bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of the Structural Response of Masonry Cross Vaults
Authors: Theodossopoulos D. , Sinha B. P. , Usmani A. S. , Macdonald A. J.
Published: March 2003

Cross vaults have been used extensively in the roofing of medieval buildings. Knowledge of the behaviour of cross vaults under load is fundamental for the planning of structurally compatible and economic conservation programmes. A method is presented here to assess their safety under various loading conditions. A 1/4‐scale model was built in wood, representing an aisle vault of the partially collapsed Abbey Church of Holyrood in Edinburgh. The structure was loaded with dead weight and deformations and strains were recorded. Subsequently, the abutments were allowed to move progressively to cause the collapse of the vault. Finite element modelling was employed to interpret the experimental pattern, confirming the collapse of the vault was due to the development of hinges along the transverse vertex and the front abutments and membrane cracks at the back groins.
Chemokine and cytokine expression in murine intestinal epithelium following Nippostrongylus brasiliensis infection
Authors: Rosbottom Anne , Knight Pamela A. , McLachlan Gerry , Thornton Elizabeth M. , Wright Steven W. , Miller Hugh R. P. , Scudamore Cheryl L.
Published: March 2003

Infection of mice with the nematode parasite Nippostrongylus brasiliensis results in a well characterized intestinal mastocytosis with intraepithelial migration of mucosal mast cells (MMC). The molecules mediating this response are unknown. We examined expression of several putative mast cell chemoattractants in intestinal epithelium following N. brasiliensis infection. Expression of the chemokines monocyte chemoattractant protein‐1 (MCP‐1), macrophage inflammatory protein‐1α(MIP‐1α), RANTES (regulated on activation normal T‐cell expressed and secreted), fractalkine, and thymocyte expressed chemokine (TECK); and the cytokines stem cell factor (SCF) and transforming growth factor β1 (TGFβ1), was constitutive and no alteration was detected following infection. MCP‐1 expression was also constitutive but at much lower levels and increased expression was detected on days 7 and 14 postinfection. Expression of MCP‐1 in whole jejunum was at much higher levels than in epithelium. Constitutive expression of MCP‐1, MIP‐1α and TGFβ1 was also detected in cultured bone marrow‐derived homologues of MMC. In an intestinal epithelial cell line (CMT‐93), there was constitutive expression of SCF, TGFα1, fractalkine and MCP‐1. The results show that, in vivo, epithelium is a potentially important source of mast cell chemoattractants.
Dynamic torque and apical forces of ProFile .04 rotary instruments during preparation of curved canals
Authors: Peters O. A. , Barbakow F.
Published: March 2003

Aim To analyse torque and force generated whilst shaping curved canals using rotary instruments.

Methodology A specially designed computer‐controlled testing platform was used to record events during the shaping of straight and curved canals in plastic blocks and in extracted human teeth using ProFile .04 instruments. Size 40 apical stops were prepared using crown‐down, apical preparation and step‐back procedures. Maximum torque, apically directed force and the numbers of revolutions were recorded at a resolution of 100 samples s−1. Load causing separation as required by the ISO 3630–1 test and cyclic fatigue was also recorded. Mean maximum scores were calculated and statistically tested using one‐ and two‐way analyses of variance.

Results Highest and lowest torque scores were recorded, respectively, in straight canals in plastic blocks at 25 Nmm and in natural canals at 14 Nmm. Significant differences were recorded for canal type and preparation phase (P < 0.0001). Loads causing separation varied from 3.7 to 32.3 Nmm. Apically directed forces ranged from 1 to 7.5 N. Again, there were significant differences depending on canal type and preparation phase (P < 0.0001). The number of revolutions during preparation ranged from 18 to 41. Size 15, 30 and 45 ProFile .04 instruments separated after 581, 430 and 402 revolutions, respectively, in a standard cyclic fatigue test.

