Testing the surface fixation method in gestational diabetes mellitus

Introduction: To test the surface fixation method contrasting urine samples of women with GDM vs healthy pregnant women. Methods: This was a pilot descriptive study. Three groups were conformed: A) Pregnant women with GDM, B) Women with healthy pregnancies and C) Non-pregnant healthy women. The positiveness of the surface fixation method was contrasted with Odds Ratio. Results: 12 women with GDM, 14 with healthy pregnancies and 9 non-pregnant women were included in the study. The OR for a positive surface fixation test when contrasting GDM vs Healthy pregnancies was of 2.7 while the value when contrasting GDM vs Healthy pregnancies + Non pregnant women was of 3.2 without reaching significant statistical difference in any case. Conclusion: the surface fixation method used with urine samples, suggests the existence of a transient antigen-antibody reaction that contributes to the inefficient insulin secretion

Transistor-Level Synthesis of Pipeline Analog-to-Digital Converters Using a Design-Space Reduction Algorithm

A novel transistor-level synthesis procedure for pipeline ADCs is presented. This procedure is able to directly map high-level converter specifications onto transistor sizes and biasing conditions. It is based on the combination of behavioral models for performance evaluation, optimization routines to minimize the power and area consumption of the circuit solution, and an algorithm to efficiently constraint the converter design space. This algorithm precludes the cost of lengthy bottom-up verifications and speeds up the synthesis task. The approach is herein demonstrated via the design of a 0.13 μm CMOS 10 bits@60 MS/s pipeline ADC with energy consumption per conversion of only 0.54 pJ@1 MHz, making it one of the most energy-efficient 10-bit video-rate pipeline ADCs reported to date. The computational cost of this design is of only 25 min of CPU time, and includes the evaluation of 13 different pipeline architectures potentially feasible for the targeted specifications. The optimum design derived from the synthesis procedure has been fine tuned to support PVT variations, laid out together with other auxiliary blocks, and fabricated. The experimental results show a power consumption of 23 [email protected] V and an effective resolution of 9.47-bit@1 MHz. Bearing in mind that no specific power reduction strategy has been applied; the mentioned results confirm the reliability of the proposed approach.Ministerio de Ciencia e Innovación TEC2009-08447Junta de Andalucía TIC-0281

Accurate Settling-Time Modeling and Design Procedures for Two-Stage Miller-Compensated Amplifiers for Switched-Capacitor Circuits

We present modeling techniques for accurate estimation of settling errors in switched-capacitor (SC) circuits built with Miller-compensated operational transconductance amplifiers (OTAs). One distinctive feature of the proposal is the computation of the impact of signal levels (on both the model parameters and the model structure) as they change during transient evolution. This is achieved by using an event-driven behavioral approach that combines small- and large-signal behavioral descriptions and keeps track of the amplifier state after each clock phase. Also, SC circuits are modeled under closed-loop conditions to guarantee that the results remain close to those obtained by electrical simulation of the actual circuits. Based on these models, which can be regarded as intermediate between the more established small-signal approach and full-fledged simulations, design procedures for dimensioning SC building blocks are presented whose targets are system-level specifications (such as ENOB and SNDR) instead of OTA specifications. The proposed techniques allow to complete top-down model-based designs with 0.3-b accuracy.Ministerio de Educación y Ciencia TEC2006-03022Junta de Andalucía TIC-0281

A 5.3mW, 2.4GHz ESD protected Low-Noise Amplifier in a 0.13μm RFCMOS technology

An Electrostatic Discharge (ESD) protected Low- Noise Amplifier (LNA) for the 2.4 GHz ISM band designed in a 0.13 mum standard RFCMOS technology is presented. The amplifier, including packaging effects, achieves 16.8 dB power gain, reflexion coefficients S 11 , S 22 < -30 dB over the 2.4 GHz ISM band, a peak noise figure of 1.8 dB, and an IIP 3 of 1 dBm, while drawing less than 4.5 mA dc biasing current from the 1.2 V power supply. Further, the LNA withstands a Human Body Model (HBM) ESD stress up to plusmn2.0 kV, by means of the additional custom protection circuitry.Comisión Interministerial de Ciencia y Tecnología TIC2003-02355Ministerio de Educación y Ciencia TEC2006-0302

A self-calibration circuit for a neural spike recording channel

This paper presents a self-calibration circuit for a neural spike recording channel. The proposed design tunes the bandwidth of the signal acquisition Band-Pass Filter (BPF), which suffers from process variations corners. It also performs the adjustment of the Programmable Gain Amplifier (PGA) gain to maximize the input voltage range of the analog-to-digital conversion. The circuit, which consists on a frequency-controlled signal generator and a digital processor, operates in foreground, is completely autonomous and integrable in an estimated area of 0.026mm 2 , with a power consumption around 450nW. The calibration procedure takes less than 250ms to select the configuration whose performance is closest to the required one.Ministerio de Ciencia e Innovación TEC2009-08447Junta de Andalucía TIC-0281

Simulation-based high-level synthesis of Nyquist-rate data converters using MATLAB/SIMULINK

