Lumichrome and phenyllactic acid as chemical markers of thistle (Galactites tomentosa Moench) honey

HPLC-DAD-MS/MS chromatograms of thistle (Galactites tomentosa Moench) unifloral honeys, previously selected by sensory evaluation and melissopalynological analysis, showed high levels of two compounds. One was characterized as phenyllactic acid, a common acid found in honeys, but the other compound was very unusual for honeys. This compound was extracted from honey with ethyl acetate and purified by SPE using C(18), SiOH, and NH(2) phases. Its structure was elucidated on the basis of extensive 1D and 2D NMR experiments as well as HPLC-MS/MS and Q-TOF analysis, and it was identified as lumichrome (7,8-dimethylalloxazine). Lumichrome is known to be the main product of degradation obtained in acid medium from riboflavin (vitamin B(2)), and this is the first report of the presence of lumichrome in honeys. Analysis of the G. tomentosa raw honey and flowers extracts confirmed the floral origin of this compound. The average amount of lumichrome in thistle honey was 29.4 ± 14.9 mg/kg, while phenyllactic acid was 418.6 ± 168.9 mg/kg. Lumichrome, along with the unusual high level of phenyllactic acid, could be used as a marker for the botanical classification of unifloral thistle (G. tomentosa) honey.     

DIFFERENTIAL TOLERANCE TO ZINC DEFICIENCY IN COFFEE-PLANT PROGENIES

The tolerance of different coffee-plant progenies to zinc (Zn) deficiency was studied in a green house experiment arranged in a completely randomized design, in a 14 × 2 factorial scheme (14 progenies and two Zn concentrations), with four replications. Coffee-plant seedlings were grown for ten months in nutritive solution with or without Zn. There were evaluated for growth characteristics, zinc concentrations, and zinc requirement. The grouping involving growth characteristics allowed discriminating the progeny ‘UFV 4066-3’ as highly zinc-demanding and ‘IAC 4376-5’ as low zinc-demanding. The data on plant dry matter and zinc accumulation showed that the progenies ‘IAC 4376-5’ and ‘UFV 4066-5’ had low zinc requirement when ‘Caturra Amarelo 1’, ‘UFV 4066-3’, ‘Caturra Amarelo 2’ and ‘Caturra Vermelho 2’ had high zinc requirement. Leaf area reduction (%), leaf number, active zinc content in completely expanded leaves and total zinc in roots were the variables of highest relative importance in discriminating coffee plant progenies.     

Phenotypic differences between hatchery-reared and wild mud crabs, <Emphasis Type="Italic">Scylla Serrata</Emphasis>, and the effects of conditioning

Hatchery-reared animals for stock enhancement should be competent to survive and grow at rates equivalent to those of wild conspecifics. However, morphological differences are often observed, and pre-conditioning steps may be required to improve the fitness of hatchery-reared juveniles prior to release. In the present study, hatchery-reared Scylla serrata juveniles were reared either individually (HR-solitary) or groups in tanks (HR-communal), the latter group being exposed to intraspecific competition and foraging for food. After 21 days, both groups were compared to similar size wild-caught juveniles in terms of morphometric measurements of carapace spination, abnormalities and carapace colouration. There were some limited significant differences between HR-communal crabs and HR-solitary crabs in terms of length of 8th and 9th lateral spines and in body-weight-carapace width ratio, but both treatments differed from wild crabs, which were heavier and had longer carapace spines for their size. In contrast, both HR treatments exhibited common abnormalities including deformities in the shape of the abdomen, in particular occurrence of an asymmetrical telson or a deeply folded telson. In all cases, abnormalities persisted through moulting. Initially, carapace colour differed in all measures of colour between HR and wild crabs. However, these differences reduced after a period of 4–8 days of conditioning on coloured tank backgrounds or dark sand or mud backgrounds, without moulting. Similarly, hatchery-reared crabs exhibited very limited burying behaviour on first exposure to sediment, but this increased to levels observed in wild crabs within 2–4 days. Thus, short-term conditioning of hatchery-reared crabs on dark sediments may be effective in increasing predator avoidance and survivorship in released animals, and present results suggest that this can be achieved after relatively short periods of 1 week or less.     

Phenotypic diversity,host range and molecular phylogeny of <Emphasis Type="Italic">Dickeya</Emphasis> isolates from Spain

Six Dickeya spp. strains representative of a larger group of bacteria isolated from potato, onion and irrigation water in Spain between years 2003–2005, were characterised by biochemical, serological, molecular and pathogenicity assays. Biochemical and serological differences, as well as pathogenic behaviour in host range and virulence levels, were observed among the strains. They were classified into biovars 3 and 6. Phylogenetic analysis and comparison of the isolates with type strains of Dickeya species characterised to date were performed using concatenated partial sequences of the housekeeping genes gapA and mdh. One of the Spanish strains was identified as D. dieffenbachiae, whereas the other ones did not fit clearly into the previously described six Dickeya species, and may therefore constitute novel species. Isolation of dissimilar pathogenic strains in different rivers and irrigation water sources supports the idea that Dickeya species is commonly present in such an environment, and contaminated water is a potential source of inoculum for the disease in different crops.     

