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Relative Yield (relative + yield)
Selected AbstractsAge and growth, mortality, reproduction and relative yield per recruit of the bogue, Boops boops Linné, 1758 (Sparidae), from the Algarve (south of Portugal) longline fisheryJOURNAL OF APPLIED ICHTHYOLOGY, Issue 5 2006P. Monteiro Summary Samples of Boops boops ranging from 7.4 to 30.5 cm were obtained mainly by longline, supplemented by beach seining in the Ria Formosa lagoon, and by market sampling in the Algarve (southern Portugal). The macroscopic analyses of the gonads and the gonad somatic index showed that the south coast of Portugal B. boops spawn mainly from late winter to spring, between February and May. The length at first maturity was similar for males and females and the value for both sexes combined was estimated to be 15.22 cm, corresponding to an age range of 1,3. Age was determined by reading growth bands on otoliths. Age determination was validated by marginal increment analysis. The estimated parameters were L, = 28.06, K = 0.22 and t0 = ,1.42. Mortality rates were calculated for fish captured with longlines, and the estimated parameters were M = 0.33, Z = 1.04 and F = 0.71. Relative yield per recruit analysis and sensitivity analysis showed that the resource is moderately exploited. From the perspective of sustainability, these results provide support for the use of longlines as a gear that is among the least harmful for species such as the bogue. [source] Plant species traits and capacity for resource reduction predict yield and abundance under competition in nitrogen-limited grasslandFUNCTIONAL ECOLOGY, Issue 3 2006J. FARGIONE Summary 1The objective of this study is to test whether plant traits that are predicted by resource-competition theory to lead to competitive dominance are correlated with competitive response and abundance in a nitrogen-limited grassland. We collected species trait and soil nutrient data on non-leguminous perennial prairie plant species in replicated monoculture plots established for this purpose. 2The soil nitrate concentration of 13 species grown in long-term (5-year) monocultures (a measure of R*) was correlated with their relative yield (a measure of competitive response) and with their abundance in competition. The trait best correlated with a species' relative yield was root length density (RLD), and the trait best correlated with abundance in competition was biomass : N ratio. 3The traits that best predicted nitrate R* were the biomass : N ratio and allocation to fine roots, where species with higher biomass : N and allocation to fine roots had lower R*. Easily measured species traits may therefore be useful proxy measures for R*. 4The dominance of species with lower nitrate R* levels and higher RLD and biomass : N in monoculture is qualitatively consistent with the prediction of resource-competition theory that the species most efficient at acquiring, retaining and using the major limiting resource will be the best competitors. Additional mechanisms are needed to explain how these species coexist. [source] Stability and Adaptability of Cultivars in Non-balanced Yield Trials.JOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 4 2002Comparison of Methods for Selecting, High Oleic' Sunflower hybrids for Grain Yield, Quality Abstract The best-yielding and most stable cultivars are identified by growing cultivars in different environments. The stability of grain-quality traits has been less thoroughly investigated than the stability of grain yield. High-oleic hybrids of sunflower have been available on the Argentinian seed market for several years. Research on the stability of these genotypes is scarce. The objectives of this work were (i) to compare, using three different methods, the stability and adaptability of high-oleic hybrids for grain yield and oil and oleic acid contents, and (ii) to explore the advantages and disadvantages of each method in selecting stable or adapted genotypes with high grain yield and high quality. Stability and adaptability analyses were performed on results for grain yields and oil and oleic acid contents of 35 high-oleic sunflower hybrids from 17 comparative yield trials conducted over 2 years in Argentina. Stability was estimated using two methods: Fisher's protected least