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1.
Joost G. Vogtländer Han C. Brezet Charles F. Hendriks 《The International Journal of Life Cycle Assessment》2001,6(3):157-166
In literature, many models (qualitatively as well as quantitatively) can be found to cope with the problem of communicating results of LCA analyses with decision takers. In a previous article of this Journal, an LCA-based single indicator for emissions is proposed: the ‘virtual pollution prevention costs ‘99’ (Vogtländer et al. 2000a). In this article, a single LCA-based indicator for sustainability is proposed. It builds on the virtual pollution prevention costs ‘99 for emissions, and adds the other two main aspects of sustainability: material depletion and energy consumption. This single indicator, the ‘virtual eco-costs ‘99’, is the sum of the marginal prevention costs of: Material depletion, applying ‘material depletion costs’, to be reduced by recycling Energy consumption, applying ‘eco-costs of energy’ being the price of renewable energy Toxic emissions, applying the ‘virtual pollution prevention costs ‘99’ The calculation model includes ‘direct’ as well as ‘indirect’ environmental impacts. The main groups of ‘indirect’ components in the life cycle of products and services are: Labour (the environmental impacts of office heating, lighting, computers, commuting, etc.) production assets (equipment, buildings, transport vehicles, etc.) To overcome allocation problems of the indirect components of complex product-service systems, a methodology of economic allocation has been developed, based on the so called Eco-costs/ Value Ratio (EVR) model. This EVR calculation model appears to be a practical and powerful tool to assess the sustainability of a product, a service, or a product-service combination. 相似文献
2.
Jean Schneider 《Origins of life and evolution of the biosphere》1977,8(1):33-38
A definition of fundamental living units is given according to which they are constituted by the material support of some ‘memory’ the latter is required - to be stable, - to contain rich information, - to diffuse it into the surrounding medium. It is then shown that the complex dislocation networks encountered in crystals can in some cases follow these criteria and lead to a crystalline physiology. The places of possible occurrence in nature of this kind of physiology, terrestrial and extraterrestrial rocks, interplanetary dust, white dwarfs and neutron stars are then discussed. 相似文献
3.
Purpose
to determine diagnosis and prognosis value of MRI in Peyronie’s disease.Material and Methods
thirty one penile MR examinations have been performed in 28 patients aged between 21 and 73. (1 tesla; surface coil; sagittal SET1, axial SET2 weighted, T1 before and after Gadolinium)Results
Conclusion
MRI can be helpfull in the pretreatment assessment and int he follow-up of Peyronie’s disease. 相似文献4.
Coexistence of plant species with similar niches 总被引:14,自引:0,他引:14
5.
John Dempsher M.D. 《Acta biotheoretica》1979,28(4):283-302
A new theory of synaptic function in the nervous system (Dempsher, 1978) is applied to the simplest system for integration of function in the nervous system. This system includes a sensory and motor neuron and three ‘synaptic’ regions associated with those two neurons; a receptor region, an interneuronal spinal synaptic region linking the two neurons, and an effector region. Information is first received and processed at the receptor region. The processing consists of five components:
- A highly selective mechanism which allows only that information to enter the receptor system which is appropriate.
- The ‘appropriateness’ of the information is determined by the alphabet (miniature potentials) already in that area.
- The information entering the system is assembled in a pattern meaningful for the next processing operation.
- The assembled information is then ‘disassembled’ into its subunits and mapped into the alphabet (miniature potentials).
- These miniature potentials are assembled into another pattern meaningful to fit the role of the receptor region.
- This new pattern is repacked for transit to the central synaptic region.
- In each region, three forms of the nerve impulse are involved: miniature graded potentials, graded potentials, action potentials.
- In each region, each component of the process is carried out by a precise mathematical operation: four each in the receptor and effector regions; five in the central synaptic region.
6.