Glutamine and glutamate supplementation raise milk glutamine concentrations in lactating gilts

Glutamine is the most abundant amino acid in milk, and lactation is associated with increased glutamine utilization both for milk synthesis and as a fuel for the enlarged small intestine. A number of recent studies have indicated that lactation is accompanied by a mild catabolic state in which skeletal muscle proteins are degraded to provide amino acids that are used to synthesize additional glutamine. In this study we tested the hypothesis that supplemental L-glutamine or the commercially available glutamine supplement Aminogut (2.5% by weight mixed into daily feed) provided to gilts from 30 days prior to parturition until 21 days post-parturition would prevent a decrease in skeletal muscle glutamine while increasing the glutamine content of the milk. Muscle glutamine content decreased (P < 0.05) in control animals during lactation but this was prevented by supplementation with either L-glutamine or Aminogut. In this study, neither lactation nor supplementation had any effect on plasma glutamine or glutamate content. Free glutamine, and the total glutamine plus glutamate concentrations in milk from the control and the Aminogut group rose (P < 0.05) during the first 7 days of lactation, with milk concentrations in the L-glutamine supplemented group showing a similar trend (P = 0.053). Milk glutamate remained constant between day 7 and 21 of lactation in the control and L-glutamine supplemented groups, but by day 21 of lactation the free glutamine, glutamate, and glutamine plus glutamate concentrations in milk from Aminogut-treated gilts were higher than those of control gilts. Thus dietary glutamine supplementation can alleviate the fall in intramuscular glutamine content during lactation in gilts, and may alleviate some of the catabolic effects of lactation. Furthermore, the increased milk glutamine content in the supplemented gilts may provide optimum nutrition for piglet development.     

Effect of the supplementation of live preys enriched in cod liver oil on the survival rate,growth and fatty acid profile of meagre (Argyrosomus regius) larvae

First‐feeding diets employed in the rearing of meagre (Argyrosomus regius) larvae are based on live preys that are commonly enriched to compensate for their deficiency of essential fatty acids. A feeding trial was conducted on meagre larvae (Argyrosomus regius) fed rotifer (Brachionus plicatilis) and Artemia salina enriched in lipids from an emulsion of cod liver oil (CLO) and a commercial product (CP). The effect of both enrichment products was evaluated on the survival rate, size and lipid composition of meagre larvae. The results showed that larvae fed CLO presented significant higher values of survival rate (35.0 ± 3.2%) and larval size (12.06 ± 1.17 mm) at the end of the experiment, compared to the CP diet (26.0 ± 2.5%, 11.41 ± 0.91 mm, respectively). Both zootechnical parameters were related to the content of polyunsaturated fatty acids in the larvae. Indeed, the larvae fed CLO presented a higher ratio DHA/EPA than those enriched in commercial product (0.82 ± 0.18 and 0.38 ± 0.12 at 26 days after hatching, respectively). Both larval groups presented similar body content of arachidonic acid (1.4 wt.% on average at 26 days after hatching), regardless the enrichment source. From all above, we can conclude that the enrichment of live preys with an emulsion of cod liver oil is an economically viable alternative to commercial products. Indeed, cod liver oil emulsions are able to fully meet the requirements for fatty acids of meagre larvae. Furthermore, cod liver oil is easily available from fish processing facilities.     

Formation of protein-oligosaccharide conjugates by laccase and tyrosinase

Proteins and certain carbohydrates contain phenolic moieties, which are potential sites for modification of the function of the biopolymers. In this study, the capability of two different fungal oxidative enzymes, laccase from Trametes hirsuta (ThL) and tyrosinase from Trichoderma reesei (TrT), to catalyze formation of hetero-cross-linking between tyrosine side chains of alpha-casein and phenolic acids of hydrolyzed oat spelt xylan (hOSX) was studied. Formation of reaction products was followed by size exclusion chromatography (SEC), fluorescence spectroscopy, and SDS-PAGE, using specific staining methods for proteins and protein-carbohydrate conjugates. ThL and TrT were observed to differ significantly in their ability to catalyze the formation of protein-carbohydrate conjugates or the linking of the small molecular weight phenolic compounds to alpha-casein. The efficiency of these enzymes to directly cross-link protein also differed notably. TrT was able to cross-link alpha-casein more efficiently than ThL. ThL-catalyzed casein cross-linking was significantly enhanced by ferulic acid, p-coumaric acid, and also hOSX. The main reaction products by ThL appeared to be phenolic acid-bridged alpha-caseins. Indications of hetero-cross-link formation between alpha-casein and hOSX by both oxidative enzymes could be visualized by glycoprotein-specific staining in the SDS-PAGE analysis, although ThL was observed to be more effective in the heteroconjugate formation than TrT.     

