bluuebunny/crossref_metadata_2025_split huggingface dataset:
Salmonella Serovars and Antimicrobial Resistance Patterns on a Sample of High Seroprevalence Pig Farms in England and Wales (2003–2008)
Authors: Miller A. J. , Twomey D. F. , Davies R. H. , Teale C. J. , Williamson S. M. , Reichel R. , Featherstone C. A. , Cook A. J. C. , Snow L. C. , Armstrong J. D. 
Published: April 2011

SummaryFollowing the introduction of a national abattoir‐based monitoring programme for Salmonella in pigs, advisory visits were made to pig farms in England and Wales with high Salmonella seroprevalence assessed by muscle tissue fluid (meat juice) ELISA. Samples (n = 15 790), including pooled pen floor faeces (n = 12 136), were collected for Salmonella culture from 296 farms, between October 2003 and February 2008. Salmonella was isolated from 4489 (28%) of all samples collected, including 3301 (27%) of pooled pen floor faecal samples, from 270 (91%) of farms visited. Salmonella Typhimurium and S. Derby were the most prevalent serovars, representing 64% and 16% of isolates serotyped, respectively. The main phage types of S. Typhimurium identified were U288 and DT193. Antimicrobial resistance (AMR) was seen in 92% of isolates tested, with the highest frequencies of resistance occurring to tetracyclines (T), sulphonamide compounds (SU), ampicillin (AM), sulphamethoxazole/trimethoprim (SXT), streptomycin (S) and chloramphenicol (C). Fifty‐nine AMR patterns were observed, the most frequent of these being T, AM, SXT, C, S, SU, seen in 35% of isolates tested. Multi‐drug resistance was commonly found, with 67% of isolates submitted for AMR testing showing resistance to between four and nine antimicrobials.
Equine Encephalomyelitis Outbreak Caused by a Genetic Lineage 2 West Nile Virus in Hungary
Authors: Kutasi O. , Bakonyi T. , Lecollinet S. , Biksi I. , Ferenczi E. , Bahuon C. , Sardi S. , Zientara S. , Szenci O. 
Published: April 2011

Background: The spread of lineage 2 West Nile virus (WNV) from sub‐Saharan regions to Europe and the unpredictable change in pathogenicity indicate a potential public and veterinary health threat and requires scientific awareness.Objectives: To describe the results of clinical and virological investigations of the 1st outbreak of a genetic lineage 2 WNV encephalomyelitis in horses.Animals: Seventeen horses with neurologic signs.Methods: Information regarding signalment, clinical signs, and outcome was obtained for each animal. Serology was performed in 15 cases, clinicopathological examination in 7 cases, and cerebrospinal fluid was collected from 2 horses. Histopathology was carried out in 4 horses, 2 of which were assessed for the presence of WNV in their nervous system.Results: WNV neutralizing antibody titers were between 10 and 270 (median, 90) and the results of other serological assays were in agreement with those of the plaque reduction neutralization test. Common signs included ataxia, weakness, asymmetric gait, muscle tremors, hypersensitivity, cranial nerve deficits, and recumbency. Twelve animals survived. Amplicons derived from the infection‐positive specimens allowed molecular characterization of the viral strain.Conclusions and Clinical Importance: From our results, we conclude that this outbreak was caused by a lineage 2 WNV strain, even though such strains often are considered nonpathogenic. Neurological signs and survival rates were similar to those reported for lineage 1 virus infections. The disease occurrence was not geographically limited as had been the typical case during European outbreaks; this report describes a substantial northwestern spread of the pathogen.
Topical anti-inflammatory activity of quillaic acid from Quillaja saponaria Mol. and some derivatives
Authors: Rodríguez-Díaz Maité , Delporte Carla , Cartagena Carlos , Cassels Bruce K , González Patricia , Silva Ximena , León Fredy , Wessjohann Ludger A 
Published: April 2011

Abstract

Objectives
Quillaic acid is the major aglycone of the widely studied saponins of the Chilean indigenous tree Quillaja saponaria Mol. The industrial availability of quillaja saponins and the extensive functionalisation of this triterpenoid provide unique opportunities for structural modification and pose a challenge from the standpoint of selectivity in regard to one or the other secondary alcohol group, the aldehyde, and the carboxylic acid functions. The anti-inflammatory activity of this sapogenin has not been studied previously and it has never been used to obtain potential anti-inflammatory derivatives.

