EEG filtering based on blind source separation (BSS) for early detection of Alzheimer's disease

Objective: Development of an EEG preprocessing technique for improvement of detection of Alzheimer’s disease (AD). The technique is based on filtering of EEG data using blind source separation (BSS) and projection of components which are possibly sensitive to cortical neuronal impairment found in early stages of AD. Method: Artifact-free 20 s intervals of raw resting EEG recordings from 22 patients with Mild Cognitive Impairment (MCI) who later proceeded to AD and 38 age-matched normal controls were decomposed into spatio-temporally decorrelated components using BSS algorithm ‘AMUSE’. Filtered EEG was obtained by back projection of components with the highest linear predictability. Relative power of filtered data in delta, theta, alpha1, alpha2, beta1, and beta 2 bands were processed with Linear Discriminant Analysis (LDA). Results: Preprocessing improved the percentage of correctly classified patients and controls computed with jack-knifing cross-validation from 59 to 73% and from 76 to 84%, correspondingly. Conclusions: The proposed approach can significantly improve the sensitivity and specificity of EEG based diagnosis. Significance: Filtering based on BSS can improve the performance of the existing EEG approaches to early diagnosis of Alzheimer’s disease. It may also have potential for improvement of EEG classification in other clinical areas or fundamental research. The developed method is quite general and flexible, allowing for various extensions and improvements. q 2004 Published by Elsevier Ireland Ltd. on behalf of International Federation of Clinical Neurophysiology

Improving the learning experience and learning environment of adults in Higher Education – Project LIHE: the Portuguese case

Project LIHE: the Portuguese Case. ESREA Fourth Access Network Conference – “Equity, Access and Participation: Research, Policy and Practice”. Edinburgh (Scotland), 11 – 13 December, 2003.The promotion of a knowledge-based society needs, on one hand, technological infrastructure and, on the other hand, a workforce with the necessary skills, knowledge and competences, supported by a well-structured initial education and by a continuous learning program. In the last years, Universities have opened their doors to all citizens, regardless of their status or origin, if they have the capacity to benefit from the educational services on offer. This strategy has allowed mature students to enter (or re-enter) the formal higher education system. Although these students may possess a richness of experience, they can also have difficulty in adapting to the pedagogical approaches of learning and teaching and their attitudes and problems are not necessarily the same as those of traditional students. It is in this context that the project LIHE – Learning in Higher Education emerges. In this paper, the background of the project and the most relevant literature for the subject are briefly described. It is followed by a presentation of the project aims, objectives and methodological approaches. The Portuguese case is introduced, together with the results of questionnaires and interviews. Some preliminary conclusions are outlined. Finally, avenues of future research are discusse

Nanomechanics of microtubules

We have determined the mechanical anisotropy of a single microtubule by simultaneously measuring the Young's and the shear moduli in vitro. This was achieved by elastically deforming the microtubule deposited on a substrate tailored by electron-beam lithography with a tip of an atomic force microscope. The shear modulus is 2 orders of magnitude lower than the Young's, giving rise to a length-dependent flexural rigidity of microtubules. The temperature dependence of the microtubule's bending stiffness in the (5-40) degreesC range shows a strong variation upon cooling coming from the increasing interaction between the protofilaments

The major component of a large, intracellular proteinase accumulated by inhibitors is a complex of [alpha]2-macroglobulin and thrombin

A large, intracellular proteinase accumulated by inhibitors (PABI) was found in cultured mammalian cells as a large, multicatalytic proteinase with a greatly elevated concentration in the presence of small peptide proteinase inhibitors (Tsuji and Kurachi (1989) J. Biol. Chem. 264, 16093). Electron microscopic analysis showed that the tertiary structure of PABI highly resembled that of [alpha]2-macroglobulin complexed with a proteinase(s). Isolation of the anti-PABI cross-reacting material from calf serum added to the culture media of baby hamster kidney cells further supported that the primary component of PABI was [alpha]2-macroglobulin. Immunoblot analyses and the substrate specificity of PABI indicated that the major proteinase component contained in PABI was thrombin. When [alpha]2-macroglobulin was added to the PABI-depleted serum, a significant accumulation or a degradation of the intracellular [alpha]2-macroglobulin was observed in the presence or absence of leupeptin, respectively. Similarly, when thrombin was added to the PABI-depleted fetal calf serum supplemented with fresh [alpha]2-macroglobulin, a significant amount of intracellular thrombin was found only in the presence of leupeptin. These results indicate that the major component of the intracellular PABI molecules is a complex of [alpha]2-macroglobulin with thrombin which is internalized from the culture media. Intracellular accumulation of PABI, therefore, is a phenomenon primarily relevant to the culture cells. Whether or not PABI is also generated in certain physiological or pathological conditions requires further study.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29323/1/0000388.pd

Widefield fluorescence imaging as an auxiliary tool to select the biopsy site for actinic cheilitis diagnosis

Actinic cheilitis (AC) is considered a potentially malignant disorder that mainly affects the lower lip, and it is caused by prolonged sun exposure. Clinical diagnosis relies on visual inspection by a trained clinician, when suspected of dysplasia changes, a biopsy is required. The heteregenous characteristics of the AC, makes the choice of the biopsy site a difficult task. Fluorescence detection has been presented as a useful tool to to detect biochemical and morphological tissue features related to cancer diagnosis, but still its effectiveness to discriminate premalignant lesion is not completely defined. In this clinical study, 57 AC patients were investigated using widefield fluorescence imaging (WFI) to evaluate the efficacy of this technique as an auxiliary tool to biopsy site location. A handheld fluorescence system based on 400-450 nm LED illumination Distinct trained clinicians evaluate the patient either with the conventional examination or the WFI, and were blinded to the other evaluation. A biopsy site was chosen based on the clinical examination, and another site was chosen using the fluorescence visualization. A total of 114 punch biopsies were performed, and 93% of the tissue samples presented epithelial dysplasia. The majority of the sites that presented moderate or severe dysplasia were sites chosen by WFI, showing its efficiency to improve the diagnosis of AC.CNPq (475322/2011-8)CEPID-CePOF/FAPESP (98/14270-8

Distinguishing among Technicolor/Warped Scenarios in Dileptons

Models of dynamical electroweak symmetry breaking usually include new spin-1 resonances, whose couplings and masses have to satisfy electroweak precision tests. We propose to use dilepton searches to probe the underlying structure responsible for satisfying these. Using the invariant mass spectrum and charge asymmetry, we can determine the number, parity, and isospin of these resonances. We pick three models of strong/warped symmetry breaking, and show that each model produces specific features that reflect this underlying structure of electroweak symmetry breaking and cancellations.Comment: Added missing referenc