bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interlaboratory reproducibility of the immunocytochemical assessment of oestrogen and progesterone receptors and proliferative activity in fine needle aspiration of breast cancer
Authors: CONFORTINI M. , CAROZZI F. , BOZZOLA L. , MICCINESI G. , MIRRI F. , MOTTOLESE M. , NOFERINI D. , NIZZOLI R. , TINACCI G. , VOCATURO A. , ZAPPA M. , MADDAU C. 
Published: March 2003

Interlaboratory reproducibility of the immunocytochemical assessment of oestrogen and progesterone receptors and proliferative activity in fine needle aspiration of breast cancer The purpose of this study was to establish the interlaboratory reproducibility of immunocytochemical analysis of oestrogen (ER) and progesterone (PR) expression and Mib1 growth fraction on fine needle aspiration (FNA) smears. A set of 44 immunostained slides for ER, PR and Mib1 were randomly selected from the archives of the Center for the Study and Prevention of Cancer (CSPO) of Florence, Italy, and submitted for reading to 6 Italian laboratories. The generalized kappa statistic was used as an indicator of agreement among the six laboratories. A good correlation for ER and PR was evident. For Mib1 the results showed some discrepancies. In addition to adequate standardization of procedures, these data confirm that the reliability of the immunocytochemistry is strictly linked to accurate analysis of the results.
Nutritional reserves regulate male participation in Mediterranean fruit fly leks
Authors: YUVAL BOAZ , KASPI ROY , SHLOUSH SHLOMIT , WARBURG MEIRAV S. 
Published: March 2003

1. The mating system of Mediterranean fruit flies (Ceratitis capitata, Diptera: Tephritidae), is based on male leks that form on the foliage of trees. Following observations that not all males participate in leks, the hypotheses that (a) small males are absent from leks and (b) males with inadequate nutrient reserves are unable to participate in leks were examined.2. The size and weight of lekking males (n = 183) and resting males captured at the same time in the vicinity of leks (n = 148) were established. In addition, using biochemical techniques, the amounts of sugar, glycogen, lipid and protein in each individual were established quantitatively.3. There was no significant size difference between lekking and resting males. However, lekking males were significantly heavier and contained significantly more sugars and protein than resting males.4. In conclusion, leks are exclusive, and only males with adequate nutritional reserves may join. Thus, in this species, reproductive success is closely linked to foraging success.
Social biology and sex ratios of the eusocial gall‐inducing thrips Kladothrips hamiltoni
Authors: Kranz Brenda D. , Schwarz Michael P. , Mound Laurence A. , Crespi Bernard J. 
Published: March 2003

Summary1. Thrips comprise the only order besides Hymenoptera where females are diploid and males are haploid. This makes them useful insects for studying the roles of kin selection and ecology in social evolution.2. Kladothrips hamiltoni is one of six species of Australian gall‐inducing thrips that have been identified as eusocial. Galls are initiated by a single foundress, who rears her brood and remains within the enclosed gall for life. The adults of both sexes of her first brood cohort are morphologically distinct from the second generation, comprising a nondispersing soldier caste. The foundress and sib‐mated soldiers jointly produce a second, dispersing generation, approximately 60–80% of which are produced by the soldiers. Mean per capita egg production of female soldiers is less than 33% that of the foundress.3. Adult eclosion of soldiers is protandrous but the overall sex ratio of the soldiers lacks bias (52% male). Protandry of soldiers increases the probability that female soldiers will be inseminated soon after their eclosion and therefore lay fertilised, female eggs. The lack of bias could be due to a balance between local resource competition and local mate competition. Gender‐specific defensive behaviour of soldiers with their enemies may also be important in explaining this unexpected sex ratio.4. The dispersing generation has an overall extreme female bias (5.6% male). Soldier incest increases relatedness between females more than between males, such that the foundress is more related to her granddaughters than her daughters, and female soldiers are more related to their daughters than their sons (assuming within‐gall relatedness < 1). A female bias in the offspring of soldiers should be preferred by both the foundress and soldiers as they are more related to soldier‐produced dispersing females than any other thrips in the gall. Female bias in the dispersing generation will also reduce local mate competition between males. Both soldier incest and local mate competition may therefore contribute to the extreme female bias in the dispersing generation.5. Selection pressures for sociality in gall‐inducing thrips appear to be more similar to those in gall‐inducing aphids and naked mole rats than to those in Hymenoptera.
The influence of host plant variation and intraspecific competition on oviposition preference and offspring performance in the host races of Eurosta solidaginis
Authors: Craig Timothy P. , Itami Joanne K. , Shantz Cathleen , Abrahamson Warren G. , Horner John. D. , Craig James V. 
Published: March 2003

