bluuebunny/crossref_metadata_2025_split huggingface dataset:
An epizootic of patent iridescent virus disease in multiple species of blackflies in Chiapas, Mexico
Authors: Hernández O. , Maldonado G. , Williams T. 
Published: March 2003

Summary Simulium blackfly larvae (Diptera: Simuliidae) were collected from rivers and streams at 500–1500 m a.s.l. in Chiapas State of southern Mexico. Among 45 sites surveyed over an area of 2300 km2 (around 15°15′ N 92°20′ W), some Simulium larvae from three sites were opalescent violet‐blue, interpreted as patent infection with invertebrate iridescent virus (IIV). Dissection confirmed the presence of putative Iridovirus particles, 130 nm diameter, but no IIV isolates were obtained from homogenates injected into Galleria mellonella (L) larvae (Lepidoptera: Pyralidae). All Simulium with patent IIV infection died before metamorphosis, whereas ∼60% of asymptomatic Simulium survived to adulthood in the laboratory. During 1997, standard monthly samples from two parallel rivers 42–50 km north‐west of Tapachula comprised the following species proportions (and rates of patent IIV infection): 41.8% (47%) Simulium mexicanum Bellardi complex, 31.3% (31.4%) S. rubicundum Knab, 10.1% (13.1%) S. paynei, 6.5% (2.9%) S. callidum (Dyar & Shannon), 6.3% (5.1%) S. ochraceum Walker complex, 3.1% (0.7%) S. downsi Vargas et al. 0.7% S. samboni Jennings and 0.2% S. metallicum Bellardi complex, showing a strong correlation between blackfly abundance and the prevalence of patent infection. An epizootic of IIV in January and February (infection rates 41–100%) was followed by absence of larvae (March–August) until the end of the rainy season, when numbers collected on nylon strings rose to ≈ 1/cm with patent IIV infection rates of 0–12.5% during September–December. Further investigations are underway to isolate this IIV and assess its potential usefulness for biological control of Simulium pests and vectors of onchocerciasis.
Domestic scorpion control with pyrethroid insecticides in Mexico
Authors: Ramsey J. M. , Salgado L. , Cruz‐Celis A. , Lopez R. , Alvear A. L. , Espinosa L. 
Published: March 2003

Abstract Scorpion stings cause more morbidity in Mexico than any other country, leading to about 100 deaths annually. In 1999, the State of Morelos reported nine deaths among 30 663 cases of scorpion sting. To replace lindane used for scorpion control, field trials of pyrethroid pesticides were undertaken in Morelos during 1998–2000 at the village of Chalcatzingo (population initially with 2760 inhabitants and 530 houses).Pre‐intervention surveys detected scorpions (Scorpiones: Buthidae) of two species in the majority of houses: Centruroides limpidus limpidus Karsch outnumbering Vaejovis mexicanus smithi Koch. Scorpion prevalence was assessed, pre‐ and post‐spray, directly by searching (40 min/house) and by householder reports of sightings inside houses. Pre‐intervention perceptions of scorpion abundance were similar for all areas, with sightings in 12–18% of houses, whereas daytime searches detected more infestations in eastern parts of the village (prevalence 17% indoors, 22% outdoors) than in other sectors (9% indoors, 14% outdoors).Pyrethroids were evaluated as residual treatments in separate sectors of Chalcatzingo, with almost complete coverage indoors and peridomestically, using the following four formulations: bifenthrin 10% wettable powder (WP) applied at 50 mg a.i./m2, cyfluthrin 10% WP (Solfac 10 WP) at 44–55 mg a.i./m2, deltamethrin 2.5% suspension concentrate (Biothrin 25 SC) at 11 mg a.i./m2 and 5% WP (K‐Othrine 50 WP) at 35 mg a.i./m2. Phase 1 compared bifenthrin 10 WP, Solfac 10 WP and Biothrin 25 SC sprayed in December 1998; phase 2 compared Solfac 10 WP and K‐Othrine 50 WP sprayed in June and again in December 2000, with follow‐up surveys of scorpions one month post‐spray and subsequently.Scorpion prevalence was reduced by 64–77% peridomestically one month post‐spray and by 83, 46 and 15% in houses sprayed with cyfluthrin WP, bifenthrin WP or deltamethrin SC, respectively. Householder reports of sighting scorpions indoors were 33–85% below pre‐intervention levels. Cumulative effects of the three spray‐rounds over 3 years reduced scorpion prevalence by ∼60% in the deltamethrin WP re‐sprayed area and by ∼90% in the cyfluthrin WP re‐sprayed area. Householder sightings also fell by 67 and 28% in the cyfluthrin and deltamethrin re‐sprayed areas, respectively. Operational efficacy of these products against scorpions at the dosages applied was ranked as cyfluthrin WP > bifenthrin WP > deltamethrin SC > WP. Reported cases of scorpion sting intoxication fell by 17% during this study after having risen by ∼40% over four previous years.
The difference between Japan and other countries, in particular the United Kingdom, in views regarding the teaching of geriatrics to undergraduate medical students
Authors: Matsuse Takeshi , Ozawa Toshio , Orimo Hajime , Fukuchi Yoshinosuke , Ouchi Yasuyoshi , Iriki Masamitsu 
Published: March 2003

