Neutron Multiplicity in Atmospheric Neutrino Events at the Sudbury Neutrino Observatory

This thesis describes the results of two separate analyses. Part I is the description of the first analysis which uses the newest measurements of neutrino mixing to study various non-standard models of neutrino interactions through their impact on solar neutrinos. These models can be motivated by the fact that solar neutrino experiments have yet to see directly the transition region between matter-enhanced and vacuum oscillations. The transition region is particularly sensitive to models of non-standard neutrino interactions and propagation. I examine several such non-standard models which predict a lower-energy transition region. I find that while several models provide a better fit to the solar neutrino data set, large experimental uncertainties lead to a low statistical significance. Part II describes the second analysis, where I look at neutron followers of contained atmospheric neutrino events in the SNO data set. These kinds of events are difficult backgrounds for nucleon decay measurements, and understanding the neutron follower multiplicity will allow for better rejection. It can also help improve measurements of the neutrino mass hierarchy and neutrino-nuclear cross sections. I find that the dependence of the average multiplicity on the visible energy agrees well with the predictions of simulations except for an unexplained deficit between 100 MeV and 600 MeV and an excess above 4 GeV. I determined the ability to distinguish neutrino and antineutrino events using the multiplicity by fitting for the double ratio $R \equiv (\overline{\nu}/\nu)_{\text{data}} / (\overline{\nu}/{\nu})_{\text{MC}})$. I find $R = 0.93^{+0.91}_{-0.63}$ for a fit to a single multiplicity distribution per phase, and $R \u3c 1.00$ for a fit to separate distributions for single electron ring, single muon ring, and multi-ring events. I also look at the agreement with a meson-exchange current cross section model developed to explain anomalous cross sections measured by MiniBooNE. Fitting for the strength of the MEC contribution as a fraction of the quasielastic charged-current cross section, I find an upper limit of $\sigma_{MEC}/\sigma_{QECC} \u3c 0.17$ for a fit to combined distributions and $\sigma_{MEC}/\sigma_{QECC} \u3c 0.04$ for a fit to separate distributions for ring count and type

Cytosolic calcium and protein kinase C reduce complement-mediated glomerular epithelial injury

Cytosolic calcium and protein kinase C reduce complement-mediated glomerular epithelial injury. In rat membranous nephropathy, proteinuria is due to formation of the C5b-9 membrane attack complex of complement (C), and is associated with morphological evidence of glomerular epithelial cell (GEC) injury. Analogous morphological changes are induced by C5b-9 in cultured GEC. In addition, in cultured GEC C5b-9 induces Ca2+ influx, as well as Ca2+ mobilization and increased 1,2-diacylglycerol due to the activation of phospholipase C. In this study we investigated how this GEC activation pattern might influence C-mecliated GEC injury. We demonstrate that the C5b-9-induced increase in cytosolic Ca2+ concentration ([Ca2+]i) did not impair ATP generation by mitochondria, suggesting that it does not contribute to cytotoxicity. Moreover, this increase in [Ca2+]i protected GEC from C-mediated cytolysis. However, a large increase in [Ca2+]i (produced by the Ca2+ ionophore A23187) impaired ATP generation and aggravated C-mediated cytotoxicity, suggesting that intact mitochondrial activity is necessary for GEC to withstand C attack. Activation of protein kinase C (PKC) by phorbol myristate acetate (PMA) also decreased C-mediated cytolysis. Conversely, C lysis was enhanced in GEC that had been pretreated for 18 hours with a high dose of PMA to deplete PKC, and following PKC inhibition with H-7. Therefore, PKC activation, possibly resulting from C5b-9-induced increase in 1,2-diacylglycerol, triggered mechanisms that protected GEC from C-mediated injury. Thus, as a consequence of C5b-9-induced phospholipase activation, the amount of C-induced GEC injury is diminished

Conditional Ablation of Macrophages Halts Progression of Crescentic Glomerulonephritis

