Rosemary, heather and heterofloral honeys protect towards cytotoxicity of acrylamide in human hepatoma cells

In April 2002 the Swedish Agency for Food Safety alerts of the presence of acrylamide (AA) in carbohydrate-rich foodstuffs subjected to elevated frying temperatures (150 - 180°C) such as fried potatoes, biscuits or breakfast cereals. The International Agency on Research on Cancer (IARC) classified acrylamide as a probable carcinogen, Group 2A. In consequence, one of the priority objectives of Food Safety is to reduce the presence of this substance in food. Numerous studies show the inhibitory effect of antioxidants present in fruit and vegetable extracts against the formation of acrylamide. Honey is also a good source of antioxidants since it contains a great variety of phenolic compounds. Therefore the main objective of this work was to evaluate the protective effect of three Madrid honeys of different floral origin against the AA-induced cytotoxicity in human hepatoma cells (HepG2). The results showed that the acrylamide in concentrations 1.4 and 2.8 mg/ml and in a 24-hour incubation period significantly reduced the percentage of cell viability (67 and 24 %, respectively). In simultaneous treatment of acrylamide (2.8 mg/ml) and the corresponding honeys we noted that rosemary honey in all concentrations tested increased the percentage of cell survival in 40-49 %, while heather honey and heterofloral honey increased cell viability by 54 and 66% respectively. The artificial honey did not mitigate the AA-induced cytotoxic effect. As a result, the protective effect of the evaluated honeys can be attributed to its polyphenolic content and not the sugar constituents.En abril del 2002 la Agencia Sueca de Seguridad Alimentaria alerta de la presencia de acrilamida (AA) en alimentos ricos en carbohidratos sometidos a temperaturas de fritura elevadas (150-180oC) como las patatas fritas, las galletas o los cereales de desayuno. La Agencia Internacional para la investigación del Cáncer (IARC) la clasifica como un agente carcinógeno probable, Grupo 2A. En consecuencia, uno de los objetivos prioritarios de la Seguridad Alimentaria ha consistido en reducir la presencia de esta sustancia en los alimentos. Numerosos estudios muestran el efecto inhibidor de los antioxidantes naturales presentes en extractos de frutas y vegetales en la formación de la acrilamida. La miel es también una buena fuente de antioxidantes ya que contiene una gran variedad de compuestos fenólicos. Por ello, el principal objetivo de este trabajo consistió en evaluar el efecto protector de tres mieles de Madrid de distinto origen floral frente a la citotoxicidad de la acrilamida, en células de hepatoma humano (HepG2). Los resultados obtenidos mostraron que la acrilamida a las concentraciones de 1,4 y de 2,8 mg/ml y un tiempo de incubación de 24 horas redujeron significativamente el porcentaje de viabilidad celular (67 y 24%, respectivamente). En los tratamientos simultáneos de acrilamida (2,8 mg/ml) y las correspondientes mieles observamos que la miel de romero a todas las concentraciones evaluadas incrementaba el porcentaje de viabilidad celular en un 40-49%. Mientras que, la miel de brezo y la miel multifloral lo hicieron en un 54 y 66% respectivamente. La miel artificial no atenúo el efecto citotóxico de la acrilamida. Por tanto, el efecto protector de las mieles evaluadas puede atribuirse a su contenido en polifenoles y no a su contenido en azúcares

Combined dark matter searches towards dwarf spheroidal galaxies with Fermi-LAT, HAWC, H.E.S.S., MAGIC, and VERITAS

Cosmological and astrophysical observations suggest that 85% of the total matter of the Universe is made of Dark Matter (DM). However, its nature remains one of the most challenging and fundamental open questions of particle physics. Assuming particle DM, this exotic form of matter cannot consist of Standard Model (SM) particles. Many models have been developed to attempt unraveling the nature of DM such as Weakly Interacting Massive Particles (WIMPs), the most favored particle candidates. WIMP annihilations and decay could produce SM particles which in turn hadronize and decay to give SM secondaries such as high energy \u1d6fe rays. In the framework of indirect DM search, observations of promising targets are used to search for signatures of DM annihilation. Among these, the dwarf spheroidal galaxies (dSphs) are commonly favored owing to their expected high DM content and negligible astrophysical background. In this work, we present the very first combination of 20 dSph observations, performed by the Fermi-LAT, HAWC, H.E.S.S., MAGIC, and VERITAS collaborations in order to maximize the sensitivity of DM searches and improve the current results. We use a joint maximum likelihood approach combining each experiment’s individual analysis to derive more constraining upper limits on the WIMP DM self-annihilation cross-section as a function of DM particle mass. We present new DM constraints over the widest mass range ever reported, extending from 5 GeV to 100 TeV thanks to the combination of these five different \u1d6fe-ray instruments

