Self-Affine Tilings with Several Tiles, I

AbstractThe tilings of Rd by a finite number of lattice translates of self-affine prototiles are studied in their own right and as they relate to multiwavelet bases of L2(Rd)

Delay of phagosome maturation by a mycobacterial lipid is reversed by nitric oxide.

Mycobacterium tuberculosis is a facultative intracellular pathogen that inhibits phagosome maturation in macrophages thereby securing survival and growth. Mycobacteria reside in an early endocytic compartment of near-neutral pH where they upregulate production of complex glycolipids such as trehalose dimycolate. Here, we report that trehalose dimycolate coated onto beads increased the bead retention in early phagosomes, i.e. at a similar stage as viable mycobacteria. Thus, a single mycobacterial lipid sufficed to divert phagosome maturation and likely contributes to mycobacterial survival in macrophages. Previous studies showed that activated macrophages promote maturation of mycobacterial phagosomes and eliminate mycobacteria through bactericidal effectors including nitric oxide generated by inducible nitric-oxide synthase. We show that deceleration of bead phagosome maturation by trehalose dimycolate was abolished in immune-activated wild type, but not in activated nitric-oxide synthase-deficient macrophages, nor when hydroxyl groups of trehalose dimycolate were chemically modified by reactive nitrogen intermediates. Thus, specific host defence effectors of activated macrophages directly target a specific virulence function of mycobacteria

Correlated SEM, FIB, and TEM Studies of Material Collected by the NASA Stardust Spacecraft

The objective of this thesis is to describe the study of cometary materials returned by NASA’s Stardust mission. The majority of the research presented in this thesis focuses on improving our characterization and understanding of the fine (\u3c 1 µm) component of comet Wild 2. Investigations of the Stardust foils are conducted with correlated Scanning Electron Microscopy (SEM), Focused Ion Beam (FIB) sample preparation, and Transmission Electron Microscopy (TEM). Investigations of the Stardust aerogels are conducted with plasma ashing sample preparation followed by detailed characterization of the material with TEM. Additional studies of the Stardust interstellar foils, as well as the use of a Convolutional Neural Network (CNN) to search images of the Stardust foils for impact features, are also presented. As a part of this thesis I have developed a new technique for analyzing the Stardust aerogels through the use of plasma ashing sample preparation. This technique is an improvement upon previous attempts to separate cometary materials from the aerogel through the use of HF vapor etching. Plasma ashing allows for cometary materials trapped within the Stardust aerogels to be deposited directly onto TEM grids allowing for detailed characterization of the cometary material with minimal interference from the aerogel itself. The correlated SEM/FIB/TEM studies of the Stardust foils demonstrated here nearly double the number of Stardust craters that have been elementally and structurally characterized in scientific literature. The crater impactor residues were largely composed of combinations of silicates and iron-nickel sulfides that, following impact, rapidly quenched into amorphous melt layers. Two craters were found to contain signatures of the refractory minerals spinel and taenite, indicating a component of the Wild 2 fines originated in the inner Solar System. However, the lack of crystalline material throughout the crater residues suggests that the fine component may largely be composed of amorphous silicates that likely formed in the outer Solar System. Additionally, the submicron Stardust craters appeared enriched in volatile elements relative to CI chondrites, further suggesting that the fine component of Wild 2 originated from a reservoir that was separate from the more refractory coarse (\u3e 1 µm) component. The Stardust aerogel samples returned carbon-rich and potential oldhamite grains. Carbon-rich materials have not been previously observed in the Stardust foils, likely due to the violent collection methods, and the result suggests the ashing technique may be used to better characterize components of the Wild 2 fines that have been difficult to investigate. The presence of oldhamite in the Stardust aerogels would be scientifically significant as it is formed in highly reducing conditions and has only been identified in enstatite chondrites and enstatite achondrites. As a result, our results may call into question the Warren gap hypothesis, which would prohibit the presence of such highly reduced materials in the outer Solar System at the time that comet Wild 2 accreted

I2B is a Small Cytosolic Protein that Participates in Vacuole Fusion

Saccharomyces cerevisiae vacuole inheritance requires two low molecular weight activities, LMA1 and LMA2. LMA1 is a heterodimer of thioredoxin and protease B inhibitor 2 (IB2). Here we show that the second low molecular weight activity (LMA2) is monomeric IB2. Though LMA2 / IB2 was initially identified as a protease B inhibitor, this protease inhibitor activity is not related to its ability to promote vacuole fusion: ( i ) Low M r protease B inhibitors cannot substitute for LMA1 or LMA2, ( ii ) LMA1 and LMA2 promote the fusionof vacuoles from a strain that has no protease B, ( iii ) low concentrations of LMA2 that fully inhibit protease B do not promote vacuole fusion, and ( iv ) LMA1, in which is complexed with thioredoxin,is far more active than LMA2 / IB2 in promoting vacuole fusion and far less active in inhibiting protease B. These studies establish a new function for IB2

Prevalence of obesity, type II diabetes mellitus, hyperlipidemia, and hypertension in the United States: findings from the GE Centricity Electronic Medical Record database.

