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1.
Understanding the state of forest resource utilization in China and correctly evaluating the role and function of forest resources in national economic development are essential for realizing balanced development of forests, the environment, and the economy. This is especially true given the present situation of increasingly scarce forest resources. Using data from Chinese forest industry statistical yearbooks, forestry development reports, and other documents, this paper examines the current state of forest resource utilization in China from the angle of combining quantities and values based on input–output tables. We show that demand for and input use of forest resources varies greatly across industrial sectors; the paper products and furniture manufacturing industries have the greatest direct consumption coefficient for timber use. When considering direct and indirect demand, it is clear that forest resources restrict different industrial sectors in diverse ways. These results provide an important set of reference values regarding the utilization of forest resources and coordinated industrial development in China. 相似文献
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3.
Risk characterization of agricultural soils in the mining areas of Singhbhum copper belt was done by determining the total concentrations of metals using inductively coupled plasma-mass spectrometry and assessing the potential ecological and human health risks. The concentrations were above the average shale values for most of the metals. Principal component analysis showed anthropogenic contributions of Cu, Ni, Co, Mn, Pb, and Cr in the soils. Ecological risk assessment revealed that 50% of the soil samples were at moderate to very high ecological risk. Health risks for adults and children were calculated using hazard quotients (HQs), hazard index (HI), and Cancer risks for the oral, dermal, and inhalation pathways. The HQs for all the metals except As and Co were below 1, which suggested that non-carcinogenic risks due to metal exposure through soils were within the safe limit. However, considering all the metals and pathways, the HI for adults and children was 0.71 and 5.61, respectively, suggesting appreciable risk to local residents. The carcinogenic risks due to As and Cr in the soils were within the acceptable value of 1E–04. For both carcinogenic and non-carcinogenic risks, oral ingestion appeared to be the primary pathway followed by dermal and inhalation pathways. 相似文献
4.
In this work, spray-dried lipid systems based on soy phosphatidylcholine, cholesterol and lauroyl polyoxylglycerides for entrapping Green tea polyphenols were produced. The aim was to study the effects of the encapsulating composition and spray drying conditions on the system performance and physicochemical product properties. The spray dryer powder production yield falls around 50.7?±?2.8%, which is typical for lab scale spray dryers. Wrinkled and rounded particles, with low surface porosities were generated, independent of the drying carriers (trehalose or lactose) used. The product showed high encapsulation efficiency of Green tea polyphenols, which was promptly redispersible in water. It presented low density, and good compressive and flow properties. The results herein reported confirm the feasibility of the entrapment of Green tea polyphenols in lipid-based compositions by spray drying in presence of the drying carriers evaluated. The spray-dried microparticles show high potential to be used as additive in food, nutraceutical and pharmaceutical products. 相似文献
5.
大别山区黑沟绿太阳鱼种群的形态特征研究 总被引:1,自引:0,他引:1
绿太阳鱼是2015年4月在大别山区淠河流域支流中新发现的入侵鱼类。利用2015年7月从黑沟中采集的78尾绿太阳鱼标本,对该物种的形态特征进行了详细测量和分析。结果发现绿太阳鱼种群内的形态相似性较高,但还存在一定的形态差异。相比性别,年龄是造成这种形态差异的主要原因。雄性从Ⅰ龄开始出现显著的形态分化,而雌性差异并不显著。这种形态学的差异完全符合雄鱼筑巢护卵的习性,具体表现在雄鱼头部指标(D1-2、D2-3、眼间距、眼后头长、头长)、臀鳍附近指标(D5-7、D5-8)、背鳍基部指标(D6-8)和尾柄处指标(D9-10)增大。同时相比Ⅰ龄以上的雄鱼,雌鱼和0龄雄鱼的尾柄指标(D8-10、D8-9)较长,身体更适于流水环境。这种雌雄体型上的变化,将有助于雄鱼占领溪流环境中的静水区(深潭),而雌鱼和0龄鱼占领流水区(急滩、湍流),这为该种群适应山区溪流的水文环境,合理分配生态位提供了便利条件,同时也使其对大别山区其他鱼类具有较大的生态危害潜力。 相似文献
6.
