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Metabolites are small molecules involved in cellular metabolism where they act as reaction substrates or products. The term ‘metabolomics’ refers to the comprehensive study of these molecules. The concentrations of metabolites in biological tissues are under genetic control, but this is limited by environmental factors such as diet. In adult mono- and dizygotic twin pairs, we estimated the contribution of genetic and shared environmental influences on metabolite levels by structural equation modeling and tested whether the familial resemblance for metabolite levels is mainly explained by genetic or by environmental factors that are shared by family members. Metabolites were measured across three platforms: two based on proton nuclear magnetic resonance techniques and one employing mass spectrometry. These three platforms comprised 237 single metabolic traits of several chemical classes. For the three platforms, metabolites were assessed in 1407, 1037 and 1116 twin pairs, respectively. We carried out power calculations to establish what percentage of shared environmental variance could be detected given these sample sizes. Our study did not find evidence for a systematic contribution of shared environment, defined as the influence of growing up together in the same household, on metabolites assessed in adulthood. Significant heritability was observed for nearly all 237 metabolites; significant contribution of the shared environment was limited to 6 metabolites. The top quartile of the heritability distribution was populated by 5 of the 11 investigated chemical classes. In this quartile, metabolites of the class lipoprotein were significantly overrepresented, whereas metabolites of classes glycerophospholipids and glycerolipids were significantly underrepresented.
Chez les patients atteints d’une épilepsie du lobe temporal (ELT), la dépression constitue la comorbidité psychiatrique la plus fréquente (Gaitatzis et al., 2004). Celle-ci peut être associée à l’apathie, mais l’apathie peut exister en tant que syndrome, indépendamment de la présence d’un trouble dépressif (Kirsch-Darrow et al., 2006). L’apathie n’ayant jamais été évaluée chez les patients avec une ELT, l’objectif de cette étude était donc de mesurer la prévalence de l’apathie dans cette population, et ses liens potentiels avec la dépression.
Cinquante patients ELT et 50 contrôles sains appariés selon leurs caractéristiques démographiques ont été inclus. Pour l’ensemble des participants, la sévérité de la symptomatologie dépressive et apathique était évaluée à l’aide de l’inventaire de dépression de Beck et de l’échelle d’apathie Lilloise (Sockeel et al., 2006).
Chez les patients ELT comparativement aux contrôles, la sévérité de la symptomatologie dépressive et apathique était significativement plus importante. Parmi les patients ELT, 18 (soit 36 %) présentaient une apathie modérée à sévère (i.e. un score > –17), et 14 (soit 28 %) présentaient une dépression modérée à sévère (i.e. un score > 19). Les niveaux de sévérité de la symptomatologie apathique et dépressive étaient positivement associés. L’apathie coexistait avec la dépression chez 8 patients ELT (soit 16 %), et 6 patients ELT (soit 12 %) présentaient une dépression sans apathie. Cependant, 10 patients ELT (soit 20 %) présentant une apathie, ne présentaient pas de dépression.
Cette étude donne des indications sur la prévalence de l’apathie dans le cadre d’une épilepsie du lobe temporal. Cette apathie peut être associée à une dépression. Néanmoins, elle est plus fréquemment relevée indépendamment de toute symptomatologie dépressive associée. D’autres études sont nécessaires afin de mieux caractériser les liens entre, apathie, dépression et épilepsie.
Results of comprehensive particle image velocimetry measurements investigating the dynamics of turbulent jets in a rotating fluid are presented. It is observed that background system rotation induces a time-periodic formation–breakdown cycle of the jets. The flow dynamics associated with this process is studied in detail. It is found that the frequency of the cycle increases linearly with the background rotation rate. The data show that the onset of the breakdown phase and of the reformation phase of the cycle can be characterized in terms of a local Rossby number employing an internal velocity and a length scale of the jet. The critical values for this local Rossby number, for onset of breakdown and reformation, scale linearly with a global Rossby number based on the flow conditions at the source. The analysis of the experimental data suggests centrifugal instability as the potential origin of the formation–breakdown cycle.
Background: Two ‘sibling’ disorders have been proposed for the fourthcoming 11th version of the International Classification of Diseases (ICD-11): post-traumatic stress disorder (PTSD) and complex PTSD (CPTSD). Examining psychological factors that may be associated with CPTSD, such as self-compassion, is an important first step in its treatment that can inform consideration of which problems are most salient and what interventions are most relevant. Aims: We set out to investigate the association between self-compassion and the two factors of CPTSD: the PTSD factor (re-experiencing, avoidance, sense of threat) and the Disturbances in Self-Organization (DSO) factor (affect dysregulation, negative self-concept and disturbances in relationships). We hypothesized that self-compassion subscales would be negatively associated with both PTSD and DSO symptom clusters. Method: A predominantly female, clinical sample (n = 106) completed self-report scales to measure traumatic life events, ICD-11 CPTSD and self-compassion. Results: Significant negative associations were found between the CPTSD DSO clusters of symptoms and self-compassion subscales, but not for the PTSD ones. Specifically it was also found that self-judgement and common humanity significantly predicted hypoactive affect dysregulation whereas self-judgement and isolation significantly predicted negative self-concept. Conclusions: Our results indicate that self-compassion may be a useful treatment target for ICD-11 CPTSD, particularly for symptoms of negative self-concept and affect dysregulation. Future research is required to investigate the efficacy and acceptability of interventions that have implicit foundations on compassion.
