bluuebunny/crossref_metadata_2025 huggingface dataset:
The use of marked bait in studies of the territorial organization of the European Badger (Meles meles)
Authors: Delahay R. J. , Brown J. A. , Mallinson P. J. , Spyvee P. D. , Handoll D. , Rogers L. M. , Cheeseman C. L.
Published: March 2003

Bait‐marking is a widely used technique for determining the territorial configuration of social groups of the European Badger (Meles meles). Applications include ecological research and applied wildlife management problems. Bait laced with indigestible plastic pellets is fed to Badger social groups, and the markers are identified in subsequent defecations. Feeding a unique colour and/or shape of pellet to each social group allows the origin of droppings to be assigned. This method is particularly suited to Badgers because they mark their territorial boundaries with communal latrines. In this paper the technique is described in detail for the first time in the scientific literature. Data from sequential visits to latrines during the survey period showed significant short‐term variation in the number of marked droppings counted at individual latrines. This suggests that counting marked droppings may be of limited value in quantifying defecation rates and latrine use. However, counts of droppings at latrines could be useful if repeated over time and/or grouped into broad categories. Bait marking does provide reliable data for the estimation of territorial boundaries between Badger groups, although it is labour intensive and time‐consuming, with the best results obtained by experienced fieldworkers.
Lessons from lean beasts: conservation biology of the mustelids
Authors: Bright Paul W.
Published: March 2003

What features of the mustelids might yield insight into issues of general importance for conservation and ecology? This review focuses attention on correlates of threat, intra‐guild competition and reintroductions. Using the IUCN classification of the status of mustelid species, I constructed a statistical model of correlates of threat. This suggested that otters and martens, and mustelids with small distributional range sizes, were the most threatened. Whether or not a species was hunted and its habitat specificity did not correlate with threat. This analysis should be treated as indicative only, because the response variable (threat) was not totally independent of the explanatory variables. There is growing evidence that intra‐guild predation influences mustelids. In Scotland, there is some evidence for spatial segregation between Pine Martens and Red Foxes (a potential predator). Pine Marten relative abundance was higher in woodland interior than woodland edge. Red Foxes were equally abundant in woodland edge and interior. However, habitat fragmentation (woodland patch size) was the strongest correlate of relative abundance of both species. Research on mustelids has demonstrated the importance of appropriate release techniques during reintroductions. It has also shown that reintroductions of small numbers of animals can be successful, provided that they are conducted in high quality habitats. The implication is that habitat suitability assessments need to be given high priority. In this respect, research in Britain suggests that inferring habitat needs from areas of relict distribution may lead to highly misleading conclusions.
Mosquito density, biting rate and cage size effects on repellent tests
Authors: BARNARD DONALD R. , POSEY KENNETH H. , SMITH DANIEL , SCHRECK CARL E.
Published: March 2003

Mosquito biting rates and the mean duration of protection (in hours) from bites (MDPB) of Aedes aegypti and Anopheles quadrimaculatus, using the repellent ‘deet’ (N,N‐diethyl‐3‐methylbenzamide) on a 50 cm2 area of healthy human skin, were observed in small (27 l), medium (≈65 l) and large (125 l) cages containing low, medium or high densities of mosquitoes: respectively, 640, 128 or 49 cm3 of cage volume per female. At the initial treatment rate of ≈ 0.4 μl/cm2 (1 ml of 25% deet in ethanol on 650 cm2 of skin), the MDPB for deet against Ae.aegypti ranged from 4.5 to 6.5 h and was significantly less (5.0 ± 0.8 h) in large cages compared with medium (6.2 ± 0.9 h) and small (6.2 ± 0.8 h) cages, regardless of the density. Against An.quadrimaculatus the MDPB for deet 0.4 μl/cm2 was 1.5–8.0 h, less in small (3.7 ± 2.3 h) and large (2.2 ± 1.1 h) cages at medium (3.7 ± 2.3 h) and high (2.5 ± 1.7 h) mosquito densities, and was longest in medium cages (6.2 ± 2.6 h) at low mosquito densities (5.8 ± 2.8 h). With equinoxial photoperiodicity (light on 06.00–18.00 hours) the biting rate was influenced by the time of observation (08.00, 12.00, 16.00 hours) for Ae.aegypti but not for An.quadrimaculatus. For both species, the biting rate was inversely proportional to mosquito density and the MDPB. The shortest MDPBs were obtained in large cages with high densities of mosquitoes and longest protection times occurred in medium sized cages with low mosquito densities.
Genetics of refractoriness to Plasmodium falciparum in the mosquito Anopheles stephensi
Authors: FELDMANN  , VAN GEMERT GEERT‐JAN , VAN DE VEGTE‐BOLMER MARGA G. , JANSEN RITSERT C.
Published: March 2003