ObjectivesTo examine differences in views on geriatrics education at the undergraduate level between Japan and other industrialized countries, including the United Kingdom.DesignWe conducted a nationwide survey of professorial staff responsible for undergraduate education in all medical schools in Japan, and an international survey of 37 medical schools and geriatric institutes in other industrialized countries, including 16 medical schools in the United Kingdom.ResultsThe results indicate that undergraduate education in geriatrics in Japan emphasizes the theoretical aspects of the aging process and the features of diseases in the elderly, and lacks attention to the practical aspects of care. In contrast, geriatrics education in the United Kingdom and other countries places emphasis on practical aspects of the care of the elderly.ConclusionsThe introduction of practical aspects of management and care of the elderly to the undergraduate education programme in geriatrics in each medical school in Japan is strongly recommended. This is especially important to meet the needs of the rapid demographic shift towards an older population in this country.
Does formal approval of educational courses guarantee quality?
Authors: Nicol  , Patterson  
Published: March 2003

ObjectivesTo assess whether organizers of continuing medical education for general practitioners used principles of adult learning when designing their meetings.DesignA questionnaire study of organizers of approved educational meetings for general medical practitioners (GPs).SettingSouth East ScotlandSubjectsOrganizers of educational meetings.ResultsOrganizers often failed to use principles of adult learning in the construction of their meetings. Organizers with prior training in medical education were, however, significantly more likely to adopt these principles.ConclusionsGiven concern about the quality of educational meetings as assessed by their educational impact, formal approval is not an indicator of quality. Postgraduate bodies should use explicit criteria both in the development and approval of continuing educational meetings.
Teaching support in the behavioural sciences for non‐English speaking background medical undergraduates
Authors: Chur‐Hansen  
Published: March 2003

IntroductionThis paper reports on a teaching strategy designed to support first year undergraduate medical students from non‐English speaking backgrounds in a behavioural science course taught at an Australian university.MethodThe strategy is described, as is the language profile of students from two successive cohorts who participated in the teaching programme. The effectiveness of the intervention in improving students’ academic performance is explored, as gauged by summative assessment and student perceptions.ConclusionsFindings suggest that students disadvantaged by difficulties with language and/or knowledge of Australian culture were able to perform at least as well as other students on a number of summative criteria. Non‐English speaking background students perceived the behavioural science course to be difficult, and indicated that they found the teaching support offered to them to be useful. The methodological difficulties and limitations involved in the evaluation of a teaching programme such as this are discussed and the conclusions that can be validly drawn are considered.
Can medical students contribute to quality assurance programmes in day surgery?
Authors: Rudkin Glenda E , O’Driscoll Mary C E , Limb Robin 
Published: March 2003

