Purification of Radioactive Ion Beams by Photodetachment in a RF Quadrupole Ion Beam Cooler

A highly efficient method for suppressing isobar contaminants in negative radioactive ion beams by photodetachment is demonstrated. A laser beam having the appropriate photon energy is used to selectively neutralize the contaminants. The efficiency of photodetachment can be substantially improved when the laser-ion interaction takes place inside a radio frequency quadrupole ion cooler. In off-line experiments with ion beams of stable isotopes, more than 99.9% suppression of Co-, S-, and O- ions has been demonstrated while under the identical conditions only 22% reduction in Ni- and no reduction in Cl- and F- ions were observed. This technique is being developed for on-line purification of a number of interesting radioactive beams, such as 56Ni, 17,18F, and 33,36Cl

Convergent finite difference methods for one-dimensional fully nonlinear second order partial differential equations

This paper develops a new framework for designing and analyzing convergent finite difference methods for approximating both classical and viscosity solutions of second order fully nonlinear partial differential equations (PDEs) in 1-D. The goal of the paper is to extend the successful framework of monotone, consistent, and stable finite difference methods for first order fully nonlinear Hamilton–Jacobi equations to second order fully nonlinear PDEs such as Monge–Ampère and Bellman type equations. New concepts of consistency, generalized monotonicity, and stability are introduced; among them, the generalized monotonicity and consistency, which are easier to verify in practice, are natural extensions of the corresponding notions of finite difference methods for first order fully nonlinear Hamilton–Jacobi equations. The main component of the proposed framework is the concept of a “numerical operator”, and the main idea used to design consistent, generalized monotone and stable finite difference methods is the concept of a “numerical moment”. These two new concepts play the same roles the “numerical Hamiltonian” and the “numerical viscosity” play in the finite difference framework for first order fully nonlinear Hamilton–Jacobi equations. In the paper, two classes of consistent and monotone finite difference methods are proposed for second order fully nonlinear PDEs. The first class contains Lax–Friedrichs-like methods which also are proved to be stable, and the second class contains Godunov-like methods. Numerical results are also presented to gauge the performance of the proposed finite difference methods and to validate the theoretical results of the paper

Use of adsorbent resins in fermentations of bacteria obtained from the red soils of the Kingdom of Jordan and the isolation and structure elucidation of cytotoxic xanthones from an unidentified fungus

Part I: Adsorbent resins are used in industrial fermentations to help boost the production of antibiotics. The resins used here were utilized to help speed the drug discovery process by eliminating the time-consuming step of freeze-drying the fermentation extract. This led to a shortened time span from receiving the fermentation to identifying the secondary metabolites via HPLC and LC/MS. Part II: Three new xanthones, 1-hydroxy-5-hydroxymethyl-6-methoxy-7-methyl-xanthone (1), 1-hydroxy-6-methoxy-7-methyl-xanthone (2), and 1-hydroxy-5,7-dimethyl-6-methoxy-xanthone (3), were isolated from an unknown fungus, MSX 68425, from the Mycosynthetix library of filamentous fungi. The compounds were discovered using bioactivity-directed fractionation, in pursuit of anticancer lead compounds. The structures of these compounds were determined by spectroscopic and spectrometric techniques, in conjunction with comparisons to the literature

Instructional geographic information science: map overlay and spatial abilities

The fundamental goal of this study is to determine if the complex spatial concept of map overlay can be effectively learned by young adolescents through the utilization of an instructional technique based within the foundations of Instructional Geographic Information Science (InGIScience). Percent correct and reaction times were the measures used to analyze the ability of young adolescents to learn the intersect, erase, and union functions of map overlay. The ability to solve for missing inputs, output, or function was also analyzed. Young adolescents of the test group scored higher percent correct and recorded faster reaction times than those of the control group or adults of the expert group by the end of the experiment. The intersect function of map overlay was more difficult in terms of percent correct and reaction time than the erase or union functions. Solving for the first or second input consistently resulted in lower percent correct and higher reaction times throughout the experiment. No overall performance differences were shown to exist between males and females. Results of a subjective "real-world" test also indicated learning by young adolescents. This study has shown that the practice of repetitive instruction and testing has proven effective for enhancing spatial abilities with regard to the map overlay concept. This study found that with practice, young adolescents can learn the map overlay concept and perform at levels equal to or greater than adults. This study has helped to answer the question of whether this development of spatial abilities is possible

Dissociative Experiences in Hypothetically Psychosis-Prone College Students

The relationship between dissociative experiences and psychosis proneness was investigated in a sample of 523 college undergraduates. Participants were administered the Dissociative Experiences Scale (DES), the Perceptual Aberration Scale, the Magical Ideation Scale, the Social Anhedonia Scale, and the Physical Anhedonia Scale. As hypothesized, the Perceptual Aberration and Magical Ideation Scales were positively correlated with the DES. The Social Anhedonia Scale had a modest correlation with the DES, but this relationship was largely mediated by the Perceptual Aberration and Magical Ideation Scales. The Physical Anhedonia Scale was uncorrelated with the DES. Exploratory factor analysis of the psychosis-proneness scales and the DES subscales resulted in a three-factor solution: dissociative experiences, positive schizotypy, and negative schizotypy. The DES depersonalization subscale loaded on both the dissociation and positive schizotypy factors

A screen for modifiers of teflon identifies novel components of the meiotic segregation pathway in male Drosophila melanogaster

The teflon (tef) gene is required specifically for ensuring adhesion between autosomes in male meiosis. In tef mutants, autosomal homologs pair correctly, but separate prior to metaphase, resulting in random segregation of homologs at meiosis I. To identify genes that interact with tef, we have performed a screen for dominant second site modifiers of a hypomorphic allele, tefP1150. We have tested the third chromosome deficiency kit, which spans ~90% of the third chromosome, as well as a collection of previously identified male meiotic mutants (Wakimoto et al. 2004). We identified 11 regions containing Enhancers, and 6 regions containing Suppressors of tef. One of the enhancing deletions removes mod(mdg4), which has been previously proposed to interact with tef to ensure autosomal conjugation (Thomas et al. 2005). A second enhancer was mapped to autophagy specific gene 2 (atg2), which is a novel component of the meiotic homolog segregation pathway in Drosophila males."--Abstract from author supplied metadata

The cliff

The Cliff is a novel whose setting is a cliff, on the central coastline of California in the year, I898. The cliff is the site of an abandoned, limestone mining operation. The principal characters in the story are: Amy Braddock, a thirty-five-year-old widow: Jason Braddock, her eleven-year-old son; and Prophet, a black man, a stranger, and an alleged friend of the deceased father's. Prophet is a mysterious person who arrives one day on foot, with nothing but the clothes on his back and what he calls a "spirit stick" in his hand. The stick appears to be a totem of some sort, possessed of magical powers. The first two chapters we see here are concerned with Prophet's attempts to win a place for himself in the family and his initial efforts to persuade them to reopen the limestone mine