Phytanic acid concentrations and diastereomer ratios in milk fat during changes in the cow’s feed from concentrate to hay and back

The phytanic acid content in milk correlates with the amount of green items in the cows’ feed. For this reason, the four-fold methyl-branched fatty acid has been suggested as a potential marker for the authentication of organic milk. In this study, we attempted to provide further support for this idea by studying the progression of the phytanic acid level and diastereomer ratio in milk fat by transition of the diets from high proportions of concentrate (typical “conventional” feed) to hay (typical “organic” feed in winter) and back to “conventional” feed. Milk samples taken from three cows were analyzed on both the phytanic acid concentration and diastereomer distribution. The cows were initially fed with “conventional” feed (ground feed with high portions (30–45?%) of concentrate), then the feed was changed within 1?week to 100?% hay (“organic” feed), and after ~6?weeks, the feed of two cows was changed back to the initial feed with concentrate (phase C_b). During the “conventional” feeding at the beginning of the experiment, the phytanic acid concentration was low (100–130?mg/100?g milk fat). When the feed was changed to hay (“organic” feed), the phytanic acid concentration immediately increased to a stable level of about 160?mg/100?g lipids. Changing back the feed to “conventional” feed, the phytanic acid concentration dropped immediately back below the value measured in the initial phase. Likewise, the SRR/RRR-diastereomer distribution of phytanic acid in the milk was an excellent indicator for the changes in the cows’ feed. While the SRR/RRR-diastereomer ratio was >1.5 during “conventional” feeding, it immediately decreased to equal amounts of both diastereomers when hay was supplied as feed. Abandonment of concentrate in conventional feeding increased the phytanic acid content but the SRR-diastereomer was still dominant and thus the SRR/RRR-diastereomer ratio was different to organic milk. Our results indicate that both parameters, i.e., the phytanic acid content and SRR/RRR-diastereomer ratio need to be measured for authentication of organic milk.     

Edible films made from blends of manioc starch and gelatin – Influence of different types of plasticizer and different levels of macromolecules on their properties

The interest in the development of edible and biodegradable films has increased because it is every day more evident that non-degradable materials are doing much damage to the environment. In this research, bioplastics were based on blends of manioc starch (native and modified) and gelatin in different proportions, added of glycerol or sorbitol, which were used as plasticizers. The objective was to study the effect of two different plasticizers, glycerol and sorbitol, and different concentrations of starch and gelatin on the barrier (water vapor permeability – WVP), mechanical (tensile strength and elongation at break), physicochemical (solubility in water and in acid) and physical properties (opacity and thickness) of the obtained bioplastics samples. As a result, all of them showed transparency and resistance to tensile strength, as well as increasing in thickness values and in the WVP, as the gelatin content increased in the formulations. Finally, all results for tensile strength and elongation at break obtained for those samples plasticized with sorbitol were better than those plasticized with glycerol.     

Chemical and antifungal investigations of six Lippia species (Verbenaceae) from Brazil

The Lippia genus is used in ethnobotany as food, beverages, seasoning and antiseptic remedies, among others. The chemical compositions of fifteen extracts of six Lippia species were investigated comparatively by HPLC-PDA. To avoid data replication of previous works on this genus, Lippia lupulina Cham. root ethanol extract was selected for isolation procedures based on Principal Component Analyses (PCA) of such data. Seven compounds previously unreported in this genus were isolated from this extract (a triterpene, two furanonaphtoquinones, a furanochromone, an isoflavone, a stilbene and an iridoid). The activities of extracts, fractions and pure compounds towards Candida albicans, Candida krusei, Candida parapsilosis and Cryptococcus neoformans were investigated. Two fractions from the extract of Lippia salviaefolia leaves showed marked inhibition of fungal growth, in addition to verbascoside and asebogenin, which showed MICs lower than 15.6μg/ml and may be promising leads for the development of new antifungal agents, especially against C. neoformans.     

