4,677 research outputs found

    Lamins in disease : why do ubiquitously expressed nuclear envelope proteins give rise to tissue-specific disease phenotypes?

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    The nuclear lamina is a filamentous structure composed of lamins that supports the inner nuclear membrane. Several integral membrane proteins including emerin, LBR, LAP1 and LAP2 bind to nuclear lamins in vitro and can influence lamin function and dynamics in vivo. Results from various studies suggest that lamins function in DNA replication and nuclear envelope assembly and determine the size and shape of the nuclear envelope. In addition, lamins also bind chromatin and certain DNA sequences, and might influence chromosome position. Recent evidence has revealed that mutations in A-type lamins give rise to a range of rare, but dominant, genetic disorders, including Emery-Dreifuss muscular dystrophy, dilated cardiomyopathy with conduction-system disease and Dunnigan-type familial partial lipodystrophy. An examination of how lamins A/C, emerin and other integral membrane proteins interact at the INM provides the basis for a novel model for how mutations that promote disease phenotypes are likely to influence these interactions and therefore cause cellular pathology through a combination of weakness of the lamina or altered gene expression

    Synchrotron radiation photoionization mass spectrometry of laser ablated species

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    The present paper describes an experimental apparatus suitable to create and study free clusters by combining laser ablation and synchrotron radiation. First tests on sulfur samples, S, showed the production, through laser ablation, of neutral Sn clusters (n = 1–8). These clusters were ionized using synchrotron radiation at photon energies from 160 eV to 175 eV, across the S 2p core edge. The feasibility of such combined ablation–synchrotron radiation experiments is demonstrated, opening new possibilities on the investigation of free clusters and radical

    Caracterización química, perfil de ácidos grasos y actividad antioxidante del mesocarpio de la fruta Gustavia macarenensis y su aceite de la región amazónica de Ecuador como fuente no convencional de aceite vegetal

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    To our knowledge, this study is the first to report on the nutritional characterization, bioactive compounds and antioxidant activity of Amazonian G. macarenensis fruit. The fatty acid profile was determined using a high performance liquid chromatography analysis. The total phenolic content and antioxidant activity were determined using Folin Ciocalteu’s method and by radical scavenging activity, respectively. Moreover, a cluster analysis was carried out in order to classify the G. macarenensis fruit oil according to its fatty acid profile. Seven Fisher linear discriminant functions were obtained from the discriminant analysis. These models allow one to classify new fruits on the basis of their fatty acid profile. A high value for total lipids was obtained (53.57%). Its main components were palmitic and oleic acid. The TPC value (156.49 ± 2.62 mg GAE/Kg of oil) obtained from the G. macarenensis fruit pulp oil is higher than what was reported for some olive oil and Brazilian mango oil varieties.Hasta donde sabemos, este estudio sería el primero sobre la caracterización nutricional, los compuestos bioactivos y la actividad antioxidante de la fruta amazónica G. macarenensis. El perfil de ácidos grasos se determinó mediante análisis de cromatografía líquida de alta resolución. El contenido fenólico total y la actividad antioxidante se determinaron utilizando el método de Folin Ciocalteu y la medida de la actividad de eliminación de radicales, respectivamente. Además, se realizó un análisis de conglomerados para clasificar el aceite de fruta G. macarenensis según su perfil de ácidos grasos. Se obtuvieron siete funciones discriminantes lineales de Fisher a partir del análisis discriminante. Estos modelos permiten clasificar frutas nuevas en función de su perfil de ácidos grasos. Se obtuvo un alto valor para el total de lípidos (53.57%). Sus componentes principales son los ácidos palmítico y oleico. El valor TPC (156.49 ± 2.62 mg GAE/Kg de aceite) obtenido del aceite de pulpa de fruta de G. macarenensis es más alto que el que se reporta para algunas variedades de aceite de oliva y aceite de mango brasileño

    SYMPA, a dedicated instrument for Jovian Seismology. II. Real performance and first results

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    Context. Due to its great mass and its rapid formation, Jupiter has played a crucial role in shaping the Solar System. The knowledge of its internal structure would strongly constrain the solar system formation mechanism. Seismology is the most efficient way to probe directly the internal structure of giant planets. Aims. SYMPA is the first instrument dedicated to the observations of free oscillations of Jupiter. Principles and theoretical performance have been presented in paper I. This second paper describes the data processing method, the real instrumental performance and presents the first results of a Jovian observation run, lead in 2005 at Teide Observatory. Methods. SYMPA is a Fourier transform spectrometer which works at fixed optical path difference. It produces Doppler shift maps of the observed object. Velocity amplitude of Jupiter's oscillations is expected below 60 cm/s. Results Despite light technical defects, the instrument demonstrated to work correctly, being limited only by photon noise, after a careful analysis. A noise level of about 12 cm/s has been reached on a 10-night observation run, with 21 % duty cycle, which is 5 time better than previous similar observations. However, no signal from Jupiter is clearly highlighted.Comment: 13 pages, 26 figure

    Morpholigical study of honey bees on the Canary Islands (Gran Canaria, Tenerife, La Palma, Gomera)

