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排序方式: 共有137条查询结果,搜索用时 15 毫秒
11.
Gabriela Vargas Jos Verdejo Adrian Rivera Domingo Surez Cristian Youlton Juan L. Celis-Diez Yves Le Bissonnais Elvira A. Dovletyarova Alexander Neaman 《植物养料与土壤学杂志》2019,182(2):159-166
The structural stability of soil is a physical characteristic that affects soil degradation processes. Calcium‐based amendments, such as calcium carbonate, calcium sulfate, and calcium oxide/hydroxide, have been shown to improve the stability of soil aggregates. This study seeks to determine which calcium‐based soil amendments, and at what concentration, are the most efficient in improving aggregate stability of sandy topsoils derived from granitic and metamorphic parent materials, and to analyze the mechanisms involved. In the pot experiment, soils amended with CaCO3, CaCl2, and CaSO4 did not present significant differences in aggregate stability compared to the control or among each other. In contrast, Ca(OH)2 soil amendment brought the greatest stability to the soil aggregates. A dose of 1% Ca(OH)2 significantly increased the stability of soil aggregates. This effect is due to the reaction of Ca(OH)2 with atmospheric CO2 which leads to the formation of CaCO3, a delayed reaction not showed by the other soil amendments tested. Likewise, the greater solubility of Ca(OH)2 compared to CaCO3 exerts a greater aggregation effect on soil. Thus, the mechanism of action of Ca(OH)2 is related to cementation, rather than flocculation. Future studies should be carried out to demonstrate the effectiveness of Ca(OH)2 under field conditions. 相似文献
12.
Decisions resulting from multi-objective planning models are quite sensitive to objective weights, and the latter are hard to determine accurately. We describe a robust formulation of a bi-objective multi-period planning problem where objective weights are random, independent and uniformly distributed in a predetermined range. We apply this model to a 245,090 ha forest in British Columbia, Canada, where the amount of employment and the proportion of old forest through the planning horizon are the two management objectives. Evaluated under simulated scenarios of weights, robust solutions produce more stable weighted sum of the objectives through the planning periods than traditional deterministic solutions. In other words, no large changes in the weighted sum of the objectives are expected even when the weights change over time. With this approach, we envision that these types of decisions will be better accepted by stakeholders and other social actors involved in the decision-making process. 相似文献
13.
Bird Michael G. Hardner Craig M. Dieters Mark Heberling Mónica Montouto Cristian Arnold Roger J. Ruiz Federico Schapovaloff Juan Gore Peter L. 《New Forests》2022,53(1):101-123
New Forests - Eucalyptus dunnii Maiden (Dunn’s white gum) is a fast-growing tall tree with a restricted natural distribution in south-east Australia and favorable wood properties for pulp... 相似文献
14.
Faridy Juárez-Chairez Milagros Stephanie Cid-Gallegos María Gabriela Meza-Márquez Ofelia Cristian Jiménez-Martínez 《Plant foods for human nutrition (Dordrecht, Netherlands)》2020,75(2):142-153
Plant Foods for Human Nutrition - Chickpea is one of the most consumed legumes worldwide. Among their benefits are the high protein concentration that reflects not only at the nutritional level but... 相似文献
15.
16.
Mocuta C Reichert H Mecke K Dosch H Drakopoulos M 《Science (New York, N.Y.)》2005,308(5726):1287-1291
By focusing a highly brilliant synchrotron x-ray beam to a micrometer spot on a sample, we measured in real time the x-ray intensity fluctuations associated with order fluctuations in crystalline materials. We applied this method to the binary alloy Fe3Al near its continuous A2-B2 phase transformation and determined a specific four-point time correlation function for the order parameter. From a detailed theoretical analysis, dynamical scaling in the time domain with a transition from noncritical to critical dynamics is disclosed. 相似文献
17.
