bluuebunny/crossref_metadata_2025 huggingface dataset:
Code of Ethics for the American Association of Physicists in Medicine: Report of Task Group 109
Authors: Serago Christopher F. , Adnani Nabil , Bank Morris I. , BenComo Jose A. , Duan Jun , Fairobent Lynne , Freedman D. Jay , Halvorsen Per H. , Hendee William R. , Herman Michael G. , Morse Richard K. , Mower Herbert W. , Pfeiffer Douglas E. , Root William J. , Sherouse George W. , Vossler Matthew K. , Wallace Robert E. , Walters Barbara
Published: January 2009

A comprehensive Code of Ethics for the members of the American Association of Physicists in Medicine (AAPM) is presented as the report of Task Group 109 which consolidates previous AAPM ethics policies into a unified document. The membership of the AAPM is increasingly diverse. Prior existing AAPM ethics polices were applicable specifically to medical physicists, and did not encompass other types of members such as health physicists, regulators, corporate affiliates, physicians, scientists, engineers, those in training, or other health care professionals. Prior AAPM ethics policies did not specifically address research, education, or business ethics. The Ethics Guidelines of this new Code of Ethics have four major sections: professional conduct, research ethics, education ethics, and business ethics. Some elements of each major section may be duplicated in other sections, so that readers interested in a particular aspect of the code do not need to read the entire document for all relevant information. The prior Complaint Procedure has also been incorporated into this Code of Ethics. This Code of Ethics (PP 24‐A) replaces the following AAPM policies: Ethical Guidelines for Vacating a Position (PP 4‐B); Ethical Guidelines for Reviewing the Work of Another Physicist (PP 5‐C); Guidelines for Ethical Practice for Medical Physicists (PP 8‐D); and Ethics Complaint Procedure (PP 21‐A). The AAPM Board of Directors approved this Code or Ethics on July 31, 2008.
A comprehensive evaluation of the PRESAGE/optical‐CT 3D dosimetry system
Authors: Sakhalkar H. S. , Adamovics J. , Ibbott G. , Oldham M.
Published: January 2009

This work presents extensive investigations to evaluate the robustness (intradosimeter consistency and temporal stability of response), reproducibility, precision, and accuracy of a relatively new 3D dosimetry system comprising a leuco‐dye doped plastic 3D dosimeter (PRESAGE) and a commercial optical‐CT scanner (OCTOPUS scanner from MGS Research, Inc). Four identical PRESAGE 3D dosimeters were created such that they were compatible with the Radiologic Physics Center (RPC) head‐and‐neck (H&N) IMRT credentialing phantom. Each dosimeter was irradiated with a rotationally symmetric arrangement of nine identical small fields impinging on the flat circular face of the dosimeter. A repetitious sequence of three dose levels (4, 2.88, and ) was delivered. The rotationally symmetric treatment resulted in a dose distribution with high spatial variation in axial planes but only gradual variation with depth along the long axis of the dosimeter. The significance of this treatment was that it facilitated accurate film dosimetry in the axial plane, for independent verification. Also, it enabled rigorous evaluation of robustness, reproducibility and accuracy of response, at the three dose levels. The OCTOPUS commercial scanner was used for dose readout from the dosimeters at daily time intervals. The use of improved optics and acquisition technique yielded substantially improved noise characteristics (reduced to ) than has been achieved previously. Intradosimeter uniformity of radiochromic response was evaluated by calculating a 3D gamma comparison between each dosimeter and axially rotated copies of the same dosimeter. This convenient technique exploits the rotational symmetry of the distribution. All points in the gamma comparison passed a 2% difference, distance‐to‐agreement criteria indicating excellent intradosimeter uniformity even at low dose levels. Postirradiation, the dosimeters were all found to exhibit a slight increase in opaqueness with time. However, the relative dose distribution was found to be extremely stable up to postirradiation indicating excellent temporal stability. Excellent interdosimeter reproducibility was also observed between the four dosimeters. Gamma comparison maps between each dosimeter and the average distribution of all four dosimeters showed full agreement at the 2% difference, distance‐to‐agreement level. Dose readout from the 3D dosimetry system was found to agree better with independent film measurement than with treatment planning system calculations in penumbral regions and was generally accurate to within 2% dose difference and distance‐to‐agreement. In conclusion, these studies demonstrate excellent precision, accuracy, robustness, and reproducibility of the PRESAGE/optical‐CT system for relative 3D dosimetry and support its potential integration with the RPC H&N credentialing phantom for IMRT verification.
In vivo verification of superficial dose for head and neck treatments using intensity‐modulated techniques
Authors: Qi Zhen‐Yu , Deng Xiao‐Wu , Huang Shao‐Min , Zhang Li , He Zhi‐Chun , Allen Li X. , Kwan Ian , Lerch Michael , Cutajar Dean , Metcalfe Peter , Rosenfeld Anatoly
Published: January 2009

