Consequences of dark matter-dark energy interaction on cosmological parameters derived from type Ia supernova data

Models where the dark matter component of the Universe interacts with the dark energy field have been proposed as a solution to the cosmic coincidence problem, since in the attractor regime both dark energy and dark matter scale in the same way. In these models the mass of the cold dark matter particles is a function of the dark energy field responsible for the present acceleration of the Universe, and different scenarios can be parametrized by how the mass of the cold dark matter particles evolves with time. In this article we study the impact of a constant coupling delta between dark energy and dark matter on the determination of a redshift dependent dark energy equation of state w(DE)(z) and on the dark matter density today from SNIa data. We derive an analytical expression for the luminosity distance in this case. In particular, we show that the presence of such a coupling increases the tension between the cosmic microwave background data from the analysis of the shift parameter in models with constant w(DE) and SNIa data for realistic values of the present dark matter density fraction. Thus, an independent measurement of the present dark matter density can place constraints on models with interacting dark energy.

Noise and ultraviolet divergences in the dynamics of the chiral condensate in QCD

The time evolution of the matter produced in high energy heavy-ion collisions seems to be well described by relativistic viscous hydrodynamics. In addition to the hydrodynamic degrees of freedom related to energy-momentum conservation, degrees of freedom associated with order parameters of broken continuous symmetries must be considered because they are all coupled to each other. of particular interest is the coupling of degrees of freedom associated with the chiral symmetry of QCD. Quantum and thermal fluctuations of the chiral fields act as noise sources in the classical equations of motion, turning them into stochastic differential equations in the form of Ginzburg-Landau-Langevin (GLL) equations. Analytic solutions of GLL equations are attainable only in very special circumstances and extensive numerical simulations are necessary, usually by discretizing the equations on a spatial lattice. However, a not much appreciated issue in the numerical simulations of GLL equations is that ultraviolet divergences in the form of lattice-spacing dependence plague the solutions. The divergences are related to the well-known Rayleigh-Jeans catastrophe in classical field theory. In the present communication we present a systematic lattice renormalization method to control the catastrophe. We discuss the implementation of the method for a GLL equation derived in the context of a model for the QCD chiral phase transition and consider the nonequilibrium evolution of the chiral condensate during the hydrodynamic flow of the quark-gluon plasma.

Two-dimensional induced gravity in reduced phase-space

We discuss the Dirac method analysis of two-dimensional induced gravity, coupled to bosonic matter fields, in reduced phase-space. After defining the extended Hamiltonian it is possible to fix the gauge completely. The Dirac brackets can all be obtained in closed form; nevertheless, the results are not particularly simple.

Influence of biosolids rate on chemical properties of an oxisol in São Paulo, Brazil

Organic residues may cause major health and environmental problems. This is the case in our study area, where more than 10 billion L per year of residential and industrial waste are produced. Land application of biosolids can be an economical solution by recycling waste and can provide valuable fertilizer if used correctly. The aim of this work was to study the effect of biosolids on the chemical properties of an Oxisol. The experiment was located at Ilha Solteira northwest of São Paulo State, Brazil. The soil was cropped to Sorghum bicolor.The field experimental design consisted of random blocks with six treatments and four replications of each treatment. Biosolids were surface applied to four treatments at rates of 5, 10, 20, and 40 Mg ha(-1) on a dry matter basis; in addition, a treatment with mineral fertilizer and a control were included. One year after biosolids application, soil samples were taken at 0-10, 10-20, and 20-40 cm. Organic matter content (Walkley-Black) and pH (CaCl2) were routinely determined. Cation exchange capacity, exchangeable bases (Ca, Mg, K), and P were determined by exchange resin extraction. No significant differences in any of the analyzed properties were found below the 20 cm depth. Extractable phosphorus (P) and potassium (K) increased with increasing biosolids rate in the top 20 cm, whereas calcium (Ca) and (Ma) magnesium content were not significantly influenced by biosolids. Soil pH decreased with increasing biosolids application. The sewage sludge application did not influence the sorghum production in the first year of culture, under unfavorable soil moisture conditions, but it influenced the dry matter.

Distribution of Neohelice granulata (Dana 1851) in its northernmost latitudinal occurrence in a tropical mangrove forest, Brazil (Crustacea, Decapoda, Brachyura, Grapsoidea, Varunidae).

Neohelice granulata ecological distribution was evaluated in its northernmost latitudinal occurrence in a Brazilian tropical mangrove (23[degree]13'4" S, 44[degree]42'47" W). Samples were collected in three sites along the main river in the mangrove. Crabs were manually captured by two people, 15 min each, at low tide periods. The sex of the animals was assessed and carapace width measured. The size-frequency distribution was determined in each site. Environmental factors (salinity, temperature, organic matter and sediment texture) were analyzed, compared among sites and related to crab abundance and size in each site. Crab abundance decreased with the distance from the sea. Juvenile crabs were more frequent next to the sea, whereas larger and ovigerous ones were mainly found in the most distant site. Crab size was proportional to the organic matter percentage in the sediment. N. granulata spatial distribution varies along the river course, which is probably related to the most productive areas that have more nutrients available; this may also occur in order to prevent intraspecific competition.

