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排序方式: 共有448条查询结果,搜索用时 328 毫秒
71.
Girennavar B Jayaprakasha GK Mclin SE Maxim J Yoo KS Patil BS 《Journal of agricultural and food chemistry》2008,56(22):10941-10946
Phytochemical levels in fruits and vegetables can be affected by several postharvest factors. In the present study, the effect of electron-beam (E-beam) irradiation was studied on grapefruit bioactive compounds. 'Rio Red' and 'Marsh White' grapefruits were irradiated with E-beam at 0, 1.0, 2.5, 5.0, and 10.0 kGy. Changes of various bioactive compounds, such as vitamin C, flavonoids, carotenoids, furocoumarins, and limonoids, were measured. The acidity decreased slightly with an increasing E-beam dose, whereas the total soluble solids were increased. Irradiation did not affect the vitamin C content at 1 kGy; however, doses beyond 1 kGy significantly reduced the vitamin C content. Lycopene and beta-carotene did not change significantly from the irradiation. Lycopene levels decreased as the E-beam dose increased, while the beta-carotene content slightly increased. Dihydroxybergamottin levels exhibited a decreasing trend, while the bergamottin content did not change. Naringin, a major flavonoid of grapefruit, showed a significant increase over the control at 10 kGy in both 'Rio Red' and 'Marsh White'. Nomilin continued to decrease with an increasing dose of E-beam irradiation, while limonin levels remained the same at all of the doses. Low-dose E-beam irradiation has very little effect on the bioactive compounds and offers a safe alternative to existing postharvest treatments for the disinfection and decontamination of grapefruits. 相似文献
72.
73.
Robinson TR Hussey SB Hill AE Heckendorf CC Stricklin JB Traub-Dargatz JL 《Journal of the American Veterinary Medical Association》2008,233(4):613-617
OBJECTIVE: To compare temperature readings from an implantable percutaneous thermal sensing microchip with temperature readings from a digital rectal thermometer, to identify factors that affect microchip readings, and to estimate the sensitivity and specificity of the microchip for fever detection. DESIGN: Prospective study. ANIMALS: 52 Welsh pony foals that were 6 to 10 months old and 30 Quarter Horses that were 2 years old. PROCEDURES: Data were collected in summer, winter, and fall in groups 1 (n = 23 ponies), 2 (29 ponies), and 3 (30 Quarter Horses), respectively. Temperature readings from a digital rectal thermometer and a percutaneous thermal sensing microchip as well as ambient temperature were recorded daily for 17, 23, and 19 days in groups 1 through 3, respectively. Effects of ambient temperature and rectal temperature on thermal sensor readings were estimated. Sensitivity and specificity of the thermal sensor for detection of fever (rectal temperature, >or= 38.9 degrees C [102 degrees F]) were estimated separately for data collection at ambient temperatures 15.6 degrees C. RESULTS: Mean ambient temperatures were 29.0 degrees C (84.2 degrees F), -2.7 degrees C (27.1 degrees F), and 10.4 degrees C (50.8 degrees F) for groups 1 through 3, respectively. Thermal sensor readings varied with ambient temperature and rectal temperature. Rectal temperatures ranged from 36.2 degrees to 41.7 degrees C (97.2 degrees to 107 degrees F), whereas thermal sensor temperature readings ranged from 23.9 degrees (75 degrees F) to 42.2 degrees C (75 degrees to 108 degrees F). Sensitivity for fever detection was 87.4%, 53.3%, and 58.3% in groups 1 to 3, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: The thermal sensor appeared to have potential use for initial screening of body temperature in equids at ambient temperatures > 15.6 degrees C. 相似文献
74.
Mhairi A. Sutherland Keith Erlandson Joe F. Connor Janeen L. Salak-Johnson Paul Matzat Jerry F. Smith John J. McGlone 《Livestock Science》2008,116(1-3):237-245
Loss of pigs during or after transport is a welfare concern, but also an economic concern for producers. Transport losses include animals that are dead on arrival (DOA) at the plant, pigs that are injured, and pigs which are not obviously injured but unwilling or unable to walk (non-ambulatory, non-injured or NANI). The objective of this research was to assess the health of non-ambulatory, non-injured (NANI) pigs relative to control pigs at the processing plant by looking at a range of measures, including complete blood chemistry, anatomy, and pathology to determine potential factors associated with pigs going down. Data were collected from NANI and control pigs at five plants in the midwest USA. Feet and legs and internal organs were inspected and the severity of the pathology scored. Alveolar macrophages were collected and counted. Blood was collected for analysis of hematology, blood chemistry and cortisol concentrations. Titers to common porcine respiratory viruses were measured in pigs from one plant. Hoof and pad problems did not differ overall between control and NANI pigs, however the percentage of severe foot problems was greater (P < 0.05) in NANI compared with control pigs at plants A and E. The percentage of total ulcers, rhinitis, and empty stomachs differed (P < 0.05) between control and NANI pigs at individual plants, but not overall. Blood hematology and chemistry differed (P < 0.05) between NANI and control pigs. Cortisol concentrations did not differ between NANI and control pigs. Titers to swine influenza virus (SIV) H1N1 and H3N2 and porcine circovirus (PCV) were lower (P < 0.01) among NANI compared with control pigs. However, more (P < 0.01) NANI pigs were positive for SIV H1N1 and H3N2 compared with control pigs. Blood hematology, chemistry, and pathology indicate a large difference between NANI and controls pigs. No single health problem was higher among NANI pigs compared to plant-matched control pigs. Rather, several problems appear to contribute to pigs becoming NANI which may differ from one plant too another. 相似文献
75.
