Effect of dietary protein:energy ratio on intake, growth and metabolism of juvenile green abalone Haliotis fulgens     

Laura Gmez-Montes  Zaul García-Esquivel  Louis R. D'Abramo  Armando Shimada  Carlos Vsquez-Pelez  María Teresa Viana 《Aquaculture (Amsterdam, Netherlands)》2003,220(1-4):769-780

Juvenile green abalone Haliotis rufescens were grown under laboratory conditions at 21±1 °C and fed formulated diets consisting of different protein:energy ratios (mg protein/kcal), 62, 74, 85, 100, 108, for 60 days. The level of crude protein ranged from approximately 26% to 44% while the energy content remained constant at about 4.1 kcal g⁻¹. Growth ranged from 3.63 to 12.33 mg day⁻¹. The growth of abalone fed the 100 and 108 diets was significantly greater than that of each of the other diets. Protein efficiency ratio increased as the dietary protein content increased except for the T108 diet (44% crude protein). Abalone apparently consume food to satisfy an energy requirement. Caloric expenditure due to metabolism was estimated for abalone fed diets with protein ratios of 62, 85, 100. Energy loss due to respiration did not vary appreciably among abalone fed the different diets. The proportional distribution of dietary energy into fecal, digestible, growth, and metabolic energy was estimated for abalone fed these diets. Apparent dry matter digestibility was among the lowest for abalone fed the 100 P:E diet, but growth of abalone fed this diet was significantly higher than that of each of the other treatments except the 108 diet. Unexplained energy loss to achieve balance ranged from 7% to 28.5%, some of which is probably due to differential mucus and ammonia production. Results suggest a potential for the reduction of both dietary protein and lipid without causing any adverse effects on the growth response.  相似文献   

Logging pattern and landscape changes over the last century at the boreal and deciduous forest transition in Eastern Canada   总被引：4，自引：0，他引：4  

Yan Boucher  Dominique Arseneault  Luc Sirois  Louis Blais 《Landscape Ecology》2009,24(2):171-184

Forestry practices associated with the industrial era (since ~1900) have altered the natural disturbance regimes and greatly impacted the world’s forests. We quantified twentieth century logging patterns and regional scale consequences in three sub-boreal forest landscapes of Eastern Canada (117,000, 49,400 and 92,300 ha), comparing forestry maps depicting age and forest cover types for early industrial (1930) and present-day (2000) conditions. Results were similar for the three landscapes, indicating large-scale forest change during the twentieth century. In 1930, previous logging activities had been concentrated in the lowlands and along the main hydrographical network, as compared to a more even distribution over the landscapes in 2000, reflecting a decreasing influence of the environmental constraints on forest harvesting. In 1930, old-aged forests (>100 years) accounted for more than 75% of the unlogged areas of the three landscapes, as compared to less than 15% for the present-day conditions. Logging practices have thus inverted the stand age distribution of the landscapes that are currently dominated by young and regenerating stands. The 1930 forest cover types showed a clear relationship with elevation, with conifers located in the lowlands and mixed and deciduous stands restricted to the upper slopes. Between 1930 and 2000, 58–64% of the conifer areas transformed to mixed and deciduous forests, such that no clear altitudinal relationships remained in 2000. We conclude that twentieth century logging practices have strongly altered the preindustrial vegetation patterns in our study area, to the point that ecosystem-based management strategies should be developed to restore conifer dominance, altitudinal gradients, as well as the irregular structure inspired from old forest stands.  相似文献   

Whitened kernel surface: A fast and reliable method for assessing Fusarium severity on cereal grains by digital picture analysis     

Marine Ollier  Vincent Talle  Anne‐Laure Brisset  Zo Le Bihan  Simon Duerr  Marc Lemmens  Ellen Goudemand  Olivier Robert  Jean‐Louis Hilbert  Hermann Buerstmayr 《Plant Breeding》2019,138(1):69-81

Fusarium head blight (FHB) is a cereal disease of major importance responsible for yield losses and mycotoxin contaminations in grains. Here, we introduce a new measurement approach to quantify FHB severity on grains based on the evaluation of the whitened kernel surface (WKS) using digital image analysis. The applicability of WKS was assessed on two bread wheat and one triticale grain sample sets (265 samples). Pearson correlation coefficients between Fusarium‐damaged kernels (FDK) and WKS range from r = 0.77 to r = 0.81 and from r = 0.61 to r = 0.86 for the correlation between deoxynivalenol (DON) content and WKS. This new scoring method facilitates fast and reliable assessment of the resistance to kernel infection and shows significant correlation with mycotoxin content. WKS can be automated and does not suffer from the “human factor” inherent to visual scorings. As a low‐cost and fast approach, this method appears particularly attractive for breeding and genetic analysis of FHB resistance where typically large numbers of experimental lines need to be evaluated, and for which WKS is suggested as an alternative to visual FDK scorings.  相似文献   

Identification of permethrin and etofenprox cross‐tolerance in Rhipicephalus sanguineus sensu lato (Acari: Ixodidae)     

