bluuebunny/crossref_metadata_2025_split huggingface dataset:
Leukoderma punctatum following systemic PUVA therapy
Authors: Dogra Sunil , Jain Rajesh , Parsad Devinder , Handa Sanjeev 
Published: March 2003

A 35‐year‐old woman with vitiligo vulgaris had been treated with psoralen plus UVA (PUVA) therapy for 15 months. She was given 4,5′,8‐trimethylpsoralen (0.6 mg/kg 3 days/week) and UVA exposure (UV 7001 K Waldmann PUVA chamber). She developed repigmentation over more than 50% of the vitiliginous area over a period of 1 year. During the last 6 months, she developed three to four episodes of acute phototoxic reactions, and UVA exposure had to be interrupted. This phototoxic response was probably partly due to excessive UV radiation exposure of the lesions on exposed sites as a result of the natural bright sunshine in India. On regular monthly assessment, numerous tiny hypopigmented macules, round to oval in shape with sharp margins and measuring about 1.5 mm, were distributed over the repigmented areas (Fig. 1). The lesions were predominantly seen over the extremities and were distributed randomly without any perifollicular or marginal predilection. Considering the typical morphology and distribution of the lesions, a clinical diagnosis of leukoderma punctatum was made and a skin biopsy was taken from one such lesion. On histopathology examination, patchy loss of melanin in the basal layer was observed without any other remarkable change in the epidermis.Multiple, discrete, hypopigmented, punctiform macules measuring about 1&ndash;1.5&nbsp;mm over the thighimage
Wells’ syndrome: a clinical and histopathologic review of seven cases
Authors: Moossavi Meena , Mehregan Darius R. 
Published: March 2003

AbstractWells’ syndrome, or eosinophilic cellulitis, is characterized clinically by an acute dermatitis resembling cellulitis, which evolves into violaceous plaques that resolve spontaneously without scarring. The histopathologic features are dynamic, starting with dermal edema and infiltration of eosinophils, the development of “flame figures,” and finishing with the appearance of phagocytic histiocytes. We present the clinical and histopathologic features of seven cases of eosinophilic cellulitis.
Genotype–environment interaction and the ontogeny of diet-induced phenotypic plasticity in size and shape of Melanoplus femurrubrum (Orthoptera: Acrididae)
Authors: Thompson  
Published: March 2003

Abstract
The developmental origin of phenotypic plasticity in morphological shape can be attributed to environment-specific changes in growth of overall body size, localized growth of a morphological structure or a combination of both. I monitored morphological development in the first four nymphal instars of grasshoppers (Melanoplus femurrubrum) raised on two different plant diets to determine the ontogenetic origins of diet-induced phenotypic plasticity and to quantify genetic variation for phenotypic plasticity. I measured diet-induced phenotypic plasticity in body size (tibia length), head size (articular width and mandible depth) and head shape (residual articular width and residual mandible depth) for grasshoppers from 37 full-sib families raised on either a hard plant diet (Lolium perenne) or a soft plant diet (Trifolium repens).
By the second to third nymphal instar, grasshoppers raised on a hard plant diet had significantly smaller mean tibia length and greater mean residual articular width (distance between mandibles adjusted for body size) compared with full-sibs raised on a soft plant diet. However, there was no significant phenotypic plasticity in mean unadjusted articular width and mandible depth, and in mean residual mandible depth. At the population level, development of diet-induced phenotypic plasticity in grasshopper head shape is mediated by plastic changes in allocation to tissue growth that maintain growth of head size on hard, low-nutrient diets while reducing growth of body size. Within the population, there was substantial variation in the plasticity of growth trajectories since different full-sib families developed phenotypic plasticity of residual articular width through different combinations of head and body size growth.
Genetic variation for diet-induced phenotypic plasticity of residual articular width, residual mandible depth and tibia length, as estimated by genotype–environment interaction, exhibited significant fluctuation through ontogeny (repeated measures MANOVA, family × plant × instar, P &lt; 0.01). For example, there was significant genetic variation for phenotypic plasticity of residual articular width in the third nymphal instar, but not earlier or later in ontogeny. The observed patterns of genetic variation are discussed with reference to short-term constraints and the evolution of phenotypic plasticity.
Does natural selection alter genetic architecture? An evaluation of quantitative genetic variation among populations of Allonemobius
socius and A. fasciatus
Authors: Roff  , Mousseau  
Published: March 2003