We previously selected a line of the malaria vector mosquito Anopheles stephensi refractory (resistant) to the human malaria parasite Plasmodium falciparum, using in vitro infections with P. falciparum gametocytes. This report presents data on the genetic background of refractoriness. The results of F1‐crosses and backcrosses show that refractoriness to P. falciparum in our A. stephensi line is autosomal and semi‐dominant to susceptibility. The expression of refractoriness is apparently affected by a cytoplasmic factor. Interpretation of data from the crosses by quantitative trait locus analysis shows that one gene or two unlinked interacting autosomal genes, or groups of closely linked genes, are involved.
Pteridine fluorescence for age determination of Anopheles mosquitoes
Authors: Wu D. , Lehane M. J.
Published: March 2003

The age structure of mosquito populations is of great relevance to understanding the dynamics of disease transmission and in monitoring the success of control operations. Unfortunately, the ovarian dissection methods currently available for determining the age of adult mosquitoes are technically difficult, slow and may be of limited value, because the proportion of diagnostic ovarioles in the ovary declines with age. By means of reversed‐phase HPLC this study investigated the malaria vectors Anopheles gambiae and An. stephensi to see if changes in fluorescent pteridine pigments, which have been used in other insects to determine the age of field‐caught individuals, may be useful for age determination in mosquitoes. Whole body fluorescence was inversely proportional to age (P < 0.001, r2 > 91%) up to 30 days postemergence, with the regression values: y = 40580–706x for An. gambiae, and y = 52896–681x for An. stephensi. In both species the main pteridines were 6‐biopterin, pterin‐6‐carboxylic acid and an unidentified fluorescent compound. An. gambiae had only 50–70% as much fluorescence as An. stephensi, and fluorescent compounds were relatively more concentrated in the head than in the thorax (ratios 1 : 0.8 An. gambiae; 1 : 0.5 An. stephensi). The results of this laboratory study are encouraging. It seems feasible that this simpler and faster technique of fluorescence quantification could yield results of equivalent accuracy to the interpretation of ovarian dissection. A double‐blind field trial comparing the accuracy of this technique to marked, released and recaptured mosquitoes is required to test the usefulness of the pteridine method in the field.
Evaluation of insecticide‐treated cattle as a barrier to re‐invasion of tsetse to cleared areas in northeastern Zimbabwe
Authors: Warnes M. L. , Van Den Bossche P. , Chihiya J. , Mudenge D. , Robinson T. P. , Shereni W. , Chadenga V.
Published: March 2003

A field trial in Zimbabwe investigated the efficacy of insecticide‐treated cattle as a barrier to prevent the re‐invasion of tsetse, Glossina morsitans and G. pallidipes (Diptera: Glossinidae), into cleared areas. The original tsetse barrier consisted of insecticide‐treated odour‐baited targets, at an operational density of four to five targets per km2, supported by insecticide‐treatments of cattle with either deltamethrin dip (Decatix®, Coopers) at two‐weekly intervals, or deltamethrin pour‐on (Spoton®, Coopers) at monthly intervals, in a band ≈ 20 km wide from the re‐invasion front. Tsetse catch, and trypanosomiasis incidence in nine sentinel herds was recorded for 7–8 months, respectively, before the targets were removed, leaving only the insecticide treatment of the local cattle to stem the re‐invasion of tsetse.

After the removal of the target barrier, the tsetse readily invaded the trial area and the incidence of trypanosomiasis in sentinel herds increased, while their PCVs decreased. After seven months without the targets in place, trypanosomiasis prevalence in the local stock had reached alarmingly high levels; the trial was terminated prematurely and the target barrier re‐deployed. Immediately after the re‐deployment of the target barrier, the tsetse catch in the trial area reverted to acceptable levels along the re‐invasion front, and trypanosomiasis incidence in the sentinel cattle decreased.

It is concluded that, under the conditions of the field trial, the insecticidal treatment of local cattle did not in itself form an effective barrier to tsetse re‐invasion. By contrast, the target barrier performed as was predicted by mathematical and experimental analysis, and readily cleared the tsetse infestation and reduced trypanosomosis incidence in the trial area.
Risk factors in habitats of the tickIxodes ricinusinfluencing human exposure toEhrlichia phagocytophilabacteria
Authors: Walker A. R. , Alberdi M. P. , Urquhart K. A. , Rose H.
Published: March 2003

Ixodes ricinusL. (Acari: Ixodida) were sampled during 1996–99 in southern Scotland, on vegetation using cloth drags, on humans by removal from clothing and on roe deer (Capreolus capreolusL.) by searching legs of culled deer. Developmental microclimate was recorded by automatic recorders and questing microclimate by portable instruments during tick collections. Ticks and deer were examined for infection withEhrlichia phagocytophilabacteria (Rickettsiales) using microscopy and polymerase chain reaction. This pathogen causes tick‐borne fever of sheep in Europe and human granulocytic ehrlichiosis in North America, but in Europe human clinical ehrlichiosis due toE. phagocytophilahas not been recorded despite serological evidence of exposure.

