bluuebunny/crossref_metadata_2025_split huggingface dataset:
Factors associated with success or failure in radiological interpretation: diagnostic thinking approaches
Authors: Peterson Cynthia 
Published: March 2003

Rationale and objectivesTo identify those radiological diagnostic thinking approaches associated with success or failure in film interpretation.MethodsA questionnaire was designed, piloted and tested for validity and reliability prior to use. This questionnaire was adapted and modified from the `diagnostic thinking inventory' by Bordage et al. 21 One hundred and eighty students anonymously answered the questionnaire prior to their 15‐case comprehensive film interpretation examination. Oral film‐reading sessions were performed on a stratified random sample (n = 48) of students with complete transcripts of each session recorded. Spearman's correlation coefficient and multiple regression analysis statistics were applied to the questionnaire data. The unpaired t‐test,
ANOVA and correlation statistics were used to analyse the oral film‐reading sessions.ResultsThe most successful students were those who could easily see the integration of radiology with other subjects (P = 0·0042), students who could easily link the clinical information to the radiographic signs (P = 0·0354), and students who could easily identify the `key' abnormal radiographic findings (P = 0·047). Students who used a flexible but complete search pattern performed significantly better (P = 0·0235) than students using any other search pattern approach.ConclusionsRadiology is a classic example of clinical problem solving and thus should be taught in that format. Those same factors which differentiate expert from novice diagnosticians are also evident in more successful vs. less successful students in radiology.
The core content of the undergraduate curriculum in Manchester
Authors: O'Neil  , Metcalfe  , David  
Published: March 2003

AimTo identify the core content for the new undergraduate medical curriculum in Manchester.MethodThe initial step was to produce a list of `index clinical situations' (ICSs), for which a newly graduated doctor must have a required level of competence. Using repeated consultation with consultants and general practitioners involved in medical education in the North‐West of England, a list of 215 ICSs was agreed. Specialists and generalists were then asked to identify the components of the knowledge base and the performance (skills) base for each ICS. The knowledge base was divided into technical (biomedical facts/concepts) and contextual (effect/management of disease within the individual, family and society) domains. The performance base was divided into intellectual (problem solving and decision making) and interpersonal (history, examination, communication and procedural skills) domains.ResultsForty specialities were consulted and 11 021 items (defined as a piece of knowledge, a concept or a skill) were identified. There was considerable overlap in the items listed, such that when the returns for each ICS were amalgamated, the 215 ICSs contained 6434 items with a mean of 34 ± 14·2 per situation (range 6–85).UtilisationWe have used the defined ICSs in the design of the trigger material used in the weekly problem‐based learning sessions. Over 4 years almost all (207/215, 96%) of the ICS are covered, with many being revisited at several points in the curriculum.
Microsatellite markers and multiple paternity in the garter snake Thamnophis sirtalis
Authors: Mccracken G. F. , Burghardt G. M. , Houts S. E. 
Published: March 2003

AbstractData from four microsatellite loci developed for the common garter snake, Thamnophis sirtalis, show that multiple paternity is common in a natural population on Beaver Island, Michigan. Six of eight litters tested, and all litters with five or more neonates, were multiply sired. At least triple paternity was documented in the largest litter examined (n = 13 neonates). Inheritance patterns and genotype frequencies in the wild population indicate the presence of null allele(s) at one of the microsatellite loci. Garter snakes are widely used in quantitative genetics research, and paternity testing is essential in studies that rely on sibling analysis.
Phylogeographical population structure of tiger quolls Dasyurus maculatus (Dasyuridae: Marsupialia), an endangered carnivorous marsupial
Authors: Firestone K. B. , Elphinstone M. S. , Sherwin W. B. , Houlden B. A. 
Published: March 2003

