bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nutritional levels of female tsetse Glossina pallidipes from artificial refuges
Authors: Hargrove J. W. 
Published: March 2003

SummaryFemale tsetse flies, Glossina pallidipes Austen, caught in artificial refuges were subjected to ovarian dissection and analysed for levels of fat, residual dry weight (RDW) and haematin. There were rather small proportions of flies in ovarian categories 0 and 1, in part due to large losses in the immature and teneral stages at the hottest time of year. The distribution of the female catch among pregnancy days was close to uniform. The wet and dry weights (WW and DW) and RDW of eggs, larvae and pupae increased by 0.821, 0.303 and 0.204 mg respectively, with each mm3 increase in volume. Water accounted for 71.7% of the fat‐free WW, and fat for 32.7% of the DW. Between birth and ovulation, fat increased from 2 to 4 mg and RDW from 7 to 11 mg; thoracic RDW increased by 2.5 mg and changed little thereafter. Fat levels increased 3.5 mg by day 6 of pregnancy, but only 0.5 mg thereafter. Over the same periods RDW corrected to zero haematin (CRDW) increased by 1 and 8 mg respectively. Full‐term fat and CRDW levels were 8.2 and 19.4 mg respectively. Cumulative haematin frequencies formed a smooth curve with a slope that increased continuously. The raw data were well fitted by a model where feeding rates increased exponentially and capture probability was independent of haematin content. The mean feeding interval was 60 h; feeding probabilities of > 0.9/day were only found in flies that had failed to feed for > 72 h. In early pregnancy, fat levels declined with haematin for flies that had fed > 36 h previously; by days 5–7 fat levels were maintained at a constant high level for 60 h post‐feeding. Fat–haematin graphs for female tsetse cannot be used to estimate rates of fat utilization. Traps sample tsetse with below‐average fat and RDW in early and late pregnancy respectively. Refuge samples are less biased than those from traps; they give a better picture of the dynamics of pregnancy in normal flies and facilitate the explanation of existing anomalies.
Lifetime changes in the nutritional characteristics of female tsetse Glossina pallidipes caught in odour‐baited traps
Authors: Hargrove J. W. 
Published: March 2003

SummaryFemale Glossina pallidipes Austen were captured in odour‐baited traps at Rekomitjie Research Station, Zambezi Valley, Zimbabwe during February 1994; 2890 were dissected and assigned to their ovarian age category and day of pregnancy using the lengths of the oocytes and uterine content. For 1838 of these flies, the nutritional state of the mother and her uterine content were estimated separately. It was thereby possible to see how, during pregnancy, the females acquired fat and residual dry weight (RDW) and transfered them to the larva. Newly emerged flies contained 1 mg fat and 6 mg RDW, of which 4 mg was in the thorax (TRDW). Fat hardly increased by the first ovulation; RDW increased by 2.5 mg and 1.5 mg of this increase was in TRDW. Mean haematin levels increased from 2 to 8 μg during each pregnancy. Fat increased from 1.2 mg to 4.5–5 mg by day 7 and was then rapidly transferred to the larva. RDW increased by only 1.8 mg by day 7, but larval RDW increased thereafter by > 6 mg. Amino acids from late‐pregnancy bloodmeals are incorporated directly, in the uterine gland, into ‘milk’ that is taken up rapidly by the larva. Capture probability was highest on day 1 of pregnancy, when nutritional levels were lowest, with lesser peaks on days 5 and 8 when the fly was nourishing a rapidly developing larva. On day 1, the peak of the logarithm of the haematin distribution corresponded to flies estimated to have fed ≈ 75 h previously; by day 8 it had shifted to ≈ 60 h post‐feeding. A model in which feeding rates and capture probabilities increased exponentially with time since feeding accounted for 97% of the variance in log haematin frequencies. On 4/9 days of pregnancy there was no significant decline in fat with haematin content during the lipolytic phase. The rate of decline is not a satisfactory estimate of the rate of fat usage. Flies in this study had longer wings and higher TRDW than those from refuges in an earlier study, but had lower levels of fat and haematin.
Estimation of survival rates in haematophagous insects
Authors: Lord C. C. , Baylis M. 
Published: March 2003

