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81.
82.
The rate of metamorphosis of larvae, duration of larval stages and carapace lengths of postlarvae were measured in the common prawn, Palaemon serratus, reared in 30 different combinations of temperature and salinity. Temperature varied from 13°C to 29°C and salinity from 13‰ to 43‰. When salinity.was 13‰, this species was able to metamorphose at a temperature of 21°C. For salinities of 19‰, 25‰, 31‰, 37‰ and 43‰, the temperature range over which metamorphosis occurs extends from 17°C to 25°C. The equation of Van't Hoff can be adapted to calculate the relation between the rearing rate, which is the converse of the duration of larval stages, and the water temperature. The Q10 values vary from 1.39 minimum at a salinity of 37‰ to 2.28 maximum at 31‰. Neither the effect of temperature (at 0.1%) nor that of salinity (at 1%) is significant for the carapace lengths of postlarvae.Tridimensional models of the combined effects of temperature and salinity on the rate of metamorphosis and on the number of metamorphosed postlarvae appearing daily were constructed for this species. 相似文献
83.
The aim of this paper is to determine whether a detectable impact of climate change is apparent in Austrian forests. In regions of complex terrain such as most of Austria, climatic trends over the past 50 years show marked geographic variability. As climate is one of the key drivers of forest growth, a comparison of growth characteristics between regions with different trends in temperature and precipitation can give insights into the impact of climatic change on forests. This study uses data from several hundred climate recording stations, interpolated to measurement sites of the Austrian National Forest Inventory (NFI). Austria as a whole shows a warming trend over the past 50 years and little overall change in precipitation. The warming trends, however, vary considerably across certain regions and regional precipitation trends vary widely in both directions, which cancel out on the national scale These differences allow the delineation of 'climatic change zones' with internally consistent climatic trends that differ from other zones. This study applies the species-specific adaptation of the biogeochemical model BIOME-BGC to Norway spruce (Picea abies (L.) Karst) across a range of Austrian climatic change zones, using input data from a number of national databases. The relative influence of extant climate change on forest growth is quantified, and compared with the far greater impact of non-climatic factors. At the national scale, climate change is found to have negligible effect on Norway spruce productivity, due in part to opposing effects at the regional level. The magnitudes of the modeled non-climatic influences on aboveground woody biomass increment increases are consistent with previously reported values of 20-40 kg of added stem carbon sequestration per kilogram of additional nitrogen deposition, while climate responses are of a magnitude difficult to detect in NFI data. 相似文献
84.
Camille Lepoittevin Jean-Pierre Rousseau Audrey Guillemin Christophe Gauvrit François Besson François Hubert Denilson da Silva Perez Luc Harvengt Christophe Plomion 《Annals of Forest Science》2011,68(4):873-884
Introduction
Tree breeding is giving an increasing attention to wood properties in order to better fit the requirements of the saw, board, pulp and paper industries. In particular, it has been reported that lignin and cellulose content display moderate to high heritabilities making them prime candidates for genetic improvement of wood chemistry. Moreover, these traits have been shown to be negatively correlated at both phenotypic and genetic levels. However, they have generally been evaluated against a narrow genetic background, and little is known about their correlations with mandatory selection criteria such as growth and straightness. 相似文献85.
Graebing PW Chib JS Hubert TD Gingerich WH 《Journal of agricultural and food chemistry》2004,52(19):5924-5932
A series of experiments analyzed the kinetics and mechanisms of [(14)C]niclosamide degradation. The aerobic aquatic metabolism of [(14)C]niclosamide was studied in nonsterile river water/sediment mixtures. Test systems, maintained under aerobic conditions, were treated with niclosamide and incubated in the dark at 25.0 +/- 1.0 degrees C for 30 days. Half-lives of 4.9 and 5.4 days were calculated for the chlorosalicylic acid- and chloronitroaniline-labeled test systems, respectively. From 0 to 21 days after treatment (DAT), the only metabolism product observed in either test system was aminoniclosamide. At the final sampling interval, five peaks were resolved from the chlorosalicylic acid label, and three peaks were resolved from the chloronitroaniline label test substance. By 30 DAT, sediment-bound residues represented approximately 70% of the observed radioactivity. For the anaerobic aquatic metabolism of [(14)C]niclosamide, test systems were incubated under anaerobic conditions for 365 days. Half-lives of 0.65 day for the chlorosalicylic acid label and 2.79 days for the chloronitroaniline label were calculated. From 0 to 3 DAT, niclosamide was first transformed into aminoniclosamide. Aminoniclosamide is readily formed, as it was observed in the chlorosalicylic acid label 0 DAT sampling. Several minor metabolites were observed in the water and sediment extracts. None of these metabolites were formed to a significant amount until the parent niclosamide dissipated below the detection limit. Two of the byproducts from these metabolism studies are polar unknowns eluting at 3 and 5 min by HPLC, similar to the unknowns observed in aqueous photolysis studies. 相似文献
86.
