Some Abnormal Reactions of Organomagnesium Halides

Nitro and nitroso groups react with methylmagnesium halides (and other RMgX compounds) to give methane and some ethane. The gases so evolved make it necessary to correct for the ordinary determination of active hydrogen by means of the Zerewitinoff method. Accordingly, the new hydroxy structure proposed for o-nitrobenzaladehyde finds no support on the basis of gas evolved when treated with alkylmagnesium halides

Chandra detection of the intracluster medium around 3C294 at z=1.786

We present a Chandra observation of the powerful radio galaxy 3C294 showing clear evidence for a surrounding intracluster medium. At a redshift of 1.786 this is the most distant cluster of galaxies yet detected in X-rays. The radio core is detected as a point source, which has a spectrum consistent with a heavily-absorbed power law implying an intrinsic 2-10 keV luminosity of ~10^45 erg/s. A small excess of emission is associated with the southern radio hotspots. The soft, diffuse emission from the intracluster medium is centred on the radio source. It has an hour-glass shape in the N-S direction, extending to radii of at least 100 kpc, well beyond the radio source. The X-ray spectrum of this extended component is fit by a thermal model with temperature ~5 keV, or by gas cooling from above 7 keV at rates of ~400-700 Msolar/yr. The rest-frame 0.3-10 keV luminosity of the cluster is ~4.5x10^44 erg/s. The existence of such a cluster is consistent with a low density universe.Comment: 5 pages, 6 figures, accepted by MNRA

The Extended Star Formation History of the Andromeda Spheroid at 35 Kpc on the Minor Axis

Using the HST ACS, we have obtained deep optical images reaching well below the oldest main sequence turnoff in fields on the southeast minor-axis of the Andromeda Galaxy, 35 kpc from the nucleus. These data probe the star formation history in the extended halo of Andromeda -- that region beyond 30 kpc that appears both chemically and morphologically distinct from the metal-rich, highly-disturbed inner spheroid. The present data, together with our previous data for fields at 11 and 21 kpc, do not show a simple trend toward older ages and lower metallicities, as one might expect for populations further removed from the obvious disturbances of the inner spheroid. Specifically, the mean ages and [Fe/H] values at 11 kpc, 21 kpc, and 35 kpc are 9.7 Gyr and -0.65, 11.0 Gyr and -0.87, and 10.5 Gyr and -0.98, respectively. In the best-fit model of the 35 kpc population, one third of the stars are younger than 10 Gyr, while only ~10% of the stars are truly ancient and metal-poor. The extended halo thus exhibits clear evidence of its hierarchical assembly, and the contribution from any classical halo formed via early monolithic collapse must be small.Comment: Accepted for publication in The Astrophysical Journal Letters. 4 pages, latex, 2 color figure

Chandra study of an overdensity of X-ray sources around two distant (z~0.5) clusters

We present results from a Chandra X-ray Observatory study of the field X-ray source populations in 4 different observations: two high-redshift (z~0.5) clusters of galaxies 3C295 and RXJ003033.2+261819; and two non-cluster fields with similar exposure time. Surprisingly, the 0.5-2 keV source surface densities (~900-1200 sources deg**-2 at a flux limit of 1.5x10**-15 erg cm**-2s**-1) measured in an ~8'x8' area surrounding each cluster exceed by a factor of ~2 the value expected on the basis of the ROSAT and Chandra logN-logS, with a significance of ~2 sigma each, or ~3.5 sigma when the 2 fields are combined (i.e. a probability to be a statistical fluctuation of <1% and <0.04%, respectively). The same analysis performed on the non-cluster fields and on the outer chips of the cluster fields does NOT show evidence of such an excess. In both cluster fields, the summed 0.5-10 keV spectrum of the detected objects is well fitted by a power-law with Gamma~1.7 similar to AGNs and shows no sign of intrinsic absorption. The few (~10 out of 35) optical identifications available to date confirm that most of them are, as expected, AGNs but the number of redshifts available is too small to allow conclusions on their nature. We discuss possible interpretations of the overdensity in terms of: a statistical variation of Cosmic Background sources; a concentration of AGNs and/or powerful starburst galaxies associated with the clusters; and g ravitational lensing of background QSO's by the galaxy clusters. All explanations are however difficult to reconcile with the large number of excess sources detected. Deeper X-ray observations and more redshifts measurements are clearly required to settle the issue.Comment: 22 LateX pages (including Tables and Figures), uses psfig.sty and emulateapj.sty. Accepted for publication in Astrophysical Journa

