Atlantic salmon (Salmo salar) possess enzymes required for the endogenous biosynthesis of n-3 long-chain PUFA (LC-PUFA), EPA and DHA, from α-linolenic acid (ALA). Linoleic acid (LA) competes with ALA for LC-PUFA biosynthesis enzymes leading to the production of n-6 LC-PUFA, including arachidonic acid (ARA). We aimed to quantify the endogenous production of EPA and DHA from ALA in salmon fed from first feeding on diets that contain no EPA and DHA and to determine the influence of dietary LA and ALA:LA ratio on LC-PUFA production. Salmon were fed from first feeding for 22 weeks with three diets formulated with linseed and sunflower oils to provide ALA:LA ratios of approximately 3:1, 1:1 and 1:3. Endogenous production of n-3 LC-PUFA was 5·9, 4·4 and 2·8 mg per g fish and that of n-6 LC-PUFA was 0·2, 0·5 and 1·4 mg per g fish in salmon fed diets with ALA:LA ratios of 3:1, 1:1 and 1:3, respectively. The ratio of n-3:n-6 LC-PUFA production decreased from 27·4 to 2·0, and DHA:EPA ratio increased and EPA:ARA and DHA:ARA ratios decreased, as dietary ALA:LA ratio decreased. In conclusion, with a dietary ALA:LA ratio of 1, salmon fry/parr produced about 28 μg n-3 LC-PUFA per g fish per d, with a DHA:EPA ratio of 3·4. Production of n-3 LC-PUFA exceeded that of n-6 LC-PUFA by almost 9-fold. Reducing the dietary ALA:LA ratio reduced n-3 LC-PUFA production and EPA:ARA and DHA:ARA ratios but increased n-6 LC-PUFA production and DHA:EPA ratio.

The effect of 0.5 wt% Mn addition on the microstructure and mechanical properties of cast Al–2Li–2Cu–0.8Mg–0.4Zn–0.2Zr (wt%) alloy was investigated. Results showed that the grain size of Mn-containing alloy was smaller than that of Mn-free alloy in both the as-cast and solution treated state. Al20Mn3Cu2 dispersoids were formed during solution treatment in the Mn-containing alloy. After aging at 175 °C for 32 h, a large volume fraction of coherent Al3Li/Al3(Li, Zr) particles were precipitated in both Mn-free and Mn-containing alloys, while more Guinier–Preston–Bagaratsky zones were observed in the Mn-free alloy. Mn addition improved the elongation significantly, which was 1.7% for Mn-free alloy and 3.3% for the alloy with 0.5 wt% Mn addition.

Embryo splitting might be used to increase offspring yield and for molecular analysis of embryo competence. How splitting affects developmental potential of embryos is unknown. This research aimed to study the effect of bovine blastocyst splitting on morphological and gene expression homogeneity of demi-embryos and on embryo competence during elongation. Grade I bovine blastocyst produced in vitro were split into halves and distributed in nine groups (3 × 3 setting according to age and stage before splitting; age: days 7–9; stage: early, expanded and hatched blastocysts). Homogeneity and survival rate in vitro after splitting (12 h, days 10 and 13) and the effect of splitting on embryo development at elongation after embryo transfer (day 17) were assessed morphologically and by RT-qPCR. The genes analysed were OCT4, SOX2, NANOG, CDX2, TP1, TKDP1, EOMES, and BAX. Approximately 90% of split embryos had a well conserved defined inner cell mass (ICM), 70% of the halves had similar size with no differences in gene expression 12 h after splitting. Split embryos cultured further conserved normal and comparable morphology at day 10 of development; this situation changes at day 13 when embryo morphology and gene expression differed markedly among demi-embryos. Split and non-split blastocysts were transferred to recipient cows and were recovered at day 17. Fifty per cent of non-split embryos were larger than 100 mm (33% for split embryos). OCT4, SOX2, TP1 and EOMES levels were down-regulated in elongated embryos derived from split blastocysts. In conclusion, splitting day-8 blastocysts yields homogenous demi-embryos in terms of developmental capability and gene expression, but the initiation of the filamentous stage seems to be affected by the splitting.

