Prions and transmissible spongiform encephalopathies: a tour around its history

Las enfermedades causadas por priones son un grupo de enfermedades neurodegenerativas, producidas por el metabolismo aberrante de una proteína, que afectan tanto a los animales como a la especie humana. Presentan un prolongado período de incubación, alta transmisibilidad y una evolución clínica fatal y careceden de tratamiento. Se ha utilizado el término de prionpatías para denominarlas y debido a la espongiosis que producen en el sistema nervioso también se les conoce con el nombre de encefalopatías espongiformes subagudas. En este trabajo se brinda un recorrido a través de la historia de los priones, las enfermedades por ellos inducidas y las diferentes teorías que intentan explicar la etiología de estas patologías.The prion diseases are a group of neurodegenerative diseases that affect both animals and human species, caused by aberrant metabolism of a protein. They have a long incubation period, high transmissibility and fatal clinical course and lack of treatment. To name them It has been used the term prionpatías, and due to the spongiosis they produce in the nervous system, they are also known as subacute spongiform encephalopathies. This paper provides a tour through the history of prion, the diseases induced by them, and the various theories which try to explain the etiology of these pathologies.Facultad de Ciencias Veterinaria

Determination of ticlopidine in human plasma by capillary gas chromatography with ion trap detection

A gas chromatographic method for determination of ticlopidine in human plasma using mass spectrometric detection was developed. A Perkin Elmer model 8500 gas chromatograph coupled to an ion trap detector (ITD) in electron impact mode (EI) was used. The gas chromatograph was fitted with a 30 m×0.32 mm i.d., DB-17 capillary column with a film thickness of 0.25 [mu]m. The compounds were isolated from plasma by Extrelut-1 solid-phase extraction using hexane as the solvent of elution. The detection and quantification limits for this method were 0.005 and 0.01 [mu]g/ml, respectively. The calibration curves were linear from 0.01 and 2.5 [mu]g/ml. Recoveries from human plasma spiked at 0.01 and 2.0 [mu]g/ml ranged from 84.4 and 87.3%. The coefficient of variation (CV) was between 5.1 and 6.9%. The results show that the sensitivity, accuracy and precision of the method are adequate for the determination of ticlopidine in human plasma samples. The ITD in SIM mode allows the unequivocal identification of ticlopidine. The suitability of this method was evaluated in the determination of ticlopidine in plasma from healthy volunteers following oral administration of a dose of 500 mg/day.http://www.sciencedirect.com/science/article/B6TGX-48R7F4V-2/1/7f0e17eaa3f9ec2ce371c06ae41c857

Cuando el docente propone y el alumno dispone o la versatilidad de las propuestas educativas

El auge del empleo de computadoras, redes informáticas y multimedia han revolucionado la enseñanza en todos los niveles educativos, y la universidad es una protagonista relevante en este cambio. El impacto de la educación a distancia ha marcado un antes y un después en la enseñanza de todas las ciencias. El avance permanente en el campo del conocimiento y la tecnología informática nos lleva a reflexionar sobre la provisionalidad del conocimiento, y a replantearnos los modos en que transmitimos la información a los alumnos. Esto nos conduce a plantear de manera diferente el objetivo de la enseñanza, ahora el desafío es: enseñar a aprender por uno mismo. En este contexto, la educación a distancia, y las tutorías virtuales ofrecen una opción educativa muy interesante, brindándonos la posibilidad de ofrecer un complemento a la enseñanza presencial. En este marco se describe una experiencia pedagógica que, a instancias de los estudiantes de la asignatura Fisiopatología Clínica Comparada, perteneciente al Segundo Ciclo de la Carrera de Microbiología Clínica e Industrial, condujo a una modificación en la implementación de una estrategia de enseñanza enmarcada en la línea temática de la docencia y las nuevas tecnologías.Eje 3: Tecnologías digitales y entornos virtuales de la enseñanza universitaria: perspectivas actuales y escenarios futuros. Experiencias de enseñanza universitaria en entornos virtualesSecretaría de Asuntos Académico

