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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
2.
Abstract A cluster of five to seven AKH-like immunoreactive cells lie in each lobe of the paired corpora cardiaca of the true armyworm, Pseudaletia unipuncta. These cells form a mesh work of immunoreactive processes within the corpora cardiaca, and immunoreactive tracts projecting posteriorly over the aorta.
Reversed-phase high performance liquid chromatography of extracts of the corpora cardiaca of P.unipuncta revealed a single large U.V. absorbent peak with a retention time identical to synthetic Manduca- AKH. Amino acid analysis of the contents of this peak yielded a composition identical to that of synthetic Manduca-AKH which was analysed in a parallel manner. Furthermore the material within the peak possessed adipokinetic activity when bioassayed in day 2 adult male P. unipuncta. The corpora cardiaca of similar individuals were found to contain approximately 17.6ng (17.6pmol) of Manduca-AKH equivalents per pair.
Injection of Manduca-AKH into 2-day-old adult male P.unipuncta resulted in a dose-dependent elevation in haemolymph lipid levels with a maximum level of 80–90μmg/μl obtained with 5–10 ng of Manduca-AKH. Continuous flight also elevated haemolymph lipid levels in day 4 adult males with a significant elevation evident in the first samples taken after 15 min of flight and lipid levels plateauing at approximately 100 μg/μl by about 60 min of flight. 相似文献
Reversed-phase high performance liquid chromatography of extracts of the corpora cardiaca of P.unipuncta revealed a single large U.V. absorbent peak with a retention time identical to synthetic Manduca- AKH. Amino acid analysis of the contents of this peak yielded a composition identical to that of synthetic Manduca-AKH which was analysed in a parallel manner. Furthermore the material within the peak possessed adipokinetic activity when bioassayed in day 2 adult male P. unipuncta. The corpora cardiaca of similar individuals were found to contain approximately 17.6ng (17.6pmol) of Manduca-AKH equivalents per pair.
Injection of Manduca-AKH into 2-day-old adult male P.unipuncta resulted in a dose-dependent elevation in haemolymph lipid levels with a maximum level of 80–90μmg/μl obtained with 5–10 ng of Manduca-AKH. Continuous flight also elevated haemolymph lipid levels in day 4 adult males with a significant elevation evident in the first samples taken after 15 min of flight and lipid levels plateauing at approximately 100 μg/μl by about 60 min of flight. 相似文献
3.
The main ecosystem services (ES) central European mountain forests provide are: protection against gravitational hazards, timber production, recreation, biodiversity conservation and carbon storage, which are all in high demand. These demands make managing mountain forests a challenging task, involving manifold synergies and conflicts between the different ES. There is therefore an urgent need for appropriate concepts and tools for support decisions in forest management and planning (FMP) to take into consideration all ES and to manage the wide variety of information types, parameters and uncertainties involved in assessing the sustainability of ES. Multi-criteria decision analysis (MCDA) provides a suitable set of methods for sustainability evaluations. In this study sustainability means the persistent fulfilment of the required ES. To address all the phases of the FMP process, MCDA and forest models should be applied together, with indicators providing the main interfaces to combine them. This paper aims to: i) review assessment approaches in order to select appropriate and widely accepted indicators for measuring and assessing the effects of different silvicultural management alternatives on forest ES, and ii) present additional standardisation approaches (value functions) for each indicator. Standardisations are necessary to make the different ES comparable and to study synergies and trade-offs between different management objectives in MCDA. The main ES in central European mountain regions are considered, with a clear focus on those indicators that are directly derivable from forest model outputs and that can refer to sustainable forest management practices. The scales considered are that of the single forest stand and of the larger forest management unit. A holistic indicator-based analysis framework for FMP in mountain forests can be built using the indicators and value functions described. The influence of different management alternatives on ES can then be evaluated, taking into consideration the instruments and information on forest management (forest models, inventory) available. All indicators are selected according to existing and approved approaches that only require data that is normally available in operational forest management. The framework can thus be an important element in developing a decision support system for FMP in mountain forests. 相似文献
4.
Patrick Porcheron 《In vitro cellular & developmental biology. Animal》1991,27(6):479-482
Summary The regulation of growth and development of insects is under endocrine control and involves both juvenile hormones and ecdysteroids.
