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31.
Color stability of fruit juice made from strawberries (Fragaria x ananassa, cv. Elsanta) that were subjected to high hydrostatic pressure was studied by measuring the anthocyanin content. High hysrostatic pressure is a method of preservation of food alternative to heat treatment. It is therefore essential to assess the impact of high pressure on color molecules. Samples were pressurized under 200, 400, 600, and 800 MPa for 15 min at a temperature controlled between 18 and 22 degrees C. After application of pressure, the anthocyanin content of the strawberry juice was analyzed by HPLC-UV using a novel isocratic elution system. The high-pressure treated samples were kept at refrigerator temperature (4 degrees C), room temperature (20 degrees C), and 30 degrees C. Two pigments were identified and quantified: pelargonidin 3-glucoside and pelargonidin 3-rutinoside. The highest stability of the anthocyanins was found when strawberries were stored at a temperature of 4 degrees C. High-pressure treatment at 800 MPa led to the lowest losses, at 4 degrees C.  相似文献   
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The evaporation from water droplets on artificial soybean leaves was modelled using an energy balance. Observations showed that while droplets were hemispherical initially, they then flattened keeping the base area virtually constant. These observations led to modelling the process as evaporation from a vertical right-circular cylinder which gave excellent agreement with indoor data.  相似文献   
33.
The level of fertility in the male ostrich exerts considerable influence on the efficiency of the fertilization procedure, and thus also on reproductive performance. The determination of the reproductive capacity is of particular interest with regard to the selection of single individuals for optimizing reproduction ratios. Although the breeding and raising of ostriches has become increasingly important in many countries, little research has been completed on reproductive parameters and factors that may possibly influence them. This study presents observations made concerning the quantity and quality of sperm as found in the spermatological testing of 411 ejaculate samples taken from male ostriches on two farms in Namibia. The semen volume varied between 0.1 and 1.5 ml (mean, 0.64 ml). Normal ejaculate colours ranged from white to ivory; the consistency ranged from thin creamy to viscous. The measured pH values lay between 6.4 and 8.0 (mean, 7.3). Microscopic investigations revealed sperm concentrations of 8.9–78.1 million/μl and individual sperm motility from 42 to 96% (mean, 78%). No mass motility was detectable in 42% of the ejaculates; weak mass motility was found in 46%, and clear mass movements were to be found in only 12% of samples. Regarding the morphology of the sperm, 5 to 26% were abnormal (mean, 17%) and 4 to 28% (mean, 20%) were dead. Seasonal patterns of sperm concentration and the influence of frequency of semen collection were investigated in a group of 56 healthy male ostriches. Peak sperm concentrations were found at the beginning of the breeding season in spring; the lowest values were found at the end of the breeding season in autumn. The highest quality ejaculate was obtained from those males whose semen was collected once a week. The results of this study provide fundamental data for the establishment of minimum quality requirements for ostrich sperm to be met by individuals receiving certification as breeding animals and for the selection of suitable males for use in artificial insemination.  相似文献   
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以杂C-546为试材,采用10、20、40、80、160 mmol/L外源CaCl_2浸种和叶面喷施不同浓度处理种子,比较分析低温胁迫下玉米种子发芽率、发芽势、发芽指数和幼苗叶片相对电导率、可溶性蛋白、Pn、Fv/Fm、POD和SOD活性等生理生化指标的变化。结果表明,在低温抑制玉米幼苗生长条件下,一定浓度CaCl_2(10~80 mmol/L)处理可降低玉米幼苗生长伤害程度。80 mmol/L CaCl_2浸种处理对玉米低温胁迫的缓解效果最佳,与对照比较,发芽率提高8%,发芽势提高24.6%,发芽指数提高33.2,相对电导率降低51.8%,可溶性蛋白含量增加76.3%,SOD活性增加35.7%。适宜浓度的CaCl_2在低温条件下可促进玉米种子的萌发,降低低温对玉米幼苗造成的伤害。  相似文献   
36.
