bluuebunny/crossref_metadata_2025_split huggingface dataset:
High Temperature Tensile Creep of Magnesium Oxide Single Crystals
Authors: CLAUER A. H. , WILCOX B. A. 
Published: June 2006

The creep behavior and the dislocation substructure developed during creep were investigated for 〈011〉 oriented MgO single crystals creep tested in tension. Creep deformation was studied over stress and temperature ranges of 29.0 to 86.2 MN/m2 and 1200 to 1500°C, and the minimum creep rate, ε, was found to obey the relation:
image
where σ= applied tensile stress, k= the Boltzmann constant, T= absolute temperature, n= 3.8 to 4.5, and A = ll × 10−2 (MN/m2)‐4 s‐1. Dislocation substructures developed during creep were studied by transmission electron microscopy and etch pitting techniques. At 1400°C, the dislocation density, ρ, at 0.10 tensile creep strain depended on applied stress as ρασ2.1. Numerous dislocation loops and long straight dislocations were present, but subboundaries were seldom observed. The results are discussed in terms of two possible operative creep mechanisms: (1) a recovery process based on annealing out of dislocation dipoles and loops, and (2) dislocation glide limited by atmospheres of charged defects surrounding dislocations.
Self‐Diffusion of 60Co in Co1‐xO Single Crystals of Controlled Stoichiometry
Authors: RAHMAN S. F. , BERARD M. F. 
Published: June 2006

Cobalt tracer self‐diffusion coefficients were determined in single crystals of Co1‐x O at 1037° to 1350°C and for x=0.002 to 0.00s. In crystals with x fixed at 0.005, the results wereThe activation energy in this constant‐stoichiometry case was identified as the enthalpy of motion for Co ions moving via a vacancy jump mechanism. Based on known stoichiometry rela‐ tions, a published activation energy for Co self‐diffusion mea‐ surements in air was corrected to yield an enthalpy of motion in excellent agreement with the number given above. At a constant temperature of 115O0°±2°C, the Po2 dependence of Co self‐ diffusion wasThe Po2 expynent suggests that the predominant mobile ion defects are singly ionized Co vacancies. Simple defect reactions with no modifications for defect clustering were adequate to explain all results obtained.
Oxygen Diffusion in Magnesium Aluminate Spinel
Authors: REDDY K. P. R. , COOPER A. R. 
Published: June 2006

Oxygen self‐diffusion in MgAl2O4 single crystals was investigated by annealing the samples in 18O enriched gas at 98 kPa (1 atm) and measuring the tracer concentration profiles using a proton activation technique. The diffusion coefficients in the range 1625 to 1925 K for stoichiometric crystals are represented by:Oxygen diffusivity in alumina‐rich nonstoichiometric samples is higher than in stoichiometric samples.
An evaluation of a brief motivational intervention among young ecstasy and cocaine users: no effect on substance and alcohol use outcomes
Authors: Marsden John , Stillwell Garry , Barlow Helen , Boys Annabel , Taylor Colin , Hunt Neil , Farrell Michael 
Published: June 2006

ABSTRACTAims  To investigate whether a stimulant‐ and alcohol‐focused brief motivational intervention induces positive behaviour change among young, regular users of MDMA (‘ecstasy’), cocaine powder and crack cocaine.Design and measurements  A randomized trial of the intervention versus a control group who received written health risk information materials only. All participants completed a baseline self‐assessment questionnaire before randomization. Outcome measures were self‐reported period prevalence abstinence from ecstasy, cocaine powder and crack cocaine and the frequency and amount of stimulant and alcohol use in the previous 90 days, recorded at 6‐month follow‐up via self‐completion questionnaire and personal interview.Participants and setting  A total of 342 adolescent and young adult stimulant users (aged 16–22 years) were recruited and 87% were followed‐up. The intervention was delivered by a team of 12 agency youth drug workers and two researchers at five locations in Greater London and south‐east England.Findings  There were no significant differences in abstinence for ecstasy, cocaine powder or crack cocaine use between the experimental and control groups. Contrasting follow‐up with baseline self‐reports, there were no between‐group effects for changes in the frequency or amount of stimulant or alcohol use. Participant follow‐up data suggested that the baseline assessment was a contributing factor in within‐group behaviour change among experimental and control condition participants.Conclusions  Our brief motivational intervention was no more effective at inducing behaviour change than the provision of information alone. We hypothesize that research recruitment, baseline self‐assessment and contact with study personnel are influences that induce positive reactive effects on stimulant use.
A match–mismatch test of a stage model of behaviour change in tobacco smoking
Authors: Dijkstra Arie , Conijn Barbara , De Vries Hein 
Published: June 2006

