97 research outputs found
Conservação e manejo dos solos. I. Planalto Rio-grandense: considerações gerais.
bitstream/item/83946/1/CNPT-CIRCULAR-2-CONSERVACAO-E-MANEJO-DOS-SOLOS-I-PLANALTO-RIO-GRANDENSE-CONSIDERACOES-GERAIS-FL.pd
Inversion formula and Parsval theorem for complex continuous wavelet transforms studied by entangled state representation
In a preceding Letter (Opt. Lett. 32, 554 (2007)) we have proposed complex
continuous wavelet transforms (CCWTs) and found Laguerre--Gaussian mother
wavelets family. In this work we present the inversion formula and Parsval
theorem for CCWT by virtue of the entangled state representation, which makes
the CCWT theory complete. A new orthogonal property of mother wavelet in
parameter space is revealed.Comment: 4 pages no figur
The HARPS search for southern extra-solar planets XLI. A dozen planets around the M dwarfs GJ 3138, GJ 3323, GJ 273, GJ 628, and GJ 3293
Context. Low mass stars are currently the best targets for searches for rocky
planets in the habitable zone of their host star. Over the last 13 years,
precise radial velocities measured with the HARPS spectrograph have identified
over a dozen super-Earths and Earth-mass planets (msin i<10Mearth ) around M
dwarfs, with a well understood selection function. This well defined sample
informs on their frequency of occurrence and on the distribution of their
orbital parameters, and therefore already constrains our understanding of
planetary formation. The subset of these low-mass planets that were found
within the habitable zone of their host star also provide prized targets for
future atmospheric biomarkers searches. Aims. We are working to extend this
planetary sample to lower masses and longer periods through dense and long-term
monitoring of the radial velocity of a small M dwarf sample. Methods. We
obtained large numbers of HARPS spectra for the M dwarfs GJ 3138, GJ 3323, GJ
273, GJ 628 and GJ 3293, from which we derived radial velocities (RVs) and
spectroscopic activity indicators. We searched them for variabilities,
periodicities, Keplerian modulations and correlations, and attribute the
radial-velocity variations to combinations of planetary companions and stellar
activity. Results. We detect 12 planets, of which 9 are new with masses ranging
from 1.17 to 10.5 Mearth . Those planets have relatively short orbital periods
(P<40 d), except two of them with periods of 217.6 and 257.8 days. Among these
systems, GJ 273 harbor two planets with masses close to the one of the Earth.
With a distance of 3.8 parsec only, GJ 273 is the second nearest known
planetary system - after Proxima Centauri - with a planet orbiting the
circumstellar habitable zone.Comment: 19 pages, 24 figures. Astronomy and Astrophysics in pres
ExTrA: Exoplanets in Transit and their Atmospheres
The ExTrA facility, located at La Silla observatory, will consist of a
near-infrared multi-object spectrograph fed by three 60-cm telescopes. ExTrA
will add the spectroscopic resolution to the traditional differential
photometry method. This shall enable the fine correction of color-dependent
systematics that would otherwise hinder ground-based observations. With both
this novel method and an infrared-enabled efficiency, ExTrA aims to find
transiting telluric planets orbiting in the habitable zone of bright nearby M
dwarfs. It shall have the versatility to do so by running its own independent
survey and also by concurrently following-up on the space candidates unveiled
by K2 and TESS. The exoplanets detected by ExTrA will be amenable to
atmospheric characterisation with VLTs, JWST, and ELTs and could give our first
peek into an exo-life laboratory.Comment: 15 pages, 11 figures, SPIE 201
The quantum state vector in phase space and Gabor's windowed Fourier transform
Representations of quantum state vectors by complex phase space amplitudes,
complementing the description of the density operator by the Wigner function,
have been defined by applying the Weyl-Wigner transform to dyadic operators,
linear in the state vector and anti-linear in a fixed `window state vector'.
Here aspects of this construction are explored, with emphasis on the connection
with Gabor's `windowed Fourier transform'. The amplitudes that arise for simple
quantum states from various choices of window are presented as illustrations.
Generalized Bargmann representations of the state vector appear as special
cases, associated with Gaussian windows. For every choice of window, amplitudes
lie in a corresponding linear subspace of square-integrable functions on phase
space. A generalized Born interpretation of amplitudes is described, with both
the Wigner function and a generalized Husimi function appearing as quantities
linear in an amplitude and anti-linear in its complex conjugate.