Mercury bioacumulation in four tissues of Podocnemis erythrocephala (Podocnemididae: Testudines) as a function of water parameters

A number of environmental factors influence the dynamics of Hg in aquatic ecosystems, yet few studies have examined these factors for turtles, especially from South America. Red-headed river turtle (Podocnemis erythrocephala) is easy to capture in the black waters of Rio Negro, making it the turtle species that is consumed most often by people of the region. In this study, environmental factors and turtle size were investigated to determine their influence on the Hg concentration in blood, muscle, liver and carapace of the red-headed river turtle. Factors investigated included turtle length, pH, dissolved organic carbon and availability of potential methylation sites (floodplain forests and hydromorphic soils). The study was conducted in the Rio Negro basin, where we collected water and turtle blood, muscle, liver and carapace samples from 12 tributaries for chemical analysis. Through radar imagery and existing soil maps with GIS, the percentage of alluvial floodplains and hydromorphic soils (potential methylation sites) was estimated for each drainage basin at sampling points. The mean Hg concentration in blood of P. erythrocephala was 1.64 ng g^− 1 (SD = 1.36), muscle 33 ng g^− 1 (SD = 11), liver 470 ng g^− 1 (SD = 313) and carapace 68 ng g^− 1 (SD = 32). Sex or length did not influence the Hg concentration in P. erythrocephala blood, muscle and liver, but Hg increased in carapace tissue when length size increased (ANCOVA p = 0.007). In the multiple regression analysis, none of the environmental factors studied had a significant relation with blood, muscle, liver and carapace. P. erythrocephala moves among habitats and in the open and interconnected aquatic systems of the Amazon basin, characterized by high levels of limnological variability, a good bioindicator of Hg concentration needs to be relatively sedentary to represent a specific habitat. However, the levels of Hg in liver were sufficient to pose a potential risk to humans that consume them, suggesting the usefulness of P. erythrocephala as a bioindicator.     

Attenuation of gastric lesions by psychological aspects of aggression in rats.

In a study with 80 male albino rats, Ss that fought with each other in response to electric shock showed reduced gastric lesions in comparison with Ss that received the same shocks alone so that fighting behavior did not occur. Also, gastric lesions were similarly reduced in Ss that fought even though they could not physically contact one another because of a barrier between them. In this case, the "protective" effect of fighting derived from the release or display of fighting behavior and did not require physical combat. A 2nd experiment with 48 rats showed that Ss that received shock together but did not engage in fighting behavior showed no reduction of gastric lesions, so that the protective effect of fighting was not an artifact of Ss receiving shock together. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A comparison of the electronic and the chemical and structural properties of quasi-1D anion deficient tetracyanoplatinates

The temperature dependences of the electrical conductivity of seven structurally similar quasi-one-dimensional anion deficient tetracyanoplatinates have been compared and discussed in terms of their chemical and structural properties. It is demonstrated that the variation from compound to compound of both the experimentally determined (κ_F, Δ) and calculated 1D parameters (?_F, λ, T_p) can be understood in terms of the influence of the anions, cations, and water of hydration on the intra-chain PtPt distance and the degree of partial oxidation. The transverse electron coupling constant, ν, is calculated using the experimentally determined 3D ordering temperature T_3D, and is also shown to be dependent on the constituents of the crystal lattice.     

Topochemical polymerization of butadiynylene dibenzamides

Summary Series of meta- and para-substituted butadiynylene dibenzamides were synthesized, and their solid state polymerization was studied. The meta-isomers were light sensitive but not heat sensitive. The polymerizability of para-isomers depended on the type of N-substitutents. The polydiacetylenes from the para-isomers were blue, while those of the meta-isomers were light purple. Studies with molecular models and computer imaging suggested that hydrogen bonding between the topochemically polymerizable dibenzamides in the polymerization array is rather unlikely.     

ADC characterization by using the histogram test stimulated by Gaussian noise: Theory and experimental results

This paper presents results relating to the measurement of differential and integral nonlinearity of ADCs using the histogram method with white Gaussian noise as the stimulus signal. We specify the optimum noise power of the generator, in the sense of number of samples minimisation, as a function of the converter range and resolution. An expression of tolerance interval as a function of the number of samples acquired given a certain confidence level is presented both for the determination of transition levels (INL) and quantization intervals (DNL). Experimental and simulation results concerning the characterization of a 12-bit PC acquisition board are shown.