Time Evolution of Electric Fields in CDMS Detectors

The Cryogenic Dark Matter Search (CDMS) utilizes large mass, 3″?diameter×1″ thick target masses as particle detectors. The target is instrumented with both phonon and ionization sensors, the later providing a ～1?V?cm^?1 electric field in the detector bulk. Cumulative radiation exposure which creates ～200×10⁶ electron-hole pairs could be sufficient to produce a comparable reverse field in the detector thereby degrading the ionization channel performance, if it was not shielded by image charges on the electrodes. To study this, the existing CDMS detector Monte Carlo has been modified to allow for an event by event evolution of the bulk electric field, in three spatial dimensions. Surprisingly, this simple model is not sufficient to explain the degradation of detector performance. Our most recent results and interpretation are discussed.     

Use of the electrohysterogram signal for characterization ofcontractions during pregnancy

This article proposes a method to evaluate the ability of the electrohysterogram signal to characterize the contractions during pregnancy, in a population with high risk of preterm deliveries. This study constitutes a first stage of a project intended to develop a monitoring system for the early diagnosis of preterm deliveries. After a proper signal denoising, we calculate some parameters characteristic of the extracted contractions. These contractions are then divided into classes of different physiological terms. Classical techniques of data analysis, such as principal component analysis and discriminant analysis, permit us to show an evolution of the contractions during pregnancy, which is different between the groups of preterm deliveries and that of deliveries at term. We show that, in an early term of pregnancy, we can separate the two populations: women delivering at term from women delivering preterm. We then show that these two kinds of pregnancy are of different evolutions. These results are encouraging, because they would permit, in a follow-up medical study, to diagnose a possible preterm delivery, as well as the proximity of the delivery.     

Denoising of the uterine EHG by an undecimated wavelet transform

The authors propose two original methods of denoising of the uterine electrohysterography (EHG) signal by wavelets. This external electrophysiological signal is corrupted by electronic, electromagnetic noises and by the remaining electrocardiogram of the mother. The interfering signals have overlapping spectra. Therefore, a classical filtering is unusable. Wavelets should be a very well-suited denoising tool. The first proposed method uses the algorithm “a trou” with nonsymmetrical filters. The computation is rapid and the results are satisfying compared to the classical denoising techniques. The second algorithm is an improvement of the first method. It uses orthogonal wavelets and the result of the thresholding corresponds to the average of all circulant shifts denoised by a decimated wavelet transform. Results are compared to traditional denoising algorithms by wavelet (orthogonal, maximally decimated). The proposed algorithms are more efficient on simulated signals as well as on uterine EHG     

Calbindin D28k expression in immunohistochemically identified Renshaw cells

Double immunofluorescence was utilized to determine whether Renshaw cells contain calbindin D28k immunoreactivity. Renshaw cells were identified by their characteristic expression patterns of gephyrin immunoreactivity in sections of rat and cat lumbar spinal cord. In the rat, all neurons classified as Renshaw cells (n = 487) also contained calbindin D28k-immunoreactivity, and all calbindin D28k-immunoreactive cells located in the ventral-most region of lamina VII expressed the characteristic gephyrin labeling and morphology of Renshaw cells. In the cat, fewer than half of the Renshaw cells (47%; n = 128) were double-labeled. In both species, occasional calbindin D28k-immunoreactive Renshaw cells were identified within motor nuclei in lamina IX. The distinctive immunolabeling of Renshaw cells allowed us to estimate that there are about 250 Renshaw cells in each ventral horn of the fourth lumbar segment of rat spinal cord, and about 750 cells per ventral horn in the L6 segment of the cat. We conclude that the functional properties of Renshaw cells, including their ability to fire action potentials at high rates, likely require specific homeostatic mechanisms including strong intracellular calcium buffering, the precise mechanisms of which may vary between species.     

