The impact of realistic models of mass segregation on the event rate of extreme-mass ratio inspirals and cusp re-growth

One of the most interesting sources of gravitational waves (GWs) for LISA is the inspiral of compact objects on to a massive black hole (MBH), commonly referred to as an "extreme-mass ratio inspiral" (EMRI). The small object, typically a stellar black hole (bh), emits significant amounts of GW along each orbit in the detector bandwidth. The slowly, adiabatic inspiral of these sources will allow us to map space-time around MBHs in detail, as well as to test our current conception of gravitation in the strong regime. The event rate of this kind of source has been addressed many times in the literature and the numbers reported fluctuate by orders of magnitude. On the other hand, recent observations of the Galactic center revealed a dearth of giant stars inside the inner parsec relative to the numbers theoretically expected for a fully relaxed stellar cusp. The possibility of unrelaxed nuclei (or, equivalently, with no or only a very shallow cusp) adds substantial uncertainty to the estimates. Having this timely question in mind, we run a significant number of direct-summation $N-$body simulations with up to half a million particles to calibrate a much faster orbit-averaged Fokker-Planck code. We then investigate the regime of strong mass segregation (SMS) for models with two different stellar mass components. We show that, under quite generic initial conditions, the time required for the growth of a relaxed, mass segregated stellar cusp is shorter than a Hubble time for MBHs with $M_\bullet \lesssim 5 \times 10^6 M_\odot$ (i.e. nuclei in the range of LISA). SMS has a significant impact boosting the EMRI rates by a factor of $\sim 10$ for our fiducial models of Milky Way type galactic nuclei.Comment: Accepted by CQG, minor changes, a bit expande

Carnian (Late Triassic) C-isotope excursions, environmental changes, and biotic turnover: a global perturbation of the Earth's surface system

Here we present the second part of the special thematic issue on the Carnian Pluvial Episode (CPE). In this issue, two works on terrestrial sedimentological and floral changes linked to the CPE, and new carbon isotope records from Oman and China are presented. The papers published in this issue complement those contained in volume 175 issue 6; they altogether give an almost complete vision of the state-of-the-art about the CPE, including the many conundrums

Intermittent chaos driven by nonlinear Alfvén waves

International audienceWe investigate the relevance of chaotic saddles and unstable periodic orbits at the onset of intermittent chaos in the phase dynamics of nonlinear Alfvén waves by using the Kuramoto-Sivashinsky (KS) equation as a model for phase dynamics. We focus on the role of nonattracting chaotic solutions of the KS equation, known as chaotic saddles, in the transition from weak chaos to strong chaos via an interior crisis and show how two of these unstable chaotic saddles can interact to produce the plasma intermittency observed in the strongly chaotic regimes. The dynamical systems approach discussed in this work can lead to a better understanding of the mechanisms responsible for the phenomena of intermittency in space plasmas

Effects of web-based electrocardiography simulation on strategies and learning styles

Objective: To identify the association between the use of web simulation electrocardiography and the learning approaches, strategies and styles of nursing degree students. Method: A descriptive and correlational design with a one-group pretest– posttest measurement was used. The study sample included 246 students in a Basic and Advanced Cardiac Life Support nursing class of nursing degree. Results: No significant differences between genders were found in any dimension of learning styles and approaches to learning. After the introduction of web simulation electrocardiography, significant differences were found in some item scores of learning styles: theorist (p < 0.040), pragmatic (p < 0.010) and approaches to learning. Conclusion: The use of a web electrocardiogram (ECG) simulation is associated with the development of active and reflexive learning styles, improving motivation and a deep approach in nursing students

Petrografia e Geoquímica do Complexo Migmatítico de Bemposta (Zona Centro Ibérica, NE de Portugal)