AbstractTiger quolls, Dasyurus maculatus, are the largest carnivorous marsupials still extant on the mainland of Australia, and occupy an important ecological niche as top predators and scavengers. Two allopatric subspecies are recognized, D.m. gracilis in north Queensland, and D.m. maculatus in the southeast of the mainland and Tasmania. D.m. gracilis is considered endangered while D.m. maculatus is listed as vulnerable to extinction; both subspecies are still in decline. Phylogeographical subdivision was examined to determine evolutionarily significant units (ESUs) and management units (MUs) among populations of tiger quolls to assist in the conservation of these taxa. Ninety‐three tiger quolls from nine representative populations were sampled from throughout the species range. Six nuclear microsatellite loci and the mitochondrial DNA (mtDNA) control region (471 bp) were used to examine ESUs and MUs in this species. We demonstrated that Tasmanian tiger quolls are reciprocally monophyletic to those from the mainland using mtDNA analysis, but D.m. gracilis was not monophyletic with respect to mainland D.m. maculatus. Analysis of microsatellite loci also revealed significant differences between the Tasmanian and mainland tiger quolls, and between D.m. gracilis and mainland D.m. maculatus. These results indicate that Tasmanian and mainland tiger quolls form two distinct evolutionary units but that D.m. gracilis and mainland D.m. maculatus are different MUs within the same ESU. The two marker types used in this study revealed different male and female dispersal patterns and indicate that the most appropriate units for short‐term management are local populations. A revised classification and management plan are needed for tiger quolls, particularly in relation to conservation of the Tasmanian and Queensland populations.
Preserving genes, species, or ecosystems? Healing the fractured foundations of conservation policy
Authors: Bowen Brian W. 
Published: March 2003

AbstractThe scientific foundations of conservation policy are the subject of a recent tripolar debate, with systematists arguing for the primacy of phylogenetic rankings, ecologists arguing for protection at the level of populations or ecosystems, and evolutionary biologists urging more attention for the factors that enhance adaptation and biodiversity. In the field of conservation genetics, this controversy is manifested in the diverse viewpoints of molecular systematists, population biologists, and evolutionary (and quantitative) geneticists. A resolution of these viewpoints is proposed here, based on the premise that preserving particularobjects(genes, species, or ecosystems) is not the ultimate goal of conservation. In order to be successful, conservation efforts must preserve theprocessesof life. This task requires the identification and protection of diverse branches in the tree of life (phylogenetics), the maintenance of life‐support systems for organisms (ecology), and the continued adaptation of organisms to changing environments (evolution). None of these objectives alone is sufficient to preserve the threads of life across time. Under this temporal perspective, molecular genetic technologies have applications in all three conservation agendas; DNA sequence comparisons serve the phylogenetic goals, population genetic markers serve the ecological goals, quantitative genetics and genome explorations serve the evolutionary goals.
Molecular genetic analysis among subspecies of two Eurasian sturgeon species, Acipenser baerii and A. stellatus
Authors: Doukakis P. , Birstein V. J. , Ruban G. I. , DeSalle R. 
Published: March 2003

AbstractTwo species, the Siberian sturgeon, Acipenser baerii, and stellate sturgeon, A. stellatus, were studied using mitochondrial DNA (mtDNA) (D‐loop, cytochrome b (cyt‐b) and ND5/6 genes) sequencing to determine whether traditionally defined subspecies correspond to taxonomic entities and conservation management units. Initially, several mtDNA regions for each taxon (A. baerii: 737 bp D‐loop, 750 bp ND5, 200 bp ND6, and 790 bp cyt‐b;A. stellatus: 737 bp D‐loop and 600 bp ND5) were examined. The D‐loop was the most variable region and was sequenced for 35 A. baerii and 82 A. stellatus individuals. No fixed, diagnostic differences were found between any of the subspecies. Geographical structuring of haplotypes was observed within A. baerii, and gene flow estimates suggest isolation of the A. baerii baicalensis subspecies and the Yenisie and Lena River populations. No intraspecific subdivisioning was found within the genetic data for A. stellatus. The use of the phylogenetic criterion (fixed diagnostic differences) for identifying conservation units is compared to the rationale and results of other methods. Overall, morphologically and geographically based subspecies designations within Acipenseridae may not directly correspond to the biological entities appropriate for management and should not be used for conservation programmes without genetic support.
The genetics of amphibian declines: population substructure and molecular differentiation in the Yosemite Toad, Bufo canorus (Anura, Bufonidae) based on single‐strand conformation polymorphism analysis (SSCP) and mitochondrial DNA sequence data
Authors: Shaffer H. Bradley , Fellers Gary M. , Magee Allison , Voss S. Randal 
Published: March 2003

