kHz Quasi Periodic Oscillations in Low Mass X-ray Binaries as Probes of General Relativity in the Strong Field Regime

We consider the interpretation of a pair of kHz Quasi Periodic Oscillations (QPOs) in the Fourier spectra of two Low Mass X-Ray Binaries, Sco X-1 and 4U1608-52, hosting an old accreting neutron star. The observed frequency difference of these QPOs decreaseas as their frequency increases, contrary to simple beat frequency models, which predict a constant frequency difference. We show that the behaviour of these QPOs is instead well matched in terms of the fundamental frequencies (in the radial and azimuthal directions) for test particle motion in the gravitational field of the neutron star, for reasonable star masses, and nearly independent of the star spin. The radial frequency must be much smaller than the azimuthal one, testifying that kHz QPOs are produced close to the innermost stable orbit. These results are not reproduced through the post--Newtonian (PN) approximation of General Relativity (GR). kHz QPOs from X-ray binaries likely provide an accurate laboratory for strong field GR.Comment: to appear in Physical Review Letters, PRL Latex plus 2 figures in standard PostScript forma

The physical parameters, excitation and chemistry of the rim, jets and knots of the planetary nebula NGC 7009

We present long-slit optical spectra along the major axis of the planetary nebula NGC 7009. These data allow us to discuss the physical, excitation and chemical properties of all the morphological components of the nebula, including its remarkable systems of knots and jets. The main results of this analysis are the following: i) the electron temperature throughout the nebula is remarkably constant, T_e[OIII] = 10200K; ii) the bright inner rim and inner pair of knots have similar densities of N_e = 6000cm^{-3}, whereas a much lower density of N_e = 1500cm^{-3} is derived for the outer knots as well as for the jets; iii) all the regions (rim, inner knots, jets and outer knots) are mainly radiatively excited; and iv) there are no clear abundance changes across the nebula for He, O, Ne, or S. There is a marginal evidence for an overabundance of nitrogen in the outer knots (ansae), but the inner ones (caps) and the rim have similar N/H values that are at variance with previous results. Our data are compared to the predictions of theoretical models, from which we conclude that the knots at the head of the jets are not matter accumulated during the jet expansion through the circumstellar medium, neither can their origin be explained by the proposed HD or MHD interacting-wind models for the formation of jets/ansae, since the densities as well as the main excitation mechanisms of the knots, disagree with model predictions.Comment: Figure 1 was changed because features were misidentified in the previous version. 17 pages including 5 figures and 3 tables. ApJ in press. Also available at http://www.iac.es/galeria/denise

Factores asociados a seropositividad para SARS-CoV-2 en pacientes atendidos en un hospital de zona altoandina peruana

