Standardized MR protocol for the evaluation of MRA sequences and/or contrast agents effects in high-degree arterial stenosis analysis

Purpose To investigate the relative role of high resolution (spatial or temporal) magnetic resonance angiography (MRA) sequence and of contrast agent properties in the evaluation of high-degree arterial stenosis. Methods We qualitatively and quantitatively studied both 50 and 95% (300 μm diameter) stenosis of a 6 mm arterial phantom with two contrast agents (CA), Gd-DOTA (r₁ =2.9 mM⁻¹ s⁻¹) versus P760 (r₁ =25 mM⁻¹ s⁻¹) at several CA concentrations, including arterial peak concentration after injection of either a single or double dose of CA, using either a high temporal (booster) or high spatial (HR) resolution 3D MRA sequences. Experimental data were then compared to theoretical data. Results With the 3D HR sequence, both visual and quantitative analysis were significantly better compared to the 3D booster sequence, at each phantom diameter. Quantitative analysis was significantly improved by injection of a double versus a single dose of each CA (Gd-DOTA or P760), primarily in high degree stenosis. Conclusion Combined MRA spatial resolution and high CA efficiency are mandatory to correctly evaluate high degree stenosis.     

Data Buffering and Allocation in Mapping Generalized Template Matching on Reconfigurable Systems

Image processing algorithms for 2D digital filtering, morphologic operations, motion estimation, and template matching involve massively parallel computations that can benefit from using reconfigurable systems with massive field programmable gate array (FPGA) hardware resources. In addition, each algorithm can be considered a special case of a generalized template matching (GTM) operation. Application performance on reconfigurable computer systems is often limited by the bandwidth to host or off chip memory. This paper describes the GTM operation and characterizes the data allocation and buffering strategies for the GTM operation on reconfigurable computers. Several mechanisms that support different levels of parallelism are proposed and summarized in the paper. Finally, the implementation of an infrared automatic target recognition application on two commercial FPGA boards is used to demonstrate the various design options with different data allocation and buffering mechanisms and the pruning of the design space based on the FPGA area and memory constraints.     

Deposition of nacystelyn from a dry powder inhaler in healthy volunteers and cystic fibrosis patients

The aim of this study was to compare, using gamma scintigraphy, the lung deposition of a novel mucoactive agent, Nacystelyn (NAL), administered as a dry powder inhaler (DPI) in six healthy volunteers, six adult patients with cystic fibrosis (CF), and six children and adolescents patients with CF. The correlation between in vitro and in vivo results was also tested. It was first demonstrated that the method of labeling of NAL with 99mTc was reliable as tested by three in vitro methods (multistage liquid impinger, multistage cascade impactor, and 2-stage glass impinger). The deposition of unlabeled NAL, labeled NAL, and the radiolabel was similar in all stages of each device. Furthermore, the fine particle fraction (FPF) was the same on all apparatuses. The mean lung deposition obtained in volunteers was 27.5 +/- 13.5%. The results are approximately three times higher than the results obtained previously in healthy volunteers with NAL metered-dose inhalers (MDIs). As expected, the lung deposition observed in patients with CF was lower, e.g., 23.5 +/- 7.0% for adults and 16.5 +/- 5.9% for children and adolescents. A significant correlation was found between lung deposition and both the patient weight (p < 0.02) and height (p < 0.04). Surprisingly, the peripheral:central (P:C) ratio was similar for the three populations, indicating that the presence of mucus in moderately ill patients with CF does not modify the lung distribution of NAL. The FPF measured in vitro was similar to that obtained in volunteers but higher than that found in both patient populations. The DPI formulation of NAL developed will probably improve patient compliance and comfort in future clinical trials and postmarketing use of the drug.     

A Combined Interleaving Technique for Trellis Coded MPSK Systems in Rayleigh Fading Channels

Freedom of mobility is the latesttrend in the evolution of digital communicationsystems. In these systems bandwidth and powerconstraints limit the mobility of the users. TCM(trellis coded modulation) is a combined coding andmodulation scheme which increases the productivity ofa digital communication system without increasing thetransmitted power or the required bandwidth. A mobilecommunication channel is affected from noise andfading because of the multipath propagation. On aRayleigh fading channel, coding should be used withtechniques which uncorrelate the received energy ofeach consecutive coded symbol. Interleaving is one ofthese techniques and used to make burst errors intorandom errors which can be corrected by errorcorrecting codes. In this paper, the trellis codingsystem which combines a regular convolutional encoder,bit interleaver, coordinate interleaver, and anappropriate decoder is considered. The analytical biterror probability upper bounds are derived for the8-PSK TCM system whose diversity is increased by usinga regular 2/3 rate convolutional code followed bythree bit interleavers and a 8-PSK signal mapperfollowed by two coordinate interleavers. Theanalytical and simulation results show that toincrease the diversity of the trellis coded M-PSKsystems in Rayleigh fading channels is the primary keyfor reliable transmission of high quality voice anddigital data.     