ABSTRACT: The Bemposta Migmatite Complex (CMB) belong to the Central-Iberian Zone, NE Portugal. It is a high-grade metamorphic belt composed by metasediments of Ediacarian-Lower Cambrian age affected by partial melting during the second Variscan deformation event (D2). The anatexis culminated with intrusion of syn-tardi-D2 leucogranite sills in the CMB. Field and petrographic evidence suggest that the anatexis of the metasediments was controlled by muscovite dehydration-melting reactions. On the other hand, the stromatic leucosomes show that they were probably produced at a slightly deeper structural level (through biotite dehydration-melting reactions) and subsequently injected in these lithologies. The geochemical data reveals that leucosomes no longer correspond to the original melt compositions. During melt migration and ascent, they underwent fractional crystallization and accumulation of K-feldspar. Syn-tardi-D2 leucogranites that intrude CMB were most likely produced by higher degrees of partial melting. They have fractionated compositions and variable degrees of contamination with residual accessory mineral phases. Thus, CMB is interpreted as a Migmatite Injection Complex, where anatectic melts produced at slightly deeper levels were accumulated.RESUMO: O Complexo Migmatítico de Bemposta (CMB) situa-se na Zona Centro Ibérica (NE Portugal) correspondendo a um cinturão metamórfico de alto grau, composto por metassedimentos do Ediacariano-Câmbrico Inferior afetados por fusão parcial durante a segunda fase de deformação Varisca (D2). A anatexia destas rochas culminou com a intrusão de leucogranitos sin-tardi-D2 do tipo sill. As evidências de campo em consonância com a petrografia sugerem que a anatexia dos metassedimentos foi controlada pela reação de desidratação da moscovite. Os leucossomas mostram evidências de terem sido produzidos em níveis estruturais inferiores (através da reação da desidratação da biotite) e subsequentemente injetados nestas litologias. Os dados de geoquímica revelam que os leucossomas durante a sua ascensão foram afetados por cristalização fracionada e acumulação de feldspato potássico. Os leucogranitos sin-tardi-D2 que intruem o CMB resultaram de altas taxas de fusão e possuem composições equivalentes a magmas afetados por cristalização fracionada, contaminados por minerais acessórios residuais. Assim, o CMB é interpretado como um Complexo Migmatítico de Injeção, onde os líquidos anatéticos produzidos em profundidade se acumularam.info:eu-repo/semantics/publishedVersio

Inflammation and performance status:the cornerstones of prognosis in advanced cancer

Context: In advanced cancer, although performance status (PS), systemic inflammatory response and nutritional status are known to have prognostic value, geographical variations and sociodemographic indexes may also impact survival. Objectives: This study compares validated prognostic factors in two international cohorts and establishes a prognostic framework for treatment. Methods: Two international biobanks of patients (n=1.518) with advanced cancer were analyzed. Prognostic factors (Eastern Cooperative Oncology Group Performance Status [ECOG-PS], body mass index [BMI] and modified Glasgow Prognostic Score [mGPS]) were assessed. The relationship between these and survival was examined using Kaplan–Meier and Cox regression methods. Results: According to multivariate analysis, in the European cohort the most highly predictive factors were BMI &lt;20 kg/m2 (hazard ratio [HR] 1.644), BMI 20-21.9 kg/m2 (HR 1.347), ECOG-PS (HR 1.597–11.992) and mGPS (HR 1.843–2.365). In the Brazilian cohort, the most highly predictive factors were ECOG-PS (HR 1.678–8.938) and mGPS (HR 2.103–2.837). Considering gastrointestinal cancers in particular (n=551), the survival rate at 3 months in both cohorts together ranged from 93% (mGPS 0, PS 0–1) to 0% (mGPS 2, PS 4), and from 81% (mGPS 0, BMI &gt;28 kg/m2) to 44% (mGPS 2, BMI &lt;20 kg/m2). Conclusion: The established prognostic factors that were compared had similar prognostic capacity in both cohorts. A high ECOG-PS and a high mGPS as outlined in the ECOG-PS/mGPS framework were consistently associated with poorer survival of patients with advanced cancer in the prospective European and Brazilian cohorts

