306 research outputs found
lmmuno Histochemical Profile of Endometrium in Patients With Genital Endometriosis
The aim of present study was to investigate the occurence of different lymphocyte
subsets in the endometrium of endometriosis patients and in healthy women on every
day of the menstrual cycle with special emphasis to the proliferative activity of
endometrial cells with Ki-S3 antibody. We also conducted immunohistochemical
studies of T-lymphocytes, B-lympho-cytes, macrophages, natural-killer-cells and also
of antigens class II of the histocompatibility complex (HLA-DR) during the different
phases of the menstrual cycle in endometriosis and non-endometriosis patients
Local environment of Nitrogen in GaN{y}As{1-y} epilayers on GaAs (001) studied using X-ray absorption near edge spectroscopy
X-ray absorption near-edge spectroscopy (XANES) is used to study the N
environment in bulk GaN and in GaN{y}As{1-y} epilayers on GaAs (001), for y
\~5%. Density-functional optimized structures were used to predict XANES via
multiple-scattering theory. We obtain striking agreement for pure GaN. An alloy
model with nitrogen pairs on Ga accurately predicts the threshold energy, the
width of the XANES ``white line'', and features above threshold, for the given
X-ray polarization. The presence of N-pairs may point to a role for molecular
N_2 in epitaxial growth kinetics.Comment: Four pages (PRL style) with two figure
A Fast Algorithm Finding the Shortest Reset Words
In this paper we present a new fast algorithm finding minimal reset words for
finite synchronizing automata. The problem is know to be computationally hard,
and our algorithm is exponential. Yet, it is faster than the algorithms used so
far and it works well in practice. The main idea is to use a bidirectional BFS
and radix (Patricia) tries to store and compare resulted subsets. We give both
theoretical and practical arguments showing that the branching factor is
reduced efficiently. As a practical test we perform an experimental study of
the length of the shortest reset word for random automata with states and 2
input letters. We follow Skvorsov and Tipikin, who have performed such a study
using a SAT solver and considering automata up to states. With our
algorithm we are able to consider much larger sample of automata with up to
states. In particular, we obtain a new more precise estimation of the
expected length of the shortest reset word .Comment: COCOON 2013. The final publication is available at
http://link.springer.com/chapter/10.1007%2F978-3-642-38768-5_1
Extraction of 2′-O-apiosyl-6′-O-crotonic acid-betanin from the ayrampo seed (Opuntia soehrensii) cuticle and its use as an emitting layer in an organic light-emitting diode
The molecule 2′-O-apiosyl-6′-O-crotonic acid-betanin (called Achkiy) was obtained after an ecofriendly and low-cost purification process of the extract from the ayrampo seed cuticle. Results from EDS give us an idea of the organic elements present in the ayrampo cuticle layer composed of carbon, oxygen and nitrogen. Further characterization analysis of ayrampo extract by Fourier Transform Infrared Spectrophotometry (FTIR) corroborated the presence of characteristic functional groups corresponding to carboxyl, carbonyls, hydroxyls and secondary amines. On the other hand, we have confirmed by absortion peak the glucose, apiosyl, crotonic acid and betanin at 227 nm, 276 nm, 291 nm and 534 nm bands respectively. Mass Spectrometry (MS) characterization was used finally to identify the electroactive Achkiy molecule. This molecule was tested in an Organic Light Emitting Diode (OLED) achieving a luminance of 4.8 Cd m when bias voltage of 16.5 V and a current of 34.1 mA was applied. In addition, the irradiance generated by the Achkiy layer reaches a value of ≈ 113.3 μW m emitting light with a λ ≈ 390.10 nm. These preliminary results report an interesting molecule extracted from a natural pigment wich emits light in the blue region
Site-Directed Insertion: Decision Problems, Maximality and Minimality
Site-directed insertion is an overlapping insertion operation that can be
viewed as analogous to the overlap assembly or chop operations that concatenate
strings by overlapping a suffix and a prefix of the argument strings. We
consider decision problems and language equations involving site-directed
insertion. By relying on the tools provided by semantic shuffle on trajectories
we show that one variable equations involving site-directed insertion and
regular constants can be solved. We consider also maximal and minimal variants
of the site-directed insertion operation