Crystallisation of selenium thin films doped with iodine after evaporation

Amorphous selenium thin films deposited under vacuum have been doped with iodine either during or after crystallisation. It is shown that when the films are first crystallised at 363 K for 6 h and then submitted to iodine atmosphere at 363 K for 1 h, the structural properties of the films are not modified while their conductivity increases by a factor of 8. Iodine atmosphere induces post crystallisation of amorphous selenium films even at room temperature by increasing the selenium atom mobility at the surface of the films, which induces growth of crystalline spherulites. With annealing, when the heating rate is high (>15 K/min), constraints appear in the films, the density of spherulites increases and the films are inhomogeneous. When the heating rate is small and constant (1 K/min) the interaction between iodine and selenium takes place all over the sample and there is only a small density of small spherulites, while the crystallisation of the whole sample is more homogeneous. XPS and microprobe analysis that the iodine is equally repartitioned in the selenium film show it. Moreover there is a mixture of neutral iodine andS I₃ ^– as shown by XPS and Raman studies. The high crystalline quality of the films can explain the high conductivity (>10^{–3 –1} cm^–1) of these selenium doped films     

SR-30 turbojet engine real-time sensor health monitoring using neural networks,and Bayesian belief networks

This paper describes the use of artificial intelligence-based techniques for detecting and isolating sensor failures in a turbojet engine. Specifically, three artificial intelligence (AI) techniques are employed: artificial neural networks (NNs), statistical expectations, and Bayesian belief networks (BBNs). These techniques are combined into an overall system that is capable of distinguishing between sensor failure and engine failure—a critical capability in the operation of turbojet engines. The turbojet engine used in this study is an SR-30 developed by Turbine Technologies. Initially, NNs were designed and trained to recognize sensor failure in the engine. The increased random noise output from failing sensors was used as the key indicator. Next, a Bayesian statistical method was used to recognize sensor failure based on the bias error occurring in the sensors. Finally, a BBN was developed to interpret the results of the NN and statistical evaluations. The BBN determines whether single or multiple sensor failures signify engine failure, or whether sensor failures represent separate, unrelated incidences. The BBN algorithm is also used to distinguish between bias and noise errors on sensors used to monitor turbojet performance. The overall system is demonstrated to work equally well during start-up and main-stage operation of the engine. Results show that the method can efficiently detect and isolate single or multiple sensor failures within this dynamic environment.     

Modeling the progression of Alzheimer’s disease for cognitive assistance in smart homes

Smart homes provide support to cognitively impaired people (such as those suffering from Alzheimer’s disease) so that they can remain at home in an autonomous and safe way. Models of this impaired population should benefit the cognitive assistance’s efficiency and responsiveness. This paper presents a way to model and simulate the progression of dementia of the Alzheimer’s type by evaluating performance in the execution of an activity of daily living (ADL). This model satisfies three objectives: first, it models an activity of daily living; second, it simulates the progression of the dementia and the errors potentially made by people suffering from it, and, finally, it simulates the support needed by the impaired person. To develop this model, we chose the ACT-R cognitive architecture, which uses symbolic and subsymbolic representations. The simulated results of 100 people suffering from Alzheimer’s disease closely resemble the results obtained by 106 people on an occupational assessment (the Kitchen Task Assessment).     

Residual-based specification of a hidden random field included in a hierarchical spatial model

A method for specifying a hidden random field (HRF) included in a hierarchical spatial model is proposed. In hierarchical models of interest the first stage describes, conditional on a realization of the HRF, a response variable which is observable on a continuous spatial domain; the second stage models the HRF which reflects unobserved spatial heterogeneity. The question which is investigated is how can the HRF be modeled, i.e. specified. The method developed to address this question is based on residuals obtained when the base model, i.e. the hierarchical model in which the HRF is assumed constant, is fitted to data. It is shown that the residuals are linked with the HRF, and the link is used to specify the HRF. The method is applied to simulated data in order to assess its performance, and then to real data on radionuclide concentrations on Rongelap Island.     

Report of the Ethics Committee, 2006.

This report summarizes the primary activities of the American Psychological Association (APA) Ethics Committee, 2006. Ethics adjudication, ethics education and consultation, and special projects are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Award for Distinguished Scientific Applications of Psychology.

Presents the citations and biographies of the 2007 recipients of the American Psychological Association's Award for Distinguished Scientific Applications of Psychology. Selected bibliographies and an article written by one of the recipients are also presented. The Award for Distinguished Scientific Applications of Psychology is presented to a person who, in the opinion of the Committee on Scientific Awards, has made distinguished theoretical or empirical advances leading to the understanding or amelioration of important practical problems. The 2007 recipients are Karl G. J?reskog and Peter M. Bentler (This award was shared; this was not an award for collaboration). (PsycINFO Database Record (c) 2010 APA, all rights reserved)