Genetic studies in tench (Tinca tinca L.): high incidence of spontaneous triploidy

A high incidence of spontaneous triploidy was found in tench broodstock hormonally treated to induce spawning but without positive response. Triploidy was also observed in random samples of fingerlings from four tench lines. Triploidy was evaluated by counting Ag-stained NORs in erythrocyte nuclei and was confirmed in 62.5% of the broodstock and in a range from 0.00% to 34.62% in fingerlings. Discrimination of tench diploids and triploids based on differences in shape and length of pelvic fins was tested in the broodstock and also in stocks of earlier artificially induced triploid tench by means of the above-mentioned cytogenetic approach and shown to be a rapid method with a high accuracy (96.43%). Natural disposition for egg overripening is one of the possible causes of highly frequent spontaneous triploidy in the analyzed samples. Genetic predisposition, i.e. occurrence of a recessive allele responsible for the failure of the 2nd polar body extrusion when homozygous, was hypothesized as another possible cause of spontaneous triploidy, based on analysis of the relationships among the tench lines.     

Effect of dietary microbially produced gamma‐linolenic acid and plant extracts on enzymatic and non‐enzymatic antioxidants in various broiler chicken organs

Plant extracts and fungal fermented feed with gamma‐linolenic acid‐rich microbial oils are perspective additives for use in animal nutrition as appetite and digestion stimulants, stimulants of physiological functions, for the prevention and treatment for certain pathological conditions, and as antioxidants. The activity of antioxidant enzymes and the level of reduced glutathione were measured in the plasma and in liver, heart and kidney mitochondria after 42 days of feeding broiler chickens both regular and combination diets. These were selected based on our previous experience. The administration of agrimony and gamma‐linolenic acid resulted in a significant decrease in superoxide dismutase activity in all four bodies in contrast to plant extracts. We conclude that the decrease in activity is due to decreased production, and hence dismutation, of superoxide radicals to peroxides followed by lower activity of glutathione peroxidase, which was not seen in the case of only plant extract administration. Generally, higher glutathione reductase activity would be in response to increased demands on reduced glutathione as a cofactor for the reaction catalysed by glutathione peroxidase and the utilization of glutathione itself. However, measured levels of reduced glutathione showed no change. The results argue against any oxidative stress conditions. The application of agrimony extract appears to be suitable for the antioxidant effect against peroxidation of gamma‐linolenic acid. As the efficacy of measuring the effects of diets on the oxidative stability of meat caused by selected antioxidant enzymes is rather low, additional data from the experiment will be processed to clearly assess the influence of this combination of diets.     

Inhibition of cholesterol oxidation products (COPs) formation in emulsified porcine patties by phenolic-rich avocado (Persea americana Mill.) extracts

The effect of phenolic-rich extracts from avocado peel on the formation of cholesterol oxidation products (COPs) in porcine patties subjected to cooking and chill storage was studied. Eight COPs (7α-hydroxycholesterol, 7β-hydroxycholesterol, 7-ketocholesterol, 20α-hydroxycholesterol, 25-hydroxycholesterol, cholestanetriol, 5,6β-epoxycholesterol, and 5,6α-epoxycholesterol) were identified and quantified by GC-MS. The addition of avocado extracts (～600 GAE/kg patty) to patties significantly inhibited the formation of COPs during cooking. Cooked control (C) patties contained a larger variety and greater amounts of COPs than the avocado-treated (T) counterparts. COPs sharply increased in cooked patties during the subsequent chilled storage. This increase was significantly higher in C patties than in the T patties. Interestingly, the amount of COPs in cooked and chilled T patties was similar to those found in cooked C patties. The mechanisms implicated in cholesterol oxidation in a processed meat product, the protective effect of avocado phenolics, and the potential implication of lipid and protein oxidation are thoroughly described in the present paper.     

The cortical topography of tonal structures underlying Western music

Western tonal music relies on a formal geometric structure that determines distance relationships within a harmonic or tonal space. In functional magnetic resonance imaging experiments, we identified an area in the rostromedial prefrontal cortex that tracks activation in tonal space. Different voxels in this area exhibited selectivity for different keys. Within the same set of consistently activated voxels, the topography of tonality selectivity rearranged itself across scanning sessions. The tonality structure was thus maintained as a dynamic topography in cortical areas known to be at a nexus of cognitive, affective, and mnemonic processing.     

Spin rate of asteroid (54509) 2000 PH5 increasing due to the YORP effect

Radar and optical observations reveal that the continuous increase in the spin rate of near-Earth asteroid (54509) 2000 PH5 can be attributed to the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect, a torque due to sunlight. The change in spin rate is in reasonable agreement with theoretical predictions for the YORP acceleration of a body with the radar-determined size, shape, and spin state of 2000 PH5. The detection of asteroid spin-up supports the YORP effect as an explanation for the anomalous distribution of spin rates for asteroids under 10 kilometers in diameter and as a binary formation mechanism.     

Effect of different types of descaling methods on shelf life of air-/vacuum-packaged common carp (<Emphasis Type="Italic">Cyprinus carpio</Emphasis> L.) fillets under refrigerated storage conditions

Microbiological quality, sensory attributes and consumer preferences of common carp (Cyprinus carpio L.) fillets descaled by four different methods under two storage conditions (air packed and vacuum packaged) and refrigerated storage conditions were studied. Farmed common carps (scaly and mirror), of marketable size (2.2 kg, 3 years old), were randomly divided into four experimental groups (n = 10), and filleted and fillets were processed by four descaling methods: without skin, without scales, undercut scales and mirror carp (without any other treatment). Microbiological analyses were determined by total viable counts (TVCs) in logarithm of colony-forming units per gram (log CFU/g), and sensory quality of fillets was classified by odour, flavour, after taste and consistency on storage days 0, 3, 6 and 9. Vacuum packaging conditions affected the growth of microbiota and extended the shelf life of fillets in all experimental groups. Microbial communities grew to between 3.19–3.90, 4.03–6.00 and 6.35–8.28 log CFU/g after 3, 6 and 9 days of storage, respectively, and fillets without skin showed the lowest TVC among all analysed groups throughout storage. Also sensory analyses showed that consistency and odour of carp fillets were influenced by packaging conditions as well as descaling methods. The survey on consumer preferences of carp found out that 58.9 % of customers preferred scaly carp with undercut scales and processed to fillets instead of mirror carp. The results of present study show that different types of descaling methods combined with air/vacuum packaging can significantly prolong the shelf life of carp fillets.