799 resultados para NESTING SUCCESS
Resumo:
The great majority of plant species in the tropics require animals to achieve pollination, but the exact role of floral signals in attraction of animal pollinators is often debated. Many plants provide a floral reward to attract a guild of pollinators, and it has been proposed that floral signals of non-rewarding species may converge on those of rewarding species to exploit the relationship of the latter with their pollinators. In the orchid family (Orchidaceae), pollination is almost universally animal-mediated, but a third of species provide no floral reward, which suggests that deceptive pollination mechanisms are prevalent. Here, we examine floral colour and shape convergence in Neotropical plant communities, focusing on certain food-deceptive Oncidiinae orchids (e.g. Trichocentrum ascendens and Oncidium nebulosum) and rewarding species of Malpighiaceae. We show that the species from these two distantly related families are often more similar in floral colour and shape than expected by chance and propose that a system of multifarious floral mimicry—a form of Batesian mimicry that involves multiple models and is more complex than a simple one model–one mimic system—operates in these orchids. The same mimetic pollination system has evolved at least 14 times within the species-rich Oncidiinae throughout the Neotropics. These results help explain the extraordinary diversification of Neotropical orchids and highlight the complexity of plant–animal interactions.
Resumo:
Grassroots innovations emerge as networks generating innovative solutions for climate change adaptation and mitigation. However, it is unclear if grassroots innovations can be successful in responding to climate change. Little evidence exists on replication, international comparisons are rare, and research tends to overlook discontinued responses in favour of successful ones. We take the Transition Movement as a case study of a rapidly spreading transnational grassroots network, and include both active and non-active local transition initiatives. We investigate the replication of grassroots innovations in different contexts with the aim to uncover general patterns of success and failure, and identify questions for future research. An online survey was carried out in 23 countries (N=276). The data analysis entailed testing the effect of internal and contextual factors of success as drawn from the existing literature, and the identification of clusters of transition initiatives with similar internal and contextual factor configurations. Most transition initiatives consider themselves successful. Success is defined along the lines of social connectivity and empowerment, and external environmental impact. We find that less successful transition initiatives might underestimate the importance of contextual factors and material resources in influencing success. We also find that their diffusion is linked to the combination of local-global learning processes, and that there is an incubation period during which a transition initiative is consolidated. Transition initiatives seem capable of generalising organisational principles derived from unique local experiences that seem to be effective in other local contexts. However, the geographical locations matter with regard to where transition initiatives take root and the extent of their success, and ‘place attachment’ may have a role in the diffusion of successful initatives. We suggest that longitudinal comparative studies can advance our understanding in this regard, as well as inform the changing nature of the definition of success at different stages of grassroots innovation development, and the dynamic nature of local and global linkages.
The EAP teacher: prophet of doom or eternal optimist? EAP teachers' predictions of students' success
Resumo:
Interest towards Enterprise Architecture (EA) has been increasing during the last few years. EA has been found to be a crucial aspect of business survival, and thus the importance of EA implementation success is also crucial. Current literature does not have a tool to be used to measure the success of EA implementation. In this paper, a tentative model for measuring success is presented and empirically validated in EA context. Results show that the success of EA implementation can be measured indirectly by measuring the achievement of the objectives set for the implementation. Results also imply that achieving individual's objectives do not necessarily mean that organisation's objectives are achieved. The presented Success Measurement Model can be used as basis for developing measurement metrics.
Resumo:
High-quality employees with international experience bring valuable advantages to internationally operating organizations. The growing number and importance of immigrants, and particularly qualified, university-educated immigrants, deserves more attention from international business practitioners and scholars. The market for highly qualified people within MNCs is increasingly becoming international, and ever more of them have migrated to a new country to advance their career. Such employees can be a source of competitive advantage for international firms. We use qualitative research with qualified immigrants (QIs) in France to argue that the success of QIs depends in large part on their motivation to integrate into their host country, which is largely explained by their motivation to migrate. From the qualitative data we derive four different types of qualified migrant, and suggest that the type will determine the success of the immigrant within, and outside, the organization. The relationship between the motivation to migrate and the motivation to integrate is moderated by “met expectations” and “organizational integration policies”, such that the effects of these, in turn, vary with type. Recognition of the types of QI and the moderating factors will be valuable for practitioners, as well as opening up research avenues for scholars.
