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101.
To elucidate the structure of the network of the water retention mechanism of fish-meat gel, the microscopic relationship between the water content and viscoelasticity was investigated, and the specific surface area (S) where the water molecules are adsorbed was also measured. The gel structures of fish-meat, actomyosin (AM), and myosin (M) were investigated. In the fish-meat gel, as the water content increased, the number of network chains (??) decreased and the molecular weight between the cross-linking points (M e) increased. At 10?% salinity and approximately 79?% moisture, ?? decreased to a minimum and M e began to increase remarkably. In addition, when the moisture increased to 78?%, S increased about 1.5 times and the elasticity decreased significantly, indicating that this level of water content is the limit for sufficiently forming a gel structure in fish-meat gel. In the AM and M gels, M e and S were similar to those observed in the fish-meat gels. When the moisture content increased, they also increased, regardless of the salt concentration. This result suggests that the size of the network was enlarged or that the network chains were cleaved.  相似文献   
102.
103.
The complex interactions among endangered ecosystems, landowners’ interests, and different models of land tenure and use, constitute an important series of challenges for those seeking to maintain and restore biodiversity and augment the flow of ecosystem services. Over the past 10 years, we have developed a data-based approach to address these challenges and to achieve medium and large-scale ecological restoration of riparian areas on private lands in the state of São Paulo, southeastern Brazil. Given varying motivations for ecological restoration, the location of riparian areas within landholdings, environmental zoning of different riparian areas, and best-practice restoration methods were developed for each situation. A total of 32 ongoing projects, covering 527,982 ha, were evaluated in large sugarcane farms and small mixed farms, and six different restoration techniques have been developed to help upscale the effort. Small mixed farms had higher portions of land requiring protection as riparian areas (13.3%), and lower forest cover of riparian areas (18.3%), than large sugarcane farms (10.0% and 36.9%, respectively for riparian areas and forest cover values). In both types of farms, forest fragments required some degree of restoration. Historical anthropogenic degradation has compromised forest ecosystem structure and functioning, despite their high-diversity of native tree and shrub species. Notably, land use patterns in riparian areas differed markedly. Large sugarcane farms had higher portions of riparian areas occupied by highly mechanized agriculture, abandoned fields, and anthropogenic wet fields created by siltation in water courses. In contrast, in small mixed crop farms, low or non-mechanized agriculture and pasturelands were predominant. Despite these differences, plantations of native tree species covering the entire area was by far the main restoration method needed both by large sugarcane farms (76.0%) and small mixed farms (92.4%), in view of the low resilience of target sites, reduced forest cover, and high fragmentation, all of which limit the potential for autogenic restoration. We propose that plantations should be carried out with a high-diversity of native species in order to create biologically viable restored forests, and to assist long-term biodiversity persistence at the landscape scale. Finally, we propose strategies to integrate the political, socio-economic and methodological aspects needed to upscale restoration efforts in tropical forest regions throughout Latin America and elsewhere.  相似文献   
104.
The vegetation of Takkobu, northern Japan, has been significantly altered by land-use development following Japanese settlement at the end of the 19th century. In order to assess the impact of human activity on vegetation dynamics in Takkobu, changes in the vegetation composition over the last 300 years were reconstructed from fossil pollen in the sediments of Lake Takkobu. The pollen assemblage represented broadleaved forests on the surrounding hills and alder forests found on the margin of the wetland bordering the lake. Prior to Japanese settlement, the hillside forests consisted predominantly of oak. However, with the onset of land-use development, a significant decline in oak relative to increasing birch was apparent, particularly after the early 1960s. These results suggest that successive logging since the 1880s had gradually undermined the resilience of oak. An increase of Artemisia and birch pollen also indicates an expansion of disturbed land. Since the 1960s, a large part of the broadleaved forests in Takkobu has been converted to larch plantations, although this was not represented in the pollen data because of the underrepresentation of larch pollen. The results of the pollen analysis have implications for forest restoration in Takkobu. The use of long-term data allows the determination of the baseline (natural) vegetation to be restored, and also illustrates the factors affecting present-day vegetation and how it may change in the future.  相似文献   
105.
GhCesA2 is a cotton (Gossypium hirsutum) homologue of the bacterial cellulose synthase gene that encodes cellulose 4--glucosyltransferase. The central catalytic region of GhCesA2 was expressed as a soluble protein in the methylotrophic yeastPichia pastoris. The molecular size of the recombinant protein was 100kDa, which decreased to 85 kDa after treatment with endoglycosidase H. The recombinant GhCesA2 catalyzed transfer of glucose from UDP-glucose into unknown products in the presence of an extract of cotton hypocotyls, but the products were not-1,4-glucan.  相似文献   
106.
The melting peach cultivar “Akatsuki” [Prunus persica L. Batsh] develops melting texture during ripening, but the stony-hard peach cultivar “Odoroki”, softens and develops a mealy texture when treated with propylene. Cell wall polysaccharides were fractionated as 1,2-diaminocyclohexanetetraacetic acid (CDTA)-, Na2CO3-, NaOH-soluble fractions, or the cellulosic residues that remained after solvent extraction. Size-exclusion chromatography of the CDTA-soluble fraction revealed a limited depolymerization of polyuronides in mealy “Odoroki” fruit, accompanying a lower level of endo-polygalacturonase (endo-PG) and a higher level of exo-PG activities compared to melting “Akatsuki” fruit. “Akatsuki” fruit showed increases in the arabinose, galactose and rhamnose contents in the CDTA-soluble fraction. These neutral sugars decreased in the Na2CO3-soluble and cellulosic residue fractions during ripening. Similar changes were observed for neutral sugars other than arabinose during softening in mealy “Odoroki” fruit. Arabinose content did not increase in the CDTA-soluble fraction of “Odoroki” fruit; however, arabinose content decreased in the Na2CO3-soluble fraction and in the cellulosic residue as observed for “Akatsuki” fruit. A significant increase in α-l-arabinofuranosidase activity, about 10 times higher than for “Akatsuki” fruit, was observed in propylene-treated mealy “Odoroki” fruit. Differences in ripening-associated metabolic changes in the cell walls of these peach cultivars seem to be related to their differences in texture.  相似文献   
107.
