bluuebunny/crossref_metadata_2025 huggingface dataset:
Absolute and relative dose measurements with Gafchromic™ EBT film for high energy electron beams with different doses per pulse
Authors: Fiandra Christian , Ragona Riccardo , Ricardi Umberto , Anglesio Silvia , Giglioli Francesca Romana
Published: December 2008

The authors have evaluated the accuracy, in absolute and relative dose measurements, of the Gafchromic™ EBT film in pulsed high‐energy electron beams. Typically, the electron beams used in radiotherapy have a dose‐per‐pulse value of less than /pulse. However, very high dose‐per‐pulse electron beams are employed in certain linear accelerators dedicated to intraoperatory radiation therapy (IORT). In this study, the absorbed dose measurements with Gafchromic™ EBT in both low (less than per pulse) and high (30 and per pulse) dose‐per‐pulse electron beams were compared with ferrous sulfate chemical Fricke dosimetry (operated by the Italian Primary Standard Dosimetry Laboratory), a method independent of the dose per pulse. A summary of Gafchromic™ EBT in relative and absolute beam output determination is reported. This study demonstrates the independence of Gafchromic™ EBT absorption as a function of dose per pulse at different dose levels. A good agreement (within 3%) was found with Fricke dosimeters for plane‐base IORT applicators. Comparison with a diode detector is presented for relative dose measurements, showing acceptable agreement both in the steep dose falloff zone and in the homogeneous dose region. This work also provides experimental values for recombination correction factor of a Roos (plane parallel) ionization chamber calculated on the basis of theoretical models for charge recombination.
AAPM Task Group 128: Quality assurance tests for prostate brachytherapy ultrasound systems
Authors: Pfeiffer Douglas , Sutlief Steven , Feng Wenzheng , Pierce Heather M. , Kofler Jim
Published: December 2008

While ultrasound guided prostate brachytherapy has gained wide acceptance as a primary treatment tool for prostate cancer, quality assurance of the ultrasound guidance system has received very little attention. Task Group 128 of the American Association of Physicists in Medicine was created to address quality assurance requirements specific to transrectal ultrasound used for guidance of prostate brachytherapy. Accurate imaging guidance and dosimetry calculation depend upon the quality and accuracy of the ultrasound image. Therefore, a robust quality assurance program for the ultrasound system is essential. A brief review of prostate brachytherapy and ultrasound physics is provided, followed by a recommendation for elements to be included in a comprehensive test phantom. Specific test recommendations are presented, covering grayscale visibility, depth of penetration, axial and lateral resolution, distance measurement, area measurement, volume measurement, needle template/electronic grid alignment, and geometric consistency with the treatment planning computer.
3D dynamic model of healthy and pathologic arteries for ultrasound technique evaluation
Authors: Balocco Simone , Basset Olivier , Azencot Jacques , Tortoli Piero , Cachard Christian
Published: December 2008

A 3D model reproducing the biomechanical behavior of human blood vessels is presented. The model, based on a multilayer geometry composed of right generalized cylinders, enables the representation of different vessel morphologies, including bifurcations, either healthy or affected by stenoses. Using a finite element approach, blood flow is simulated by considering a dynamic displacement of the scatterers (erythrocytes), while arterial pulsation due to the hydraulic pressure is taken into account through a fluid‐structure interaction based on a wall model. Each region is acoustically characterized using FIELD II software, which produces the radio frequency echo signals corresponding to echographic scans. Three acoustic physiological phantoms of carotid arteries surrounded by elastic tissue are presented to illustrate the model's capability. The first corresponds to a healthy blood vessel, the second includes a 50% stenosis, and the third represents a carotid bifurcation. Examples of mode, mode and color Doppler images derived from these phantoms are shown. Two examples of ‐mode image segmentation and the identification of the atherosclerotic plaque boundaries on Doppler color images are reported. The model could be used as a tool for the preliminary evaluation of ultrasound signal processing and visualization techniques.
Comparison of two‐dimensional and three‐dimensional iterative watershed segmentation methods in hepatic tumor volumetrics
Authors: Ray Shonket , Hagge Rosalie , Gillen Marijo , Cerejo Miguel , Shakeri Shidrokh , Beckett Laurel , Greasby Tamara , Badawi Ramsey D.
Published: December 2008