Abstract
To make long-term predictions using present quantitative genetic theory it is necessary to assume that the genetic variance–covariance matrix (G) remains constant or at least changes by a constant fraction. In this paper we examine the stability of the genetic architecture of two traits known to be subject to natural selection; femur length and ovipositor length in two species of the cricket Allonemobius. Previous studies have shown that in A. fasciatus and A. socius natural selection favours an increased body size southwards but a decreased ovipositor length. Such countergradient selection should tend to favour a change in G. In the total sample of eight populations of A. socius and one of A. fasciatus we show that there is significant variation in all genetic covariance components, i.e. VA for body size, VA for ovipositor length, and CovA. This variation results entirely from an increase in the covariances of A. fasciatus. However, although larger, these components are approximately proportionally increased, thereby leading to no statistically significant change in the genetic correlation. A proportional increase in the covariance components is consistent with changes resulting from genetic drift. On the other hand, the genetic covariance components are significantly correlated with the length of the growing season suggesting that the change in the genetic architecture is the result of selection and drift.
Reaction norms across and genetic parameters at different temperatures for thorax and wing size traits in Drosophila aldrichi and D. buzzatii
Authors: Loeschcke  , Bundgaard  , Barker  
Published: March 2003

Abstract
Reaction norms across seven constant and one fluctuating temperature of development were measured for thorax length and several wing size traits for up to 10 isofemale lines of each of the cactophilic Drosophila species, D. aldrichi and D. buzzatii, originating from the same locality. Maximum thorax length was reached at different low to intermediate temperatures for the two species, whereas wing length was highest at the lowest temperature in both species. Various ratio parameters showed pronounced species differences. The reaction norm for the wing loading index (wing length/thorax length) decreased monotonically with temperature in both species, but was much steeper and spanned a wider range in D. aldrichi than in D. buzzatii, suggesting either that wing loading is not a good characterization of flight capacity or, more likely, that flight optimization does not occur in the same manner in both species. The vein ratio (distal length/proximal length of the third vein) increased with temperature in D. buzzatii but decreased in D. aldrichi. Wing development in the two species thus is very different, with the proximal part of the wing in D. buzzatii more closely allied to the thorax than to the distal part. Among line variation was significant for all traits in both species, and most pronounced for thorax length and the ratio parameters. Coefficients of variation were significantly different between the species for all traits, with those in D. aldrichi higher than in D. buzzatii. Genetic variance in plasticity was significant for all traits in D. buzzatii, but only for seven out of 12 in D. aldrichi. Additive genetic variances for all traits in both species were significantly larger than zero. Genetic correlations between thorax length and several wing length parameters, and between these and wing area, were positive and generally significant in both species. The genetic correlation between the distal and the proximal length of the third vein was not significantly different from zero in D. aldrichi, but negative and significant in D. buzzatii. Heritabilites varied significantly among temperatures for almost all traits in both species. Phenotypic variances were generally higher in D. aldrichi than in D. buzzatii, and commonly highest at the extreme temperatures in the former species. At the high temperature the genetic variances also were usually highest in D. aldrichi. The data clearly suggest that the process of thermal adaptation is species specific and caution against generalizations based on the study of single species.
Vertebral numbers in male and female snakes: the roles of natural, sexual and fecundity selection
Authors: Shine  
Published: March 2003

Abstract
The relative numbers of trunk (body) and caudal (tail) vertebrae in snakes might be influenced by at least four processes: (1) natural selection for crawling speed, (2) fecundity selection for larger trunk size in females, (3) sexual selection for longer bodies or tails in males and/or (4) developmental constraints (if an increase in the number of body vertebrae requires a decrease in the number of tail vertebrae, or vice versa). These four hypotheses generate different predictions about the relationship between sex differences in the numbers of body vertebrae vs. tail vertebrae. I collated published data to test these predictions, both with raw data and using phylogenetically independent contrasts. Some snake lineages show a negative correlation between the magnitude of sex disparities in trunk vs. caudal vertebrae whereas other lineages show the reverse pattern, or no correlation. Thus, different selective pressures seem to have been important in different lineages. Vertebral numbers in snakes may offer a useful model system in which to explore the conflicts between natural, fecundity and sexual selection.
Effective population size, reproductive success and sperm precedence in the butterfly, Bicyclus anynana, in captivity
Authors: Brakefield P. M. , El Filali E. , Van Der Laan R. , Breuker C. J. , Saccheri I. J. , Zwaan B. 
Published: March 2003

