Theoretical and Empirical Relationships Between Oat Test Weight and Groat Proportion     

Douglas C. Doehlert  Jae‐Bom Ohm  Michael S. McMullen  Neil R. Riveland 《Cereal Chemistry》2009,86(2):239-246

Test weight and groat proportion are two very important quality characteristics of oat grain. In this study, we pose the hypothesis that these two characteristics are related through characteristics of grain density. Test weight is defined as the product of kernel density and packing proportion. Groat proportion, in theory, is the ratio of the groat mass to the kernel mass. We present two theoretical constructions expressing test weight in terms of groat proportion, packing proportion and kernel density components. To test these, we have applied measurements of test weight, groat proportion, kernel density components, and packing proportion of 18 oat cultivars grown at six environments. Whereas the groat proportion alone accounted for only 34% of the variation in test weight, our theoretical constructions that included groat proportion could account for ≤82% of variation in test weight. Also, we present previously undescribed variation in oat kernel density components across genotypes and environments. Although the kernel density alone could account for most of the variation in test weight across genotypes, packing proportion appeared to be more important in describing variation in test weight of a genotype across different environments. We observed significant variation in both groat and hull density which, together with groat proportion, described most of the variation in kernel density.  相似文献   

Measurements of ozone deposition to a potato canopy     

Mhairi Coyle  Eiko Nemitz  Robert Storeton-West  David Fowler  J. Neil Cape 《Agricultural and Forest Meteorology》2009,149(3-4):655-666

Potatoes are an important staple crop, grown in many parts of the world. Although ozone deposition to many vegetation types has been measured in the field, no data have been reported for potatoes. Such measurements, including the latent-heat flux, were made over a fully grown potato field in central Scotland during the summer of 2006, covering a 4-week period just after rainfall and then dry, sunny weather. The magnitude of the flux was typical of many canopies showing the expected diurnal cycles. Although the bulk-canopy stomatal conductance declined as the field dried out (～300 mmol-O₃ m^?2 s^?1 to ～70 mmol-O₃ m^?2 s^?1), the total ozone flux did not follow the same trend, indicating that non-stomatal deposition was significant. Over a dry surface non-stomatal resistance (R_ns) was 270–450 s m^?1, while over a wet surface R_ns was ～50% smaller and both decreased with increasing surface temperature and friction velocity. From the variation with relative humidity (RH) it is suggested that three processes occur on leaf surfaces: on a very dry surface ozone is removed by thermal decomposition, possibly enhanced by photolytic reactions in the daytime and so R_ns decreases as temperature increases; at 50–70% RH a thin film of liquid blocks the “dry” process and resistance increases; above 60–70% RH sufficient surface water is present for aqueous reactions to remove ozone and resistance decreases.  相似文献   

Hydrocortisone aceponate     

Ms Vanessa Schmidt  Dr Neil McEwan  and Dr Tim Nuttall 《The Journal of small animal practice》2009,50(6):317-317

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Mycoplasma bovis and otitis in dairy calves in the United Kingdom     

Foster AP  Naylor RD  Howie NM  Nicholas RA  Ayling RD 《Veterinary journal (London, England : 1997)》2009,179(3):455-457

Signs of severe otitis media in 20% of dairy calves on one farm were associated with Mycoplasma bovis infection, based on isolation from the external ear canal and nares. Affected calves seroconverted to M. bovis and no other significant bacteria were isolated. Infection was considered likely to have originated from cows in the milking herd based on evidence of seroconversion and detection of infection in a milk sample. M. bovis infection should be considered when investigating otitis problems in calves.  相似文献   

Collaborative development of the Arrowsmith two node search interface designed for laboratory investigators     

Neil R Smalheiser  Vetle I Torvik  Amanda Bischoff-Grethe  Lauren B Burhans  Michael Gabriel  Ramin Homayouni  Alireza Kashef  Maryann E Martone  Guy A Perkins  Diana L Price  Andrew C Talk  Ruth West 《Journal of Biomedical Discovery and Collaboration》2006,1(1):8