Among three types of habitat, coniferous woodland was most infested with questing ticks (560 ticks/km of drag; mean numbers collected on long trousers: 24.3 larvae, 13.5 nymphs and 0.8 adult ticks/km walked), deciduous woodland had slightly lower infestation (426 ticks/km drag) and upland sheep pasture had much lower infestation (220 ticks/km drag). Of the three main vegetation types, bracken was least infested (360 ticks/km drag), ericas most (430 ticks/km drag) and grassland had intermediate infestation density (413 ticks/km drag). Questing and developmental microclimates were poor predictors of exposure within these habitats, except lower infestation of pastures was attributed to greater illumination there. Collectors who walked a total of 300 km through all habitats (taking 360 h in all seasons), wearing cotton trousers hanging outside rubber boots, were bitten by only four nymphs and 11 larvae ofI. ricinus(but no adult ticks). There was a negative correlation between densities of deer and ticks collected, although presence of deer remains a major indicator of exposure.

The proportion of infected ticks was fairly uniform at four sites studied. Overall prevalence ofE. phagocytophilainI. ricinuswas 3.3% in nymphs (40/1203) but only ∼1.5% in adults of both sexes (although males do not bite). It was estimated that nymphs ofI. ricinusgave 4.4% probability of one infected bite/person/year (for occupational exposure during this research) due to presence in all seasons and habitats, their human biting rate of 0.011 nymphs/h or 0.013 nymphs/km and widespread infection withE. phagocytophila.The frequency distribution of intensity of infection in ticks was approximately normal (mean 98 morulae/nymph infected), thus there is a high risk of receiving a high dose from any one infected tick bite.
Dipsticks for rapid detection of Plasmodium in vectoring Anopheles mosquitoes
Authors: Ryan J. R. , Dave K. , Emmerich E. , Garcia L. , Yi L. , Coleman R. E. , Sattabongkot J. , Dunton R. F. , Chan A. S. T. , Wirtz R. A.
Published: March 2003

Abstract. Malaria remains the most serious vector‐borne disease, affecting some 300–500 million people annually, transmitted by many species of Anopheles mosquitoes (Diptera: Culicidae). Monoclonal antibodies developed against specific circumsporozoite (CS) proteins of the main malaria parasites Plasmodium falciparum and P. vivax have been used previously for enzyme‐linked immunosorbent assays (ELISA), widely employed for detection of malaria sporozoites in vector Anopheles for local risk assessment, epidemiological studies and targeting vector control. However, ELISA procedures are relatively slow and impractical for field use. To circumvent this, we developed rapid wicking assays that identify the presence or absence of specific peptide epitopes of CS protein of the most important P. falciparum and two strains (variants 210 and 247) of the more widespread P. vivax. The resulting assay is a rapid, one‐step procedure using a ‘dipstick’ wicking test strip. In laboratory assessment, dipsticks identified 1 ng/mL of any of these three CS protein antigens, with sensitivity nearly equal to the CS standard ELISA. We have developed and are evaluating a combined panel assay that will be both qualitative and quantitative. This quick and easy dipstick test (VecTest™ Malaria) offers practical advantages for field workers needing to make rapid surveys of malaria vectors.
Personal protection against mosquitoes in Dar es Salaam, Tanzania, by using a kerosene oil lamp to vaporize transfluthrin
Authors: PATES H. V. , LINES J. D. , KETO A. J. , MILLER J. E.
Published: March 2003

Abstract The effectiveness of a cheap and easy method of household protection against Culex quinquefasciatus Say and other mosquitoes (Diptera: Culicidae) was investigated in Dar es Salaam, Tanzania. Kerosene‐burning lamps (korobois) were modified to heat and vaporize transfluthrin, a volatile pyrethroid insecticide. When transfluthrin was added to fuel of the lamp, protection against biting was poor unless a very high concentration of insecticide was used. A modified lamp (= vaporizing koroboi) was designed to overcome this problem by mixing the insecticide with vegetable oil and heating it to 120 °C in a tin held just above the flame. The concentration of 0.1% transfluthrin in vegetable oil gave 50–75% reduction in biting, a similar degree of protection to that obtained from burning a mosquito coil containing a synthetic pyrethroid (0.25% d‐allethrin) and significantly better protection than a locally bought coil (brand ‘White Crane’, probably containing DDT). Greater protection (consistently > 90%) was achieved with a higher concentration of transfluthrin (0.5%) in the vegetable oil. This modified lamp is simple, cheap and employs locally available technology. With further development, and due regard to inhalation toxicity of the vaporized materials, it may offer a more cost‐effective alternative to a mosquito coil as a means of personal protection, and a useful complement to a net for the early part of the evening before bedtime.
Presence of Anopheles culicifacies B in Cambodia established by the PCR‐RFLP assay developed for the identification of Anopheles minimus species A and C and four related species
Authors: VAN BORTEL W. , SOCHANTA T. , HARBACH R. E. , SOCHEAT D. , ROELANTS P. , BACKELJAU T. , COOSEMANS M.
Published: March 2003

