bluuebunny/crossref_metadata_2025_split huggingface dataset:
DEVELOPMENT AND CHARACTERIZATION OF GENETIC STOCKS AND THEIR HYBRIDS IN Macrobrachium rosenbergii: PHYSIOLOGICAL RESPONSES AND LARVAL DEVELOPMENT RATES
Authors: Sarver D. , Onizuka D. , Malecha S. 
Published: August 2010

ABSTRACTSeveral genetic stocks of Macrobrachium rosenbergii were examined with respect to their physiological responses to different laboratory culture environments as juveniles and their development rates as larvae. Results indicate that physiological genetic differences exist between these genotypes and that these differences may be important for genetic improvement. Early growth rates for Thai, Sarawak, and Australian stocks were compared to those for the Anuenue stock (originally brought from Malaysia) at 19, 23, and 29°C. Growth at 19°C was very poor for all genotypes. At 23 and 29°C the Anuenue strain grew faster than the Thai and Australian strains and about equal to the Sarawak strain.Growth of Anuenue, Australian, Thai and Sarawak strains at 0, 5, and 10 ppt salinities was also compared. The Anuenue and Thai strains grew as well at 5 ppt as in freshwater while 10 ppt significantly depressed growth. In the Australian and Sarawak groups growth was depressed in both 5 and 10 ppt treatments.Temperature tolerance was found to increase with age for all strains although the Anuenue strain appeared to be the most tolerant to low temperatures. The prawns were tested just after metamorphosis at two weeks post‐metamorphosis and one month post‐metamorphosis.Tolerance to high pH was tested for the Anuenue and found to increase with age. Mortality at a pH of 9.5 at 29°C went from 80% for newly metamorphosed juveniles to 43% for two‐week‐old animals and 50% for one‐month‐old animals.Among the “pure” strains only the Australian strain showed significantly faster development times in replicated trials. The first Australian postlarvae appeared after an average of 15.5 days and 95% metamorphosed after 20.5 days compared to 24 and 32 days for the Anuenue strain. In unreplicated trials involving hybrids between Anuenue stocks and over two dozen other stocks only the Australian‐Anuenue hybrid showed faster larval development times with time to 95% settling at 35 days compared to 47 days for the Anuenue controls.
Influence of the Photostabilizer in the Photoprotective Effects of a Formulation Containing UV‐Filters and Vitamin A
Authors: Benevenuto Carolina Gomes , Sala Di Matteo Miguel A. , Maia Campos Patrícia M. B. G. , Gaspar Lorena Rigo 
Published: August 2010

AbstractVitamin A palmitate has been used in cosmetics; however, studies report that this substance shows photoreactivity that can lead to loss of safety and efficacy. On the other hand, photostabilizers have been used to increase sunscreen photostability and consequently their safety and effectiveness. Thus, this study aimed to evaluate the influence of photostabilizers on the photoprotective effects of a cosmetic formulation containing UV‐filters and vitamin A palmitate. The formulation containing UV‐filters was supplemented with vitamin A palmitate and the photostabilizers diethylhexyl 2,6‐naphthalate (DEHN), bumetrizole and benzotriazolyl dodecyl p‐cresol (BTDC). Hairless mice were treated daily by topical applications and irradiated (UVA/B). Erythema index, transepidermal water loss, histological/histometric analysis and number of sunburn cells (SBC) were evaluated. The results showed that all formulations protected from UV‐induced enhancement of erythema and SBC but there was no difference among them. The formulation with no stabilizers reduced viable epidermis thickness due to atrophy induced by UV radiation. Thus, it can be concluded that the presence of photostabilizers influenced the effects of formulations containing UV‐filters and vitamin A palmitate, which could be seen by histological and histometric analysis. Furthermore, the formulations containing the stabilizers DEHN and BTDC showed better protective effects on hairless mice skin.
A Retrospective Economic Analysis of the Ontario Red Fox Oral Rabies Vaccination Programme
Authors: Shwiff S. A. , Nunan C. P. , Kirkpatrick K. N. , Shwiff S. S. 
Published: August 2010