Growth stresses and strains in cork

Summary A detailed study of the growth stresses and strains in the cork shell of the cork-oak was undertaken based on experimentally determined constitutive relations for cork in tension and compression. The stresses depend on the thicknesses of the cork shell and of the back layer around the cork shell, on the radius of the trunk and on its increase due to growth. The circumferential stresses in the cork shell and back layer are tensile and increase with increasing distance to the tree axis. The radial stresses are compressive and decrease with increasing distance to the tree axis. The strains due to growth are not recovered when the cork boards are removed, unless the boards are heated, for example, by immersion in boiling water. Other consequences of the growth stresses are analysed, such as the occurrence of corrugations in the lateral cell walls of cork, the variation of width of the successive growth rings and the occurrence of cracks in the back layer and outer cork layers.     

Novel findings regarding Glut-4 expression in adipose tissue and muscle in horses--a preliminary report

One of the hallmarks of insulin resistance is a reduction in glucose transporter-4 (Glut-4) expression in adipose tissue but not in skeletal muscle. However, while Glut-4 has been demonstrated in skeletal and cardiac muscles in horses it has not been demonstrated in adipose tissue. The initial objectives of the present study were: (1) to test the hypothesis that Glut-4 expression would vary between selected key skeletal muscles; (2) to test the hypothesis that it would also vary between representative adipose tissue depots, and (3) to see whether expression would be greater in adipose tissue compared to muscle. Glut-4 expression was determined by Western blot using samples obtained from post mortem biopsies obtained from four muscles (gluteus medius, semitendinosus, heart, and diaphragm), and four adipose tissues (subcutaneous, retroperitoneal, mesenteric, and omental) in three horses. There were no differences (P>0.05) in Glut-4 protein expression between the muscles sampled. Likewise there were no differences (P>0.05) in Glut-4 protein expression between fat depots. There was a significant difference (P=0.03) when pooled means for Glut-4 expression in muscle (58.8+/-2.5 densitometry units) were compared with adipose tissue (115.8+/-15.7). This difference in Glut-4 expression in these two tissues with distinctly different metabolic reasons for taking up glucose may warrant further investigation to see if there are more pronounced differences in Glut-4 expression in muscle and adipose tissue in various populations of horses.     

Changes in testicular size,echotexture, and arterial blood flow associated with the attainment of puberty in Dorper rams raised in a subtropical climate

There is a paucity of information on the relationships of testicular morphology, echotextural attributes, and blood flow dynamics with pubertal development of rams raised in a subtropical climate. Forty‐five Dorper rams (24 rams aged 8–11 months and 21 rams aged 12–24 months) were examined using a portable ultrasound scanner connected to a 7.5‐MHz transducer. Computer‐assisted analyses of testicular ultrasonograms utilized commercially available Image ProPlus^® analytical software. Spectral Doppler scans of testicular arteries were performed immediately after scrotal (B‐mode) ultrasonography to determine peak systolic velocity (PSV), end‐diastolic velocity (EDV), resistive index (RI = [PSV?EDV]/PSV), and pulsatility index (PI = [SPV–EDV]/mean velocity) of the blood vessels. The length of the testes (9.7 ± 0.3 compared with 9.0 ± 0.2 cm) and scrotal circumference (33.3 ± 0.5 compared with 31.8 ± 0.4 cm) were greater (p < 0.05) but testicular depth (4.5 ± 0.1  compared with 4.9 ± 0.08 cm) was less (p < 0.05) in sexually mature compared with peripubertal rams. [Corrections added on 9 Jan 2019 after initial online publication: The testicular size values in the sentence were corrected.] There were no differences (p > 0.05) between the two age groups of Dorper rams in blood flow indices of testicular arteries. Mean numerical pixel values (100.5 ± 4.1 compared with 89.2 ± 4.8) and pixel heterogeneity (25.6 ± 0.6 compared with 23.6 ± 0.5) of testicular parenchyma were greater (p < 0.05) in peripubertal than in postpubertal rams. Semen volume was negatively correlated with PI of testicular arteries (r = ?0.57, p = 0.04). In summary, the attainment of sexual maturity in the rams of the present study was associated with significant changes in testicular length and depth, scrotal circumference, and parenchymal echogenicity/hetrogeneity but not in testicular volume and blood perfusion rates. Testicular artery PI can be used to predict the volume of ejaculate in rams.