Conclusions The new torque‐testing platform details physical parameters during preparation of curved canals. To improve predictability, instrumentation sequences must be tested for excessively high torsional moments or forces. This study indicated that up to 10 curved canals could be safely prepared with a sequence of ProFile. 04 rotary instruments without separation due to cyclic fatigue. Efforts should continue to correlate root canal anatomy with torque and force generated during rotary root canal preparation.
Plagioclase replacement textures in partially eclogitised gabbros from the Sanddal mafic‐ultramafic complex, Greenland Caledonides
Authors: Lang H. M. , Gilotti J. A.
Published: March 2003

The Sanddal mafic‐ultramafic complex (SMUK) is a cluster of variably eclogitised mafic and ultramafic bodies that comprise the westernmost known eclogite facies locality in the North‐East Greenland eclogite province (NEGEP). Although there are no true eclogites in the SMUK, we interpret three distinct textural types of plagioclase replacement to record sequential stages in adjustment of SMUK olivine gabbro‐norites to eclogite facies conditions. The earliest stage, in which plagioclase was replaced by omphacite/spinel symplectite before nucleation of garnet (Type 1A & 1B) has not previously been described. Documentation of this texture provides clear evidence that, at least in some cases, garnet nucleation is delayed relative to nucleation of omphacite and is a rate‐limiting step for eclogitisation. Type 1C domains were produced by scattered nucleation of garnet in the same sample. In Type 2 domains, plagioclase was replaced by a layered corona with an outer layer of garnet, an inner layer of omphacite and an interior of inclusion‐rich plagioclase. In Type 3 domains, the omphacite layer was overgrown by the garnet rim, and omphacite is preserved only as inclusions in garnet. In more coarse grained leucogabbros, recrystallization was more complete, plagioclase replacement textures were less localised, and could not be divided into distinct stages. Plagioclase replacement in SMUK samples was not isochemical, and required diffusion of at least Mg and Fe from replacement of mafic phases in the surroundings. Strong compositional gradients in garnet reflect disequilibrium and were controlled by the different diffusion rates of Mg/Fe and Ca, different local chemical environments, and progress of the plagioclase breakdown reaction. The presence of small amounts of hydrous minerals (amphibole, phlogopite and clinozoisite) in local equilibrium in plagioclase domains of most SMUK samples indicates that a small amount of H2O was present during high pressure metamorphism.
Stepwise accumulation and ascent of magmas
Authors: Bons P. D. , Dougherty‐Page J. , Elburg M. A.
Published: March 2003

One of the currently popular theories on magma ascent is that it mainly occurs by propagating hydrofractures (dykes) and that magma viscosity is the primary rate‐controlling factor. This theory is based on mathematical models for single hydrofractures under idealised conditions. We simulated magma ascent with air ascending through gelatine and observed that the air ascended in batches, following paths made by their predecessors. Multiple batches accumulate at obstacles along the path. Although magma viscosity may control ascent rate during movement, obstacles ultimately control the size and average ascent velocity of ascending batches. We propose that step‐wise movement of magma batches is the mechanism of primary accumulation and ascent from the partially molten source rock of a magma to its first emplacement site and therefore the main ascent mechanism for granitic magmas. ‘Classical’ dyking is the mechanism for secondary ascent from a magma chamber.
Examining learning in relation to the contexts of use of ICT
Authors: Tolmie A.
Published: March 2003

Abstract Although ICT resources are commonly expected to produce uniform benefits, they are necessarily employed within pre‐existing contexts of educational and social activity, and the outcome in terms of both pattern of use and learning depends on how they fit in with these. As a result, the same technology or software may have unexpectedly diverse effects, according to specific setting. If the object is to exercise control over outcome, then the conditions of use need to be planned for within the design and implementation of the technology. In order to do this, it is crucial that research gathers data on how outcomes are affected by the interplay between technology and context. This raises questions about the methods that would be appropriate for the conduct and dissemination of such research. These points are discussed in relation to three studies, one each at primary, secondary and university levels of education.
Contributions of professional community to exemplary use of ICT
Authors: Dexter S. , Seashore K.R. , Anderson R.E.
Published: March 2003

Abstract  In these six case study sites, the commitment to teachers' individual learning about technology as a support to instruction was very strong and was complemented by technology leadership, support staff and professional development programming dedicated towards this end. This paper describes some conclusions about how the presence of this need to learn and the supportive conditions to do so was reciprocal, or mutually supportive, of the development of professional community around technology use. The professional community deepened and refined the shared vision related to the purposes of instructional technology, and the technology support. The supposition is that effective use of technology and professional community are mutually supportive in that increases in one create conditions for increases in the other.
Old World screwworm fly, Chrysomya bezziana, occurs as two geographical races
Authors: Hall M. J. R. , Edge W. , Testa J. M. , Adams Z. J. O. , Ready P. D.
Published: March 2003