Gastroenteropancreatic Neuroendocrine Neoplasia Characterization in Portugal: Results from the NETs Study Group of the Portuguese Society of Endocrinology, Diabetes and Metabolism

Background: The incidence of gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) has been increasing in the last five decades, but there is no large-scale data regarding these tumours in Portugal. We conducted a cross-sectional, multicentric study in main Portuguese centers to evaluate the clinical, pathological, and therapeutic profile of GEP-NENs. Methods: From November, 2012, to July, 2014, data from 293 patients diagnosed with GEP-NENs from 15 centers in Portugal was collected and registered in an online electronic platform. Results: Median age at diagnosis was 56.5 (range: 15-87) years with a preponderance of females (54.6%). The most frequent primary sites were the pancreas (31.1%), jejunum-ileum (24.2%), stomach (13.7%), and rectum (8.5%). Data regarding hormonal status was not available in most patients (82.3%). Stratified by the tumour grade (WHO 2010 classification), we observed 64.0% of NET G1, 24.7% of NET G2, and 11.3% of NEC. Poorly differentiated tumours occurred mainly in older patients (p = 0.017), were larger (p < 0.001), and presented more vascular (p = 0.004) and lymphatic (p = 0.001) invasion. At the time of diagnosis, 44.4% of GEP-NENs presented metastatic disease. Surgery (79.6%) and somatostatin analogues (30.7%) were the most frequently used therapies of GEP-NENs with reported grading. Conclusion: In general, Portuguese patients with GEP-NENs presented similar characteristics to other populations described in the literature. This cross-sectional study represents the first step to establish a national database of GEP-NENs that may aid in understanding the clinical and epidemiological features of these tumours in Portugal. Methods: From November, 2012, to July, 2014, data from 293 patients diagnosed with GEP-NENs from 15 centers in Portugal was collected and registered in an online electronic platform. Results: Median age at diagnosis was 56.5 (range: 15-87) years with a preponderance of females (54.6%). The most frequent primary sites were the pancreas (31.1%), jejunum-ileum (24.2%), stomach (13.7%), and rectum (8.5%). Data regarding hormonal status was not available in most patients (82.3%). Stratified by the tumour grade (WHO 2010 classification), we observed 64.0% of NET G1, 24.7% of NET G2, and 11.3% of NEC. Poorly differentiated tumours occurred mainly in older patients (p = 0.017), were larger (p < 0.001), and presented more vascular (p = 0.004) and lymphatic (p = 0.001) invasion. At the time of diagnosis, 44.4% of GEP-NENs presented metastatic disease. Surgery (79.6%) and somatostatin analogues (30.7%) were the most frequently used therapies of GEP-NENs with reported grading. Conclusion: In general, Portuguese patients with GEP-NENs presented similar characteristics to other populations described in the literature. This cross-sectional study represents the first step to establish a national database of GEP-NENs that may aid in understanding the clinical and epidemiological features of these tumours in Portugal.This study was industry-sponsored by the pharmaceutical company Ipsen Portugal. João Vinagre (CEECIND/00201/2017) and Paula Soares receive funding from the Operational Program for Competitiveness and Internationalization (POCI), Portugal 2020; Portuguese funds through FCT (Fundação para a Ciência e a Tecnologia)/Ministério da Ciência, Tecnologia e Inovação in the framework of the project “Institute for Research and Innovation in Health Sciences” (POCI-01-0145-FEDER-007274) and the project “Advancing Cancer Research: From Basic Knowledge to Application” (NORTE-01-0145-FEDER-000029); and “Projetos Estruturados de I&D&I,” funded by Norte 2020—Programa Operacional Regional do Norte. Further funding was from the European Regional Development Fund (ERDF) through the Operational Program for Competitiveness and Internationalization (COMPETE 2020) and Portuguese national funds via FCT (Fundação para a Ciência e a Tecnologia), under the project “POCI-01-0145-FEDER-016390: CANCEL STEM.” Maria João Bugalho and João Vinagre were funded by the Sociedade Portuguesa de Endocrinologia, Diabetes e Metabolismo through the Study Group for Neuroendocrine Tumours.info:eu-repo/semantics/publishedVersio

Padronização da produção de inóculo de fungos micorrízicos arbusculares.