Schr\"odinger's time-dependent and time-independent equations are represented
on phase space amplitudes, and their solutions described in simple cases.Comment: 36 pages, 6 figures. Revised in light of referees' comments, and
further references adde
An Algebraic Approach to Linear-Optical Schemes for Deterministic Quantum Computing
Linear-Optical Passive (LOP) devices and photon counters are sufficient to
implement universal quantum computation with single photons, and particular
schemes have already been proposed. In this paper we discuss the link between
the algebraic structure of LOP transformations and quantum computing. We first
show how to decompose the Fock space of N optical modes in finite-dimensional
subspaces that are suitable for encoding strings of qubits and invariant under
LOP transformations (these subspaces are related to the spaces of irreducible
unitary representations of U(N)). Next we show how to design in algorithmic
fashion
LOP circuits which implement any quantum circuit deterministically. We also
present some simple examples, such as the circuits implementing a CNOT gate and
a Bell-State Generator/Analyzer.Comment: new version with minor modification
Multichannel response analysis on 2D projection views for detection of clustered microcalcifications in digital breast tomosynthesis
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134871/1/mp8694.pd
Homogeneously derived transit timings for 17 exoplanets and reassessed TTV trends for WASP-12 and WASP-4
We homogeneously analyse ∼3.2 × 105 photometric measurements for ∼1100 transit lightcurves belonging to 17 exoplanet hosts. The photometric data cover 16 years 2004–2019 and include amateur and professional observations. Old archival lightcurves were reprocessed using up-to-date exoplanetary parameters and empirically debiased limb-darkening models. We also derive self-consistent transit and radial-velocity fits for 13 targets. We confirm the nonlinear TTV trend in the WASP-12 data at a high significance, and with a consistent magnitude. However, Doppler data reveal hints of a radial acceleration about ( − 7.5 ± 2.2) m/s/yr, indicating the presence of unseen distant companions, and suggesting that roughly 10 per cent of the observed TTV was induced via the light-travel (or Roemer) effect. For WASP-4, a similar TTV trend suspected after the recent TESS observations appears controversial and model-dependent. It is not supported by our homogeneus TTV sample, including 10 ground-based EXPANSION lightcurves obtained in 2018 simultaneously with TESS. Even if the TTV trend itself does exist in WASP-4, its magnitude and tidal nature are uncertain. Doppler data cannot entirely rule out the Roemer effect induced by possible distant companions
Ectodysplasin A in Biological Fluids and Diagnosis of Ectodermal Dysplasia
The tumor necrosis factor (TNF) family ligand ectodysplasin A (EDA) is produced as 2 full-length splice variants, EDA1 and EDA2, that bind to EDA receptor (EDAR) and X-linked EDA receptor (XEDAR/EDA2R), respectively. Inactivating mutations in Eda or Edar cause hypohidrotic ectodermal dysplasia (HED), a condition characterized by malformations of the teeth, hair and glands, with milder deficiencies affecting only the teeth. EDA acts early during the development of ectodermal appendages-as early as the embryonic placode stage-and plays a role in adult appendage function. In this study, the authors measured EDA in serum, saliva and dried blood spots. The authors detected 3- to 4-fold higher levels of circulating EDA in cord blood than in adult sera. A receptor binding-competent form of EDA1 was the main form of EDA but a minor fraction of EDA2 was also found in fetal bovine serum. Sera of EDA-deficient patients contained either background EDA levels or low levels of EDA that could not bind to recombinant EDAR. The serum of a patient with a V262F missense mutation in Eda, which caused a milder form of X-linked HED (XLHED), contained low levels of EDA capable of binding to EDAR. In 2 mildly affected carriers, intermediate levels of EDA were detected, whereas a severely affected carrier had no active EDA in the serum. Small amounts of EDA were also detectable in normal adult saliva. Finally, EDA could be measured in spots of wild-type adult or cord blood dried onto filter paper at levels significantly higher than that measured in EDA-deficient blood. Measurement of EDA levels combined with receptor-binding assays might be of relevance to aid in the diagnosis of total or partial EDA deficiencies
What is Donald Trump?:Forms of 'Celebrity' in Celebrity Politics
It is widely assumed that Donald Trump is a ‘celebrity politician’, and that he has cashed in his success on the reality show The Apprentice to secure political credibility and attention. In this respect he fits what Matthew Wood et al (2016) have labelled the ‘superstar celebrity politician’. This characterisation is the latest in a number of refinements to the definition and understanding of the celebrity politician. While this is a helpful move, I want to suggest that it might overlook one key dimension of the phenomenon. Definitions of the celebrity politician tend to focus on the source of their ‘celebrity’ – how they became famous, rather than on how they act out their celebrity role. This latter dimension features in media coverage, where journalists and commentators borrow from showbusiness to describe politics, but is less often analysed in the political science literature. It matters because, I want to suggest, celebrity politicians like Trump act as stars, whether of reality television, rock music or film. They do not just resemble stars; they are them. This is evident in how they are represented, how they perform and how their ‘fans’ respond to them. It is also symptomatic of wider changes in the conduct and form of the contemporary, mediatised political realm
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