bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diminution of early insulin response to glucose in subjects with normal but minimally elevated fasting plasma glucose. Evidence for early β‐cell dysfunction
Authors: Sato Y. , Komatsu M. , Katakura M. , Ohfusa H. , Yamada S. , Yamauchi K. , Hiramatsu K. , Ichikawa K. , Aizawa T. , Hashizume K. 
Published: March 2003

AbstractAim Systematic analysis of β‐cell function in Japanese health examinees.Methods In 938 Japanese health examinees (627 men and 311 women, mean age and body mass index, 54.0 years and 23.6 kg/m2, respectively), plasma specific insulin was measured at fasting and during a 75‐g oral glucose tolerance test. The subjects were stratified into six groups based on fasting plasma glucose ≤ 5.1 mmol/l, 5.2–6.0 mmol/l, 6.1–6.9 mmol/l, 7.0–7.8 mmol/l, 7.9–8.7 mmol/l, and ≥ 8.8 mmol/l as the 1st, 2nd, 3rd, 4th, 5th and 6th groups, respectively.Results Distribution of fasting insulin showed a very modest ‘inverted U’ shape, with the peak in the 5th group. Progressive increase from the 1st toward the 5th group was significant. In contrast, the ratio of change in insulin to change in glucose from 0 to 30 min during the glucose tolerance test was greatest in the 1st group and progressively declined in the groups with higher fasting glycaemia. Difference in the ratio was most striking and highly significant between the 1st and 2nd groups. Distribution of the insulin to glucose ratio of subjects with normal glucose tolerance significantly overlapped with that of untreated patients with diabetes.Conclusions In a Japanese population, (i) β‐cell starts to deteriorate during normoglycaemia with a minimal elevation of fasting plasma glucose, and (ii) there are glucose‐tolerant subjects with β‐cell dysfunction.
Space–time clustering of childhood Type 1 diabetes in Devon and Cornwall, England
Authors: Zhao H. X. , Moyeed R. A. , Stenhouse E. A. , Demaine A. G. , Millward B. A. 
Published: March 2003

AbstractAims Several studies on space–time clustering have been reported in childhood diabetes, but the findings are conflicting. The present study was undertaken to examine whether such clustering could be detected at either birth or the time of diagnosis in the far South‐west of England.Methods A cohort of 518 children aged 0–15 years and diagnosed with Type 1 diabetes from 1975 to 1996 contained in the population‐based Cornwall and Plymouth Children's Diabetes Register (CPCDR) were included in the analyses. The case ascertainment for this register is estimated to be 94.4% complete. Mantel's modification of Knox's method was employed. A method based on K‐function was also used, for the first time, to investigate the space–time clustering of diabetes.Results Significant space–time clustering at diagnosis was found by the Knox's test in the following combinations of critical cut‐off thresholds: 25, 35 and 50 km and 90, 270 and 360 days (all P < 0.05), with the highest significance found at 35 km and 360 days (P = 0.0011). K‐function analysis also confirmed the overall clustering (P = 0.013).Conclusions There is strong evidence of space–time clustering in the onset of childhood Type 1 diabetes in Devon and Cornwall, England. These results lend some support to the hypothesis that viral infections and some unknown localized environmental factors play a role in the development of childhood Type 1 diabetes.Diabet. Med. 19, 667–672 (2002)
Type 2 diabetes, obesity, and the renal response to blocking the renin system with irbesartan
Authors: Price D. A. , Lansang M. C. , Osei S. Y. , Fisher N. D. L. , Laffel L. M. B. , Hollenberg N. K. 
Published: March 2003

AbstractAim Our recent studies revealed a striking but variable enhancement of renal vasodilator responses to blockers of the renin‐angiotensin system in subjects with diabetes mellitus, possibly reflecting the level of intrarenal activation of the renin‐angiotensin system, and thus a risk of nephropathy. As obesity is a common finding in diabetic individuals, and obesity has been linked to an increase in plasma angiotensinogen levels, we enrolled diabetic subjects with a wide range of body mass index (BMI) for this study.Methods Twelve Type 2 diabetic subjects in balance on a low sodium diet participated after baseline renal plasma flow and glomerular filtration measurements were made. Each subject then received 150 mg irbesartan, and renal function was measured every 45 min for 4 h.Results The average vasodilator response to irbesartan was 174 ± 33 ml/min. No correlation was found between renal plasma flow response to irbesartan and duration of diabetes, baseline glucose, or HbA1c level. BMI, our measure of obesity, was highly correlated to the renal response to irbesartan (r