Abstract A polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP) assay developed for identification of five species of the Anopheles minimus Theobald group and a related mosquito species of the Myzomyia Series (Diptera: Culicidae) was applied to morphologically identified adult female specimens collected in Ratanakiri Province, north‐eastern Cambodia. In addition to finding An. aconitus Dönitz, An. minimus species A and An. pampanai Büttiker & Beales, some specimens showed a new restriction banding pattern. Siblings of specimens that exhibited this new PCR‐RFLP pattern were morphologically identified as An. culicifacies James sensu lato. Based on nucleotide sequences of the ribonuclear DNA internal transcribed spacer 2 region (ITS2) and the mitochondrial cytochrome oxidase I gene (COI), these specimens were recognized as An. culicifacies species B (sensuGreen & Miles, 1980), the first confirmed record of the An. culicifacies complex from Cambodia. This study shows that the PCR‐RFLP assay can detect species not included in the initial set‐up and is capable of identifying at least seven species of the Myzomyia Series, allowing better definition of those malaria vector and non‐vector anophelines in South‐east Asia.
Dermatitis in humans associated with the mites Pyemotes tritici, Dermanyssus gallinae, Ornithonyssus bacoti and Androlaelaps casalis in Israel
Authors: Rosen S. , Yeruham I. , Braverman Y.
Published: March 2003

Abstract Multiple erythematous papules accompanied by severe pruritus were observed in humans bitten by the mites (Acari) Pyemotes tritici (Newport) (Pyemotidae), Dermanyssus gallinae (De Geer) (Dermanyssidae), Ornithonyssus bacoti Hirst (Macronyssidae) and Androlaelaps casalis (Berlese) (Laelapidae). Eight case histories are presented and the impact of these species on human health is discussed.
Transmission dynamics of lymphatic filariasis: density‐dependence in the uptake ofWuchereria bancroftimicrofilariae by vector mosquitoes
Authors: Snow L. C. , Michael E.
Published: March 2003

AbstractGaining a better understanding of parasite infection dynamics in the vector mosquito (Diptera: Culicidae) population is central to improving knowledge regarding the transmission, persistence and hence control of lymphatic filariasis. Here, we use data on mosquito feeding experiments collated from the published literature to examine the available evidence regarding the functional form of the first component of this parasite–vector relationship forWuchereria bancrofti(Filarioidea: Onchocercidae) causing Bancroftian filariasis, i.e. the rate of microfilariae (mf) uptake from the blood of infected humans by the feeding mosquito vector. Using a simple logarithmic regression model for describing the observed relationships between the mean numbers of mf ingested per mosquito and parasite load in humans in each study, and a linear mixed‐effects meta‐analytical framework for synthesizing the observed regressions across studies, we show here for the first time clear evidence for the existence of density‐dependence in this process for all the three major filariasis transmitting mosquito vectors. An important finding of this study is that this regulation of mf uptake also varies significantly between the vector genera, being weakest inCulex, comparatively stronger inAedesand most severe and occurring at significantly lower human mf loads inAnophelesmosquitoes. The analysis of the corresponding mf uptake prevalence data has further highlighted how density‐dependence in mf uptake may influence the observed distributions of mf in vector populations. These results show that whereas strong regulation of mf uptake, especially when it leads to saturation in uptake at low human parasite intensities, can lead to static distributions of mf per mosquito with host parasite intensity, a weaker regulation of mf ingestion can give rise to changes in both mean mf loads and in the frequency distribution of parasites/mosquito with increasing human parasite intensity. These findings highlight the importance of considering local vector infection dynamics when attempting to predict the impacts of community‐based filariasis control. They also emphasize the value of developing and applying robust meta‐analytic methods for estimating functional relationships regarding parasitic infection from population ecological data.
Resourcing innovative teaching of audit – models, methods and MAAGs
Authors: Howe  , Purkiss
Published: March 2003

Audit is an important part of clinical practice, and has been promoted as a core aspect of undergraduate and postgraduate medical education. Few examples of how audit is taught in the undergraduate curriculum exist. This article presents a model for student teaching using innovative methods, which include an extended role for teaching and learning support from Medical Audit Advisory Group staff. This may be a unique arrangement in the UK. We recommend this approach as using skilled resources effectively and encouraging a positive learning experience for students, which should contribute to their motivation and ability to carry out audit at postgraduate level.
An exploratory student learning model of clinical diagnosis
Authors: Meyer  , Cleary
Published: March 2003

This paper investigates how students vary in their conception and engagement of the diagnostic process. The research question is whether it is possible to isolate appropriate sources of variation that are sufficiently psychometrically and conceptually robust for modelling purposes. Eleven such sources of variation are reported, together with an associated common‐factor empirical model that is readily interpretable in conceptual terms.
Experiences and career intentions of general practice registrars from the Netherlands
Authors: Pitts John , Holloway Immy , Holloway Jill , Attwood Margareth , Percy David , Kooij Lourens
Published: March 2003