Nicholas SG Tucker  Phillip E Kaufman  Emma NI Weeks 《Pest management science》2019,75(10):2794-2801

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Vectorizing agrochemicals: enhancing bioavailability via carrier‐mediated transport     

Hanxiang Wu  Hanhong Xu  Ccile Marivingt‐Mounir  Jean‐Louis Bonnemain  Jean‐Franois Chollet 《Pest management science》2019,75(6):1507-1516

Systemicity of agrochemicals is an advantageous property for controlling phloem sucking insects, as well as pathogens and pests not accessible to contact products. After the penetration of the cuticle, the plasma membrane constitutes the main barrier to the entry of an agrochemical into the sap flow. The current strategy for developing systemic agrochemicals is to optimize the physicochemical properties of the molecules so that they can cross the plasma membrane by simple diffusion or ion trapping mechanisms. The main problem with current systemic compounds is that they move everywhere within the plant, and this non‐controlled mobility results in the contamination of the plant parts consumed by vertebrates and pollinators. To achieve the site‐targeted distribution of agrochemicals, a carrier‐mediated propesticide strategy is proposed in this review. After conjugating a non‐systemic agrochemical with a nutrient (α‐amino acids or sugars), the resulting conjugate may be actively transported across the plasma membrane by nutrient‐specific carriers. By applying this strategy, non‐systemic active ingredients are expected to be delivered into the target organs of young plants, thus avoiding or minimizing subsequent undesirable redistribution. The development of this innovative strategy presents many challenges, but opens up a wide range of exciting possibilities. © 2018 Society of Chemical Industry  相似文献   

Multi-model comparison on the effects of climate change on tree species in the eastern U.S.: results from an enhanced niche model and process-based ecosystem and landscape models     

Louis R. Iverson  Frank R. ThompsonIII  Stephen Matthews  Matthew Peters  Anantha Prasad  William D. Dijak  Jacob Fraser  Wen J. Wang  Brice Hanberry  Hong He  Maria Janowiak  Patricia Butler  Leslie Brandt  Christopher Swanston 《Landscape Ecology》2017,32(7):1327-1346

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Infrared thermometry to quantify in-field soil moisture variability     

Jeff Siegfried  Louis Longchamps 《Journal of Crop Improvement》2017,31(1):72-90

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Baculoviruses as vectors for foreign gene expression in insect cells     

Allan E. Atkinson  Matthew D. Weitzman  Louis Obosi  David J. Beadle  Linda A. King 《Pest management science》1990,28(2):215-224

Recombinant DNA technology has enabled the expression of a large number of eukaryotic genes in vitro. There has been growing interest in recent years in the development of baculovirus expression vectors as an easily manipulated gene expression system. Both virus and insect cell culture are relatively easy to handle, and biologically active proteins have been produced abundantly from a variety of eukaryotic, prokaryotic and viral genes. This review describes the molecular biology of baculoviruses and some of the current applications of the baculovirus expression system in insect cells. Specific emphasis is placed on those features relevant to the use of this system in pesticide research.  相似文献   

Comparative purification methods for determination of triadimenol residues in plant material     

Patricia V. Reynaud  Sylvaine D. Rolle  Louis De Cormis 《Pest management science》1991,32(1):121-131

Two procedures are described for the determination of residues of triadimenol and compared on cereal material. After extraction, purification is carried out by Florisil column chromatography in method I and by semi-preparative High-Performance Liquid Chromatography in method II. Triadimenol residues are quantified by gas chromatography with a thermoionic detector. With method I, interference was observed but not with method II. This specific procedure has been tested on other plant materials. Recoveries in the range of 90–98% indicate that this procedure is suitable for residue analysis of this fungicide with detection limits of 0·008 mg kg^?1 in wheat grains, 0·03 mg kg^?1 in wheat straw and 0·004–0·008 mg kg^?1 in other plants. Maximum residue limits in France are: 0·1 mg kg^?1 in grain, 2·0 mg kg^?1 in straw and 1·0 mg kg^?1 in other vegetables and fruit.  相似文献   

Abstracts of papers presented at the second otto warburg symposim on biotechnology: plant - microorganism interaction in the rhizosphere     

A. HüTtermann Marie-Therese Oelbe  E. Fritz  G. Schlechte  A. Bytom  A. D. Jungk  Y. Okon  E. Fallik  Rivka Hadas  S. Sarig  E. Yahalom  Sara Tal  A. Hartmann  B. Kishinevsky  Debora Gurfel  Rina Lobel  Y. Kapulnik  D. A. Phillips  Y. Hadar  Y. Chen  E. Jurkevitch  J. Katan  A. Gamliel  H. Ziegler  I. Chet  A. Ordentlich  Hadar Kless  A. Oppenheim  Avia Zilberstein  D. Holland  J. Berman  A. Zamir  R. Kaufman  N. Bawnik  C. Koncz  J. Schell 《Phytoparasitica》1987,15(2):141-147

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