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The COllaborative project of Development of Anthropometrical measures in Twins (CODATwins) project is a large international collaborative effort to analyze individual-level phenotype data from twins in multiple cohorts from different environments. The main objective is to study factors that modify genetic and environmental variation of height, body mass index (BMI, kg/m2) and size at birth, and additionally to address other research questions such as long-term consequences of birth size. The project started in 2013 and is open to all twin projects in the world having height and weight measures on twins with information on zygosity. Thus far, 54 twin projects from 24 countries have provided individual-level data. The CODATwins database includes 489,981 twin individuals (228,635 complete twin pairs). Since many twin cohorts have collected longitudinal data, there is a total of 1,049,785 height and weight observations. For many cohorts, we also have information on birth weight and length, own smoking behavior and own or parental education. We found that the heritability estimates of height and BMI systematically changed from infancy to old age. Remarkably, only minor differences in the heritability estimates were found across cultural–geographic regions, measurement time and birth cohort for height and BMI. In addition to genetic epidemiological studies, we looked at associations of height and BMI with education, birth weight and smoking status. Within-family analyses examined differences within same-sex and opposite-sex dizygotic twins in birth size and later development. The CODATwins project demonstrates the feasibility and value of international collaboration to address gene-by-exposure interactions that require large sample sizes and address the effects of different exposures across time, geographical regions and socioeconomic status.
Systematic effects on HI and Hα long-slit observations make a measurement of the inner slope of the dark matter density distribution difficult to determine. Halos with constant density cores and ones with r–1 profiles both appear consistent with the data, although constant density cores generally provide better fits. High-resolution, two-dimensional velocity fields remove most of the systematic effects, yet as a result of noncircular and random motions the inner slopes still cannot be accurately measured. Halo concentration parameters provide a more useful test of cosmological models because they are more tightly constrained by observations. the concentration parameters for LSB galaxies appear consistent with, but on the low end of the distribution predicted by CDM.
Research on close binary systems has continued at a high level during the past triennium, although the rate of growth is noticeably slower – probably reflecting the cutbacks in funds to which many of us are subject. There have also been changes of emphasis within the field, which are commented on in the pages that follow. These reflect both changing opportunities for observation and the natural development of the subject. In many areas, the time is ripe for a more critical look at ideas that previously seemed adequate.
We analyzed birth order differences in means and variances of height and body mass index (BMI) in monozygotic (MZ) and dizygotic (DZ) twins from infancy to old age. The data were derived from the international CODATwins database. The total number of height and BMI measures from 0.5 to 79.5 years of age was 397,466. As expected, first-born twins had greater birth weight than second-born twins. With respect to height, first-born twins were slightly taller than second-born twins in childhood. After adjusting the results for birth weight, the birth order differences decreased and were no longer statistically significant. First-born twins had greater BMI than the second-born twins over childhood and adolescence. After adjusting the results for birth weight, birth order was still associated with BMI until 12 years of age. No interaction effect between birth order and zygosity was found. Only limited evidence was found that birth order influenced variances of height or BMI. The results were similar among boys and girls and also in MZ and DZ twins. Overall, the differences in height and BMI between first- and second-born twins were modest even in early childhood, while adjustment for birth weight reduced the birth order differences but did not remove them for BMI.
A trend toward greater body size in dizygotic (DZ) than in monozygotic (MZ) twins has been suggested by some but not all studies, and this difference may also vary by age. We analyzed zygosity differences in mean values and variances of height and body mass index (BMI) among male and female twins from infancy to old age. Data were derived from an international database of 54 twin cohorts participating in the COllaborative project of Development of Anthropometrical measures in Twins (CODATwins), and included 842,951 height and BMI measurements from twins aged 1 to 102 years. The results showed that DZ twins were consistently taller than MZ twins, with differences of up to 2.0 cm in childhood and adolescence and up to 0.9 cm in adulthood. Similarly, a greater mean BMI of up to 0.3 kg/m2 in childhood and adolescence and up to 0.2 kg/m2 in adulthood was observed in DZ twins, although the pattern was less consistent. DZ twins presented up to 1.7% greater height and 1.9% greater BMI than MZ twins; these percentage differences were largest in middle and late childhood and decreased with age in both sexes. The variance of height was similar in MZ and DZ twins at most ages. In contrast, the variance of BMI was significantly higher in DZ than in MZ twins, particularly in childhood. In conclusion, DZ twins were generally taller and had greater BMI than MZ twins, but the differences decreased with age in both sexes.
