نتایج جستجو برای: diversification

تعداد نتایج: 20860  

Journal: :Systematic biology 2016
Eric H Roalson Wade R Roberts

Using a time-calibrated phylogenetic hypothesis including 768 Gesneriaceae species (out of [Formula: see text]3300 species) and more than 29,000 aligned bases from 26 gene regions, we test Gesneriaceae for diversification rate shifts and the possible proximal drivers of these shifts: geographic distributions, growth forms, and pollination syndromes. Bayesian Analysis of Macroevolutionary Mixtur...

Journal: :Proceedings. Biological sciences 2015
Cortland K Griswold

A fundamental goal of the biological sciences is to determine processes that facilitate the evolution of diversity. These processes can be separated into ecological, physiological, developmental and genetic. An ecological process that facilitates diversification is frequency-dependent selection caused by competition. Models of frequency-dependent adaptive diversification have generally assumed ...

Journal: :Trends in ecology & evolution 2014
David M Althoff Kari A Segraves Marc T J Johnson

Coevolutionary diversification is cited as a major mechanism driving the evolution of diversity, particularly in plants and insects. However, tests of coevolutionary diversification have focused on elucidating macroevolutionary patterns rather than the processes giving rise to such patterns. Hence, there is weak evidence that coevolution promotes diversification. This is in part due to a lack o...

Journal: :PLoS ONE 2008
Judith X. Becerra D. Lawrence Venable

Elucidating the geographical history of diversification is critical for inferring where future diversification may occur and thus could be a valuable aid in determining conservation priorities. However, it has been difficult to recognize areas with a higher likelihood of promoting diversification. We reconstructed centres of origin of lineages and identified areas in the Mexican tropical dry fo...

2007
Francisco Javier Forcadell

We study the dynamic bidirectional relationship between firm R&D intensity and corporate diversification, using longitudinal data of Spanish manufacturing companies. Our empirical approach takes into account the censored nature of the dependent variables and the existence of firm-specific unobserved heterogeneity. Whereas we find a positive linear effect of R&D intensity on related diversificat...

Journal: :Agriculture 2022

Agricultural intensification is a highly specialized agri-food system that has contributed to raising food production worldwide due progress in agricultural machinery and technologies, the use of improved cultivars, external inputs such as fertilizers, irrigation, pesticides [...]

Journal: :مدیریت بازرگانی 0
علی ملاحسینی دانشیار دانشگاه شهید باهنر کرمان، مدیریت، دانشگاه تهران، تهران، ایران فریده تاج الدینی کارشناس ارشد مدیریت بازرگانی، دانشگاه شهید باهنر کرمان، کرمان، ایران

the purpose of this research is to examine consumers’ brand value and brand loyalty toward luxury brands and current distribution channels for those brands (i.e. free standing, shopping center, specialty store, internet retailing). the population consisted of  the costumers, aged 19-39 years, who use branded apparel that is in kerman. about 200 questionnaires were distributed among the consumer...

Journal: :Evolution; international journal of organic evolution 2018
Andreas L S Meyer John J Wiens

Estimates of diversification rates are invaluable for many macroevolutionary studies. Recently, an approach called BAMM (Bayesian Analysis of Macro-evolutionary Mixtures) has become widely used for estimating diversification rates and rate shifts. At the same time, several articles have concluded that estimates of net diversification rates from the method-of-moments (MS) estimators are inaccura...

Journal: :Journal of Economic Perspectives 1994

Journal: :The Geneva Papers on Risk and Insurance - Issues and Practice 2007

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