The correlations between optical variability and physical parameters of quasars in SDSS Stripe 82

We investigate the optical variability of 7658 quasars from SDSS Stripe 82. Taking advantage of a larger sample and relatively more data points for each quasar, we estimate variability amplitudes and divide the sample into small bins of redshift, rest-frame wavelength, black hole mass, Eddington ratio and bolometric luminosity respectively, to investigate the relationships between variability and these parameters. An anti-correlation between variability and rest-frame wavelength is found. The variability amplitude of radio-quiet quasars shows almost no cosmological evolution, but that of radio-loud ones may weakly anti-correlate with redshift. In addition, variability increases as either luminosity or Eddington ratio decreases. However, the relationship between variability and black hole mass is uncertain; it is negative when the influence of Eddington ratio is excluded, but positive when the influence of luminosity is excluded. The intrinsic distribution of variability amplitudes for radio-loud and radio-quiet quasars are different. Both radio-loud and radio-quiet quasars exhibit a bluer-when-brighter chromatism. Assuming that quasar variability is caused by variations of accretion rate, the Shakura-Sunyaev disk model can reproduce the tendencies of observed correlations between variability and rest-frame wavelength, luminosity as well as Eddington ratio, supporting that changes of accretion rate plays an important role in producing the observed optical variability. However, the predicted positive correlation between variability and black hole mass seems to be inconsistent with the observed negative correlation between them in small bins of Eddington ratio, which suggests that other physical mechanisms may still need to be considered in modifying the simple accretion disk model.Comment: 51 pages, 28 figures, 2 tables, ApJ accepte

Measuring Lensing Magnification of Quasars by Large Scale Structure using the Variability-Luminosity Relation

We introduce a technique to measure gravitational lensing magnification using the variability of type I quasars. Quasars' variability amplitudes and luminosities are tightly correlated, on average. Magnification due to gravitational lensing increases the quasars' apparent luminosity, while leaving the variability amplitude unchanged. Therefore, the mean magnification of an ensemble of quasars can be measured through the mean shift in the variability-luminosity relation. As a proof of principle, we use this technique to measure the magnification of quasars spectroscopically identified in the Sloan Digital Sky Survey, due to gravitational lensing by galaxy clusters in the SDSS MaxBCG catalog. The Palomar-QUEST Variability Survey, reduced using the DeepSky pipeline, provides variability data for the sources. We measure the average quasar magnification as a function of scaled distance (r/R200) from the nearest cluster; our measurements are consistent with expectations assuming NFW cluster profiles, particularly after accounting for the known uncertainty in the clusters' centers. Variability-based lensing measurements are a valuable complement to shape-based techniques because their systematic errors are very different, and also because the variability measurements are amenable to photometric errors of a few percent and to depths seen in current wide-field surveys. Given the data volume expected from current and upcoming surveys, this new technique has the potential to be competitive with weak lensing shear measurements of large scale structure.Comment: Accepted for publication in Ap

Theory of mind in children with attention deficit hyperactivity disorder

Introduction. Theory of mind (TM) is involved in social cognition, as it evaluates our ability to impute our mental states to the others in order to predict and explain behaviour. In the literature, it has been noticed that children with attention deficit hyperactivity disorder (ADHD) show some impairments of TM when compared with children not neurodevelopmental impaired. Our goal in this study was to compare the TM in two groups: schooler children with normal development and schooler children with ADHD. Subjects and methods. A total of 35 children, aged between 6 and 12 years, were recruited: 17 with ADHD and 18 not neurodevelopmental impaired. TM was evaluated using an assessment method validated for the Portuguese population: Turtle on the Island-Battery of Assessment of Executive Functions in Children. Results. We obtained two comparable groups concerning sociodemographic data. There were no significant differences between the two groups regarding TM. Conclusion. The TM assessment in Portuguese children did not reveal significant impairment regarding this cognitive skill in children with ADHD

Nowhere safe? Exploring the influence of urbanization across mainland and insular seashores in continental Portugal and the Azorean Archipelago