For over 100 years, the genetics of human anthropometric traits has attracted scientific interest. In particular, height and body mass index (BMI, calculated as kg/m2) have been under intensive genetic research. However, it is still largely unknown whether and how heritability estimates vary between human populations. Opportunities to address this question have increased recently because of the establishment of many new twin cohorts and the increasing accumulation of data in established twin cohorts. We started a new research project to analyze systematically (1) the variation of heritability estimates of height, BMI and their trajectories over the life course between birth cohorts, ethnicities and countries, and (2) to study the effects of birth-related factors, education and smoking on these anthropometric traits and whether these effects vary between twin cohorts. We identified 67 twin projects, including both monozygotic (MZ) and dizygotic (DZ) twins, using various sources. We asked for individual level data on height and weight including repeated measurements, birth related traits, background variables, education and smoking. By the end of 2014, 48 projects participated. Together, we have 893,458 height and weight measures (52% females) from 434,723 twin individuals, including 201,192 complete twin pairs (40% monozygotic, 40% same-sex dizygotic and 20% opposite-sex dizygotic) representing 22 countries. This project demonstrates that large-scale international twin studies are feasible and can promote the use of existing data for novel research purposes.
This study aims to assess current practices of Canadian physicians providing botulinum toxin-A (BoNT-A) treatments for children with hypertonia and to contrast these with international “best practice” recommendations, in order to identify practice variability and opportunities for knowledge translation.
Thirteen Canadian physicians assembled to develop and analyze results of a cross-sectional electronic survey, sent to 50 physicians across Canada.
Seventy-eight percent (39/50) of physicians completed the survey. The most frequently identified assessment tools were Gross Motor Function Classification System, Modified Tardieu Scale and neurological examination. Goal-setting tools were infrequently utilized. Common indications for BoNT-A injections and the muscles injected were identified. Significant variability was identified in using BoNT-A for hip displacement associated with hypertonia. The most frequent adverse event reported was localized weakness; 54% reporting this “occasionally“ and 15% “frequently”. Generalized weakness, fatigue, ptosis, diplopia, dysphagia, aspiration, respiratory distress, dysphonia and urinary incontinence were reported rarely or never. For dosage, 52% identified 16 Units/kg body weight of Botox® as maximum. A majority (64%) reported a maximum 400 Units for injection at one time. For localization, electrical stimulation and ultrasound were used infrequently (38% and 19% respectively). Distraction was the most frequently used pain-management technique (64%).
Canadian physicians generally adhere to international best practices when using BoNT-A to treat paediatric hypertonia. Two knowledge-translation opportunities were identified: use of individualized goal setting prior to BoNT-A and enhancing localization techniques. Physicians reported a good safety profile of BoNT-A in children.
The purpose of the study was to support the selection process of the most valuable currant and gooseberry accessions cultivated in Northern Europe, in order to establish a decentralized core collection and, following the selection, to ensure sufficient genetic diversity in the selected collection. Molecular analyses of the material from nine project partners were run at seven different laboratories. The results were first analysed for each partner separately, and then combined to ensure sufficient genetic diversity in the core collection.
Polydimethylsiloxane [PDMS]-modified SiO2-TiO2, glasses have been prepared via the sol-gel route. Polymer compositions varied between 17 and 67 wt% PDMS, using PDMS of molecular weights 1,700 and 36,000. Also varied was the Si/Ti ratio for a given polymer content and the nature of the Ti alkoxide.A general synthetic procedure was found which made optically clear samples. Dense monolithic structures were obtained at room temperature for all compositions. The room temperature densification is attributed to relaxation and flow in the sample due to the presence of the polymer. The effects on properties of the overall composition and molecular weight of the polymer are reported, and implications in terms of structural models are considered.
