Major phenolic compounds in olive oil modulate bone loss in an ovariectomy/inflammation experimental model

This study was conducted to determine whether the daily consumption for 84 days of tyrosol and hydroxytyrosol, the main olive oil phenolic compounds, and olive oil mill wastewater (OMWW), a byproduct of olive oil production, rich in micronutrients, may improve bone loss in ovariectomized rats (an experimental model of postmenopausal osteoporosis) and in ovariectomized rats with granulomatosis inflammation (a model set up for senile osteoporosis). As expected, an induced chronic inflammation provoked further bone loss at total, metaphyseal, and diaphyseal sites in ovariectomized rats. Tyrosol and hydroxytyrosol prevented this osteopenia by increasing bone formation ( p < 0.05), probably because of their antioxidant properties. The two doses of OMWW extracts had the same protective effect on bone ( p < 0.05), whereas OMWW did not reverse established osteopenia. In conclusion, polyphenol consumption seems to be an interesting way to prevent bone loss.     

Cold acclimation in white clover subjected to chilling and frost: Changes in water and carbohydrates status

The effect of cold acclimation on the water status and the fate of carbohydrates was studied in white clover (Trifolium repens L., cv Huia) subjected to chilling and/or freeze-thaw cycles. Treatments were applied in a controlled environment, with a constant photoperiod, for 6 weeks to plants either acclimated or non-acclimated to low temperature.

Cold acclimated plants had a higher concentration of starch in the stolons at the end of the acclimation period than non-acclimated plants (54 vs. 15 mg g⁻¹ DW). During the experiment, the leaves of cold acclimated plants subjected to frosts maintained a higher relative water content (RWC) than did leaves of plants not acclimated for which we observed a strong dehydration of 80%.

Under chilling, cold acclimated plants demonstrated an osmotic adjustment. We showed that only 30–40% of the variation of the osmotic potential was explained by variation in free sugar concentration, suggesting that compounds other than carbohydrates participated in the osmotic regulation.

Chilling increased the carbohydrate content and frost decreased the starch concentration in non-acclimated plants only.

We showed in white clover that the cold acclimation contributed to frost and chilling tolerance by the maintenance of the hydration of tissues. We demonstrated that osmotic adjustment was not completely explain by the accumulation of free sugars.     

A first insight into genotype × diet interactions in European sea bass (Dicentrarchus labrax L. 1756) in the context of plant‐based diet use

This preliminary study assessed genotype × diet interaction in late growth of European sea bass (Dicentrarchus labrax) fed with either a fish meal (FM)‐ or a fish oil (FO)‐based diet (M) or an all‐plant‐based (PB) diet. A total of 550 fish from 224 families were reared together and tagged. DNA was sampled and microsatellites were used to assign parentage. When fish weight was 192 ± 54 g, two tanks were fed with M (FM: 100%; FO: 100%) and two others with PB (FM: 0% and FO: 0%). Body weight (BW), fork length (FL) and fillet lipid content (CorrFat) were analysed with a linear model and with REML methodology. We observed no significant differences between groups, but a slightly lower (P=0.03) daily growth coefficient in sea bass fed PB than in those fed M. Heritability estimates of BW differed significantly from zero (PB: 0.37 ± 0.18; M: 0.47 ± 0.24). Sire × diet interactions were significant and genetic correlations ranged between 0.51 and 0.87, showing genotype × diet interaction for BW and CorrFat. For the first time, genetic parameters in the context of total replacement of marine fishery by‐products were estimated in European sea bass, showing re‐ranking of family performances with extremely contrasted diets.     

Strategies of attack and defence in woody plant–Phytophthora interactions

This review comprises both well‐known and recently described Phytophthora species and concentrates on Phytophthora–woody plant interactions. First, comprehensive data on infection strategies are presented which were the basis for three models that explain invasion and spread of Phytophthora pathogens in different woody host plants. The first model describes infection of roots, the second concentrates on invasion of the trunk, and the last one summarizes infection and invasion of host plants via leaves. On the basis of morphological, physiological, biochemical and molecular data, scenarios are suggested which explain the sequences of reactions that occur in susceptible and tolerant plants following infections of roots or of stem bark. Particular emphasis is paid to the significance of Phytophthora elicitins for such host–pathogen interactions. The overall goal is to shed light on the sequences of pathogenesis to better understand how Phytophthora pathogens harm their host plants.     

Slurry-application implement tine modification of soil hydraulic properties under different soil water content conditions for silt–clay loam soils

Tillage action associated with liquid slurry application systems/management practices can modify soil infiltration properties. The degree or nature of such modification will depend largely on the type of tillage implement used, and the soil conditions at time of tillage activity. The specific objective of this study is to evaluate differences in soil infiltration properties, as measured using pressure infiltrometers and Guelph permeameters, resulting from the immediate tine action of two commonly used slurry application tillage implements (Kongskilde Vibro-Flex (S-tine) and the AerWay SSD (rolling aerator-type tine)) over a variety of silt–clay loam soil water content conditions. The results indicated that there were consistent negative correlations between field saturated hydraulic conductivity and soil water content for all tine-disturbed and undisturbed soil treatments. For Kongskilde, field-saturated hydraulic conductivity was, on average, lower in tine-influenced furrow bottoms, relative to those measured in undisturbed conditions at similar depths for most water content conditions. Generally, the Kongskilde tine-action reduced macropore-based infiltration in the bottom of the furrow for most soil conditions, albeit, this effect was most pronounced at the higher soil water contents. For AerWay, the tine-disturbed soils had generally higher field saturated hydraulic conductivities than undisturbed soil treatments over the observed water content range. This effect was manifested to a greater degree at higher, relative to lower observed water contents.     

冰滑坡涌浪下冰碛坝溃决机理试验研究

[目的]对冰滑坡涌浪导致的冰碛坝溃决过程与溃决机理进行试验研究,为冰川区重大工程建设和冰湖冰碛坝溃决灾害防治提供科技支撑.[方法]开展不同滑块体积、滑动角度、滑动距离、坝体物质组成和坝体几何形态的水槽模型试验.基于试验现象、试验数据与理论推导,对涌浪过程、坝体物质起动和坝体溃决临界条件进行分析.[结果]①冰滑坡涌浪随时...     

Enzymatic and Acidic Hydrolysis of Cationized Waxy Maize Starch Granules

A series of wet‐cationized starch granules from waxy maize with different degrees of substitution (DS) were solubilized with either 2.2M HCl (lintnerization) or with the α‐amylase of Bacillus amyloliquefaciens. The maximum rate of the enzymatic hydrolysis occurred in starches with intermediate DS. It appeared that the cationic substituents interfered with the binding to the active site of the enzyme at high levels of substitution. The DS remained fairly constant in the granular residues after the enzymatic attack. The rate of the acidic hydrolysis increased with increasing DS but the final level of solubilization slightly decreased. The DS of the residual starch material decreased to 40% of the original level, showing that a large part of the cationic groups was found within the amorphous parts of the granules. A dry‐cationized sample with a high DS was also treated with the acid and lost a major part of its substituents at low levels of lintnerization. Probably most of the substituents were associated with the surface and channels of these granules. The cationized starches possessed branches that were resistant to isoamylase attack and the samples also contained β‐amylolysis resistant dextrins. The proportion of resistant dextrins in the granular residues decreased after lintnerization, but remained constant after the enzymatic hydrolysis.