Deep-MEG: spatiotemporal CNN features and multiband ensemble classification for predicting the early signs of Alzheimer’s disease with magnetoencephalography

Neural Computing and Applications - In this paper, we present the novel Deep-MEG approach in which image-based representations of magnetoencephalography (MEG) data are combined with ensemble...     

Failures induced by electromigration in ECL 100k devices

Reliability of ECL 100k devices using Al (4%wt Cu, 1%wt Si) double level metallization, isoplanar technology with shallow, 0.25 μm, base-emitter junctions was evaluated by means of high current and high temperature stresses. Three failure modes connected with electromigration phenomena were found in the output transistor: (a) base-emitter shunts owing to junction spiking caused by Al-Si interdiffusion enhanced by electromigration; (b) collector-emitter shorts due to the breaking of the dielectric oxide between two superimposed metal levels owing to material transport and pile-up in the underlying metallization; (c) open circuit of the output emitter due to void growth in the Cu-depleted areas of the Al interconnections. After B-E shunts, failure mechanism evolves towards two different sequences of failure modes, according to the different transistor structures; in fact C-E shorts were found to occur only when collector and emitter metals are superimposed, while the open circuit of the output emitter is the final failure for all configurations. The earlier and more frequent failure mode observed is the resistive shunt of the base-emitter junction of the output transistor, in agreement with previously reported data on electromigration effects in Al (Cu, Si) metallizations used both as interconnections and as contacts to shallow junctions.     

From Böhm's Theorem to Observational Equivalences: an Informal Account

There are essentially two ways of looking at the computational behaviours of λ-terms. One consists in putting the term within a context (possibly of λ-calculus extensions) and observing some properties (typically termination). The other consists in reducing the term until some meaningful information is obtained: this naturally leads to a tree representation of the information implicitly contained in the original term. The paper is an informal overview of the role played by Böhm's Theorem in these observations of terms.     

Magnetic resonance butterfly coils: Design and application for hyperpolarized C studies

Hyperpolarized ¹³C magnetic resonance spectroscopy in pig models enables cardiac metabolism assessment and provides a powerful tool for heart physiology studies, although the low molar concentration of derivate metabolites gives rise to technological limitations in terms of data quality. The design of dedicated coils capable of providing large field of view with high Signal-to-Noise Ratio (SNR) data is of fundamental importance.     

Impairment in category fluency in ischemic vascular dementia.

The underlying mechanisms for impaired output on letter (F, A, and S) and category (e.g., animal) word list generation (WLG) tasks in subcortical ischemic vascular dementia (IVD) were investigated. Normal control (NC) and Alzheimer's disease (AD) participants were also studied. IVD and NC participants performed better on category than letter WLG tasks, whereas the opposite was observed among AD participants. IVD participants produced fewer responses than AD participants on letter WLG tasks, but there was no difference between AD and IVD participants on the "animal" WLG task. AD participants scored lower than IVD and NC participants on animal WLG indexes measuring semantic knowledge. There were few differences between IVD and NC participants. The reduced output on the animal WLG task for IVD participants is consistent with search-retrieval deficits. The reduced output of AD participants may be caused by degraded semantic knowledge. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Awareness of errors in naturalistic action after traumatic brain injury

A prospective study was performed to develop a method for assessing "on-line" error detection and correction during performance of naturalistic action, to determine whether traumatic brain injury (TBI) affects error detection and correction, and to compare actual task performance with verbal self-ratings of performance. Participants included 18 persons who had sustained severe TBI from 34 to 186 days prior to study and who were comparable to controls in their rate of naturalistic action error, along with 18 control subjects chosen to be demographically comparable to subjects with TBI. Subjects performed two different tests of naturalistic action in which they completed everyday activities (eg, wrapping a gift, making toast) at different levels of complexity, as manipulated by the addition of distractor objects, the number of tasks that had to be completed per trial, and other demands on planning and working memory. Using a specially developed coding system, each error on these tasks was scored as to whether the subject corrected it and whether the subject otherwise demonstrated awareness of the error. Error scores were also compared to subjects' responses to a questionnaire in which they rated their own performance on the most challenging level of the naturalistic action test. In general, subjects with TBI corrected and showed awareness of proportionally fewer of their errors when compared to controls. Qualitative patterns for some error types also differed between groups. Despite making more errors than control subjects on the most challenging task, subjects with TBI did not rate themselves as performing more poorly with respect to its cognitive demands. However, for subjects with TBI, the number of errors was correlated with performance ratings on certain questionnaire items. This study showed that error detection and correction can be reliably measured during naturalistic action and appear to be impaired in severe TBI even when the base rate of error is controlled. TBI may affect error detection and correction by reducing, or impairing the allocation of, attentional resources needed for the simultaneous execution and monitoring of routine action.     

1,2,4-Oxadiazole Topsentin Analogs with Antiproliferative Activity against Pancreatic Cancer Cells,Targeting GSK3β Kinase

A new series of topsentin analogs, in which the central imidazole ring of the natural lead was replaced by a 1,2,4-oxadiazole moiety, was efficiently synthesized. All derivatives were pre-screened for antiproliferative activity against the National Cancer Institute (NCI-60) cell lines panel. The five most potent compounds were further investigated in various pancreatic ductal adenocarcinoma (PDAC) cell lines, including SUIT-2, Capan-1, and Panc-1 cells, eliciting EC₅₀ values in the micromolar and sub-micromolar range, associated with significant reduction of cell migration. These remarkable results might be explained by the effects of these new topsentin analogues on epithelial-to-mesenchymal transition markers, including SNAIL-1/2 and metalloproteinase-9. Moreover, flow cytometric analysis after Annexin V-FITC and propidium iodide staining demonstrated that these derivatives enhanced apoptosis of PDAC cells. Keeping with these data, the PathScan intracellular signaling and ELISA array revealed cleavage of caspase-3 and PARP and a significant inhibition of GSK3β phosphorylation, suggesting this kinase as a potential downstream target of our novel compounds. This was further supported by a specific assay for the evaluation of GSK3β activity, showing IC₅₀ values for the most active compounds against this enzyme in the micromolar range.     

Efficiency evaluation of a C Magnetic Resonance birdcage coil: Theory and comparison of four methods

Radiofrequency coils in Magnetic Resonance systems are used to produce a homogeneous B₁ field for exciting the nuclei and to pick up the signals emitted by the nuclei with high signal-to-noise ratio. Accordingly, coil performance affects strongly the quality of the obtained data and images.