In this work the authors compare the accuracy of two‐dimensional (2D) and three‐dimensional (3D) implementations of a computer‐aided image segmentation method to that of physician observers (using manual outlining) for volume measurements of liver tumors visualized with diagnostic contrast‐enhanced and PET/CT‐based non‐contrast‐enhanced (PET‐CT) CT scans. The method assessed is a hybridization of the watershed method using observer‐set markers with a gradient vector flow approach. This method is known as the iterative watershed segmentation (IWS) method. Initial assessments are performed using software phantoms that model a range of tumor shapes, noise levels, and noise qualities. IWS is then applied to CT image sets of patients with identified hepatic tumors and compared to the physicians’ manual outlines on the same tumors. The repeatability of the physicians’ measurements is also assessed. IWS utilizes multiple levels of segmentation performed with the use of “fuzzy regions” that could be considered part of a selected tumor. In phantom studies, the outermost volume outline for level 1 (called level 1_1 consisting of inner region plus fuzzy region) was generally the most accurate. For in vivo studies, the level 1_1 and the second outermost outline for level 2 (called level 2_2 consisting of inner region plus two fuzzy regions) typically had the smallest percent error values when compared to physician observer volume estimates. Our data indicate that allowing the operator to choose the “best result” level iteration outline from all generated outlines would likely give the more accurate volume for a given tumor rather than automatically choosing a particular level iteration outline. The preliminary in vivo results indicate that 2D‐IWS is likely to be more accurate than 3D‐IWS in relation to the observer volume estimates.
Overview of patient dosimetry in diagnostic radiology in the USA for the past
Authors: Huda Walter , Nickoloff Edward L. , Boone John M.
Published: December 2008

This review covers the role of medical physics in addressing issues directly related to patient dosimetry in radiography, fluoroscopy, mammography, and CT. The sections on radiography and fluoroscopy radiation doses review the changes that have occurred during the last . A number of technological improvements have contributed to both a significant reduction in patient and staff radiation doses and improvements to the image quality during this period of time. There has been a transition from film‐screen radiography with hand dip film processing to electronic digital imaging utilizing CR and DR. Similarly, fluoroscopy has progressed by directly viewing image intensifiers in darkened rooms to modern flat panel image receptor systems utilizing pulsed radiation, automated variable filtration, and digitally processed images. Mammography is one of the most highly optimized imaging procedures performed, because it is a repetitive screening procedure that results in annual radiation exposure. Mammography is also the only imaging procedure in the United States in which the radiation dose is regulated by the federal government. Consequently, many medical physicists have studied the dosimetry associated with screen‐film and digital mammography. In this review, a brief history of mammography dose assessment by medical physicists is discussed. CT was introduced into clinical practice in the early 1970s, and has grown into one of the most important modalities available for diagnostic imaging. CT dose quantities and measurement techniques are described, and values of radiation dose for different types of scanner are presented. Organ and effective doses to adult patients are surveyed from the earliest single slice scanners, to the latest versions that include up to two x‐ray tubes and can incorporate as many as 256 detector channels. An overview is provided of doses received by pediatric patients undergoing CT examinations, as well as methods, and results, of studies performed to assess the radiation absorbed by the conceptus of pregnant patients.
Characterization of a novel anthropomorphic plastinated lung phantom
Authors: Yoon Sungwon , Henry Robert W. , Bouley Donna M. , Bennett N. Robert , Fahrig Rebecca
Published: December 2008

Phantoms are widely used during the development of new imaging systems and algorithms. For development and optimization of new imaging systems such as tomosynthesis, where conventional image quality metrics may not be applicable, a realistic phantom that can be used across imaging systems is desirable. A novel anthropomorphic lung phantom was developed by plastination of an actual pig lung. The plastinated phantom is characterized and compared with reference to in vivo images of the same tissue prior to plastination using high resolution 3D CT. The phantom is stable over time and preserves the anatomical features and relative locations of the in vivo sample. The volumes for different tissue types in the phantom are comparable to the in vivo counterparts, and CT numbers for different tissue types fall within a clinically useful range. Based on the measured CT numbers, the phantom cardiac tissue experienced a 92% decrease in bulk density and the phantom pulmonary tissue experienced a 78% decrease in bulk density compared to their in vivo counterparts. By‐products in the phantom from the room temperature vulcanizing silicone and plastination process are also identified. A second generation phantom, which eliminates most of the by‐products, is presented. Such anthropomorphic phantoms can be used to evaluate a wide range of novel imaging systems.
A method for quantitative assessment of renal function using dynamic contrast‐enhanced computed tomography: Evaluation of drug‐induced nephrotoxicity in rats
Authors: Murase Kenya , Tachibana Atsushi , Kusakabe Yoshinori , Matsuura Risa , Miyazaki Shohei
Published: December 2008

The authors developed a method to quantitatively evaluate renal function using dynamic contrast‐enhanced computed tomography (DCE‐CT) and a compartment model. They applied this method to evaluation of drug‐induced nephrotoxicity in rats. They performed the DCE‐CT studies using a total of 36 male Sprague–Dawley rats ( for control and for treatment). The rats in the drug‐treated groups were given of cis‐dichlorodiammineplatinum (cisplatin) intraperitoneally every other day twice , four times , or six times . The rate constants for the transfer of the contrast agent (CA) from the intravascular space to the renal corpuscle and tubular space via glomerular filtration , outflow of the CA from the renal tubules , and the fraction of blood volume were estimated from the DCE‐CT data, and their functional images were generated using the linear least squares method. When estimating the above parameters, the partial volume effect (PVE) on the arterial input function was corrected using a calibration curve obtained by phantom experiments. The endogenous creatinine clearance (Ccr) was also measured for comparison. The images became lower and more heterogeneous and the values decreased significantly with increasing cisplatin injection number (, , , and for control, two‐, four‐, and six‐times treated groups, respectively). When the PVE was not corrected, the values were overestimated by as compared with the case when the PVE was corrected. There was a good correlation between and Ccr ( and 0.901 for cases with and without correction of PVE, respectively). In conclusion, the authors' method using DCE‐CT appears to be useful for quantitatively evaluating the extent of renal dysfunction such as renal damage due to drug‐induced nephrotoxicity.
Origin of Stem Cells in Organogenesis
Authors: Slack J. M. W.
Published: December 2008

