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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.
Self-similar solutions to the compressible Euler equations with nonlinear conduction are considered as particular instances of unsteady radiative deflagration – or ‘ablation’ – waves with the goal of characterizing the actual hydrodynamic properties that such flows may present. The chosen family of solutions, corresponding to the ablation of an initially quiescent perfectly cold and homogeneous semi-infinite slab of inviscid compressible gas under the action of increasing external pressures and radiation fluxes, is well suited to the description of the early ablation of a target by gas-filled cavity X-rays in experiments of high energy density physics. These solutions are presently computed by means of a highly accurate numerical method for the radiative conduction model of a fully ionized plasma under the approximation of a non-isothermal leading shock wave. The resulting set of solutions is unique for its high fidelity description of the flows down to their finest scales and its extensive exploration of external pressure and radiative flux ranges. Two different dimensionless formulations of the equations of motion are put forth, yielding two classifications of these solutions which are used for carrying out a quantitative hydrodynamic analysis of the corresponding flows. Based on the main flow characteristic lengths and on standard characteristic numbers (Mach, Péclet, stratification and Froude numbers), this analysis points out the compressibility and inhomogeneity of the present ablative waves. This compressibility is further analysed to be too high, whether in terms of flow speed or stratification, for the low Mach number approximation, often used in hydrodynamic stability analyses of ablation fronts in inertial confinement fusion (ICF), to be relevant for describing these waves, and more specifically those with fast expansions which are of interest in ICF. Temperature stratification is also shown to induce, through the nonlinear conductivity, supersonic upstream propagation of heat-flux waves, besides a modified propagation of quasi-isothermal acoustic waves, in the flow conduction regions. This description significantly departs from the commonly admitted depiction of a quasi-isothermal conduction region where wave propagation is exclusively ascribed to isothermal acoustics and temperature fluctuations are only diffused.
Measurements are reported of the target neutralization current, the target charge, and the tangential component of the magnetic field generated as a result of laser–target interaction by pulses with the energy in the range of 45–92 mJ on target and the pulse duration from 39 to 1000 fs. The experiment was performed at the Eclipse facility in CELIA, Bordeaux. The aim of the experiment was to extend investigations performed for the thick (mm scale) targets to the case of thin (μm thickness) targets in a way that would allow for a straightforward comparison of the results. We found that thin foil targets tend to generate 20–50% higher neutralization current and the target charge than the thick targets. The measurement of the tangential component of the magnetic field had shown that the initial spike is dominated by the 1 ns pulse consistent with the 1 ns pulse of the neutralization current, but there are some differences between targets of different types on sub-ns scale, which is an effect going beyond a simple picture of the target acting as an antenna. The sub-ns structure appears to be reproducible to surprising degree. We found that there is in general a linear correlation between the maximum value of the magnetic field and the maximum neutralization current, which supports the target-antenna picture, except for pulses 100s of fs long.
Ecoevolutionary processes affecting hosts, vectors and pathogens are important drivers of zoonotic disease emergence. In this study, we focused on nephropathia epidemica (NE), which is caused by Puumala hantavirus (PUUV) whose natural reservoir is the bank vole, Myodes glareolus. We questioned the possibility of NE emergence in a French region that is considered to be NE-free but that is adjacent to a NE-endemic region. We first confirmed the epidemiology of these two regions and we demonstrated the absence of spatial barriers that could have limited dispersal, and consequently, the spread of PUUV into the NE-free region. We next tested whether regional immunoheterogeneity could impact PUUV chances to circulate and persist in the NE-free region. We showed that bank voles from the NE-free region were sensitive to experimental PUUV infection. We observed high levels of immunoheterogeneity between individuals and also between regions. Antiviral gene expression (Tnf and Mx2) reached higher levels in bank voles from the NE-free region. During experimental infections, anti-PUUV antibody production was higher in bank voles from the NE-endemic region. These results indicated a lower susceptibility to PUUV for bank voles from this NE-free region, which might limit PUUV persistence and therefore, the risk of NE.
Previous research has shown relatively diminished medial prefrontal cortex activation and heightened psychophysiological responses during the recollection of personal events in post-traumatic stress disorder (PTSD), but the origin of these abnormalities is unknown. Twin studies provide the opportunity to determine whether such abnormalities reflect familial vulnerabilities, result from trauma exposure, or are acquired characteristics of PTSD.
In this case–control twin study, 26 male identical twin pairs (12 PTSD; 14 non-PTSD) discordant for PTSD and combat exposure recalled and imagined trauma-unrelated stressful and neutral life events using a standard script-driven imagery paradigm during functional magnetic resonance imaging and concurrent skin conductance measurement.
