38,216 research outputs found
Witt kernels of quadratic forms for multiquadratic extensions in characteristic 2
Let be a field of characteristic and let be a purely
inseparable extension of exponent . We show that the extension is excellent
for quadratic forms. Using the excellence we recover and extend results by
Aravire and Laghribi who computed generators for the kernel of the
natural restriction map between the Witt groups of quadratic
forms of and , respectively, where is a finite multiquadratic
extension of separability degree at most .Comment: 9 page
The Symmetrical Immune Network Theory and a New HIV Vaccine Concept
The symmetrical immune network theory is based on Jerne’s network hypothesis. An improved version of the theory is presented. The theory is characterized by symmetrical stimulatory, inhibitory and killing interactions between idiotypic and antiidiotypic immune system components. In this version killing is ascribed to IgM antibodies, while IgG antibodies are stimulatory. In the symmetrical immune network theory T cells make specific T cell factors, that have a single V region, and are cytophilic for non-specific accessory cells (A cells, including macrophages and monocytes) and play a role in the system switching between stable steady states. A recurring theme in the theory is the concept of co selection. Co-selection is the mutual positive selection of individual members from within two diverse populations, such that selection of members within each population is dependent on interaction with (recognition of) one or more members within the other population. Prior to exposure to an antigen, antigen-specific and antiidiotypic T cells are equally diverse. This equality is a form of symmetry. Immune responses with the production of IgG involve co selection of the antigen-specific and antiidiotypic classes with the breaking of this diversity symmetry, while induction of unresponsiveness involves co-selection without the breaking of diversity symmetry. The theory resolves the famous I-J paradox of the 1980s, based on co selection of helper T cells with some affinity for MHC class II and suppressor T cells that are anti-anti-MHC class II. The theory leads to three experimentally testable predictions concerning I-J. The theory includes a model for HIV pathogenesis, and suggests that polyclonal IgG from many donors given in immunogenic form may be an effective vaccine for protection against infection with HIV. Surprisingly, a mathematical model that simulates the autonomous dynamics of the system is the same as one that models a previously described neural network
Torts and the Protection of "Legally Recognized" Interests
The law of torts plays an important role in completing the legal property rights system by defining the extent to which property is protected from harm. It does this by defining the kinds of interests that will be recognized and protected from harm by the courts, the duty of care owed these recognized interests by others, and the manner in which they will be protected through monetary compensation, restitution, or injunction. Together, these three elements of torts define a right in the “bundle of rights” that constitute property. In this paper, we develop a systematic approach to formalizing the nature of the property rights protected by tort law. We use this approach to reexamine the literature on compensation for nonpecuniary damages. This reexamination demonstrates how recognizing tort’s role in defining property rights and having a way of formalizing these rights can provide deeper insight into old questions torts scholarship.torts, property rights, liability, compensation, damages, insurance
Dielectric relaxation in chevron surface stabilized ferroelectric liquid crystals
The dielectric response of surface stabilized ferroelectric liquid crystals
with chevron layer structure is studied within low and intermediate frequency
ranges, characteristic for collective molecular excitations. By analytically
solving the dynamic equation for collective molecular fluctuations under a weak
alternating electric field, it is demonstrated that chevron cells stabilized by
both nonpolar and polar surface interactions undergo at medium frequencies two
Debye relaxation processes, connected with two chevron slabs, on opposite sides
of the interface plane. This result is confirmed, experimentally, making use of
the electro-optic technique. Based on qualitative arguments supported by
microscopic observations of zigzag defects at different frequencies and
amplitudes of the external electric field, it is shown that, at low
frequencies, the electro-optic response of chevron samples is determined by
three kinds of motions of zigzag walls. The first two dynamic categories are
related to collective relaxation processes at weak fields, within smectic A
layers forming zigzag walls, and drift or creep motions of thick walls occuring
at stronger field amplitudes. Dynamic processes of the third kind correspond to
sliding of zigzag walls, which appear at yet stronger field amplitudes, but
below the switching threshold.Comment: 9 pages 10 figure
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