significant difference (LSD) test, which compared hybrids with the best-yielding hybrid in each environment, and the test of relative yield (RY), which uses standard deviation as the measure of stability. Adaptability was estimated using Piepho's method of ,multiple comparisons with the best'. These three methods can be applied to unbalanced data. Piepho's method made little discrimination amongst the hybrids. The LSD and RY tests coincided in classifying the hybrids as stable and unstable in 85 % of cases for grain yield and 76 % for oil content. It is concluded that the most convenient method depends on characteristics of the experimental design and of variability of the evaluated trait. Results from the LSD test depend on the number of environments in which the cultivar is tested. The RY method is valuable for classifying some cultivars as high-yielding and stable, avoiding the problem of high-yielding environments biasing the general average. Use of both methods together could be effective for classifying hybrids when the number of environments is adequate. Zusammenfassung Stabilität und Adaptabilität von Kultivaren in nicht balancierten Ertragsversuchen. Methodenvergleich für Kornertrag und Qualität in ölsäurereichen-Sonnenblumen Höchste Erträge und Stabilität von Kultivaren werden durch Teste in verschiedenen Umwelten ermittelt. Stabilität der Qualitätseigenschaften des Korns sind bisher weniger untersucht worden als Stabilität des Kornertrages. Ölsäurereiche Hybriden von Sonnenblumen sind auf dem argentinischen Saatgutmarkt während der letzten Jahre angeboten worden. Untersuchungen zur Stabilität dieser Genotypen sind selten. Ziele dieser Arbeit waren es (i) drei unterschiedliche Methoden im Hinblick auf ihre Eignung für die Messung von Stabilität und Adaptabilität von ölsäurereichen Hybriden hinsichtlich Kornertrag, Öl- sowie Ölsäuregehalte zu vergleichen, und (ii) die Vorteile und Nachteile dieser Methoden zu analysieren, die eine Selektion stabiler und angepasster Genotypen mit hohem Kornertrag und hoher Qualität erlauben. Eine Analyse für Stabilität und Adaptabilität wurden aufgrund der Ergebnisse für Kornertrag, Öl- sowie Ölsäuregehalte von 35 Sonnenblumen, als Hybriden mit hohem Ölgehalt, auf der Grundlage von 17 vergleichenden Ertragsversuchen, die während zwei Jahren in Argentinien durchgeführt wurden, vorgenommen. Die Stabilität wurde unter Verwendung von zwei Methoden bestimmt: Der ,protected-LSD-Test' von Fisher, mit dem die Hybriden mit ertragshöchsten in jeder Umwelt verglichen werden; ferner der Test mit einem Vergleich des relativen Ertrags (RY), bei dem die Standardabweichung als Maß für die Stabilität verwendet wird; schließlich wurde die Adatabilität mit Piephos Methode eines multiplen Vergleichs mit der Besten durchgeführt. Die drei Methoden können nicht bancierten Daten angewendet werden. Piephos Methode ergab eine geringe Diskrimination für die Hybriden. LSD und RY stimmten bei einer Klassifizierung der Hybriden als stabile und nicht stabile in 85 % der Fälle hinsichtlich Kornertrag und 76 % für Ölgehalt überein. Es wird angenommen, dass geeignetere Methoden von den Eigenschaften der Experimentstruktur und der Variabilität der bewerteten Eigenschaften abhängen. Die Ergebnisse des LSD-Tests sind von der Anzahl der Umwelten abhängig, in denen die Kultivare getestet wurden. Die RY-Methode ist wertvoll, um einige Kultivare als hochertragreich und stabil zu klassifizieren, wobei der Einfluss hochertragreicher Umwelten zum Gesamtmittelwirt vermieden wird. Eine gemeinsame Anwendung der beiden Methoden könnte nützlich sein, um Hybriden zu klassifizieren, wenn eine geeignete Anzahl von Umwelten gegeben ist. [source] Age and growth, mortality, reproduction and relative yield per recruit of the bogue, Boops boops Linné, 1758 (Sparidae), from the Algarve (south of Portugal) longline fisheryJOURNAL OF APPLIED ICHTHYOLOGY, Issue 5 2006P. Monteiro Summary Samples of Boops boops ranging from 7.4 to 30.5 cm were obtained mainly by longline, supplemented by beach seining in the Ria Formosa lagoon, and by market sampling in the Algarve (southern Portugal). The macroscopic analyses of the gonads and the gonad somatic index showed that the south coast of Portugal B. boops spawn mainly from late winter to spring, between February and May. The length