Effects of calcium deficiency on nutrient concentration of xylem sap of excised tomato plants

The effects of calcium (Ca) deficiency on cation uptake and concentration of xylem sap from tomato roots after excision of the aerial parts, were studied. The measurements were made on tomato plants grown on nutrient solutions with +Ca or without‐Ca, over a period of 48 hours. Calcium deficiency entailed a significant increase of the flux of xylem sap between the 6th and 14th hour on the first day after excision. In spite of the lack of Ca in the nutrient solution, the Ca concentration in xylem sap was unaffected in regard to that of excised roots with +Ca. The maintenance of the Ca concentration in xylem sap of plants grown on a Ca deficient solution was related to a reuse of the Ca from the apoplastic root stores. So, this regulation indicates a possible translocation of the Ca available in the root supply and a mobility of this element out of the roots only during the early stages of exposure to a Ca deficiency. The presence of NH₄ ⁺ in xylem sap with both +Ca and‐Ca treatments confirms the nitrogenous reduction activity of tomato roots. The accumulation of free ammonium 24 h after excision in both xylem saps (+Ca and‐Ca) is likely to be evidence of an alteration process of protein synthesis which is related to the depletion of the root water soluble carbohydrate supply.     

Passive hip laxity in Estrela Mountain Dog--distraction index, heritability and breeding values

Two hundred and fifteen Estrela Mountain Dogs (EMD) were examined using the PennHIP method between 2002 and 2006. Passive hip laxity (PHL) was estimated calculating the distraction index (DI). Pedigree information was obtained from the Portuguese Kennel Club. The heritability and breeding values were estimated using the linear Animal Model. The DI, using as reference the worst joint of each animal, ranged from 0.15 to 1.12 (0.55 +/- 0.19). The PHL was equal in right and left sides, and was higher in females than in males (P > 0.05 and P <0.01 in the t-test, respectively). The estimated heritability was 0.83 +/- 0.11. The mean breeding values for PHL were stable in EMD born between 1991 and 2003, and showed an improvement in 2004 and 2005. The data confirm high PHL in breeds with high prevalence and severity of canine hip dysplasia. The high heritability indicates that the DI could be reduced in the breed if PHL were used as a selection criterion. The early favourable evolution of DI breeding values could be related with the increase of voluntary radiographic hip screening in the last years, and the subsequent introduction of hip quality as a breeding criterion.     

Quercus suber and Betula pendula outer barks as renewable sources of oleochemicals: A comparative study

A comparative study on the chemical composition of oak cork (Quercus suber L.) and corresponding industrial residues and birch (Betula pendula L.) outer bark is reported. Cork oak samples have lower extractives contents (6–9%) and higher contents of carbohydrates and lignin (23–27 and 33–38%, respectively) than those found for birch outer bark (40, 6 and 9%, respectively); suberin contents accounted for around 30% of cork, 11% of industrial cork powder and 45% of birch outer bark. Analysis of the suberin monomeric composition revealed that C18 and C22 ω-hydroxyfatty acids (including mid-chain epoxy- and dihydroxy-derivatives), followed by α,ω-dicarboxylic acids, are the main components in both suberins, with 9,10-epoxy-18-hydroxyoctadecanoic, 18-hydroxyoctadec-9-enoic, 9,10,18-trihydroxyoctadecanoic and octadec-9-enoic acids as the major components. The differences in the relative amounts of these acids in the suberin samples and the impact on the potential exploitation of the different industrial by-products are discussed.     

