bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cytological diagnosis of bronchopneumonia at post mortem
Authors: Beer T. W. , Maidment G. , Mikel J. J. , van Wyk Q. , Pullinger N. C. 
Published: March 2003

Cytological diagnosis of bronchopneumonia at post mortemWe assessed the value of cytology in the rapid diagnosis of bronchopneumonia at post mortem. Cytology scrapes were taken from 249 lung lobes during 50 autopsies. Slides were stained with a modified Giemsa technique and a neutrophil polymorph score recorded on a scale of 0–3. Histology blocks from the same area were then scored for the degree of bronchopneumonia present. Bronchopneumonia was found histologically in 22 patients, but macroscopic examination had identified only eight of these. A cytological neutrophil polymorph score of 2 or more to indicate bronchopneumonia yielded a sensitivity of 52% and a specificity of 98% in terms of lobes. This gave a positive predictive value of 92% and a negative predictive value of 86% for the presence of bronchopneumonia. All eight patients with a cytology score of 3 had histological evidence of bronchopneumonia. Conversely, all patients with a definitive diagnosis of bronchopneumonia exhibited cytology scores of at least 1. Post mortem cytology scrapes reliably predict bronchopneumonia and are superior to gross examination. This is a rapid, reliable and cheap method that can be readily performed in all necropsy practices.
The effect of nonscreening smears on screening smear results: a statistical analysis with its implications for the NHS cervical screening programme
Authors: Rice S. , Slater D. N. , Hewer E. M. 
Published: March 2003

The effect of nonscreening smears on screening smear results: a statistical analysis with its implications for the NHS cervical screening programmeThis is a statistical analysis of individual NHS Cervical Screening Programme laboratories screening smear ‘pick‐up’ rates (defined here as percentage low grade and percentage high grade of total adequate smears for ages 20–64 years derived from general practitioners and community clinics) in relation to their nonscreening smear workload proportion (here defined as percentage nonscreening smears of total laboratory workload from all sources for all ages). This was achieved by the use of three one way anova models in order to receive a complete overview of the results. The models were applied to the following: (1) Laboratories with a total workload of less than 15 000 general practitioner (GP) and community clinic smears; (2) laboratories with a total workload of greater than 15000 GP and community smears and; (3) all laboratories (i.e. a combination of 1 and 2). The ‘test’ groups within each of these models comprised three subgroups based on the percentage of laboratory workload that consisted of smears from a nonscreening source. This figure ranged from 2.8% to 82.6%. The subgroups were divided so as to contain approximately the same number of laboratories in each one (172 laboratories in total, 42 with workload < 15000 and 130 with > 15000). The results show that laboratories high and low grade pick‐up rates have a positively correlated but variable relationship with the proportion of their workload that consists of nonscreening smears. The results show significance overall at the 5% level for high grade and the 10% level for low grade (high grade at P= 0.045 and low grade at P= 0.071). Significance for laboratories viewing less than 15000 screening smears at the 1% level (high grade P= 0.006 and low grade P= 0.005). They show no significance, however, for laboratories viewing more than 15000 screening smears (high grade P= 0.457 and low grade P= 0.622). There is an intriguing possibility that a greater exposure to abnormal smears results in a greater tendency to detect them. The current data provides no evidence to support the NHS Executive's use of 15000 as a designated figure when quality monitoring and service provision becomes a specific issue. The closure or amalgamation of laboratories with workloads less than this would appear to have no scientific evidence base.
Heterogeneous selective pressures on egg‐hatching time and the maintenance of its genetic variance in a Tetraneura gall‐forming aphid
Authors: AKIMOTO SHIN‐ICHI 
Published: March 2003