at first maturity was similar for males and females and the value for both sexes combined was estimated to be 15.22 cm, corresponding to an age range of 1,3. Age was determined by reading growth bands on otoliths. Age determination was validated by marginal increment analysis. The estimated parameters were L, = 28.06, K = 0.22 and t0 = ,1.42. Mortality rates were calculated for fish captured with longlines, and the estimated parameters were M = 0.33, Z = 1.04 and F = 0.71. Relative yield per recruit analysis and sensitivity analysis showed that the resource is moderately exploited. From the perspective of sustainability, these results provide support for the use of longlines as a gear that is among the least harmful for species such as the bogue. [source] Variety-specific Epidemiology of Cercospora beticola Sacc. and Consequences for Threshold-based Timing of Fungicide Application in Sugar BeetJOURNAL OF PHYTOPATHOLOGY, Issue 4 2010Ulrike Kaiser Abstract In Central Europe, fungicides to control leaf spot disease in sugar beet caused by Cercospora beticola are applied based on thresholds of disease incidence (DI, per cent of infected plants). As variety-specific fungicide application was not analyzed to date, the epidemiology of C. beticola and its effect on white sugar yield (WSY) in varieties with different susceptibility were investigated at seven sites in Germany and Austria in 2004 and 2005. All varieties reached the summary thresholds 5 / 15 / 45% DI in all environments. Fitting a logistic growth curve to DI revealed significant differences among varieties. At high disease pressure, susceptible varieties reached a considerably higher disease severity (DS, per cent of infected leaf area) at harvest and a larger area under disease progress curve (AUDPC) than resistant varieties. Fitting a logistic growth curve to DS showed an increasing differentiation among varieties with time. The growth rate estimated based on the logistic growth curve was the only variable that performed equally well in differentiating varieties under low and high disease pressure. With increasing disease pressure, varieties differed considerably in WSY, but differences between susceptible and resistant varieties were significant only in some environments. The disease-loss relation between AUDPC and relative WSY was variety-specific. Resistant varieties had an approximately identical WSY with and without infection and compensated for negative infection effects even at higher AUDPC. Therefore, at high disease pressure, resistant varieties had a higher relative yield compared to susceptible ones. However, our results indicate that there is no need to develop variety-specific thresholds, but resistant varieties reach the established thresholds later than susceptible ones. Consequently, the time of fungicide application can be delayed in resistant varieties. This will help to reduce the use of fungicides to the bare essentials as requested for the integrated crop protection management. [source] The effect of pH on horseradish peroxidase-catalyzed oxidation of melatonin: production of N1 -acetyl- N2 -formyl-5-methoxykynuramine versus radical-mediated degradationJOURNAL OF PINEAL RESEARCH, Issue 3 2007Valdecir F. Ximenes Abstract:, There is a growing body of evidence that melatonin and its oxidation product, N1 -acetyl- N2 -formyl-5-methoxykynuramine (AFMK), have anti-inflammatory properties. From a nutritional point of view, the discovery of melatonin in plant tissues emphasizes the importance of its relationship with plant peroxidases. Here we found that the pH of the reaction mixture has a profound influence in the reaction rate and products distribution when melatonin is oxidized by the plant enzyme horseradish peroxidase. At pH 5.5, 1 mm of melatonin was almost completely oxidized within 2 min, whereas only about 3% was consumed at pH 7.4. However, the relative yield of AFMK was higher in physiological pH. Radical-mediated oxidation products, including 2-hydroxymelatonin, a dimer of 2-hydroxymelatonin and O -demethylated dimer of melatonin account for the fast consumption of melatonin at pH 5.5. The higher production of AFMK at pH 7.4 was explained by the involvement of compound III of peroxidases as evidenced by spectral studies. On the other hand, the fast oxidative degradation at pH 5.5 