Future Models (future + models)

Distribution by Scientific Domains

Selected Abstracts


EVOLUTION, Issue 6 2009
Keiko Miyake
After over a half century of empirical and theoretical research regarding the evolution and maintenance of gynodioecy in plants, unexplored factors influencing the relative fitnesses of females and hermaphrodites remain. Theoretical studies suggest that hermaphrodite self-fertilization (selfing) rate influences the maintenance of gynodioecy and we hypothesized that population sex ratio may influence hermaphrodite selfing rate. An experimental test for frequency-dependent self-fertilization was conducted using replicated populations constructed with different sex ratios of the gynodioecious plant Silene vulgaris. We found that hermaphrodite selfing increased with decreased hermaphrodite frequency, whereas evidence for increased inbreeding depression was equivocal. We argue that incorporation of context dependent inbreeding into future models of the evolution of gynodioecy is likely to yield novel insights into sex ratio evolution. [source]

Implementation of cognitive pharmaceutical services (CPS) in professionally active pharmacies

Trine R. Hopp Phd student
Objective To investigate the implementation process of cognitive pharmaceutical services (CPS) in ,professionally active' pharmacies in Denmark; to describe the factors that influence the implementation process in the context of organisational theory. Method Twenty semi-structured interviews were conducted with pharmacy staff and owners in ,professionally active' pharmacies from 16 community pharmacies in Denmark. Key findings Fifty-one factors that influence the implementation process were identified. Based on their content and relationships, the factors were categorised into nine ,common sense' dimensions: network and relations with the environment; the environment's expectations and pressure for change; barriers to implementation of CPS; competence in relation to CPS; organising the pharmacy for provision of CPS; culture of the pharmacy; resources within the pharmacy; management within the pharmacy; the role of the pharmacy. Subsequently the 51 factors were categorised and described in relation to Leavitt's model of an organisation. Conclusion Implementation of CPS in the pharmacy is a very complex process, which is unique to the individual pharmacy. The model formed a relevant basis for describing the factors, and the theoretical analysis showed a complex interdependence of the factors identified in the study. Many interdependent factors influence the process and this has to be taken into account in designing future models for implementation of CPS. Such models should support comprehensive and flexible strategies that can be adapted to the dynamics of the individual organisation. [source]

Paediatric training for family doctors: principals and practice

C Melville
Background There is controversy as to how best to train general practitioners for the paediatric challenges they will meet in practice, in particular what should be included in training, what should be left out and how long should it last? Subjects and methods All 615 general practice principals referring to 6 hospitals were surveyed (40% response rate). Setting West Midlands region of England. Study design Postal questionnaire. Statistics Quantitative and qualitative assessment of responses. Quantitative responses were analysed by hospital, decade of qualification, and duration of paediatric training. Qualitative responses were analysed using grounded theory. Results Satisfaction with training was directly related to its duration, with low levels of satisfaction for less than 6 months paediatrics, moderate levels for 6,11 months, and high levels with 12 months or more. The most important item of training was recognition of the sick child. Acute and chronic paediatrics was generally well covered. Psychosocial aspects, public health and immunisation were poorly addressed. Neonatal resuscitation and first day checks were seen as relevant, but neonatal intensive care was not. Conclusions At least 6 months of paediatrics is necessary for GPs in training, but longer paediatric exposure further increases their satisfaction with training. GPs have a biopsychosocial rather than biomedical approach to their child patients, suggesting potential benefits from a greater emphasis on psychosocial and public health aspects at the expense of neonatal intensive care. Recognition of the sick child is essential, and acute and chronic organic illness should be covered in breadth. Possible future models for GP training in paediatrics are discussed. [source]

The genetic architecture of disease resistance in plants and the maintenance of recombination by parasites

Paula X. Kover
Abstract Parasites represent strong selection on host populations because they are ubiquitous and can drastically reduce host fitness. It has been hypothesized that parasite selection could explain the widespread occurrence of recombination because it is a coevolving force that favours new genetic combinations in the host. A review of deterministic models for the maintenance of recombination reveals that for recombination to be favoured, multiple genes that interact with each other must be under selection. To evaluate whether parasite selection can explain the maintenance of recombination, we review 85 studies that investigated the genetic architecture of plant disease resistance and discuss whether they conform to the requirements that emerge from theoretical models. General characteristics of disease resistance in plants and problems in evaluating resistance experimentally are also discussed. We found strong evidence that disease resistance in plants is determined by multiple loci. Furthermore, in most cases where loci were tested for interactions, epistasis between loci that affect resistance was found. However, we found weak support for the idea that specific allelic combinations determine resistance to different host genotypes and there was little data on whether epistasis between resistance genes is negative or positive. Thus, the current data indicate that it is possible that parasite selection can favour recombination, but more studies in natural populations that specifically address the nature of the interactions between resistance genes are necessary. The data summarized here suggest that disease resistance is a complex trait and that environmental effects and fitness trade-offs should be considered in future models of the coevolutionary dynamics of host and parasites. [source]