Polarization observables in the longitudinal basis for pseudo-scalar meson photoproduction using a density matrix approach

The complete expression for the intensity in pseudo-scalar meson photoproduction with a polarized beam, target, and recoil baryon is derived using a density matrix approach that offers great economy of notation. A Cartesian basis with spins for all particles quantized along a single direction, the longitudinal beam direction, is used for consistency and clarity in interpretation. A single spin-quantization axis for all particles enables the amplitudes to be written in a manifestly covariant fashion with simple relations to those of the well-known CGLN formalism. Possible sign discrepancies between theoretical amplitude-level expressions and experimentally measurable intensity profiles are dealt with carefully. Our motivation is to provide a coherent framework for coupled-channel partial-wave analysis of several meson photoproduction reactions, incorporating recently published and forthcoming polarization data from Jefferson Lab.Comment: 11 pages, 2 figure

Gap Cycling for SWIFT

Purpose: SWIFT (SWeep Imaging with Fourier Transformation) is a non- Cartesian MRI method with unique features and capabilities. In SWIFT, radiofrequency (RF) excitation and reception are performed nearly simultaneously, by rapidly switching between transmit and receive during a frequency-swept RF pulse. Because both the transmitted pulse and data acquisition are simultaneously amplitude-modulated in SWIFT (in contrast to continuous RF excitation and uninterrupted data acquisition in more familiar MRI sequences), crosstalk between different frequency bands occurs in the data. This crosstalk leads to a "bulls-eye" artifact in SWIFT images. We present a method to cancel this inter-band crosstalk by cycling the pulse and receive gap positions relative to the un-gapped pulse shape. We call this strategy "gap cycling." Methods: We carry out theoretical analysis, simulation and experiments to characterize the signal chain, resulting artifacts, and their elimination for SWIFT. Results: Theoretical analysis reveals the mechanism for gap-cycling's effectiveness in canceling inter-band crosstalk. We show phantom and in-vivo results demonstrating bulls-eye artifact free images. Conclusion: Gap cycling is an effective method to remove bulls-eye artifact resulting from inter-band crosstalk in SWIFT data.Comment: Technical Note 2173 Words 5 figures version 130710 final draft, preprint submitted to MR

Total hemispherical emittance measured at high temperatures by the calorimetric method

A calorimetric vacuum emissometer (CVE) capable of measuring total hemispherical emittance of surfaces at elevated temperatures was designed, built, and tested. Several materials with a wide range of emittances were measured in the CVE between 773 to 923 K. These results were compared to values calculated from spectral emittance curves measured in a room temperature Hohlraum reflectometer and in an open-air elevated temperature emissometer. The results differed by as much as 0.2 for some materials but were in closer agreement for the more highly-emitting, diffuse-reflecting samples. The differences were attributed to temperature, atmospheric, and directional effects, and errors in the Hohlraum and emissometer measurements (plus or minus 5 percent). The probable error of the CVE measurements was typically less than 1 percent

Arc-textured metal surfaces for high thermal emittance space radiators

Carbon arc electrical discharges struck across the surfaces of metals such as Nb-1 percent Zr, alter the morphology to produce a high thermal emittance surface. Metal from the surface and carbon from the arc electrode vaporize during arcing, and then condense on the metal surface to produce a microscopically rough surface having a high thermal emittance. Quantitative spectral reflectance measurements from 0.33 to 15 microns were made on metal surfaces which were carbon arc treated in an inert gas environment. The resulting spectral reflectance data were then used to calculate thermal emittance as a function of temperature for various methods of arc treatment. The results of arc treatment on various metals are presented for both ac and dc arcs. Surface characterization data, including thermal emittance as a function of temperature, scanning electron microscopy, and atomic oxygen durability, are also presented. The ac arc texturing was found to increase the thermal emittance at 800 K from 0.05 to 0.70

Evolution of Preprofessional Pharmacy Curricula

Objectives. To examine changes in preprofessional pharmacy curricular requirements and trends, and determine rationales for and implications of modifications. Methods. Prerequisite curricular requirements compiled between 2006 and 2011 from all doctor of pharmacy (PharmD) programs approved by the Accreditation Council of Pharmacy Education were reviewed to ascertain trends over the past 5 years. An online survey was conducted of 20 programs that required either 3 years of prerequisite courses or a bachelor’s degree, and a random sample of 20 programs that required 2 years of prerequisites. Standardized telephone interviews were then conducted with representatives of 9 programs. Results. In 2006, 4 programs required 3 years of prerequisite courses and none required a bachelor’s degree; by 2011, these increased to 18 programs and 7 programs, respectively. Of 40 programs surveyed, responses were received from 28 (70%), 9 (32%) of which reported having increased the number of prerequisite courses since 2006. Reasons given for changes included desire to raise the level of academic achievement of students entering the PharmD program, desire to increase incoming student maturity, and desire to add clinical sciences and experiential coursework to the pharmacy curriculum. Some colleges and schools experienced a temporary decrease in applicants. Conclusions. The preprofessional curriculum continues to evolve, with many programs increasing the number of course prerequisites. The implications of increasing prerequisites were variable and included a perceived increase in maturity and quality of applicants and, for some schools, a temporary decrease in the number of applicants

Rural Water Districts Costs and Funding

The 1977 Census of Public Water Supplies in Missouri, published by the Missouri Department of Natural Resources, lists 179 public water supply districts serving rural areas and 180 communities in the state. Many Missouri rural areas experienced considerable population growth during the 1970s. As rural population increases, especially in the Ozarks, there will likely occur an increasing need for safe drinking water. In 1977, 34 counties had no rural public water supply districts; 18 of those were in the Ozarks.Reviewed October 1993

Response and Resistance to Paradox-Breaking BRAF Inhibitor in Melanomas

FDA-approved BRAF inhibitors produce high response rates and improve overall survival in patients with BRAF V600E/K-mutant melanoma, but are linked to pathologies associated with paradoxical ERK1/2 activation in wild-type BRAF cells. To overcome this limitation, a next-generation paradox-breaking RAF inhibitor (PLX8394) has been designed. Here, we show that by using a quantitative reporter assay, PLX8394 rapidly suppressed ERK1/2 reporter activity and growth of mutant BRAF melanoma xenografts. Ex vivo treatment of xenografts and use of a patient-derived explant system (PDeX) revealed that PLX8394 suppressed ERK1/2 signaling and elicited apoptosis more effectively than the FDA-approved BRAF inhibitor, vemurafenib. Furthermore, PLX8394 was efficacious against vemurafenibresistant BRAF splice variant-expressing tumors and reduced splice variant homodimerization. Importantly, PLX8394 did not induce paradoxical activation of ERK1/2 in wild-type BRAF cell lines or PDeX. Continued in vivo dosing of xenografts with PLX8394 led to the development of acquired resistance via ERK1/2 reactivation through heterogeneous mechanisms; however, resistant cells were found to have differential sensitivity to ERK1/2 inhibitor. These findings highlight the efficacy of a paradox-breaking selective BRAF inhibitor and the use of PDeX system to test the efficacy of therapeutic agents. © 2017 American Association for Cancer Research