7,456 research outputs found
On the proof of some theorem on locally nilpotent subgroups in division rings
In Hai-Thin (2009), there is a theorem, stating that every locally nilpotent
subnormal subgroup in a division ring is central (see Hai-Thin (2009, Th.
2.2)). Unfortunately, there is some mistake in the proof of this theorem. In
this note we give the another proof of this theorem.Comment: 3 page
Prediction of Protein Secondary Structures From Conformational Biases
We use LINUS, a procedure developed by Srinivasan and Rose, to provide a
physical interpretation of and to predict the secondary structures of proteins.
The secondary structure type at a given site is identified by the largest
conformational bias during short time simulations. We examine the rate of
successful prediction as a function of temperature and the interaction window.
At high temperatures, there is a large propensity for the establishment of
-strands whereas -helices appear only when the temperature is
lower than a certain threshold value. It is found that there exists an optimal
temperature at which the correct secondary structures are predicted most
accurately. We find that this temperature is close to the peak temperature of
the specific heat. Changing the interaction window or carrying out longer
simulations approaching equilibrium lead to little change in the optimal
success rate. Our findings are in accord with the observation by Srinivasan and
Rose that the secondary structures are mainly determined by local interactions
and they appear in the early stage of folding.Comment: 9 pages, 9 figures, to appear in Protein
Equity Returns and Business Cycles in Small Open Economies
This is the first paper in the literature to match key business cycle moments and long-run equity returns in a small open economy with production. These results are achieved by introducing three modications to a standard real business cycle model: (1) borrowing and lending costs are imposed to increase the volatility of the intertemporal marginal rate of substitution; (2) investment adjustment costs are assumed to make equity returns more volatile; and (3) GHH preferences are employed to smooth consumption. We also decompose the contributions of productivity, the world interest rate, and government expenditure shocks to the equity premium. Our results are based on data from Argentina, Brazil, and Chile.Asset Pricing; Equity Returns; Dynamic Stochastic General Equilibrium Model; Real Business Cycle; Small Open Economy.
Unified perspective on proteins: A physics approach
We study a physical system which, while devoid of the complexity one usually
associates with proteins, nevertheless displays a remarkable array of
protein-like properties. The constructive hypothesis that this striking
resemblance is not accidental leads not only to a unified framework for
understanding protein folding, amyloid formation and protein interactions but
also has implications for natural selection.Comment: 26 pages, 15 figures, to appear on Phys. Rev.
Model Counting for Formulas of Bounded Clique-Width
We show that #SAT is polynomial-time tractable for classes of CNF formulas
whose incidence graphs have bounded symmetric clique-width (or bounded
clique-width, or bounded rank-width). This result strictly generalizes
polynomial-time tractability results for classes of formulas with signed
incidence graphs of bounded clique-width and classes of formulas with incidence
graphs of bounded modular treewidth, which were the most general results of
this kind known so far.Comment: Extended version of a paper published at ISAAC 201
Proteins and polymers
Proteins, chain molecules of amino acids, behave in ways which are similar to
each other yet quite distinct from standard compact polymers. We demonstrate
that the Flory theorem, derived for polymer melts, holds for compact protein
native state structures and is not incompatible with the existence of
structured building blocks such as -helices and -strands. We
present a discussion on how the notion of the thickness of a polymer chain,
besides being useful in describing a chain molecule in the continuum limit,
plays a vital role in interpolating between conventional polymer physics and
the phase of matter associated with protein structures.Comment: 7 pages, 6 figure
Macroporous materials: microfluidic fabrication, functionalization and applications
This article provides an up-to-date highly comprehensive overview (594 references) on the state of the art of the synthesis and design of macroporous materials using microfluidics and their applications in different fields
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