Application of the Soil and Water Assessment Tool (SWAT) to predict the impact of alternative management practices on water quality and quantity   总被引：10，自引：0，他引：10  

Antje Ullrich  Martin Volk 《Agricultural Water Management》2009,96(8):1207-1217

Alternative land management practices such as conservation or no-tillage, contour farming, terraces, and buffer strips are increasingly used to reduce nonpoint source and water pollution resulting from agricultural activities. Models are useful tools to investigate effects of such management practice alternatives on the watershed level. However, there is a lack of knowledge about the sensitivity of such models to parameters used to represent these conservation practices. Knowledge about the sensitivity to these parameters would help models better simulate the effects of land management. Hence, this paper presents in the first step a sensitivity analysis for conservation management parameters (specifically tillage depth, mechanical soil mixing efficiency, biological soil mixing efficiency, curve number, Manning's roughness coefficient for overland flow, USLE support practice factor, and filter strip width) in the Soil and Water Assessment Tool (SWAT). With this analysis we aimed to improve model parameterisation and calibration efficiency. In contrast to less sensitive parameters such as tillage depth and mixing efficiency we parameterised sensitive parameters such as curve number values in detail.In the second step the analysis consisted of varying management practices (conventional tillage, conservation tillage, and no-tillage) for different crops (spring barley, winter barley, and sugar beet) and varying operation dates. Results showed that the model is very sensitive to applied crop rotations and in some cases even to small variations of management practices. But the different settings do not have the same sensitivity. Duration of vegetation period and soil cover over time was most sensitive followed by soil cover characteristics of applied crops.  相似文献   

Effects of sex and age on behavior and weight gain in beef calves after abrupt weaning          下载免费PDF全文

Christian Lambertz  Antje Farke‐Röver  Matthias Gauly 《Animal Science Journal》2015,86(3):345-350

The effects of weaning on beef calves of different ages were investigated. Forty male and 40 female calves were either weaned at 6 (W6, n = 40) or 8 (W8, n = 40) months of age. The vocalization activity and behaviors (feeding, lying and standing/walking) were observed during the first 3 days following weaning. Body weight was recorded at 6 and 8 months and 2 weeks following weaning. W6 animals vocalized more often than W8 calves and females more than males on day 1 (P < 0.05). The vocalization activity decreased at a higher rate in W8 than in W6 from days 1 to 3. On day 2, W6 calves spent less time lying and more standing/walking than W8 calves (P < 0.05). The behaviors did not differ between males and females. The average daily gain after weaning did not differ between weaning ages (P > 0.05), but W8 calves gained more from 6 to 8 months of age. In conclusion, weaning distress was more pronounced in W6 than in W8 calves. W8 calves also had a superior growth performance during 6 to 8 months of age. The effect of the calves' sex was less pronounced. Therefore, it is recommended to wean beef calves later than 6 months of age.  相似文献   

Ultrasonographic appearance of intestinal roundworms in a dog and a cat     

Wigger A  Peppler C  Kramer M 《The Veterinary record》2007,161(6):200-201

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Temperature signals contribute to the timing of photoperiodic growth cessation and bud set in poplar     

Rohde A  Bastien C  Boerjan W 《Tree physiology》2011,31(5):472-482

Bud set, the cornerstone delimiting the seasonal growth period in trees, is the dynamic net result of the often photoperiod-controlled growth cessation and the subsequent bud formation. Here, we show that in hybrid poplar, the critical day length for growth cessation and the duration of bud formation each vary with local climatic conditions in identical genotypes. The detailed dissection of bud set suggests temperature as one additional environmental factor that modifies the sensitivity to day-length signals at growth cessation and influences the duration of bud formation in poplar. The ability of perennial plants to integrate additional environmental signals with photoperiod signaling may add to short-term acclimatization to the predicted longer growing seasons in future climates.  相似文献   

Cleavage products of lycopene produced by in vitro oxidations: characterization and mechanisms of formation     

Caris-Veyrat C  Schmid A  Carail M  Böhm V 《Journal of agricultural and food chemistry》2003,51(25):7318-7325

The aim of this study was to produce in vitro oxidation products of lycopene, which could be possible in vivo metabolites. An oxidation of lycopene with potassium permanganate gave a range of lycopene degradation compounds resulting from the oxidative cleavage of one or two carbon-carbon double bonds. Eleven apo-lycopenals/ones and six apo-carotendials were obtained and tentatively characterized by HPLC-DAD-MS. Apo-11-lycopenal and apo-8,6'-carotendial were isolated and characterized by (1)H NMR for the first time. Lycopene was submitted to an oxidation by atmospheric oxygen catalyzed by a metalloporphyrin, a model system of the active center of cytochrome P450 enzymes. (Z)-Isomers, monoxides, and cleavage compounds of (E)-lycopene were formed. We propose a mechanism of oxidation of lycopene by this system.  相似文献   