1. The performance of gall‐forming aphids is largely dependent on the timing of egg hatch relative to host budburst. This study examined the mode of natural selection acting on egg‐hatching time and the extent of its genetic variance in a Tetraneura aphid.2. The budburst time of the primary host of the aphid varied greatly among individual trees. Egg hatch on a host tree was often asynchronous with host budburst.3. Transplant experiments indicated that egg‐hatching time was subject to heterogeneous selective pressures in heterogeneous host environments.4. Hatching time was compared between half‐sib families. Small nymphs in a half‐sib family tended to hatch later, and this resulted in large within‐family variance in hatching time.5. Small nymphs that hatched late were likely to be selected out during the galling process. Thus, these nymphs may be produced not as bet‐hedging but due to maternal effects. When such maladapted nymphs were not included in analysis, a significant amount of additive genetic variance was detected in hatching time.6. Heterogeneous selection, coupled with density‐dependent regulation of population on respective host trees, probably maintains additive genetic variance in this trait.
Escaping an ecological dead‐end: asexual overwintering and morph determination in the lettuce root aphid Pemphigus bursarius L.
Authors: Phillips S. W. , Bale J. S. , Tatchell G. M. 
Published: March 2003

Summary1. Pemphigus bursarius exhibits a host‐alternating life‐cycle, overwintering as eggs on the primary host plant (poplar) before migrating in summer to the secondary host plant (mainly annual Compositae). A proportion of the population does not produce return migrants (sexuparae) in the autumn but remains in the soil and overwinters as asexual apterae, even after the annual plants have died in early winter. Laboratory and field experiments investigated the biology and overwintering success of these asexual apterae.2. Both temperature and photoperiod are important in morph determination. The highest number of apterae (approximately 50% of progeny) was produced in a 20 °C, LD 18 : 6 h regime. Very few apterae were produced in an alatae‐inducing environment (15 °C, LD 12 : 12 h), but the proportion increased over successive generations.3. Apterae remaining in the soil in the autumn overwintered successfully in large numbers and were able to reinfest directly the root systems of newly planted lettuce grown in the same field in the following growing season.4. Overwintered asexual populations also produced alates in July, which were able to colonise other lettuce plants, indicating that they were not sexuparae. Hence, P. bursarius can avoid the ecological dead‐end that would occur through local patch extinction. Clones can therefore persist indefinitely as both asexual apterae and alatae without the need to return to poplar and undergo the sexual phase of the life‐cycle.
Host‐mediated effects of feeding by winter moth on the survival of Euceraphis betulae
Authors: Staley J. T. , Hartley S. E. 
Published: March 2003

Abstract 1. A potential host‐mediated interaction between the birch‐feeding aphid Euceraphis betulae Koch (Homoptera: Aphididae) and Operophtera brumata L. (Geometridae: Lepidoptera) was investigated, by measuring survival and feeding preference responses of E. betulae to leaves damaged recently by O. brumata larvae.2. Euceraphis betulae survival was considerably lower on damaged foliage than on undamaged foliage, both in field experiments using cages and on potted saplings in laboratory tests.3. Euceraphis betulae did not avoid damaged foliage in field experiments although they did avoid damaged foliage in laboratory preference tests using individual leaves. A link between aphid preference and performance on damaged foliage could therefore be demonstrated in the greenhouse/laboratory but not in the field. Multiple factors may influence feeding preference in the more complex field environment.4. These results suggest that host‐mediated competition may occur between O. brumata and E. betulae, especially in outbreak years when winter moth populations are very high.
Co‐evolution between ectoparasites and their insect hosts: a simulation study of a damselfly–water mite interaction
Authors: Rolff Jens , Vogel Christine , Poethke Hans‐Joachim 
Published: March 2003

Summary1. A simulation model investigating the co‐evolution of water mites infesting their aquatic insect hosts during emergence is presented. The model is based on field and experimental studies of the ectoparasitic water mite Arrenurus cuspidator and the damselfly Coenagrion puella.2. Three scenarios were studied: (1) Only the host was allowed to evolve timing of emergence, while the timing of the parasites' infestation opportunity was held constant. (2) Both host and parasite were allowed to evolve. (3) Only the parasite's timing was allowed to evolve, while the host was constrained completely.3. In the first two scenarios, parasite abundances decreased in the course of evolution and reached values well below those found in the field, whereas in the third scenario, parasite abundances were maintained at a level close to that found in the field. In the second scenario (co‐evolution), the host seemed to be the leader in the evolutionary race.4. It is concluded that water mite parasitism is capable of shaping emergence patterns in aquatic insects and, despite the same life‐cycle length for host and parasite, the parasite evolves fast enough to shape its hatching pattern to match the emergence pattern of its host.
The effect of past and current hosts on reproductive investment by the adult cowpea aphid Aphis craccivora
Authors: Traicevski Violeta , Ward Seamus A. 
Published: March 2003