Background: COVID 19 is an infectious disease caused by SARS-CoV-2 that has affected Peru on a large scale. Potential clinical and/or epidemiological factors that are related to the positivity of SARS-CoV-2 in the high Andean population are not documented. Objective: To determine factors associated with positivity of SARS-CoV-2 in people living in Ancash. Material and methods: Analytical transversal study. We used the records of patients treated for suspected COVID-19 in a public hospital in Huaraz in March-May 2020. Prevalence ratios (PR) with confidence intervals were estimated. In simple regression analysis, prevalence ratios and 95% confidence intervals were estimated, using Poisson distribution family, log-link function and robust variance. Results: Out of 903 patients, 13.7% tested positive for SARS-CoV-2. In simple regression, male (RP=2.98), cough (RP=2.27), respiratory distress (RP=2.97), diarrhea (RP=2.69), general malaise (RP=1.82), odynophagia (RP=1.69) were positively associated with having a positive SARS-CoV-2 test. In the multiple regressions, the association was maintained in four characteristics: being male (RP=2.7), having a cough (RP=1.45), respiratory distress (RP=2.15), and diarrhea (RP=1.89). Conclusion: In high Andean areas, most positive cases present typical symptoms. The factors associated with positivity were male sex and the presence of cough, respiratory difficulty and diarrhea.Introducción: El COVID 19 es una enfermedad infecciosa causada por el SARS-CoV-2 que ha afectado en gran escala al Perú. No están documentados los potenciales factores clínicos y/o epidemiológicos que están relacionados a la positividad de SARS-CoV-2 en población altoandina. Objetivo: Determinar los factores asociados a positividad de SARS-Cov-2 en personas que viven en Ancash. Material y métodos: Estudio transversal analítico. Se utilizaron los registros de pacientes atendidos por sospecha de COVID-19 en un hospital público de Huaraz en marzo-mayo 2020. Se estimaron razones de prevalencia (RP) con intervalos de confianza. En el análisis de regresión simple, se estimaron razones de prevalencia e intervalos de confianza al 95%, utilizando familia de distribución Poisson, función de enlace log y varianza robusta Resultados: De 903 pacientes, 13,7% pacientes resultaron positivos a SARS-CoV-2. En la regresión simple, resultó que el sexo masculino (RP=2,98), presentar tos (RP=2,27), dificultad respiratoria (RP=2,97), diarrea (RP=2,69), malestar general (RP=1,82), odinofagia (RP=1,69) se asociaron positivamente a tener prueba SARS-CoV-2 positiva. En la regresión múltiple se mantuvo la asociación en cuatro características: ser varón (RP=2,7), presentar tos (RP=1,45), dificultad respiratoria (RP=2,15) y diarrea (RP=1,89). Conclusión: En zona altoandina, los casos positivos en su mayoría presentan síntomas típicos. Los factores asociados a la positividad fueron el sexo masculino y la presencia de dificultad tos, respiratoria y diarrea

Single versus tandem autologous stem-cell transplantation in patients with newly diagnosed multiple myeloma and high-risk cytogenetics. A retrospective, open-label study of the PETHEMA/Spanish Myeloma Group (GEM)

Tandem ASCT has been suggested as a valid approach to improve the prognosis of patients with MM and HR cytogenetic. In this observational, retrospective study, 213 patients with newly diagnosed MM and HR cytogenetic in 35 hospitals from the Spanish Myeloma Group underwent single or tandem ASCT between January 2015 and December 2019 after induction with VTD/VRD. HR cytogenetic was defined as having ≥1 of the following: del17p, t(4;14), t(14;16) or gain 1q21. More patients in the tandem group had R-ISS 3 and >1 cytogenetic abnormality at diagnosis. With a median follow-up of 31 months (range, 10–82), PFS after single ASCT was 41 months versus 48 months with tandem ASCT (p = 0.33). PFS in patients with del17p undergoing single ASCT was 41 months, while 52% of patients undergoing tandem ASCT were alive and disease free at 48 months. In conclusion, tandem ASCT partly overcomes the bad prognosis of HR cytogenetic

P1‐349: Advancing Clinical And Biomarker Research In Ad: The Lead Study

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152716/1/alzjjalz201906904.pd

A Multiancestral Genome-Wide Exome Array Study of Alzheimer Disease, Frontotemporal Dementia, and Progressive Supranuclear Palsy

