2,379 research outputs found

    Generalized Hermite-Gauss decomposition of the two-photon state produced by spontaneous parametric down-conversion

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    We provide a general decomposition of the two-photon state produced by spontaneous parametric down-conversion in Hermite-Gaussian modes, in the case that the pump beam is described by a Hermite-Gaussian beam of any order. We show that the spatial correlations depend explicitly on the order of the pump beam, as well as other experimental parameters. We use the decomposition to demonstrate a few interesting cases. Our results are applicable to the engineering of two-photon spatial entanglement, in particular for non-Gaussian states.Comment: 14 page draft, 5 figure

    A BCG with Offset Cooling:Is the AGN Feedback Cycle Broken in A2495?

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    We present a combined radio/X-ray analysis of the poorly studied galaxy cluster A2495 (z = 0.07923) based on new EVLA and Chandra data. We also analyze and discuss Hα emission and optical continuum data retrieved from the literature. We find an offset of ∼6 kpc between the cluster brightest cluster galaxy (BCG) (MCG+02-58-021) and the peak of the X-ray emission, suggesting that the cooling process is not taking place on the central galaxy nucleus. We propose that sloshing of the intracluster medium (ICM) could be responsible for this separation. Furthermore, we detect a second, ∼4 kpc offset between the peak of the Hα emission and that of the X-ray emission. Optical images highlight the presence of a dust filament extending up to ∼6 kpc in the cluster BCG and allow us to estimate a dust mass within the central 7 kpc of 1.7 × 105 M . Exploiting the dust-to-gas ratio and the L Hα-M mol relation, we argue that a significant amount (up to 109 M ) of molecular gas should be present in the BCG of this cluster. We also investigate the presence of ICM depressions, finding two putative systems of cavities; the inner pair is characterized by t age ∼ 18 Myr and P cav ∼ 1.2 × 1043 erg s-1, the outer one by t age ∼ 53 Myr and P cav ∼ 5.6 × 1042 erg s-1. Their age difference appears to be consistent with the freefall time of the central cooling gas and with the offset timescale estimated with the Hα kinematic data, suggesting that sloshing is likely playing a key role in this environment. Furthermore, the cavities' power analysis shows that the active galactic nucleus energy injection is able to sustain the feedback cycle, despite cooling being offset from the BCG nucleus.</p

    Tambaqui (Colossoma macropomum) is not sensitive to endocrine-disruption chemicals during gonad development.

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    The aim of this study was to better understand the physiological roles of estrogens during the process of gonad differentiation in Colossoma macropomum as it is known that ovary formation in this species takes place with no transcription of cyp19a1a (the gene that codes for aromatase)

    Postpartum physiology, psychology and paediatric follow up study (P4 Study) – Study protocol

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    © 2016 International Society for the Study of Hypertension in Pregnancy Background Women who have had hypertension in pregnancy are at greater risk of long term cardiovascular disease (CVD). Little is known about their cardiovascular risk postpartum or the effects on the woman's mental health and the outcomes of their infants. In this project we will study the physiological and psychological health of women and the physical health and development of their infants six months, two years and five years after birth. We will establish normal blood pressure (BP) and metabolic function for women who were normotensive in pregnancy and use these to assess women who had gestational hypertension (GH) or preeclampsia (PE). Design/methods Women will be asked to participate if they have given birth in the preceding six months. They will be excluded if they had diabetes, hypertension, renal or other serious maternal disease prior to pregnancy or congenital anomaly in the pregnancy. We will recruit 292 women who were normotensive and their babies, 100 who had GH and 100 who had PE and their babies. They will be assessed at six months, two and five years after birth. At each assessment mothers will have their blood pressure (BP) assessed peripherally with a liquid crystal sphygmomanometer and 24 h ambulatory blood pressure monitoring (ABPM), and centrally with non-invasive applanation tonometry. Additional physiological testing will include: body composition; energy balance; vascular compliance; cardiac function; liver and renal function, lipids and biochemistry; glucose and insulin; and urinalysis. Psychological status will be assessed with validated self-report questionnaires for depression, anxiety, post-traumatic stress disorder (PTSD) and mother-infant bonding. The babies will have a medical examination by a paediatrician at each assessment. Their behavioural development will be assessed with an Ages and Stages Questionnaire completed by their mother at each assessment and a developmental assessment by a child psychologist at two and five years. Conclusions This study will re-define normal BP and other physiological parameters for young parous women thereby permitting a more sensitive assessment of post-partum BP and other cardiovascular risk markers in women who have had GH or PE. It will also determine the extent, if any, of psychological disorders in these women and developmental or other concerns in their babies. Trials registration Australian and New Zealand Clinical Trials Registry Number: ACTRN12613001260718

    Caracterização in silico de genes parálogos do hormônio liberador de gonadotrofinas (GnRH) em tambaqui Colossoma macropomum.

