bluuebunny/crossref_metadata_2025_split huggingface dataset:
metasim 1.0: an individual‐based environment for simulating population genetics of complex population dynamics
Authors: Strand Allan E. 
Published: March 2003

Abstract metasim provides a flexible environment in which to perform individual‐based population genetic simulations. A wide range of landscape‐level dynamics, population structures, and within‐population demographies can be represented using the framework implemented in this software. In addition, temporal variation in all demographic characteristics can be simulated, both deterministically and stochastically. Such simulations can be used to produce null distributions of genotypes under realistic conditions. These genotypic data can then be used by a variety of analytical programs to develop null expectations of any population genetic statistic estimated from genotypic data.
Characterization of polymorphic microsatellite loci in the red harvester ant, Pogonomyrmex barbatus
Authors: Volny Veronica P. , Gordon Deborah M. 
Published: March 2003

AbstractThe red harvester ant, Pogonomyrmex barbatus, is a monogynous, polyandrous species: each ant colony is founded by a single queen that has mated with one or more males. To study levels of polyandry within a colony, as well as relationships among colonies, we developed 10 polymorphic microsatellite loci for P. barbatus. With the number of alleles per locus ranging from 3 to 39, and expected heterozygosities of 0.58–0.95, these markers promise to be useful in the study of colony and population genetic structure.
Group‐specific polymerase chain reaction amplification of SSU rRNA‐encoding gene fragments from 12 microbial taxa
Authors: Van Borm Steven , Boomsma Jacobus J. 
Published: March 2003

AbstractStarting from an alignment of all known representatives in GenBank, we designed group specific primers targeting SSU rRNA‐encoding sequences of 12 microbial taxa known to contain insect pathogens and symbionts. We tested the specificity of these primers using representative species of all 12 groups as control templates. Polymerase chain reaction amplification conditions were modified until only group‐specific templates yielded a positive signal. The presented primer pairs thus allow for the amplification of SSU rRNA‐encoding sequences representing specific microbial groups directly from the environment (a social insect host in our study). We discuss possible applications of the identified molecular tools.
identix, a software to test for relatedness in a population using permutation methods
Authors: Belkhir Khalid , Castric Vincent , Bonhomme François 
Published: March 2003

AbstractThe computer program identix estimates relatedness in natural populations using multilocus genotypic data. Queller & Goodnight's (1989) and Lynch & Ritland's (1999) estimators of pairwise relatedness are implemented, as well as the identity index of Mathieu et al. (1990). Estimates of the confidence intervals around these pairwise values are also provided. The null hypothesis of no relatedness (multilocus genotypes are independent draws from a panmictic population) is tested using a permutation method that compares the observed distribution of the moments of pairwise relatedness coefficients to that expected in unstructured population.
Characterization of polymorphic microsatellite markers in the adder, Vipera berus
Authors: Carlsson M. , Isaksson M. , Höggren M. , Tegelström H. 
Published: March 2003

AbstractMicrosatellite DNA markers can yield sufficient resolution for individual identification as well as provide genetic information on a larger, interpopulational scale. Here we present details on six microsatellite primer pairs developed for the adder, Vipera berus. The number of alleles found varied between 2 and 38 per locus. The objectives behind developing these markers included assessment both of paternity and population histories from different parts of the species’ range. Cross‐species amplification indicated that these markers may also be useful for studies of other species within the Viperidae family.
Microsatellite loci in the cactophilic species Drosophila antonietae (Diptera; Drosophilidae)
Authors: Machado L. P. B. , Manfrin M. H. , Silva‐Junior W. A. , Sene F. M. 
Published: March 2003

AbstractMorphometric and isoenzymatic data have showed little variation among Drosophila antonietae populations. This suggests historic gene flow, due to the distribution of these populations, which are associated with cacti along rivers, and natural selection on these markers. Microsatellite loci have high variability and are ideal for detecting gene flow and analysing population structure. Here we describe the isolation of seven polymorphic microsatellite loci in D. antonietae.
Polymorphic microsatellites isolated from the cave fish Astyanax fasciatus
Authors: Strecker U. 
Published: March 2003

