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91.
The role of urban expansion on bee diversity is poorly understood, but it may play an important role in restructuring pollinator diversity observed in rural regions at the urban perimeter. We studied bee communities in two habitats essential for pollinators (residential gardens and semi-natural areas) at 42 sites situated at the edge of greater Montreal, Canada. Bee species richness, abundance and functional diversity all increased with urbanization in both habitat types, but gardens and semi-natural areas supported distinct bee communities with unique responses to urbanization in terms of species turnover. Compared to semi-natural sites, residential gardens supported bees that foraged from a greater number but a lower proportion of available plant species. Bees did not discriminate between exotic and indigenous plant species in either gardens or semi-natural sites and were attracted to flowers in either habitat irrespective of their origins. Protecting semi-natural ruderal areas and providing residential garden habitats for pollinators are both effective means of promoting regional bee diversity in urbanizing regions.  相似文献   
92.
While nature is widely acknowledged to contribute to people’s well-being, nature based well-being indicators at city-level appear to be underprovided. This study aims at filling this gap by introducing a novel indicator based on the proximity of city-residents to nature that is of high-amenity. High-amenity nature is operationalized by combining unique systematic data on people’s perceptions of what are the locations of attractive natural areas with data on natural land cover. The proposed indicator departs from the usual assumption of equal well-being from any nature, as it approximates the ‘actual’ subjective quality of nature near people’s homes in a spatially explicit way. Such indicator is used to rank 148 ‘cities’ in the Netherlands, Denmark, and Germany. International comparability of the indicator is enhanced by the use of a definition of cities as functional urban areas (FUAs), which are consistently identified across countries. Results demonstrate that the average ‘nearness’ of FUA populations to high amenity nature varies widely across the observed FUAs. A key finding, that complements insights from existing city-level indicators, is that while populations of FUAs with higher population densities may live relatively far from nature in general, they also live, on average, closer to high-amenity nature than inhabitants of lower density FUAs. Our results may stimulate policy-debates on how to combine urban agglomeration with access to natural amenities in order to account for people’s wellbeing.  相似文献   
93.
研究发现首都圈的劳动力分布呈现以北京为中心向外围递减的趋势,对于这一分布格局,本文以新经济地理学"中心—外围"理论为基础采用全面FGLS估计方法进行实证分析,得到以下结论:首都圈劳动力分布格局是由历史政治等偶然因素引发了地区发展的初始不平衡并通过产业集聚引致劳动力集聚,循环累积形成的.由于产业存在异质性,其对劳动力集聚的影响也存在差异,其中第三产业的集聚是引致劳动力集聚的主要力量,第二产业吸纳劳动力的能力有限,并不利于劳动力的集聚.地理区位与首都圈劳动力集聚度呈现"∽"形曲线的形态,在200公里左右的范围内,劳动力集聚度是不断下降的,而200公里以外,劳动力集聚度有小幅上升,说明存在"集聚阴影".  相似文献   
94.
建号于1925年的“义顺”商号发展历程表明,老字号企业商道形成的过程也是老字号集体记忆内容的建构过程.老字号企业的集体记忆,既在社会环境中创造集体认同感,连接过去获得老字号商道的传承,又在群体的框架中去创新,重新建构老字号商道的时代性.老字号的商道传承,可以用集体记忆的时间机制实现商道的代际传递,用集体记忆的空间机制实现商道影响力的扩大,用集体记忆的升华机制实现商道从言行到制度、从制度到文化的转化,用集体记忆的强化机制不断重复商道,使得商道在实践中稳定延续和发展.  相似文献   
95.
This paper offers a contribution to the call for research on the effectiveness of regulatory interventions governing management commentary disclosure. Specifically, we focus on the mandatory requirement concerning performance indicator disclosure introduced by the Modernisation Directive (2003/51/EC). In keeping with other regulators, the European legislator opted to implement a regulatory approach based on a rule with loose specifications. To understand the effects of this Directive, we have investigated the Italian context, in which neither the national legislator nor the standard setter have supported companies with detailed specifications or guidelines aimed at integrating the European provision. We have compared companies’ disclosure practices before and after the adoption of the Directive, investigating the number of disclosed indicators and also their modalities of presentation, as they are considered essential to guaranteeing the quality of this disclosure. Our results document that a mandatory intervention, even if based on loose specifications, is associated with an increase in disclosure practices. Nevertheless, such regulation does not seem able to guarantee high quality disclosure practices. In fact, before and after the regulation, companies primarily disclose common financial measures. Moreover, the usefulness of such disclosure is undermined by a limited compliance with the international guidelines concerning the modalities of presentation. These results reveal some weaknesses in the European approach to performance indicator regulation. In general, the EU legislator fails to explain the purpose and the objective of performance indicator disclosure and does not take into account the differences between financial and non-financial indicators. Furthermore, it does not provide firms with clear guidelines concerning the presentation modalities.  相似文献   
96.