Skin dose is one of the key issues for clinical dosimetry in radiation therapy. Currently planning computer systems are unable to accurately predict dose in the buildup region, leaving ambiguity as to the dose levels actually received by the patient's skin during radiotherapy. This is one of the prime reasons why in vivo measurements are necessary to estimate the dose in the buildup region. A newly developed metal‐oxide‐semiconductor‐field‐effect‐transistor (MOSFET) detector designed specifically for dose measurements in rapidly changing dose gradients was introduced for accurate in vivo skin dosimetry. The feasibility of this detector for skin dose measurements was verified in comparison with plane parallel ionization chamber and radiochromic films. The accuracy of a commercial treatment planning system (TPS) in skin dose calculations for intensity‐modulated radiation therapy treatment of nasopharyngeal carcinoma was evaluated using MOSFET detectors in an anthropomorphic phantom as well as on the patients. Results show that this newly developed MOSFET detector can provide a minimal but highly reproducible intrinsic buildup of corresponding to the requirements of personal surface dose equivalent Hp (0.07). The reproducibility of the MOSFET response, in high sensitivity mode, is found to be better than 2% at the phantom surface for the doses normally delivered to the patients. The MOSFET detector agrees well with the Attix chamber and the EBT Gafchromic® film in terms of surface and buildup region dose measurements, even for oblique incident beams. While the dose difference between MOSFET measurements and TPS calculations is within measurement uncertainty for the depths equal to or greater than , an overestimation of up to 8.5% was found for the surface dose calculations in the anthropomorphic phantom study. In vivo skin dose measurements reveal that the dose difference between the MOSFET results and the TPS calculations was on average , ranging from to . The newly designed MOSFET detector encapsulated into a thin water protective film has a minimal reproducible intrinsic buildup recommended for skin dosimetry. This feature makes it very suitable for routine IMRT QA and accurate in vivo skin dosimetry.
The effect of rectal heterogeneity on wall dose in high dose rate brachytherapy
Authors: Kwan I. S. , Wilkinson D. , Cutajar D. , Lerch M. , Rosenfeld A. , Howie A. , Bucci J. , Chin Y. , Perevertaylo V. L.
Published: January 2009

When treating prostate cancer using high dose rate (HDR) brachytherapy, overdosing the rectal wall may lead to post‐treatment rectal complications. An area of concern is related to how the rectal wall dose is calculated by treatment planning systems (TPSs). TPSs are used to calculate the dose delivered to the rectal wall, but they assume that the rectum is a water‐equivalent homogeneous medium of infinite size and do not consider the effect that an air‐filled “empty” rectal cavity would have on the dose absorbed along the rectal wall. The aim of this research is to quantify the effect that an air cavity has on the rectal wall dose, as its presence changes the backscatter conditions in the region. The MO Skin and RADFET dosimeters proved capable of measuring absolute dose with increasing distance from the HDR Ir‐192 brachytherapy source. However, the anterior rectal wall doses measured by the MOSkin and RADFET in an empty rectal cavity were and lower than the dose measured in a homogeneous rectal phantom. Monte Carlo simulations corroborated the experimentally obtained results, reporting a difference. The dose measured at the posterior wall of an empty rectal cavity was between 22% and 26% greater than the dose measured in a full rectal cavity. The heterogeneity of the rectal volume appears to have a significant effect on the rectal dose when compared to calculated rectal dose.
Validation of CT dose‐reduction simulation
Authors: Massoumzadeh Parinaz , Don Steven , Hildebolt Charles F. , Bae Kyongtae T. , Whiting Bruce R.
Published: January 2009

The objective of this research was to develop and validate a custom computed tomography dose‐reduction simulation technique for producing images that have an appearance consistent with the same scan performed at a lower mAs (with fixed kVp, rotation time, and collimation). Synthetic noise is added to projection (sinogram) data, incorporating a stochastic noise model that includes energy‐integrating detectors, tube‐current modulation, bowtie beam filtering, and electronic system noise. Experimental methods were developed to determine the parameters required for each component of the noise model. As a validation, the outputs of the simulations were compared to measurements with cadavers in the image domain and with phantoms in both the sinogram and image domain, using an unbiased root‐mean‐square relative error metric to quantify agreement in noise processes. Four‐alternative forced‐choice (4AFC) observer studies were conducted to confirm the realistic appearance of simulated noise, and the effects of various system model components on visual noise were studied. The “just noticeable difference (JND)” in noise levels was analyzed to determine the sensitivity of observers to changes in noise level. Individual detector measurements were shown to be normally distributed , justifying the use of a Gaussian random noise generator for simulations. Phantom tests showed the ability to match original and simulated noise variance in the sinogram domain to within (standard deviation), which was then propagated into the image domain with errors less than . Cadaver measurements indicated that image noise was matched to within . More importantly, the 4AFC observer studies indicated that the simulated images were realistic, i.e., no detectable difference between simulated and original images was observed. JND studies indicated that observers’ sensitivity to change in noise levels corresponded to a 25% difference in dose, which is far larger than the noise accuracy achieved by simulation. In summary, the dose‐reduction simulation tool demonstrated excellent accuracy in providing realistic images. The methodology promises to be a useful tool for researchers and radiologists to explore dose reduction protocols in an effort to produce diagnostic images with radiation dose “as low as reasonably achievable.”
Evaluation of radiation dose delivered by cone beam CT and tomosynthesis employed for setup of external breast irradiation
Authors: Winey Brian , Zygmanski Piotr , Lyatskaya Yulia
Published: January 2009

