399 research outputs found

    Entrepreneurial Creativity and Growth

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    The concept of creativity is multidimensional, helping to take advantage of entrepreneurial opportunities and favoring in this way economic growth. Next to this basic argument of neoclassical theory, which ignores the role of entrepreneurship in growth, the present chapter states that entrepreneurship should be included as a contributing factor of growth. Through this key argument, this chapter attempts to clarify the importance of creativity to entrepreneurial activity, concentrating on the factors that influence entrepreneurial creativity that in turn lead to economic growth, as well as to capture the way in which entrepreneurial creativity is affected by this procedure. These factors are knowledge and education, the management of disrupting technologies, spill-over creativity, the role of cultural background and personal characteristics of individuals, the motives and incentives of individuals, the existence of—and access to—resources, and the institutions that delineate the environment of action of the entrepreneur

    Non-parametric Estimation of Geometric Anisotropy from Environmental Sensor Network Measurements

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    This paper addresses the estimation of geometric anisotropy parameters from scattered data in two dimensional spaces. The parameters involve the orientation angle of the principal anisotropy axes and the anisotropy ratio (i.e., the ratio of the principal correlation lengths). The mathematical background is based on the covariance Hessian identity (CHI) method developed in [3, 1]. CHI links the expectation of the first-order sample derivatives tensor with the Hessian matrix of the covariance function [6]. The paper focuses on the application of CHI to samples that require segmentation into clusters, either due to sampling density variations or due to systematic changes in the process values. A non-parametric isotropy test is also presented. Finally, a composite (real and synthetic) data set is used to investigate the impact of CHI anisotropy estimation on spatial interpolation with ordinary kriging

    Why Coevolution of Culture and Institutions Matters for Economic Development and Growth?

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    Theoretical considerations that choose to make reference to the institutional and cultural considerations presuppose that these are in an optimal form. However, this is not the case in the real world. This chapter argues that the coevolution requirements of institutional and culture change are critical for economic outcomes. When institutions and culture coevolve in an optimal pattern, economic development and growth are facilitated. In contrast, when institutions and culture deviate from the optimal pace of coevolution, incompatible alterations of institutions and culture may end up causing an inability of the policy designers to implement the required changes in institutions and/or cultural behaviors. The result can be a series of failing attempts to implement a modernized progrowth framework of institutional settings and cultural behaviors. Using a dataset of 80 countries for the period 1981–2019, the analysis concludes that institutions and culture are complements—and not substitutes—in terms of their role in economic development, as when both sizes are strong it leads to higher levels of GDP per capita. When either or both of them are at a weak level, economic development is much lower

    Ascending Combinatorial Auctions with Risk Averse Bidders

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    Ascending combinatorial auctions are being used in an increasing number of spectrum sales worldwide, as well as in other multi-item markets in procurement and logistics. Much research has focused on pricing and payment rules in such ascending auctions. However, recent game-theoretical research has shown that such auctions can even lead to inefficient perfect Bayesian equilibria with risk-neutral bidders. There is a fundamental free-rider problem without a simple solution, raising the question whether ascending combinatorial auctions can be expected to be efficient in the field. Risk aversion is arguably a significant driver of bidding behavior in high-stakes auctions. We analyze the impact of risk aversion on equilibrium bidding strategies and efficiency in a threshold problem with one global and several local bidders. Due to the underlying free-rider problem, the impact of risk-aversion on equilibrium bidding strategies of local bidders is not obvious. We characterize the necessary and sufficient conditions for the perfect Bayesian equilibria of the ascending auction mechanism to have the local bidders to drop at the reserve price. Interestingly, in spite of the free-riding opportunities of local bidders, risk-aversion reduces the scope of the non-bidding equilibrium. The results help explain the high efficiency of ascending combinatorial auctions observed in the lab. © 2015, Springer Science+Business Media Dordrecht

    An Operational System For Monitoring Oil Spills In The Mediterranean Sea: The PROMED System

