3种不同规模化培养模式对湛江等鞭金藻生产力及色素含量的影响     

吕布  杨守国  VASQUEZ Hebert Ely  王爱民  郑兴  顾志峰 《渔业现代化》2022,(1):11-17

为进一步提高湛江等鞭金藻室外规模化培养效率,对管道式光生物反应器、聚乙烯桶和水泥池3种微藻室外规模化培养模式下湛江等鞭金藻的藻密度进行了评估比较.试验将接种藻密度控制为10.0×104 cells/mL,培养周期为16 d.结果显示:管道式光生物反应器培养模式下,生产力相对最高为0.0543 g/L/d、比生长速率为0...  相似文献   

Estimation of the developmental age of the bovine fetus and newborn calf   总被引：1，自引：0，他引：1  

C Richardson  P C Jones  V Barnard  C N Hebert  S Terlecki  W V Wijeratne 《The Veterinary record》1990,126(12):279-284

Jersey cows from several herds provided 97 fetuses and 24 calves at fixed gestational intervals between 80 and 290 days after conception. The fetuses and calves were killed, weighed and measured and, after dissection, the sizes and weights of a range of skeletal and soft tissues were recorded. Six morphological measurements emerged as most suitable for the determination of developmental age in the normal fetus. By plotting their mean values and 95 per cent tolerance limits, the rates of growth and the variability of each measurement were defined. Long bone length was the most useful single measurement for predicting the developmental age of the fetus. Brain weight, bodyweight, crown-anus length and long bone length showed curvilinear growth patterns; age prediction equations derived from these measurements are complicated to use and additional simplified formulae have been derived. The number of appendicular ossification centres also had predictive value, but it could not be used to determine fetal developmental age between 100 and 160 days gestation.  相似文献   

Socioenvironmental influences on children's fruit, juice and vegetable consumption as reported by parents: reliability and validity of measures     

Weber Cullen K  Baranowski T  Rittenberry L  Cosart C  Owens E  Hebert D  de Moor C 《Public health nutrition》2000,3(3):345-356

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Vertical nitrate fluxes in the oligotrophic ocean     

Lewis MR  Hebert D  Harrison WG  Platt T  Oakey NS 《Science (New York, N.Y.)》1986,234(4778):870-873

The vertical flux of nitrate across the thermocline in the upper ocean imposes a rigorous constraint on the rate of export of organic carbon from the surface layer of the sea. This export is the primary means by which the oceans can serve as a sink for atmospheric carbon dioxide. For the oligotrophic open ocean regions, which make up more than 75% of the world's ocean, the rate of export is currently uncertain by an order of magnitude. For most of the year, the vertical flux of nitrate is that due to vertical turbulent transport of deep water rich in nitrate into the relatively impoverished surface layer. Direct measurements of rates of turbulent kinetic energy dissipation, coupled with highly resolved vertical profiles of nitrate and density in the oligotrophic eastern Atlantic showed that the rate of transport, averaged over 2 weeks, was 0.14 (0.002 to 0.89, 95% confidence interval) millimole of nitrate per square meter per day and was statistically no different from the integrated rate of nitrate uptake as measured by incorporation of (15)N-labeled nitrate. The stoichiometrically equivalent loss of carbon from the upper ocean, which is the relevant quantity for the carbon dioxide and climate question, is then fixed at 0.90 (0.01 to 5.70) millimole of carbon per square meter per day. These rates are much lower than recent estimates based on in situ changes in oxygen over annual scales; they are consistent with a biologically unproductive oligotrophic ocean.  相似文献   

Microelectrodes     

N C Hebert  M Lavallée  O Schanne 《Science (New York, N.Y.)》1968,160(825):333-334

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Sources of variation in nutrient intakes among men in Shanghai, China     

Cai H  Yang G  Xiang YB  Hebert JR  Liu DK  Zheng W  Shu XO 《Public health nutrition》2005,8(8):1293-1299

