49 research outputs found
Multi-messenger observations of a binary neutron star merger
On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta
Multimessenger Search for Sources of Gravitational Waves and High-Energy Neutrinos: Results for Initial LIGO-Virgo and IceCube
We report the results of a multimessenger search for coincident signals from
the LIGO and Virgo gravitational-wave observatories and the partially completed
IceCube high-energy neutrino detector, including periods of joint operation
between 2007-2010. These include parts of the 2005-2007 run and the 2009-2010
run for LIGO-Virgo, and IceCube's observation periods with 22, 59 and 79
strings. We find no significant coincident events, and use the search results
to derive upper limits on the rate of joint sources for a range of source
emission parameters. For the optimistic assumption of gravitational-wave
emission energy of \,Mc at \,Hz with \,ms duration, and high-energy neutrino emission of \,erg
comparable to the isotropic gamma-ray energy of gamma-ray bursts, we limit the
source rate below \,Mpcyr. We also examine
how combining information from gravitational waves and neutrinos will aid
discovery in the advanced gravitational-wave detector era
Searching for stochastic gravitational waves using data from the two colocated LIGO Hanford detectors
Searches for a stochastic gravitational-wave background (SGWB) using terrestrial detectors typically involve cross-correlating data from pairs of detectors. The sensitivity of such cross-correlation analyses depends, among other things, on the separation between the two detectors: the smaller the separation, the better the sensitivity. Hence, a colocated detector pair is more sensitive to a gravitational-wave background than a noncolocated detector pair. However, colocated detectors are also expected to suffer from correlated noise from instrumental and environmental effects that could contaminate the measurement of the background. Hence, methods to identify and mitigate the effects of correlated noise are necessary to achieve the potential increase in sensitivity of colocated detectors. Here we report on the first SGWB analysis using the two LIGO Hanford detectors and address the complications arising from correlated environmental noise. We apply correlated noise identification and mitigation techniques to data taken by the two LIGO Hanford detectors, H1 and H2, during LIGO’s fifth science run. At low frequencies, 40–460 Hz, we are unable to sufficiently mitigate the correlated noise to a level where we may confidently measure or bound the stochastic gravitational-wave signal. However, at high frequencies, 460–1000 Hz, these techniques are sufficient to set a 95% confidence level upper limit on the gravitational-wave energy density of Ω(f) < 7.7 × 10[superscript -4](f/900 Hz)[superscript 3], which improves on the previous upper limit by a factor of ~180. In doing so, we demonstrate techniques that will be useful for future searches using advanced detectors, where correlated noise (e.g., from global magnetic fields) may affect even widely separated detectors.National Science Foundation (U.S.)United States. National Aeronautics and Space AdministrationCarnegie TrustDavid & Lucile Packard FoundationAlfred P. Sloan Foundatio
Search for High-energy Neutrinos from Binary Neutron Star Merger GW170817 with ANTARES, IceCube, and the Pierre Auger Observatory
Polimorfismos genéticos relacionados con fenotipos de capacidad física en niños con fibrosis quística
Tesis inédita presentada en la Universidad Europea de Madrid. Facultad de Ciencias de la Actividad Física y DeporteLa fibrosis quística (FQ) es la enfermedad genética mortal con herencia autosómica recesiva más frecuente en la población caucásica, con una incidencia en la población española de ~1/5.000 nacidos vivos. Hoy en día, no existen tratamientos curativos.
La actividad física es un elemento clave en el tratamiento de los pacientes con FQ ya que se ha demostrado que el incremento de la capacidad física influye directamente sobre el estado de salud y la esperanza de vida de estos pacientes. La capacidad física en sus diversas facetas depende de múltiples factores, entre los que destaca la herencia genética, habiéndose descrito ya diferentes polimorfismos genéticos que pueden influir en la capacidad física de las personas.
En el presente trabajo se analizó, en niños y adolescentes con FQ de ambos sexos (n=66) y niños y adolescentes sanos pareado por edad y sexo (n=113), si distintos polimorfismos genéticos influyen en fenotipos indicadores de capacidad física (consumo oxígeno pico (VO2pico), volumen espirado en el 1er segundo (VEF1), capacidad vital forzada (CVF), presión inspiratoria máxima (PImax) y fuerza muscular) al estar potencialmente asociados con los siguientes rasgos fenotípicos: (I) fuerza y masa muscular, y función contráctil de las fibras musculares (ECA I/D rs1799752; AGT M235T rs699, ACTN3 R577X rs1815739; PTK2 rs7843014 y rs7460; MSTN K153R rs1805086; TRHR rs7832552; NOS3 rs2070744); y (II) metabolismo energético y biogénesis mitocondrial (PGC-1¿ G482S rs8192678 ; NRF1 rs6949152; NRF2 rs12594956; TFAM S12T rs1937; PPARD rs2267668; ACSL1 rs6552828).
