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21.
Mean July temperatures across Europe 6000 years before present were reconstructed from palynological data by the transfer function method. Reconstructed summer temperatures were warmer than those at present over most of Europe with the greatest heating, more than 2 degrees C, in the midcontinent and the far north. This pattern is explained by high summer insolation and a weak zonal insolation gradient 6000 years before present and the effective heating of the landmass relative to ocean and coastal areas. A strong land-sea pressure gradient may in turn have increased westerly air flow into southern Europe, which is consistent with cooler reconstructed summer temperatures in the Mediterranean region, and reduced the environmental lapse rate in the central European mountains.  相似文献   
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In 1958, at three sites in the Vale of Evesham, a progressive increase in the yield of spring cabbage was obtained from increasing rates of application of nitrogenous fertilizers up to 279 lb. N per acre, as Nitrochalk. At a fourth, with later application of fertilizers and a relatively early cutting date, 6 cwt. per acre gave a yield response rather greater than at the other three sites, but higher rates of application of Nitrochalk produced no further increases in yield.

No yield advantage was gained by applying the fertilizer dressing in three doses during the growth of the crop rather than in one dose in the very early spring.

The uptake of potassium, phosphorus, magnesium and calcium by the plants increased as the rate of nitrogenous fertilizer increased. The need to maintain an adequate level of available potassium in the soil when using heavy dressings of nitrogenous fertilizers is emphasized.

The effect of a ploughed-in ley on the recovery of added nitrogen is discussed.  相似文献   
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Understanding the mechanisms that maintain protective antibody levels after immunisation is important for vaccine design. In this study, we have determined the kinetics of plasma and memory B cells detectable in the blood of cattle immunised with model T-dependent or T-independent antigens. Immunisation with the T-D antigen resulted in an expansion of TNP-specific plasma cells post-TNP primary and booster immunisations, which was associated with increased titres of TNP-specific IgG antibodies. Although no TNP-specific memory B cells were detected in the T-D group following the primary immunisation, we detected an increase in the number of TNP-specific memory B cells post-TNP boost. In contrast, no TNP-specific plasma or memory B cells were detected after primary or secondary immunisation with the T-I antigen. We then investigated if immunisation with a third party antigen (tetanus toxin fragment C, TTC) would result in a bystander stimulation and increase the number of TNP-specific plasma and memory B cells in the T-D and/or T-I group. TTC immunisation in the T-D group resulted in a small increase in the number of TNP-specific plasma cells post-TTC primary immunisation and boost, and in an increase in the number of TNP-specific memory B cells post-TTC boost. This bystander effect was not observed in the animals previously immunised with the T-I antigen. In conclusion, the present study characterised for the first time the B cell response in cattle to immunisation with T-D and T-I antigens and showed that bystander stimulation of an established T-D B cell memory response may occur in cattle.  相似文献   
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The objective of this study was to obtain protein hydrolysate from the mechanically separated meat of blackfin pacu to evaluate the influence by ultrafiltration in the antioxidant and antimicrobial activities of the peptide fractions obtained and to apply in ground beef to evaluate the lipid stability. The enzymatic hydrolysis was performed using the enzyme Protamex (pH 7.0, 60°C) for 240 min. The protein hydrolysate was fractionated by ultrafiltration. Then, the antioxidant capacity of the protein hydrolysate and the peptide fractions were evaluated in vitro by the methods of 2,2’-azinobis (3-ethylbenzothiazoline sulfonic acid) radical capture, 2,2-diphenyl-1-picrylhydrazyl radical-scavenging assay, reducing power, and hydroxyl radical scavenging activity. The antimicrobial activity of the samples was evaluated by disc-diffusion against Staphylococcus aureus and Escherichia coli. After evaluation, the peptide fractions did not present higher bioactivities than that shown for the hydrolysate. The protein hydrolysate was applied to ground beef, where the substances reactive to thiobarbituric acid and color were evaluated during 7 days of storage at 4°C. Lipid oxidation was reduced up to 60.9% and there was no modification of the natural coloration. Thus, the protein hydrolysate can be used as an alternative source of antioxidant for the preservation of refrigerated meats.  相似文献   
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Freshness is the main concern of seafood quality, and the principal method to evaluate seafood freshness is sensory evaluation. The aim of this work was to study the quality changes of cobia, Rachycentron canadum, under ice storage through sensory and physical analysis as well as bacterial counting of specific spoilage organisms (SSOs). In particular, the utilization of a quality index method (QIM) scheme was proposed. Samples stored for 0–30 d were analyzed with the QIM. Ten panelists observed and registered the changes occurring in the fish starting on day zero and ending when the fish were spoiled. After developing the scheme, 11 sensory attributes were described in 23 points, which detailed the appearance of skin, eyes, abdomen, gills, and flesh deterioration. The volatile nitrogen compound measurements and microbiological data of the SSOs determined a shelf‐life of 19 d for the samples. Sensory analysis showed a rejection point at 15.67 d of ice storage. The natural degradation of myofibrillar proteins and collagen was observed during ice storage. In conclusion, a shelf‐life of 15 d was defined for raw cobia stored on ice.  相似文献   
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