Reconstructing 3D x-ray CT images of polymer gel dosimeters using the zero-scan method

In this study x-ray CT has been used to produce a 3D image of an irradiated PAGAT gel sample, with noise-reduction achieved using the ‘zero-scan’ method. The gel was repeatedly CT scanned and a linear fit to the varying Hounsfield unit of each pixel in the 3D volume was evaluated across the repeated scans, allowing a zero-scan extrapolation of the image to be obtained. To minimise heating of the CT scanner’s x-ray tube, this study used a large slice thickness (1 cm), to provide image slices across the irradiated region of the gel, and a relatively small number of CT scans (63), to extrapolate the zero-scan image. The resulting set of transverse images shows reduced noise compared to images from the initial CT scan of the gel, without being degraded by the additional radiation dose delivered to the gel during the repeated scanning. The full, 3D image of the gel has a low spatial resolution in the longitudinal direction, due to the selected scan parameters. Nonetheless, important features of the dose distribution are apparent in the 3D x-ray CT scan of the gel. The results of this study demonstrate that the zero-scan extrapolation method can be applied to the reconstruction of multiple x-ray CT slices, to provide useful 2D and 3D images of irradiated dosimetry gels

Review: ‘Gimme five’: future challenges in multiple sclerosis. ECTRIMS Lecture 2009

This article is based on the ECTRIMS lecture given at the 25th ECTRIMS meeting which was held in Düsseldorf, Germany, from 9 to 12 September 2009. Five challenges have been identified: (1) safeguarding the principles of medical ethics; (2) optimizing the risk/benefit ratio; (3) bridging the gap between multiple sclerosis and experimental autoimmune encephalitis; (4) promoting neuroprotection and repair; and (5) tailoring multiple sclerosis therapy to the individual patient. Each of these challenges will be discussed and placed in the context of current research into the pathogenesis and treatment of multiple sclerosis

Lixiviação de nitrogênio em um Cambissolo cultivado com pessegueiro e submetido à aplicação de composto orgânico.

A aplicação de composto orgânico em solos cultivados com pessegueiro pode potencializar a transferência de N por lixiviação. O trabalho objetivou avaliar a lixiviação de N em um solo cultivado com pessegueiro e submetido à aplicação de composto orgânico. Em um pomar comercial de pessegueiro no município de Bento Gonçalves (RS) foram instalados lisímetros a 20 cm de profundidade. O solo recebeu a aplicação de 0 e 144 litros de composto orgânico por planta-1 ano-1 nas safras de 2010, 2011 e 2012. A solução do solo foi coletada no período de julho a outubro de 2012 e submetida à análise de nitrato, amônio e N mineral. As maiores concentrações de N lixiviado foram encontradas no tratamento com 144 litros de composto orgânico por planta-1. A adubação com composto orgânico apresentou baixas concentrações de N lixiviado, o que pode contribuir com a redução de contaminação ambiental.Resumo expandido

Iron biogeochemistry across marine systems progress from the past decade

Based on an international workshop (Gothenburg, 14–16 May 2008), this review article aims to combine interdisciplinary knowledge from coastal and open ocean research on iron biogeochemistry. The major scientific findings of the past decade are structured into sections on natural and artificial iron fertilization, iron inputs into coastal and estuarine systems, colloidal iron and organic matter, and biological processes. Potential effects of global climate change, particularly ocean acidification, on iron biogeochemistry are discussed. The findings are synthesized into recommendations for future research areas

A hybrid radiation detector for simultaneous spatial and temporal dosimetry

In this feasibility study an organic plastic scintillator is calibrated against ionisation chamber measurements and then embedded in a polymer gel dosimeter to obtain a quasi-4D experimental measurement of a radiation field. This hybrid dosimeter was irradiated with a linear accelerator, with temporal measurements of the dose rate being acquired by the scintillator and spatial measurements acquired with the gel dosimeter. The detectors employed in this work are radiologically equivalent; and we show that neither detector perturbs the intensity of the radiation field of the other. By employing these detectors in concert, spatial and temporal variations in the radiation intensity can now be detected and gel dosimeters can be calibrated for absolute dose from a single irradiation

Is axonal degeneration a key early event in Parkinson’s disease?

Author Posting. © The Author(s), 2016. This is the author's version of the work. It is posted here by permission of IOS Press for personal use, not for redistribution. The definitive version was published in Journal of Parkinson's Disease 6 (2016): 703-707, doi:10.3233/JPD-160881.Recent research suggests that in Parkinson’s disease the long, thin and unmyelinated axons of dopaminergic neurons degenerate early in the disease process. We organized a workshop entitled ‘Axonal Pathology in Parkinson’s disease’, on March 23rd, 2016, in Cleveland, Ohio with the goals of summarizing the state-of-the-art and defining key gaps in knowledge. A group of eight research leaders discussed new developments in clinical pathology, functional imaging, animal models, and mechanisms of degeneration including neuroinflammation, autophagy and axonal transport deficits. While the workshop focused on PD, comparisons were made to other neurological conditions where axonal degeneration is well recognized

JAEPL, Vol. 20, Winter 2014-2015

Essays Libby Falk Jones - Praisesong: One (Worn) Path through AEPL Alice Brand - Twenty Years: Reflections and Questions Tom Gage - Hitchhiking the Labyrinth Susan Schiller - The Dance of Spirit in AEPL Kristie S. Fleckenstein - Stepping Beyond, In, and With JAEPL: Twenty Years of Hope Paul Heilker - Coming to Nonviolence Beth Daniell - To the Contrary John Creger - The Personal Creed Project: Portal to Deepened Learning Jessica Jones - Put Your Ear Close to the Whispering Branch... Deep Listening in the English Classroom Out of the Box Laurence Musgrove & Myra Musgrove - Drawing is Learning Book Reviews Judy Halden-Sullivan - Embracing the Beginner\u27s Mind Elizabeth French - Richardson, Scott. eleMENtary School—(Hyper) Masculinity in a Feminized Context. Rotterdam: Sense Publishers, 2012. Print. Brad Lucas - Ryden, Wendy and Ian Marshall. Reading, Writing, and the Rhetorics of Whiteness. NY: Routledge, 2012. Print. Candace Walworth - Kroll, Barry. The Open Hand: Arguing as an Art of Peace. Logan, UT: Utah State UP, 2013. Print. Caleb Corkery - Conway, Jeremiah. The Alchemy of Teaching: The Transformation of Lives. Boulder, CO: Sentient Publications, 2013. Print. Connecting Helen Walker - Widening Circles Wanda Njoya - Miracles Happen Ann Wachira - Using a Model David Bedsole - To the Dog Next Door Who Barks All Day W. Keith Duffy - Aisle Four: Ice Cream, TV Dinners, Humilit