Metabolomics and pharmacogenetics based 5-fluorouracil monitoring in colorectal cancer patients

Objective: To provide quick and accurate clinical diagnostic tools those are currently not available leading to improper management of colorectal cancer (CRC) patients. Methods: The metabolomic profiles of 10 CRC patients treated with 5-fluorouracil and 24 healthy volunteers were analysed. The subjects were genotyped for UGT1A1*28, DPYD 1896 T>C and DPYD*5. Results: Our results show alterations in the metabolism of bile acid, glycolysis and fatty acid in patients. The distinctive metabolite profiles established using PLSDA identify several biomarkers for diagnostic use in clinical settings. The predictive PLSDA model revealed 100% accuracy of metabolites differentiating CRC patients and healthy volunteers. In addition, the metabolic profiles associated with different genotypes of DPYD and UGT1A1 explains the impact of genetic variation on differential drug responses. Conclusion: Pharmacogenetics and metabolomics profiles are potential platforms for more comprehensive monitoring of patient's disease progress and drug response. Further study is however needed to validate the use of biomarkers identified

Improving Student Engagement in Veterinary Business Studies

In a densely packed veterinary curriculum, students may find it particularly challenging to engage in the less overtly clinical subjects, yet pressure from industry and an increasingly competitive employment market necessitate improved veterinary student education in business and management skills. We describe a curriculum intervention (formative reflective assignment) that optimizes workplace learning opportunities and aims to provide better student scaffolding for their in-context business learning. Students were asked to analyze a business practice they experienced during a period of extra-mural studies (external work placement). Following return to the college, they were then instructed to discuss their findings in their study group, and produce a group reflection on their learning. To better understand student engagement in this area, we analyzed individual and group components of the assignment. Thematic analysis revealed evidence of various depths of student engagement, and provided indications of the behaviors they used when engaging at different levels. Interactive and social practices (discussing business strategies with veterinary employees and student peers) appeared to facilitate student engagement, assist the perception of relevance of these skills, and encourage integration with other curriculum elements such as communication skills and clinical problem solving

TNOs are Cool: A survey of the trans-Neptunian region V. Physical characterization of 18 Plutinos using Herschel PACS observations

We present Herschel PACS photometry of 18 Plutinos and determine sizes and albedos for these objects using thermal modeling. We analyze our results for correlations, draw conclusions on the Plutino size distribution, and compare to earlier results. Flux densities are derived from PACS mini scan-maps using specialized data reduction and photometry methods. In order to improve the quality of our results, we combine our PACS data with existing Spitzer MIPS data where possible, and refine existing absolute magnitudes for the targets. The physical characterization of our sample is done using a thermal model. Uncertainties of the physical parameters are derived using customized Monte Carlo methods. The correlation analysis is performed using a bootstrap Spearman rank analysis. We find the sizes of our Plutinos to range from 150 to 730 km and geometric albedos to vary between 0.04 and 0.28. The average albedo of the sample is 0.08 \pm 0.03, which is comparable to the mean albedo of Centaurs, Jupiter Family comets and other Trans-Neptunian Objects. We were able to calibrate the Plutino size scale for the first time and find the cumulative Plutino size distribution to be best fit using a cumulative power law with q = 2 at sizes ranging from 120-400 km and q = 3 at larger sizes. We revise the bulk density of 1999 TC36 and find a density of 0.64 (+0.15/-0.11) g cm-3. On the basis of a modified Spearman rank analysis technique our Plutino sample appears to be biased with respect to object size but unbiased with respect to albedo. Furthermore, we find biases based on geometrical aspects and color in our sample. There is qualitative evidence that icy Plutinos have higher albedos than the average of the sample.Comment: 18 pages, 8 figures, 8 tables, accepted for publication in A&