Theoretical and empirical evidence suggests that avian females are able to manipulate the offspring sex ratio at birth. Although
mating with an attractive male may induce females to skew the sex ratio toward males, the balance between the benefits of
producing attractive sons and the costs of competing with other females for mates could vary with female age, a possibility
that had not been previously explored. In this paper we increment experimentally the attractiveness of males of the polygynous
spotless starling (Sturnus unicolor) by adding green plants to their nests, a trait involved in courtship, and look for female age-differential effects on offspring
primary sex ratio. Young and middle aged females produced more sons in experimental than in control nests, as expected, but
old females showed the opposite tendency. To explain this novel result, we speculate that older females are limited to produce
the most costly sex because the physiological drawbacks imposed by ageing reduce their ability to compete with younger ones
for the non-shareable resources offered by males. We discuss that this evolutionary scenario may be widespread in avian polygynous
systems. 相似文献
7.
8.
Ping Su Anders Henriksson Christina Nilsson Hazel Mitchell 《World journal of microbiology & biotechnology》2008,24(9):1837-1842
The aim of this study was to assess the effect of a commercial green tea extract (TEAVIGO™) on the microbial growth of three
probiotic strains (Lactobacillus and Bifidobacterium), as well as three pathogenic bacteria. MIC and co-culture studies were performed. The MICs of the green tea extract against
Staphylococcus aureus and Streptococcus pyogenes (100 μg ml−1) were considerably lower than those against the probiotic strains tested (>800 μg ml−1) and Escherichia coli (800 μg ml−1). In co-culture studies, a synergistic effect of the probiotic strains and the green tea extract was observed against both
Staph. aureus and Strep. pyogenes. Green tea extract in combination with probiotics significantly reduced the viable count of both pathogens at 4 h and by
24 h had completely abolished the recovery of viable Staph. aureus and Strep. pyogenes. These reductions were more significant than the reductions induced by probiotics or green tea extracts used separately.
These results demonstrate the potential for combined therapy using the green tea extract plus probiotics on microbial infections
caused by Staph. aureus and Strep. pyogenes. As probiotics and the green tea extract are derived from natural products, treatment with these agents may represent important
adjuncts to, or alternatives to, conventional antibiotic therapy. 相似文献
9.
An oxidative and salinity stress induced peroxisomal ascorbate peroxidase from Avicennia marina: Molecular and functional characterization 总被引:1,自引:0,他引:1
Kumaresan Kavitha Gayatri Venkataraman Ajay Parida 《Plant Physiology and Biochemistry》2008,46(8-9):794-804
APX (EC, 1.11.1.11) has a key role in scavenging ROS and in protecting cells against their toxic effects in algae and higher plants. A cDNA encoding a peroxisomal ascorbate peroxidase, Am-pAPX1, was isolated from salt stressed leaves of Avicennia marina (Forsk.) Vierh. by EST library screening and its expression in the context of various environmental stresses was investigated. Am-pAPX1 contains an ORF of 286 amino acids coding for a 31.4kDa protein. The C-terminal region of the Am-pAPX1 ORF has a putative transmembrane domain and a peroxisomal targeting signal (RKKMK), suggesting peroxisomal localization. The peroxisomal localization of Am-pAPX1 was confirmed by stable transformation of the GFP-(Ala)(10)-Am-pAPX1 fusion in tobacco. RNA blot analysis revealed that Am-pAPX1 is expressed in response to salinity (NaCl) and oxidative stress (high intensity light, hydrogen peroxide application and excess iron). The isolated genomic clone of Am-pAPX1 was found to contain nine exons. A fragment of 1616bp corresponding to the 5' upstream region of Am-pAPX1 was isolated by TAIL-PCR. In silico analysis of this sequence reveals the presence of putative light and abiotic stress regulatory elements. 相似文献
10.
Summary Secretion of the cell wall (theca) in the scaly green flagellateScherffelia dubia (Prasinophyceae) has been examined by electron microscopy during cytokinesis. The bi-laminate wall forms by the extracellular amalgamation of two layers of scales produced in the Golgi apparatus (GA). Each mature GA cisterna contains ca. 12,000 scales of two distinct varieties arranged in two layers on the cisternal membrane. GA cisternae undergo turnover and one scale containing cisterna matures from thetransface of each dictyosome every 3–4 minutes. Cisternae then fuse with the plasma membrane at the anterior end of the cell releasing the scales onto the cell surface. The two layers of wall scales integrate on the cell surface in a time-dependent self-assembly process. The first scales deposited commence assembly at the cell posterior and the wall develops anteriorly by edge growth. The daughter cell wall is composed of ca. 1.2 million scales deposited in about 3 hours. Calculations of net membrane flow strongly indicate extensive endocytosis during wall deposition. 相似文献