SummaryOntario initiated a red fox (Vulpes vulpes) oral rabies vaccination (ORV) programme in 1989. This study utilized a benefit‐cost analysis to determine if this ORV programme was economically worthwhile. Between 1979 and 1989, prior to ORV baiting, the average annual human post‐exposure treatments, positive red fox rabies diagnostic tests and indemnity payments for livestock lost to rabies were 2248, 1861 and $246 809, respectively. After baiting, from 1990 to 2000, a 35%, 66% and 41% decrease in post‐exposure treatments, animal rabies tests and indemnity payments was observed, respectively. These reductions were viewed as benefits of the ORV programme, whereas total costs were those associated with ORV baiting. Multiple techniques were used to estimate four different benefit streams and the total estimated benefits ranged from $35 486 316 to $98 413 217. The annual mean ORV programme cost was $6 447 720, with total programme costs of $77 372 637. The average benefit‐cost ratios over the analysis period were .49, 1.06, 1.27 and 1.36, indicating overall programme efficiency in three of the four conservative scenarios.
QA procedures for multimodality preclinical tumor drug response testing
Authors: Lee Yongsook C. , Goins Beth A. , Fullerton Gary D. 
Published: August 2010

Purpose:There are growing expectations that imaging biomarkers for tumor therapeutic drug response assessment will speed up preclinical testing of anticancer drugs in rodent models. The only imaging biomarker presently approved by the U.S. Food and Drug Administration is tumor size measurement based on either World Health Organization (WHO) criteria or Response Evaluation Criteria in Solid Tumors (RECIST). Frequently, preclinical data are accumulated from multiple research centers on multiple continents using scanners from different manufacturers and sometimes even using different imaging modalities. Very expensive cancer drug response studies can be compromised by inadequate controls to assure precision and accuracy of tumor size measurements. This project was undertaken to develop standardized quality assurance (QA) procedures using a multimodality preclinical tumor response phantom to validate the accuracy of tumor size measurements based on WHO criteria, RECIST, or global tumor volume criteria for evaluation of cytostatic drugs.Methods:A tumor response phantom containing five low contrast test objects designed to simulate animal tumor models was made of tissue‐mimicking materials. Imaging of the phantom was performed using three modalities in two institutions to evaluate size measurement of tumor‐simulating test objects.Results:Evaluation of tumor measurements from the three commonly used imaging devices in two different institutions for monitoring tumor size changes showed that a single phantom for multiple modalities was feasible. The tumor response phantom validated precision and accuracy of tumor response data input from ultrasound, computed tomography, and/or magnetic resonance imaging devices.Conclusions:Measurement results show that the standardized QA procedures using the tumor response phantom can provide a rationale check of data that excludes input from poorly maintained instruments, inadequate measurement protocols, or random operator error that frequently introduce unacceptable variability or systematic error in multiple institutions trials.
SPECT region of interest reconstruction with truncated transmission and emission data
Authors: Zeng Gengsheng L. , Gullberg Grant T. 
Published: August 2010

Purpose:The aim of this article is to propose an exact SPECT region of interest (ROI) reconstruction method using truncated transmission and truncated emission data.Methods:Recently, the authors published two articles in Physics in Medicine and Biology with two results in SPECT ROI emission image reconstruction. The first result states that if the transmission data are truncated but the emission data are not truncated, the emission image can be exactly reconstructed, provided the entire emission image is inside the region where the transmission data are not truncated. The second result states that if the transmission data are not truncated, the emission ROI can be exactly reconstructed with truncated emission data. This article combines these two results and obtains a new result that the emission ROI can be exactly reconstructed if both transmission and emission data are truncated.Results:Computer simulations are performed to verify the proposed ROI image reconstruction algorithm.Conclusions:Exact SPECT ROI image reconstruction is possible using truncated transmission and emission projections with some prior information about the attenuator and the emission distribution.
Hybrid referenceless and multibaseline subtraction MR thermometry for monitoring thermal therapies in moving organs
Authors: Grissom William A. , Rieke Viola , Holbrook Andrew B. , Medan Yoav , Lustig Michael , Santos Juan , McConnell Michael V. , Pauly Kim Butts 
Published: August 2010