SummaryEstimation of the survival rate through a gonotrophic cycle is an important factor in determining the vectorial capacity of a population of haematophagous insects in a disease cycle. Most methods used to calculate survival rates make stringent assumptions which may not be valid for all species. Birley and colleagues used a time series analysis of samples collected over several consecutive days, the lagged parous rate. Here, we use a simulation model to investigate (i) the length of data series needed and (ii) the consequences of failures in the assumptions of this method for the estimated survival rate. The accuracy of the estimated survival rate per cycle was high with sample periods of 10–100 days. The standard deviation (a measure of precision) decreased with the length of the sample period. When random sampling efficiency was included, the accuracy remained high but the estimates were less precise (larger standard deviations). If the sampling was biased in favour of either nulliparous or parous females, estimates of the survival rate were not accurate. The relationship between estimated survival rate, bias in collection, and true survival rate was non‐linear. Thus, correction for the bias requires (i) prior knowledge of the direction and the severity of the bias and (ii) an independent estimate of the survival rate. This method of estimating survival rates is less accurate when the collection method is biased for or against parous females, although robust to other assumptions.
PCR‐based methods for identification of species of the Anopheles minimus group: allele‐specific amplification and single‐strand conformation polymorphism
Authors: Sharpe R. G. , Hims M. M. , Harbach R. E. , Butlin R. K. 
Published: March 2003

SummaryWe report two polymerase chain reaction (PCR)‐based methods for distinguishing morphologically similar species based on amplification of a variable region of the 28S gene of ribosomal DNA. The four species we investigated are mosquitoes of the Anopheles minimus group: An. aconitus, An. varuna and An. minimus species A and C. The formally named species are vectors of human malaria parasites in south‐east Asia but are difficult to distinguish with certainty on the basis of morphology. Allele‐specific amplification was used to differentiate An. minimus A from An. minimus C. This technique has been widely used for the diagnosis of species. Single‐strand conformation polymorphisms (SSCPs) were used to separate all four species. This technique, which has seldom been used for species identification, has many advantages: it does not require sequence information beyond that needed for amplification; it is ideally suited for the detection of heterozygotes; it utilizes more of the information in the PCR product than allele‐specific amplification; it distinguishes all four species considered here and could easily be extended to other species; previously unknown intraspecific variation and additional species are likely to be detected. Thus, SSCPs provide valuable population genetic information which allele‐specific amplification does not.
Abrocomaphthirus hoplai, a new genus and species of sucking louse from Chile and its relevance to zoogeography
Authors: Durden L. A. , Webb J. P. 
Published: March 2003

SummaryBoth sexes of Abrocomaphthirus hoplai, new genus and new species (Anoplura: Polyplacidae), are described and illustrated. The endemic Chilean chinchilla rat Abrocoma bennetti Waterhouse (Rodentia: Abrocomidae) is the type host. The definition of the family Polyplacidae is amended to accommodate the new genus. Polyplax longa (Werneck), also referred to in the literature as Neohaematopinus longus Werneck, is reassigned to Abrocomaphthirus. The host of A. longus comb.n., is Abrocoma cinerea Thomas, another chinchilla rat, which inhabits parts of Argentina, Bolivia, Chile and Peru. The erection of Abrocomaphthirus as a distinct genus has important zoogeographical and evolutionary implications. The tenuous anomaly of P. longa being the sole native representative of the genus Polyplax in South America, possibly with African affinities, is now refuted. Instead, partial colonization of the neotropics by native species of both Polyplax and Neohaematopinus appears to have been relatively recent and from North America. The phylogenetic affinities of Abrocomaphthirus are unknown, but it appears to be closely related to other, more ancient, native South American polyplacid louse genera, such as Cuyana, Eulinognathus, Galeophthirus, and Lagidiophthirus. Arguments are presented in support of an ancestral zoogeographical link to Africa for these louse genera.
Cytogenetics of the Anopheles gambiae complex in Sudan, with special reference to An. arabiensis: relationships with East and West African populations
Authors: Petrarca V. , Nugud A. D. , Ahmed M. A. Elkarim , Haridi A. M. , Di Deco M. A. , Coluzzi M. 
Published: March 2003

