13 research outputs found
El sesgo condicionado en el análisis de influencia: una revisión
El sesgo condicionado se ha propuesto como diagnóstico de influencia en distintos modelos y técnicas estadísticas. Tratando de recoger una visión global de la utilidad del concepto, en este trabajo se hace una revisión general del mismo relacionándolo con la curva de sensibilidad y la curva de influencia muestral. Además, se señalan posibles líneas de trabajo que permitirán abordar el análisis de la influencia a través de este enfoque en una gran variedad de técnicas estadísticas
H-band discovery of additional second-generation stars in the Galactic bulge globular cluster NGC 6522 as observed by APOGEE and Gaia
We present an elemental abundance analysis of high-resolution spectra for five giant stars spatially located within the innermost regions of the bulge globular cluster NGC 6522 and derive Fe, Mg, Al, C, N, O, Si, and Ce abundances based on H-band spectra taken with the multi-object APOGEE-north spectrograph from the SDSS-IV Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey. Of the five cluster candidates, two previously unremarked stars are confirmed to have second-generation (SG) abundance patterns, with the basic pattern of depletion in C and Mg simultaneous with enrichment in N and Al as seen in other SG globular cluster populations at similar metallicity. In agreement with the most recent optical studies, the NGC 6522 stars analyzed exhibit (when available) only mild overabundances of the s-process element Ce, contradicting the idea that NGC 6522 stars are formed from gas enriched by spinstars and indicating that other stellar sources such as massive AGB stars could be the primary polluters of intra-cluster medium. The peculiar abundance signatures of SG stars have been observed in our data, confirming the presence of multiple generations of stars in NGC 6522
Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2
The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality
Influence diagnostics in regression with complex designs through conditional bias
Conditional bias, influential observation, design-based regression, survey sampling, 62D05, 62J20,
Facies analysis, foraminiferal record and chronostratigraphy of Holocene sequences from Saltés Island (Tinto-Odiel estuary, SW Spain): The origin of high-energy deposits
A multidisciplinary analysis of Holocene sediments from La Cascajera (Tinto-Odiel estuary, SW Spain) has al lowed to differentiate five sedimentary facies (sandy tidal flat, clayey tidal flat, washover fan, salt marsh,
edaphic horizon), according to their granulometric characteristics, internal structure, mineralogical composi tion, clay mineral assemblage and paleontological record. These data, coupled to 14C AMS dating, suggest an
evolution from a sandy tidal plain to a chenier before 2100 cal yr BP. This initial chenier was partially eroded
later by regional storms between 2100 cal yr BP and 1900 cal yr BP, leading to the deposition of two washover
fans. These facies have been eroded in the last centuries by the action of an ebb-tide channelJunta de Andalucía CORPVS VRBIVM BAETICARVM (I) (CUB)Ministerio de Economía, Industria y Competitividad DEATLANTIR II - HAR2017-89154-
Influence diagnostics in multiple discriminant analysis
Discriminant analysis, Influence analysis, L 2 -norm, 62H30, 62H99,