AbstractWe present a comprehensive survey of genetic variation across the range of the narrowly distributed endemic Yosemite toad Bufo canorus, a declining amphibian restricted to the Sierra Nevada of California. Based on 322 bp of mitochondrial cytochrome b sequence data, we found limited support for the monophyly of B. canorus and its closely related congener B. exsul to the exclusion of the widespread western toad B. boreas. However, B. exsul was always phylogenetically nested within B. canorus, suggesting that the latter may not be monophyletic. SSCP (single‐strand conformation polymorphism) analysis of 372 individual B. canorus from 28 localities in Yosemite and Kings Canyon National Parks revealed no shared haplotypes among these two regions and lead us to interpret these two parks as distinct management units for B. canorus. Within Yosemite, we found significant genetic substructure both at the level of major drainages and among breeding ponds. Kings Canyon samples show a different pattern, with substantial variation among breeding sites, but no substructure among drainages. Across the range of B. canorus as well as among Yosemite ponds, we found an isolation‐by‐distance pattern suggestive of a stepping stone model of migration. However, in Kings Canyon we found no hint of such a pattern, suggesting that movement patterns of toads may be quite different in these nearby parklands. Our data imply that management for B. canorus should focus at the individual pond level, and effective management may necessitate reintroductions if local extirpations occur. A brief review of other pond‐breeding anurans suggests that highly structured populations are often the case, and thus that our results for B. canorus may be general for other species of frogs and toads.
Postsealing genetic variation and population structure of two species of fur seal (Arctocephalus gazella and A. tropicalis)
Authors: Wynen Louise P. , Goldsworthy Simon D. , Guinet Christophe , Bester Marthán N. , Boyd Ian L. , Gjertz Ian , Hofmeyr Greg J. G. , White Robert W. G. , Slade Rob 
Published: March 2003

AbstractCommercial sealing in the 18th and 19th centuries had a major impact on the Antarctic and subantarctic fur seal populations (Arctocephalus gazella and A. tropicalis) in the Southern Ocean. The intensive and unrestricted nature of the industry ensured substantial reductions in population sizes and resulted in both species becoming locally extinct at some sites. However, both species are continuing to recover, through the recolonization of islands across their former range and increasing population size. This study investigated the extent and pattern of genetic variation in each species to examine the hypothesis that higher levels of historic sealing in A. gazella have resulted in a greater loss of genetic variability and population structure compared with A. tropicalis. A 316‐bp section of the mitochondrial control region was sequenced and revealed nucleotide diversities of 3.2% and 4.8% for A. gazella and A. tropicalis, respectively. There was no geographical distribution of lineages observed within either species, although the respective ΦST values of 0.074 and 0.19 were significantly greater than zero. These data indicate low levels of population structure in A. gazella and relatively high levels in A. tropicalis. Additional samples screened with restriction endonucleases were incorporated, and the distribution of restriction fragment length polymorphism (RFLP) and sequence haplotypes were examined to identify the main source populations of newly recolonized islands. For A. tropicalis, the data suggest that Macquarie Island and Iles Crozet were probably recolonized by females from Marion Island, and to a lesser extent Ile Amsterdam. Although there was less population structure within A. gazella, there were two geographical regions identified: a western region containing the populations of South Georgia and Bouvetøya, which were the probable sources for populations at Marion, the South Shetland and Heard Islands; and an eastern region containing the panmictic populations of Iles Kerguelen and Macquarie Island. The latter region may be a result of a pronounced founder effect, or represent a remnant population that survived sealing at Iles Kerguelen.
Postglacial recolonization routes for Picea abies K. in Italy as suggested by the analysis of sequence‐characterized amplified region (SCAR) markers
Authors: Scotti I. , Vendramin G. G. , Matteotti L. S. , Scarponi C. , Sari‐Gorla M. , Binelli G. 
Published: March 2003

