Polarized quark distributions in nuclear matter

We compute the polarized quark distribution function of a bound nucleon. The Chiral Quark-Soliton model provides the quark and antiquark substructure of the nucleon embedded in nuclear matter. Nuclear effects cause significant modifications to the polarized distributions including an enhancement of the axial coupling constant.Comment: 5 Pages, 2 Postscript figures, Version to be published in Phys. Rev.

Chiral solitons in nuclei: Electromagnetic form factors

We calculate the electromagnetic form factors of a bound proton. The Chiral Quark-Soliton model provides the quark and antiquark substructure of the proton, which is embedded in nuclear matter. This procedure yields significant modifications of the form factors in the nuclear environment. The sea quarks are almost completely unaffected, and serve to mitigate the valence quark effect. In particular, the ratio of the isoscalar electric to the isovector magnetic form factor decreases by 20% at Q^2=1 GeV^2 at nuclear density, and we do not see a strong enhancement of the magnetic moment.Comment: 13 pages, 6 figures, Added references and a clearer connection to experimen

Development of new dielectric materials for pulsed power applications

Title from PDF of title page (University of Missouri--Columbia, viewed on May 30, 2013).The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.Thesis advisor: Dr. Randy CurryIncludes bibliographical references.M.S. University of Missouri--Columbia 2012."May 2012"This study looks at the development of new dielectrics, which blend characteristic of different materials for use in high voltage capacitors and antennas. As new needs arise in electrical engineering including pulsed power and directed energy, new materials are needed reduce the size and cost of electrical assemblies. This study investigates new composite dielectrics made of mixes of two different ceramic nanopowders in a matrix of two different melted thermoplastics. The intent of this study is to blend the high dielectric constant of ceramic nanopowder with the high dielectric strength and the mechanical qualities of a thermoplastic. The measured dielectric strength and the dielectric constant of the composite material is reported and compared to commercial plastics. The result is the development of a new dielectric material with a dielectric constant that is higher than most thermoplastics while still displaying good mechanical properties. The results also show that a major challenge of developing a successful composite is obtaining an adequate level of mixing between the two phases of the material. This study is a starting point from which new dielectric materials can be developed that could impact a wide range of electrical engineering disciplines

Calcium-Sensing Receptor Regulates Cytosolic [Ca 2+ ] and Plays a Major Role in the Development of Pulmonary Hypertension.

Pulmonary arterial hypertension (PAH) is a progressive disease characterized by elevated pulmonary vascular resistance (PVR) leading to right heart failure and premature death. The increased PVR results in part from pulmonary vascular remodeling and sustained pulmonary vasoconstriction. Excessive pulmonary vascular remodeling stems from increased pulmonary arterial smooth muscle cell (PASMC) proliferation and decreased PASMC apoptosis. A rise in cytosolic free Ca2+ concentration ([Ca2+]cyt) in PASMC is a major trigger for pulmonary vasoconstriction and a key stimulus for PASMC proliferation and migration, both contributing to the development of pulmonary vascular remodeling. PASMC from patients with idiopathic PAH (IPAH) have increased resting [Ca2+]cyt and enhanced Ca2+ influx. Enhanced Ca2+ entry into PASMC due to upregulation of membrane receptors and/or Ca2+ channels may contribute to PASMC contraction and proliferation and to pulmonary vasoconstriction and pulmonary vascular remodeling. We have shown that the extracellular Ca2+-sensing receptor (CaSR), which is a member of G protein-coupled receptor (GPCR) subfamily C, is upregulated, and the extracellular Ca2+-induced increase in [Ca2+]cyt is enhanced in PASMC from patients with IPAH in comparison to PASMC from normal subjects. Pharmacologically blockade of CaSR significantly attenuate the development and progression of experimental pulmonary hypertension in animals. Additionally, we have demonstrated that dihydropyridine Ca2+ channel blockers (e.g., nifedipine), which are used to treat PAH patients but are only effective in 15-20% of patients, activate CaSR resulting in an increase in [Ca2+]cyt in IPAH-PASMC, but not normal PASMC. Our data indicate that CaSR functionally couples with transient receptor potential canonical (TRPC) channels to mediate extracellular Ca2+-induced Ca2+ influx and increase in [Ca2+]cyt in IPAH-PASMC. Upregulated CaSR is necessary for the enhanced extracellular Ca2+-induced increase in [Ca2+]cyt and the augmented proliferation of PASMC in patients with IPAH. This review will highlight the pathogenic role of CaSR in the development and progression of PAH

Memorandum of understandings promise nothing; media mergers require close scrutiny by the FCC for their impacts on Latinas/os

Mergers have become an increasing frequent part of the American media landscape, and alongside this consolidation interest groups have sprung up to challenge them on the grounds of minority representation, In new work, Jason A. Smith and Randy Abreu take a close look at the effects on Latina/o representation of the 2011 merger between Comcast and NBC Universal. They write that while the memorandum of understandings signed by Comcast and Latina/o organizations promised increased minority representation, this has not come to pass in the intervening years. Such voluntary agreements, they write, have no teeth and need to be superseded by greater federal oversight

Decay estimates for variable coefficient wave equations in exterior domains

In this article we consider variable coefficient, time dependent wave equations in exterior domains. We prove localized energy estimates if the domain is star-shaped and global in time Strichartz estimates if the domain is strictly convex.Comment: 15 pages. In the new version, some typos are fixed and a minor correction was made to the proof of Lemma 1

Changing teacher perceptions and actions through Trauma-Responsive Professional Development

Most teachers are not trained on how to support students who struggle with trauma. Childhood trauma not only impacts a teacher’s ability to teach, but also threatens their students’ futures. The purpose of this qualitative study was to investigate teachers’ perceptions and actions when they participated in trauma professional development. Interviews were conducted with 5 teachers and 10 students in a Midwestern urban intermediate/middle school. By the end of the study, teachers stated that they had begun responding to disruptions in more child-centered approaches, and students noticed that their teachers began treating all students more equitably in trauma-informed manners. The implications from this study are that educating teachers on the impact of childhood trauma can change the way that teachers perceive and react to dysregulated students. Another implication is that changing teachers’ beliefs, perceptions, and attitudes can be difficult if teachers retain a deficit-thinking focus