Methods
A series of quillaic acid derivatives were prepared and subjected to topical assays for the inhibition of inflammation induced by arachidonic acid or phorbol ester.

Key findings
Quillaic acid exhibited strong topical anti-inflammatory activity in both models. Most of its derivatives were less potent, but the hydrazone 8 showed similar potency to quillaic acid in the TPA assay.

Conclusions
The structural modifications performed and the biological results suggest that the aldehyde and carboxyl groups are relevant to the anti-inflammatory activity in these models.
Correction for patient table‐induced scattered radiation in cone‐beam computed tomography (CBCT)
Authors: Sun Mingshan , Nagy Tamás , Virshup Gary , Partain Larry , Oelhafen Markus , Star‐Lack Josh 
Published: April 2011

Purpose:In image‐guided radiotherapy, an artifact typically seen in axial slices of x‐ray cone‐beam computed tomography (CBCT) reconstructions is a dark region or “black hole” situated below the scan isocenter. The authors trace the cause of the artifact to scattered radiation produced by radiotherapy patient tabletops and show it is linked to the use of the offset‐detector acquisition mode to enlarge the imaging field‐of‐view. The authors present a hybrid scatter kernel superposition (SKS) algorithm to correct for scatter from both the object‐of‐interest and the tabletop.Methods:Monte Carlo simulations and phantom experiments were first performed to identify the source of the black hole artifact. For correction, a SKS algorithm was developed that uses separate kernels to estimate scatter from the patient tabletop and the object‐of‐interest. Each projection is divided into two regions, one defined by the shadow cast by the tabletop on the imager and one defined by the unshadowed region. The region not shadowed by the tabletop is processed using the recently developed fast adaptive scatter kernel superposition (fASKS) method which employs asymmetric kernels that best model scatter transport through bodylike objects. The shadowed region is convolved with a combination of slab‐derived symmetric SKS kernels and asymmetric fASKS kernels. The composition of the hybrid kernels is projection‐angle‐dependent. To test the algorithm, pelvis phantom andin vivo data were acquired using a CBCT test stand, a Varian Acuity simulator, and a Varian On‐Board Imager, all of which have similar geometries and components. Artifact intensities and Hounsfield unit (HU) accuracies in the reconstructions were assessed before and after the correction.Results:The hybrid kernel algorithm provided effective correction and produced substantially better scatter estimates than the symmetric SKS or asymmetric fASKS methods alone. HU nonuniformities in the reconstructed pelvis phantom were reduced from 220 to 50 HU (i.e., 22%–5%). In thein vivo scans, the black hole artifact was reduced by up to 147 HU, a 73% improvement, and anatomical details in the prostate and rectum areas were made considerably more visible.Conclusions:Radiotherapy tabletops, which are generally flatter and larger than those used for diagnostic CT, can produce significant scatter‐related artifacts. The proposed hybrid SKS algorithm accurately estimates scatter from both the object‐of‐interest and the patient tabletop, and resulting image uniformities and HU accuracies are greatly improved.
Multisource modeling of flattening filter free (FFF) beam and the optimization of model parameters
Authors: Cho Woong , Kielar Kayla N. , Mok Ed , Xing Lei , Park Jeong‐Hoon , Jung Won‐Gyun , Suh Tae‐Suk 
Published: April 2011