The presence of macrophages in inflamed glomeruli of rat kidney correlates with proliferation and apoptosis of resident glomerular mesangial cells. We assessed the contribution of inflammatory macrophages to progressive renal injury in murine crescentic glomerulonephritis (GN). Using a novel transgenic mouse (CD11b-DTR) in which tissue macrophages can be specifically and selectively ablated by minute injections of diphtheria toxin, we depleted renal inflammatory macrophages through days 15 and 20 of progressive crescentic GN. Macrophage depletion reduced the number of glomerular crescents, improved renal function, and reduced proteinuria. Morphometric analysis of renal tubules and interstitium revealed a marked attenuation of tubular injury that was associated with reduced proliferation and apoptosis of tubular cells. The population of interstitial myofibroblasts decreased after macrophage depletion and interstitial fibrosis also decreased. In the presence of macrophages, interstitial myofibroblasts exhibited increased levels of both proliferation and apoptosis, suggesting that macrophages act to support a population of renal myofibroblasts in a high turnover state and in matrix deposition. Finally, deletion of macrophages reduced CD4 T cells in the diseased kidney. This study demonstrates that macrophages are key effectors of disease progression in crescentic GN, acting to regulate parenchymal cell populations by modulating both cell proliferation and apoptosis

Staphylococcal Toxic Shock Syndrome 2000–2006: Epidemiology, Clinical Features, and Molecular Characteristics

Circulating strains of Staphylococcus aureus (SA) have changed in the last 30 years including the emergence of community-associated methicillin-resistant SA (MRSA). A report suggested staphylococcal toxic shock syndrome (TSS) was increasing over 2000-2003. The last population-based assessment of TSS was 1986.Population-based active surveillance for TSS meeting the CDC definition using ICD-9 codes was conducted in the Minneapolis-St. Paul area (population 2,642,056) from 2000-2006. Medical records of potential cases were reviewed for case criteria, antimicrobial susceptibility, risk factors, and outcome. Superantigen PCR testing and PFGE were performed on available isolates from probable and confirmed cases.Of 7,491 hospitalizations that received one of the ICD-9 study codes, 61 TSS cases (33 menstrual, 28 non-menstrual) were identified. The average annual incidence per 100,000 of all, menstrual, and non-menstrual TSS was 0.52 (95% CI, 0.32-0.77), 0.69 (0.39-1.16), and 0.32 (0.12-0.67), respectively. Women 13-24 years had the highest incidence at 1.41 (0.63-2.61). No increase in incidence was observed from 2000-2006. MRSA was isolated in 1 menstrual and 3 non-menstrual cases (7% of TSS cases); 1 isolate was USA400. The superantigen gene tst-1 was identified in 20 (80%) of isolates and was more common in menstrual compared to non-menstrual isolates (89% vs. 50%, p = 0.07). Superantigen genes sea, seb and sec were found more frequently among non-menstrual compared to menstrual isolates [100% vs 25% (p = 0.4), 60% vs 0% (p<0.01), and 25% vs 13% (p = 0.5), respectively].TSS incidence remained stable across our surveillance period of 2000-2006 and compared to past population-based estimates in the 1980s. MRSA accounted for a small percentage of TSS cases. tst-1 continues to be the superantigen associated with the majority of menstrual cases. The CDC case definition identifies the most severe cases and has been consistently used but likely results in a substantial underestimation of the total TSS disease burden

Applications and Techniques for Fast Machine Learning in Science

In this community review report, we discuss applications and techniques for fast machine learning (ML) in science - the concept of integrating powerful ML methods into the real-time experimental data processing loop to accelerate scientific discovery. The material for the report builds on two workshops held by the Fast ML for Science community and covers three main areas: applications for fast ML across a number of scientific domains; techniques for training and implementing performant and resource-efficient ML algorithms; and computing architectures, platforms, and technologies for deploying these algorithms. We also present overlapping challenges across the multiple scientific domains where common solutions can be found. This community report is intended to give plenty of examples and inspiration for scientific discovery through integrated and accelerated ML solutions. This is followed by a high-level overview and organization of technical advances, including an abundance of pointers to source material, which can enable these breakthroughs

