Chaotic cold accretion on to black holes in rotating atmospheres

Chaotic cold accretion (CCA) profoundly differs from classic black hole accretion models. Using 3D high-resolution simulations, we probe the impact of rotation on the hot and cold accretion flow in a typical massive galaxy. In the hot mode, with or without turbulence, the pressure-dominated flow forms a geometrically thick rotational barrier, suppressing the accretion rate to ~1/3 of the Bondi rate. When radiative cooling is dominant, the gas loses pressure support and quickly circularizes in a cold thin disk. In the more common state of a turbulent and heated atmosphere, CCA drives the dynamics if the gas velocity dispersion exceeds the rotational velocity, i.e., turbulent Taylor number < 1. Extended multiphase filaments condense out of the hot phase via thermal instability and rain toward the black hole, boosting the accretion rate up to 100 times the Bondi rate. Initially, turbulence broadens the angular momentum distribution of the hot gas, allowing the cold phase to condense with prograde or retrograde motion. Subsequent chaotic collisions between the cold filaments, clouds, and a clumpy variable torus promote the cancellation of angular momentum, leading to high accretion rates. The simulated sub-Eddington accretion rates cover the range inferred from AGN cavity observations. CCA predicts inner flat X-ray temperature and $r^{-1}$ density profiles, as recently discovered in M 87 and NGC 3115. The synthetic H{\alpha} images reproduce the main features of cold gas observations in massive ellipticals, as the line fluxes and the filaments versus disk morphology. Such dichotomy is key for the long-term AGN feedback cycle. As gas cools, filamentary CCA develops and boosts AGN heating; the cold mode is thus reduced and the rotating disk remains the sole cold structure. Its consumption leaves the atmosphere in hot mode with suppressed accretion and feedback, reloading the cycle.Comment: 18 pages, 21 figures, published in A&A; fully revised version with new major results related to H{\alpha} and X-ray observation

Where does the gas fueling star formation in BCGs originate?

We investigate the relationship between X-ray cooling and star formation in brightest cluster galaxies (BCGs). We present an X-ray spectral analysis of the inner regions, 10-40 kpc, of six nearby cool core clusters (z<0.35) observed with Chandra ACIS. This sample is selected on the basis of the high star formation rate (SFR) observed in the BCGs. We restrict our search for cooling gas to regions that are roughly cospatial with the starburst. We fit single- and multi-temperature mkcflow models to constrain the amount of isobarically cooling intracluster medium (ICM). We find that in all clusters, below a threshold temperature ranging between 0.9 and 3 keV, only upper limits can be obtained. In four out of six objects, the upper limits are significantly below the SFR and in two, namely A1835 and A1068, they are less than a tenth of the SFR. Our results suggests that a number of mechanisms conspire to hide the cooling signature in our spectra. In a few systems the lack of a cooling signature may be attributed to a relatively long delay time between the X-ray cooling and the star burst. However, for A1835 and A1068, where the X-ray cooling time is shorter than the timescale of the starburst, a possible explanation is that the region where gas cools out of the X-ray phase extends to very large radii, likely beyond the core of these systems.Comment: to appear in A&

Novel therapeutic approaches to familial HLH (emapalumab in FHL)

Primary Hemophagocytic lymphohistiocytosis (pHLH) is a rare, life-threatening, hyperinflammatory disorder, characterized by uncontrolled activation of the immune system. Mutations affecting several genes coding for proteins involved in the cytotoxicity machinery of both natural killer (NK) and T cells have been found to be responsible for the development of pHLH. So far, front-line treatment, established on the results of large international trials, is based on the use of glucocorticoids, etoposide ± cyclosporine, followed by allogeneic hematopoietic stem cell transplantation (HSCT), the sole curative treatment for the genetic forms of the disease. However, despite major efforts to improve the outcome of pHLH, many patients still experience unfavorable outcomes, as well as severe toxicities; moreover, treatment-refractory or relapsing disease is a major challenge for pediatricians/hematologists. In this article, we review the epidemiology, etiology and pathophysiology of pHLH, with a particular focus on different cytokines at the origin of the disease. The central role of interferon-γ (IFNγ) in the development and maintenance of hyperinflammation is analyzed. The value of emapalumab, a novel IFNγ-neutralizing monoclonal antibody is discussed. Available data support the use of emapalumab for treatment of pHLH patients with refractory, recurrent or progressive disease, or intolerance to conventional therapy, recently, leading to FDA approval of the drug for these indications. Additional data are needed to define the role of emapalumab in front-line treatment or in combination with other drugs

Caracterização de genes expressos durante o crescimento e maturação de frutos de café.

