Effects of municipal solid waste compost and sewage sludge on mineralization of soil organic matter

This work sets out to verify whether the application of municipal solid waste compost (MSWC) or treated urban sewage sludge (USS) organic amendments efficiently promote organic matter (OM) increases in a Haplic Podzol (PZha) and in a Calcic Vertisol (VRcc). For that purpose, carbon (C) mineralization and C kinetic parameters were studied, using a laboratory experimental incubation setup. The results showed that the addition of the amendments to the soils increased their mineralization capacities, and that the highest C mineralization rate was reached at the end of the first 2 d of incubation. The different characteristics of the soils seem to have influenced the C mineralization rates during the 28-d incubation. The USS induced higher C mineralization than the MSWC, and the PZha soil gave rise to higher C mineralization than VRcc. For all treatments, C mineralization adjusted well to an exponential plus linear kinetic model, suggesting that the organic C of the amendments was made up of two organic pools of differing degrees of stability. With the exception of the application of USS 60 t ha⁻¹, all the treatments increased the OM content on both soils, or at least the OM remained constant throughout the incubation.     

Lutein from ozone-treated corn retains antimutagenic properties

The present study was conducted to determine the influence of an ozonation process on lutein and protein in clean and contaminated corns. This study aimed to determine the levels of lutein and protein in corn before and after ozonation and to verify the antimutagenic potential of the extracted lutein against aflatoxin using the Ames test. The lutein content was analyzed by high-performance liquid chromatography. Nitrogen analysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis were used to analyze protein. Clean ozone-treated corn had a total lutein content of 28.36 microg/g, which was higher than that of 22.75 microg/g in the untreated clean corn. However, the lutein content was 11.69 microg/g in the ozone-treated contaminated corn, which was lower than that of 16.42 microg/g in the untreated contaminated corn. In both corn samples, the protein content of ozone-treated corn was lower than that of untreated corn, indicating that protein could be destroyed by the ozonation process, which may influence the nutritious value of the corn. Lutein extracts alone showed no mutagenic potential against Salmonella typhimurium tester strains TA100. Lutein extracts from corn inhibited the mutagenicity of AFB1 in a dose-response manner more efficiently than lutein standard. Lutein extracts from different corn samples had similar antimutagenic potentials against AFB1, so the ozone treatment did not affect the antimutagenic potentials of lutein extracts.     

Genetic Diversity in Argentine Andean Potatoes by Means of Functional Markers

Andean Potato is a major crop for farmers in the Andes and represents an important gene pool for potato improvement. We present the population structure and genetic diversity of 88 Andigena accessions collected in Northwestern Argentina based on functional markers (25 SSR) distributed along 12 chromosomes. Polymorphic information content ranged from 0.40 to 0.87. A Bayesian approach, a Principal Coordinate Analysis and a Cluster Analysis revealed the presence of: I) a major group containing most of the Andean accessions and II) a smaller group including the out-group cv. Spunta and the sequenced genotype DM. Several group specific alleles were detected. AMOVA showed that 81% of the variability was within each group. Eleven of the SSRs analyzed are linked or within genes reported to regulate traits of nutritional and industrial interest. Additionally, the allelic variant of a photoperiod dependent tuberization regulator gene, StCDF1.2, was exclusively detected in accessions clustered in group II.     

The effect of sex and genotype on growth performance,feed efficiency,and carcass traits of local sheep group Pantaneiro and Texel or Santa Inês crossbred finished on feedlot

This study aimed to assess and compare the growth performance, feed efficiency, and carcass traits of Pantaneiro sheep and their Texel and Santa Inês crossbreds. Ninety-six lambs, fifty-one males, and forty-five females, with a mean weaning weight of 15.21?±?1.25 kg and 78?±?13 days of age, were slaughtered at a 32-kg body weight. The results showed better production efficiency from males compared with females. Texel-crossed lambs had a better growth performance than the other genotypes. The Texel?×?Pantaneiro lambs were more efficient with a better feedlot performance, higher ribeye muscle area, and better carcass characteristics with an adequate amount of fat cover. Pantaneiro lambs and their crosses with meat breeds could be useful in meat production systems under Savanna environmental conditions.     

Composite Likelihood Inference for Multivariate Gaussian Random Fields

In the recent years, there has been a growing interest in proposing covariance models for multivariate Gaussian random fields. Some of these covariance models are very flexible and can capture both the marginal and the cross-spatial dependence of the components of the associated multivariate Gaussian random field. However, effective estimation methods for these models are somehow unexplored. Maximum likelihood is certainly a useful tool, but it is impractical in all the circumstances where the number of observations is very large. In this work, we consider two possible approaches based on composite likelihood for multivariate covariance model estimation. We illustrate, through simulation experiments, that our methods offer a good balance between statistical efficiency and computational complexity. Asymptotic properties of the proposed estimators are assessed under increasing domain asymptotics. Finally, we apply the method for the analysis of a bivariate dataset on chlorophyll concentration and sea surface temperature in the Chilean coast.     

Water quality,phytoplankton composition and growth of Litopenaeus vannamei (Boone) in an integrated biofloc system with Gracilaria birdiae (Greville) and Gracilaria domingensis (Kützing)

A 28-day indoor trial was conducted to evaluate the water quality, phytoplankton composition and growth of Litopenaeus vannamei in an integrated biofloc system with Gracilaria birdiae and Gracilaria domingensis. The experimental design was completely randomized with three treatments: control (shrimp monoculture); SB (shrimp and G. birdiae) and SD (shrimp and G. domingensis), all with three replicates. Random sampling was done (6 % of total population per experimental unit) to confirm white spot syndrome Virus (WSSV) infection using nested-PCR analysis due to suspicion of presence of the virus in the experiment (treatment and control groups). Shrimp L. vannamei (2.63 ± 0.10 g) were stocked in experimental tanks at a density of 425 shrimp m^?3, and the Gracilaria was stocked at a biomass of 2.0 kg m^?3. Shrimp mortality began in both the experimental and control groups at 10 days of culture. The integrated biofloc system (shrimp and seaweed) increased settleable solids (by 26–52 %); final weight (by 6–21 %); weekly growth (by 17–43 %); weight gain (by 17–43 %); specific growth rate (by 16–36 %); and yield (by 5–7 %) and decreased feed conversion ratio (by 21–28 %) and Cyanobacteria density about 16 % as compared to the control (shrimp monoculture). The use of red seaweed Gracilaria in an integrated biofloc system can enhance shrimp growth and reduce Cyanobacteria density in the presence of WSSV.