Tutoría virtual: La interpretación clínica de los análisis diagnósticos de laboratorio

El auge del empleo de computadoras, redes informáticas y multimedia han revolucionado la enseñanza en todos los niveles educativos, y la Universidad es protagonista relevante en este cambio. El impacto de la educación a distancia ha marcado un antes y un después en la enseñanza de todas las ciencias. El avance permanente en el campo del conocimiento y la tecnología informática nos lleva a reflexionar sobre la provisionalidad del conocimiento y a replantearnos los modos en que transmitimos la información y las diversas técnicas a los alumnos. Esto, nos conduce a planear de manera diferente el objetivo de la enseñanza; ahora el desafío es: enseñar a aprender por uno mismo. En la sociedad del conocimiento actual, se requiere una dinámica de impartir el saber, que implique el entrenamiento del alumno en el manejo de las fuentes de información, que el estudiante aprenda a razonar, desarrollando sus habilidades y destrezas analíticas, críticas, de síntesis y de relación. En este contexto, la educación a distancia y las tutorías virtuales, ofrecen una opción educativa muy interesante, brindándonos la posibilidad de procurar un complemento a la enseñanza presencial. En este marco, se propone la realización de un trabajo de intervención, encuadrado en la línea temática de la docencia y las nuevas tecnologías, a través del desarrollo de una Tutoría virtual para “la interpretación de los análisis diagnósticos de laboratorio”, con el objetivo de facilitar la enseñanza y comprensión de la asignatura Fisiopatología Clínica Comparada, perteneciente al Segundo Ciclo de la Carrera de Microbiología Clínica e Industrial.Facultad de Ciencias Veterinaria

Prions and transmissible spongiform encephalopathies: a tour around its history

Las enfermedades causadas por priones son un grupo de enfermedades neurodegenerativas, producidas por el metabolismo aberrante de una proteína, que afectan tanto a los animales como a la especie humana. Presentan un prolongado período de incubación, alta transmisibilidad y una evolución clínica fatal y careceden de tratamiento. Se ha utilizado el término de prionpatías para denominarlas y debido a la espongiosis que producen en el sistema nervioso también se les conoce con el nombre de encefalopatías espongiformes subagudas. En este trabajo se brinda un recorrido a través de la historia de los priones, las enfermedades por ellos inducidas y las diferentes teorías que intentan explicar la etiología de estas patologías.The prion diseases are a group of neurodegenerative diseases that affect both animals and human species, caused by aberrant metabolism of a protein. They have a long incubation period, high transmissibility and fatal clinical course and lack of treatment. To name them It has been used the term prionpatías, and due to the spongiosis they produce in the nervous system, they are also known as subacute spongiform encephalopathies. This paper provides a tour through the history of prion, the diseases induced by them, and the various theories which try to explain the etiology of these pathologies.Facultad de Ciencias Veterinaria

Assessment of Pesticide Residues in Honey Samples from Portugal and Spain

Fifty samples of honey collected from local markets of Portugal and Spain during year 2002 were analyzed for 42 organochlorine, carbamate, and organophosphorus pesticide residues. An analytical procedure based on solid-phase extraction with octadecyl sorbent followed by gas chromatography−mass spectrometry (GC−MS), for organochlorines, and by liquid chromatography−atmospheric pressure chemical ionization-mass spectrometry (LC−APCI-MS), for organophosphorus and carbamates, has been developed. Recoveries of spiked samples ranged from 73 to 98%, except for dimethoate (40%), with relative standard deviations from 3 to16% in terms of repeatability, and from 6 to 19% in terms of reproducibility. Limits of quantification were from 0.003 to 0.1 mg kg-1. Most of the pesticides found in honey were organochlorines. Among them, γ-HCH was the most frequently detected in 50% of the samples, followed by HCB in 32% of the samples and the other isomers of HCH (α-HCH and β-HCH) in 28 and 26% of the samples, respectively. Residues of DDT and their metabolites were detected in 20% of the samples. Of the studied carbamates, both methiocarb and carbofuran were detected in 10% of the samples, pirimicarb in 4% and carbaryl in 2%. The only organophosphorus pesticides found were heptenophos in 16%, methidathion in 4%, and parathion methyl in 2% of honey samples. Results indicate that Portuguese honeys were more contaminated than Spanish ones. However, honey consumers of both countries should not be concerned about the amounts of pesticide residues found in honeys available on the market

