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61.
Fresh elder flowers (Sambucus nigra L.) were extracted with an aqueous solution containing sucrose, peeled lemon slices, tartaric acid, and sodium benzoate to make elder flower syrup. Aroma compounds emitted from the elder flower syrup were collected by the dynamic headspace technique and analyzed by GC-FID and GC-MS. A total of 59 compounds were identified, 18 of which have not previously been detected in elder flower products. The concentrations of the identified volatiles were measured in five elder cultivars, Allesoe, Donau, Sambu, Sampo, and Samyl, and significant differences were detected among cultivars in the concentration levels of 48 compounds. The odor of the volatiles was evaluated by the GC-sniffing technique. cis-Rose oxide, nerol oxide, hotrienol, and nonanal contributed to the characteristic elder flower odor, whereas linalool, alpha-terpineol, 4-methyl-3-penten-2-one, and (Z)-beta-ocimene contributed with floral notes. Fruity odors were associated with pentanal, heptanal, and beta-damascenone. Fresh and grassy odors were primarily correlated with hexanal, hexanol, and (Z)-3-hexenol.  相似文献   
62.
The emission of nitrous oxide (N2O) from soil under grass was measured, following applications of cow slurry and NH4NO3 fertilizer. The N2O-flux from untreated soil averaged 0.58 mg Nm?2 day?1 through April to August. Application of slurry at the end of April and at the middle of July caused increases in the daily N2O-flux of up to 40-fold, compared to untreated grass. Applications of NH4NO3 increased the N2O-flux up to 5 times during the same period. The N2O-flux often showed marked diurnal fluctuations. These fluctuations are not solely associated with change in temperature, but may also be related to grass root activity and to photosynthesis.  相似文献   
63.
Abstract.— Refrigerated storage of sperm is useful for genetic study and artificial breeding of fishes. Due to the potential loss of donor males, storage is important in species such as channel catfish Icralurus punctatus from which sperm cannot be stripped. This study addresses short-term storage (at 4 C) of channel catfish sperm by evaluation of storage methods employed for other species and for cryopreservation of channel catfish sperm. The objectives were to evaluate: 1) storage of intact testes and storage of sperm suspended in an extender solution; 2) use of various storage containers with and without supplemental oxygen; 3) use of extender solution with and without the addition of an antibiotic/antimycotic cocktail; 4) use of extender solution with and without the addition of methanol; and 5) use of extender solution with and without the addition of glucose and methanol. Sperm suspended in extender solution retained motility significantly longer (9 d) than did sperm in intact testis (2 d). Sperm stored in Zip-loc® plastic bags inflated with pure oxygen retained motility significantly longer (12 d) than did sperm stored in Zip-loc® plastic bags without supplemental oxygen (7 d), or sperm stored in plastic beakers (8 d) or test tubes (8 d) without supplemental oxygen. Sperm stored with the addition of antibiotic/antimycotic cocktail or methanol retained motility significantly longer (10–12 d) than did sperm stored without additives (6–8 d). Sperm stored in extender solution without glucose retained motility significantly longer (19–21 d) than did sperm stored in extender with glucose (13–16 d). Motility was retained for as long as 21 d in sperm stored in extender solution with 5% methanol and without glucose. In each experiment, loss of motility was associated with bacterial growth.  相似文献   
64.
65.
When leaf-bud cuttings from Hedera canariensis Willd. ‘Gloire de Marengo’ were prepared with various stem lengths, the subsequent shoot length was inversely correlated with the stem length below the axil. The shoot growth was also correlated with the size of the leaf of the cutting but not by the position along the stem of the stock plant. Certain stock plants yielded cuttings with significantly greater shoot lengths than did others.The shoot length obtained was variable (coefficient of variation 36%), and this variation was reduced neither by standardising the length of the stem below the axil, nor by standardising the area of the original leaf on the cuttings. However, some stock plants produced less variable cuttings than others, and variability was shown to be inversely correlated with the shoot length of the propagated plants.  相似文献   
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67.