AbstractSix polymorphic microsatellite loci from a library of the tetra Astyanax fasciatus from Mexico were isolated. Amplification and heterozygosity were tested in four cave and four surface populations. These loci were developed for population genetic study to detect gene flow between cave and surface populations.
Human papillomavirus molecular biology and pathogenesis
Authors: Sanclemente G , Gill DK 
Published: March 2003

AbstractHuman papillomavirus (HPV) infection is the most common sexually transmitted disease in the world and accounts for an estimated 11% of the global cancer incidence in women. HPV‐16 is the most prevalent type detected in cervical cancer and along with types 18, 31, 33 and 45 has been classified as a class I carcinogen. In addition to cervical cancer, HPVs are also associated with the malignant transformation of other mucosal and skin cancers. Thus, the combination of the malignant potential of HPV and its high prevalence of infection confers to it an importance of generalized clinical and virological significance. The natural history of HPV infection with or without treatment varies from spontaneous regression to persistence. The most important mechanism for wart regression appears to be cell‐mediated immunity. Cytokines released by keratinocytes or cells of the immune system may play a part in the induction of an effective immune response against HPV infection and the subsequent regression of lesions. This review discusses the molecular biology, pathogenesis and immunology of HPV infections.
Terbinafine: efficacy and tolerability in young children with tinea capitis due to Microsporum canis
Authors: Silm H , Karelson M 
Published: March 2003

AbstractAims  We carried out an open, prospective, uncontrolled study to evaluate the efficacy and tolerability of terbinafine in the treatment of young children with tinea capitis due to Microsporum canis.Methods  A total of 83 healthy, immunocompetent children (age range 2–13 years) were enrolled in eight centres in Estonia, Latvia and Lithuania. Patients received oral terbinafine in dosages based on weight, 62.5 mg for those weighing 10–20 kg, 125 mg for 20–40 kg, plus application of topical 1% terbinafine cream twice daily to affected areas. Treatment lasted for 4 weeks, followed by an 8‐week observation (treatment‐free) period. All the subjects were assessed for efficacy and tolerability at 12 weeks.Results  Eighty‐one subjects were available for assessment at 12 weeks: 32 had completely recovered, with no evidence of relapse during the observation period, and 21 showed mycological cure, but presented residual physical signs of infection. Thus the effective cure rate was 65.4% in an infection known to be more difficult to cure than other causes of tinea capitis. Terbinafine was well tolerated by these children.Conclusions  This study showed effective cure of two‐thirds of 81 cases of tinea capitis caused by M. canis with a 4‐week course of treatment. As one‐third of the cases did not respond to treatment, we suggest using combined oral and topical treatment with terbinafine in children with tinea capitis caused by M. canis.
Individual dispersal among colonies of Little EgretsEgretta garzetta
Authors: Fasola Mauro , Hafner Heinz , Kayser Yves , Bennetts Robert E. , Cezilly Frank 
Published: March 2003

Colonial waterbirds are unusual in that competition for nest‐sites or mates may occur at a scale of a few metres, whereas thousands of birds may overlap in their foraging range at a larger scale. Dispersal has been evaluated for only a few such species, and its adaptive significance remains unclear. We studied Little Egret dispersal among all the colonies within the Camargue, southern France. The overall probability of dispersal between successive years was 0.45. The probability of dispersal was unaffected by a bird’s age, or by any density‐dependent effect of colony size. Juveniles dispersed at distances that would be expected if colony selection were random, while adults tended to remain within 10 km of their previous colony. We found no obvious environmental ‘trigger’ for an individual to disperse. Although our evidence is inconclusive, the short dispersal distances of adults are not consistent with foraging conditions as the primary trigger for dispersal. Little Egrets generally forage within 8 km of their colony, so birds dispersing less than 10 km would gain little advantage in response to unfavourable foraging conditions. Our data, with 75% of dispersing birds coming from decreasing colonies and 72% joining increasing colonies, suggest that individual dispersal depended on colony dynamics as a whole, i.e. (1) a social component of dispersal at the individual level, or (2) a simultaneous colony response to unfavourable environmental conditions or (3) both. Further investigation at a higher social level may be necessary to understand dispersal of this colonial nesting species.
Nesting area fidelity and survival of female Common Goldeneyes Bucephala clangula: are they density‐dependent?
Authors: Ludwichowski Ingo , Barker Richard , Bräger Stefan 
Published: March 2003

