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1.
"This article reports findings that have emerged from an effort made at statistically measuring the effects of immigration on the earnings of U.S.-born youth. The presence of immigrants arriving before 1965 has a positive impact on youth earnings. Recently arrived immigrants impact negatively, however. These results are consistent with recent findings that the skill level of immigrants arriving within the last two decades is lower relative to that of immigrants arriving earlier. The results also show that the negative effects diminish as the youth ages, reflecting skill acquisition and job mobility of the young worker into jobs less vulnerable to competition from immigrant workers." 相似文献
2.
Recent research suggests that unequal access to home country institutional resources affects firm internationalization strategies. We add to this debate, based on an analysis of state-owned (SOEs) and non-state-owned (NSOEs) Chinese mining firms, by developing a more dynamic and multi-layered understanding of this interplay. We find that home institutional support can be ownership-based or performance-based, whereby the former benefits SOEs and the latter favors high-performing NSOEs. Combined, these support structures serve as institutional control mechanisms in promoting competition, performance and loyalty to national policies. In addition, they establish a permanent link between firm- and home country-specific assets and incentivize firms to develop dynamic resource access capabilities at home and abroad. Our findings inform our understanding of the firms-institutions nexus and Chinese foreign direct investment dynamics, especially in industries of strategic importance to the state. 相似文献
3.
We propose two preprocessing algorithms suitable for climate time series. The first algorithm detects outliers based on an autoregressive cost update mechanism. The second one is based on the wavelet transform, a method from pattern recognition. In order to benchmark the algorithms'' performance we compare them to existing methods based on a synthetic data set. Eventually, for exemplary purposes, the proposed methods are applied to a data set of high-frequent temperature measurements from Novi Sad, Serbia. The results show that both methods together form a powerful tool for signal preprocessing: In case of solitary outliers the autoregressive cost update mechanism prevails, whereas the wavelet-based mechanism is the method of choice in the presence of multiple consecutive outliers. 相似文献
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Byungwon Kim Stephan Huckemann Jrn Schulz Sungkyu Jung 《Scandinavian Journal of Statistics》2019,46(4):1047-1071
We propose novel parametric concentric multi‐unimodal small‐subsphere families of densities for p ? 1 ≥ 2‐dimensional spherical data. Their parameters describe a common axis for K small hypersubspheres, an array of K directional modes, one mode for each subsphere, and K pairs of concentrations parameters, each pair governing horizontal (within the subsphere) and vertical (orthogonal to the subsphere) concentrations. We introduce two kinds of distributions. In its one‐subsphere version, the first kind coincides with a special case of the Fisher–Bingham distribution, and the second kind is a novel adaption that models independent horizontal and vertical variations. In its multisubsphere version, the second kind allows for a correlation of horizontal variation over different subspheres. In medical imaging, the situation of p ? 1 = 2 occurs precisely in modeling the variation of a skeletally represented organ shape due to rotation, twisting, and bending. For both kinds, we provide new computationally feasible algorithms for simulation and estimation and propose several tests. To the best knowledge of the authors, our proposed models are the first to treat the variation of directional data along several concentric small hypersubspheres, concentrated near modes on each subsphere, let alone horizontal dependence. Using several simulations, we show that our methods are more powerful than a recent nonparametric method and ad hoc methods. Using data from medical imaging, we demonstrate the advantage of our method and infer on the dominating axis of rotation of the human knee joint at different walking phases. 相似文献
6.
Pétremand Gaël Chittaro Yannick Braaker Sonja Brenneisen Stephan Gerner Magdalena Obrist Martin K. Rochefort Sophie Szallies Alexander Moretti Marco 《Urban Ecosystems》2018,21(1):119-132
Urban Ecosystems - Green roofs have recently gained recognition for their potential contribution to urban ecosystems by providing, among other services, habitat for plants and animals, and stepping... 相似文献
7.