Design and performance of the Fermilab Constant Fraction Discriminator ASIC

We present the design and performance characterization results of the novel Fermilab Constant Fraction Discriminator ASIC (FCFD) developed to readout low gain avalanche detector (LGAD) signals by directly using a constant fraction discriminator (CFD) to measure signal arrival time. Silicon detectors with time resolutions less than 30 ps will play a critical role in future collider experiments, and LGADs have been demonstrated to provide the required time resolution and radiation tolerance for many such applications. The FCFD has a specially designed discriminator that is robust against amplitude variations of the signal from the LGAD that normally requires an additional correction step when using a traditional leading edge discriminator based measurement. The application of the CFD directly in the ASIC promises to be more reliable and reduces the complication of timing detectors during their operation. We will present a summary of the measured performance of the FCFD for input signals generated by internal charge injection, LGAD signals from an infrared laser, and LGAD signals from minimum-ionizing particles. The mean time response for a wide range of LGAD signal amplitudes has been measured to vary no more than 15 ps, orders of magnitude more stable than an uncorrected leading edge discriminator based measurement, and effectively removes the need for any additional time-walk correction. The measured contribution to the time resolution from the FCFD ASIC is also found to be 10 ps for signals with charge above 20 fC

Mental Health and Paranoid Thoughts in College Students from Juarez

Paranoid thoughts are a psychological consequence of the social violence lived by the people in Juarez, which in 2010 was the most violent city in the world. Most people in Juarez report some degree of paranoid thoughts and these thoughts have been related to mental health. This study analyzes the relationship between paranoid thoughts and mental health. The sample consisted of 315 college students with a mean age of 23.05 (SD = 0.59) years, 70.5% females and 29.5% males. Most of the sample was single (86.0%) and married (9.2%). The Paranoid Thoughts Scale and the Symptom Checklist-90-Revised were used to measure paranoid thoughts and mental health (e.g. depression, or anxiety), respectively. All of the mental health factors had statistically significant correlations with paranoid thoughts with correlations ranging from .38 to .57. The people that reported higher levels of paranoid thoughts also reported higher levels of psychological problems or distress. Paranoid thoughts can be considered a predictor of low mental health in people from Juarez

Mathematical modeling of microbial growth in refrigerated horsemeat : it's importance in the quality of meat

Horsemeat is an important economic resource for our country, as Argentina is considered one of the leading world exporters of horsemeat. But there is little research about the quality of it. It was examined the effect of: (i) storage temperature (0, 4ºC) and (ii) gaseous permeability of the packaging film (polyethylene and EVA SARAN EVA for vacuum packaging) on the growth of bacteria (Total Aerobic Mesophilic Heterotrophic Bacteria, Enterobacteriaceae and Pseudomonas sp.) isolated from horse muscle. Microbial growth was modelled using Gompertz or the Linear Regression Models. The lowest final bacteria counts were obtained with the combination of 0ºC and vacuum packaging. At higher temperatures, 4ºC, there were no significant differences (p<0.05) among the final counts in relation to both films. The lowest values of µ (microbial growth rate) for the development of studied microorganisms were observed in samples stored in EVA SARAN EVA DOI:http://dx.doi.org/10.19137/cienvet2013-151