Purpose:With the introduction of flattening filter free (FFF) linear accelerators to radiation oncology, new analytical source models for a FFF beam applicable to current treatment planning systems is needed. In this work, a multisource model for the FFF beam and the optimization of involved model parameters were designed.Methods:The model is based on a previous three source model proposed by Yang et al. [“A three‐source model for the calculation of head scatter factors,” Med. Phys. 29, 2024–2033 (2002)]. An off axis ratio (OAR) of photon fluence was introduced to the primary source term to generate cone shaped profiles. The parameters of the source model were determined from measured head scatter factors using a line search optimization technique. The OAR of the photon fluence was determined from a measured dose profile of a field size with the same optimization technique, but a new method to acquire gradient terms for OARs was developed to enhance the speed of the optimization process. The improved model was validated with measured dose profiles from to field sizes at 6 and 10 MV from a TrueBeam™ STx linear accelerator. Furthermore, planar dose distributions for clinically used radiation fields were also calculated and compared to measurements using a 2D array detector using the gamma index method.Results:All dose values for the calculated profiles agreed with the measured dose profiles within 0.5% at 6 and 10 MV beams, except for some low dose regions for larger field sizes. A slight overestimation was seen in the lower penumbra region near the field edge for the large field sizes by 1%–4%. The planar dose calculations showed comparable passing rates when the criterion of the gamma index method was selected to be 3%/3 mm.Conclusions:The developed source model showed good agreements between measured and calculated dose distributions. The model is easily applicable to any other linear accelerator using FFF beams as the required data include only the measured PDD, dose profiles, and output factors for various field sizes, which are easily acquired during conventional beam commissioning process.
Computer‐aided detection of breast masses: Four‐view strategy for screening mammography
Authors: Wei Jun , Chan Heang‐Ping , Zhou Chuan , Wu Yi‐Ta , Sahiner Berkman , Hadjiiski Lubomir M. , Roubidoux Marilyn A. , Helvie Mark A. 
Published: April 2011

Purpose:To improve the performance of a computer‐aided detection (CAD) system for mass detection by using four‐view information in screening mammography.Methods:The authors developed a four‐view CAD system that emulates radiologists' reading by using the craniocaudal and mediolateral oblique views of the ipsilateral breast to reduce false positives (FPs) and the corresponding views of the contralateral breast to detect asymmetry. The CAD system consists of four major components: (1) Initial detection of breast masses on individual views, (2) information fusion of the ipsilateral views of the breast (referred to as two‐view analysis), (3) information fusion of the corresponding views of the contralateral breast (referred to as bilateral analysis), and (4) fusion of the four‐view information with a decision tree. The authors collected two data sets for training and testing of the CAD system: A mass set containing 389 patients with 389 biopsy‐proven masses and a normal set containing 200 normal subjects. All cases had four‐view mammograms. The true locations of the masses on the mammograms were identified by an experienced MQSA radiologist. The authors randomly divided the mass set into two independent sets for cross validation training and testing. The overall test performance was assessed by averaging the free response receiver operating characteristic (FROC) curves of the two test subsets. The FP rates during the FROC analysis were estimated by using the normal set only. The jackknife free‐response ROC (JAFROC) method was used to estimate the statistical significance of the difference between the test FROC curves obtained with the single‐view and the four‐view CAD systems.Results:Using the single‐view CAD system, the breast‐based test sensitivities were 58% and 77% at the FP rates of 0.5 and 1.0 per image, respectively. With the four‐view CAD system, the breast‐based test sensitivities were improved to 76% and 87% at the corresponding FP rates, respectively. The improvement was found to be statistically significant by JAFROC analysis.Conclusions:The four‐view information fusion approach that emulates radiologists' reading strategy significantly improves the performance of breast mass detection of the CAD system in comparison with the single‐view approach.
Investigation of radiological properties and water equivalency of PRESAGE® dosimeters
Authors: Gorjiara Tina , Hill Robin , Kuncic Zdenka , Adamovics John , Bosi Stephen , Kim Jung‐Ha , Baldock Clive 
Published: April 2011