The aim of this study was to assess cellular proliferation using silver-stained nucleolar organizer regions (AgNOR) and the proliferating cell nuclear antigen (PCNA) in various tissues in the prostate of ram lambs implanted with increasing zeranol doses and to compare the sensitivity of different tissues of lamb prostate to zeranol. Twenty-four Akkaraman lambs were implanted with increasing zeranol doses, including 12 mg (n = 8), 24 mg (n = 8) and 96 mg (n = 8), with eight lambs serving as controls. After 33 days, the prostate tissues of the lambs were stained using AgNOR and PCNA techniques. The prostate tissues were divided into two compartments--the epithelial tissues, including glandular acinus, collecting duct and penile urethra, and the non-epithelial tissues, including interstitial tissue and striated muscle. AgNOR dots and PCNA index on each prostatic tissue were counted under a light microscope and were evaluated statistically. AgNOR staining in the treatment groups showed a higher score in the non-epithelial tissues than the epithelial components, whereas the PCNA index was significant in the epithelial tissues and non-epithelial tissues had very low PCNA immunostaining. According to the PCNA index, collecting duct epithelium showed more sensitivity to increasing zeranol doses and according to AgNOR counts, there was no difference of sensitivity to zeranol among tissues of the same origin. Both AgNOR counts and PCNA indexes seem to be valuable proliferating markers for the epithelial components of ram prostate, but PCNA index had no significance in relation to the non-epithelial components in contrast to AgNOR counts. Therefore, the controversial results arising from the combined use of both techniques as proliferating markers for the ram prostate should be considered in further studies.  相似文献   
37.
One hundred and thirty European and North American potato cultivars were assayedin vitro for salinity (NaCl) tolerance. A modified single-node cutting bioassay was used in which cultivars were exposed to a range of NaCl levels (0, 40, 80, and 120 mM), in a Murashige and Skoog-based medium, for 1 month. Evaluations were performed twice for each cultivar at each salt level, using five single-node cuttings. Six vegetative growth parameters (shoot and root lengths, fresh and dry weights) were measured at the time of harvest and corrected for differences in cultivar vigor. These relative values were subjected to multivariate cluster analysis. The sum of the relative rankings at 40, 80, and 120 mM NaCl partitioned the cultivars into 8 units. The cultivars Amisk, BelRus, Bintje, Onaway, Sierra, and Tobique were in the most salinity tolerant unit and in the top cluster group for vigor with the exception of Tobique. These cultivars can be recommended for further study.  相似文献   
38.
Understanding the transmission of plant pathogen inoculum during the periods when the host plants are not present is crucial for predicting the initiation of epidemics and optimizing mitigation strategies. However, inoculum production at the end of the cropping season, survival during the intercrop period, and the emergence or release of inoculum can be highly variable, difficult to assess, and generally inferred indirectly from symptom data. As a result, a lack of large datasets hampers the study of these epidemiological processes. Here, inoculum production was studied in Leptosphaeria maculans, the cause of phoma stem canker of oilseed rape. The fungus survives on stubble left in the field, from which ascospores are released at the beginning of the next cropping season. An image processing framework was developed to estimate the density of fruiting bodies produced on stem pieces following incubation in field conditions, and a quality assessment of the processing chain was performed. A total of 2540 standardized RGB digital images of stems were then analysed, collected from 27 oilseed rape fields in Brittany over four cropping seasons. Manual post-processing removed 16% of the pictures, e.g. when moisture-induced darkening of the oilseed rape stems caused overestimation of the area covered with fruiting bodies. The potential level of inoculum increased with increasing phoma stem canker severity at harvest, and depended on the source field and the cropping season. This work shows how image-based phenotyping generates high-throughput disease data, opening up the prospect of substantially increased precision in epidemiological studies.  相似文献   
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A 6-year-old 18-kg (39-lb) spayed female Standard Poodle was referred for treatment of pneumopericardium. The dog did not have severe clinical signs relating to the pneumopericardium, and the diagnosis was made incidentally while investigating the cause of a cough. Computed tomography revealed an air-filled structure consistent with a bulla to the right of the heart base that appeared to communicate with the pericardial cavity Because spontaneous resolution of the pneumopericardium seemed unlikely and cardiac tamponade was a possibility, exploratory thoracotomy was performed. A lobulated bulla was found at the hilus of the right middle lung lobe adhered to the underlying pericardial sac, and a 4-cm-diameter communication from the pericardium to the pulmonary bulla was found. Right middle lung lobectomy was performed, and the pericardiotomy and pericardial opening were sutured. The dog recovered without complications. In previously reported cases of pneumopericardium involving a cat and a dog, the condition resolved spontaneously. In this dog, in contrast, surgical resection of the affected lung lobe with pericardial reconstruction was required for resolution of the pneumopericardium.  相似文献   
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