This paper investigates the relationships of the choice of philanthropic strategy with board capital (diversity and networks), board activities (board processes, internal board committees, and board effectiveness), and CEO leadership. Using a sample of 110 Italian foundations, the research shows that board processes have the strongest positive association with an evolved strategic approach to philanthropic institutional grant-giving, while board diversity and strong CEO leadership are associated with the strategic approach only under certain conditions. In particular, good governance processes (e.g., training the board, self-evaluation of trustees, setting the stage for effective board and committee meetings, implementing control software, and steering meetings to improve the board’s analysis) are positively associated with evolved strategic approaches to philanthropy (e.g., signaling other funders for the best grantees, improving the performance of grant recipients, and advancing selected social fields’ state of knowledge and practice).  相似文献   
97.
The study shows that a structural conflict of interest in non-executive boards exists due to missing corporate governance structures and a lack of awareness for legal issues with regard to information security risks. Non-executive boards receive information on strategic security threats as a part of their oversight function to fulfill investor interest in transparency. At the same time, they act as representatives of company stakeholders and have an interest to counteract to information security risks based on the stakeholder’s risk disposition. If not properly structured by corporate governance rules, these different interests may lead to regulatory aberrations on non-executive board level. The study analyses a Deutsche Telekom AG case where non-executive board members, employees, and journalists fell victim to a spying scandal subject to the German telecommunications secrecy law in 2005–2006. The analysis demonstrates how the handling of information security on non-executive board level bears governance risks as well as legal risks that are insufficiently addressed in corporate governance research. The paper contributes to avoid a reproduction of events in the future, by suggesting the principle of a segregation of duties on non-executive boards as well as providing an overview of relevant legislative requirements that clarify tasks of non-executive board members with regard to information security. The study therefore helps protecting corporations and their stakeholders from similar consequences of missing corporate security governance.  相似文献   
98.
This paper adds to the literature on the determinants of the effects of private equity (PE) investments. Using an original dataset of 191 target firms in Italy, we study the effects on performance and governance of the stakes acquired by the PE investor. We employ a difference-in-differences approach and compare target and control firms sharing similar characteristics and performance in the years preceding the deal. We find that PE investment has a positive effect on profitability, sales, and employment; these effects are larger for minority investments. We argue that this signals effective governance that follows from complementing rather than substituting incumbent managers in minority investments.  相似文献   
99.
This study aims to identify whether a relationship exists between the controlling shareholders’ voting power and outside directors’ effectiveness in maximizing firms’ financial performance. We analyze a panel data with 3057 observations for the 2000–2012 period using a random effects model, logit and probit regressions, and the two-stage model of Heckman in the Brazilian stock market. Our findings show that firms whose controlling shareholders use dual class shares to leverage their voting power have less independence from the board and worse financial performance and market value. Further, the percentage of outside directors tends to be ineffective in increasing the firm’s value, and in changing the firm’s chief executive officer (CEO) when (1) the controlling shareholder’s voting power is leveraged, or (2) when the CEO assumes a position on the board of directors simultaneously. We interpreted that these results are in line with the arguments in favor of the existence of a new agency cost, which is related to the undue obedience of board members to authority, such as the largest controlling shareholder or the CEO in Brazilian listed firms.  相似文献   
100.
A hamiltonian walk of a digraph is a closed spanning directed walk with minimum length in the digraph. The length of a hamiltonian walk in a digraph D is called the hamiltonian number of D, denoted by h(D). In Chang and Tong (J Comb Optim 25:694–701, 2013), Chang and Tong proved that for a strongly connected digraph D of order n, \(n\le h(D)\le \lfloor \frac{(n+1)^2}{4} \rfloor \), and characterized the strongly connected digraphs of order n with hamiltonian number \(\lfloor \frac{(n+1)^2}{4} \rfloor \). In the paper, we characterized the strongly connected digraphs of order n with hamiltonian number \(\lfloor \frac{(n+1)^2}{4} \rfloor -1\) and show that for any triple of integers n, k and t with \(n\ge 5\), \(n\ge k\ge 3\) and \(t\ge 0\), there is a class of nonisomorphic digraphs with order n and hamiltonian number \(n(n-k+1)-t\).  相似文献   
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