Diminished activation in the medial prefrontal cortex during Stressful v. Neutral script-driven imagery was observed in the individuals with PTSD, relative to other groups.
Diminished medial prefrontal cortex activation during Stressful v. Neutral script-driven imagery may be an acquired characteristic of PTSD. If replicated, this finding could be used prospectively to inform diagnosis and the assessment of treatment response.
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.
The aim of this work was to study the effects of incorporating sugar beet pulp (SBP) into the diet on the development of the crop and performance of geese. A total of 480 1-day-old ganders were divided into three groups differing in the composition and mode of distribution of the diet offered from day 56 to 89. The following two diets were used: a standard diet (nitrogen-corrected apparent metabolizable energy, AMEn 11.44 MJ/kg; 160 g/kg CP) or a diet containing 10% of SBP (SBP diet; AMEn 11.47 MJ/kg; 160 g/kg CP). The swelling capacity (SC) hydration was higher for SBP than for the standard diet (3.62 v. 2.72 ml of H2O/g of dry matter at 60 min; P<0.05). In the Control group, birds were fed with a controlled time of access to a standard diet. Other birds were fed the SBP diet with a controlled time of access (SBPt group) or a controlled quantity offered (SBPq). From day 90 to 104, 88 birds/group were overfed with a mixture containing mainly corn. Body traits including volume of the crop were measured at day 89. Fatty liver weight and commercial grading were measured at d 104. Feed intake from day 56 to 89 was higher in the Control group than in the SBPt group (8097 v. 7545 g; P<0.05), feed intake in the SBPq group being intermediate (7801 g); however, live weights (LW) of the birds were similar in the three groups measured at day 89 (5746 g; P>0.05). At day 89, the volume of the crop tended to be higher in the SBPt compared with the Control group (52.8 v. 48.8 ml/kg of LW; P=0.101). After overfeeding, feed intake (12 922 g), weight gain (2412 g), LW (8170 g), fatty liver weight (875 g) and commercial grading of the fatty liver were similar (P>0.1) for all the three groups. Therefore, SBP could help adapt the digestive tract of waterfowl to high feed intake through an increase in the crop volume, but its method of use – that is, level of incorporation and mode of distribution – should continue to be investigated.
Improving health through better nutrition of the population may contribute to enhanced efficiency and sustainability of healthcare systems. A recent expert meeting investigated in detail a number of methodological aspects related to the discipline of nutrition economics. The role of nutrition in health maintenance and in the prevention of non-communicable diseases is now generally recognised. However, the main scope of those seeking to contain healthcare expenditures tends to focus on the management of existing chronic diseases. Identifying additional relevant dimensions to measure and the context of use will become increasingly important in selecting and developing outcome measurements for nutrition interventions. The translation of nutrition-related research data into public health guidance raises the challenging issue of carrying out more pragmatic trials in many areas where these would generate the most useful evidence for health policy decision-making. Nutrition exemplifies all the types of interventions and policy which need evaluating across the health field. There is a need to start actively engaging key stakeholders in order to collect data and to widen health technology assessment approaches for achieving a policy shift from evidence-based medicine to evidence-based decision-making in the field of nutrition.
The aim of this trial was to study the influence of feed form on the performance, gizzard development and carcass traits of growing geese. Between 42 and 98 days of age, 360 geese (type Maxipalm®) were fed a diet containing 500 g sorghum/kg (nitrogen-corrected apparent metabolizable energy 12.6 MJ/kg, 15.1 g/kg CP). Birds were divided into three groups differing in feed form: complete pellets (Control group, n = 120); a coarse-ground meal (CG group, n = 120); or a mixture containing protein-rich pellets and sorghum whole grains (M group, n = 120). Feed intake per pen (40 birds/pen) was measured weekly between 42 and 98 days of age, and individual live weight (LW) was measured every 2 weeks. At 84 and 98 days of age, 12 birds were slaughtered in each group to measure the gizzard development and body traits. Irrespective of the goose sex, LW at 98 days was lower for the CG group than for the Control group (5555 v. 5888 g, P < 0.05 for males and 5039 v. 5215 g, P < 0.05 for females). The feed intake over the entire period was 5.5% higher in the M group (P < 0.05) than in the Control and CG groups but the feed conversion ratio (6.91, P > 0.05) was similar in the three groups. The gizzard development (as % of LW) was higher in birds of the CG group than those of the Control and M groups at 84 days of age (+13.98% and +13.51%, respectively; P < 0.05) but was similar in all three groups at 98 days of age (4.01%, P > 0.05). The relative liver development was lower in the birds of the CG group than those of the other two groups at 84 and 98 days of age (−20%, P < 0.001 and −10%, P < 0.05, respectively). The other body traits were similar in the three groups at both 84 and 98 days of age. The present results suggest that a simplified diet presented in the form of a mixture of sorghum whole grains and protein-rich pellets did not reduce the performance of growing geese.