Estudio exploratorio para el desarrollo de un dispositivo de asistencia cardíaca

Proyecto de Investigación. Instituto Tecnológico de Costa Rica. Vicerrectoría de Investigación y Extensión (VIE). Escuela de Ingeniería Electrónica, Escuela de Física; Hospital Rafael Ángel Calderón Guardia; Clínica El Roble, 2012Las enfermedades cardiovasculares son la causa principal de muerte en Costa Rica. Los dispositivos de asistencia circulatoria pueden ser utilizados en operaciones del corazón o como asistencia en casos de insuficiencia cardíaca severa, dependiendo del diseño y configuración del mismo. Este documento plantea el estudio exploratorio realizado con miras a proponer un proyecto a largo plazo para desarrollar un dispositivo de asistencia ventricular autóctono, que presente mejoras sustanciales a dispositivos aplicables en el tratamiento de personas con insuficiencia cardíaca, particularmente de aquellas en fases terminales de su enfermedad. La disponibilidad a estos sistemas de asistencia circulatoria en el país es limitada, debido a su escaso número y su precio. Los resultados tratados en este documento se pueden agrupar en cuatro temas: estadísticas de enfermedades cardíacas en el país, modelos del sistema cardiovascular, modelos de sangre en los vasos sanguíneos y funcionamiento de dispositivos de asistencia ventricular actuales. Por otra parte, este proyecto ha permitido determinar que la implementación de un sistema de apoyo circulatorio con capacidad de asistir las funciones cardíacas comprende aspectos técnicos como la especificación, desarrollo y escogencia de probables fuentes de energía, posibles materiales, sistema de control adecuado y posibilidad de aplicabilidad y maniobrabilidad según la condición clínica de cada posible receptor. Por está razón se presenta un diagrama de ruta con las etapas que, hasta la entrega de este informe, se ha determinado son necesarias para el desarrollo de un sistema de asistencia ventricular en el TEC.Cardiovascular diseases are the major cause of death in Costa Rica. Circulatory assist devices can be used in heart surgeries or as assistance in severe heart failure cases, this function depends on its design and configuration. This document presents the results of an exploratory study conducted in order to propose a project with the aim to develop and improve devices used in heart failure treatments, especially for those patients with an advanced stage of this disease.. Costa Rica has limited access to this kind of systems due to the low number of available devices and their price. The results discussed in this report can be grouped into four themes: heart disease statistics in the country, cardiovascular system models, models of blood in blood vessels and performance and characteristics of existing ventricular assist devices. Furthermore, this project has allowed to identified several requierements to implement a circulatory support system able to assist heart function, such as technical aspects like specification, development and selection of energy sources, possible materials, proper control system, applicability and maneuverability depending on the clinical condition of each patient. For this reason, we present a route map with the steps we have determined are necessary for the development of a ventricular assist system in the TEC

Ciencias Sociales y Relaciones Internacionales : nuevas perspectivas desde América Latina

Esta obra es un modesto intento para situar la disciplina de las Relaciones Internacionales dentro de las Ciencias Sociales, pero con una visión desde América Latina. El conjunto de trabajos, que se solicitaron expresamente a autoras y autores, se agrupa en tres secciones: i) Epistemología e Investigación; ii) Enfoques teóricos y metodológicos y iii) Estudio de casos.This work is a modest attempt to place the discipline of International Relations within the Social Sciences, but with a view from Latin America. The set of works, which is expressly requested from authors, is grouped into three sections: i) Epistemology and Research; ii) Theoretical and methodological approaches and iii) Case studies.Universidad Nacional, Costa RicaIDESPOCLACSOEscuela de Relaciones Internacionale

Calibration and performance of the readout system based on switched capacitor arrays for the Large-Sized Telescope of the Cherenkov Telescope Array

