Seasonal forcing on the dynamics ofClethrionomys rufocanus: Modeling geographic gradients in population dynamics

We interpret gradients in population dynamics of the gray-sided vole from the southwestern part of the island of Hokkaido to its northeastern part within the framework of a phenomenological model involving the relative length of summer and winter. In Hokkaido, as in other northern regions, both spring and fall is considered as short transition periods between the two main seasons — summer (the primary breeding season) and winter (the non-reproductive or secondary breeding season). We show that the geographic transition in dynamics may be understood as the combined consequence of different patterns of density-dependence during summer and winter, and geographically varying season lengths. Differences are shown to exist between summer and winter with respect to strength of density-dependence. Direct density-dependence, in particular, is stronger during winter than during summer. A model is presented to show how relative lengths of seasons can induce both stable and periodically fluctuating population dynamics. The results are compared and contrasted with what is otherwise known about the gradient in rodent dynamics in Fennoscandia.     

Hybridization and speciation in the carabid beetles of the subgenusOhomopterus (Coleoptera, Carabidae, genusCarabus)

Natural hybridization among wingless carabid beetles of the subgenusOhomopterus (Carabidae, genusCarabus) is reviewed, and its significance in the evolution of this subgenus discussed. Natural hybridization occurs between parapatric species of similar size. Two case studies of natural hybridization suggest that natural hybridization could have affected the evolution of this subgenus in different ways. When there is a large difference in genital morphology between hybridizing species, interspecific copulation often results in genital injuries that causes mortality of copulating individuals, and hence reduces the fitness of hybridizing individuals greatly. In such a case, hybridization may be effective in maintaining the parapatric distribution of the two species, and in the long term, may promote reinforcement selection for traits which are effective in prezygotic reproductive isolation. When the morphological difference in genitalia is not so large as to cause genital injury, a hybrid population may be established at the intermediate zone between two parental species, provided that the immigration rates of the two species into the intermediate zone are small. Thus, natural hybridization may have contributed to both divergence and reticulate evolution in this subgenus.     

Family Responsibilities,Productivity, and Earnings: A Study of Gender Differences Among Canadian Lawyers

This study examines whether men and women invest in different determinants of productivity and whether these investments affect productivity and salary in different ways. Hypotheses are tested from human and social capital theories that include more direct measures for family responsibilities and family-friendly firm arguments. Data from 670 law firm lawyers were used given they report a standardized measure of productivity in billable hours. Despite men investing more in their careers and women investing more in their families, both report similar productivity and their productivity is affected similarly by these factors. In addition, equally productive men and women are paid the same. The findings further our understanding of productivity and salary and the relevance of family responsibilities and family-friendly firms.

试论企业技术创新激励与约束机制

由于缺乏有效的企业技术创新的激励机制和约束机制,致使相当部分国有企业缺乏创新的热情和责任,不能成为技术创新的主体,激励机制与约束机制是企业技术创新的动力机制,只有尽快建立相对完善的激励机制和约束机制,才能保证企业技术创新活动的健康发展.     

Determinanten des Informationsgehalts von Managementprognosen – eine empirische Untersuchung anhand der DAX und MDAX-Unternehmen

In this article the characteristics and determinants of the information content of management earnings forecasts of the German DAX and MDAX companies between 2002 and 2005 are analyzed. As proxy for the information content I use the precision of the wording of a forecast. I can show that the forecasts of MDAX companies are more precisely formulated than those of DAX companies. Furthermore forecasts are formulated more precisely, when companies have, (1) a lower percentage of intangible assets, (2) lower market capitalization, (3) lower volatility of earnings and (4) a higher need for external financing.     

Managing cohesion in transnational organizations: an introduction

Aesthetic approaches seek to enrich knowledge about the ‘sensible’ aspects of experience. The ‘aesthetic dimension’ of shipboard organizational life is evoked and co‐created through multiple aesthetic categories such as the agogic, the sacred, and the sublime rendered through multiple sensory experiences of life aboard. A researcher and sailor‐informant co‐authored aesthetic reading contributes to a growing niche of aesthetic‐based research within organization studies. Our article explores collaboration as an important element of the aesthetic project. Possibilities for future aesthetic inquiries are also considered.     

Childcare costs and the demand for children—evidence from a nationwide reform

Exploiting the exogenous variation in user fees caused by a Swedish childcare reform, we are able to identify the causal effect of childcare costs on fertility in a context in which childcare enrollment is almost universal, user fees are low, and labor force participation of mothers is very high. Anticipation of a reduction in childcare costs increased the number of first and higher-order births, but only seemed to affect the timing of second births. For families with many children we also find a marginally significant negative income effect on fertility.     

Liberalisierungspolitik

Political-economic classics of different schools agreed that capitalism inherently and inevitably leads to a decline of market principles. We analyze indicators of liberalization policies for 21 OECD-countries in five economic and social policy fields and demonstrate that western industrialized countries are subject of a convergent trend towards market-creating policies??in stark contrast to the theoretical expectations of several political economy authors. At the latest during the first half of the eighties, the western democracies entered a new phase of economic liberalization, which continues up to the present. A methodological implication of our findings suggests that the methods of causal analysis of convergent liberalization policies may not be the same as those who have been applied for the analysis of development and consolidation of the varieties of capitalism in the postwar era.