bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of a novel gene HYS1/CPR5 that has a repressive role in the induction of leaf senescence and pathogen‐defence responses in Arabidopsis thaliana
Authors: Yoshida Satoko , Ito Masaki , Nishida Ikuo , Watanabe Akira 
Published: March 2003

SummaryWe isolated two allelic mutants of Arabidopsis thaliana that showed an early senescence phenotype under light/dark and continuous dark photo regimes, and designated the mutant hypersenescence1 (hys1). The hys1 mutants decreased chlorophyll and protein content, lowered the efficiency of photosystem II, and accumulated several senescence upregulated gene transcripts earlier than the wild‐type plants. In addition to these senescence features, the hys1 seedlings responded more intensely to exogenously applied sugars than did wild‐type seedlings in sugar‐induced growth inhibition and sugar‐mediated transcript accumulation, both of which are known to be regulated by the sugar sensor hexokinase. The hys1 mutant also had abnormal trichomes. Map‐based cloning of the HYS1 gene identified a novel gene that encodes a protein with a potential nuclear localization signal in the amino‐terminal region, and five putative transmembrane domains in the carboxyl‐terminal region. Furthermore, we found that the constitutive expresser of pathogenesis‐related genes 5 (cpr5) mutant, which shows spontaneous pathogen‐defence responses and abnormal trichomes, has a point mutation in the HYS1 gene, suggesting that these independently isolated mutants are allelic to each other. Although no definite conclusion can be drawn from these results, we suggest that altered sensitivity to sugars and/or enhanced efficiency of sugar signalling in the hys1/cpr5 mutant may have important roles in the initiation processes of leaf senescence and pathogen‐defence responses in Arabidopsis.
The release of genetically modified crops into the environment
Authors: Nap Jan‐Peter , Metz Peter L. J. , Escaler Marga , Conner Anthony J. 
Published: March 2003

SummaryIn the past 6 years, the global area of commercially grown, genetically modified (GM) crops has increased more than 30‐fold to over 52 million hectares. The number of countries involved has more than doubled. Especially in developing countries, the GM crop area is anticipated to increase rapidly in the coming years. Despite this high adoption rate and future promises, there is a multitude of concerns about the impact of GM crops on the environment. Regulatory approaches in Europe and North America are essentially different. In the EU, it is based on the process of making GM crops; in the US, on the characteristics of the GM product. Many other countries are in the process of establishing regulation based on either system or a mixture. Despite these differences, the information required for risk assessment tends to be similar. Each risk assessment considers the possibility, probability and consequence of harm on a case‐by‐case basis. For GM crops, the impact of non‐use should be added to this evaluation. It is important that the regulation of risk should not turn into the risk of regulation. The best and most appropriate baseline for comparison when performing risk assessment on GM crops is the impact of plants developed by traditional breeding. The latter is an integral and accepted part of agriculture.
Oral and dental care in acute lymphoblastic leukaemia: a survey of United Kingdom Children’s Cancer Study Group Centres
Authors: Collard M. M. , Hunter M. L. 
Published: March 2003

Summary.Objectives. To examine the provision of oral and dental care for children receiving treatment for acute lymphoblastic leukaemia (ALL) in United Kingdom Children’s Cancer Study Group (UKCCSG) centres.Sample and methods. A postal questionnaire was sent to a named consultant at each centre. All 22 centres responded.Results. The majority of centres carry out an oral assessment at the time of diagnosis, although various health care professionals are responsible for this. A dentist routinely attends out‐patient clinics in only a minority of centres, although the majority have facilities for the provision of dental treatment ‘on site’. In the main, children requiring dental treatment are referred to the Hospital Dental Service. Almost a quarter of centres do not have an oral care protocol.Conclusions. The development of appropriate dental services at tertiary referral centres should be vigorously pursued.
The prevalence and pattern of nursing caries in Saudi preschool children
Authors: Wyne A. , Darwish S. , Adenubi J. , Battata S. , Khan N. 
Published: March 2003