ABSTRACTAims  An innovation offered by stage models of behaviour change is that of stage‐matched interventions. Match–mismatch studies are the primary test of this idea but also the primary test of the validity of stage models. This study aimed at conducting such a test among tobacco smokers using the Social Cognitive Stage Model.Design  A match–mismatch field‐experiment was conducted in which smokers and ex‐smokers in different stages were assigned randomly to one of three information conditions.Participants  Smokers in the pre‐contemplation stage, the contemplation stage and the preparation stage, and ex‐smokers in the action stage (n = 481), who were recruited through mass media, were assigned randomly to one of three information conditions.Intervention  In each of the three information conditions, participants received a four‐ to six‐page computer‐tailored letter designed to: (1) increase the positive outcome expectations of quitting, (2) decrease the negative outcome expectations of quitting or (3) increase self‐efficacy.Measurements  Forward stage transition was the primary outcome measure, which was assessed 2 months after the participants received the information.Findings  At the 2‐month follow‐up, the matched interventions were significantly more effective in stimulating forward stage transition (44.7%) than were mismatched interventions (25.8%; odds ratio = 2.78; confidence interval = 1.85–4.35).Conclusion  The present study provides experimental support for the benefits of stage‐matching and for the validity of the Social Cognitive Stage Model.
The long and the short of it: evidence that FGF5 is a major determinant of canine ‘hair’‐itability
Authors: Housley D. J. E. , Venta P. J. 
Published: June 2006

SummaryHair length in dogs has been known for many years to be primarily controlled by a limited number of genes, but none of the genes have been identified. One of these genes produces a recessively inherited long‐haired phenotype that has been thought to explain the bulk of hair‐length variation among many breeds. Sequence analysis of the FGF5 gene in short and long‐haired corgis resulted in the identification of two coding region differences: a duplication in a relatively non‐conserved region of the gene and a missense mutation, resulting in the substitution of Phe for Cys, in a highly conserved region. Genotyping of 218 dogs from three breeds fixed for long hair, eight breeds fixed for short hair and five breeds in which long hair is segregating provided evidence that the missense mutation is associated with the hair‐length differences among these breeds.
Chicken major histocompatibility complex class II molecules of the B19 haplotype present self and foreign peptides
Authors: Cumberbatch J. A. , Brewer D. , Vidavsky I. , Sharif S. 
Published: June 2006

SummaryThe chicken major histocompatibility complex (MHC), or B‐complex, mediates genetic resistance and susceptibility to infectious disease. For example, the B19 haplotype is associated with susceptibility to Marek's disease. Here, we describe the sequencing and analysis of peptides presented by B19 MHC class II molecules. A B19/B19 B‐cell line was used for the immunoaffinity purification of MHC class II molecules, which was followed by acid elution of the bound peptides. The eluted peptides were then analysed using tandem mass spectrometry. Thirty peptide sequences were obtained, ranging from 11 to 25 amino acids in length. Source protein cellular localization included the plasma membrane, cytosol and endosomal pathway. In addition, five peptides from the envelope glycoprotein of chicken syncytial virus (CSV) were identified. Chicken syncytial virus had been used as a helper virus along with reticuloendotheliosis virus strain T for transformation of B19/B19B cells. Alignment and analysis of the peptide sequence pool provided a putative peptide‐binding motif for the B19 MHC class II.
Health, economy and social capital in Nordic children and their families: a comparison between 1984 and 1996
Authors: Berntsson L. , Köhler L. , Vuille J.‐C. 
Published: June 2006