Beneficial Effect of Two Culture Systems with Small Groups of Embryos on the Development and Quality of In Vitro‐Produced Bovine Embryos

Currently, in vitro‐produced embryos derived by ovum pick up (OPU) and in vitro fertilization (IVF) technologies represent approximately one‐third of the embryos worldwide in cattle. Nevertheless, the culture of small groups of embryos from an individual egg donor is an issue that OPU‐IVF laboratories have to face. In this work, we tested whether the development and quality of the preimplantation embryos in vitro cultured in low numbers (five embryos) could be improved by the addition of epidermal growth factor, insulin, transferrin and selenium (EGF‐ITS) or by the WOW system. With this aim, immature oocytes recovered from slaughtered heifers were in vitro matured and in vitro fertilized. Presumptive zygotes were then randomly cultured in four culture conditions: one large group (LG) (50 embryos/500 μl medium) and three smaller groups [five embryos/50 μl medium without (control) or with EGF‐ITS (EGF‐ITS) and five embryos per microwell in the WOW system (WOW)]. Embryos cultured in LG showed a greater ability to develop to blastocyst stage than embryos cultured in smaller groups, while the blastocyst rate of WOW group was significantly higher than in control. The number of cells/blastocyst in LG was higher than control or WOW, whereas the apoptosis rate per blastocyst was lower. On the other hand, the addition of EGF‐ITS significantly improved both parameters compared to the control and resulted in similar embryo quality to LG. In conclusion, the WOW system improved embryo development, while the addition of EGF‐ITS improved the embryo quality when smaller groups of embryos were cultured.     

Structural characterization of the lignin from the nodes and internodes of Arundo donax reed

Milled wood lignin (MWL) and dioxane lignin (DL) from different morphological regions (nodes and internodes) of Arundo donax reed were subjected to a comprehensive structural characterization by (13)C, (1)H NMR, FTIR, and UV spectroscopies and functional analysis. The permanganate and nitrobenzene oxidation methods were also applied to the in situ lignins. Both node and internode lignins are HGS-type lignins, with a significant amount of H units (including p-coumaric acid type structures). The S/G ratio (1.13-1.32), the weight-average molecular weight (20,400-24,500), the methoxyl group content (0.90-0.98), the phenolic hydroxyl group content (0.23-0.27), and the aliphatic hydroxyl group content (1.00-1.09) are not very different in the lignins from nodes and internodes. However, some structural differences between node and internode lignins were observed. The former has much more phenolic acids (p-coumaric and ferulic), 8.8% in node versus 1.2% in internode and less beta-O-4 (0. 32 and 0.49 per aromatic unit in node and internode, respectively). In situ node lignin is more condensed than internode lignin.     

Ability of surfactant headgroup size to alter lipid and antioxidant oxidation in oil-in-water emulsions

Oxidation of oil-in-water emulsion droplets is influenced by the properties of the interfacial membrane surrounding the lipid core. To evaluate how surfactant headgroup size influences lipid oxidation rates, emulsions were prepared with polyoxyethylene 10 stearyl ether (Brij 76) or polyoxyethylene 100 stearyl ether (Brij 700), which are structurally identical except for their hydrophilic headgroups, with Brij 700 containing 10 times more polyoxyethylene groups than Brij 76. Fe(2+)-promoted decomposition of cumene hydroperoxide was lower in Brij 700-stabilized than in Brij 76-stabilized hexadecane emulsions. Fe(2+)-promoted alpha-tocopherol oxidation rates were similar in hexadecane emulsion regardless of surfactant type. Brij 700 decreased production of hexanal from methyl linoleate and the formation of lipid peroxides and propanal from salmon oil compared to emulsions stabilized by Brij 76. These results indicate that emulsion droplet interfacial thickness could be an important determinant in the oxidative stability of food emulsions.     

