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91.
Pascal Jouquet Ga?lle Huchet Nicolas Bottinelli Thuy Doan Thu Toan Tran Duc 《Biology and Fertility of Soils》2012,48(5):561-567
Soil compaction has a negative impact on both earthworm abundance and diversity. Recent studies, however, suggest that earthworm cast properties are not influenced by the initial soil bulk density. With time, earthworms could therefore transform soils with different bulk densities into a soil with the same physical state and thus with a similar ecological functioning. This study aimed to test this hypothesis in two laboratory incubation experiments. First, we measured the influence of soil bulk density (1.1 or 1.4?g?cm?3) on the production of cast by the endogeic earthworm species Metaphire posthuma. In a second experiment, we investigated the effect of M. posthuma on water infiltration, NH 4 + , and NO 3 ? leaching and soil respiration at the same two soil bulk densities. Although initially higher, earthworm casting activity in soil at 1.4?g?cm?3 decreased until it reached the same level of activity as earthworms in soil at 1.1?g?cm?3. This behavioral plasticity led to a transformation of compacted and loose soils, with their own functioning, to a third and similar state with similar hydraulic conductivity, nitrogen leaching, and soil respiration. The consequences for soil organization and soil functioning are discussed. 相似文献
92.
Do?Thi?XuanEmail author Vo?Thi?Guong Anna?Rosling Sadhna?Alstr?m Benli?Chai Nils?H?gberg 《Biology and Fertility of Soils》2012,48(2):217-225
Intensive cropping, especially of rice, is considered to contribute to negative effects not only on soil chemical and biological
properties but also on long-term grain yield. Appropriate crop rotation is often practiced as an alternative strategy to overcome
the negative side effects of intensive cropping. Although soil microbial diversity and community structure have been shown
to respond differently to altered agricultural management practices, little is known about possible links between crop rotation
and grain yield on bacterial communities in rice paddy soil. In this study, we investigated the impact of specific rotational
crops and compared it with intensive rice cultivation. The main crop rice (Oryza sativa) was rotated with maize (Zea mays) and mungbean (Phaseolus aureus) in different combinations in a system cultivating three crops per year. Soil bacterial communities were studied in two different
cropping periods using pyrosequencing of the variable V4 region of the 16S rRNA. Our results showed that rotation with alternative
crops increased rice yield by 24–46% depending on rotation structure and that bacterial community structure was altered in
the presence of mungbean and/or maize compared to that in rice monoculture. In the crop rotation systems, composition, abundance,
and diversity of soil bacterial communities were significantly different and higher than those in rice monoculture. Our results
show that effects of crop rotation relate to changes in soil bacterial community structure suggesting that appropriate crop
rotations provide a feasible practice to maintain the equilibrium in soil microbial environment for sustainable rice cultivation. 相似文献
93.
以毛竹Phyllostachys edulis集成材为研究对象,在不同条件下进行高频热压,通过对竹集成材板坯高频热压过程中芯层温度变化的统计分析,得到了竹集成材高频热压过程中板坯温度的变化规律。结果表明:在试验条件范围内,随着板坯含水率从6%增加到18%,涂胶量从200 g·m-2增加到300 g·m-2,板坯的温度明显升高。升温过程可以分为快速升温和慢速升温2个阶段。在快速升温阶段板坯内的温度随板坯初含水率、涂胶量及加热时间的提高而递增;在慢速升温阶段板坯初含水率及涂胶量对板坯内的温度的影响很小,板坯芯层升温速度随加热时间的增加而减少。通过试验数据分析,得出较优的高频热压胶合工艺条件为:涂胶量300 g·m-2,竹条含水率12%,高频热压时间7 min。 相似文献
94.
Nhung Thi Nguyen Nguyen Xuan Bui Viet Linh Nguyen Van Khanh Nguyen Kazuhiro Kikuchi Hiep Thi Nguyen Hong Thi Nguyen Hoang Thinh Nguyen Quyen Van Dong Hoang Ha Chu Ngo Thi Kim Cuc Tamas Somfai 《Animal Science Journal》2020,91(1)
The Vietnamese Ban pig is a precious genetic resource that needs to be preserved. In vitro embryo production from in vitro matured (IVM) oocytes is an important tool for the utilization of cryopreserved porcine sperm. The aim of this study was to compare two media for the IVM of Ban pig oocytes. Immature oocytes were subjected to IVM either in a non‐defined (TCM‐199 + pig follicular fluid) or in a defined base medium (POM + epidermal growth factor). At the end of IVM, the oocytes were in vitro fertilized (IVF) with frozen Ban sperm. Ten hours after IVF, the oocytes were either subjected to orcein staining to check fertilization and maturation status or cultured in vitro for 7 days. There was no difference between the two IVM media in terms of percentages of oocyte maturation and blastocyst production. However, the percentage of male pronuclear formation after IVF and the total cell numbers in blastocysts were higher with the defined system. Zygotes obtained by the two IVM systems survived vitrification at similar rates. In conclusion, the two IVM systems were both effective for the production of Ban pig embryos; however, better embryo quality was achieved with the defined one. 相似文献
95.
