195 research outputs found
Bogomolov multipliers for some -groups of nilpotency class 2
The Bogomolov multiplier of a finite group is defined as the
subgroup of the Schur multiplier consisting of the cohomology classes vanishing
after restriction to all abelian subgroups of . The triviality of the
Bogomolov multiplier is an obstruction to Noether's problem. We show that if
is a central product of and , regarding ,
and is a group homomorphism such that its restriction
is an isomorphism, then the triviality of
and implies the triviality of . We
give a positive answer to Noether's problem for all -generator -groups of
nilpotency class , and for one series of -generator -groups of
nilpotency class (with the usual requirement for the roots of unity).Comment: This is the revised version which appeared in Acta Math. Sinica
(English Series). arXiv admin note: text overlap with arXiv:1304.189
On realizability of -groups as Galois groups
In this article we survey and examine the realizability of -groups as
Galois groups over arbitrary fields. In particular we consider various
cohomological criteria that lead to necessary and sufficient conditions for the
realizability of such a group as a Galois group, the embedding problem (i.e.,
realizability over a given subextension), descriptions of such extensions,
automatic realizations among -groups, and related topics.Comment: In this version is added an example at the end of Section 6. Also,
some mistakes are corrected and the references are update
The behavior of fatty acids in the blood plasma of monkeys following exposure to short term stresses
Monkeys exposed to short term stresses (immobilization, jealousy) were found to develop hyperlipacidemia with a rise in concentration of unsaturated fatty acids in blood plasma, especially of oleic acid, and a relative decrease of saturated free fatty acids, chiefly of palmitinic acid. This finding was more pronounced under immobilization stress than in the jealousy situation. Meanwhile, the composition of triglycerides did not change essentially under the conditions used
Induced orthogonal representations of Galois groups
We prove a result showing the connection between induced orthogonal representations and corestrictions of group extensions derived from their Clifford groups. By the means of the corestriction map we then obtain new obstructions to the μ p -embedding problems given by the group extensions of the modular p-group, and to one μ 2 -embedding problem given by a group extension of the dihedral group
Cost-effectiveness of extended-release niacin/laropiprant added to a stable simvastatin dose in secondary prevention patients not at cholesterol goal in Germany
Coronary heart disease (CHD) remains the leading cause of death in Germany despite statin use to reduce low-density lipoprotein cholesterol (LDL-C) levels; improving lipids beyond LDL-C may further reduce cardiovascular risk. A fixed-dose combination of extended-release niacin (ERN) with laropiprant (LRPT) provides comprehensive lipid management. We adapted a decision-analytic model to evaluate the economic value (incremental cost-effectiveness ratio [ICER] in terms of costs per life-years gained [LYG]) of ERN/LRPT 2 g over a lifetime in secondary prevention patients in a German setting. Two scenarios were modelled: (1) ERN/LRPT 2 g added to simvastatin 40 mg in patients not at LDL-C goal with simvastatin 40 mg; (2) adding ERN/LRPT 2 g compared with titration to simvastatin 40 mg in patients not at LDL-C goal with simvastatin 20 mg. In both scenarios, adding ERN/LRPT was cost-effective relative to simvastatin monotherapy at a commonly accepted threshold of €30,000 per LYG; ICERs for ERN/LRPT were €13,331 per LYG in scenario 1 and €17,684 per LYG in scenario 2. Subgroup analyses showed that ERN/LRPT was cost-effective in patients with or without diabetes, patients aged ≤65 or >65 years and patients with low baseline high-density lipoprotein cholesterol levels; ICERs ranged from €10,342 to €15,579 in scenario 1, and from €14,081 to €20,462 in scenario 2. In conclusion, comprehensive lipid management with ERN/LRPT 2 g is cost-effective in secondary prevention patients in Germany who have not achieved LDL-C goal with simvastatin monotherapy
The microwave induced resistance response of a high mobility 2DEG from the quasi-classical limit to the quantum Hall regime
Microwave induced resistance oscillations (MIROs) were studied experimentally
over a very wide range of frequencies ranging from ~20 GHz up to ~4 THz, and
from the quasi-classical regime to the quantum Hall effect regime. At low
frequencies regular MIROs were observed, with a periodicity determined by the
ratio of the microwave to cyclotron frequencies. For frequencies below 150 GHz
the magnetic field dependence of MIROs waveform is well described by a
simplified version of an existing theoretical model, where the damping is
controlled by the width of the Landau levels. In the THz frequency range MIROs
vanish and only pronounced resistance changes are observed at the cyclotron
resonance. The evolution of MIROs with frequency are presented and discussed.Comment: 4 pages, presented at EP2DS, to be published in Physica
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