Beyond relevance and recall: testing new user‐centred measures of database performance     

Peter Stokes  Allen Foster  Christine Urquhart 《Health information and libraries journal》2009,26(3):220-231

Background: Measures of the effectiveness of databases have traditionally focused on recall, precision, with some debate on how relevance can be assessed, and by whom. New measures of database performance are required when users are familiar with search engines, and expect full text availability. Objectives: This research ascertained which of four bibliographic databases (bni, cinahl, medline and embase ) could be considered most useful to nursing and midwifery students searching for information for an undergraduate dissertation. Methods: Searches on title were performed for dissertation topics supplied by nursing students (n = 9), who made the relevance judgements. Measures of recall and precision were combined with additional factors to provide measures of effectiveness, while efficiency combined measures of novelty and originality and accessibility combined measures for availability and retrievability, based on obtainability. Results: There were significant differences among the databases in precision, originality and availability, but other differences were not significant (Friedman test). Odds ratio tests indicated that bni , followed by cinahl were the most effective, cinahl the most efficient, and bni the most accessible. Conclusions: The methodology could help library services in purchase decisions as the measure for accessibility, and odds ratio testing helped to differentiate database performance.  相似文献   

The Dawkins revolution 25 years on,edited by Gwilym Croucher     

Terry Stokes 《Journal of Higher Education Policy & Management》2014,36(3):357-365

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Life under flow: A novel microfluidic device for the assessment of anti-biofilm technologies     

Maria Salta  Lorenzo Capretto  Dario Carugo  Julian A. Wharton  Keith R. Stokes 《Biomicrofluidics》2013,7(6)

In the current study, we have developed and fabricated a novel lab-on-a-chip device for the investigation of biofilm responses, such as attachment kinetics and initial biofilm formation, to different hydrodynamic conditions. The microfluidic flow channels are designed using computational fluid dynamic simulations so as to have a pre-defined, homogeneous wall shear stress in the channels, ranging from 0.03 to 4.30 Pa, which are relevant to in-service conditions on a ship hull, as well as other man-made marine platforms. Temporal variations of biofilm formation in the microfluidic device were assessed using time-lapse microscopy, nucleic acid staining, and confocal laser scanning microscopy (CLSM). Differences in attachment kinetics were observed with increasing shear stress, i.e., with increasing shear stress there appeared to be a delay in bacterial attachment, i.e., at 55, 120, 150, and 155 min for 0.03, 0.60, 2.15, and 4.30 Pa, respectively. CLSM confirmed marked variations in colony architecture, i.e.,: (i) lower shear stresses resulted in biofilms with distinctive morphologies mainly characterised by mushroom-like structures, interstitial channels, and internal voids, and (ii) for the higher shear stresses compact clusters with large interspaces between them were formed. The key advantage of the developed microfluidic device is the combination of three architectural features in one device, i.e., an open-system design, channel replication, and multiple fully developed shear stresses.  相似文献   

The time course of the human growth hormone response to a 6 s and a 30 s cycle ergometer sprint     

K.A. Stokes  M.E. Nevill  G.M. Hall  H.K.A. Lakomy 《Journal of sports sciences》2013,31(6):487-494

Exercise is a potent stimulus for the release of human growth hormone (hGH), but the time course of the hGH response to sprint exercise has not been studied. The aim of the present study was to determine the time course of the hGH response to a 6 s and a 30 s maximal sprint on a cycle ergometer. Nine males completed two trials, on one occasion performing a single 6 s sprint and on another a single 30 s sprint. They then rested on a couch for 4 h while blood samples were obtained. Three of the participants completed a further control trial involving no exercise. Metabolic responses were greater after the 30 s sprint than after the 6 s sprint. The highest measured mean serum hGH concentrations after the 30 s sprint were more than 450% greater than after the 6 s sprint (18.5 - 3.1 vs 4.0 - 1.5 w g·l -1 , P ? 0.05). Serum hGH also remained elevated for 90-120 min after the 30 s sprint compared with ~ 60 min after the 6 s sprint. There was a large inter-individual variation in the hGH response to the 30 s sprint. In the control trial, serum hGH concentrations were not elevated above baseline at any time. It would appear that the duration of a bout of maximal sprint exercise determines the magnitude of the hGH response, although the mechanism for this is still unclear.  相似文献   

Effect of combined carbohydrate-protein ingestion on markers of recovery after simulated rugby union match-play     

Simon P. Roberts  Keith A. Stokes  Grant Trewartha  Patrick Hogben  Jenny Doyle  Dylan Thompson 《Journal of sports sciences》2013,31(12):1253-1262

Abstract

In this study, we investigated the effect of ingesting carbohydrate alone or carbohydrate with protein on functional and metabolic markers of recovery from a rugby union-specific shuttle running protocol. On three occasions, at least one week apart in a counterbalanced order, nine experienced male rugby union forwards ingested placebo, carbohydrate (1.2 g · kg body mass^?1 · h^?1) or carbohydrate with protein (0.4 g · kg body mass^?1 · h^?1) before, during, and after a rugby union-specific protocol. Markers of muscle damage (creatine kinase: before, 258 ± 171 U · L^?1 vs. 24 h after, 574 ± 285 U · L^?1; myoglobin: pre, 50 ± 18 vs. immediately after, 210 ± 84 nmol · L^?1; P < 0.05) and muscle soreness (1, 2, and 3 [maximum soreness = 8] for before, immediately after, and 24 h after exercise, respectively) increased. Leg strength and repeated 6-s cycle sprint mean power were slightly reduced after exercise (93% and 95% of pre-exercise values, respectively; P < 0.05), but were almost fully recovered after 24 h (97% and 99% of pre-exercise values, respectively). There were no differences between trials for any measure. These results indicate that in experienced rugby players, the small degree of muscle damage and reduction in function induced by the exercise protocol were not attenuated by the ingestion of carbohydrate and protein.  相似文献   

Measuring gains with standardized tests or flies in the performance contract ointment     

Charles W. Stokes 《Performance Improvement》1971,10(5):5-6

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