The breeding histories of 218 female Common Goldeneyes Bucephala clangula were recorded between 1971 and 2000 in a study area in Schleswig‐Holstein, northern Germany. Females were first recorded breeding at a median age of 2 years usually in their area of hatching (philopatry). One hundred and two of 140 females (73%) re‐nested only in one of the 13 nesting areas (clusters of nestboxes) for all their known life of up to 13 breeding seasons. The remaining 38 individuals moved between different nesting areas at least once between breeding attempts. The two oldest females were still breeding at a minimum age of 15 years (i.e. 13 years between first and last recorded breeding attempt). Temporal variations in annual survival rates of adult females could best be explained by a model with annual survival rate varying independently and randomly about a mean of 0.830 (se = ±0.023) with an estimated sd of ±0.092 (95% CI = 0.064, 0.138). No trend in the annual survival rate was detected over the study period of 30 years, although the presence of a moderate trend could not be ruled out. The absence of any discernible trend in survival at a time when the population size increased substantially indicates little, if any, density‐dependence in survival of female Goldeneyes during this study.
On the taxonomic status of the Indian Spotted EagleAquila hastata
Authors: Parry S. J. , Clark W. S. , Prakash V. 
Published: March 2003

We review the status of the two currently recognized subspecies of Lesser Spotted EagleAquila p. pomarina(western Eurasia) andA. p. hastata(Indian subcontinent) on the basis of museum diagnosis and field observations. We present differences between these two allopatric taxa which demonstrate that they should be treated as distinct species. Specifically, we present evidence of differences in plumage (both for adults and juveniles), external morphology, osteology, clutch size and behaviour. Particular emphasis is placed on differences in gape size and general cranial structure.
Spatially resolved polarization properties for in vitro corneas
Authors: Bueno Juan M. , Jaronski Jaroslaw 
Published: March 2003

SummarySpatially resolved polarization properties of in vitro mammalian corneas have been studied by using a Mueller‐matrix imaging polarimeter in transmission mode. Sixteen images corresponding to independent combinations of polarization states in the illumination and analyzing pathways are recorded. Spatially resolved Mueller matrices of the samples are calculated from them. Results show that the birefringence of the cornea is almost linear. Although the magnitude of retardation depends on the sample, it is approximately constant at the center and increases towards the periphery. Dichroism and polarizing power are negligible. Maps of the degree of polarization indicate that the cornea basically does not depolarize the totally polarized incident light.
A retrospective pilot study to assess the impact of strabismus surgery on the corneal endothelium in children
Authors: Müller Andreas , Doughty Michael J. , Watson Lesley 
Published: March 2003