Abstract 1. A general index of accumulated investment that alate aphids make into reproduction with respect to environmental changes (specifically changes in host at adult moult) was investigated to determine whether and how reproduction in Aphis craccivora Koch changes once aphids migrate to a different host from the one on which they were born and reared. The aphids were monitored for 4 days to determine the immediate effects of a change in host.2. A general index of accumulated investment defined as reproductive index was used; reproductive index is equal to the reproductive output (weight of nymphs born; actual fecundity) plus potential reproduction (weight of embryos within the ovarioles with red eye spots; future fecundity).3. The results revealed that reproductive index is affected by adult weight. The host on which the aphids have been born and reared (source host) has no effect on reproduction other than its influence on adult weight.
Relationships between oviposition date, hatch date, and offspring size in the grasshopper Chorthippus brunneus
Authors: Cherrill Andrew 
Published: March 2003

Abstract 1. The grasshopper Chorthippus brunneus has been shown to increase egg size with maternal age under constant laboratory conditions, such that late‐laid eggs are larger than early laid eggs. In this study, an increase in the size of eggs (and hatchlings from those eggs) was recorded with date of oviposition in a field cage population. This suggests that the relationship between maternal age and egg size, observed previously in the laboratory, also occurs in the field. There was, however, some evidence that the behaviour of the maternal females in field cages was modified by the onset of autumnal weather at the end of the breeding season. Only a small number of eggs was laid in the last 3 weeks of the summer but these yielded relatively small hatchlings.2. The date on which eggs were laid was correlated positively with their date of hatch in the following year. A consequence of this relationship, and that between oviposition date and egg size, was that size at hatch increased with date of hatch through most of the spring but then declined as the last few eggs hatched. Temporal variation in size at hatch parallelled temporal variation in the maternal females' investment in egg size in the previous year.3. An undisturbed field population was monitored to assess whether the temporal variation in size at hatch resulted in size variation at eclosion in subsequent developmental stages. There were negative correlations between size at eclosion and date of eclosion at the third and fourth instars, suggesting that despite their smaller size at hatch, early hatchers experienced more favourable conditions for juvenile growth than late hatchers. The larger size at hatch of late hatchers may enhance their survival and compensate (albeit incompletely) for their reduced opportunity for growth. Female reproductive behaviour may represent an adaptive response to a predictable seasonal decline in offspring fitness at hatch.
Spatial and temporal variation in the parasitoid assemblage of an exophytic polyphagous caterpillar
Authors: Stireman John O. , Singer Michael S. 
Published: March 2003

Abstract1. Over 3400 larvae of the polyphagous ground dwelling arctiidGrammia geneurawere sampled and reared over seven generations in order to characterise its parasitoid assemblage and examine how and why this assemblage varies over time and space at a variety of scales.2. The total parasitoid assemblage of 14 species was dominated both in diversity and frequency by relatively polyphagous tachinid flies.3. Both the composition of the parasitoid assemblage and frequency of parasitism varied strikingly among and within sampling sites, seasons, and years.4. Overall rates of parasitism increased consistently over the duration of caterpillar development.5. Within sampling sites, parasitism rates were non‐random with respect to habitat structure and caterpillar behaviour for the most abundant parasitoid species.6. The large variability in parasitoid assemblage structure over space and time in this system may be a function of local host population abundance, habitat‐specific parasitism, and indirect interactions betweenG. geneuraand other Macrolepidoptera through shared oligophagous and polyphagous parasitoids.
Measuring the sperm competition successes of field males of the yellow dung fly
Authors: Ward Paul I. , Wedell Nina , Hosken David J. , Tregenza Tom 
Published: March 2003

