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

Avaliação do potencial de estirpes de rizóbio em fixar nitrogênio associadas ao feijão-caupi em Petrolina-PE.

O feijão-caupi é uma cultura leguminosa de grande importância para a alimentação humana, constituindo-se em uma fonte de proteína para a maioria da população rural. A eficiência de diferentes estirpes de rizóbio em fixar o nitrogênio atmosférico em associação com o feijão-caupi foi testada ao nível de campo na Estação Experimental da Caatinga, da Embrapa Semi-Árido, localizada no município de Petrolina-PE (09o23'S e 40o30'W, altitude: 350 m). O experimento foi implantado em condições de sequeiro, com delineamento de blocos ao acaso e seis repetições, constando de seis tratamentos, sendo quatro estirpes de rizóbio - BR 3267, BR 3299, BR 33o1 e BR 3302, uma dose de nitrogênio mineral - 50 kg ha-1 e uma testemunha. Aos trinta dias após o plantio, o número e peso seco de nódulos, peso de matéria seca e concentração de nitrogênio na parte aérea da planta foram determinados. Todas as estirpes superaram significativamente o tratamento testemunha, tanto em número como em peso seco de nódulos, denotando uma alta eficiência em nodular as raízes de feijão-caupi em relação às estirpes de rizóbio existentes no solo da área experimental

Scaling properties of granular materials

Given an assembly of viscoelastic spheres with certain material properties, we raise the question how the macroscopic properties of the assembly will change if all lengths of the system, i.e. radii, container size etc., are scaled by a constant. The result leads to a method to scale down experiments to lab-size.Comment: 4 pages, 2 figure

Non-exponential relaxation for anomalous diffusion

We study the relaxation process in normal and anomalous diffusion regimes for systems described by a generalized Langevin equation (GLE). We demonstrate the existence of a very general correlation function which describes the relaxation phenomena. Such function is even; therefore, it cannot be an exponential or a stretched exponential. However, for a proper choice of the parameters, those functions can be reproduced within certain intervals with good precision. We also show the passage from the non-Markovian to the Markovian behaviour in the normal diffusion regime. For times longer than the relaxation time, the correlation function for anomalous diffusion becomes a power law for broad-band noise.Comment: 6 pages, 2 figure

p62/SQSTM1 is required for cell survival of apoptosis-resistant bone metastatic prostate cancer cell lines

BACKGROUND: Bone marrow stromal cell (BMSC) paracrine factor(s) can induce apoptosis in bone metastatic prostate cancer (PCa) cell lines. However, the PCa cells that escape BMSC-induced apoptosis can upregulate cytoprotective autophagy. METHODS: C4-2, C4-2B, MDA PCa 2a, MDA PCa 2b, VCaP, PC3, or DU145 PCa cell lines were grown in BMSC conditioned medium and analyzed for mRNA and/or protein accumulation of p62 (also known as sequestome-1/SQSTM1), Microtubule-associated protein 1 light chain 3B (LC3B), or lysosomal-associated membrane protein 1 (LAMP1) using quantitative polymerase chain reaction (QPCR), Western blot, or immunofluorescence. Small interfering RNA (siRNA) was used to determine if p62 is necessary PCa cell survival. RESULTS: BMSC paracrine signaling upregulated p62 mRNA and protein in a subset of the PCa cell lines. The PCa cell lines that were insensitive to BMSC-induced apoptosis and autophagy induction had elevated basal p62 mRNA and protein. In the BMSC-insensitive PCa cell lines, siRNA knockdown of p62 was cytotoxic and immunostaining showed peri-nuclear clustering of autolysosomes. However, in the BMSC-sensitive PCa cell lines, p62 siRNA knockdown was not appreciably cytotoxic and did not affect autolysosome subcellular localization. CONCLUSIONS: A pattern emerges wherein the BMSC-sensitive PCa cell lines are known to be osteoblastic and express the androgen receptor, while the BMSC-insensitive PCa cell lines are characteristically osteolytic and do not express the androgen receptor. Furthermore, BMSC-insensitive PCa may have evolved a dependency on p62 for cell survival that could be exploited to target and kill these apoptosis-resistant PCa cells in the bone

US/Russian cooperative efforts in nuclear material protection, control, and accounting at the Siberian Chemical Combine

The Siberian Chemical Combine (SKhK) is the largest multifunction nuclear production facility in the Russian nuclear complex. Until recently, it produced and processed special nuclear material for the Russian Defense Ministry. SKhK and its US partners in the Department of Energy (DOE) US/Russian Materials Protection, Control, and Accountability (MPC and A) Program are nearing completion of the initial MPC and A upgrades at the six SKhK plant sites that were begun three years ago. Comprehensive enhancements to the physical protection and access control systems are progressing on a site-wide basis while a comprehensive MC and A system is being implemented at the Radiochemical Plant site. SKhK now produces thermal and electrical power, enriches uranium for commercial reactor fuel, reprocesses irradiated fuel, converts high-enriched uranium metal into high-enriched oxide for blending into reactor-grade, low-enriched uranium, and manufactures civilian products. The authors review the progress to date and outline plans for continuing the work in 1999

Technological Challenges in Risk Management of Carbon Capture and Geological Storage (CCGS) Projects

Abstract This article presents the future trend of the Brazilian energy matrix front the immense energy potential of their growing reserves of fossil fuels. This course shift to an energy matrix with more carbon emissions makes necessary the use of mitigation actions among which the Carbon Capture and Geological Storage (CCGS) is the most effective. The paper shows that the risks of CCGS projects are of hybrid origin, a combination of natural and technological hazards, because some of the causes of possible leaks don't depend only on technology operation. This risk management is a technological challenge since there are currently no consolidated technologies commercially available

Eficiência simbiótica e componentes de produção de caupi (Vigna unguiculata (L) Walp) em área irrigada do semi-árido baiano.

O objetivo deste trabalho foi o de avaliar a eficiência simbiótica e os componentes de produção do cultivo de feijão caupi inoculado com estirpes específicas em uma área irrigada do semi-árido baiano