476 research outputs found
Steady state entanglement of two superconducting qubits engineered by dissipation
We present a scheme for the dissipative preparation of an entangled steady
state of two superconducting qubits in a circuit QED setup. Combining resonator
photon loss, a dissipative process already present in the setup, with an
effective two-photon microwave drive, we engineer an effective decay mechanism
which prepares a maximally entangled state of the two qubits. This state is
then maintained as the steady state of the driven, dissipative evolution. The
performance of the dissipative state preparation protocol is studied
analytically and verified numerically. In view of the experimental
implementation of the presented scheme we investigate the effects of potential
experimental imperfections and show that our scheme is robust to small
deviations in the parameters. We find that high fidelities with the target
state can be achieved both with state-of-the-art 3D, as well as with the more
commonly used 2D transmons. The promising results of our study thus open a
route for the demonstration of an entangled steady state in circuit QED.Comment: 12 pages, 5 figures; close to published versio
Desarrollo vegetativo y fenología del Mamón (Carica papaya L.) bajo dos condiciones de cultivo
La región NEA cuenta con zonas aptas para el cultivo de mamón, sin embargo las condiciones durante el invierno hacen que estos cultivos sean destinados principalmente a la industria. Las bajas temperaturas y más aún las heladas, son los principales factores limitantes para la producción de este cultivo en zonas subtropicales. Sin embargo en el NEA y en Corrientes en particular, el uso de invernaderos favorecería el desarrollo de este cultivo. Las condiciones micro-meteorológicas en este tipo de sistemas de producción se modifican por el forzado traduciéndose estas modificaciones en un comportamiento diferente del cultivo comparado con su producción al aire libre. El objetivo de este trabajo fue evaluar el desarrollo vegetativo y la fenología del cultivo de mamón bajo dos condiciones de cultivo, en invernadero y al aire libre. Se realizó la comparación entre dos tratamientos de mamón cv. Formosa: uno en condiciones de aire libre y otro en invernadero. Se midió el crecimiento vegetativo a través de la: Altura de planta; Número de hojas; Número de nudos; Volumen de copa; Diámetro de tronco y se realizó el seguimiento fenológico. Las condiciones de cultivo bajo invernadero favorecieron el desarrollo vegetativo, principalmente en altura de planta y volumen de copa en comparación con el cultivo al aire libre. La entrada en producción en condiciones de invernadero fue antes de los meses de menor temperatura. Las plantas que crecieron al aire libre presentaron un periodo desde floración a cuajado de frutos más extenso que aquellas cultivadas en invernadero, afectando la entrada en producción coincidente con los meses más fríos del año.In the Northeast region of Argentina (NEA) there are suitable zones for papaya crop, however winter conditions made that fruit destination be the industry. Low temperatures and even more the frost, are the principal limitations for papaya crop in subtropical region. However in NEA, and moreover at Corrientes, there are many greenhouse structures that could be used for papaya production. Micrometeorological condition in this type of production could influence on crop behavior compared with outside production. The aim of this work was to evaluate the vegetative development and phenology of papaya plant under two growth conditions, greenhouse and field cultivation. Two experimental plots were made using cultivar Formosa: under field cultivation and the other under greenhouse conditions. Vegetative growth was measured through plant height, number of leaves, number of nodes, canopy volume and trunk diameter. Phenological stage was monitored. Cultivation under greenhouse conditions improved vegetative growth, mainly in plant height and canopy volume compared to field conditions. Under greenhouse conditions, plants begin its production before the cooler months. Under field conditions plants had a more extensive period from flowering to fruit set that coincides with the coldest months of the year affecting the productivity.Fil: Collavino, Agostina Antonella. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; ArgentinaFil: Florentin, Jorge L.. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; ArgentinaFil: Gaiad, José Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; Argentina. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; ArgentinaFil: Alayón Luaces, Paula. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Química Básica y Aplicada del Nordeste Argentino. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Química Básica y Aplicada del Nordeste Argentino; Argentin
Brorfelde Schmidt CCD Catalog (BSCC)
The Brorfelde Schmidt CCD Catalog (BSCC) contains about 13.7 million stars,
north of +49 deg Declination with precise positions and V, R photometry. The
catalog has been constructed from the reductions of 18,667 CCD frames observed
with the Brorfelde Schmidt Telescope between 2000 and 2007. The Tycho-2 catalog
was used for astrometric and photometric reference stars. Errors of individual
positions are about 20 to 200 mas for stars in the R = 10 to 18 mag range.
