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Average Yield (average + yield)
Selected AbstractsAverage yields of the four principal vegetable oilsLIPID TECHNOLOGY, Issue 11-12 2009Frank D. Gunstone No abstracts. [source] Nitrogen uptake and utilization efficiency of European maize hybrids developed under conditions of low and high nitrogen inputPLANT BREEDING, Issue 6 2002T. Presterl Abstract Maize varieties with improved nitrogen(N)-use efficiency under low soil N conditions can contribute to sustainable agriculture. Tests were carried to see whether selection of European elite lines at low and high N supply would result in hybrids with differential adaptation to these contrasting N conditions. The objective was to analyze whether genotypic differences in N uptake and N-utilization efficiency existed in this material and to what extent these factors contributed to adaptation to low N supply. Twenty-four hybrids developed at low N supply (L × L) were compared with 25 hybrids developed at high N supply (H × H). The N uptake was determined as total above-ground N in whole plants, and N-utilization efficiency as the ratio between grain yield and N uptake in yield trials at four locations and at three N levels each. Highly significant variations as a result of hybrids and hybrids × N-level interaction were observed for grain yield as well as for N uptake and N-utilization efficiency in both hybrid types. Average yields of the L × L hybrids were higher than those of the H × H hybrids by 11.5% at low N supply and 5.4% at medium N level. There was no significant yield difference between the two hybrid types at high N supply. The L × L hybrids showed significantly higher N uptake at the low (12%) and medium (6%) N levels than the H × H hybrids. In contrast, no differences in N-utilization efficiency were observed between the hybrid types. These results indicate that adaptation of hybrids from European elite breeding material to conditions with reduced nitrogen input was possible and was mainly the result of an increase in N-uptake efficiency. [source] The growth respiration component in eddy CO2 flux from a Quercus ilex mediterranean forestGLOBAL CHANGE BIOLOGY, Issue 9 2004S. Rambal Abstract Ecosystem respiration, arising from soil decomposition as well as from plant maintenance and growth, has been shown to be the most important component of carbon exchange in most terrestrial ecosystems. The goal of this study was to estimate the growth component of whole-ecosystem respiration in a Mediterranean evergreen oak (Quercus ilex) forest over the course of 3 years. Ecosystem respiration (Reco) was determined from night-time carbon dioxide flux (Fc) using eddy correlation when friction velocity (u*) was greater than 0.35 m s,1 We postulated that growth respiration could be evaluated as a residual after removing modeled base Reco from whole-ecosystem Reco during periods when growth was most likely occurring. We observed that the model deviated from the night-time Fc -based Reco during the period from early February to early July with the largest discrepancies occurring at the end of May, coinciding with budburst when active aboveground growth and radial growth increment are greatest. The highest growth respiration rates were observed in 2001 with daily fluxes reaching up to 4 g C m,2. The cumulative growth respiration for the entire growth period gave total carbon losses of 170, 208, and 142 g C m,2 for 1999, 2001, and 2002, respectively. Biochemical analysis of soluble carbohydrates, starch, cellulose, hemicellulose, proteins, lignin, and lipids for leaves and stems allowed calculation of the total construction costs of the different growth components, which yielded values of 154, 200, and 150 g C for 3 years, respectively, corresponding well to estimated growth respiration. Estimates of both leaf and stem growth showed very large interannual variation, although average growth respiration coefficients and average yield of growth processes were fairly constant over the 3 years and close to literature values. The time course of the growth respiration may be explained by the growth pattern of leaves and stems and by cambial activity. This approach has potential applications for interpreting the effects of climate variation, disturbances, and management practices on growth and ecosystem respiration. [source] CONSTANT EFFORT AND CONSTANT QUOTAFISHING POLICIES WITH CUT-OFFS IN A RANDOM ENVIRONMENTNATURAL RESOURCE MODELING, Issue 2 2001CARLOS A. BRAUMANN ABSTRACT. Consider a population subjected to constant effort or constant quota fishing with a generaldensity-dependence population growth function (because that function is poorly known). Consider environmental random fluctuations that either affect an intrinsic growth parameter or birth/death rates, thus resulting in two stochastic differential equations