Co-resident Parents and Young People Aged 15–34: Who Does What Housework?

Young adults are now more likely to co-reside with their parents than previous generations, but domestic work patterns among this family type are largely unexplored. This study addresses this issue using Australian Bureau of Statistics Time Use Surveys (1992, 1997, 2006) and Poisson–Gamma regression analyses. It examines patterns in and correlates of domestic labor in two-generation households in which young people aged 15–34 co-reside with their parents (n = 1,946 households comprised of 2,806 young people and 5,129 parents). It differentiates between routine indoor tasks (cooking, cleaning, laundry), non-routine tasks (outdoor work, household management and maintenance, car care) and grocery shopping. Predictors of more time in some domestic activities by young people include being in neither employment nor education/training (NEET), being older, having a single parent and being in a non-English speaking household (young women). Young people being NEET, or female, are associated with less cooking time for mothers, but in the main when young people do perform domestic activities, they do not relieve their parents of those same activities, suggesting more time is spent by the household in total

Large sulfur isotope fractionations in Martian sediments at Gale crater

Variability in the sulfur isotopic composition in sediments can reflect atmospheric, geologic and biological processes. Evidence for ancient fluvio-lacustrine environments at Gale crater on Mars and a lack of efficient crustal recycling mechanisms on the planet suggests a surface environment that was once warm enough to allow the presence of liquid water, at least for discrete periods of time, and implies a greenhouse effect that may have been influenced by sulfur-bearing volcanic gases. Here we report in situ analyses of the sulfur isotopic compositions of SO2 volatilized from ten sediment samples acquired by NASA's Curiosity rover along a 13 km traverse of Gale crater. We find large variations in sulfur isotopic composition that exceed those measured for Martian meteorites and show both depletion and enrichment in 34S. Measured values of Δ34S range from - 47 ± 14‰ to 28 ± 7‰, similar to the range typical of terrestrial environments. Although limited geochronological constraints on the stratigraphy traversed by Curiosity are available, we propose that the observed sulfur isotopic signatures at Gale crater can be explained by equilibrium fractionation between sulfate and sulfide in an impact-driven hydrothermal system and atmospheric processing of sulfur-bearing gases during transient warm periods

Nitrogen speciation in upper mantle fluids and the origin of Earth's nitrogen-rich atmosphere

Volatile elements stored in the mantles of terrestrial planets escape through volcanic degassing, and thereby influence planetary atmospheric evolution and habitability. Compared with the atmospheres of Venus and Mars, Earth's atmosphere is nitrogen-rich relative to primordial noble gas concentrations1, 2, 3. The compatibility of volatile elements in mantle minerals versus melts and fluids controls how readily these elements are degassed. However, the speciation of nitrogen in mantle fluids is not well constrained4, 5, 6. Here we present thermodynamic calculations that establish the speciation of nitrogen in aqueous fluids under upper mantle conditions. We find that, under the relatively oxidized conditions of Earth's mantle wedges at convergent plate margins7, 8, 9, nitrogen is expected to exist predominantly as N2 in fluids and, therefore, be degassed easily. In contrast, under more reducing conditions elsewhere in the Earth's upper mantle and in the mantles of Venus and Mars, nitrogen is expected predominantly in the form of ammonium (NH4+) in aqueous fluids. Ammonium is moderately compatible in upper mantle minerals10, 11 and unconducive to nitrogen degassing. We conclude that Earth's oxidized mantle wedge conditions—a result of subduction and hence plate tectonics—favour the development of a nitrogen-enriched atmosphere, relative to the primordial noble gases, whereas the atmospheres of Venus and Mars have less nitrogen because they lack plate tectonics.</p

Mars Methane Detection and Variability at Gale Crater

Reports of plumes or patches of methane in the Martian atmosphere that vary over monthly timescales have defied explanation to date. From in situ measurements made over a 20-month period by the Tunable Laser Spectrometer (TLS) of the Sample Analysis at Mars (SAM) instrument suite on Curiosity at Gale Crater, we report detection of background levels of atmospheric methane of mean value 0.69 ±0.21 ppbv at the 95% confidence interval (CI). This abundance is lower than model estimates of ultraviolet (UV) degradation of accreted interplanetary dust particles (IDP’s) or carbonaceous chondrite material. Additionally, in four sequential measurements spanning a 60-sol period, we observed elevated levels of methane of 7.19 ±1.99 (95% CI) ppbv implying that Mars is episodically producing methane from an additional unknown source

Proteomic profiling of human retinal pigment epithelium exposed to an advanced glycation-modified substrate

PURPOSE: The retinal pigment epithelium (RPE) and underlying Bruch’s membrane undergo significant modulation during ageing. Progressive, age-related modifications of lipids and proteins by advanced glycation end products (AGEs) at this cell–substrate interface have been implicated in RPE dysfunction and the progression to age-related macular degeneration (AMD). The pathogenic nature of these adducts in Bruch’s membrane and their influence on the overlying RPE remains unclear. This study aimed to identify alterations in RPE protein expression in cells exposed to AGE-modified basement membrane (AGE-BM), to determine how this “aged” substrate impacts RPE function and to map the localisation of identified proteins in ageing retina. METHODS: Confluent ARPE-19 monolayers were cultured on AGE-BM and native, non-modified BM (BM). Following 28-day incubation, the proteome was profiled using 2-dimensional gel electrophoresis (2D), densitometry and image analysis was employed to map proteins of interest that were identified by electrospray ionisation mass spectrometry (ESI MS/MS). Immunocytochemistry was employed to localise identified proteins in ARPE-19 monolayers cultured on unmodified and AGE-BM and to analyze aged human retina. RESULTS: Image analysis detected altered protein spot densities between treatment groups, and proteins of interest were identified by LC ESI MS/MS which included heat-shock proteins, cytoskeletal and metabolic regulators. Immunocytochemistry revealed deubiquitinating enzyme ubiquitin carboxyterminal hydrolase-1 (UCH-L1), which was upregulated in AGE-exposed RPE and was also localised to RPE in human retinal sections. CONCLUSIONS: This study has demonstrated that AGE-modification of basement membrane alters the RPE proteome. Many proteins are changed in this ageing model, including UCHL-1, which could impact upon RPE degradative capacity. Accumulation of AGEs at Bruch”s membrane could play a significant role in age-related dysfunction of the RPE