121 research outputs found
Quasar Clustering in Cosmological Hydrodynamic Simulations: Evidence for mergers
We examine the clustering properties of a population of quasars drawn from
fully hydrodynamic cosmological simulations that directly follow black hole
growth. We find that the black hole correlation function is best described by
two distinct components: contributions from BH pairs occupying the same dark
matter halo ('1-halo term') which dominate at scales below 300 kpc/h, and
contributions from BHs occupying separate halos ('2-halo term') which dominate
at larger scales. From the 2-halo BH term we find a typical host halo mass for
faint-end quasars (those probed in our simulation volumes) ranging from 10^11
to a few 10^12 solar masses from z=5 to z=1 respectively (consistent with the
mean halo host mass). The BH correlation function shows a luminosity dependence
as a function of redshift, though weak enough to be consistent with
observational constraints. At small scales, the high resolution of our
simulations allows us to probe the 1-halo clustering in detail, finding that
the 1-halo term follows an approximate power law, lacking the characteristic
decrease in slope at small scales found in 1-halo terms for galaxies and dark
matter. We show that this difference is a direct result of a boost in the
small-scale quasar bias caused by galaxies hosting multiple quasars (1-subhalo
term) following a merger event, typically between a large central subgroup and
a smaller, satellite subgroup hosting a relatively small black hole. We show
that our predicted small-scale excess caused by such mergers is in good
agreement with both the slope and amplitude indicated by recent small-scale
measurements. Finally, we note the excess to be a strong function of halo mass,
such that the observed excess is well matched by the multiple black holes of
intermediate mass (10^7-10^8 solar masses) found in hosts of 4-8*10^11 solar
masses, a range well probed by our simulations.Comment: 12 pages, 10 figures. Submitted to MNRA
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Navigating Musical Periodicities: Modes of Perception and Types of Temporal Knowledge
This dissertation explores multi-modal, symbolic, and embodied strategies for navigating musical periodicity, or “meter.” In the first half, I argue that these resources and techniques are often marginalized or sidelined in music theory and psychology on the basis of definition or context, regardless of usefulness. In the second half, I explore how expanded notions of metric experience can enrich musical analysis. I then relate them to existing approaches in music pedagogy.
Music theory and music psychology commonly assume experience to be perceptual, music to be a sound object, and perception of music to mean listening. In addition, observable actions of a metaphorical “body” (and, similarly, performers’ perspectives) are often subordinate to internal processes of a metaphorical “mind” (and listeners’ experiences). These general preferences, priorities, and contextual norms have culminated in a model of “attentional entrainment” for meter perception, emerging through work by Mari Riess Jones, Robert Gjerdingen, and Justin London, and drawing upon laboratory experiments in which listeners interact with a novel sound stimulus. I hold that this starting point reflects a desire to focus upon essential and universal aspects of experience, at the expense of other useful resources and strategies (e.g. extensive practice with a particular piece, abstract ideas of what will occur, symbolic cues)
Opening discussion of musical periodicity without these restrictions acknowledges experiences beyond attending, beyond listening, and perhaps beyond perceiving. I construct two categories for various resources and strategies: those which involve dynamic symbolic encoding (such as conducting patterns and tala gestures) and those which utilize static theoretical information (such as score-based knowledge and calculation of abstract relationships). My primary means of revealing and exploring these additional resources involves instances of “metric multi-tasking,” in which musicians keep track of multiple non-nested periodicities occurring simultaneously. One of the reasons these situations work so well at revealing additional resources is that attentional entrainment offers no explanation for how one might be able to do such a thing (only that attention is insufficient for the task). I do not make these moves in an attempt to significantly alter the theory of attentional entrainment. Rather, I frame that model as but one mode of temporal perception among many. I also leave room for types of temporal knowledge which may not be perceptual at all, but are nonetheless useful in situations involving musical periodicity. Pedagogical systems already make use of dynamic symbols and theoretical knowledge to help with temporally difficult tasks, and generally not virtuosic feats of metric multi-tasking. With these ideas in mind, I return to more straightforward “mono-metric” contexts and reconsider what to do with the concepts of “meter” and “perception.