A systematic set of measurements is reported for evaluation of doses to critical organs resulting from cone‐beam CT (CB‐CT) and cone‐beam tomosynthesis (CB‐TS) as applied to breast setup for external beam irradiation. The specific focus of this study was on evaluation of doses from these modalities in a setting of volumetric breast imaging for target localization in radiotherapy treatments with the goal of minimizing radiation to healthy organs. Ion chamber measurements were performed in an anthropomorphic female thorax phantom at the center of each breast and lung and on the phantom surface at one anterior and two lateral locations (seven points total). The measurements were performed for three different isocenters located at the center of the phantom and at offset locations of the right and left breast. The dependence of the dose on angle selection for the CB‐TS arc was also studied. For the most typical situation of centrally located CB‐CT isocenter the measured doses ranged between 3 and , in good agreement with previous reports. Dose measurements were performed for a range of start/stop angles commonly used for CB‐TS and the impact of direct and scatter dose on organs at risk was analyzed. All measured CB‐TS doses were considerably lower than CB‐CT doses, with greater decrease in dose for the organs outside of the beam (up to 98% decrease in dose). Remarkably, offsetting the isocenter towards the ipsilateral breast resulted on average to additional 46% dose reduction to organs at risk. The lowest doses to the contralateral breast and lung were less than when they were measured for the offset isocenter. The biggest reduction in dose was obtained by using CB‐TS beams that completely avoid the critical organ. For points inside the CB‐TS beam, the dose was reduced in a linear relation with distance from the center of the imaging arc. The data indicate that it is possible to reduce substantially radiation doses to the contralateral organs by proper selection of CB‐TS angles and imaging field sizes. Our results provide the first systematic study on CB‐TS doses from setup imaging for external breast irradiation and can be a useful resource for estimating anticipated radiation doses as a function of the conditions chosen for imaging breast setup.
Optimizing computer‐aided colonic polyp detection for CT colonography by evolving the Pareto fronta)
Authors: Li Jiang , Huang Adam , Yao Jack , Liu Jiamin , Van Uitert Robert L. , Petrick Nicholas , Summers Ronald M.
Published: January 2009

A multiobjective genetic algorithm is designed to optimize a computer‐aided detection (CAD) system for identifying colonic polyps. Colonic polyps appear as elliptical protrusions on the inner surface of the colon. Curvature‐based features for colonic polyp detection have proved to be successful in several CT colonography (CTC) CAD systems. Our CTC CAD program uses a sequential classifier to form initial polyp detections on the colon surface. The classifier utilizes a set of thresholds on curvature‐based features to cluster suspicious colon surface regions into polyp candidates. The thresholds were previously chosen experimentally by using feature histograms. The chosen thresholds were effective for detecting polyps sized or larger in diameter. However, many medium‐sized polyps, in diameter, were missed in the initial detection procedure. In this paper, the task of finding optimal thresholds as a multiobjective optimization problem was formulated, and a genetic algorithm to solve it was utilized by evolving the Pareto front of the Pareto optimal set. The new CTC CAD system was tested on 792 patients. The sensitivities of the optimized system improved significantly, from 61.68% to 74.71% with an increase of 13.03% (95% CI [6.57%, 19.5%], ) for the size category of polyps, from 65.02% to 77.4% with an increase of 12.38% (95% CI [6.23%, 18.53%], ) for polyps or larger, and from 82.2% to 90.58% with an increase of 8.38% (95%CI [0.75%, 16%], ) for polyps or larger at comparable false positive rates. The sensitivities of the optimized system are nearly equivalent to those of expert radiologists.
Experimental validation of a three‐dimensional linear system model for breast tomosynthesis
Authors: Zhao Bo , Zhou Jun , Hu Yue‐Houng , Mertelmeier Thomas , Ludwig Jasmina , Zhao Wei
Published: January 2009

A three‐dimensional (3D) linear model for digital breast tomosynthesis (DBT) was developed to investigate the effects of different imaging system parameters on the reconstructed image quality. In the present work, experimental validation of the model was performed on a prototype DBT system equipped with an amorphous selenium (a‐Se) digital mammography detector and filtered backprojection (FBP) reconstruction methods. The detector can be operated in either full resolution with pixel size or binning mode to reduce acquisition time. Twenty‐five projection images were acquired with a nominal angular range of . The images were reconstructed using a slice thickness of with in‐plane pixel dimension. The imaging performance was characterized by spatial frequency‐dependent parameters including a 3D noise power spectrum (NPS) and in‐plane modulation transfer function (MTF). Scatter‐free uniform x‐ray images were acquired at four different exposure levels for noise analysis. An aluminum (Al) edge phantom with thickness was imaged to measure the in‐plane presampling MTF. The measured in‐plane MTF and 3D NPS were both in good agreement with the model. The dependence of DBT image quality on reconstruction filters was investigated. It was found that the slice thickness (ST) filter, a Hanning window to limit the high‐frequency components in the slice thickness direction, reduces noise aliasing and improves 3D DQE. An ACR phantom was imaged to investigate the effects of angular range and detector operational modes on reconstructed image quality. It was found that increasing the angular range improves the MTF at low frequencies, resulting in better detection of large‐area, low‐contrast mass lesions in the phantom. There is a trade‐off between noise and resolution for pixel binning and full resolution modes, and the choice of detector mode will depend on radiation dose and the targeted lesion.
Medical Physics: Tenth Mexican Symposium on Medical Physics, México City, México, 17–19 March 2008
Authors: Mallah Jacques
Published: January 2009

