Supersymmetric Theory and Models

In these introductory lectures, we review the theoretical tools used in constructing supersymmetric field theories and their application to physical models. We first introduce the technology of two-component spinors, which is convenient for describing spin-$1/2$ fermions. After motivating why a theory of nature may be supersymmetric at the TeV energy scale, we show how supersymmetry (SUSY) arises as an extension of the Poincar\'e algebra of spacetime symmetries. We then obtain the representations of the SUSY algebra and discuss its simplest realization in the Wess-Zumino model. In order to have a systematic approach for obtaining supersymmetric Lagrangians, we introduce the formalism of superspace and superfields and recover the Wess-Zumino Lagrangian. These methods are then extended to encompass supersymmetric abelian and non-abelian gauge theories coupled to supermatter. Since supersymmetry is not an exact symmetry of nature, it must ultimately be broken. We discuss several mechanisms of SUSY-breaking (both spontaneous and explicit) and briefly survey various proposals for realizing SUSY-breaking in nature. Finally, we construct the the Minimal Supersymmetric extension of the Standard Model (MSSM), and consider the implications for the future of SUSY in particle physics.Comment: Lecture notes, TASI 2016. 144 pages, typographical errors correcte

Inclusion of non-spherical components of the Pauli blocking operator in (p,p') reactions

We present the first calculations of proton elastic and inelastic scattering in which the Pauli blocking operator contains the leading non-spherical components as well as the usual spherical (angle-averaged) part. We develop a formalism for including the contributions to the effective nucleon-nucleon interaction from the resulting new G-matrix elements that extend the usual two-nucleon spin structure and may not conserve angular momentum. We explore the consequences of parity conservation, time reversal invariance, and nucleon-nucleon antisymmetrization for the new effective interaction. Changes to the calculated cross section and spin observables are small in the energy range from 100 to 200 MeV.Comment: 24 pages, 4 figures, to be published in Physical Review

Derivation of human embryonic stem cells to study early development and genetic disease

Stem cells are unique cells that have both the capacity for self-renewal and, depending on their origin, the ability to form at least one, and sometimes many, specialised cell types of all three embryonic germ lineages - germ cells (endoderm, mesoderm and ectoderm), extra-embryonic tissue and trophoblast. Since the derivation of the fi�rst human embryonic stem cell (hESC) line in 1998, there has been substantial interest in the potential of these cells both for regenerative medicine and cell therapy, and as disease models for monogenic disorders. Aside from the need to improve derivation efficiency and further the understanding of the basic biology of these cells, the ability to work with hESC opens up three broad research areas. The �first is the development of clinical grade culture systems with the aim of producing cell lines suitable for subsequent manipulation for therapy. The second is the opportunity to use these cells as a tool to study the earliest determinative events in mammalian development, such as the origins of patterning in the mammalian embryo. The third is the use of hESCs carrying clinically relevant genetic mutations as models for disease research and therapeutic target identifi�cation. The development of several methods of embryo manipulation tailored to the morphology of the blastocyst is described here, which resulted in the derivation of seven lines from four di�fferent procedures and provided the tools for subsequent research. Acknowledging that each laboratory in isolation is unlikely to derive sufficient lines to draw signifi�cant conclusions regarding manipulation methodology and culture parameters, an international collaboration was initiated with the aim of standardising the reporting of derivation and thus obtaining the maximum information from the generation of each new hESC line. To address the need for the development of clinical grade culture systems, alternative feeder cells were assessed for their suitability in hESC culture and derivation. Modi�fied human foreskin fi�broblasts and human amniotic epithelial cells (hAECs) were investigated, as both cell types can be fully qualifi�ed and validated. Whilst both were able to support the culture of existing lines, only the hAECs showed promise in supporting derivation. In addition, analysis of in-house and commercially available media showed that neither were physiologically optimal for the growth of inner cell mass (ICM) cells or putative hESC, as metabolite concentrations were in excess and subsequent catabolite levels exceeded known toxic levels. The timing and mechanisms establishing patterning and future polarity in the mammalian embryo remains a subject of intense debate. Here, the potential of single blastomeres to generate hESC was used as an assessment of pluripotency. The determination of the most appropriate day for attempting derivation was performed by assessing blastomere development and pluripotent marker expression, and the predicted success of derivation was considered in the light of division patterns. Putative stem-like cells were visible in several cultures. Furthermore, isolated blastomeres from two-, four-, and eight-cell embryos were analysed for the quantitative expression of multiple target genes known to be associated with lineage formation and the stem cell state. Analysis suggested that broad changes in gene expression were occurring with development stage. However, no consistent grouping structure for cells within embryos was observed, and no convincing pattern was seen when considering the individual embryo variance scores. Several approaches are discussed to diff�erentiate between the biological and methodological variability in this experimental design. The suitability of hESC as models for genetic disease was studied following the derivation of two lines carrying Huntington disease (HD). Subsequent di�fferentiation using a stromal co-culture neural induction protocol resulted in the establishment of a stable, highly proliferative cell population which was simple to culture and bank. The cells were of an astroglial phenotype, and therefore highly suited for subsequent studies regarding HD pathophysiology, as glial cells are severely aff�ected in HD. During diff�erentiation the CAG repeat size increased from 46 to 70, showing the salient feature of somatic instability of the huntingtin gene. Therefore this cell population provides a valuable tool in the study of disease pathogenesis and transmission

