669 research outputs found
Quasi-randomness and algorithmic regularity for graphs with general degree distributions
We deal with two intimately related subjects: quasi-randomness and regular partitions. The purpose of the concept of quasi-randomness is to express how much a given graph “resembles” a random one. Moreover, a regular partition approximates a given graph by a bounded number of quasi-random graphs. Regarding quasi-randomness, we present a new spectral characterization of low discrepancy, which extends to sparse graphs. Concerning regular partitions, we introduce a concept of regularity that takes into account vertex weights, and show that if satisfies a certain boundedness condition, then admits a regular partition. In addition, building on the work of Alon and Naor [Proceedings of the 36th ACM Symposium on Theory of Computing (STOC), Chicago, IL, ACM, New York, 2004, pp. 72–80], we provide an algorithm that computes a regular partition of a given (possibly sparse) graph in polynomial time. As an application, we present a polynomial time approximation scheme for MAX CUT on (sparse) graphs without “dense spots.
Analytical two-center integrals over Slater geminal functions
We present analytical formulas for the calculation of the two-center
two-electron integrals in the basis of Slater geminals and products of Slater
orbitals. Our derivation starts with establishing a inhomogeneous fourth-order
ordinary differential equation that is obeyed by the master integral, the
simplest integral with inverse powers of all interparticle distances. To solve
this equation it was necessary to introduce a new family of special functions
which are defined through their series expansions around regular singular
points of the differential equation. To increase the power of the interparticle
distances under the sign of the integral we developed a family of open-ended
recursion relations. A handful of special cases of the integrals is also
analysed with some remarks on simplifications that occur. Additionally, we
present some numerical examples of the master integral that validate the
usefulness and correctness of the key equations derived in this paper. In
particular, we compare our results with the calculations based on the series
expansion of the exp(-\gamma r12) term in the master integral.Comment: 28 pages, 0 figures, 7 table
Improvement of Mg uptake of grapevine by use of rapeseed oil ethoxylates for foliar application of Mg
To improve the uptake of foliar-applied Mg a new group of toxicological and ecotoxicological harmless surfactants (rapeseed oil ethoxylates) with an average of 5 (Agnique RSO 5®), 10 (Agnique RSO 10®), 30 (Agnique RSO 30®) and 60 (Agnique RSO 60®) units of ethylene oxide (EO) was evaluated as adjuvants for a MgSO4 and Mg(NO3) formulation. The impact of the surfactants on Mg penetration was studied using astomatous cuticular membranes isolated from mature tomato fruit. The biological efficacy of a formulation, containing castor oil, ionic and non-ionic surfactants with and without addition of RSO 5 was investigated in two vineyards at the Moselle valley, cvs Riesling and Regent. Especially RSO 5-surfactant increased Mg penetration through isolated cuticles. Under field conditions, Mg application enhanced significantly the Mg content in leaves. The Mg level in bunch stems merely increased when formulated 'Bittersalz' was applied. 'Magnisal' and formulated 'Magnisal' reduced markedly Mg deficiency symptoms in leaves and increased Mg content in leaves of cv. Regent.
Anatomical analysis of preangular mandibular notch in humans
The authors have analysed in detail the mandibular preangular notch on the
basis of 273 human cadaver mandibles. They have revealed that the pregonial
notch is present in almost 90% of cases and that it is generally asymmetric and
elliptical in shape. The depth and length of the anterior part of the notch is
greater in males. Moreover, the preangular notch depth is greater on the right
side (regardless of sex). Knowledge of the preangular notch anatomy can be
useful for surgeons during reconstructive and plastic procedures on the mandibular
shaft
Creating Modern Community Conservation Organizations and Institutions to Effect Successful Forest Conservation Change
Despite increased investment, current conservation strategies have failed to stop environmental degradation and loss of biodiversity of the earth’s ecosystems with consequent climate change. Community Conservation’s (CC) 30 years of experience has produced a successful, cost-effective, field-tested flexible formula to catalyze communities to stop deforestation and biodiversity loss. Our method focuses on four concepts: 1) catalyzing projects, leaving ownership to on-site community-based organizations (CBOs) or local nongovernmental organizations (NGOs); 2) encouraging creation of CBOs; 3) helping build complex federations or networks for a stronger community voice; and 4) creating conservation contagion for regional change. Based on trust, we initially make the community aware of their special forests and wildlife and ask their help in protecting them. Then we help them create CBOs and build federations of conservation activists to strengthen and empower them to manage their projects and their natural resources. By bringing community members to interact together from within a large region, we strive to create conservation contagion. Case histories from Assam, India; northern Peru; the Huon Peninsula in Papua New Guinea; Madagascar; Belize; and Wisconsin, USA demonstrate successes based on the formation of CBOs and community federations, allowing communities to play a powerful role in protecting and restoring forests
Ground-state properties of rutile: electron-correlation effects
Electron-correlation effects on cohesive energy, lattice constant and bulk
compressibility of rutile are calculated using an ab-initio scheme. A
competition between the two groups of partially covalent Ti-O bonds is the
reason that the correlation energy does not change linearly with deviations
from the equilibrium geometry, but is dominated by quadratic terms instead. As
a consequence, the Hartree-Fock lattice constants are close to the experimental
ones, while the compressibility is strongly renormalized by electronic
correlations.Comment: 1 figure to appear in Phys. Rev.
Omalizumab may decrease IgE synthesis by targeting membrane IgE+ human B cells
Omalizumab, is a humanized anti-IgE monoclonal antibody used to treat allergic asthma. Decreased serum IgE levels, lower eosinophil and B cell counts have been noted as a result of treatment. In vitro studies and animal models support the hypothesis that omalizumab inhibits IgE synthesis by B cells and causes elimination of IgE-expressing cells either by induction of apoptosis or induction of anergy or tolerance. METHODS: We examined the influence of omalizumab on human tonsillar B cell survival and on the genes involved in IgE synthesis. Tonsillar B cells were stimulated with IL-4 plus anti-CD40 antibody to induce class switch recombination to IgE production in the presence or absence of omalizumab. Cell viability was assessed and RNA extracted to examine specific genes involved in IgE synthesis. CONCLUSIONS: We found that omalizumab reduced viable cell numbers but this was not through induction of apoptosis. IL-4R and germline Cϵ mRNA levels were decreased as well as the number of membrane IgE+ cells in B cells treated with omalizumab. These data suggest that omalizumab may decrease IgE synthesis by human B cells by specifically targeting membrane IgE-bearing B cells and inducing a state of anergy
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