AbstractObjective  The aim of the study was to analyse the development in the health of children that occurred in the five Nordic countries (Denmark, Finland, Iceland, Norway and Sweden) between 1984 and 1996 and relate it to the changes in economic growth and social capital in these countries during the same period.Methods  Two cross‐sectional studies covered a representative sample of children, aged 2–17 years in each country, a total of 10 291 in 1984 and 10 317 in 1996. The data were collected by mailed questionnaires. Statistical associations between a health indicator (the absence of psychosomatic complaints), economic indicators (social class, housing and disposable income) and social capital indicators (parents’ and children’s organized group activities, parents playing with their children and the absence of bullying) within samples and between corresponding values in different samples across subgroups (defined by country and area of residence) were evaluated using multiple linear regression.Results  In both surveys, there was a statistically highly significant association between the health indicator and the social capital indicators, whereas the economy indicators were not related to either of the other two types of measure. Change in health was associated positively with change in social capital and negatively with change in economy.Conclusion  The study provides strong support for the concept of social capital as an important determinant of children’s health.
Children’s cortisol levels and quality of child care provision
Authors: Sims M. , Guilfoyle A. , Parry T. S. 
Published: June 2006

AbstractBackground  Cortisol levels are increasingly being used as an indicator of stress levels. Research suggests that children who attend child care demonstrate higher cortisol levels than children in their homes, suggesting that child care acts as a risk factor for poor child outcomes. However, it is also suggested that quality influences outcomes.Methods  Cortisol levels were measured through samples of saliva taken from children (3–5 years of age) attending long‐day care centres in Perth, Western Australia. Quality of the programme was measured using industry national quality assurance indicators designed for child care centres. The analysis employed a 2 (time of collection: average am cortisol, average pm cortisol) by 3 (centre quality: high, satisfactory, unsatisfactory) split plot anova with repeated measures on the time factor.Results  Cortisol levels of children attending high‐quality programmes demonstrated a decline across the child care day. Levels in children attending unsatisfactory programmes demonstrated an increase across the day.Conclusions  Although we do not yet know how high, and for how long, cortisol levels need to be elevated for risk of undesirable outcomes to increase, this research signals the importance of emphasizing the need for high‐quality care for young children.
Towards a typology of specific language impairment
Authors: Cundall David 
Published: June 2006

.

Van Weerdenburg M.,
Verhoeven L. &
Van Balkom H.
(
2006
)

,
47
,
176
–
189
.
Background  The population of children with specific language impairments (SLI) is heterogeneous.Objective  To examine this heterogeneity more closely, by identifying and describing subgroups within the population of children with SLI in the Netherlands.Method  A broad battery of language tests and language‐related cognitive tests were administered to 147 6‐year‐old and 136 8‐year‐old children with SLI.Results  Factor analysis revealed four factors indicating four distinct linguistic domains for both age samples: (i) lexical‐semantic abilities; (ii) auditory conceptualization; (iii) verbal sequential memory; and (iv) speech production. These empirical findings were further validated by the positive correlations found between the language factors and the judgements of teachers and speech therapists. Finally, a cluster analysis revealed four distinct clusters of SLI children for each sample with specific language profiles based on the four clusters.Conclusions  The language problems that emerged from the two samples of children with SLI could be described as falling into four types. Based on these language types, four subgroups of children with SLI could be distinguished, each with a separate profile. Some subgroups had severe problems on one specific type of language problem; others had severe problems in more than one type of language problem when compared with the other subgroups in the same age sample. The different profiles may indicate a more dynamic approach is needed in intervention, considering the presence of both compensating and restricting factors within each child with SLI.
Cross‐reactive and species‐specific immunoglobulin E epitopes of plant profilins: an experimental and structure‐based analysis
Authors: Radauer C. , Willerroider M. , Fuchs H. , Hoffmann‐Sommergruber K. , Thalhamer J. , Ferreira F. , Scheiner O. , Breiteneder H. 
Published: June 2006