This study analyzed GE Centricity Electronic Medical Record (EMR) data to examine the effects of body mass index (BMI) and obesity, key risk factor components of metabolic syndrome, on the prevalence of 3 chronic diseases: type II diabetes mellitus, hyperlipidemia, and hypertension. These chronic diseases occur with high prevalence and impose high disease burdens. The rationale for using Centricity EMR data is 2-fold. First, EMRs may be a good source of BMI/obesity data, which are often underreported in surveys and administrative databases. Second, EMRs provide an ideal means to track variables over time and, thus, allow longitudinal analyses of relationships between risk factors and disease prevalence and progression. Analysis of Centricity EMR data showed associations of age, sex, race/ethnicity, and BMI with diagnosed prevalence of the 3 conditions. Results include uniform direct correlations between age and BMI and prevalence of each disease; uniformly greater disease prevalence for males than females; varying differences by race/ethnicity (ie, African Americans have the highest prevalence of diagnosed type II diabetes and hypertension, while whites have the highest prevalence of diagnosed hypertension); and adverse effects of comorbidities. The direct associations between BMI and disease prevalence are consistent for males and females and across all racial/ethnic groups. The results reported herein contribute to the growing literature about the adverse effects of obesity on chronic disease prevalence and about the potential value of EMR data to elucidate trends in disease prevalence and facilitate longitudinal analyses

Chandra Studies of the X-ray Point Source Luminosity Functions of M31

Three different M31 disk fields, spanning a range of stellar populations, were observed by Chandra. We report the X-ray point source luminosity function (LF) of each region, and the LF of M31's globular clusters, and compare these with each other and with the LF of the galaxy's bulge. To interpret the results we also consider tracers of the stellar population, such as OB associations and supernova remnants. We find differences in the LFs among the fields, but cannot definitively relate them to the stellar content of the fields. We find that stellar population information, average and maximum source luminosities, X-ray source densities, and slopes of the LF are useful in combination.Comment: 7 pages, 3 figures, accepted for publication in ApJ. Higher-resolution figures available on reques

A Letter of Intent to Install a milli-charged Particle Detector at LHC P5

In this LOI we propose a dedicated experiment that would detect "milli-charged" particles produced by pp collisions at LHC Point 5. The experiment would be installed during LS2 in the vestigial drainage gallery above UXC and would not interfere with CMS operations. With 300 fb$^{-1}$ of integrated luminosity, sensitivity to a particle with charge $\mathcal{O}(10^{-3})~e$ can be achieved for masses of $\mathcal{O}(1)$ GeV, and charge $\mathcal{O}(10^{-2})~e$ for masses of $\mathcal{O}(10)$ GeV, greatly extending the parameter space explored for particles with small charge and masses above 100 MeV.Comment: 19 pages, 7 figure

Evaluation and management of leukolysis-mediated pseudohyperkalemia in paediatric leukemic samples

Leukolysis-related pseudohyperkalemia due to preanalytical procedures may lead to erroneous (or absence of) treatment based on an invalid lab test result. We aimed to obtain a leukocyte threshold above which leukolysis-related pseudohyperkalemia becomes clinical relevant. Secondly, temporal dynamics of treatment-induced leukocyte decrease were studied to allow tailored implementation of laboratory information system (LIS) decision rules based on the leukocyte threshold to avoid leukolysis-related pseudohyperkalemia. Potassium results of AU5811 routine chemistry (Beckman Coulter, Brea, California, USA) and iStat point of care (POC) (Abbott Diagnostics, Chicago, Illinois, USA) analysers were compared, the latter method being insensitive to leukolysis caused by pre-analytical procedures. Potassium results were combined with leukocyte counts obtained using a Cell-Dyn Sapphire haematology analyser (Abbott Diagnostics, Santa Clara, California, USA), resulting in 132 unique data triplets. Regression analysis was performed to establish a leukocyte threshold. The Reference Change Value (√2 x Z x √(CVa2 + CVi2)) was used to calculate maximum allowable difference between routine analyser and POC potassium results (deltamax + 0.58 mmol/L). Temporal analysis on the treatment-induced leukocyte decrease was performed by plotting leukocyte counts in time for all patients above the threshold leukocyte count (N = 41). Established leukocyte threshold was 63 x109/L. Temporal analysis showed leukocyte counts below the threshold within 8 days of treatment for all patients. Based on performed analyses we were able to implement LIS decision rules to reduce pseudohyperkalemia due to preanalytical procedures. This implementation can contribute to a reduction in erroneous (or absence of) treatments in the clinic