Summary.Objectives. To determine the prevalence and pattern of nursing caries in Saudi preschool children of Riyadh area.Design. Cross‐sectional.Subjects and methods. A list of kindergartens was derived through random selection of one kindergarten from every area of Riyadh. A sample of 1016 children with primary dentition only was examined for dental caries. The criterion used for nursing caries was presence of caries on the labial or lingual surfaces of at least two maxillary incisors with absence of caries in mandibular incisors.Results. Two hundred and seventy‐seven (27·3%) children were diagnosed as having nursing caries. The mean dmft of nursing caries children was 8·6 (± 3·4), with dt component of 7·6 (± 3·5), mt of 0·4 (± 0·9) and ft of 0·6 (± 1·7). The older children had significantly higher mean dmft as compared with younger children. The teeth most affected by caries were maxillary central incisors (93·9%), whereas the least affected were mandibular canines (9·6%). A great majority of children (95·7%) had caries in both anterior and posterior teeth. The probability of bilateral molar caries was very high in nursing caries children; highest (94·7%) in mandibular first molars.Conclusions. The caries prevalence was high in the study population. The maxillary central incisors were most affected by caries. The probability of bilateral molar caries was very high.
Twin chorionicity and pre‐eclampsia
Authors: Savvidou M. D. , Karanastasi E. , Skentou C. , Geerts L. , Nicolaides K. H. 
Published: March 2003

AbstractObjectiveTo determine whether the incidence of pre‐eclampsia is different in dichorionic compared to monochorionic twin pregnancies.MethodsThe study involved 666 twin pregnancies resulting in two live births after 24 weeks of gestation. Ultrasound examination at 10–14 weeks of gestation demonstrated that 171 (25.7%) were monochorionic and 495 (74.3%) were dichorionic twins. Pregnancy outcome information regarding the development of pre‐eclampsia was obtained from the maternity units. The incidence of pre‐eclampsia in the dichorionic and monochorionic twin pregnancies was compared.ResultsThe incidence of pre‐eclampsia in monochorionic twin pregnancies (9.4%) was not significantly different from that in dichorionic pregnancies (7.3%) (P = 0.48). Multiple logistic regression revealed that chorionicity has no effect on the development of pre‐eclampsia after adjusting for maternal age, ethnic group, maternal smoking, parity and gestational age at delivery (P = 0.6; odds ratio for monochorionic compared with dichorionic twin pregnancies, 1.19; 95% confidence interval, 0.61–2.3).ConclusionIn twin pregnancies chorionicity does not affect the incidence of pre‐eclampsia. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
In utero ultrasound detection of a large fetal sarcoma of the back
Authors: Meizner I. , Potlog‐Nahari C. , Mashiach R. , Shalev J. , Vardimon D. , Ben‐Sira L. 
Published: March 2003

AbstractA congenital fibrosarcoma, a very rare soft‐tissue tumor of infancy, was suspected on prenatal ultrasound at 23 weeks' gestation. On sonography, a large soft tissue growth on the left side of the fetal back, measuring 53 × 65 × 22 mm, was observed. The diagnosis was further validated by magnetic resonance imaging. Delivery by Cesarian section occurred at 31 weeks of gestation, due to fetal distress. The baby underwent an unusual embolization of the tumor‐feeding arteries and an operation at the age of 1 month to remove the tumor. The pathological and cytogenetic examinations were consistent with the diagnosis of a fibrosarcoma. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Receipt of information and women's attitudes towards ultrasound scanning during pregnancy
Authors: Whynes D. K. 
Published: March 2003

