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排序方式: 共有498条查询结果,搜索用时 156 毫秒
431.
Alejandro Moreno-Reséndez Homero Meza-Morales Norma Rodríguez-Dimas José Luis Reyes-Carrillo 《Journal of plant nutrition》2013,36(11):1672-1680
In order to evaluate vermicompost:sand mixtures on the development of muskmelon under greenhouse conditions, four periods of watering were applied. Four types of vermicompost (VC) mixed with sand (S): 25:75, 30:70, 35:65 and 40:60 (VC:S;%:% by volume) were used. Each mixture, due to the water-holding capacity of VC, was watered at 24, 48, 72, or 96 h respectively. The watering each 96 h and the mixture VC:S, independent of the manure type used to prepare the VC, had favorable effect on yield, fruit weight, equatorial and polar diameters, pulp thickness, placenta cavity, fruits per plant, and days to harvest (74.39 t·ha?1, 1,334.00 g·fruit?1, 13.27, 14.79, 3.42, and 5.11 cm, 15 fruits, 94.6 days average, respectively). Since synthetic fertilizers were not used during the crop growth and the vegetative and reproductive cycle were completed it is possible to conclude that the VC: S mixtures satisfied the muskmelon nutrimental requirements. 相似文献
432.
Sergio Zeferino Garza-Vara Juan Francisco Pissani-Zuñiga Alejandro Isabel Luna-Maldonado Emilio Olivares-Saenz Daniel Gómez-García Javier de Jesús Cortés-Bracho 《Paddy and Water Environment》2013,11(1-4):423-431
The basic concepts from a hydraulic and mathematical point of view were introduced to describe the operation of a hydraulic branched network of water distribution. Moreover, each one of the elements (simples and complex) of the system was identified. Classic hydraulic equations were inputted to apply them to branched networks and obtain a standard solution. A set of linear and non-linear equations, through the Newton–Raphson method with the jacobian matrix were required to solve the branched network that interconnects two kinds of very different pumps: a volute type centrifugal pump and another one is submersible pump, both of them installed in a deep well. The system is a branched network with two nodes and five pipe lines, to adequately supply two pressure irrigation systems: a central pivot and a semi-portable sprinkler, where the pumps are located in different places and heights. The solution was obtained by solving a system of two linear equations and three non-linear, simultaneously. 相似文献
433.
Daniela T Pezzini Dominic D Reisig G David Buntin Alejandro I Del Pozo-Valdivia Fred Gould Silvana V Paula-Moraes Francis PF Reay-Jones 《Pest management science》2023,79(10):3493-3503
BACKGROUND
Helicoverpa zea, an economic pest in the south-eastern United States, has evolved practical resistance to Bacillus thuringiensis (Bt) Cry toxins in maize and cotton. Insect resistance management (IRM) programs have historically required planting of structured non-Bt maize, but because of its low adoption, the use of seed blends has been considered. To generate knowledge on target pest biology and ecology to help improve IRM strategies, nine field trials were conducted in 2019 and 2020 in Florida, Georgia, North Carolina, and South Carolina to evaluate the impact of Bt (Cry1Ab + Cry1F or Cry1Ab + Cry1F + Vip3A) and non-Bt maize plants in blended and structured refuge treatments on H. zea pupal survival, weight, soil pupation depth, adult flight parameters, and adult time to eclosion.RESULTS
From a very large sample size and geography, we found a significant difference in pupal mortality and weight among treatments in seed blends with Vip3A, implying that cross-pollination occurred between Bt and non-Bt maize ears. There was no treatment effect for pupation depth, adult flight distance, and eclosion time.CONCLUSION
Results of this study demonstrate the potential impact of different refuge strategies on phenological development and survival of an important pest species of regulatory concern. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. 相似文献434.
Román B Vercellino Fernando Hernández Claudio Pandolfo Soledad Ureta Alejandro Presotto 《Pest management science》2023,79(3):922-934
Agricultural weeds descended from domesticated ancestors, directly from crops (endoferality) and/or from crop–wild hybridization (exoferality), may have evolutionary advantages by rapidly acquiring traits pre-adapted to agricultural habitats. Understanding the role of crops on the origin and evolution of agricultural weeds is essential to develop more effective weed management programs, minimize crop losses due to weeds, and accurately assess the risks of cultivated genes escaping. In this review, we first describe relevant traits of weediness: shattering, seed dormancy, branching, early flowering and rapid growth, and their role in the feralization process. Furthermore, we discuss how the design of “super-crops” can affect weed evolution. We then searched for literature documenting cases of agricultural weeds descended from well-domesticated crops, and describe six case studies of feral weeds evolved from major crops: maize, radish, rapeseed, rice, sorghum, and sunflower. Further studies on the origin and evolution of feral weeds can improve our understanding of the physiological and genetic mechanisms underpinning the adaptation to agricultural habitats and may help to develop more effective weed-control practices and breeding better crops. © 2022 Society of Chemical Industry. 相似文献
435.