The Al-Mg-Si (6xxx-series) alloy system is a precipitation hardened alloy gaining much of its strength from precipitate phases acting as pinning centers for dislocation movement. Five years ago, Zandbergen, Andersen and coworkers identified the crystallography of the so-called β″ phase, one of the main hardening phases, using solely electron microscopy techniques . Later, several other phases have been identified using high resolution microscopy. To solve the crystallography of these phases and to get an increased understanding of the electronic structure and bonding, ab initio modeling has proven to be a valuable tool. We present results from calculations on two recently discovered phases and show how ab initio modeling can give insight into the bonding trends and electronic structure of the phases in this alloy system.
In order to elucidate the mechanism of spin-polarized electron tunneling in thin-film ferromagnet-insulator junctions, self-consistent band structure calculations of the CO/Al2O3 interface have been performed using a new LMTO technique. Since the results of the calculations are very sensitive to the distance between the Co and Al planes, we have minimised the total energy with respect to this distance. Our calculations show that at the Fermi energy a strong bonding between the 3d-electrons of Co with the sp-electrons of Al at the interface can have an important influence on the spin polarization of the layer-projected density of states (LPDOS) of inner Al and O layers. Since the Fermi energy lies within the minority-spin d-band of Co but above the majority-spin d-band, the sp-d bonding results in a smaller LPDOS of the minority-spin electrons of the interfacial Al layers in comparison to that of the majority-spin electrons. This asymmetry in the LPDOS extends to the inner Al2O3 layers implying a positive spin polarization of the tunneling density of states. The result is consistent with experimental observations on tunnelling from cobalt through alumina where positive values of the spin polarization of the tunnelling current were measured.
Thermal comfort sensations are often studied in isolation, with the subjects' attention specifically directed towards their evaluation, both by instructions and by the recurrent act of questioning. A closer approach to the field situation, in which room temperature is at most a background stimulus, is made possible by the method of spontaneous magnitude estimation of thermal sensation. Thirty-six male and 36 female 17-year-old subjects in standard cotton uniforms (0·7 clo) were exposed in groups of 4 in a climate chamber to patterns of changing air temperature typical of conditions in occupied classrooms. Temperatures remained within the range 20–29° C. and did not increase more rapidly than 4° C./hr. Each individual recorded his thermal sensation on a dial voting apparatus, registering changes spontaneously as a secondary task while performing mental work during three successive 50 min. periods, with 10 min. breaks between. It was thus possible to obtain a measure of the time course of thermal discomfort sensations, including the extent to which they distracted attention. Significant differences were found between the responses of males and females, males in general feeling hotter and reacting more rapidly to changes in temperature. Response distributions are given in detail.
In correspondence arising out of our recent paper (Wyon, Andersen & Lundqvist, 1972), interest has been expressed in the relative widths of the comfort zones obtained by using the Bedford 7-point scale and our proposed dial-vote scale. It was possible to make a direct comparison on our original data, using votes registered simultaneously on the two scales at the end of each hour of exposure. Air temperature rose only slowly towards the end of each hour, and the comparison is probably valid also for steady-state conditions. The proportions voting ‘too hot’ (Bedford categories 6, 7, dial vote >66·6%) and ‘too cold’ (Bedford categories 1, 2, dial vote <33·3%) were derived and probit analysis was performed (Pinney, 1947). Only responses obtained from the 36 female subjects are considered, for very few males were too cold in the temperature range 23–29° C The results are shown in Fig. 1, using the same presentation as in fig. 7 of the original paper. No statistically significant differences could be shown between the pairs of regression lines, either in terms of their slopes or median values. However, the tendency is clearly for the dial-vote method to yield if anything a rather narrower and lower comfort distribution, and hence a narrower zone of comfort, however defined. This in spite of a marked ‘comfort zone’ occupying as much as one-third full scale. As pointed out in our original paper, the comfort zone yielded by either scale should be regarded as a zone of tolerance and not as a zone of ideal comfort.