=
0.7; P = 0.01).Conclusions Our findings suggest an important role for obesity in activating the intrarenal renin system, perhaps via production of angiotensinogen. BMI may be an indicator of risk of nephropathy.
Efficacy of Humalog® injections before an afternoon meal and their acceptance by children and adolescents with Type 1 diabetes
Authors: Martin D. , Licha‐Müntz G. , Grasset E. , Grenèche M. O. , Nouet D. , François L. , Legrand C. , Polak M. , Augendre‐Ferrante B. , Tubiana‐Rufi N. , Robert J. J. 
Published: March 2003

AbstractAims To evaluate the acceptability and efficacy of an injection of insulin lispro, before an afternoon meal.Methods The subjects, 43 patients with Type 1 diabetes, 16 boys and 27 girls, aged 12.4 ± 2.4 years, were randomly assigned to the treatment (n = 20) or the untreated control group (n = 23). The treatment was an injection of insulin lispro immediately before the afternoon meal. The control group had no injection. The treatment and the control group consumed identical types of meals for 2 months. The mean before‐dinner blood glucose was measured during the last 2 weeks of the study.Results Injection of insulin lispro resulted in a significant reduction in the before‐dinner blood glucose compared with the untreated control group (10.4 ± 3.8 mmol/l vs. 14.7 ± 3.9 mmol/l, respectively). The number of days on which the blood glucose was > 10 mmol/l was reduced by half in the insulin lispro group. The difference in HbA1c between baseline and endpoint differed slightly but significantly between the two groups, in boys. Treated patients ate the meal less frequently (11.4 ± 3.0 times per 15 days) than the control patients (14.4 ± 0.6 times per 15 days) and injected themselves with insulin 8.9 ± 3.6 times per 15 days. The HbA1c increased significantly with the number of meals taken without injection. There was no statistically significant difference in the frequency of hypoglycaemia or changes in weight between the two groups.Conclusions We conclude that an injection of insulin lispro before the afternoon meal can effectively lower the before‐dinner blood glucose, and in boys also lowers the HbA1c. Patients were satisfied with the lower blood glucose before dinner, and did not find the insulin lispro injection difficult. However, compliance with the protocol procedures decreased during a subsequent 6‐month period.Diabet. Med. 19, 1026–1031 (2002)
The nature and diversity of neotropical savanna vegetation with particular reference to the Brazilian cerrados
Authors: Furley Peter A. 
Published: March 2003

Summary 1. The South and Middle American tropics contain the world's largest area of moist savanna. Despite an apparent uniformity in appearance, floristic groupings can be detected and four zones are provisionally outlined with a number of character‐ istic plants.2. Although current knowledge of their bio‐ geography and palaeoecology is scattered and incomplete, it is evident that there have been significant changes throughout the neotropics since the glacial maximum.3. The largest and most significant savanna formations are the Brazilian cerrados, which occupy nearly 23% of that country, an area equivalent to that of western Europe. The cerrados range from savanna woodlands (cerradão), through progres‐ sively less arboreal formations (cerrado), to nearly treeless grasslands (campo). A number of adjoining vegetation formations are closely related, including evergreen and deciduous forests, scrub woodlands and wetlands.4. Until the last decade, the biological diversity of the neotropical savannas was thought to be limited since, structurally, they appeared to form a relatively simple mosaic of repeated physiognomic units. New evidence reveals a rich diversity of tree, shrub and herbaceous plants in a continuously changing spatial pattern. Such diversity reflects the great area of the biome, together with local differences in topography and drainage, soil conditions and fire frequency.5. Research on the dynamic processes affecting savannas is of increasing importance and urgency given the potential value of the area that is still relatively undisturbed (about 50% of the original, but with less than 2% having federal reserve status) and the pace of current conversion to different forms of land use.
Taxonomic level, trophic biology and the regulation of local abundance
Authors: Kaspari Michael 
Published: March 2003

