Geochemical-geophysical investigations, Fairbanks district

Trace element distribution in a subarctic valley in the Cleary Hill area of the Fairbanks gold district has been studied. Zinc and arsenic have been found excellent pathfinder elements for auriferous deposits. Methods of analysis for copper, lead, zinc, molybdenum, silver and arsenic as well as heavy metals are discussed. The University of Alaska method #2 has been improved, Terrain, slope, and frozen ground have little effect upon the distribution of trace elements associated with the Cleary H i l l vein. A new method for the determination of zinc using dilute acid is proposed. Analysis of geochemical data by trend surface procedures proved effective for localization of anomalies

Developmental cell lineage dynamics in Bicuspid Aortic Valve disease

The bicuspid aortic valve (BAV) is a congenital heart defect which is characterized by the formation of two aortic leaflets instead of the normal three leaflets within the tricuspid aortic valve (TAV). Whilst all BAV patients have a bicuspid valve, extended patient monitoring has revealed a large variation of disease progression trajectories during a patient’s lifetime. This large variation troubles clinical decision making due to the uncertain proliferation of BAV disease. More knowledge of the biological mechanisms underlying BAV could address that uncertainty and thus help stratify patient risk with more accuracy. Therefore this thesis aims to advance our current understanding regarding the biological impact and developmental mechanisms underlying congenital BAV and BAV related aortopathy.LUMC / Geneeskund

The movement of spray drift near a live shelterbelt

Non-Peer ReviewedThere has been recent interest in the use of shelterbelts to mitigate spray drift and protect downwind areas. Previous research has investigated the interaction of spray drift and shelterbelts using model shelterbelts, wind tunnel experiments, and numerical modeling; however, there is limited knowledge on the movement of spray drift near a live shelterbelt in field conditions. These experiments measured the ground deposition and airborne concentration of drift near a live carragana/chokecherry mix shelterbelt. It was found that when compared to open field experiments where there was no shelterbelt, the mass of ground deposit was less in the lee of the shelterbelt for a distance of 0-10H downwind of the shelterbelt (where H is the height of the shelterbelt). Further than 10H downwind of the shelterbelt, the mass of ground deposit was similar to the open field. There was an 88% reduction in airborne drift exiting the shelterbelt as compared to the drift entering the shelterbelt, which likely caused the reduction in deposition in the shelterbelt’s lee. It was shown that there was a larger proportion of drift diverted over the top of the shelterbelt as compared to the drift exiting the shelterbelt. Although not apparent in these experiments, this suggested that there may be increased deposition further downwind from the shelterbelt as compared to the open field

On the intrinsic charm and the recombination mechanisms in charm hadron production

We study $\Lambda_c^\pm$ production in $pN$ and $\pi^-N$ interactions. Recent experimental data from the SELEX and E791 Collaborations at FNAL provide important information on the production mechanism of charm hadrons. In particular, the production of the $\Lambda_c$ baryon provides a good test of the intrinsic charm and the recombination mechanisms, which have been proposed to explain the so called leading particle effects.Comment: 11 pages, two figures (postscript), late

Development of ultrasonic methods for examining stainless steel welds. Interim progress report

Spurious ultrasonic (UT) signals obtained during the examination of austenitic stainless steel welds in LMFBR components have emphasized the need to develop more effective UT methods to supplement the examination processes presently employed during fabrication, and for use during subsequent in-service inspection of LMFBR plants. This interim report documents the first year's effort on a program that was designed to investigate this problem and develop viable solutions. Sixty-eight weld samples were acquired, cataloged, and subjected to a series of ultrasonic, radiographic, and metallographic examination procedures. It was determined that although spurious UT noise signals could usually be associated with major dendritic grain growth patterns, the existence and magnitude of some of the observed noise signals could not be explained simply on the basis of dendritic microstructure. The results obtained during application of a series of ultrasonic and radiographic characterization procedures are included, in addition to photomicrographs and photomicrographic montages taken in the vicinity of numerous sites which produced ultrasonic noise signals of various amplitudes. A concurrent investigation was conducted to evaluate the performance of conventional ultrasonic examination procedures. These results are compared with the laboratory investigation results, and a brief outline of future work planned under this program is presented. (auth

Perturbative QCD Fragmentation Functions for BcB_c and Bc∗B_c^* Production

The dominant production mechanism for ${\bar b} c$ bound states in high energy processes is the production of a high energy ${\bar b}$ or $c$ quark, followed by its fragmentation into the ${\bar b} c$ state. We calculate the fragmentation functions for the production of the S-wave states $B_c$ and $B_c^*$ to leading order in the QCD coupling constant. The fragmentation probabilities for ${\bar b} \rightarrow B_c$ and ${\bar b} \rightarrow B_c^*$ are approximately $2.2 \times 10^{-4}$ and $3.1 \times 10^{-4}$, while those for $c \rightarrow B_c$ and $c \rightarrow B_c^*$ are smaller by almost two orders of magnitude.Comment: Latex, 12 pages, 3 figures available upon request, NUHEP-TH-93-

