Sympathetic Neurotransmitters and Tumor Angiogenesis—Link between Stress and Cancer Progression

Recent evidence supports a longstanding hypothesis that chronic stress can influence tumor growth and progression. It has been shown that sympathetic neurotransmitters, such as catecholamines and neuropeptides, can affect both cancer cell growth and tumor vascularization. Depending on neurotransmitter and type of tumor, these effects can be both stimulatory and inhibitory. Norepinephrine (NE) and epinephrine (E) are potent stimulators of vascularization, acting both by inducing the release of angiogenic factors from tumor cells and directly on endothelial cell (EC) functions. As a result, activation of the adrenergic system increases growth of various types of tumors and has been shown to mediate stress-induced augmentation of tumor progression. Dopamine (DA), on the other hand, interferes with VEGF signaling in endothelial cells, blocks its angiogenic functions and inhibits tumor growth. Another sympathetic neurotransmitter coreleased with NE, neuropeptide Y (NPY), directly stimulates angiogenesis. However, proangiogenic actions of NPY can be altered by its direct effect on tumor cell proliferation and survival. In consequence, NPY can either stimulate or inhibit tumor growth, depending on tumor type. Hence, sympathetic neurotransmitters are powerful modulators of tumor growth and can become new targets in cancer therapy

The Impact of Horizontal Mergers on Plan Premiums and Drug Formularies in Medicare Part D

In this paper, we examine the impact of horizontal mergers amongst insurers on competition in the Medicare Part D prescription drug market. Theory predictions about the effect of mergers on price and product quality are confounded by three competing forces: increased cost efficiency, market power, and bargaining power with upstream suppliers. Using panel data for the full set of plans offered by Part D insurers between 2006-2012, we use a differences-in-differences identification strategy to document the effect that merger activity has on plan pricing and drug coverage characteristics. We find that plans affected by a merger experience higher premiums as a result of increased market power. However, for merging insurers that restructure their plan offerings, price falls to offset the market power effect. The results on drug formulary measures show that merging on its own has no effect on the generosity of drug coverage. Yet for restructured plans, there are sizable merger effects on coverage in the form of reduced copay/coinsurance rates and increased scope in the set of covered drugs. The lowered prices and improved drug coverage for restructured plans suggest cost efficiencies and bargaining power with drug suppliers are a major source of gains stemming from mergers

A Correlation of Spectral Lag Evolution with Prompt Optical Emission in GRBs?

We report on observations of correlated behavior between the prompt gamma-ray and optical emission from GRB 080319B, which (i) strongly suggest that they occurred within the same astrophysical source region and (ii) indicate that their respective radiation mechanisms were most likely dynamically coupled. Our preliminary results, based upon a new cross-correlation function (CCF) methodology for determining the time-resolved spectral lag, are summarized as follows. First, the evolution in the arrival offset of prompt gamma-ray photon counts between Swift-BAT 15-25 keV and 50-100 keV energy bands (intrinsic gamma-ray spectral lag) appears to be anti-correlated with the arrival offset between prompt 15-350 keV gamma-rays and the optical emission observed by TORTORA (extrinsic optical/gamma-ray spectral lag), thus effectively partitioning the burst into two main episodes at ~T+28+/-2 sec. Second, prompt optical emission is nested within intervals of (a) trivial intrinsic gamma-ray spectral lag (~T+12+-2 and ~T+50+/-2 sec) with (b) discontinuities in the hard to soft evolution of the photon index for a power law fit to 15-150 keV Swift-BAT data (~T+8+/-2 and ~T+48+/-1 sec), both of which coincide with the rise (~T+10+/-1 sec) and decline (~T+50+/-1 sec) of prompt optical emission. This potential discovery, robust across heuristic permutations of BAT energy channels and varying temporal bin resolution, provides the first observational evidence for an implicit connection between spectral lag and the dynamics of shocks in the context of canonical fireball phenomenology.Comment: 5 pages. Adapted from a contribution to the Proceedings of the 2008 Nanjing GRB Conference. Edited by Y. F. Huang, Z. G. Dai and B. Zhan

The Correlation of Spectral Lag Evolution with Prompt Optical Emission in GRB 080319B

