Opportunities and Challenges in Developing Nuclear Security in Africa

Those involved in nuclear security recognize that regions of significant instability in Africa have an impact on the safety and security of the continent\u27s nuclear material and un-enriched uranium; however, some countries outside of continental Africa have taken counterproductive approaches to this issue. Despite challenges, the nuclear security community continues to develop and apply appropriate levels of nuclear security where needed. The community also takes every opportunity to make significant contributions to the global discourse on nuclear security culture

A survey of vote slacking in five communities with implications for social studies curriculum

Thesis (Ed.M.)--Boston University, 1947. This item was digitized by the Internet Archive

Activity and Diversity of Collembola (Insecta) and Mites (Acari) in Litter of a Degraded Midwestern Oak Woodland

Litter-inhabiting Collembola and mites were sampled using pitfall traps over a twelve-month period from four sub-communities within a 100-acre (40-ha) oak-woodland complex in northern Cook County, Illinois. Sampled locations included four areas where future ecological restoration was planned (mesic woodland, dry-mesic woodland, mesic upland forest, and buckthorn-dominated savanna) and a mesic woodland control that would not be restored. Fifty-eight mite and 30 Collembola taxa were identified out of 5,308 and 190,402 individuals trapped, respectively. There was a significant positive relationship between litter mass and both mite diversity and the ratio of Oribatida to Prostigmata and a significant negative relationship between Collembola diversity and litter. Based on multivariate analysis, Collembola and mite composition differed by sub-community and season interaction

The role of the kidney in diabetic thiamine deficiency

Diabetes is a chronic epidemic compounded by a burden of vascular complications including diabetic nephropathy. Diabetic nephropathy affects ~40% of patients and is characterised by increased urinary albumin excretion and decreased glomerular filtration rate. Diabetic patients exhibit ~75% decreased plasma thiamine concentration, linked to increased renal thiamine clearance. In streptozotocin-induced diabetic rats, decreased plasma thiamine concentration was also associated with a reduction in expression and activity of transketolase. Transketolase is a thiamine pyrophosphate-dependent enzyme and a critical component of the reductive pentose phosphate pathway, a metabolic pathway leading from glycolysis involved with the synthesis of ribose sugars. It is proposed that increasing the relative flux of glucose through the pentose phosphate pathway can ameliorate hyperglycaemic damage. This thesis investigates mechanisms mediating the increased renal thiamine clearance and the effects of thiamine therapy on type 2 diabetic patients with nephropathy. The hypothesis that hyperglycaemia increases flux through the hexosamine pathway, leading to increased O-glycosylation of the transcription factor Sp1 and subsequent decreased expression of thiamine transporters is investigated. Thiamine transporters in normal human kidney sections were found to be localised to the proximal tubule. Investigations in primary cultures of human proximal tubule epithelial cells and the HK-2 cell line have shown that there is a decreased expression (-48 to -80%) and abundance (-52 to -77%) of thiamine transporters in cells cultured in high glucose concentrations (26mM) with respect to low glucose concentrations (5 mM). There is only limited evidence supporting the involvement of the hexosamine pathway in these decreases. A double-blind, placebo-controlled study investigated the effect of thiamine supplementation on type 2 diabetic patients with microalbuminuria. Thiamine therapy restored plasma thiamine concentrations from 11nM to 98nM, exceeding the published median concentration observed in normal patients (64nM). After three months, thiamine therapy, but not placebo, caused a decrease in the urinary albumin excretion rate relative to baseline (-18 mg day-1). These results show promise for thiamine as a therapy for diabetic nephropathy

FFLO states and quantum oscillations in mesoscopic superconductors and superfluid ultracold Fermi gases

We have studied the distinctive features of the Fulde-Ferrel-Larkin-Ovchinnikov (FFLO) instability and phase transitions in two--dimensional (2D) mesoscopic superconductors placed in magnetic field of arbitrary orientation and rotating superfluid Fermi gases with imbalanced state populations. Using a generalized version of the phenomenological Ginzburg-Landau theory we have shown that the FFLO states are strongly modified by the effect of the trapping potential confining the condensate. The phenomenon of the inhomogeneous state formation is determined by the interplay of three length scales: (i) length scale of the FFLO instability; (ii) 2D system size; (iii) length scale associated with the orbital effect caused either by the Fermi condensate rotation or magnetic field component applied perpendicular to the superconducting disc. We have studied this interplay and resulting quantum oscillation effects in both superconducting and superfluid finite -- size systems with FFLO instability and described the hallmarks of the FFLO phenomenon in a restricted geometry. The finite size of the system is shown to affect strongly the conditions of the observability of switching between the states with different vorticities.Comment: 11 pages, 5 figures, Submitted to PR