Finding character strengths through loss: an extension of Peterson and Seligman (2003)

People can experience positive changes even in the midst of adversity and loss. We investigated character strengths following three recent shooting tragedies. Using an Internet database of respondents to the Values in Action Inventory of Strengths (VIA-IS), we compared responses from three groups of participants (N = 31,429) within close proximity of each event: those who completed it eight months prior to the event, and one month and two months after. Results suggested that for one of the events, participants who completed the VIA-IS after the event showed slightly different levels of self-reported character strengths compared to participants who completed the VIA-IS before the event, with some mean levels higher and others lower. The observed differences in character strengths were inconsistent across follow-up periods, and effect sizes were small (d values from –0.13 to 0.15). These findings raise questions about whether and how tragedies might catalyze differences in character strengths

In-hospital mortality of non-st segment elevation myocardial infarction in a Puerto Rican population

Introduction: Currently, there is limited published information on in-hospital mortality regarding ST segment elevation and non-ST segment elevation myocardial infarction. This information is even scarcer on the Hispanic population. We aim to study if there is a difference on in-hospital mortality between ST elevation myocardial infarction (STEMI) and non-ST elevation myocardial infarction (NSTEMI) in a mostly Hispanic population. Methods: A secondary data analysis of a non-concurrent prospective study was performed using the Puerto Rican Heart Attack study database. Dependent variable was in-hospital mortality and independent variable was type of myocardial infarction (STEMI or NSTEMI). We conducted, sequentially, a descriptive, bivariate and multivariate analysis. The chi-squared test was used to compare categorical variables and t-test for continuous variables. Finally, a logistic regression model was used to perform the multivariate analysis. Results: From the 838 Puerto Rican patients hospitalized with ST classification, 310 (37%) were diagnosed with STEMI. Patients with STEMI were younger (65 years vs 68 years; p=0.008), more likely to receive invasive treatment (47.9% vs 27.5%, p<0.001), and less likely to have a history of hypertension (72.5% vs 79.0%, p=0.033) compared to NSTEMI patients. For every 1- year increase in age, there is a 4% increase in in-hospital mortality. Patients with hyperlipidemia were approximately two times more likely to die in the hospital compared to patients without hyperlipidemia. In the unadjusted analysis, there was no significant association between STEMI and NSTEMI patients and in-hospital mortality. After adjusting for confounders, patients with STEMI had twice the risk of dying than those with NSTEMI. Conclusions: Findings from this study suggest that Puerto Ricans with STEMI have double the risk of in-hospital mortality than NSTEMI patients. Our findings were similar to those reported in the literature. A timely recognition of at-risk patients, especially among STEMI patients, may help reduce short-term morality among patients hospitalized with acute myocardial infarction in Puerto Rico

The role of cell tracing and fate mapping experiments in cardiac outflow tract development, new opportunities through emerging technologies

Whilst knowledge regarding the pathophysiology of congenital heart disease (CHDs) has advanced greatly in recent years, the underlying developmental processes affecting the cardiac outflow tract (OFT) such as bicuspid aortic valve, tetralogy of Fallot and transposition of the great arteries remain poorly understood. Common among CHDs affecting the OFT, is a large variation in disease phenotypes. Even though the different cell lineages contributing to OFT development have been studied for many decades, it remains challenging to relate cell lineage dynamics to the morphologic variation observed in OFT pathologies. We postulate that the variation observed in cellular contribution in these congenital heart diseases might be related to underlying cell lineage dynamics of which little is known. We believe this gap in knowledge is mainly the result of technical limitations in experimental methods used for cell lineage analysis. The aim of this review is to provide an overview of historical fate mapping and cell tracing techniques used to study OFT development and introduce emerging technologies which provide new opportunities that will aid our understanding of the cellular dynamics underlying OFT pathology.Cardiolog

Computing SL(2,C) Central Functions with Spin Networks

Let G=SL(2,C) and F_r be a rank r free group. Given an admissible weight in N^{3r-3}, there exists a class function defined on Hom(F_r,G) called a central function. We show that these functions admit a combinatorial description in terms of graphs called trace diagrams. We then describe two algorithms (implemented in Mathematica) to compute these functions.Comment: to appear in Geometriae Dedicat