Endomorphism rings of finite global dimension

For a commutative local ring $R$, consider (noncommutative) $R$-algebras $\Lambda$ of the form $\Lambda = End_R(M)$ where $M$ is a reflexive $R$-module with nonzero free direct summand. Such algebras $\Lambda$ of finite global dimension can be viewed as potential substitutes for, or analogues of, a resolution of singularities of $Spec R$. For example, Van den Bergh has shown that a three-dimensional Gorenstein normal $C$-algebra with isolated terminal singularities has a crepant resolution of singularities if and only if it has such an algebra $\Lambda$ with finite global dimension and which is maximal Cohen--Macaulay over $R$ (a ``noncommutative crepant resolution of singularities''). We produce algebras $\Lambda=End_R(M)$ having finite global dimension in two contexts: when $R$ is a reduced one-dimensional complete local ring, or when $R$ is a Cohen--Macaulay local ring of finite Cohen--Macaulay type. If in the latter case $R$ is Gorenstein, then the construction gives a noncommutative crepant resolution of singularities in the sense of Van den Bergh.Comment: 13 pages, to appear in Canadian J. Mat

An exploration of own and cross-price elasticity of demand for residential heating in the Fairbanks North Star Borough

Thesis (M.S.) University of Alaska Fairbanks, 2019The purpose of this study is to utilize community level household energy consumption data to determine the short-run own- and cross-price elasticity of heating oil and wood using the proportionally calibrated almost idea demand system model. Elasticity values can identify how residents of the Fairbanks North Star Borough will potentially alter home heating practices in response to a change in home heating oil price. Results indicate that values for own-price elasticity for oil is -0.259, with a 95% confidence interval of [-0.272, -0.246]. Based on predicted values a 1% increase in the price of heating oil is estimated to result in a reduction of 0.259% in the quantity of residential heating oil consumed by the average household. Cross-price elasticity estimates of wood with respect to a change in the price of oil is 0.198 with a 95% confidence interval of [0.171, 0.234]. Based on predicted values, a 1% increase in the price of oil is predicted to increase wood consumption by 0.198%. In addition, this study utilized a Monte Carlo Simulation with estimated elasticity parameters to predict the change in household level energy consumption of wood and heating oil given an increase in heating oil prices. Approximately 71% of households are predicted to decrease overall energy consumption. 83.5% of households are predicted to decrease oil consumption, and 57.3% of houses are predicted to increase wood consumption. Through evaluating household's energy consumption decisions in the face of changing prices, these results can inform effective air quality policies

Decay and interference effects in visuospatial short-term memory

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FirstLight: Pluggable Optical Interconnect Technologies for Polymeric Electro-Optical Printed Circuit Boards in Data Centers

The protocol data rate governing data storage devices will increase to over 12 Gb/s by 2013 thereby imposing unmanageable cost and performance burdens on future digital data storage systems. The resulting performance bottleneck can be substantially reduced by conveying high-speed data optically instead of electronically. A novel active pluggable 82.5 Gb/s aggregate bit rate optical connector technology, the design and fabrication of a compact electro-optical printed circuit board to meet exacting specifications, and a method for low cost, high precision, passive optical assembly are presented. A demonstration platform was constructed to assess the viability of embedded electro-optical midplane technology in such systems including the first ever demonstration of a pluggable active optical waveguide printed circuit board connector. High-speed optical data transfer at 10.3125 Gb/s was demonstrated through a complex polymer waveguide interconnect layer embedded into a 262 mm × 240 mm × 4.3 mm electro-optical midplane. Bit error rates of less than 10-12 and optical losses as low as 6 dB were demonstrated through nine multimode polymer wave guides with an aggregate data bandwidth of 92.8125 Gb/s

Oncolytic herpes viruses, chemotherapeutics, and other cancer drugs

Oncolytic viruses are emerging as a potential new way of treating cancers. They are selectively replication-competent viruses that propagate only in actively dividing tumor cells but not in normal cells and, as a result, destroy the tumor cells by consequence of lytic infection. At least six different oncolytic herpes simplex viruses (oHSVs) have undergone clinical trials worldwide to date, and they have demonstrated an excellent safety profile and intimations of efficacy. The first pivotal Phase III trial with an oHSV, talimogene laherparepvec (T-Vec [OncoVex<sup>GM-CSF</sup>]), is almost complete, with extremely positive early results reported. Intuitively, therapeutically beneficial interactions between oHSV and chemotherapeutic and targeted therapeutic drugs would be limited as the virus requires actively dividing cells for maximum replication efficiency and most anticancer agents are cytotoxic or cytostatic. However, combinations of such agents display a range of responses, with antagonistic, additive, or, perhaps most surprisingly, synergistic enhancement of antitumor activity. When synergistic interactions in cancer cell killing are observed, chemotherapy dose reductions that achieve the same overall efficacy may be possible, resulting in a valuable reduction of adverse side effects. Therefore, the combination of an oHSV with “standard-of-care” drugs makes a logical and reasonable approach to improved therapy, and the addition of a targeted oncolytic therapy with “standard-of-care” drugs merits further investigation, both preclinically and in the clinic. Numerous publications report such studies of oncolytic HSV in combination with other drugs, and we review their findings here. Viral interactions with cellular hosts are complex and frequently involve intracellular signaling networks, thus creating diverse opportunities for synergistic or additive combinations with many anticancer drugs. We discuss potential mechanisms that may lead to synergistic interactions

Bioinformatics: A challenge for statisticians

Bioinformatics is a subject that requires the skills of biologists, computer scientists, mathematicians and staisticians. This paper introduces the reader to one small aspect of the subject: the study of microarrays. It describes some of the complexities of the enormous amounts of data that are available and shows how simple statistical techniques can be used to highlight deficiencies in that data

The offshoring of financial services : a reassessment

Operating in increasingly competitive market environment, financial services companies are engaged in international re-engineering of business processes mirroring developments in manufacturing over the past four decades. Drawing upon interviews conducted with senior managers and partners from two leading international banks, a multinational 'consumables' provider and a leading finance consultancy, as well as extensive published surveys, we examine the distinctive 'anatomy' of offshoring in financial services, and industry which also manifests a high degree of geographical concentration for 'higher order' functions. We conclude that the reality of process re-engineering in the sector has frequently failed to meet business objectives, and has run the risk of creating 'backlash' from employees in both home and host environments