The present study was conducted to evaluate the effect of different dietary lipid sources, age and sex on the SFA and MUFA metabolism in broiler chickens using a whole body fatty acid balance method. Four dietary lipid sources (palm fat, Palm; soyabean oil, Soya; linseed oil, Lin; and fish oil, Fish) were added at 3 % to a basal diet containing 5 % Palm. Diets were fed to female and male chickens from day 1 to either day 21 or day 42 of age. The accumulation (percentage of net intake and ex novo production) of SFA and MUFA was significantly lower in broilers fed on Palm than in broilers fed on the other diets (85·7 v. 97·4 %). Conversely, β-oxidation was significantly higher in Palm-fed birds than the average of the other dietary treatments (14·3 v. 2·6 %). On average, 33·1 % of total SFA and MUFA accumulated in the body were elongated, and 13·8 % were Δ-9 desaturated to longer chain or more unsaturated metabolites, with lower proportions being elongated and desaturated for the Palm and Fish diets than for the Soya and Lin diets. Total in vivo apparent elongase activity decreased exponentially in relation to the net intake of SFA and MUFA, while it increased with age. Total in vivo apparent Δ-9 desaturase activity was not significantly affected by dietary treatment or age. Total ex novo production and β-oxidation of SFA and MUFA showed a negative and positive curvilinear relationship with net intake of SFA and MUFA, respectively. Sex had no effect on SFA and MUFA metabolism.

The PUFA metabolism in broiler chicken was studied through the whole body fatty acid balance method. Four dietary lipid sources (palm fat, Palm; soyabean oil, Soya; linseed oil, Lin; fish oil, Fish) were added at 3 % to a basal diet containing 5 % palm fat. Diets were fed to female and male birds from day 1 to either day 21 or day 42 of age. Birds fed the Lin diet showed a significantly higher 18 : 2n-6 accumulation compared with the other diets (85·2 v. 73·6 % of net intake), whereas diet did not affect 18 : 3n-3 accumulation (mean 63 % of net intake). Bioconversion of 18 : 2n-6 significantly decreased in the order Palm>Lin>Soya>Fish (4·7, 3·9, 3·4 and 1 % of net intake, respectively). The 18 : 3n-3 bioconversion on the Palm and Soya diets was similar and significantly higher than in broilers on the Lin diet (9·1 v. 5·8 % of net intake). The β-oxidation of 18 : 2n-6 was significantly lower on the Lin diet than on the other diets (10·8 v. 23·3 % of net intake), whereas β-oxidation of 18 : 3n-3 was significantly higher on the Fish diet than on the other diets (41·5 v. 27·3 % of net intake). Feeding fish oil suppressed apparent elongase and desaturase activity, whereas a higher dietary supply of 18 : 3n-3 and 18 : 2n-6 enhanced apparent elongation and desaturation activity on the PUFA involved in the n-3 and n-6 pathway, respectively. Accumulation of 18 : 2n-6 and 18 : 3n-3 increased and β-oxidation decreased with age. Sex had a marginal effect on the PUFA metabolism.

Elongated embryos provide a unique source of information about trophoblastic differentiation, gene expression and maternal-embryonic interactions; however they are difficult and costly to obtain, especially elongated cloned embryos. One alternative is their production in heterologous temporary recipients such as sheep and goats. We aimed to produce elongated bovine cloned embryos using heterologous transfer to temporary recipients. Day-7 cloned cattle blastocysts were transferred to the uteri of ewes and goats and recovered as elongated structures at day 17. We evaluated elongation, length, presence of embryonic disc and expression of several important genes for embryonic development. We also produced homologous (cloned cattle embryos transferred into cattle uteri). Cloned bovine blastocysts were able to proceed with preimplantation development through elongation with high efficiency despite the species to which they were transferred. In qualitative and quantitative RT-PCR experiments we found differences in the pattern of gene expression among embryos recovered from different species. Sox2, Nanog and FGF-4 were markedly deregulated. No previous reports about the expression pattern of the studied genes had been published for elongated bovine cloned embryos produced in intermediate recipients, furthermore, the pattern of expression of Nanog, Oct4, Eomes, Cdx2, IFN-tau, Dicer, FGF-4 and Sox2 shown here are novel for elongated cloned bovine embryos created by hand-made cloning. Our data confirmed that sheep and goats can be used as temporary recipients. This model could serve as a basis for further research on gene expression and cellular changes during bovine peri-implantation development.