International audienceThe Cherenkov Telescope Array1 (CTA) is the next-generation ground-based observatory for very-high-energy gamma rays. The CTA consists of three types of telescopes with different mirror areas to cover a wide energy range (20 GeV–300 TeV) with an order of magnitude higher sensitivity than the predecessors. Among those telescopes, the Large-Sized Telescope (LST) is designed to detect low-energy gamma rays between 20 GeV and a few TeV with a 23 m diameter mirror. To make the most of such a large light collection area (about 400 m2), the focal plane camera must detect as much reflected Cherenkov light as possible. We have developed each camera component to meet the CTA performance requirements for more than ten years and performed quality-control tests before installing the camera to the telescope.2, 3 The first LST (LST-1) was inaugurated in October 2018 in La Palma, Spain (Figure 1).4 After the inauguration, various calibration tests were performed to adjust hardware parameters and verify the camera performance. In parallel, we have been developing the analysis software to extract physical parameters from low-level data, taking into account some intrinsic characteristics of the switched capacitor arrays, Domino Ring Sampler version 4 (DRS4), used for sampling the waveform of a Cherenkov signal. In this contribution, we describe the hard- ware design of the LST camera in Section 2, a procedure for low-level calibration in Section 3, and the readout e of the LST camera after the hardware calibration with a dedicated analysis chain in Section 4

Combined dark matter searches towards dwarf spheroidal galaxies with Fermi-LAT, HAWC, H.E.S.S., MAGIC, and VERITAS

Cosmological and astrophysical observations suggest that 85\% of the total matter of the Universe is made of Dark Matter (DM). However, its nature remains one of the most challenging and fundamental open questions of particle physics. Assuming particle DM, this exotic form of matter cannot consist of Standard Model (SM) particles. Many models have been developed to attempt unraveling the nature of DM such as Weakly Interacting Massive Particles (WIMPs), the most favored particle candidates. WIMP annihilations and decay could produce SM particles which in turn hadronize and decay to give SM secondaries such as high energy $\gamma$ rays. In the framework of indirect DM search, observations of promising targets are used to search for signatures of DM annihilation. Among these, the dwarf spheroidal galaxies (dSphs) are commonly favored owing to their expected high DM content and negligible astrophysical background. In this work, we present the very first combination of 20 dSph observations, performed by the Fermi-LAT, HAWC, H.E.S.S., MAGIC, and VERITAS collaborations in order to maximize the sensitivity of DM searches and improve the current results. We use a joint maximum likelihood approach combining each experiment's individual analysis to derive more constraining upper limits on the WIMP DM self-annihilation cross-section as a function of DM particle mass. We present new DM constraints over the widest mass range ever reported, extending from 5 GeV to 100 TeV thanks to the combination of these five different $\gamma$-ray instruments

Combined dark matter searches towards dwarf spheroidal galaxies with Fermi-LAT, HAWC, H.E.S.S., MAGIC, and VERITAS

Cosmological and astrophysical observations suggest that 85% of the total matter of the Universe is made of Dark Matter (DM). However, its nature remains one of the most challenging and fundamental open questions of particle physics. Assuming particle DM, this exotic form of matter cannot consist of Standard Model (SM) particles. Many models have been developed to attempt unraveling the nature of DM such as Weakly Interacting Massive Particles (WIMPs), the most favored particle candidates. WIMP annihilations and decay could produce SM particles which in turn hadronize and decay to give SM secondaries such as high energy \u1d6fe rays. In the framework of indirect DM search, observations of promising targets are used to search for signatures of DM annihilation. Among these, the dwarf spheroidal galaxies (dSphs) are commonly favored owing to their expected high DM content and negligible astrophysical background. In this work, we present the very first combination of 20 dSph observations, performed by the Fermi-LAT, HAWC, H.E.S.S., MAGIC, and VERITAS collaborations in order to maximize the sensitivity of DM searches and improve the current results. We use a joint maximum likelihood approach combining each experiment’s individual analysis to derive more constraining upper limits on the WIMP DM self-annihilation cross-section as a function of DM particle mass. We present new DM constraints over the widest mass range ever reported, extending from 5 GeV to 100 TeV thanks to the combination of these five different \u1d6fe-ray instruments

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field