Subjects and methodsHealth care delivery has undertaken a major shift from inpatient management to ambulatory surgical care with increasing emphasis on quality assurance (QA) processes. Educational opportunities for medical undergraduate programmes are being sought in the day surgery environment. Our study was undertaken to explore ways in which senior medical students can actively contribute to the QA processes as part of an undergraduate day surgery educational programme.Subjects and methodsFifty‐nine final year medical students followed allocated patients with common surgical conditions through all phases of the day surgery process. Students kept records about each case in a log book and also presented their cases at weekly Problem Based Learning tutorials. An audit of student log books and review of tutorial records was conducted for the 1996 and 1997 academic years, in order to evaluate student contribution to QA.ResultsStudents followed 621 cases, representing a sampling of 14·1% day surgery cases. Categories of problems highlighted by students included inappropriate patient and procedure selection, inadequate pain management, discharge, communication and resource issues. Students made a number of recommendations including the development of multilingual videotapes and patient information sheets for non‐English speaking patients, avoidance of bilateral surgical procedures and improved links with local medical officers. They also developed new guidelines and protocols.ConclusionsOur study confirms that students are able to identify QA issues and propose solutions. We recommend that students have a formally recognized place in day surgery QA programmes, to close the QA loop and to adequately prepare them for medical practice in the 21st century.
Population genetics of the yellow fever mosquito in Trinidad: comparisons of amplified fragment length polymorphism (AFLP) and restriction fragment length polymorphism (RFLP) markers
Authors: Yan G. , Romero‐Severson J. , Walton M. , Chadee D. D. , Severson D. W. 
Published: March 2003

AbstractRecent development of DNA markers provides powerful tools for population genetic analyses. Amplified fragment length polymorphism (AFLP) markers result from a polymerase chain reaction (PCR)‐based DNA fingerprinting technique that can detect multiple restriction fragments in a single polyacrylamide gel, and thus are potentially useful for population genetic studies. Because AFLP markers have to be analysed as dominant loci in order to estimate population genetic diversity and genetic structure parameters, one must assume that dominant (amplified) alleles are identical in state, recessive (unamplified) alleles are identical in state, AFLP fragments segregate according to Mendelian expectations and that the genotypes of an AFLP locus are in Hardy–Weinberg equilibrium (HWE). The HWE assumption is untestable for natural populations using dominant markers. Restriction fragment length polymorphism (RFLP) markers segregate as codominant alleles, and can therefore be used to test the HWE assumption that is critical for analysing AFLP data. This study examined whether the dominant AFLP markers could provide accurate estimates of genetic variability for the Aedes aegypti mosquito populations of Trinidad, West Indies, by comparing genetic structure parameters using AFLP and RFLP markers. For AFLP markers, we tested a total of five primer combinations and scored 137 putative loci. For RFLP, we examined a total of eight mapped markers that provide a broad coverage of mosquito genome. The estimated average heterozygosity with AFLP markers was similar among the populations (0.39), and the observed average heterozygosity with RFLP markers varied from 0.44 to 0.58. The average FST (standardized among‐population genetic variance) estimates were 0.033 for AFLP and 0.063 for RFLP markers. The genotypes at several RFLP loci were not in HWE, suggesting that the assumption critical for analysing AFLP data was invalid for some loci of the mosquito populations in Trinidad. Therefore, the results suggest that, compared with dominant molecular markers, codominant DNA markers provide better estimates of population genetic variability, and offer more statistical power for detecting population genetic structure.
Molecular markers linked to breeding system differences in segregating and natural populations of the cereal aphid Rhopalosiphum padi L.
Authors: Simon J.‐C. , Leterme N. , Latorre A. 
Published: March 2003