No se hallaron asociaciones significativas en la mayor parte de los análisis realizados, aunque se observaron algunas asociaciones marginales entre:
(i) NOS3 rs2070744 con VO2pico y VEF1, PTK2 rs7843014 con PImax y PImax/CFV, y PGC-1¿ rs8192678 con VEF1, en niños con FQ;
(ii) ACTN3 rs1815739 con VO2pico, NOS3 rs2070744 con VO2pico, y NRF2 rs12594956 con fuerza total en niños sanos.
Entre los resultados más interesantes destaca la asociación positiva, en los niños con FQ, entre un perfil poligénico teóricamente `optimo¿ para la resistencia, utilizando el método del `Total genotype score¿, y la pertenencia al decil superior del grupo según los datos de VO2pico, PImax y CVF. Estas asociaciones deberían ser objeto de investigaciones adicionales para poder extraer conclusiones sólidas. [Resumen Teseo]UE
Efecto del polimorfismo Val66Met del BDNF en el rendimiento académico y cognitivo en adolescentes y posible papel modular de la actividad física (Estudio UP&DOWN)
Introducción: El gen del factor neurotrófico derivado del cerebro (BDNF) modula la función cerebral mientras la presencia del alelo Met en los polimorfismos Val66Met y Met66Met afecta a su función (Baj et al.,2013). La inducción de BDNF mediante la práctica de actividad física es un potente modulador positivo de la función cerebral (Cotman y Berchtold, 2002). Objetivos: Analizar el efecto de los polimorfismos de BDNF sobre el rendimiento académico y la función cognitiva en adolescentes y el posible efecto modulador de la actividad física. Metodología: 846 adolescentes (13-20 años; 15,31±1,51; 48% mujeres) pertenecientes al estudio UP&DOWM fueron incluidos. Durante 3 años se evaluó los niveles de actividad física/sedentarismo por acelerometría y rendimiento académico con las calificaciones escolares. La cognición fue valorada con test informatizados de inhibición cognitiva y memoria de trabajo. Los SNPs del gen BDNF (rs6265) se analizaron mediante sondas Taqman (C_11592758_10) en RT-PCR StepOne™ (Life Technologies). Resultados: : El 63.5% de los sujetos fueron homocigotos Val/Val (sin mutación), el 31.4% heterocigotos Val/Met (un alelo mutado) y el 4.6% de los adolescentes presentaron homocigosis Met/Met (ambos alelos mutados). No se observaron diferencias estadísticamente significativas (p>0,05) entre los valores de notas académicas en función del genotipo de BDNF. Los resultados de los test cognitivos tampoco mostraron diferencias estadísticamente significativas (p>0,05) en función del genotipo de BDNF. Conclusiones: Este estudio no encontró diferencias significativas en las notas académicas o en los resultados de los test cognitivos en función del genotipo de BDNF en adolescentes. A pesar de este hecho, son necesarios más estudios que nos permitan descartar su influencia en adolescentes, además de explorar el efecto podría tener la actividad física como efecto moduladorSin financiaciónNo data WoSNo data Scopus12.000 SPI – ICEE (2018), 93/104 General – Editoriales españolasUE
Is the PPARGC1A RS 8192678 polymorphism, a genetic marker of physical performance and fitness, a risk factor for the colorectal cancer development in women?
INTRODUCTION: Exercise is one of the main mitochondrial regulation factors. The number of mitochondria can increase by 50-100%
depending on the training program, improving the energy production capacity of the organism, thus, improving global health. Besides,
several genetic polymorphisms in the nuclear genes related to the PPARGC1A-NRF-TFAM mitochondrial biogenesis pathway have been
found to correlate with the elite athlete status and with other markers of physical performance and fitness. In addition, several authors have shown that alterations in mitochondrial biogenesis of tumor cells could be risk factors for cancer progression. Thus, the aim of this study is to analyze the frequency of the main genetic polymorphisms involved in these mitochondrial biogenesis pathways in samples of healthy women and women with colorectal cancer.
METHODS: We analyzed 84 DNA samples from tumors of women with colorectal cancer (group 1) and 449 DNA samples from peripheral
blood of healthy women as control group (group 2) paired by age with group 1. All the samples were ceded by the Spanish National DNA
Bank Carlos III (BNADN) and donated voluntarily after informed consent signature. The genetic polymorphisms rs2267668, rs8192678,
rs6949152, rs12594956 and rs1937 of the genes PPARD, PPARGC1A, NRF1, NRF2 y TFAM, respectively, were analyzed by Q-PCR with a StepOne equipment (Life Technologies) with Taqman probes pre-designed for Life Technologies.