Peter Chow-White Stephan Struve Alberto Lusoli Frederik Lesage Nilesh Saraf Amanda Oldring 《Information, Communication & Society》2018,21(3):448-464
Scholars, educators, regulators, pundits, and other observers are advocating for regulation and oversight of direct-to-consumer (DTC) genomic testing. As a result, the technology has been subject of highly visible public and regulatory controversy. In this article, we explore the nature and the shape of the sentiment of public discourse about the DTC company, 23andMe. We conduct a quantitative content analysis and qualitative framing analysis on Tweets. We find that the discourse surrounding DTC genomics and 23andMe is largely positive. We also identify a number of frames users deploy to debate, discuss, and share their experiences with DTC genomics and 23andMe. We argue that these frames create meaning around this emerging technology for its users. 相似文献
8.
Katarzyna Kulej-Lyko Jacek Majda Stephan von Haehling Wolfram Doehner Monika Lopuszanska Alicja Szklarska 《The aging male》2016,19(4):221-230
Background: Testosterone (TT) and dehydroepiandrosterone sulphate (DHEAS) are neurosteroids and their deficiencies constitute the hormone risk factors promoting the development of depression in elderly otherwise healthy men. We investigated the link between hypogonadism and depression in accordance with age and concomitant diseases in men with systolic HF using the novel scale previously dedicated for elderly population.Methods: We analysed the prevalence of depression and severity of depressive symptoms in population of 226 men with systolic HF (40–80 years) compared to 379 healthy peers. The severity of depression was assessed using the Polish long version of Geriatric Depression Scale (GDS).Results: In men aged 40–59 years the severity of depressive symptoms was greater in NYHA classes III–IV compared to NYHA classes I–II and reference group. In men aged 60–80 years depressive symptoms were more severe in NYHA class III-IV compared to controls (all p?≤?0.001). In multivariate logistic regression model in men aged 40–59 years advanced NYHA class was associated with higher prevalence of mild depression (OR?=?2.14, 95%CI: 1.07–4.29) and chronic obstructive pulmonary disease (COPD) with higher prevalence of severe depression (OR?=?69.1, 95%CI: 2.11–2264.3). In men aged 60–80 years advanced NYHA class and TT deficiency were related to higher prevalence of mild depression (respectively: OR?=?2.9, 95%CI: 1.3–6.4; OR?=?3.6, 95%CI: 1.2–10.63).Conclusion: TT deficiency, COPD and advanced NYHA class were associated with higher prevalence of depression in men with systolic HF. 相似文献
9.
Prenatal Reflective Functioning and Accumulated Risk as Predictors of Maternal Interactive Behavior During Free Play,the Still‐Face Paradigm,and Two Teaching Tasks 下载免费PDF全文
Hanneke J. A. Smaling Stephan C. J. Huijbregts Jill Suurland Kristiaan B. van der Heijden Judi Mesman Stephanie H. M. van Goozen Hanna Swaab 《Infancy》2016,21(6):766-784
This study examined whether prenatal reflective functioning (RF) was related to mothers’ interactive style across contexts with their 6‐month‐old infants (M age = 6.02 months, SD = 0.41, 54% boys), and to what extent quality of prenatal RF could account for the influence of accumulated risk on maternal interactive behavior. Accumulated risk was defined as the sum‐score of a selection of risk factors that have been associated with suboptimal infant development. Mother–infant dyads (N = 133) were observed during free play, two teaching tasks, and the Still‐Face Paradigm (SFP). Better prenatal RF was associated with more positive maternal behavior in all settings and less negative behavior during teaching and SFP reengagement. Accumulated risk and prenatal RF predicted shared variance in maternal interactive behavior (with unique predictive effects observed only for RF on sensitivity during teaching and SFP play, and for accumulated risk on sensitivity and positive engagement during SFP play, and internalizing‐helplessness during SFP reengagement). Accumulated risk had an indirect effect on maternal sensitivity during teaching and SFP play through prenatal RF. These findings suggest not only that RF may be targeted prenatally to improve mother–infant interactions, but also that enhancing RF skills may ameliorate some of the negative consequences from more stable perinatal risk factors that influence parent–child interactions. 相似文献
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