Abstract
A pedigree approach is used to estimate the effective population size yn two population cages of the butterfly, Bicyclus anynana. Each cage was founded with 54 individually marked adults of each sex. Matings were recorded over a 3-day period. Eggs were then collected from each female over a similar period before the numbers of hatching larvae were counted to assess progeny number. The males showed a higher variance in reproductive success than the females. Since about one-quarter of all females mated more than once, we also examined the pattern of sperm precedence using molecular markers or, in separate crossing experiments, wing pattern mutants. Both instances of complete first and last male sperm precedence, as well as of sperm mixing, were found. In some crosses a ‘leakiness’ was found in which some of the early eggs laid by a female were fertilized by a male partner which was subsequently completely unsuccessful. However, the estimates of effective population size were largely unaffected by the pattern of sperm precedence. Estimates for Ne : N in each cage were close to 0.60. The possibility of obtaining comparable estimates in selected natural populations of butterflies is discussed.
Immune stress and facultative sex in a parasitic nematode
Authors: West S. A. , Gemmill A. W. , Graham A. , Viney M. E. , Read A. F. 
Published: March 2003

Abstract
It has been suggested that sexual reproduction in parasites may be advantageous because it helps evade genotype-specific host immune responses. Indirect support for this hypothesis has recently come from work on Strongyloides ratti, a parasitic nematode of rats that develops and reproduces sexually or asexually. In this species, host immune responses against S. ratti lead to a higher proportion of individuals reproducing sexually. However, an alternative explanation for these results is that sex is favoured by general environmental stress, including host responses against antigen sources other than S. ratti. Here we test this hypothesis, by determining how host immunity against two other parasitic nematode species (Nippostrongylus brasiliensis & Strongyloides venezuelensis) and commonly used mammalian antigens (sheep red blood cells) affects the likelihood of S. ratti larvae developing sexually. Our results show that increased levels of sex occur in response to immune responses generated against these other species, and not just host immunity elicited by S. ratti. This is consistent with the idea that sex is favoured under stressful conditions, and does not support the immune evasion hypothesis.
Sexual selection in an isopod with Wolbachia-induced sex reversal: males prefer real females
Authors: Moreau J. , Bertin A. , Caubet Y. , Rigaud T. 
Published: March 2003

Abstract
A variety of genetic elements encode traits beneficial to their own transmission. Despite their ‘selfish’ behaviour, most of these elements are often found at relatively low frequencies in host populations. This is the case of intracytoplasmic Wolbachia bacteria hosted by the isopod Armadillidium vulgare that distort the host sex ratio towards females by feminizing the genetic males they infect. Here we tested the hypothesis that sexual selection against Wolbachia-infected females could maintain a polymorphism of the infection in populations. The infected neo-females (feminized males) have lower mating rates and received less sperm relative to uninfected females. Males exhibited an active choice: they interacted more with uninfected females and made more mating attempts. A female behavioural difference was also observed in response to male mating attempts: infected neo-females more often exhibited behaviours that stop the mating sequence. The difference in mating rate was significant only when males could choose between the two female types. This process could maintain a polymorphism of the infection in populations. Genetic females experimentally infected with Wolbachia are not exposed to the same sexual selection pressure, so the infection alone cannot explain these differences.
Deconstructing a floral phenotype: do pollinators select for corolla integration in Lavandula latifolia?
Authors: Herrera C. M. 
Published: March 2003

Abstract
An experimental field study was undertaken to assess whether correlational selection generated by pollinators can account for observed phenotypic integration of the two corolla lips in the zygomorphic flowers of the insect-pollinated Mediterranean shrub, Lavandula latifolia (Labiatae). The experiment consisted of manipulating the upper and lower corolla lips according to a two-way factorial design with interaction, and involved the complete (lower lip) or extensive (distal two thirds of upper lip) excision of one or the two lips. Per-flower male (proportion of pollen grains removed) and female (number of pollen tubes down the style) pollination success, and maternal fecundity (seed set), of experimental flowers were evaluated after exposure to natural pollination in the field. Artificially induced corolla variation had no significant effects on either male or female pollination success, and two aberrant floral morphologies, characterized by lack of corolla integration, had a maternal fecundity advantage over normal two-lipped phenotypes. These results do not support a predominant role of correlational selection by pollinators in maintaining corolla integration in L. latifolia, but are instead consistent with the alternative view that integration is mainly the consequence of genetic and/or developmental factors.
Sex differences in survival selection in the serin, Serinus serinus
Authors: Björklund M. , Senar J. C. 
Published: March 2003

Abstract
Natural selection is demonstrated in most natural populations which suggests that populations are dispatched from their adaptive peaks as a result of selection on correlated characters, or conflicting selection between the sexes. We analysed patterns of survival selection in a population of serins (Serinus serinus) outside Barcelona over a period of 13 years. There was directional selection for increased wing length in males and females accompanied by strong disruptive selection on both tail and wing length in males and a selection against a positive correlation between the two characters in males. In females there was directional selection for increased bill width but decreased bill depth, which should be contrasted to the stabilizing selection acting on bill depth in males. There were conflicting selection on the characters within a sex and conflicting selection of the same characters between sexes, which constrain the rate of access to the nearest adaptive peak.
Phylogeography of a Palaearctic sedentary passerine, the willow tit (Parus montanus)
Authors: Kvist L. , Martens J. , Ahola A. , Orell M. 
Published: March 2003