For some years prospective general practitioners (GPs) from the Netherlands have come to Britain to complete their training. Not all report enjoying their time here, and many leave this country after training. The aim of this study was to examine reasons for coming to Britain, experiences, perceptions and career intentions. The sample consisted of 14 general practice registrars working in their practice year in Southern England. Data were collected through in‐depth semistructured interviews and analysed by thematic qualitative analysis. The main reasons for training in this country were easier access, a quicker route to specialization and the quality of training provided. Most had positive professional and personal experiences and saw the British system of training GPs as up to date and supportive of their educational and professional needs. They highlighted some of the positive aspects of the British system, such as the emphasis on teamwork and collaboration with other primary care professionals. They did, however, point out problems and conflicts; for instance, they saw the health care system in Britain as more bureaucratic and as providing unequal access for different groups of the population. Despite their fear of litigation, which they saw as one of the drawbacks for British general practitioners, most looked favourably on the option of staying in or returning to this country if possible. All registrars valued their stay in Britain; however, personal circumstances often dictated a return to Holland. Our findings have implications for manpower planning and recruitment for general practice in both Britain and Holland.
The effect of a ‘don't know’ option on test scores: number‐right and formula scoring compared
Authors: Muijtjens  , Mameren H van , Hoogenboom  , Evers  , Vleuten C P M van der
Published: March 2003

Objectives

In multiple‐choice tests using a `don't‐know' option the number of correct minus incorrect answers was used as the test score (formula scoring) in order to reduce the measurement error resulting from random guessing. In the literature diverging results are reported when comparing formula scoring and number‐right scoring, the scoring method without the don't‐know option.

Design

To investigate which method was most appropriate, both scoring methods were used in true–false tests (block tests) taken at the end of a second‐ and third‐year educational module (block). The students were asked to answer each item initially by choosing from the response options true, false or don't know, and secondly to replace all don't‐know answers by a true–false answer.

Setting

Maastricht University, The Netherlands.

Subjects

Medical students.

Results

The correct scores for the don't‐know answered items were found to be 4·5% and 5·9%, respectively, higher than expected with pure random guesswork. This represents a source of bias with formula scoring, because students who were less willing to guess obtained lower scores. The average difference in the correct minus incorrect score for the two scoring methods (2·5%, P < 0·001, and 3·4%, P < 0·001, respectively) indicates the size of the bias (compare: the standard deviation of the score equals 11%). Test reliability was higher with formula scoring (0·72 vs. 0·66 and 0·74 vs. 0·66), but the difference decreased when the test was restricted to items which were close to the core content of the block (0·81 vs. 0·77, resp. 0·75 vs. 0·70).

Conclusions

In deciding what scoring method to use, less bias (number‐right scoring) has to be weighed against higher reliability (formula scoring). Apart from these psychometric reasons educational factors must be considered.
Assessment of general practitioners by video observation of communicative and medical performance in daily practice: issues of validity, reliability and feasibility
Authors: Ram  , Grol  , Rethans  , Schouten  , Vleuten  , Kester
Published: March 2003

Objectives

To develop a video assessment method for General Practitioners (GPs) by analysing issues of validity, reliability and feasibility of observation of videotaped regular consultations.

Design

In a cross‐sectional study consultations of 93 GPs were video recorded in the practice during 1 week. The GPs registered consultation and patient data in a logbook; 16 consultations per GP were selected using preset criteria. The quality of communicative and medical performance of these consultations was assessed by GP observers with a validated instrument. The validity of the procedure was evaluated by checking the content of each GP’s sample using specific sample criteria. Selection bias was estimated by multiple regression analysis, with sample characteristics as independent variables and scores on communication and medical performance as dependent variables. The influence of observation on GPs and patients was assessed by a questionnaire. Generalizability theory was used to estimate reliability. Feasibility was assessed by conducting a questionnaire, by keeping accounts, and by checking the technical quality of the videotaped consultations.

Setting

Universities of Nijmegen and Maastricht, The Netherlands.

Subjects

General Practitioners (GPs).

Results

The domain of general practice was well covered in the samples; content validity was satisfactory. With regard to the sample characteristics, only the total duration of consultations appeared to correlate significantly with both the score on communication and the score on medical performance. A majority (71%) of GPs reported not being influenced by the observation, except in the first cases, and recognizing their usual daily performance in the videotaped consultations. An acceptable level of reliability was reached after 2·5 hours of observation, i.e. 12 cases by a single observer. The method was well accepted by both GPs and patients. The costs were £250 per GP.

Conclusions

Video assessment of GPs in daily practice according to the procedures described is a valid and reliable method, one which is useful for education and quality improvement. There is a trade‐off between feasibility on one hand and validity, reliability and credibility on the other hand. Compared to investments in observation methods in standardized settings, the costs of video observation of GPs’ actual performance are acceptable.
Gender, sequence of cases and day effects on clinical skills assessment with standardized patients
Authors: Gispert R , Rué M , Roma J , Martinez‐Carretero J M
Published: March 2003

Objective

Clinical skills assessment using standardized patients (SPs) is an accepted method of professional testing, but some factors can threaten the validity of the scores obtained.

Objective

The main objective of this work was to test whether the gender of the patients, the sequence of cases and the day of the examination have any impact on the scores of the examinees.