External comparisons with 2MASS and SDSS reveal possible small systematic
errors in the BSCC of up to about 30 mas. The catalog is supplemented with J,
H, and K_s magnitudes from the 2MASS catalog. The catalog data file (about 550
MB ASCII, compressed) will be made available at the Strasbourg Data Center
(CDS).Comment: 16 pages, 22 figures, 2 tables, accepted by A
A Robust Determination of the Time Delay in 0957+561A,B and a Measurement of the Global Value of Hubble's Constant
Photometric monitoring of the gravitational lens system 0957+561A,B in the g
and r bands with the Apache Point Observatory (APO) 3.5 m telescope during 1996
shows a sharp g band event in the trailing (B) image light curve at the precise
time predicted from the observation of an event during 1995 in the leading (A)
image with a delay of 415 days. This success confirms the "short delay," and
the lack of any feature at a delay near 540 days rejects the "long delay" for
this system, resolving a long-standing controversy. A series of statistical
analyses of our light curve data yield a best fit delay of 417 +/- 3 days (95%
confidence interval). Recent improvements in the modeling of the lens system
(consisting of a galaxy and cluster) allow us to derive a value of the global
(at z = 0.36) value of Hubble's constant H_0 using Refsdal's method, a simple
and direct distance determination based on securely understood physics and
geometry. The result is H_0 = 63 +/- 12 km/s/Mpc (for Omega = 1) where this 95%
confidence interval is dominated by remaining lens model uncertainties.Comment: accepted by ApJ, AASTeX 4.0 preprint, 4 PostScript figure
Further Investigation of the Time Delay, Magnification Ratios, and Variability in the Gravitational Lens 0218+357
High precision VLA flux density measurements for the lensed images of
0218+357 yield a time delay of 10.1(+1.5-1.6)days (95% confidence). This is
consistent with independent measurements carried out at the same epoch (Biggs
et al. 1999), lending confidence in the robustness of the time delay
measurement. However, since both measurements make use of the same features in
the light curves, it is possible that the effects of unmodelled processes, such
as scintillation or microlensing, are biasing both time delay measurements in
the same way. Our time delay estimates result in confidence intervals that are
somewhat larger than those of Biggs et al., probably because we adopt a more
general model of the source variability, allowing for constant and variable
components. When considered in relation to the lens mass model of Biggs et al.,
our best-fit time delay implies a Hubble constant of H_o = 71(+17-23) km/s-Mpc
for Omega_o=1 and lambda_o=0 (95% confidence; filled beam). This confidence
interval for H_o does not reflect systematic error, which may be substantial,
due to uncertainty in the position of the lens galaxy. We also measure the flux
ratio of the variable components of 0218+357, a measurement of a small region
that should more closely represent the true lens magnification ratio. We find
ratios of 3.2(+0.3-0.4) (95% confidence; 8 GHz) and 4.3(+0.5-0.8) (15 GHz).