As the fruits of loquat (Eriobotrya japonica, 2n = 2x = 34) carry large seeds, the breeding of seedless loquat has long been a goal. The recent creation of triploid cultivars (2n = 3x = 51) and the application of gibberellins allow commercial production of seedless loquat, but the possibility of seed formation in triploid loquats has not been carefully investigated. Through crossing experiments and cytological observations of meiosis and pollen tube growth, we found that the triploid line 3N-N28 was essentially self-sterile, but developed seeds on pollination with pollen from diploid cultivars at rates of up to 5.5%. Almost half of the seedlings survived to 5 months, and carried diploid (2n = 34), tetraploid (2n = 68), or aneuploid chromosome numbers. Our results suggest that triploid loquat cultivars might retain the risk of seed formation. Protection from pollination by diploid cultivars or the development of new triploid cultivars will be necessary to ensure the production of seedless loquat fruits.  相似文献   
108.
The effects of postharvest application of aminoethoxyvinylglycine (AVG) and 1-methylcyclopropene (1-MCP) on ethylene production and fruit quality, and thus on transportation and shelf-life, were evaluated in melting-flesh peaches. AVG (150 mg L−1) significantly reduced ethylene production, and the effect was enhanced in combination with 1-MCP (1 μL L−1). However, fruit treated with AVG alone softened to untreated control levels 2 d after harvest (DAH). Treatment with 1-MCP significantly reduced the rate of softening until 2 DAH, but the fruit rapidly softened thereafter, and reached untreated control levels by 4 DAH. A combination of AVG and 1-MCP significantly reduced fruit tissue softening throughout ripening. The effect of each chemical on flesh firmness indicated that 1-MCP affected fruit response in the early stages of ripening up to 4 DAH, and AVG significantly reduced softening in the latter stages from 4 to 9 DAH. Peaches treated with AVG and 1-MCP retained their ground color during ripening, but the effect of each chemical on color is unclear. The present study indicates that combined treatment with AVG and 1-MCP significantly delays the ripening of melting-flesh peaches.  相似文献   
109.
The goal of our study was to identify pharmaceuticals, their potential sources and consumption level in two different socioeconomic and geographical regions??Bordeaux, France and Kharkiv, Ukraine. These substances were monitored in rivers water during contrasted seasonal conditions with application of passive samplers. The 21 pharmaceuticals (psychiatric drugs: alprazolam, amitriptyline, diazepam, fluoxetine, nordiazepam, carbamazepine, bromazepam; analgesics: aspirin, paracetamol; broncholidator: clenbuterol, salbutamol, terbutaline; non-steroidal anti-inflammatory drug: diclofenac, ibuprofen, ketoprofen, naproxen; lipid regulator: gemfibrozil; stimulants: caffeine, theophylline) were identified in sites upstream and downstream of urban areas and discharge of wastewaters. Caffeine, carbamazepine, and diclofenac were relatively abundant into the surface water and could be considered as potential anthropogenic markers of wastewater discharges into rivers. A mass balance modeling has been applied to calculate approximate consumption rates for carbamazepine, diclofenac, and caffeine in both regions to assess socio-economic factors linked with pharmaceuticals behavior.  相似文献   
110.
Electrolysis of a 0.1% (17.1 mM) solution of NaCl using separate anode and cathode compartments gives rise to solutions containing active chemical species. The strongly acidic "anode solution" (EW+) has high levels of dissolved oxygen and available chlorine in a form of hypochlorous acid (HOCl) with a strong potential for sterilization, which we have investigated here. Exposing Aspergillus parasiticus at an initial density of 10(3)spores in 10 microL to a 50-fold volume (500 microL) of EW+ containing ca. 390 micromol HOCl for 15 min at room temperature resulted in a complete inhibition of fungal growth, whereas the cathode solution (EW-) had negligible inhibitory effects. Moreover, the mutagenicity of aflatoxin B(1) (AFB(1)) for Salmonella typhimurium TA-98 and TA-100 strains was strongly reduced after AFB(1) exposure to the EW+ but not with the EW-. In high-performance liquid chromatography analysis, the peak corresponding to AFB(1) disappeared after treatment with the EW+, indicating decomposition of the aflatoxin. In contrast, the routinely used disinfectant sodium hypochlorite, NaOCl, of the same available chlorine content as that of EW+ but in a different chemical form, hypochlorite (OCl-) ion, did not decompose AFB(1) at pH 11. However, NaOCl did decompose AFB(1) at pH 3, which indicated that the principle chemical formula to participate in the decomposition of AFB(1) is not the OCl- ion but HOCl. Furthermore, because the decomposition of AFB(1) was suppressed by pretreating the EW+ with the OH radical scavenger thiourea, the chemical species responsible for the AFB(1)-decomposing property of the EW+ should be at least due to the OH radical originated from HOCl. The OH in EW+ was proved by electron spin resonance analysis.  相似文献   
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