The development of individual organs in animal embryos involves the formation of tissue-specific stem cells that sustain cell renewal of their own tissue for the lifetime of the organism. Although details of their origin are not always known, tissue-specific stem cells usually share the expression of key transcription factors with cells of the embryonic rudiment from which they arise, and are probably in a similar developmental state. On the other hand, the isolation of pluripotent stem cells from the postnatal organism has encouraged the formulation of models of embryonic and postnatal development that are at variance with the conventional ones. Possible explanations for the existence of such cells, and the issue of whether they also exist in vivo, are discussed.
Inhibition of Rac by the GAP Activity of Centralspindlin Is Essential for Cytokinesis
Authors: Canman Julie C. , Lewellyn Lindsay , Laband Kimberley , Smerdon Stephen J. , Desai Arshad , Bowerman Bruce , Oegema Karen
Published: December 2008

During cytokinesis, the guanosine triphosphatase (GTPase) RhoA orchestrates contractile ring assembly and constriction. RhoA signaling is controlled by the central spindle, a set of microtubule bundles that forms between the separating chromosomes. Centralspindlin, a protein complex consisting of the kinesin-6 ZEN-4 and the Rho family GTPase activating protein (GAP) CYK-4, is required for central spindle assembly and cytokinesis in
Caenorhabditis elegans
. However, the importance of the CYK-4 GAP activity and whether it regulates RhoA remain unclear. We found that two separation-of-function mutations in the GAP domain of CYK-4 lead to cytokinesis defects that mimic centralspindlin loss of function. These defects could be rescued by depletion of the GTPase Rac or its effectors, but not by depletion of RhoA. Thus, inactivation of Rac by centralspindlin functions in parallel with RhoA activation to drive contractile ring constriction during cytokinesis.
Development of an Immunoglobulin M Capture-Based Enzyme-Linked Immunosorbent Assay for Diagnosis of Acute Infections withBartonella henselae
Authors: Hoey John G. , Valois-Cruz Fernando , Goldenberg Hannah , Voskoboynik Yekaterina , Pfiffner Jenna , Tilton Richard C. , Mordechai Eli , Adelson Martin E.
Published: December 2008

We describe the development of an immunoglobulin M-specific enzyme-linked immunosorbent assay for the detection of an early antibody response toBartonella henselae, the causative agent of cat scratch disease, bacillary angiomatosis, and endocarditis. This assay discriminates betweenB. henselae-positive and -negative patient samples with sensitivity and specificity values of 100% and 97.1%, respectively.
Severe Pneumonia withLeptotrichiasp. Detected Predominantly in Bronchoalveolar Lavage Fluid by Use of 16S rRNA Gene Sequencing Analysis
Authors: Kawanami Toshinori , Fukuda Kazumasa , Yatera Kazuhiro , Kido Takashi , Yoshii Chiharu , Taniguchi Hatsumi , Kido Masamitsu
Published: December 2008

We present the first case of severe pneumonia possibly caused byLeptotrichiaspecies with oral bacteria. This was found in a healthy but elderly subject whose bronchoalveolar lavage fluid was analyzed by 16S rRNA gene sequencing analysis. The combination of this method and microscopic observation provided useful information for diagnosis and treatment.
Correlation of Virus and Host Response Markers with Circulating Immune Complexes during Acute and Chronic Woodchuck Hepatitis Virus Infection
Authors: Glebe Dieter , Lorenz Heike , Gerlich Wolfram H. , Butler Scott D. , Tochkov Ilia A. , Tennant Bud C. , Cote Paul , Menne Stephan
Published: December 2008

Woodchuck hepatitis virus (WHV) is an established model for human hepatitis B virus. The kinetics of virus and host responses in serum and liver during acute, self-limited WHV infection in adult woodchucks were studied. Serum WHV DNA and surface antigen (WHsAg) were detected as early as 1 to 3 weeks following experimental infection and peaked between 1 and 5 weeks postinfection. Thereafter, serum WHsAg levels declined rapidly and became undetectable, while WHV DNA levels became undetectable much later, between 4 and 20 weeks postinfection. Decreasing viremia correlated with transient liver injury marked by an increase in serum sorbitol dehydrogenase (SDH) levels. Clearance of WHV DNA from serum was associated with the normalization of serum SDH. Circulating immune complexes (CICs) of WHsAg and antibodies against WHsAg (anti-WHs) that correlated temporarily with the peaks in serum viremia and WHs antigenemia were detected. CICs were no longer detected in serum once free anti-WHs became detectable. The detection of CICs around the peak in serum viremia and WHs antigenemia in resolving woodchucks suggests a critical role for the humoral immune response against WHsAg in the early elimination of viral and subviral particles from the peripheral blood. Individual kinetic variation during WHV infections in resolving woodchucks infected with the same WHV inoculum and dose is likely due to the outbred nature of the animals, indicating that the onset and magnitude of the individual immune response determine the intensity of virus inhibition and the timing of virus elimination from serum.
Population Dynamics and Rates of Molecular Evolution of a Recently Emerged Paramyxovirus, Avian Metapneumovirus Subtype C
Authors: Padhi Abinash , Poss Mary
Published: December 2008

