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Immigration and multiculturalism are important and much debated questions in contemporary Europe. Whereas considerable scholarship has examined how political institutions and Right-wing organizations have responded to these questions, little research has focused on the Left. This article examines the multicultural politics of the latter by considering ethnographically the experience of Bologna, the showcase city of the Italian Left, in the second half of the 1990s. The Left is here examined in terms of ideology, party, public policy and civil society in the context of everyday governance and with special reference to the discourses and practices concerning a group of Rom refugees from the former Yugoslavia. This article argues that the mainstream Italian Left (in its civil societal as well as party and administrative components) is characterized by a politics that fails to “integrate” ethno-cultural recognition with material justice and that, partly because of such failure, contributes little to the “integration” of immigrants.  相似文献   

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Eucalyptus globulus wood samples were treated with NaOH solutions in order to obtain substrates highly susceptible to enzymatic hydrolysis. The experiments performed in the extraction and hydrolysis stages followed an incomplete factorial design. Temperature, NaOH concentration and extraction time were considered as independent variables. Their influence on five dependent variables (defined to measure the extraction yield, the chemical composition of processed samples and the enzymatic conversion) was assessed using second order, empirical models. In addition to the experimental results, other aspects related to the extraction selectivity are discussed.  相似文献   

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A model of evolution of human society and biosphere, which is based on concepts of V.I. Vernadskii and of L.N. Gumilev about ethnogenesis has been developed and studied. The mathematical apparatus of the model is composition of finite stochastic automats. By using this model, a possibility of the global ecological crisis is demonstrated in the case of preservation of the current tendencies of interaction of the biosphere and the human civilization.  相似文献   

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This study focuses on earnings disadvantages experienced by three ethnic groups of Jewish immigrants in Israel. Data were obtained from the 2011 Income Survey gathered by the Israel Central Bureau of Statistics. The findings reveal that when compared to Israeli-born, all ethnic groups are disadvantaged in earnings attainment in the first generation. The earnings disadvantages of immigrants as compared to Israeli-born decrease with the passage of time and become negligible in the second generation. To disentangle the impact on earnings penalty of ethnic origin from that of immigrant status, a procedure for decomposing mean differences between groups is introduced. The analysis reveals that earnings disadvantage among Ashkenazim and Soviet immigrants can be attributed to immigrant status but not to ethnicity. By contrast, earnings penalties among Sephardim immigrants can be attributed to both ethnicity and immigrant status. The implications of the long-lasting effect of ethnicity versus the short-term effect of immigrant status are discussed.  相似文献   

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罗开盛  陶福禄 《生态学报》2018,38(23):8593-8603
以西北干旱区的临泽县为例,利用1980—2012年的气象数据、土地利用数据、土壤数据、数字高程数据驱动SWAT模型,对县域水文过程进行了模拟并对行政区内的水资源状况进行了时空特征分析。研究表明临泽县1980—2012年均实际蒸发量、下渗量、壤中流补给量、地下水补给量、产流量、可用地表水资源量和产流系数分别为130.53、49.78、68.95、48.00、53.47 mm、(13.17±0.60)×108m3和0.16;生态用水量大(3.56±0.12)×1011m3),且呈现出增加趋势。由于黑河分水措施的影响,各水量要素的突变年份出现在2000年之后的5年内。从空间分布上看,地下水补给量和产流系数都呈现“南高北低”的趋势。研究结果也表明临泽县1980—2012年的产流量由地下水补给量控制,壤中流和地下径流的贡献分别为43%和57%;而可利用水资源量主要依赖上游的来水,上游来水量的贡献率达到83%。此外,我们的研究也发现临泽县2007—2012的实际蒸发持续增加,从而导致“蒸发悖论”现象的存在。  相似文献   