The Halo Occupation Distribution of Active Galactic Nuclei
Using a fully cosmological hydrodynamic simulation that self-consistently
incorporates the growth and feedback of supermassive black holes and the
physics of galaxy formation, we examine the effects of environmental factors
(e.g., local gas density, black hole feedback) on the halo occupation
distribution of low luminosity active galactic nuclei (AGN). We decompose the
mean occupation function into central and satellite contribution and compute
the conditional luminosity functions (CLF). The CLF of the central AGN follows
a log-normal distribution with the mean increasing and scatter decreasing with
increasing redshifts. We analyze the light curves of individual AGN and show
that the peak luminosity of the AGN has a tighter correlation with halo mass
compared to instantaneous luminosity. We also compute the CLF of satellite AGN
at a given central AGN luminosity. We do not see any significant correlation
between the number of satellites with the luminosity of the central AGN at a
fixed halo mass. We also show that for a sample of AGN with luminosity above
10^42 ergs/s the mean occupation function can be modeled as a softened step
function for central AGN and a power law for the satellite population. The
radial distribution of AGN inside halos follows a power law at all redshifts
with a mean index of -2.33 +/- 0.08. Incorporating the environmental dependence
of supermassive black hole accretion and feedback, our formalism provides a
theoretical tool for interpreting current and future measurements of AGN
clustering.Comment: 14 pages, 11 figures, 2 Tables (Matches the MNRAS accepted version
Black hole clustering and duty cycles in the Illustris simulation
We use the high-resolution cosmological simulation Illustris to investigate the clustering of supermassive black holes across cosmic time, the link between black hole clustering and host halo masses, and the implications for black hole duty cycles. Our predicted black hole correlation length and bias match the observational data very well across the full redshift range probed. Black hole clustering is strongly luminosity dependent on small, 1-halo scales, with some moderate dependence on larger scales of a few Mpc at intermediate redshifts. We find black hole clustering to evolve only weakly with redshift, initially following the behaviour of their hosts. However, below z ~ 2 black hole clustering increases faster than that of their hosts, which leads to a significant overestimate of the clustering-predicted host halo mass. The full distribution of host halo masses is very wide, including a low-mass tail extending up to an order of magnitude below the naive prediction for minimum host mass. Our black hole duty cycles, duty, follow a power-law dependence on black hole mass and decrease with redshift, and we provide accurate analytic fits to these. The increase in clustering amplitude at late times, however, means that duty cycle estimates based on black hole clustering can overestimate duty substantially, by more than two orders of magnitude. We find the best agreement when the minimum host mass is assumed to be 10M⊙, which provides an accurate measure across all redshifts and luminosity ranges probed by our simulation.CD and DS acknowledge support by the ERC starting grant 638707 ‘Black holes and their host galaxies: co-evolution across cosmic time’. DS further acknowledges support from the STFC. Simulations were run on the Harvard Odyssey and CfA/ITC clusters, the Ranger and Stampede supercomputers at the Texas Advanced Computing Center as part of XSEDE, the Kraken supercomputer at Oak Ridge National Laboratory as part of XSEDE, the CURIE supercomputer at CEA/France as part of PRACE project RA0844 and the SuperMUC computer at the Leibniz Computing Center, as part of project pr85je
O princípio da publicidade na administração pública
A presente monografia concentra-se no princípio constitucional da publicidade na administração pública. Busca delimitar e esclarecer o conteúdo jurídico do princípio da publicidade, estabelecido no artigo 37, caput, da Constituição Federal, com o apoio bibliográfico e doutrinário de autores que valorizaram os aspectos principiológicos do direito administrativo. O trabalho também faz um estudo sucinto da força normativa dos princípios constitucionais, além de descrever a repercussão do princípio da publicidade no regime jurídico administrativo. Analisa-se o direito do cidadão à informação pública e o correlato dever de transparência da administração pública - binómio que resume o conteúdo jurídico do princípio da publicidade. O trabalho também discorre sobre a identidade entre o princípio e a noção de transparência administrativa. Traça-se um breve panorama internacional das principais leis de transparência, e da discussão no Brasil sobre a adoção de lei semelhante. Por fim, descreve os principais mecanismos jurisdicionais oferecidos ao cidadão para a garantia da publicidade administrativa
Mecanismos de HARQ usando códigos LDPC com retransmissão parcial e combinação por diversidade