Effects of season and superovulatory treatment on embryo yields in fine-wool Merinos maintained under field conditions

The aim of the study was to assess the effects of superovulatory treatment (multiple FSH‐dose vs single‐shot FSH treatment) and seasonality on embryo yields in fine‐wool Merino ewes. Treatment based on multiple FSH‐dose consisted of 200 mg of FSH (Folltropin^®) administered in seven decreasing doses. Single‐shot treatment consisted of a single dose of 70 mg of FSH + eCG. In ewes treated with multiple FSH doses, number of recovered embryos was higher (6.0 ± 0.5 vs 3.5 ± 1.0), while non‐fertilization rate was lower (12.8 ± 3.9 vs 40.3 ± 9.5) during the breeding season when compared to the non‐breeding season (p < 0.05); although similar values of recovered Grades 1–2 embryos were observed between seasons. During the breeding season, proportion of responding ewes (98.1 vs 57.1%), ovulation rate (13.9 ± 0.8 vs 3.2 ± 1.2), recovered structures (7.9 ± 0.6 vs 1.7 ± 0.7), total recovered embryos (6.0 ± 0.5 vs 1.2 ± 0.6) and good‐quality embryos (5.1 ± 0.5 vs 0.9 ± 0.6) were higher for the multiple FSH‐dose treatment than for the single‐shot protocol. In a similar way, in the non‐breeding season, ovulation rate (11.3 ± 1.8 vs 6.0 ± 1.1) and recovered structures (6.6 ± 1.2 vs 2.7 ± 0.6) were higher for the multiple FSH injections protocol than those for the single‐shot treatment, resulting in higher recovered Grades 1–2 embryos (3.2 ± 0.9 vs 1.4 ± 0.5). Current results indicate that seasonal anestrus affected embryo yields when applying multiple FSH‐dose superovulatory treatment in Merino ewes, by decreasing the number of recovered embryos although the number of recovered good‐quality embryos was not affected. During both seasons, multiple FSH injections produced higher ovarian response and number of viable embryos than the single‐shot treatment.     

Beneficial Effect of Melatonin on Blastocyst In Vitro Production from Heat‐Stressed Bovine Oocytes

Melatonin may play an important role in protecting gametes and embryos from the potential harmful effects of oxidative stress. In this study, we first examined two different heat stress (HS) treatments for in vitro oocyte maturation (Experiment 1: 38.5 vs 41.0°C, during the first 20 h; Experiment 2: 38.5 vs 41.5°C, during the entire period) on bovine oocyte maturation and embryo development. Second, we tested different melatonin concentrations added to the maturation and culture medium (Experiment 3: 0, 10^?12, 10^?9, 10^?4 m ; Experiment 4: 0, 10^?3 m ), both with and without HS (38.5 or 41.5°C, respectively). In Experiment 1, the HS treatment resulted in a lower maturation rate and number of cells/blastocyst (C/B) and a higher blastocyst rate than that in the control group. In Experiment 2, oocytes/embryos from heat‐stressed oocytes (HSO) had a lower maturation, cleavage and blastocyst rates, as well as a lower C/B compared with the control. In Experiment 3, in HSO groups, 10^?4 m melatonin resulted in an increased blastocyst rate compared with 0 m melatonin, with a similar blastocyst rate to the non‐HSO without melatonin. Melatonin did not have any effect in embryos from non‐HSO groups compared with the control. In Experiment 4, 10^?3 m melatonin produced lower cleavage and blastocyst rates in HSO and lower blastocyst rate in non‐HSO when compared to melatonin‐untreated oocytes/embryos. In conclusion, 10^?4 m melatonin was found to alleviate bovine oocytes from the harmful effects of HS.     

Analysis of linoleic acid hydroperoxides generated by biomimetic and enzymatic systems through an integrated methodology

An integrated methodology for the identification and quantification of linoleic acid hydroperoxides (HPODEs) mixtures, obtained by the Fenton's reaction and by enzymatic oxidation, is reported. Unambiguous identification of the HPODEs formed (13-hydroperoxy-(9Z,11E)-octadecadienoic acid, 13-hydroperoxy-(9E,11E)-octadecadienoic acid and 9-hydroperoxyoctadecadienoic acid) was performed by HPLC-MS/MS analysis, while quantification was carried out by HPLC-UV using an external calibration, based on the collection of chromatographic peaks, and measuring of total hydroperoxides by ferrous oxidation-xylenol orange (FOX) method.