bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparisons of toxic baits for controlling the cockroach,Blattella germanica: attractiveness and feeding stimulation
Authors: Durier V. , Rivault C. 
Published: March 2003

SummaryFemale German cockroaches,Blattella germanica(L.) (Dictyoptera: Blattellidae) and nymphs (stages 1, 3 and 6) were used to test the attractiveness and the feeding stimulation of several commercial gel formulations of insecticide food baits in laboratory binary choice tests. The four toxic gel baits tested were: ‘Avert’ (0.05% abamectin = avermectin B1), ‘Drax’ (33.3% boric acid), ‘Goliath’ (0.05% fipronil) and ‘Maxforce’ (2.15% hydramethylnon). The attractiveness of a bait was estimated by the number of cockroaches that chose it first, and by their tendency to change to it secondarily. Feeding stimulation was estimated by the mean duration of feeding bouts and total duration of food intake. Variability of these factors was assessed in relation to age of cockroaches and to age of baits. With a few exceptions, cockroach age did not affect performance in any of these tests. Attractiveness toB. germanicaranked ‘Goliath’ gel higher than ‘Avert’, ‘Drax’ and ‘Maxforce’ gels, whether or not the active ingredient fipronil was present in ‘Goliath’ gel. Feeding stimulation ranked ‘Avert’ and ‘Maxforce’ gels higher than ‘Goliath’ gel, and ‘Drax’ gel was inferior. With ageing up to 3 months, the feeding stimulation power of ‘Goliath’ and ‘Maxforce’ gels increased, whereas that of ‘Avert’ fluctuated. Assuming that all types of bait effectively kill cockroaches once ingested, these results illustrate the importance of behavioural observations on bait efficiency and show that ranking of these different food baits varies in relation to the parameter analysed.
The United Medical and Dental School of Guy's and St Thomas' Hospitals' MSc in general practice: graduates' perspectives
Authors: Calvert Graham , Britten Nicky 
Published: March 2003

AimHigher degrees have been proposed as one means whereby general practitioners can continue their professional development and avoid a slow decline into professional isolation and burnout. The United Medical and Dental School of Guy's and St Thomas' Hospitals' MSc in general practice has been available to experienced general practitioners for over a decade. This study reports some of the outcomes of participation for the 76 graduates of the first nine cohorts.MethodAs part of an ongoing programme of evaluation the graduates were sent a questionnaire which, in addition to seeking information about attainment of intended outcomes, gave respondents the opportunity to write freely about the contribution made by the course to their own professional and personal development. Seventy‐one graduates completed the questionnaire, a response rate of 93%.Results and conclusionsAn increased confidence that arises not only from a broadened knowledge base and increased skills but also from a sense of having been enabled to explore more deeply into their discipline, is the most frequently and highly valued outcome of participation. Graduates appreciated having additional protected time and demonstrated an ability to use it productively. A further significant outcome was the ability of the course to confront those habitual assumptions of doctors which inform their practice in a manner that was both challenging and supportive. Tendencies to professional isolation and burnout appear to have been reversed with a greater sense of connectedness to their discipline. Doctors seeking to diversify their general practice careers beyond the task of providing medical services have found the MSc an important route for change.
Genetic detection of sex‐biased dispersal
Authors: Mossman C. A. , Waser P. M. 
Published: March 2003

AbstractWe investigated the application of a recently developed genetic test for sex bias in dispersal. This test determines an animal's ‘assignment index’ or the expected frequency of its genotype in the population in which it is captured. Low assignment indices indicate a low probability of being born locally. We investigated the use of this test with the white‐footed mouse, Peromyscus leucopus, in which dispersal is predominantly male‐biased, but not extreme. We found that male P. leucopus had significantly lower assignment indices than females. These data suggest that the genetic test for sex bias in dispersal has potential to be used with species that do not have extreme sex‐biased dispersal tendencies.
Genetic relationships of populations and the origins of new infestations of the Mediterranean fruit fly
Authors: He M. , Haymer D. S. 
Published: March 2003