Medical Physics: Tenth Mexican Symposium on Medical Physics, México City, México, 17–19 March 2008 Corral Geraldo Herrera Zetina Luis Manuel Montaño American Institute of Physics, Melville, New York, USA, 2008. Price: $180. Hardcover, 328 p. ISBN 978‐0‐7354‐0056‐1
Fundamentals of Nuclear Medicine Dosimetry
Authors: Mihailidis Dimitris N.
Published: January 2009

Fundamentals of Nuclear Medicine Dosimetry Stabin Michael G. Springer Science+Business Media, LLC, New York, USA, 2008. New York, NY, 2008. Price: $49.95. Paperback, 240 p. ISBN 978‐0‐387‐74578‐7.
Serrated and non-serrated polyps of the colorectum: their prevalence in an unselected case series and correlation ofBRAFmutation analysis with the diagnosis of sessile serrated adenoma
Authors: Carr N J , Mahajan H , Tan K L , Hawkins N J , Ward R L
Published: January 2009

Aims:

To determine the prevalence of colorectal polyps of different types in an unselected population, and to correlate the morphological diagnoses withBRAFmutation analysis.

Methods:

Cases of colorectal polyps diagnosed at endoscopy were retrieved from the files of Southern.IML Pathology. All slides were reviewed and the lesions classified histologically. A diagnosis of sessile serrated adenoma was made even if the characteristic features were present only focally. If there was more than one polyp of a particular type in any patient, one lesion was chosen at random so that the results represent the number of patients with each type of polyp rather than the total number of polyps. A proportion of the polyps was subjected toBRAFmutation analysis.

Results:

A total of 1479 patients were identified. Non-serrated (“conventional”) adenomas were found in 964 patients (65%), hyperplastic polyps in 437 (30%), sessile serrated adenomas in 57 (3.9%), traditional serrated adenomas in 11 (0.7%) and mixed hyperplastic adenomatous polyps in 10 (0.7%).BRAFV600E mutation analysis was performed in 148 selected cases; mutations were found in 44/49 (90%) of lesions diagnosed as sessile serrated adenoma, in 10/34 (29%) of hyperplastic polyps of microvesicular type, in 4/11 (36%) of traditional serrated adenomas, in 10/10 (100%) of mixed hyperplastic adenomatous polyps, and in 2/42 (5%) of “conventional” adenomas.

Conclusions:

Sessile serrated adenomas are encountered commonly in routine endoscopy practice. The histological diagnosis correlates strongly with the presence ofBRAFmutation.
cGMP-dependent protein kinase: linking foraging to energy homeostasis
Authors: Kaun Karla R. , Sokolowski Marla B.
Published: January 2009

Successful foraging is necessary for procurement of nutritional resources essential for an animal’s survival. Maintenance of foraging and food acquisition is dependent on the ability to balance food intake and energy expenditure. This review examines the role of cGMP-dependent protein kinase (PKG) as a regulator of foraging behaviour, food acquisition, and energy balance. The role of PKG in food-related behaviours is highly conserved among worms, flies, bees, ants, and mammals. A growing body of literature suggests that PKG plays an integral role in the component behaviours and physiologies underlying foraging behaviour. These include energy acquisition, nutrient absorption, nutrient allocation, nutrient storage, and energy use. New evidence suggests that PKG mediates both neural and physiological mechanisms underlying these processes. This review illustrates how investigating the role of PKG in energy homeostasis in a diversity of organisms can offer a broad perspective on the mechanisms mediating energy balance.
A quantitative genomic imbalance gene expression assay in a hexaploid species: wheat (Triticum aestivum)
Authors: Stamati K. , Mackay I. , Powell W.
Published: January 2009

Responses to allopolyploidy include unequal expression of duplicated genes, gene silencing, and sometimes genomic rearrangements. In plants, the relationship between allelic expression differences arising from changes in regulatory regions and the resulting phenotype is poorly understood because of the complexity of their genomes and lack of efficient methodology to identify regulatory variation. Identifying functionally important regulatory variation in crops such as hexaploid wheat ( Triticum aestivum ) is in its infancy. More knowledge is required about the contribution of participatory genomes to its transcriptome. In this paper, we demonstrate the use of allelic imbalance assays to quantify relative expression levels across tissues and growth regimes of homoeologous transcripts of the A, B, and D genomes. Polymorphisms in the type I thionins have been used as an example. We show that expression levels vary markedly and interactively over all factors. For this gene, the B genome is the smallest contributor to the transcriptome and the D genome the largest. As additional sequence information is accumulated across genomes, this assay will allow the simple study of relative expression across multiple homeologous loci.
Mitotic and polytene chromosome analysis in the Mexican fruit fly,Anastrepha ludens(Loew) (Diptera: Tephritidae)
Authors: Garcia-Martinez V. , Hernandez-Ortiz E. , Zepeta-Cisneros C. S. , Robinson A. S. , Zacharopoulou A. , Franz G.
Published: January 2009

