Studies in hard pion photoproduction

The production of high transverse momenta mesons via polarized photoproduction can be a means of determining the parton structure of the target. at the regions of highest transverse pion momenta, kT, it can be shown that short distance, direct, pion production dominates and is sensitive to the polarized quark distributions. as the produced pions transverse momenta decreases the importance of pions produced through fragmentation following photon-gluon fusion increases. This process give us sensitivity to the form of the polarized gluon distribution. Both processes are calculable with perturbative Quantum Chromodynamics (pQCD) due to the high kT of the pion produced. Numerical results are presented for conditions in current g1 experiments. In order to determine the region in which the kT is sufficient for the use of pQCD, and to separate the desired processes from unwanted background functions, a calculation of the soft processes is undertaken. Vector meson dominance is the largest contributor to the soft processes and can be large enough to make a measurement of the asymmetries susceptible to the polarized gluon distributions difficult at the kinematics of existing g1 experiments. Once all of the contributions are known I can use the above processes to extend Bloom-Giliman scaling and duality to semi-exclusive processes. It will be shown that the scaling behavior should exist for the direct process and that regions where this process is dominant do exist. I will also show that the constancy with changing momentum transfer of the resonance peak/scaling curve ratio, familiar for many resonances in deep inelastic scattering, is also expected in the semi-exclusive case

Tobacco use among blue collar workers in Nigeria: A survey of Construction Artisans in Ekiti state

The prevalence of tobacco use among blue-collar workers such as construction artisans is disproportionately higher than in the general population, yet very limited studies have been conducted about such workers in Nigeria, the most populous country in sub-Sahara African (SSA). Therefore, this study aims to assess the prevalence and the associated risk factors of tobacco use among construction artisans in Ekiti State, Nigeria. This cross-sectional study employed a multi-stage stratified sampling technique to select participants (carpenters and bricklayers) artisans, journeymen, and their apprentices who were working in Ekiti State. Chi-square and logistic regression were conducted to delineate factors that are associated with tobacco use in this population. The results show that the prevalence of ever-smoke amongst respondents was 19.3%, and multivariate analysis showed that artisans who were within the age range 31-40 years were four times more likely to use tobacco (aOR=3.410; CI=1.476-7.878), compared with those that are less than 20 years. Additionally, being in school (aOR 2.007; CI= 1.026-3.927) and divorced/separated (aOR4.240; CI=1.307-13.759) were associated with tobacco use, compared with the respective populations. The increased prevalence of tobacco use among construction artisans is noteworthy, and few self-reported cases of addiction amongst users demand action from communities and government at all levels. There is need to improved access of artisans to accurate information and tailored messages on dangers of tobacco use. Moreover, smoking and worksite regulations and policies would be needed to curtail the smoking tendencies of these worker

Scaling and Duality in Semi-exclusive Processes

We discuss extending scaling and duality studies to semi-exclusive processes. We show that semi-exclusive hard pion photoproduction should exhibit scaling behavior in kinematic regions where the photon and pion both interact directly with the same quark. We show that such kinematic regions exist. We also show that the constancy with changing momentum transfer of the resonance peak/scaling curve ratio, familiar for many resonances in deep inelastic scattering, is also expected in the semi-exclusive case.Comment: 8 pages, 4 figures, submitted to Phys.Rev.

Soft Contributions to Hard Pion Photoproduction

Hard, or high transverse momentum, pion photoproduction can be a tool for probing the parton structure of the beam and target. We estimate the soft contributions to this process, with an eye toward delineating the region where perturbatively calculable processes dominate. Our soft process estimate is based on vector meson dominance and data based parameterizations of semiexclusive hadronic cross sections. We find that soft processes dominate in single pion photoproduction somewhat past 2 GeV transverse momentum at a few times 10 GeV incoming energy. The recent polarization asymmetry data is consistent with the perturbative asymmetry being diluted by polarization insensitive soft processes. Determining the polarized gluon distribution using hard pion photoproduction appears feasible with a few hundred GeV incoming energy (in the target rest frame).Comment: 6 pages, 5 figure

Probing Polarized Parton Distributions with Meson Photoproduction

Polarization asymmetries in photoproduction of high transverse momentum mesons are a flavor sensitive way to measure the polarized quark distributions. We calculate the expected asymmetries in several models, and find that the asymmetries are significant and also significantly different from model to model. Suitable data may come as a by-product of deep inelastic experiments to measure $g_1$ or from dedicated experiments.Comment: RevTeX, 5 pages, 5 postscript figures; minor corrections made, references adde

Measuring Polarized Gluon and Quark Distributions with Meson Photoproduction

We calculate polarization asymmetries in photoproduction of high transverse momentum mesons, focusing on charged pions, considering the direct, fragmentation, and resolved photon processes. The results at very high meson momentum measure the polarized quark distributions and are sensitive to differences among the existing models. The results at moderate meson momentum are sensitive to the polarized gluon distribution and can provide a good way to measure it. Suitable data may come as a by-product of deep inelastic experiments to measure $g_1$ or from dedicated experiments.Comment: RevTeX, 11 pages, 13 postscript figures; changes made in response to the referee's comment

A randomized, open- label, phase 2, multicenter trial of gemcitabine with pazopanib or gemcitabine with docetaxel in patients with advanced soft- tissue sarcoma

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/167073/1/cncr33216_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/167073/2/cncr33216.pd

Metabolic Maturation Media Improve Physiological Function of Human iPSC-Derived Cardiomyocytes.

Induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) have enormous potential for the study of human cardiac disorders. However, their physiological immaturity severely limits their utility as a model system and their adoption for drug discovery. Here, we describe maturation media designed to provide oxidative substrates adapted to the metabolic needs of human iPSC (hiPSC)-CMs. Compared with conventionally cultured hiPSC-CMs, metabolically matured hiPSC-CMs contract with greater force and show an increased reliance on cardiac sodium (Na+) channels and sarcoplasmic reticulum calcium (Ca2+) cycling. The media enhance the function, long-term survival, and sarcomere structures in engineered heart tissues. Use of the maturation media made it possible to reliably model two genetic cardiac diseases: long QT syndrome type 3 due to a mutation in the cardiac Na+ channel SCN5A and dilated cardiomyopathy due to a mutation in the RNA splicing factor RBM20. The maturation media should increase the fidelity of hiPSC-CMs as disease models