ABSTRACT
Known as the ‘Missing Baryon Problem’, about one-third of baryons in the local universe remain unaccounted for. The missing baryons are thought to reside in the warm–hot intergalactic medium ...(WHIM) of the cosmic web filaments, which are challenging to detect. Recent Chandra X-ray observations used a novel stacking analysis and detected an O vii absorption line towards the sightline of a luminous quasar, hinting that the missing baryons may reside in the WHIM. To explore how the properties of the O vii absorption line depend on feedback physics, we compare the observational results with predictions obtained from the Cosmology and Astrophysics with MachinE Learning (CAMEL) Simulation suite. CAMELS consists of cosmological simulations with state-of-the-art supernova (SN) and active galactic nuclei (AGNs) feedback models from the IllustrisTNG and SIMBA simulations, with varying strengths. We find that the simulated O vii column densities are higher in the outskirts of galaxies than in the large-scale WHIM, but they are consistently lower than those obtained in the Chandra observations, for all feedback runs. We establish that the O vii distribution is primarily sensitive to changes in the SN feedback prescription, whereas changes in the AGN feedback prescription have minimal impact. We also find significant differences in the O vii column densities between the IllustrisTNG and SIMBA runs. We conclude that the tension between the observed and simulated O vii column densities cannot be explained by the wide range of feedback models implemented in CAMELS.
Recent advancements in the imaging of low-surface-brightness objects revealed numerous ultra-diffuse galaxies in the local universe. These peculiar objects are unusually extended and faint: their ...effective radii are comparable to the Milky Way, but their surface brightnesses are lower than that of dwarf galaxies. Their ambiguous properties motivate two potential formation scenarios: the "failed" Milky Way, and the dwarf galaxy scenario. In this Letter, for the first time, we employ X-ray observations to test these formation scenarios on a sample of isolated, low-surface-brightness galaxies (LSBGs). Because hot gas X-ray luminosities correlate with the dark-matter halo mass, "failed" Milky-Way-type galaxies, which reside in massive dark-matter halos, are expected to have significantly higher X-ray luminosities than dwarf galaxies, which reside in low-mass dark-matter halos. We perform X-ray photometry on a subset of LSBGs identified in the Hyper Suprime-Cam Subaru survey, utilizing the XMM-Newton XXL North survey. We find that none of the individual galaxies show significant X-ray emission. By co-adding the signal of individual galaxies, the stacked galaxies remain undetected and we set an X-ray luminosity upper limit of for an average isolated LSBG. This upper limit is about 40 times lower than that expected in a galaxy with massive dark-matter halo, implying that the majority of isolated LSBGs reside in dwarf-size dark-matter halos.
Summary
The scale of the obesity epidemic creates a pressing consumer need as well as an enormous business opportunity for successful development and marketing of food products with added benefits ...for weight control. A number of proposed functional food ingredients have been shown to act post‐absorptively to influence substrate utilization or thermogenesis. Characteristics and supporting data on conjugated linoleic acid, diglycerides, medium‐chain triglycerides, green tea, ephedrine, caffeine, capsaicin and calcium, are reviewed here, giving examples of how these could act to alter energy expenditure or appetite control. Consideration is also given to other factors, in addition to efficacy, which must be satisfied to get such ingredients into foods. We conclude that, for each of the safe, putatively metabolically active agents, there remain gaps in clinical evidence or knowledge of mechanisms, which need to be addressed in order to specify the dietary conditions and food product compositions where these ingredients could be of most benefit for weight control.
Summary
What is already known about this subject
Overweight and obesity can be linked to different parental socioeconomic factors already in very young children.
In Western developed countries, the ...association of childhood overweight and obesity and parental socioeconomic status shows a negative gradient.
Ambiguous results have been obtained regarding the association between socioeconomic factors and childhood overweight and obesity in different countries and over time.
What this study adds
European regions show heterogeneous associations between socioeconomic factors and overweight and obesity in a multi‐centre study with highly standardized study protoco.
The strength of association between SES and overweight and obesity varies across European regions.
