426 research outputs found
Enabling Entrepreneurial Ecosystems
Inspired by research on the importance of entrepreneurship for sustained economic growth and improved wellbeing, many governments and non-governmental grantmaking organizations have sought over the past decade to implement policies and programs intended to support entrepreneurs. Over this interval, growing appreciation of the limits of strategies focused narrowly on financing or training entrepreneurs has prompted a number of such entities to shift their efforts toward more broadbased strategies aimed at enabling "entrepreneurial ecosystems" at the city or sub-national regional scale.This paper takes the metaphor of the "ecosystem" seriously, seeking to draw lessons from evolutionary biology and ecology to inform policy for entrepreneurship. In so doing, the paper provides a framework for data gathering and analysis of practical value in assessing the vibrancy of entrepreneurial ecosystems
Foreign and defense policy in the Obama administration
Comunicação proferida pelo Prof. Doutor David Auerswald, no IDN no dia 10 de Novembro de 2009, no âmbito do ciclo de conferências intitulado
Visões Globais para a Defesa
HESS Opinions: Socio-economic and ecological trade-offs of flood management – benefits of a transdisciplinary approach
In light of climate change and growing numbers of people
inhabiting riverine floodplains, worldwide demand for flood protection is
increasing, typically through engineering approaches such as more and bigger
levees. However, the well-documented “levee effect” of increased
floodplain use following levee construction or enhancement often results in
increased problems, especially when levees fail or are compromised by big
flood events. Herein, we argue that there are also unintended socio-economic
and ecological consequences of traditional engineering solutions that need
to be better considered, communicated and weighed against alternative
solutions. Socio-economic consequences include reduced aesthetic and
recreational values as well as increased downstream flooding risk and
reduced ecosystem services. Ecological consequences include hydraulic
decoupling, loss of biodiversity and increased risk of contamination during
flooding. In addition, beyond river losses of connectivity and natural
riparian vegetation created by levees, changes in groundwater levels and
increased greenhouse gas emissions are likely. Because flood protection
requires huge financial investments and results in major and persistent
changes to the landscape, more balanced decisions that involve all
stakeholders and policymakers should be made in the future. This requires a
transdisciplinary approach that considers alternative solutions such as
green infrastructure and places emphasis on integrated flood management
rather than on reliance on technical protection measures.</p
Intrinsic water-use efficiency of temperate seminatural grassland has increased since 1857: an analysis of carbon isotope discrimination of herbage from the Park Grass Experiment
A 150-year-long record of intrinsic water-use efficiency (W-i) was derived from community-level carbon isotope discrimination (13 delta) in the herbage of the unfertilized, unlimed control treatment (plot 3) of the Park Grass Experiment at Rothamsted (England) between 1857 and 2007. 13 delta during spring growth (first cut harvested in June) averaged 21.0 parts per thousand (+/- 0.5 parts per thousand SD) and has not shown a long-term trend (P=0.5) since 1857. 13 delta of summer/autumn growth (second cut harvested between September and November) increased from 21.3 parts per thousand to 22.0 parts per thousand (P < 0.001) between 1875 and 2007. W-i during spring growth has therefore increased by 33% since the beginning of the experiment, and W-i of summer/autumn growth has increased by 18%. The variation in 13 delta was mainly related to weather conditions. Plant available soil water explained 51% and 40% of the variation in spring growth 13 delta and summer/autumn growth 13 delta, respectively. In the 1857-2007 period yields have not increased, suggesting that community-level photosynthesis has not increased either. Therefore, the increased W-i probably resulted from a decreased stomatal conductance. Vapour pressure deficit (VPD) during spring growth (March-June) has not changed since 1915, meaning that instantaneous water-use efficiency (W-t) in spring time has increased and transpiration has probably decreased, provided that leaf temperature followed air temperature. Conversely, VPD in the months between the first and second cut has increased by 0.07 kPa since 1915, offsetting the effect of increased W-i on W-t during summer and early autumn. Our results suggest that vegetation has adjusted physiologically to elevated CO2 by decreasing stomatal conductance in this nutrient-limited grassland
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Enhanced attraction between drops carrying fluctuating charge distributions
The electrostatic force between conductive spheres is always attractive at small separations, irrespective of their mean charge, when the charge on the spheres is constant. In many situations, the charge may not be fixed, such as for water drops in the natural atmosphere which vary in size and charge. We show that the attractive force between charged conductive spheres increases with increasing charge variance. The importance of this unrecognized electrostatic effect between water drops is evaluated for its potential to enhance rain formation
A manifesto for researching entrepreneurial ecosystems
Entrepreneurial ecosystems are the focus of government economic policies around the world for their potential to generate entrepreneur-led economic development. The paper identifies key research questions and challenges to building effective public policy: (i) the limitations of existing data sources, (ii) the need to balance findings from quantitative and qualitative studies, (iii) the danger that entrepreneurial ecosystems will be just a policy fad, (iv) the narrow focus of policy and research on high tech firms and scale-ups, and (v) the need to balance research approaches between simplified models and a complex systems approach. There is a need for a better understanding of the diversity of policy contexts (level of government, country context) and model of ecosystem governance. A more granulated understanding of ecosystem thinking is required, with greater consideration of the diversity of actors and the institutional context, with more attention given to the heterogeneous nature of places and complex interactions between actors and networks. Looking to the future, the potential of new data sources and methodologies is identified. Future research should give greater consideration to the institutional context to understand how policy can better support entrepreneurial activity and the extent to which specific policies can be replicated elsewhere
Decreased Type I Interferon Production by Plasmacytoid Dendritic Cells Contributes to Severe Dengue
The clinical presentation of dengue virus (DENV) infection is variable. Severe complications mainly result from exacerbated immune responses. Type I interferons (IFN-I) are important in antiviral responses and form a crucial link between innate and adaptive immunity. Their contribution to host defense during DENV infection remains under-studied, as direct quantification of IFN-I is challenging. We combined ultra-sensitive single-molecule array (Simoa) digital ELISA with IFN-I gene expression to elucidate the role of IFN-I in a well-characterized cohort of hospitalized Cambodian children undergoing acute DENV infection. Higher concentrations of type I IFN proteins were observed in blood of DENV patients, compared to healthy donors, and correlated with viral load. Stratifying patients for disease severity, we found a decreased expression of IFN-I in patients with a more severe clinical outcome, such as dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS). This was seen in parallel to a correlation between low IFNα protein concentrations and decreased platelet counts. Type I IFNs concentrations were correlated to frequencies of plasmacytoid DCs, not DENV-infected myloid DCs and correlated inversely with neutralizing anti-DENV antibody titers. Hence, type I IFN produced in the acute phase of infection is associated with less severe outcome of dengue disease
Projectification and Partnering::An Amalgamated Approach for New Venture Creation in an Entrepreneurial Ecosystem
Pleosporales
One hundred and five generic types of Pleosporales are described and illustrated. A brief introduction and detailed history with short notes on morphology, molecular phylogeny as well as a general conclusion of each genus are provided. For those genera where the type or a representative specimen is unavailable, a brief note is given. Altogether 174 genera of Pleosporales are treated. Phaeotrichaceae as well as Kriegeriella, Zeuctomorpha and Muroia are excluded from Pleosporales. Based on the multigene phylogenetic analysis, the suborder Massarineae is emended to accommodate five families, viz. Lentitheciaceae, Massarinaceae, Montagnulaceae, Morosphaeriaceae and Trematosphaeriaceae
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