Inland water bodies contain significant amounts of carbon in the form of dissolved inorganic carbon (DIC) derived from a mixture of modern atmospheric and pre-aged sources, which needs to be considered in radiocarbon-based dating and natural isotope tracer studies. While reservoir effects in hardwater lakes are generally considered to be constant through time, a comparison of recent and historical DI14C data from 2013 and 1969 for Lake Constance reveals that this is not a valid assumption. We hypothesize that changes in atmospheric carbon contributions to lake water DIC have taken place due to anthropogenically forced eutrophication in the 20th century. A return to more oligotrophic conditions in the lake led to reoxygenation and enhanced terrigenous organic matter remineralization, contributing to lake water DIC. Such comparisons using DI14C measurements from different points in time enable nonlinear changes in lake water DIC source and signature to be disentangled from concurrent anthropogenically induced changes in atmospheric 14C. In the future, coeval changes in lake dynamics due to climate change are expected to further perturb these balances. Depending on the scenario, Lake Constance DI14C is projected to decrease from the 2013 measured value of 0.856 Fm to 0.54–0.62 Fm by the end of the century.
Whether monozygotic (MZ) and dizygotic (DZ) twins differ from each other in a variety of phenotypes is important for genetic twin modeling and for inferences made from twin studies in general. We analyzed whether there were differences in individual, maternal and paternal education between MZ and DZ twins in a large pooled dataset. Information was gathered on individual education for 218,362 adult twins from 27 twin cohorts (53% females; 39% MZ twins), and on maternal and paternal education for 147,315 and 143,056 twins respectively, from 28 twin cohorts (52% females; 38% MZ twins). Together, we had information on individual or parental education from 42 twin cohorts representing 19 countries. The original education classifications were transformed to education years and analyzed using linear regression models. Overall, MZ males had 0.26 (95% CI [0.21, 0.31]) years and MZ females 0.17 (95% CI [0.12, 0.21]) years longer education than DZ twins. The zygosity difference became smaller in more recent birth cohorts for both males and females. Parental education was somewhat longer for fathers of DZ twins in cohorts born in 1990–1999 (0.16 years, 95% CI [0.08, 0.25]) and 2000 or later (0.11 years, 95% CI [0.00, 0.22]), compared with fathers of MZ twins. The results show that the years of both individual and parental education are largely similar in MZ and DZ twins. We suggest that the socio-economic differences between MZ and DZ twins are so small that inferences based upon genetic modeling of twin data are not affected.
Araucaria goroensis R.R.Mill & Ruhsam sp. nov., a new monkey puzzle species from New Caledonia, is described and illustrated with photographs from the field and from herbarium specimens. Previously confused with Araucaria muelleri, it is more similar to A. rulei. It is distinguished from the latter species by its larger leaves, microsporophylls without a shouldered base, and shorter female cone bracts. It occurs in a very limited area of south-east New Caledonia, where its existence is threatened by nickel mining. Using the guidelines of the International Union for Conservation of Nature, we propose an assessment of Endangered for the new species and reassess Araucaria muelleri also as Endangered. A key to the seven species in the ‘large-leaved clade’ of New Caledonian species of Araucaria is given. The name Eutassa latifolia de Laub. is synonymised with Araucaria muelleri, and the recent typification of the latter name by Vieillard 1276 is rejected. Detailed reasoning is given for these nomenclatural acts.
Studies using carbon isotopes to understand the global carbon cycle are critical to identify and quantify sources, sinks, and processes and how humans may impact them. 13C and 14C are routinely measured individually; however, there is a need to develop instrumentation that can perform concurrent online analyses that can generate rich data sets conveniently and efficiently. To satisfy these requirements, we coupled an elemental analyzer to a stable isotope mass spectrometer and an accelerator mass spectrometer system fitted with a gas ion source. We first tested the system with standard materials and then reanalyzed a sediment core from the Bay of Bengal that had been analyzed for 14C by conventional methods. The system was able to produce %C, 13C, and 14C data that were accurate and precise, and suitable for the purposes of our biogeochemistry group. The system was compact and convenient and is appropriate for use in a range of fields of research.
