Astrophysical Constraints on Modifying Gravity at Large Distances

Recently, several interesting proposals were made modifying the law of gravity on large scales, within a sensible relativistic formulation. This allows a precise formulation of the idea that such a modification might account for galaxy rotation curves, instead of the usual interpretation of these curves as evidence for dark matter. We here summarize several observational constraints which any such modification must satisfy, and which we believe make more challenging any interpretation of galaxy rotation curves in terms of new gravitational physics.Comment: References added, submitted to Classical & Quantum Gravit

Library Design in Combinatorial Chemistry by Monte Carlo Methods

Strategies for searching the space of variables in combinatorial chemistry experiments are presented, and a random energy model of combinatorial chemistry experiments is introduced. The search strategies, derived by analogy with the computer modeling technique of Monte Carlo, effectively search the variable space even in combinatorial chemistry experiments of modest size. Efficient implementations of the library design and redesign strategies are feasible with current experimental capabilities.Comment: 5 pages, 3 figure

CT colonography’s role in the COVID-19 pandemic: a safe(r), socially distanced total colon examination

© 2020, Springer Science+Business Media, LLC, part of Springer Nature. Purpose: To describe the favorable procedural profile of CT colonography (CTC) during the COVID-19 pandemic. Conclusion: Postponement of cancer screening due to COVID-19 has resulted in a backlog of individuals needing to undergo structural examination of the colon. The experience during the initial COVID-19 surge with urgent evaluation of the colon for transplant patients prior to transplant suggests that CTC can be done in a lower risk manner as compared to other structural examinations. The procedural profile of CTC is advantageous during this pandemic as maintaining social distancing and preserving healthcare supplies including PPE are of paramount importance. CTC is an important option to utilize in the screening armamentarium to allow effective screening of average risk asymptomatic individuals in the COVID-19 era

Development and Evaluation of a Trapping System for Anoplophora glabripennis (Coleoptera: Cerambycidae) in the United States

Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae), commonly known as the Asian longhorned beetle, is an invasive wood-boring pest that infests a number of hardwood species and causes considerable economic losses in North America, several countries in Europe, and in its native range in Asia. The success of eradication efforts may depend on early detection of introduced populations; however, detection has been limited to identification of tree damage (oviposition pits and exit holes), and the serendipitous collection of adults, often by members of the public. Here we describe the development, deployment, and evaluation of semiochemical-baited traps in the greater Worcester area in Massachusetts. Over 4 yr of trap evaluation (2009-2012), 1013 intercept panel traps were deployed, 876 of which were baited with three different families of lures. The families included lures exhibiting different rates of release of the male-produced A. glabripennis pheromone, lures with various combinations of plant volatiles, and lures with both the pheromone and plant volatiles combined. Overall, 45 individual beetles were captured in 40 different traps. Beetles were found only in traps with lures. In several cases, trap catches led to the more rapid discovery and management of previously unknown areas of infestation in the Worcester county regulated area. Analysis of the spatial distribution of traps and the known infested trees within the regulated area provides an estimate of the relationship between trap catch and beetle pressure exerted on the traps. Studies continue to optimize lure composition and trap placemen

The MINERν\nuA Data Acquisition System and Infrastructure

MINER$\nu$A (Main INjector ExpeRiment $\nu$-A) is a new few-GeV neutrino cross section experiment that began taking data in the FNAL NuMI (Fermi National Accelerator Laboratory Neutrinos at the Main Injector) beam-line in March of 2010. MINER$\nu$A employs a fine-grained scintillator detector capable of complete kinematic characterization of neutrino interactions. This paper describes the MINER$\nu$A data acquisition system (DAQ) including the read-out electronics, software, and computing architecture.Comment: 34 pages, 16 figure

A High Statistics Search for Electron-Neutrino --> Tau-Neutrino Oscillations

We present new limits on nu_e to nu_tau and nu_e to nu_sterile oscillations by searching for electron neutrino dissappearance in the high-energy wide-band CCFR neutrino beam. Sensitivity to nu_tau appearance comes from tau decay modes in which a large fraction of the energy deposited is electromagnetic. The beam is composed primarily of muon neutrinos but this analysis uses the 2.3% electron neutrino component of the beam. Electron neutrino energies range from 30 to 600 GeV and flight lengths vary from 0.9 to 1.4 km. This limit improves the sensitivity of existing limits and obtains a lowest 90% confidence upper limit in sin**2(2*alpha) of 9.9 x 10**(-2) at delta-m**2 of 125 eV**2.Comment: submitted to Phys. Rev. D. Rapid Com

Multi-Epoch Multiwavelength Spectra and Models for Blazar 3C~279

Of the blazars detected by EGRET in GeV gamma rays, 3C 279 is not only the best-observed by EGRET, but also one of the best-monitored at lower frequencies. We have assembled eleven spectra, from GHz radio through GeV gamma rays, from the time intervals of EGRET observations. Although some of the data have appeared in previous publications, most are new, including data taken during the high states in early 1999 and early 2000. All of the spectra show substantial gamma-ray contribution to the total luminosity of the object; in a high state, the gamma-ray luminosity dominates over that at all other frequencies by a factor of more than 10. There is no clear pattern of time correlation; different bands do not always rise and fall together, even in the optical, X-ray, and gamma-ray bands. The spectra are modeled using a leptonic jet, with combined synchrotron self-Compton + external Compton gamma-ray production. Spectral variability of 3C 279 is consistent with variations of the bulk Lorentz factor of the jet, accompanied by changes in the spectral shape of the electron distribution. Our modeling results are consistent with the UV spectrum of 3C 279 being dominated by accretion disk radiation during times of low gamma-ray intensity.Comment: 39 pages including 13 figures; data tables not included (see ApJ web version or contact author