Purpose: To investigate if strabismus surgery has an impact on the corneal endothelium in children. Methods: Fourteen children who had undergone uncomplicated strabismus surgery an average of 41 months previously (range 24–73 months) were compared with a group of age‐matched (range 5–12 years) and refractive error (RE)‐matched (range –4.74 to +4.25 D) children. Following non‐contact specular microscopy, areas of at least 100 cells were measured, the number of sides for each cell recorded, and endothelial cell density (ECD) calculated from the area measures. Corneal diameter was measured with a clinical rule, corneal curvature with a manual keratometer, central corneal thickness (CCT) by ultrasound pachometry, and IOP by non‐contact tonometry. Results: The average ECD (±S.D.) in the post‐surgery group was 4467 ± 627 cells mm–2, which was significantly higher (p < 0.02) than in the control group (3781 ± 452 cells mm–2). This was because the average endothelial cell area in the surgery group was significantly smaller than in the control group (p < 0.005; 252 ± 25 μm2 vs 296 ± 29 μm2). Differences in cell areas were slightly greater for smaller cells (–15.7% for five‐sided cells, –15.6% for six‐sided cells, –14.3% for seven‐sided cells and –13.8% for eight‐sided cells). The cell differences appear to be related to both a slightly smaller corneal diameter (11.00 ± 0.52 mm vs. 11.21 ± 0.58 mm) and a slightly higher CCT (0.528 ± 0.033 mm vs. 0.515 ± 0.032 mm) in the post‐operative group. Conclusion: The endothelial mosaic in children after strabismus surgery can show a higher than expected ECD value and slight cell pleomorphism. These signs indicate that there might be differences in eye growth and endothelial inflammatory stress associated with uneventful strabismus surgery.
Modified attentional fields in ageing
Authors: Cunningham I. , Knox P. C. , Rowe F. 
Published: March 2003

Purpose:  Clinical vision testing tends to underestimate age‐related visual decline. We have modified an automated perimeter by adding a second task at fixation and have investigated visual fields in conditions of focused (FA) and divided attention (DA).Methods:  Two lasers were mounted on a Humphrey Visual Field Analyzer (Carl Zeiss, Jena, Germany). They projected red targets 2 mm either side of the standard fixation target. Fifteen young (mean age: 20 ± 1.4 years; range: 18–23) and 15 healthy old subjects (72 ± 5.1 years; range: 65–80) were assessed under FA using Fastpac 30–2 program (sequence 1). Subjects then repeated the test twice under DA (sequences 2 and 3), in which they were instructed to press a second handheld button in response to an asynchronously presented central laser target. They also responded to continuing laser targets after the threshold program finished.Results:  For old subjects under DA, the mean threshold increased by 2.87 cd m−2 (sequence 2) and 0.8 cd m−2 (sequence 3) compared with FA (sequence 1). By comparison young subjects increased by 0.03 cd m−2 (sequence 2) and decreased by 0.55 cd m−2 (sequence 3). Compared with young subjects, mean threshold for old subjects was 8.44 cd m−2 (sequence 2) and 6.89 cd m−2 (sequence 3) greater. Mean reaction times for the fixation task alone were comparable (young: 353 ± 46 ms vs old: 352 ± 52 ms). However, when combined with the threshold field task, reaction times increased by much more in the old group (e.g. 497 ± 46 ms vs 557 ± 50 ms sequence 2).Conclusion:  The visual fields of old subjects were only slightly reduced in DA conditions although the reduction was clearly greater than for the young group. There were marked increases in the reaction times of the older group to targets presented at fixation. Continuing studies will assess impact of DA on patients with ocular and cerebral disease.
Digital imaging system for assessing posterior capsular opacification: a preliminary report
Authors: Al‐Farhan H. , Hull C. C. , Hameed R. , Horgan S. E. , Woodward E. G. 
Published: March 2003

Purpose:  Posterior capsular opacification (PCO) is the commonest complication of cataract surgery. The aim of this work is to develop a system that could be used by primary care practitioners to monitor the progression of PCO using familiar equipment.Methods:  A Kodak DCS 100 (Eastman Kodak, Rochester, NY, USA) digital data back, which uses a Nikon F3 body, was connected to the camera port of a Nikon FS‐2 photo slit‐lamp. A fixation stimulus was developed and systematic studies carried out to determine optimum exposure and slit‐lamp settings using patients recruited from the YAG laser capsulotomy clinic at the Royal Eye Unit, Kingston Hospital. In all cases conventional illumination was used. Inter and intraobserver trials were then carried out using observers ranging from a non‐clinician to an experienced ophthalmologist. All images were analysed using ImagePro Plus image processing software prior to statistical analysis.Results:  Optimum slit‐lamp parameters were found to be a 45° slit beam angle, 3 mm slit width and 25× magnification. The flash intensity was set to 2. The optimum camera and digital storage unit speed settings were both ISO 200 for fibrotic PCO but 800 and 1600, respectively, for Elschnig pearl type PCO. Intra‐observer repeatability gave ±0.375 mm (95% confidence) variation in fixation. However, initial results from interobserver trials showed significant variability.Conclusions:  The current digital assessment system uses a standard piece of consulting room equipment coupled to a digital 35 mm camera. Initial results indicate that it should be suitable for use in monitoring PCO although a more exact measurement protocol is required to reduce interobserver variability. Work is currently underway to complete validation trials and to find suitable image statistics.
Computer colour tests for the major causes of blindness using an inexpensive PC system
Authors: Arden G. B. , Wood N. , Fiori B. , Wolf J. E. , Hogg C. H. , Berninger T. , Perry S. , Perry L. 
Published: March 2003

