacteriocin ST4V to target cells is pH-dependent, with the highest adsorption (88 %) recorded at pH=8.0 and pH=10.0. Maximum adsorption of bacteriocin ST4V (75 %) to Enterococcus faecalis and Listeria innocua was recorded at 25 to 37 °C. Growth of E. mundtii ST4V was inhibited only by a few antibiotics and anti-inflammatory medicaments, suggesting that the strain may be used as a probiotic by individuals receiving medical treatment.Boza je napitak od žitarica, male pH-vrijednosti i neznatnog udjela alkohola, koji se priprema na Balkanu. U istraživanju je upotrijebljena boza pripremljena kuhanjem ječma prema tradicionalnom receptu, inokulirana bakterijskim sojem Enterococcus mundtii ST4V (koji proizvodi bakteriocin i ima probiotička svojstva), bozom proizvedenom na komercijalan način, kvascem Saccharomyces cerevisiae i kombinacijom bakterijskog soja i kvasca. Tim stručnjaka ispitao je organoleptička svojstva proizvoda dobivenih nakon 3 sata fermentacije pri 37 ºC. Nije utvrđena značajna razlika u reološkim svojstvima dobivenih proizvoda, što upućuje na zaključak da inokulacija sojem E. mundtii ST4V nije utjecala na kakvoću proizvoda. Čak ni nakon tjedan dana skladištenja nije se promijenio broj stanica mikroorganizama u proizvodima. Da bi se procijenio zaštitni učinak bakteriocina ST4V, ispitana je boza inokulirana sojem Lactobacillus sakei DSM 20017, pa je mikrobna populacija praćena klasičnim mikrobiološkim metodama, reakcijom polimeraze (PCR) sa specifičnim početnicama i elektroforezom u gradijentu denaturirajućega gela (DGGE). Adsorpcija bakteriocina ST4V na ciljane stanice ovisi o pH-vrijednosti, s najvećom adsorpcijom (88 %) zabilježenom pri pH=8 i pH=10. Maksimalna adsorpcija bakteriocina (75 %) na stanice Enterococcus faecalis i Listeria innocua zabilježena je u rasponu temperature od 25 do 37 ºC. Rast bakterije E. mundtii ST4V inhibirali su samo neki antibiotici i protuupalni lijekovi, što upućuje na to da taj soj ima probiotički učinak i na pacijente koji primaju određenu terapiju

O MAPA “SOLIDARIEDADE E ASSISTÊNCIA SOCIAL”: LITORAL NORTE (RS) - PANDEMIA COVID-19

A Pandemia da COVID-19 ilumina necessidades históricas das trabalhadoras(es) no país, escancara-se a desigualdade e a precarização da vida. Neste momento, ações populares despem as demandas sociais exigindo a presença do Estado Brasileiro, que imbuído da prática neoliberal, aprofunda uma política de destruição de direitos sociais. O contexto exige que as instituições públicas insurjam contra as determinações políticas deste Governo, e nas universidades, que seja fortalecida a relação entre pesquisa, extensão e ensino, sob uma perspectiva popular. Como força somatória a essas ações, pesquisadoras(es) da UFRGS Litoral produziu um mapa articulado à mobilização de solidariedade promovida por lideranças comunitárias na região. Tais movimentações são importantes: a produção do mapa forjado na prática social; o envolvimento expressivo de estudantes; a problematização da ausência dos dados públicos para a análise social e o debate político sobre as estratégias para o enfrentamento da Pandemia. Reconhecemos que a necessidade do isolamento social tem evidenciado: as condições de vida no Litoral Norte/RS e a urgência da universalização das políticas sociais para a consolidação do Sistema Único de Assistência Social. Este trabalho contribui na efervescência dos mapeamentos que se colocam estrategicamente como representações críticas e ao mesmo tempo como mobilizador das lutas sociais, sem perder de vista o fundamento histórico da miséria no Brasil

SOCIO-POLITICAL CONFLICT AND ECONOMIC PERFORMANCE IN BOLIVIA*

ABSTRACT: We examine how socio-political conflict in Bolivia has affected its economic performance since the 1970s. Such conflict includes strikes, demonstrations, road blockades, and conventional rent-seeking. Since conflict has costs, it diverts resources away from production, tends to reduce investment and could therefore reduce economic growth. We first review the characteristics of conflict in Bolivia using a unique data set. We then provide estimates of the direct costs of conflict and examine the relationship with economic performance using hypotheses derived from a simple model. In particular, we make a distinction between economic growth that is due to external factors -like changes in income due to movements in the terms of trade -and economic growth that is due to productive investment. Growth due to external factors tends to be positively related to conflict, whereas growth due to productive investment should be negatively related to conflict. Finally, we discuss how levels of conflict, economic performance, and governance might be related in Bolivia's recent history. * We would like to thank participants at the conference on Bolivia, held the Kennedy School of Government in November 2006, for their comments, and especially Francisco Rodriguez for his detailed suggestions. For discussions and background information, we are also very grateful t