Julián Félix

Coincident frequencies and relative phases among brain activity and hormonal signals.

BackgroundFourier transform is a basic tool for analyzing biological signals and is computed for a finite sequence of data sample. The electroencephalographic (EEG) signals analyzed with this method provide only information based on the frequency range, for short periods. In some cases, for long periods it can be useful to know whether EEG signals coincide or have a relative phase between them or with other biological signals. Some studies have evidenced that sex hormones and EEG signals show oscillations in their frequencies across a period of 28 days; so it seems of relevance to seek after possible patterns relating EEG signals and endogenous sex hormones, assumed as long time-periodic functions to determine their typical periods, frequencies and relative phases.MethodsIn this work we propose a method that can be used to analyze brain signals and hormonal levels and obtain frequencies and relative phases among them. This method involves the application of a discrete Fourier Transform on previously reported datasets of absolute power of brain signals delta, theta, alpha1, alpha2, beta1 and beta2 and the endogenous estrogen and progesterone levels along 28 days.ResultsApplying the proposed method to exemplary datasets and comparing each brain signal with both sex hormones signals, we found a characteristic profile of coincident periods and typical relative phases. For the corresponding coincident periods the progesterone seems to be essentially in phase with theta, alpha1, alpha2 and beta1, while delta and beta2 go oppositely. For the relevant coincident periods, the estrogen goes in phase with delta and theta and goes oppositely with alpha2.ConclusionFindings suggest that the procedure applied here provides a method to analyze typical frequencies, or periods and phases between signals with the same period. It generates specific patterns for brain signals and hormones and relations among them.

Hybrid cosmic rays detector

It has been developed at the Laboratorio de Partículas Elementales of the DCI, http://laboratoriodeparticulaselementales.blogspot.mx/, a four channel hybrid cosmic ray detector, that combines two detection techniques: ionization and Cherenkov light detection in a gaseous medium of 90%Ar+10%CH4. The basic detection cell consists of a quadrangular Aluminium tube of 1.01 m length, 2.54 cm x 2.54 cm cross section, and 0.1 cm thickness. Furthermore, inside it has been polished to mirror. For ionization detection channels, there is a metallic Tungsten fibre coated in Gold, with diameter of one thousandth inch. The fibre is coaxially to the Aluminium tube and welded to Gold connectors which are over caps, the ones are fixed at both tube’s ends. A high voltage, around2200V, is supplied to the metallic fibre which has been instrumented to read out the output signals. Besides, for Cherenkov detection channels, a Hamamatsu S10362-11-100U photodiode is placed and instrumented in each cap. Moreover the main cell, the hybrid cosmic ray detector comprises a gas system, the read out, amplification and discrimination electronic boards, as well as a data acquisition system. The DAQ system performs at 40MHz, and writes data into a file every 1ms for off line analysis. Technical information about this hybrid cosmic ray detector as the design, the construction, the characterization and the tests are treated here. The results on cosmic ray flux measurements obtained so far are discussed too.

Design, construction and characterization of a three channels detector of cosmic rays

Cosmic rays are particles produced by Astrophysical sources, currently they are being studied to obtain information about the sources and their properties. Cosmic rays research can be used to improve new technology in science, for instance, spectroscopy for material distinction. A three-channel detector was built using three photo-multipliers, two scintillation plastic and common materials -water, air, oil, aluminum, and others-. They were allocated in a vertical position, where materials channel is between scintillation plastics channels to validate the signal captured and study the interaction of cosmic rays with these materials. The characterization process is reported achieving positive results in the materials distinction using cosmic rays.

Design, construction and characterization of a mini cosmic ray spectrometer

This article describes the design and construction of a prototype called mini spectrometer to see if materials can be characterized using cosmic rays flux around the Earth. It started with common materials like water, air and oil. The mini spectrometer is implemented by two optical techniques: Cherenkov effect and scintillation. The interaction is observed with materials favoring the possibility of characterizing through a digital process.

Λ0 polarization as function of target density

Λ0 polarization (P) depends on xf and pt; it depends also on the density of the target material: P(xf, pt, ρ) = (κ0/(λ0 + ρ/ρw))xf pt, with κ0 = −0.423 ± 0.065 (GeV/c)−1 and λ0 = 1.191 ± 0.200 in the range 0 < pt < 1.2 GeV. Here ρ is the target material density and ρw is the Tungsten density. From this equation, it follows that Λ0 polarization is reduced by target density.

Λ0 POLARIZATION AS FUNCTION OF TARGET DENSITY

Λ0 polarization (P) depends on xf and pt; it depends also on the density of the target material: P(xf, pt, ρ) = (κ0/(λ0 + ρ/ρw))xfpt, with κ0 = -0.423±0.065 (GeV/c)-1 and λ0 = 1.191±0.200 in the range 0<pt<1.2 GeV. Here ρ is the target material density and ρw is the Tungsten density. From this equation, it follows that Λ0 polarization is reduced by target density.

Polarization in pp → p(baryon)

It’s introduced a calculation, which is based on symmetries followed by high energy hadronic interactions, of resonance polarization and specific angular momentum state polarization created in pp → p(baryon).