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This study aims to characterize salmonid manures and to determine their potential use in agricultural soils. Sampling was carried out below salmon and trout cages in farms located in lakes and in the sea in the South of Chile during 2002-2003. Manure was analyzed for macronutrients, micronutrients and heavy metals. Results showed a high variability between samples and differences between sea and lake manure. Dry matter contents were low averaging c. 12-15%. Manures showed low OM contents with values 相似文献   

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Soyfoods and soybean products: from traditional use to modern applications   总被引:3,自引:0,他引:3  
Soybean products (soyfoods), reported as potential functional foods, are implicated in several health-enhancing properties, such as easing the symptoms of postmenopausal women, reducing the risk of osteoporosis, preventing cardiovascular disease, and antimutagenic effects. Isoflavone, for example, is one of the most important compounds abundantly found in soybean, mainly accounting for the health-enhancing properties as mentioned earlier. However, most biological activities of isoflavones are mainly attributed to their aglycone forms. It has also been demonstrated that isoflavone aglycones are absorbed faster and in greater amount than their glycosides in human intestines. Fortunately, deglycosylation of isoflavones can be achieved during fermentation process by several strains such as lactic acid bacteria, basidiomycetes, filamentous fungus, and Bacillus subtilis with their β-glucosidase activity. This article presents an overview of soybean's chemistry, application, state-of-the-art advances in soybean fermentation processing and products as well as their applications in food and pharmaceutical industries. Different compounds, such as isoflavone, dietary fibers, and proteins which exhibit significant bioactivities, are summarized. The roles of different microorganisms in bioconversion and enhancement of bioactivities of fermented soybean are also discussed.  相似文献   

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Bacterial outputs from ponds and tanks used in intensive fish farming   总被引:2,自引:1,他引:1  
Abundance and activity of bacteria and extracellular enzyme activity, increased through fish ponds and tanks. Outputs of bacteria, glucose mineralization capacity and extracellular enzyme capacity, which originated in the ponds/tanks, were calculated. Management variables (i.e. total fish weight, fish number, feed weight) were found to be poor predictors of output variables.  相似文献   

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Butein (2′,3,4,4′-tetrahydroxychalcone), a simple chalcone derivative, occurs in many unrelated genera including Butea Dahlia, Coreopsis and Searsia. It is a reputed food additive and a common ingredient of botanicals used in herbal medicine formulations, particularly in Asian countries. Although a simple polyphenol, this molecule exhibits a range of pharmacological properties, most notably acting as a potent protein tyrosine kinase inhibitor and as an antineoplastic agent. Researchers have convincingly demonstrated that butein inhibits the epidermal growth factor receptor in HepG2 cells and the tyrosine-specific protein kinase activities of the epidermal growth factor receptor. In addition, it also exhibits promising anti-inflammatory, antidiabetic, antinephritic, antithrombin, anti-angiogenic and hepatoprotective activities in various animal models. Although this molecule is endowed with an impressive list of biological properties, which have acted as scientific support for its commercialization, there are no review articles that coherently discuss various aspects of this chalcanoid. This review aims to explore the pharmacological relevance of butein, together with its structure–activity relationships and mechanisms of action. In addition, the occurrence, chemical synthesis and biosynthesis of butein are discussed.  相似文献   

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正Dear Editor,Sex determination is highly plastic across vertebrates. The mechanisms of sex determination can be broadly divided into genetic sex determination (GSD) and environmental sex determination (ESD). GSD is the most popular sex-determining type in vertebrates, while ESD mainly occurred in  相似文献   