Summary1. A series of experiments was conducted to measure the impact of plant genotype, plant growth rate, and intraspecific competition on the oviposition preference and offspring performance of the host races of Eurosta solidaginis (Diptera: Tephritidae), a fly that forms galls on Solidago altissima and Solidago gigantea (Asteraceae). Previous research has shown that both host races prefer to oviposit on their own host plant where survival is much higher than on the alternate host plant. In this study, neither host race showed any relationship between oviposition preference and offspring performance in choosing among plants of their natal host species.2. The larval survival of both host races differed among plant genotypes when each host race oviposited on its natal host species. In one experiment, altissima host race females showed a preference among plant genotypes that was not correlated with offspring performance on those genotypes. In all other experiments, neither the altissima nor gigantea host race demonstrated a preference for specific host plant genotypes.3. Eurosta solidaginis had a preference for ovipositing on rapidly growing ramets in all experiments, however larval survival was not correlated with ramet growth rate at the time of oviposition.4. Eurosta solidaginis suffered high mortality from intraspecific competition in the early larval stage. There was little evidence, however, that females avoided ovipositing on ramets that had been attacked previously. This led to an aggregated distribution of eggs among ramets and strong intraspecific competition.5. There was no interaction among plant genotype, plant growth rate, or intraspecific competition in determining oviposition preference or offspring performance.
A comparison of bumblebees’ movements in uniform and aggregated distributions of their forage plant
Authors: Cresswell James E. 
Published: March 2003

Summary1. Movements by bumblebees Bombus lapidarius were studied in arrays of plants of oil‐seed rape Brassica napus cv Westar. In the arrays, plants were arranged into either a uniformly dispersed configuration or a patchily dispersed configuration.2. Progress across an array was measured as the distance bumblebees had moved away from an original plant location after eight subsequent, successive plant visits. Movements were analysed in units of both metres and inter‐plant spaces. In both units, bumblebees progressed more slowly across patchily dispersed arrays.3. Plant dispersion had a detectable effect on certain components of bees’ individual inter‐plant moves (e.g. move length in metres) but not on others (e.g. mean turning angle). In some cases, the effects of aggregation on the components of individual moves were probably too small to detect statistically and only emerged in their cumulative effect on bees’ progress.4. Over short sequences of plant visits, bumblebees revisited plants rarely, but the frequency of revisits was almost twice as high in patchy arrays as in uniform arrays, and economic penalties may result from foraging among highly aggregated plants.5. The effects of plant dispersion on pollinator movements detected in this study are unlikely to have a major impact on pollen transfer in B. napus because differences in pollinator progress only emerged after several successive inter‐plant flights away from a potential pollen source, by which time the limited extent of pollen carryover in this species means that fertilisations from the source plant would be very rare.
Marginal range expansion in a host‐limited butterfly species Gonepteryx rhamni
Authors: Gutiérrez David , Thomas Chris D. 
Published: March 2003

