Institution
University of Exeter
Education•Exeter, United Kingdom•
About: University of Exeter is a education organization based out in Exeter, United Kingdom. It is known for research contribution in the topics: Population & Context (language use). The organization has 15820 authors who have published 50650 publications receiving 1793046 citations. The organization is also known as: Exeter University & University of the South West of England.
Papers published on a yearly basis
Papers
More filters
••
TL;DR: Clear evidence is shown from this manipulative experiment that rare-color morphs have reproductive advantage through male and female components, the first demonstration, to the authors' knowledge, that negative frequency-dependent selection through pollinator preference for rare morphs can cause the maintenance of a flower-color polymorphism.
Abstract: The orchid Dactylorhiza sambucina shows a stable and dramatic flower-color polymorphism, with both yellow- and purple-flowered individuals present in natural populations throughout the range of the species in Europe. The evolutionary significance of flower-color polymorphisms found in many rewardless orchid species has been discussed at length, but the mechanisms responsible for their maintenance remain unclear. Laboratory experiments have suggested that behavioral responses by pollinators to lack of reward availability might result in a reproductive advantage for rare-color morphs. Consequently, we performed an experiment varying the relative frequency of the two color morphs of D. sambucina to test whether rare morph advantage acted in the natural habitat of the species. We show here clear evidence from this manipulative experiment that rare-color morphs have reproductive advantage through male and female components. This is the first demonstration, to our knowledge, that negative frequency-dependent selection through pollinator preference for rare morphs can cause the maintenance of a flower-color polymorphism.
309 citations
••
Seattle Children's1, University of Washington2, University of Exeter3, Wake Forest University4, University of Cincinnati Academic Health Center5, Benaroya Research Institute6, Centers for Disease Control and Prevention7, Kaiser Permanente8, University of North Carolina at Chapel Hill9, Kuakini Medical Center10, Colorado School of Public Health11
TL;DR: In this systematic study of MODY in a large pediatric US diabetes cohort, unselected by referral pattern or family history, MODY was usually misdiagnosed and incorrectly treated with insulin, although many type 2 diabetes-like metabolic features were less common in the mutation-positive group, no single characteristic identified all patients with mutations.
Abstract: Aims: Our study aims were to determine the frequency of MODY mutations (HNF1A, HNF4A, glucokinase) in a diverse population of youth with diabetes and to assess how well clinical features identify youth with maturity-onset diabetes of the young (MODY). Methods: The SEARCH for Diabetes in Youth study is a US multicenter, population-based study of youth with diabetes diagnosed at age younger than 20 years. We sequenced genomic DNA for mutations in the HNF1A, HNF4A, and glucokinase genes in 586 participants enrolled in SEARCH between 2001 and 2006. Selection criteria included diabetes autoantibody negativity and fasting C-peptide levels of 0.8 ng/mL or greater. Results: We identified a mutation in one of three MODY genes in 47 participants, or 8.0% of the tested sample, for a prevalence of at least 1.2% in the pediatric diabetes population. Of these, only 3 had a clinical diagnosis of MODY, and the majority was treated with insulin. Compared with the MODY-negative group, MODY-positive participants had lower F...
309 citations
••
TL;DR: In this paper, pigeons were trained in a Skinner box on a reinforcement schedule that simulated a foraging situation, where pecks on a central key occasionally illuminated a side key which, if pecked, led to food reward after a delay that varied with the side key colour.
309 citations
••
TL;DR: Preliminary evidence that rumination-focused CBT may be an efficacious treatment for medication--refractory residual depression is provided, with generalised improvement in depression and co-morbidity.
308 citations
••
TL;DR: An algorithm for iterative learning control is developed on the basis of an optimization principle which has been used previously to derive gradient-type algorithms and has numerous benefits which include realization in terms of Riccati feedback and feedforward components.
Abstract: An algorithm for iterative learning control is developed on the basis of an optimization principle which has been used previously to derive gradient-type algorithms. The new algorithm has numerous benefits which include realization in terms of Riccati feedback and feedforward components. This realization also has the advantage of implicitly ensuring automatic step size selection and hence guaranteeing convergence without the need for empirical choice of parameters. The algorithm is expressed as a very general norm optimization problem in a Hilbert space setting and hence, in principle, can be used for both continuous and discrete time systems. A basic relationship with almost singular optimal control is outlined. The theoretical results are illustrated by simulation studies which highlight the dependence of the speed of convergence on parameters chosen to represent the norm of the signals appearing in the optimization problem.
308 citations
Authors
Showing all 16338 results
Name | H-index | Papers | Citations |
---|---|---|---|
Frank B. Hu | 250 | 1675 | 253464 |
John C. Morris | 183 | 1441 | 168413 |
David W. Johnson | 160 | 2714 | 140778 |
Kevin J. Gaston | 150 | 750 | 85635 |
Andrew T. Hattersley | 146 | 768 | 106949 |
Timothy M. Frayling | 133 | 500 | 100344 |
Joel N. Hirschhorn | 133 | 431 | 101061 |
Jonathan D. G. Jones | 129 | 417 | 80908 |
Graeme I. Bell | 127 | 531 | 61011 |
Mark D. Griffiths | 124 | 1238 | 61335 |
Tao Zhang | 123 | 2772 | 83866 |
Brinick Simmons | 122 | 691 | 69350 |
Edzard Ernst | 120 | 1326 | 55266 |
Michael Stumvoll | 119 | 655 | 69891 |
Peter McGuffin | 117 | 624 | 62968 |