Arsenic is a very common by-product of the processing of Cu, Au and polymetallic ores worldwide, where the ore is roasted (calcined) to remove volatile elements. In southwest England, a diverse range of As-mineral species occur as efflorescent secondary mineral growths on historic calciner buildings. Gypsum occurs as abundant dendritic growths comprising either interlocking blades or tabular crystals. Ca-arsenate minerals are locally very abundant as white colloform masses. Positively identified Ca arsenates include pharmacolite, weilite and haidingerite. Other secondary minerals include arsenolite, scorodite, bukovskyite and an As-bearing potassium alum, together with a wide variety of unidentified minerals, including an Al-As-S phase and As-rich F-bearing phases. Gypsum contains As concentrations up to ~7 wt.%. Efflorescent growth at sites exposed to the prevailing weather systems is less abundant than at sheltered sites. This is interpreted as being due to ‘pressure washing’ of exposed sites by driving rain. Successive concentric growths of gypsum and Ca arsenate on masonry are interpreted as being the result of seasonal crystallization.
Understanding both current and historicalmining and mineralprocessing methods is criticalin the evaluation of the potential impact on the modern environment. In particular, due to the abundance of As-bearing minerals in a wide range of ore types, many buildings worldwide are potentially significantly contaminated with As even though few are directly related to As production or handling. Characterizing the secondary As mineralspecies present at mine and mineralprocessing sites is critical in understanding the potentialheal th risk these sites might pose.
Felsic volcanic rocks exposed in the Frasnian Gafo Formation, in the Azinhalinho area of Portugal, display very similar geochemical signatures to volcanic rocks from the Iberian Pyrite Belt (IPB). located immediately to the south. The similarities include anomalously low high field-strength elements (HFSE) concentrations, possibly caused by low-temperature crustal melting, which translate into classification problems.
A geochronological study, using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) analyses of zircon grains from these rocks, has provided concordia ages of 356±1.5 Ma and 355±2.5 Ma for two samples of rhyodacite porphyry, and 356±1.4 Ma for a granular rhyodacite. These results show that volcanism at Azinhalinho was broadly contemporaneous with IPB volcanism, widely interpreted as being of Famennian to Visean age. Considering that the host rocks of the Azinhalinho volcanic rocks are Frasnian, and therefore deposited synchronously with the Upper Devonian Phyllite-Quartzite Group sedimentation in the IPB basin, the radiometric ages imply that the Azinhalinho felsic rocks are intrusive and likely represent conduits or feeders to the volcanism of the IPB.
To determine the long-term significance of right bundle branch block on left ventricular systolic and diastolic function in children subsequent to surgical closure of ventricular septal defect.
We studied 26 children who underwent surgical closure of a ventricular septal defect 11 ± 2 years postoperatively by use of conventional and tissue Doppler echocardiography, comparing the findings to those obtained from a control group. Of those having surgical correction 14 had postoperative right bundle branch block.
Irrespective of the presence of right bundle branch block, the peak systolic velocity of the mitral ring was lower in those undergoing surgical correction, with values of 5.2 ± 1.4 cm/s in those with right bundle branch block, 5.4 ± 1.2 cm/s in those without right bundle branch block after surgical correction, and 6.6 ± 1.0 cm/s in the control subjects (p < 0.01). In terms of diastolic function, the early septal velocity of transmitral inflow divided by the early diastolic mitral annular velocity was significantly higher in children with right bundle branch block, at 12 ± 3.0 cm/s compared to 8.4 ± 1.5 cm/s in the control subjects (p < 0.01), but not significantly higher in the children without right bundle branch block after correction compared to the control group. The fractional shortening percentage was similar in both patients and control subjects. The changes noted in left ventricular function were not significantly related to age at surgery, the period of follow-up, or the surgical method.
Systolic long axis function is significantly reduced in children after surgical closure of ventricular septal defects, irrespective of the presence of right bundle branch block. Diastolic dysfunction, in contrast, was observed primarily in children with post-operative right bundle branch block.