The Dark Energy Survey is undertaking an observational programme imaging 1/4 of the southern hemisphere sky with unprecedented photometric accuracy. In the process of observing millions of faint stars and galaxies to constrain the parameters of the dark energy equation of state, the Dark Energy Survey will obtain pre-discovery images of the regions surrounding an estimated 100 gamma-ray bursts over 5 yr. Once gamma-ray bursts are detected by, e.g., the Swift satellite, the DES data will be extremely useful for follow-up observations by the transient astronomy community. We describe a recently-commissioned suite of software that listens continuously for automated notices of gamma-ray burst activity, collates information from archival DES data, and disseminates relevant data products back to the community in near-real-time. Of particular importance are the opportunities that non-public DES data provide for relative photometry of the optical counterparts of gamma-ray bursts, as well as for identifying key characteristics (e.g., photometric redshifts) of potential gamma-ray burst host galaxies. We provide the functional details of the DESAlert software, and its data products, and we show sample results from the application of DESAlert to numerous previously detected gamma-ray bursts, including the possible identification of several heretofore unknown gamma-ray burst hosts.
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.
Physical inactivity and low birth weight (LBW) may lead to an increased risk for developing type 2 diabetes. The extent to which LBW individuals may benefit from physical exercise training when compared with those with normal birth weight (NBW) controls is uncertain. We assessed the impact of an outdoor exercise intervention on body composition, insulin secretion and action in young men born with LBW and NBW in rural India. A total of 61 LBW and 56 NBW healthy young men were recruited into the study. The individuals were instructed to perform outdoor bicycle exercise training for 45 min every day. Fasting blood samples, intravenous glucose tolerance tests and bioimpedance body composition assessment were carried out. Physical activity was measured using combined accelerometry and heart rate monitoring during the first and the last week of the intervention. Following the exercise intervention, the LBW group displayed an increase in physical fitness [55.0 ml (O2)/kg min (52.0−58.0)−57.5 ml (O2)/kg min (54.4−60.5)] level and total fat-free mass [10.9% (8.0−13.4)−11.4% (8.0−14.6)], as well as a corresponding decline in the ratio of total fat mass/fat-free mass. In contrast, an increase in total fat percentage as well as total fat mass was observed in the NBW group. After intervention, fasting plasma insulin levels, homoeostasis model assessments (HOMA) of insulin resistance (HOMA-IR) and insulin secretion (HOMA-IS), improved to the same extent in both the groups. In summary, young men born with LBW in rural India benefit metabolically from exercise training to an extent comparable with NBW controls.
Risk for depression is expressed across multiple levels of analysis. For example, parental depression and cognitive vulnerability are known markers of depression risk, but no study has examined their interactive effects on children's cortisol reactivity, a likely mediator of early depression risk. We examined relations across these different levels of vulnerability using cross-sectional and longitudinal methods in two community samples of children. Children were assessed for cognitive vulnerability using self-reports (Study 1; n = 244) and tasks tapping memory and attentional bias (Study 2; n = 205), and their parents were assessed for depression history using structured clinical interviews. In both samples, children participated in standardized stress tasks and cortisol reactivity was assessed. Cross-sectionally and longitudinally, parental depression history and child cognitive vulnerability interacted to predict children's cortisol reactivity; associations between parent depression and elevated child cortisol activity were found when children also showed elevated depressotypic attributions as well as attentional and memory biases. Findings indicate that models of children's emerging depression risk may benefit from the examination of the interactive effects of multiple sources of vulnerability across levels of analysis.
Prosocial emotions related to self-blame are important in guiding human altruistic decisions. These emotions are elevated in major depressive disorder (MDD), such that MDD has been associated with guilt-driven pathological hyper-altruism. However, the impact of such emotional impairments in MDD on different types of social decision-making is unknown.
In order to address this issue, we investigated different kinds of altruistic behaviour (interpersonal cooperation and fund allocation, altruistic punishment and charitable donation) in 33 healthy subjects, 35 patients in full remission (unmedicated) and 24 currently depressed patients (11 on medication) using behavioural-economical paradigms.
We show a significant main effect of clinical status on altruistic decisions (p = 0.04) and a significant interaction between clinical status and type of altruistic decisions (p = 0.03). More specifically, symptomatic patients defected significantly more in the Prisoner's Dilemma game (p < 0.05) and made significantly lower charitable donations, whether or not these incurred a personal cost (p < 0.05 and p < 0.01, respectively). Currently depressed patients also reported significantly higher guilt elicited by receiving unfair financial offers in the Ultimatum Game (p < 0.05).
Currently depressed individuals were less altruistic in both a charitable donation and an interpersonal cooperation task. Taken together, our results challenge the guilt-driven pathological hyper-altruism hypothesis in depression. There were also differences in both current and remitted patients in the relationship between altruistic behaviour and pathological self-blaming, suggesting an important role for these emotions in moral and social decision-making abnormalities in depression.