SummaryThe species composition of malaria vector mosquitoes belonging to the Anopheles gambiae complex (Diptera: Culicidae) from > 40 localities in Sudan, representing most ecological situations, was determined by analysis of ovarian polytene chromosomes. Of 2162 females, 93% were identified as An. arabiensis Patton and 7% were An. gambiae Giles sensu stricto. No hybrids were found between the two species. Anopheles arabiensis occurred in all but two sites, whereas An. gambiae s.s. was effectively limited to the southernmost, more humid localities. For chromosomal paracentric inversions, the degree of polymorphism was low in An. gambiae s.s. (inversions 2La, 2Rb and 2Rd), higher in An. arabiensis (inversions Xe, 2Ra, b, bc, d1, s; 3Ra, d). Anopheles gambiae samples from Sudan were all apparently panmictic, i.e. they did not show restricted gene flow such as observed among West African populations (interpreted as incipient speciation). Chromosomal inversion patterns of An. gambiae in southern Sudan showed characteristics of intergrading Savanna/Forest populations similar to those observed in comparable eco‐climatic situations of West Africa. Anopheles arabiensis was polymorphic for inversion systems recorded in West Africa (2Ra, 2Rb, 2Rd1, 3Ra) and for a novel 2Rs polymorphism, overlapping with inversion systems 2Rb and 2Rd1. Samples carrying the 2Rs inversion were mostly from Khashm‐el‐Girba area in central‐eastern Sudan. In the great majority of the samples all polymorphic inversions were found to be in Hardy–Weinberg equilibrium. Sudan populations of An. arabiensis should therefore be considered as generally panmictic. Anopheles arabiensis shows more inversion polymorphism in west than in east African populations. Sudan populations have more evident similarities with those from westwards than those from eastwards of the Great Rift Valley. The possible influence of the Rift on evolution of An. arabiensis is discussed.
The ixodid tick species attaching to domestic dogs and cats in Great Britain and Ireland
Authors: Ogden N. H. , Cripps P. , Davison C. C. , Owen G. , Parry J. M. , Timms B. J. , Forbes A. B. 
Published: March 2003

SummaryThe species of ixodid ticks, attached to dogs and cats presented to veterinary practices in Great Britain and Ireland were identified. Most host animals carried only one tick species with Ixodes ricinus Linné (Acari: Ixodidae) being the most common, identified on 52% of animals, Ixodes hexagonus Leach (Acari: Ixodidae) the second most common (on 39%) and Ixodes canisuga Johnston (Acari: Ixodidae) the third most common (on 11%). A significantly higher proportion of dogs than cats carried I. ricinus, while I. hexagonus was more frequently carried by cats. One animal carried a single specimen of Haemaphysalis punctata Canestrini & Fanzago (Acari: Ixodidae), one carried a Dermacentor reticulatus Fabricius (Acari: Ixodidae) but none carried Rhipicephalus sanguineus Latreille (Acari: Ixodidae). This indicates that the latter two species, vectors of ‘exotic’ tick‐borne diseases, remain at low densities in Great Britain and Ireland. Retrospective information on exposure of the animals to different habitats and geographic regions was collected by questionnaire and subject to contingency table and logistic regression analysis. Woodlands and moorlands were habitats significantly associated with I. ricinus attachment. Exposure to urban parks was significantly associated with I. hexagonus attachment and exposure to boarding kennels and catteries was significantly associated with I. canisuga attachment. Ixodes hexagonus, rather than I. ricinus, was the ixodid tick species most likely to be encountered by urban populations of dogs and cats and, by inference, possibly also humans. The implications of these findings, for the transmission of tick‐borne pathogens to dogs, cats and humans are discussed.
Diversion of Anopheles gambiae from children to other hosts following exposure to permethrin‐treated bednets
Authors: Quiñones M. L. , Drakeley C. J. , Müller O. , Lines J. D. , Haywood M. , Greenwood B. M. 
Published: March 2003

