86 research outputs found
Integración de impactos ecológicos causados por plantas exóticas invasoras: propuesta metodológica
Tanto en España como en Europa existen demasiadas plantas exóticas invasoras para poder afrontar la gestión de todas ellas, por lo que es necesario priorizar las más nocivas. Sin embargo, ello requiere disponer de medidas cuantitativas, sistemáticas y comparables de su impacto. La información disponible es desigual en cuanto a los criterios y variables para medir impactos y por tanto difícil de integrar. Proponemos el siguiente método para integrar medidas de impactos procedentes de distintos estudios: 1) Búsqueda de casos de estudio, 2) cálculo de tamaños del efecto; 3) clasificación de los casos por nivel de organización, 4) integración de los tamaños del efecto para cada especie y nivel de impacto con técnicas de meta-análisis, y 5) estima de un índice de fiabilidad (basado en el número de casos) y otro de consistencia (basado en la heterogeneidad entre casos). Aplicamos este método para estimar los impactos en España de tres árboles invasores (Ailanthus altissima, Robinia pseudoacacia y Ulmus pumila). Encontramos 50 casos para A. altissima, 39 para R. pseudoacacia y 15 para U. pumila. Los impactos en el nivel de ecosistema (fertilidad) fueron los más estudiados, mientras que los de comunidad e individuo están menos documentados. Robinia pseudoacacia tiende a incrementar la fertilidad, mientras que A. altissima no altera esta propiedad. La metodología propuesta tiene la ventaja de permitir estimar el impacto con datos de estudios diversos, pero su aplicación está limitada por la disponibilidad de casos de estudio
Unprecedented pathway of reducing equivalents in a diflavin-linked disulfide oxidoreductase
Flavoproteinsparticipateinawidevarietyofphysiologicallyrelevant processes that typically involve redox reactions. Within this protein superfamily, there exists a group that is able to transfer reducing equivalents from FAD to a redox-active disulfide bridge, which further reduces disulfide bridges in target proteins to regulate their structure and function. We have identified a previously undescribed type of flavin enzyme that is exclusive to oxygenic photosynthetic prokaryotes and that is based on the primary sequence that had been assigned as an NADPH-dependent thioredoxin reductase (NTR). However, our experimental data show that the protein does not transfer reducing equivalents from flavins to disulfides as in NTRs but functions in the opposite direction. High-resolution structures of the protein from Gloeobacter violaceus and Synechocystis sp. PCC6803 obtained by X-ray crystallography showed two juxtaposed FADmoleculespermonomerinredoxcommunicationwithanactive disulfide bridge in a variant of the fold adopted by NTRs. We have tentatively named the flavoprotein “DDOR” (diflavin-linked disulfide oxidoreductase) and propose that its activity is linked to a thiol-basedtransferofreducingequivalentsinbacterialmembranes. These findings expand the structural and mechanistic repertoire of flavoenzymes with oxidoreductase activity and pave the way to explore new protein engineering approaches aimed at designing redox-active proteins for diverse biotechnological applications.Spanish Ministerio de Economía, Industria y Competitividad BFU2016-80343-P, BIO2016-75634-
Ejecta Evolution Following a Planned Impact into an Asteroid: The First Five Weeks
The impact of the DART spacecraft into Dimorphos, moon of the asteroid
Didymos, changed Dimorphos' orbit substantially, largely from the ejection of
material. We present results from twelve Earth-based facilities involved in a
world-wide campaign to monitor the brightness and morphology of the ejecta in
the first 35 days after impact. After an initial brightening of ~1.4
magnitudes, we find consistent dimming rates of 0.11-0.12 magnitudes/day in the
first week, and 0.08-0.09 magnitudes/day over the entire study period. The
system returned to its pre-impact brightness 24.3-25.3 days after impact
through the primary ejecta tail remained. The dimming paused briefly eight days
after impact, near in time to the appearance of the second tail. This was
likely due to a secondary release of material after re-impact of a boulder
released in the initial impact, through movement of the primary ejecta through
the aperture likely played a role.Comment: 16 pages, 5 Figures, accepted in the Astrophysical Journal Letters
(ApJL) on October 16, 202
Ejecta Evolution Following a Planned Impact into an Asteroid: The First Five Weeks