A 16-wk growth trial was conducted to examine the effects of dietary replacement of fish meal by defatted soybean meal (SBM) and fermented soybean meal (FSBM) with taurine supplementation on growth performance, nutrient apparent digestibility coefficient (ADC) and biological parameters of pompano fish. The FSBM was produced by fermenting SBM with Lactobacillus spp. Seven isonitrogenous and isoenergetic diets were formulated to replace 35% or 50% of fish meal by SBM or FSBM with taurine supplementation. The diets are denoted as follows: FM, SBM35, SBM35T, FSBM35T, SBM50, SBM50T, and FSBM50T. The FM (the basal diet) contained fish meal as a main source of dietary protein. Taurine was supplemented to SBM35T, FSBM35T, SBM50T, and FSBM50T at the level of 15 g/kg diet. Pompano juveniles with an initial body weight (BW) of 80 g reared in floating net cages were fed the experimental diets twice daily for 16 wk. Results showed that the final BW, weight gain, and feed conversion ratio of fish fed SBM35 and SBM50 were significantly lower than those of fish fed FM (P < 0.05), indicating that the replacement of fish meal by SBM at the rate of 35% in the diet is excessive for pompano. Supplementation of taurine to the SBM-included diets significantly increased growth performance and feed utilization (P < 0.05); however, these diets did not restore the performance back to a level equivalent to that of fish offered the basal diet. Meanwhile, fish fed FSBM35T had comparable growth and feed performances to those fed FM. Hematocrit values, total biliary bile acid levels, whole body lipid contents, and tissue taurine concentrations of fish fed SBM35 and SBM50 were the lowest among the treatments, but these parameters were improved by taurine supplementation and FSBM inclusion in the diet. Taurine supplementation increased lipid ADC, and SBM fermentation slightly enhanced both lipid and protein ADCs of the fish. These findings suggest that the combination of FSBM and taurine supplementation is an effective way to improve growth performance, nutrient digestibility, and biological parameters, and that FSBM with taurine supplementation can replace 35% of fish meal in pompano diets without any negative effects on growth and feed performances in a long-term feeding period. 相似文献
96.
Nguyen Thi Thuy Man Dorny Pierre Lebailly Philippe Le Thi Minh Chau Nguyen Thi Thu Huyen Dermauw Veronique 《Tropical animal health and production》2020,52(6):2799-2808
Tropical Animal Health and Production - In Vietnam, pork is the most commonly consumed type of meat, and the demand is expected to rise even further. Nevertheless, food safety is a major concern,... 相似文献
97.
Olesya I. Zhuravleva Alexandr S. Antonov Vo Thi Dieu Trang Mikhail V. Pivkin Yuliya V. Khudyakova Vladimir A. Denisenko Roman S. Popov Natalya Y. Kim Ekaterina A. Yurchenko Andrey V. Gerasimenko Anatoly A. Udovenko Gunhild von Amsberg Sergey A. Dyshlovoy Shamil S. Afiyatullov 《Marine drugs》2021,19(1)
Seven new deoxyisoaustamide derivatives (1–7) together with known compounds (8–10) were isolated from the coral-derived fungus Penicillium dimorphosporum KMM 4689. Their structures were established using spectroscopic methods, X-ray diffraction analysis and by comparison with related known compounds. The absolute configurations of some alkaloids were determined based on CD and NOESY data as well as biogenetic considerations. The cytotoxic and neuroprotective activities of some of the isolated compounds were examined and structure-activity relationships were pointed out. New deoxyisoaustamides 4–6 at concentration of 1 µM revealed a statistical increase of PQ(paraquat)-treated Neuro-2a cell viability by 30–39%. 相似文献
98.
Lina Bernaola Molly Darlington Kadie Britt Patricia Prade Morgan Roth Adrian Pekarcik Michelle Boone Dylan Ricke Anh Tran Joanie King Kelly Carruthers Morgan Thompson John J Ternest Sarah E Anderson Scott W Gula Kayleigh C Hauri Jacob R Pecenka Sajjan Grover Heena Puri Surabhi Gupta Vakil 《Journal of insect science (Online)》2021,21(2)
The 2020 Student Debates of the Entomological Society of America (ESA) were live-streamed during the Virtual Annual Meeting to debate current, prominent entomological issues of interest to members. The Student Debates Subcommittee of the National ESA Student Affairs Committee coordinated the student efforts throughout the year and hosted the live event. This year, four unbiased introductory speakers provided background for each debate topic while four multi-university teams were each assigned a debate topic under the theme ‘Technological Advances to Address Current Issues in Entomology’. The two debate topics selected were as follows: 1) What is the best taxonomic approach to identify and classify insects? and 2) What is the best current technology to address the locust swarms worldwide? Unbiased introduction speakers and debate teams began preparing approximately six months before the live event. During the live event, teams shared their critical thinking and practiced communication skills by defending their positions on either taxonomical identification and classification of insects or managing the damaging outbreaks of locusts in crops. 相似文献
99.
Sponges are prolific sources of various natural products that have provided the chemical scaffolds for new drugs. The sponges of the genus Petrosia inhabit various regions and contain a variety of biologically active natural products such as polyacetylenes, sterols, meroterpenoids, and alkaloids. This review aims to provide a comprehensive summary of the chemical structures and biological activities of Petrosia metabolites covering a period of more than four decades (between 1978 and 2020). It is also described in this review that the major groups of metabolites from members of the genus Petrosia differed with latitude. The polyacetylenes were identified to be the most predominant metabolites in Petrosia sponges in temperate regions, while tropical Petrosia species were sources of a greater variety of metabolites, such as meroterpenoids, sterols, polyacetylenes, and alkaloids. 相似文献
100.