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Genetic Diversity of Darnel (Lolium temulentum L.) in Malo, Ethiopia Depends on Traditional Farming Systems. Economic Botany 58(4):568–577, 2004. Darnel (Lolium temulentum L.) is a mimic weed associated with wheat and barley cultivation. Mimic weeds have evolved along with cultivated crops. Human impact on the genetic diversity of agricultural weeds was elucidated using darnel as a model. Three strains in each field in Gaitza village, Malo region, Ethiopia were randomly sampled, and the genetic composition of 120 samples was analyzed using RAPD analysis. Genetic diversity and distances were calculated using Nei’s analysis, and cluster analysis was performed. These results indicated the occurrence of seed migration among the fields and a high genetic diversity of darnel in this region. Crop seed exchange and contamination of crop seeds with darnel seeds lead to the unintended artificial gene flow of darnel. Because darnel seeds and seedlings resemble their associated crop seeds and seedlings, traditional methods of crop cultivation have the unintended consequence of conserving the genetic diversity of darnel.  相似文献   

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A post-Pleistocene reduction trend in the dimensions of the masticatory complex followed the transition to agricultural lifestyle in several world regions. A major limitation of previous studies is large temporal gaps between the analyzed skeletal populations, which do not allow the detection and analysis of a diachronic morphological transition. In this work, we analyze a large number of specimens from the southern Levant, where agriculture first emerged in situ and for which there is a good diachronic sequence of the shift from a hunting-gathering way of life to a food producing, farming economy (12,000-7,000 uncalibrated bp). Changes in the masticatory complex are examined in the context of three prevailing dental reduction models: the Probable Mutation Effect (Brace,1963; Brace and Mahler,1971), Increasing Population Density Effect (Macchiarelli and Bondioli,1986) and Selective Compromise Effect (SCE) (Calcagno,1989). A series of linear regressions of dimension vs. time and coefficients of variation for each dimension are analyzed. Our results indicate significant reduction in the buccolingual but not mesiodistal dental dimensions and in the ramus breadth and anterior height dimensions of the mandible but not in its overall size. These findings, taken together with low coefficients of variation for the buccolingual dimensions, suggest selective pressure resulting in reduction of specific dimensions. The observed trend is in partial accordance with the SCE but differs from the trends observed in other regions, and is therefore best explained as a region-specific variant of the SCE.  相似文献   

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AIMS: To evaluate the intraspecific diversity of the fish pathogen Flavobacterium columnare. METHODS AND RESULTS: Genetic variability among Fl. columnare isolates was characterized using restriction fragment length polymorphism analysis of the 16S rDNA gene, intergenic spacer region (ISR) sequencing, and amplified fragment length polymorphism (AFLP) fingerprinting. Thirty Fl. columnare cultures isolated from different fish species and geographical origins as well as reference strains were included in the study. Fifteen isolates belonged to genomovar I while eleven were ascribed to genomovar II. Analysis of the ISR sequence confirmed the genetic differences between both genomovars but revealed a higher diversity among genomovar I isolates. The maximum resolution was provided by AFLP fingerprinting, as up to 22 AFLP profiles could be defined within the species. CONCLUSIONS: We confirmed the division of Fl. columnare isolates from cultured fish into different genogroups. We showed that both genomovars I and II are present in channel catfish from the US. We described a unique genetic group represented by four Fl. columnare isolates from tilapia in Brazil which appears to be related to both genomovars. We were able to further subdivide the species by analysing the ISR. Finally, the use of AFLP allowed us to fingerprint the species at clone level without losing the higher genetic hierarchy of genomovar division. SIGNIFICANCE AND IMPACT OF THE STUDY: This paper reports on an extensive assessment of the use of molecular tools for the study of the epidemiology of the fish pathogen Fl. columnare.  相似文献   