Abstract

Taxocenes — monophyletic ecological assemblages — are a key focus of macroecology. Abundance (individuals per area) is a basic property of taxocenes but has received less attention than diversity, although the two are probably related. Abundance reflects a taxocene’s ability to harvest and sequester available energy and divide it among individuals. This paper explores how two properties of all taxocenes — trophic makeup and taxonomic level (e.g. genus, tribe, subfamily, family … ) — may contribute to patterns of local abundance at geographical scales.
Forty‐nine ground ant taxocenes, in habitats ranging from New World deserts to rain forests, were surveyed along a three‐orders of magnitude productivity gradient using transects of 30 1‐m2 quadrats at each site. Abundance — the number of nests per transect — varied over two orders of magnitude.
Over 80% of the genera collected were omnivores. However, herbivore, omnivore, and predator taxa were added to ant taxocenes in roughly 1 order of magnitude steps up the productivity gradient. Specialist detritivores were added last.
Net primary productivity and mean monthly temperature both consistently entered regression models predicting abundance. However, while productivity was the dominant predictor of abundance for higher taxa (families, subfamilies), temperature was the dominant predictor of abundance for lower taxa (tribes, genera). The answer to the question ‘What regulates the abundance of a taxocene?’ is thus sensitive to the taxonomic level of analysis.
These data support the following scenario. Lower taxa are abiotic specialists given the insufficient number of genomes and generations required for the exploration of the entire abiotic envelope. Higher taxa, in contrast, consist of suites of abiotic specialists arrayed along the entire productivity gradient, with access to productivity everywhere the taxon occurs. If this scenario is true, individual species may respond to global changes in temperature; the higher taxa they belong to may most respond to global changes in productivity.
Vegetation regeneration on blanket mire after mechanized peat‐cutting
Authors: Cooper A. , Mccann T. P. , Hamill B. 
Published: March 2003

Abstract

Blanket mire in Northern Ireland is an ecologically threatened habitat in which land use for hand peat‐cutting, forestry and agriculture has had a major influence. A recent land use change is the introduction of tractor‐powered peat‐harvesting. In this paper, the effect of machine peat‐cutting on ombrotrophic blanket mire vegetation is assessed from a regional sample of cut and uncut plots.
Principal components analysis identified water‐table depth and grazing intensity as major factors influencing the species composition of uncut mire. A key variable affecting the composition of machine‐cut mire across the drainage gradient was the number of times cut, with multiple annual cutting causing progressive decreases in acrotelm depth, catotelm bulk density and plant cover. Ericaceous species and Sphagnum spp. were particularly sensitive to cutting, with Eriophorum angustifolium and Campylopus introflexus characteristic of multiple‐cut sites.
Redundancy analysis, with number of times cut partialled out, showed that recovery time accounted for a significant amount of variance in vegetation composition. Species that significantly increased in abundance with recovery time were Sphagnum spp., Odontoschisma sphagni

, Erica tetralix and Drosera rotundifolia.
Sites cut frequently, or which were grazed, recovered more slowly. Recovery from cutting was partly dependent on the post‐cutting structure of the mire surface and the species that survive cutting. The rate of recovery on sites cut once, then abandoned, is relatively rapid compared with multiple‐cut sites where species colonization is constrained by bare compacted peat.
Evidence for non‐uniform dispersal in the biological invasions of two naturalized North American bird species
Authors: Gammon David E. , Maurer Brian A. 
Published: March 2003

AbstractMost previous attempts to model the geographical range expansion of an invading species assume random dispersal of organisms through a homogeneous environment. These models result in a series of uniformly increasing circles radiating out from the centre of origin over time. Although these models often give reasonable fits to available data, they do not typically include mechanisms of dispersal. Alternatively, models that include assumptions of non‐random dispersal and a heterogeneous environment inevitably result in an anisotropic or jagged invasion front. This front will include propagules of pioneer individuals for the expanding species. Existing data from biological invasions reveal that the spatial structure of an invading species usually exhibits these propagules. Using population data gathered from the past century, we investigated the propagules of two North American invading bird species: the European starling (Sturnus vulgaris Linnaeus), and the house finch (Carpodacus mexicanus Müller), and found a correlation between propagule location and habitat quality. These results suggest that dispersing individuals seek out favourable habitat and remain there, thus introducing a possible mechanism for explaining non‐uniform dispersal during invasions. When combined with results from other studies, our results suggest that propagules provide starting points for future population expansion of an invading species.
Efficient SNP‐based tests of association for quantitative phenotypes using pooled DNA
Authors: Bader Joel S. , Bansal Aruna , Sham Pak 
Published: March 2003