Soluble solids comprise most of onion bulb dry mass, and dehydrator onion cultivars are developed from breeding populations
that have high dry mass content. Realized and narrow-sense heritability estimates were obtained for the soluble solids content
(SSC) trait in two open-pollinated dehydrator onion breeding populations (BP) using response to selection and half-sib family
analysis. Parental populations, designated as BP9335-U and BP9243-U, were derived from two-way crosses of lines advanced as
open- pollinated (OP) populations to the F7 or F_6 generation, respectively. BP9335-U had one previous selection cycle for
increased SSC and BP9243-U had three SSC selection cycles. In these experiments, parental populations were screened again
for high SSC, and selected bulbs were intermated to form half-sib progeny groups, designated as BP9335-S and BP9243-S. Mean
SSC was increased by 6.6% and a realized heritability estimate of 0.64 was obtained for BP9335-S. Mean SSC was increased by
6.3% and a realized heritability estimate of 0.36 was obtained for BP9243-S. Narrow-sense heritability estimates of 0.58 ±0.05
and 0.30 ±0.03 were obtained for parental populations BP9335-U and BP9243-U, respectively. Narrow-sense heritability estimates
of 0.40 ± 0.03 and 0.63 ± 0.23 were obtained for progeny populations derived from selected high-SSC bulbs of these lines (BP9335-S
and BP9243-S), respectively, indicating that there is significant additive genetic control of the SSC trait in these populations.
Significant differences in half-sib family performance in the advanced groups BP9335-S and BP9243-S demonstrate that progeny
testing was effective for evaluating phenotypic selections.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
76.
77.
Joe M. Fox Addison L. Lawrence Eunice Li‐Chan 《Journal of the World Aquaculture Society》2009,40(2):171-181
Tail muscle tissue free amino acids (FAA) concentration is reported for subadult (4.3 g) Litopenaeus vannamei fed diets containing only protein‐bound amino acids, crystalline lysine as a supplement to protein‐bound lysine, and only crystalline amino acids (CAA). FAA were determined in shrimp at 0.00, 0.25, 0.5, 1, 2, 4, and 8 h postfeeding. Highest total tissue concentrations of essential amino acids and individual amino acids were typically observed 4 h postfeeding for shrimp fed intact and crystalline lysine‐supplemented feeds. Those shrimp offered diets containing only CAA showed no tissue maxima. Similar uptake patterns for lysine shown by shrimp fed the intact and crystalline lysine‐supplemented diet indicate the potential use of small amounts of crystalline lysine in shrimp feeds. 相似文献
78.
基于修正双作物系数模型估算温室黄瓜不同季节腾发量 总被引:6,自引:5,他引:1
为估算温室黄瓜植株蒸腾与土面蒸发,该研究基于FAO-56推荐的双作物系数模型,应用温室内实测微气象、叶面积指数(LAI)及土壤水分数据,对模型中基础作物系数(Kcb)和土面蒸发系数(Ke)进行修正,并基于修正后FAO-56Penman-Monteith(P-M)模型,确定温室参考作物蒸发蒸腾量(ET0),进而估算温室黄瓜蒸发蒸腾量(ETc)和植株蒸腾(Tr)。基于Venlo型温室内黄瓜不同种植季节(春夏季和秋冬季)Lysimeter和茎流计观测的黄瓜ETc和Tr,对修正后的双作物系数模型预测结果进行验证。结果表明,应用修正后的双作物系数模型估算的温室黄瓜ETc和Tr与实测值具有较好地一致性,春夏季温室黄瓜全生育期ETc估算值与实测值的日均值分别为3.05和2.94 mm/d,秋冬季分别为2.53和2.76 mm/d。修正后的双作物系数模型估算春夏季温室黄瓜日ETc的决定系数(R2)、均方根误差(RMSE)和模型效率系数(Ens)分别为0.95、0.41 mm/d和0.93;估算秋冬季ETc的误差计算结果依次为0.91(R2)、0.48 mm/d(RMSE)和0.90(Ens)。修正后的双作物系数模型估算春夏季日平均Tr与实测值分别为2.37和2.19mm/d,秋冬季分别为1.43和1.34 mm/d。研究结果还显示,不同种植季节温室黄瓜全生育期日平均Tr占ETc的比例分别为64.62%(春夏季)和68.59%(秋冬季)。该研究成果不仅为制定准确的温室黄瓜灌溉制度提供了理论依据,而且对实现温室环境智能化控制及减少温室内无效的土面蒸发具有重要意义。 相似文献
79.
微喷灌结合滴灌对温室高温环境和作物生长生理特性的影响 总被引:4,自引:3,他引:1
微喷灌结合滴灌是指在作物根区滴灌的基础上对作物冠层进行微喷灌来改善作物生长环境的一种灌水方式。为了探明微喷灌结合滴灌(micro-sprinkler irrigation combined with drip irrigation,MSDI)和地表滴灌(surface drip irrigation,SDI)2种灌水方式下温室高温环境及作物生长生理特性的差异及响应规律,该研究以黄瓜为试验对象,于2017年2-6月开展了2种灌水方式下温室环境及黄瓜生长生理特性的观测试验。结果表明:在改变温室环境方面,MSDI灌水方式较SDI可增加温室内相对湿度,降低气温,同时降低叶片温度约4℃;在作物生长生理特性方面,采用MSDI可增加黄瓜株高与茎粗,降低作物茎流速率,促进黄瓜生长;2种灌水方式下黄瓜最大光合效率几乎一致,分别为0.74和0.77,但日平均实际光合效率差异明显,分别为0.57和0.47,MSDI灌水方式下黄瓜叶片日平均气孔导度和光合速率比SDI方式分别高182.8%和92.4%。该研究成果对于合理调控温室高温环境、提高温室作物产量具有重要的指导意义。 相似文献
80.