Resumo:
Purpose – There is a wealth of studies which suggest that managers' positive perceptions/expectations can considerably influence the organisational performance; unfortunately, little empirical evidence has been obtained from development studies. This research aims to focus on the perceptual and behavioural trait differences of successful and unsuccessful aid workers, and their relationship with organisational performance. Design/methodology/approach – Through web-based survey, 244 valid responses were obtained from the Japan International Cooperation Agency (JICA)-aid managers worldwide. Five perception related factors were extracted and used for cluster analysis to group the respondents. Each cluster's perception/behaviour-related factors and organisational performance variables were compared by ANOVA. Findings – It was discovered that Japanese's positive perception/expectation about work and their local colleagues was related to higher organisational performance, and conversely, the negative perception on their part was generally associated with negative behaviour and lower organisational performance. Moreover, in a development context, lower work-related stress and feelings of resignation toward work were strongly associated with the acceptability of cross-cultural work environment. Practical implications – The differences in perceptual tendencies suggest that cautious consideration is advised since these findings may mainly apply to Japanese aid managers. However, as human nature is universal, positive perception and behaviour would bring out positive output in most organisations. Originality/value – This study extended the contextualised “Pygmalion effect” and has clarified the influence of perception/expectation on counter-part behaviour and organisational performance in development aid context, where people-related issues have often been ignored. This first-time research provides imperial data on the significant role of positive perception on the incumbent role holder.
Resumo:
1.Habitat conversion for agriculture is a major driver of biodiversity loss, but our understanding of the demographic processes involved remains poor. We typically investigate the impacts of agriculture in isolation even though populations are likely to experience multiple, concurrent changes in the environment (e.g. land and climate change). Drivers of environmental change may interact to affect demography but the mechanisms have yet to be explored fully in wild populations. 2.Here, we investigate the mechanisms linking agricultural land-use with breeding success using long-term data for the formerly Critically Endangered Mauritius kestrel Falco punctatus; a tropical forest specialist that also occupies agricultural habitats. We specifically focused on the relationship between breeding success, agriculture and the timing of breeding because the latter is sensitive to changes in climatic conditions (spring rainfall), and enables us to explore the interactive effects of different (land and climate) drivers of environmental change. 3.Breeding success, measured as egg survival to fledging, declines seasonally in this population, but we found that the rate of this decline became increasingly rapid as the area of agriculture around a nest site increased. If the relationship between breeding success and agriculture was used in isolation to estimate the demographic impact of agriculture it would significantly under-estimate breeding success in dry (early) springs, and over-estimate breeding success in wet (late) springs. 4.Analysis of prey delivered to nests suggests that the relationship between breeding success and agriculture might be due, in part, to spatial variation in the availability of native, arboreal geckos. 5.Synthesis and applications. Agriculture modifies the seasonal decline in breeding success in this population. As springs are becoming wetter in our study area and since the kestrels breed later in wetter springs, the impact of agriculture on breeding success will become worse over time. Our results suggest that forest restoration designed to reduce the detrimental impacts of agriculture on breeding may also help reduce the detrimental effects of breeding late due to wetter springs. Our results therefore highlight the importance of considering the interactive effects of environmental change when managing wild populations.
Resumo:
1. Pollinating insects provide crucial and economically important ecosystem services to crops and wild plants, but pollinators, particularly bees, are globally declining as a result of various driving factors, including the prevalent use of pesticides for crop protection. Sublethal pesticide exposure negatively impacts numerous pollinator lifehistory traits, but its influence on reproductive success remains largely unknown. Such information is pivotal, however, to our understanding of the long-term effects on population dynamics. 2 We investigated the influence of field-realistic trace residues of the routinely used neonicotinoid insecticides thiamethoxam and clothianidin in nectar substitutes on the entire life-time fitness performance of the red mason bee Osmia bicornis. 3 We show that chronic, dietary neonicotinoid exposure has severe detrimental effects on solitary bee reproductive output. Neonicotinoids did not affect adult bee mortality; however, monitoring of fully controlled experimental populations revealed that sublethal exposure resulted in almost 50% reduced total offspring production and a significantly male-biased offspring sex ratio. 4 Our data add to the accumulating evidence indicating that sublethal neonicotinoid effects on non-Apis pollinators are expressed most strongly in a rather complex, fitness-related context. Consequently, to fully mitigate long-term impacts on pollinator population dynamics, present pesticide risk assessments need to be expanded to include whole life-cycle fitness estimates, as demonstrated in the present study using O. bicornis as a model.