Tuning Electronic Structure To Control Manganese Nitride Activation

Investigation of a series of oxidized nitridomanganese(V) salen complexes with different para ring substituents (R = CF3, tBu, and NMe2) demonstrates that nitride activation is dictated by remote ligand electronics. For R = CF3 and tBu, oxidation affords a Mn(VI) species and nitride activation, with dinitrogen homocoupling accelerated by the more electron-withdrawing CF3 substituent. Employing an electron-donating substituent (R = NMe2) results in a localized ligand radical species that is resistant to N coupling of the nitrides and is stable in solution at both 195 and 298 K

75th Anniversary American Abstract Artists Print Portfolio (Exhibition Catalogue)

Catalogue documenting the 75th Anniversary digital print portfolio of the American Abstract Artists. Participating artists were: Alice Adams, Siri Berg, Emily Berger, Susan Bonfils, Power Boothe, Henry Brown, Kenneth Bushnell, James O. Clark, Gabriele Evertz, John Goodyear, Gail Gregg, James Gross, Lynne Harlow, Mara Held, Daniel G. Hill, Gilbert Hsaio, Phillis Ideal, Julian Jackson, James Juszczyk, Cecily Kahn, Steve Karlik, Marthe Keller, Irene Lawrence, Jane Logemann, Vincent Longo, David Mackenzie, Stephen Maine, Katinka Mann, Nancy Manter, Creighton Michael, Manfred Mohr, Hiroshi Murata, John Phillips, Lucio Pozzi, Leo Rabkin, Ce Roser, David Row, Edward Shalala, Robert Storr, Robert Swain, Clover Vail, Vera Vasek, Don Voisine,Stephen Westfall, Jeanne Wilkinson, Mark Williams, Thornton Willis, and Nola Zirin

Selling volunteering or developing volunteers? Approaches to promoting sports volunteering

This article considers the balance between promoting volunteering in sport by emphasising the personal rewards to prospective volunteers themselves – the dominant management approach – and promoting it by the long-term development of the values of volunteering. We review the motivations and rewards of sports volunteers and how these can be used to promote volunteering as being a transaction between the volunteer and the organisation. This is contrasted with a lifecourse approach to understanding volunteering, and evidence that an understanding of the value of volunteering can be inculcated that underpins continued volunteering. The two approaches regard potential volunteers respectively as ‘consumers’ and as ‘citizens’. We suggest that a shift to treating volunteers as consumers can lead to volunteering being regarded as transactional. The discussion has implications for volunteering in general – in particular, how it can be promoted in a society where narratives of ‘the consumer’ increasingly dominate over those of ‘the citizen’

Non-specific abdominal pain and air pollution: a novel association.

We studied whether short-term exposure to air pollution was associated with non-specific abdominal pain in epidemiologic and animal studies. Patients visiting the emergency department with non-specific abdominal pain were identified in Edmonton (1992 to 2002, n = 95,173) and Montreal (1997 to 2002, n = 25,852). We calculated the daily concentrations for ozone (O(3)), nitrogen dioxide (NO(2)), sulfur dioxide (SO(2)), carbon monoxide (CO), and particles <10 (PM(10)) or <2.5 (PM(2.5)) µm. A case crossover study design was used to estimate the odds ratio (OR) and 95% confidence interval (CI) associated with an increase in the interquartile range of the air pollutants. We investigated differential effects by age and sex. Mice were gavaged with urban particle extracts. In animal models, colonic motility was tested, and visceral abdominal pain was measured using a writhing test, and behavioral response to oil of mustard and neostigmine. Motility and pain was measured acutely (1.5 hours after gavage) and chronically (7-days and 21-days after gavage). Emergency department visits for non-specific abdominal pain were primarily by women between the ages of 15-24 years. Individuals aged 15 to 24 years were at increased risk of non-specific abdominal pain in Edmonton (same day CO: OR = 1.04, 95% CI = 1.02-1.06; and NO(2): OR = 1.06, 95% CI = 1.03-1.09). The risk of air pollution among 15-24 year olds in Montreal was significantly positive (same day CO: OR = 1.11, 95% CI = 1.05-1.17; NO(2): OR = 1.09, 95% CI = 1.01-1.16; SO(2): OR = 1.17, 95% CI = 1.10-1.25; PM(2.5): OR = 1.09, 95% CI = 1.04-1.15). Abdominal pain was increased by an acute gavage of pollution extract but not to chronic exposure to pollutants. Colonic transit was delayed following chronic but not acute exposure with the pollutants. Epidemiological and animal data suggest that short-term exposure to air pollution may trigger non-specific abdominal pain in young individuals

