72 research outputs found
An Enhanced Electrocardiogram biometric authentication system using machine learning
Traditional authentication systems use alphanumeric or graphical passwords, or token-based techniques that require âsomething you know and something you haveâ. The disadvantages of these systems include the risks of forgetfulness, loss, and theft. To address these shortcomings, biometric authentication is rapidly replacing traditional authentication methods and is becoming an everyday part of life. The electrocardiogram (ECG) is one of the most recent traits considered for biometric purposes, and three typical use cases have been described: security checks, hospitals and wearable devices. Here we describe an ECG-based authentication system suitable for security checks and hospital environments. The proposed authentication system will help investigators studying ECG-based biometric authentication techniques to define dataset boundaries and to acquire high-quality training data. We evaluated the performance of the proposed system using a confusion matrix and also by applying the Amang ECG (amgecg) toolbox in MATLAB to investigate two parameters that directly affect the accuracy of authentication: the ECG slicing time (sliding window) and sampling time. Using this approach, we found that accuracy was optimized by using a sliding window of 0.4 s and a sampling time of 37 s
New Lymphogranuloma Venereum Chlamydia trachomatis Variant, Amsterdam
We retrospectively conducted a study of men who have sex with men who visited the Amsterdam, the Netherlands, sexually transmitted diseases clinic from January 2002 to December 2003 and had rectal Chlamydia trachomatis infections. We found that symptomatic (73%) as well as asymptomatic (43%) patients were infected with a new C. trachomatis LGV variant
SARS Coronavirus Detection Methods
Using clinical samples from patients with severe acute respiratory syndrome, we showed that the sensitivities of a quantitative reverse transcriptionâpolymerase chain reaction (80% for fecal samples and 25% for urine samples) were higher than those of the polyclonal (50% and 5%) and monoclonal (35% and 8%) antibody-based nucleocapsid antigen capture enzyme-linked immunosorbent assays
Transport in rough self-affine fractures
Transport properties of three-dimensional self-affine rough fractures are
studied by means of an effective-medium analysis and numerical simulations
using the Lattice-Boltzmann method. The numerical results show that the
effective-medium approximation predicts the right scaling behavior of the
permeability and of the velocity fluctuations, in terms of the aperture of the
fracture, the roughness exponent and the characteristic length of the fracture
surfaces, in the limit of small separation between surfaces. The permeability
of the fractures is also investigated as a function of the normal and lateral
relative displacements between surfaces, and is shown that it can be bounded by
the permeability of two-dimensional fractures. The development of channel-like
structures in the velocity field is also numerically investigated for different
relative displacements between surfaces. Finally, the dispersion of tracer
particles in the velocity field of the fractures is investigated by analytic
and numerical methods. The asymptotic dominant role of the geometric
dispersion, due to velocity fluctuations and their spatial correlations, is
shown in the limit of very small separation between fracture surfaces.Comment: submitted to PR
New insights into the genetic etiology of Alzheimer's disease and related dementias
Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE Δ4 allele
Expression and reconstitution of the bioluminescent Ca2+ reporter aequorin in human embryonic stem cells, and exploration of the presence of functional IP3 and ryanodine receptors during the early stages of their differentiation into cardiomyocytes
Microring resonator-coupled waveguide crossings in silicon nitride: Waveguide width tuning
We report high refractive-index contrast microring resonators laterally coupled with waveguide crossings as add-drop filters in silicon nitride. We demonstrate tuning of filter characteristics by simultaneously varying the widths of waveguide crossing and microring. © 2004 IEEE
TFT fabrication on MILC polysilicon film with pulsed rapid thermal annealing
Thin film transistors have been fabricated on the polysilicon from the process of metal induced lateral crystallization and pulsed rapid thermal annealing. The result shows that process of 10 cycles of 1 second at 800 °C thermal pulse annealing has enhanced the grain sizes and the transistors fabricated have improvement which almost doubled the performance of those without the rapid thermal annealing. This method has high potential for use in the fabrication of thin film transistors on low temperature glass substrate and application in solar cell and LCD
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