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Power-aware computing has emerged as a significant concern in data centers. In this work, we develop empirical models for estimating the power consumed by web servers. These models can be used by on-the-fly power-saving algorithms and are imperative for simulators that evaluate the power behavior of workloads. To apply power saving methodologies and algorithms at the data center level, we must first be able to measure or estimate the power and performance of individual servers running in the data centers. We show a novel method for developing full system web server power models that reduces non-linear relationships among performance measurements and system power and prunes model parameters. The web server power models use as parameters performance indicators read from the machine internal performance counters. We evaluate our approach on an AMD Opteron-based web server and on an Intel i7-based web sever. Our best model displays an average absolute error of 1.92 % for Intel i7 server and 1.46 % for AMD Opteron as compared to actual measurements, and 90th percentile for the absolute percent error equals to 2.66 % for Intel i7 and 2.08 % for AMD Opteron.  相似文献   

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Senescence or ageing is an increase in mortality and/or decline in fertility with increasing age. Evolutionary theories predict that ageing or longevity evolves in response to patterns of extrinsic mortality or intrinsic damage. If ageing is viewed as the outcome of the processes of behaviour, growth and reproduction then it should be possible to predict mortality rate. Recent developments have shown that it is now possible to integrate these ecological and physiological processes and predict the shape of mortality trajectories. By drawing on the key exciting developments in the cellular, physiological and ecological process of longevity the evolutionary consequences of ageing are reviewed. In presenting these ideas an evolutionary demographic framework is used to argue how trade-offs in life-history strategies are important in the maintenance of variation in longevity within and between species. Evolutionary processes associated with longevity have an important role in explaining levels of biological diversity and speciation. In particular, the effects of life-history trait trade-offs in maintaining and promoting species diversity are explored. Such trade-offs can alleviate the effects of intense competition between species and promote species coexistence and diversification. These results have important implications for understanding a number of core ecological processes such as how species are divided among niches, how closely related species co-occur and the rules by which species assemble into food-webs. Theoretical work reveals that the proximate physiological processes are as important as the ecological factors in explaining the variation in the evolution of longevity. Possible future research challenges integrating work on the evolution and mechanisms of growing old are briefly discussed.  相似文献   

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Biologists and economists use models to study complex systems. This similarity between these disciplines has led to an interesting development: the borrowing of various components of model-based theorizing between the two domains. A major recent example of this strategy is economists’ utilization of the resources of evolutionary biology in order to construct models of economic systems. This general strategy has come to be called “evolutionary economics” and has been a source of much debate among economists. Although philosophers have developed literatures on the nature of models and modeling, the unique issues surrounding this kind of interdisciplinary model building have yet to be independently investigated. In this paper, we utilize evolutionary economics as a case study in the investigation of more general issues concerning interdisciplinary modeling. We begin by critiquing the distinctions currently used within the evolutionary economics literature and propose an alternative carving of the conceptual terrain. We then argue that the three types of evolutionary economics we distinguish capture distinctions that will be important whenever resources of model-based theorizing are borrowed across distinct scientific domains. Our analysis of these model-building strategies identifies several of the unique methodological and philosophical issues that confront interdisciplinary modeling.  相似文献   

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Based on energy and CO2 emission efficiencies, this paper proposes a definition of the elasticity of the potential of emission reduction to energy saving (Eperes), and measures the elasticity in China’s 30 provincial regions. Although Eperes is a relative definition, it can be used (1) to measure the amount of reduced CO2 emissions per unit fossil energy saving, (2) to reflect the effectiveness of fossil energy saving for CO2 emission reduction in different regions, and (3) to provide decision-making criteria for selecting pathways for emission reductions in different regions. The results show that compared with energy saving, emission reduction is a more serious issue in China. This indicates that energy saving policies have been highly effective since their implementation during the 11th “Five-Year Plan”. With respect to provincial disparities, the emission reductions caused by fossil energy saving are not significant in Beijing, Shanghai, and Guangdong. Fujian province has significant Eperes, indicating that emission reduction causing by fossil energy saving is effective. Eperes has been increasing over time in Hunan and Hubei. Hainan’s Eperes has remained less than 1, indicating that its emission-reduction effect of fossil energy saving is worse than in other provinces. Moreover, the elasticity of Eastern China is greater than that of Central China and Western China. This finding sheds light on pathway selection for energy saving and emission reduction in China: it would be more appropriate to encourage fossil energy saving in Eastern China, and to promote clean energy use (e.g., water electricity and solar energy) in Central China and Western China.  相似文献   