Purpose:PRESAGE® is a dosimeter made of polyurethane, which is suitable for 3D dosimetry in modern radiation treatment techniques. Since an ideal dosimeter is radiologically water equivalent, the authors investigated water equivalency and the radiological properties of three different PRESAGE® formulations that differ primarily in their elemental compositions. Two of the formulations are new and have lower halogen content than the original formulation.Methods:The radiological water equivalence was assessed by comparing the densities, interaction probabilities, and radiation dosimetry properties of the three different PRESAGE® formulations to the corresponding values for water. The relative depth doses were calculated using Monte Carlo methods for 50, 100, 200, and 350 kVp and 6 MV x‐ray beams.Results:The mass densities of the three PRESAGE® formulations varied from 5.3% higher than that of water to as much as 10% higher than that of water for the original formulation. The probability of photoelectric absorption in the three different PRESAGE® formulations varied from 2.2 times greater than that of water for the new formulations to 3.5 times greater than that of water for the original formulation. The mass attenuation coefficient for the three formulations is 12%–50% higher than the value for water. These differences occur over an energy range (10–100 keV) in which the photoelectric effect is the dominant interaction. The collision mass stopping powers of the relatively lower halogen‐containing PRESAGE® formulations also exhibit marginally better water equivalency than the original higher halogen‐containing PRESAGE® formulation. Furthermore, the depth dose curves for the lower halogen‐containing PRESAGE® formulations are slightly closer to that of water for a 6 MV beam. In the kilovoltage energy range, the depth dose curves for the lower halogen‐containing PRESAGE® formulations are in better agreement with water than the original PRESAGE® formulation.Conclusions:Based on the results of this study, the new PRESAGE® formulations with lower halogen content are more radiologically water equivalent overall than the original formulation. This indicates that the new PRESAGE® formulations are better suited to clinical applications and are more accurate dosimeters and phantoms than the original PRESAGE® formulation. While correction factors are still needed to convert the dose measured by the dosimeter to an absorbed dose in water in the kilovoltage energy range, these correction factors are considerably smaller for the new PRESAGE® formulations compared to the original PRESAGE® and the existing polymer gel dosimeters.
Dosimetric accuracy of a deterministic radiation transport based brachytherapy treatment planning system. Part II: Monte Carlo and experimental verification of a multiple source dwell position plan employing a shielded applicator
Authors: Petrokokkinos L. , Zourari K. , Pantelis E. , Moutsatsos A. , Karaiskos P. , Sakelliou L. , Seimenis I. , Georgiou E. , Papagiannis P. 
Published: April 2011

Purpose:The aim of this work is the dosimetric validation of a deterministic radiation transport based treatment planning system (BRACHYVISION™ v. 8.8, referred to as TPS in the following) for multiple source dwell position brachytherapy applications employing a shielded applicator in homogeneous water geometries.Methods:TPS calculations for an irradiation plan employing seven VS2000 high dose rate (HDR) source dwell positions and a partially shielded applicator (GM11004380) were compared to corresponding Monte Carlo (MC) simulation results, as well as experimental results obtained using the VIP polymer gel–magnetic resonance imaging three‐dimensional dosimetry method with a custom made phantom.Results:TPS and MC dose distributions were found in agreement which is mainly within ±2%. Considerable differences between TPS and MC results (greater than 2%) were observed at points in the penumbra of the shields (i.e., close to the edges of the “shielded” segment of the geometries). These differences were experimentally verified and therefore attributed to the TPS. Apart from these regions, experimental and TPS dose distributions were found in agreement within 2 mm distance to agreement and 5% dose difference criteria. As shown in this work, these results mark a significant improvement relative to dosimetry algorithms that disregard the presence of the shielded applicator since the use of the latter leads to dosimetry errors on the order of 20%–30% at the edge of the “unshielded” segment of the geometry and even 2%–6% at points corresponding to the potential location of the target volume in clinical applications using the applicator (points in the unshielded segment at short distances from the applicator).Conclusions:Results of this work attest the capability of the TPS to accurately account for the scatter conditions and the increased attenuation involved in HDR brachytherapy applications employing multiple source dwell positions and partially shielded applicators.
Effect of exercise-induced dehydration on time-trial exercise performance: a meta-analysis
Authors: Goulet Eric D B 
Published: April 2011