AbstractObjectiveTo audit women's receipt of information during routine antenatal ultrasound investigations; and to investigate women's perceptions of, and attitudes towards, routine screening.DesignAnalysis of the records of 384 women from in and around Nottingham, UK, who maintained a diary throughout the course of their pregnancies.ResultsThe mean number of ultrasound scans received by each women during her pregnancy was 2.6, with more than 96% of women receiving at least one scan. Women initially scanned earlier received more scans in total. Women appeared aware of the specific reasons for each scan being undertaken, and only a minority were dissatisfied by the information they had received. The preponderance of information received during the scans related to results and arrangements for subsequent visits, with only 10% of women reporting receiving information about the procedure itself. Most women reported positive feelings towards scanning, and few gave indications that they would prefer changes in the conduct of the procedure.ConclusionsThe great majority of the women in our study were satisfied with their experiences of routine ultrasound scanning, accepting the procedure uncritically. Copyright © 2002 ISUOG
Prospective sonographic assessment of uterine artery embolization for the treatment of fibroids
Authors: Tranquart F. , Brunereau L. , Cottier J.‐P. , Marret H. , Gallas S. , Lebrun J.‐L. , Body G. , Herbreteau D. , Pourcelot L. 
Published: March 2003

AbstractObjectivesTo evaluate sonographic features following uterine artery embolization and to assess using ultrasound the efficacy of embolization as the primary treatment of fibroids.DesignFifty‐eight women (mean age, 44.5 years; range, 33–65 years) suffering from symptoms due to fibroids (menometrorrhagia, bulk‐related symptoms, pelvic pain) were followed‐up after uterine artery embolization by ultrasound examination at 3 months, 6 months, 1 year and 2 years with assessment of volume and vascularization of fibroids as well as uterine vascularization.ResultsFifty‐eight patients were examined at 3 months, 46 at 6 months, 36 at 1 year and 19 at 2 years. Most patients were improved or free of symptoms at 3 months (90%), 6 months (92%) and 1 year (87%) and all monitored patients were free of symptoms at 2 years. Clinical failure of treatment occurred in only two cases (3%). Progressive significant reduction in fibroid size with reference to the baseline was demonstrated during follow‐up from 3 months (−29%) to 24 months (−86%). Absence of intrafibroid vessels was observed in all except three cases as early as 3 months, whereas perifibroid vessels persisted in 21 cases. No changes in uterine vascularization or uterine artery resistance were noted.ConclusionsUterine artery embolization is a valuable endovascular method for the treatment of fibroids, resulting in marked reduction in fibroid size and disappearance of intrafibroid vessels without reduction in uterine vascularization which is well depicted by sonography. Copyright © 2002 ISUOG
Identification and characterization of a homologue of the pro‐inflammatory cytokine Macrophage Migration Inhibitory Factor in the tick, Amblyomma americanum
Authors: Jaworski D. C. , Jasinskas A. , Metz C. N. , Bucala R. , Barbour A. G. 
Published: March 2003

AbstractStudying tick feeding and digestion, we discovered in a cDNA library from partially fed Amblyomma americanum ticks the first known arthropod homologue of a human cytokine, the pro‐inflammatory Macrophage Migration Inhibitory Factor (MIF). The tick origin of the MIF cDNA clone was confirmed by sequencing a genomic fragment that contained the full‐length tick MIF gene with two introns. Antiserum to a tick MIF‐specific peptide as well as antiserum to complete tick MIF revealed the expression of tick MIF in the salivary gland and midgut tissues of A. americanum ticks. In an in vitro functional assay, recombinant tick MIF inhibited the migration of human macrophages to the same extent that recombinant human MIF did.
Functional expression of a locust tyramine receptor in murine erythroleukaemia cells
Authors: Poels J. , Suner M.‐M. , Needham M. , Torfs H. , De Rijck J. , De Loof A. , Dunbar S. J. , Vanden Broeck J. 
Published: March 2003