Soyasaponins are phytochemicals of major interest for health. Their identification and quantification remain difficult owing to the large number of structural isomers in soybeans and the lack of stable standards. In this study, a rapid method using high performance liquid chromatography (HPLC) using a UV detector (205 nm) was developed to identify and quantify soyasaponins belonging to group B and compare them with isoflavones in different soy materials. 2,3-Dihydro-2,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP)-conjugated soyasaponins were determined using external calibration or a molecular mass ratio after alkaline hydrolysis to cleave their DDMP moieties. The detection limit of soyasaponin I, used as a reference molecule to simplify the analysis, was 0.065 micromol/g. Soyasaponin contents in seven soybean varieties ranged from 13.20 to 42.40 micromol/g in the germ and from 2.76 to 6.43 micromol/g in the cotyledons. The within-day and between-days variation coefficients did not exceed 7.9 and 9.0%, respectively, for the major soyasaponins. Soyasaponin B quantification in different soy-based health supplements was reported along with measurements of their isoflavone content to provide information on the variability of these bioactive compounds among different types of soy food materials. 相似文献
87.
88.
Waguespack RW Burba DJ Hubert JD Vidal MA Lomax LG Chirgwin SR Lopez MJ 《Veterinary surgery : VS》2011,40(4):450-456
Objective: To evaluate the effects of extracorporeal shock wave therapy (ESWT) on collagenase‐induced lesions in the accessory ligament of the deep digital flexor tendon (ALDDFT) of horses. Study Design: Paired, blinded controlled study. Animals: Eight Thoroughbred horses (3 mares, 5 geldings; mean±SD weight, 464±26 kg, mean age, 8±1.7 years). Methods: Lesions were created in both ALDDFTs of all horses by injection of 2 × 103 IU of collagenase type I. Percent lesion and structure (fiber alignment and echogenicity) were quantified with ultrasonographic imaging 3, 6, and 9 weeks after collagenase injection. After ultrasound examinations, ESWT (1000 shocks at 0.15 mJ/mm2) was applied to 1 ALDDFT in each horse. ALDDFT were harvested 15 weeks after collagenase injection and the microstructure, mRNA levels of collagen types I and III, and collagen and glycosaminoglycan content were evaluated. Results: There were no differences in percent lesion, echogenicity, or fiber alignment between control‐ and ESWT‐treated ligaments at each evaluation time; however, compared with 3‐week values, there was a significant increase in percent lesion and echogenicity for EWST treated ligaments at 6 weeks and significant decrease in both variables for treated and control ligaments at 12 weeks. Fiber alignment improved significantly at 9 weeks in controls and at 12 weeks in treated and control ligaments. Collagen type I mRNA levels were significantly higher in the ESWT treatment group compared with the control group 15 weeks after collagenase injection though differences in other mRNA levels, microstructure, and composition were not significant. Conclusions: Our results do not support an effect of ESWT on collagenase‐induced lesions in the equine ALDDFT. 相似文献
89.
90.
Gerrienne P Gensel PG Strullu-Derrien C Lardeux H Steemans P Prestianni C 《Science (New York, N.Y.)》2011,333(6044):837
The advent of wood (secondary xylem) is a major event of the Paleozoic Era, facilitating the evolution of large perennial plants. The first steps of wood evolution are unknown. We describe two small Early Devonian (407 to 397 million years ago) plants with secondary xylem including simple rays. Their wood currently represents the earliest evidence of secondary growth in plants. The small size of the plants and the presence of thick-walled cortical cells confirm that wood early evolution was driven by hydraulic constraints rather than by the necessity of mechanical support for increasing height. The plants described here are most probably precursors of lignophytes. 相似文献