Garbage In, Garbage Out: Model Uncertainty in Wealth Simulations

From the Washington University Senior Honors Thesis Abstracts (WUSHTA), 2017. Published by the Office of Undergraduate Research. Joy Zalis Kiefer, Director of Undergraduate Research and Associate Dean in the College of Arts & Sciences; Lindsey Paunovich, Editor; Helen Human, Programs Manager and Assistant Dean in the College of Arts and Sciences Mentor: Philip H. Dybvi

Galactic Scale Feedback Observed in the 3C 298 Quasar Host Galaxy

We present high angular resolution multi-wavelength data of the 3C 298 radio-loud quasar host galaxy (z=1.439) taken using the W.M. Keck Observatory OSIRIS integral field spectrograph with adaptive optics, Atacama Large Millimeter/submillimeter Array (ALMA), Hubble Space Telescope (HST) WFC3, and the Very Large Array (VLA). Extended emission is detected in the rest-frame optical nebular emission lines H$\beta$, [OIII], H$\alpha$, [NII], and [SII], as well as molecular lines CO (J=3-2) and (J=5-4). Along the path of 3C 298's relativistic jets we detect conical outflows of ionized gas with velocities up to 1700 km s$^{-1}$ and outflow rate of 450-1500 M$_\odot$yr$^{-1}$. Near the spatial center of the conical outflow, CO (J=3-2) emission shows a molecular gas disc with a total molecular mass ($\rm M_{H_{2}}$) of 6.6$\pm0.36\times10^{9}$M$_{\odot}$. On the molecular disc's blueshifted side we observe a molecular outflow with a rate of 2300 M$_\odot$yr$^{-1}$ and depletion time scale of 3 Myr. We detect no narrow H$\alpha$ emission in the outflow regions, suggesting a limit on star formation of 0.3 M$_\odot$yr$^{-1}$kpc$^{-2}$. Quasar driven winds are evacuating the molecular gas reservoir thereby directly impacting star formation in the host galaxy. The observed mass of the supermassive black hole is $10^{9.37-9.56}$M$_{\odot}$ and we determine a dynamical bulge mass of 1-1.7$\rm\times10^{10}\frac{R}{1.6 kpc}$ M$_{\odot}$. The bulge mass of 3C 298 resides 2-2.5 orders of magnitude below the expected value from the local M$\rm_{bulge}-M_{BH}$ relationship. A second galactic disc observed in nebular emission is offset from the quasar by 9 kpc suggesting the system is an intermediate stage merger. These results show that galactic scale negative feedback is occurring early in the merger phase of 3C 298, well before the coalescence of the galactic nuclei and assembly on the local relationship.Comment: 23 pages, 11 figures, 4 tables, Accepted for publication in the Astrophysical Journa

Immunotherapies in Early and Advanced Renal Cell Cancer

The development of new immunomodulatory monoclonal antibodies targeting the CTLA-4 or PD-1 axis has led to a revival of research on immunotherapies in solid tumours including renal cell cancer (RCC). The initial results observed with these monoclonal antibodies in the treatment of advanced melanoma have resulted in considerable interest in this treatment strategy in all tumour types. Preliminary data of these new antibodies in advanced RCC are promising and they have good safety profiles. Response rates are low but durable tumour control has been observed in some patients. However, at the moment there is no evidence that targeting the CTLA-4 or PD-1 axis provides a substantial clinical benefit compared to established treatment with tyrosine kinase or mTOR inhibitors. There are also no reliable predictive markers. At the moment, several randomised trials have been initiated to investigate the new immunomodulatory antibodies either as single agents or in combination with anti-VEGF targeted therapy. Vaccines have continued to be investigated in advanced and adjuvant settings. No trial has so far established vaccines as a standard treatment in either situation. There are still large randomised trials ongoing investigating the potential benefit of a vaccine in combination with standard tyrosine kinase inhibitor therapy. In this chapter we will summarise selected studies on immunotherapy in advanced RCC with a focus on anti-PD-1, anti-PD-L1, and anti-CTLA-4 antibodies. We will also touch briefly on the adjuvant situation and tumour vaccines