bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential patterns of spatial divergence in microsatellite and allozyme alleles: further evidence for locus‐specific selection in the acorn barnacle,Semibalanus balanoides?
Authors: Dufresne F , Bourget E , Bernatchez L 
Published: March 2003

AbstractWe compared patterns of genetic structure at potentially selected (two allozyme loci) and neutral molecular markers (six microsatellite loci) in the acorn barnacle,Semibalanus balanoidesfrom the Gulf of St. Lawrence. Our results confirmed the presence of a geographical shift in allelesMPIandGPInear the Miramichi River. In contrast, no significant patterns of population differentiation among samples located north and south of the river mouth were detected for four of six microsatellite loci. However, analysis of molecular variance (amova) at individual loci revealed that a significant proportion of the total variance in allele frequencies was partitioned among samples located north and south of the river for both the allozyme and the other two microsatellite loci. The two most common alleles at these microsatellites showed frequencies that were highly correlated (r = 0.65–0.74,P < 0.05) with those of theMPI*2 allele, perhaps because of either physical linkage or epistasis. The two allozyme loci were significantly correlated in barnacles located north of the Miramichi River (r = 0.86,P < 0.05). Overall, our results supported the hypothesis that the broad scale pattern of allozyme allelic shifts is maintained by selection. They also indicated that microsatellites may not always behave in a neutral way and must be used cautiously, especially when evidence for genetic structuring relies on only a few assayed loci.
Male reproductive competition in spawning aggregations of cod (Gadus morhua, L.)
Authors: Bekkevold D , Hansen M. M , Loeschcke V 
Published: March 2003

AbstractReproductive competition may lead to a large skew in reproductive success among individuals. Very few studies have analysed the paternity contribution of individual males in spawning aggregations of fish species with huge census population sizes. We quantified the variance in male reproductive success in spawning aggregations of cod under experimental conditions over an entire spawning season. Male reproductive success was estimated by microsatellite‐based parentage analysis of offspring produced in six separate groups of spawning cod. In total, 1340 offspring and 102 spawnings distributed across a spawning season were analysed. Our results show that multiple males contributed sperm to most spawnings but that paternity frequencies were highly skewed among males, with larger males on average siring higher proportions of offspring. It was further indicated that male reproductive success was dependent on the magnitude of the size difference between a female and a male. We discuss our results in relation to the cod mating system. Finally, we suggest that the highly skewed distribution of paternity success observed in cod may be a factor contributing to the low effective population size/census population size ratios observed in many marine organisms.
The estimation of population differentiation with microsatellite markers
Authors: Balloux François , Lugon‐Moulin Nicolas 
Published: March 2003

AbstractMicrosatellite markers are routinely used to investigate the genetic structuring of natural populations. The knowledge of how genetic variation is partitioned among populations may have important implications not only in evolutionary biology and ecology, but also in conservation biology. Hence, reliable estimates of population differentiation are crucial to understand the connectivity among populations and represent important tools to develop conservation strategies. The estimation of differentiation is c from Wright’s FST and/or Slatkin’s RST, an FST‐analogue assuming a stepwise mutation model. Both these statistics have their drawbacks. Furthermore, there is no clear consensus over their relative accuracy. In this review, we first discuss the consequences of different temporal and spatial sampling strategies on differentiation estimation. Then, we move to statistical problems directly associated with the estimation of population structuring itself, with particular emphasis on the effects of high mutation rates and mutation patterns of microsatellite loci. Finally, we discuss the biological interpretation of population structuring estimates.
Amplified fragment length polymorphism analysis identifies hybrids between two subspecies of warblers
Authors: Bensch Staffan , Helbig Andreas J. , Salomon Marc , Seibold Ingrid 
Published: March 2003