models. From previous results of ours, we obtain conditions for non-extinction and for existence of a population size stationary density. Constant quota (which always leads to extinction in random environments) and constant effort policies are studied; they are hard to implement for extreme population sizes. Introducing cut-offs circumvents these drawbacks. In a deterministic environment, for a wide range of values, cutting-off does not affect the steady-state yield. This is not so in a random environment and we will give expressions showing how steady-state average yield and population size distribution vary as functions of cut-off choices. We illustrate these general results with function plots for the particular case of logistic growth. [source] Heck reaction catalyzed by a recyclable palladium supported on shell powderAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 9 2010Yong-Miao Shen Abstract A novel palladium catalyst supported on shell powder has been prepared, and its application to the Heck reaction of aryl iodides with olefins has been reported. The results showed that the novel catalyst had extremely high activities for the reactions with the average yield over 90%. Also, this catalyst showed excellent stability in Heck reactions, being reused three times. The catalyst was characterized by X-ray powder diffraction and field-emission scanned electron microscopy images, and the energy dispersive X-ray analyzer. Copyright © 2010 John Wiley & Sons, Ltd. [source] Development and evaluation of efficient recombinant Escherichia coli strains for the production of 3-hydroxypropionic acid from glycerol,BIOTECHNOLOGY & BIOENGINEERING, Issue 4 2009Chelladurai Rathnasingh Abstract 3-Hydroxypropionic acid (3-HP) is a commercially valuable chemical with the potential to be a key building block for deriving many industrially important chemicals. However, its biological production has not been well documented. Our previous study demonstrated the feasibility of producing 3-HP from glycerol using the recombinant Escherichia coli SH254 expressing glycerol dehydratase (DhaB) and aldehyde dehydrogenase (AldH), and reported that an "imbalance between the two enzymes" and the "instability of the first enzyme DhaB" were the major factors limiting 3-HP production. In this study, the efficiency of the recombinant strain(s) was improved by expressing DhaB and AldH in two compatible isopropyl-thio-,-galactoside (IPTG) inducible plasmids along with glycerol dehydratase reactivase (GDR). The expression levels of the two proteins were measured. It was found that the changes in protein expression were associated with their enzymatic activity and balance. While cloning an alternate aldehyde dehydrogenase (ALDH), ,-ketoglutaric semialdehyde dehydrogenase (KGSADH), instead of AldH, the recombinant E. coli SH-BGK1 showed the highest level of 3-HP production (2.8,g/L) under shake-flask conditions. When an aerobic fed-batch process was carried out under bioreactor conditions at pH 7.0, the recombinant SH-BGK1 produced 38.7,g 3-HP/L with an average yield of 35%. This article reports the highest level of 3-HP production from glycerol thus far. Biotechnol. Bioeng. 2009; 104: 729,739 © 2009 Wiley Periodicals, Inc. [source] Generation of high-quality protein extracts from formalin-fixed, paraffin-embedded tissuesPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 15 2009Maria Filippa Addis Abstract A wealth of information on proteins involved in many aspects of disease is encased within formalin-fixed paraffin-embedded (FFPE) tissue repositories stored in hospitals worldwide. Recently, access to this "hidden treasure" is being actively pursued by the application of two main extraction strategies: digestion of the entangled protein matrix with generation of tryptic peptides, or decrosslinking and extraction of full-length proteins. Here, we describe an optimised method for extraction of full-length proteins from FFPE tissues. This method builds on the classical "antigen retrieval" technique used for immunohistochemistry, and allows generation of protein extracts with elevated and reproducible yields. In model animal tissues, average yields of 16.3,,g and 86.8,,g of proteins were obtained per 80,mm2 tissue slice of formalin-fixed paraffin-embedded skeletal muscle and liver, respectively. Protein extracts generated with this method can be used for the reproducible investigation of the proteome with a wide array of techniques. The results obtained by SDS-PAGE, western immunoblotting, protein arrays, ELISA, and, most importantly, nanoHPLC-nanoESI-Q-TOF MS of FFPE proteins resolved by SDS-PAGE, are presented and discussed. An evaluation of the extent of modifications introduced on proteins by formalin fixation and crosslink reversal, and their impact on quality of MS results, is also reported. [source] | |||||||||||||