Film dosimetry in water in a 23 MV therapeutic photon beam

The field size and water depth dependence of the measured optical density of Kodak XV-2 film, irradiated in a 23 MV photon beam has been investigated. The films were positioned in a water tank in a vertical plane containing the beam axis with the upper film edge parallel to the water surface at a depth of 0.3 mm. The observed field size and water depth dependence of the film sensitivity cannot be fully attributed to the usual variation of the photon spectrum with field size and water depth: measured optical densities do significantly depend on the amount of film material above the point of measurement and on the film orientation. A method for application of film for relative water dose measurements in a plane containing the beam axis in a 23 MV therapeutic photon beam is presented; the observed agreement between film and ionisation chamber measurements is very good: typically within 1% or 2 mm

Формирование изображения нарушителя в радиолучевых системах охраны

В статье рассмотрены вопросы улучшения информационных характеристик двухпозиционных радио- лучевых технических систем охраны. В качестве первого приближения сигналообразования использована лучевая модель формирования интерференционной картины ЭМ-волны. Разработан метод формирования двумерного изображения нарушителя в виде теневого силуэта. Получено обратное преобразование Кирхгофа, связывающее функцию пропускания объекта с распределением комплексной амплитуды ЭМ-волны в плоскости приема.У статті розглянуті питання поліпшення інформаційних характеристик двопозиційних радіопроменевих технічних систем охорони. Як перше наближення сигналостворення використана променева модель формування інтерференційної картини ЕМ-хвилі. Розроблено метод формування двовимірного зображення порушника у вигляді тіньового силуету. Отримано зворотне перетворення Кірхгофа, що зв’язує функцію пропускання об’єкта з розподілом комплексної амплітуди ЕМ-хвилі в площині прийому.The article deals with the issues of improving information characteristics of two-position radio-beam technical protection systems. The beam model of forming EM wav interference pattern is used as the first approximation of signal forming. The method of forming the intruder’s two-dimensional image as a shadow silhouette has been developed. The author has drawn the Kirchhoff inversion connecting the object’s transmission function with the distribution of the EM wave complex amplitude in the reception plane

Companding technique for high dynamic range measurements using gafchromic films

We propose a methodology to perform dose measurements using gafchromic films which can span several decades of dose levels. The technique is based on a rescaling approach using different films irradiated at different dose levels. This is combined with a registration protocol correcting positioning and scaling factors for each film.Comment: Preprint submitted to Medical Physics, 10 pages, 4 figures, 1 tabl

Analysis of variation in calibration curves for Kodak XV radiographic film using modelâ based parameters

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135597/1/acm20222.pd

D5.2 - Data Management Plan (DMP)

The purpose of the DMP is to provide an analysis of the main elements of the data management policy that will be used by the applications with regard to all the datasets that will be generated by the project. The DMP should ensure that most important aspects regarding data management, like metadata generation, data preservation, and responsibilities, are identified in an early stage of the project. This ensures that data is well-managed during the project and also beyond the end of the project. Data which will be generated in the course of the project include output data of random number generators, PUF output data, measurement data, and source code. As the DMP is an incremental tool, it will be adapted in the course of the project

Developmental and Activity-Dependent miRNA Expression Profiling in Primary Hippocampal Neuron Cultures

MicroRNAs (miRNAs) are evolutionarily conserved non-coding RNAs of ∼22 nucleotides that regulate gene expression at the level of translation and play vital roles in hippocampal neuron development, function and plasticity. Here, we performed a systematic and in-depth analysis of miRNA expression profiles in cultured hippocampal neurons during development and after induction of neuronal activity. MiRNA profiling of primary hippocampal cultures was carried out using locked nucleic-acid-based miRNA arrays. The expression of 264 different miRNAs was tested in young neurons, at various developmental stages (stage 2-4) and in mature fully differentiated neurons (stage 5) following the induction of neuronal activity using chemical stimulation protocols. We identified 210 miRNAs in mature hippocampal neurons; the expression of most neuronal miRNAs is low at early stages of development and steadily increases during neuronal differentiation. We found a specific subset of 14 miRNAs with reduced expression at stage 3 and showed that sustained expression of these miRNAs stimulates axonal outgrowth. Expression profiling following induction of neuronal activity demonstrates that 51 miRNAs, including miR-134, miR-146, miR-181, miR-185, miR-191 and miR-200a show altered patterns of expression after NMDA receptor-dependent plasticity, and 31 miRNAs, including miR-107, miR-134, miR-470 and miR-546 were upregulated by homeostatic plasticity protocols. Our results indicate that specific miRNA expression profiles correlate with changes in neuronal development and neuronal activity. Identification and characterization of miRNA targets may further elucidate translational control mechanisms involved in hippocampal development, differentiation and activity-depended processes