Abstract 1. Sperm competition is extremely common in many species but conclusions about the relative successes of males, measured as the proportion of a female's offspring fertilised by the second male to mate with it, are based largely on laboratory studies using two laboratory‐bred males or on interrupted last copulations.2. A study was conducted in which virgin female yellow dung flies Scathophaga stercoraria mated uninterrupted with two field‐captured males.3. The results confirmed two previous conclusions: the proportion of a female's offspring fertilised by the second male was related strongly to the copula duration of the second male, and the proportion of a female's offspring fertilised by the second male was lower in larger females, though this effect was weak.4. The results indicate that previous experiments on laboratory populations of this species are likely to be relevant to wild situations, but researchers are urged to conduct studies that will improve the confidence with which laboratory measures of the proportion of a female's offspring fertilised by the second male can be assumed to reflect the sperm precedence of the last male to mate in natural situations.
Life history of Kladothrips ellobus and Oncothrips rodwayi: insight into the origin and loss of soldiers in gall‐inducing thrips
Authors: Kranz Brenda D. , Schwarz Michael P. , Morris David C. , Crespi Bernard J. 
Published: March 2003

Summary1. The evolution of eusociality in Australian gall‐inducing thrips cannot be understood without comparisons among closely related solitary species. The life history of two solitary, gall‐inducing thrips, Kladothrips ellobus and Oncothrips rodwayi, was investigated, and data for solitary and eusocial species from previous studies were re‐analysed. Kladothrips ellobus is in a clade that is closely related to the eusocial species. Oncothrips rodwayi is in the same clade as the eusocial species and appears to have undergone an evolutionary loss of eusociality. It is the only galling thrips on Acacia in temperate environments.2. The brood size of K. ellobus is eight to 23 times larger than broods of foundresses in eusocial species whereas the brood size of O. rodwayi is not significantly different from those of foundresses in eusocial species.3. In K. ellobus, the mean sex ratio was not significantly different from parity but in O. rodwayi the mean sex ratio was 0.13 male. In O. rodwayi, 77% of females were inseminated by their brothers before dispersal, which is consistent with high levels of inbreeding in eusocial species of the same clade. Sex ratios suggest random mating in K. ellobus whereas female‐biased sex ratios in O. rodwayi are consistent with inbreeding and local mate competition.4. Comparisons among solitary and eusocial species suggest that large brood size is an ancestral trait for eusociality in thrips, and this trait persists in solitary species as an r‐selection strategy. Soldiers may have evolved in arid environments to minimise the risks of dispersal and the costs of latency to reproduction, and to maximise gall defence.5. Temperate conditions could have facilitated the evolutionary loss of soldiers in O. rodwayi, as there should be a shorter, safer, more predictable window period between dispersal and gall induction, reducing the period of latency to reproduction following dispersal and lowering risks of dispersal.6. The loss of soldiers in O. rodwayi is not associated with a reversion to the large brood sizes of solitary species in ancestral lineages.
Augmentation of the number of nucleolar organizer regions in human megakaryocyte cell lines after induction of polyploidization by a microtubule inhibitor
Authors: Baatout  , Chatelain  , Staquet  , Symann  , Chatelain  
Published: March 2003