We report the existence of two distinct sublineages of avian metapneumovirus (MPV) subtype C, a virus which has caused serious economic loss in commercial turkey farms in the United States. This subtype is closely related to human MPV, infects multiple avian species, and is globally distributed. The evolutionary rates of this virus are estimated to be 1.3 × 10
−3
to 7 × 10
−3
substitutions per site per year, and coalescent estimates place its emergence between 1991 and 1996. The four genes examined show a concordant demographic pattern which is characterized by a rapid increase in population size followed by stable population grown until the present.
Higher expression of deoxyuridine triphosphatase (dUTPase) may predict the metastasis potential of colorectal cancer
Authors: Kawahara A , Akagi Y , Hattori S , Mizobe T , Shirouzu K , Ono M , Yanagawa T , Kuwano M , Kage M
Published: December 2008

Aims:

5-Fluorouracil (5-FU) is one of the most widely used anticancer drugs; however, the activity of 5-FU is determined by the presence of several enzymes that limit its activation or degradation, and these include dihydropyrimidine dehydrogenase (DPD), orotate phosphoribosyl transferase (OPRT), thymidylate synthase (TS), thymidine kinase (TK), thymidine phosphorylase (TP) and deoxyuridine triphosphatase (dUTPase). The aim of this study was to compare the expression levels of these enzymes between the primary colorectal cancer of patients with and without distant metastases. Furthermore, there was a comparison of these expression levels between the primary tumour and the corresponding metastasis.

Methods:

Of 55 patients with colorectal cancer, 20 had no metastasis and the other 35 had distant metastasis. A strong expression was classified as positive, while weak to moderate or no expression was negative by immunohistochemistry.

Results:

Of the six 5-FU-related enzymes, the numbers of patients with expression of dUTPase (54% versus 15%; p = 0.005), TK (26% versus 0%; p = 0.019) and DPD (17% versus 45%; p = 0.033) were significantly different in those with primary tumours with metastasis compared with those with non-metastasis, respectively. The altered expression of OPRT (34.3%), TS (40.0%) and dUTPase (42.9%) was significantly greater from primary to metastasis among the 35 patients with metastasis. By contrast, the expression of OPRT, TS and dUTPase was decreased in 6, 5 and 7 patients, respectively, in metastatic sites.

Conclusions:

From this comparative study of the six 5-FU-related enzymes in colorectal cancer, the expression of dUTPase was most significantly different between primary tumours and their corresponding metastatic tumour. It is suggested that dUTPase may be a predictive biomarker for the metastatic potential of colorectal cancer.
ADVANCED HYPERSPECTRAL ALGORITHMS FOR TACTICAL TARGET DETECTION AND DISCRIMINATION
Authors: SCHAUM A.
Published: December 2008

Region-of-interest cueing by hyperspectral imaging systems for tactical reconnaissance has emphasized wide area coverage, low false alarm rates, and the search for manmade objects. Because they often appear embedded in complex environments and can exhibit large intrinsic spectral variability, these targets usually cannot be characterized by consistent signatures that might facilitate the detection process. Template matching techniques that focus on distinctive and persistent absorption features, such as those characterizing gases or liquids, prove ineffectual for most hard-body targets. High-performance autonomous detection requires instead the integration of limited and uncertain signature knowledge with a statistical approach. Effective techniques devised in this way using Gaussian models have transitioned to fielded systems. These first-generation algorithms are described here, along with heuristic modifications that have proven beneficial. Higher-performance Gaussian-based algorithms are also described, but sensitivity to parameter selection can prove problematical. Finally, a next-generation parameter-free non-Gaussian method is outlined whose performance compares favorably with the best Gaussian methods.
AIRIS — THE CANADIAN HYPERSPECTRAL IMAGER: CURRENT STATUS AND FUTURE DEVELOPMENTS
Authors: FOURNIER PIERRE , SMITHSON TRACY , ST-GERMAIN DANIEL
Published: December 2008

