Shiga Toxin Detection Methods : A Short Review

The Shiga toxins comprise a family of related protein toxins secreted by certain types of bacteria. Shigella dysenteriae, some strain of Escherichia coli and other bacterias can express toxins which caused serious complication during the infection. Shiga toxin and the closely related Shiga-like toxins represent a group of very similar cytotoxins that may play an important role in diarrheal disease and hemolytic-uremic syndrome. The outbreaks caused by this toxin raised serious public health crisis and caused economic losses. These toxins have the same biologic activities and according to recent studies also share the same binding receptor, globotriosyl ceramide (Gb3). Rapid detection of food contamination is therefore relevant for the containment of food-borne pathogens. The conventional methods to detect pathogens, such as microbiological and biochemical identification are time-consuming and laborious. The immunological or nucleic acid-based techniques require extensive sample preparation and are not amenable to miniaturization for on-site detection. In the present are necessary of techniques of rapid identification, simple and sensitive which can be employed in the countryside with minimally-sophisticated instrumentation. Biosensors have shown tremendous promise to overcome these limitations and are being aggressively studied to provide rapid, reliable and sensitive detection platforms for such applications.Comment: 16 pages, 2 figure

Tourism and productivity: Case study of the hotel and catering industry in the Andalusian region

The object of this paper is to analyse the situation and evolution of the productivity of the tourism industry in the Andalusian region, and more specifically of the hotel and catering branch, relating it to the organisational structure of its businesses. First of all, the issue of the definition and limitation of the concept of productivity applied to the services sector is addressed, as traditionally this concept is focused on manufacturing, and the different ways of measuring and the analysis methods are reviewed. Then, using the accounting information provided by the Balances Centre of Andalusia (CBA), the general features of the organisational structure of the hotel and catering industry in de Andalusian region, stratifying the samples by the size of the companies and examining the medium size of the Andalusian hotel and catering businesses. Once the organisational structure of the sector is analysed, it is related to the state and evolution of its productivity, using a simple ratio between the brute added value and the personnel expenses, and completing this analysis with a relative efficiency index, the Baldwin efficiency index, with which the technical efficiency of each company is compared to the mass of most efficient companies. As a result of this research it is observed that the productivity indexes increase as web as the size of the companies and during the considered period, especially in the case of the medium sized and large companies. Nevertheless, these productivity increases are less relevant than the increase of employment, especially in case of smaller companies.

Minimal formulation of the linear spatial analysis of capillary jets: Validity of the two-mode approach

A rigorous and complete formulation of the linear evolution of harmonically stimulated capillary jets should include infinitely many spatial modes to account for arbitrary exit conditions [J. Guerrero et al., J. Fluid Mech. 702, 354 (2012)]. However, it is not rare to find works in which only the downstream capillary dominant mode, the sole unstable one, is retained, with amplitude determined by the jet deformation at the exit. This procedure constitutes an oversimplification, unable to handle a flow rate perturbation without jet deformation at the exit (the most usual conditions). In spite of its decaying behavior, the other capillary mode (subdominant) must be included in what can be called a “minimal linear formulation.” Deformation and mean axial velocity amplitudes at the jet exit are the two relevant parameters to simultaneously find the amplitudes of both capillary modes. Only once these amplitudes are found, the calculation of the breakup length may be eventually simplified by disregarding the subdominant mode. Simple recipes are provided for predicting the breakup length, which are checked against our own numerical simulations. The agreement is better than in previous attempts in the literature. Besides, the limits of validity of the linear formulation are explored in terms of the exit velocity amplitude, the wave number, the Weber number, and the Ohnesorge number. Including the subdominant mode extends the range of amplitudes for which the linear model gives accurate predictions, the criterion for keeping this mode being that the breakup time must be shorter than a given formula. It has been generally assumed that the shortest intact length happens for the stimulation frequency with the highest growth rate. However, we show that this correlation is not strict because the amplitude of the dominant mode has a role in the breakup process and it depends on the stimulation frequency.Ministerio de Economía, Industria y Competitividad, Spain, under Contract No. FIS2014-25161Junta de Andalucía under Contract No. P11-FQM-791