SummaryBackground
Profilins are cross‐reactive plant allergens responsible for multiple pollen sensitization and pollen‐associated food allergy. While it is assumed that profilins from different species are immunologically equivalent, some studies suggest partial or even lacking IgE cross‐reactivity between certain profilins.Objective
We aimed to obtain a semi‐quantitative assessment of the contributions of conserved and species‐specific epitopes to IgE binding of plant profilins.Methods
We compared model structures of profilins from timothy, mugwort, celery and bell pepper with crystal structures of birch and latex profilins. We predicted potential conformational epitopes that consisted of contiguous patches of at least 20% surface‐exposed residues. Celery and timothy profilins were purified from their natural sources, and profilins from birch, mugwort, bell pepper and latex were expressed in Escherichia coli. The structural integrity of all purified proteins was confirmed by circular dichroism spectroscopy. IgE ELISAs and ELISA inhibitions using sera from 22 profilin‐sensitized allergic patients were carried out.Results
Peptide backbone conformations of all six profilins were highly similar. Nine variable epitopes and two containing high proportions of conserved residues were predicted. IgE from all sera bound to all tested profilins and the amounts were highly correlated. However, IgE inhibition experiments revealed that up to 60% of total IgE binding was mediated by species‐specific epitopes. The extent of cross‐reactivity among profilins from timothy, birch, latex and celery was greater than cross‐reactivity to mugwort and bell pepper profilins. This pattern was mirrored by sequence similarities among one of the predicted variable epitopes. Patients with IgE to cross‐reactive epitopes displayed allergic reactions to a greater number of plant foods than patients having IgE directed to species‐specific epitopes.Conclusion
The large extent of cross‐reactivity among plant profilins justifies using a single profilin for diagnosis. However, the fine specificity of IgE directed to variable epitopes may influence the clinical manifestation of profilin sensitization.
Are increased frequency of macrophage-like and natural killer (NK) cells, together with high levels of NKT and CD4+CD25high T cells balancing activated CD8+ T cells, the key to control Chagas’ disease morbidity?
Authors: Vitelli-Avelar D M , Sathler-Avelar R , Massara R L , Borges J D , Lage P S , Lana M , Teixeira-Carvalho A , Dias J C P , Elói-Santos S M , Martins-Filho O A 
Published: June 2006

SummaryThe immunological response during early human Trypanosoma cruzi infection is not completely understood, despite its role in driving the development of distinct clinical manifestations of chronic infection. Herein we report the results of a descriptive flow cytometric immunophenotyping investigation of major and minor peripheral blood leucocyte subpopulations in T. cruzi-infected children, characterizing the early stages of the indeterminate clinical form of Chagas’ disease. Our results indicated significant alterations by comparison with uninfected children, including increased values of pre-natural killer (NK)-cells (CD3– CD16+ CD56–), and higher values of proinflammatory monocytes (CD14+ CD16+ HLA-DR++). The higher values of activated B lymphocytes (CD19+ CD23+) contrasted with impaired T cell activation, indicated by lower values of CD4+ CD38+ and CD4+ HLA-DR+ lymphocytes, a lower frequency of CD8+ CD38+ and CD8+ HLA-DR+ cells; a decreased frequency of CD4+ CD25HIGH regulatory T cells was also observed. These findings reinforce the hypothesis that simultaneous activation of innate and adaptive immunity mechanisms in addition to suppression of adaptive cellular immune response occur during early events of Chagas’ disease. Comparative cross-sectional analysis of these immunophenotypes with those exhibited by patients with late chronic indeterminate and cardiac forms of disease suggested that a shift toward high values of macrophage-like cells extended to basal levels of proinflammatory monocytes as well as high values of mature NK cells, NKT and regulatory T cells, may account for limited tissue damage during chronic infection favouring the establishment/maintenance of a lifelong indeterminate clinical form of the disease. On the other hand, development of an adaptive cell-mediated inflammatory immunoprofile characterized by high levels of activated CD8+ cells and basal levels of mature NK cells, NKT and CD4+ CD25HIGH cells might lead to late chronic pathologies associated with chagasic heart disease.
Metformin therapy improves coronary microvascular function in patients with polycystic ovary syndrome and insulin resistance
Authors: Topcu Semra , Tok Derya , Caliskan Mustafa , Ozcimen Emel Ebru , Gullu Hakan , Uckuyu Ayla , Erdogan Dogan , Zeyneloglu Hulusi , Muderrisoglu Haldun 
Published: June 2006

