6,577 research outputs found
Lie group analysis of a generalized Krichever-Novikov differential-difference equation
The symmetry algebra of the differential--difference equation
where , and are arbitrary analytic functions is shown to have the
dimension 1 \le \mbox{dim}L \le 5. When , and are specific second
order polynomials in (depending on 6 constants) this is the integrable
discretization of the Krichever--Novikov equation. We find 3 cases when the
arbitrary functions are not polynomials and the symmetry algebra satisfies
\mbox{dim}L=2. These cases are shown not to be integrable. The symmetry
algebras are used to reduce the equations to purely difference ones. The
symmetry group is also used to impose periodicity and thus to
reduce the differential--difference equation to a system of coupled
ordinary three points difference equations
Molecular beam epitaxy of InAs nanowires in SiO2 nanotube templates: challenges and prospects for integration of III-Vs on Si
Guided growth of semiconductor nanowires in nanotube templates has been
considered as a potential platform for reproducible integration of III-Vs on
silicon or other mismatched substrates. Herein, we report on the challenges and
prospects of molecular beam epitaxy of InAs nanowires on SiO2/Si nanotube
templates. We show how and under which conditions the nanowire growth is
initiated by In-assisted vapor-liquid-solid growth enabled by the local
conditions inside the nanotube template. The conditions for high yield of
vertical nanowires are investigated in terms of the nanotube depth, diameter
and V/III flux ratios. We present a model that further substantiates our
findings. This work opens new perspectives for monolithic integration of III-Vs
on the silicon platform enabling new applications in the electronics,
optoelectronics and energy harvesting arena
De novo 1q21.3q22 duplication revaluation in a “cold” complex neuropsychiatric case with syndromic intellectual disability
Syndromic intellectual disability often obtains a genetic diagnosis due to the combination of first and next generation sequencing techniques, although their interpretation may require revaluation over the years. Here we report on a composite neuropsychiatric case whose phenotype includes moderate intellectual disability, spastic paraparesis, movement disorder, and bipolar disorder, harboring a 1.802 Mb de novo 1q21.3q22 duplication. The role of this duplication has been reconsidered in the light of negativity of many other genetic exams, and of the possible pathogenic role of many genes included in this duplication, potentially configuring a contiguous gene-duplication syndrome
Hubungan Baik Dengan Orang Yang Signifikan Dan Kontribusinya Terhadap Kebahagiaan Remaja Indonesia
Budaya memainkan peran penting terhadap upaya orang dalam meraih kebahagiaan. Di budaya kolektif, kebahagiaan dikonstruksikan sebagai harmoni sosial. Dengan demikian,bagi individu yang besar di budaya kolektif hubungan baik dengan orang-orang yang signifikan, seperti di Indonesia, akan mempengaruhi kebahagiaannya. Penelitian ini memiliki tiga tujuan yaitu untuk mengidentifikasi faktor-faktor yang membuat individubahagia, orang-orang yang mendukung kebahagiaan individu, dan orang-orang yang kepada mereka individu akan berbagi kebahagiaan. Responden penelitian adalah411 orang mahasiswa dari berbagai universitas di Pekanbaru.. Hasil analisis data menunjukkan bahwa memiliki relasi positif (49,7%), mendapatkan apreasiasi (23,9%), menikmati waktu luang (22,4%), dan melakukan aktifitas religius (2,8%) merupakan faktor utama bagi kebahagiaan individu di dalam kehidupan sehari-hari. Orang-orang yang mendukung dan membuat individu merasa bahagia adalah keluarga (66,8%), teman-teman (20,6%), dan orang-orang spesial (12,3%). Sementara itu, individu berbagikebahagiaan pada sahabat (47,5%), keluarga (31,9%), and pacar (14,1%). Ketiga hasil ini memperkuat gagasan bahwa hubungan dengan orang-orang yang signifikan memiliki kontribusi penting bagi kebahagiaan individu, khususnya remaja
Evidence for the naphthalene cation in a region of the interstellar medium with anomalous microwave emission
We report high resolution spectroscopy of the moderately reddened (A=3)
early type star Cernis 52 located in a region of the Perseus molecular cloud
complex with anomalous microwave emission. In addition to the presence of the
most common diffuse interstellar bands (DIBs) we detect two new interstellar or
circumstellar bands coincident to within 0.01% in wavelength with the two
strongest bands of the naphthalene cation (CH) as measured in
gas-phase laboratory spectroscopy at low temperatures and find marginal
evidence for the third strongest band.