The c-fos and c-jun proto-oncogenes are involved in the regulation of gene expression, cell proliferation, differentiation and tumorigenesis. Embryogenesis, like tumorigenesis, involves dramatic cell growth, cleavage and differentiation processes. Activation of the c-fos and c-jun proto-oncogenes in sheep conceptuses during the period of rapid growth and elongation was examined using reverse transcription and polymerase chain reaction (RT-PCR). The specificity of PCR products was determined by Southern blot hybridisation analysis with a non-radioactive DNA probe. A band corresponding to a 507 bp fragment (predicted amplified c-fos gene cDNA product) was observed in 3 of 9 day-13, 1 of 4 day-14 and 1 of 2 day-16 embryos. Meanwhile, a 400 bp c-jun transcript was aslo detected in 1 or 2 day-12, 3 of 9 day-13 and 2 of 2 day-16 embroyos. These results suggest that mRNA transcripts of c-fos and c-jun proto-oncogenes were specifically expressed during the period of ovine embryonic elongation and may have a possible role in preimplantation embryonic development of sheep.

This study develops a neural network system to monitor the safety of a bridge structure. A truck of constant mass is driven at constant speed through the target bridge. Then, the maximal and minimal values of the bridge elongations are processed by a monitoring system to evaluate the current condition of the bridge. The monitoring system is composed of parallel backpropagation neural networks. Each neural network monitors a part of the bridge. The neural networks are trained using simulation data. The numerical example shows that the monitoring system is effective in the damage detection of the bridge.

Elongation factor Tu (EF-Tu) promotes the binding of aminoacyl-tRNA (aa-tRNA) to the acceptor site of the ribosome. During the elongation cycle, EF-Tu interacts with guanine nucleotides, aa-tRNA and its nucleotide exchange factor (EF-Ts). Quantitative determination of the equilibrium dissociation constants that govern the interactions of mammalian mitochondrial EF-Tu (EF-Tumt) with guanine nucleotides was the focus of the work reported here. Equilibrium dialysis with [3H]GDP was used to measure the equilibrium dissociation constant of the EF-Tumt·GDP complex (KGDP = 1.0 ± 0.1 μM). Competition of GTP with a fluorescent derivative of GDP (mantGDP) for binding to EF-Tumt was used to measure the dissociation constant of the EF-Tumt·GTP complex (KGTP = 18 ± 9 μM). The analysis of these data required information on the dissociation constant of the EF-Tumt·mantGDP complex (KmGDP = 2.0 ± 0.5 μM), which was measured by equilibrium dialysis. Both KGDP and KGTP for EF-Tumt are quite different (about two orders of magnitude higher) than the dissociation constants of the corresponding complexes formed by Escherichia coli EF-Tu. The forward and reverse rate constants for the association and dissociation of the EF-Tumt·GDP complex were determined using the change in the fluorescence of mantGDP upon interaction with EF-Tumt. These values are in agreement with a simple equilibrium binding interaction between EF-Tumt and GDP. The results obtained are discussed in terms of the recently described crystal structure of the EF-Tumt·GDP complex.

Lipids were extracted from needles of Norway spruce plants of different provenances. The plants, seeds of which were originally collected from all over Europe, were grown at two sites in England at the same longitude but one 350 km north of the other. Significant correlations were observed between monogalactosyl diglyceride (MGDG) and digalactosyl diglyceride (DGDG) ratios on the one hand and, on the other, the lowest extreme winter temperature at the original site of seed collection (EWTS).

In the case of lipid changes, however, environmental differences due to site were more important than the inherent genotypic characteristics of the planted trees while provenances with the lowest EWTS values had more MGDG than DGDG. This implies that existing winter hardiness under mild climatic conditions does not come from changes in this ratio although DGDG formation from MGDG is known to be an important feature of winter hardening in Norway spruce elsewhere in Europe. However, closer analysis of the fatty acids in lipids from provenances at individual sites did reveal significant correlations between those provenances with low EWTS values and certain molar amounts or ratios of fatty acids in DGDG, some of which could be traced to genotypic expression. These partly involved the unusual Δ5 desaturations which are mainly confined to the fatty acids of those conifers like Norway spruce that harden to very low temperatures.