AbstractIn the western Pyrenees (Southwest France and Northwest Spain), a narrow hybrid zone exists between the common chiffchaffPhylloscopus (collybita) collybitaand the Iberian chiffchaffPhylloscopus (c.) brehmii. In this zone, which is approximately 20 km wide, mixed matings and individuals singing the songs of both taxa occur at substantial frequencies (24 and 8.6%, respectively), suggesting frequent hybridization. Previous studies have shown very weak mitochondrial gene flow (Nm = 0.065), whereas four microsatellites suggested much higher nuclear gene flow (Nm = 4.9). In this study we used the amplified fragment length polymorphism (AFLP) method in order to identify hybrids and early backcrosses. We typed 91 birds from both allopatric and sympatric areas for 12 informative AFLP markers (of > 141 polymorphic fragments), obtained by screening 13 AFLP primer combinations. These individuals were previously typed for song (brehmii, collybitaor mixed singers), mitochondrial DNA (mtDNA) haplotype and allelic genotypes at four microsatellite loci. Assignment tests demonstrated that in the zone of sympatry, a substantial number of intermediate genotypes existed among the birds previously believed to be purecollybitaandbrehmii, based on song and mtDNA haplotype. The majority of the mixed singers had intermediate genotypes. Our data suggest that the fraction of the adult population having a hybrid origin (hybrids or backcrosses) is in the order of 10%. With such a frequency of genetic hybrids, there would have been much more mtDNA introgression than observed, had female hybrids been perfectly fertile/viable. This result is consistent with male‐biased gene flow and Haldane’s rule.
Sonographic features of trisomy 18 at midpregnancy
Authors: Tongsong Theera , Sirichotiyakul Supatra , Wanapirak Chanane , Chanprapaph Pharuhas 
Published: March 2003

Abstract
Objective:
To evaluate the sonographic characteristics of the fetuses with trisomy 18 at 16–22 weeks of gestation.
Methods:
The subjects were recruited from pregnant women undergoing prenatal sonographic examinations at 16–22 weeks of gestation and subsequently proven to be trisomy 18. The results of ultrasound findings were retrospectively reviewed in 25 cases with chromosomes which were confirmed as trisomy 18.
Results:
All cases had at least one abnormal sonographic finding. There was only one case that had no structural abnormality, but fetal growth restriction was documented. The common sonographic findings included fetal growth restriction, choroid plexus cysts, cardiac anomalies, clenched hand, omphalocele and cleft lip. Fetal growth restriction was the most common finding demonstrated in nearly half of all cases. Other less common findings were diaphragmatic hernia, abnormal head shape, polyhydramnios, single umbilical artery.
Conclusion:
Nearly all fetuses with trisomy 18 had characteristic sonographic patterns of abnormalities demonstrated at midpregnancy. Detailed ultrasound at midpregnancy could effectively screen fetuses with trisomy 18 for further genetic testing.
Immature brain injury via peroxynitrite production induced by inducible nitric oxide synthase after hypoxia‐ischemia in rats
Authors: Ikeno Shinji , Nagata Naoki , Yoshida Souichi , Takahashi Hiroyuki , Kigawa Junzo , Terakawa Naoki 
Published: March 2003

Objective:
To determine whether, and if so, how, iNOS expresses and affects brain injury induced by hypoxia‐ischemia in an immature brain.
Material and Methods:
Seven‐day‐old Wistar rat pups were exposed to right common carotid artery ligation followed by 1.5 hours of hypoxia. The time course of iNOS mRNA expression, enzymatic activity, and protein production in the cerebral cortex were determined. The extent of the infarct area in the cerebral cortex and the production of 3‐nitrotyrosine (a biomarker of peroxynitrite) were compared between the control pups and pups treated with S‐methyl‐isothiourea (a selective iNOS inhibitor).
Results:
In the cortex ipsilateral to carotid ligation, iNOS mRNA appeared from 6 hours to 24 hours after hypoxia‐ischemia and disappeared at 48 hours. The iNOS protein and its activity also increased at 12 hours and reached a maximum level at 48 hours after the insult. The percentage of damage in the cerebral cortex was significantly higher in the control pups than in treated pups (31.9 vs 10.6%). Tri‐nitrotyrosine following iNOS expression‐positive cells were located predominantly at the infarct and peri‐infarct regions.
Conclusion:
iNOS expression might be an important determinant of ischemic immature brain injury.
Defective sexuality and female circumcision: The cause and the possible management
Authors: Thabet Saeed Mohamad Ahmad , Thabet Ahmed S.M.A. 
Published: March 2003

