25 resultados para diversification in employment
em BORIS: Bern Open Repository and Information System - Berna - Suiça
Resumo:
Understanding the spatiotemporal distribution of genetic variation and the ways in which this distribution is connected to the ecological context of natural populations is fundamental for understanding the nature and mode of intraspecific and, ultimately, interspecific differentiation. The Petunia axillaris complex is endemic to the grasslands of southern South America and includes three subspecies: P.a.axillaris, P.a.parodii and P.a.subandina. These subspecies are traditionally delimited based on both geography and floral morphology, although the latter is highly variable. Here, we determined the patterns of genetic (nuclear and cpDNA), morphological and ecological (bioclimatic) variation of a large number of P.axillaris populations and found that they are mostly coincident with subspecies delimitation. The nuclear data suggest that the subspecies are likely independent evolutionary units, and their morphological differences may be associated with local adaptations to diverse climatic and/or edaphic conditions and population isolation. The demographic dynamics over time estimated by skyline plot analyses showed different patterns for each subspecies in the last 100000years, which is compatible with a divergence time between 35000 and 107000years ago between P.a.axillaris and P.a.parodii, as estimated with the IMa program. Coalescent simulation tests using Approximate Bayesian Computation do not support previous suggestions of extensive gene flow between P.a.axillaris and P.a.parodii in their contact zone.
Resumo:
Cases of evolutionary diversification can be characterized along a continuum from weak to strong genetic and phenotypic differentiation. Several factors may facilitate or constrain the differentiation process. Comparative analyses of replicates of the same taxon at different stages of differentiation can be useful to identify these factors. We estimated the number of distinct phenotypic groups in threespine stickleback populations from nine lakes in Iceland and in one marine population. Using the inferred number of phenotypic groups in each lake, genetic divergence from the marine population, and physical lake and landscape variables, we tested if ecosystem size, approximated by lake size and depth, or isolation from the ancestral marine gene pool predict the occurrence and the extent of phenotypic and genetic diversification within lakes. We find intralacustrine phenotypic diversification to be the rule rather than the exception, occurring in all but the youngest lake population and being manifest in ecologically important phenotypic traits. Neutral genetic data further indicates non-random mating in four out of nine studied lakes, and restricted gene flow between sympatric phenotypic groups in two. Although neither the phenotypic variation nor the number of intralacustrine phenotypic groups were associated with any of our environmental variables, the number of phenotypic traits that were differentiated was significantly positively related to lake size, and evidence for restricted gene flow between sympatric phenotypic groups was only found in the largest lakes where trait specific phenotypic differentiation was highest.
Resumo:
Subjective quality of life (SQOL) is an important outcome in the treatment of patients with schizophrenia. However, there is only limited evidence on factors influencing SQOL, and little is known about whether the same factors influence SQOL in patients with schizophrenia and other mental disorders. This study aimed to identify the factors associated with SQOL and test whether these factors are equally important in schizophrenia and other disorders. For this we used a pooled data set obtained from 16 studies that had used either the Lancashire Quality of Life Profile or the Manchester Short Assessment of Quality of Life for assessing SQOL. The sample comprised 3936 patients with schizophrenia, mood disorders, and neurotic disorders. After controlling for confounding factors, within-subject clustering, and heterogeneity of findings across studies in linear mixed models, patients with schizophrenia had more favourable SQOL scores than those with mood and neurotic disorders. In all diagnostic groups, older patients, those in employment, and those with lower symptom scores had higher SQOL scores. Whilst the strength of the association between age and SQOL did not differ across diagnostic groups, symptom levels were more strongly associated with SQOL in neurotic than in mood disorders and schizophrenia. The association of employment and SQOL was stronger in mood and neurotic disorders than in schizophrenia. The findings may inform the use and interpretation of SQOL data for patients with schizophrenia.
Resumo:
Background: Deterministic evolution, phylogenetic contingency and evolutionary chance each can influence patterns of morphological diversification during adaptive radiation. In comparative studies of replicate radiations, convergence in a common morphospace implicates determinism, whereas non-convergence suggests the importance of contingency or chance. Methodology/Principal Findings: The endemic cichlid fish assemblages of the three African great lakes have evolved similar sets of ecomorphs but show evidence of non-convergence when compared in a common morphospace, suggesting the importance of contingency and/or chance. We then analyzed the morphological diversity of each assemblage independently and compared their axes of diversification in the unconstrained global morphospace. We find that despite differences in phylogenetic composition, invasion history, and ecological setting, the three assemblages are diversifying along parallel axes through morphospace and have nearly identical variance-covariance structures among morphological elements. Conclusions/Significance: By demonstrating that replicate adaptive radiations are diverging along parallel axes, we have shown that non-convergence in the common morphospace is associated with convergence in the global morphospace. Applying these complimentary analyses to future comparative studies will improve our understanding of the relationship between morphological convergence and non-convergence, and the roles of contingency, chance and determinism in driving morphological diversification.