Bayesian Model Fusion for Forecasting Civil Unrest

With the rapid rise in social media, alternative news sources, and blogs, ordinary citizens have become information producers as much as information consumers. Highly charged prose, images, and videos spread virally, and stoke the embers of social unrest by alerting fellow citizens to relevant happenings and spurring them into action. We are interested in using Big Data approaches to generate forecasts of civil unrest from open source indicators. The heterogenous nature of data coupled with the rich and diverse origins of civil unrest call for a multi-model approach to such forecasting. We present a modular approach wherein a collection of models use overlapping sources of data to independently forecast protests. Fusion of alerts into one single alert stream becomes a key system informatics problem and we present a statistical framework to accomplish such fusion. Given an alert from one of the numerous models, the decision space for fusion has two possibilities: (i) release the alert or (ii) suppress the alert. Using a Bayesian decision theoretical framework, we present a fusion approach for releasing or suppressing alerts. The resulting system enables real-time decisions and more importantly tuning of precision and recall. Supplementary materials for this article are available online.     

Application of the method of the experimental design to the study of a processing of unshrinkableness of wool fibers

The objective of this study was to optimize the character of the unshrinkableness of wool fibers. A study of the processing of fibers of wool by an oxidative processing by performic acid was carried out by a complete factorial design to determine the most influential parameters of this study and then to optimize this process by the method of simplex. In parallel, a new ozone treatment was applied and a central composite design adapted to this protocol made it possible to identify the most influential parameters. This last type of processing has the advantage of being less polluting. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 535–547, 2003     

The theory of tone semantics: Concept,foundation, and application

Tone semantics is a psychoacoustic-based theory of gestalt perception that deals with tone perception and the assignment of functional relationships between tones in the musical context. The theory provides an operational account of semantics in terms of complex dynamic systems theory and forms the basis for non-symbolic research in music imagination. This is illustrated by an application in the automatic recognition of tone centers from acoustical input. An analysis of the basic concepts and related epistemological and methodological principles reveals a promising paradigm for music research.     

Modeling and system-level simulation of a CMOS convective accelerometer

This paper introduces an analytical modeling of a convective CMOS accelerometer. The device is a one-axis accelerometer based on a three bridges structure (one heater and two detectors). The modeling relies on the use of heat transfer fundamentals and is validated using experimental data issued from both test-vehicles and FEM analysis. It describes the heat conduction phenomenon that determines the thermal initial condition and then the convection mechanism that provides the sensitivity to the acceleration. Although only the static model is detailed, the dynamic behavior of test samples has been characterized and included into the HDL module. In order to illustrate the use of the model, the sensor is simulated together with its control electronics in an implementation of an A/D modulator. Simulation results are then compared with physical measurement with good agreement.     

Effectiveness of Alkali and Sodium Bicarbonate Treatments on Sugar Palm Fiber: Mechanical,Thermal, and Chemical Investigations

ABSTRACT

Sugar palm fiber (SPF) as one of the attractive natural fibers to reinforce matrix is gaining attention. This is largely due to its similar properties when compared with other established natural fibers. The aim of this study is to investigate the effectiveness of sodium bicarbonate as a treatment chemical for SPF in comparison with established alkaline treatment. Both treated and untreated fibers were characterized and it was found that the treated fiber shows an increase in crystallinity, thermal stability, and surface’s roughness when compared with the untreated. Among the two different treatments, SPF treated with alkali has an initial decomposition temperature of 255.47°C, while sodium bicarbonate treated and untreated fibers have 250.19°C and 246.76°C, respectively. In both cases, the thermal stability of the fiber was improved. Also, as revealed by the X-ray diffraction (XRD) analysis, the crystallinity index of SPF treated with alkali and sodium bicarbonate increased by 18.43% and 13.60%, respectively, when compared with untreated fiber. In conclusion, the investigation proved that treatment with the sodium bicarbonate has a significant effect on the physicochemical properties of SPF and the chemical could be an alternative chemical for treating other cellulose fibers.