Materials

Data from examinations conducted at three Medical Schools are used. Each student encountered 10 different SPs (5 men and 5 women).

Methods

Analysis of variance was used to test the existence of association between the variables.

Results

The results showed no significant differences or association between the scores and the three variables analysed.

Conclusions

The results are coherent with the studies that show that performance based examination using SPs can be used without introducing biases into students score.
Teaching clinical reasoning – a preliminary controlled study
Authors: Round A P
Published: March 2003

Background

The formal and explicit teaching of clinical reasoning is rarely undertaken in medical schools despite widespread recognition that knowledge acquisition alone may be insufficient to develop good clinical judgement. Previous work studying the effects of such teaching is inconclusive.

Design and methods

A controlled observational study of 4th year medical students considered the effect of a brief teaching intervention on clinical reasoning skills. A validated measure of clinical reasoning – the diagnostic thinking inventory – was used as the outcome measure.

Results

Students participating in the teaching intervention performed significantly better on the diagnostic thinking inventory than control students.

Conclusion

Further research is necessary to evaluate the long‐term impact of such teaching.
The clinical skills resource: a review of current practice
Authors: Boulay Clair du , Medway Christine
Published: March 2003

This review is based on the findings of the Southampton Clinical Skills Project, which was a needs assessment and feasibility study to consider the development of a multiprofessional Clinical Skills Resource at Southampton. The project spanned a period of 18 months and used a range of methods of data collection, including visits to 12 clinical skills facilities in the UK.

Most existing clinical skills centres have developed in response to changing healthcare policy, curricular initiatives and increasing emphasis on the quality of assessments and competencies. There is also increasing recognition that clinicians are no longer able to teach effectively all skills to students in the traditional ways, and that clinical skills training and assessment, particularly for undergraduates, is an area of deficiency.

The potential scope of clinical skills centres is broad and encompasses not only clinical and communication skills but medical informatics, computer assisted learning, multiprofessional learning and assessment. Skills centres can also promote self directed and lifelong learning methods. The planning of skills centres involves a variety of stakeholders and users, including undergraduates, postgraduates, acute and community Trusts, Postgraduate Deans and medical schools. A successful skills centre needs to be flexible in its design, integral to the curriculum and relevant to educational and training requirements. This requires planning, organization and resources. Different organizational models can be used, depending on local factors.

The management of skills centres involves consideration of issues such as security, safety, supervision of learners and staff development, informed by a network of experts and everyday users. The development of skills centres should include ongoing educational evaluation of outcomes and educational research.

The use of a clinical skills centre has potential benefits for staff and students, including the provision of a safe environment in which to learn and practise skills before using them in the real clinical setting. This can reduce anxiety in students and protect patients from novice practice. Clinical skills centres provide a setting for structured learning with feedback as well as assessment of competence. The limitations of a skills centre are that it can only provide simulated experiences which are an adjunct to, but can never replace real clinical experience.
Education and training in the senior house officer grade: results from a cohort study of United Kingdom medical graduates
Authors: Cooke  , Hurlock
Published: March 2003

Introduction

This paper shows the findings from a survey of 439 senior house officers undertaken as part of the British Medical Association cohort study of 1995 medical graduates. The aim of the study was to assess the quality of senior house officer training in the United Kingdom.

Method

In July 1997 a postal questionnaire was sent to a sample of 545 doctors who graduated from medical school in 1995. Responses were received from 515 (95%). Only those doctors who had worked as a senior house officer in the previous 12 months were included in the analysis (n = 439).

Results

Encouraging results are that 69% of the senior house officers surveyed had discussed their progress directly with their consultant, and 24% rated their supervision by their consultant as ‘excellent’. Of concern are the findings that 47% of respondents did not receive protected teaching time and 16% were unable to take study leave.

Discussion

The study revealed wide variability in the quality of training received by senior house officers in the United Kingdom. Whilst some respondents – notably those in general practice, accident and emergency, paediatrics and psychiatry – had enjoyed a high standard of education and training, it was clear that a minority of posts continue to offer little if any educational value to the post holder. The results point to a need for a more systematic approach to maintaining standards in senior house officer training with greater incentives for under‐performing trusts.
Single paternity of clutches and sperm storage in the promiscuous green turtle (Chelonia mydas)
Authors: FITZSIMMONS N. N.
Published: March 2003

Paternity of 22 green turtle (Chelonia mydas) clutches from 13 females of the southern Great Barrier Reef breeding population was determined through microsatellite analyses at five loci, including the analysis of successive clutches for nine of the females. A large number of alleles per locus (10–40) provided probabilities of detecting multiple paternity that were quite high, particularly at all loci combined (99.9%). Although green turtles are promiscuous breeders and there was an expectation of finding extensive multiple paternity, only two clutches were multiply sired and, in these, very few eggs had been fertilized by a secondary male. The rarity of multiple paternity may reflect either a low proportion of multiple matings by females in this population, or sperm competition, possibly resulting from a first‐male sperm preference. Additionally, the analysis of > 900 offspring provided data on mutations, which included 20 mutation events that were observed in 27 offspring and involved both maternal and paternal lineages. Most mutations (n= 16) occurred at a single highly variable locus and their presence emphasizes the need to use multiple loci in paternity studies.
Spontaneous hybridizations between oilseed rape and wild radish
Authors: DARMENCY H. , LEFOL E. , FLEURY A.
Published: March 2003