AbstractA polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) approach based on the variation in intron sequences of the glucose‐6‐phosphate dehydrogenase (Zw) gene was used to assess genetic variability in 26 populations and infestations of the Mediterranean fruit fly (medfly), Ceratitis capitata. Beginning with the exon‐primed intron‐crossing PCR (EPIC–PCR) method to amplify introns of this gene, five alleles were identified on the basis of DNA sequence variants. Several of these variants affect recognition sites for the restriction enzymes RsaI and TaqI. Using these enzymes in successive digestions of the EPIC‐PCR products, each of these alleles can be identified directly from individuals. From this, surveys were conducted to document genotypes and allele frequencies in these samples. The relationships of existing populations and the invasion process represented by new infestations of the medfly were analysed using a principal coordinate analysis and the amova method to quantify the distribution of genetic diversity at different levels in a hierarchical manner. From these results, a framework of genetic relationships among the populations and infestations is presented. In addition, for at least some of the infestations, populations that are probably acting as sources of origin have been identified.
Where have all the fathers gone? An extensive microsatellite analysis of paternity in the grey seal (Halichoerus grypus)
Authors: Worthington Wilmer J. , Allen P. J. , Pomeroy P. P. , Twiss S. D. , Amos W. 
Published: March 2003

AbstractMicrosatellites were used to conduct an extensive analysis of paternity of grey seals from two Scottish breeding colonies at North Rona (n = 1189) and the Isle of May (n = 694), spanning more than a decade. A maximum of 46% of pups at North Rona and 29% of pups at the Isle of May could be allocated a father, even though the majority of candidate males for specific study sites within each colony were believed to have been sampled. Based on the paternities which could be assigned, both colonies showed evidence of reproductive skew, apparently due to the presence of approximately five males who were exceptionally successful. Some males were assigned paternities at least 10 years before, and colleagues 10 years after, being sampled, implying a reproductive lifespan of at least 10 years, and there are indications that the real maximum lies in the range 15–20 years. Male grey seals appear to have at least two breeding strategies they can adopt. On land, some males benefit from a traditionally polygynous system. However, between 50 and 70% of grey seal pups born at a particular colony are not fathered by males who are likely to be sampled by us, implying that these males seldom venture ashore here. We conclude that aquatic mating may play a much larger role in the grey seal than has previously been thought.
Rangewide variation of the maritime pine bast scale Matsucoccus feytaudi Duc. (Homoptera: Matsucoccidae) in relation to the genetic structure of its host
Authors: Burban C. , Petit R. J. , Carcreff E. , Jactel H. 
Published: March 2003

AbstractThe bast scale Matsucoccus feytaudi is a specific pest of maritime pine, but the damage inflicted by the insect on the host trees is variable, ranging from no apparent effect to severe decline of the maritime pine stands. Rangewide variation of mitochondrial DNA among M. feytaudi populations was analysed by polymerase chain reaction–restriction fragment length–single‐strand conformation polymorphism (PCR–RFLP–SSCP) analysis and the results compared with the genetic information already available for its host. Three main nonoverlapping lineages can be distinguished in M. feytaudi. The phylogeography of the pest population is clearly related to the history of its host. Most local associations could result from common evolution while others must be interpreted as intraspecific host shifts. Because the distribution of cultivated tree species is greatly influenced by humans, much may be learned concerning their genetic structure from the indirect study of their specific pests.
Small effective population size in the long‐toed salamander
Authors: Funk W. Chris , Tallmon David A. , Allendorf Fred W. 
Published: March 2003

