A comparison of porosity, fabric and fractal dimension as predictors of the Young''s modulus of equine cancellous bone

Ependymomas are rare neuroectodermal tumors arising from ependymal cells of the ventricular system, choroid plexus, filum terminale, and central canal of the spinal cord (1,2). This review focuses on intracranial ependymomas with special emphasis on pathology, etiology, cytogenetic characteristics, and adjuvant radiation therapy. Recent advances in neurosurgical technique, radiation therapy, and molecular biology have affected management of these tumors and have the potential to increase long-term cure rates. The role of highly advanced radiation therapy techniques such as stereotactic radiosurgery will need to be better defined.     

Psychological problems relevant to business and industry.

Psychologists' interest in problems related to industry has grown phenomenally over the past 10 years. Within the area of industrial psychology 3 subfields are distinguished: personnel psychology, developing out of the tradition of individual differences; human engineering, developing out of applied experimental psychology; industrial social psychology, developing from social-psychological theory. Each of these subareas are examined in the light of their conceptual history and the research problems they have raised. 98 refs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Measurement of Electromagnetic Shower Position and Size with a Saturated Avalanche Tube Hodoscope and a Fine Grained Scintillation Hodoscope

A hodoscope has been constructed from 100 ?m diameter wires and brass tubes (1.2 × 0.7 cm2 cross section) filled with a mixture of argon, ethane and ethyl alchohol. It has been tested in the saturated avalanche mode in an SCG1-C electromagnetic shower detector to determine its properties for the measurement of the position and size of electromagnetic showers. Two of these tube hodoscopes were positioned 3.5 radiation lengths deep in the detector and the profiles of 1-25 GeV electromagnetic showers were measured. Simultaneous measurements were performed using a plane of twenty, 0.5 cm wide scintillation counters positioned immediately behind the gas tube hodoscope. In addition the transition between saturated avalanche and limited streamer modes has been measured for the tube hodoscopes.     

Silver-doped sol-gel film as a surface-enhanced Raman scattering substrate for detection of uranyl and neptunyl ions

A surface-enhanced Raman scattering (SERS) substrate containing silver particles was prepared by an acid-catalyzed sol-gel method. Silver nitrate was first doped into the sol-gel film followed by chemical reduction of the silver ions with sodium borohydride to produce silver particles. This silver-doped sol-gel substrate exhibits strong enhancement of Raman scattering from adsorbed uranyl ions with a detection limit of 8.5 x 10(-8) M, which is comparable to existing methods of uranyl detection such as spectrophotometry, fluorometry, and a SERS method based on ligand-modified solution silver colloids. However, in the present method, no preconcentration steps, chromogens, or complexing ligands are needed. Compared with the SERS method using Ag colloidal sols, the silver-doped sol-gel film has the advantage that the silver particles trapped in the sol-gel matrix are much more stable than Ag colloids in liquid media. Furthermore, porous silica sol-gel materials are known to have affinities toward many inorganic and organic molecules. The enhanced adsorption affinities could also lead to the increased SERS sensitivity. The performance of the new silver-doped sol-gel substrate was evaluated with uranyl ions and compared to that of a SERS substrate based on silver-coated silica beads prepared by vacuum deposition. The detection limit for the silver-doped sol-gel film was 104 times lower than that for the silver-coated silica beads. The sol-gel substrate was further used to obtain, for the first time, the surface-enhanced Raman spectrum of neptunyl ions in dilute aqueous solutions.