Fernando R Silva‐Aciares Paolo O Carvajal Cristian A Mejías Carlos E Riquelme 《Aquaculture Research》2011,42(7):953-961
In this study, we evaluate the use of macroalgae as vectors of probiotics bacteria into the digestive tract of abalone to improve their survival and growth. It is shown that when abalone Haliotis rufescens of different sizes were fed with a natural diet composed of fronds of the macroalga Macrocystis integrifolia supplemented with a mixture of Vibrio sp. C21‐UMA, Agarivorans albus F1‐UMA and Vibrio sp. F15‐UMA bacteria, there was a significant increase (P<0.05) in the average monthly growth rate and survival (%)in a period of 210 days, compared with the control without a probiotic supplement. The permanence of the probiotics in the digestive tract of the animals was monitored, and it was found that the number of culturable C21‐UMA and F1‐UMA bacteria decreased significantly (P<0.05) in recently weaned and adult abalone, and they almost disappeared completely on day 19 of the bioassay. However, the culturable Vibrio sp. F15‐UMA disappeared completely from the digestive tract on day 22 of the bioassay, and these were the bacteria that remained at the highest concentration compared with the other two bacterial strains over the experimental period. It is therefore shown that it is feasible to use a probiotic mixture to improve the profitability of the H. rufescens culture. 相似文献
18.
Gabriel Amar‐Basulto Fabiola Lafarga‐De la Cruz Patricia Iturra‐Constant Cristian Gallardo‐Escárate 《Aquaculture Research》2011,42(10):1460-1466
Evidence of hybridization in Haliotis has been mainly supported by hatchery experiences and collection of wild hybrid abalones among several species from natural populations worldwide. However, despite the importance to understand the role of the hybridization process through Haliotidae evolution, and also its impact on the abalone aquaculture, genetic studies in hybrid abalones have been poorly developed. Herein, cytogenetic approach allows studying the genetic conformation in hybrid organisms at the chromosome level. This paper reports a quantitative karyotype analysis in Haliotis rufescens, Haliotis discus hannai and their interspecific hybrid. Thus, to characterize chromosome pairs and establish cytogenetic comparisons, chromosome banding with distamycin‐A/4,6‐diamidino‐2‐phenylindole fluorochromes and morphologic measurements were performed. The results showed that the hybrids are successfully viable and their karyotypes evidenced a conservative chromosome number of 2n=36. The karyo‐idiogram showed a high correspondence in chromosome pair morphology among the hybrids and their parental species, except for a single heteromorphic pair that corresponds to the chromosome 16 from H. rufescens andH. d. hannai respectively. The implications of the abalone hybrid viability derived from its chromosome composition are discussed. 相似文献
19.
Elva Mayra Toledo‐Cuevas Francisco J Moyano López Dariel Tovar Ramírez Carlos A Strüssmann Carlos Alfonso Álvarez‐González Carlos Cristian Martínez‐Chávez Carlos A Martínez‐Palacios 《Aquaculture Research》2011,42(6):776-786
The early development of the digestive biochemistry of three cultured Atherinopsids (two Odontesthes species and Chirostoma estor) was investigated. Relatively high lipolytic and high alkaline proteolytic activities were found in all species. In addition, gene expression of lipase and trypsin during the early development of C. estor not only indicates an early onset of the lipase activity but also demonstrates a major importance of protein digestion in this species. However, despite all of them share similar habitats, differences in their digestive activities were evident. The rise in the activities of brush border membrane enzymes correlated with the decrease in cytosolic activities, used as indicator of maturation of the digestive tract, was detected in both species of Odontesthes at 9 weeks after hatching. In contrast, no similar signs were measured in C. estor, this being in agreement to the long weaning period (nearly 5 months) reported for this species. 相似文献
20.
Margarita P. Gonzlez Gmez Loreto Ovalle Mylena Menanteau Claudia Spinetto Renato Oyarzún Mario Rivas Cristian Oyarzo 《Journal of fish diseases》2019,42(8):1143-1149
A major challenge for Chilean salmon farming is infestation by the ectoparasite Caligus rogercresseyi. In addition, there is evidence that a loss of chemotherapeutic treatment efficacy against important fish pathogens is occurring in salmon farming, including antiparasitic efficacy. Currently, there are known techniques that allow the determination of the susceptibility profile of parasites to antiparasitic treatment. However, there is scarce information about both threshold values and categorization of antiparasitic susceptibility for C. rogercresseyi. Bioassay technique allowed the determination of both mean values and the natural variation of EC50%, which were contrasted with available susceptibility thresholds. Results allowed to determine that parasites from the native fish host, Eleginops maclovinus, are susceptible to azamethiphos, deltamethrin and cypermethrin treatments, showing a high susceptibility profile to antiparasitics. 相似文献