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Dataset for: Biogeographic processes determining the distributions of European bats across spatial scales: The role of biotic interactions and habitat preferences
No full textDataset supports chapter 3 of the thesis - Biogeographic processes determining the distributions of European bats across spatial scales: The role of biotic interactions and habitat preferences</span
Biogeographic processes determining the distributions of European bats across spatial scales: the role of biotic interactions and habitat preferences
No full textA better comprehension of how natural systems will respond to global environmental changes requires a deeper understanding of the processes that drive diversity. In this thesis I show how environmental filtering and biotic interactions operate across spatial scales contributing to shaping biogeographic patterns. Among the different environmental filtering factors that drive species’ geographical ranges, habitat structure is thought to operate generally at more local scales than climatic factors. I show, however, that forest characteristics can be a primary factor driving the regional distribution of forest-specialist bats in a Mediterranean system, which has direct consequences for their vulnerability to climate change. The strength of this dependence on forests is driven by species’ roosting ecology, being higher in species that roost in trees. Alongside environmental filtering, biotic interactions can impact species distributions by preventing functionally similar species from coexisting. I show how local-scale trophic shift can facilitate coexistence between the morphologically almost identical forest bats Myotis escalerai and Myotis crypticus. Increasing evidence supports the effect of biotic interactions on broader scale biogeographic patterns. I develop a measure that uses outputs of Species Distribution Models to detect the expected broad-scale patterns of geographic avoidance between pairs of species if competition contributes to shaping their ranges. When applying it to different sets of bats with high potential for competition, the measure showed higher values than random for two pairs of species that are ecologically very similar and have no known local-scale coexistence mechanisms. This suggests that local-scale coexistence mechanisms are a key process preventing biotic interactions from scaling up and having broader-scale consequences. Overall, this thesis highlights the importance of integrating new molecular techniques, functional analyses and a careful consideration of spatial scale for disentangling ecological and biogeographic processes. <br/
Tipping Points: The Gender Segregating and Desegregating Effects of Network Recruitment
Get PDFCurrent scholarship commonly posits that network recruitment contributes to job sex segregation and that the segregated nature of personal contact networks explains this effect. A variety of empirical findings inconsistent with this explanation demonstrate its inadequacy. Building on Kanter’s observation that recruitment processes often resemble “homosocial reproduction” [Kanter RM (1977) Men and Women of the Corporation (Basic Books, New York)], we develop a population dynamics model of network recruitment. The resulting formal model builds a parsimonious theory regarding the segregating effects of network recruitment, resolving the puzzles and inconsistencies revealed by recent empirical findings. This revised theory also challenges conventional understandings of how network recruitment segregates: in isolation, network recruitment—even with segregated networks—is more likely to desegregate rather than segregate. Network recruitment segregates primarily through its interactions with other supply-side (e.g., gendered self-sorting) or demand-side (e.g., gendered referring rates) biasing mechanisms. Our model reveals whether and to what extent network recruitment segregates or desegregates, and it reveals opportunities for organizational intervention. There is an easily calculable tipping point where demand-side factors such as gender differences in referring can counteract and neutralize other segregating effects from referring. Independent of other personnel practices, organizational policies affecting employees’ referring behaviors can tip the balance to determine whether network recruitment serves as a segregating or desegregating force. We ground our model empirically using three organizational cases
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Strength matters: Tie strength as a causal driver of networks’ information benefits
Get PDFStudies of social networks have often taken the existence of a social tie as a proxy for the transmission of information. However, other studies of social networks in the labor market propose that the likelihood of information transmission might depend on strength of the tie; and that tie strength is a potentially important source of the tie's value. After all, even if job seekers have social ties to those who have valuable job information, the seekers will gain little information benefit when the ties do not actually transmit the information. This paper clarifies the conditions under which social ties might provide information benefits. We use a survey vignette experiment and ask MBA students about their likelihood of relaying job information via strong ties (to friends) or weak ties (to acquaintances), holding constant the structural locations spanned by the tie and job seekers' fit with the job. The results support the claim that strength of tie has a causal effect on the chances of information transmission: potential referrers are more likely to relay job information to their friends than to acquaintances. The larger implication of these findings is that whatever benefits there might be to using weak ties to reach distant non-redundant information during job search, these benefits need to be considered against the likely fact that people connected via weak ties are less likely to actually share information about job opportunities than are people to whom the job seeker is strongly tied
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Bending the Pipeline? Executive Search and Gender Inequality in Hiring for Top Management Jobs
Get PDFWe study the sources of women’s underrepresentation in hiring for top management jobs by focusing on the context of executive search. Using data that include proprietary information on 10,970 individuals considered by a search firm, we examine the sources of the low proportion of women placed in senior roles. Contrary to received wisdom, we find limited evidence that demand-side screeners strongly contribute to gender disadvantage in this setting. What gender differences exist tend to play out at the start of the hiring process and are driven both by supply-side and demand-side actors. Once considered for a position, women are no less likely than men to be hired—though they are slightly less likely to be interviewed by the search firm. Our findings highlight the theoretical importance of disentangling candidates’ “self-steering” behavior from the “pipeline bending” of hiring agents. We discuss the implications of our results for understanding gender inequality at upper echelons of the labor market
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
From Metaphors to Mechanisms: Gender Sorting In(to) an Organizational Hierarchy
Get PDFNumerous studies have examined patterns of gender inequality in organizational advancement, with some
showing results indicative of “glass ceilings,” where gender disparities are strong at the upper reaches of the
organization, while others suggest “sticky floors,” where the gender differences in advancement occur at the lower
levels of the organization. These studies, however, have been less clear on the mechanisms that produce these
descriptive patterns. With few exceptions, extant studies have focused on internal promotion practices and have not
addressed the extent to which these patterns might reflect gender differences in external recruitment and hiring into
the organization. We construct queues consisting of both external and internal candidates—the set of candidates
under consideration—for over 2,200 job openings during a 27-month period for a large retail bank. We find that
women are more likely than men to be hired, and that this pattern holds for jobs up and down the organizational
hierarchy. The applicant pools are themselves gendered, however, with women comprising a lower percentage of the
applicant pools for high-level jobs, but a greater proportion of the pools for lower-level jobs. Since women are more
likely than men to advance from each applicant pool to hire at all levels of the hierarchy, the apparent “glass ceiling”
observed among job incumbents is not due to gendered screening practices. Instead, the roots of gender inequality in
this firm lie in the initial sorting of applicants into queues
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