Qualitative and quantitative analysis of mixtures of compounds containing both hydrogen and deuterium

Method allows qualitative and quantitative analysis of mixtures of partially deuterated compounds. Nuclear magnetic resonance spectroscopy determines location and amount of deuterium in organic compounds but not fully deuterated compounds. Mass spectroscopy can detect fully deuterated species but not the location

Catalytic constructive deoxygenation of lignin-derived phenols: new C-C bond formation processes from imidazole-sulfonates and ether cleavage reactions

Funding: UK Engineering and Physical Sciences Research Council (EPSRC)As part of a programme aimed at exploiting lignin as a chemical feedstock for less oxygenated fine chemicals, several catalytic C-C bond forming reactions utilising guaiacol imidazole sulfonate are demonstrated. These include the cross-coupling of a Grignard, a non-toxic cyanide source, a benzoxazole, and nitromethane. A modified Meyers reaction is used to accomplish a second constructive deoxygenation on a benzoxazole functionalised anisole.Publisher PDFPeer reviewe

Just picking it up? Young children learning with technology at home

We describe a two-year empirical investigation of three- and four-year-old children's uses of technology at home, based on a survey of 346 families and 24 case studies. Using a sociocultural approach, we discuss the range of technologies children encounter in the home, the different forms their learning takes, the roles of adults and other children, and how family practices support this learning. Many parents believed that they do not teach children how to use technology. We discuss parents' beliefs that their children 'pick up' their competences with technology and identify trial and error, copying and demonstration as typical modes of learning. Parents tend to consider that their children are mainly self-taught and underestimate their own role in supporting learning and the extent to which learning with technology is culturally transmitted within the family

Why We Read Wikipedia

Wikipedia is one of the most popular sites on the Web, with millions of users relying on it to satisfy a broad range of information needs every day. Although it is crucial to understand what exactly these needs are in order to be able to meet them, little is currently known about why users visit Wikipedia. The goal of this paper is to fill this gap by combining a survey of Wikipedia readers with a log-based analysis of user activity. Based on an initial series of user surveys, we build a taxonomy of Wikipedia use cases along several dimensions, capturing users' motivations to visit Wikipedia, the depth of knowledge they are seeking, and their knowledge of the topic of interest prior to visiting Wikipedia. Then, we quantify the prevalence of these use cases via a large-scale user survey conducted on live Wikipedia with almost 30,000 responses. Our analyses highlight the variety of factors driving users to Wikipedia, such as current events, media coverage of a topic, personal curiosity, work or school assignments, or boredom. Finally, we match survey responses to the respondents' digital traces in Wikipedia's server logs, enabling the discovery of behavioral patterns associated with specific use cases. For instance, we observe long and fast-paced page sequences across topics for users who are bored or exploring randomly, whereas those using Wikipedia for work or school spend more time on individual articles focused on topics such as science. Our findings advance our understanding of reader motivations and behavior on Wikipedia and can have implications for developers aiming to improve Wikipedia's user experience, editors striving to cater to their readers' needs, third-party services (such as search engines) providing access to Wikipedia content, and researchers aiming to build tools such as recommendation engines.Comment: Published in WWW'17; v2 fixes caption of Table

The Santa Fe Light Cone Simulation Project: I. Confusion and the WHIM in Upcoming Sunyaev-Zel'dovich Effect Surveys

We present the first results from a new generation of simulated large sky coverage (~100 square degrees) Sunyaev-Zeldovich effect (SZE) cluster surveys using the cosmological adaptive mesh refinement N-body/hydro code Enzo. We have simulated a very large (512^3h^{-3}Mpc^3) volume with unprecedented dynamic range. We have generated simulated light cones to match the resolution and sensitivity of current and future SZE instruments. Unlike many previous studies of this type, our simulation includes unbound gas, where an appreciable fraction of the baryons in the universe reside. We have found that cluster line-of-sight overlap may be a significant issue in upcoming single-dish SZE surveys. Smaller beam surveys (~1 arcmin) have more than one massive cluster within a beam diameter 5-10% of the time, and a larger beam experiment like Planck has multiple clusters per beam 60% of the time. We explore the contribution of unresolved halos and unbound gas to the SZE signature at the maximum decrement. We find that there is a contribution from gas outside clusters of ~16% per object on average for upcoming surveys. This adds both bias and scatter to the deduced value of the integrated SZE, adding difficulty in accurately calibrating a cluster Y-M relationship. Finally, we find that in images where objects with M > 5x10^{13} M_{\odot} have had their SZE signatures removed, roughly a third of the total SZE flux still remains. This gas exists at least partially in the Warm Hot Intergalactic Medium (WHIM), and will possibly be detectable with the upcoming generation of SZE surveys.Comment: 14 pages, 13 figures, version accepted to ApJ. Major revisions mad

Cancer incidence in a population potentially exposed to radium-226 at Dalgety Bay, Scotland.