AbstractThe aphid Rhopalosiphum padi shows coexistence of sexual and asexual populations, providing an opportunity to study the evolution of breeding system variation in the context of theories on the origin and maintenance of sex. However, assessments of the distribution of sexual and asexual lineages of this aphid are complicated by the difficulties in rapidly characterizing their breeding system. To facilitate this task and to gain insight into the genetic relatedness between sexual and asexual genotypes, molecular markers linked to breeding system differences were recently developed. In this study, we have successfully converted a random amplified polymorphic DNA (RAPD) marker associated with life‐cycle variation in R. padi into a codominant sequence‐characterized amplified region (SCAR). Segregating and natural populations of known breeding systems were examined to evaluate the life cycle–SCAR marker association. Complete linkage was found in segregating populations while the association averaged 94% in field populations. Detailed analysis of allelic distribution and sequence divergence of the SCAR locus among sexual and asexual populations provides further evidence for a unique and apparently ancient loss of sexuality in this aphid. It also suggests that occasional gene flow occurs between populations differing in their breeding system, mediated by males produced by ‘asexual’ lineages. This system provides the possibility for the recurrent emergence of new asexual lineages, ensuring the longer persistence of asexuality, and would have important implications for the assessment of costs and benefits of sex in aphids.
Temporal genetic variation of mitochondrial DNA and the female effective population size of red drum (Sciaenops ocellatus) in the northern Gulf of Mexico
Authors: Turner Thomas F. , Richardson Linda R. , Gold John R. 
Published: March 2003

AbstractWe studied genetic drift of mitochondrial DNA (mtDNA) haplotype frequencies in a natural population of red drum (Sciaenops ocellatus) from the northern Gulf of Mexico (Gulf). The amount of genetic drift observed across temporally adjacent year classes (1986–89) was used to estimate variance effective (female) population size (Nef). Nef was estimated to be 14 308 and the ratio of female effective size to adult female census size was approximately 0.004, which is among the lowest value reported for vertebrate animals. Low effective size relative to census size among red drum in the northern Gulf may result from yearly fluctuations in the number of breeding females, high variance in female reproductive success, or both. Despite low genetic effective size relative to census size, the genetic effective population size of red drum in the northern Gulf appears sufficiently large to preclude potentially deleterious effects of inbreeding.
High level of variation at Abies alba chloroplast microsatellite loci in Europe
Authors: Vendramin G. G. , Degen B. , Petit R. J. , Anzidei M. , Madaghiele A. , Ziegenhagen B. 
Published: March 2003

AbstractBased on two polymorphic chloroplast microsatellites that had been previously identified and sequence characterized in the genus Abies, genetic variation was studied in a total of 714 individuals from 17 European silver fir (Abies alba Mill.) populations distributed all over the natural range. We found eight and 18 different length variants at each locus, respectively, which combined into 90 different haplotypes. Genetic distances between most populations were high and significant. There is also evidence for spatial organization of the distribution of haplotypes, as shown by permutation tests, which demonstrate that genetic distances increase with spatial distances. A large heterogeneity in levels of diversity across populations was observed. Furthermore, there is good congruence in the levels of allelic richness of the two loci across populations. The present organization of levels of allelic richness across the range of the species is likely to have been shaped by the distribution of refugia during the last glaciation and the subsequent recolonization processes.
A mitochondrial marker for red algal intraspecific relationships
Authors: Zuccarello G. C. , Burger G. , West J. A. , King R. J. 
Published: March 2003

AbstractIntraspecific studies of red algae have relied on nuclear or plastid markers rather than mitochondrial data to address questions of systematics, biogeography or population genetics. In this study, primers were developed that spanned the noncoding intergenic region between the mitochondrial cytochrome oxidase subunit 2 and cytochrome oxidase subunit 3 genes. These primers were demonstrated to be successful on a variety of red algae in different orders: Gracilariales, Bonnemaisoniales and Ceramiales (families: Delesseriaceae, Ceramiaceae and Rhodomelaceae). Amplification products were between 450 and 320 bp in length, with variation in length shown among geographically distant isolates within a species. The region was variable within a single species, as shown for Bostrychia moritziana and B. radicans, and within populations of Caloglossa leprieurii. In the latter species, four mitochondrial haplotypes were observed in isolates from a single locality in Woolooware Bay, New South Wales, Australia. Analysis of hybrids between different mitochondrial haplotypes of B. moritziana revealed that the mitochondria are maternally inherited in this species. This is the first report of a mitochondrial marker that is variable within red algal populations and may lead to a better understanding of the population ecology of these important marine organisms.
Genetic structure of the world’s polar bear populations
Authors: Paetkau D. , Amstrup S. C. , Born E. W. , Calvert W. , Derocher A. E. , Garner G. W. , Messier F. , Stirling I. , Taylor M. K. , Wiig Ø. , Strobeck C. 
Published: March 2003

