Energy Positivity, Non-Renormalization, and Holomorphy in Lorentz-Violating Supersymmetric Theories

This paper shows that the positive-energy and non-renormalization theorems of traditional supersymmetry survive the addition of Lorentz violating interactions. The Lorentz-violating coupling constants in theories using the construction of Berger and Kostelecky must obey certain constraints in order to preserve the positive energy theorem. Seiberg's holomorphic arguments are used to prove that the superpotential remains non-renormalized (perturbatively) in the presence of Lorentz-violating interactions of the Berger-Kostelecky type. We briefly comment on Lorentz-violating theories of the type constructed by Nibbelink and Pospelov to note that holomorphy arguments offer elegant proofs of many non-renormalization results, some known by other arguments, some new.Comment: v3: Discussion and clarification added. References added. Results on gauge-kinetic function expande

Trust on the Internet: A Virtual Reality?

Social capital has recently gained popularity, but it is not a new topic. The relationship between civic engagement and trust has been well tested, and it has been used in the past to help diagnose the well being of a society. Unfortunately with evolving technology, some of this research may be now obsolete. The internet has changed the way that people communicate and learn. Since the internet has reached such high proliferation rates, especially among the younger generations, it is likely to have an effect on the relationship between civic engagement and trust. Usin

PMMA Mechanical Test for the Medium Scale High Voltage Apparatus (MSHV)

This experiment at Oak Ridge National Laboratory (ORNL) aims to search for the electric dipole moment of the neutron (nEDM) at the 10^-28 level. One of the variables proportional to the sensitivity of the measurement is the strength of the electric field. The electrodes that generate the field will be made of polymethyl methacrylate (PMMA) and coated with a conductive material. This unique condition is further complicated by the fact that the system will be cooled to a temperature of 0.4 K. These conditions have not been attempted in the past and provide new challenges. In order to test solutions to these challenges, the MSHV was constructed. This apparatus allows potential coatings to be tested at 0.4 K to ensure that the electrodes for the final design will function as required. Due to stresses from thermal contraction occurring during cool down, components to transition from the PMMA electrodes to the existing support structure had to be selected to minimize the stress on each material. A mechanical test of this structure was performed at Los Alamos National Laboratory (LANL) to ensure that there are no failures of either structure or electrode. The results of this mechanical test, as well as the design and materials selected, will be discussed

The role of vitamin A during bio-mineral tissue development in pigs

PhD ThesisSkeletal health is a critical determinant of animal health and welfare. Kyphosis is one such idiopathic skeletal disease that compromises the welfare of commercial pigs. Vitamin A regulates the expression of genes that define bone growth and development, and has been suggested to associate with kyphosis. This thesis aimed to establish the molecular basis of kyphosis, clarify vitamin A’s role on the expression of genes that regulate skeletal development, and to ascertain vitamin A’s role on gene expression in kyphotic pigs. The TGF-β signalling pathway was associated with kyphotic bone and cartilage tissues. This was due to bone and cartilage tissues showing associations with small-leucine rich proteoglycans, ASPN and DCN respectively, which regulate TGF- β signalling. Potential effects as a result of differential gene expression include reduced endochondral bone growth and deterioration of articular cartilage. The dose of vitamin A was observed to be a critical factor in the regulation of expression of skeletal genes within bone tissue. Genes related to the family of Rho-GTPases, which control cytoskeletal dynamics, were observed to be differentially regulated within the trabecular bone in response to vitamin A. In addition, vitamin A dose was observed to initially antagonise serum 25(OH) D, and upon full saturation of the liver with vitamin A, serum 25(OH) D was restored through, as of yet, unknown mechanisms. The gene GIT2, which associates with Rho-GTPases, was observed to be differentially downregulated within kyphotic trabecular bone, and showed a dose-response relationship with vitamin A supplementation. Furthermore, kyphotic pigs were indicated to have reduced vitamin D status. This research has outlined the molecular basis of kyphosis in pigs, and has indicated vitamin A and vitamin D drive the disease. The research also outlines the role of how excessive vitamin A controls the expression of genes that regulate bio-mineralisation in trabecular bone. The thesis has also offered novel insights into vitamin A’s potential role in regulating gene expression during kyphotic development

