Investigating the Distribution and Source(s) of Lunar Volatiles

Following the renewed interest in the volatile inventory of the Moon witnessed in the last decade, from both sample studies and data from orbital missions, it is timely to reassess the distribution and likely source(s) of light element volatiles (C, N, He, Ne, and Ar) in a diverse suite of lunar mare basalts and soils, providing new insights about volatiles indigenous to the lunar interior, volatiles produced in situ at the lunar surface, and volatiles delivered to and implanted into the lunar surface. Simultaneous static-mode mass spectrometric measurements of these key volatiles, extracted from the same aliquot of sample by high-resolution stepped combustion, enable a more detailed identification of the different volatile components present by comparing their varying release patterns across a range of temperature steps. Taken in context with other studies of different volatile elements, this new data contributes towards a greater understanding of the Earth-Moon system, with additional implications for future in situ resource utilisation at the lunar surface. With an average δ15N value of +0.93 ± 9.39 ‰, the indigenous N component measured in mare basalts is most compatible with a CO carbonaceous chondrite source for nitrogen in the lunar interior, although some caveats exist. Variations in abundance and isotopic composition of indigenous nitrogen imply a heterogeneous lunar mantle. Assuming up to ~50 % loss of solar wind 36Ar from lunar soils, nitrogen trapped in soils can be reconciled with up to 87 % being contributed from a non-solar source with an isotopic composition of between +87 ‰ and +160 ‰. Noble gases in soils are dominated by solar wind components, with only minor amounts of cosmogenic neon being released at the highest temperature steps. In mare basalts, noble gases are a mixture of trapped, radiogenic, and cosmogenic components (from which cosmogenic production rates can be calculated and exposure ages for previously undated samples suggeste

Mechanism of Vanadium Leaching during Surface Weathering of Basic Oxygen Furnace Steel Slag Blocks: A Microfocus X-ray Absorption Spectroscopy and Electron Microscopy Study

© 2017 American Chemical Society. Basic oxygen furnace (BOF) steelmaking slag is enriched in potentially toxic V which may become mobilized in high pH leachate during weathering. BOF slag was weathered under aerated and air-excluded conditions for 6 months prior to SEM/EDS and μXANES analysis to determine V host phases and speciation in both primary and secondary phases. Leached blocks show development of an altered region in which free lime and dicalcium silicate phases were absent and Ca-Si-H was precipitated (CaCO 3 was also present under aerated conditions). μXANES analyses show that V was released to solution as V(V) during dicalcium silicate dissolution and some V was incorporated into neo-formed Ca-Si-H. Higher V concentrations were observed in leachate under aerated conditions than in the air-excluded leaching experiment. Aqueous V concentrations were controlled by Ca 3 (VO 4 ) 2 solubility, which demonstrate an inverse relationship between Ca and V concentrations. Under air-excluded conditions Ca concentrations were controlled by dicalcium silicate dissolution and Ca-Si-H precipitation, leading to relatively high Ca and correspondingly low V concentrations. Formation of CaCO 3 under aerated conditions provided a sink for aqueous Ca, allowing higher V concentrations limited by kinetic dissolution rates of dicalcium silicate. Thus, V release may be slowed by the precipitation of secondary phases in the altered region, improving the prospects for slag reuse

The Relevance of the Colon to Zinc Nutrition

Globally, zinc deficiency is widespread, despite decades of research highlighting its negative effects on health, and in particular upon child health in low-income countries. Apart from inadequate dietary intake of bioavailable zinc, other significant contributors to zinc deficiency include the excessive intestinal loss of endogenously secreted zinc and impairment in small intestinal absorptive function. Such changes are likely to occur in children suffering from environmental (or tropical) enteropathy (EE)—an almost universal condition among inhabitants of developing countries characterized by morphologic and functional changes in the small intestine. Changes to the proximal gut in environmental enteropathy will likely influence the nature and amount of zinc delivered into the large intestine. Consequently, we reviewed the current literature to determine if colonic absorption of endogenous or exogenous (dietary) zinc could contribute to overall zinc nutriture. Whilst we found evidence that significant zinc absorption occurs in the rodent colon, and is favoured when microbially-fermentable carbohydrates (specifically resistant starch) are consumed, it is unclear whether this process occur in humans and/or to what degree. Constraints in study design in the few available studies may well have masked a possible colonic contribution to zinc nutrition. Furthermore these few available human studies have failed to include the actual target population that would benefit, namely infants affected by EE where zinc delivery to the colon may be increased and who are also at risk of zinc deficiency. In conducting this review we have not been able to confirm a colonic contribution to zinc absorption in humans. However, given the observations in rodents and that feeding resistant starch to children is feasible, definitive studies utilising the dual stable isotope method in children with EE should be undertaken.G.L. Gopalsamy, D.H Alpers, H.J Binder, C.D. Tran, B.S. Ramakrishna, I. Brown, M. Manary, Elissa Mortimer and G.P. Youn

Family-Centred Unemployment in Four Disadvantaged Areas in Australia

Australia’s unemployment rate is one of the lowest of any OECD country. However, for families with children, partnered and lone parents, the rate of unemployment and most importantly joblessness is one of the highest at 14.7% and 46% respectively in 2009. This research project aims to better understand problems and issues that face families in which there is at least one family member who is long­term unemployed. The study focuses on the experiences on jobless families in four disadvantaged areas in Australia, with three surveyed at the beginning of the global financial crisis (GFC) and one area to be studied post the GFC. This paper will present methodologies of quantitative survey of long term jobless coupled with qualitative data obtained from the conduct of focus groups and interviews; and findings of the major contributors of the jobless families’ current circumstances including lack of basic skills and qualifications, low levels of formal education and deep lack of confidence and motivation.