Background:  Computer‐graphics methods of assessing acquired losses of colour vision are superior in many ways to all others. They can employ briefly flashed stimuli, that can be presented in the retinal periphery; any luminance signal can also be masked by dynamic random luminance noise; and chromaticity can be varied very precisely. We have devised a program that is designed to detect and quantify disturbances in the three major blinding conditions (glaucoma, ARM and diabetes).Methods:  The tests can be performed very rapidly, using standard PCs.Results:  Normal results from age‐matched groups prove prominent tritan losses in all 3 three conditions. In diabetes, relatively large abnormalities can be detected before the appearance of mild background retinopathy, and worsen with the appearance of microaneurysms. In suspected glaucoma, abnormalities can be detected when conventional perimetry is ambiguous. There is a good correlation with minor changes on the Heidelberg Retinal Tomograph (HRT). The loss is related to IOP. In ARM, even with normal visual acuity, very large losses of tritan contrast sensitivity can be seen. Although patients can see the colours on the monitor screen, the targets (small optotypes) cannot be recognised, apparently because of the presence of very small tritan scotomas, which can be demonstrated when the target is flashed briefly.Conclusions:  Colour vision testing permits rapid screening of patients at risk of developing sight‐threatening disorders, and thus is potentially of considerable use in health‐care programmes.
Relative letter legibility of Punjabi optotypes
Authors: Sailoganathan A. , Siderov J. , Osuobeni E. 
Published: March 2003

Purpose:  To investigate relative letter legibility of Punjabi optotypes.Methods:  In experiment 1, the influence of font type on letter legibility was studied on nine subjects optically defocused using a +1.00 DS lens in front of one eye. Two Punjabi font types used in widely read Punjabi language newspapers and magazines were selected. Legibility was determined according to the method of Strong and Woo (1985). In experiment 2, a single Punjabi font (selected from experiment 1) was used to investigate relative letter legibility in 10 subjects who were optically defocused with a +1.00 DS, +2.00 DC, axis 180 and 90. The Punjabi letters were modified to fit into a 5 × 5‐grid using Coral draw and presented on a standard PC monitor at high contrast using Powerpoint. The method of Strong and Woo (1985) was used to determine relative letter legibility.Results:  The results of experiment 1 showed no effect of font type on letter legibility (anova, p > 0.05). The results of experiment 2 were analysed in two ways. Firstly, anova revealed an interaction between blur condition (sphere, cyl axis 90, cyl axis 180) and letter legibility (p < 0.05). Post‐hoc analysis (analysis of main effects and Tukey HSD test) showed a significant effect of letter legibility only under the +2.00 DC axis 90 blur condition (p < 0.05). Secondly, the percentage difference in relative legibility under cylinder blur (axes 180 and 90) was plotted against the legibility under spherical blur. We selected 11 letters of equal legibility on the basis of a difference in relative legibility for each cyl condition of no more than 10% of the value of the spherical blur condition.Conclusion:  Relative legibility of Punjabi letters was determined resulting in the selection of 11 letters. These letters will form the basis of a new, standardised vision chart in Punjabi.