The impact of the Double Asteroid Redirection Test spacecraft into Dimorphos, moon of the asteroid Didymos, changed Dimorphos’s orbit substantially, largely from the ejection of material. We present results from 12 Earth-based facilities involved in a world-wide campaign to monitor the brightness and morphology of the ejecta in the first 35 days after impact. After an initial brightening of ∼1.4 mag, we find consistent dimming rates of 0.11–0.12 mag day−1 in the first week, and 0.08–0.09 mag day−1 over the entire study period. The system returned to its pre-impact brightness 24.3–25.3 days after impact though the primary ejecta tail remained. The dimming paused briefly eight days after impact, near in time to the appearance of the second tail. This was likely due to a secondary release of material after re-impact of a boulder released in the initial impact, though movement of the primary ejecta through the aperture likely played a role
Identification of genetic variants associated with Huntington's disease progression: a genome-wide association study
Background Huntington's disease is caused by a CAG repeat expansion in the huntingtin gene, HTT. Age at onset has been used as a quantitative phenotype in genetic analysis looking for Huntington's disease modifiers, but is hard to define and not always available. Therefore, we aimed to generate a novel measure of disease progression and to identify genetic markers associated with this progression measure. Methods We generated a progression score on the basis of principal component analysis of prospectively acquired longitudinal changes in motor, cognitive, and imaging measures in the 218 indivduals in the TRACK-HD cohort of Huntington's disease gene mutation carriers (data collected 2008–11). We generated a parallel progression score using data from 1773 previously genotyped participants from the European Huntington's Disease Network REGISTRY study of Huntington's disease mutation carriers (data collected 2003–13). We did a genome-wide association analyses in terms of progression for 216 TRACK-HD participants and 1773 REGISTRY participants, then a meta-analysis of these results was undertaken. Findings Longitudinal motor, cognitive, and imaging scores were correlated with each other in TRACK-HD participants, justifying use of a single, cross-domain measure of disease progression in both studies. The TRACK-HD and REGISTRY progression measures were correlated with each other (r=0·674), and with age at onset (TRACK-HD, r=0·315; REGISTRY, r=0·234). The meta-analysis of progression in TRACK-HD and REGISTRY gave a genome-wide significant signal (p=1·12 × 10−10) on chromosome 5 spanning three genes: MSH3, DHFR, and MTRNR2L2. The genes in this locus were associated with progression in TRACK-HD (MSH3 p=2·94 × 10−8 DHFR p=8·37 × 10−7 MTRNR2L2 p=2·15 × 10−9) and to a lesser extent in REGISTRY (MSH3 p=9·36 × 10−4 DHFR p=8·45 × 10−4 MTRNR2L2 p=1·20 × 10−3). The lead single nucleotide polymorphism (SNP) in TRACK-HD (rs557874766) was genome-wide significant in the meta-analysis (p=1·58 × 10−8), and encodes an aminoacid change (Pro67Ala) in MSH3. In TRACK-HD, each copy of the minor allele at this SNP was associated with a 0·4 units per year (95% CI 0·16–0·66) reduction in the rate of change of the Unified Huntington's Disease Rating Scale (UHDRS) Total Motor Score, and a reduction of 0·12 units per year (95% CI 0·06–0·18) in the rate of change of UHDRS Total Functional Capacity score. These associations remained significant after adjusting for age of onset. Interpretation The multidomain progression measure in TRACK-HD was associated with a functional variant that was genome-wide significant in our meta-analysis. The association in only 216 participants implies that the progression measure is a sensitive reflection of disease burden, that the effect size at this locus is large, or both. Knockout of Msh3 reduces somatic expansion in Huntington's disease mouse models, suggesting this mechanism as an area for future therapeutic investigation
Measurement of the (eta c)(1S) production cross-section in proton-proton collisions via the decay (eta c)(1S) -> p(p)over-bar
The production of the state in proton-proton collisions is probed via its decay to the final state with the LHCb detector, in the rapidity range GeV/c. The cross-section for prompt production of mesons relative to the prompt cross-section is measured, for the first time, to be at a centre-of-mass energy TeV using data corresponding to an integrated luminosity of 0.7 fb, and at TeV using 2.0 fb. The uncertainties quoted are, in order, statistical, systematic, and that on the ratio of branching fractions of the and decays to the final state. In addition, the inclusive branching fraction of -hadron decays into mesons is measured, for the first time, to be , where the third uncertainty includes also the uncertainty on the inclusive branching