Effects of dietary fish oil and soya bean lecithin on gonad index,colour and biochemical composition of the purple sea urchin,Strongylocentrotus purpuratus (Stimpson 1857)

The effects of increasing soya bean lecithin (SL) levels (0%, 2% and 4% of diet dry matter, DM) at two fish oil (FO) levels (0% and 3% DM) on gonad index, colour and biochemical composition of Strongylocentrotus purpuratus were evaluated using a 3 × 2 factorial design with six iso‐nitrogenous formulated diets. All diets generated an increase in gonad index of more than 9%. Dietary FO had a positive effect on diet digestibility and accumulation of proteins in the gonad. Soy lecithin did not affect gonad composition, but improved its coloration, decreased gonad feed conversion ratio and increased gonad protein efficiency. There was a clear effect of diets on sea urchins gonad protein, ash and fatty acid content, in particular, decreasing the n‐3/n‐6 ratio associated with a decrease in 20:5n‐3 when SL levels increased. Nevertheless, 22:6n‐3 levels increased by week 12 in all treatments, and diets with SL increased the content of 20:4n‐6 in gonads. A decrease in bitter‐tasting amino acids such as histidine, cysteine, valine and methionine was observed in all treatments with a concomitant increase in isoleucine levels. We recommend using a diet containing 3% of FO and 2% of SL to increase food consumption, diet digestibility, improving marketable gonad colour and an increasing gonad n‐6 fatty acids and C22:6n‐3. In addition, the present study paves the way for future research in the use of FO and SL as an additive in diets for S. purpuratus towards the goal of increasing gonad size and nutritional quality.     

Effects of two diets on lipid composition and reproductive performance of brill (Scophthalmus rhombus) eggs

The effects of two diets with different lipid composition (squid Loligo gahi and one commercial pellet for breeders) on reproductive performance and egg lipid composition of brill (Scophthalmus rhombus) were compared. A total of 36 adult brill weighing 1482 ± 432 g were randomly distributed in the experimental tanks. A flow‐through system composed of four tanks with 4.2 m² of bottom area (5.0 m³ × 1.2 m water depth) was used. The experiment lasted for approximately 5 months (168 days). From the four mature females fed squid, three ovulated. Five females fed pellets matured and ovulated. Total ovulations were of 10 and 44, by the three females fed squid and the five ovulating female fed pellets respectively. Egg viability was higher, although not significantly, for females fed pellets. This indicates that pellets could be a better food for breeding females. In general, the egg total lipid content and the lipid classes composition did not seem to be affected by diet. In contrast, results indicate that not only diets but also individual females, regardless of the diet consumed, are determinant for egg fatty acid composition, clearly modulating their composition.     

Carbon and nitrogen mineralization and ammonia volatilization from fresh,aerobically and anaerobically treated pig manure during incubation with soil

Summary We studied the decomposition of aerobically and anaerobically treated pig manure during a 2-month incubation with soil. The manure samples had not been in contact with straw or with animal urine. The aerobically decomposed manure proved to be the most stable (23% C mineralization), followed by fresh (75%) and anaerobically treated manure (105%, priming effect). The course of mineralization fitted combined first- and zeroorder kinetics. In the anaerobically treated manure, 76% of NH ₄ ⁺ -N was immobilized during the initial incubation phase, followed by a slow linear mineralization. In the aerobically treated manure there was a slow linear mineralization after 5 days, and in the fresh material, a slightly faster linear mineralization after 6 days. Total mineralized N was very similar after 2 months (12%) in all treatments. Total NH₃ losses were highest from the anaerobically treated manure (14%), reflecting a higher NH ₄ ⁺ content with N mineralization following first-order kinetics. Relating NH₃ losses to the initial NH ₄ ⁺ content showed that all NH₃ in the aerobically treated manure was volatilized, whereas only 28% was volatilized from the fresh and the anaerobically treated manure. Present address: Department of Soil Science, Rothamsted Experimental Station, Harpenden Herts, AL5 2JQ, UK     

Alkylating potential of potassium sorbate

A kinetic study of the alkylating potential of potassium sorbate (S)-a food preservative used worldwide-in 7:3 water/dioxane medium was performed. The following conclusions were drawn: (i) Potassium sorbate shows alkylating activity on the nucleophile 4-(p-nitrobenzyl)pyridine (NBP), a trap for alkylating agents with nucleophilic characteristics similar to those of DNA bases, (ii) The NBP alkylation reaction complies with the rate equation r = k(alk)[H+][S][NBP]/(K(a) + [H+]), K(a) being the sorbic acid dissociation constant and k(alk) the rate constant of NBP alkylation by the undissociated acid. In the range of pH 5-6, the alkylation time ranges between 18 days (pH 5.2) and >1 month (pH > or = 6). (iii) NBP alkylation occurs through a reaction with deltaH# = 78 kJ mol(-1), which is much higher than those of NBP alkylation by stronger alkylating agents. (iv) The absorption coefficient of the sorbate-NBP adduct was determined to be epsilon = 204 M(-1) cm(-1) (lambda = 580 nm), this value being rationalized in terms of the adduct structure. (v) The results can help to establish suitable expiration times for products preserved with potassium sorbate.     