The Defence Research and Development Canada Agency has successfully completed a Technology Demonstration Program to assess the military utility of airborne hyperspectral Imagery. This required developing a sensor, the Airborne Infrared Imaging Spectrometer (AIRIS), and collecting in-flight imagery data. AIRIS was designed as a flexible instrument using a Fourier Transform spectrometer with a spectral resolution ranging from 1 to 16 cm−1, wide spectral coverage (2 to 12 microns), and different optical configurations. This paper provides a description of AIRIS and discusses examples of the spectral images collected during one air-trial. Emphasis is put on images of sub-pixel targets. Processing AIRIS data is labor intensive and can only be performed during post-trial analysis. Hardware and software modifications to AIRIS will implement a real-time processing capability over the next three years. These modifications will enable the instrument to output radiometrically calibrated digital spectrograms. These spectrograms will then be processed in real-time to output target detection and identification for selected target types.
THE HYPERTEMPORAL-HYPERSPECTRAL ANALYSIS TEST STATION — HYHATS
Authors: OLD TOM , HENDRICK ROY , HIGHAM DAVE , PALMER NELSON , MANNING CHRIS
Published: December 2008

ATK Mission Research will describe a very high speed FT-IR spectrometer that collects 1000 interferograms per second at a 4 cm−1 resolution in the 2-5 micrometer bandpass. The field of view of the instrument is about 1 degree. Collection of photons is on a single cryo-cooled InSb detector with output data streamed to a RAID device for later processing. The system uses a rotating lightweight air bearing mirror to achieve rapid variation of optical path length. Tilt compensation optics include a corner cube in a variation of the Michelson arrangement. The instrument is a one-man portable, tripod-mounted unit with off-unit data collection electronics. The system is designed for field deployment where measurements of energetic events are desired. Applications are commercial and military.
BACKGROUND CHARACTERIZATION WITH A SCANNED FOURIER TRANSFORM SPECTROMETER
Authors: LAZAREVICH ALISON K. , OURSLER DOUGLAS A. , DUNCAN DONALD D.
Published: December 2008

Background scene characterization in the long wave infrared (LWIR) region of the electromagnetic spectrum is of particular interest for simulating the operational environment of passive standoff chemical detection systems. In conjunction with collections of local metrological data and temperature and water vapor profiles, spectrally resolved LWIR imagery, acquired using a scanned Fourier Transform Spectrometer, and boresighted visible imagery were collected during Fall 2005. Resulting spectra in the 700 – 1450 cm−1 frequency range were analyzed to provide estimates of the foreground/background temperature differential that can then be used as a metric to assess the information content in the resulting IR imagery. Measurements were performed at two geographical sites and over 100 GBs of raw data were accumulated. Through spatio-temporal analysis of the resulting temperature differential maps, we have derived strategies for optimizing scan patterns. These optimized strategies attempt to minimize the amount of redundant data thus providing shorter inter-sample times for temporally varying portions of the scene. Considerations include the first and second order spatial and temporal statistics as well as information content as quantified by average pixel entropy. This research was financed by the U.S. Army Joint Project Manager for Nuclear, Biological, and Chemical Contamination Avoidance under contract number N00024-03-D-6606.
SIGNAL PROCESSING ALGORITHMS FOR STARING SINGLE PIXEL HYPERSPECTRAL SENSORS
Authors: MANOLAKIS DIMITRIS , ROSSACCI MICHAEL , O'DONNELL ERIN , D'AMICO FRANCIS M.
Published: December 2008

Remote sensing of chemical warfare agents (CWA) with stand-off hyperspectral sensors has a wide range of civilian and military applications. These sensors exploit the spectral changes in the ambient photon flux produced thermal emission or absorption after passage through a region containing the CWA cloud. In this work we focus on (a) staring single-pixel sensors that sample their field of view at regular intervals of time to produce a time series of spectra and (b) scanning single or multiple pixel sensors that sample their FOV as they scan. The main objective of signal processing algorithms is to determine if and when a CWA enters the FOV of the sensor.

We shall first develop and evaluate algorithms for staring sensors following two different approaches. First, we will assume that no threat information is available and we design an adaptive anomaly detection algorithm to detect a statistically-significant change in the observed spectrum. The algorithm processes the observed spectra sequentially-in-time, estimates adaptively the background, and checks whether the next spectrum differs significantly from the background based on the Mahalanobis distance or the distance from the background subspace. In the second approach, we will assume that we know the spectral signature of the CWA and develop sequential-in-time adaptive matched filter detectors. In both cases, we assume that the sensor starts its operation before the release of the CWA; otherwise, staring at a nearby CWA-free area is required for background estimation. Experimental evaluation and comparison of the proposed algorithms is accomplished using data from a long-wave infrared (LWIR) Fourier transform spectrometer.
AEROSOL TYPE-IDENTIFICATION USING UV-NIR-IR LIDAR SYSTEM
Authors: EGERT S. , PERI D.
Published: December 2008

