Optimal alarm systems for FIAPARCH processes

In this work, an optimal alarm system is developed to predict whether a financial time series modeled via Fractionally Integrated Asymmetric Power ARCH (FIAPARCH) models, up/downcrosses some particular level and give an alarm whenever this crossing is predicted. The paper presents classical and Bayesian methodology for producing optimal alarm systems. Both methodologies are illustrated and their performance compared through a simulation study. The work finishes with an empirical application to a set of data concerning daily returns of the Sao Paulo Stock Market

Fast cold gas in hot AGN outflows

Observations of the emission from spatially extended cold gas around bright high-redshift QSOs reveal surprisingly large velocity widths exceeding 2000 km s^(-1), out to projected distances as large as 30 kpc. The high velocity widths have been interpreted as the signature of powerful AGN-driven outflows. Naively, these findings appear in tension with hydrodynamic models in which AGN-driven outflows are energy-driven and thus very hot with typical temperatures T = 10^6-7 K. Using the moving-mesh code Arepo, we perform 'zoom-in' cosmological simulations of a z = 6 QSO and its environment, following black hole growth and feedback via energy-driven outflows. In the simulations, the QSO host galaxy is surrounded by a clumpy circum-galactic medium pre-enriched with metals due to supernovae-driven galactic outflows. As a result, part of the AGN-driven hot outflowing gas can cool radiatively, leading to large amounts (> 10^9 M_sun) of cold gas comoving with the hot bipolar outflow. This results in velocity widths of spatially extended cold gas similar to those observed. We caution, however, that gas inflows, random motions in the deep potential well of the QSO host galaxy and cooling of supernovae-driven winds contribute significantly to the large velocity width of the cold gas in the simulations, complicating the interpretation of observational data

Feedback from active galactic nuclei: Energy- versus momentum-driving

We employ hydrodynamical simulations using the moving-mesh code AREPO to investigate the role of energy and momentum input from Active Galactic Nuclei (AGN) in driving large-scale galactic outflows. We start by reproducing analytic solutions for both energy- and momentum-driven outflowing shells in simulations of a spherical isolated dark matter potential with gas in hydrostatic equilibrium and with no radiative cooling. We confirm that for this simplified setup, galactic outflows driven by a momentum input rate of order L_Edd/c can establish an M_BH - sigma relation with slope and normalisation similar to that observed. We show that momentum input at a rate of L_Edd/c is however insufficient to drive efficient outflows once cooling and gas inflows as predicted by cosmological simulations at resolved scales are taken into account. We argue that observed large-scale AGN-driven outflows are instead likely to be energy-driven and show that such outflows can reach momentum fluxes exceeding 10 L_Edd/c within the innermost 10 kpc of the galaxy. The outflows are highly anisotropic, with outflow rates and a velocity structure found to be inadequately described by spherical outflow models. We verify that the hot energy-driven outflowing gas is expected to be strongly affected by metal-line cooling, leading to significant amounts (>10^9 M_sun) of entrained cold gas

Differential diagnosis between functional and organic intestinal disorders: is there a role for non-invasive tests?

Abdominal pain and bowel habits alterations are common symptoms in the general population. The investigation to differentiate organic from functional bowel disorders represents a considerable burden both for patients and public health service. The selection of patients who should undergo endoscopic and/or radiological procedures is one of the key points of the diagnostic process, which should avoid the abuse of invasive and expensive tests as well as the underestimation of potentially harmful diseases. Over the coming years, clinicians and researchers will be challenged to develop strategies to increase the patient's compliance and to reduce the economic and social costs of the intestinal diseases

The environment of bright QSOs at z̃6: Star-forming galaxies and X-ray emission

We employ cosmological hydrodynamical simulations to investigate models in which the supermassive black holes (BHs) powering luminous z ~ 6 QSOs grow from massive seeds. We simulate at high resolution 18 fields sampling regions with densities ranging from the mean cosmic density all the way to the highest sigma peaks in the Millennium simulation volume. Only in the most massive halos, BHs can grow to masses up to ~ 10^9 Msun by z ~ 6 without invoking super-Eddington accretion. Accretion onto the most massive BHs becomes limited by thermal AGN feedback by z ~ 9-8 with further BH growth proceeding in short Eddington limited bursts. Our modelling suggests that current flux-limited surveys of QSOs at high redshift preferentially detect objects at their peak luminosity and therefore miss a substantial population of QSOs powered by similarly massive BHs but with low accretion rates. To test whether the required host halo masses are consistent with the observed galaxy environment of z ~ 6 QSOs, we produce realistic rest-frame UV images of our simulated galaxies. Without strong stellar feedback, our simulations predict numbers of bright galaxies larger than observed by a factor ten or more. Supernova-driven galactic winds reduce the predicted numbers to a level consistent with observations indicating that stellar feedback was already very efficient at high redshifts. We have further investigated the effect of thermal AGN feedback on the surrounding gas. Our adopted AGN feedback prescription drives mostly energy-driven highly anisotropic outflows with gas speeds of >= 1000 km/s to distances of >= 10 kpc consistent with observations. The spatially extended thermal X-ray emission around bright QSOs powered by these outflows can exceed by large factors the emission expected without AGN feedback and is an important diagnostic of the mechanism whereby AGN feedback energy couples to surrounding gas