This paper presents a toolbox for the simulation, optimization and high-level synthesis of Nyquist-rate Analog-to-Digital (A/D) and Digital-to-Analog (D/A) Converters in MATLAB®. The embedded simulator uses SIMULINK® C-coded S-functions to model all required subcircuits including their main error mechanisms. This approach allows to drastically speed up the simulation CPU-time up to 2 orders of magnitude as compared with previous approaches - based on the use of SIMULINK® elementary blocks. Moreover, S-functions are more suitable for implementing a more detailed description of the circuit. For all subcircuits, the accuracy of the behavioral models has been verified by electrical simulation using HSPICE. For synthesis purposes, the simulator is used for performance evaluation and combined with an hybrid optimizer for design parameter selection. The optimizer combines adaptive statistical optimization algorithm inspired in simulated annealing with a design-oriented formulation of the cost function. It has been integrated in the MATLAB/SIMULINK® platform by using the MATLAB® engine library, so that the optimization core runs in background while MATLAB® acts as a computation engine. The implementation on the MATLAB® platform brings numerous advantages in terms of signal processing, high flexibility for tool expansion and simulation with other electronic subsystems. Additionally, the presented toolbox comprises a friendly graphical user interface to allow the designer to browse through all steps of the simulation, synthesis and post-processing of results. In order to illustrate the capabilities of the toolbox, a 0.13)im CMOS 12bit@80MS/s analog front-end for broadband power line communications, made up of a pipeline ADC and a current steering DAC, is synthesized and high-level sized. Different experiments show the effectiveness of the proposed methodology.Ministerio de Ciencia y Tecnología TIC2003-02355RAICONI

Proliferación algal nociva (marea roja) ocurrida en marzo de 2012 en la costa salvadoreña: organismos causantes, ensayos de saxitoxinas y condiciones oceanografías.

La marea roja es un término comúnmente asignado a las Proliferaciones Algales Nocivas, que ocasionan confusión, ya que generalmente no se presentan en color rojo y no siempre es tóxica para el ser humano. Con respecto a El Salvador se ve afectado por intensos episodios de fitoplancton tóxico o nocivo que suceden a nivel local o regional en la costa Pacífica de Centroamérica. Por eso mismo el laboratorio de toxinas marinas de la Universidad de El Salvador LABTOX-UES, efectúa un monitoreo permanente del fitoplancton en toda la línea costera, con el propósito de verificar la presencia de especies tóxicas, nocivas, densidad celular, concentración de toxinas y generar información oportuna mediante sistemas de alerta temprana

A power efficient neural spike recording channel with data bandwidth reduction

This paper presents a mixed-signal neural spike recording channel which features, as an added value, a simple and low-power data compression mechanism. The channel uses a band-limited differential low noise amplifier and a binary search data converter, together with other digital and analog blocks for control, programming and spike characterization. The channel offers a self-calibration operation mode and it can be configured both for signal tracking (to raw digitize the acquired neural waveform) and feature extraction (to build a first-order PWL approximation of the spikes). The prototype has been fabricated in a standard CMOS 0.13μm and occupies 400μm×400μm. The overall power consumption of the channel during signal tracking is 2.8μW and increases to 3.0μW average when the feature extraction operation mode is programmed.Ministerio de Ciencia e Innovación TEC2009-08447Junta de Andalucía TIC-0281

Diseño, implementación y evaluación de un proyecto sobre el tema de energía para 4º ESO basado en la técnica de aprendizaje basado en proyectos

En este trabajo se desarrolla un proyecto ABP sobre el tema de Energía en 4º ESO. Se ha llevado a cabo desde la inquietud de implementar un método novedoso en el centro Santa María la Real (Maristas). En un comienzo estudiamos los orígenes y características de la metodología ABP. A continuación, se detalla cómo se diseñó e implementó el proyecto en 4 sesiones. En cada sesión se planteaba un reto que debía resolver el alumnado, gracias al trabajo por grupos realizado. Además el alumnado realizaba un acta individual en la que asentaba los conceptos y procedimientos de la sesión correspondiente. Por último se especifica cómo se realizó la evaluación del proyecto. Aunque era una metodología nueva para el alumnado, consiguieron adaptarse y se obtuvieron unos resultados en el rango de lo esperado. Además se consiguió que la motivación del alumnado por la materia aumentase, aspecto que se valoró muy positivamente.In this paper we develop a PBL project about Energy for 4th ESO. This project was carried out bearing in mind the future implementation of a new method of education in Santa María la Real (Marist) school. We first study the origins and characteristics of the PBL methodology, and then explain how the project was designed and implemented in 4 sessions. In each session, the students were presented a challenge which they had to tackle in groups. In addition each student had to redact individually a report in order to remember the concepts and procedures of each session. Finally we specify how the project evaluation was performed. Although it was a new methodology for students, they managed to adapt well and the results obtained were in the expected range. In addition it was possible to increase the students´ motivation for the subject, a very positive result which was acclaimed.Máster Universitario en Profesorado de Educación Secundaria por la Universidad Pública de NavarraBigarren Hezkuntzako Irakasletzako Unibertsitate Masterra Nafarroako Unibertsitate Publikoa