Diocesan Licensing and Medical Practitioners in South-West England, 1660–1780

The licensing of provincial surgeons and physicians in the post-Restoration period has proved an awkward subject for medical historians. It has divided writers between those who regard the possession of a local licence as a mark of professionalism or proficiency, those who see the existence of diocesan licences as a mark of an essentially unregulated and decentralized trade, and those who discount the distinction of licensing in assessing medical expertise availability in a given region. Such a diversity of interpretations has meant that the very descriptors by which practitioners were known to their contemporaries (and are referred to by historians) have become fragmented and difficult to use without a specific context. As David Harley has pointed out in his study of licensed physicians in the north-west of England, “historians often define eighteenth-century physicians as men with medical degrees, thus ignoring … the many licensed physicians throughout the country”. One could similarly draw attention to the inadequacy of the word “surgeon” to cover licensed and unlicensed practitioners, barber-surgeons, Company members in towns, self-taught practitioners using surgical manuals, and procedural specialists whose work came under the umbrella of surgery, such as bonesetters, midwives and phlebotomists. Although such fragmentation of meaning reflects a diversity of practices carried on under the same occupational descriptors in early modern England, the result is an imprecise historical literature in which the importance of licensing, and especially local licensing, is either ignored as a delimiter or viewed as an inaccurate gauge of medical proficiency.</jats:p

Use of bauxite residue (red mud) as a low cost sorbent for sulfide removal in polluted water remediation

Sulfide is an important pollutant in aqueous systems. Sulfide removal from polluted waters is required prior to discharge. Red mud RM) is a solid waste of bauxite processing that is rich in reactive iron oxides and consequently has the potential to be used to remove sulfide from aqueous systems. A series of experiments were undertaken using raw and sintered RM to remove sulfide from waters. RM was highly efficient at sulfide removal (average 75% sulfide removal at initial concentration of ~5 mg L-1, with 500 mg L-1 RM addition) due to both physical adsorption (high specific area) and chemical reaction (with amorphous Fe). Sintered RM, which has a lower surface area and lower mineral reactivity, was much less efficient at removing sulfide (~20% removal under equivalent experimental conditions). Furthermore, concomitant metal release from raw RM was lower than for sintered RM during the sulfide removal process. The results showed that raw RM is a potentially suitable material for sulfide removal from polluted waters and consequently could be used as a low cost alternative treatment in certain engineering applications

Managing Relationships: Insights from a Student Gratitude Model

This paper develops a student relationship model which highlights the role of gratitude in impacting students’ positive perceptions, attitudes, and behavioral intentions towards their higher education providers. Using theories from services marketing and positive psychology, we develop and test a gratitude relationship model. A field survey, employing existing measures, was used to elicit data from 1,104 respondents of public, private, and semi-public Pakistani universities. The results of this current research empirically demonstrate the role of gratitude as a mediating mechanism that explains the impact of a university’s relationship investments on students’ positive perceptions, attitudes, and behavioral intentions. This study contributes to higher education and services marketing literature by examining the emergent role of gratitude in students’ perceptions of investments made by their universities and students’ positive emotions, attitudes, and behavioral intentions, such as involvement and long-term relationship intentions, respectively. This research encourages university decision-makers to implement relationship-building strategies beyond that of the purely economic, such as scholarships, that seek to enhance the emotion of gratitude, which will lead to higher levels of perceived value of the relationship, involvement, and intentions to build long-term relationships with the university. This is the first study that highlights the role of gratitude as having an impact on students’ perceptions, attitude, and behavioral intentions. Our student relationship model offers a better psychological explanation of how student gratitude may generate direct benefits for universities

Diel surface temperature range scales with lake size

Ecological and biogeochemical processes in lakes are strongly dependent upon water temperature. Long-term surface warming of many lakes is unequivocal, but little is known about the comparative magnitude of temperature variation at diel timescales, due to a lack of appropriately resolved data. Here we quantify the pattern and magnitude of diel temperature variability of surface waters using high-frequency data from 100 lakes. We show that the near-surface diel temperature range can be substantial in summer relative to long-term change and, for lakes smaller than 3 km2, increases sharply and predictably with decreasing lake area. Most small lakes included in this study experience average summer diel ranges in their near-surface temperatures of between 4 and 7°C. Large diel temperature fluctuations in the majority of lakes undoubtedly influence their structure, function and role in biogeochemical cycles, but the full implications remain largely unexplored

Birch bark tar in early Medieval England:continuity of tradition or technological revival?

International audienc