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稻渔综合种养的科学范式   总被引:2,自引:0,他引:2  
管卫兵  刘凯  石伟  宣富君  王为东 《生态学报》2020,40(16):5451-5464
21世纪是渔业的世纪。中国和世界水产业历经数十年的发展为人类应对食品危机做出了巨大贡献。然而,我国传统的水产业对产量的片面追求导致养殖环境日趋恶化,养殖生态系统不断退化,养殖业的可持续发展受到限制。传统稻田其氮素的流失亦是导致农业面源污染的主要原因之一。我国当前的环境问题源于复合生态系统演化进程的缺陷,解决当前的环境问题,必须从优化复合生态系统演化进程着眼。采用优化的生态循环水产养殖模式,如综合水产养殖则可以大大提高氮、磷等养分物质的利用率。稻渔综合种养是一种科学的复合生态模式,可以概括为三种模式,一种是在我国传统稻田养鱼的基础上,逐步发展起来的一种稻渔共生模式,可采取稻鱼、稻蟹、稻虾等多种共作形式;二是稻田作为湿地用于处理水产养殖尾水的模式,属于异位处理形式;三是将稻渔共生和水产养殖相耦合的模式,尤其是与多种水产养殖形式结合或与复合水产养殖系统相结合,甚至是与农牧系统相结合。这第三种稻渔共作模式又称为陆基生态渔场,具有高产、高品质、高生态可持续性等特点,应加强对该创新养殖模式中有机碳、氮、磷等营养收支平衡和循环利用的相关机制以及复合生态系统对外源营养输入的整体响应机制开展研究。概括而...  相似文献   

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Demersal, non-cryptic, wild fishes were counted in replicate 100 m2 transects beneath a floating sea-cage fish farm and two nearby sandy locations at Gran Canaria (Canary Islands, eastern Atlantic) four times before and after the cessation of farming. Cessation of farming involved the removal of farmed fishes and ceasing of the daily feeding, although farm structures (cages and moorings) remained. A 'beyond-BACI' sampling design provided the framework to detect the effect of the cessation of farming, which produced qualitative and quantitative changes in the composition and structure of the fishes assemblages beneath the sea-cage fish farm compared with two nearby controls. The aggregative effect on wild fishes due to the existence of the farm decreased from c. 50 times compared to nearby controls when the farm was in full operation to less than two times when only the farm structures remained. Abundances of particulate organic matter feeders (large-sized mugilids), large benthic chondrichthyid rays and Pagellus spp. declined markedly at the fish farm after the cessation of farming, suggesting that the removal of daily feeding was responsible for their disappearance. In contrast, abundances of herbivores, benthic macro- and meso-carnivores were similar beneath the fish farm both before and after the cessation of farming. Benthic macro-carnivores, however, were more abundant beneath the sea-cages compared to control locations, supporting the hypothesis that the increase in the physical structure beneath farms plays a role in aggregating these species. Sparids occurred beneath the sea-cages only after the cessation of farming, while the two natural control locations did not show differences from before to after the cessation of farming. Overall, the results show that the wild fish assemblage beneath the farm partially changed after the cessation of farming to a more natural state, approaching the assemblages observed at the control sites.  相似文献   

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Genetic and biochemical aspects of trehalase from Drosophila melanogaster   总被引:1,自引:0,他引:1  
Only one molecular form of trehalase (E.C. 3.2.1.28) was detectable in adult Drosophila melanogaster by polyacrylamide gel electrophoresis and isoelectric focusing. An examination of duplication- and deletion-bearing aneuploids exhibiting dosage sensitivity indicated that the enzyme is encoded by a gene, Treh+, located between 55B and 55E of the second chromosome. The tissue-specific soluble and particulate forms of trehalase appear to be manifestations of a single protein encoded by a single gene.  相似文献   

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Isoelectrofocusing of abdominal extracts of Drosophila melanogaster revealed the existence of two forms of sucrase (E.C. 3.2.1.26). One form exhibited an isoelectric point of 4.63 +/- 0.02 while the other form exhibited an isoelectric point of 4.83 +/- 0.02. The localization of the structural gene for sucrase is proposed on the basis of enzyme determinations in a series of duplication- and deletion-bearing aneuploids. We suggest that the sucrase structural gene lies between 31CD and 31EF on the left arm of chromosome 2 and that the two forms of abdominal sucrase derive from a common protein coded for by a single sucrase gene designated Sucr+.  相似文献   

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