AbstractAim:  To verify the effect of circumcision on female sexuality and to define the need for clitorolabioplasty in these cases.Methods:  Thirty uncircumcised controls, 30 minorly circumcised, 30 minorly circumcised mutilated, and 57 circumcised cases having clitoral cysts were selected on random bases at Kasr El Aini School of Medicine. Sexuality was assessed by a special questionnaire sheet prepared by the authors to fit the circumcised cases. Clitorolabioplasty and clitoral cyst excision were also done in cases of sexual defects.Results:  Sexuality was not affected in minorly circumcised cases. However, sexuality was markedly affected in the mutilated cases. The scores for sex desire and arousal and for orgasm were especially affected in such cases. These defects were not detected in cases having clitoral cysts until late, when cysts enlarged. The role of clitorolabioplasty in restoration of sexuality was confirmed.The loss of certain clitoral and labial bulk, necessary for orienting the woman towards her genitalia and initiating her interest in their function, was responsible for the occurrence of such defects; this was able to be restored by surgery.Conclusion:  Counseling parents about these sexual defects and asserting the need for correcting the mutilation, which resulted from these circumcisions, are effective steps in banning such procedures.
Gasless laparoscopic hysterectomy: A comparative study with total abdominal hysterectomy
Authors: Tintara Hatern , Choobun Thanapan , Geater Alan 
Published: March 2003

AbstractAim:  To evaluate the short‐term results of gasless laparoscopic hysterectomy (GLH) compared to total abdominal hysterectomy.Methods:  A comparative study of GLH using an abdominal wall‐lifting device (n = 31) and total abdominal hysterectomy (TAH) (n = 31) was carried out between July 1999 and July 2001.Results:  One patient (3.2%) in the GLH group required conversion to TAH. The operative time was 168 ± 38 min and 112 ± 29 min (P < 0.001) for the GLH and TAH groups, respectively. Gasless laparoscopic hysterectomy cases had a shorter hospital stay and convalescent period (2.6 ± 0.9 days vs 5.0 ± 1.3 days, P < 0.001 and 8.0 ± 3.0 days vs 15.8 ± 2.4 days, P < 0.001, respectively). Postoperative meperidine use and estimated blood loss were lower for GLH (P < 0.001). Complications were comparable in the two groups. Hospital charges were 8.5% higher for GLH (P = 0.02).Conclusions:  Gasless laparoscopic hysterectomy may be an alternative technique for hysterectomy which provides laparoscopic benefit with minimal increase in hospital charges.
Impact of Surgical and Orthotic Intervention on the Quality of Life of People with Profound Intellectual and Multiple Disabilities and Their Carers
Authors: Neilson Aileen , Hogg James , Malek Mo , Rowley David 
Published: March 2003

AbstractThe increasing analysis of quality of life issues for people with disabilities has not been paralleled in relation to people with profound intellectual and multiple disabilities (PIMDs). This is nowhere more the case than with regard to the impact of health status on their quality of life. In addition, people with PIMDs, and the interventions which they require, have not been included within wider considerations of the economics of healthcare and its relation to rational decision‐making regarding medical provision. The present exploratory study considered the impact of a wide range of surgical and orthotic interventions on the quality of life of 27 children and adults with PIMDs. These were explored on a pre–post‐test basis with respect to: (1) the economic costs associated with surgical and orthotic interventions; (2) clinical assessment of function and behaviour; (3) the participants' and carers' quality of life; and (4) carer satisfaction with the interventions. The results are presented with respect to these individual areas and the extent to which the findings are congruent. The need for the development of these measures to meet the specific requirements of this population and the development of a more formal model integrating these steps are considered.
Tomato spotted wilt virus—positive steps towards negative success
Authors: Adkins Scott 
Published: March 2003

