Search results for "Gamma"
showing 10 items of 3093 documents
Smad7 controls resistance of colitogenic T cells to regulatory T cell-mediated suppression.
2008
Background & Aims Foxp3-expressing regulatory T cells (Tregs) play a key role in the maintenance of the gut immune homeostasis, and an intact transforming growth factor (TGF)-β signaling is required for their function. In inflammatory bowel disease (IBD), the TGF-β signaling is impaired because of high expression of the inhibitory molecule Smad7. Although no intrinsic defects in Tregs function have been shown in IBD, it is still unknown whether colitogenic T cells are susceptible to Treg-mediated suppression. In this study, we have investigated whether IBD mucosal CD4+ T cells are resistant to Tregs and whether Smad7 is involved in this process. Methods IBD lamina propria mononuclear cells …
Efecto de la activación del receptor PPARγ/RxR como posible tratamiento de la Enfermedad de Alzheimer. Papel de la genisteína
2020
La enfermedad de Alzheimer (EA) es una forma de demencia que empeora gradualmente con el tiempo y afecta de forma negativa a las funciones cognitivas. El tratamiento actual consiste en inhibidores de la acetilcolinesterasa y un antagonista NMDA. A pesar de que nunca hasta ahora se había dispuesto de un arsenal terapéutico en investigación tan amplio y variado frente a la EA, no se puede decir que sea efectivo. La enfermedad de Alzheimer conlleva un enorme gasto sanitario y social que se agrava con el envejecimiento de la población y el aumento de la prevalencia que este conlleva. En la presente tesis nos planteamos la administración de genisteína en fases iniciales de la enfermedad, buscand…
New constraints on the Al25(p,γ) reaction and its influence on the flux of cosmic γ rays from classical nova explosions
2021
The astrophysical 25Al(p,γ)26Si reaction represents one of the key remaining uncertainties in accurately modeling the abundance of radiogenic 26Al ejected from classical novae. Specifically, the strengths of key proton-unbound resonances in 26Si, that govern the rate of the 25Al(p,γ) reaction under explosive astrophysical conditions, remain unsettled. Here, we present a detailed spectroscopy study of the 26Si mirror nucleus 26Mg. We have measured the lifetime of the 3+, 6.125-MeV state in 26Mg to be 19(3)fs and provide compelling evidence for the existence of a 1− state in the T=1,A=26 system, indicating a previously unaccounted for ℓ=1 resonance in the 25Al(p,γ) reaction. Using the present…
Revised decay properties of the key 93-keV resonance in the 25Mg(p,γ) reaction and its influence on the MgAl cycle in astrophysical environments
2022
The γ-decay properties of an excited state in 26Al at 6398.3(8) keV have been reexamined using the 11B+16O fusion-evaporation reaction. This level represents a key 93.1(8)-keV resonance in the 25Mg+p system and its relative branching to the 26Al ground state, f0, has been determined to be 0.76±0.03 (stat.) ±0.10 (syst.). This is a significantly higher value than the most recent evaluation and implies a considerable increase in the production of cosmic γ rays from 26Al radioactivity. peerReviewed
Development of imaging techniques in gamma-ray astronomy using coded mask systems : application to the telescope LEGRI = Desarrollo de técnicas de ob…
1996
En el rango de energías de la radiación gamma no es posible usar lentes o espejos para formar imágenes; por tanto es necesario usar otros sistemas. Una solución al problema son los telescopios de mascara codificada que consisten en un plano detector y un patrón de elementos transparentes y opacos antepuesto a el. Lo que detectamos es la sombra que producen las diferentes fuentes gamma del patrón de la mascara en el plano detector. A partir de ello, y conocido el patrón que produce las sombras (la mascara), reconstruimos el campo de fuentes. En este trabajo, y aplicado al telescopio LEGRI, se han estudiado cuatro algoritmos de reconstrucción de las fuentes (correlación balanceada de muestreo…
The Origins of Northern European Autographa Gamma Individuals Evaluated Using Hydrogen Stable Isotopes
2018
1. Many insect species are migratory. As the spring progresses, adults gradually depart from their over‐wintering habitats and arrive in northern zones where they reproduce during the summer. Understanding this transgenerational and highly adaptive migratory behaviour is crucial when interpreting life cycle dynamics of many insect pests. 2. Origins of migratory silver Y moths, Autographa gamma (Linnaeus, 1758), captured from Finland, were studied with stable hydrogen analysis of their wings (δ2Hw). 3. The difference between spring and autumn generation δ2Hw values indicate different geographical natal origins. The probability surface map shows that the spring generation probably emerged in …
Gamma Oscillations in the Temporal Pole Reflect the Contribution of Approach and Avoidance Motivational Systems to the Processing of Fear and Anger W…
2022
Prior reports suggest that affective effects in visual word processing cannot be fully explained by a dimensional perspective of emotions based on valence and arousal. In the current study, we focused on the contribution of approach and avoidance motivational systems that are related to different action components to the processing of emotional words. To this aim, we compared frontal alpha asymmetries and brain oscillations elicited by anger words associated with approach (fighting) motivational tendencies, and fear words that may trigger either avoidance (escaping), approach (fighting) or no (freezing) action tendencies. The participants’ task was to make decisions about approaching or dis…
Neutrinos below 100 TeV from the southern sky employing refined veto techniques to IceCube data
2020
Many Galactic sources of gamma rays, such as supernova remnants, are expected to produce neutrinos with a typical energy cutoff well below 100 TeV. For the IceCube Neutrino Observatory located at the South Pole, the southern sky, containing the inner part of the Galactic plane and the Galactic Center, is a particularly challenging region at these energies, because of the large background of atmospheric muons. In this paper, we present recent advancements in data selection strategies for track-like muon neutrino events with energies below 100 TeV from the southern sky. The strategies utilize the outer detector regions as veto and features of the signal pattern to reduce the background of atm…
Tempo and mode of early gene loss in endosymbiotic bacteria from insects
2006
Abstract Background Understanding evolutionary processes that drive genome reduction requires determining the tempo (rate) and the mode (size and types of deletions) of gene losses. In this study, we analysed five endosymbiotic genome sequences of the gamma-proteobacteria (three different Buchnera aphidicola strains, Wigglesworthia glossinidia, Blochmannia floridanus) to test if gene loss could be driven by the selective importance of genes. We used a parsimony method to reconstruct a minimal ancestral genome of insect endosymbionts and quantified gene loss along the branches of the phylogenetic tree. To evaluate the selective or functional importance of genes, we used a parameter that meas…
Shaping the antipredator strategy: flexibility, consistency, and behavioral correlations under varying predation threat
2014
9 pages; International audience; Recent ecological and evolutionary research emphasizes the importance of adaptive trait integration. For instance, antipredator defenses are built up of several morphological and behavioral components in many species, yet their functional relationships are still poorly documented. Using field-collected freshwater crustaceans Gammarus fossarum in a within-subject design, we investigated the flexibility and consistency of refuge use, photophobia, and exploration behavior as well as their associations, quantified both when predation risk was absent or artificially simulated. In agreement with the "threat-sensitivity" hypothesis, both refuge use and photophobia …