AbstractIntroduction  Genetic factors underlying complex diseases are difficult to identify: many polymorphisms may contribute, each having a small effect and low penetrance. These factors may be identified by association studies of large populations, an alternative to family‐based linkage studies. Allele frequency measurements of pooled DNA selected from population‐level DNA repositories can reduce the costs of these studies. We provide guidance for selecting unrelated individuals for pooling and for comparing the power of studies based on pooled measurements to the power of individual genotyping, particularly for studies using single‐nucleotide polymorphism (SNP) markers.Materials and methods  We used exact numerical calculations to set pooling criteria that maximized the power to detect association as a function of marker frequency, inheritance mode, and additive variance. Analytical approximations are also provided.Results and discussion  Power estimates are provided for two pooled DNA designs: the classification of individuals as affected or unaffected, analogous to a case‐control design, and the optimized selection of individuals with extreme phenotypic values. Optimized selection is approximately fourfold more efficient than affected/unaffected classification. The optimal design for most markers is to pool the top and bottom 27% of individuals. Neglecting experimental measurement error, this design requires a population only 1.24‐fold larger than that required for individual genotyping. When measurement error is included, the pooled DNA association test serves better as a pre‐screen to identify candidate markers which then proceed to individual genotyping. This strategy can still provide a 100‐fold savings over individual genotyping.
The histamine 1 and histamine 2 receptor genes—candidates for schizophrenia and clozapine drug response
Authors: Mancama D. , Arranz M. J. , Munro J. , Makoff A. , Kerwin R. 
Published: March 2003

AbstractIntroduction There is growing evidence to suggest the involvement of histaminergic pathways in the pathophysiology of schizophrenia. Overactive histamine activity is thought to contribute significantly to deficit symptoms such as apathy and social withdrawal associated with the disorder, while the efficacy of certain atypical antipsychotics may include their action at histamine receptors. By selecting the histamine 1 (H1) and histamine 2 (H2) receptor genes as candidates, the aim of this study was to investigate the possible involvement of these receptors both in schizophrenia and in the clinical response of patients undergoing clozapine treatment.Method Using single strand conformation polymorphism (SSCP) analysis we screened the complete coding region of each receptor gene for mutations in 50 schizophrenics and 50 unaffected individuals. Automated sequencing was used to confirm the presence and nature of each detected polymorphism.Results We report here the identification of five previously undescribed H1 receptor polymorphisms (Lys19Asn, Asp349Glu, 1068‐A/G, Phe358Δ and Leu449Ser) and a single novel H2 receptor polymorphism (543‐G/A). Initial analysis of these polymorphisms in case vs. control association studies revealed a significant increase in distribution of one, the H1Ser449 allele, in our control sample (13/97) compared with the group of schizophrenics (0/90), prompting further analysis of this polymorphism in an extended patient sample population. Overall we observed a trend towards increased frequency of this allele amongst our controls compared with the corresponding group of schizophrenics, though the significance was estimated to be marginal (χ2 = 3.94, P = 0.047). Similarly, no conclusive evidence could be found to suggest the involvement of any other H1 and H2 receptor variants in schizophrenia or clozapine response. Further investigation of the five polymorphic H1 loci by haplotype analysis indicated a lack of association between these loci and both schizophrenia and clozapine response.Conclusions These results suggest that histamine H1 and H2 receptor variants do not bear significant influence on the susceptibility of individuals to schizophrenia, nor do they appear to influence clinical response to clozapine treatment.
Power of the TDT to detect association: effect of linkage disequilibrium between genetic markers and an unobserved disease mutation
Authors: Lewis Cathryn M. , Fisher Sheila A. 
Published: March 2003