ObjectiveTo use the meta-analytical procedures to determine the magnitude of the effect of exercise-induced dehydration (EID) upon time-trial (TT) exercise performance.MethodsStudies were located via database searches and cross-referencing. TT performance outcomes were converted to mean percentage changes in power output. Random-effects model meta-regressions, analogue to the ANOVA and weighted mean effect summaries were used to delineate the effect of the EID-associated body weight (BW) loss on TT performance.ResultsFive research articles, all using cycling TTs, were included, producing 13 effect estimates and representing 39 subjects. The mean ambient temperature, relative humidity, exercise intensity and duration of the exercise trials were 26.0±6.7°C, 61±9%, 68±14% of VO2max and 86±34 min, respectively. The effect of EID (mean BW loss of 2.20±1.0%) during self-paced exercise conditions was to produce a non-significant increase in endurance performance of 0.06±2.72% (p=0.94), compared with the maintenance of euhydration (mean BW loss of 0.44±0.48%). Meta-regression analyses revealed a statistically significant relationship between the percentage changes in power output and exercise intensity and duration, but not with the EID-associated percentage changes in BW loss. Drinking according to the dictate of thirst was associated with an increase in TT performance compared with a rate of drinking below (+5.2±4.6%, p=0.01) or above (+2.4±5.0%, p=0.40) thirst. The probability that drinking to thirst confers a real and meaningful advantage on TT performances conducted under field conditions compared with a rate of drinking below and above thirst sensation is of the order of 98% and 62%, respectively.Conclusions(1) Compared with euhydration, EID (up to 4% BW loss) does not alter cycling performances during out-of-door exercise conditions; (2) exercise intensity and duration have a much greater impact on cycling TT performances than EID and; (3) relying on thirst sensation to gauge the need for fluid replacement maximises cycling TT performances.
Republished paper: The WHO patient safety curriculum guide for medical schools
Authors: Walton Merrilyn , Woodward Helen , Van Staalduinen Samantha , Lemer C , Greaves F , Noble D , Ellis B , Donaldson L , Barraclough B ,   Expert Group convened by the World Alliance of Patient Safety, as Expert Lead for the Sub-Programme
Published: April 2011

ABSTRACT

Background
The urgent need for patient safety education for healthcare students has been recognised by many accreditation bodies, but to date there has been sporadic attention to undergraduate/graduate medical programmes. Medical students themselves have identified quality and safety of care as an important area of instruction; as future doctors and healthcare leaders, they must be prepared to practise safe healthcare. Medical education has yet to fully embrace patient safety concepts and principles into existing medical curricula. Universities are continuing to produce graduate doctors lacking in the patient safety knowledge, skills and behaviours thought necessary to deliver safe care. A significant challenge is that patient safety is still a relatively new concept and area of study; thus, many medical educators are unfamiliar with the literature and unsure how to integrate patient safety learning into existing curriculum.

Design
To address this gap and provide a foothold for medical schools all around the world, the WHO's World Alliance for Patient Safety sponsored the development of a patient safety curriculum guide for medical students. The WHO Patient Safety Curriculum Guide for Medical Schools adopts a ‘one-stop-shop’ approach in that it includes a teacher's manual providing a step-by-step guide for teachers new to patient safety learning as well as a comprehensive curriculum on the main patient safety areas. This paper establishes the need for patient safety education of medical students, describes the development of the WHO Patient Safety Curriculum Guide for Medical Schools and outlines the content of the Guide.
Benchmarking and modelling of POWER7, Westmere, BG/P, and GPUs
Authors: Herdman J. A. , Gaudin W. P. , Turland D. , Hammond S. D. 
Published: April 2011

This paper introduces an industry strength, multi-purpose, benchmark: Shamrock. Developed at the Atomic Weapons Establishment (AWE), Shamrock is a two dimensional (2D) structured hydrocode; one of its aims is to assess the impacts of a change in hardware, and (in conjunction with a larger HPC Benchmark Suite) to provide guidance in procurement of future systems.
A suitable test problem is described and executed on a local, high-end, workstation for a range of compilers and MPI implementations. Based on these observations, specific configurations are subsequently built and executed on a selection of HPC architectures, including Intel's Nehalem and Westmere micro architectures, IBM's POWER-5, POWER-6, POWER-7, BlueGene/L, BlueGene/P, and AMD's Opteron chip set. Comparisons are made between these architectures, for the Shamrock benchmark, and relative compute resources are specified that deliver similar time to solution, along with their associated power budgets.
Additionally, performance comparisons are made for a port of the benchmark to a Nehalem based cluster, accelerated with Tesla C1060 GPUs, with details of the port, and extrapolations to possible performance of the GPU.