Implementation of Code Properties via Transducers
The FAdo system is a symbolic manipulator of formal language objects, implemented in Python. In this work, we extend its capabilities by implementing methods to manipulate transducers and we go one level higher than existing formal language systems and implement methods to manipulate objects representing classes of independent languages (widely known as code properties). Our methods allow users to define their own code properties and combine them between themselves or with fixed properties such as prefix codes, suffix codes, error detecting codes, etc. The satisfaction and maximality decision questions are solvable for any of the definable properties. The new online system LaSer allows one to query about a code property and obtain the answer in a batch mode. Our work is founded on independence theory as well as the theory of rational relations and transducers, and contributes with improved algorithms on these objects
Multi-orbital and density-induced tunneling of bosons in optical lattices
We show that multi-orbital and density-induced tunneling have a significant
impact on the phase diagram of bosonic atoms in optical lattices. Off-site
interactions lead to density-induced hopping, the so-called bond-charge
interactions, which can be identified with an effective tunneling potential and
can reach the same order of magnitude as conventional tunneling. In addition,
interaction-induced higher-band processes also give rise to strongly modified
tunneling, on-site and bond-charge interactions. We derive an extended
occupation-dependent Hubbard model with multi-orbitally renormalized processes
and compute the corresponding phase diagram. It substantially deviates from the
single-band Bose-Hubbard model and predicts strong changes of the superfluid to
Mott-insulator transition. In general, the presented beyond-Hubbard physics
plays an essential role in bosonic lattice systems and has an observable
influence on experiments with tunable interactions.Comment: 21 pages, 7 figure
Algebraic synchronization criterion and computing reset words
We refine a uniform algebraic approach for deriving upper bounds on reset
thresholds of synchronizing automata. We express the condition that an
automaton is synchronizing in terms of linear algebra, and obtain upper bounds
for the reset thresholds of automata with a short word of a small rank. The
results are applied to make several improvements in the area.
We improve the best general upper bound for reset thresholds of finite prefix
codes (Huffman codes): we show that an -state synchronizing decoder has a
reset word of length at most . In addition to that, we prove
that the expected reset threshold of a uniformly random synchronizing binary
-state decoder is at most . We also show that for any non-unary
alphabet there exist decoders whose reset threshold is in .
We prove the \v{C}ern\'{y} conjecture for -state automata with a letter of
rank at most . In another corollary, based on the recent
results of Nicaud, we show that the probability that the \v{C}ern\'y conjecture
does not hold for a random synchronizing binary automaton is exponentially
small in terms of the number of states, and also that the expected value of the
reset threshold of an -state random synchronizing binary automaton is at
most .
Moreover, reset words of lengths within all of our bounds are computable in
polynomial time. We present suitable algorithms for this task for various
classes of automata, such as (quasi-)one-cluster and (quasi-)Eulerian automata,
for which our results can be applied.Comment: 18 pages, 2 figure
Coherent multi-flavour spin dynamics in a fermionic quantum gas
Microscopic spin interaction processes are fundamental for global static and
dynamical magnetic properties of many-body systems. Quantum gases as pure and
well isolated systems offer intriguing possibilities to study basic magnetic
processes including non-equilibrium dynamics. Here, we report on the
realization of a well-controlled fermionic spinor gas in an optical lattice
with tunable effective spin ranging from 1/2 to 9/2. We observe long-lived
intrinsic spin oscillations and investigate the transition from two-body to
many-body dynamics. The latter results in a spin-interaction driven melting of
a band insulator. Via an external magnetic field we control the system's
dimensionality and tune the spin oscillations in and out of resonance. Our
results open new routes to study quantum magnetism of fermionic particles
beyond conventional spin 1/2 systems.Comment: 9 pages, 5 figure
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