Identification of aerosol type and chemical composition may help to trace their origin and estimate their impact on land and people. Aerosols chemical composition, size distribution and particles shape, manifest themselves in their spectral scattering cross-section. In order to make a reliable identification, comprehensive spectral analysis of aerosol scattering should be carried out. Usually, spectral LIDAR measurements of aerosols are most efficiently performed using an Nd:YAG laser transmitter in the fundamental frequency and its 2nd, 3rd and 4th harmonics. In this paper we describe automatic detection and identification of several aerosol types and size distributions, using a multi-spectral lidar system operating in the IR, NIR and UV spectral regions. The LIDAR transmitter is based on a single Nd:YAG laser. In addition to the 3rd and 4th harmonics in the UV, two optical parametric oscillator units produce the eye-safe 1.5 µm wavelength in the near IR and up to 40 separable spectral lines in the 8-11 µm IR. The combination of a wide spectral coverage required for backscattering analysis combined with fluorescence data, enable the generation of a large spectral data set for aerosols identification. Several natural and anthropogenic aerosol types were disseminated in controlled conditions, to test system capabilities. Reliable identification of transient and continuous phenomena demands fast and efficient control and detection algorithms. System performance, using the specially designed algorithms, is described below.
A PERFORMANCE EVALUATION OF THE NEHALEM QUAD-CORE PROCESSOR FOR SCIENTIFIC COMPUTING
Authors: BARKER KEVIN J. , DAVIS KEI , HOISIE ADOLFY , KERBYSON DARREN J. , LANG MIKE , PAKIN SCOTT , SANCHO JOSE CARLOS
Published: December 2008

In this work we present an initial performance evaluation of Intel's latest, second-generation quad-core processor, Nehalem, and provide a comparison to first-generation AMD and Intel quad-core processors Barcelona and Tigerton. Nehalem is the first Intel processor to implement a NUMA architecture incorporating QuickPath Interconnect for interconnecting processors within a node, and the first to incorporate an integrated memory controller. We evaluate the suitability of these processors in quad-socket compute nodes as building blocks for large-scale scientific computing clusters. Our analysis of intra-processor and intra-node scalability of microbenchmarks, and a range of large-scale scientific applications, indicates that quad-core processors can deliver an improvement in performance of up to 4x over a single core depending on the workload being processed. However, scalability can be less when considering a full node. We show that Nehalem outperforms Barcelona on memory-intensive codes by a factor of two for a Nehalem node with 8 cores and a Barcelona node containing 16 cores. Further optimizations are possible with Nehalem, including the use of Simultaneous Multithreading, which improves the performance of some applications by up to 50%.
USING HARDWARE MULTITHREADING TO OVERCOME BROADCAST/REDUCTION LATENCY IN AN ASSOCIATIVE SIMD PROCESSOR
Authors: SCHAFFER KEVIN , WALKER ROBERT A.
Published: December 2008

The latency of broadcast/reduction operations has a significant impact on the performance of SIMD processors. This is especially true for associative programs, which make extensive use of global search operations. Previously, we developed a prototype associative SIMD processor that uses hardware multithreading to overcome the broadcast/reduction latency. In this paper we show, through simulations of the processor running an associative program, that hardware multithreading is able to improve performance by increasing system utilization, even for processors with hundreds or thousands of processing elements. However, the choice of thread scheduling policy used by the hardware is critical in determining the actual utilization achieved. We consider three thread scheduling policies and show that a thread scheduler that avoids issuing threads that will stall due to pipeline dependencies or thread synchronization operations is able to maintain system utilization independent of the number of threads.
UNIFORM Lp-STABILITY ESTIMATE FOR THE SPATIALLY INHOMOGENEOUS BOLTZMANN EQUATION NEAR VACUUM
Authors: HA SEUNG-YEAL , YAMAZAKI MITSURU , YUN SEOK-BAE
Published: December 2008

We present a new uniform Lp-stability theory for the spatially inhomogeneous Boltzmann equation near vacuum via the nonlinear functional approach proposed by the first author. Our stability analysis is based on new nonlinear functionals which are equivalent to the pth power of Lp-distance. The L1-nonlinear functionals play the key role of "modulators" which make the accumulative functional be non-increasing in time t along classical solutions.
An analysis of data corruption in the storage stack
Authors: Bairavasundaram Lakshmi N. , Arpaci-Dusseau Andrea C. , Arpaci-Dusseau Remzi H. , Goodson Garth R. , Schroeder Bianca
Published: December 2008

An important threat to reliable storage of data is silent data corruption. In order to develop suitable protection mechanisms against data corruption, it is essential to understand its characteristics. In this article, we present the first large-scale study of data corruption. We analyze corruption instances recorded in production storage systems containing a total of 1.53 million disk drives, over a period of 41 months. We study three classes of corruption: checksum mismatches, identity discrepancies, and parity inconsistencies. We focus on checksum mismatches since they occur the most.

We find more than 400,000 instances of checksum mismatches over the 41-month period. We find many interesting trends among these instances, including: (i) nearline disks (and their adapters) develop checksum mismatches an order of magnitude more often than enterprise-class disk drives, (ii) checksum mismatches within the same disk are not independent events and they show high spatial and temporal locality, and (iii) checksum mismatches across different disks in the same storage system are not independent. We use our observations to derive lessons for corruption-proof system design.
Measuring changeability for generic aspect-oriented systems
Authors: Grover P. S. , Kumar Rajesh , Kumar Avadhesh
Published: December 2008