The present study constitutes the first attempt to construct a polytene chromosome map of an Anastrepha species, Anastrepha ludens (Loew), a major agricultural pest. The mitotic karyotype has a diploid complement of 12 acrocentric chromosomes, including five pairs of autosomes and an XX/XY sex chromosome pair. The analysis of salivary gland polytene chromosomes has shown a total number of five polytene elements that correspond to the five autosomes. The characteristic features and the most prominent landmarks of each chromosome are described. By comparing chromosome banding patterns, the possible chromosomal homology between A. ludens and Ceratitis capitata (Wiedemann) is presented. This work shows that polytene maps of A. ludens are suitable for cytogenetic studies in this species and may be used as reference for other Anastrepha species, most of which are also serious agricultural pests.
Allopolyploidization reduces alternative splicing efficiency for transcripts of the wheatDREB2homolog,WDREB2
Authors: Terashima Akihiro , Takumi Shigeo
Published: January 2009

The wheat DREB2 homolog, WDREB2, encodes an EREBP/AP2-type transcription factor that activates downstream Cor/Lea genes and plays important roles in abiotic stress responses. WDREB2 expression is posttranscriptionally regulated by alternative splicing. In this study, the alternative splicing patterns of WDREB2 transcripts were compared among wheats of different ploidy levels. In diploid progenitors, alternative splicing rapidly produced functional forms from the WDREB2 transcripts and the levels of the nonfunctional form gradually decreased in response to drought stress; however, in hexaploid wheat lines, including both cultivars and synthetic lines, the nonfunctional form failed to decrease. The accumulation levels of the three spliced forms in synthetic allopolyploids were not equal to the sum of those in the parental lines. These results indicated that allopolyploidization during wheat polyploid evolution inhibited efficient alternative splicing of WDREB2 transcripts.
Repetitive genome elements in a European corn borer, Ostrinia nubilalis, bacterial artificial chromosome library were indicated by bacterial artificial chromosome end sequencing and development of sequence tag site markers: implications for lepidopteran genomic research
Authors: Coates Brad S. , Sumerford Douglas V. , Hellmich Richard L. , Lewis Leslie C.
Published: January 2009

The European corn borer, Ostrinia nubilalis , is a serious pest of food, fiber, and biofuel crops in Europe, North America, and Asia and a model system for insect olfaction and speciation. A bacterial artificial chromosome library constructed for O. nubilalis contains 36 864 clones with an estimated average insert size of ≥120 kb and genome coverage of 8.8-fold. Screening OnB1 clones comprising approximately 2.76 genome equivalents determined the physical position of 24 sequence tag site markers, including markers linked to ecologically important and Bacillus thuringiensis toxin resistance traits. OnB1 bacterial artificial chromosome end sequence reads (GenBank dbGSS accessions ET217010 to ET217273) showed homology to annotated genes or expressed sequence tags and identified repetitive genome elements, O. nubilalis miniature subterminal inverted repeat transposable elements (OnMITE01 and OnMITE02), and ezi-like long interspersed nuclear elements. Mobility of OnMITE01 was demonstrated by the presence or absence in O. nubilalis of introns at two different loci. A (GTCT)n tetranucleotide repeat at the 5′ ends of OnMITE01 and OnMITE02 are evidence for transposon-mediated movement of lepidopteran microsatellite loci. The number of repetitive elements in lepidopteran genomes will affect genome assembly and marker development. Single-locus sequence tag site markers described here have downstream application for integration within linkage maps and comparative genomic studies.
Horizontal displacements induced by rock excavation: Scotia Plaza, Toronto, Ontario
Authors: Trow W. A. , Lo K. Y.
Published: January 2009

The design and construction of a 69-storey building, the Scotia Plaza in downtown Toronto, Ontario, necessitated an assessment of the horizontal displacements induced onto adjacent existing structures as a result of rock excavation. Field and laboratory tests were performed to measure the elastic and time-dependent deformation parameters as well as the in situ horizontal stresses in rock. With the deformation parameters and initial state of stresses determined, analyses were performed to predict the magnitude and distribution of elastic and time-dependent deformation. During excavation, horizontal displacements were monitored by (a) a field slot test to verify the rock mass modulus, (b) inclinometers and extensometers, and (c) internal taping of floors of adjacent structures. The results of these field measurements are compared with those predicted in the design analysis, and are found to be within the predicted limits and design requirements. The use of rock anchors to partially suppress time-dependent displacements is also briefly discussed. Key words: rock excavation, horizontal displacement, time-dependent deformation, in situ stresses, rock anchors.
Geotechnical investigations of dredged overburden at the Syncrude oil sand mine in northern Alberta, Canada
Authors: Lord E. R. F. , Isaac B. A. A.
Published: January 2009

The feasibility of constructing a stable overburden waste dump using hydraulic techniques has been investigated. A joint Alberta Oil Sands Technology and Research Authority - Syncrude field pilot resulted in a total of 25 000 m3 of overburden being dredged, hydraulically transported in lump form, and deposited in a number of study cells. The geotechnical properties of the deposits were tested in the field and laboratory. The results indicate that the potential exists to hydraulically construct waste dumps with Pleistocene materials. Clearwater Formation clay shale can also be hydraulically transported in lump form but the resulting deposit requires containment. Key words: dredging, overburden, clay lumps, geotechnical testing, case histories, waste dump.
PROBABILISTIC ADAPTIVE CROSSOVER (PAX): A NOVEL GENETIC ALGORITHM CROSSOVER METHODOLOGY
Authors: SALAH SEBASTIÁN A. , DUARTE-MERMOUD MANUEL A. , BELTRÁN NICOLÁS H.
Published: January 2009