Modern standards of communication systems are including in their standards retransmission mechanisms. This work presents mechanisms for retransmission of packets by simpler and more efficient than the classical mechanisms of packet retransmissions. The proposed schemes are presented that use packet retransmission with partial retransmission and diversity combining. In addition, theoretical analysis will be presented to validate the results of the simulations. These theoretical analysis are obtained through the analysis EXIT charts and mutual information. The results and analysis were performed on channels such as AWGN and Block-Fading. The computational complexity, ease implementation and low average energy consumption for transmission of the proposed methods are some of the reasons they become interesting both for academia and for industry.Os recentes padrões de sistemas de comunicação estão incluindo em suas normas mecanismos de retransmissão de pacotes. Este trabalho apresenta mecanismos de retransmissão de pacotes de formas simples e mais eficientes do que os mecanismos clássicos de retransmissão de pacotes. São apresentados esquemas de retransmissão de pacotes que utilizam retransmissões parciais e combinação por diversidade. Além disso, serão apresentadas análises teóricas para validar os resultados obtidos das simulações. Estas análises teóricas são obtidas através das análises de EXIT charts e da informação mútua. Os resultados e análises foram realizados em canais do tipo AWGN e com desvanecimento por blocos (Block-Fading). A complexidade computacional, facilidade de implementação e baixo consumo médio de energia por transmissão dos métodos propostos são alguns dos motivos pelos quais, tornam-se interessantes tanto para a área acadêmica quanto para a indústria
Análise in silico de dados imuno-oncogenômicos em carcinoma de córtex adrenal
Orientadora: Profa. Dra. Juliana Ferreira de MouraCoorientadores: Prof. Dr. Mauro Antônio Alves Castro, Prof. Dr. Bonald Cavalcante FigueiredoTese (doutorado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Microbiologia, Parasitologia e Patologia. Defesa : Curitiba, 30/11/2022Inclui referênciasResumo: O carcinoma de córtex adrenal (CCA) é um tumor raro e agressivo com poucas alternativas de tratamento e mau prognóstico. Ensaios clínicos com imunoterápicos tiveram resultados modestos em parte devido ao microambiente tumoral imunologicamente "frio" desse tipo de tumor. Alguns autores afirmaram que pacientes de CCA dificilmente se beneficiariam de imunoterapia devido à baixa presença do infiltrado linfocitário nos estágios 3 e 4. Nesse trabalho, utilizamos dados públicos para investigar as características imunológicas do ambiente intratumoral de CCA de adultos correlacionando-as a fenótipos moleculares, dados clínicos e ao cenário regulatório. Nós mostramos que o fenótipo esteroidal distingue a resposta imunológica e pode ser usado para selecionar pacientes passíveis de se beneficiarem da imunoterapia. Mostramos que pacientes com o perfil esteroidal baixo apresentam uma presença significativa de infiltrado leucocitário e de marcadores de ativação imunológica, comparável a outros tumores considerados como imunologicamente "quentes". Apresentamos o cenário regulatório de CCA e como ele se correlaciona a essa classificação molecular, assim como a marcadores de proliferação. Finalmente, apontamos possíveis alvos e os principais reguladores associados a esse fenótipo e às variáveis imunológicas. Além da presença de hormônios imunossupressores, destacamos como possíveis causas para os resultados modestos de imunoterápicos a alta expressão de CD276 (B7-H3), um inibidor de resposta às terapias de bloqueio anti-PD-1/PD-L1, e a maior expressividade de PDCD1LG2 (PD-L2) comparada à de CD274 (PD-L1) em pacientes com baixo perfil esteroidal. No cenário regulatório, destacamos o CENPA como um fator de transcrição a ser investigado, visto sua alta correlação com proliferação e prognóstico e ZBTB-4 como um possível alvo anti-tumorigênico drogável. Nossos resultados apontam para um novo critério de seleção de pacientes à imunoterapia, além de indicar possíveis alvos a serem investigados em estudos in vivo e in vitro. Antecipamos que os dados aqui apresentados poderão servir como base para novas frentes de esforço clínico e científico no combate a esse câncer de difícil tratamento.Abstract: Adrenal cortex carcinoma (ACC) is a rare and aggressive tumor with few treatment alternatives and poor prognosis. Clinical trials with immunotherapeutics had modest results in part due to the immunologically "cold" tumor microenvironment of this type of tumor. Some authors stated that ACC patients would hardly benefit from immunotherapy due to the low presence of lymphocytic infiltrate. In this work, we used public data to investigate the immunological characteristics of the intratumoral environment of ACC by correlating them with molecular phenotypes, clinical data and the regulatory scenario. We show that the steroid phenotype distinguishes the immune response and can be used to select patients likely to benefit from immunotherapy. We showed that patients with a low steroid profile have a significant presence of leukocyte infiltrate and markers of immunological activation, comparable to other tumors considered to be immunologically "hot". We present the regulatory landscape of CCA and how it correlates to this molecular classification, as well as to markers of proliferation. Finally, we point out possible targets and the main regulators associated with this phenotype and immunological variables. Beyond the presence of immunosuppressive hormones, we highlight as possible causes for the modest results of immunotherapies the high expression of CD276 (B7-H3), an inhibitor of response to anti-PD-1/PD-L1 blocking therapies, and the greater expressiveness of PDCD1LG2 (PD-L2) compared to that of CD274 (PD-L1) in patients with a low steroid profile. In the regulatory scenario, we highlight CENPA as a transcription factor to be investigated, given its high correlation with proliferation and prognosis, and ZBTB-4 as a possible druggable anti-tumorigenic target. Our results point to a new criterion for selecting patients for immunotherapy, in addition to indicating possible targets to be investigated in in vivo and in vitro studies. We anticipate that the data presented here may serve as a basis for new fronts of clinical and scientific effort in the fight against this difficult-to-treat cancer
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