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1.  Sperm competition and the evolution of gamete morphology in frogs. 
Despite detailed knowledge of the ultrastructure of spermatozoa, there is a paucity of information on the selective pressures that influence sperm form and function. Theoretical models for both internal and external fertilizers predict that sperm competition could favour the evolution of longer sperm. Empirical tests of the external-fertilization model have been restricted to just one group, the fishes, and these tests have proved equivocal. We investigated how sperm competition affects sperm morphology in externally fertilizing myobatrachid frogs. We also examined selection acting on egg size, and covariation between sperm and egg morphology. Species were ranked according to probability of group spawning and hence risk of sperm competition. Body size, testis size and oviposition environment may also influence gamete traits and were included in our analyses. After controlling for phylogenetic relationships between the species examined, we found that an increased risk of sperm competition was associated with increased sperm head and tail lengths. Path analysis showed that sperm competition had its greatest direct effect on sperm tail length, as might be expected under selection resulting from competitive fertilization. Sperm competition did not influence egg size. Oviposition location had a strong influence on egg size and a weak influence on sperm length, with terrestrial spawners having larger gametes than aquatic spawners. Our analysis revealed significant correlated evolution between egg morphology and sperm morphology. These data provide a conclusive demonstration that sperm competition selects for increased sperm length in frogs, and evidence for evolutionary covariance between aspects of male and female gamete morphology.
doi:10.1098/rspb.2003.2433
PMCID: PMC1691467  PMID: 14561298
3.  External validity of a prediction rule for residual mass histology in testicular cancer: an evaluation for good prognosis patients 
British Journal of Cancer  2003;88(6):843-847.
doi:10.1038/sj.bjc.6600759
PMCID: PMC2377085  PMID: 12644820
testis; residual neoplasms; histology; statistical models; validity
4.  Virtual outreach: economic evaluation of joint teleconsultations for patients referred by their general practitioner for a specialist opinion 
BMJ : British Medical Journal  2003;327(7406):84.
Objectives To test the hypotheses that, compared with conventional outpatient consultations, joint teleconsultation (virtual outreach) would incur no increased costs to the NHS, reduce costs to patients, and reduce absences from work by patients and their carers.
Design Cost consequences study alongside randomised controlled trial.
Setting Two hospitals in London and Shrewsbury and 29 general practices in inner London and Wales.
Participants 3170 patients identified; 2094 eligible for inclusion and willing to participate. 1051 randomised to virtual outreach and 1043 to standard outpatient appointments.
Main outcome measures NHS costs, patient costs, health status (SF-12), time spent attending index consultation, patient satisfaction.
Results Overall six months costs were greater for the virtual outreach consultations (£724 per patient) than for conventional outpatient appointments (£625): difference in means £99 ($162; €138) (95% confidence interval £10 to £187, P=0.03). If the analysis is restricted to resource items deemed “attributable” to the index consultation, six month costs were still greater for virtual outreach: difference in means £108 (£73 to £142, P < 0.0001). In both analyses the index consultation accounted for the excess cost. Savings to patients in terms of costs and time occurred in both centres: difference in mean total patient cost £8 (£5 to £10, P < 0.0001). Loss of productive time was less in the virtual outreach group: difference in mean cost £11 (£10 to £12, P < 0.0001).
Conclusion The main hypothesis that virtual outreach would be cost neutral is rejected, but the hypotheses that costs to patients and losses in productivity would be lower are supported.
PMCID: PMC164917  PMID: 12855528

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