A new crossover technique for genetic algorithms is proposed in this paper. The technique is called probabilistic adaptive crossover and denoted by PAX. The method includes the estimation of the probability distribution of the population, in order to store in a unique probability vector P information about the best and the worse solutions of the problem to be solved. The proposed methodology is compared with six crossover techniques namely: one-point crossover, two-point crossover, SANUX, discrete crossover, uniform crossover and selective crossover. These methodologies were simulated and compared over five test problems described by ONEMAX Function, Royal Road Function, Random L-MaxSAT, Bohachevsky Function, and the Himmelblau Function.
A TEAM OF HUMANOID GAME COMMENTATORS
Authors: VELOSO MANUELA , ARMSTRONG-CREWS NICHOLAS , CHERNOVA SONIA , CRAWFORD ELISABETH , MCMILLEN COLIN , ROTH MAAYAN , VAIL DOUGLAS , ZICKLER STEFAN
Published: January 2009

We present a team of two humanoid robot commentators for AIBO robot soccer games. The two humanoids stand by the side lines of the playing field, autonomously observe the game, wirelessly listen to a "game controller" computer, recognize events, and select announcing actions that may require coordination with each other. Given the large degree of uncertainty and dynamics of the robot soccer games, we further introduce a "Puppet Master" control that allows humans to intervene, prompting the robots to commentate an event if previously undefined or undetected. The robots recognize events based on input from these three sources, namely own and shared vision, game controller, and occasional Puppet Master. We present the two-humanoid behavioral architecture and the vision-based event recognition, including a SIFT-based vision processing algorithm that allows for the detection of multiple similar objects, such as the identical shaped robot players. We introduce the commentating algorithm that probabilistically selects a commentating action from a set of weighted actions corresponding to a detected event. The probabilistic selection uses the game history and updates the action weights to effectively avoid repetition of comments to enable entertainment. Our work, corresponding to a fully implemented system, CMCast, with two QRIO robots, contributes a team of two humanoids fully executing a challenging observation, modeling, coordination, and reporting task.
VERSATILE, HIGH-QUALITY MOTIONS AND BEHAVIOR CONTROL OF A HUMANOID SOCCER ROBOT
Authors: FRIEDMANN MARTIN , KIENER JUTTA , PETTERS SEBASTIAN , THOMAS DIRK , VON STRYK OSKAR , SAKAMOTO HAJIME
Published: January 2009

Autonomous soccer games represent an extraordinary challenge for autonomous humanoid robots which must act fast and stable while carrying all needed onboard computers, sensors and batteries. In this paper, the development and system integration of hardware and software modules of the 55-cm tall, autonomous humanoid soccer robot Bruno is described to cope with this challenge. Although based on a "minimalistic" design which only uses gyroscopes in the hip but not foot-ground contact sensors for control of balance, versatile and high-quality walking motions have been developed. Fast forward walking of about 1.5 km/h has been obtained using an efficient sequential surrogate optimization method and walking through uneven terrain with a newly designed passively compliant foot sole. Further modules of the software and control architecture which are needed for an adaptive selection of different motions and autonomous robot behavior are briefly described. Experimental results are reported, which have been obtained under the conditions of a live competition. The robot's hardware is mainly based on standard components which can therefore be easily adapted by new designers, as no comparable, standard humanoid robot platforms are available.
GAIT GENERATION AND OPTIMIZATION USING THE ESTIMATION OF DISTRIBUTION ALGORITHM FOR TEENSIZE HUMANOID SOCCER ROBOT RESr-1
Authors: HU LINGYUN , ZHOU CHANGJIU
Published: January 2009

This paper gives an overview of locomotion planning and control of a TeenSize humanoid soccer robot, Robo-Erectus Senior (RESr-1), which has been developed as an experimental platform for human–robot interaction and cooperative research in general and robotics soccer games in particular. The locomotion planning and control, along with an introduction of hierarchical control architecture, vision-based behavior and its application in the Humanoid TeenSize soccer challenge, are elaborated. The Estimation of Distribution Algorithm (EDA) is used in locomotion generation and optimization to achieves dynamically stable walk and a powerful kick. By setting different objective functions, smooth walking and powerful kicking can be generated quickly. RESr-1 made its debut at RoboCup 2007, and got fourth place in the Humanoid TeenSize penalty kick competition. In addition, some experimental results on RESr-1's walking, tracking and kicking are presented.
FIDES
Authors: Inoue Hiroaki , Sakai Junji , Torii Sunao , Edahiro Masato
Published: January 2009

We propose a secure platform on a chip multiprocessor, FIDES, in order to enable next generation mobile terminals to execute downloaded native applications for Linux. Its most important feature is the higher security based on multigrained separation mechanisms. Four new technologies support the FIDES platform: bus filter logic, XIP kernels, policy separation, and dynamic access control. With these technologies, the FIDES platform can tolerate both application-level and kernel-level bugs on an actual download subsystem. Thus, the best-suited platform to secure next generation mobile terminals is FIDES.
Quantitative analysis of the speed/accuracy trade-off in transaction level modeling
Authors: Schirner Gunar , Dömer Rainer
Published: January 2009

The increasing complexity of embedded systems requires modeling at higher levels of abstraction. Transaction level modeling (TLM) has been proposed to abstract communication for high-speed system simulation and rapid design space exploration. Although being widely accepted for its high performance and efficiency, TLM often exhibits a significant loss in model accuracy.