The Efficacy of Mindfulness Based Interventions for Soldiers and Veterans

The psychological impacts of war can be devastating for soldiers and veterans. Even for those who have not seen combat, military service can be a stressful experience. Although posttraumatic stress disorder (PTSD) has been identified as the most common form of psychopathology in this population, military personnel are susceptible to a variety of other mental illnesses, including anxiety, depression, and substance use disorders (Prigerson, Maciejewski, & Rosenheck, 2002). Meta-analytic reviews demonstrate the efficacy of exposure-based interventions for soldiers and veterans with symptoms of posttraumatic stress (PTS), but results are inconclusive regarding the efficacy of other treatments for military servicemembers (Kitchiner, Roberts, Wilcox, & Bisson, 2012). Further, there appears to be a significant portion of soldiers and veterans with PTSD that does not respond to exposure-based treatments (Sher & Yehuda, 2011). Mindfulness-based interventions have shown to be effective in treating a breadth of psychopathology in civilian populations (Khoury et al., 2013). The purpose of the proposed study was to conduct a meta-analysis analyzing the efficacy of such interventions, specifically with soldiers and veterans. Three major literature databases, PsycINFO, Medline, and Cochrane were searched for randomized controlled studies that used mindfulness-based interventions with soldiers and veterans. It was hypothesized that mindfulness-based interventions would be shown to be efficacious for soldiers and veterans. Format and dosage of treatment, study quality, and diagnosis were coded and examined as potential moderator variables. General support was found for the efficacy of mindfulness-based interventions with soldiers in terms of reduction of symptoms of PTS and depression and positive changes in various “other” outcome areas. Future meta-analyses on this topic would benefit from incorporating biological and physical health outcome data (which were excluded from the present study)

Neutral Pion Background Analysis at STAR

The STAR detector at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory takes measurements of cross section and spin observables of polarized proton collisions. The Endcap Electromagnetic Calorimeter (EEMC) allows measurements of electromagnetic particles in the forward direction, 1 \u3c η \u3c 2. The EEMC detector will be used to measure the neutral pion (π0) double longitudinal spin asymmetry which gives us information about the gluon contribution to the proton\u27s spin. The π0 cross section is an important measurement to verify our signal reconstruction and the background characterization. In order to measure the π0 cross section and asymmetry, the backgrounds must be identified (such as those from photon conversions and reconstruction errors where one photon reconstructs as two clusters). This project describes efforts toward measuring the π0 cross section and asymmetry, specifically efforts to understand π0 background using Monte Carlo computer simulation events and collision data

Seed Tick: A Palimpsest

pages 37-3

Quantifying Glacier-Derived Summer Runoff in Northwest Montana

Glacier National Park, located in northwest Montana contains the second largest concentration of glaciers in the U.S. Rocky Mountains. However, total glacier-covered area has shrunk by almost 30% over the past 50 years. This has important implications for local glacier-fed streams, especially during the typically hot and dry summer month of August. This study is the first attempt to quantify the volume of glacier meltwater entering local streams. We simulate glacier-melt generation during the summers of 2009 and 2010 using a modified temperature-index model that includes solar radiation as input. The model was calibrated with data from weather stations installed on five different glaciers and in situ measurements of surface ablation. Simulated glacier-melt hereafter glacier runoff from within gauged basins was then compared to measured stream discharge for the month of August to assess the relative contribution of glacier runoff to stream flows. We find the fraction of August stream discharge potentially derived from glaciers is not linearly proportionate to glacier cover. In watersheds only 0.12% glacierized, glacier runoff equals 5%-6% of the August total discharge; glacier runoff is 23%-28% of the discharge in a stream draining a basin 1.4% glacierized; and, in the small alpine catchments where glacier cover exceeds 25% of the basin area, glacier runoff likely accounts for almost all of the total runoff. Our work suggests that during dry summer months, glacier runoff is a primary control on both water availability and water temperature in small alpine basins with a catchment area on the order of tens of km2 and smaller and that are located within 20 km of the continental divide. However, the significance of meltwater diminishes quickly when travelling downstream and that in larger rivers situated 50 km or more from glaciers, glacier runoff is minimally important

Combined scattering and spectroscopic structure determination of nano-catalysts

Several types of nano-catalysts, which includes oxides, supported mono and bimetallic catalysts have been used extensively for a range of catalytic reactions. Understanding the structure and reactivity has been a main theme to elucidate structure-function relationships. Herein, the behaviour of nano-catalysts has been studied using a range of experimental tools, with Synchrotron Radiation techniques as the major component. In addition, a range of analysis methods have been explored to determine structure using in situ and ex situ methods. Investigations into the structure of bimetallic silica supported PtZn nano-particles were conducted in situ during exposure to formic acid using X-ray absorption spectroscopy (XAS). Here it has been demonstrated that Zn is highly dispersed and bonded to the channel walls within the SBA-15 porous silica, whilst Pt forms oxide particles within the channels, in the as-synthesised form. On exposure to formic acid conversion of ZnO like species to Zn formate is observed to occur concurrent to the reduction of Pt oxide to Pt metal nano-particles. The redox characteristics of ceria supported platinum group metal (PGM) samples and ceria coated PGM metals supported on alumina have been studied in detail. XAS has been employed following the oxidation state of both the cerium and supported PGM, in addition to X-ray total scattering following the lattice structural changes, under in situ reduction-oxidation conditions. Detailed analysis has elucidated a promoted reduction of ceria upon reduction of the initial PGM oxide is observed. In the case of the inverse ceria alumina catalysts partial re-oxidation is observed upon cooling under a reducing atmosphere. Upon exposure to air, a full re-oxidation of the ceria support takes place, however only a partial oxidation (passivation), of the PGM to occur. Further reduction cycles result in ca room temperature reduction of the PGM and ceria