Cyclotron production and cyclometallation chemistry of 192Ir

Introduction To explore new questions and techniques in nuclear medicine, new isotopes with novel chemical and nuclear properties must be developed. We are interested in the small cyclotron production of new radiometals for the development of new radiopharmaceuticals (RX). In an example of RX multifunctionality, Luminescence Cell Imaging (LCI) has been combined with radio-isotopes to allow compounds that can be imaged with both optical microscopy and nuclear techniques [1]. Within this field, iridium cy-clometalates have good potential with excellent photophysical properties [2]. As well, low specific activity iridium-192 has found use in brachy-therapy as a high-intensity beta emitter [3]. Despite this, iridium radioisotopes have yet to be applied to cyclometalation chemistry, or a radiochemical isolation method developed for carrier free production on a medical cyclotron. Our goal is to demonstrate the feasibility of the production and isolation of radio-iridium, and its application to cyclometalate chemistry as a potentially interesting tool for nuclear medicine research. Materials and Methods Following literature precedent [4], natural osmium was electroplated onto a silver disc from basic media containing osmium tetroxide and sulphamic acid. The thin deposits obtained (15–20 mg cm−2) were weighed and characterized with scanning electron microscopy. Targets were irradiated using the TRIUMF TR13 cyclotron, delivering 12.5 MeV protons to the target disc. Initial bombardments were per-formed at 5 μA; gamma spectra of the targets were collected 24 hours after end of bombardment. The irradiated material was oxidized, dissolved from the target backing, and separated via anion exchange. In parallel to the isotope production work, non-radioactive iridium was used to define a chemical procedure suitable for the synthesis of model iridium cyclometalate compounds given low concentrations of radioiridium. These experiments will be performed with radioactive iridium in the next step of the research project. Results and Conclusion Proton bombardment of natural osmium yielded a range of iridium isotopes, with characteristic spectral lines corresponding to 186-190Ir, and 192Ir; no other characteristic radiation was observed. The EOB activity of each isotope was then used in thin target calculations to approximate their (p,n) cross section. Preliminary cross section measurements of the 192Os(p,n)192Ir reaction (53 ± 13 mb @ 12.5 MeV) confirm published data (52.3 ± 5.7 mb @ 12.2 MeV) [6], and provide as-yet unpublished data on the lower mass number isotopes. The progress of radioactive iridium through the radiochemical separation was tracked with a dose calibrator; the osmium complex formed was brightly coloured and could be seen retained on the column. The overall efficiency of the process is estimated at 80 %. Radioactive cyclometallation chemistry is currently under-way. The production and isolation of a range of iridium isotopes in a chemically useful form was demonstrated, and is ready to be applied to a cyclometalate model compound. Future work will investigate the production of 192Ir from enriched 192Os

Shubnikov de Haas effect in the metallic state of Na0.3_{0.3}CoO2_2

Shubnikov de Haas oscillations for two well defined frequencies, corresponding respectively to areas of 0.8 and 1.36% of the first Brillouin zone (FBZ), were observed in single crystals of Na$_{0.3}$CoO$_2$. The existence of Na superstructures in Na$_{0.3}$CoO$_2$, coupled with this observation, suggests the possibility that the periods are due to the reconstruction of the large Fermi surface around the $\Gamma$ point. An alternative interpretation in terms of the long sought-after $\epsilon_g^\prime$ pockets is also considered but found to be incompatible with existing specific heat data.Comment: 5 pages 4 figure