530 research outputs found

    First Light and Reionisation Epoch Simulations (FLARES) X: Environmental Galaxy Bias and Survey Variance at High Redshift

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    Upcoming deep galaxy surveys with JWST will probe galaxy evolution during the epoch of reionisation (EoR, 5z105\leq z\leq10) over relatively compact areas (e.g. \sim 300\,arcmin2^2 for the JADES GTO survey). It is therefore imperative that we understand the degree of survey variance, to evaluate how representative the galaxy populations in these studies will be. We use the First Light And Reionisation Epoch Simulations (FLARES) to measure the galaxy bias of various tracers over an unprecedentedly large range in overdensity for a hydrodynamic simulation, and use these relations to assess the impact of bias and clustering on survey variance in the EoR. Star formation is highly biased relative to the underlying dark matter distribution, with the mean ratio of the stellar to dark matter density varying by a factor of 100 between regions of low and high matter overdensity (smoothed on a scale of 14\,h1h^{-1}cMpc). This is reflected in the galaxy distribution -- the most massive galaxies are found solely in regions of high overdensity. As a consequence of the above, galaxies in the EoR are highly clustered, which can lead to large variance in survey number counts. For mean number counts N100N\lesssim 100 (1000), in a unit redshift slice of angular area 300\,arcmin2^2 (1.4\,deg2^2), the 2-sigma range in NN is roughly a factor of four (two). We present relations between the expected variance and survey area for different survey geometries; these relations will be of use to observers wishing to understand the impact of survey variance on their results.Comment: 14 pages, 17 figures. Paper 10 in the First Light and Reionisation Epoch Simulations (FLARES) serie

    Electrochromism and Swelling of Polypyrrole Membranes: An Electrochemical and Ellipsometric Study

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    The growth of polypyrrole (Ppy) layers on gold electrodes in nearly neutral pH solutions is analysed using “in situ” voltametric and ellipsometric techniques. Different film structures are obtained depending on the potentiodynamic programme and the composition of the electrolyte. More compact dodecylsulphate-(DS) doped Ppy layers were grown at 1.2 V versus RHE than those obtained by applying a higher potential. The more compact layers correspond to the growth of an oxidised Ppy/DS layer that shows low pseudo capacity behaviour. After dipping, the doped Ppy/DS film in KCl solution-significant variations in optical indices and thickness are detected as a function of the applied potential. Higher electrochromism as well as decrease in film thickness after cathodisation is achieved. The optical indices and the thickness of the Ppy layer formed under different applied potential/time programmes are estimated.Instituto de Investigaciones Fisicoquímicas Teóricas y AplicadasDepartamento de Matemátic

    Amoebic liver abscess – a cause of acute respiratory distress in an infant: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>The usual presentation of amebic liver abscess in children is extremely variable and unpredictable. It presents with a picture of common pediatric illness that is fever, lethargy, and abdominal pain, and can go on to develop into a rare complication of rupture into the pleura to cause acute respiratory distress, which is another common pediatric illness. In our patient, diagnosis was not made or suspected in these two stages.</p> <p>Case presentation</p> <p>This is the report of a 2-year-old male infant who presented with a 2-week history of anorexia, fever, and abdominal pain. A few hours after admission, he suddenly developed acute respiratory distress; chest X-ray demonstrated massive right pleural effusion that failed to response to tube thoracostomy. Limited thoracotomy revealed a ruptured amebic liver abscess through the right cupola of the diaphragm. The content of the abscess was evacuated from the pleural cavity, which was drained with two large chest tubes. Serological examination confirmed the diagnosis of ruptured amebic liver abscess. Postoperative treatment with antibiotics including metronidazole continued until full recovery.</p> <p>Conclusion</p> <p>Diagnosis of such a rare disease requires a high degree of suspicion. In this patient, the diagnosis was only made postoperatively. The delay in presentation and the sudden onset of respiratory distress must be emphasized for all those physicians who care for children.</p