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    A morphological study was made of worker bees from 49 hives located at four island from the Canary archipelago. The study analysed 18 morphological characters and we have found that the bees from Gran Canaria and Tenerife belong to the same groupe, the animals from Gomera constitute a group near the afore mentioned, and the bees from La Palma form an independent group. Also, we have compared the data with data to come from hives placed in the south of the Iberian peninsula and in the north of Africa. We have found that the bees from Africa form an independent group, and the bees from the Iberian peninsula are included in the La Palma group.Se ha llevado a cabo un estudio morfológico de las abejas obreras procedentes de 49 colmenas situadas en cuatro islas del Archipiélago Canario. Se han analizado 18 características morfológicas, encontrando que las abejas procedentes de Gran Canaria y Tenerife pertenecen al mismo grupo; los animales de Gomera constituyen un grupo cercano al anterior y las abejas de La Palma forman un grupo independiente. También hemos comparado los datos obtenidos, con los procedentes de colmenas situadas en el sur de la península Ibérica y en el norte de África. Encontramos que las abejas del norte de África constituyen un grupo independiente y que los animales del sur de la península se incluyen en el grupo de las abejas de La Palma

    The MIDAS experiment: A prototype for the microwave emission of Ultra-High Energy Cosmic Rays

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    Recent measurements suggest that extensive air showers initiated by ultra-high energy cosmic rays (UHECR) emit signals in the microwave band of the electromagnetic spectrum caused by the collisions of the free-electrons with the atmospheric neutral molecules in the plasma produced by the passage of the shower. Such emission is isotropic and could allow the detection of air showers with 100% duty cycle and a calorimetric-like energy measurement, a significant improvement over current detection techniques. We have built MIDAS (MIcrowave Detection of Air Showers), a prototype of microwave detector, which consists of a 4.5 m diameter antenna with a cluster of 53 feed-horns in the 4 GHz range. The details of the prototype and first results will be presented.Comment: To appear in the proceedings of 12th Topical Seminar on Innovative Particle and Radiation Detectors (IPRD10), Siena, Italy, 7 - 10 June 201

    The MIDAS telescope for microwave detection of ultra-high energy cosmic rays

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    We present the design, implementation and data taking performance of the MIcrowave Detection of Air Showers (MIDAS) experiment, a large field of view imaging telescope designed to detect microwave radiation from extensive air showers induced by ultra-high energy cosmic rays. This novel technique may bring a tenfold increase in detector duty cycle when compared to the standard fluorescence technique based on detection of ultraviolet photons. The MIDAS telescope consists of a 4.5 m diameter dish with a 53-pixel receiver camera, instrumented with feed horns operating in the commercial extended C-Band (3.4 -- 4.2 GHz). A self-trigger capability is implemented in the digital electronics. The main objectives of this first prototype of the MIDAS telescope - to validate the telescope design, and to demonstrate a large detector duty cycle - were successfully accomplished in a dedicated data taking run at the University of Chicago campus prior to installation at the Pierre Auger Observatory.Comment: 13 pages, 18 figure

    A Feasibility Study on Disasters and Disaster Risk Reduction Factors Awareness of LSPU Students

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    This study determined the students' degree of awareness at Laguna State Polytechnic University (LSPU) Sta. Cruz, Laguna in terms of disaster risk reduction and its significance, which was the basis of the LSPU DRRM Center construct. This employed a descriptive- correlational study and used a purposive sampling technique. The results revealed that the respondents had experienced various types of disasters. They are slightly aware, at least, of risk reduction factors anchoring on political commitment, while they are no less than slightly aware of the particulars related to risk reduction measures. Moreover, the results of χ² Tests of Independence revealed that the awareness of Disaster Risk Reduction Factors depends on the individual's exposure to a single or a combination of natural disasters. On the contrary, the extent of awareness of those factors does not depend on the respondent's exposure or experience with global viral diseases and man-made disasters

    Influencia de grelina y leptina sobre alteraciones psiquiátricas en sujetos con obesidad

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    La obesidad (índice de masa corporal [IMC] > 30 kg/m2) se define como el exceso en la proporción del tejido adiposo; consecuencia de un ingreso calórico superior al gasto energético del individuo. Es considerada un problema inflamatorio, sistémico, crónico y recurrente que causa diversas complicaciones. Esta enfermedad se ha relacionado con diversos problemas metabólicos y fisiológicos ampliamente estudiados; además de psicopatológicos.La obesidad es un problema de salud pública en diversos países, principalmente en Norteamérica. Se ha observado que sujetos que presentan obesidad manifiestan numerosas alteraciones psiquiátricas, entre ellas: depresión, ansiedad y trastorno por atracón. Por ello, diversos estudios han llegado a la conclusión de que las hormonas gastrointestinales fungen un papel crucial en el establecimiento de conductas, siendo la orexigénica grelina y la anorexigénica leptina 2 de las hormonas con mayor participación activa. Dicha intervención se debe a que ambas hormonas presentan receptores en sistema nervioso central, primordialmente en áreas del sistema límbico, regulador crucial de conductas hedónicas. Por lo tanto, en la presente revisión bibliográfica describiremos el papel de la grelina y la leptina sobre la expresión de conductas psicopatológicas comunes en sujetos que padecen obesidad
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