969 resultados para Ladoga and Onego : great European lakes
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Globalized interurban competition is affecting cities of various sizes and locations. Small and medium-sized cities have to find ways to position themselves in global markets by formulating locational policies. This paper outlines an analytical framework of locational policies that cities adopt in order to increase their competitiveness. By comparing two European small and mediumsized cities (Lucerne and Ulm), we examine manifestations of locational policies and compare if these policies are being diverse or resemble each other. We found that strategies of both cities are sharing the intentions to be competitive, but their policy choices differ because the economic and political context is enabling or restricting certain kinds of locational policies. Furthermore, the findings point to the high explanatory power of municipal tax autonomy when studying locational policies.
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The Earth’s carbon and hydrologic cycles are intimately coupled by gas exchange through plant stomata1, 2, 3. However, uncertainties in the magnitude4, 5, 6 and consequences7, 8 of the physiological responses9, 10 of plants to elevated CO2 in natural environments hinders modelling of terrestrial water cycling and carbon storage11. Here we use annually resolved long-term δ13C tree-ring measurements across a European forest network to reconstruct the physiologically driven response of intercellular CO2 (Ci) caused by atmospheric CO2 (Ca) trends. When removing meteorological signals from the δ13C measurements, we find that trees across Europe regulated gas exchange so that for one ppmv atmospheric CO2 increase, Ci increased by ~0.76 ppmv, most consistent with moderate control towards a constant Ci/Ca ratio. This response corresponds to twentieth-century intrinsic water-use efficiency (iWUE) increases of 14 ± 10 and 22 ± 6% at broadleaf and coniferous sites, respectively. An ensemble of process-based global vegetation models shows similar CO2 effects on iWUE trends. Yet, when operating these models with climate drivers reintroduced, despite decreased stomatal opening, 5% increases in European forest transpiration are calculated over the twentieth century. This counterintuitive result arises from lengthened growing seasons, enhanced evaporative demand in a warming climate, and increased leaf area, which together oppose effects of CO2-induced stomatal closure. Our study questions changes to the hydrological cycle, such as reductions in transpiration and air humidity, hypothesized to result from plant responses to anthropogenic emissions.
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The consequences of quota-based hiring policies on women’s and men’s self-ascribed fit and motivation to apply for leadership positions were investigated in the European context. 389 management students (195 women, 194 men) from Switzerland, Germany, and Austria received job advertisements varying in their gender policies. Interestingly, women’s and men’s self-ascribed fit and motivation to apply did not differ when no policy was included. Instead, participant’s agency was the relevant predictor leading to higher perceived fit, resulting in higher inclination to apply. When women were either explicitly invited to apply or preferentially treated when equally qualified, they reported higher fit and inclination to apply compared to both the control condition and men. In contrast, when a quota of 40% women should be established, neither women’s fit nor motivation to apply were increased beyond the levels of the control or men’s. Men were not affected by the different policies.
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from the journals of the late J. Frederick Elton, F.R.G.S., H.B.M. Consul at Mozambique ; edited and compiled by H.B. Cotterill
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Digitalisiert in Kooperation mit dem YIVO Institute for Jewish Research am Center for Jewish History, NY
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Peat plateaus are widespread at high northern latitudes and are important soil organic carbon reservoirs. A warming climate can cause either increased ground subsidence (thermokarst) resulting in lake formation or increased drainage as the permafrost thaws. A better understanding of spatiotemporal variations in these landforms in relation to climate change is important for predicting the future thawing permafrost carbon feedback. In this study, dynamics in thermokarst lake extent during the last 35-50 years has been quantified through time series analysis of aerial photographs and high-resolution satellite images (IKONOS/QuickBird) in three peat plateau complexes, spread out across the northern circumpolar region along a climatic and permafrost gradient. From the mid-1970s until the mid-2000s there has been an increase in mean annual air temperature, winter precipitation, and ground temperature in all three study areas. The two peat plateaus located in the continuous and discontinuous permafrost zones, respectively, where mean annual air temperatures are below -5°C and ground temperatures are -2°C or colder, have experienced small changes in thermokarst lake extent. In the peat plateau located in the sporadic permafrost zone where the mean annual air temperature is around -3°C, and the ground temperature is close to 0°C, lake drainage and infilling with fen vegetation has been extensive and many new thermokarst lakes have formed. In a future progressively warmer and wetter climate permafrost degradation can cause significant impacts on landscape composition and greenhouse gas exchange also in areas with extensive peat plateaus, which presently still experience stable permafrost conditions.