    Analytic Continuation of Liouville Theory

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    Correlation functions in Liouville theory are meromorphic functions of the Liouville momenta, as is shown explicitly by the DOZZ formula for the three-point function on the sphere. In a certain physical region, where a real classical solution exists, the semiclassical limit of the DOZZ formula is known to agree with what one would expect from the action of the classical solution. In this paper, we ask what happens outside of this physical region. Perhaps surprisingly we find that, while in some range of the Liouville momenta the semiclassical limit is associated to complex saddle points, in general Liouville's equations do not have enough complex-valued solutions to account for the semiclassical behavior. For a full picture, we either must include "solutions" of Liouville's equations in which the Liouville field is multivalued (as well as being complex-valued), or else we can reformulate Liouville theory as a Chern-Simons theory in three dimensions, in which the requisite solutions exist in a more conventional sense. We also study the case of "timelike" Liouville theory, where we show that a proposal of Al. B. Zamolodchikov for the exact three-point function on the sphere can be computed by the original Liouville path integral evaluated on a new integration cycle.Comment: 86 pages plus appendices, 9 figures, minor typos fixed, references added, more discussion of the literature adde

    Electrochemical and optical study of the confined aqueous layer adsorbed on gold electrodes cycled in phosphate and dodecylsulphate solutions

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    The properties of the confined aqueous layer potentiodynamically formed on polycrystalline gold in aqueous phosphate and sodium dodecylsulphate solutions were studied using voltammetry, ellipsometry, and contact angle measurements. The nature of the incipient oxide layer was analyzed as a function of the cycling time in the double layer-oxide monolayer potential region. The replacement of the electrolyte by hexane allows the increase of the optical signal. Different potential cycling conditions change the homogeneity of the confined aqueous incipient oxide layer leading to different structural characteristics.Instituto de Investigaciones Fisicoquímicas Teóricas y AplicadasFacultad de Ciencias Exacta

    Managing carious lesions:consensus recommendations on carious tissue removal

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    The International Caries Consensus Collaboration undertook a consensus process and here presents clinical recommendations for carious tissue removal and managing cavitated carious lesions, including restoration, based on texture of demineralized dentine. Dentists should manage the disease dental caries and control activity of existing cavitated lesions to preserve hard tissues and retain teeth long-term. Entering the restorative cycle should be avoided as far as possible. Controlling the disease in cavitated carious lesions should be attempted using methods which are aimed at biofilm removal or control first. Only when cavitated carious lesions either are noncleansable or can no longer be sealed are restorative interventions indicated. When a restoration is indicated, the priorities are as follows: preserving healthy and remineralizable tissue, achieving a restorative seal, maintaining pulpal health, and maximizing restoration success. Carious tissue is removed purely to create conditions for long-lasting restorations. Bacterially contaminated or demineralized tissues close to the pulp do not need to be removed. In deeper lesions in teeth with sensible (vital) pulps, preserving pulpal health should be prioritized, while in shallow or moderately deep lesions, restoration longevity becomes more important. For teeth with shallow or moderately deep cavitated lesions, carious tissue removal is performed according toselective removal to firm dentine.In deep cavitated lesions in primary or permanent teeth,selective removal to soft dentineshould be performed, although in permanent teeth,stepwise removalis an option. The evidence and, therefore, these recommendations support less invasive carious lesion management, delaying entry to, and slowing down, the restorative cycle by preserving tooth tissue and retaining teeth long-term.status: publishe

    Do incarcerated male juvenile recidivists differ from first-time offenders on self-reported psychopathic traits? A retrospective study

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    The current study analyzed the relation between recidivism and self-reported psychopathic traits, more specifically the callous-unemotional, impulsivity, and narcissism dimensions of the psychopathy construct. The Antisocial Process Screening Device – Self-Report (APSD-SR) and other self- report instruments independently measuring the three different dimensions of psychopathy (that is, Inventory of Callous-Unemotional Traits, Barratt Impulsiveness Scale-11, Narcissistic Personality-13) were completed by a sample of incarcerated male juvenile offenders (N = 244) who were retrospectively classified as recidivists versus non-recidivists. The only statistically significant relation found between recidivism and self-reported psychopathic traits after controlling for age and socioeconomic status was with the impulsivity dimension of the APSD-SR. Additionally, results showed that recidivism was associated with alcohol use but not with drug use or crime seriousness.This study was supported by the Portuguese Foundation for Science and Technology (FCT; Grant SFRH/BPD/86666/2012) with co-financing of the European Social Fund (POPH/FSE), the Portuguese Ministry of Education and Science (MEC), and the PT2020 Partnership Agreement (UID/PSI/01662/2013)
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