Cancer incidence in the Dalgety Bay area of Fife, Scotland, was examined following the detection of radium-226 particles by routine radiation monitoring. The study was confounded by rapid population growth, demographic change and the relatively high socioeconomic status of the Dalgety Bay population. Health Board Primary Care Division records were used to calculate population estimates and Carstairs deprivation score was used to adjust for socioeconomic characteristics. In the period 1975-90, 211 residents were registered as having cancer compared with 214.21 expected from Scottish national rates. Of specific cancers possibly associated with radiation, the incidence of stomach, liver, lung, bone, prostate, bladder and kidney cancer and lymphoma were lower than expected while colon, rectum, pancreas, skin, breast and thyroid cancer and multiple myeloma and leukaemia were higher. There were three cases of childhood leukaemia compared with 1.22 expected. The only statistically significant differences observed were for pancreas (11 cases, O/E 2.28), lung (25 cases, O/E 0.65) and non-melanoma skin (36 cases, O/E 1.50). Stomach cancer was of borderline statistical significance (four cases, O/E 0.40). Adjustments for socioeconomic factors accounted for the apparently low incidence of stomach and lung cancer and, to a lesser extent, skin cancer, which remained of borderline statistical significance. Results in relation to pancreas cancer were unchanged. The observations of raised incidence of pancreas and skin cancer arose in the context of a survey of 17 cancer sites, from which the finding of two or more statistically significant results is not unusual (P = 0.21), and the numbers of cases involved were small. The epidemiological evidence for an association between radiation exposure and pancreas cancer risk is weak. Stronger evidence exists for an association with skin cancer. In the present study the anatomical distribution of the 36 cases was similar to that found elsewhere in Scotland

A new technique for elucidating β\beta-decay schemes which involve daughter nuclei with very low energy excited states

A new technique of elucidating $\beta$-decay schemes of isotopes with large density of states at low excitation energies has been developed, in which a Broad Energy Germanium (BEGe) detector is used in conjunction with coaxial hyper-pure germanium detectors. The power of this technique has been demonstrated on the example of 183Hg decay. Mass-separated samples of 183Hg were produced by a deposition of the low-energy radioactive-ion beam delivered by the ISOLDE facility at CERN. The excellent energy resolution of the BEGe detector allowed $\gamma$ rays energies to be determined with a precision of a few tens of electronvolts, which was sufficient for the analysis of the Rydberg-Ritz combinations in the level scheme. The timestamped structure of the data was used for unambiguous separation of $\gamma$ rays arising from the decay of 183Hg from those due to the daughter decays

Less hindered ligands give improved catalysts for the nickel catalysed Grignard cross-coupling of aromatic ethers

The authors thanks the EPSRC for funding in the initial stages of this work from EP/J018139/1 and from the DTG.The challenging reaction of unactivated ortho-substituted aromatic ethers with Grignard reagents has been found to be most effectively catalysed using nickel complexes of less sterically hindered ligands. Air stable, cheap, commercially available [NiCl2(PnBu3)2] stands out as an improved catalyst for this type of transformation. The improved results with this catalyst even extend to some couplings of a more activated substrate when examined at higher temperatures and at catalyst loadings down to 0.1 mol%. Unusual induction periods in these latter reactions have been related to the by-product magnesium salts acting as co-catalysts.PostprintPeer reviewe

Increasing doses of fiber do not influence short-term satiety or food intake and are inconsistently linked to gut hormone levels

Background: People who eat more fiber often have a lower body weight than people who eat less fiber. The mechanism for this relationship has been explained, in part, by increased satiety, which may occur as a result of changes in appetite-suppressing gut hormone levels, and decreases in food intake at subsequent meals. Objective: We hypothesized that increasing doses of mixed fiber, consumed in muffins for breakfast, would proportionally influence satiety, gut hormone levels, and subsequent food intake. Design: This was a randomized, double-blind, crossover study. Healthy men (n=10) and women (n=10) with a BMI of 24±2 (mean±SEM) participated in this study. Fasting subjects consumed a muffin with 0, 4, 8, or 12 g of mixed fibers and approximately 500 kcal. Visual analog scales rated hunger and satiety for 3 h; blood was drawn to measure ghrelin, glucagon-like peptide-1 (GLP-1), and peptide YY3–36 (PYY3–36) at various intervals; and food intake was measured at an ad libitum lunch. Results: Responses to satiety-related questions did not differ among treatments. However, despite lack of differences in satiety, gut hormone levels differed among treatments. Ghrelin was higher after the 12 g fiber dose than after the 4 and 8 g fiber doses. GLP-1 was higher after the 0 g fiber dose than after the 12 and 4 g fiber doses, and PYY3–36 did not differ among fiber doses. Food intake was also indistinguishable among doses. Conclusion: Satiety, gut hormone response, and food intake did not change in a dose-dependent manner after subjects consumed 0, 4, 8, and 12 g of mixed fiber in muffins for breakfast