Abstract. A morphological and molecular analysis was undertaken with the objective of identifying markers for geographical populations of Old World screwworm flies, Chrysomya bezziana Villeneuve (Diptera: Calliphoridae). The morphological analysis involved 192 adult flies from 14 countries, and the molecular analysis involved 45 larvae or adults from 14 populations in 11 countries. Principal components and cluster analysis of 10 morphological characters indicated that flies from Papua New Guinea (PNG) were a distinct group and most similar to flies from nearby Asian islands (Java, Sabah). There was poor resolution of other geographical regions, but some support for clustering of flies from Africa or India. Cladistic analysis of mitochondrial DNA sequences gave strong support for recognizing two races of Old World screwworm, one from sub‐Saharan Africa and the other from the Gulf region and Asia. This latter race could be further divided into two lineages, i.e. one from mainland Asia (from Iraq to the Malay Peninsula) and the other from two islands of PNG.
Population morphometric analysis of the tropicopolitan bug Triatoma rubrofasciata and relationships with Old World species of Triatoma: evidence of New World ancestry
Authors: Patterson J. S. , Schofield C. J. , Dujardin J. P. , Miles M. A.
Published: March 2003

Abstract. Quantitative analysis of morphological characters of the head was used to reconstruct the evolutionary history of the tropicopolitan bug Triatoma rubrofasciata (De Geer) (Hemiptera: Reduviidae) and seven species of Old World Triatoma. Multivariate analysis demonstrates that T. rubrofasciata and the Old World species have a high degree of similarity with Nearctic Triatoma species, particularly T. rubida (Uhler). We interpret this to imply a common ancestry for these groups. Dissemination of T. rubrofasciata and subsequent derivation of the Old World species of Triatoma is deduced to have occurred over a period of not more than 350 years.
Mutational analysis of TSC1 and TSC2 genes in gangliogliomas
Authors: Becker A. J. , Löbach M. , Klein H. , Normann S. , Nöthen M. M. , Von Deimling A. , Mizuguchi M. , Elger C. E. , Schramm J. , Wiestler O. D. , Blümcke I.
Published: March 2003

Gangliogliomas constitute the most frequent tumour entity in patients with temporal lobe epilepsy. The characteristic histopathological admixture of glial and neuronal elements, the focal nature and their differentiated phenotype and benign biological behaviour suggest an origin from a developmentally compromised or dysplastic precursor lesion. The present study analysed TSC1 and TSC2 genes as potential candidates involved in the pathogenesis of this intriguing neoplasm. Recent data suggest that both genes play a role in cortical differentiation and growth control. DNA sequence analysis of TSC1 and TSC2 was studied in 20 patients with gangliogliomas. Fifteen of these tumours (75%) carried polymorphisms in the TSC2 gene. The frequency of these polymorphisms was significantly increased in intron 4 (12.5%) and exon 41 (15%) compared to control individuals (8.1 and 6.5%, respectively, n = 100). A somatic mutation in intron 32 of the TSC2 gene was encountered in one patient. In the TSC1 gene, seven polymorphisms occurred as a combination of base exchanges in exon 14 and intron 13. No mutations were observed in this gene. Laser microdissection and harvesting of individual neuronal and glial elements identified the intron 32 mutation within the glial portion but not in dysplastic neurones of the tumour. The data demonstrate numerous polymorphisms as well as a novel TSC2 mutation in gangliogliomas from patients with chronic epilepsies. The selective detection of the TSC2 mutation within the glial component of a ganglioglioma suggests that the glioma portion has undergone clonal evolution in this case.
Bilateral hippocampal granule cell dispersion: autopsy study of 3 infants
Authors: Harding Brian , Thom Maria
Published: March 2003

