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Displays Characteristics (display + characteristic)
Selected AbstractsInfluence of forage fish and dietary lipid supplements on egg quality and fry production in channel catfish (Ictalurus punctatus) × blue catfish (Ictalurus furcatus) hybridizationAQUACULTURE NUTRITION, Issue 2 2010E.R. DURLAND Abstract Hybrid catfish (channel catfish Ictalurus punctatus × blue catfish Ictalurus furcatus) display characteristics that are favourable to aquaculture production. Low hatch percentages are a principal reason this hybrid is not used widely in the catfish industry. This study was conducted to determine whether additional food source rich in lipids may lead to a higher quality egg production. A 10-week feed trial was conducted in ponds in Auburn, AL. A total of 219 female Kansas Select channel catfish were stocked into nine ponds, 0.04 ha in size. Three dietary treatments were randomly allocated to the ponds. Diet-1 was a standard 60 g kg,1 lipid floating catfish feed. Diet-2 was the same feed supplemented with forage fish at ,28 kg ha,1. The third diet was the aforementioned catfish feed topcoated with 20 g kg,1 lipid [10 g kg,1 menhaden fish oil, 5 g kg,1 high docosahexaenoic acid (DHA) oil and 5 g kg,1 high arachidonic acid oil]. Results indicate that brood fish fed the high lipid diet spawned larger egg masses and had larger eggs both in weight and in diameter, with increased complements of fatty acids such as DHA, eicosapentaenoic acid and total n-3 fatty acids. The neutral and polar lipid fractions are also presented. [source] Modelling canopy CO2 fluxes: are ,big-leaf' simplifications justified?GLOBAL ECOLOGY, Issue 6 2001A. D. Friend Abstract 1The ,big-leaf' approach to calculating the carbon balance of plant canopies is evaluated for inclusion in the ETEMA model framework. This approach assumes that canopy carbon fluxes have the same relative responses to the environment as any single leaf, and that the scaling from leaf to canopy is therefore linear. 2A series of model simulations was performed with two models of leaf photosynthesis, three distributions of canopy nitrogen, and two levels of canopy radiation detail. Leaf- and canopy-level responses to light and nitrogen, both as instantaneous rates and daily integrals, are presented. 3Observed leaf nitrogen contents of unshaded leaves are over 40% lower than the big-leaf approach requires. Scaling from these leaves to the canopy using the big-leaf approach may underestimate canopy photosynthesis by ~20%. A leaf photosynthesis model that treats within-leaf light extinction displays characteristics that contradict the big-leaf theory. Observed distributions of canopy nitrogen are closer to those required to optimize this model than the homogeneous model used in the big-leaf approach. 4It is theoretically consistent to use the big-leaf approach with the homogeneous photosynthesis model to estimate canopy carbon fluxes if canopy nitrogen and leaf area are known and if the distribution of nitrogen is assumed optimal. However, real nitrogen profiles are not optimal for this photosynthesis model, and caution is necessary in using the big-leaf approach to scale satellite estimates of leaf physiology to canopies. Accurate prediction of canopy carbon fluxes requires canopy nitrogen, leaf area, declining nitrogen with canopy depth, the heterogeneous model of leaf photosynthesis and the separation of sunlit and shaded leaves. The exact nitrogen profile is not critical, but realistic distributions can be predicted using a simple model of canopy nitrogen allocation. [source] The structural evolution of the English Channel areaJOURNAL OF QUATERNARY SCIENCE, Issue 3-4 2003J. L. Lagarde Abstract The structural evolution of the English Channel area is controlled by structure and particularly by the pre-existing Cadomian and Variscan crustal discontinuities, which have been reactivated repeatedly in post-Variscan times. They controlled the crustal subsidence that produced basin development in the Mesozoic, prior to the sea-floor spreading in the North Atlantic region. They were then reactivated during the Cenozoic compression and basin inversion. The English Channel development is ascribed to mid-Tertiary differential uplift (Oligocene to Miocene). During late Tertiary to Quaternary times the Channel displays characteristics of a tectonically controlled fluvial basin periodically invaded by the sea. At the lithospheric scale, the Channel can be considered as an active intraplate area influenced by the NW,SE ,Alpine push', the NW,SE ,Atlantic ridge push' and glacial rebound stresses. Copyright © 2003 John Wiley & Sons, Ltd. [source] Melancholy and Mourning in Jonathan Safran Foer's Extremely Loud and Incredibly CloseORBIS LITERARUM, Issue 3 2008Sien Uytterschout Whereas melancholy (or ,acting out') entails a complete repression of all trauma-related memory, mourning (or ,working through') is an endeavour to remember the traumatic event and fit it into a coherent whole. In Extremely Loud and Incredibly Close, these two ways of reacting to and dealing with trauma are embodied respectively by the protagonist's paternal grandfather and by his paternal grandmother, both survivors of the Allied firebombing of Dresden in 1945. Foer ties up this ,old' trauma with a fresh one , 11 September 2001 , by having the Schells lose their only son, the protagonist's father, in the attacks on the World Trade Center. Aspects of both acting out and working through are in turn synthesised in the protagonist himself , Oskar Schell. In his behaviour, the boy displays characteristics of both a melancholic and a mourner. [source] Strong decrease in lignin content without significant alteration of plant development is induced by simultaneous down-regulation of cinnamoyl CoA reductase (CCR) and cinnamyl alcohol dehydrogenase (CAD) in tobacco plantsTHE PLANT JOURNAL, Issue 3 2001Matthieu Chabannes Summary Different transgenic tobacco lines down-regulated for either one or two enzymes of the monolignol pathway were compared for their lignin content and composition, and developmental patterns. The comparison concerned CCR and CAD down-regulated lines (homozygous or heterozygous for the transgene) and the hybrids resulting from the crossing of transgenic lines individually altered for CCR or CAD activities. Surprisingly, the crosses containing only one allele of each antisense transgene, exhibit a dramatic reduction of lignin content similar to the CCR down-regulated parent but, in contrast to this transgenic line, display a normal phenotype and only slight alterations of the shape of the vessels. Qualitatively the lignin of the double transformant displays characteristics more like the wild type control than either of the other transgenics. In the transgenics with a low lignin content, the transformations induced other biochemical changes involving polysaccharides, phenolic components of the cell wall and also soluble phenolics. These results show that the ectopic expression of a specific transgene may have a different impact depending on the genetic background and suggest that the two transgenes present in the crosses may operate synergistically to reduce the lignin content. In addition, these data confirm that plants with a severe reduction in lignin content may undergo normal development at least in controlled conditions. [source] | |||||||||||||