774 research outputs found
Superposition in nonlinear wave and evolution equations
Real and bounded elliptic solutions suitable for applying the Khare-Sukhatme
superposition procedure are presented and used to generate superposition
solutions of the generalized modified Kadomtsev-Petviashvili equation (gmKPE)
and the nonlinear cubic-quintic Schroedinger equation (NLCQSE).Comment: submitted to International Journal of Theoretical Physics, 23 pages,
2 figures, style change
Soil fertility management for organic rice production in the Lao PDR
Rice is the most important agricultural commodity of the Lao People's Democratic Republic (Lao PDR), produced largely using traditional methods with limited inputs of fertilizers and other chemicals. The country has a wide diversity in rice production systems and rice varieties, with over 3000 different varieties recorded. The rich diversity and the production environment and methods are favorable for organic rice production. Investigations were carried out to describe soil fertility conditions, management practices, opportunities and problems associated with organic production methods for rice. Soils used for rice production are mostly of low fertility, with low organic matter and N-availability. In spite of this, virtually no fertilizer inputs are used for upland rice production. Inorganic fertilizer inputs for lowland rice production have increased rapidly over the past decade, but are still below 20 kg ha−1. The most important nutrient sources are rice straw and manure from buffalo and cattle. Chromolaena odorata plays an important role in nutrient cycling in upland rice systems and is sometimes added to lowland fields. In a range of fertility management studies, yield increase ranged from 2 to 89% for manure, straw or rice husk applied at modest rates (3 t ha−1), 32-156% for modest rates of inorganic fertilizer (60 kg N ha−1) and 36-167% for combined application of manure or crop residues with inorganic fertilizer. The response to locally produced commercial organic fertilizer was poor. The most promising inputs and strategies available to optimize yields in organic rice production systems are (1) optimizing use of locally available nutrients, mostly from manure, crop residues and weed biomass, (2) N addition through green manure and legumes growing in rotation and (3) additions of P through guano or rock-phosphate. The Lao PDR is fortunate to have substantial bat guano deposits in limestone caves. Extensive experience is available on straw and husk management for lowland systems and green manure species for upland production system
The isodiametric problem with lattice-point constraints
In this paper, the isodiametric problem for centrally symmetric convex bodies
in the Euclidean d-space R^d containing no interior non-zero point of a lattice
L is studied. It is shown that the intersection of a suitable ball with the
Dirichlet-Voronoi cell of 2L is extremal, i.e., it has minimum diameter among
all bodies with the same volume. It is conjectured that these sets are the only
extremal bodies, which is proved for all three dimensional and several
prominent lattices.Comment: 12 pages, 4 figures, (v2) referee comments and suggestions
incorporated, accepted in Monatshefte fuer Mathemati
Der Einfluss von Prostaglandin E2 auf die Pgp - abhängige Multidrug - Resistance in AML - Blasten beim Kind
Die Überexpression von P-Glykoprotein (Pgp) ist mit einem schlechten Therapieergebnis bei Kindern mit akuter myeloischer Leukämie (AML) korreliert. Die Ergebnisse dieser Arbeit zeigen, dass die Cyclooxygenase-2 (COX-2) eine wichtige Rolle bei der Anthracyclin-vermittelten Pgp-Überexpression spielt. Die Vorinkubation mit Meloxicam konnte die zytostatische Effizienz von Doxorubicin und liposomalem Daunorubicin verbessern. Als entscheidender Mediator scheint Prostaglandin E2 (PGE2) zu fungieren, da es einen deutlichen Anstieg der Pgp-Expression verursachte und den Pgp-abhängigen Efflux steigerte. Die Vorinkubation mit AH6809 vermochte die Effektivität des Zytostatikums durch eine Hemmung des Doxorubicin-induzierten Effluxes zu erhöhen. Die Hemmung der Pgp-Expression durch COX-2-Inhibitoren
sowie durch Antagonisten an EP-Rezeptoren stellt ein neues Prinzip der Resistenzintervention dar, welches die Therapie der AML selektiver und nebenwirkungsärmer optimieren kann
Logic, logical form and the disunity of truth
Monists say that the nature of truth is invariant, whichever sentence you consider; pluralists say that the nature of truth varies between different sets of sentences. The orthodoxy is that logic and logical form favour monism: there must be a single property that is preserved in any valid inference; and any truth-functional complex must be true in the same way as its components. The orthodoxy, I argue, is mistaken. Logic and logical form impose only structural constraints on a metaphysics of truth. Monistic theories are not guaranteed to satisfy these constraints, and there is a pluralistic theory that does so
Discovering SUSY in the first LHC run
4 páginas, 1 figura.-- Trabajo presentado a la Fifth Conference on Physics at LHC celebrada en Hamburgo (Alemania) del 7 al 12 de junio de 2010.We analyze the potential of the first LHC physics run, assuming 1 fb−1 at ps = 7 TeV, to
discover Supersymmetry (SUSY). The results are based on SUSY parameter fits following a
frequentist approach. They include the experimental constraints from electroweak precision
data, (g − 2)μ, B physics and cosmological data. The two SUSY models under consideration
are the constrained MSSM (CMSSM) with universal soft supersymmetry-breaking
mass parameters, and a model with common non-universal Higgs mass parameters in the
superpotential (NUHM1). We find that large parts of the regions preferred at the 68%
C.L. are accessible to early LHC running.Work
supported in part by the European Community’s Marie-Curie Research Training Network under
contract MRTN-CT-2006-035505 ‘Tools and Precision Calculations for Physics Discoveries at
Colliders’ (HEPTOOLS).Peer reviewe
External carotid steal and lateral medullary infarction - is there a pathogenetic connection?
Enlarged scaling ranges for the KS-entropy and the information dimension
Numerical estimates of the Kolmogorov-Sinai entropy based on a finite amount
of data decay towards zero in the relevant limits. Rewriting differences of
block entropies as averages over decay rates, and ignoring all parts of the
sample where these rates are uncomputable because of the lack of neighbours,
yields improved entropy estimates. In the same way, the scaling range for
estimates of the information dimension can be extended considerably. The
improvement is demonstrated for experimental data.Comment: 5 pages, 6 figure
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