Short-term spatiotemporal variation of soil CO2 emission,temperature, moisture and aeration in sugarcane field reform areas under the influence of precipitation events

Soil CO₂ emission (FCO₂) in agricultural areas results from the interaction of different factors such as climate and soil conditions. Our objective was to investigate the spatiotemporal variation of FCO₂, temperature (T_soil), moisture (M_soil) and air-filled pore space (AFPS), as well as their interactions, during the sugarcane field reform. The study was conducted on a 90 × 90 m sampling grid with 100 points at 10 m spacings. Ten assessments of FCO₂, T_soil and M_soil were carried out at each point over a 28-day period. The greatest mean values of FCO₂ (0.74 g m⁻² hr⁻¹) and M_soil (31.7%) were obtained on Julian day 276, 2013, being associated with precipitation events at the study site. Also, the smallest values of AFPS (19.17%) and T_soil (20.90°C) were observed on the same day. The spatial variability of FCO₂, T_soil, M_soil and AFPS was best described by an adjusted spherical model, although an exponential model better fitted some results. The spatial pattern of all soil attributes showed little temporal persistency, indicating a high complexity for FCO₂ during precipitation. Correlation maps assisted in identifying regions where M_soil and AFPS better controlled the emission process and where T_soil was important. A major challenge for world agriculture is to increase the efficiency of conventional soil management practices. We highlight the importance of the spatial pattern of soil properties that directly influence the CO₂ emission dynamics. Future mitigation actions should involve less intense tillage and ensure homogeneous applications of soil inputs, thereby reducing production costs and the contribution of these activities to CO₂ emissions during the sugarcane field reform.     

Ultrasound-Assisted Extraction for the Recovery of Carotenoids from Guava’s Pulp and Waste Powders

Plant Foods for Human Nutrition - In this work, lycopene- and β-carotene-rich extracts were obtained from guava’s pulp and waste powders using maceration (ME), ultrasonic bath (BUAE,...     

Application of Cost Criteria for Selection of Municipal Wastewater Treatment Systems

Analysis of economic data pertinent to the existing municipal wastewater treatment plants (MWTP) in Greece is presented. Thisinformation is important when budgeting for future plants. Thedata include land usage and the costs for construction, operationand maintenance of the form y = ax ^b, where a and b are calculated coefficients. Equations for cost and landuse were produced for specific systems. Personnel and energy aspects are analysed as they are major contributors to operationalcost. A life cycle analysis (LCA) of plants is undertaken. The results of such an analysis should suggest the most preferabletechnology under given circumstances. Thus, under high energy costs and low level of automation and operation, at low F/M ratios, conventional activated sludge systems are relatively notcost effective. In addition, for cost of land less than US$30 per m², waste stabilisation ponds are cost effective subjected to minor earthworks.     

Removal of Copper and Cadmium Ions from Diluted Aqueous Solutions by Low Cost and Waste Material Adsorbents

The sorption of copper and cadmium ions using activated carbon,kaolin, bentonite, diatomite and waste materials such as compost,cellulose pulp waste and anaerobic sludge as sorbents is reported. Equilibrium isotherms were obtained for the adsorption of these metals in single and binary solutions. Bentonite presented the highest adsorption capacities for both copper and cadmium. A competitive uptake was observed when both metals are present; copper being preferentially adsorbed by all materials with theexception of anaerobic sludge. Equilibrium data were fitted toLangmuir and Freundlich models, with satisfactory results for most of the adsorbent-metal systems studied.Of all the adsorbents studied, bentonite and compost presentedthe highest removal efficiencies, reaching 99% for copper whencadmium is also present, for initial solution concentrations ofup to 100 mg L^-1. Anaerobic sludge has a greater preferencefor cadmium, even in the presence of copper, with removal efficiencies of 98% for similar concentrations to those mentioned above.     

Resveratrol and a novel tyrosinase in Carignan grape juice

Polyphenol levels in wines are affected by the wine-making process. Resveratrol is one polyphenol which has been the subject of a commendable amount of recent research. In this work, we found that resveratrol is immediately degraded by tyrosinase. A novel tyrosinase was purified from Carignan grapes. The purification process included salting out and separation on a cation-exchange column, followed by gel filtration. Tyrosinase was purified in a homogeneous form by SDS-PAGE and was characterized: its specific activity toward 3-(3,4-dihydroxyphenyl)-L-alanine (DOPA) increased by a factor of 24 with an overall recovery of 3% of initial activity. The apparent molecular mass of the purified tyrosinase was 40 kDa as determined by SDS-PAGE, and 42 kDa as determined by gel filtration. Its activity was optimal at pH 6 and at 25 degrees C. The enzyme exhibited high activity toward phenylenediamine, epicatechin, pyrogallol, DOPA, and resveratrol. Tyrosinase activity was inhibited by KCN, thiourea, and SO(2). Resveratrol levels were stable following the removal of proteins from the juice, suggesting that early spraying of grapes with SO(2) is an important factor affecting the final amount of resveratrol in wine.     

Classification of cereal flours by chemometric analysis of MIR spectra

Different kinds of cereal flours submitted to various technological treatments were classified on the basis of their mid-infrared spectra by pattern recognition techniques. Classification in the wavelet domain was achieved by using the wavelet packet transform for efficient pattern recognition (WPTER) algorithm, which allowed singling out the most discriminant spectral regions. Principal component analysis (PCA) on the selected features showed an effective clustering of the analyzed flours. Satisfactory classification models were obtained both on training and test samples. Furthermore, mixtures of varying composition of the studied flours were distributed in the PCA space according to their composition.     

Modified Pollard transects for assessing tropical butterfly abundance and diversity

This paper introduces and discusses the consistency and effectiveness of an inexpensive modification of Pollard transects for assessing the diversity and abundance of tropical butterfly communities in two national parks in Rio de Janeiro, Brazil. To measure butterfly abundance, students walked simultaneous timed transects at the interface of forest and cleared areas. They either counted the number of individuals observed or tabulated the number of specimens collected with nets. After a short training period, the number of butterflies observed or collected on simultaneous transects was statistically indistinguishable among student groups, and there was a significant positive correlation between observation counts and collected number of individuals. As a measure of species richness, the number of butterfly species sampled on each simultaneous transect was tabulated and did not differ statistically. To measure diversity, alpha of the logseries model was calculated for each collected sample, and statistical fit to a logseries model was determined. Although virtually all daily samples and the year's accumulated sample at one park fit the logseries model, about 35% of the daily samples and the entire year's sample did not fit at the other park. Despite these differences between the two parks, values for alpha from daily samples at both parks varied similarly (from 15 to 50 in almost all cases), and values from the entire year's samples were statistically indistinguishable. The repeatability of results among novices, such as students, suggests that timed transects have great promise for furthering our understanding of butterfly community demographics.