Unlike the reported flux ratios on scales of 0.1", these ratios are not
strongly significantly different. We investigate the significance of apparent
differences in the variability properties of the two images of the background
active galactic nucleus. We conclude that the differences are not significant,
and that time series much longer than our 100-day time series will be required
to investigate propagation effects in this way.Comment: 33 pages, 9 figures. Accepted for publication in ApJ. Light curve
data may be found at http://space.mit.edu/RADIO/papers.htm
Antimicrobial use in European acute care hospitals: results from the second point prevalence survey (PPS) of healthcare-associated infections and antimicrobial use, 2016 to 2017
Antimicrobial agents used to treat infections are life-saving. Overuse may result in more frequent adverse effects and emergence of multidrug-resistant microorganisms. In 2016-17, we performed the second point-prevalence survey (PPS) of healthcare-associated infections (HAIs) and antimicrobial use in European acute care hospitals. We included 1,209 hospitals and 310,755 patients in 28 of 31 European Union/European Economic Area (EU/EEA) countries. The weighted prevalence of antimicrobial use in the EU/EEA was 30.5% (95% CI: 29.2-31.9%). The most common indication for prescribing antimicrobials was treatment of a community-acquired infection, followed by treatment of HAI and surgical prophylaxis. Over half (54.2%) of antimicrobials for surgical prophylaxis were prescribed for more than 1 day. The most common infections treated by antimicrobials were respiratory tract infections and the most commonly prescribed antimicrobial agents were penicillins with beta-lactamase inhibitors. There was wide variation of patients on antimicrobials, in the selection of antimicrobial agents and in antimicrobial stewardship resources and activities across the participating countries. The results of the PPS provide detailed information on antimicrobial use in European acute care hospitals, enable comparisons between countries and hospitals, and highlight key areas for national and European action that will support efforts towards prudent use of antimicrobials
The Aesthetics of Paradoxism (Second Edition)
In the history of thought and creation, the decisive events, the great and significant moments, the strongly affirmative stages - then the imposition of the optimizing novelties - have depended on the name and prestige of a personality. Referring to those, we personalize further on. The examples are extremely numerous, even in our nearest past. When we mention a creation - in the largest sense of the term - with the name of the personality who illustrates it most extensively at a given time, we state precisely the specific importance of it; we give it, with other words, the identity to which we can refer continuously with full knowledge and without causing any confusion among the receivers. The facts are called with the name of the man who produced them, and in this way we can compose a parallel onomastic dictionary, in which the work is included in the person’s space, keeping its content. The consecrated proper names evolve through quickly imposed habits, a large range of increments that announce the essential outline of their peak production. No space for ambiguity remains when we address to readers or listeners who are somewhat acquainted with the subject and we use such terms as Aristotelianism, Platonism, Kantianism, Hegelianism, Proustianism, Eminescianism, Barbianism, etc. We have even the advantage of a centered communication when we suggest with a sole notion the work as well as its dominant features, linked with the renown of the concerned author. There is no doubt that this way of denomination, when practiced a long time, has become a reflex and now is part of the habits of a correct expression. And neither the semantic objectification of works by a person nor the inherent axiological sanction disturb anybody. Personification being inevitable in creation, the history of art can be superposed to the history of the authors or, at, least gets tangled very strongly with them. It is precisely the case with the recent literary movement of Paradoxism, conceived in Romania and affirmed in the United States, which is closely bound to the temperament, inclination, taste and creative disposition of its initiator and organizer, the poet-mathematician Florentin Smarandache (paradoxism = smarandachism, in an “internal” and already notorious interpretation)
A binary engine fuelling HD87643' s complex circumstellar environment, using AMBER/VLTI
International audienceContext. The star HD 87643, exhibiting the “B[e] phenomenon”, has one of the most extreme infrared excesses for this object class. It harbours a large amount of both hot and cold dust, and is surrounded by an extended reflection nebula. Aims. One of our major goals was to investigate the presence of a companion in HD87643. In addition, the presence of close dusty material was tested through a combination of multi-wavelength high spatial resolution observations. Methods. We observed HD 87643 with high spatial resolution techniques, using the near-IR AMBER/VLTI interferometer with baselines ranging from 60 m to 130 m and the mid-IR MIDI/VLTI interferometer with baselines ranging from 25 m to 65 m. These observations are complemented by NACO/VLT adaptive-optics-corrected images in the K and L-bands, ESO-2.2m optical Wide-Field Imager large-scale images in the B, V and R-bands, Results. We report the direct detection of a companion to HD 87643 by means of image synthesis using the AMBER/VLTI instrument. The presence of the companion is confirmed by the MIDI and NACO data, although with a lower confidence. The companion is separated by ∼ 34 mas with a roughly north-south orientation. The period must be large (several tens of years) and hence the orbital parameters are not determined yet. Binarity with high eccentricity might be the key to interpreting the extreme characteristics of this system, namely a dusty circumstellar envelope around the primary, a compact dust nebulosity around the binary system and a complex extended nebula witnessing past violent ejections
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