The occurence of spontaneous hybridization between Brassica napus (oilseed rape) and Raphanus raphanistrum (wild radish) was investigated under different density conditions in cages and open‐field experiments. Hybrids with wild radish as the seed parent were identified by screening for herbicide resistance belonging to rape. Small seed size and intermediate morphology were used to screen for hybrids with rape as the seed parent. Leaf isozyme patterns and flow cytometry provided confirmation of hybrids. Wild radish in an oilseed rape field produced as many as three interspecific hybrids per 100 plants. This is the first report of such a spontaneous event. The frequency of hybrids is expected to range from 0.006 to 0.2% of the total seed produced, at P = 0.05. Male‐sterile oilseed rape plants surrounded by wild radish can produce up to 37 hybrids per plant. Seed production of the F1 hybrids and their F2 descendants was up to 0.4% and 2%, respectively, of that of wild radish. Gene escape from transgenic oilseed rape to wild related species is discussed.
Genetic differentiation within and between isolated Algerian subpopulations of Barbary macaques (Macaca sylvanus): evidence from microsatellites
Authors: VON SEGESSER F. , MENARD N. , GACI B. , MARTIN R. D.
Published: March 2003

This study of wild‐living Algerian Barbary macaques (Macaca sylvanus) was designed to examine genetic variability in subpopulations isolated in residual forest patches, in an attempt to obtain data on the effects of habitat fragmentation. The wild population of this species (estimated at a maximum of 15 000) is vulnerable and this study therefore has direct relevance for conservation measures. Data from five microsatellite loci were analysed for 159 individuals from nine different groups living in four isolates in Algeria. Genetic polymorphism was found to be relatively high (4–12 alleles per locus) compared with other genetic markers used in previous studies of this species; mean expected heterozygosity was 65%. The four isolates are all genetically distinct (FST = 0; P < 0.001). Indeed, the results suggest that dispersal is limited even between some social groups within a single isolate. Genetic distances based on models not assuming stepwise mutation (FST and chord distance) gave very similar results and are highly correlated with geographical distances within one isolate but not between isolates. This may indicate that isolation by distance exerts a significant influence within an isolate but that genetic drift prevails between the four isolates. After allowing for variation in sample size, we found no evidence of reduced allelic diversity within small isolates that may have been separated for 250 years or more. The surviving population of Algerian Barbary macaques taken as a whole still shows marked variability in microsatellite alleles, but maintenance of genetic variability over the long term will surely require effective protection of all isolates.
Amplified fragment length polymorphism (AFLP) reveals introgression in weedyOnopordumthistles: hybridization and invasion
Authors: O’Hanlon P. C. , Peakall Rod , Briese D. T.
Published: March 2003

OnopordumL. (Compositae) is an extremely diverse genus of thistles, which includes several species that have become serious pasture weeds in several regions of the world. We present a comparison of the genetic diversity in invasive forms ofOnopordumfrom Australia with several known native European species. A total of 108 polymorphic genetic markers was generated using amplified fragment length polymorphism (AFLP) fingerprinting. Non‐metric multidimensional scaling (NMDS) revealed that Australia containedO. acanthium,O. illyricumand a full range of genetic intermediates between these species. Intermediates largely comprised segregating fragments diagnostic for EuropeanO. acanthiumandO. illyricumwith a low frequency of fragments that were diagnostic for other species never recorded in Australia. The current genetic patterns in Australia may be best explained by a combination of processes, both in the native and in the alien range. These include multiple introductions of seed, including hybrid material, and the continuous dispersal in Australia, leading to an increase in the contact among hybridizing taxa. Such processes appear to have produced more widespread hybridization and introgression in AustralianOnopordumthan is found in Europe.
Phylogeography and postglacial dispersion of the chub (Leuciscus cephalus) in Europe
Authors: Durand J. D. , Persat H. , Bouvet Y.
Published: March 2003

A phylogeographic analysis of mitochondrial DNA variation was performed in order to test the hypothesis of a postglacial recolonization of mid‐ and north‐European rivers from a Danubian refuge. Over 345 chub specimens from European rivers covering most of the species’ native range were investigated using 600 bp of the cytochrome b gene. Chub in European rivers belong to four highly divergent mitochondrial groups (lineages) differing by mean divergence estimates from 5.2% to 7.89%. These four lineages have a largely allopatric distribution, implying four geographical sets: two Mediterranean, and two north‐European sets. This pattern provided strong evidence for: (i) the eradication of this species from most of Europe during maximum ice extent; (ii) its survival in four refugia (Adriatic side of the Balkans, eastern Greece (Aegean Rivers), southern tributaries of the Danube, and periphery of Black and Caspian Seas); (iii) a differential postglacial recolonization of mid‐ and northern Europe from the last two refugia only; (iv) the occurrence of this recolonization in two steps for the Danubian (western) lineage that entered western Europe (Rhine–Rhone–Loire drainages) during the Riss–Würm interglacial period and survived the last glaciation there before colonizing Garonne, UK and German drainages up to the Elbe during the Holocene; and (v) the occurrence of this recolonization in a single step for the Ponto‐Caspian (eastern) lineage that entered the Baltic area as far as the Oder in the Holocene. Both lineages came into contact in the River Elbe without evident mixing.
Population genetic structure of the African elephant in Uganda based on variation at mitochondrial and nuclear loci: evidence for male‐biased gene flow
Authors: Nyakaana Silvester , Arctander Peter
Published: March 2003