AbstractTaxonomy: Tomato spotted wilt virus (TSWV) is the type member of the plant‐infecting Tospovirus genus in the family Bunyaviridae, a large group of predominantly vertebrate‐ and insect‐infecting RNA viruses.Physical properties: Virions are 80–120‐nm pleomorphic particles with surface projections composed of two viral glycoproteins, G1 and G2 ( Fig. 1). Virion composition is 5% nucleic acid, 70% protein, 5% carbohydrate and 20% lipid. The genome consists of three negative or ambisense ssRNAs designated S (2.9 kb), M (4.8 kb) and L (8.9 kb), with partially complementary terminal sequences that allow the RNA to adopt a pseudocircular or panhandle conformation. Each genomic RNA is encapsidated by multiple copies of the viral nucleocapsid (N) protein to form ribonucleoprotein structures also known as nucleocapsids. The nucleocapsids are enclosed in a host‐derived membrane bilayer along with an estimated 10–20 copies of the L protein, the putative RNA‐dependent RNA polymerase.Transmission electron micrograph of isolated TSWV virions. Unfixed virion preparation stained with 1% (w/v) methylamine tungstate.imageHosts: Over 800 plant species, both dicots and monocots, in more than 80 plant families are susceptible to TSWV ( Goldbach and Peters, 1994). The Solanaceae and Compositae families contain the largest numbers of susceptible plant species (
Prins and Kormelink, 1998). TSWV also replicates in its insect vector, thrips (Thysanoptera: Thripidae) (
Ullman et al., 1993
;
Wijkamp et al., 1993
).Useful web site: http://www4.ncbi.nlm.nih.gov/ICTVdb/ICTVdB/11050003.htm
Molecular characterization of Fusarium subglutinans associated with mango malformation
Authors: Steenkamp Emma , Britz Henriette , Coutinho Teresa , Wingfield Brenda , Marasas Walter , Wingfield Michael 
Published: March 2003

AbstractMango malformation is a serious disease of Mangifera indica in tropical and subtropical regions of the world. This disease is caused by Fusarium subglutinans, which is also associated with diseases on many other hosts, such as pineapple, pine, maize and sugarcane. The F. subglutinans strains associated with different hosts are virtually indistinguishable using morphological characters, but can be easily differentiated using histone and β‐tubulin gene sequencing, and some have subsequently been assigned to distinct species. The aim of this study was to characterize F. subglutinans isolates associated with mango malformation using histone H3 gene sequencing and to compare them with other isolates in the Gibberella fujikuroi complex. Analysis of histone sequence data revealed the presence of two phylogenetically distinct groups of F. subglutinans isolates associated with mango malformation. We also considered the identity of the two groups of isolates associated with mango malformation and determined their relatedness to other Fusarium spp. For this purpose, portions of the β‐tubulin gene were sequenced and compared with the β‐tubulin sequences deposited in the National Center for Biotechnology Information (NCBI) nucleotide database. This comparison to the NCBI database indicated that one group of F. subglutinans strains isolated from mango constitutes a unique lineage in the G. fujikuroi complex. Based on β‐tubulin and histone H3 sequencing, the second group of isolates is conspecific with the F. subglutinans strains previously reported to be the causal agent of mango malformation.
Genome analysis of the plant pathogenic ascomycete Leptosphaeria maculans; mapping mating type and host specificity loci
Authors: Cozijnsen Anton J. , Popa Kerryn M. , Purwantara Agus , Rolls Barbara D. , Howlett Barbara J. 
Published: March 2003

AbstractA genetic and physical map has been developed for the loculoascomycete Leptosphaeria maculans, a pathogen of oilseed Brassicas. The genetic map was constructed from 58 F1 progeny and comprises 155 amplified fragment length polymorphic (AFLP) markers, three random amplified polymorphic DNA (RAPD) markers, the mating type locus and a host specificity locus conferring the ability to form lesions on Brassica juncea. Twenty‐one linkage groups, 5 pairs, and 18 unlinked markers were assigned, and the genome size was 1520 cM. Pulsed field gel electrophoresis experiments showed that the parental isolates each had 16 chromosomes and a genome size of about 33.5 Mb. Attempts to anchor a large number of markers to chromosomes were hampered by difficulties in converting AFLPs into RFLP markers, and because many markers bound to every chromosome, indicating that L. maculans has a high level of dispersed repetitive sequences. This fungus displays chromosomal length polymorphisms, but in the cross examined, the linkage and physical maps were essentially congruent and there was no evidence of translocations. The host specificity locus is 18 cM from the nearest AFLP marker and is located on a chromosome sized 1.85 Mb in the virulent parent. The mating type locus is on a chromosome sized 2.6 Mb and coincident on an AFLP marker amplified from the virulent parent. The derived amino acid sequence of part of this marker has some conserved amino acids present in the High Mobility Group DNA binding domain of MAT‐2 mating type genes of other ascomycetes.
The DspB/F protein of Erwinia amylovora is a type III secretion chaperone ensuring efficient intrabacterial production of the Hrp‐secreted DspA/E pathogenicity factor
Authors: Gaudriault Sophie , Paulin Jean‐Pierre , Barny Marie‐Anne 
Published: March 2003