SummaryBackground  Women with polycystic ovary syndrome (PCOS) are thought to have increased cardiovascular risk. Metformin therapy reduces whole‐body insulin resistance (IR) in patients with type‐2 diabetes mellitus (DM).Objective  As insulin resistance accompanying PCOS may be reversed by metformin therapy, we hypothesized that metformin therapy might improve coronary microvascular functions in women with PCOS and IR.Patients and methods  We treated 16 women with PCOS and IR with metformin, and measured coronary flow reserve (CFR) at the beginning and after 6 months of metformin therapy using transthoracic second‐harmonic Doppler echocardiography.Results  At the end of the 6 months of metformin therapy, baseline coronary diastolic peak flow velocity (DPFV) did not change significantly (from 24·6 ± 4·3 to 23·0 ± 3·1, P = 0·106); however, hyperaemic coronary DPFV (from 68·2 ± 12·7 to 74·5 ± 9·7, P = 0·08), and CFR (from 2·75 ± 0·48 to 3·3 ± 0·5, P = 0·016) was significantly improved by metformin therapy.Conclusion  In women with PCOS, coronary microvascular function and CFR are significantly improved by 6 months of therapy with metformin.
Evaluation by magnetic resonance imaging of aortic dilatation and coarctation in adult Turner syndrome patients
Authors: Ilyas Mohammad , Chu Carol , Ettles Duncan , Mathew Verghese , Atkin Stephen 
Published: June 2006

SummaryObjective  Turner syndrome has well‐recognized cardiovascular complications that appear in up to 40% of the patients and are more common in monosomy X. Left‐sided obstructive lesions are relatively more frequent and predispose to aortic root dilatation and life‐threatening aortic dissection. However, bicuspid aortic valves, hypertension, coarctation and aortic stenosis are also at risk of aortic dissection. Currently there is no clear guideline regarding the best single test for detection or monitoring aortic disease progression.Design  Routine thoracic aortic magnetic resonance imaging (MRI) was introduced to the dedicated Turner syndrome clinic, with repeated MRI examination every 2 years to detect or assess progression of aortic lesions.Results  Seven out of a total of 17 patients developed aortic anomalies during the course of surveillance, which included coarctation as well as aortic dilatation. None of these patients had any cardiovascular symptoms and the vascular abnormalities were detected on MRI at presentation or during the course of their follow‐up. In patients with previously normal aortic imaging, the time interval for the lesion to be detectable varied between 2 and 6 years. In one patient there was progression of an established lesion over the 2‐year period.Conclusion  In the few patients presented here, regular imaging at first consultation followed by every 2 years would appear to be warranted, although the exact frequency of imaging and by what modality still need to be ascertained definitively.
Determination of zooplankton dietary shift following a zebra mussel invasion, as indicated by stable isotope analysis
Authors: MAGUIRE CAITRIONA M. , GREY JONATHAN 
Published: June 2006

Summary1. Freshwaters with established zebra mussel populations typically exhibit reduced chlorophyll a concentrations, but the subsequent impacts upon zooplankton are varied. We hypothesised that in an invaded system with less phytoplankton but available allochthonous subsidy, zooplankton may utilise greater proportions of allochthonous matter and that this could be traced by analysis of stable carbon and nitrogen isotopes.2. We used archived zooplankton samples which had been consistently preserved and which spanned the invasion period of an Irish lake, Lough Erne. Increasing reliance upon allochthonous resources would be reflected in an increase in zooplankton δ13C away from phytoplankton which is relatively 13C‐depleted in humic‐stained L. Erne.3. Analysis of a series of monthly samples (1992–96, 1999–2003) revealed significant 13C‐enrichment of mixed zooplankton, Eudiaptomus gracilis and Mysis relicta post‐zebra mussel invasion; δ13C values approached −27‰ typical of terrestrial organic matter during spring and autumn. Changes in zooplankton elemental composition also suggested a switch to a lower quality diet. However, analysis of zooplankton δ13C from an annual, single‐point (June) time series spanning 28 years (1977–2004) suggested that when phytoplankton was sufficiently abundant, zooplankton used this resource and their δ13C remained relatively constant around −32‰. Post‐invasion enrichment of mysid δ15N may reflect a shift towards carnivory, but planktonic prey abundance was reduced and a subsequent loss of body condition could result in the same isotopic changes.4. Our results indicate that in L. Erne, when phytoplankton was reduced by zebra mussel filtering, zooplankton assimilated more from allochthonous matter, and potentially sustained a higher population than would otherwise be possible. Thus, zebra mussel impact on foodweb structure and function is likely to be different in lakes subject to varying subsidy levels.