Neuropeptides are master regulators which control the secretion of these hormones. Most experiments in insect endocrinology
have been conducted in vivo, but tissue culture methodology is playing an increasing role due to the great interest in simpler
model systems for the study of complex processes that occur in vivo. The availability of appropriate media has allowed the
culture of a variety of insect organs and cell lines of defined origin which have kept certain properties of the parent tissues.
Tissue culture approaches have been useful for studying hormonal control of morphogenetic processes. Cell lines are particularly
suited to the study of hormonally regulated mechanisms of macromolecular biosynthesis and gene expression. Thus, the value
of in vitro analysis in studies of regulation of hormone production is now recognized. Results obtained from tissue culture
allow more precise definition of the hormonal requirements of insect cells and tissues for growth and differentiation and
might make possible the discovery of new growth regulators. 相似文献
5.
6.
Felipe Silva de Andrade Thiago Ribeiro de Carvalho Lucas Borges Martins Ariovaldo Antonio Giaretta 《Studies on Neotropical Fauna and Environment》2017,52(2):157-167
In this study, we re-describe the advertisement and territorial calls of Boana pardalis, carry out an acoustic comparison between the studied species and the other congeners of the B. faber group, and report for the first time the tympanic amplexus for the studied species. The advertisement call of B. pardalis can be used to supplement its diagnosis in the B. faber group based on temporal call traits, e.g. emission rate and emission pattern, as well as the call envelope. 相似文献
7.
The flesh fly Sarcophaga similis show a clear photoperiodic response; they develop into adults under long days, whereas they arrest their development at the pupal stage under short days. Although the involvement of a circadian clock in photoperiodic time measurement is suggested in this species, the anatomical location of the clock neurons responsible for the time measurement has been unknown. We detected two PERIOD-immunoreactive cell clusters in the larval brain; one cluster was located at the dorsoanterior region and the other at the medial region. We further investigated their temporal changes in PERIOD-immunoreactivity and compared their patterns under different photoperiods. 相似文献
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10.
Abstract. 1. We examined the plant-mediated indirect effects of the stem-boring moth Endoclita excrescens (Lepidoptera: Hepialidae) on the leaf beetle Plagiodera versicolora (Coleoptera: Chrysomelidae) in three willow species, Salix gilgiana , S. eriocarpa , and S. serissaefolia.
2. When the stem-boring moth larvae damaged stems in the previous year, willows were stimulated to produce vigorously growing lateral shoots on these stems. These new lateral shoots were significantly longer and the upper leaves had significantly higher nitrogen and water content than current-year shoots on unbored stems, although the carbon content and leaf dry mass were not different between lateral and current-year shoots.
3. In the field, leaf beetle larvae and adults had significantly greater densities on lateral shoots of bored stems than on current-year shoots of unbored stems. A laboratory experiment showed that female beetles had significantly greater mass and fecundity when fed on leaves of newly-emerged lateral shoots. Thus, the stem-boring moth had a positive effect on the temporally and spatially separated leaf beetle by increasing resource availability by inducing compensatory regrowth.
4. The strength of the indirect effects on the density and performance of the leaf beetle differed among willow species, because there was interspecific variation in host quality and herbivore-induced changes in plant traits. In particular, we suggest that the differences in magnitude of the changes among willow species in shoot length and leaf nitrogen content greatly affected the strength of the plant-regrowth mediated indirect effect, coupled with host-plant preference of the leaf beetle. 相似文献
2. When the stem-boring moth larvae damaged stems in the previous year, willows were stimulated to produce vigorously growing lateral shoots on these stems. These new lateral shoots were significantly longer and the upper leaves had significantly higher nitrogen and water content than current-year shoots on unbored stems, although the carbon content and leaf dry mass were not different between lateral and current-year shoots.
3. In the field, leaf beetle larvae and adults had significantly greater densities on lateral shoots of bored stems than on current-year shoots of unbored stems. A laboratory experiment showed that female beetles had significantly greater mass and fecundity when fed on leaves of newly-emerged lateral shoots. Thus, the stem-boring moth had a positive effect on the temporally and spatially separated leaf beetle by increasing resource availability by inducing compensatory regrowth.
4. The strength of the indirect effects on the density and performance of the leaf beetle differed among willow species, because there was interspecific variation in host quality and herbivore-induced changes in plant traits. In particular, we suggest that the differences in magnitude of the changes among willow species in shoot length and leaf nitrogen content greatly affected the strength of the plant-regrowth mediated indirect effect, coupled with host-plant preference of the leaf beetle. 相似文献