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1.
Updated evaluation of exergy and emergy driving the geobiosphere: A review and refinement of the emergy baseline 总被引:2,自引:0,他引:2
Crucial to the method of emergy synthesis are the main driving emergy flows of the geobiosphere to which all other flows are referenced. They form the baseline for the construction of tables of Unit Emergy Values (UEVs) to be used in emergy evaluations. We provide here an updated calculation of the geobiosphere emergy baseline and UEVs for tidal and geothermal flows. First, we recalculate the flows using more recent values that have resulted from satellite measurements and generally better measurement techniques. Second, we have recalculated these global flows according to their available energy content (exergy) in order to be consistent with Odum's (1996) definition of emergy. Finally, we have reinterpreted the interaction of geothermal energy with biosphere processes thus changing the relationship between geothermal energy and the emergy baseline. In this analysis we also acknowledge the significant uncertainties related to most estimates of global data. In all, these modifications to the methodology have resulted in changes in the transformities for tidal momentum and geothermal energy and a minor change in the emergy baseline from 15.8E24 seJ/J to 15.2E24 seJ/J. As in all fields of science basic constants and standards are not really constant but change according to new knowledge. This is especially true of earth and ecological sciences where a large uncertainty is also to be found. As a consequence, while these are the most updated values today, they may change as better understanding is gained and uncertainties are reduced. 相似文献
2.
A method that allows the estimation of the thermodynamic parameters of the biosphere has been developed. It results in the subdivision of the following four phase states of the biosphere: three equilibrium states: “white planet” with high albedo and low entropy; temperate forest in winter with high entropy; and desert with high entropy; and one nonequilibrium state: the “active forests” with low entropy, high information gain and the highest exergy values. The phase shift to a nonequilibrium state happens when albedo is less than 0.2. 相似文献
3.
The marine pseudomonad bacterium PL1 contains an intracellular pool of free amino acids which consist mainly of glutamate with small amounts of glutamine and aspartate when grown in a nutrient medium containing 0.2 M NaCl. When the NaCl concentration of the growth medium is increased to 0.8 M, proline becomes a major component of the intracellular pool together with glutamate—at this molarity and under suitable nutrient conditions these amino acids comprise 20% of total bacterial amino acid nitrogen. When grown in a nutrient growth medium containing a constant level of NaCl, the intracellular pool size can vary by a factor of 4 depending on the concentration of carbon and nitrogen in the medium. Experiments show that the amino acid pool can act as a nitrogen reserve but has little function as a carbon reserve. At high NaCl concentrations there is a marked dependence for growth on the presence of sufficient potassium in the medium. However, no correlation between K+ and glutamate concentration in either nitrogen or K+-limited cultures has been found. None of the enzymes associated with glutamate biosynthesis was influenced by NaCl levels between 0.2 and 0.5 M. Neither Na+ or K+ stimulated the activity of these enzymes when tested in vitro. 相似文献
4.
Modulation of the free amino acid pool and protein content in populations of the brine shrimp Artemia spp. 总被引:3,自引:0,他引:3
S. Helland G. V. Triantaphyllidis H. J. Fyhn M. S. Evjen P. Lavens P. Sorgeloos 《Marine Biology》2000,137(5-6):1005-1016
Free amino acid (FAA) and protein content were measured in various developmental stages of Artemia franciscana, from cysts to Instar III metanauplii. In addition, decapsulated cysts of 15 Artemia populations from different localities were compared with respect to their FAA and protein content. Furthermore, the content
and composition of the FAA pool were modulated by hatching the cysts at various salinities, and by enriching the nauplii with
algae or a lipid-enrichment emulsion. The FAA content increased threefold from cysts to nauplii, and Instar III metanauplii
contained nearly 50% taurine of total FAA. Cysts of A. franciscana were found to contain one-third the amount of FAA compared to the other Artemia species investigated. The content and pool composition of FAA was successfully modulated in 11 of 13 populations, where by
the content of FAA was significantly increased when hatched at high salinity. Finally, enrichment elevated the content of
FAA and changed the pool composition, thereby showing a dietary effect. Algal enrichment also increased the protein content.