Fungos micorrízicos arbusculares (FMA) são organismos benéficos às plantas, formando associação simbiótica com estas. Em virtude de que os FMAs necessitam da presença de raízes vivas para se multiplicarem, torna-se fundamental o aperfeiçoamento das metodologias de produção de inóculo de forma tradicional ou in vitro. Para produção de inóculo, normalmente são empregadas plantas de crescimento rápido, mas a quantidade de inóculo a ser utilizada por planta pode ser definida em relação ao peso do inóculo, utilizando-se normalmente 20 a 30g por vaso, ou pela quantidade de esporos presentes, sendo ideal ter no mínimo 100 esporos/100g de inóculo. Neste trabalho, foi avaliado a variação da colonização de cinco espécies de FMA (Acalospora colombiana - AC, Claroideoglomus etunicatun - CE, Dentiscutta heterogama - DH, Acalospora scrobiculata - AS e Rhizophagus clarus - RC) inoculadas em Avena strigosa Schre, cultivada em casa de vegetação.(Embrapa Uva e Vinho. Documentos, 99

Pulsar timing arrays and the challenge of massive black hole binary astrophysics

Pulsar timing arrays (PTAs) are designed to detect gravitational waves (GWs) at nHz frequencies. The expected dominant signal is given by the superposition of all waves emitted by the cosmological population of supermassive black hole (SMBH) binaries. Such superposition creates an incoherent stochastic background, on top of which particularly bright or nearby sources might be individually resolved. In this contribution I describe the properties of the expected GW signal, highlighting its dependence on the overall binary population, the relation between SMBHs and their hosts, and their coupling with the stellar and gaseous environment. I describe the status of current PTA efforts, and prospect of future detection and SMBH binary astrophysics.Comment: 18 pages, 4 figures. To appear in the Proceedings of the 2014 Sant Cugat Forum on Astrophysics. Astrophysics and Space Science Proceedings, ed. C.Sopuerta (Berlin: Springer-Verlag

The origin of variability of the intermediate-mass black-hole ULX system HLX-1 in ESO 243-49

The ultra-luminous intermediate-mass black-hole system HLX-1 in the ESO 243-49 galaxy exhibits variability with a possible recurrence time of a few hundred days. Finding the origin of this variability would constrain the still largely unknown properties of this extraordinary object. Since it exhibits an intensity-hardness behavior characteristic of black-hole X-ray transients, we have analyzed the variability of HLX-1 in the framework of the disk instability model that explains outbursts of such systems. We find that the long-term variability of HLX-1 is unlikely to be explained by a model in which outbursts are triggered by thermal-viscous instabilities in an accretion disc. Possible alternatives include the instability in a radiation-pressure dominated disk but we argue that a more likely explanation is a modulated mass-transfer due to tidal stripping of a star on an eccentric orbit around the intermediate-mass black hole. We consider an evolutionary scenario leading to the creation of such a system and estimate the probability of its observation. We conclude, using a simplified dynamical model of the post-collapse cluster, that no more than 1/100 to 1/10 of Mbh < 10^4 Msun IMBHs - formed by run-away stellar mergers in the dense collapsed cores of young clusters - could have a few times 1 Msun Main-Sequence star evolve to an AGB on an orbit eccentric enough for mass transfer at periapse, while avoiding collisional destruction or being scattered into the IMBH by 2-body encounters. The finite but low probability of this configuration is consistent with the uniqueness of HLX-1. We note, however, that the actual response of a standard accretion disk to bursts of mass transfer may be too slow to explain the observations unless the orbit is close to parabolic (and hence even rarer) and/or additional heating, presumably linked to the highly time-dependent gravitational potential, are invoked.Comment: 8 pages, 2 figures. Additional figure, extended discussion. To be published in ApJ, June 10, 2011, v734 -