Sánchez-Cordón PJ Cerón JJ Núñez A Martínez-Subiela S Pedrera M Romero-Trevejo JL Garrido MR Gómez-Villamandos JC 《American journal of veterinary research》2007,68(7):772-777
OBJECTIVE: To determine serum concentrations of the selected acute-phase proteins (APPs) haptoglobin, serum amyloid A (SAA), and C-reactive protein (CRP) in pigs experimentally inoculated with classical swine fever (CSF) and African swine fever (ASF) viruses. ANIMALS: 8 crossbred (Large White x Landrace) 10-week-old pigs. PROCEDURES: Pigs were allocated to 2 groups (4 pigs/group). One group was inoculated with the CSF virus Alfort 187 strain, whereas the other groupwas inoculated with the ASF virus Spain 70 isolate. Blood samples were collected at various time points. At the end of the study, pigs were euthanized and a complete necropsy was performed, including histologic and immunohistochemical analyses. RESULTS: Serum concentrations of APPs increased in pigs inoculated with CSF and ASF viruses, which suggested an acute-phase response in the course of both diseases. The most noticeable increase in concentration was recorded for SAA in both groups (up to a 300-fold increase for CSF virus and an approx 40-fold increase for ASF virus), followed by CRP and then haptoglobin, which each had only 3- to 4-fold increases. CONCLUSIONS AND CLINICAL RELEVANCE: Serum concentrations of APPs increased significantly in pigs inoculated with CSF and ASF viruses. However, differences were evident in serum concentrations of the proteins evaluated in this study. 相似文献
436.
437.
Erika ORNELAS-EUSEBIO Alejandro OBREGóN-ASCENCIO Fernando CHáVEZ-MAYA Gary GARCíA-ESPINOSA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(3):365-369
Wild waterfowl and their habitats are the main reservoirs of influenza A virus (IAV)
mainly during the breeding season and prior to migration. This study describes the
molecular characterization of an IAV isolated from 240 water samples of a small wetland
during non-breeding season of migratory wild ducks in the State of Mexico, Mexico. The
results showed that the virus belongs to the H4N2 subtype and each of its eight segments
of the viral genome has similarity to IAV isolated from ducks in North America. This study
suggests that IAV can be isolated from small wetland during non-breeding season of
migrating waterfowl. 相似文献
438.
EFFECTS OF TWO DIFFERENT ANESTHETIC PROTOCOLS ON CARDIAC FLOW MEASURED BY TWO DIMENSIONAL PHASE CONTRAST MAGNETIC RESONANCE IMAGING
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Randi Drees Rebecca A. Johnson Rebecca L. Stepien Alejandro Munoz Del Rio Christopher J. François 《Veterinary radiology & ultrasound》2015,56(2):168-175
Companion animals are routinely anesthetized or heavily sedated for cardiac MRI studies, however effects of varying anesthetic protocols on cardiac function measurements are incompletely understood. The purpose of this prospective study was to compare effects of two anesthetic protocols (Protocol A: Midazolam, fentanyl; Protocol B: Dexmedetomidine) on quantitative and qualitative blood flow values measured through the aortic, pulmonic, mitral, and tricuspid valves using two‐dimensional phase contrast magnetic resonance imaging (2D PC MRI) in healthy dogs. Mean flow per heartbeat values through the pulmonary artery (Qp) and aorta (Qs) were compared to right and left ventricular stroke volumes (RVSV, LVSV) measured using a reference standard of 2D Cine balanced steady‐state free precession MRI. Pulmonary to systemic flow ratio (Qp/Qs) was also calculated. Differences in flow and Qp/Qs values generated using 2D PC MRI did not differ between the two anesthetic protocols (P = 1). Mean differences between Qp and RVSV were 3.82 ml/beat (95% limits of agreement: 3.62, ?11.26) and 1.9 ml/beat (?7.86, 11.66) for anesthesia protocols A and B, respectively. Mean differences between Qs and LVSV were 1.65 ml/beat (?5.04, 8.34) and 0.03 ml/beat (?4.65, 4.72) for anesthesia protocols A and B, respectively. Mild tricuspid or mitral reflux was seen in 2/10 dogs using 2D PC MRI. No aortic or pulmonic insufficiency was observed. Findings from the current study indicated that these two anesthetic protocols yield similar functional measures of cardiac blood flow using 2D PC MRI in healthy dogs. Future studies in clinically affected patients are needed. 相似文献
439.
Singh AP Bertoli C Rousset PR Marangoni AG 《Journal of agricultural and food chemistry》2004,52(6):1551-1557
This study demonstrates how chemically interesterified hydrogenated palm oil (IHPO) and partially hydrogenated palm oil (PHPO) can be structured to have similar mechanical properties. Crystallization of IHPO at 30 degrees C for 24 h yielded a fat with a solid fat content (SFC) of 45% and a yield force of 51.5 N. On the other hand, PHPO had a SFC of 50% and a yield force of 44 N when crystallized under the same conditions. The result was opposite from what would be expected from the SFC point of view, thus suggesting that the microstructure of the fat plays a key role in determining mechanical properties. By matching crystallization behavior using the Avrami index as a guide, microstructures and material hardness were successfully matched. These results suggest that the dynamics of structure formation was a key factor influencing the macroscopic mechanical properties of palm oil-based fats. 相似文献
440.
Sinagawa-García SR Rascón-Cruz Q Valdez-Ortiz A Medina-Godoy S Escobar-Gutiérrez A Paredes-López O 《Journal of agricultural and food chemistry》2004,52(9):2709-2714
Prospective testing for allergenicity of proteins obtained from sources with no prior history of causing allergy has been difficult to perform. Thus, the objective of this work was to assess the food safety of genetically modified maize with an amaranth globulin protein termed amarantin. Transgenic maize lines evaluated showed, in relation to nontransgenic, 4-35% more protein and 0-44% higher contents of specific essential amino acids. Individual sequence analysis with known amino acid sequences, reported as allergens, showed that none of these IgE elicitors were identified in amarantin. Amarantin was digested within the first 15 min by Simulated Gastric Fluid treatment as observed by Western blot. Expressed amarantin did not induce important levels of specific IgE antibodies in BALB/c mice, as analyzed by ELISA. We conclude that the transgenic maize with amarantin is not an important allergenicity inducer, just as nontransgenic maize. 相似文献