1,276 research outputs found
New genera and species of leaf beetles (Coleoptera: Chrysomelidae) from China and South Korea
Two new genera from China (Taumaceroides Lopatin and Yunnaniata Lopatin) and 11 new species (Smaragdina quadrimaculata Lopatin, S. oblongum Lopatin, Hyphaenia volkovitshi Lopatin, Arthrotus daliensis Lopatin, Taumaceroides sinicus Lopatin, Yunnaniata konstantinovi Lopatin, Calomicrus yunnanus Lopatin, C. minutissimus Lopatin, Hermaeophaga belkadavi Konstantinov, H. dali Konstantinov from China, and H. korotyaevi Konstantinov from South Korea) are described and illustrated. A key to Hermaeophaga species of Eurasia is presented. Since Hermaeophaga dali was collected feeding on Paederia foetida L. (Rubiaceae), which is an invasive noxious weed in the United States, this species has potential as a biological control agent of this weed
REVIEW OF THE LONGITARSUS ASPERIFOLIARUM GROUP OF SPECIES (COLEOPTERA: CHRYSOMELIDAE: ALTICINAE)
The Longitarsus asperifoliarum species group is reviewed. Four new species are de- scribed: L. hissaricus Lopatin, new species (Tadzhikistan), L. marguzoricus Konstanti- nov, new species (Tadzhikistan), L. tishechkini Konstantinov, new species (Kazakhstan), and L. violentoides Konstantinov, new species (Armenia). Longitarsus afghanicus Lo- patin is elevated to species status from its former status as L. asperifoliarum afghanicus. A key to the species and diagnostic characters for the group are provided. The setation of the apical and preapical abdominal tergites of females is recognized as a novel source of characters. Host plant and distributional data are included
Semi-invariants of symmetric quivers of finite type
Let be a symmetric quiver, where is a finite
quiver without oriented cycles and is a contravariant involution on
. The involution allows us to define a nondegenerate bilinear
form on a representation $V$ of $Q$. We shall call the representation
orthogonal if is symmetric and symplectic if is skew-symmetric.
Moreover we can define an action of products of classical groups on the space
of orthogonal representations and on the space of symplectic representations.
For symmetric quivers of finite type, we prove that the rings of
semi-invariants for this action are spanned by the semi-invariants of
determinantal type and, in the case when matrix defining is
skew-symmetric, by the Pfaffians
The H.E.S.S. central data acquisition system
The High Energy Stereoscopic System (H.E.S.S.) is a system of Imaging
Atmospheric Cherenkov Telescopes (IACTs) located in the Khomas Highland in
Namibia. It measures cosmic gamma rays of very high energies (VHE; >100 GeV)
using the Earth's atmosphere as a calorimeter. The H.E.S.S. Array entered Phase
II in September 2012 with the inauguration of a fifth telescope that is larger
and more complex than the other four. This paper will give an overview of the
current H.E.S.S. central data acquisition (DAQ) system with particular emphasis
on the upgrades made to integrate the fifth telescope into the array. At first,
the various requirements for the central DAQ are discussed then the general
design principles employed to fulfil these requirements are described. Finally,
the performance, stability and reliability of the H.E.S.S. central DAQ are
presented. One of the major accomplishments is that less than 0.8% of
observation time has been lost due to central DAQ problems since 2009.Comment: 17 pages, 8 figures, published in Astroparticle Physic
Cadaveric renal transplantation at the University of Pittsburgh: a two and one-half-year experience with the point system.
From January 1, 1986 to July 30, 1988, 530 consecutive cadaver kidney transplantations were performed with patient selection by a point system that took into account time awaiting an organ, donor-recipient matching, degree of presensitization, and some less important factors. The effect of the system was to diminish judgmental factors in case selection which in the past, had probably operated to the disadvantage of "undesirable" potential recipients, including older ones. Primary 1-year graft survival (74%) and graft survival after retransplantation (71%) were lower than in the earlier time. However, the results with triple-drug therapy using CsA, AZA and P demonstrated 88% 1-year graft survival for primary graft recipients and 74% in highly sensitized patients, with comparable patient mortality. These latter observations provide some assurance that the concepts of equitable access and efficient utilization of a scarce resource are not mutually exclusive
Instanton approach to the Langevin motion of a particle in a random potential
We develop an instanton approach to the non-equilibrium dynamics in
one-dimensional random environments. The long time behavior is controlled by
rare fluctuations of the disorder potential and, accordingly, by the tail of
the distribution function for the time a particle needs to propagate along the
system (the delay time). The proposed method allows us to find the tail of the
delay time distribution function and delay time moments, providing thus an
exact description of the long-time dynamics. We analyze arbitrary environments
covering different types of glassy dynamics: dynamics in a short-range random
field, creep, and Sinai's motion.Comment: 4 pages, 1 figur
Generation of low-temperature plasma by low-pressure arcs for synthesis of nitride coatings
Experiments were performed to study gas, metal, and mixed metal-gas plasmas. The plasmas were generated with the use of an arc evaporator and a gas-plasma source with a hot filament and hollow cathode that were operated independently or simultaneously. It has been revealed that the arc current of gas-plasma source affects the parameters of the metal-gas plasma and the element concentrations in the coatings. It has been demonstrated that the characteristics of the nitride coatings produced by plasma-assisted vacuum-arc deposition can be controlled by varying the parameters of the arc in the gas-plasma source
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