Summary1. The British distribution of the butterfly Gonepteryx rhamni (L.) follows closely the range of its natural host plants, Rhamnus catharticus L. and Frangula alnus Miller, suggesting that it is one of the few British butterflies that has a host‐limited distribution. In North Wales, this species has its range margin, and it was recorded only occasionally in a 35‐km2 area prior to the 1980s. Frangula alnus bushes were planted in the area in about 1986, allowing the hypothesis that G. rhamni would expand its range following increased host plant availability to be tested.2. From 1996 to 1998, the distribution of the butterfly and its host plants, R. catharticus (native), Rhamnus alaternus L. (introduced), and F. alnus (introduced to the area but native to Britain), was mapped in the study area. It was found that the butterfly was more widespread than any of its host plants. Frangula alnus was the most widespread of the host plants, and received most eggs, suggesting that the carrying capacity of the habitat would have increased substantially following the planting of this species. Gonepteryx rhamni was able to complete its lifecycle on both introduced species in the study area.3. A mark–release–recapture study showed that adult G. rhamni moved an average of 512 m, and 50% of movements were further than 400 m; these values are underestimates. The relatively high mobility of this species suggests that it probably perceives host plants and nectar sources as resource patches (patchy population) in this fragmented landscape, and this population now represents a satellite population of the butterfly's main distribution in Britain.4. The results presented here confirm empirically the host‐limited distribution of G. rhamni, which expanded following the planting of extra host plants.
Associations between host migration and the prevalence of a protozoan parasite in natural populations of adult monarch butterflies
Authors: Altizer Sonia M. , Oberhauser Karen S. , Brower Lincoln P. 
Published: March 2003

Summary1. Monarch butterfliesDanaus plexippus(L.) (Lepidoptera: Nymphalidae) are susceptible to infection by the obligate protozoan parasiteOphryocystis elektroscirrha(McLaughlin and Myers) (Apicomplexa: Neogregarinida). Because monarchs form resident and migratory populations in different parts of the world, this host–parasite system provides the opportunity to examine how variation in parasite prevalence relates to host movement patterns.2. Parasite prevalence was evaluated using 14 790 adult monarchs captured between 1968 and 1997. Comparison of three populations in North America indicated that parasite prevalence is associated negatively with host dispersal distances. A continuously breeding, nonmigratory population in southern Florida showed high prevalence (over 70% heavily infected). The western population migrates moderate distances to overwintering sites on the Pacific Coast and has intermediate prevalence (30% heavily infected). The eastern migratory population, which travels the longest distance to Mexican overwintering sites, has exhibited less than 8% infection throughout the past 30 years.3. Variation in parasite loads within North American migratory populations was investigated to determine whether the prevalence of heavy infection and average parasite loads declined during migration or overwintering. Average parasite loads of summer‐breeding adults in western North America decreased with increasing distance from overwintering sites. This suggests that heavily infected monarchs are less likely to remigrate long distances in spring. No differences in the frequency of heavily infected adults were found among eastern or western North American monarchs throughout the overwintering period, however, suggesting that this parasite does not affect overwintering mortality.4. Changes in the prevalence of monarchs with low parasite loads demonstrate that spore transfer occurs during migration and overwintering, possibly when adult butterflies contact each other as a result of their clustering behaviour.5. This study of geographical and temporal variation inO. elektroscirrhaamong populations ofD. plexippusdemonstrates the potential role of seasonal migration in mediating interactions between hosts and parasites, and suggests several mechanisms through which migratory behaviour may influence parasite prevalence.
Fitness and body size in mature odonates
Authors: Sokolovska Natalia , Rowe Locke , Johansson Frank 
Published: March 2003