Maintenance of software systems has become a major concern for software developers and users. In environments, where software changes are frequently required to improve software quality, chan-geability is an important characteristic of maintainability in ISO/IEC 9126 quality standards. Many researchers and practition-ers have proposed changeability assessment techniques for Object-Oriented Programming (OOP) and Aspect-Oriented Programming (AOP). To the best of our knowledge, no one has proposed chan-geability assessment technique for generic Aspect-Oriented (AO) Systems. AOP is an emerging technique that provides a means to clearly encapsulate and implement aspects that crosscut other modules. In this paper, we have defined a generic changeability assessment technique that takes into account two well known fami-lies of available AOP languages viz, AspectJ and CaesarJ. A co-relation analysis between changeability and dependency has been performed. Result shows that highly dependent AO systems will absorb low changeability.
Nutrient-driven incretin secretion into intestinal lymph is different between diabetic Goto-Kakizaki rats and Wistar rats
Authors: Kindel Tammy L. , Yang Qing , Yoder Stephanie M. , Tso Patrick
Published: December 2008

The incretin hormones gastric inhibitory polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) augment postprandial glucose-mediated insulin release from pancreatic β-cells. The Goto-Kakizaki (GK) rat is a widely used, lean rodent model of Type 2 diabetes; however, little is known regarding the incretin secretion profile to different nutrients in these rats. We have recently shown that lymph is a sensitive medium to measure incretin secretion in rodents and probably the preferred compartment for GLP-1 monitoring. To characterize the meal-induced incretin profile, we compared lymphatic incretin concentrations in the GK and Wistar rat after enteral macronutrient administration. After cannulation of the major mesenteric lymphatic duct and duodenum, each animal received an intraduodenal bolus of either a fat emulsion, dextrin, a mixed meal, or saline. Lymph was collected for 3 h and analyzed for triglyceride, glucose, GLP-1, and GIP content. There was no statistical difference in GIP or GLP-1 secretion after a lipid bolus between GK and Wistar rats. Dextrin and a mixed meal both increased incretin concentration area under the curve, however, significantly less in GK rats compared with Wistar rats (dextrin GIP: 707 ± 106 vs. 1,373 ± 114 pg·ml−1·h, respectively, P < 0.001; dextrin GLP-1: 82.7 ± 24.3 vs. 208.3 ± 26.3 pM/h, respectively, P = 0.001). After administration of a carbohydrate-containing meal, GK rats were unable to mount as robust a response of both GIP and GLP-1 compared with Wistar rats, a phenomenon not seen after a lipid meal. We propose a similar, glucose-mediated incretin secretion pathway defect of both K and L cells in GK rats.
Primary Care Physicians' Experience with Electronic Medical Records: Barriers to Implementation in a Fee-for-Service Environment
Authors: Ludwick D. A. , Doucette John
Published: December 2008

Our aging population has exacerbated strong and divergent trends between health human resource supply and demand. One way to mitigate future inequities is through the adoption of health information technology (HIT). Our previous research showed a number of risks and mitigating factors which affected HIT implementation success. We confirmed these findings through semistructured interviews with nine Alberta clinics. Sociotechnical factors significantly affected physicians' implementation success. Physicians reported that the time constraints limited their willingness to investigate, procure, and implement an EMR. The combination of antiquated exam room design, complex HIT user interfaces, insufficient physician computer skills, and the urgency in patient encounters precipitated by a fee-for-service remuneration model and long waitlists compromised the quantity, if not the quality, of the information exchange. Alternative remuneration and access to services plans might be considered to drive prudent behavior during physician office system implementation.
Proteomic analysis of breast cancer molecular subtypes and biomarkers of response to targeted kinase inhibitors using reverse-phase protein microarrays
Authors: Boyd Zachary S. , Wu Qun Jenny , O'Brien Carol , Spoerke Jill , Savage Heidi , Fielder Paul J. , Amler Lukas , Yan Yibing , Lackner Mark R.
Published: December 2008

Although breast cancer molecular subtypes have been extensively defined by means of gene expression profiling over the past decade, little is known, at the proteomic level, as to how signaling pathways are differentially activated and serve to control proliferation in different breast cancer subtypes. We used reverse-phase protein arrays to examine phosphorylation status of 100 proteins in a panel of 30 breast cancer cell lines and showed distinct pathway activation differences between different subtypes that are not obvious from previous gene expression studies. We also show that basal levels of phosphorylation of key signaling nodes may have diagnostic utility in predicting response to selective inhibitors of phosphatidylinositol 3-kinase and mitogen-activated protein kinase/extracellular signal-regulated kinase kinase. Finally, we show that reverse-phase protein arrays allow the parallel analysis of multiple pharmacodynamic biomarkers of response to targeted kinase inhibitors and that inhibitors of epidermal growth factor receptor and mitogen-activated protein kinase/extracellular signal-regulated kinase kinase result in compensatory up-regulation of the phosphatidylinositol 3-kinase/Akt signaling pathway. [Mol Cancer Ther 2008;7(12):3695–706]
Can I Make my Own Decision? A Cross-Cultural Study of Perceived Social Network Influence in Mate Selection
Authors: Shuangyue Zhang  , Kline Susan L.
Published: December 2008