SummaryPermethrin‐treated bednets reduce mortality and morbidity from malaria in Gambian children. However, it is not certain how this effect is achieved, as neither mosquito numbers nor the human blood index of indoor‐resting female Anopheles gambiae Giles sensu lato (Diptera: Culicidae) mosquitoes have been reduced when treated bednets were introduced into a community. One possibility is that insecticide‐treated bednets divert mosquitoes from children to adults. To investigate this hypothesis, a cross‐over trial with insecticide‐treated bednets was undertaken in two small Gambian villages. To differentiate mosquitoes that had fed on children from those that had fed on adults, all children in the study villages were immunized with rabies vaccine before the trial. Using the detection of rabies antibody in a bloodmeal as an indicator that a mosquito had bitten a child, it was found that the percentage of blood‐fed mosquitoes caught indoors that had bitten a child fell significantly from 30.8% to 9.2% and from 28.0% to 6.9% in each village after insecticide‐treated bednets were introduced. To investigate the possibility that some diversion to animals had occurred, a PCR analysis for human β‐globin DNA was undertaken on selected samples. The results of this investigation were confusing, as some rabies‐antibody positive bloodmeals were negative for human DNA. This may have been due to cross‐reacting antibodies in animal sera and/or DNA degradation by digestion in the mosquito. Although good evidence for diversion of mosquitoes away from children was obtained, it remains uncertain whether diversion was mainly to adult humans, to animals or to both.
Abiotic factors influencing the ecology of wild rabbit fleas in north‐eastern Spain
Authors: Osacar‐Jimenez J. J. , Lucientes‐Curdi J. , Calvete‐Margolles C. 
Published: March 2003

SummaryDuring 1992, the population dynamics of rabbit fleas were compared at two sites in north‐eastern Spain. The sites differed mainly in terms of annual rainfall and soil type. All flea species showed seasonal cycles of abundance, although peaks in numbers occurred at different times, reflecting their specific adaptations for coping with climatic variables. Adult Spilopsyllus cuniculi (Dale) (Siphonaptera: Pulicidae) were found largely parasitizing rabbits in spring and adult Caenopsylla laptevi (Beaucournu et al. ) (Siphonaptera: Ceratophyllidae) in the autumn. In contrast, monthly flea indices of Xenopsylla cunicularis (Smit) (Siphonaptera: Pulicidae) and Echidnophaga iberica (Ribeiro et al. ) (Siphonaptera: Pulicidae) peaked in summer. Spilopsyllus cuniculi was present at both sites, but was less common on the drier site, where monthly mean temperature and annual rainfall approached the flea's physiological limits. By contrast, E. iberica, X. cunicularis and C. laptevi, known to be better adapted for dryness, showed the opposite patterns of abundance. Nevertheless, even these arid‐adapted species took advantage of the milder and wetter spring (X. cunicularis and E. iberica) or autumn (C. laptevi) for breeding and larval development. Although environmental temperature, rainfall and soil texture will influence the microclimate of the burrows where the flea larvae develop, burrow humidity seems to be more dependent on soil characteristics and past rainfall rather than the humidity of the external air.
Attitudes to recertification measured over time using a validated semantic differential scale
Authors: Tracey  , Arroll  , Richmond  
Published: March 2003

ObjectivesThis study was designed to measure the acceptability of the Royal New Zealand College of GPs' Recertification programme to the GPs in the programme.DesignQuestionaire study of a stratified random sample of members of the RNZCGP.MethodA semantic differential attitude scale was developed and validated. The scale was administered to 300 GPs before the Recertification programme began and repeated with 100 of these GPs 18 months later. After 3 years of the programme the questionnaire was administered to the original 300 GPs.ResultsBaseline data showed reasonable acceptance of the concept of recertification but by 18 months there was a significant deterioration in the way the programme was perceived and this did not change over 3 years. Many GPs were not convinced of the value of the programme.
The performance of foreign medical graduates on the National Board of Medical Examiners (NBME) standardized patient examination prototype: a collaborative study of the NBME and the educational Commission for Foreign Medical Graduates (ECFMG)
Authors: Ben‐David  , Klass  , Boulet  , Champlain  , King  , Pohl  , Gary  
Published: March 2003