In this article, we systematically analyze and quantify the speed/accuracy trade-off in TLM. To this end, we provide a classification of TLM abstraction levels based on model granularity and define appropriate metrics and test setups to quantitatively measure and compare the performance and accuracy of such models.

Addressing several classes of embedded communication protocols, we apply our analysis to three common bus architectures, the industry-standard AMBA advanced high-performance bus (AHB) as an on-chip parallel bus, the controller area network (CAN) as an off-chip serial bus, and the Motorola ColdFire Master Bus as an example for a custom embedded processor bus.

Based on the analysis of these individual busses, we then generalize our results for a broader conclusion. The general TLM trade-off offers gains of up to four orders of magnitude in simulation speed, generally however, at the price of low accuracy. We conclude further that model granularity is the key to efficient TLM abstraction, and we identify conditions for accuracy of abstract models. As a result, this article provides general guidelines that allow the system designer to navigate the TLM trade-off effectively and choose the most suitable model for the given application with fast and accurate results.
Quasistatic shared libraries and XIP for memory footprint reduction in MMU-less embedded systems
Authors: Park Jiyong , Lee Jaesoo , Kim Saehwa , Hong Seongsoo
Published: January 2009

Despite a rapid decrease in the price of solid state memory devices, system memory is still a very precious resource in embedded systems. The use of shared libraries and execution-in-place (XIP) is known to be effective in significantly reducing memory usage. Unfortunately, many resource-constrained embedded systems lack an MMU, making it extremely difficult to support these techniques. To address this problem, we propose a novel shared library technique called a quasi-static shared library and an XIP, both based on our enhanced position independent code technique. In our quasistatic shared libraries, global symbols are bound to pseudoaddresses at linking time and actual physical addresses are bound at loading time. Unlike conventional shared libraries, they do not require symbol tables that take up valuable memory space and, therefore, allow for expedited address translation at runtime. Our XIP technique is facilitated by our enhanced position independent code where a data section can be arbitrarily located. Both the shared library and XIP techniques are made possible by emulating an MMU's memory mapping feature with a data section base register (DSBR) and a data section base table (DSBT).

We have implemented these proposed techniques in a commercial ADSL (Asymmetric Digital Subscriber Line) home network gateway equipped with an MMU-less ARM7TDMI processor core, 2MB flash memory, and 16MB RAM. We measured its memory usage and evaluated its performance overhead by conducting a series of experiments. These experiments clearly demonstrate the effectiveness of our techniques in reducing memory usage. The results are impressive: 35% reduction in flash memory usage when using only the shared library and 30% reduction in RAM usage when using the shared library and XIP together. These results were achieved with only a negligible performance penalty of less than 4%. Even though these techniques were applied to uClinux-based embedded systems, they can be used for any MMU-less real-time operating system.
Shared spaces
Authors: Velonaki Mari , Scheding Steve , Rye David , Durrant-Whyte Hugh
Published: January 2009

This article describes aspects of collaboration between a media artist (Velonaki) and robotics scientists (Scheding, Rye, Stefan Williams, and Durrant-Whyte) who have been working together over the last five years, leading to the formation of a center dedicated to cross-disciplinary research, called the Centre for Social Robotics. Both media arts and robotics have strong research directions in human-machine interaction, using computer technology as a tool to realize their visions. The article begins with a brief review of Velonaki's earlier work in media art, followed by a description of the major interactive autokinetic artwork, Fish-Bird Circle B--Movement C, that was created by the team. The technological realization of the artwork is described, as are aspects of the team's model of collaboration. Finally, the article describes some of their current projects.
Field—a new environment for making digital art
Authors: Downie Marc
Published: January 2009

This article will describe an environment for developing digital artworks, named Field, that has underpinned some of the most technically challenging real-time artworks made to date. This new tool was recently released by the author under an open source license. Created to specifically support exploratory and improvisory code writing, this environment, which hybridizes text-based programming with dynamic visual metaphors, stands in contrast with the dominant tools available to digital artists today—either the graphical data-flow programming systems or the more recent interest in “live” code-based tools. Field creates an environment where the boundaries between design, development, debugging, and deployment are explicitly porous and ready to shift as the process of forming the artwork out of its formal algorithmic conception demands. This article will articulate the philosophy of this tool by comparison with programming systems, old and new, and describe in detail the ways in which code can be written in it. Examples showing how the fusion of graphical and text-based programming representations can foster specifically the practices demanded by large collaborative artworks will be drawn from the recent work of the OpenEnded Group, spanning real-time graphics, interactive performance, music, and print media.
Level design optimization guidelines for game artists using the epic games
Authors: Rubino Christian , Power John
Published: January 2009

This article aims to provide guidelines for artists during the planning stages of game-level design and production that will anticipate an optimal balancing point between rich graphical content and sufficiently fast frame rates. To achieve this end, a detailed examination will be undertaken on data optimization methods, occlusion systems, and planning strategies with the intention of streamlining game production and level design to give the result of expertly optimized game levels.

The means to achieving this aim are

• to define what factors affect frame rates: terrain, binary space partitioning (bsp), static mesh, decorators, and particle emitters; and

• to discuss potential occlusion solutions and test them: zone fog, anti portals, and zone portals; and

• to combine the results into a guide.

