Novel estimation of the humification degree of soil organic matter by laser-induced breakdown spectroscopy

Soil organic matter (SOM) constitutes an important reservoir of terrestrial carbon and can be considered an alternative for atmospheric carbon storage, contributing to global warming mitigation. Soil management can favor atmospheric carbon incorporation into SUM or its release from SOM to atmosphere. Thus, the evaluation of the humification degree (HD), which is an indication of the recalcitrance of SOM, can provide an estimation of the capacity of carbon sequestration by soils under various managements. The HD of SOM can be estimated by using various analytical techniques including fluorescence spectroscopy. In the present work, the potential of laser-induced breakdown spectroscopy (LIBS) to estimate the HD of SUM was evaluated for the first time. Intensities of emission lines of Al, Mg and Ca from LIBS spectra showing correlation with fluorescence emissions determined by laser-induced fluorescence spectroscopy (LIFS) reference technique were used to obtain a multivaried calibration model based on the k-nearest neighbor (k-NN) method. The values predicted by the proposed model (A-LIBS) showed strong correlation with LIFS results with a Pearson's coefficient of 0.87. The HD of SUM obtained after normalizing A-LIBS by total carbon in the sample showed a strong correlation to that determined by LIFS (0.94), thus suggesting the great potential of LIBS for this novel application. (C) 2014 Elsevier B.V. All rights reserved.

Evaluation of Fe uptake and translocation in transgenic and non-transgenic soybean plants using enriched stable Fe-57 as a tracer

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sexual maturation of the Mongolian gerbil (Meriones unguiculatus): a histological, hormonal and spermatic evaluation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Physical and chemical matrix effects in soil carbon quantification using laser-induced breakdown spectroscopy

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Produção de mudas de espécies florestais de restinga, com base em estudos florísticos e fitossociológicos, visando a recuperação de áreas degradadas, em Ilha Comprida - SP

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Control Methods and Evaluation of Bacterial Growth on Fresh and Cooled Stallion Semen

The penis and prepuce of the stallion have a high bacterial load on its surface, forming a natural microbial flora that contaminates the semen during ejaculation. Bacterial growth in semen may cause a decline on sperm quality, viability, and fertility and predisposes the occurrence of endometritis in inseminated mares. Thus, the aim of this study was to evaluate the effect of penile wash before semen collection, the addition of different commercial skim milk-based extenders containing antibiotics (BotuSemen and INRA96), and the removal of seminal plasma by filtration on the quality, viability, and bacterial proliferation on fresh and cooled stallion semen. Animals that were never submitted to penile wash before semen collection tended to have lower bacterial contamination in the ejaculate. Semen samples extended in BotuSemen showed superiority in total motility, progressive motility, average path velocity, and rapid sperm and lower bacterial contamination in relation to semen samples extended in INRA96 after 24 hours of cooling. No difference was found in these parameters between the storage temperatures (5 degrees C and 15 degrees C). Furthermore, the removal of seminal plasma by filtration reduced the bacterial load in semen after cooling. In conclusion, the penile wash before semen collection tended to reduce the bacterial growth in fresh semen. The use of a semen extender with appropriate antibiotics and removal of seminal plasma by filtration were effective in reducing the bacterial contamination and preserved the quality of cooled stallion semen. (C) 2015 Elsevier Inc. All rights reserved.

Seasonal fluctuation of soil carbon dioxide emission in differently managed pastures

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influence of soil texture in the recovery of Toxocara canis eggs by a flotation method

In epidemiological surveys, the evaluation of soil contamination by Toxocara canis eggs requires a quick and easy method for the isolation of parasite eggs from soil samples. The efficiency of flotation methods is influenced by sample size, soil texture, degree of soil contamination, pretreatment, flotation solutions and time of flotation. This investigation was designed to evaluate the influence of soil texture in the recovery of T. canis eggs with the centrifugal flotation technique of Dada (Dada, B.J.O., 1979. A new technique for the recovery of Toxocara eggs from soil. J. Helminthol., 53: 141-144). Four types of soil (clay silt, sandy, silty clay and sand) were artificially contaminated with T. canis eggs (200 eggs per gram). Zinc sulphate (specific gravity 1.20) and sodium dichromate (specific gravity 1.35) were used as flotation solutions. Twenty replicated examinations were performed for each type of soil and flotation solution. There was a statistically significant difference in the results depending on soil type. The highest recovery percentages were observed in soils rich in sand (62.5% for sand and 38.0% for sandy soil). Differences were also observed with different flotation solutions. Sodium dichromate solution was more efficient for recovering T. canis eggs, regardless of the soil texture. © 1994.

Evaluation of area contaminated by wood treatment activities: genetic markers in the environment and in the child population

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Metabolomic evaluation of interactions in rhizosphere between Senna spectabilis and associated microorganisms

Pós-graduação em Química - IQ

Effects in mechanical properties and structure of the soil tillage with rotary paraplow

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effects in mechanical properties and structure of the soil after tillage with rotary paraplow

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

An Evaluation of Diazacon as a Potential Contraceptive in Non-Native Rose-Ringed Parakeets

Rose-ringed parakeets (Psittacula krameri) have become widely established outside their native range through accidental or deliberate release. Potential economic impacts on agriculture, conservation concerns, and mixed public opinion regarding the species have highlighted the need to develop effective but humane management options. Fertility control might provide such a solution if a safe and environmentally benign contraceptive was available. The chemical 20,25-diazacholesterol dihydrochloride (diazacon) has previously been used to reduce reproductive output in avian species through reduction of blood cholesterol and cholesterol-dependent reproductive hormones. We orally dosed captive rose-ringed parakeets with a solution of either 9 mg/kg or 18 mg/kg of diazacon for up to 10 days and found that a dose of 18 mg/kg for 10 days temporarily reduced blood cholesterol levels with no adverse side effects. We evaluated this dose level in a captive population in semi-natural conditions during the 2008 breeding season and found a significant decrease in fertility. We concluded that diazacon has potential for fertility control in this species if a suitable formulation and delivery system is developed for free-living populations.