Purpose: Magnetic resonance thermometry using the proton resonance frequency (PRF) shift is a promising technique for guiding thermal ablation. For temperature monitoring in moving organs, such as the liver and the heart, problems with motion must be addressed. Multi‐baseline subtraction techniques have been proposed, which use a library of baseline images covering the respiratory and cardiac cycle. However, main field shifts due to lung and diaphragm motion can cause large inaccuracies in multi‐baseline subtraction. Referenceless thermometry methods based on polynomial phase regression are immune to motion and susceptibility shifts. While referenceless methods can accurately estimate temperature within the organ, in general, the background phase at organ/tissue interfaces requires large polynomial orders to fit, leading to increased danger that the heated region itself will be fitted by the polynomial and thermal dose will be underestimated. In this paper, a hybrid method for PRF thermometry in moving organs is presented that combines the strengths of referenceless and multi‐baseline thermometry.Methods: The hybrid image model assumes that three sources contribute to image phase during thermal treatment: Background anatomical phase, spatially smooth phase deviations, and focal, heat‐induced phase shifts. The new model and temperature estimation algorithm were tested in the heart and liver of normal volunteers, in a moving phantom HIFU heating experiment, and in numerical simulations of thermal ablation. The results were compared to multi‐baseline and referenceless methods alone.Results: The hybrid method allows forin vivo temperature estimation in the liver and the heart with lower temperature uncertainty compared to multi‐baseline and referenceless methods. The moving phantom HIFU experiment showed that the method accurately estimates temperature during motion in the presence of smooth main field shifts. Numerical simulations illustrated the method's sensitivity to algorithm parameters and hot spot features.Conclusions: This new hybrid method for MR thermometry in moving organs combines the strengths of both multi‐baseline subtraction and referenceless thermometry and overcomes their fundamental weaknesses.
Standardized evaluation methodology for 3D/2D registration based on the Visible Human data set
Authors: Markelj Primož , Likar Boštjan , Pernuš Franjo 
Published: August 2010

Purpose:A new image database with a reference‐based standardized evaluation methodology for objective evaluation and comparison of three‐dimensional/two‐dimensional (3D/2D) registration methods has been introduced.Methods:Computed tomography (CT) images of a male and female from the Visible Human Project were used and 16 subvolumes, each containing one of vertebrae T3‐T12 and L1‐L5 and the pelvis, were defined from the CTs. Six pairs of 2D fluoroscopic x‐ray images from different views, showing the thoracic, lumbar, and pelvic regions, were rendered from the CT data using a ray‐casting algorithm with an energy conversion function. Furthermore, a single 13‐gauge needle was analytically simulated and projected onto the 2D images. By the novel standardized evaluation methodology, a 3D/2D registration method is evaluated by four evaluation criteria: Accuracy, reliability, robustness, and algorithm complexity.Results:To demonstrate the usefulness of the proposed data set and the standardized evaluation methodology, a part of the data set was used in an evaluation study of two gradient‐based 3D/2D registration methods. It was shown that the use of a failure criterion to calculate the registration accuracy and reliability is not required, since all the information about a registration method can be determined from the estimated distribution of registration errors.Conclusions:The proposed simulated image data set with quite realistic synthetic 2D images, depicting soft tissues and outliers, is especially suitable for preliminary testing of 3D/2D registration algorithms. Since the aim of this article is to provide objective comparison and unbiased evaluation of 3D/2D registration methods, the standardized evaluation methodology is available upon request from the authors.
An MCNPX Monte Carlo model of a discrete spot scanning proton beam therapy nozzle
Authors: Sawakuchi Gabriel O. , Mirkovic Dragan , Perles Luis A. , Sahoo Narayan , Zhu X. Ron , Ciangaru George , Suzuki Kazumichi , Gillin Michael T. , Mohan Radhe , Titt Uwe 
Published: August 2010