BACKGROUND AND OBJECTIVE: Random errors, from any source, will attenuate epidemiological risk estimates. Before we launched the Shanghai Men's Health Study (SMHS), a large population-based cohort study investigating the diet-cancer association among Chinese men, a dietary calibration study was conducted among 96 men aged 40-75 years (mean age 56.5 years), with biweekly 24-hour dietary recalls (24HDRs) implemented over a 1-year period. Data from this study were analysed to evaluate the nature and magnitude of variances for intake of 26 nutrients among SMHS participants, to compare variance ratios of 26 nutrients among Chinese men and women and individuals in other studies, and to estimate the number of 24HDRs required for future dietary calibration studies in similar populations. DESIGN: Ninety-six healthy, free-living men in Shanghai were administered biweekly 24HDR interviews 24 times over a 1-year period. To assess between-individual and within-individual contributions to variance, a mixed effects model was fitted and ratios of within-individual to between-individual (sigma(w)(2)/sigma(b)(2)) dietary intake variances were computed. SETTING: Shanghai, China. RESULTS: In agreement with reports from studies conducted in the USA and many other countries, we found that within-individual variances were usually larger than between-individual variances in dietary intake for all nutrients. The sum of all other variation (e.g. weekday and weekend, seasonal, interviewer) accounted for less than 5% of total variation. Ratios of within- to between-individual variances (for log-transformed data) ranged from 1.25 for carbohydrate intake to near 8 for delta-tocopherol intake. CONCLUSIONS: The results of this study suggest that among middle-aged and elderly Chinese men in Shanghai, within- and between-individual variation account for more than 95% of the total variation for 26 nutrients. Further dietary validation studies in the same population could be adequately carried out with only 12 days of dietary recalls, if 100 participants were enrolled.  相似文献   

Use of stable tracer studies to evaluate pesticide photolysis at elevated temperatures   总被引：1，自引：0，他引：1  

Hebert VR  Hoonhout C  Miller GC 《Journal of agricultural and food chemistry》2000,48(5):1916-1921

New methods were developed to determine photolysis rates of medium-weight pesticides in the gas phase using elevated air temperatures and solid-phase microextraction (SPME). A 57-L glass chamber was constructed that utilized collimated xenon arc irradiation that could heat chamber air to increase the amount of pesticide in the gas phase. Gas-phase photolysis rates were determined at various air temperatures by comparing the rate of loss of each of the tested pesticides to a photochemically stable tracer, hexachlorobenzene. Interval sampling of gas-phase constituents was performed using SPME immediately followed by GC-ECD or GC-MSD analysis. The two pesticides under examination were the dinitroaniline herbicide trifluralin and the organophosphorus insecticide chlorpyrifos. The gas-phase photolysis for trifluralin was found to be rapid with half-lives of 22-24 min corrected for sunlight. These results were comparable to photochemical lifetime estimates from other investigators under sunlight conditions. Elevating temperatures from 60 to 80 degrees C did not affect photolysis rates, and these rates could be extrapolated to environmental temperatures. From 60 to 80 degrees C, gas-phase chlorpyrifos photolysis lifetimes were observed to range from 1.4 to 2.2 h corrected for sunlight and will thus be important together with hydroxyl radical reactions for removing this substance from the atmosphere. At these elevated temperatures, pesticides and tracer compounds were found to be substantially in the gas phase, and possible effects on reaction rates from wall interactions were minimized.  相似文献   

Residue levels and cholinesterase activities in sheep poisoned experimentally with diazinon     

Antony F. Machin  Peter H. Anderson  C. Nancy Hebert 《Pest management science》1974,5(1):49-56

Sheep were dosed orally with diazinon at 450 and 600 mg/kg: residues of diazinon were determined in the blood, brain, liver, kidney cortex and medulla, muscle, fat and rumen contents at intervals after dosing, and cholinesterase activities in the erythrocytes and the brain were determined at the same intervals. The relations between residues, cholinesterase activity and clinical symptoms are discussed from the points of view of their diagnostic value and the possibility of undesirable residues occurring in poisoned animals. Rough estimates of the residues of two metabolites, hydroxydiazinon and dehydro-diazinon, in one sheep are also discussed. The oxygen analogue of diazinon was not detected although it was specifically sought.  相似文献   

Survival of infectious bovine rhinotracheitis virus in stored bovine semen     

M. S. Chapman  M. H. Lucas  C. N. Hebert  R. G. Goodey 《Veterinary research communications》1979,3(1):137-139

No loss in the titre of infectious bovine rhinotracheitis virus was found during storage in semen at –196°C for 1 year.  相似文献   

Quantitative anatomical study of methallibure-induced malformations in piglets     

J P Vente  A E Wrathall  N Hebert  B D Hoskin 《Research in veterinary science》1972,13(2):169-176

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