We report on observations of correlated behavior between the prompt gamma-ray and optical emission from GRB 080319B, which confirm that (i) they occurred within the same astrophysical source region and (ii) their respective radiation mechanisms were dynamically coupled. Our results, based upon a new CCF methodology for determining the time-resolved spectral lag, are summarized as follows. First, the evolution in the arrival offset of prompt gamma-ray photon counts between Swift-BAT 15-25 keV and 50-100 keV energy bands (intrinsic gamma-ray spectral lag) appears to be anti-correlated with the arrival offset between prompt 15-350 keV gamma-rays and the optical emission observed by TORTORA (extrinsic optical/gamma-ray spectral lag), thus effectively partitioning the burst into two main episodes at ~T+28+/-2 sec. Second, the rise and decline of prompt optical emission at ~T+10+/-1 sec and ~T+50+/-1 sec, respectively, both coincide with discontinuities in the hard to soft evolution of the photon index for a power law fit to 15-150 keV Swift-BAT data at ~T+8+/-2 sec and ~T+48+/-1 sec. These spectral energy changes also coincide with intervals whose time-resolved spectral lag values are consistent with zero, at ~T+12+/-2 sec and ~T+50+/-2 sec. These results, which are robust across heuristic permutations of Swift-BAT energy channels and varying temporal bin resolution, have also been corroborated via independent analysis of Konus-Wind data. This potential discovery may provide the first observational evidence for an implicit connection between spectral lags and GRB emission mechanisms in the context of canonical fireball phenomenology. Future work includes exploring a subset of bursts with prompt optical emission to probe the unique or ubiquitous nature of this result.Comment: 6 pages, 3 figures. Contributed to the Proceedings of the Sixth Huntsville GRB Symposium. Edited by C.A. Meegan, N. Gehrels, and C. Kouvelioto

Systemic levels of neuropeptide Y and dipeptidyl peptidase activity in patients with Ewing sarcoma—Associations with tumor phenotype and survival

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110734/1/cncr29090.pd

Fundamental Surface Properties and Gas-Surface Interactions of Two-Dimensional Materials

Heterogeneous model catalysis with supported nanomaterials on ultra-thin two-dimensional films has contributed significantly to improve the existing industrial catalytic processes, as well as to discover novel ways to enhance selectivity, specificity, and stability of the catalysts. Silica and zeolites are of particular interest, which has been widely utilized as catalysts and catalytic supports in several industrial processes. However, there are a limited number of surface science studies with zeolites due to the lack of surface analogs. Understanding the fundamental surface properties of silica and zeolites, involving the synthesis of surface analogs of silica and zeolites, characterization, surface modification, and screening for chemical and physical properties connected to the heterogeneous catalysis related applications utilizing advanced ultra-high vacuum-based surface science techniques is the main focus of this dissertation. Catalyst particles should be finely distributed on high surface area supports, in order to have high selectivity and specificity. Particle agglomeration during extreme catalyst operation (reaction) conditions decreases the efficiency of the catalysts over time. One common strategy to address the issue of particle agglomeration is to promote strong catalyst-support interactions. In this study, chemical reactivity of the inert silica was improved by doping with aluminum, which enhanced the polarity of silica (2D-zeolites) and hence the catalyst-support interactions compared to inert silica. Organohalide perovskite thin films are a fascinating class of material, which attract much attention in the recent past as the light harvesting materials in solar cells due to excellent power conversion efficiencies. However, poor thermal, chemical, and long-term stability limit the industrial applications of these organohalide perovskites. Gas-surface interactions on methylammonium lead iodide perovskite thin films were investigated in order to understand the thermal and the chemical degradation mechanisms utilizing UHV-based surface analytical techniques combined with computational calculations. Thermal stability improvement of the perovskite thin films by surface passivation using a protective chemical inhibition layer was successfully investigated experimentally.ACS-PRFNorth Dakota State University. Department of Chemistry and BiochemistryNorth Dakota State University. Research and Creative Activit

The Absence of the Cone-Specific Visual Cycle in Sea Lamprey and Its Evolutionary Implications

Unlike rods which mediate low-light/night vision, cones which mediate day-vision never saturate despite exposure to intense, ambient light. A contributing explanation is a M�ller cell-mediated visual cycle, found in mammalian models, that continually regenerates photopigment in cones (Wang et al., 2011). Given our knowledge of the “camera” eye (Lamb et al., 2007), we wanted to know if this cone-specific visual cycle was also highly conserved in vertebrates prompting the use of sea lamprey, an ideal model for evolutionary study. Using ERG recordings, we found no significant regaining of response sensitivity in isolated retinas, indicative of pigment regeneration, after a substantial bleaching light exposure. These results confirm the absence of a cone-specific visual cycle in sea lamprey and suggest that this pathway had arisen after the divergence of jawed and jawless vertebrates ~500 mya