AbstractThe effective population sizes (Ne) of six populations of the long‐toed salamander (Ambystoma macrodactylum) from Montana and Idaho, USA were estimated from allozyme data from samples collected in 1978, 1996 and 1997 using the temporal allele frequency method. Five of the six estimates ranged from 23 to 207 (mean = 123 ± 79); one estimate was indistinguishable from infinity. In order to infer the actual Ne of salamander populations, we compared the frequency distribution of our observed Ne estimates with distributions obtained from simulated populations of known Ne. Our observed Ne estimate distribution was consistent with distributions from simulated populations with Ne values of 10, 25, and 50, suggesting an actual Ne for each of the six salamander populations of less than 100. This Ne estimate agrees with most other Ne estimates for amphibians. We conclude by discussing the conservation implications of small Ne values in amphibians in the context of increasing isolation of populations due to habitat fragmentation.
Evolutionary transition from single to multiple mating in fungus‐growing ants
Authors: Villesen P. , Gertsch P. J. , Frydenberg J. , Mueller U. G. , Boomsma J. J. 
Published: March 2003

AbstractQueens of leafcutter ants exhibit the highest known levels of multiple mating (up to 10 mates per queen) among ants. Multiple mating may have been selected to increase genetic diversity among nestmate workers, which is hypothesized to be critical in social systems with large, long‐lived colonies under severe pressure of pathogens. Advanced fungus‐growing (leafcutter) ants have large numbers (104–106workers) and long‐lived colonies, whereas basal genera in the attine tribe have small (< 200 workers) colonies with probably substantially shorter lifespans. Basal attines are therefore expected to have lower queen mating frequencies, similar to those found in most other ants. We tested this prediction by analysing queen mating frequency and colony kin structure in three basal attine species:Myrmicocrypta ednaella,Apterostigma collareandCyphomyrmex longiscapus. Microsatellite marker analyses revealed that queens in all three species were single mated, and that worker‐to‐worker relatedness in these basal attine species is very close to 0.75, the value expected under exclusively single mating. Fungus growingper sehas therefore not selected for multiple queen mating. Instead, the advanced and highly productive social structure of the higher attine ants, which is fully dependent on the rearing of an ancient clonal fungus, may have necessitated high genetic diversity among nestmate workers. This is not the case in the lower attines, which rear fungi that were more recently derived from free‐living fungal populations.
Genetic structure of brown trout, Salmo trutta L., at the southern limit of the distribution range of the anadromous form
Authors: Bouza C. , Arias J. , Castro J. , Sánchez L. , Martínez P. 
Published: March 2003

AbstractGenetic variation at 33 protein loci was investigated in 41 wild brown trout populations from four river basins in Galicia (northwest Spain) to analyse the amount and distribution of genetic diversity in a marginal area, located in the distribution limit of the anadromous form of this species. The genetic diversity detected within populations (H between 0 and 6%) lies within the range quoted for this species in previous reports. The Miño, the most southern river basin analysed, showed a significantly lower genetic diversity and the highest genetic differentiation among the river basins studied. The hierarchical gene diversity analysis showed high population differentiation in a restricted area (GST = 27%), mostly due to differences among populations within basins (GSC = 22%). The reduction of GST observed when the isolated samples were excluded from the analysis (GST = 17%) showed the importance of habitat fragmentation on the heterogeneity detected. Gene flow among populations was comparatively evaluated by three indirect methods, which in general revealed low figures of absolute number of migrants per generation, slightly higher than 1. The gene flow among basins reflected a positive relationship with geographical distance. This trend was confirmed by the significant correlation observed between geographical and genetic distances, including all population pairs, which suggests a component of isolation by distance in brown trout genetic structure. Nevertheless, the nonsignificant intrabasin correlation demonstrates the complexity of genetic relationships among populations in this species. The model of genetic structure in brown trout is discussed in the light of the results obtained.
Intraspecific phylogeography in the sedge frog Litoria fallax (Hylidae) indicates pre‐Pleistocene vicariance of an open forest species from eastern Australia
Authors: James C. H. , Moritz C. 
Published: March 2003