AbstractWe studied genetic structure in polar bear (Ursus maritimus) populations by typing a sample of 473 individuals spanning the species distribution at 16 highly variable microsatellite loci. No genetic discontinuities were found that would be consistent with evolutionarily significant periods of isolation between groups. Direct comparison of movement data and genetic data from the Canadian Arctic revealed a highly significant correlation. Genetic data generally supported existing population (management unit) designations, although there were two cases where genetic data failed to differentiate between pairs of populations previously resolved by movement data. A sharp contrast was found between the minimal genetic structure observed among populations surrounding the polar basin and the presence of several marked genetic discontinuities in the Canadian Arctic. The discontinuities in the Canadian Arctic caused the appearance of four genetic clusters of polar bear populations. These clusters vary in total estimated population size from 100 to over 10 000, and the smallest may merit a relatively conservative management strategy in consideration of its apparent isolation. We suggest that the observed pattern of genetic discontinuities has developed in response to differences in the seasonal distribution and pattern of sea ice habitat and the effects of these differences on the distribution and abundance of seals.
Amplified fragment length polymorphism (AFLP) markers reveal that population structure of triploid dandelions (Taraxacum officinale) exhibits both clonality and recombination
Authors: Van Der Hulst R. G. M. , Mes T. H. M. , Den Nijs J. C. M. , Bachmann K. 
Published: March 2003

AbstractHighly variable amplified fragment length polymorphism (AFLP) fingerprints of triploid apomictic dandelions obtained from three localities in an area where diploids are lacking were analysed to infer the predominant modes of reproduction. The distribution of markers was analysed using character compatibility to infer whether many genotypes agree with a tree‐like structure in the data set. The presence of incompatible character state combinations (matrix incompatibility; MI) was used as a measure of genetic exchange. The detection of overrepresented genotypes, of which some were widespread, confirmed asexual reproduction. Not all genotypes were overrepresented; approximately half of the genotypes in the three localities were found only once. Because, in terms of genotype frequencies, only a part of the genetic variation is described, more important aspects of the molecular data such as relationships between markers or genotypes have been studied. The analysis of character compatibility indicated a disagreement of the data with a clonal structure. Nearly all genotypes contributed to MI and this contribution varied considerably among genotypes in each sampled locality. A gradual decrease of matrix incompatibility upon successive deletion of genotypes showing the highest contribution to MI indicated that marker distribution of virtually all genotypes disagreed with a tree‐like structure in the data. This result suggested that many genotypes were separated by one or more sexual generations. Consistent with this conclusion was the fact that markers that show a low probability of contributing to MI are different in every sampled locality, which is most easily explained as the result of recombination. Apparently, asexual reproduction has resulted in overrepresented, widespread genotypes but sexual recombination has also substantially contributed to genetic variation in the sites studied.
Multiple paternity in side‐neck turtlesPodocnemis expansa: evidence from microsatellite DNA data
Authors: Valenzuela N. 
Published: March 2003

AbstractMultiple paternity was found in two clutches ofPodocnemis expansausing eight microsatellite loci. When loci were analysed separately a minimum of two males was estimated for nest N23, and three for nest C17. When all loci were combined, three patrilines were detected in N23, and six in C17. The distribution of full‐sib cluster sizes indicated a disproportionate contribution of one male to clutch C17, consistent with possible sperm competition, or the mixing of leftover and newly acquired sperm. High mutation rates were detected at several loci. Multiple paternity has positive implications for this endangered species as it may slow the loss of genetic variability caused by drift. This is the first report of multiple paternity in the suborder Pleurodira.