94 research outputs found
Nanofabricated media with negative permeability at visible frequencies
We report a nanofabricated medium made of electromagnetically coupled pairs
of gold dots with geometry carefully designed at a 10-nm level. The medium
exhibits strong magnetic response at visible-light frequencies, including bands
with negative \mu. The magnetism arises due to the excitation of quadrupole
plasmon resonances. Our approach shows for the first time the feasibility of
magnetism at optical frequencies and paves a way towards magnetic and
left-handed components for visible optics.Comment: 16 pages, 4 figures. submitted to Nature on 1 April 200
Gain switching of an external cavity grating-coupled surface emitting laser with wide tunability
The gain-switched, single frequency operation of an external cavity grating-coupled surface emitting laser with a wavelength tuning range of 100 nm was presented. The light in the grating section was coupled out of the laser at a specific angle to the surface of the device. Analysis showed that within the driving current range, lasing in the device only occurred when the external cavity was properly aligned
Multipoint Schur algorithm and orthogonal rational functions: convergence properties, I
Classical Schur analysis is intimately connected to the theory of orthogonal
polynomials on the circle [Simon, 2005]. We investigate here the connection
between multipoint Schur analysis and orthogonal rational functions.
Specifically, we study the convergence of the Wall rational functions via the
development of a rational analogue to the Szeg\H o theory, in the case where
the interpolation points may accumulate on the unit circle. This leads us to
generalize results from [Khrushchev,2001], [Bultheel et al., 1999], and yields
asymptotics of a novel type.Comment: a preliminary version, 39 pages; some changes in the Introduction,
Section 5 (Szeg\H o type asymptotics) is extende
Influence of boric anhydride upon the physical and chemical properties of ferrosilicon slag
The authors study the influence of boric anhydride upon the physical and chemical properties of slag in the manufacture of ferrosilicon. It is established that adding boric anhydride to the slag changes its refractory quality and its viscosity and eases pouring slag and metal. Slags with optimal composition and properties are described
Description of a new species of soil algae, Parietochloris grandis sp. nov., and study of its fatty acid profiles under different culturing conditions
© 2018 Elsevier B.V. The new species Parietochloris grandis sp. nov. is described from forest soil in the Dnipropetrovsk region, Ukraine. The description is based on morphological features and the phylogenetic analysis of partial SSU rDNA and rbcL genes. Phylogenetic analysis places P. grandis in the Parietochloris clade, within the family Trebouxiophyceae. The novel strain formed a strongly supported monophyletic lineage with the type species of Parietochloris, P. alveolaris. P. grandis differed from other species in the Parietochloris clade by the size and form of vegetative cells and the large number of zoospores in zoosporangia. A number of experiments with different phosphates and nitrates concentrations were conducted to evaluate changes in fatty acid profile and biomass. The dominant fatty acids during cultivation on standard BG-11 medium, as well as with the phosphates concentrations ranged from 0.22 to 2 mM, were linoleic acid (24–25%), palmitic acid (12–14%), linolenic acid (9–12%), and oleic acid (7–11%). The content of arachidonic acid and eicosapentaenoic acid ranged from 3.5 to 4.5% and 0.7% to 0.8%, respectively. The fatty acid profile and total fatty acids varied significantly under different nutrient deficiency. The greatest variation was found for oleic acid (9–46%) and linolenic acid (2–13%). The percentage of arachidonic acid was the highest with a standard nitrates concentration in the medium (5%) and the lowest in the absence of phosphates and nitrates (1.3–1.5%), but the absolute content in dry biomass was similar in all variants of the experiment (6.5–9.3 mg g−1 dry weight). The absence of nitrogen and both nitrogen and phosphorus led to a 3–fold increase in TFA in comparison with the control. Thus, this strain can be considered in biotechnological application as a potential producer of the essential linoleic acid or oleic acid
Differential diagnostic utilities of combined testing for islet cell antibody, glutamic acid decarboxylase antibody, and tyrosine phosphatase antibody
Background. Beta-cell antibody tests are used for the differential diagnosis of diabetes mellitus. They permit to discriminate between the type 1 diabetes (T1D) and non-autoimmune diabetes types. To choose an appropriate test for ruling in or ruling out the T1D a physician needs to know how conclusive test results are. The most powerful estimate of test conclusiveness is its likelihood ratio (LHR). The higher LHR of a positive result (LHR+), the more posttest probability of T1D; the lower LHR of a negative result (LHR), the less posttest probability of T1D.
Aims. To compare conclusiveness of single and combined tests for antibodies to islet cells (ICA), glutamate decarboxylase (GADA), and tyrosine phosphatase IA-2 (IA-2A), and to evaluate posttest probabilities of T1D at various pretest probabilities.
Methods. All antibodies were tested in parallel in 169 children and adolescents with a new-onset T1D, and in 169 persons without this disease. ICA, GADA, and IA-2A were determined by indirect immunofluorescence, radioimmune assay, and ELISA, respectively. LHR+ and LHR were calculated with the MedCalc Statistical Software. Posttest T1D probabilities were calculated from Bayes theorem-based equation.
Results. Among single tests, an ICA test had the greatest LHR+ and the smallest LHR, and consequently was the most reliable either for ruling in or ruling out the T1D. Among test combinations, an ICAGADA combination had the greatest LHR+ and was the most suitable for T1D confirmation. The triple combination ICAGADAIA-2A had the smallest LHR and was the most suitable for T1D exclusion.
Conclusions. In the differential diagnosis of diabetes, the most appropriate test for ruling in the T1D is the double combination ICAGADA. With both antibodies positive, this combination provides the highest posttest T1D probabilities at any pretest probability. The most appropriate test for ruling out the T1D is the triple combination ICAGADAIA-2A. With all three antibodies negative, this combination provides the lowest posttest T1D probabilities
Language of Lullabies: The Russification and De-Russification of the Baltic States
This article argues that the laws for promotion of the national languages are a legitimate means for the Baltic states to establish their cultural independence from Russia and the former Soviet Union
Price and Price Formation in the USSR
In the course of building communism, it is our task to make still greater use of, and to improve, the financial and credit levers, financial control, prices, and profits.
Algorithms of master models for designing generators and power system parts synchronizer
The technique for designing the automated control systems with a master model is proposed to be used for developing the adaptive devices for synchronizing generators and power system parts with high performance. The program motion trajectories for relative movement parameters of generator stress vectors and the parts of power systems formed on a control interval by synchronization are considered as the master models. The paper introduces the generalized structural-functional scheme of adaptive synchronization device and two advanced algorithms of master model operation. Each algorithm without overshoot delivers zero kinetic and potential energy values of synchronized object relative motion at the end of control interval. The authors tested the algorithms modeling synchronization of power system parts in Mustang
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