Differences in the structure and functioning of intensively urbanized vs. less human-affected systems are reported, but such evidence is available for amuch larger extent in terrestrial than in marine systems.Weexamined the hypotheses that (i) urbanization was associated to different patterns of variation of intertidal assemblages between urban and extra-urban environments; (ii) such patterns were consistent acrossmainland and insular systems, spatial scales from 10s cm to 100s km, and a three months period. Several trends emerged: (i) a more homogeneous distribution of most algal groups in the urban compared to the extra-urban condition and the opposite pattern of most invertebrates; (ii) smaller/larger variances of most organisms where these were, respectively, less/more abundant; (iii) largest variability of most response variables at small scale; (iv) no facilitation of invasive species by urbanization and larger cover of canopy-forming algae in the insular extra-urban condition. Present findings confirmthe acknowledged notion that futuremanagement strategieswill require to include representative assemblages and their relevant scales of variation associated to urbanization gradients on both the mainland and the islands

A Close Nuclear Black Hole Pair in the Spiral Galaxy NGC 3393

The current picture of galaxy evolution advocates co-evolution of galaxies and their nuclear massive black holes (MBHs), through accretion and merging. Quasar pairs (6,000-300,000 light-years separation) exemplify the first stages of this gravitational interaction. The final stages, through binary MBHs and final collapse with gravitational wave emission, are consistent with the sub-light-year separation MBHs inferred from optical spectra and light-variability of two quasars. The double active nuclei of few nearby galaxies with disrupted morphology and intense star formation (e.g., NGC 6240 and Mkn 463; ~2,400 and ~12,000 light-years separation respectively) demonstrate the importance of major mergers of equal mass spirals in this evolution, leading to an elliptical galaxy, as in the case of the double radio nucleus (~15 light-years separation) elliptical 0402+379. Minor mergers of galaxies with a smaller companion should be a more common occurrence, evolving into spiral galaxies with active MBH pairs, but have hitherto not been seen. Here we report the presence of two active MBHs, separated by ~430 light-years, in the Seyfert galaxy NGC 3393. The regular spiral morphology and predominantly old circum-nuclear stellar population of this galaxy, and the closeness of the MBHs embedded in the bulge, suggest the result of minor merger evolution.Comment: Preprint (not final) version of a paper to appear in Natur

Serum amyloid A proteins reduce bone mass during mycobacterial infections

IntroductionOsteopenia has been associated to several inflammatory conditions, including mycobacterial infections. How mycobacteria cause bone loss remains elusive, but direct bone infection may not be required. MethodsGenetically engineered mice and morphometric, transcriptomic, and functional analyses were used. Additionally, inflammatory mediators and bone turnover markers were measured in the serum of healthy controls, individuals with latent tuberculosis and patients with active tuberculosis. Results and discussionWe found that infection with Mycobacterium avium impacts bone turnover by decreasing bone formation and increasing bone resorption, in an IFN gamma- and TNF alpha-dependent manner. IFN gamma produced during infection enhanced macrophage TNF alpha secretion, which in turn increased the production of serum amyloid A (SAA) 3. Saa3 expression was upregulated in the bone of both M. avium- and M. tuberculosis-infected mice and SAA1 and 2 proteins (that share a high homology with murine SAA3 protein) were increased in the serum of patients with active tuberculosis. Furthermore, the increased SAA levels seen in active tuberculosis patients correlated with altered serum bone turnover markers. Additionally, human SAA proteins impaired bone matrix deposition and increased osteoclastogenesis in vitro. Overall, we report a novel crosstalk between the cytokine-SAA network operating in macrophages and bone homeostasis. These findings contribute to a better understanding of the mechanisms of bone loss during infection and open the way to pharmacological intervention. Additionally, our data and disclose SAA proteins as potential biomarkers of bone loss during infection by mycobacteria.This article is a result of the project HEALTH-UNORTE: Setting-up biobanks and regenerative medicine strategies to boost research in cardiovascular, musculoskeletal, neurological, oncological, immunological and infectious diseases (NORTE-01-0145-FEDER-000039), supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). This work was supported by KOG-202108-00929 from the European Haematology Society, awarded to AG. Work in the MS lab was financed by FEDER - Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020 - Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by Portuguese funds through FCT - Fundacao para a Ciencia e a Tecnologia/Ministerio da Ciencia, Tecnologia e Ensino Superior in the framework of the project POCI-01-0145-FEDER-028955 (PTDC/SAU-INF/28955/2017). AG and MS are supported by an Individual Scientific Employment contract (CEECIND/00048/2017; CEECIND/00241/2017 respectively). DS acknowledges the Portuguese Foundation for Science and Technology (FCT) for the Post-Doc fellowship (SFRH/BPD/115341/2016). RP, DS and AF have PhD grants (SFRH/BD/145217/2019; SFRH/BD/143536/2019; 2020.05949.BD, respectively) financed by FCT