An Introduction to the mathematical formalization of quantum mechanics

Early in the development of quantum mechanics, there were two competing theories; the matrix mechanics proposed by Heisenberg, and the wave mechanics developed by Schrodinger. In 1932, John von Neumann was able to unify these theories and prove their equivalence. We will discuss operators in Hilbert Space; the mathematical formalization of quantum mechanics developed by Von Neumann. We will then look at the notation developed by Paul Dirac, and use it to prove some basic theorems of quantum mechanics. We will show how these theorems apply as a general statement about Hilbert spaces

Photoproduction of neutral mesons from hydrogen and helium targets in CLAS

The photoproduction of p0 and h mesons from hydrogen and 3He targets over an incident photon energy range of 0.5 - 1.5 GeV was studied using data from the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. This was part of a systematic study of meson photoproduction from the proton and light nuclear targets to investigate possible nuclear medium modifications of nucleon resonances and meson-nucleon interactions. A preliminary analysis of h cross sections was done using missing mass analysis and the results were compared to known data. Several corrections were then done to account for momentum loss of charged particles, as well as to determine fiducial volumes for charged particles and photons. The final analysis involved reconstructing the neutral mesons from their two-photon decay. Two-photon invariant mass spectra binned in incident photon energy and production angle were fitted to extract yields for p0 and h meson photoproduction. Monte Carlo simulations were also performed to determine the acceptance of the CLAS detector for these reactions. The analysis will be described and the procedures used to extract the yields and determine the acceptance will be discussed. Finally, preliminary cross section results will be presented. We saw an unexpected bump in the cross sections for the p0 at around 50 to 60 degrees. Further study is needed in order to determine whether this bump is due to an unknown phenomenon or an error in our analysis

The Physiological Basis Of Toxigenicity Of Clostridium Botulinum Types A And B.

Ph.D.MicrobiologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/182024/2/5803640.pd

Comparison of proteomic methods in evaluating biomarker-AKI associations in cardiac surgery patients

Although immunoassays are the most widely used protein measurement method, aptamer-based methods such as the SomaScan platform can quantify up to 7000 proteins per biosample, creating new opportunities for unbiased discovery. However, there is limited research comparing the consistency of biomarker-disease associations between immunoassay and aptamer-based platforms. In a substudy of the TRIBE-AKI cohort, preoperative and postoperative plasma samples from 294 patients with previous immunoassay measurements were analyzed using the SomaScan platform. Inter-platform Spearman correlations (rs) and biomarker-AKI associations were compared across 30 preoperative and 34 postoperative immunoassay-aptamer pairs. Possible factors contributing to inter-platform differences were examined including target protein characteristics, immunoassay, and SomaScan coefficients of variation, other assay characteristics, and sample storage time. The median rs was 0.54 (interquartile range [IQR] 0.34-0.83) in postoperative samples and 0.41 (IQR 0.21-0.69) in preoperative samples. We observed a trend of greater rs in biomarkers with greater concentrations; the Spearman correlation between the concentration of protein and the inter-platform correlation was 0.64 in preoperative pairs and 0.53 in postoperative pairs. Of proteins measured by immunoassays, we observed significant biomarker-AKI associations for 13 proteins preop and 24 postop; of all corresponding aptamers, 8 proteins preop and 12 postop. All proteins significantly associated with AKI as measured by SomaScan were also significantly associated with AKI as measured by immunoassay. All biomarker-AKI odds ratios were significantly different (P &lt; 0.05) between platforms in 14% of aptamer-immunoassay pairs, none of which had high (rs &gt; 0.50) inter-platform correlations. Although similar biomarker-disease associations were observed overall, biomarkers with high physiological concentrations tended to have the highest-confidence inter-platform operability in correlations and biomarker-disease associations. Aptamer assays provide excellent precision and an unprecedented coverage and promise for disease associations but interpretation of results should keep in mind a broad range of correlations with immunoassays