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    The primary objective of this work was the development of an operational system for early detection of oil-spills, monitoring of their evolution, and provision of support to responsible Public Authorities during cleanup operations, based on Remote Sensing and GIS technologies. In case of emergency, the principal characteristics of the oil spill are defined with the aid of a space-borne synthetic aperture radar (SAR). The transport, spreading and dispersion of the oil spill is subsequently simulated on the basis of wind forecasts of the area. The use of thematic maps of protected, fishing and urban areas, and regions of high tourism allows the better assessment of the impact of an oil spill on the areas to be affected in terms of environmental sensitivity. Finally, reports are generated notifying port authorities, the media, and local organizations to be potentially affected by the presence of the oil spill. The pilot site for testing the PROMED System in Greece is the island of Crete

    Prevalence, risk and protective factors of alcohol use disorder during the COVID-19 pandemic in U.S. military veterans

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    BackgroundThere have been reports of increased alcohol consumption during the COVID-19 pandemic in the general population. However, little is known about the impact of the pandemic on the prevalence of alcohol use disorder (AUD), especially in high-risk samples such as U.S. military veterans.MethodsData were analyzed from the 2019-2020 National Health and Resilience in Veterans Study, which surveyed a nationally representative, prospective cohort of 3078 U.S. veterans. Pre-pandemic and 1-year peri-pandemic risk and protective factors associated with incident and chronic probable AUD were examined.ResultsA total of 6.9 % (n = 183) of veterans were classified as chronic probable AUD, 3.2 % (n = 85) as remitted from AUD, and 2.7 % (n = 71) as incident probable AUD during the pandemic; the prevalence of probable AUD in the full sample remained stable -10.1 % pre-pandemic and 9.6 % peri-pandemic. Younger age, greater pre-pandemic alcohol use severity, and COVID-related stressors were associated with incident AUD during the pandemic, whereas higher pre-pandemic household income was associated with lower risk of this outcome. Younger age, combat experience, lifetime substance use disorder, greater drug use severity, lower dispositional optimism, and more COVID-related worries and social restriction stress were associated with higher risk of chronic AUD.ConclusionsNearly 1-in-10 US veterans screened positive for AUD 1-year into the pandemic; however, the pre- and 1-year peri-pandemic prevalence of probable AUD remained stable. Veterans who are younger, have served in combat roles, endorse more COVID-related stressors, and have fewer socioeconomic resources may be at higher risk for AUD during the pandemic

    The Total Solar Eclipse of March 2006: overview

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    International audienceThis paper provides an overview of integrated, multi-disciplinary effort to study the effects of a total solar eclipse on the environment, with special focus on the atmosphere. On the occasion of the 29 March 2006 total solar eclipse, visible over the Eastern Mediterranean, several research and academic institutes organised co-ordinated experimental campaigns, at different distances from the totality and in various environments in terms of air quality. The detailed results are presented in a number of scientific papers included in a Special Issue of Atmospheric Chemistry and Physics. The effects of the eclipse on the meteorology and the spectral solar radiation, the chemical response of the atmosphere to the abrupt "switch off" of the sun and the induced changes in the stratosphere and the ionosphere, have been among the issues covered. The rare event of a total solar eclipse provided the opportunity to evaluate 1-D and 3-D radiative transfer models (in the atmosphere and underwater), mesoscale meteorological, regional air quality and photochemical box models, against measurements. Within the challenging topics of this effort has been the investigation of eclipse impacts on ecosystems (field crops and marine plankton) and the identification of eclipse induced gravity waves, for the first time with simultaneous measurements at three altitudes namely the troposphere, the stratosphere and the ionosphere

    Towards effective COVID\u201119 vaccines: Updates, perspectives and challenges (Review)

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    In the current context of the pandemic triggered by SARS-COV-2, the immunization of the population through vaccination is recognized as a public health priority. In the case of SARS\u2011COV\u20112, the genetic sequencing was done quickly, in one month. Since then, worldwide research has focused on obtaining a vaccine. This has a major economic impact because new technological platforms and advanced genetic engineering procedures are required to obtain a COVID\u201119 vaccine. The most difficult scientific challenge for this future vaccine obtained in the laboratory is the proof of clinical safety and efficacy. The biggest challenge of manufacturing is the construction and validation of production platforms capable of making the vaccine on a large scale
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