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The development and clinical use of patient-specific models of the heart is now a feasible goal. Models have the potential to aid in diagnosis and support decision-making in clinical cardiology. Several groups are now working on developing multi-scale models of the heart for understanding therapeutic mechanisms and better predicting clinical outcomes of interventions such as cardiac resynchronization therapy. Here we describe the methodology for generating a patient-specific model of the failing heart with a myocardial infarct and left ventricular bundle branch block. We discuss some of the remaining challenges in developing reliable patient-specific models of cardiac electromechanical activity, and identify some of the main areas for focusing future research efforts. Key challenges include: efficiently generating accurate patient-specific geometric meshes and mapping regional myofiber architecture to them; modeling electrical activation patterns based on cellular alterations in human heart failure, and estimating regional tissue conductivities based on clinically available electrocardiographic recordings; estimating unloaded ventricular reference geometry and material properties for biomechanical simulations; and parameterizing systemic models of circulatory dynamics from available hemodynamic measurements.  相似文献   

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Human beings are not only the most sociable animals on Earth, but also the only animals that have to ponder the separateness that comes with having a conscious self. The philosophical problem of 'other minds' nags away at people's sense of who--and why--they are. But the privacy of consciousness has an evolutionary history--and maybe even an evolutionary function. While recognizing the importance to humans of mind-reading and psychic transparency, we should consider the consequences and possible benefits of being--ultimately--psychically opaque.  相似文献   

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Switchgrass (Panicum virgatum L.) is a perennial grass native to the United States that has been studied as a sustainable source of biomass fuel. Although many field‐scale studies have examined the potential of this grass as a bioenergy crop, these studies have not been integrated. In this study, we present an empirical model for switchgrass yield and use this model to predict yield for the conterminous United States. We added environmental covariates to assembled yield data from field trials based on geographic location. We developed empirical models based on these data. The resulting empirical models, which account for spatial autocorrelation in the field data, provide the ability to estimate yield from factors associated with climate, soils, and management for both lowland and upland varieties of switchgrass. Yields of both ecotypes showed quadratic responses to temperature, increased with precipitation and minimum winter temperature, and decreased with stand age. Only the upland ecotype showed a positive response to our index of soil wetness and only the lowland ecotype showed a positive response to fertilizer. We view this empirical modeling effort, not as an alternative to mechanistic plant‐growth modeling, but rather as a first step in the process of functional validation that will compare patterns produced by the models with those found in data. For the upland variety, the correlation between measured yields and yields predicted by empirical models was 0.62 for the training subset and 0.58 for the test subset. For the lowland variety, the correlation was 0.46 for the training subset and 0.19 for the test subset. Because considerable variation in yield remains unexplained, it will be important in the future to characterize spatial and local sources of uncertainty associated with empirical yield estimates.  相似文献   

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Rapid increase in the use of numerical techniques to predict current density or specific absorption rate (SAR) in sophisticated three dimensional anatomical computer models of man and animals has resulted in the need to understand how numerical solutions of the complex electrodynamics equations match with empirical measurements. This aspect is particularly important because different numerical codes and computer models are used in research settings as a guide in designing clinical devices, telecommunication systems, and safety standards. To ensure compliance with safety guidelines during equipment design, manufacturing and maintenance, realistic and accurate models could be used as a bridge between empirical data and actual exposure conditions. Before these tools are transitioned into the hands of health safety officers and system designers, their accuracy and limitations must be verified under a variety of exposure conditions using available analytical and empirical dosimetry techniques. In this paper, empirical validation of SAR values predicted by finite difference time domain (FDTD) numerical code on sphere and rat is presented. The results of this study show a good agreement between empirical and theoretical methods and, thus, offer a relatively high confidence in SAR predictions obtained from digital anatomical models based on the FDTD numerical code.  相似文献   

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