Resumo:
Background Using a unique, longitudinal survey that follows school-to-work transitions of pupils who participated in PISA 2000, this paper investigates adverse consequences, so-called scarring effects, of early unemployment among young adults who acquired vocational credentials in Switzerland. Methods As social, individual and contextual factors influence both early unemployment and later employment outcomes, taking into account endogeneity is of utmost importance when investigating scarring effects. In this regard we make use of nearest-neighbour propensity score matching and set up statistical control groups. Results Our results suggest that young adults who hold vocational credentials are more likely to be neither in employment nor in education, and to earn less and be more dissatisfied with their career progress later in work life than they would be, had they not experienced early unemployment. Conclusions We conclude that unemployment scarring also affects young adults with vocational credentials in a liberal labour market setting that otherwise allows for smooth school-to-work transitions. This finding runs counter to expectations that standardised vocational degrees, a liberal and flexible labour market structure, and predominantly short unemployment spells protect young skilled workers from scarring in case they happen to experience early career instability.
Resumo:
School-to-work transitions are embedded in the institutional structures of educational systems. In particular, vocational education has been linked to greater horizontal gender segregation in employment. Similarly, research on higher education has uncovered how stratification at the tertiary level can promote gender segregation in the labour market. This paper investigates how gender typical employment is conditioned by the institutional features of the educational system in Bulgaria. Despite the post-socialist transformations of Bulgaria's educational system and its labour market, horizontal gender segregation has remained rather moderate from an international perspective. We use data from a 2012 nationally representative survey. We find that the educational system shapes the gendered occupational trajectories for men but it does not hold the same explanatory power for women. Neither vocational nor higher education has a significant effect for women. In contrast, men with vocational education are more likely to work in male-typed occupations and, in line with the literature, higher education steers men toward gender mixed and a-typical occupations. Our study points to the importance of educational institutional factors in shaping gender (a)-typical career paths. The Bulgarian case, in particular, offers insights into the mechanisms that can potentially decrease horizontal gender segregation in the labour market.
Resumo:
A major goal of evolutionary biology is to unravel the molecular genetic mechanisms that underlie functional diversification and adaptation. We investigated how changes in gene regulation and coding sequence contribute to sensory diversification in two replicate radiations of cichlid fishes. In the clear waters of Lake Malawi, differential opsin expression generates diverse visual systems, with sensitivities extending from the ultraviolet to the red regions of the spectrum. These sensitivities fall into three distinct clusters and are correlated with foraging habits. In the turbid waters of Lake Victoria, visual sensitivity is constrained to longer wavelengths, and opsin expression is correlated with ambient light. In addition to regulatory changes, we found that the opsins coding for the shortest-and longest-wavelength visual pigments have elevated numbers of potentially functional substitutions. Thus, we present a model of sensory evolution in which both molecular genetic mechanisms work in concert. Changes in gene expression generate large shifts in visual pigment sensitivity across the collective opsin spectral range, but changes in coding sequence appear to fine-tune visual pigment sensitivity at the short-and long-wavelength ends of this range, where differential opsin expression can no longer extend visual pigment sensitivity.
Resumo:
Purpose When applying for leadership positions or acting as leaders, women are still perceived with a ‘lack of fit’, thus hired less likely and evaluated less favorably than their male counterparts. In many languages, different language forms can be used to refer to both women and men: masculine forms (e.g., CEO in German: ‘Geschäftsführer’) and alternative forms (e.g., feminine‐masculine word pairs, CEO in German ‘Geschäftsführerin/Geschäftsführer’). We assumed that the use of masculine forms endorses the ‘lack of fit’ for women in leadership, whereas alternative forms reduce it. Design/Methodology Two studies tested the hypotheses by manipulating language forms (masculine forms vs. alternative forms) and gender of the target to hire/evaluate (female vs. male). Results The results indicated as predicted that masculine forms lead to the ‘lack of fit’ for women in the leadership context, whereas alternative forms reduce it. Women were less likely to be employed for leadership positions (Study 1) and evaluated less favorably as leaders (Study 2) than their male counterparts with masculine forms. However, with alternative forms no differences in employment decisions and evaluations of women and men were found. Limitations These two studies were conducted with student‐samples. Further research is needed to replicate effects with relevant samples as HRmanagers and to investigate underlying mechanisms. Research/Practical Implications Organizations may use alternative forms instead of masculine forms in job advertisements for leadership positions to overcome barriers for women in leadership. Originality/Value These are the first studies in testing the effects of language forms in the leader selection and evaluation.
Resumo:
Lake Tanganyika, Africa’s oldest lake, harbours an impressive diversity of cichlid fishes. Although diversification in its radiating groups is thought to have been initially rapid, cichlids from Lake Tanganyika show little evidence for ongoing speciation. In contrast, examples of recent divergence among sympatric colour morphs are well known in haplochromine cichlids from Lakes Malawi and Victoria. Here, we report genetic evidence for recent divergence between two sympatric Tanganyikan cichlid colour morphs. These Petrochromis morphs share mitochondrial haplotypes, yet microsatellite loci reveal that their sympatric populations form distinct genetic groups. Nuclear divergence between the two morphs is equivalent to that which arises geographically within one of the morphs over short distances and is substantially smaller than that among other sympatric species in this genus. These patterns suggest that these morphs diverged only recently, yet that barriers to gene flow exist which prevent extensive admixture despite their sympatric distribution. The morphs studied here provide an unusual example of active diversification in Lake Tanganyika’s generally ancient cichlid fauna and enable comparisons of speciation processes between Lake Tanganyika and other African lakes.