Recent morphologic studies of Ammon's horn sclerosis (AHS) have recorded granule cell dispersion (GCD) in a significant proportion of temporal lobes surgically resected for temporal lobe epilepsy (TLE). We report the first post‐mortem descriptions of GCD in three unrelated infants. GCD was bilateral in all three and there were also migrational defects, heterotopias or polymicrogyria. Only one child, a 2.5‐year‐old boy, presented with a severe seizural disorder and exhibited bilateral AHS. But in the two younger children, deceased at 12 weeks and 5 months, respectively, no seizures were observed and hippocampal neuronal populations were intact. To date, GCD has only been reported in association with epilepsy and has not been observed bilaterally or in neurologically normal individuals. The present observations bring into question the hypothesis that GCD is causally related to seizure activity in early life, suggesting an opposing view that it is an independent developmental disorder.
In situ hybridization analysis of PrP mRNA in human CNS tissues
Authors: McLennan N. F. , Rennison K. A. , Bell J. E. , Ironside J. W.
Published: March 2003

Expression of the prion protein gene (Prnp) and production of the PrP protein are essential requirements for acquisition and spread of transmissible spongiform encephalopathies such as Creutzfeldt–Jakob disease (CJD) in humans. Here we have developed an in situ hybridization method for use on human post‐mortem central nervous system (CNS) tissues in order to determine those cell which are transcribing the Prnp gene and thus expressing PrP mRNA. Tissues from 11 adult individuals (age range 21–79 years) were analysed. Similar to previous studies in other animal systems, it was shown that PrP production occurs primarily in neuronal populations throughout the human brain. Neurones of the hippocampus, cortex, thalamus, cerebellum and medulla all synthesize PrP mRNA at readily detectable levels. No age‐related differences were observed between the cases studied. It was also found that the ependymal cells produced PrP mRNA; these were the only non‐neuronal cell type expressing the Prnp gene in the CNS. It is hoped that the information produced here will be helpful in understanding the pathology associated with CJD and other prion diseases in humans.
Heritability and physiological correlates of migratory tendency in the grasshopper Melanoplus sanguinipes
Authors: Kent Jack W. , Rankin Mary Ann
Published: March 2003

Abstract. Durations of tethered flights by the North American migratory grasshopper Melanoplus sanguinipes Fabricius are bimodally distributed: most individuals either will not fly, or else will fly for many hours. This observation suggests a simple measure (the ‘one‐hour rule’) for distinguishing migrants from non‐migrants. This measure is repeatable (repeatability = 0.6–0.7). Using laboratory‐reared offspring of grasshoppers from an Arizona population of mixed migratory tendency, a breeding experiment was conducted to determine the heritability of migratory tendency and possible correlated responses to selection on migratory behaviour. When migratory tendency is considered as a threshold trait, the heritability of liability is in the range 0.5–0.6. Most families in the breeding experiment had at least some migrants among their offspring; selection on migratory incidence had a correlated effect on the durations of flights by these individuals. The magnitude of thoracic lipid reserves showed a modest correlated response to selection on migratory behaviour. Thoracic and abdominal lipid reserves in identified migrants are reduced by flight, indicating that lipid is mobilized and consumed during flight in this species.
Determinants of Exercise in Adults with Cerebral Palsy
Authors: Heller Tamar , Ying Gui‐shuang , Rimmer James␣H. , Marks Beth A.
Published: March 2003

This study examined the impact of environmental factors and caregiver attitudes on exercise participation in adults with cerebral palsy using a social–cognitive model. The sample included 83 adults with cerebral palsy (47.0% males and 53.0% females). Hierarchical regression analysis was conducted with exercise frequency as the dependent variable. Independent variables included personal characteristics of persons with cerebral palsy (age, level of mental retardation, health status, mobility, and arm/hand limitation), type of residence, exercise facility access, and caregiver‐perceived benefits of exercise for people with cerebral palsy. The significant determinants of exercise participation were the caregiver's perceived benefits of exercise for persons with cerebral palsy and the type of residence. When caregivers perceived greater benefits of exercise, adults with cerebral palsy were likely to exercise more frequently. Non‐nursing home residents were more likely to exercise than nursing home residents. This difference was related to differences in the caregivers' perceived benefits of exercise and not because of the personal characteristics of the residents or access to the exercise facility. Results of this study point to the need to inform and educate caregivers about the benefits and importance of exercise for adults with cerebral palsy.
Anaplastic ganglioglioma with sarcomatous component: An immunohistochemical study and molecular analysis of p53 tumor suppressor gene
Authors: Suzuki Hiroyoshi , Otsuki Taisuke , Iwasaki Yuzo , Katakura Ryuichi , Asano Hideshi , Tadokoro Mamoru , Suzuki Yoichi , Tezuka Fumiaki , Takei Hidehiro
Published: March 2003