Purpose:The purposes of this study were to validate a discrete spot scanning proton beam nozzle using the Monte Carlo (MC) codeMCNPX and use the MC validated model to investigate the effects of a low‐dose envelope, which surrounds the beam's central axis, on measurements of integral depth dose (IDD) profiles.Methods:An accurate model of the discrete spot scanning beam nozzle from The University of Texas M. D. Anderson Cancer Center (Houston, Texas) was developed on the basis of blueprints provided by the manufacturer of the nozzle. The authors performed simulations of single proton pencil beams of various energies using the standard multiple Coulomb scattering (MCS) algorithm within theMCNPX source code and a new MCS algorithm, which was implemented in the MCNPX source code. The MC models were validated by comparing calculated in‐air and in‐water lateral profiles and percentage depth dose profiles for single pencil beams with their corresponding measured values. The models were then further tested by comparing the calculated and measured three‐dimensional (3‐D) dose distributions. Finally, an IDD profile was calculated with different scoring radii to determine the limitations on the use of commercially available plane‐parallel ionization chambers to measure IDD.Results:The distance to agreement, defined as the distance between the nearest positions of two equivalent distributions with the same value of dose, between measured and simulated ranges was within 0.13 cm for both MCS algorithms. For low and intermediate pencil beam energies, the MC simulations using the standard MCS algorithm were in better agreement with measurements. Conversely, the new MCS algorithm produced better results for high‐energy single pencil beams. The IDD profile calculated with cylindrical tallies with an area equivalent to the area of the largest commercially available ionization chamber showed up to 7.8% underestimation of the integral dose in certain depths of the IDD profile.Conclusions:The authors conclude that a combination of MCS algorithms is required to accurately reproduce experimental data of single pencil beams and 3‐D dose distributions for the scanning beam nozzle. In addition, the MC simulations showed that because of the low‐dose envelope, ionization chambers with radii as large as 4.08 cm are insufficient to accurately measure IDD profiles for a 221.8 MeV pencil beam in the scanning beam nozzle.
Intensity modulated dose calculation with an improved experimental pencil‐beam kernel
Authors: Azcona Juan Diego , Burguete Javier 
Published: August 2010

Purpose:This article presents an improved pencil‐beam dose calculation formalism based on an experimental kernel obtained by deconvolution. The new algorithm makes it possible to calculate the absorbed dose for all field sizes.Methods:The authors have enhanced their previous work [J. D. Azcona and J. Burguete, Med. Phys. 35, 248–259 (2008)] by correcting the kernel tail representing the contribution to the absorbed dose far from the photon interaction point. The correction was performed by comparing the calculated and measured output factors. Dose distributions and absolute dose values calculated using the new formalism have been compared to measurements. The agreement between calculated and measured dose distributions was evaluated according to the ‐index criteria. In addition, 35 individual intensity‐modulated radiation therapy (IMRT) fields were calculated and measured in polystyrene using an ionization chamber. Furthermore, a series of 541 IMRT fields was calculated using the algorithm proposed here and using a commercial IMRT optimization and calculation software package. Comparisons were made between the calculations at single points located at the isocenter for all the beams, as well as between beams grouped by anatomic location.Results:The percentage of points passing the‐index criteria (3%, 3 mm) when comparing calculated and measured dose distributions is generally greater than 99% for the cases studied. The agreement between the calculations and the experimental measurements generally lies in the ±2% interval for single points, with a mean value of 0.2%. The agreement between calculations using the proposed algorithm and using a commercial treatment planning system is also between ±5%.Conclusions:An improved algorithm based on an experimental pencil‐beam kernel obtained by deconvolution has been developed. It has been validated clinically and promises to be a valuable tool for IMRT quality assurance as an independent calculation system for monitor units and dose distributions. An important point is that the algorithm presented here uses an experimental kernel, which is therefore independent of Monte‐Carlo‐calculated kernels.
Characterization of the ringing artifacts in rotator‐based reconstruction with Monte Carlo‐based resolution compensation for PET
Authors: Zhang Long , Staelens Steven , Van Holen Roel , Verhaeghe Jeroen , Vandenberghe Stefaan 
Published: August 2010