Summary Erwinia amylovora is a Gram‐negative bacterium responsible for fire blight, a necrotic disease affecting plants of the Rosaceae family. E. amylovora virulence is dependent on a functional type III secretion system. To date, four proteins have been shown to travel through this secretion system: HrpN, HrpW, HrpA, and DspA/E. Next to dspA/E, dspB/F encodes a small acidic protein sharing features similar to those of type III secretion chaperones described in animal systems. Here, we show that DspA/E was not secreted in a dspB/F background, while other known type III secreted proteins (HrpN, HrpW, and HrpA) remained secreted to wild‐type level. A functional copy of dspB/F introduced in trans in a dspB/F background restored DspA/E secretion. Further analysis showed that DspA/E was not detected in a dspB/F background. This effect was post‐transcriptional as the expression of a dspA/E::uidA transcriptional fusion was not reduced in a dspB/F background. Affinity blot analysis experiments demonstrated that DspB/F specifically interacts with DspA/E in vitro. Therefore, DspB/F acts as a specific DspA/E chaperone and DspB/F prevents intrabacterial DspA/E degradation. dspB/F mutants were found to retain some pathogenicity to pear seedlings. This phenotype contrasts with the non‐pathogenic phenotype of the dspA/E mutant and suggests that the DspA/E protein still transits through the type III secretion machinery in a dspB/F mutant even though it is not detected in vitro.
Tomato yellow leaf curl virus, the intracellular dynamics of a plant DNA virus
Authors: Gafni Yedidya 
Published: March 2003

SUMMARY Tomato yellow leaf curl virus
is a geminivirus, transmitted by whitefly (
Bemisia tabaci ) and causing the most destructive disease of tomato throughout the Mediterranean region, the Middle East and the tropical regions of Africa and Central America. Affected plants produce either no fruits or a few small fruits. Since it is an ssDNA virus which replicates in the host cell nucleus, the molecular mechanisms involved in the viral nuclear import have been the focus of our studies in recent years and results as well as prospects will be discussed.Taxonomy: Tomato yellow leaf curl virus
(TYLCV) is a ssDNA plant virus, a member of the family
Geminiviridae
, of the genus
Begomovirus. Physical properties:  TYLCV, like all members of Geminiviridae, has geminate (twinned) particles, 18–20 nm in diameter, 30 nm long, apparently consisting of two incomplete T = 1 icosahedra joined together in a structure with 22 pentameric capsomers and 110 identical protein subunits (Fig. 1).Particles of TYLCV. Electron micrograph of purified, negatively stained TYLCV particles. Bar = 100 nm.imageDisease symptoms:  Symptoms become visible in tomato in approximately 2–3 weeks after infection (Fig. 2). Leaf symptoms include chlorotic margins, small leaves that are cupped, thick and rubbery. The majority (up to 90%) of flowers abscise after infection, and therefore few fruits are produced. In Israel and elsewhere, weeds bridge the gap as potential perennial host and source of the virus between tomato growing seasons.Tomato yellow leaf curl symptoms on tomato plant. Leaves show yellowing on the edges accompanied by upward curling.imageDisease control:  Control of TYLCV is currently based on insecticide treatments and/or physical barriers against the insect vector (Bemisia tabaci), and on tomato breeding programs based on introgression of resistance or tolerance from wild species to cultivated tomato.Useful website:  <http://www.danforthcentre.org/iltab/geminiviridae/>
Costing the library services. Cairns Library: a case study
Authors: FORREST MAUREEN , CAWASJEE ANNE‐MARIE 
Published: March 2003

In the present climate libraries have to adopt a business approach to funding submissions; detailed management information must be produced in support of expenditure and to ensure that the services are cost‐effective. In addition to the grant from its parent body (the Faculty of Clinical Medicine, University of Oxford), the Cairns Library obtains funding from five other bodies, including National Health Service Hospital Trusts.The Cairns Library has introduced an ongoing costing exercise covering the different services. The costs are divided into three categories: salary costs, other direct costs and indirect costs. Staff time has been identified from detailed time‐sheets kept by each member of staff; the time recorded is assigned to the individual services. The direct costs and the indirect costs have been identified and allocated/apportioned similarly.The services are divided into five packages: core, current awareness, document delivery, enquiries and user education. The costs for each package have been apportioned to the funding bodies on the basis of the number of registered users from each body.