A spectrum of proliferative cutaneous lesions occurred in 12 dogs at the injection site of live canine oral papillomavirus (COP) vaccine, suggesting a viral etiology for the masses. Lesions included epidermal hyperplasia, epidermal cysts, squamous papilloma, basal cell epithelioma, and squamous cell carcinoma. Peroxidase-antiperoxidase staining of tumor sections revealed nuclei which stained for group-specific papillomavirus antigen in five of 12 masses. Electron microscopic examination of tumor sections did not reveal virions. In transmission studies, macerated tumor tissue did not produce oral papillomas on the scarified mucosa of puppies; this procedure did protect the puppies from development of lesions when challenged with infectious papilloma material. These findings are evidence that COP can induce hyperplastic and neoplastic lesions in sites other than oral, pharyngeal, and ocular mucosa.  相似文献   
68.
Immunity to Ostertagia ostertagi infections in calves develops slowly and only becomes manifest towards the end of a grazing season in which they have been exposed to the parasite. In an attempt to hasten the onset of immune reactions, three immunization protocols were set up. Twenty four heifers were allocated into four groups. Beginning in January, animals in two of the groups were inoculated with four 1-monthly increasing dosages of either 'normal' or 'chilled' (hypobiosis-prone) larvae, those in the third group received a single large infection with 'chilled' larvae and those in the fourth group served as non-infected controls. All animals were turned out on a common pasture in late April. Development of immunity was evaluated through determinations of faecal egg counts, live weight gains, serum pepsinogen levels and specific serum antibody responses of three isotypes (IgG1, IgG2 and IgA). Significantly reduced egg excretions in the immunized groups were apparent early in the season, indicating that the immunizations had, in this respect, been efficacious. The 'chilled' and 'normal' larvae seemed equally efficient given as multiple and single infections. A single large dosage of 'chilled' larvae seemed to have adverse effects. Only moderate antibody responses were elicited probably because of low challenge infection level on pasture. Considerable variation in responses existed between and within the four groups, for which reason conclusions regarding correlations between antibody isotype responses and immune effects on parasites could not be made.  相似文献   
69.
A total of 578 slaughter pigs from 2 Danish conventional farrow-to-finish operations (Herds a and B) were followed from an age of 14 days to slaughter. Pigs were weighed at 3 weeks intervals and at slaughter and extended post mortem examination of the plucks was done. Regression models with second and third order interaction terms demonstrated that Mycoplasma-like pneumonia, complicated pneumonia, anterio-ventral pleuritis, pericarditis, fissures and atrophic rhinitis, separately and through interactions with other lesions, significantly reduced mean daily gains during specific intervals of the growth period in 2 conventional swine herds. It is likely that the periods of reduced growth reflect the times when the diseases were in the acute and early recovery stages. Maximum estimated reductions in daily gains associated with the combined lesions were 82 grams and 283 grams during the interval 120-140 days in Herds A and B, respectively. Although dorso-caudal pleuritis and parietal pleuritis had minor negative effects during 2 intervals neither had a significant adverse effect on total growth rate in either herd (Paisley et al. 1993). R2 values for the regression models were less than 0.27 showing that the lesions present at slaughter explained less than 27% of the variation in herd mean daily gains during any interval.  相似文献   
70.
A single-plant-plot design was found very suitable for a study of growth and yield effect of tree density, rectangularity and row orientation on a wide range of intra and inter-row planting-distances.Densities from about 250 to 40 000 trees per hectare were studied in 2 apple cultivars on 2 weak-growing rootstocks over a period of 8 years. On unpruned trees a maximum yield of 80 tons per hectare of ‘James Grieve’ and about 95 tons of ‘Spartan’ was recorded. At the highest densities these yields were reached 2–3 years after planting.As early as the second to third year the growth was restricted at densities over about 1000 trees per hectare. A higher yield per tree at medium densities than at lower densities for the first fruiting-years is supposed to be an effect of growth resulting in earlier fruiting.A high rate of rectangularity reduced the yield only on densities of 1200–1550 trees per hectare. The lack of a significant effect on lower and higher densities is discussed.The growth and yield of rows oriented North—South were 17% higher than of those oriented East—West.  相似文献   
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