Ultrasonographic appearance of the craniocervical junction in normal brachycephalic dogs and dogs with caudal occipital (Chiari-like) malformation     

Martin J Schmidt  Antje Wigger  Sebastian Jawinski  Tanja Golla  Martin Kramer 《Veterinary radiology & ultrasound》2008,49(5):472-476

Ultrasonographic evaluation of the spine, especially of the spinal cord, has been rarely reported in dogs. The atlanto-occipital junction provides a small acoustic window through which examination of the craniocervical transition can be performed. Normal sonographic findings of this region in 10 normal brachycephalic dogs are presented and compared with sonographic findings from 25 Cavalier King Charles Spaniels with the caudal occipital malformation syndrome. Sonographic findings were compared with magnetic resonance imaging findings to determine the extent of cerebellar herniation and syringohydromyelia. Cerebellar displacement into the foramen magnum was clearly identified sonographically; however, syringohydromyelia was not discernable due to bone overlay.  相似文献   

Sustainable Aquaculture Products: Implications of Consumer Awareness and of Consumer Preferences for Promising Market Communication in Germany     

Katrin Zander  Antje Risius  Yvonne Feucht  Meike Janssen  Ulrich Hamm 《Journal Of Aquatic Food Product Technology》2018,27(1):5-20

Sustainability issues are becoming increasingly important in Western food consumption. This research aims at identifying ways to increase the market share of sustainable fish from aquaculture by analyzing consumer awareness and preferences for sustainable aquaculture products and by drawing conclusions on improving communication in the German market. An integrative research approach was used: it began with an inventory of sustainable seafood products on the German market, followed by qualitative and quantitative consumer research, and ending with a stakeholder workshop, which reflected on the research outcome with practitioners. Sustainability and country of origin proved to be of minor relevance to the vast majority of the consumers interviewed. Indeed, attributes such as freshness, taste, and price frequently ranked higher. Like most of the other consumers, the small consumer segment that is generally interested in sustainability issues of food also often lacks knowledge of fish farming and its products. Consequently, communication of sustainability in aquaculture is challenging, and the development of this market requires concerted actions along the whole value chain, with the retail sector as the main actor.  相似文献   

Binding of the respiratory chain inhibitor ametoctradin to the mitochondrial bc1 complex          下载免费PDF全文

Marcus Fehr  Antje Wolf  Gerd Stammler 《Pest management science》2016,72(3):591-602

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Wheat yellow mosaic virus resistance in wheat cultivar Madsen acts in roots but not in leaves     

Cheng Liu  Takako Suzuki  Kohei Mishina  Antje Habekuss  Angelika Ziegler  Chao Li  Shun Sakuma  Guoxiong Chen  Mohammad Pourkheirandish  Takao Komatsuda 《Journal of General Plant Pathology》2016,82(5):261-267

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Duration of the effects of anionic salts on the acid–base status in cows fed different anionic salts only once daily     

Carl-Christian Gelfert  Antje Lptien  Nicole Montag  Rudolf Staufenbiel 《Research in veterinary science》2009,86(3):529-532

Seeing the fact that farm managers in Germany feed anionic salts to transition cows once daily, this study set out to evaluate whether the effects on the acid–base status (ABS) and calcium excretion in urine would persist throughout the entire day beyond this feeding practice. Eleven non-lactating, non-pregnant, Holstein–Friesian-cows with a rumen fistula were administered 2Eq of calcium chloride (CaCl₂/five cows) or calcium sulfate (CaSO₄/six cows) once daily for a period of 1 week. At day 7, blood and urine samples were taken every 4 h starting at 06:00 a.m. before feeding the anionic salts, and then ending at the same time the next day. Feeding anionic salts to the cows induced metabolic acidosis in both of the groups. The changes tended to be greater in CaCl₂-cows. After 12 h, the acidosis lessened and the initial values were reached after 24 h. The CaCl₂-cows, however, still showed signs of compensated metabolic acidosis. The results of the present study showed that feeding anionic salts once daily confined the risk of an interrupted effect of the anionic salts on the acid–base status as well as calcium metabolism after 12 h.  相似文献