Morphine-induced delay of normal cell death in the avian ciliary ganglion

Repeated administration of morphine in increasing doses delayed normal cell death in the ciliary ganglion of the chick embryo; the effect was completely blocked by naloxone. Survival of spinal motoneurons was not affected. Morphine also inhibited potassium-stimulated synthesis of acetylcholine in ganglion cells cultured with muscle, suggesting that morphine can influence neurotransmission. Morphine's effect on cell death may be due to an inhibition of transmission at the neuromuscular junction, but opiates may also directly affect cell death. Although it is now known whether the endogenous opiates in the ciliary ganglion influence neuronal survival during embryogenesis, exogenous opiates can affect normal cell death in the autonomic nervous system.     

Hidden degrees of freedom in aperiodic materials

Numerous crystalline materials, including those of bioorganic origin, comprise incommensurate sublattices whose mutual arrangement is described in a superspace framework exceeding three dimensions. We report direct observation by neutron diffraction of superspace symmetry breaking in a solid-solid phase transition of an incommensurate host-guest system: the channel inclusion compound of nonadecane/urea. Strikingly, this phase transition generates a unit cell doubling that concerns only the modulation of one substructure by the other-an internal variable available only in superspace. This unanticipated pathway for degrees of freedom to rearrange leads to a second phase transition, which again is controlled by the higher dimensionality of superspace. These results reveal nature's capacity to explore the increased number of phases allowed in aperiodic crystals.     

An Exceptional Rainfall Event in the Central Western Pyrenees: Spatial Patterns in Discharge and Impact

An exceptional rainfall and hydrological event occurred on 19–21 October 2012 in the central western Pyrenees and was particularly significant in the Upper Aragón River basin and its tributaries, mainly the Irati River. Analysis of historical records showed that, considered separately, the event of 19 and 20 October ranked between the second and fifth highest most extreme daily precipitation events. For the two days combined (with a total between 200 and 260 mm), the precipitation event was the most extreme 2‐day event among all observation stations but one. The consequent flood destroyed part of an urban area, and a long stretch of a national road triggered landslides, enlarged the alluvial plain and caused generalised soil erosion in cultivated fields cropped with winter cereals. Badlands in the marls of the Inner Depression yielded high volumes of sediment. The floods in the tributaries were relatively moderate (return periods of 14–42 years), whereas in the Upper Aragón River, the flood corresponded to a return period of approximately 400–500 years and to 142 years at the end of the Yesa reservoir, although difficulties in estimating the discharge increased the uncertainty of these values. The Yesa and Itoiz reservoirs considerably reduced the intensity of the flood in the middle and lower Aragón River and confirmed the importance of the water level in the reservoirs when such rainfall events occur. The water storage in the Yesa reservoir increased from 16% to 53% as a consequence of the event. More integrated studies are necessary to decrease the risks associated with flood hazards. This is particularly the case in mountain areas, where the steep slopes and longitudinal gradients of the rivers shorten the concentration time of floods and increase the energy that erodes channels and riverbanks. Copyright © 2013 John Wiley & Sons, Ltd.     

The effect of pig slurry on exchangeable potassium in calcareous soils

Pig slurry in quantities of 200, 400, 500, 600, 800, and 1000 m³ ha^-1 year^-1 was added to two calcareous soils, which differed in concentration and type of clay minerals. The soils were cultivated with two successive crops of pepper and tomatoes grown in containers. A control was given no slurry. The soils were analysed after harvesting for exchangeable K⁺. Differences in exchangeable K⁺ were studied in relation to the concentration and type of clay minerals. The soil with the higher clay content and of the illite type retained K in the exchangeable form to a much greater extent than the soil with the low clay content. In the soil with the lower clay content, of the interstratified illitic — montmorillonite type, very little K was incorporated into the exchange complex. The exchange capacity being low, the amount of K added had little effect on the level of exchangeable K⁺.     

Liquid chromatographic analysis of riboflavin vitamers in foods using fluorescence detection

The analysis of free riboflavin (RF) and its two coenzymes, flavin mononucleotide (FMN) and flavin-adenine dinucleotide (FAD), is optimized using reversed phase liquid chromatography with fluorescence detection. The stationary phase was amide-based and endcapped with trimethylsilyl, and the isocratic mobile phase consisted of a 10:90 v/v acetonitrile/phosphate buffer (pH 5). Peaks were identified by the retention characteristics and fluorescence spectra. Detection limits were 0.03, 0.05, and 0.24 ng for RF, FMN, and FAD, respectively. The vitamins were extracted using acetonitrile and the phosphate buffer. The procedure was applied to the determination of B2 vitamers in different types of food such as milk and soy-based infant formulas, beer, fruit juices, and honey of different types. Most B2 vitamin appeared as RF, while the coenzymes were present in lower amounts. The method was validated using two certified reference materials, and results within the certified range were obtained.     

Role of olive seed in the biogenesis of virgin olive oil aroma

Results obtained in a set of experiments point to an effective participation of olive seeds in the biosynthesis of olive oil aroma through the lipoxygenase pathway during the extraction process to produce virgin olive oil. Data showed that olive seeds should contain enzymatic activities metabolizing 13-hydroperoxides other than hydroperoxide lyase, giving rise to a net decrease in the content of C6 unsaturated aldehydes during the olive oil extraction process. Olive seeds seem also to supply this process with alcohol dehydrogenase activity, being more specific for saturated C6 aldehydes and not acting on C5 alcohols. Moreover, olive seeds would be responsible for the biosynthesis of 30-50% esters during the olive oil extraction process of intact fruits. Thus, olive seeds would afford a load of alcohol acyltransferase activity that might be quite unspecific in terms of substrate, producing any kind of esters.