Resumo:
Paper prepared by Marion Panizzon and Charlotte Sieber-Gasser for the International Conference on the Political Economy of Liberalising Trade in Services, Hebrew University of Jerusalem, 14-15 June 2010 Recent literature has shed light on the economic potential of cross-border networks. These networks, consisting of expatriates and their acquaintances from abroad and at home, provide the basis for the creation of cross-border value added chains and therewith the means for turning brain drain into brain circulation. Both aspects are potentially valuable for economic growth in the developing world. Unilateral co-development policies operating through co-funding of expatriate business ventures, but also bilateral agreements liberalising circular migration for a limited set of per-sons testify to the increasing awareness of governments about the potential, which expatriate networks hold for economic growth in developing countries. Whereas such punctual efforts are valuable, viewed from a long term perspective, these top-down, government mandated Diaspora stimulation programs, will not replace, this paper argues, the market-driven liberalisation of infrastructure and other services in developing countries. Nor will they carry, in the case of circular labour migration, the political momentum to liberalise labour market admission for those non-nationals, who will eventually emerge as the future transnational entrepreneurs. It will take a combination of mode 4 and infrastructure services openings-cum regulation for countries at both sides of the spectrum to provide the basis and precondition for transnational business and entrepreneurial networks to emerge and translate into cross-border, value added production chains. Two key issues are of particular relevance in this context: (i) the services sector, especially in infrastructure, tends to suffer from inefficiencies, particularly in developing countries, and (ii) labour migration, a highly complex issue, still faces disproportionately rigid barriers despite well-documented global welfare gains. Both are hindrances for emerging markets to fully take advantage of the potential of these cross-border networks. Adapting the legal framework for enhancing the regulatory and institutional frameworks for services trade, especially in infrastructure services sectors (ISS) and labour migration could provide the incentives necessary for brain circulation and strengthen cross-border value added chains by lowering transaction costs. This paper analyses the shortfalls of the global legal framework – the shallow status quo of GATS commitments in ISS and mode 4 particular – in relation to stimulating brain circulation and the creation of cross-border value added chains in emerging markets. It highlights the necessity of adapting the legal framework, both on the global and the regional level, to stimulate broader and wider market access in the four key ISS sectors (telecommunications, transport, professional and financial services) in developing countries, as domestic supply capacity, global competitiveness and economic diversification in ISS sectors are necessary for mobilising expatriate re-turns, both physical and virtual. The paper argues that industrialised, labour receiving countries need to offer mode 4 market access to wider categories of persons, especially to students, graduate trainees and young professionals from abroad. Further-more, free trade in semi-finished products and mode 4 market access are crucial for the creation of cross-border value added chains across the developing world. Finally, the paper discusses on the basis of a case study on Jordan why the key features of trade agreements, which promote circular migration and the creation of cross-border value added chains, consist of trade liberalisation in services and liberal migration policies.
Resumo:
Aim Parrots are thought to have originated on Gondwana during the Cretaceous. The initial split within crown group parrots separated the New Zealand taxa from the remaining extant species and was considered to coincide with the separation of New Zealand from Gondwana 82-85 Ma, assuming that the diversification of parrots was mainly shaped by vicariance. However, the distribution patterns of several extant parrot groups cannot be explained without invoking transoceanic dispersal, challenging this assumption. Here, we present a temporal and spatial framework for the diversification of parrots using external avian fossils as calibration points in order to evaluate the relative importance of the influences of past climate change, plate tectonics and ecological opportunity. Location Australasian, African, Indo-Malayan and Neotropical regions. Methods Phylogenetic relationships were investigated using partial sequences of the nuclear genes c-mos, RAG-1 and Zenk of 75 parrot and 21 other avian taxa. Divergence dates and confidence intervals were estimated using a Bayesian relaxed molecular clock approach. Biogeographic patterns were evaluated taking temporal connectivity between areas into account. We tested whether diversification remained constant over time and if some parrot groups were more species-rich than expected given their age. Results Crown group diversification of parrots started only about 58 Ma, in the Palaeogene, significantly later than previously thought. The Australasian lories and possibly also the Neotropical Arini were found to be unexpectedly species-rich. Diversification rates probably increased around the Eocene/Oligocene boundary and in the middle Miocene, during two periods of major global climatic aberrations characterized by global cooling. Main conclusions The diversification of parrots was shaped by climatic and geological events as well as by key innovations. Initial vicariance events caused by continental break-up were followed by transoceanic dispersal and local radiations. Habitat shifts caused by climate change and mountain orogenesis may have acted as a catalyst to the diversification by providing new ecological opportunities and challenges as well as by causing isolation as a result of habitat fragmentation. The lories constitute the only highly nectarivorous parrot clade, and their diet shift, associated with morphological innovation, may have acted as an evolutionary key innovation, allowing them to explore underutilized niches and promoting their diversification.