Municipal solid waste compost amendment in agricultural soil: changes in soil microbial biomass

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Amphetamine Poisoning in a Dog: Case Report, Literature Review and Veterinary Medical Perspectives

Amphetamine abuse in human beings has increased, resulting in many reports of toxicity and death. In the US over 4 million people have abused amphetamines at least once, thus small animals are exposed to increased accidental poisoning risk. This report describes an acute amphetamine poisoning in a dog due to ingestion of 15 mg/kg fenproporex, leading to typical signs of catecholamines release and effects in different organ systems. Similar clinical and laboratory findings observed in human beings are reviewed and physiopathogenic mechanisms discussed, as well as the therapeutic approaches available in veterinary medicine.

Status and promise of particle interferometry in heavy-ion collisions

After five years of running at RHIC, and on the eve of the LHC heavy-ion program, we highlight the status of femtoscopic measurements. We emphasize the role interferometry plays in addressing fundamental questions about the state of matter created in such collisions, and present an enumerated list of measurements, analyses and calculations that are needed to advance the field in the coming years.

Barriers to Latin American and Caribbean exports in the US market, 1998-1999

Includes bibliography

Module for the analysis of growth in international commerce (MAGIC Plus): user guide (updated)

Includes bibliography

Forage mass production and grazing loss of sorghum hybrid in response to the density of the sowing and the spacing between planting lines

The objective of this experiment was to evaluate dry matter yield and loss of grazing due to animal trampling in response to sowing density and spacing between lines in the planting. Sorghum hybrid 1P400 was submitted to six treatments, composed of three sowing density combinations (12; 16 and 20 kg/ha of seeds) and two spacing between lines (0.40 and 0.80 m). Sorghum hybrid 1P400 was sowed in two seasons, at the end of spring (December 3rd, 2005) and the other at the end of summer (March 20th, 2006). Cultivation strategies influenced plant population in the two experimental seasons. Diameter of the stem in season 1 decreased with density increase, whereas in the second season, interaction between sowing density and spacing was significant. In the first season, 0.40-m spacing promoted greater losses due to grazing stepping, that is, 891 kg/ha of DM, whereas in the second season there was no statistical difference. There was no significant difference in forage dry matter yield in sowing densities among the two studied seasons. Dry mater production of sorghum hybrids 1P400 did not increase with the increase of the sowing density in the two sowing seasons, therefore it is recommended 12 kg/ha of seeds for the sowing. Sorghum IP400 cultivated in 0.80-m spacing resulted in lower forage loss caused by grazing bovine trampling. © 2011 Sociedade Brasileira de Zootecnia.

What schools teach us about educating poor children in Chile?

Includes bibliography

Cover crops and no-till effects on physical fractions of soil organic matter

Physical fractions (free light fraction, intra-aggregate light fraction and heavy fraction) of soil organic matter (SOM) are good indicators of soil quality for sustainable land use. The objective of this study was to evaluate the effect of cover crops on total organic carbon (TOC) and physical fractions of soil organic matter in soil under a no-tillage system (NTS) and a conventional tillage system (CTS, one plowing and two disking). A three-year field experiment was carried out as a cover crop-rice (Oryza sativa)-cover crop-rice rotation. Treatments included cover crops (Panicum maximum, Brachiaria ruziziensis, Brachiaria brizantha, and pearl millet (Pennisetum glaucum), fallow, till or no till. The SOM was physically fractionated in free light fraction (FLF), intra-aggregates light fraction (IALF) and heavy fraction (HF). The levels of C in whole soil were also evaluated, as well as C in the light fractions (FLF+IALF) and in the HF. Results indicated that concentrations of C in the FLF and IALF in surface soils (0-0.05m) were much higher (10.8 and 1.95gkg-1, respectively) than that in the 0.05-0.1m soil depth (7.68 and 1.54gkg-1, respectively) and in the 0.1-0.2m soil depth (4.98 and 1.24gkg-1, respectively). The NTS resulted in higher levels of FLF (12.2gkg-1) and IALF (2.19gkg-1) than with CTS (1.37-7.30gkg-1). Millet had the highest C (19.5gkg-1) and N (1.1gkg-1) concentrations in soil. There was an accumulation of TOC and total N in the surface soil with cover crops, and concentrations of TOC were higher in the HF (79.0%) than in the light fractions (21.0%). Although SOM changed little during the two years of this experiment, the various C fractions were significantly affected by the tillage treatments. We conclude that SOM physical fractionation allowed seeing significant differences caused by the soil management in the organic matter dynamics in a short period of time. © 2013 Elsevier B.V.

Relationship between age of waste and natural electric potential generation in Sanitary Landfill

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Barriers to Latin American and Caribbean exports in the US market, 2000-2001

Includes bibliography