Received: 27 September 1999 / Accepted: 17 July 2000 相似文献
5.
Woon-Seok Cho 《Ecological modelling》2011,222(3):407-418
The genotypic and phenotypic processes were incorporated into one system in the gene-individual-population relationships under the framework of Individual based models (IBMs). The gene types addressing different degrees of metabolic efficiency and toxin susceptibility were provided as attributes in the individuals. Subsequently ecological processes such as food competition and movement were allowed concurrently on the 2-D space to determine the suitable species adapted to the system. The integrative gene-individual-population model accordingly responded to gene exchanges between the neighboring individuals through conjugation. At a substantially low level of gene exchange, system heterogeneity increased to produce high levels of eco-exergy, being presented by species diversity and total population size in the system. The issues related to genetic and ecological effects in the integrative gene-individual-population relationships were further discussed. 相似文献
6.
Effects of the heavy metals zinc and cadmium on the free amino acid (FAA) pool of Gammarus pulex were studied at different metal concentrations and combinations as well as different exposure times. The dominant effect of these two metals was the reduction of most free amino acids and the whole FAA pool, except in the 10‐day low zinc and cadmium concentration exposures which resulted in a rise of free amino acid pool. Among the free amino acids, the most sensitive to zinc exposure, were alanine, glutamic acid, arginine, and taurine; valine, leucine, asparagine, and isoleucine were among the most sensitive to cadmium. No predictable changes of individual free amino acids were shown in the mixed metals exposures. Elevation of taurine concentration was constant in seven of the eight treatments, it is suggested that this elevation may be related to the hepatopancreatic damage observed and induced synthesis of metallothioneins. 相似文献
7.
It is possible to calculate the exergy for organisms based on classic thermodynamics as already demonstrated by Mejer and Jorgensen [Mejer, H., Jorgensen, S.E., 1979. Exergy and ecological buffer capacity. State-of-the-art in Ecol. Model. 7, 829–846]. The calculation of exergy as eco-exergy, which is based on the information stored in the genome, has lately been proposed by Jørgensen and co-workers. Recently, Ludovisi [Ludovisi, A., 2009. Exergy vs information in ecological successions: interpreting community changes by a classical thermodynamic approach. Ecol. Model. 220, 1566–1577] has put forward a method based on classical thermodynamics, which leads to the calculation of “virtual” values of concentration at equilibrium for a number of organic compounds (VEC) and freshwater organisms (VECE). This paper compares the two approaches by analysing the correlation existing between the VECE- and the β-values derived by Jørgensen et al. [Jørgensen, S.E., Ladegaard, N., Debeljak, M., Marques, J.C., 2005. Calculations of exergy for organisms. Ecol. Model. 185, 165–175]. It was found that there was a good correlation, which can be useful for estimating β-values for organisms whose genome is not known in a sufficient detail. The relationship between VECE- and β-values suggests that two proposed thermodynamic orientors based on these quantities – the eco-exergy index and the structural information – should lead to coherent results when applied to the evaluation of the development state of ecosystems. A numerical simulation shows that this expectation is verified in a major case, but also that different, even opposite, responses can arise, depending on the biological composition of the biocoenosis investigated. 相似文献
8.
The amino acid and sugar composition of diatom cell-walls 总被引:20,自引:0,他引:20
The cell walls of diatoms consist of a silica frustule encased in an organic coating. Biochemical characterization of this coating should allow insight into: (1) the mechanism of silicification; (2) taxonomy and evolution of diatoms; (3) preservation of fossil frustules. The amino acid and sugar composition of cell walls from 6 diatom species have been elucidated. When compared to cellular protein, cell-wall protein is enriched in serine plus threonine and glycine, and depleted in acidic, sulfur-containing and aromatic amino acids. The sugars of the cell-wall carbohydrates are quite variable and fucose tends to replace glucose in estuarine species. Condensation of silicic acid, in epitaxial order, on a protein template enriched in serine and threonine, is suggested as the Si-depositing mechanism in diatoms. The nature of this template and the polysaccharides in the cell wall may determine the solubility of diatom frustules in various environments. There is sufficient variability in cell-wall amino acids to warrant further investigation of their taxonomic utility. The sugars appear to be related to environmental factors, but they may also serve in biosystematic studies.Contribution No. 2928 from the Woods Hole Oceanographic Institution. This work was supported by a Woods Hole Oceanographic Institution Postdoctoral Fellowship to R. E. Hecky, a National Science Foundation Postdoctoral Fellowship to P. Kilham, and a Woods Hole Oceanographic Institution Fellowship to K. Mopper. 相似文献
9.
