Randomized controlled trials (RCTs) have been criticized for lacking external validity. We assessed whether a trial in people with type I diabetes mellitus mirrored the wider population and applied ...sample-weighting methods to assess the impact of differences on our trial's findings.
The Relative Effectiveness of Pumps over MDI and Structured Education trial was nested within a large UK cohort capturing demographic, clinical, and quality of life data for people with type I diabetes mellitus undergoing structured diabetes-specific education. We first assessed whether our RCT participants were comparable with this cohort using propensity score modeling. After this, we reweighted the trial population to better match the wider cohort and re-estimated the treatment effect.
Trial participants differed from the cohort in regard to sex, weight, HbA1c, and also quality of life and satisfaction with current treatment. Nevertheless, the treatment effects derived from alternative model weightings were similar to that of the original RCT.
Our RCT participants differed in composition to the wider population, but the original findings were unaffected by sampling adjustments. We encourage investigators take steps to address criticisms of generalizability but doing so is problematic; external data, even if available, may contain limited information and analyses can be susceptible to model misspecification.
Disease of the cardiovascular system is the main cause of long-term complications and mortality in patients with type I (insulin-dependent) and type II (non-insulin-dependent) diabetes. ...Cerebrovascular mortality rates have been shown to be raised in patients with type II diabetes but have not previously been reported by age and sex in patients with type I diabetes.
A cohort of 23 751 patients with insulin-treated diabetes, diagnosed under the age of 30 years from throughout the United Kingdom, was identified during 1972 to 1993 and followed up for mortality until the end of December 2000. Age- and sex-specific mortality rates and standardized mortality ratios (SMRs) were calculated.
There were 1437 deaths during the follow-up, 80 due to cerebrovascular disease. Overall, the cerebrovascular mortality rates in the cohort were higher than the corresponding rates in the general population, and the SMRs were 3.1 (95% CI, 2.2 to 4.3) for men and 4.4 (95% CI, 3.1 to 6.0) for women. When stratified by age, the SMRs were highest in the 20- to 39-year age group. After subdivision of cause of death into hemorrhagic and nonhemorrhagic origins, there remained a significant increase in mortality from stroke of nonhemorrhagic origin.
Analyses of mortality from this cohort, essentially one of patients with type I diabetes, has shown for the first time that cerebrovascular mortality is raised at all ages in these patients. Type I diabetes is at least as great a risk factor for cerebrovascular mortality as type II diabetes.
The use of an aerosol delivery system enabled fluorine‐doped tin dioxide films to be formed from monobutyltin trichloride methanolic solutions at 350–550 °C with enhanced functional properties ...compared with commercial standards. It was noted that small aerosol droplets (0.3 μm) gave films with better figures of merit than larger aerosol droplets (45 μm) or use of a similar precursor set using atmospheric pressure chemical vapour deposition (CVD) conditions. Control over the surface texturing and physical properties of the thin films were investigated by variation in the deposition temperature and dopant concentration. Optimum deposition conditions for low‐emissivity coatings were found to be at a substrate temperature of about 450 °C with a dopant concentration of 1.6 atm % (30 mol % F:Sn in solution), which resulted in films with a low visible light haze value (1.74 %), a high charge‐carrier mobility (25 cm2 V s−1) and a high charge‐carrier density (5.7×1020 cm−3) resulting in a high transmittance across the visible (≈80 %), a high reflectance in the IR (80 % at 2500 nm) and plasma‐edge onset at 1400 nm. Optimum deposition conditions for coatings with applications as top electrodes in thin film photovoltaics were found to be a substrate temperature of about 500 °C with a dopant concentration of 2.2 atm % (30 mol % F:Sn in solution), which resulted in films with a low sheet resistance (3 Ω sq−1), high charge‐carrier density (6.4×1020 cm−3), a plasma edge onset of 1440 nm and the films also showed pyramidal surface texturing on the micrometer scale which corresponded to a high visible light haze value (8 %) for light scattering and trapping within thin film photovoltaic devices.
Smart windows, solar cells and invisible electronics: The coexistence of optical transparency with electrical conductivity is unexpected, since large band gaps predict insulating materials. Transparent conducting oxides are used in solar control coatings, solar cells, flat panel displays and invisible electronics. Highly conductive and transparent fluorine‐doped tin dioxide films were produced by chemical vapour deposition; they exhibited enhanced functional properties compared with commercial standards (see figure).
Aim - to survey members of Diabetes UK who had Type 2 diabetes and who used self monitoring of blood glucose (SMBG), to elicit their views on its usefulness in the management of their diabetes, and ...how they used the results. A questionnaire was developed for the Diabetes UK website. The questionnaire was posted on the Diabetes UK website until over 500 people had responded. Questions asked users to specify the benefits gained from SMBG, and how these benefits were achieved. We carried out both quantitative analysis and a thematic analysis for the open ended free-text questions.