Importance Previous studies have indicated a heritable component of the etiology of neurodegenerative diseases such as Alzheimer disease (AD), frontotemporal dementia (FTD), and progressive supranuclear palsy (PSP). However, few have examined the contribution of low-frequency coding variants on a genome-wide level. Objective To identify low-frequency coding variants that affect susceptibility to AD, FTD, and PSP. Design, Setting, and Participants We used the Illumina HumanExome BeadChip array to genotype a large number of variants (most of which are low-frequency coding variants) in a cohort of patients with neurodegenerative disease (224 with AD, 168 with FTD, and 48 with PSP) and in 224 control individuals without dementia enrolled between 2005-2012 from multiple centers participating in the Genetic Investigation in Frontotemporal Dementia and Alzheimer’s Disease (GIFT) Study. An additional multiancestral replication cohort of 240 patients with AD and 240 controls without dementia was used to validate suggestive findings. Variant-level association testing and gene-based testing were performed. Main Outcomes and Measures Statistical association of genetic variants with clinical diagnosis of AD, FTD, and PSP. Results Genetic variants typed by the exome array explained 44%, 53%, and 57% of the total phenotypic variance of AD, FTD, and PSP, respectively. An association with the known AD gene ABCA7 was replicated in several ancestries (discovery P = .0049, European P = .041, African American P = .043, and Asian P = .027), suggesting that exonic variants within this gene modify AD susceptibility. In addition, 2 suggestive candidate genes, DYSF (P = 5.53 × 10−5) and PAXIP1 (P = 2.26 × 10−4), were highlighted in patients with AD and differentially expressed in AD brain. Corroborating evidence from other exome array studies and gene expression data points toward potential involvement of these genes in the pathogenesis of AD. Conclusions and Relevance Low-frequency coding variants with intermediate effect size may account for a significant fraction of the genetic susceptibility to AD and FTD. Furthermore, we found evidence that coding variants in the known susceptibility gene ABCA7, as well as candidate genes DYSF and PAXIP1, confer risk for AD

Consensus classification of posterior cortical atrophy

INTRODUCTION: A classification framework for posterior cortical atrophy (PCA) is proposed to improve the uniformity of definition of the syndrome in a variety of research settings. METHODS: Consensus statements about PCA were developed through a detailed literature review, the formation of an international multidisciplinary working party which convened on four occasions, and a Web-based quantitative survey regarding symptom frequency and the conceptualization of PCA. RESULTS: A three-level classification framework for PCA is described comprising both syndrome- and disease-level descriptions. Classification level 1 (PCA) defines the core clinical, cognitive, and neuroimaging features and exclusion criteria of the clinico-radiological syndrome. Classification level 2 (PCA-pure, PCA-plus) establishes whether, in addition to the core PCA syndrome, the core features of any other neurodegenerative syndromes are present. Classification level 3 (PCA attributable to AD [PCA-AD], Lewy body disease [PCA-LBD], corticobasal degeneration [PCA-CBD], prion disease [PCA-prion]) provides a more formal determination of the underlying cause of the PCA syndrome, based on available pathophysiological biomarker evidence. The issue of additional syndrome-level descriptors is discussed in relation to the challenges of defining stages of syndrome severity and characterizing phenotypic heterogeneity within the PCA spectrum. DISCUSSION: There was strong agreement regarding the definition of the core clinico-radiological syndrome, meaning that the current consensus statement should be regarded as a refinement, development, and extension of previous single-center PCA criteria rather than any wholesale alteration or redescription of the syndrome. The framework and terminology may facilitate the interpretation of research data across studies, be applicable across a broad range of research scenarios (e.g., behavioral interventions, pharmacological trials), and provide a foundation for future collaborative work

Quantum gravity phenomenology at the dawn of the multi-messenger era-A review

The exploration of the universe has recently entered a new era thanks to the multi-messenger paradigm, characterized by a continuous increase in the quantity and quality of experimental data that is obtained by the detection of the various cosmic messengers (photons, neutrinos, cosmic rays and gravitational waves) from numerous origins. They give us information about their sources in the universe and the properties of the intergalactic medium. Moreover, multi-messenger astronomy opens up the possibility to search for phenomenological signatures of quantum gravity. On the one hand, the most energetic events allow us to test our physical theories at energy regimes which are not directly accessible in accelerators; on the other hand, tiny effects in the propagation of very high energy particles could be amplified by cosmological distances. After decades of merely theoretical investigations, the possibility of obtaining phenomenological indications of Planck-scale effects is a revolutionary step in the quest for a quantum theory of gravity, but it requires cooperation between different communities of physicists (both theoretical and experimental). This review, prepared within the COST Action CA18108 "Quantum gravity phenomenology in the multi-messenger approach", is aimed at promoting this cooperation by giving a state-of-the art account of the interdisciplinary expertise that is needed in the effective search of quantum gravity footprints in the production, propagation and detection of cosmic messengers. (C) 2022 The Authors. Published by Elsevier B.V.Peer reviewe