J. J. Kendall Jr. E. N. Powell S. J. Connor T. J. Bright C. E. Zastrow 《Marine Biology》1985,87(1):33-46
Calcification rate in the coral Acropora cervicornis was reduced significantly when exposed for 24 h to 100-ppm kaolin, but was unchanged in corals exposed to 50-ppm kaolin. Calcification rate returned to control levels during a 48-h recovery period. Most free amino acids (FAA) in the FAA pool decreased significantly in corals exposed to 100-ppm kaolin, but were unchanged in corals exposed to 50-ppm kaolin. After a 48-h recovery period, the FAA pool remained considerably below control levels in the 100-ppm exposed corals and dropped below control levels in the 50-ppm exposed corals. Calcification rate dropped less and later during the exposure period in the growing tip than in sections further down the stalk. The reduction in FAA pool size was considerably larger in the growing tip than further down the stalk. Soluble protein concentration remained unchanged during both exposure and recovery. The data are consistent with the interpretation that turbidity not only causes a decrease in photosynthetic rate and the synthesis of small molecules, but also causes a large increase in the utilization of stored organic molecules for such metabolically costly processes as mucus production and sediment removal. 相似文献
10.
Michela Marchi Sven Erik JørgensenEloy Bécares Ilaria CorsiNadia Marchettini Simone Bastianoni 《Ecological modelling》2011,222(16):2992-3001
Using a dynamic model of Lake Chozas developed by Marchi et al. (2011), we tested three hypotheses about recovery of the indigenous community and water quality after radical changes caused by introduction of an invasive allochthonous crayfish, Procambarus clarkii:
- 1.
- Can the lake resist the pressure of an invasive species, like P. clarkii, by adaptation?
- 2.
- Can the ecosystem recover when all the crayfish are removed and low phosphorus concentrations persist in inflow water?
- 3.
- Does the simulated recovery of submerged vegetation occur at a total phosphorus concentration below 100 mg TP m−3, as estimated by Scheffer et al. (1993), Scheffer (1997), Jeppesen et al. (1998) and Zhang et al. (2003)?
- 1.
- Lake Chozas can at least partly resist by adaptation. A combination of possible parameter changes could lead to a significant increase in eco-exergy.
- 2.
- Removal of the phosphorus represented by crayfish (by harvesting) implies complete recovery of the lake and its eco-exergy, albeit not necessarily with the same organisms having the same properties.
- 3.
- The expected hysteresis created by introduction and harvesting of crayfish is observed under the following conditions: phytoplankton dominance at total phosphorus ≥ about 200-250 mg TP m−3 and submerged vegetation returns at total phosphorus < 100 mg TP m−3.
11.
An investigation of the free amino acid patterns of 67 species representing 50 genera of West Indian Demospongiae has been undertaken to examine the value of this biochemical approach in adding another parameter to phylogenetic inquiries. Two-dimensional thin-layer electrophoresis and chromatography were used to separate mixtures of naturally occurring ninhydrin-positive compounds. Individual components were identified as far as possible, and the fingerprints or patterns of the species studied were used as a basis for evaluating relationships. The subclass Ceractinomorpha is a relatively homogeneous group, with free amino acid patterns characterized by a consistent representation of protein amino acids and by the absence of compounds other than taurine and hypotaurine in the neutral region of the chromatogram. Two variants of this general pattern can be recognized, one found in the orders Dictyoceratida and Poecilosclerida, the other occurring in the order Haplosclerida and the family Halichondriidae of the order Halichondrida. Unexpected results within this subclass are the wide separation of the dictyoceratid families Spongiidae and Verongiidae, the anomolous patterns of the genera Agelas and Iotrochota and of the family Callyspongiidae, and the suggestive affinities of the family Hymeniacidonidae with the order Hadromerida. The subclass Tetractinomorpha appears to represent a polyphyletic assemblage in which 5 recognizable patterns can be distinguished. These represent the orders Homosclerophorida, Choristida, Spirophorida, Hadromerida and Axinellida. Of interest are the suggestions that the order Choristida is in itself a heterogeneous group, and that certain genera now placed in the order Axinellida may in fact be more closely related to the Poecilosclerida. 相似文献
12.