Abstract
We analysed variation of the mitochondrial control region from willow tits through its Palaearctic distribution range. Although we found high amount of genetic variation (π=1.114%), there was almost no differentiation between subspecies or geographical localities. This may be because of a combination of several ecological and genetic factors, including a relatively homogenic habitat through the distribution range, lack of geographical barriers, high gene flow and a large long-term effective population size. On the contrary, in the songar tit, which is sometimes considered to be conspecific with the willow tit, the mitochondrial lineages seem to correlate with the geographical locality and are clearly distinct from the willow tit. We concluded that the common ancestors of willow and songar tits existed some 1.5–2 Myr ago in the south-eastern Asia. After the last Ice Ages, the willow tit expanded all through the Palaearctic, whereas the songar tit remained in eastern Asia.
Multiple mating, sperm transfer and oviposition pattern in the giant sperm species, Drosophila bifurca
Authors: Méry F. , Joly D. 
Published: March 2003

Abstract
Many diverse traits are involved in gamete systems, and several models have analysed sperm length variation in terms of the intensity of sperm competition. This study investigates mating, sperm transfer and oviposition patterns in Drosophila bifurca, which possesses the longest sperm in the animal kingdom (about 6 cm). The prediction is that sperm gigantism should prevent male–male interaction. In this study, we examine how sperm transfer varies as males mate with a series of females, and how female receptivity changes with time after mating. As predicted, we found an extremely limited overlap of ejaculates owing to (1) reduced sperm transfer to females that had already mated, and (2) female remating depended both on the amount of sperm transferred and the modes of egg laying. The amount of sperm transferred to the female is discussed in relation to the peculiar morphology of the male reproductive tract and to sexual dimorphism and ecological hypotheses.
Genetic variability and phylogeographical patterns of a nonindigenous species invasion: a comparison of exotic vs. native zebra and quagga mussel populations
Authors: Stepien C. A. , Taylor C. D. , Dabrowska K. A. 
Published: March 2003

Abstract
There have been few investigations of the number of founding sources and amount of genetic variability that lead to a successful nonindigenous species invasion, although genetic diversity is believed to play a central role. In the present study, population genetic structure, diversity and divergence patterns were analysed for the zebra mussel Dreissena polymorpha [n=280 samples and 63 putative randomly amplified polymorphic DNA (RAPDs) gene loci] and the quagga mussel D. bugensis (n=136 and 52 loci) from 10 nonindigenous North American and six Eurasian sampling sites, representing their present-day ranges. Results showed that exotic populations of zebra and quagga mussels had surprisingly high genetic variability, similar to those in the Eurasian populations, suggesting large numbers of founding individuals and consistent with the hypothesis of multiple colonizations. Patterns of genetic relationships indicate that the North American populations of D. polymorpha likely were founded by multiple source populations from north-western and northcentral Europe, but not from southcentral or eastern Europe. Sampling areas within North America also were significantly divergent, having levels of gene flow and migration about twice those separating long-established Eurasian populations. Samples of D. bugensis in Lakes Erie and Ontario were significantly different, with the former being more closely related to a native population from the Dnieper River, Ukraine. No evidence for a founder effect was discerned for either species.
The Ratchet and the Red Queen: the maintenance of sex in parasites
Authors: Howard R. S. , Lively C. M. 
Published: March 2003

Abstract
The adaptive significance of sexual reproduction remains as an unsolved problem in evolutionary biology. One promising hypothesis is that frequency-dependent selection by parasites selects for sexual reproduction in hosts, but it is unclear whether such selection on hosts would feed back to select for sexual reproduction in parasites. Here we used individual-based computer simulations to explore this possibility. Specifically, we tracked the dynamics of asexual parasites following their introduction into sexual parasite populations for different combinations of parasite virulence and transmission. Our results suggest that coevolutionary interactions with hosts would generally lead to a stable coexistence between sexual parasites and a single parasite clone. However, if multiple mutations to asexual reproduction were allowed, we found that the interaction led to the accumulation of clonal diversity in the asexual parasite population, which led to the eventual extinction of the sexual parasites. Thus, coevolution with sexual hosts may not be generally sufficient to select for sex in parasites. We then allowed for the stochastic accumulation of mutations in the finite parasite populations (Muller's Ratchet). We found that, for higher levels of parasite virulence and transmission, the population bottlenecks resulting from host–parasite coevolution led to the rapid accumulation of mutations in the clonal parasites and their elimination from the population. This result may explain the observation that sexual reproduction is more common in parasitic animals than in their free-living relatives.