4,255 research outputs found
Trial incentives in sequential litigation
We analyze when and why trials can emerge in equilibrium when a defendant may face future plaintiffs. An initial trial serves as an experiment that the defendant can run to induce subsequent potential plaintiffs to learn about their chances of winning. The initial case may go to trial when a favorable trial outcome for the defense can deter potential future plaintiffs from filing lawsuits. Possible future meritless lawsuits further raise the attraction of an initial trial. We also derive the impact of the plaintiff's bargaining power and the heterogeneity in the body of future plaintiffs
Quantum simulation of exotic PT-invariant topological nodal loop bands with ultracold atoms in an optical lattice
Since the well-known PT symmetry has its fundamental significance and
implication in physics, where PT denotes the combined operation of
space-inversion P and time-reversal T, it is extremely important and intriguing
to completely classify exotic PT-invariant topological metals and to physically
realize them. Here we, for the first time, establish a rigorous classification
of topological metals that are protected by the PT symmetry using KO-theory. As
a physically realistic example, a PT-invariant nodal loop (NL) model in a 3D
Brillouin zone is constructed, whose topological stability is revealed through
its PT-symmetry-protected nontrivial Z2 topological charge. Based on these
exact results, we propose an experimental scheme to realize and to detect
tunable PT-invariant topological NL states with ultracold atoms in an optical
lattice, in which atoms with two hyperfine spin states are loaded in a
spin-dependent 3D OL and two pairs of Raman lasers are used to create
out-of-plane spin-flip hopping with site-dependent phase. Such a realistic
cold-atom setup can yield topological NL states, having a tunable ring-shaped
band-touching line with the two-fold degeneracy in the bulk spectrum and
non-trivial surface states. The states are actually protected by the combined
PT symmetry even in the absence of both P and T symmetries, and are
characterized by a Z2-type invariant (a quantized Berry phase). Remarkably, we
demonstrate with numerical simulations that (i) the characteristic NL can be
detected by measuring the atomic transfer fractions in a Bloch-Zener
oscillation; (ii) the topological invariant may be measured based on the
time-of-flight imaging; and (iii) the surface states may be probed through
Bragg spectroscopy. The present proposal for realizing topological NL states in
cold atom systems may provide a unique experimental platform for exploring
exotic PT-invariant topological physics.Comment: 11 pages, 6 figures; accepted for publication in Phys. Rev.
Itk and Fyn Make Independent Contributions to T Cell Activation
Itk is a member of the Btk/Tec/Itk family of nonreceptor protein tyrosine kinases (PTKs), and has been implicated in T cell antigen receptor (TCR) signal transduction. Lck and Fyn are the Src-family nonreceptor PTKs that are involved in TCR signaling. To address the question of how these members of different families of PTKs functionally contribute to T cell development and to T cell activation, mice deficient for both Itk and either Lck or Fyn were generated. The Itk/Lck doubly deficient mice exhibited a phenotype similar to that of Lck-deficient mice. The phenotype of the Itk/Fyn doubly deficient mice was similar to that of Itk deficient mice. However the Itk/Fyn doubly deficient mice exhibited a more severe defect in TCR-induced proliferation of thymocytes and peripheral T cells than did mice deficient in either kinase alone. These data support the notion that Itk and Fyn both make independent contributions to TCR-induced T cell activation
The effect of NaCl stress on the germination of seed and growth of wild species and cultivated varieties of tomato
In this study, a cultivated species (Lycopersicon esculentum 'Moneymaker') and a salt-tolerant wild species of tomato (Lycopersicon pimpinellifolium 'PI365967') were used to study growth characteristics within solutions of varying NaCl concentrations. Results show that the germination rates of PI365967 and Moneymaker were 100% under concentrations of 0 mmol/L NaCl. The germination of both types of plants delayed when treated with a 100 mmol/L NaCl conditional, but the germination rate of PI365967 was always significantly higher than Moneymaker. In the seedling growth period, the growth of roots and aerial parts of PI365967 and Moneymaker were inhibited under NaCl stress. However, the latter suffered a greater extent of inhibition than the former. Under a 200 mmol/L NaCl treatment, the growth of Moneymaker was strongly inhibited, and accompanied by chlorosis, but PI365967 maintained a good growth trend. Moreover, the degree of inhibition was small. Whilst gradually increasing the concentration of NaCl to 200 mmol/L, we found that the adaptation of the two types of tomato to salt stress increased (35 days after treatment). The plants of Moneymaker treated directly with concentrations of 200 mmol/L NaCl all died, but the plants treated with a gradual increase in NaCl concentration continued to grow at a slow rate. PI365967 had new lateral roots and buds grew as well. The results indicate that appropriate exercise of the salt stress can improve the salt-tolerance of tomato. It should be noted that PI365967 had greater capability of salt-tolerance.Key words: Wild species and cultivated variety of tomato, germination of seed, growth of seedling, NaCl stress, salt-tolerant
L'utilité du programme d'extension du doctorat en médecine dans l'éducation médicale canadienne
The performance of distance protection relay on series compensated line under fault conditions
Abstract: This paper presents the behaviour of the distance protection relays on a series compensated transmission line under fault conditions. Series compensation presents distance protection elements with unorthodox line impedance and as a result the relays may operate incorrectly. Sub-harmonic oscillations and non-linearity of the line impedance are some of the challenges introduced by series compensation of transmission lines. The study is carried out in a Digsilent power factory environment and results pertaining to the response of the distance relay on a 400 kV series compensated line under fault conditions are presente
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