Execution of the SimSET Monte Carlo PET/SPECT Simulator in the Condor Distributed Computing Environment

SimSET is a package for simulation of emission tomography data sets. Condor is a popular distributed computing environment. Simple C/C++ applications and shell scripts are presented which allow the execution of SimSET on the Condor environment. This is accomplished without any modification to SimSET by executing multiple instances and using its combinebin utility. This enables research facilities without dedicated parallel computing systems to utilize the idle cycles of desktop workstations to greatly reduce the run times of their SimSET simulations. The necessary steps to implement this approach in other environments are presented along with sample results

Stream Simulation Design of Conn Creek Culvert

Abstract Conventional culvert designs based on hydraulic capacity often result in high velocities or inadequate water levels that are not conducive for fish migration. For fish-bearing stream crossings, alternative designs need to be developed in order to secure timely approval from Fisheries and Oceans Canada (DFO). Stream simulation is one of those alternatives. It was proposed to, and accepted by, DFO for the Conn Creek Culvert replacement in Fort McMurray, an environmentally sensitive site due to the controversy over Alberta oil sand projects. The existing 4.2 m diameter, 82 m long culvert carries four lanes of Highway 63 traffic across Conn Creek, a tributary to the Athabasca River. As part of the $530 million Highway 63:11 upgrading project, the existing culvert required extension. During the review of the proposed alternatives, DFO cited the high flow velocity within the existing culvert as a barrier to fish passage, resulting in the separation of upstream and downstream habitats. Authorization for the works would need to ensure fish passage was restored. Challenges encountered during the design and construction of the replacement culvert included: Traffic accommodation for a busy highway with over 50K Average Annual Daily Traffic (AADT) Tight construction schedule demanding a quick approval from DFO Providing fish passage for weak swimming fish species across a 120 m span Enabling fish passage by reducing flows and providing velocity refuge while also addressing constructability and economics. Reducing flow velocity in a system that had been significantly altered historically (stream length shortened by removal of large meander sections of the natural stream). Shallow limestone bedrock demanding blasting for closed bottom culvert installation Owner's concerns of high construction cost and potential scouring of open bottom culvert This paper presents the background of the project, the existing fisheries, and details of the stream simulation design used to satisfy regulatory and project requirements. It is also the authors' intention to share their experiences and lessons learned in securing a timely approval from DFO on an extremely tight schedule.

Why Some Interfaces Cannot be Sharp

A central goal of modern materials physics and nanoscience is control of materials and their interfaces to atomic dimensions. For interfaces between polar and non-polar layers, this goal is thwarted by a polar catastrophe that forces an interfacial reconstruction. In traditional semiconductors this reconstruction is achieved by an atomic disordering and stoichiometry change at the interface, but in multivalent oxides a new option is available: if the electrons can move, the atoms don`t have to. Using atomic-scale electron energy loss spectroscopy we find that there is a fundamental asymmetry between ionically and electronically compensated interfaces, both in interfacial sharpness and carrier density. This suggests a general strategy to design sharp interfaces, remove interfacial screening charges, control the band offset, and hence dramatically improving the performance of oxide devices.Comment: 12 pages of text, 6 figure

A mathematical modelling study of an athlete's sprint time when towing a weighted sled

This is the author's accepted manuscript. The final publication is available at Springer via http://dx.doi.org/10.1007/s12283-013-0114-2.This study used a mathematical model to examine the effects of the sled, the running surface, and the athlete on sprint time when towing a weighted sled. Simulations showed that ratio scaling is an appropriate method of normalising the weight of the sled for athletes of different body size. The relationship between sprint time and the weight of the sled was almost linear, as long as the sled was not excessively heavy. The athlete’s sprint time and rate of increase in sprint time were greater on running surfaces with a greater coefficient of friction, and on any given running surface an athlete with a greater power-to-weight ratio had a lower rate of increase in sprint time. The angle of the tow cord did not have a substantial effect on an athlete’s sprint time. This greater understanding should help coaches set the training intensity experienced by an athlete when performing a sled-towing exercise

Three dimensional evaluation of posture in standing with the PosturePrint: an intra- and inter-examiner reliability study

Abstract Background Few digitizers can measure the complexity of upright human postural displacements in six degrees of freedom of the head, rib cage, and pelvis. Methods In a University laboratory, three examiners performed delayed repeated postural measurements on forty subjects over two days. Three digital photographs (left lateral, AP, right lateral) of each of 40 volunteer participants were obtained, twice, by three examiners. Examiners placed 13 markers on the subjects before photography and chose 16 points on the photographic images. Using the PosturePrint® internet computer system, head, rib cage, and pelvic postures were calculated as rotations (Rx, Ry, Rz) in degrees and translations (Tx, Tz) in millimeters. For reliability, two different types (liberal = ICC3,1 & conservative = ICC2,1) of inter- and intra-examiner correlation coefficients (ICC) were calculated. Standard error of measurements (SEM) and mean absolute differences within and between observers' measurements were also determined. Results All of the "liberal" ICCs were in the excellent range (> 0.84). For the more "conservative" type ICCs, four Inter-examiner ICCs were in the interval (0.5–0.6), 10 ICCs were in the interval (0.61–0.74), and the remainder were greater than 0.75. SEMs were 2.7° or less for all rotations and 5.9 mm or less for all translations. Mean absolute differences within examiners and between examiners were 3.5° or less for all rotations and 8.4 mm or less for all translations. Conclusion For the PosturePrint® system, the combined inter-examiner and intra-examiner correlation coefficients were in the good (14/44) and excellent (30/44) ranges. SEMs and mean absolute differences within and between examiners' measurements were small. Thus, this posture digitizer is reliable for clinical use

Intensive support for adults with intellectual disability and behaviours that challenge: a survey of provision and service typologies in England

BACKGROUND: Approximately 18% of adults with intellectual disabilities living in the community display behaviours that challenge. Intensive support teams (ISTs) have been recommended to provide high-quality responsive care aimed at avoiding unnecessary admissions and reducing lengthy in-patient stays. AIMS: To identify and describe the geographical distribution and characteristics of ISTs, and to develop a typology of IST service models in England. METHOD: We undertook a national cross-sectional survey of 73 ISTs. A hierarchical cluster analysis was performed based on six prespecified grouping factors (mode of referrals, size of case-load, use of outcome measures, staff composition, hours of operation and setting of service). A simplified form of thematic analysis was used to explore free-text responses. RESULTS: Cluster analysis identified two models of IST provision: (a) independent and (b) enhanced provision based around a community intellectual disability service. ISTs aspire to adopt person-centred care, mostly use the framework of positive behaviour support for behaviour that challenges, and report concerns about organisational and wider context issues. CONCLUSIONS: This is the first study to examine the delivery of intensive support to people with intellectual disability and behaviour that challenges. A two-cluster model of ISTs was found to have statistical validity and clinical utility. The clinical heterogeneity indicates that further evaluation of these service models is needed to establish their clinical and cost-effectiveness

Longitudinal variation in O6-alkylguanine DNA-alkyltransferase activity in the human colon and rectum

In a systematic study of O6-alkylguanine DNA-alkyltransferase activity in the human colon and rectum, tumours were found to occur in regions of low activity. These results are consistent with the hypothesis that O6-alkylguanine DNA-alkyltransferase levels and alkylating agent exposure may be important determinants of large bowel tumorigenesis