AbstractThe transmission disequilibrium test (TDT) is widely used to test for association in families. Many previous papers have shown sample size calculations where the true disease mutation is tested. When a neighbouring marker is used in place of the mutation, the power to detect association depends on the linkage disequilibrium between the loci. A difference in frequency between the mutation and the tested allele, or a reduction in linkage disequilibrium will substantially increase the required sample size. If a study design includes reasonable assumptions regarding linkage disequilibrium, using the TDT with anonymous nonfunctional markers may not be feasible.
Precise mapping of the fragile siteFRA12Aon chromosome 12q13.1
Authors: Winnepenninckx Birgitta , Reyniers Edwin , Bossuyt Paul , Smits Arie , Wauters Jan , Kooy R. Frank 
Published: March 2003

AbstractIntroduction A causative relationship has been reported between fragile site expression and disease forFRA12A, a rare, folate‐sensitive fragile site on chromosome 12q13.1.FRA12Aexpression has been described in a number of patients with mental retardation, sometimes in combination with clinical abnormalities. In correspondence to the molecular mechanism of previously cloned, rare, fragile sites, it may be expected thatFRA12Ais caused by repeat expansion, affecting the expression of genes in the region. To identify the repeat and the associated gene, this paper reports the precise mapping ofFRA12Aon chromosome 12q12–13.Methods Fluorescencein situhybridization (FISH) techniques were used to mapYACandPACclones in the neighbourhood ofFRA12A.PACDNA pools andPACfilters were screened to find additionalPACclones spanning the candidate region. Markers in the region were obtained via web searches and used to construct bothPACandYACcontigs.Results and Discussion A singleYACclone that overspans the fragile site was identified and a completeYACandPACcontig for theFRA12Aregion was constructed. The region contains several candidate genes, including a calcium ion channel (CACNLB3), a GTP‐binding factor (ARF3), a gene involved in brain development (INT1) and two other genes involved in developmental processes (WNT10BandALR). TheFXR1gene, a homologue of theFMR1gene, that is associated with fragile X syndrome and that maps to chromosome 12q12–13, was ruled out as a possible candidate gene for theFRA12Asite.
How behavioural studies contribute to the species problem: a piscine perspective
Authors: Barlow George W 
Published: March 2003

AbstractDuring the ascendency of ethology, the study of animal behaviour contributed to taxonomic and phyletic issues, but the approach faded in parallel with the waning of systematic studies in general. Systematics and particularly phylogeny has experienced a resurgence with the advent of molecular tools. The understanding of behavioural evolution has benefited from molecular phylogenies. Behaviour's reciprocal contribution, however, currently lies chiefly in resolving the validity of species designation of allopatric species and in potentially helping in the overall classification of species. I review and evaluate the experimental methods favoured in seeking behavioural isolating mechanisms, and the challenge to the species concept when gene trees and species trees disagree. The dynamic situation in the Great Lakes of Africa offers under‐exploited opportunities to test whether behavioural isolating mechanisms evolve in the absence of secondary contact. Given that behaviour is more immediately responsive to changes in the physical and biological environment, behaviour may be the single most salient adaptive feature in speciation events. The species concept is viewed as a fuzzy but nonetheless useful set.
The relationship between fishing methods, fisheries management and the estimation of maximum sustainable yield
Authors: Maunder Mark N 
Published: March 2003

AbstractThe allocation of effort among fishing gears is as important as controlling effort with respect to both sustainable yield and ecosystem management. Differences in age‐specific vulnerability to the fishing method can modify the maximum sustainable yield (MSY) that is obtainable from a fish stock. Different gears or methods are more or less selective for the species targeted, and MSY is rarely, if ever, attainable simultaneously for all species. The different fishing methods capture different types of nontarget species. Some methods will often be more profitable than others, and different user groups will prefer different methods. In many fisheries, it is unlikely that fishing can be limited to a single gear or method, so compromises among them will be required. Global MSY is discussed as a possible reference point for fisheries management. The yellowfin tuna fishery in the eastern Pacific Ocean (EPO) shows all the above characteristics and is used to illustrate effort allocation among fishing methods.