AbstractThe eastern sedge frog Litoria fallax (Anura: Hylidae) is common throughout the open forests and coastal wetlands along the eastern coast of Australia. Its range spans four biogeographical zones from northern Queensland to central New South Wales. Phylogenetic analysis of mitochondrial DNA (mtDNA) haplotypes of 87 L. fallax individuals from 22 populations identified two major mtDNA lineages, differing by 11–12% sequence divergence. The two clades of haplotypes were separated by the McPherson Range, indicating that this mesic upland area has acted as a major long‐term barrier to gene flow for this open forest species. Slight isolation by distance was observed within both the northern and southern lineages but was insufficient to explain the large sequence divergence between lineages. Within the northern lineage, additional phylogeographical structure was observed across the relatively dry Burdekin Gap which separates Atherton populations from all populations in the central and eastern Queensland biogeographical zones. There was less phylogeographical structure in the southern lineage suggesting historical gene flow across the drier portions of the Great Dividing Range. These data, together with recent observations of deep phylogeographical divergences in rainforest‐restricted Litoria suggest that the east coast hylids of Australia represent an old (Tertiary) radiation. Individual species of Litoria have been strongly affected by climatic and ecological barriers to gene flow during the Quaternary.
A population genetic analysis of migration: the case of the noctule bat (Nyctalus noctula)
Authors: Petit Eric , Mayer Frieder 
Published: March 2003

AbstractAlthough rarely assessed, the population genetics of hibernating colonies can help to understand some aspects of population structure, even when samples from nursery or mating colonies are not available, or in studies of migration when both types of samples are available and can be compared. Here we illustrate both points in a survey of mitochondrial DNA (mtDNA) control region sequences used to study the population genetics of hibernating colonies of a migrating species, the noctule bat (Nyctalus noctula). Lacking samples from Scandinavian nursery colonies, we use a North European hibernacula to suggest that Scandinavian populations are isolated from Central and East European colonies. Then, we compare genetic diversities of nursery and hibernating colonies. We find a significantly higher haplotype diversity in hibernacula, confirming that they consist of individuals from different nursery colonies. Finally, we show that pairwise comparisons of the haplotype frequencies of nursery and hibernating colonies contain some information on the migration direction of the noctule bat.
Do hornets have zombie workers?
Authors: Foster Kevin R. , Ratnieks Francis L. W. , Raybould Alan F. 
Published: March 2003

AbstractColonies of the European hornet,Vespa crabro, are typically founded by a single queen mated to a single male.From the resulting colony relatedness pattern we predicted strong worker–queen conflict over male production where both the workers and the queen attempt to produce the colony’s males. To test for this conflict, male production was studied in 15 hornet nests using a combination of DNA microsatellite analysis (282 males), worker ovary dissections (500 workers from eight nests) and 50 h of observation (four nests). In contrast to our prediction, the data show that hornet males are queens’ sons, that workers never attempt to lay eggs, rarely have activated ovaries, and that there is no direct aggression between the queen and the workers. This contrasts with other data for vespine wasps, which support relatedness predictions.Dolichovespula arenariahas the same kin structure asV. crabroand workers produce males in many colonies. The similarity between these two species makes it difficult to explain why workers do not reproduce inV. crabro. Self‐restraint is expected if worker reproduction significantly reduces colony productivity but there is no obvious reason why this should be important toV. crabrobut not toD. arenaria. Alternatively, queen control may be important. The absence of expressed queen–worker conflict rules out physical control. Indirect pheromonal control is a possibility and is supported by the occurrence of royal courts and queen pheromone inVespabut notDolichovespula. Pheromonal queen control is considered evolutionarily unstable, but could result from a queen–worker arms race over reproductive control in which the queen is ahead. The genetic data also revealed diploid males in one colony, the first example in the vespine wasps, and two colonies with double matrilines, suggesting that occasional usurpation by spring queens occurs.
Phylogenetic divergence in leatherside chub (Gila copei) inferred from mitochondrial cytochrome b sequences
Authors: Johnson Jerald B. , Jordan Steve 
Published: March 2003

