19,015 research outputs found
The Inhomogeneous Hall's Ray
We show that the inhomogenous approximation spectrum, associated to an
irrational number \alpha\ always has a Hall's Ray; that is, there is an
\epsilon>0 such that [0,\epsilon) is a subset of the spectrum. In the case when
\alpha\ has unbounded partial quotients we show that the spectrum is just a
ray.Comment: Fixed typos in bibliograph
Maximum-entropy Surrogation in Network Signal Detection
Multiple-channel detection is considered in the context of a sensor network
where raw data are shared only by nodes that have a common edge in the network
graph. Established multiple-channel detectors, such as those based on
generalized coherence or multiple coherence, use pairwise measurements from
every pair of sensors in the network and are thus directly applicable only to
networks whose graphs are completely connected. An approach introduced here
uses a maximum-entropy technique to formulate surrogate values for missing
measurements corresponding to pairs of nodes that do not share an edge in the
network graph. The broader potential merit of maximum-entropy baselines in
quantifying the value of information in sensor network applications is also
noted.Comment: 4 pages, submitted to IEEE Statistical Signal Processing Workshop,
August 201
Female impersonation as an alternative reproductive strategy in giant cuttlefish
Out of all the animals, cephalopods possess an unrivalled ability to change their shape and body patterns. Our observations of giant cuttlefish (Sepia apama) suggest this ability has allowed them to evolve alternative mating strategies in which males can switch between the appearance of a female and that of a male in order to foil the guarding attempts of larger males. At a mass breeding aggregation in South Australia, we repeatedly observed single small males accompanying mating pairs. While doing so, the small male assumed the body shape and patterns of a female. Such males were never attacked by the larger mate-guarding male. On more than 20 occasions, when the larger male was distracted by another male intruder, these small males, previously indistinguishable from a female, were observed to change body pattern and behaviour to that of a male in mating display. These small males then attempted to mate with the female, often with success. This potential for dynamic sexual mimicry may have played a part in driving the evolution of the remarkable powers of colour and shape transformation which characterize the cephalopods
Reconciling taxonomy and phylogenetic inference: formalism and algorithms for describing discord and inferring taxonomic roots
Although taxonomy is often used informally to evaluate the results of
phylogenetic inference and find the root of phylogenetic trees, algorithmic
methods to do so are lacking. In this paper we formalize these procedures and
develop algorithms to solve the relevant problems. In particular, we introduce
a new algorithm that solves a "subcoloring" problem for expressing the
difference between the taxonomy and phylogeny at a given rank. This algorithm
improves upon the current best algorithm in terms of asymptotic complexity for
the parameter regime of interest; we also describe a branch-and-bound algorithm
that saves orders of magnitude in computation on real data sets. We also
develop a formalism and an algorithm for rooting phylogenetic trees according
to a taxonomy. All of these algorithms are implemented in freely-available
software.Comment: Version submitted to Algorithms for Molecular Biology. A number of
fixes from previous versio
Sun-Sized Water Vapor Masers in Cepheus A
We present the first VLBI observations of a Galactic water maser (in Chepeus
A) made with a very long baseline interferometric array involving the
RadioAstron Earth-orbiting satellite station as one of its elements. We
detected two distinct components at -16.9 and 0.6 km/s with a fringe spacing of
66 microarcseconds. In total power, the 0.6 km/s component appears to be a
single Gaussian component of strength 580 Jy and width of 0.7 km/s.
Single-telescope monitoring showed that its lifetime was only 8~months. The
absence of a Zeeman pattern implies the longitudinal magnetic field component
is weaker than 120 mG. The space-Earth cross power spectrum shows two
unresolved components smaller than 15 microarcseconds, corresponding to a
linear scale of 1.6 x 10^11 cm, about the diameter of the Sun, for a distance
of 700 pc, separated by 0.54 km/s in velocity and by 160 +/-35 microarcseconds
in angle. This is the smallest angular structure ever observed in a Galactic
maser. The brightness temperatures are greater than 2 x 10^14K, and the line
widths are 0.5 km/s. Most of the flux (about 87%) is contained in a halo of
angular size of 400 +/- 150 microarcseconds. This structure is associated with
the compact HII region HW3diii. We have probably picked up the most prominent
peaks in the angular size range of our interferometer. We discuss three
dynamical models: (1) Keplerian motion around a central object, (2) two chance
overlapping clouds, and (3) vortices caused by flow around an obstacle (i.e.,
von Karman vortex street) with Strouhal number of about~0.3.Comment: 15 pages, 9 figures. Accepted for publication in ApJ, February 16,
201
String effects and the distribution of the glue in mesons at finite temperature
The distribution of the gluon action density in mesonic systems is
investigated at finite temperature. The simulations are performed in quenched
QCD for two temperatures below the deconfinment phase. Unlike the gluonic
profiles displayed at T=0, the action density iso-surfaces display a
prolate-spheroid like shape. The curved width profile of the flux-tube is found
to be consistent with the prediction of the free Bosonic string model at large
distances.Comment: 14 pages,10 figure
Preparation and Characterization of Cerium (III) Doped Captopril Nanoparticles and Study of their Photoluminescence Properties
Indexación: Web of Science. DOAJ.In this research Ce3+ doped Captopril nanoparticles (Ce3+ doped CAP-NP) were prepared by a cold welding process and have been studied. Captopril may be applied in the treatment of hypertension and some types of congestive heart failure and for preventing kidney failure due to high blood pressure and diabetes. CAP-NP was synthesized by a cold welding process. The cerium nitrate was added at a ratio of 10% and the optical properties have been studied by photoluminescence (PL). The synthesized compounds were characterized by Fourier transform infrared spectroscopy. The size of CAP-NP was calculated by X-ray diffraction (XRD). The size of CAP-NP was in the range of 50 nm. Morphology of surface of synthesized nanoparticles was studied by scanning electron microscopy (SEM). Finally the luminescence properties of undoped and doped CAP-NP were compared. PL spectra from undoped CAP-NP show a strong pack in the range of 546 nm after doped cerium ion into the captopril appeared two bands at 680 and 357 nm, which is ascribed to the well-known 5d–4f emission band of the cerium.http://www.degruyter.com/view/j/chem.2016.14.issue-1/chem-2016-0008/chem-2016-0008.xm
Substance Abuse, Families, and Unified Family Courts: The Creation of a Caring Justice System
This article proposes an approach to family law decision-making tailored to assist families plagued by substance abuse. Substance abuse is linked to social, health, and economic problems facing Americans today and is a factor for a substantial number of family law litigants. By failing to address substance abuse issues, the family repeatedly may need to seek court intervention. The unified family court model is the concept of a single court that coordinates the work of independent agencies and tribunals, each with some limited role in resolving the problems incident to a family\u27s legal matters. Professor Babb has created an interdisciplinary framework for a unified family court, based on therapeutic jurisprudence and the ecology of human development, to help judges and other court professionals consider the many influences on human behavior and family life, thereby empowering the system to offer more pragmatic and effective solutions to contemporary family legal issues. The authors use the Family Division of the Circuit Court for Baltimore City, Maryland, as a case study to illustrate the proposed model. The authors describe the court structure, role of court personnel, and court services. Among the court services are substance abuse resources for litigants. If a judge and/or other court personnel are concerned about substance abuse, they may refer the litigant to a court clinical social worker, who evaluates litigants for substance abuse, prepares a court report, and refers family members to treatment as necessary. For this system to work, expertise in addiction and substance abuse is imperative. The authors conclude that all family justice systems must make a commitment to address substance abuse issues, both by understanding how these issues affect family law cases and by developing policies and procedures to effectively respond to the problem
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