The present case report describes a case of ganglioglioma with a distinct sarcomatous component in the left temporal lobe of a 59‐year‐old Japanese man. Neoplastic neuroglial tissue contained both benign and anaplastic glial components with a MIB‐1 labeling index of 0.1% and 12.0%, respectively. Sarcomatous tissue adjacent to the anaplastic glial tissue was dominated by pleomorphic fibroblastic cells with a MIB‐1 labeling index of 10.8%. They were immunoreactive for smooth muscle actin, type IV collagen, and alpha 1 antitrypsin, but not for desmin and CD34. Interestingly, some of the sarcomatous cells were double‐positive for smooth muscle actin and GFAP. The p53 protein had accumulated in the anaplastic astrocytes and sarcomatous cells, but direct DNA sequencing of PCR products failed to detect any mutation in the p53 gene (from exon 4 to exon 10).
Substance P: a pioneer amongst neuropeptides
Authors: Hökfelt T. , Pernow B. , Wahren J.
Published: March 2003

Abstract.   Hökfelt T, Pernow B, Wahren J (Karolinska Institutet, Stockholm, Sweden). Substance P: a pioneer amongst neuropeptides. J Intern Med 2001; 249: 27–40.

A brief overview of recent developments in the substance P field is provided, in addition to a historical introduction. It is emphasized that there are multiple tachykinins and tachykinin receptors and that there are examples of coexistence of several tachykinin peptides and of several tachykinin receptors in single cells, and there is evidence for tachykininergic cotransmission. The distribution and functional significance of tachykinins in the gastrointestinal tract and in sensory neurones, and interactions with other peptides and transmitters, are reviewed. The recent production of knock‐out mice for either substance P or the NK1 receptor is discussed, as well as the exciting concept of substance P receptor internalization. Finally, the development of specific substance P antagonists is summarized, and possible clinical implications discussed, and, in particular, a recent study which reports that a substance P antagonist shows clinical efficacy in depression.
Sebaceous adenitis in the Akita: clinical observations, histopathology and heredity
Authors: Reichler Iris M. , Hauser Beat , Schiller Irene , Dunstan Robert W. , Credille Kelly M. , Binder Heinrich , Glaus Toni , Arnold Susi
Published: March 2003

Ninety‐seven pure‐bred Akitas were examined clinically and histologically for sebaceous adenitis. The diagnosis was established histologically in 23 Akitas by demonstrating an inflammatory reaction targeted against the sebaceous glands or a reduction in the number of glands. The clinical course of sebaceous adenitis in the Akita was similar to that seen in other breeds. The first skin lesions occurred mainly on the dorsal midline and ears. Compared with the Poodle, the age at first onset of the disease was more variable and the hair loss affected mainly the undercoat. The progression of sebaceous gland destruction varied between dogs and was not seen in all cases. Because bud‐like sebaceous gland proliferation could be identified, it seems that regeneration of the sebaceous glands may occur. An autosomal recessive inheritance appears to be possible. Apart from a genetic background, immune‐mediated factors possibly influence the onset and course of sebaceous adenitis.
Characterization and translational regulation of the arginine decarboxylase gene in carnation (Dianthus caryophyllus L.)
Authors: Chang Kwang Suk , Lee Sun Hi , Hwang Seong Bin , Park Ky Young
Published: March 2003