AbstractWe examined intra‐specific phylogenetic relationships in leatherside chub, Gila copei. The complete mitochondrial (mt) cytochrome b gene (1140 bp) was sequenced for 30 individuals from 10 populations that span the geographical distribution of this species. Traditional phylogenetic analyses revealed two deeply divergent and evolutionarily distinct mtDNA clades that are geographically separated in northern and southern drainage basins. Inter‐population sequence variation between clades ranged from 7.7 to 8.1%. The northern clade was genetically more similar and phylogenetically more closely related to the selected out‐group Lepidomeda m. mollispinus than to the southern clade, suggesting that the taxonomy of this species may require revision. Sequence variation among populations within clades ranged from 0 to 0.3% in the north and from 0 to 0.7% in the south. Statistical parsimony was used to construct phylogenetic networks of haplotypes within clades. Nested clade analysis revealed that geographical fragmentation has played an important role in genetic structuring within northern and southern clades.
Genetic compatibility, mate choice and patterns of parentage: Invited Review
Authors: Tregenza T. , Wedell N. 
Published: March 2003

AbstractThere is growing interest in the possibility that genetic compatibility may drive mate choice, including gamete choice, particularly from the perspective of understanding why females frequently mate with more than one male. Mate choice for compatibility differs from other forms of choice for genetic benefits (such as ‘good genes’) because individuals are expected to differ in their mate preferences, changing the evolutionary dynamics of sexual selection. Recent experiments designed to investigate genetic benefits of polyandry suggest that mate choice on the basis of genetic compatibility may be widespread. However, in most systems the mechanisms responsible for variation in compatibility are unknown. We review potential sources of variation in genetic compatibility and whether there is any evidence for mate choice driven by these factors. Selfish genetic elements appear to have the potential to drive mate compatibility mate choice, though as yet there is only one convincing example. There is abundant evidence for assortative mating between populations in hybrid zones, but very few examples where this is clearly a result of selection against mating with genetically less compatible individuals. There are also numerous cases of inbreeding avoidance, but little evidence that mate choice or differential fertilization success driven by genetic compatibility occurs between unrelated individuals. The exceptions to this are a handful of situations where both the alleles causing incompatibility and the alleles involved in mate choice are located in a chromosome region where recombination is suppressed. As yet there are only a few potential sources of genetic compatibility which have clearly been shown to drive mate choice. This may reflect limitations in the potential for the evolution of mate choice for genetic compatibility within populations, although the most promising sources of such incompatibilities have received relatively little research.
Patterns of variation at a mitochondrial sequence‐tagged‐site locus provides new insights into the postglacial history of European Pinus sylvestris populations
Authors: Soranzo N. , Alia R. , Provan J. , Powell W. 
Published: March 2003

AbstractDue to their maternal mode of inheritance, mitochondrial markers can be regarded as almost ‘ideal’ tools in evolutionary studies of conifer populations. In the present study, polymorphism was analysed at one mitochondrial intron (nad 1, exon B/C) in 23 native European Pinus sylvestris populations. In a preliminary screening for variation using a polymerase chain reaction–restriction fragment length polymorphism approach, two length variants were identified. By fully sequencing the 2.5 kb region, the observed length polymorphism was found to result from the insertion of a 31 bp sequence, with no other mutations observed within the intron. A set of primers was designed flanking the observed mutation, which identified a novel sequence‐tagged‐site mitochondrial marker for P. sylvestris. Analysis of 747 trees from the 23 populations using these primers revealed the occurrence of two distinct haplotypes in Europe. Within the Iberian Peninsula, the two haplotypes exhibited extensive population differentiation (ΦST = 0.59; P ≤ 0.001) and a marked geographical structuring. In the populations of central and northern Europe, one haplotype largely predominated, with the second being found in only one individual of one population.