fraction from -hadron decays. The difference between the and meson masses is determined to be MeV/c.The production of the state in proton-proton collisions is probed via its decay to the final state with the LHCb detector, in the rapidity range . The cross-section for prompt production of mesons relative to the prompt cross-section is measured, for the first time, to be at a centre-of-mass energy using data corresponding to an integrated luminosity of 0.7 fb , and at using 2.0 fb . The uncertainties quoted are, in order, statistical, systematic, and that on the ratio of branching fractions of the and decays to the final state. In addition, the inclusive branching fraction of -hadron decays into mesons is measured, for the first time, to be , where the third uncertainty includes also the uncertainty on the inclusive branching fraction from -hadron decays. The difference between the and meson masses is determined to be .The production of the state in proton-proton collisions is probed via its decay to the final state with the LHCb detector, in the rapidity range GeV/c. The cross-section for prompt production of mesons relative to the prompt cross-section is measured, for the first time, to be at a centre-of-mass energy TeV using data corresponding to an integrated luminosity of 0.7 fb, and at TeV using 2.0 fb. The uncertainties quoted are, in order, statistical, systematic, and that on the ratio of branching fractions of the and decays to the final state. In addition, the inclusive branching fraction of -hadron decays into mesons is measured, for the first time, to be , where the third uncertainty includes also the uncertainty on the inclusive branching fraction from -hadron decays. The difference between the and meson masses is determined to be MeV/c
A study of CP violation in B-+/- -> DK +/- and B-+/- -> D pi(+/-) decays with D -> (KSK +/-)-K-0 pi(-/+) final states
A first study of CP violation in the decay modes and , where labels a or meson and labels a or meson, is performed. The analysis uses the LHCb data set collected in collisions, corresponding to an integrated luminosity of 3 fb. The analysis is sensitive to the CP-violating CKM phase through seven observables: one charge asymmetry in each of the four modes and three ratios of the charge-integrated yields. The results are consistent with measurements of using other decay modes
Search for CP violation using T-odd correlations in D-0 -> K+K-pi(+)pi(-) decays
A search for violation using -odd correlations is performed using the four-body decay, selected from semileptonic decays. The data sample corresponds to integrated luminosities of and recorded at the centre-of-mass energies of 7 TeV and 8 TeV, respectively. The -violating asymmetry is measured to be . Searches for violation in different regions of phase space of the four-body decay, and as a function of the decay time, are also presented. No significant deviation from the conservation hypothesis is found
Measurement of CP asymmetry in B-s(0) -> D-s(-/+) K--/+ decays
We report on measurements of the time-dependent CP violating observables in decays using a dataset corresponding to 1.0 fb of pp collisions recorded with the LHCb detector. We find the CP violating observables , , , , , where the uncertainties are statistical and systematic, respectively. We use these observables to make the first measurement of the CKM angle in decays, finding = (115) modulo 180 at 68% CL, where the error contains both statistical and systematic uncertainties.We report on measurements of the time-dependent CP violating observables in B → D K decays using a dataset corresponding to 1.0 fb of pp collisions recorded with the LHCb detector. We find the CP violating observables C = 0.53±0.25±0.04, A = 0.37 ± 0.42 ± 0.20, , S = −1.09±0.33±0.08, , where the uncertainties are statistical and systematic, respectively. Using these observables together with a recent measurement of the B mixing phase −2β leads to the first extraction of the CKM angle γ from B → D K decays, finding γ = (115 )° modulo 180° at 68% CL, where the error contains both statistical and systematic uncertainties.We report on measurements of the time-dependent CP violating observables in decays using a dataset corresponding to 1.0 fb of pp collisions recorded with the LHCb detector. We find the CP violating observables , , , , , where the uncertainties are statistical and systematic, respectively. Using these observables together with a recent measurement of the mixing phase leads to the first extraction of the CKM angle from decays, finding = (115) modulo 180 at 68% CL, where the error contains both statistical and systematic uncertainties
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