BackgroundMegakaryocyte polyploidization is an advantageous and regulated mechanism that leads to an increase in platelet production. In megakaryocytic cell lines, polyploidization can be obtained by using colchicine, an inhibitor of the tubulin spindle. The nucleolar organizer regions (AgNORs) are parts of nucleolar DNA transcribed into ribosomal RNA and are detected by the silver‐staining technique. Their number is proportional to protein synthesis.ResultsTo estimate protein synthesis in polyploid megakaryocytes, AgNORs are measured in three cell lines with megakaryocyte properties (DAMI, HEL and K562) after a 4‐day culture in the presence or absence of colchicine. The mean number of AgNORs per cell was 16 ± 4 (mean ± SEM), 24 ± 3 and 14 ± 3 for DAMI, HEL and K‐562 cell lines respectively. The addition of colchicine (10 ng mL−1) significantly increased the number of AgNORs per cell (DAMI 556%, HEL 338% and K‐562 300% of controls, P < 0.05 using the t‐test). Moreover, the number of nucleoles per cell after the addition of colchicine was augmented significantly (DAMI 246%; HEL 237% and K‐562 148% of controls, P < 0.05 using the t‐test). The total protein content estimated by Bradford's method increased significantly to 226%, 215% and 304% of controls in DAMI, HEL and K562 respectively (P < 0.05 using the t‐test). After treatment with colchicine, the endomitotic index (EI) [mean of (log2 DNA content expressed in N) — 1] measured by flow cytometry (and reflecting ploidy) increased to 234%, 255% and 301%, respectively, in DAMI, HEL and K‐562 cell lines (P < 0.05 using the t‐test). Concomitantly, the number of AgNORs per unit of DNA increased in the DAMI and HEL cell lines (P < 0.05 using the t‐test) from 48 ± 8 and 39 ± 5, respectively, to 79 ± 11 and 61 ± 10. In contrast, the number of nucleoles and the total protein content per endomitotic index were not affected by colchicine (P  > 0.05 using the t‐test), but the number of nucleoles per endomitotic index of DAMI cells was affected.ConclusionThe increase in the number of the NORs induced by an agent known to stimulate polyploidization of megakaryocytic cell lines suggests that polyploidization occurs by a proportional increase in protein synthesis per DNA unit.
Forearm composition contributes to differences in reactive hyperaemia between healthy men and women
Authors: Wascher  , Bammer  , Stollberger  , Bahadori  , Wallner  , Toplak  
Published: March 2003

BackgroundPost‐ischaemic reactive hyperaemia in the forearm has been suggested as a marker of resistance vessel function. The contribution of forearm composition to the kinetics of reactive hyperaemia is largely unknown. The body composition of men and women differs in that women have a higher body fat content and less lean body mass.MethodsIn the present study, we investigated whether the kinetics of reactive hyperaemia in the forearm in 14 healthy subjects (seven men and seven women) show gender‐specific differences and whether forearm composition contributes to such differences.ResultsPeak reactive hyperaemic flow as well as 1‐min‐flow debt repayment (measured by venous occlusion plethysmography) were significantly higher in male than in female study participants. This difference was explained to > 60% by gender‐specific differences in forearm relative muscle mass (as determined by magnetic resonance imaging). The half‐life of the reactive hyperaemic response, on the other hand, was not different between men and women and did not show an association with forearm muscle.ConclusionOur results demonstrate that forearm composition must be considered if peak reactive hyperaemia or flow debt repayment is used as a target, and that dynamic measurements of the reactive hyperaemic process are more suitable to describe the function of resistance arteries than single‐point observations.
Gastric emptying of the liquid, solid and oil phase of a meal in normal volunteers and patients with Billroth II gastrojejunostomy
Authors: Maes  , Hiele  , Geypens  , Ghoos  , Rutgeerts  
Published: March 2003

BackgroundThe relationship between gastric emptying of different phases of a meal in humans has only been partly studied in normal subjects and in patients with previous gastric surgery.MethodsIn the present study, gastric emptying of the liquid, solid and oil phase and the relationship between the phases was evaluated in 10 normal control subjects and in seven patients with Billroth II gastrojejunostomy using breath test technology.ResultsGastric emptying in normal subjects showed a clear separation between the emptying of the liquid, solid and oil phase. In healthy volunteers, the liquid phase emptied in the same manner in the presence of a solid phase as in the presence of an oil phase. In contrast, the oil phase emptied more slowly with liquids than with solids. The emptying rate of the oil phase was not only inversely related to the amount administered but was also dependent on its chemical composition. Gastric emptying in patients with Billroth II gastroenterostomy was characterized by a complete loss of discrimination between the different phases of the meal, with an extremely fast emptying of the oil phase compared with normal control subjects.ConclusionIn normal subjects, the liquid, solid and oil phase of a meal are emptied differently. In patients with Billroth II gastrojejunostomy, dumping of the oil phase is the most pronounced difference from the normal physiology of gastric emptying. This could be one of the reasons why Billroth II gastrectomy may be associated with fat malabsorption.