Excavations in the South Transept of St. Mary's Abbey, York

Landscaping developments on the site of St Mary’s Abbey, situated within the Museum Gardens, encountered in situ archaeological remains in the south transept. A substantial area of a wall foundation was uncovered and a chapel apse discovered. The published record of the architectural features within this area is piecemeal and does not account for the unusual position of this feature within the transept

Hedgehog Bases for A_n Cluster Polylogarithms and An Application to Six-Point Amplitudes

Multi-loop scattering amplitudes in N=4 Yang-Mills theory possess cluster algebra structure. In order to develop a computational framework which exploits this connection, we show how to construct bases of Goncharov polylogarithm functions, at any weight, whose symbol alphabet consists of cluster coordinates on the $A_n$ cluster algebra. Using such a basis we present a new expression for the 2-loop 6-particle NMHV amplitude which makes some of its cluster structure manifest.Comment: 32 pages; v2: minor corrections and clarification

The Effects of Vespa Amino Acid Mixture on Cycling Performance During a 20k Time Trial

The effects of Vespa Amino Acid Mixture on cycling performance during a 20k time trial. Sebastian Haynes and Adam Parker, Ph.D. Department of Kinesiology Angelo State University, San Angelo, TX Category: Undergraduate Mentor: Adam Parker ([email protected]) Abstract Vespa amino acid mixture (VAAM) is a nutritional supplement derived from the Asian Mandarin Wasp (Vespa Mandarina). VAAM has been shown to enhance lipolysis in rat adipocytes and is purported to improve endurance performance via enhanced fat metabolism. The purpose of this study was to examine the effects VAAM on cycling performance during a 20k time trial. 10 trained, male cyclists participated in this single-blind, randomized, cross-over study. Participants were asked to perform two 20 kilometer time trials on a CompuTrainer (RacerMate, Inc. Seattle, WA) on two separate occasions separated by at least 48 hours. Participants consumed either an 80 mL serving of VAAM (70 mg of wasp extract, 8 g of carbohydrate, 31 kcal) or 80 mL of sports drink placebo (PL) (4.7 g carbohydrate, 18 kcal) in a randomized, cross-over fashion. Dependent variables included time to complete the 20k distance (TT), peak power, average power, max heart rate (MHR), and average heart rate. Data was analyzed using paired t-tests. The participants’ MHR was significantly lower (p = .021) after consuming VAAM (174.4 + 13.6 bpm) vs. PL (178.8 + 14 bpm). There was no significant difference (p = .349) in TT performance; VAAM (38.3 + 3.5 min) vs. PL (37.96 + 2.87 min). There were no other significant differences between supplement groups. Although we found no significant effects on cycling performance, future research should examine the effects of VAAM during more prolonged and/or exhaustive endurance exercise

Terrace grading of SiGe for high-quality virtual substrates

Silicon germanium (SiGe) virtual substrates of final germanium composition x = 0.50 have been fabricated using solid-source molecular beam epitaxy with a thickness of 2 µm. A layer structure that helps limit the size of dislocation pileups associated with the modified Frank–Read dislocation multiplication mechanism has been studied. It is shown that this structure can produce lower threading dislocation densities than conventional linearly graded virtual substrates. Cross-sectional transmission electron microscopy shows the superior quality of the dislocation network in the graded regions with a lower rms roughness shown by atomic force microscopy. X-ray diffractometry shows these layers to be highly relaxed. This method of Ge grading suggests that high-quality virtual substrates can be grown considerably thinner than with conventional grading methods