was explained by the classic peroxidase cycle. [source] Yield and cooking qualities of somaclonal variants of cv. Russet Burbank selected for resistance to common scab disease of potatoANNALS OF APPLIED BIOLOGY, Issue 2 2010C.R. Wilson We previously obtained somaclonal variants of the important French fry processing cultivar Russet Burbank with significantly enhanced resistance to common scab disease. In this study we have shown the commercial merit of a proportion of these variants through comparison of relative yield and tuber quality with the parent cultivar Russet Burbank. Whilst we showed a weak negative correlation between tuber yield (as assessed by weight of tubers per plant) and relative disease resistance within selected variants, we identified several with equivalent yields to the parent cultivar. Furthermore, two disease-resistant variants (TC-RB8 and NZ-24B) consistently yielded more tuber mass than the parent. The majority of our Russet Burbank variants showed equivalent tuber quality characteristics (occurrence of defects, tuber specific gravity and dry matter content, and flesh colour) and cooking qualities (fry colour and presence of dark end defects) to the parent cultivar. Independent testing by a commercial French fry processor confirmed these quality characteristics. We present data demonstrating that highly common scab disease-resistant somaclonal variants of Russet Burbank have commercially acceptable tuber yield and quality characteristics, comparable to the industry standard and parent Russet Burbank cultivar. We also demonstrate the value of in vitro cell selection techniques for potato cultivar improvement. [source] Gadolinium-Based Mixed-Metal Nitride Clusterfullerenes GdxSc3,xN@C80 (x=1, 2),CHEMPHYSCHEM, Issue 9 2006Shangfeng Yang Dr. Abstract The first gadolinium-based mixed-metal nitride clusterfullerenes GdxSc3,xN@C80 (I) (1, x=2; 2, x=1) have been successfully synthesized by the reactive gas atmosphere method and isolated facilely by recycling high-performance liquid chromatography (HPLC). The sum yield of 1 and 2 is 30,40 times higher than that of Gd3N@C80 (I). Moreover, an enhanced relative yield of 2 over the Sc3N@C80 (I) is achieved under the optimized synthesis conditions. According to the UV/Vis/NIR spectroscopic characterization, 1 and 2 are both stable fullerenes with large optical band-gaps while 1 has higher similarity to Gd3N@C80 (I) and 2 resembles Sc3N@C80 (I). The vibrational structures of 1 and 2 are studied by Fourier-transform infrared (FTIR) spectroscopy as well as density functional theory (DFT) computations. In particular, the structures of the encaged GdxSc3,xN clusters within 1 and 2 are analyzed. [source] Manipulation of end-product quality of rainbow trout with finishing dietsAQUACULTURE NUTRITION, Issue 1 2000Rasmussen The effect of dietary lipid level upon various quality parameters of smoked rainbow trout were examined. Fish were fed four experimental diets differing in lipid content (18.8,31.4%). Groups received either a lipid-rich diet throughout the trial (101 days), a lipid-rich feed for 46 days followed by a lower fat diet for 55 days and vice versa, or a low fat diet throughout. A fifth group (controls), consisting of commercially reared animals, was employed for comparative purposes. The visceral fraction of experimental fish increased with increasing lipid ingestion, whereas final process yield decreased. Chemical analyses following salting and hot-smoking revealed that fillet lipid and ash was higher (P < 0.05) and moisture lower (P < 0.05) for fish fed the high-lipid diet throughout and during the last 55 days of trial. No differences were recorded with respect to sensory attributes between treatment groups, although differences were observed between tank-reared and control fish. In experimental animals, fillet protein content was negatively correlated with juiciness and fibreness, while dry matter was correlated with juiciness, fresh oily taste and rose flesh colour. The present study indicates that high lipid feeds can be employed without negatively influencing sensory characteristics or yield provided that lean finishing diets are fed prior to slaughter. Fasting of fish for 61 days improved slaughter yields without affecting relative yields among dietary groups. [source] | |||||||||||||