In our study, the SES gradient is correlated with the regional mean income and the country‐specific Human development index indicating a strong influence not only of the family but also of region and country on the overweight and obesity prevalence.
Objective
To assess the association between different macro‐ and micro‐level socioeconomic factors and childhood overweight.
Methods
Data from the IDEFICS baseline survey is used to investigate the cross‐sectional association between socioeconomic factors, like socioeconomic status (SES), and the prevalence of childhood overweight. Differences and similarities regarding this relationship in eight European regions (located in Belgium, Cyprus, Estonia, Germany, Hungary, Italy, Spain and Sweden) are explored. 11 994 children (50.9% boys, 49.1% girls) and their parents were included in the analyses.
Results
In five of the eight investigated regions (in Belgium, Estonia, Germany, Spain and Sweden), the prevalence of childhood overweight followed an inverse SES gradient. In the other three regions (in Cyprus, Hungary and Italy), no association between SES and childhood overweight was found. The SES‐overweight association in a region was best explained by the country‐specific human development index and the centre‐specific mean income. For the investigated association between other socioeconomic factors and overweight, no clear pattern could be found in the different regions.
Conclusion
The association between socioeconomic factors and childhood overweight was shown to be heterogeneous across different European regions. Further research on nationwide European data is needed to confirm the results and to identify target groups for prevention.
Major extinction events appear coincident with the emplacement of large igneous provinces (LIPs) throughout Earth's past, but the cause-and-effect relationship is often poorly understood due to ...challenges in the stratigraphical correlation between LIP occurrence and sedimentary archives. Large igneous provinces are thought to have released large amounts of greenhouse gasses and toxic compounds (including mercury) into the global ocean-atmosphere system, leading to major climatic and environmental perturbations and ecosystem deterioration. In recent years, the analyses of bulk sedimentary mercury (Hg) concentrations have increasingly been used to assess the temporal occurrence and geographic reach of LIPs, as observed through elevated Hg concentrations in sedimentary archives which otherwise show no direct evidence of volcanism at those times.
Mercury can be sequestered into sediments in different ways, but dominant Hg sequestration pathways can vary through space and time depending on the depositional environment and changes therein, which may disguise changes in global Hg fluxes into Earth's surficial environments, significantly complicating the interpretation of sedimentary Hg-records. Here, we statistically analyse sedimentary geochemical records from three distinctly different depositional environments that occurred during the Toarcian Oceanic Anoxic Event (T-OAE, at ∼183 Ma, and coincident with Karoo-Ferrar LIP volcanism), and assess the temporal and spatial variability in dominant Hg sequestration pathways during LIP volcanism.
The geochemical data show significantly different affinities of mercury with assessed sedimentary geochemical parameters in each of the studied successions. Principal component analyses (PCA) of sedimentary geochemical data (including Hg), from the restricted, anoxic-euxinic Cleveland Basin (Yorkshire, UK) show that Hg covaries mostly with organic-sulphide-associated elements and to a lesser extent with the redox-sensitive elements, as opposed to the semi-restricted, sub-oxic Cardigan Bay Basin (Wales, UK) and the well-connected, oxygenated Subbetic Basin (South Iberian Palaeomargin, SE Spain), where Hg covaries dominantly with the redox-sensitive elements and secondarily with detrital elements. These findings show that mineral phases and materials other than organic matter need to be considered as dominant Hg carriers in non-anoxic depositional settings. Furthermore, observed differences between the studied sites regarding the dominant Hg-sequestration processes, suggest temporal and spatial variance in Hg drawdown fluxes, and possibly local marine residence times.
•Past environmental mercury loading contemporaneous with LIP volcanism.•Hg sequester into sediments with organic matter, sulphides and detrital components.•Local mercury sequestration pathways depend on dominant depositional conditions.