Arginine decarboxylase (ADC; EC 4.1.1.9) is a key enzyme in polyamine biosynthesis in plants. We characterized a carnation genomic clone, gDcADC8, in which the deduced polypeptide of ADC was 725 amino acids with a molecular mass of 77.7 kDa. The unusually long 5′‐UTR that contained a short upstream open reading frame (uORF) of seven amino acids (MQKSLHI) was predicted to form an extensive secondary structure (free energy of approximately −117 kcal mol−1) using the Zuker m‐fold algorithm. The result that an ADC antibody detected two bands of 45 and 33 kDa in a petal extract suggested the full length of the 78 kDa polypeptide precursor converted into two polypeptides in the processing reaction. To investigate the role of the transcript leader in translation, in vitro transcription/translation reactions with various constructs of deletion and mutation were performed using wheat germ extract. The ADC transcript leader affected positively downstream translation in both wheatgerm extract and primary transformant overexpressing ADC gene. It was demonstrated that heptapeptide (8.6 kDa) encoded by the ADC uORF was synthesized in vitro. Both uORF peptide, and the synthetic heptapeptide MQKSLHI of the uORF, repressed the translation of downstream ORF. Mutation of the uORF ATG codon alleviated the inhibitory effect. ORF translation was not affected by either a frame‐shift mutation in uORF or a random peptide. To our knowledge, this is the first report to provide evidence that a uORF may inhibit the translation of a downstream ORF, not only in cis but also in trans, and that the leader sequence of the ADC gene is important for efficient translation.
Pistillody, homeotic transformation of stamens into pistil‐like structures, caused by nuclear–cytoplasm interaction in wheat
Authors: Murai Koji , Takumi Shigeo , Koga Hironori , Ogihara Yasunari
Published: March 2003

Homeotic transformation of stamens into pistil‐like structures (pistillody) has been observed in a cytoplasmic substitution (alloplasmic) line of wheat (Triticum aestivum L.) cv. Norin 26, which has the cytoplasm of a wild relative species, Aegilops crassa L. On the other hand, an alloplasmic line of wheat cv. Chinese Spring (CS) with Ae. crassa cytoplasm has normal flowers. This is due to the presence in the CS nucleus of a fertility‐restoring gene, Rfd1. Deletion mapping analysis revealed that Rfd1 is located on the middle part of the long arm of chromosome 7B. To investigate the function of the Rfd1 gene by a loss‐of‐function strategy, we produced alloplasmic lines of CS ditelosomic 7BS [(cr)‐CSdt7BS] and CS monotelodisomic 7BS [(cr)‐CSmd7BS] with the Ae. crassa cytoplasm, and characterized their phenotypes. The line (cr)‐CSdt7BS without Rfd1 exhibited pistillody in all florets, and also female sterility. Scanning electron microscopy of the young spikes revealed that the pistillody was induced at an early stage of stamen development. The pistillate stamens often developed incomplete ovule‐like structures with integuments instead of tapetum and pollen grains. It is possible that MADS box genes are associated with the induction of pistillody, because the expression of wheat APETALA3 homologue (WAP3) was reduced in the young spikes of (cr)‐CSdt7BS. In addition, a histological study indicated that the female sterility in (cr)‐CSdt7BS is due to the abnormality of the ovule, which fails to form an inner epidermis and integuments in the chalaza region. The line (cr)‐CSmd7BS, hemizygous for Rfd1, showed partial pistillody (51%) and restored female fertility up to 72%. These results suggest that the induction of both pistillody and ovule deficiency caused by the Ae. crassa cytoplasm is inhibited by the Rfd1 gene in a dose‐dependent manner.
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

We 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

In 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

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

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

Objective

To determine whether the incidence of pre‐eclampsia is different in dichorionic compared to monochorionic twin pregnancies.

Methods

The 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.

Results

The 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).

Conclusion

In 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

A 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

Objective

To audit women's receipt of information during routine antenatal ultrasound investigations; and to investigate women's perceptions of, and attitudes towards, routine screening.

Design

Analysis of the records of 384 women from in and around Nottingham, UK, who maintained a diary throughout the course of their pregnancies.

Results

The 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.

Conclusions

The 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

Objectives

To evaluate sonographic features following uterine artery embolization and to assess using ultrasound the efficacy of embolization as the primary treatment of fibroids.

Design

Fifty‐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.

Results

Fifty‐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.

Conclusions

Uterine 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

Studying 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

The 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

The 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

The 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

The 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

Multiple 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.