A drastic decline has occurred in the size of the Uganda elephant population in the last 40 years, exacerbated by two main factors; an increase in the size of the human population and poaching for ivory. One of the attendant consequences of such a decline is a reduction in the amount of genetic diversity in the surviving populations due to increased effects of random genetic drift. Information about the amount of genetic variation within and between the remaining populations is vital for their future conservation and management. The genetic structure of the African elephant in Uganda was examined using nucleotide variation of mitochondrial control region sequences and four nuclear microsatellite loci in 72 individuals from three localities. Eleven mitochondrial DNA (mtDNA) haplotypes were observed, nine of which were geographically localized. We found significant genetic differentiation between the three populations at the mitochondrial locus while three out of the four microsatellite loci differentiated KV and QE, one locus differentiated KV and MF and no loci differentiated MF and QE. Expected heterozygosity at the four loci varied between 0.51 and 0.84 while nucleotide diversity at the mitochondrial locus was 1.4%. Incongruent patterns of genetic variation within and between populations were revealed by the two genetic systems, and we have explained these in terms of the differences in the effective population sizes of the two genomes and male‐biased gene flow between populations.
Spatial and temporal population genetic structure of the butterfly Aglais urticae L. (Lepidoptera, Nymphalidae)
Authors: Vandewoestijne Sofie , Nève Gabriel , Baguette Michel
Published: March 2003

The genetic diversity and the temporal and spatial genetic population structure of the butterfly Aglais urticae, a highly mobile species, were studied by allozyme electrophoresis. High levels of allozyme diversity were found. Most of the total genetic diversity occurred at the within‐population scale rather than at the between‐population scale. This variation could not be accounted for by Wright’s model of ‘isolation by distance’. No significant temporal variation was observed for those populations that were sampled in different years. A process combining high movement rate between neighbouring patches, long‐distance migration and rare extinction/recolonization is suggested to explain the observed genetic structure. This hypothesis is favoured over an island model of population structure because migration in A. urticae is uniform neither with distance nor with time.
A comparison of two indirect methods for estimating average levels of gene flow using microsatellite data
Authors: Gaggiotti O. E. , Lange O. , Rassmann K. , Gliddon C.
Published: March 2003

We compare the performance of Nm estimates based on FST and RST obtained from microsatellite data using simulations of the stepwise mutation model with range constraints in allele size classes. The results of the simulations suggest that the use of microsatellite loci can lead to serious overestimations of Nm, particularly when population sizes are large (N > 5000) and range constraints are high (K < 20). The simulations also indicate that, when population sizes are small (N ≤ 500) and migration rates are moderate (Nm ≈ 2), violations to the assumption used to derive the Nm estimators lead to biased results. Under ideal conditions, i.e. large sample sizes (ns ≥ 50) and many loci (nl ≥ 20), RST performs better than FST for most of the parameter space. However, FST‐based estimates are always better than RST when sample sizes are moderate or small (ns ≤ 10) and the number of loci scored is low (nl < 20). These are the conditions under which many real investigations are carried out and therefore we conclude that in many cases the most conservative approach is to use FST.
Population structure delineated with microsatellite markers in fragmented populations of a tropical tree, Carapa guianensis (Meliaceae)
Authors: Dayanandan S. , Dole J. , Bawa K. , Kesseli R.
Published: March 2003

Deforestation and selective logging in the tropics may have serious consequences on genetic processes in tropical tree populations, affecting long‐term survival of a given species as well as tropical forest communities. Because understanding the effects of human‐induced changes on genetic processes is of utmost importance in formulating sound conservation and management plans for tropical forest communities, we developed microsatellite or simple sequence repeat (SSR) markers for the tropical tree Carapa guianensis (Meliaceae) and assessed the polymorphism of SSRs in adult and sapling populations in a large contiguous forest and in selectively logged and fragmented forests. The number of alleles in polymorphic loci ranged between 4 and 28. No inbreeding was detected in saplings or adult cohorts, but the allelic richness was lower in the sapling cohort of the isolated fragment. Genetic distances, Nei’s D and (δµ)2, and RST values among saplings were greater than among adult cohorts, suggesting restriction of gene flow due to deforestation and habitat fragmentation. These SSR loci may be used to address many related questions regarding the population and conservation genetics of tropical trees.