The Arabidopsis AtCRK5 protein kinase is involved in the establishment of the proper auxin gradient in many developmental processes. Among others, the At
mutant was reported to exhibit a delayed ...gravitropic response via compromised PIN2-mediated auxin transport at the root tip. Here, we report that this phenotype correlates with lower superoxide anion (O
) and hydrogen peroxide (H
O
) levels but a higher nitric oxide (NO) content in the mutant root tips in comparison to the wild type (AtCol-0). The oxidative stress inducer paraquat (PQ) triggering formation of O
(and consequently, H
O
) was able to rescue the gravitropic response of At
roots. The direct application of H
O
had the same effect. Under gravistimulation, correct auxin distribution was restored (at least partially) by PQ or H
O
treatment in the mutant root tips. In agreement, the redistribution of the PIN2 auxin efflux carrier was similar in the gravistimulated PQ-treated mutant and untreated wild type roots. It was also found that PQ-treatment decreased the endogenous NO level at the root tip to normal levels. Furthermore, the mutant phenotype could be reverted by direct manipulation of the endogenous NO level using an NO scavenger (cPTIO). The potential involvement of AtCRK5 protein kinase in the control of auxin-ROS-NO-PIN2-auxin regulatory loop is discussed.
Ultradiffuse galaxies (UDGs) exhibit low surface brightness, but their optical extent is comparable to that of Milky Way-type galaxies. In this work, we utilize Chandra X-ray observations of 404 UDGs ...in the Coma cluster and address two crucial goals. First, we constrain the formation scenario of UDGs by probing the X-ray emission originating from diffuse gas and from the population of unresolved low-mass X-ray binaries (LMXBs) residing in globular clusters (GCs). It is expected that both the luminosity of the hot gas and the number of GCs, and hence the luminosity from GC-LMXBs, are proportional to the total mass of the dark matter halo. We do not detect statistically significant emission from the hot gas or from GC-LMXBs. The upper limits on the X-ray luminosities suggest that the bulk of the UDGs reside in low-mass dark matter halos, implying that they are genuine dwarf galaxies. This conclusion agrees with our previous results obtained for isolated UDGs, arguing that UDGs are a homogeneous population of galaxies. Second, we constrain the AGN occupation fraction of UDGs, i.e., the fraction of UDGs that are occupied by an active galactic nucleus, for the first time. To this end, we cross-correlate the position of detected X-ray sources in the Coma cluster with the position of UDGs. We identify two UDGs that have a luminous X-ray source at 3 0 and 3 2 from their center, which could be off-center AGNs. However, Monte Carlo simulations suggest that one of these sources could be the result of spatial coincidence with a background AGN. Therefore, we place an upper limit of 0.5% on the AGN occupation fraction of UDGs.
The European Union-as well as other parts of the world-faces a major challenge of increasing incidence of overweight/obesity. In particular, the increase in childhood obesity gives rise to a strong ...imperative for immediate action. Yet, little is known about the effectiveness of community interventions, and further research in this field is needed. There is, however, a growing consensus that such research should start from the paradigm that the current living environments tend to counteract healthy lifestyles. Questioning these environments thoroughly can help to develop new pathways for sustainable health-promoting communities. Against this background, the IDEFICS (Identification and prevention of dietary- and lifestyle-induced health effects in children and infants) study developed and implemented innovative community-oriented intervention programmes for obesity prevention and healthy lifestyle primarily in children aged 2-10 years in eight European countries: Sweden, Estonia, Germany, Belgium, Hungary, Italy, Spain and Cyprus.
The IDEFICS community-oriented intervention study mobilised an integrated set of interventional efforts at different levels of society, with the aim of facilitating the adoption of a healthy obesity-preventing lifestyle. The overall programme has been composed of 10 modules: three at community level, six at school level and one for parents. The main focus was on diet, physical activity and stress-coping capacity. The sphere of action encompassed both children and their (grand) parents, schools, local public authorities and influential stakeholders in the community. All materials for the interventions were centrally developed and culturally adapted.
So far, the following has been achieved: focus group research, literature review and expert consultations were done in an early phase as a basis for the development of the intervention modules. The intervention mapping protocol was followed as guide for structuring the intervention research. The overall intervention programme's duration was 2 years, but a longer-term follow-up programme is under development.
This large-scale European effort is expected to contribute significantly to the understanding of this major public health challenge.
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