AbstractThe LCR/MEL system (Locus Control Region/Murine Erythroleukaemia cells) was employed to express and characterize the Locusta migratoria tyramine receptor (TyrLoc), an insect G protein‐coupled receptor. Functional agonist‐dependent responses were recorded in stable, tyramine receptor expressing cell clones (MEL‐TyrLoc). Tyramine elicited a dose‐dependent increase of cytosolic Ca2+‐ions and an attenuation of forskolin‐induced cyclic adenosine monophosphate (AMP) production. Octopamine was shown to be a weak agonist for both responses. In addition, yohimbine proved to be a potent tyramine receptor antagonist. This study reports the first application of the LCR/MEL expression system in functional assays for G protein‐coupled receptors and therefore expands the capabilities of this system by exploiting the functionality of the signal transduction pathways.
Relationships among native and introduced populations of the Argentine ant (Linepithema humile) and the source of introduced populations
Authors: Tsutsui Neil D. , Suarez Andrew V. , Holway David A. , Case Ted J. 
Published: March 2003

AbstractThe Argentine ant (Linepithema humile) is a damaging invasive species that has become established in many Mediterranean‐type ecosystems worldwide. To identify likely sources of introduced populations we examined the relationships among native Linepithema populations from Argentina and Brazil and introduced populations of L. humile using mitochondrial cytochrome b sequence data and nuclear microsatellite allele frequencies. The mitochondrial phylogeny revealed that the populations in Brazil were only distantly related to both the introduced populations and the native populations in Argentina, and confirmed that populations in Brazil, previously identified as L. humile, are likely a different species. The microsatellite‐based analysis provided resolution among native and introduced populations of L. humile that could not be resolved using the mitochondrial sequences. In the native range, colonies that were geographically close to one another tended to be genetically similar, whereas more distant colonies were genetically different. Most samples from the introduced range were genetically similar, although some exceptions were noted. Most introduced populations were similar to native populations from the southern Rio Parana and were particularly similar to a population from Rosario, Argentina. These findings implicate populations from the southern Rio Parana as the most likely source of introduced populations. Moreover, these data suggest that current efforts to identify natural enemies of the Argentine ant for biological control should focus on native populations in the southern Rio Parana watershed.
Rapid genetic divergence in postglacial populations of threespine stickleback (Gasterosteus aculeatus): the role of habitat type, drainage and geographical proximity
Authors: Reusch T. B. H. , Wegner K. M. , Kalbe M. 
Published: March 2003

AbstractThe goal of this study was to evaluate the role of common ancestry, and of geographical or reproductive isolation, in genetic divergence in populations of threespine sticklebacks (Gasterosteus aculeatus). Using seven DNA microsatellite loci we compared the effects of habitat type, drainage system and geographical proximity on genetic distance among 16 populations situated in an area in Schleswig‐Holstein (Germany) that became deglaciated ≈12 000 years ago. Stickleback population structure correlated only weakly with drainage system, whereas the primary divergence was among habitat types. Phylogenetic analysis revealed that lake (n = 7) and river (n = 5) populations formed two distinct clades (Cavalli‐Sforza’s and Edwards’ chord distance, 82–100% bootstrap support) at approximately equal genetic distances to a third clade, comprising putative estuarine (n = 4) ancestors. Allele frequencies in lake and river populations represented different subsets of the genetically more diverse estuarine populations. In nestedamovas approximately twice the genetic variance was distributed among lake vs. river vs. estuarine populations as compared with the combined effects of drainage system and geographical distance. Limited gene flow between habitat types must have been established after postglacial colonization, suggesting ecological hybrid inferiority or behavioural mating barriers between ecotypes. Within estuarine and lake populations, population differentiation followed an isolation‐by‐distance model. Given the high observed heterozygosities within the 16 study populations (HO = 0.65–0.87), the mean divergence between lake and river population pairs (FST = 0.18 ± 0.007) would be reached after 300–6000 generations in a stepwise mutation model, depending on the size of Ne. This demonstrates both the utility of hypervariable microsatellites for detecting recent population divergences and the danger of operating at temporal or spatial scales which are beyond their resolution.
Global relationships amongst black‐browed and grey‐headed albatrosses: analysis of population structure using mitochondrial DNA and microsatellites
Authors: Burg T. M. , Croxall J. P. 
Published: March 2003