AbstractThe routes through which Norway spruce recolonized the Alps after the last ice age were investigated at the genetic level. Seven populations along the Alpine range plus one Apennine population were characterized for seven sequence‐characterized amplified region (SCAR) loci, detecting an overall FST = 0.118. This rather high value for forest species reflects an uneven distribution of genetic variability, and was analysed through different statistical methods. Alternative hypotheses were tested under the isolation‐by‐distance model and using the analysis of molecular variance (
amova) frame. We conclude that the hypothesis of the existence of a glacial refugium in the Apennines should be rejected, while a putative relict population is identified in the Maritime Alps. The Alpine range of Norway spruce appears to be split in two parts across a north–south line. The results are discussed in comparison with data based on morphological markers, isozymes, chloroplast microsatellites and mitochondrial markers.
Matrilineal history of the endangered Cape Sable seaside sparrow inferred from mitochondrial DNA polymorphism
Authors: Nelson William S. , Dean Tylan , Avise John C. 
Published: March 2003

AbstractRestriction analyses were conducted on mitochondrial DNA (mtDNA) amplified by long‐PCR from an endangered bird, the Cape Sable seaside sparrow. The first of several successful mtDNA amplifications was accomplished using the partially digested tissue remains of a transmitter‐monitored bird retrieved from the gut of a snake. As many as 91 mtDNA restriction fragments produced by 18 endonucleases were compared in this and four other Cape Sable specimens against mtDNA similarly amplified by long‐PCR from other taxonomic forms in the seaside sparrow complex. Results indicate that the Cape Sable birds belong to an ‘Atlantic’ matrilineal clade, and are highly divergent from other seaside sparrows along the Gulf of Mexico.
Genetic variation and structure in sixRhododendronspecies (Ericaceae) with contrasting local distribution patterns in Hong Kong, China
Authors: Ng Sai‐Chit , Corlett Richard T. 
Published: March 2003

AbstractGenetic variability of six rhododendrons with contrasting local distribution patterns in Hong Kong was assessed by starch gel electrophoresis.Rhododendron championiae,R. hongkongenseandR. simiarumare locally rare with disjunct distributions,R. moulmainenseis restricted andR. farreraeandR. simsiiare common. For each species, 13–18 allozyme loci representing 12–16 enzyme systems were scored. The six species showed similar levels of genetic variations (HTranged from 0.209 to 0.386 andATranged from 2.4 to 4.1) which are high compared to plants with similar life history traits. Genetic structure, in contrast, varied greatly between species, withFSTranging from 0.056 to 0.393. The three rarest species had high genetic differentiation (FSTandFPT) and distinct geographical patterns, while the other three had low differentiation and little or no geographical structure. These differences are attributed to both present distributions and historical changes following deforestation within the last 1000 years. The conservation implications of these results are discussed.
Comparative avian phylogeography of Cameroon and Equatorial Guinea mountains: implications for conservation
Authors: Smith T. B. , Holder K. , Girman D. , O’Keefe K. , Larison B. , Chan Y. 
Published: March 2003

AbstractWe illustrate the use of Faith’s ‘Phylogenetic Diversity’ measure to compare the phylogeographic structure of two bird species with patterns of avian endemism across six mountains in Cameroon and Equatorial Guinea. The Mountain Greenbul and Cameroon Blue‐headed Sunbird showed phylogeographic patterns that together defined three biogeographic regions: Bioko, Mt. Cameroon, and the northern mountains of Cameroon. In contrast, the distributions of endemic species were largely a function of geographical distance, with close mountains sharing more endemic species than distant mountains. Moreover, for both species, populations on Mt. Cameroon were distinctive with respect to the ecologically relevant character bill size. Our results, while preliminary, illustrate the utility of a comparative approach for identifying geographical regions that harbour evolutionarily distinct populations and caution against using only the distributional patterns of endemics to prioritize regions for conservation. Results show that patterns of endemism may not be concordant with patterns of phylogenetic diversity nor morphological variation in a character important in fitness. While incorporation of additional species from unrelated taxa will be necessary to draw definitive conclusions about evolutionarily distinct regions, our preliminary results suggest a conservation approach for the Afromontane region of the Gulf of Guinea that would: (i) emphasize protection of both Bioko and Mt. Cameroon, thereby maximizing preservation of within–species phylogenetic and morphologic diversity; (ii) emphasize protection within the northern mountains to further conserve intraspecific phylogenetic diversity and maximize protection of endemic species.
Genetic evidence for a family structure in stable social aggregations of the Australian lizard Egernia stokesii
Authors: Gardner M. G. , Bull C. M. , Cooper S. J. B. , Duffield G. A. 
Published: March 2003