The vertical distribution of chlorophylla, copepods, dissolved free amino acid concentration and the fixation of14C by phytoplankton were monitored in the springs of 1983, 1987 and 1988 in the Ushant front region, shelf edge of the Celtic Sea and central Irish Sea, respectively. In each area, two stations characterized by mixed and stratified water conditions were compared. Vertical distributions of amino acids coincided with the distribution of copepods. A positive and significant correlation was found between the abudance of copepods and the concentration of amino acids dissolved in seawater. A negative and significant correlation was found between chlorophylla and the concentration of amino acids. Enrichment of amino acids ( 20 to 500 nM l–1 at specific depths) due to aspartic and glutamic acids, glutamine and ornithine, was assumed to reflect copepod feeding activity and faecal production. At these depths, the natural concentration and diversity of amino acids, including aspartic acid, glutamic acid, asparagine, serine, histidine, glutamine, arginine, threonine, glycine, alanine, tyrosine, valine, phenylalanine, ornithine and lysine, were high enough and in the correct proportions for triggering feeding and swimming and swarming behavior of copepods, as well as their remote detection of food at the micro- and meso-scales (1 to 10 m). This accumulation of amino acids also constitutes a potential additional source of organic nitrogen for bacteria and phytoplankton. 相似文献
13.
In the presence of local (sulfur) and global (carbon) pollutants, we examine the pollution haven hypothesis and free riding behavior. Under domestic emissions trading, poorer Southern countries become pollution havens when free trade opens up whenever sulfur damage functions are linear or when sulfur levels in equilibrium are not higher in the South. With global trading of carbon permits, the pollution haven effect emerges in equilibrium whenever the convex sulfur damage functions are nonlinear. Countries that do not participate in a Global Protocol designed to reduce carbon emissions enjoy double benefits, stemming from free riding and cleaner local environments. 相似文献
14.
Henri Volohonsky 《Ecological modelling》1982,15(4):313-329
A general formula defining the free energy expenditures in the processes of algal nutrition and zooplankton feeding has been derived. It appears to be symmetrical in respect of space and time scales. In conditions of optimal control the theoretical relationship between effective free energy expenditures and losses appears to be the ‘golden proportion’. The general trends of the system due to the first and second laws of thermodynamics and Prigogine's theorem form a theoretical basis for phenomenological rules of ecosystem's development. 相似文献
15.
吴佐礼 《生态与农村环境学报》1994,(3)
本文就目前广泛应用的农业生态系统能流分析方法及有关概念作了分析,提出了辅助能替代率的概念。建议用辅助能替代率代替能量产投比对农业生态系统进行能流分析。文中还讨论了工业辅助能的计算及其在不同系统间或同一系统不同时段的可比性。 相似文献
16.
根据历年<山西统计年鉴>提供的能源输出数据,分析了1985-2007年间山西省煤炭的输出情况,并借助于GIS软件,分析了2006年山西省煤炭的流向及流量.山西省是一个大的能源辐射基地,每年产出煤炭的三分之二左右供应外省市,在外省市的经济水平、人民生活质量不断得到提升的同时,对于为周边地区的发展做出巨大贡献的能源输出地--山西来说,人均地区生产总值却低于全国平均水平,更低于其能源辐射到的其它省市区.山西省在不断向外省市输出能源的同时,也产生了巨大的环境辐射效应,但这种效应对于山西这个能源输出地来说却是负向的.主要表现在:山西省由于煤炭开采导致空气污染、地下水位下降、地面塌陷等地质灾害,而这些环境压力有三分之二是替煤炭输入地所承担的.输送电力,山西省不仅要承担煤炭开采造成的环境破坏,还要承担火力发电所造成的巨大环境二次污染,仅2007年,山西省生产外调电量就产生381.75×10~4 tSO_2,139.98×10~4 tNO_2,2799.51×10~4 t灰粉. 相似文献
17.