Two studies examined the comparative influence of network members on one's intention to marry and relational commitment among 616 college students in both China and the United States. Compared with U.S. participants, Chinese students believed that their dating partners would meet their filial piety beliefs, that such beliefs were more important in their potential decision to marrying their dating partners, and that they were more likely to comply with network members regarding the decision to marry. Network influence predicted Chinese marital intentions and relationship commitment, whereas relationship length and beliefs about support, care, living a better life, and network influence predicted U.S. participants' marital intentions and/or relationship commitment.
Acculturation Strategies and Integrative Complexity
Authors: Tadmor Carmit T. , Tetlock Philip E. , Kaiping Peng
Published: December 2008

People are being exposed to second cultures in growing numbers, yet the role played by second-culture exposure in shaping sociocognitive skills has received little theoretical attention. The authors address this gap by exploring the relationship between acculturation strategies and integrative complexity. Consistent with the acculturation complexity model, studies of both Asian American college students (Study 1) and Israelis working in the United States (Study 2) show that biculturals are more integratively complex across domains (e.g., culture, work) than either assimilated or separated individuals. Using priming manipulations to clarify the directional flow of causality between acculturation and integrative complexity, the authors also find that greater integrative complexity among biculturals is driven by acculturation pressures (Study 3). Finally, the authors discuss the adaptive implications of multiculturalism.
Rehabilitation Counseling in the State or Federal Program
Authors: O'Brien Michael , Graham Michael
Published: December 2008

Rehabilitation counseling has played a significant role in the public rehabilitation program since its inception. Rehabilitation educators have also been critical in this partnership. This article reviews current trends in the relationships between public rehabilitation agencies, university programs, accreditation bodies, and others to discuss future potential paths. Also reviewed are current expectations for skills and opportunities for rehabilitation counselors in the state/federal vocational rehabilitation programs. Opposing alternatives for how these relationships may affect the future of rehabilitation counseling practice are suggested.
Rehabilitation Counselor Education Accreditation
Authors: Shaw Linda R. , Kuehn Marvin D.
Published: December 2008

This review examines some of the critical factors that influenced the evolution of rehabilitation counselor education accreditation. The article discusses the history and structure of the accreditation process and the activities that have occurred to maintain the relevancy and viability of the process. Major issues that the Council on Rehabilitation Education (CORE) has addressed in recent years are highlighted and examples are provided to illustrate the scope and importance of the accreditation process. Commentary is included to help the reader understand the issues that CORE will be addressing and the directions that may become priorities in the future.
Predicting Recidivism by Mentally Disordered Offenders Using the LSI-R:SV
Authors: Ferguson A. Murray , Ogloff James R.P. , Thomson Lindsay
Published: December 2008

The Level of Service Inventory—Revised: Screening Version (LSI-R:SV) has proven to validly predict reoffending in general offender populations but has not previously been studied specifically with offenders who have a major mental illness, including those with a dual diagnosis. This research project measures the validity of the LSI-R:SV for use with 208 mentally ill offenders who were released from a secure forensic hospital in Melbourne, Australia. Results indicate that the LSI-R:SV is a good predictor of recidivism among mentally disordered offenders. However, the LSI-R:SV does not reliably predict recidivism in individuals who attracted a dual diagnosis. Further research needs to reevaluate risk factors associated with recidivism in offenders with a dual diagnosis.
Closing the Revolving Door?
Authors: Warner Tara D. , Kramer John H.
Published: December 2008

The criminal justice system is often viewed as a revolving door for drug-dependent offenders due to its failure to recognize the association between addiction and offending, and repeated incarceration of drug-dependent offenders has contributed to prison overcrowding. The authors evaluated the effectiveness of Pennsylvania's drug and alcohol treatment-based intermediate punishment, Restrictive Intermediate Punishments (RIP/D&A), at reducing the risk of rearrest. Rearrest was compared at 12, 24, and 36 months postrelease. Offenders who successfully completed treatment had a lower risk of rearrest than traditionally sentenced offenders in general and county jail and probation offenders specifically. However, offenders sentenced to RIP/D&A who did not successfully complete treatment were more at risk for rearrest than traditionally sentenced offenders in general. Also, offenders sentenced to state incarceration had a lower risk of rearrest than RIP/D&A participants, regardless of program completion.
“The Emperor and the People in One Body”
Authors: Kuo Ya-pei
Published: December 2008

This article uses the changing status of Confucius and his worship during the Xinzheng reforms (1902—1911) to investigate the transformation of imperial ritual into a political apparatus for the imagining of the nation. It first surveys the practices of Confucius worship in late imperial China and discusses its multivalent meanings. It then analyzes the Xinzheng reformers' reconstruction of Confucius into a symbol of Chineseness and situates it in the late Qing debate on citizen formation and nation building. Finally, it looks into the planning of a new ritual scheme for worshiping Confucius and highlights its departure from imperial precedents. Previous research has suggested that the Xinzheng reforms followed the Meiji example. This article shows that, by weaving the emperor and the people into one collective ritual act, the ritual scheme relativized the emperor's status and significantly diverged from its Japanese model.