Assuming these features are caused by the naphthalene cation, from the
measured intensity and available oscillator strengths we find that 0.008 % of
the carbon in the cloud could be in the form of this molecule. We expect
hydrogen additions to cause hydronaphthalene cations to be abundant in the
cloud and to contribute via electric dipole radiation to the anomalous
microwave emission. The identification of new interstellar features consistent
with transitions of the simplest polycyclic aromatic hydrocarbon adds support
to the hypothesis that this type of molecules are the carriers of both diffuse
interstellar bands and anomalous microwave emission.Comment: Accepted for publication in The Astrophysical Journa
Can Fraction of Inspired Oxygen Predict Extubation Failure in Preterm Infants?
Background: Prolonged mechanical ventilation in preterm infants may cause complications. We aimed to analyze the variables affecting extubation outcomes in preterm infants at high risk of extubation failure. Methods: This was a single-center, observational, retrospective study. Extubation failure was defined as survival with the need for reintubation within 72 h. Successfully extubated neonates (group 1) were compared to those with failed extubation (group 2). Multivariate logistic regression analysis evaluated factors that predicted extubation outcomes. Results: Eighty infants with a birth weight under 1000 g and/or gestational age (GA) under 28 weeks were included. Extubation failure occurred in 29 (36.2%) and success in 51 (63.8%) neonates. Most failures (75.9%) occurred within 24 h. Pre-extubation inspired oxygen fraction (FiO2) of 27% had a sensitivity of 58.6% and specificity of 64.7% for extubation failure. Post-extubation FiO2 of 32% had a sensitivity of 65.5% and specificity of 62.8% for failure. Prolonged membrane rupture (PROM) and high GA were associated with extubation success in multivariate logistic regression analysis. Conclusions: High GA and PROM were associated with extubation success. Pre-and post-extubation FiO2 values were not significantly predictive of extubation failure. Further studies should evaluate if overall assessment, including ventilatory parameters and clinical factors, can predict extubation success in neonates
Is baryon number violated when electroweak strings intercommute?
We reexamine the self-helicity and the intercommutation of electroweak
strings. A plausible argument for baryon number conservation when electroweak
strings intercommute is presented. The connection between a segment of
electroweak strings and a sphaleron is also discussed.Comment: CALT-68-1948, 11 pages, 5 figures available upon request. Replaced
with revised version. (Request should be sent to [email protected]
Some polynomial special cases for the Minimum Gap Graph Partitioning Problem
We study various polynomial special cases for the problem of partitioning a vertex-weighted undirected graph into p connected subgraphs with minimum gap between the largest and the smallest vertex weight
Finite-gap Solutions of the Vortex Filament Equation: Isoperiodic Deformations
We study the topology of quasiperiodic solutions of the vortex filament
equation in a neighborhood of multiply covered circles. We construct these
solutions by means of a sequence of isoperiodic deformations, at each step of
which a real double point is "unpinched" to produce a new pair of branch points
and therefore a solution of higher genus. We prove that every step in this
process corresponds to a cabling operation on the previous curve, and we
provide a labelling scheme that matches the deformation data with the knot type
of the resulting filament.Comment: 33 pages, 5 figures; submitted to Journal of Nonlinear Scienc
Boron and Nitrogen Doped Single walled Carbon Nanotubes as Possible Dilute Magnetic Semiconductors
The structure of single walled armchair and zig-zag carbon nanotubes having 70 atoms and two carbons replaced by boron or nitrogen is obtained at minium energy using HF/6-31G* molecular orbital theory. The calculations show that the ground state of the zig-zag tubes is a triplet state while for the armchair tubes it is a singlet. In the zig-zag tubes the density of states at the Fermi level is greater for the spin down states compared to the spin up state indicating that the doped tubes could be ferromagnetic
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