AbstractIn this study we used data from six unlinked microsatellite loci to examine stable aggregations of Egernia stokesii, from a population in the southern Flinders Ranges of South Australia. We show that these aggregations are comprised of breeding partners, their offspring from two or more cohorts, and related adults, providing the first genetic evidence of a family structure in any lizard species. Despite this high level of relatedness within aggregations, most breeding pairs were unrelated and partners were less closely related to each other than they were to other potential within‐group partners. Where individuals dispersed, both sexes usually moved to social groups close to their natal group. Although both sexes showed natal philopatry, there was some evidence that females in groups were more related than males in groups. These data suggest that an active choice of unrelated partners and male‐biased dispersal may be the mechanisms used by E. stokesii to avoid inbreeding within groups.
Mitochondrial DNA, ecology and morphology: interpreting the phylogeography of the Nesotes (Coleoptera: Tenebrionidae) of Gran Canaria (Canary Islands)
Authors: Rees D. J. , Emerson B. C. , Oromí P. , Hewitt G. M. 
Published: March 2003

AbstractThe genus Nesotes (Coleoptera: Tenebrionidae) is represented in the Canary Islands by 19 endemic species, the majority of which are single island endemics. Nesotes conformis and N. fusculus are described on four and three islands, respectively, but each forms a paraphyletic assemblage between Gran Canaria and the other islands. The other described species for Gran Canaria are N. quadratus, N. lindbergi and N. piliger. Thirty‐six individuals representing the five species on Gran Canaria have been sequenced for 675 bp of the mitochondrial DNA (mtDNA) cytochrome oxidase II gene. Neighbour‐joining analysis of maximum likelihood distances resulted in five distinct mtDNA lineages for N. quadratus, two of which also include mitotypes of N. conformis. Each of the other three species is found on only one mtDNA lineage. We propose from the molecular data that differentiation in a widespread N. quadratus‐type ancestor was followed by morphological adaptation to coastal, pine and laurel forest habitats.
Haplotype variation in a mitochondrial tandem repeat of Norway spruce (Picea abies) populations suggests a serious founder effect during postglacial re‐colonization of the western Alps
Authors: Gugerli Felix , Sperisen Christoph , Büchler Urs , Magni Federica , Geburek Thomas , Jeandroz Sylvain , Senn Josef 
Published: March 2003

AbstractPopulations from 13 elevational transects of Norway spruce [Picea abies (L.) Karst] across the Alpine range were sampled to elucidate the geographical pattern of genetic variation in relation to postglacial re‐colonization and to study elevational effects on haplotypic diversity. We assessed fragment length variation in a tandem repeat region of the mitochondrial (mt) nad1 intron 2. This maternally inherited genetic marker is suited to infer migration as it is dispersed by seed only. A total of 10 haplotypes was found, most of which were due to repeat copy number variation. An analysis of molecular variance (amova) showed that overall population differentiation was high (FST = 0.41), and it revealed a significant differentiation between monomorphic western and moderately to highly variable eastern Alpine populations. This phylogeographic pattern may be explained by a founder effect during postglacial re‐colonization. An early arriving haplotype, assumed to originate from a western Carpathian refugium, could expand into suitable habitats, reducing the chances for establishment of subsequently arriving haplotypes. On the other hand, the high variation in populations within an Italian transect of the south‐eastern Alps may be the consequence of merging migration pathways from and close distance to putative glacial refugia, most likely those assumed in the Carpathian mountains and on the Balkan peninsula or possibly in the central plains of Italy. An effect of elevation on haplotypic diversity was not evident, though a low, but significant, partition of total genetic variation was attributed to among‐population variation in one Italian transect. Various factors, such as vertical seed dispersal and forest management, may account for blurring an otherwise established pattern of genetic variation on a small geographical scale.