64 research outputs found

    Experimental evolution of adaptive divergence under varying degrees of gene flow

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    Adaptive divergence is the key evolutionary process generating biodiversity by means of natural selection. Yet, the conditions under which it can arise in the presence of gene flow remain contentious. To address this question, we subjected 132 sexually reproducing fission yeast populations, sourced from two independent genetic backgrounds, to disruptive ecological selection and manipulated the level of migration between environments. Contrary to theoretical expectations, adaptive divergence was most pronounced when migration was either absent (allopatry) or maximal (sympatry), but was much reduced at intermediate rates (parapatry and local mating). This effect was apparent across central life-history components (survival, asexual growth and mating) but differed in magnitude between ancestral genetic backgrounds. The evolution of some fitness components was constrained by pervasive negative correlations (trade-off between asexual growth and mating), while others changed direction under the influence of migration (for example, survival and mating). In allopatry, adaptive divergence was mainly conferred by standing genetic variation and resulted in ecological specialization. In sympatry, divergence was mainly mediated by novel mutations enriched in a subset of genes and was characterized by the repeated emergence of two strategies: an ecological generalist and an asexual growth specialist. Multiple loci showed consistent evidence for antagonistic pleiotropy across migration treatments providing a conceptual link between adaptation and divergence. This evolve-and-resequence experiment shows that rapid ecological differentiation can arise even under high rates of gene flow. It further highlights that adaptive trajectories are governed by complex interactions of gene flow, ancestral variation and genetic correlations

    A review of current surgical practice in the operative treatment of proximal humeral fractures: Does the PROFHER trial demonstrate a need for change?

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    Objectives: The PROximal Fracture of the Humerus: Evaluation by Randomisation (PROFHER) trial has recently demonstrated that surgery is non-superior to non-operative treatment in the management of displaced proximal humeral fractures. The objective of this study was to assess current surgical practice in the context of the PROFHER trial in terms of patient demographics, injury characteristics and the nature of the surgical treatment. Methods: A total of ten consecutive patients undergoing surgery for the treatment of a proximal humeral fracture from each of 11 United Kingdom hospitals were retrospectively identified over a 15 month period between January 2014 and March 2015. Data gathered for the 110 patients included patient demographics, injury characteristics, mode of surgical fixation, the grade of operating surgeon and the cost of the surgical implants. Results: A majority of the patients were female (66%, 73 of 110). The mean patient age was 62 years (range 18 to 89). A majority of patients met the inclusion criteria for the PROFHER trial (75%, 83 of 110). Plate fixation was the most common mode of surgery (68%, 75 patients), followed by intramedullary fixation (12%, 13 patients), reverse shoulder arthroplasty (10%, 11 patients) and hemiarthroplasty (7%, eight patients). The consultant was either the primary operating surgeon or supervising the operating surgeon in a large majority of cases (91%, 100 patients). Implant costs for plate fixation were significantly less than both hemiarthroplasty (p &lt; 0.05) and reverse shoulder arthroplasty (p &lt; 0.0001). Implant costs for intramedullary fixation were significantly less than plate fixation (p &lt; 0.01), hemiarthroplasty (p &lt; 0.0001) and reverse shoulder arthroplasty (p &lt; 0.0001). Conclusions: Our study has shown that the majority of a representative sample of patients currently undergoing surgical treatment for a proximal humeral fracture in these United Kingdom centres met the inclusion criteria for the PROFHER trial and that a proportion of these patients may, therefore, have been effectively managed non-operatively.</p

    A review of current surgical practice in the operative treatment of proximal humeral fractures: Does the PROFHER trial demonstrate a need for change?

    No full text
    Objectives: The PROximal Fracture of the Humerus: Evaluation by Randomisation (PROFHER) trial has recently demonstrated that surgery is non-superior to non-operative treatment in the management of displaced proximal humeral fractures. The objective of this study was to assess current surgical practice in the context of the PROFHER trial in terms of patient demographics, injury characteristics and the nature of the surgical treatment. Methods: A total of ten consecutive patients undergoing surgery for the treatment of a proximal humeral fracture from each of 11 United Kingdom hospitals were retrospectively identified over a 15 month period between January 2014 and March 2015. Data gathered for the 110 patients included patient demographics, injury characteristics, mode of surgical fixation, the grade of operating surgeon and the cost of the surgical implants. Results: A majority of the patients were female (66%, 73 of 110). The mean patient age was 62 years (range 18 to 89). A majority of patients met the inclusion criteria for the PROFHER trial (75%, 83 of 110). Plate fixation was the most common mode of surgery (68%, 75 patients), followed by intramedullary fixation (12%, 13 patients), reverse shoulder arthroplasty (10%, 11 patients) and hemiarthroplasty (7%, eight patients). The consultant was either the primary operating surgeon or supervising the operating surgeon in a large majority of cases (91%, 100 patients). Implant costs for plate fixation were significantly less than both hemiarthroplasty (p andlt; 0.05) and reverse shoulder arthroplasty (p andlt; 0.0001). Implant costs for intramedullary fixation were significantly less than plate fixation (p andlt; 0.01), hemiarthroplasty (p andlt; 0.0001) and reverse shoulder arthroplasty (p andlt; 0.0001). Conclusions: Our study has shown that the majority of a representative sample of patients currently undergoing surgical treatment for a proximal humeral fracture in these United Kingdom centres met the inclusion criteria for the PROFHER trial and that a proportion of these patients may, therefore, have been effectively managed non-operatively.</p

    Co-segregation analysis of cadmium and zinc accumulation in Thlaspi caerulescens interecotypic crosses.

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    Cadmium (Cd) hyperaccumulation in Thlaspi caerulescens varies among ecotypes. Here we investigated segregation of Cd and zinc (Zn) accumulation in
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