O objetivo do estudo foi caracterizar funcionalmente genes-chave expressos durante o crescimento e a maturação de frutos de cultivares de Coffea arabica L, pois a planta apresenta várias floradas, fato que resulta na maturação desigual de frutos, inclusive na mesma florada. Para o estudo foram utilizadas frutos em desenvolvimento das cultivares: Mundo Novo IAC 388-17, Catuaí Vermelho IAC 144, Icatu Vermelho IAC 4045, Obatã IAC 1669-20 e Icatu Precoce IAC 3282. Os genes escolhidos para análise foram: o fator de transcrição Leafy Cotyledon (LEC1) e as enzimas álcool acyl transferase e ácido 1-carboxílico 1-aminociclopropano (ACC) oxidase, os quais estão relacionados com os processos de desenvolvimento do embrião, composição química da semente e maturação do fruto, respectivamente. A expressão dos genes foi avaliada através da metodologia de RT-PCR, utilizando RNA total extraído dos frutos. Os resultados apresentados evidenciam que o padrão de expressão dos genes ACC oxidase, LEC1 e álcool acyl transferase são compatíveis com o esperado em frutos climatéricos e, as variações na expressão dos genes observada entre as cultivares sugerem que a composição química e a maturação dos frutos podem diferir ao longo do desenvolvimento dos frutos

Kinetic or thermal AGN feedback in simulations of isolated and merging disc galaxies calibrated by the M-\ua0 relation

We investigate two modes of coupling the feedback energy from a central active galacticnucleus (AGN) to the neighbouring gas in galaxy simulations: kinetic - velocity boost andthermal - heating. We formulate kinetic feedback models for energy-driven wind (EDW)and momentum-driven wind (MDW), using two free parameters: feedback efficiency \u3b5f and AGN wind velocity \u3bd w. A novel numerical algorithm is implemented in the smoothed particlehydrodynamics code GADGET-3, to prevent the expansion of a hole in the gas distributionaround the black hole (BH). We perform simulations of isolated evolution and merger ofdisc galaxies, of Milky Way mass as well as lower and higher masses. We find that in theisolated galaxy BH kinetic feedback generates intermittent bipolar jet-like gas outflows. Weinfer that current prescriptions for BH subgrid physics in galaxy simulations can grow theBH to observed values even in an isolated disc galaxy. The BH growth is enhanced in agalaxy merger, which consequently requires different model parameters to fit the observationsthan an isolated case. Comparing the [MBH-\u3c3*] relation obtained in our simulations withobservational data, we conclude that it is possible to find parameter sets for a fit in all themodels (e.g. \u3bdw = 10 000 km s-1 and \u3b5f = 0.25 for BH kinetic EDW), except for the casewith MDW feedback in a galaxy merger, in which the BH is always too massive. The BHthermal feedback implementation of Springel et al. within the multiphase star formation modelis found to have negligible impact on gas properties, and the effect claimed in all previousstudies is attributed to gas depletion around the BH by the creation of an artificial hole. TheBH mass accretion rate in our simulations exhibit heavy fluctuations. The star formation rate isquenched with feedback by removal of gas. The circumgalactic medium gas at galactocentricdistances (20-100) h-1 kpc is found to give the best metallicity observational diagnostic todistinguish between BH model

Development and validation of a novel image quality rating scale for echocardiography during cardiac arrest

Objective: Research into echocardiography (echo) during cardiac arrest has suffered from methodological flaws that limit aggregation of findings. We developed and validated a novel image rating scale for qualitative analysis of echo images obtained during resuscitation. Methods: A novel 5-point ordinal rating scale was developed and validated using recorded echo images from 145 consecutive cardiac arrest patients. Recorded echo images were reviewed in a blinded fashion by investigators experienced in cardiac arrest echo, and image quality was rated using this scale. Cardiac activity was subsequently classified as no activity, disorganized activity and organized activity. The primary outcome was inter-rater agreement using the image quality rating scale. Secondary outcome was the qualitative evaluation of the type of cardiac activity. Results: A total of 235 ultrasounds were analyzed by study investigators using the image quality rating scale. The overall image quality agreement between reviewers using the scale was good with a weighted kappa of 0.65. Agreement for image quality in subxyphoid images was greater than in parasternal images (0.65-0.52). Echo analysis of cardiac activity showed no activity (33%), disorganized activity (18%), and organized activity (49%). Agreement was great for presence or absence of cardiac activity and organized cardiac activity with a kappa of 0.84 and 0.78. Conclusions: A novel image quality rating scale for echo during cardiac arrest demonstrates substantial agreement between reviewers. Agreement regarding the presence or absence, as well as the organization of cardiac activity was substantial