AbstractThe population structure of black‐browed (Thalassarche melanophris and T. impavida) and grey‐headed (T. chrysostoma) albatrosses was examined using both mitochondrial DNA (mtDNA) and microsatellite analyses. mtDNA sequences from 73 black‐browed and 50 grey‐headed albatrosses were obtained from five island groups in the Southern Ocean. High levels of sequence divergence were found in both taxa (0.55–7.20% in black‐browed albatrosses and 2.10–3.90% in grey‐headed albatrosses). Black‐browed albatrosses form three distinct groups: Falklands, Diego Ramirez/South Georgia/Kerguelen, and Campbell Island (T. impavida). T. melanophris from Campbell Island contain birds from each of the three groups, indicating high levels of mixture and hybridization. In contrast, grey‐headed albatrosses form one globally panmictic population. Microsatellite analyses on a larger number of samples using seven highly variable markers found similar population structure to the mtDNA analyses in both black‐browed and grey‐headed albatrosses. Differences in population structure between these two very similar and closely related species could be the result of differences in foraging and dispersal patterns. Breeding black‐browed albatrosses forage mainly over continental shelves and migrate to similar areas when not breeding. Grey‐headed albatrosses forage mainly at frontal systems, travelling widely across oceanic habitats outside the breeding season. Genetic analyses support the current classification of T. impavida as being distinct from T. melanophris, but would also suggest splitting T. melanophris into two groups: Falkland Islands, and Diego Ramirez/South Georgia/Kerguelen.
Mating frequency and mating system of the polygynous ant,Leptothorax acervorum
Authors: Hammond R. L. , Bourke A. F. G. , Bruford M. W. 
Published: March 2003

AbstractMultiple mating by queens (polyandry) and the occurrence of multiple queens in the same colony (polygyny) alter patterns of relatedness within societies of eusocial insects. This is predicted to influence kin‐selected conflicts over reproduction. We investigated the mating system of a facultatively polygynous UK population of the antLeptothorax acervorumusing up to six microsatellite loci. We estimated mating frequency by genotyping 79 dealate (colony) queens and the contents of their sperm receptacles and by detailed genetic analysis of 11 monogynous (single‐queen) and nine polygynous colonies. Results indicated that 95% of queens were singly mated and 5% of queens were doubly mated. The corrected population mean mating frequency was 1.06. Parentage analysis of adults and brood in 17 colonies (10 monogynous, 7 polygynous) showed that female offspring attributable to each of 31 queens were full sisters, confirming that queens typically mate once. Inbreeding coefficients, queen–mate relatedness of zero and the low incidence of diploid males provided evidence thatL. acervorumsexuals mate entirely or almost entirely at random. Males mated to queens in the same polygynous colony were not related to one another. Our data also confirmed that polygynous colonies contain queens that are related on average and that their workers had a mixed maternity. We conclude that the mating system ofL. acervoruminvolves queens that mate near nests with unrelated males and then seek readoption by those nests, and queens that mate in mating aggregations away from nests, also with unrelated males.
Sex‐specific genetic differentiation and coalescence times: estimating sex‐biased dispersal rates
Authors: Vitalis Renaud 
Published: March 2003

AbstractI derive the equilibrium values of sex‐specific FST parameters, in an island model for a dioecious species with sex‐biased dispersal and binomial distribution of family size before dispersal (as assumed in a Wright–Fisher population). I show that FST may take different values among males and among females whenever dispersal is a trait conditioned on gender. This has not always been recognized, because some models assumed that genes are sampled before dispersal. In particular, the ratios of sex‐specific FST parameters evaluated after dispersal over FST evaluated before dispersal are simple functions of sex‐specific dispersal rates. Therefore, a simple moment‐based estimator of sex‐specific dispersal rate is proposed. This method is based on the comparison of FST estimated before and after dispersal and assumes equilibrium between migration and drift. I evaluate this method through stochastic simulations for a range of sex‐specific dispersal rates and sampling effort (sample size, number of loci scored).