Perseverations during paired-associate learning in Huntington''s disease

Raw 30-MHz intravascular ultrasound data have been captured from postmortem coronary arteries (n = 4) to develop radio frequency analysis techniques for the characterisation of atherosclerotic plaque. Digitised data acquired from positions (n = 8) within diseased sections of artery were compared with the corresponding histology and radiology. Scan-converted images were used to locate regions of interest (ROI = 33) within areas of tissue composition: loose fibrotic tissue (LFT), dense fibrotic tissue (DFT) and calcium (CA). A range of parameters was extracted from the normalised power spectrum of each ROI within the bandwidth 17-42 MHz. Significant discrimination between LFT/DFT and between LFT/CA was provided by maximum power and spectral slope (dBMHz-1). However, the greatest discriminative power was given by the y-axis (0 Hz) intercept of the spectral slope: LFT/DFT (p = 0.001); LFT/CA (p = 0.0001); and DFT/CA (p = 0.089).     

The cathode strip chamber data acquisition electronics for CMS

Data Acquisition (DAQ) electronics for Cathode Strip Chambers (CSC) [CMS Collaboration, The Muon Project Technical Design Report, CERN/LHCC 97-32, CMS TDR3, 1997] in the Compact Muon Solenoid (CMS) [CMS Collaboration, The Compact Muon Solenoid Technical Proposal, CERN/LHCC 94-38, 1994] experiment at the Large Hadron Collider (LHC) [The LHC study group, The Large Hadron Collider: Conceptual Design, CERN/AC 1995-05, 1995] is described. The CSC DAQ system [B. Bylsma, et al., in: Proceedings of the Topical Workshop on Electronics for Particle Physics, Prague, Czech Republic, CERN-2007-007, 2007, pp. 195–198] includes on-detector and off-detector electronics, encompassing five different types of custom circuit boards designed to handle the high event rate at the LHC. The on-detector electronics includes Cathode Front End Boards (CFEB) [R. Breedon, et al., Nucl. Instr. and Meth. A 471 (2001) 340], which amplify, shape, store, and digitize chamber cathode signals; Anode Front End Boards (AFEB) [T. Ferguson, et al., Nucl. Instr. and Meth. A 539 (2005) 386], which amplify, shape and discriminate chamber anode signals; and Data Acquisition Motherboards (DAQMB), which controls the on-chamber electronics and the readout of the chamber. The off-detector electronics, located in the underground service cavern, includes Detector Dependent Unit (DDU) boards, which perform real time data error checking, electronics reset requests and data concentration; and Data Concentrator Card (DCC) boards, which further compact the data and send it to the CMS DAQ System [CMS Collaboration, The TriDAS Project Technical Design Report, Volume 2: Data Acquisition and High-level Trigger, CERN/LHCC 2002-26, 2002], and serve as an interface to the CMS Trigger Timing Control (TTC) [TTC system http://ttc.web.cern.ch/TTC/intro.html] system.Application Specific Integrated Circuits (ASIC) are utilized for analogous signal processing on front end boards. Field Programmable Gate Arrays (FPGA) are utilized on all boards in the system to provide programmability. The DAQ system has been installed and commissioned, and is ready for LHC data taking.     

Odor identification in Huntington's disease patients and asymptomatic gene carriers

Odor identification was assessed in 20 Huntington's disease (HD) patients, 20 normal adults with the genetic mutation that causes HD, and 20 mutation-negative adults. The University of Pennsylvania Smell Identification Test (UPSIT) revealed substantial odor identification deficits only in HD patients.     

Regularization in Short-Term Memory for Serial Order.

Previous research has shown that short-term memory for serial order can be influenced by background knowledge concerning regularities of sequential structure. Specifically, it has been shown that recall is superior for sequences that fit well with familiar sequencing constraints. The authors report a corresponding effect pertaining to serial recall errors. Undergraduate participants performed immediate serial recall on sequences of pseudowords generated on the basis of an artificial grammar. After extensive experience with this material, recall errors displayed a bias toward regularizing responses, response sequences more probable, with respect to the artificial grammar, than the originally presented stimulus sequence. This regularization effect squares well with recent trace redintegration and Bayesian models of serial recall, and appears to represent an analog of the schema-based error patterns observed in other domains of memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conceptual and perceptual implicit memory in Huntington's disease.

The aims of this study were to examine and compare perceptual and conceptual implicit memory (CIM) in Huntington's disease (HD) and to characterize the relationship between tests of frontal lobe functioning and CIM. Sixteen HD patients and 16 normal controls completed structurally parallel tests of perceptual implicit memory and CIM (i.e., rhyme and category exemplar generation), tests of explicit memory, and verbal fluency. HID patients showed intact implicit memory for both rhyme and category exemplars, despite evidence of frontal dysfunction on other tests. An unexpected finding was that patients showed a deficit in cued rhyme generation that correlated with severity of neurological impairment. The authors replicated findings in controls of a correlation between letter fluency and CIM but found no relationship in patients. Frontal dysfunction in HID may lessen the influence of generative strategies on tests of CIM without compromising performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

High-speed signal switching with a monolithic integrated p-i-n/amp/switch on indium phosphide

Operation of an optoelectronic integrated circuit which includes two p-i-n photodetectors, preamplifiers, a 2*2 crosspoint switch, and output buffers has been demonstrated. These circuits are fabricated in semi-insulating InP:Fe substrates by vapor-phase epitaxy and ion implantation using a planar horizontally integrated technology. Signals modulated at 150 MHz are shown to be switched at 15 MHz, with the circuits capable of detecting and passing data modulated at approximately 1 GHz.<>     

Application of a growth curve approach to modeling the progression of Alzheimer's disease

BACKGROUND: Studies using clinical measures to track AD progression often assume linear declines over the entire course of the disease, which may not be justified. The objective of this study was to model change in measures of the clinical severity of Alzheimer's disease (AD) over time. METHODS: We developed a method to apply growth curve models to prospective data and characterize AD patients' functional change over time. Data from the modified Mini-Mental State Examination (mMMSE) and measures of basic and instrumental ADL, administered semiannually for up to 5 years to 236 patients with probable AD, were modeled. RESULTS: The rate of decline in mMMS scores per 6-month interval gradually increased as scores dropped from the maximum of 57 to 20. The rate of decline then decreased as scores approached 0, resulting in an inverse "S" curve. The rate of increase in instrumental ADL scores per interval attenuated as the scores increased, while that for basic ADL scores across intervals was constant. CONCLUSIONS: Differences in the pattern of progression of the three measures is in part a function of their psychometric properties. The progression curves may also reflect content-specific features of the instruments. Superimposition of the modeled decline in these three content areas suggests a hypothetical model of the relative timing of cognitive and functional changes in AD.