Diseño y prototipado mediante impresión 3D de antenas para comunicaciones por satélite

Este Trabajo Fin de Grado consiste en la comparación de diferentes antenas de bocina circulares. Se trabaja en condiciones de espacio libre y en frecuencias en banda K, concretamente entre 17 GHz y 20 GHz. Primero se introducirán una serie de conceptos básicos usados a lo largo de este TFG, tales como, teoría de guías de onda, teoría de antenas, diagrama de radicación, coeficiente de reflexión, ganancia… Posteriormente se desarrolla un programa que grafique el campo de los diferentes modos que se propagan en la guía de onda circular, así como otra versión que realice la suma ponderada de los mismos, mostrando en la memoria algunos ejemplos. A continuación, se diseñan una antena de bocina monomodo y una antena de bocina multimodo siguiendo el ejemplo de la antena de bocina Potter. Esta última se diseña para que propague el modo Híbrido HE11, previamente graficado en el programa Matlab. Se comparan los diferentes resultados de las dos antenas diseñadas, ambas de la misma longitud total, en cuanto a reflexión y a radiación, observando que las dos tienen diferentes aspectos positivos. Para construir la antena se ve la necesidad de diseñar un transformador al no disponer de una transición de guía circular a coaxial. Por lo que con el mismo programa se diseña un transformador de guía de onda circular a guía de onda rectangular, concretamente la WR51. Se añade a ambas antenas de bocina el transformador y el flange WR51 y se comparan las simulaciones. Por problemas técnicos ajenos a este TFG solo se construye la antena de bocina monomodo y se mide en la cámara anecoica, comparando las medidas con las simulaciones. Los resultados varían respecto a las simulaciones teóricas debido a las pérdidas de los materiales, ya que no son ideales

Control de agarre y posicionamiento en una plataforma robot con sensores táctiles

En este artículo se presenta una plataforma formada por un brazo robot de 5 grados de libertad y una pinza robot de 1 sólo grado de libertad, con superficies táctiles. Este sistema obtiene, en tiempo real, las distribuciones de presión cuando un objeto ha sido agarrado, produciendo una realimentación del control de la posición y fuerza

Laparoscopic image analysis for automatic tracking of surgical tools

Laparoscopy is a surgical technique nowadays embedded in the clinical routine. Recent researches have been focused on analysing video information captured by the endoscope for extracting cues useful for surgeons, such as depth information. In particular, the 3D pose estimation of the surgical tools presents three important added values: (1) to extract objective parameters for the surgical training stage, (2) to develop an image-guided surgery based on the knowledge of the surgery tools localization, (3) to design new roboticsystems for an automatic laparoscope positioning, according to the visual feedback. Tool’s shape and orientation in the image is the key to get its 3D position. This work presents an image analysis for automatic laparoscopic tool’s detection along the recorded video without extra tool markers, using an edges detection strategy. Also, this analysis includes a previous stage of barrel distortion correction for videoendoscopic image

A new multisensor software architecture for movement detection: Preliminary study with people with cerebral palsy

A five-layered software architecture translating movements into mouse clicks has been developed and tested on an Arduino platform with two different sensors: accelerometer and flex sensor. The archi-tecture comprises low-pass and derivative filters, an unsupervised classifier that adapts continuously to the strength of the user's movements and a finite state machine which sets up a timer to prevent in-voluntary movements from triggering false positives. Four people without disabilities and four people with cerebral palsy (CP) took part in the experi-ments. People without disabilities obtained an average of 100% and 99.3% in precision and true positive rate (TPR) respectively and there were no statistically significant differences among type of sensors and placement. In the same experiment, people with disabilities obtained 97.9% and 100% in precision and TPR respectively. However, these results worsened when subjects used the system to access a commu-nication board, 89.6% and 94.8% respectively. With their usual method of access-an adapted switch- they obtained a precision and TPR of 86.7% and 97.8% respectively. For 3-outof- 4 participants with disabilities our system detected the movement faster than the switch. For subjects with CP, the accelerometer was the easiest to use because it is more sensitive to gross motor motion than the flex sensor which requires more complex movements. A final survey showed that 3-out-of-4 participants with disabilities would prefer to use this new technology instead of their tra-ditional method of access