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Amino acids composition and oxygen isotopes in the Shisr 033 CR chondrite
Exploiting Resolution-based Representations for MaxSAT Solving
Most recent MaxSAT algorithms rely on a succession of calls to a SAT solver
in order to find an optimal solution. In particular, several algorithms take
advantage of the ability of SAT solvers to identify unsatisfiable subformulas.
Usually, these MaxSAT algorithms perform better when small unsatisfiable
subformulas are found early. However, this is not the case in many problem
instances, since the whole formula is given to the SAT solver in each call. In
this paper, we propose to partition the MaxSAT formula using a resolution-based
graph representation. Partitions are then iteratively joined by using a
proximity measure extracted from the graph representation of the formula. The
algorithm ends when only one partition remains and the optimal solution is
found. Experimental results show that this new approach further enhances a
state of the art MaxSAT solver to optimally solve a larger set of industrial
problem instances
Pyrrolizidine Alkaloids In The Pericopine Moth Scearctia Figulina (erebidae: Arctiinae): Metabolism And Chemical Defense
Pyrrolizidine alkaloids (PAs) are defensive compounds present in several plant families. However, some specialist herbivore insects have overcome these toxic compounds and sequester PAs converted to N-oxide as a defense against predators and a precursor of male sexual pheromones. In this context, we investigated PA sequestration by the specialist pericopine moth Scearctia figulina (Erebidae: Arctiinae), which feeds on leaves of Heliotropium transalpinum (Boraginaceae) as larvae. Additionally, we examined the role of PAs against different predators. The PAs sequestered from the host plant were metabolized by larvae and transferred to adults via two main pathways: (i) rinderine and its acetyl derivative (7S, 3' R) were epimerized to intermedine (7R, 3' R) and lycopsamine (7R, 3' S), and (ii) insect PAs were biosynthesized from necine bases obtained from plant-acquired PAs, with necic acids of insect origin. Both metabolic products may be related to the biosynthesis of 7R male pheromone and to chemical defense. Larvae and adults were chemically protected against the spiders Nephila clavipes and Lycosa erythrognatha and the chick Gallus gallus, and this defense may be associated to PAs.2781437144
Integrable variant of the one-dimensional Hubbard model
A new integrable model which is a variant of the one-dimensional Hubbard
model is proposed. The integrability of the model is verified by presenting the
associated quantum R-matrix which satisfies the Yang-Baxter equation. We argue
that the new model possesses the SO(4) algebra symmetry, which contains a
representation of the -pairing SU(2) algebra and a spin SU(2) algebra.
Additionally, the algebraic Bethe ansatz is studied by means of the quantum
inverse scattering method. The spectrum of the Hamiltonian, eigenvectors, as
well as the Bethe ansatz equations, are discussed
Hidrolisado de peixe causa alterações nas características microbiológicas e químicas de substrato.
O hidrolisado de peixe é um fertilizante orgânico obtido da fermentação de resíduos do processamento de pescados marinhos. O presente estudo avaliou os efeitos do hidrolisado de peixe em características microbiológicas e químicas de substrato à base de casca de pinus e solo, em microcosmos. O hidrolisado de peixe estimulou a comunidade de Trichoderma, aumentou a liberação de amônia e aumentou a condutividade elétrica do substrato de forma proporcional à sua concentração no substrato esterilizado e no não esterilizado. O hidrolisado não interferiu nas comunidades de Bacillus, de Pseudomonas e de Fusarium oxysporum f.sp. lycopersici. Também não foram verificadas alterações significativas no pH e na concentração de nitrato do substrato
Algebraic Bethe ansatz approach for the one-dimensional Hubbard model
We formulate in terms of the quantum inverse scattering method the algebraic
Bethe ansatz solution of the one-dimensional Hubbard model. The method
developed is based on a new set of commutation relations which encodes a hidden
symmetry of 6-vertex type.Comment: appendix additioned with Boltzmann weigths and R-matrix. Version to
be published in J.Phys.A:math.Gen. (1997
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