Irrigated sugarcane crops improve the quality of soil organic carbon over time

The substitution of native vegetation in agricultural systems can cause several changes in the chemical and physical soil attributes, and in the dynamics of soil organic carbon. This study aimed to evaluate changes in soil physical attributes and carbon stock in soil organic matter fractions in irrigated sugarcane crops, as a function of land use and straw management practices over time, in the North of Minas Gerais State, Brazil. Four sugarcane fields with different ages and management systems were studied: Cane 6, Cane 7, Cane 8, and Cane 10. The data obtained were compared with a native vegetation area located near the sugarcane fields, and used as reference for unmanaged soil. In each system, soil samples were collected in the 0-10, 10-20, and 20-30 cm depth layers, to determine the physical attributes, the total organic carbon, and the physical fractions of the soil organic matter. We found that the sugarcane management with the maintenance of a part of the straw on the soil surface contributes to the preservation of the soil structure and the most stable fractions of organic carbon over time. However, in the regions with high annual mean temperature and in the irrigated systems, the soil tillage for the renewal of the sugarcane fields significantly decreases the total soil organic carbon.

Melting, Crystallization, and In Vitro Digestion Properties of Fats Containing Stearoyl-Rich Triacylglycerols

Fats containing the stearoyl-rich triacylglycerols (TAGs) of 1,2-distearoyl-3-oleoylglycerol (SSO) and 1,3-dioleoyl-2-stearoylglycerol (OSO) were synthesized via the lipase-catalyzed acidolysis of tristearin (SSS)-rich fat and oleic acids, followed by solvent fractionation. Their physicochemical properties and in vitro digestibilities were compared. The SSS-, SSO-, and OSO-rich fats comprised 81.6%, 52.9%, and 33.1% stearic acid, respectively, whereas oleic acid comprised 2.9%, 37.5%, and 56.2%, respectively. The SSS-, SSO-, and OSO-rich fats contained the TAGs of SaSaSa (100.00%), SaSaMo (86.98%), and MoSaMo (67.12%), respectively, and the major TAGs were SSS, SSO, and OSO, respectively. Melting and crystallization temperatures were higher and fat crystals were larger and densely packed in the descending order of SSS-, SSO and OSO-rich fats. Both in vitro multi-step digestion and pH-stat digestion were more rapid for OSO- than SSO-rich fat. Oleic acid was digested faster than stearic acid during the initial digestion, then the rate decreased, whereas that of stearic acid increased over prolonged digestion. Fats that were richer in stearoyl at the sn-1,3 position of TAG melted and crystallized at higher temperatures, had a densely packed microstructure of large fat crystals and were poorly digested. Stearic acid imparts the essential physical attributes of melting and crystallization in solid fats, and the low digestible stearoyl-rich fat would be a viable substitute for trans fatty acids in food lipid industry.

Effect of citrus fruit (Citrus sinensis, Citrus limon and Citrus aurantifolia) rind essential oils on preservation of chicken meat artificially infected with bacteria

Essential oils (EOs) obtained from a wide variety of plants have become popular with increased scientific interest as potential natural agents for food preservation. Two concentrations of rind EOs (400 mg/ml and 200 mg/ml) from three species of citrus fruit; Citrus sinensis (Sweet orange), Citrus limon (Lemon), and Citrus aurantifolia (Lime) were used to treat fresh chicken meat inoculated with Escherichia coli ATCC 25922, Salmonella typhi ATCC 20971 and Salmonella enterica ATCC 14028 to evaluate their protective abilities on bacteria-contaminated meat The EOs were extracted from the ground rinds by hydro-distillation. Alongside the EOs, sodium nitrate (NaNO3) was used as a positive control preservative. A viable count was carried out to determine the bacteria load reduction on the inoculated fresh chicken meat. After 24 hours of treatment, the results showed that the EOs had no adverse effect on the physical attributes of the meat: the color and smell of the chicken meat were unaltered compared with the negative control (None EO and NaNO3 treated meat) that showed evidence of putrefaction through color change and foul smell. The two- lime rind EOs concentrations used to treat the Escherichia coli ATCC 25922 inoculated meat reduced the viable count of the organism by 7.9 log compared to the Escherichia coli ATCC 25922-inoculated meat which received no rind EOs or NaNO3 treatment. Other results showed that sweet orange (SO) rind EOs (400 mg/ml and 200 mg/ml) treatment of meat inoculated with Salmonella enterica ATCC 14028 had similar but mild preservative effects as both treatments reduced the log of the bacteria by 1.1 and 0.8, respectively. In comparison with NaNO3, the EOs treatment had a significant (p<0.05) preservative effect on the bacteria-inoculated meats. Findings from this study, therefore, suggest that Citrus spp. rind EOs have good potential as natural preservative for chicken meat. However, notwithstanding the relative positive organoleptic results observed in this study, further investigations on the prolonged preservation effect of the EOs on the physical attributes of fresh chicken meat need to be undertaken.

Nitrogen, phosphorus, water and sediment losses under sugarcane (Saccharum spp.) and peanut (Arachis hypogaea l.) cultivation

Sertãozinho-SP is a major world producer of sugarcane and peanuts. The crop rotation technique recovers soils and brings commercial benefits to producers. Objective: to determine the losses of water, nitrogen (N), phosphorus (P) and sediments, due to the use and occupation of the soil in the peanut and sugarcane crop, using the SWAT model, maintaining the topographic and physical attributes and climatic conditions of the Mogi-Guaçu River sub-watershed, in the Sertãozinho city – SP. To carry out this study, local data from digital elevation maps and soil pedological maps, precipitation, wind, solar radiation, and relative humidity were used. The actual accumulated evapotranspiration was higher in sugarcane (906.7 mm) when compared to peanuts (886.1 mm). Sediment losses were higher in peanuts (300.66 mm) when compared to sugarcane (280.69 mm), as well as losses of N (118.44 and 34.48 kg ha-1) and P (5.456 and 0.805 kg ha-1), respectively. It is concluded that the peanut crop showed the greatest losses of water, nutrients, and sediments, when compared to sugarcane, showing that the land cover directly influenced these losses. Studies like these can aid in decision-making about environmental policies, helping with soil and water conservation in Brazilian sub-watershed.

On the Reformulated Second Zagreb Index of Graph Operations

Topological indices (TIs) are expressed by constant real numbers that reveal the structure of the graphs in QSAR/QSPR investigation. The reformulated second Zagreb index (RSZI) is such a novel TI having good correlations with various physical attributes, chemical reactivities, or biological activities/properties. The RSZI is defined as the sum of products of edge degrees of the adjacent edges, where the edge degree of an edge is taken to be the sum of vertex degrees of two end vertices of that edge with minus 2. In this study, the behaviour of RSZI under graph operations containing Cartesian product, join, composition, and corona product of two graphs has been established. We have also applied these results to compute RSZI for some important classes of molecular graphs and nanostructures.

Inconsistency of time-symmetry model

Can physical objects be in time-symmetry? Physical objects can only exist in a medium that has physical attributes, which means this medium is a type of energy. Is time energy? This article will show that time is not energy, and there is no possibility that physical objects could be in time-symmetry. Physical objects can only be in symmetry in the time-invariant space, in which they exist. In this perspective, time measured with clocks is the result of the observer’s measurement in the time-invariant space. The time-symmetry model is flawed.