Historical greenhouse gas concentrations for climate modelling (CMIP6)

Atmospheric greenhouse gas (GHG) concentrations are at unprecedented, record-high levels compared to the last 800 000 years. Those elevated GHG concentrations warm the planet and – partially offset by net cooling effects by aerosols – are largely responsible for the observed warming over the past 150 years. An accurate representation of GHG concentrations is hence important to understand and model recent climate change. So far, community efforts to create composite datasets of GHG concentrations with seasonal and latitudinal information have focused on marine boundary layer conditions and recent trends since the 1980s. Here, we provide consolidated datasets of historical atmospheric concentrations (mole fractions) of 43 GHGs to be used in the Climate Model Intercomparison Project – Phase 6 (CMIP6) experiments. The presented datasets are based on AGAGE and NOAA networks, firn and ice core data, and archived air data, and a large set of published studies. In contrast to previous intercomparisons, the new datasets are latitudinally resolved and include seasonality. We focus on the period 1850–2014 for historical CMIP6 runs, but data are also provided for the last 2000 years. We provide consolidated datasets in various spatiotemporal resolutions for carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), as well as 40 other GHGs, namely 17 ozone-depleting substances, 11 hydrofluorocarbons (HFCs), 9 perfluorocarbons (PFCs), sulfur hexafluoride (SF6), nitrogen trifluoride (NF3) and sulfuryl fluoride (SO2F2). In addition, we provide three equivalence species that aggregate concentrations of GHGs other than CO2, CH4 and N2O, weighted by their radiative forcing efficiencies. For the year 1850, which is used for pre-industrial control runs, we estimate annual global-mean surface concentrations of CO2 at 284.3 ppm, CH4 at 808.2 ppb and N2O at 273.0 ppb. The data are available at https://esgfnode.llnl.gov/search/input4mips/ and http://www.climatecollege.unimelb.edu.au/cmip6. While the minimum CMIP6 recommendation is to use the global- and annual-mean time series, modelling groups can also choose our monthly and latitudinally resolved concentrations, which imply a stronger radiative forcing in the Northern Hemisphere winter (due to the latitudinal gradient and seasonality)

Intracellular iron uptake is favored in Hfe-KO mouse primary chondrocytes mimicking an osteoarthritis-related phenotype

HFE-hemochromatosis is a disease characterized by a systemic iron overload phenotype mainly associated with mutations in the HFE protein (HFE) gene. Osteoarthritis (OA) has been reported as one of the most prevalent complications in HFE-hemochromatosis patients, but the mechanisms associated with its onset and progression remain incompletely understood. In this study, we have characterized the response to high iron concentrations of a primary culture of articular chondrocytes isolated from newborn Hfe-KO mice and compared the results with that of a similar experiment developed in cells from C57BL/6 wild-type (wt) mice. Our data provide evidence that both wt- and Hfe-KO-derived chondrocytes, when exposed to 50 mu M iron, develop characteristics of an OA-related phenotype, such as an increased expression of metalloproteases, a decreased extracellular matrix production, and a lower expression level of aggrecan. In addition, Hfe-KO cells also showed an increased expression of iron metabolism markers and MMP3, indicating an increased susceptibility to intracellular iron accumulation and higher levels of chondrocyte catabolism. Accordingly, upon treatment with 50 mu M iron, these chondrocytes were found to preferentially differentiate toward hypertrophy with increased expression of collagen I and transferrin and downregulation of SRY (sex-determining region Y)-box containing gene 9 (Sox9). In conclusion, high iron exposure can compromise chondrocyte metabolism, which, when simultaneously affected by an Hfe loss of function, appears to be more susceptible to the establishment of an OA-related phenotype.European Regional Development FundEuropean Union (EU) [EMBRC.PT Alg-01-0145-FEDER-022121, Norte-01-0145-FEDER-000012]Fundacao para a Ciencia e a TecnologiaPortuguese Foundation for Science and Technology [SFRH/BD/77056/2011]Portuguese Foundation for Science and TechnologyPortuguese Foundation for Science and TechnologyPortuguese Science and Technology FoundationPortuguese Foundation for Science and Technologyinfo:eu-repo/semantics/publishedVersio

Compulsive Internet Use Among Adolescents: Bidirectional Parent–Child Relationships

Although parents experience growing concerns about their children’s excessive internet use, little is known about the role parents can play to prevent their children from developing Compulsive Internet Use (CIU). The present study addresses associations between internet-specific parenting practices and CIU among adolescents, as well as the bidirectionality of these associations. Two studies were conducted: a cross-sectional study using a representative sample of 4,483 Dutch students and a longitudinal study using a self-selected sample of 510 Dutch adolescents. Results suggest that qualitatively good communication regarding internet use is a promising tool for parents to prevent their teenage children from developing CIU. Besides, parental reactions to excessive internet use and parental rules regarding the content of internet use may help prevent CIU. Strict rules about time of internet use, however, may promote compulsive tendencies. Finally, one opposite link was found whereby CIU predicted a decrease in frequency of parental communication regarding internet use

Controlling waves in space and time for imaging and focusing in complex media

In complex media such as white paint and biological tissue, light encounters nanoscale refractive-index inhomogeneities that cause multiple scattering. Such scattering is usually seen as an impediment to focusing and imaging. However, scientists have recently used strongly scattering materials to focus, shape and compress waves by controlling the many degrees of freedom in the incident waves. This was first demonstrated in the acoustic and microwave domains using time reversal, and is now being performed in the optical realm using spatial light modulators to address the many thousands of spatial degrees of freedom of light. This approach is being used to investigate phenomena such as optical super-resolution and the time reversal of light, thus opening many new avenues for imaging and focusing in turbid medi

The trans-ancestral genomic architecture of glycemic traits

Glycemic traits are used to diagnose and monitor type 2 diabetes and cardiometabolic health. To date, most genetic studies of glycemic traits have focused on individuals of European ancestry. Here we aggregated genome-wide association studies comprising up to 281,416 individuals without diabetes (30% non-European ancestry) for whom fasting glucose, 2-h glucose after an oral glucose challenge, glycated hemoglobin and fasting insulin data were available. Trans-ancestry and single-ancestry meta-analyses identified 242 loci (99 novel; P < 5 x 10(-8)), 80% of which had no significant evidence of between-ancestry heterogeneity. Analyses restricted to individuals of European ancestry with equivalent sample size would have led to 24 fewer new loci. Compared with single-ancestry analyses, equivalent-sized trans-ancestry fine-mapping reduced the number of estimated variants in 99% credible sets by a median of 37.5%. Genomic-feature, gene-expression and gene-set analyses revealed distinct biological signatures for each trait, highlighting different underlying biological pathways. Our results increase our understanding of diabetes pathophysiology by using trans-ancestry studies for improved power and resolution. A trans-ancestry meta-analysis of GWAS of glycemic traits in up to 281,416 individuals identifies 99 novel loci, of which one quarter was found due to the multi-ancestry approach, which also improves fine-mapping of credible variant sets.Peer reviewe