A survey of the material and intellectual consequences of trading in undocumented ancient coins : a case study on the North American trade

Ancient coins are among the most widely collected and demanded objects among American collectors of antiquities. A vocal lobby of ancient coin dealers/collectors has arisen to protect the importation of undocumented material into the United States and also seeks to make a distinction between antiquities trafficking and that in ancient coins. Coins are an equally important historical source and are no less important 'antiquities' than a Greek painted vase. I examine the scale of the trade in ancient coins in North America and address some points made by proponents of a continued unfettered ancient coin trade

Electroweak Vacuum Geometry

We analyse symmetry breaking in the Weinberg-Salam model paying particular attention to the underlying geometry of the theory. In this context we find two natural metrics upon the vacuum manifold: an isotropic metric associated with the scalar sector, and a squashed metric associated with the gauge sector. Physically, the interplay between these metrics gives rise to many of the non-perturbative features of Weinberg-Salam theory.Comment: 20 pages. Late

Assessing student perceptions of the Pharm.D. degree at a private tertiary medical university in India

Background: Pharmacy education in India has expanded to include the Doctorate of Pharmacy degree (Pharm.D.). With clinical practice in early development, job opportunities in India are limited. Graduates often consider pharmacy opportunities abroad. Aims: This study compares Indian students’ career aspirations related to the Pharm.D. degree before and after beginning their programmes. Methods: A 5-point Likert scale paper survey with open ended questions was distributed to all Pharm.D. students (Year 1- 6) at a medical university in India. Results: With a response rate of 83% (144/173), over half of the students’ primary goal was to pursue careers abroad post-graduation (54.2% before, 51.4% after). Data from the last three graduating classes indicated that 28.3% travelled abroad for future studies while 62.3% secured positions in India. Conclusions: Opportunities abroad remain challenging for Indian trained Pharm.D.s’; graduates may consider the expanding clinical opportunities in India

Improvements to context based self-supervised learning

We develop a set of methods to improve on the results of self-supervised learning using context. We start with a baseline of patch based arrangement context learning and go from there. Our methods address some overt problems such as chromatic aberration as well as other potential problems such as spatial skew and mid-level feature neglect. We prevent problems with testing generalization on common self-supervised benchmark tests by using different datasets during our development. The results of our methods combined yield top scores on all standard self-supervised benchmarks, including classification and detection on PASCAL VOC 2007, segmentation on PASCAL VOC 2012, and "linear tests" on the ImageNet and CSAIL Places datasets. We obtain an improvement over our baseline method of between 4.0 to 7.1 percentage points on transfer learning classification tests. We also show results on different standard network architectures to demonstrate generalization as well as portability. All data, models and programs are available at: https://gdo-datasci.llnl.gov/selfsupervised/.Comment: Accepted paper at CVPR 201

The Effect of Zonally Asymmetric Ozone Heating on the Northern Hemisphere Winter Polar Stratosphere

[1] Previous modeling studies have found significant differences in winter extratropical stratospheric temperatures depending on the presence or absence of zonally asymmetric ozone heating (ZAOH), yet the physical mechanism causing these differences has not been fully explained. The present study describes the effect of ZAOH on the dynamics of the Northern Hemisphere extratropical stratosphere using an ensemble of free-running atmospheric general circulation model simulations over the 1 December - 31 March period. We find that the simulations including ZAOH produce a significantly warmer and weaker stratospheric polar vortex in mid-February due to more frequent major stratospheric sudden warmings compared to the simulations using only zonal mean ozone heating. This is due to regions of enhanced Eliassen-Palm flux convergence found in the region between 40°N–70°N latitude and 10–0.05 hPa. These results are consistent with changes in the propagation of planetary waves in the presence of ZAOH predicted by an ozone-modified refractive index