437 research outputs found
Electric dipole moments in supersymmetric theories
Intrinsic EDMs in microscopic systems at a level of sensitivity achievable in
experiments under way or foreseen are predicted in supersymmetric unified
theories. I describe this and other sources of measurable EDMs and I show how
these sources can be distinguished through experiments in different systems.Comment: 5 pages, LaTex2e using amstex.sty, amssymb.sty, apalike.sty, no
figs., to appear in Proceedings of the XXIV ITEP Winter School of Physic
Are Boltzmann Plots of Hydrogen Balmer lines a tool for identifying a subclass of S1 AGN?
It is becoming clear that we can define two different types of nearby AGN
belonging to the Seyfert 1 class (S1), on the basis of the match of the
intensities of their Broad Balmer Lines (BBL) with the Boltzmann Plots (BP).
These two types of S1 galaxies, that we call BP-S1 and NoBP-S1, are
characterized, in first approximation, by Broad Line Regions (BLR) with
different structural and physical properties. In this communication, we show
that these features can be well pointed out by a multi-wavelength analysis of
the continuum and of the broad recombination Hydrogen lines, that we carry out
on a sample of objects detected at optical and X-ray frequencies. The
investigation is addressed to verify whether BP-S1 are the ideal candidates for
the study of the kinematical and structural properties of the BLR, in order to
derive reliable estimates of the mass of their central engine and to constrain
the properties of their nuclear continuum spectrum.Comment: 26 pages, 4 figures (1 multi-paged). Accepted for publication on
Advances in Space Research. Contribution to the IX SCSLS
Distributed under Creative Commons Attribution License Contents 1 Intensity enhancement 2
We present a semi-automatic algorithm for Carotid lumen segmentation on CTA images. Our method is based on a variant of the minimal path method that models the vessel as a centerline and boundary. This is done by adding one dimension for the local radius around the centerline. The crucial step of our method is the definition of the local metrics to minimize. We have chosen to exploit the tubular structure of the vessels one wants to extract to built an anisotropic metric giving higher speed on the center of the vessels and also when the minimal path tangent is coherent with the vessels direction. Due to carotid stenosis or occlusions on the provided data, segmentation is refined using a region-based level sets
Symbiotic Stars in OGLE Data I. Large Magellanic Cloud Systems
Symbiotic stars are long-orbital-period interacting-binaries characterized by
extended emission over the whole electromagnetic range and by complex
photometric and spectroscopic variability. In this paper, the first of a
series, we present OGLE light curves of all the confirmed symbiotic stars in
the Large Magellanic Cloud, with one exception. By careful visual inspection
and combined time-series analysis techniques, we investigate for the first time
in a systematic way the photometric properties of these astrophysical objects,
trying in particular to distinguish the nature of the cool component (e.g.,
Semi-Regular Variable vs. OGLE Small-Amplitude Red Giant), to provide its
first-order pulsational ephemerides, and to link all this information with the
physical parameters of the binary system as a whole. Among the most interesting
results, there is the discovery of a 20-year-long steady fading of Sanduleak's
star, a peculiar symbiotic star known to produce the largest stellar jet ever
discovered. We discuss by means of direct examples the crucial need for
long-term multi-band observations to get a real understanding of symbiotic and
other interacting binary stars. We eventually introduce BOMBOLO, a multi-band
simultaneous imager for the SOAR 4m Telescope, whose design and construction we
are currently leading.Comment: 16 pages, 4 Tables, 12 Figures. Accepted for publication in MNRA
Automatic Construction of Evaluation Suites for Natural Language Generation Datasets
Machine learning approaches applied to NLP are often evaluated by summarizing
their performance in a single number, for example accuracy. Since most test
sets are constructed as an i.i.d. sample from the overall data, this approach
overly simplifies the complexity of language and encourages overfitting to the
head of the data distribution. As such, rare language phenomena or text about
underrepresented groups are not equally included in the evaluation. To
encourage more in-depth model analyses, researchers have proposed the use of
multiple test sets, also called challenge sets, that assess specific
capabilities of a model. In this paper, we develop a framework based on this
idea which is able to generate controlled perturbations and identify subsets in
text-to-scalar, text-to-text, or data-to-text settings. By applying this
framework to the GEM generation benchmark, we propose an evaluation suite made
of 80 challenge sets, demonstrate the kinds of analyses that it enables and
shed light onto the limits of current generation models
Posture and Locomotion Coupling: A Target for Rehabilitation Interventions in Persons with Parkinson's Disease
Disorders of posture, balance, and gait are debilitating motor manifestations of advancing Parkinson's disease requiring rehabilitation intervention. These problems often reflect difficulties with coupling or sequencing posture and locomotion during complex whole body movements linked with falls. Considerable progress has been made with demonstrating the effectiveness of exercise interventions for individuals with Parkinson's disease. However, gaps remain in the evidence base for specific interventions and the optimal content of exercise interventions. Using a conceptual theoretical framework and experimental findings, this perspective and review advances the viewpoint that rehabilitation interventions focused on separate or isolated components of posture, balance, or gait may limit the effectiveness of current clinical practices. It is argued that treatment effectiveness may be improved by directly targeting posture and locomotion coupling problems as causal factors contributing to balance and gait dysfunction. This approach may help advance current clinical practice and improve outcomes in rehabilitation for persons with Parkinson's disease
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