Using occlusion systems in the right way almost always results in faster frame rates and smoother playability, and therefore in an opportunity to supply more or at least maximize the graphical in-game content.
Style learning with feature-based texture synthesis
Authors: Xie Xuexiang , Tian Feng , Seah Hock Soon
Published: January 2009

The objective of artistic style learning is to synthesize a new image from a source image with the style learnt from example images. Existing example-based texture synthesis (EBTS) techniques model style with low-level statistical properties. These methods work well with some artistic styles such as oil painting, but have difficulties in preserving image details and features for other styles such as pencil hatching. In this article, an improved artistic style-learning algorithm with
feature-based texture synthesis
(FBTS) is introduced. Compared with existing EBTS methods, in our FBTS algorithm, image details and features are better defined with a feature field generated from the source image. Also, an improved L2 neighborhood distance metric which provides better measures of perceptual similarity is proposed. Results and comparisons are given to demonstrate the effectiveness of the FBTS algorithm with applications in the areas of stylized shading and artistic style transfer.
Shotgun lipidomics of neutral lipids as an enabling technology for elucidation of lipid-related diseases
Authors: Gross Richard W. , Han Xianlin
Published: January 2009

Neutral lipids fulfill multiple specialized roles in cellular function. These roles include energy storage and utilization, the synthesis of complex lipids in cellular membranes, lipid second messengers for cellular signaling, and the modulation of membrane molecular dynamics. We have developed a novel mass spectrometric technology, now termed shotgun lipidomics, that can identify the types and amounts of thousands of lipids directly from extracts of biological samples. Shotgun lipidomics is well suited for the identification and measurement of the types and amounts of neutral lipid classes and individual molecular species through the use of multidimensional mass spectrometry. This review summarizes the basic principles underlying the use of shotgun lipidomics for the direct measurement of neutral lipids from extracts of biological tissues or fluids. Through exploiting the high information content inherent in shotgun lipidomics, this technology promises to greatly facilitate advances in our understanding of alterations in neutral lipid metabolism in health and disease.
Genetic Regulation of Atherosclerotic Plaque Size and Morphology in the Innominate Artery of Hyperlipidemic Mice
Authors: Bennett Brian J. , Wang Susanna S. , Wang Xuping , Wu Xiaohui , Lusis Aldons J.
Published: January 2009

Objective—

We sought to determine the genetic factors contributing to atherosclerotic plaque size and cellular composition in the innominate artery, a murine model of advanced atherosclerosis.

Methods and Results—

We examined genetic contributions to innominate atherosclerotic plaque size and cellular composition in an intercross between C57BL/6J.Apoe
−/−
, a strain susceptible to aortic lesions, and C3H/HeJ.Apoe
−/−
, a strain resistant to aortic lesions. Surprisingly, total innominate lesion size was similar in the two strains. Genetic analyses identified one novel locus on Chromosome 2 for innominate artery lesion size, a significant locus for fibrous cap thickness on Chromosome 15, and several suggestive loci for cellular composition, all distinct from loci influencing aortic lesions. The Chromosome 2 locus contains a candidate, CD44. We show that CD44 is expressed in the innominate artery and differs strikingly in expression between the parental strains.

Conclusion—

Multiple aspects of innominate lesion composition are genetically determined, but in a manner largely independent of the genetic contributions to aortic lesions.
Statins Control Oxidized LDL-Mediated Histone Modifications and Gene Expression in Cultured Human Endothelial Cells
Authors: N'Guessan Philippe Dje , Riediger Fabian , Vardarova Kremena , Scharf Stefanie , Eitel Julia , Opitz Bastian , Slevogt Hortense , Weichert Wilko , Hocke Andreas C. , Schmeck Bernd , Suttorp Norbert , Hippenstiel Stefan
Published: January 2009

Objective—

Activation of the endothelium by oxidized low-density lipoprotein (oxLDL) has been implicated in the development of atherosclerosis. Histone modifications impact on the transcriptional activity state of genes. We tested the hypothesis that oxLDL-induced inflammatory gene expression is regulated by histone modifications and experienced the effect of statins on these alterations.

Methods and Results—

OxLDL-related interleukin-8 (IL-8) and monocyte-chemoattractant protein-1 (MCP-1) secretion in endothelial cells was reduced by statins but enhanced by histone deacetylase inhibitors. OxLDL induced lectin-like oxidized LDL receptor-1 (LOX-1) and extracellular regulated kinases (ERK1/2)-dependent acetylation of histone H3 and H4 as well as phosphorylation of histone H3, both globally and on the promoters of
il8
and
mcp1
. Pretreatment of oxLDL-exposed cells with statins reduced the above mentioned histone modification, as well as recruitment of CREB binding protein (CBP) 300, NF-κB, and of RNA polymerase II but prevented loss of binding of histone deacetylase (HDAC)-1 and -2 at the
il8
and
mcp1
gene promoters. OxLDL reduced HDAC1 and 2 expression, and statins partly restored global HDAC-activity. Statin-related effects were reverted with mevalonate. In situ experiments indicated decreased expression of HDAC2 in endothelial cells in atherosclerotic plaques of human coronary arteries.

Conclusions—

Histone modifications seem to play an important role in atherosclerosis.