SummaryThe relationship between body size and fitness components in odonates was examined using a meta‐analysis of 33 published studies. There was a positive and significant overall effect of body size on mating rate and lifetime mating success among males. There was also a weaker but still significant positive effect of body size on survivorship of males. The relationship between body size, mating rate, longevity, and lifetime mating success differed significantly between males of territorial and nonterritorial species. The effect of body size was significant for all fitness components in territorial species but significant only for longevity and lifetime mating success in nonterritorial species. Effect sizes appeared to be strongest on longevity in both sexes, and on male mating rate in territorial species. Other effect sizes, even when significant, were small. Despite a much smaller data set, female fitness also increased significantly with body size. Both clutch size and longevity showed a significant positive relationship with body size. These results suggest that there is a general fitness benefit to large size in odonates. Nevertheless, significant heterogeneity is apparent in this effect, which can be attributed to sex, mating system, and fitness component. Finally, these analyses point to inadequacies in the current data that need further study before the potentially rich patterns in size effects on fitness can be explored more thoroughly.
An economic model of the limits to foraging range in central place foragers with numerical solutions for bumblebees
Authors: Cresswell James E. , Osborne Juliet L. , Goulson David 
Published: March 2003

Summary1. A model is described that evaluates the maximum economic foraging range in central place foragers by using optimality criteria to discriminate between foraging sites at different distances from the forager's central place.2. The basic model can be varied to suit foragers that optimise either their rate of net energy uptake or their foraging efficiency.3. The model requires specification of the time and energy budgets of travel and foraging, and of the rewards obtainable at potential foraging sites.4. The specific case of bumblebees, whose foraging ranges are poorly known, is considered.5. Numerical solutions of the model for parameter values that represent bumblebees and their forage predict economic foraging ranges exceeding several kilometres. The model demonstrates that economics alone can explain extensive flight ranges in bees.
Aphid‐induced reduction of shoot and root growth in Douglas‐fir seedlings
Authors: Smith J. P. , Schowalter T. D. 
Published: March 2003

Summary1. The short‐ and long‐term effects of photosynthate removal by sap‐sucking herbivores on plant growth were examined by experimentally manipulating densities of an aphid Cinara pseudotsugae (Wilson) on 2‐year‐old Douglas‐fir seedlings Pseudotsuga menziesii (Mirb.) Franco under greenhouse conditions. An 18‐week test was conducted to determine short‐term effects. Effects of long‐term aphid feeding were examined by exposing seedlings to aphid feeding for two consecutive growing seasons. A third experiment evaluated the extent of recovery during 1 year following a single season of aphid feeding. At least 35 seedlings were used in each test.2. Volume and dry weight of both shoots and roots decreased significantly with increasing aphid feeding in all three experiments.3. The most significant and severe aphid effect was reduced root tissue density, suggesting carbohydrate depletion due to translocation from roots to shoots.4. There was no sign of recovery, of either root or shoot growth, during the year following one season of feeding.5. The results of this study indicate that short‐term feeding by aphids can affect plant growth and structure for a relatively long time.
Spiders and harvestmen as gastropod predators
Authors: Nyffeler Martin , Symondson William O. C. 
Published: March 2003

Summary1. Reports are reviewed of gastropod feeding (malacophagy) by spiders and harvestmen. Although the standard textbooks on arachnids recognise the importance of gastropods as prey of harvestmen, none apparently refers to malacophagy by spiders. A review of several hundred papers on spider feeding habits revealed that species from several families kill and devour slugs and snails in the laboratory and/or field.2. Malacophagy has been reported most frequently among mygalomorph spiders, and can make up a substantial proportion of the diets of some species, however gastropods make up an insignificant percentage of the prey of most araneomorph spiders. The spiders that eat gastropods are species with broad diets composed predominantly of arthropod prey. No species of spider appears to feed exclusively on gastropod prey.3. Harvestmen from several families have broad diets that often include gastropods. Several species of the family Trogulidae and at least one species of the family Ischyropsalididae [Ischyropsalis hellwigi (Panzer)] are specialised gastropod predators. The trogulids are slender animals that attack the snail through the shell aperture (shell intruders). Ischyropsalis hellwigi, on the other hand, can crush snail shells with its powerful chelicerae (shell breakers).4. The review highlights apparent convergent evolution by harvestmen and Carabidae of two mutually exclusive morphologies found among gastropod predators. It also suggests that there is an urgent need for systematic studies to be conducted to establish the extent and ecological importance of malacophagy in natural and anthropogenically altered habitats.
Gamete production and sexual size dimorphism in an insect (Orchesella cincta) with indeterminate growth
Authors: Ernsting G. , Isaaks J. A. 
Published: March 2003