闻大中 《生态与农村环境学报》1995,(2)
对近年来农业生态系统能流和能量分析研究的某些新进展进行了介绍和评述,重点介绍了HTOdum所创立的能值概念和Giampietro等人提出的生物物理资本概念。对这些新概念在农业生态系统分析中的应用进行了讨论。 相似文献
18.
Studies of adsorption of cadmium by free bacterial and free actinomycete cells, alginate beads and immobilised bacterial or
actinomycete cells in alginate beads were performed in ultrapure water. The immobilisation in alginate beads allows the survival
of the microorganisms in non-ideal conditions. Here, we found the following affinity for the cadmium ion: R25 free cells<alginate
beads<R25 immobilised cells<ZAN 044 immobilised cells<ZAN 044 free cells, obtained with the b Langmuir parameter. The maximum uptakes gave the series: ZAN 044 free cells<ZAN 044 immobilised cells<R25 free cells<alginate
beads<R25 immobilised cells. 相似文献
19.
Using the starvation technique, changes in protein and free amino acids were examined in Penaeus esculentus Haswell collected from Moreton Bay, Australia, by trawling in 1985. Prawns of 17.7±0.26 g wet weight were held at 25°C until 2 d after moulting. Groups of seven or eight were then starved fro 5, 10, or 15 d, with appropriate control groups. At the end of each period, ecreted amino acids were collected for 24 h and whole-muscle amino acids and free amino acids (FAA) g-1 in each prawn were analysed. Concentrations of whole-muscle amino acids showed only minor changes with starvation, but concentrations of many of the FAA changed significantly. Total FAA averaged 1 182±45 mol g-1 dry weight. Individual FAA, in order of abundance, were glycine, arginine, proline, taurine, threonine, hydroxyproline, alanine, glutamic acid, valine, aspartic acid and lysine; the remaining FAA each contributed <0.2% of the total. Only taurine and alanine did not show significant changes with starvation. Concentrations of glycine, arginine, hydroxyproline, glutamic and aspartic acid increased, while those of proline, threonine, valine and lysine decreased with starvation, that of proline approaching zero after 15 d starvation. Excreted amino acid-nitrogen represented <2% of excreted ammonianitrogen ornithine being the most abundant (35%), followed by leucine (22%) and lysine (17%). The relative abundance of excreted amino acids did not correspond with those of the FAA. It is suggested that, as starvation progresses, the muscle protein is progressively hydrolysed, but with the remaining muscle maintaining its amino acid composition. The liberated amino acids enter the FAA pool and become available for energy production. Proline may have an important role as an energy source, but the ability to synthesise proline may be limited, and thus the artificial food of penaeid prawns may be improved by its addition. 相似文献
20.
C. H. Huang 《Environmental Fluid Mechanics》2009,9(3):359-366
In the condition of free convection, the Charnock relation is inadequate. In this paper we extend the Charnock relation to
include the effect of free convection on the roughness length. As a result, the singularity in the Monin–Obukhov similarity
theory can be avoided. This paper shows two approaches to derive the roughness length formula in the forced and free convections.
The first approach is based on the mixing length theory and the use of the observational data of the vertical velocity variance.
We introduce a new vertical velocity scale based on the vertical velocity variance; this velocity variance is well behaved
in the atmospheric boundary layer and easy to obtain from field experiments. The second approach is based on the theoretical
framework of Sykes et al. (Q R Met Soc, 119: 409–421). From that framework, we develop a theory to obtain the roughness length
formula. The results of these two approaches are in agreement with each other. In the past, a multiplication factor associated
with free convection was considered to be a constant. This paper shows that this multiplication factor is, in fact, also dependent
on the depth of the mixing height. In previous studies, experimental works were often conducted without taking into account
the depth of the mixing height. Not taking into account the mixing height in the estimation of the roughness length in free
convection would result in an inaccurate estimate of the roughness length and hence the drag coefficient.
An erratum to this article can be found at 相似文献