RESULTS: All the genetic polymorphisms (rs2267668, rs8192678, rs6949152, rs12594956 and rs1937) satisfied the Hardy-Weinberg equilibrium (p>0,05), except for the NRF-1 rs6949152 polymorphism in colorectal cancer (p=0.044). No significant differences were found between the genotypic frequencies of the control group and the colorectal cancer group, except for PPARGC1A and NRF-1 (p=0.035 and p=0.023, respectively). Furthermore, comparing the two groups for the TT genotype frequencies vs. CT and CC genotypes requencies of the PPARGC1A rs8192678 polymorphism, we found that having the TT genotype increase 1.9 times the probability to develop colorectal cancer (OR 95% CI=1.905; 3.598-1.008).
CONCLUSION: The presence of the T allele in homozygosis of the PPARGC1A rs8192678 polymorphism may represent a risk factor for the
colorectal cancer development. Our results highlight the possible important role of the mitochondrial biogenesis in the development of
this kind of cancer. Taking into account that mitochondrial biogenesis is strongly increased by physical exercise, we suggest that it is necessary to further study: i) the role of mitochondrial biogenesis in cancer development and ii) the protective role that physical exercise may play against cancer through the stimulation of mitochondrial activity.Universidad Europea (Ref. 2016/UEM12)No data 2018UE
Mitochondriogenesis genes and extreme longevity
Genes of the proliferator-activated receptor delta (PPARD)-peroxisome proliferator-activated receptor γ coactivator 1α (PPARGC1A, also termed PGC1-α)-nuclear respiratory factor (NRF)-mitochondrial transcription Factor A (TFAM) mitochondriogenesis pathway can influence health/disease phenotypes, yet their association with extreme longevity is not known. We studied the association of five common polymorphisms in genes of this pathway (rs2267668, rs8192678, rs6949152, rs12594956, rs1937) and extreme longevity using a case (107 centenarians)-control (284 young adults) design. We found no between-group differences in allele/genotype frequencies, except for CC genotype in rs1937 (p=0.003), with no representation in controls (0%), versus 2.8% in centenarians (2 men, 1 woman). In summary, the studied genetic variants of the PPARD-PPARGC1A-NRF-TFAM pathway were not associated with extreme longevity, yet a marginal association could exist for rs1937.3.931 JCR (2013) Q1, 7/49 Geriatrics & gerontologyUE
MSTN K153R polymorphism as candidate gene to influence extreme longevity in spanish centenarian women
El gen de la miostatina (MSTN) es uno de los genes candidatos que podría influir en la longevidad extrema, debido a su papel en la modulación de masa muscular y sarcopenia, además de su papel en la inhibición de la principal vía de señalización de nutrientes relacionada con la longevidad, mTOR (del inglés, ‘mammalian target-of-rapamycin’). Comparamos la distribución alélica/genotípica de las variantes exónicas de la MSTN K153R (rs1805086), E164K (rs35781413), I225T y P198A, en centenarias (casos, n=132; rango edad: 100-107) y mujeres jóvenes (controles, n=167, < 50 años). La frecuencia de la variante alélica R y de los portadores de este la misma (genotipos KR o RR) fue significativamente superior en centenarias (6.8% y 12.1%) que en controles (1.5% y 3.8%) (p=0.0008 y p=0.0022 respectivamente). La razón de verosimilitud (‘odds ratio’, abreviado ‘OR’) de ser un centenaria si el sujeto tiene un alelo-R fue 4.47 (con un intervalo de confianza del 95% (CI): 1.59-12.54; p=0.004), comparado con el grupo control. Aunque son necesarias nuevas investigaciones, el alelo variante R del polimorfismo MSTN K153R podría ser uno de los contribuidores genéticos asociados con excepcional longevidad.The myostatin (MSTN) gene is a candidate to influence extreme longevity owing to its role in modulating muscle mass and sarcopenia, and especially in inhibiting the main nutrient-sensing pathway involved in longevity, i.e. mTOR (mammalian target-of-rapamycin). We compared allele/genotype distributions of the exonic MSTN variants K153R (rs1805086), E164K (rs35781413), I225T and P198A, in women centenarians (cases, n=132; age range: 100-107 years) and younger women adults (controls, n=167; age < 50 years). The frequency of the variant R-allele and of R-allele carriers was significantly higher in centenarians (6.8% and 12.1%) than in controls (1.5% and 3.8%) (p=0.0008 and p=0.0022 respectively). The odds ratio (OR) of being a centenarian if the subject had the R allele was 4.47 (95% confidence interval (CI): 1.59-12.54 p=0.004), compared to the control group. Although more research is needed, the variant allele of the MSTN K153R polymorphism could be among the genetic contributors associated with exceptional longevity.Sin financiaciónNo data 2014UE