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Thermokarst lakes are typical features of the northern permafrost ecosystems, and play an important role in the thermal exchange between atmosphere and subsurface. The objective of this study is to describe the main thermal processes of the lakes and to quantify the heat exchange with the underlying sediments. The thermal regimes of five lakes located within the continuous permafrost zone of northern Siberia (Lena River Delta) were investigated using hourly water temperature and water level records covering a 3-year period (2009-2012), together with bathymetric survey data. The lakes included thermokarst lakes located on Holocene river terraces that may be connected to Lena River water during spring flooding, and a thermokarst lake located on deposits of the Pleistocene Ice Complex. Lakes were covered by ice up to 2 m thick that persisted for more than 7 months of the year, from October until about mid-June. Lake-bottom temperatures increased at the start of the ice-covered period due to upward-directed heat flux from the underlying thawed sediment. Prior to ice break-up, solar radiation effectively warmed the water beneath the ice cover and induced convective mixing. Ice break-up started at the beginning of June and lasted until the middle or end of June. Mixing occurred within the entire water column from the start of ice break-up and continued during the ice-free periods, as confirmed by the Wedderburn numbers, a quantitative measure of the balance between wind mixing and stratification that is important for describing the biogeochemical cycles of lakes. The lake thermal regime was modeled numerically using the FLake model. The model demonstrated good agreement with observations with regard to the mean lake temperature, with a good reproduction of the summer stratification during the ice-free period, but poor agreement during the ice-covered period. Modeled sensitivity to lake depth demonstrated that lakes in this climatic zone with mean depths > 5 m develop continuous stratification in summer for at least 1 month. The modeled vertical heat flux across the bottom sediment tends towards an annual mean of zero, with maximum downward fluxes of about 5 W/m**2 in summer and with heat released back into the water column at a rate of less than 1 W/m**2 during the ice-covered period. The lakes are shown to be efficient heat absorbers and effectively distribute the heat through mixing. Monthly bottom water temperatures during the ice-free period range up to 15 °C and are therefore higher than the associated monthly air or ground temperatures in the surrounding frozen permafrost landscape. The investigated lakes remain unfrozen at depth, with mean annual lake-bottom temperatures of between 2.7 and 4 °C.
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Peer reviewed
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Few studies have analyzed how family firms have acted during the global great crisis in comparison to their nonfamily counterparts. This paper tries to fill this gap on the basis of the Italian experience using a sample of almost 4,500 for 2007 and 2010. We study whether family control affects labour productivity, labour costs and competitiveness and if the adoption of performance related pay (PRP) reveals an efficacious strategy to mitigate the effects of the crisis and reduce the gap in competitiveness with respect to nonfamily firms. We use quantile regression techniques to test the heterogeneous role of PRP and pay attention for its possible endogeneity. We have observed that after the outburst of the crisis, the distance in terms of competitiveness of family firms with respect to their nonfamily counterparts has been amplified. We also find that family firms may take advantage from the adoption of incentive schemes, such as PRP, to encourage commitment and motivation from their employees more than nonfamily firms. The positive role of PRP on labour productivity, coupled with a moderate influence of these schemes on wage premiums, enable them to regain competitiveness also under hostile pressures, as those featuring the strong global crisis.
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no.74 (1983)