Purpose:Studies have shown that Monte Carlo‐based reconstruction could effectively improve the image quality of positron emission tomography. The authors have previously used a Gaussian rotator‐based algorithm to efficiently reduce the computational cost for system matrix (SM) calculation and to meet the large memory requirements for SM storage. However, pronounced ringing artifacts were observed in the reconstructed image. In this article, the authors investigated and characterized these artifacts.Methods:The authors proposed an “ideal” rotator and used it as a baseline in the artifacts evaluation. This ideal rotator produces perfectly rotated images. The Gaussian rotator method was evaluated by a full system model and a partial system model without positron range and acolinearity, which could be compensated for by the blurring of the Gaussian rotator for studies. Noiseless data, Monte Carlo simulation data, as well as acquired experimental data were used to quantitatively characterize the behavior of the artifacts.Results:The study of the noiseless data indicated that the artifacts were mainly attributed to the rotator, which further blurred the simulated system responses. The simulation study suggested that the artifacts become less pronounced and not quantitatively significant in practice. This result is consistent with the experimental data study. Better contrast recovery was achieved with an overcompensated system model. Traditionally, an undercompensated system model was preferred to avoid artifacts. The authors’ studies suggest that the Gaussian rotator with the full system model yields the best image quality among the evaluated methods with considerably reduced quantitative error and quantitatively insignificant artifacts in practice.Conclusions:The authors’ investigation indicated that a moderately overcompensated system model (about 2 mm FWHM in this study) yielded better contrast recovery and quantitatively insignificant artifacts in practice.
Direction‐dependent localization errors in SPECT images
Authors: Roper Justin , Bowsher James , Yin Fang‐Fang 
Published: August 2010

Purpose:Single photon emission computed tomography (SPECT) is being investigated for imaging inside radiation therapy treatment rooms to localize biological targets. Here, computer simulations were used to analyze locational and directional dependencies in localization errors and to assess the effects of spatial resolution modeling and observer normalization on localization performance.Methods:SPECT images of the XCAT phantom, containing 12 hot tumors, were reconstructed with detector response function compensation (DRC) and without DRC (nDRC). Numerical observers were forced to select the most suspicious tumor location, using normalized cross correlation (NXC) or un‐normalized cross correlation (XC), from 3 cm diameter search volumes that each contained only one tumor. For each tumor site, localization was optimized as a function of the iteration number and postreconstruction smoothing. Localization error, the distance between true and estimated tumor positions, was calculated across the ensembles of 80 images. Direction‐dependent localization bias and precision were estimated from the image ensemble.Results:For the six superficial tumors in close proximity to the detector trajectory, mean localization errors were and were lowest or comparable using DRC‐NXC, though differences from DRC‐XC and nDRC‐NXC were not statistically significant. DRC‐NXC did provide statistically significantly better localization than nDRC‐XC for five of these six tumors. At the other six sites where attenuation was more severe and the distance was generally greater between the tumor and detector, DRC typically did not show better localization than nDRC. Observer normalization improved the localization substantially for a tumor near the hotter heart. Localization errors were anisotropic and dependent on tumor location relative to the detector trajectory.Conclusions:This computer‐simulation study compared localization performance for normalized and un‐normalized numerical observers, which were used to estimate tumor positions in SPECT images, reconstructed with and without DRC. For tumors localized to on average, which are good candidates for SPECT‐guided radiation therapy, localization performance typically improved by compensating for the detector response function and by using a normalized observer. The observed direction‐dependent localization errors have important implications for radiation therapy and are relevant to SPECT imaging in general.