G. Peres 《Andrologie》1995,5(3):326-331
Androgenic hormones seem to be of beneficial effects on sports performance: - they increase motivation, will, aggressiveness, resistance to the stress and to the fatigue, leading to an increase of the training quantity, - they increase bone mineralization and probably mechanical resistance, - they stimulate the bone marrow and so, with the erythropoietin, the erythropoiesis, - they increase the tendancy to hyperglycemia, but with a decrease of the tolerance to the glucose, - they stimulate the fatty acids mobilization from the adipose tissue, for their utilization in the muscle during the exercise, - they participate, for the trained sportmen, to a better gestion of the muscle glycogen storage: their utilization during exercise is decreased, - they increase the lean body mass, with an increase of the protein synthesis and a decrease of the protein catabolism, leading also to an increase of the muscle force under training. There is no beneficial effect upon the tendons, - they have an immunomodulation action. 相似文献
7.
B. Thiébaut 《Plant Ecology》1982,50(1):23-42
The study area is at the southern limit of the beech area, between the rivers Rhône in France and Ebro in Spain. From an analysis of the occurrence of beechwoods in this region and the pluviometric climate, it appears that part of the beechwood is found in a dry climate, which is still mediterranean. This argument seems sufficient to justify the existence of a ‘mediterranean’ beechwood, at least on a climatic level. Beechwood when occurring in a dry climate has special characteristics: - The development of the wood differs with the climate. Young beeches need shadow in a dry climate; they can grow in full light in a moist climate. - The floristic composition is different. - The understorey of dry woods is less structured than that of moist woods. - The genetic structure as measured in the enzymatic system Px1 is polymorphic in the dry and monomorphic in the moist conditions studied. It would be interesting to verify if the characters noted in a dry mediterranean climate are also present in dry atlantic or continental beechwoods. Since the mediterranean climate is drier and more unfavorable to beech than other climates, the particular characters of ‘dry’ beechwoods will be more pronounced near the Mediterranean. 相似文献
8.
R. Kanzaki A. Ikeda T. Shibuya 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1994,175(1):1-14
- The morphology of descending interneurons (DNs) which have arborizations in the lateral accessory lobe (LAL) of the protocerebrum, the higher order olfactory center, and have an axon in the ventral nerve cord (VNC), were characterized in the male silkworm moth, Bombyx mori.
- Two clusters (group I, group II) of DNs which have arborizations mainly in the LALs were morphologically characterized. The axons of these DNs are restricted to the dorsal part of the each connective (Figs. 1–5).
- Pheromonal responses of the group I and group II DNs were characterized. Flipflopping activity patterns, which have two distinct firing frequencies (high and low) in response to sequential pheromonal stimulation, were usually recorded (Figs.6–10).
- Two types of flipflopping activity patterns were classified into those that had an antiphasic relationship (called the ‘FF’ type) between the left and right connectives and those with a synchronized relationship (‘ff’ type) (Figs. 8–12). We propose that some group II DNs show ‘FF’ flipflopping activity patterns (Fig. 10).
- A state transition was usually elicited by less than 10 ng bombykol, the principal pheromone component. Extra impulses were elicited during constant light stimulation (Fig. 9).
- Our results suggest that the LAL olfactory pathways might be important for producing flipflopping activity patterns (Fig. 11).
9.
Hilmar Brunn Rolf Bretz Peter Fankhauser Thomas Spengler Otto Rentz 《The International Journal of Life Cycle Assessment》1996,1(4):221-225
Synthetic sulfuric acid is used in a wide range of applications in fine chemical industry. Despite an already performed optimization of input amounts, used sulfuric acid is still a quantitatively important waste by-product. As a result, different utilization technologies for used sulfuric acid exist: ? the starting point for a comparative LCA of the above mentioned utilization technologies at a concrete situation is explained, in a work of Ciba-Geigy Corp. ? a short summary of the comparative LCA is presented ? lessons learned from performing the LCA and using it in a decision process are described. 相似文献
- production of gypsum
- thermal reductive cracking
- thermal cracking and oxidation
10.