Preslaughter Mortality in Broiler Chickens, Turkeys, and Spent Hens Under Commercial Slaughtering

Abstract The incidence of dead on arrival (DOA) birds was surveyed over 33 broiler, 11 turkey, and 19 spent hen abattoirs representing the majority (around 70%) of the Italian poultry slaughter plants. Data were recorded monthly during a 4-yr period (August 2001 to July 2005), considering a total of 1,266 million chicken broilers, 118 million turkeys, and 54 million spent hens, which represent 67.7, 84.0, and 28.4% of the national production, respectively. The overall average incidence of DOA was found to be 0.35, 0.38, and 1.22% in broilers, turkeys, and spent hens, respectively. The season significantly (P ≤ 0.01) influenced the mortality of all considered poultry categories, with higher incidence being observed during the summer (0.47, 0.52, and 1.62% for broilers, turkeys, and spent layers, respectively). The incidence of DOA broilers was found to be lower in small slaughter plants compared with medium and large slaughter plants (0.28 vs. 0.38 and 0.35%, P ≤ 0.01). The data obtained in this study might be used for establishing limit values of DOA as a welfare indicator during the preslaughter time of birds, including catching, loading, transportation, and lairage

Expressão gênica diferencial em fruto de Coffea arabica L. em diferentes estádios de desenvolvimento e maturação.

O cafeeiro arábica apresenta além da florada principal outras sucessivas floradas, o que resulta em uma maturação desuniforme dos frutos. A diferença de maturação entre e dentro de floradas, traz inconvenientes à colheita, tornando-a onerosa e prejudicando a qualidade final da bebida. Durante o processo de desenvolvimento e maturação dos frutos de café vários genes são ativados. O objetivo desse trabalho é então avaliar como os genes ?galactosidase e ?mannanase relacionados ao desenvolvimento e aturação dos frutos se comportam nas diferentes fases de maturação dos frutos. O datamining foi realizado utilizando-se seqüências dos genes ?galactosidase e ?mannanase de Coffea presentes no GenBank. Oligos gene específicos foram desenhados a partir das seqüências identificadas no Banco do Genoma Café. Análises do padrão de expressão demonstraram que transcritos correspondentes à galactosidase são observados a partir da fase de frutos em expansão e se mantém presentes até o estágio de fruto cereja. Já a expressão da ?mannanase é observada ao longo de todo o desenvolvimento do fruto, com um maior acúmulo na fase de frutos verdes. Estes resultados, apesar de representarem uma caracterização inicial do padrão de expressão em frutos, são essenciais para estabelecimento de parâmetros agronômicos e da metodologia para análise molecular em frutos de cultivares comerciais do IA

Theoretical Study of Electronic Structure and Superconductivity in Nb_(1-x)B_2 Alloys

Using the Korringa-Kohn-Rostoker coherent-potential approximation in the atomic-sphere approximation (KKR-ASA CPA) we have studied the changes in the electronic structure and the superconducting transition temperature T_{c} in Nb_{1-x}B_{2} alloys as a function of x. We find that the variation in the electronic structure of Nb_{1-x}B_{2} alloys as a function of x is consistent with the rigid-band model. However, the variation of T_{c}, obtained using the Allen-Dynes equation within the Gaspari-Gyorffy formalism to estimate the electron-phonon matrix elements, does not follow the expected trend. We associate this disagreement to the use of a constant \omega_{rms} in the Allen-Dynes equation over the whole range of vacancy concentration, thereby indicating the importance of lattice dynamical effects in these systems.Comment: 10 pages, 4 figure

Hole-doped, High-Temperature Superconductors Li_{x}BC, Na_{x}BC and C_{x} : A Coherent-Potential-Based Prediction

Using density-functional-based methods, we show that the hole-doped Li_{x}BC and Na_{x}BC in P6_{3}/mmc crystal structure and C_{x} in graphite structure are capable of showing superconductivity, possibly with a T_{c} much higher than that of MgB_{2}. We use full-potential methods to obtain the optimized lattice constants a and c, coherent-potential approximation to describe the effects of disorder, Gaspari-Gyorffy formalism to obtain the electron-phonon coupling constant $\lambda$, and Allen-Dynes equation to calculate T_{c} as a function of hole concentration in these alloys.Comment: 4 pages, 5 figure