Electrochemical Detection of Prostate Carcinoma Biomarkers Using Nanotechnology

The first chapter of this thesis speaks about prostate specific antigen, carbon nanotubes and horseradish peroxidase. The second chapter discusses the electrochemistry and catalysis of horseradish peroxidase (HRP) and myoglobin (Mb) covalently attached to vertically aligned carbon nanotube arrays used as a tranducer. Cyclic voltammetry results gave quasi-reversible FeIII/FeII voltammetry and electrochemical catalysis involving catalytic reduction of hydrogen peroxide for both the iron-heme enzymes in myoglobin and horseradish peroxidase coupled to the carboxylated ends of the carbon nanotube arrays by amine bioconjugation reactions. Reduction peak currents gave linear relationships with scan-rates, typical of thin layer voltammetry. Results suggest that the vertically aligned nanotube arrays behave like metal electrical conductors shuttling electrons from the external circuit to redox active sites of the enzymes. Electrode-driven peroxidase activity of myoglobin and horseradish peroxidase attached to the carbon nanotube arrays was demonstrated, with detection limits for hydrogen peroxide in buffer solutions of 100nM. Moreover, Resonance Raman characterization gave spectral signatures indicating successful fabrication of the SWNT arrays with optimum 100% coverage at FeCl3 solution at a pH of 1.7. These prototype carbon nanotube biosensors are easy to prepare, and the enzyme films were stable for weeks. The third chapter describes our initial studies in the development of our prototype immunosensor using SWNT nanotubes for electrochemical detection prostate specific antigen (PSA), a cancer biomarker protein in serum. This novel immunosensor features vertically aligned nanotubes with captured immunological complex in a sandwich format. The antigen-antibody biorecognition event was monitored using catalytic reaction involving horseradish peroxidase conjugated to a secondary antibody. This initial non-amplified approach provided a decent detection limit of 0.4ng/mL for Prostate Specific Antigen, which compare favorably with the standard enzyme-linked immunosorbent assay (ELISA). Work is in progress to lower the detection limits using specially designed bioconjuates with multiple enzyme labels for signal amplifications. These easily fabricated SWNT immunosensors show excellent promise for clinical screening of cancer biomarkers and point-of-care diagnosis. Chapter 4 is describing The Pell Scholars Honors Program Connection

An Efficiency Criterion for 2D Shape Model Selection

We propose efficiency of representation as a criterion for evaluating shape models, then apply this criterion to compare the boundary curve representation with the medial axis. We estimate the å-entropy of two compact classes of curves. We then construct two adaptive encodings for noncompact classes of shapes, one using the boundary curve and the other using the medial axis, and determine precise conditions for when the medial axis is more efficient. Along the way we construct explicit near-optimal boundarybased approximations for compact classes of shapes and an explicit compression scheme for non-compact classes of shapes based on the medial axis. We end with an application of the criterion to shape data

As Good as the Networks They Keep?: Improving Outcomes through Weak Ties in Rural Uganda

We examine an intervention randomized at the village level in which female farmers invited to a single training session were randomly paired with farmers whom they did not know and encouraged to share new agricultural information throughout the growing season for a recently adopted cash crop. We show that the intervention significantly increased the productivity of all farmers except of those who were already in the highest quintile of productivity, and that there were significant spillovers in productivity to male farmers

As Good as the Networks They Keep?: Improving Outcomes through Weak Ties in Rural Uganda

We examine an intervention randomized at the village level in which female farmers invited to a single training session were randomly paired with farmers whom they did not know and encouraged to share new agricultural information throughout the growing season for a recently adopted cash crop. We show that the intervention significantly increased the productivity of all farmers except of those who were already in the highest quintile of productivity, and that there were significant spillovers in productivity to male farmers

A 2D Shape Structure for Decomposition and Part Similarity

International audienceThis paper presents a multilevel analysis of 2D shapes and uses it to find similarities between the different parts of a shape. Such an analysis is important for many applications such as shape comparison, editing, and compression. Our robust and stable method decomposes a shape into parts, determines a parts hierarchy, and measures similarity between parts based on a salience measure on the medial axis, the Weighted Extended Distance Function, providing a multi-resolution partition of the shape that is stable across scale and articulation. Comparison with an extensive user study on the MPEG-7 database demonstrates that our geometric results are consistent with user perception

How social structure shapes female competition throughout her lifetime

Many studies find a consistent gender gap in competitiveness where men are more likely to compete than women given the same level of ability. Using data from experiments with women ages 12 through 90 in matrilocal and patrilocal communities in rural Malawi, we show that this gender gap does not exist uniformly for all women nor across their whole lifetime. We first replicate three main findings from the gender and competition literature: (i) women are less likely to compete on average; and the gender gap differs by (ii) culture and by (iii) age. In a new finding, we show that the gender gap changes in a theoretically-predicted manner with motherhood status. We argue that these results, when combined, point to an overarching theory of gender and competition–one that is driven by environmental constraints that vary with age, fertility, and social structure. © 202

Image processing mini manual

The intent is to provide an introduction to the image processing capabilities available at the Langley Research Center (LaRC) Central Scientific Computing Complex (CSCC). Various image processing software components are described. Information is given concerning the use of these components in the Data Visualization and Animation Laboratory at LaRC

Multifaceted Management of COVID in the Medical Student Population of Sidney Kimmel Medical College

COVID has created hardships in the lives of many persons. In a time of chaos, it was clear our institution needed an efficient workflow to track all students requiring quarantine, so that academic progress and student wellness would not be casualties. This presentation reviews that workflow in detail, for the purpose of sharing strengths of the process for the greater GSA/OSR network’s benefit.https://jdc.jefferson.edu/emposters/1002/thumbnail.jp