554 participants completed the survey, of whom 289 (52.2%) were male. 20% of respondents were recently diagnosed (< 6 months). Frequency of SMBG varied, with 43% of participants testing between once and four times a day and 22% testing less than once a month or for occasional periods.80% of respondents reported high satisfaction with SMBG, and reported feeling more 'in control' of their diabetes management using it. The most frequently reported use of SMBG was to make adjustments to food intake or confirm a hyperglycaemic episode.Women were significantly more likely to report feelings of guilt or self-chastisement associated with out of range readings (p = < .001).
SMBG was clearly of benefit to this group of confirmed users, who used the results to adjust diet, physical activity or medications. However many individuals (particularly women) reported feelings of anxiety and depression associated with its use.
Distal localisation of chiasmata is common to many cereals and grasses, which consigns many genes of the complement to recombination backwaters. Releasing this potential untapped genetic variation ...for use in advanced breeding programmes is an ambitious and technically demanding challenge, necessitating controlled shifts in the distribution of crossover events. As part of a collaborative programme to manipulate recombination in barley, we are developing a robust and reliable molecular cytogenetic assay for recombination in this species, which will be used to gauge the success of our forward and reverse genetic interventions. Single-locus bacterial artificial chromosome clones and rDNA probes identify the 7 somatic chromosomes of the complement. Meiocytes at pachytene of meiosis were embedded in polyacrylamide and hybridised in situ with centromere and telomere probes, followed by immunolocalisation of the synaptonemal complex-associated protein Asy1 which highlights the bivalents' axes. Optical sectioning, deconvolution and image analysis of the z-stacks of the nuclei allowed the disentanglement of each bivalent and the construction of an accurate meiotic ideogram. The landing of single-locus bacterial artificial chromosomes and the detection of late recombination proteins will complete the assay and provide a means of discerning subtle changes in recombination in this species.
Motivation to Achieve Academically has been used in many educational and other studies in many countries and the large majority has not used an interval level scale based on a good theoretical model ...in which the items are linked to behaviour. This study aimed firstly to create an interval level, unidimensional scale of Motivation, with attitude items linked to behaviour items, based on a conceptual model of Motivation, involving Striving for Excellence (Standards, Goals, Tasks, Effort, Values and Ability), Desire to Learn (Interest, Learning from Others and Responsibility for Learning), and Rewards (Extrinsic, Intrinsic and Social). Secondly, it aimed analyse its psychometric properties using the Extended Logistic Model of Rasch. Thirdly, it aimed to investigate the structure and meaning of the scale. The convenience person sample was 239 first-year students selected for three special entry programmes at an Australian university. The stem-item sample was initially 45, reduced to 24, that fitted the measurement model to form a valid and reliable scale. Based on recent literature, a conceptual model of Motivation was devised and items written in line with the model. Data were collected by self-report questionnaire and analysed with the computer program Rasch Unidimensional Measurement Models (RUMM). A scale was created in which the Motivation measures were calibrated on the same scale as the item 'difficulties'. Twenty-four Motivation items fitted the model and were 'easier' than their corresponding behaviour items, as conceptualised. They formed an excellent scale in which the proportion of observed variance considered true was 0.93. Items from all aspects of the Motivation model named in the aims above, except Ability and Extrinsic Rewards, fitted the measurement model. Conclusion. The Rasch model and the RUMM computing program were very useful in creating a unidimensional, interval level scale of Motivation to achieve academically, with good psychometric properties. Author abstract, ed
Twenty-two landrace-derived inbred lines from the Spanish Barley Core Collection (SBCC) were found to display high levels of resistance to a panel of 27 isolates of the fungus Blumeria graminis that ...exhibit a wide variety of virulences. Among these lines, SBCC145 showed high overall resistance and a distinctive spectrum of resistance compared with the other lines. Against this background, the main goal of the present work was to investigate the genetic basis underlying such resistance using a doubled haploid population derived from a cross between SBCC145 and the elite spring cultivar Beatrix. The population was genotyped with the 1,536-SNP Illumina GoldenGate Oligonucleotide Pool Assay (Barley OPA-1 or BOPA1 for short), whereas phenotypic analysis was performed using two B. graminis isolates. A major quantitative trait locus (QTL) for resistance to both isolates was identified on the long arm of chromosome 6H (6HL) and accounted for ca. 60% of the phenotypic variance. Depending on the B. graminis isolate tested, three other minor QTLs were detected on chromosomes 2H and 7H, which explained less than 5% of the phenotypic variation each. In all cases, the alleles for resistance derived from the Spanish parent SBCC145. The position, the magnitude of the effect observed and the proportion of phenotypic variation accounted for by the QTL on 6HL suggest this is a newly identified locus for broad-based resistance to powdery mildew.
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