Arrowsmith is a unique computer-assisted strategy designed to assist investigators in detecting biologically-relevant connections between two disparate sets of articles in Medline. This paper describes how an inter-institutional consortium of neuroscientists used the UIC Arrowsmith web interface http://arrowsmith.psych.uic.edu in their daily work and guided the development, refinement and expansion of the system into a suite of tools intended for use by the wider scientific community.  相似文献   

Modified 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (abts) method to measure antioxidant capacity of Selected small fruits and comparison to ferric reducing antioxidant power (FRAP) and 2,2'-diphenyl-1-picrylhydrazyl (DPPH) methods     

Ozgen M  Reese RN  Tulio AZ  Scheerens JC  Miller AR 《Journal of agricultural and food chemistry》2006,54(4):1151-1157

The measurement of antioxidant capacity in fruits differs from that of other biological samples due to their low pH and very low lipophilic antioxidant capacity. In this report, we present a modified 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) method for fruits and compare its performance with the other commonly used antioxidant methods of 2,2'-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP). The antioxidant capacity and reaction kinetics of four phenolic compounds, two antioxidant standards, and five fruits were also investigated. The modified ABTS method prepared at a pH of 4.5 with sodium acetate buffer is highly stable and easily applied to fruit samples as compared to the standard (pH 7.4) version. The measured antioxidant capacity of samples varied with the assay method used, pH, and time of reaction. Traditional antioxidant standards (trolox, ascorbic acid) displayed stable, simple reaction kinetics, which allowed end point analysis with all of assays. Of the phenolic compounds examined, chlorogenic and caffeic acids exhibited the most complex reaction kinetics and reaction rates that precluded end point analysis while gallic acid and quercetin reached stable end points. All fruit extracts exhibited complex and varied kinetics and required long reaction times to approach an end point. Because the antioxidant capacity of fruit extracts is a function of the array of individual antioxidants present, accurate comparisons among fruit samples require that reaction times be standardized and of sufficient length to reach steady state conditions and that more than one assay be used to describe the total antioxidant activity of fruit samples.  相似文献   

Prediction of human cases of West Nile virus by equine cases, Saskatchewan, Canada, 2003     

Corrigan RL  Waldner C  Epp T  Wright J  Whitehead SM  Bangura H  Young E  Townsend HG 《Preventive veterinary medicine》2006,76(3-4):263-272

In 2003, an outbreak of West Nile virus (WNV) occurred in Saskatchewan, Canada from July to September. One-hundred thirty-three horse cases and 947 human cases were recorded and data were analyzed retrospectively for evidence of clustering to determine if clinical infection in the horse population could be used to estimate human risk of infection with WNV. Kulldorff's scan statistic was used to identify spatial-temporal clusters in both the human and horse cases. In most areas, human clusters were not preceded by horse clusters. In one area, a significant cluster of horse cases preceded human cases by 1 week; however, 1 week does not provide sufficient time for human-health authorities to act and provide advance warning for the public.  相似文献   

The long-term effects of catchment liming and reduced sulphur deposition on forest soils and runoff chemistry in southwest Sweden     

Stefan Löfgren  Neil Cory  Therese Zetterberg  Per-Erik Larsson  Veronika Kronnäs 《Forest Ecology and Management》2009