A reduction method for semi-infinite programming by means of a global stochastic approach

We describe a reduction algorithm for solving semi-infinite programming problems. The proposed algorithm uses the simulated annealing method equipped with a function stretching as a multi-local procedure, and a penalty technique for the finite optimization process. An exponential penalty merit function is reduced along each search direction to ensure convergence from any starting point. Our preliminary numerical results seem to show that the algorithm is very promising in practice.Algoritmi Research CenterFundação para a Ciência e a Tecnologia (FCT) - bolsa POCI/MAT/58957/200

Orodispersible tablets: therapeutic and technological advantages of development

Los comprimidos bucodispersables se definen como comprimidos no recubiertos destinados a ser colocados en la boca, donde se dispersan rápidamente antes de ser tragados. Estas formulaciones son conocidas por las siglas FDDT´s (Fast Dissolving Disintegrating Tablets). Son útiles para la administración a pacientes con dificultades en la deglución, presentan una elevada aceptación por parte del paciente, mejoran de la biodisponibilidad del principio activo y suponen una nueva alternativa para la industria farmacéutica. Dentro de sus inconvenientes destacan el poco conocimiento por parte del paciente, la baja resistencia mecánica, su mayor susceptibilidad a la degradación por temperatura y humedad; la falta, a veces, de bioequivalencia con las formulaciones convencionales, y la dificultad de obtener liberaciones prolongadas o retardadas del principio activo.A nivel tecnológico, existen varios procesos que se pueden aplicar en su elaboración. Con los métodos clásicos de elaboración de comprimidos, mediante la correcta selección de los excipientes y de las variables de la etapa de compresión se obtienen unos comprimidos en los que existe un equilibrio entre dureza y disgregación. Han surgido una serie de tecnologías novedosas: Flashtab, Wowtab, Orasolv y Durasolv. Otra opción es el empleo de técnicas de liofilización, aunque presenta como desventaja su alto coste. Algunas tecnologías especiales patentadas como son Lyoc, QuickSolv y Zydis. Por último, estos comprimidos se pueden elaborar por el método de los polímeros entrecruzados, también conocido como FlashDose y se basa en la formación de una matriz de hilos de azúcares entrelazados.The orally disintegrating tablets are defined as non-coated tablets intended to be placed in the mouth where they disperse rapidly before being swallowed. These formulations are known by the acronym FDDT's (Fast Dissolving Disintegrating Tablets). They are useful for administration to patients with swallowing difficulties, have a high acceptance by the patient, improve bioavailability of the active ingredient and represent a new alternative for the pharmaceutical industry. Among its disadvantages include limited knowledge by the patient, low mechanical strength, increased susceptibility to degradation by temperature and humidity; lack sometimes bioequivalence with conventional formulations, and the difficulty of obtaining prolonged release or delayed active ingredient. At the technological level, there are several processes that can be applied in their preparation. With classical methods of tabletting, by proper selection of excipients and the variables of the compression stage a tablet in which there is a balance between hardness and disintegration are obtained. Flashtab, Wowtab, Orasolv and Durasolv: They have a number of new technologies emerged. Another option is the use of freeze drying techniques, but has the disadvantage of its high cost. Some special patented technologies such as Lyoc, QuickSolv and Zydis. Finally, these tablets may be made by the method of Crosslinked polymers, also known as FlashDose and is based on the formation of a matrix of interwoven threads sugars

A Critical Analysis of Our Experience As Participants in an External Quality Assessment Scheme for Blood Coagulation

info:eu-repo/semantics/publishedVersio