ObjectivesThe purpose of the study was to explore foreign medical graduates’ (FMGs) performance on a clinical skills (SPX) examination. The National Board of Medical Examiners (NBME) is in the process of developing an SPX for potential use in the United States Medical Licensing Examination (USMLE). The Educational Commission for Foreign Medical Graduates (ECFMG) is developing the Clinical Skills Assessment (CSA) as an additional requirement for FMGs who wish to be certified by ECFMG.DesignThirty‐three FMGs and 151 United States medical students (USMSs) took the SPX during the winter of 1996 as part of the ongoing pilot studies conducted by the NBME. Four clinical skill areas were assessed: history‐taking, physical examination, communication and interpersonal skills. The examination used in this research consisted of 12 cases. The examination utilizes standardized patients (SPs) who are trained to document examinee behaviours and evaluate the communication component of the test. The SPs were also trained to evaluate the English proficiency of the candidates. Candidates were also administered the Test of Spoken English developed by the Educational Testing Services (ETS).SettingThe examination was conducted in one medical school which served as an SPX centre for NBME pilot studies.SubjectsThirty‐three foreign medical students and 151 US medical students.ResultsThe indications were that the majority of candidates in both groups felt the examination was moderately fair but 78% of FMGs felt moderately pressed for time, vs. 80% of the USMSs who did not feel pressed for time. Reliabilities obtained for the various SPX components were somewhat higher for the FMGs reflecting the heterogeneity of this group.ConclusionsThe NBME–ECFMG collaborative study yielded important information regarding the NBME SPX prototype as a performance measure for FMGs.
Population boundaries and genetic diversity in the endangered Mariana crow (Corvus kubaryi)
Authors: Tarr C. L. , Fleischer R. C. 
Published: March 2003

AbstractThe Mariana crow (Corvus kubaryi) is an endangered species that is restricted to the islands of Guam and Rota in the Mariana archipelago. Predation by the introduced brown tree snake (Boiga irregularis) has decimated bird populations on Guam, and the crow population there is the last wild remnant of the endemic forest avifauna. The population on Guam is critically endangered and, despite intensive management, the population has continued to decline. Additional management options include intermixing the Guam and Rota populations, but such options are best evaluated within a population genetics framework. We used three types of molecular markers to assay genetic variation in the Mariana crow: mitochondrial DNA (mtDNA) sequences, minisatellites and microsatellites. The two populations could be differentiated by mtDNA sequencing and they differed in allele frequencies at nuclear markers. Thus, the populations could be designated as evolutionarily significant units. However, the Guam population is genetically more diverse than the Rota population, and its survival probability if managed separately is very low. All markers did indicate that the two populations are closely related and separated by a shallow genealogical division. Intermixing the populations is justified by two rationales. First, the apparent population differences may result from recent human activities. Second, a greater amount of genetic information may be preserved by joint management. The translocation of birds from Rota to Guam has begun, but strategies that will ensure maintenance of the variation in the Guam population warrant further exploration.
Extensive intraspecific chloroplast DNA (cpDNA) variation in the alpine Draba aizoides L. (Brassicaceae): haplotype relationships and population structure
Authors: Widmer A. , Baltisberger M. 
Published: March 2003

AbstractChloroplast DNA (cpDNA) sequence variation is currently the most widely used tool for the inference of phylogenetic relationships among plants at all taxonomic levels. Generally, noncoding regions tend to evolve faster than coding sequences and have recently been applied to the study of phylogenetic relationships among closely related taxa. An implicit assumption of many of these studies is that intraspecific cpDNA variation is either absent or low and therefore will not interfere with the reconstruction of interspecific relationships. A survey of cpDNA sequence variation in the common alpine plant species Draba aizoides L. was undertaken to assess levels of intraspecific cpDNA sequence variation. These levels were compared to levels of interspecific sequence divergence between D. aizoides and related alpine Draba species. Intraspecific cpDNA sequence divergence was extensive in D. aizoides, and intraspecific differences were often larger than interspecific differences. cpDNA haplotype relationships were explored using a maximum parsimony approach and minimum‐spanning networks. Results from both methods were largely congruent but comparisons provided interesting insights into the presumed evolutionary history of cpDNA haplotypes. A combined effect of cpDNA introgression and complex lineage sorting was inferred to explain the pattern of cpDNA variation found in D. aizoides. Our results suggest that intraspecific cpDNA variation can be extensive and that intraspecific variation needs to be taken into account when inferring phylogenetic relationships among closely related taxa.