A Comparison of Enzyme Converted Starches Used in Surface Sizing

A literature survey shows an increasing trend in the direction of using enzyme converted starch tub sizing solutions in paper making. Bacterial alpha amylase seems indicated as the best available enzyme for this type of conversion. Little or no information concerning the differences in sizing solutions prepared from different varieties of starch was found. Laboratory work comparing corn and potato starch, both enzymes converted under comparable conditions, indicates a conclusion that the optimum point of starch conversion is obtained by using the minimum concentration of enzyme which is capable of producing the desired sizing solution viscosity. Potato starch seems to possess the property of reaching sizing viscosities at a lower enzyme conversion concentration than corn starch

Greenhouse Gas Emissions and Emissions Trading in North America: Kyoto Treaty and U.S. Initiatives

greenhouse gas emission

The Role of the Complement System in Cigarette Smoke Induced Emphysema Development and Progression

Emphysema is a complex inflammatory condition of the respiratory tract with an incompletely elucidated pathogenesis. Due to the complexity of the disease, treatment options are limited for patients and have poor efficacy. Therefore a greater understanding of disease pathogenesis is imperative to expand therapeutic strategies. Central to disease development is the activation of the innate and adaptive immune system, however, targeting blockade of only one side of the immune response, has shown little clinical benefit. The complement system, while regarded as an innate immune mechanism, can modulate both innate and adaptive immune responses. Given these dual modulatory effects, the complement system may be an ideal target for the management of emphysema. Complement activation has been reported in emphysema patients, demonstrated by increased plasma C3 concentrations, increased BAL complement cleavage fragments, and complement deposition within the emphysematous lungs. Therefore we hypothesize that by targeting the complement cascade we can modulate innate and adaptive immunity, and subsequently rescue lungs from the chronic inflammatory response that persists in emphysema. We demonstrate that deficiency in key complement components, C3, C5 and fB, provides protection from emphysema development. To test the therapeutic significance of these findings, we designed, established and characterized a novel rodent model of smoking cessation, and demonstrate that post smoking cessation modulation of the complement system, with CR2-fH or anti-C5 mAb, significantly reduced inflammation, lung destruction, and improved lung function. Together our multiple mouse models demonstrate that blocking complement protects against lung injury, inflammation, and T cell activation. Further we demonstrate reduced B cell infiltration and circulating autoantibody levels in our complement deficient active smoking models, but that autoantibody levels were unaltered in smoking cessation therapeutic studies. Whether these antibodies are biomarkers of disease or pathogenically contribute to disease development has yet to be elucidated. Using an elastin immunization model we show that increased anti-elastin autoantibodies are associated with exacerbated emphysema disease, thus demonstrating that these antibodies have pathogenic significance. In conclusion, these studies delineate a role for the complement system in the development, and persistence of emphysema, and further highlight the potential clinical benefits for utilization of targeted complement therapeutics for the management of emphysema

Graduates : University of Missouri School of Medicine, 1841-1997

This list was extracted from: Aesculapius was a Mizzou tiger : an illustrated history of medicine at Ol' Mizzou, by Hugh E. Stephenson, Jr., M.D., F.A.C.S.This list includes names of University of Missouri School of Medicine graduates from 1841-1997