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    O presente estudo objetivou identificar e caracterizar os diferentes peptídeos e genes parálogos para o GnRH na espécie tambaqui Colossoma macropomum, caracídeo nativo da bacia amazônica e de importância para a aquicultura Brasileira

    Can Protostellar Jets Drive Supersonic Turbulence in Molecular Clouds?

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    Jets and outflows from young stellar objects are proposed candidates to drive supersonic turbulence in molecular clouds. Here, we present the results from multi-dimensional jet simulations where we investigate in detail the energy and momentum deposition from jets into their surrounding environment and quantify the character of the excited turbulence with velocity probability density functions. Our study include jet--clump interaction, transient jets, and magnetised jets. We find that collimated supersonic jets do not excite supersonic motions far from the vicinity of the jet. Supersonic fluctuations are damped quickly and do not spread into the parent cloud. Instead subsonic, non-compressional modes occupy most of the excited volume. This is a generic feature which can not be fully circumvented by overdense jets or magnetic fields. Nevertheless, jets are able to leave strong imprints in their cloud structure and can disrupt dense clumps. Our results question the ability of collimated jets to sustain supersonic turbulence in molecular clouds.Comment: 33 pages, 18 figures, accepted by ApJ, version with high resolution figures at: http://www.ita.uni-heidelberg.de/~banerjee/publications/jet_paper.pd

    Realizing a deep reinforcement learning agent discovering real-time feedback control strategies for a quantum system

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    To realize the full potential of quantum technologies, finding good strategies to control quantum information processing devices in real time becomes increasingly important. Usually these strategies require a precise understanding of the device itself, which is generally not available. Model-free reinforcement learning circumvents this need by discovering control strategies from scratch without relying on an accurate description of the quantum system. Furthermore, important tasks like state preparation, gate teleportation and error correction need feedback at time scales much shorter than the coherence time, which for superconducting circuits is in the microsecond range. Developing and training a deep reinforcement learning agent able to operate in this real-time feedback regime has been an open challenge. Here, we have implemented such an agent in the form of a latency-optimized deep neural network on a field-programmable gate array (FPGA). We demonstrate its use to efficiently initialize a superconducting qubit into a target state. To train the agent, we use model-free reinforcement learning that is based solely on measurement data. We study the agent’s performance for strong and weak measurements, and for three-level readout, and compare with simple strategies based on thresholding. This demonstration motivates further research towards adoption of reinforcement learning for real-time feedback control of quantum devices and more generally any physical system requiring learnable low-latency feedback control

    Reprodução e engorda do pirarucu: levantamento de processos produtivos e tecnologias.

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    Dados gerais das pisciculturas de reprodução e engorda. Propriedades de reprodução: número médio de reprodutores e idade; origem dos reprodutores por bacias hidrográficas; estruturas de cultivo, densidade de estocagem e casais formados; manejo alimentar de reprodutores; monitoramento da qualidade da água e fertilização dos viveiros e barragens; manejos no acasalamento e comportamento reprodutivo; caracterização de ninhos; período reprodutivo e idade na primeira reprodução; manejo e sanidade dos reprodutores; captura dos alevinos; alevinagem; treinamento alimentar; sanidade dos alevinos; pré-comercialização e comercialização dos alevinos; transporte e destinação dos alevinos. Propriedades de engorda: aquisição de alevinos; estruturas de cultivo; preparação dos viveiros; fase de recria; manejo alimentar na recria; fase de engorda; manejo alimentar na engorda; biometrias; mortalidades e sanidade; monitoramento da qualidade da água; assistência técnica, abate e comercialização.bitstream/item/144252/1/CNPASA-2015-lv.pd
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