Abstract 1. The relationship of growth and body size with reproductive effort in animal species has been studied much less for males than for females. This imbalance applies to Orchesella cincta (L.) (Collembola), an insect with indeterminate growth, in which egg production is related positively to body size and negatively to growth.2. To allow a comparison of the reproductive effort of male and female O. cincta, development and growth in immature stages of both sexes, and growth and spermatophore production for adult males were studied.3. Embryonic development time and hatchling size did not differ between prospective males and females, but from hatching on the trajectories diverged, with males growing more slowly and maturing earlier and at a much smaller body size than females.4. Neither the number of spermatophores deposited in the first adult instar (= inter‐moult period) nor the total number of spermatophores deposited during seven instars was related to body size or growth.5. Differences in growth rate between instars with and without spermatophore deposition indicated that the physiology of spermatophore production inhibits growth, which, however, was compensated for during the next instar.6. The difference in the relationship of gamete production with body size and growth between males and females explains the divergence of their size at maturity.
Migration and Allee effects in the six‐spot burnet mothZygaena filipendulae
Authors: Menéndez Rosa , Gutiérrez David , Thomas Chris D. 
Published: March 2003

Abstract1. Migration into local populations may increase the likelihood of persistence but emigration may decrease the persistence of small and isolated populations. The dispersal behaviour of a day‐flying mothZygaena filipendulaewas examined to determine whether emigration is correlated positively or negatively with population size and host plant density.2. A mark–release–recapture study showed that most moths moved small distances (< 40 m on average) and only 6% of movements were > 100 m.3. Twenty‐five individuals moved between populations, a measured exchange rate of 8%. Moths were more likely to move between patches that were close together and they moved to relatively large patches.4. The fraction of residents increased with increasing population size in the patch and increasing host plant cover. Relatively high proportions of individuals left small patches with small moth populations.5. Moths released in grassland lackingLotus corniculatus(the host plant) tended to leave the area and biased their movement towards host plant areas, whereas those released within an area containingL. corniculatustended to stay in that area.6. Biased movement away from small populations and areas of low host plant density (normally with low population density) was found. This migration‐mediated Allee effect is likely to decrease patch occupancy in metapopulations, the opposite of the rescue effect. The effects on metapopulation persistence are not known.
An experimental examination of the effects of habitat quality on the dispersal and local abundance of the butterfly Parnassius smintheus
Authors: Matter Stephen F. , Roland Jens 
Published: March 2003

Abstract 1. Nectar flower abundance was manipulated through flower removal, and sex ratio was manipulated by moving individual butterflies within a series of nine alpine meadows. The movement and abundance of the butterfly Parnassius smintheus in the meadows were monitored using mark–release–recapture methods.2. A total of 937 butterflies, 698 males and 239 females, was captured. There were 223 observed between‐meadow movements. Fifty‐two per cent of males and 35% of females moved among meadows.3. The immigration of male butterflies was related positively to nectar flowers, host plant abundance, and female butterflies. Male emigration was not affected by any of the treatments. The number of males captured was related positively to nectar flowers and host plants but not affected by sex ratio. The number of resident male butterflies was greater in meadows containing flowers and was related positively to host plant abundance, but unaffected by sex ratio.4. Flower removal, sex ratio, and abundance of Sedum had no significant effect on the abundance, movement, or residence time for female butterflies, in part due to small sample size.5. The fact that males immigrate to higher quality meadows suggests that male butterflies are assessing meadow quality, either by sampling meadows or potentially from a distance using olfactory cues.