3,039 research outputs found
Antibody response to streptococcal cell wall antigens associated with experimental arthritis in rats.
The antibody response to group A streptococcal cell wall components was measured in rats during the development of chronic, remittent experimental arthritis. The arthritis was induced by a single intraperitoneal injection of an aqueous suspension of group A streptococcal cell wall fragments and antibodies were measured by a radioactive antigen-binding assay. Antibodies in serum against both peptidoglycan and A polysaccharide reached maximum levels at 1 or 2 weeks and declined to preimmunization levels by day 63. The kinetics and magnitude of the antibody responses were similar in neonatally thymectomized and non-thymectomized rats. A relationship between chronic joint lesions and anti-peptidoglycan concentration in serum was indicated, since all rats which produced high levels of antibody developed severe chronic arthritis. However, 46% of the rats which produced very low levels of antibody also developed moderate to severe arthritis. There was no correlation between anti-A polysaccharide antibodies and joint disease, although the concentration of this antibody was 10- to 100-fold greater than the anti-peptidoglycan. We conclude that antibody can be a component in the pathogenesis of this experimental model of arthritis, but its role requires further elucidation
ARPES and NMTO Wannier Orbital Theory of LiMoO - Implications for Unusually Robust Quasi-One Dimensional Behavior
We present the results of a combined study by band theory and angle resolved
photoemission spectroscopy (ARPES) of the purple bronze,
LiMoO. Structural and electronic origins of its unusually
robust quasi-one dimensional (quasi-1D) behavior are investigated in detail.
The band structure, in a large energy window around the Fermi energy, is
basically 2D and formed by three Mo -like extended Wannier orbitals,
each one giving rise to a 1D band running at a 120 angle to the two
others. A structural "dimerization" from to gaps
the and bands while leaving the bands metallic in the gap, but
resonantly coupled to the gap edges and, hence, to the other directions. The
resulting complex shape of the quasi-1D Fermi surface (FS), verified by our
ARPES, thus depends strongly on the Fermi energy position in the gap, implying
a great sensitivity to Li stoichiometry of properties dependent on the FS, such
as FS nesting or superconductivity. The strong resonances prevent either a
two-band tight-binding model or a related real-space ladder picture from giving
a valid description of the low-energy electronic structure. We use our extended
knowledge of the electronic structure to newly advocate for framing
LiMoO as a weak-coupling material and in that framework can
rationalize both the robustness of its quasi-1D behavior and the rather large
value of its Luttinger liquid (LL) exponent . Down to a temperature of
6K we find no evidence for a theoretically expected downward
renormalization of perpendicular single particle hopping due to LL fluctuations
in the quasi-1D chains.Comment: 53 pages, 17 Figures, 6 year
Product Measure Steady States of Generalized Zero Range Processes
We establish necessary and sufficient conditions for the existence of
factorizable steady states of the Generalized Zero Range Process. This process
allows transitions from a site to a site involving multiple particles
with rates depending on the content of the site , the direction of
movement, and the number of particles moving. We also show the sufficiency of a
similar condition for the continuous time Mass Transport Process, where the
mass at each site and the amount transferred in each transition are continuous
variables; we conjecture that this is also a necessary condition.Comment: 9 pages, LaTeX with IOP style files. v2 has minor corrections; v3 has
been rewritten for greater clarit
Recent Developments in the Law of the Sea IV: A Synopsis
This Article presents an annual synopsis of important events pertaining to the law of the sea which occurred between February 1, 1972, and January 31, 1973. Our major sources of information included the New York Times, the Environmental Reporter, the United States Code Congressional and Administrative News, the Congressional Record, the United Nations Chronicle, and International Legal Materials. It is our hope that the search through a seemingly endless array of indices, newspapers, microfilms, and dusty shelves will prove to be of value. We regret that the synopsis must once again report more problems than solutions, but it is with great optimism that we look to the forthcoming United Nations Conference on the Law of the Sea. Perhaps the next synopsis will report some far-reaching accomplishments of that Conference. Finally, we express our sincerest appreciation to Professor H. Gary Knight. His faith in the value of the synopsis has been a great encouragement
Non-Fermi liquid angle resolved photoemission lineshapes of Li0.9Mo6O17
A recent letter by Xue et al. (PRL v.83, 1235 ('99)) reports a Fermi-Liquid
(FL) angle resolved photoemission (ARPES) lineshape for quasi one-dimensional
Li0.9Mo6O17, contradicting our report (PRL v.82, 2540 ('99)) of a non-FL
lineshape in this material. Xue et al. attributed the difference to the
improved angle resolution. In this comment, we point out that this reasoning is
flawed. Rather, we find that their data have fundamental differences from other
ARPES results and also band theory.Comment: To be published as a PRL Commen
Educational Psychology in the Virtual World: A Small Study on Practice Adaptations During the COVID-19 Pandemic and Potential Benefits for Future Services
Educational psychologists (EPs) have made significant adaptations to their practice during the COVID-19 pandemic due to educational and practice restrictions in England. These adaptations, whilst facing many challenges, have also presented opportunities for growth within the profession. The current study gained a small group of EPs’ views of their experiences of working remotely through the completion of an online questionnaire. Subsequent data analysis found that EPs increased their confidence working remotely and using technology during the pandemic. The main changes reported by the participating EPs related to how they accessed clients and adapted their practice to suit remote working. Personal and professional successes were identified, and many EPs indicated it would be useful to continue some elements of remote working following the pandemic. An important area for future exploration would be to further investigate the benefits of remote working and gain the views of other stakeholders regarding their experiences of remote EP practice
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