Whole catchment liming or forest liming has been proposed and implemented as a countermeasure to the effects of elevated sulphur deposition. Since the end of the 1980s the Swedish Forest Agency has undertaken experimental forest liming experiments in selected catchments in southern Sweden. These studies were with low doses (3 tonnes ha⁻¹) of lime (CaCO₃) and dolomite (CaMg(CO₃)₂). Data from both soil samples and stream water samples have been collected for the 16 years following treatment. The stream data has been complemented with data from untreated catchments, from the Swedish monitoring stream network. Significant differences due to treatment were seen for Ca, cation exchange capacity (CEC) and base saturation (BS) in the humus layer, none of these variables showed a statistically significant change in the mineral soil due to treatment alone. Soil samples from both the treated and untreated sites showed temporal changes in both the humus layer and the mineral soils with increases in pH, Ca and CEC and decreases in BS and Al which were independent of treatment. A combination of treatment and time, gave significant changes in BS and TA down to 10 cm in the mineral soil. In the stream water samples no statistically significant differences were observed between treated and untreated sites. Regardless of treatment, the streams exhibited a general pattern of declining concentrations of SO₄, Ca, sum of base cations (BC) and increasing acid neutralizing capacity (ANC). In summary, the application of a low dose of lime (3 tonnes ha⁻¹) did not result in significant changes in surface water chemistry in the study catchments and changes in soil chemistry were mainly restricted to the humus layer during the 16 years following treatment. The natural recovery, as a result of reductions in sulphur deposition, dominated the effects and was clearly seen in both the treated and untreated study sites. MAGIC simulations indicate that this recovery will continue in the coming decades.  相似文献   

玉米花粉寿命及有效控制花粉飘逸的隔离距离研究     

S.Luna V.  J.Figueroa M.  B.Baltazar M.  R.Gomez L.  R.Townsend  J.B.Schoper  马志强  何庆学 《中国农技推广》2009,25(12):12-13

花粉是玉米基因飘逸的重要载体。研究了花粉活力的持续时间和有效控制基因飘逸的隔离距离。在花药刚开裂时采集花粉,置于薄膜层上,放在室外自然条件下保存,每隔一定时间对采集的花粉进行目测和授粉．通过对花粉的目测评判和计算结实率评估花粉活力。试验花粉源区域4000m^2,在其周围不同距离的地方种植若干玉米小区,每个小区面积为12．8m^2,以测定隔离距离的有效性。作为花粉源的玉米材料包含可用于测定花粉飘逸的叶色标记或种子标记。由于大气压不同,花粉可在花药开裂后1～2小时内保持活力。假定花粉以当地下午平均最大风速直线传播,并可在2小时内保持花粉活力,且忽略花粉沉降率因素,理论上讲,具有活力的花粉可以传播的最大距离为32km。试验结果是在离花粉源100m发生了一定数量的异花授粉,离花粉源200m处有个别异花授粉发生。离花粉源300m处没有异花授粉发生。试验结果与玉米花粉不耐干燥并具高沉降速率的结论一致。试验结果表明距离隔离是控制玉米因授粉而发生基因飘逸的有效方法。  相似文献   

Influence of imidacloprid seed treatments on rice germination and early seedling growth     

Stevens MM  Reinke RF  Coombes NE  Helliwell S  Mo J 《Pest management science》2008,64(3):215-222

BACKGROUND: Seed treatments with the chloronicotinyl insecticide imidacloprid (Gaucho 600 FS) were evaluated to determine whether differences in concentration and exposure regime influence the germination and early growth of rice. RESULTS: Continuous exposure to imidacloprid (4 days at 2000 mg AI L(-1)) significantly (P < 0.001) reduced normal germination by an average of 18% across the 15 cultivars examined. Nine days after sowing, plants showed no adverse effects from continuous imidacloprid treatment during germination, with shoot lengths and root system dry weights equalling, or occasionally exceeding (P < 0.05), those of untreated plants. Short-term imidacloprid exposure (2 h at 2000 mg L(-1)) at initial seed wetting did not affect germination (P > 0.05), and short-term (1 h) exposure of 48 h pregerminated seed to imidacloprid (2000 mg L(-1)) similarly had no significant effect on early subsequent growth. Plants arising from 48 h pregerminated seed exposed to imidacloprid (1 h) at concentrations up to 4000 mg L(-1) immediately before sowing were not significantly different from control plants at either 9 or 25 days post-sowing. CONCLUSION: Results show that imidacloprid will have no adverse effects on plant growth if applied to pregerminated rice shortly before sowing. Continuous exposure of seed during germination had more pronounced effects, and the initial response of different cultivars was highly variable. Cultivars with high levels of sensitivity (such as IR72) require further testing before continuous exposure to imidacloprid during germination can be recommended.  相似文献