The Midwest after-school center occupies a building that housed a bank for many years. It is the smallest of the three clubs, particularly in the size of the gym. The former bank lobby, which has been converted to a gym, has less space and lower ceilings than gyms in the other clubs. The center is located in a community that used to be predominantly Latino, but has recently witnessed the arrival of increasing numbers of African American families. As is true of the neighborhoods near all of the centers we studied, there are a number of gangs in the area. Violence and drugs are major concerns. The crime rate in the area surrounding Midwest is higher than that found in 90 percent of neighborhoods in the city.
Our initial survey questionnaire provides a good sense of those youth who came to the center who were at least ten years old. The survey was completed by 62 youth ages 10–16, with a mean (average) age of 12.16 (of the clubs we studied, Midwest has the fewest youth). The sample was 66 percent Hispanic, 34 percent African American, 8 percent white, and 2 percent Asian American (figures sum to more than 100%, as some youth checked more than one box). It was a high-poverty sample, as 83 percent reported receiving free or reduced-price lunch. It was also a high-attendance sample, as most of the young people had been coming to Midwest for several years and came almost every weekday for at least two to four hours daily. At the beginning of the year, there were five full-time and two part-time staff (which includes a full-time administrator); by the end of the year, two additional full-time staff had joined the center.
Ethnographic Observations: Trained members of the research team visited each club to conduct ethnographic observations, typically two times a week, beginning in September and continuing through the end of the school year in June. Observers recorded detailed field notes after each visit (see Field Note Template later in this appendix). Each field note included the team member’s observations and reflections as well as an account of any conversations with youth or staff. The principal investigator (Hirsch) reviewed the field notes on an ongoing basis. Developments or issues that might benefit from additional investigation were highlighted for follow-up during subsequent visits to the club.
Social Climate Ratings: Following each visit to a club, the research team member involved completed ratings of the social climate of the club on several different dimensions, such as cooperation and conflict among staff and youth enjoyment and participation in decision making (see Field Note Template later in this appendix).
All Youth Attending Each Center
Youth Background Questionnaire: This questionnaire was completed at the start of the year by all youth at each of the clubs who were ten years of age or older. The survey included questions that asked youth for basic demographic information, their levels and history of participation in the club, how safe they felt in their neighborhoods, and whether they experienced the club setting as a “second home.” Each youth also was asked on the survey to identify the staff person at the center with whom he or she had the closest relationship.
This book examines after-school programs in light of their explosive growth in recent years. In the rush to mount programs, there is a danger of promoting weak ones of little value and failing to implement strong ones adequately. But what is quality and how can it be achieved? This book presents findings from an intensive study of three after-school centers that differed dramatically in quality. Drawing from 233 site visits, the authors examine how – and why – young people thrive in good programs and suffer in weak ones. The book features engaging, in-depth case studies of each of the three centers and of six youths, two from each center. Written in a highly accessible style for academics, youth workers, after-school program leaders and policy makers, the study breaks new ground in highlighting the importance of factors such as collective mentoring, synergies among different programs and activities, and organizational culture and practices.
This research project has gone through some interesting transformations. Our original grant application to the William T. Grant Foundation proposed a year of qualitative research followed by a year of quantitative research. We were very grateful when the foundation’s then senior vice president, Robert Granger, encouraged us to focus on the qualitative portion only.
We hadn’t expected to be taken by surprise by the nature of the three after-school centers that we were going to study, but we were. A few years earlier, we had studied six Boys and Girls Clubs and had written two books based on that experience: Hirsch’s A Place to Call Home: After–School Programs for Urban Youth, and Deutsch’s Pride in the Projects: Teens Building Identities in Urban Contexts. We had thought that the clubs in the current research would be reasonably similar to the six we had studied earlier, but that was not the case. With one of the clubs (referred to as North River), it was clear from the very beginning that it was a lot worse than any of the clubs we had come to know previously. Nothing during the rest of our year of data collection served to change our mind about this. Indeed, as time went on, we became more sharply aware of differences across all three of the clubs. We became convinced that to do justice to this situation, we needed to expand our research focus. Our initial objective was to conduct an intensive study of youth-staff relationships, as such relationships had emerged as an important factor in our prior studies. We have done that. But we also added an organizational level of analysis to capture the different cultures and operations at the three sites. The varying perspectives are reported via case studies of each club and of two youth at each club. The book that grew out of this more comprehensive effort is richer, and it is both more theoretical and more applied as a result.