Caffeine, sleep duration and adolescents’ perception of health related quality of life

© 2016 Matos et al.; This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Introduction: The main objective of this study was to understand the impact of caffeine on adolescents’ health and health related behaviours, namely sleep duration and health related quality of life. Methods: Students in the 6th, 8th and 10th grades were chosen randomly from clusters of schools for this study. A questionnaire designed to measure caffeine consumption, sleep quantity and quality and health related quality of life was used. ANOVAs were used for gender and grade and three multilinear regression models were conducted. Results: Coffee and soft drinks with caffeine have a negative impact in sleep duration. Both sleep duration and quality have a positive effect on health related quality of life. Although the use of energetic drinks with alcohol is low, it has a negative impact on the perception of health quality of life. Males have shown a better perception of health related quality of life and greater quantity and quality of sleep while females report more difficulties falling asleep and report more fatigue. Conclusions: Caffeine intake has a negative impact on sleep duration and perception of health related quality of life, although accounting for a relatively low variance.info:eu-repo/semantics/publishedVersio

Hemossiderose Pulmonar: Revisão Casuística da Consulta de Hematologia Pediátrica do Hospital de Dona Estefânia Durante o Período 1976-1994

Os autores fazem uma análise retrospectiva dos processos de crianças com hemossiderose pulmonar (HP) inscritas na Consulta de Hematologia Pediátrica do Hospital de Dona Estefânia no período de 1976 a 1994. Foram caracterizados o sexo e a raça dos doentes, a idade de aparecimento da sintomatologia inicial, o período que decorreu entre esta e a confirmação do diagnóstico e os aspectos clínicos, laboratoriais e radiológicos respeitantes ao diagnóstico, terapêutica e evolução clínica. A propósito desta entidade nosológica, é feita uma revisão bibliográfica. Confirma-se que a HP é uma doença rara, que inicialmente se apresenta com um quadro de anemia ferropénica arrastada com ou sem sintomatologia respiratória. O diagnóstico faz-se pelo achado de hemossiderófagos no lavado gástrico ou bronco-alvéolar. A etiopatogenia mantém-se desconhecida e a corticoterapia continua a ser a terapêutica mais eficaz no controlo da hemorragia pulmonar. A doença tem uma evolução inconstante, persistente ou intermitente, com um prognóstico variável, geralmente grave

O Valor dos Indices Plaquetários na Púrpura Trombocitopénica Imune e Leucémia Linfo e Mieloblástica Aguda. Bases Clínico-Laboratoriais no Contributo para o Diagnóstico Diferencial Entre Estas Duas Patologias

Os autores apresentam um trabalho onde se pretende avaliar a utilidade dos índices plaquetários — volume plaquetário médio (VPM) e o coeficiente de variação do diâmetro plaquetário (CVDP ou PDW = Platelet Distribution Width) — e do número de plaquetas (PLAQ) no diagnóstico diferencial da trombocitopénia na púrpura trombocitopénica aguda (PTI) e na leucémia linfoblástica ou mieloblástica aguda (LLAULMA). Do mesmo modo, estudam comparativamente os dados clínicos e laboratoriais nestes dois grupos de doentes. Caracterizam 59 casos de doentes em idade pediátrica com PTI e 19 casos com LLA/LMA, seguidos na Unidade de Hematologia Infantil do Hospital de Dona Estefânia. Concluem não existir diferenças significativas entre as variáveis VPM e PDW entre os dois grupos de doentes. Com base nas três variáveis (VPM, PDW, PLAQ) foi construída uma regra de discriminação que fornece uma boa separação entre os grupos. Da caracterização clínico-laboratorial ressaltaram diferenças significativas entre as duas entidades nosológicas, o que permitiria prescindir a realização do mielograma para exclusão do diagnóstico de LLA/LMA numa criança com trombocitopénia significativa isolada