A Comparative Study on in Vitro Invasion Rates by Melanoma Cells in the Human Amniotic Basement Membrane Model Versus in Vivo Tumor Nodule Formation in C57BL6 Mice

Invasion by murine B16-F10 melanoma cells was studied using the human amniotic basement membrane (HABM) assay. B16-F10 cells were collected after a single passage through the amnion and grown to near confluency. The cycle of plating, passaging, collecting, and culturing B16-F10 cells was repeated five times. The invasion rate for B16-F10 cells remained relatively unchanged after six passages through the amnion. Injection of first-passage B16-F10 cells into C57BL6 mice resulted in 29 lung tumors per animal whereas sixth-passage cells resulted in 300+ lung tumors. While there exists no correlation of the number of cells penetrating the amnion with colonization number, lung colonization appears correlated with increased number of passages through the amnion

Global discretization of continuous attributes as preprocessing for machine learning

AbstractReal-life data usually are presented in databases by real numbers. On the other hand, most inductive learning methods require a small number of attribute values. Thus it is necessary to convert input data sets with continuous attributes into input data sets with discrete attributes. Methods of discretization restricted to single continuous attributes will be called local, while methods that simultaneously convert all continuous attributes will be called global. In this paper, a method of transforming any local discretization method into a global one is presented. A global discretization method, based on cluster analysis, is presented and compared experimentally with three known local methods, transformed into global. Experiments include tenfold cross-validation and leaving-one-out methods for ten real-life data sets

Formation of Microcages from a Collagen Mimetic Peptide via Metal-Ligand Interactions

Here, the hierarchical assembly of a collagen mimetic peptide (CMP) displaying four bipyridine moieties is described. The CMP was capable of forming triple helices followed by self-assembly into disks and domes. Treatment of these disks and domes with metal ions such as Fe(II), Cu(II), Zn(II), Co(II), and Ru(III) triggered the formation of microcages, and micron-sized cup-like structures. Mechanistic studies suggest that the formation of the microcages proceeds from the disks and domes in a metal-dependent fashion. Fluorescently-labeled dextrans were encapsulated within the cages and displayed a time-dependent release using thermal conditions

Chromium coated silicon nitride electron beam exit window

A Si3N4 membrane with a thin Cr coating is proposed and demonstrated as an electron beam exit window. On average, 85% electron power transmission efficiency was achieved with a 1 μm thick Si3N4 membrane coated with 1 μm thick Cr and the membrane sustained a beam current of up to 3 mA at 60 keV electron energy for the continuous operation of 3 min. However, for an uncoated membrane of same thickness, the average electron power transmission efficiency was 71% and the maximum beam current sustained was 800 μA. It was also shown that a one micron thick Si3N4 square membrane window of 10 mm × 10 mm could withstand a differential pressure of 1.3 bars.The work carried out at Brunel University was co-funded by the EC Seventh Framework Programme theme FP7-SST-2011-RTD-1 for the DEECON project (grant number 284745)

PATHFINDER ATOMIC POWER PLANT. IBM-704 PROGRAM FOR REACTOR CONTAINMENT, PRESSURE SUPPRESSION ANALYSIS

A research and development program to investigate the feasibility of eliminating vapor closure for the Pathfinder Reactor was conducted. The major inquiry under the feasibility study involved an analysis of the complex transient conditions occurring in the reactor cavity, the pump rooms, and the entire reactor building following a primary system rupture. To solve the simultaneous nonlinear set of equations evolving from the heat, mass, and force balances in the system, an IBM-704 digital computer program was developed. The program has a very general input and can therefore be used with other containment designs. Input parameters include: initial pressures in reactor and throughout the containment building, hent capacity of vessel, decay heat, feedwater flow rate, enthalpy of feedwater, and volume of primary coolant system. (auth

Global discretization of continuous attributes as preprocessing for machine learning

Real-life data usually are presented in databases by real numbers. On the other hand, most inductive learning methods require a small number of attribute values. Thus it is necessary to convert input data sets with continuous attributes into input data sets with discrete attributes. Methods of discretization restricted to single continuous attributes will be called local, while methods that simultaneously convert all continuous attributes will be called global. in this paper, a method of transforming any local discretization method into a global one is presented. A global discretization method, based on cluster analysis is presented and compared experimentally with three known local methods, transformed into global. Experiments include tenfold cross-validation and leaving-one-out methods for ten real-life data sets

Three- and Four-Body Scattering Calculations including the Coulomb Force

The method of screening and renormalization for including the Coulomb interaction in the framework of momentum-space integral equations is applied to the three- and four-body nuclear reactions. The Coulomb effect on the observables and the ability of the present nuclear potential models to describe the experimental data is discussed.Comment: Proceedings of the Critical Stability workshop, Erice, Sicily, October 2008, to be published in Few-Body System

Preferential uptake of polyunsaturated fatty acids by colorectal cancer cells

Although a growing body of evidence suggests that colorectal cancer (CRC) is associated with alterations of fatty acid (FA) profiles in serum and tumor tissues, available data about polyunsaturated fatty acid (PUFA) content in CRC patients are inconclusive. Our study showed that CRC tissues contained more PUFAs than normal large intestinal mucosa. However, serum levels of PUFAs in CRC patients were lower than in healthy controls. To explain the mechanism of PUFA alterations in CRC, we measured FA uptake by the colon cancer cells and normal colon cells. The levels of PUFAs in colon cancer cell culture medium decreased significantly with incubation time, while no changes were observed in the medium in which normal colon cells were incubated. Our findings suggest that the alterations in tumor and serum PUFA profiles result from preferential uptake of these FAs by cancer cells; indeed, PUFAs are essential for formation of cell membrane phospholipids during rapid proliferation of cancer cells. This observation puts into question potential benefits of PUFA supplementation in CRC patients

Evolution of Li, Be and B in the Galaxy

In this paper we study the production of Li, Be and B nuclei by Galactic cosmic ray spallation processes. We include three kinds of processes: (i) spallation by light cosmic rays impinging on interstellar CNO nuclei (direct processes); (ii) spallation by CNO cosmic ray nuclei impinging on interstellar p and 4He (inverse processes); and (iii) alpha-alpha fusion reactions. The latter dominate the production of 6Li and 7Li. We calculate production rates for a closed-box Galactic model, verifying the quadratic dependence of the Be and B abundances for low values of Z. These are quite general results and are known to disagree with observations. We then show that the multi-zone multi-population model we used previously for other aspects of Galactic evolution produces quite good agreement with the linear trend observed at low metallicities without fine tuning. We argue that reported discrepancies between theory and observations do not represent a nucleosynthetic problem, but instead are the consequences of inaccurate treatments of Galactic evolution.Comment: 26 pages, 5 figures, LaTeX. The Astrophysical Journal, in pres