D2.1 - Report on Selected TRNG and PUF Principles

This report represents the final version of Deliverable 2.1 of the HECTOR work package WP2. It is a result of discussions and work on Task 2.1 of all HECTOR partners involved in WP2. The aim of the Deliverable 2.1 is to select principles of random number generators (RNGs) and physical unclonable functions (PUFs) that fulfill strict technology, design and security criteria. For example, the selected RNGs must be suitable for implementation in logic devices according to the German AIS20/31 standard. Correspondingly, the selected PUFs must be suitable for applying similar security approach. A standard PUF evaluation approach does not exist, yet, but it should be proposed in the framework of the project. Selected RNGs and PUFs should be then thoroughly evaluated from the point of view of security and the most suitable principles should be implemented in logic devices, such as Field Programmable Logic Arrays (FPGAs) and Application Specific Integrated Circuits (ASICs) during the next phases of the project

Use of new radiochromic devices for peripheral dose measurement: potential in-vivo dosimetry application

The authors have studied the feasibility of using three new high-sensitivity radiochromic devices in measuring the doses to peripheral points outside the primary megavoltage photon beams. The three devices were GAFCHROMIC® EBT film, prototype Low Dose (LD) Film, and prototype LD Card. The authors performed point dosimetry using these three devices in water-equivalent solid phantoms at x = 3,5,8,10, and 15 cm from the edge of 6 MV and 15 MV photon beams of 10x10 cm2, and at depths of 0, 0.5 cm, and depth of maximum dose. A full sheet of EBT film was exposed with 5000 MU. The prototype LD film pieces were 1.5x2 cm2 in size. Some LD films were provided in the form of a card in 1.8x5 cm2 holding an active film in 1.8x2 cm2. These are referred to as “LD dosimeter cards”. The small LD films and cards were exposed with 500 MU. For each scanned film, a 6 mm circular area centered at the measurement point was sampled and the mean pixel value was obtained. The calibration curves were established from the calibration data for each combination of film/cards and densitometer/scanner. The doses at the peripheral points determined from the films were compared with those obtained using ion chamber at respective locations in a water phantom and general agreements were found. It is feasible to accurately measure peripheral doses of megavoltage photon beams using the new high-sensitivity radiochromic devices. This near real-time and inexpensive method can be applied in a clinical setting for dose measurements to critical organs and sensitive patient implant devices

Female Genitalia Concealment Promotes Intimate Male Courtship in a Water Strider

Violent coercive mating initiation is typical for animals with sexual conflict over mating. In these species, the coevolutionary arms-race between female defenses against coercive mating and male counter-adaptations for increased mating success leads to coevolutionary chases of male and female traits that influence the mating. It has been controversial whether one of the sexes can evolve traits that allow them to “win” this arms race. Here, we use morphological analysis (traditional and scanning electron micrographs), laboratory experiments and comparative methods to show how females of a species characterized by typical coercive mating initiation appear to “win” a particular stage of the sexual conflict by evolving morphology to hide their genitalia from direct, forceful access by males. In an apparent response to the female morphological adaptation, males of this species added to their typically violent coercive mounting of the female new post-mounting, pre-copulatory courtship signals produced by tapping the water's surface with the mid-legs. These courtship signals are intimate in the sense that they are aimed at the female, on whom the male is already mounted. Females respond to the signals by exposing their hidden genitalia for copulatory intromission. Our results indicate that the apparent victory of coevolutionary arms race by one sex in terms of morphology may trigger evolution of a behavioral phenotype in the opposite sex