Murad-B. M. Mohammad F. L. S. 《Hydrobiologia》1972,40(4):553-559
- A collection of polychaetous annelids made by the Japanese research vessel ‘Umitaka-Maru’ in December 1968 from the Arabian Gulf was examined.
- Seventeen species, belonging to twelve families, are identified.
- Two pelagic families (Alciopidae, Tomopteridae) and five species (Plotohelmis capitata, Tomopteris sp.,Autolytus cf.A. longistaffi, Lysidice ninetta, Pista cristata) are recorded new to the fauna of the Arabian Gulf.
11.
Two novel techniques improve division and colony formation from protoplasts:
- Plating in agarose stimulates colony formation of protoplasts from a wide range of species. Protoplasts from Nicotiana tabacum developed to colonies from lower initial population densities in agarose than in agar or liquid. Protoplasts from Hyoscyamus muticus which do not divide in agar divided and formed colonies in agarose at higher efficiencies than in liquid medium.
- Culture of gel embedded protoplasts in large volumes of liquid medium on a gyrotatory shaker (‘bead culture’) further improved plating efficiencies in some species (e.g. Lycopersicon esculentum and Crepis capillaris) and enabled sustained proliferation of protoplasts which had not previously developed beyond the few cell colony stage (Brassica rapa and a mutator gene variety of Petunia hybrida).
12.
The following scheme lists the problems which have been and will continue to be encountered in grazing experiments on natural particle assemblages. In some cases there are solutions, but many of the problems listed below remain intractable. To solve them will require innovative approaches, most probably combining the use of particle counters with other techniques to approach the problem to be solved from several angles at once. Variance between samples due to - statistical causes (especially caused by large particles) and - differences between experimental bottles and between experimentals and controls at start of experiment. Shifts in particle distribution during experiment due to - increase in small particles - growth of bacteria and other organisms due to excretion of grazers and - breakage during handling by grazers into fragments. Processes, independent of grazing, leading to changes in particle size distribution due to - primary production - grazing by additional components and - bacterial growth on detrital particles and the formation of detrital flocs. 相似文献
13.
We describe and recommend the following improvements of DNA:rRNA membrane filter hybridization methods. One of our aims was to avoid DNA release from filter discs during hybridization.
- Our hybridization conditions are 2 SSC in aq. dest., with 20% formamide, 50 C, overnight for 16 hr.
- Duplexing is over in 8–10 hr.
- Formamide has to be very pure (O.D.≤0.2/cm light path at 270 nm).
- RNAase treatment: 250 μg/5 ml 2 SSC/filter at 37 C for 1 hr.
- Our conditions for stepwise thermal denaturation are: 5°C steps from 50C to 90C in 1.5 SSC in 20% formamide.
- Single-stranded DNA, fixed on membrane filters, and stored in vacuo at 4C, can be used reliably for hybridization for up to 20 months.
- Concentrated DNA in 0.1 SSC, quick-frozen at ?50 C and stored at ?90 C for up to 2 years can be used for hybridization without much change.
- A CsCl gradient purification step yields much purer DNA, but increases the release of DNA from filters by about 20%. Filters with 20% more DNA is a compensation.
- rRNA can be stored for 20 months in SSC or 2 SSC at ?12C without changing the hybridization results.
14.
15.
Michael Evenari 《The Botanical review》1984,50(2):143-170
- The future of the seed is partly predetermined by events (flower formation, flowering, nutrient flow from mother plant, etc.) preceding fertilization and the formation of the gametophyte.
- The environmental conditions under which the seed matures affect its final physiological constitution. This faet has mostly been neglected by seed physiologists.
- It is not known how far the triantic nature of the diaspore (seed coat, pulp, etc., 2n of mother plant, embryon of δ +n of Φ, endosperm 2n of Φ +n of δ) affects seed development and germination.
- The integuments of the ovules of some species have stomata. It is not known if they are functional in gas exchange or are constitutional non-functioning relics.
- The causes of the growth-degeneration pattern of the nucellus are unknown.
- During the development of the megaspore mother cell into the mature embryo sac dramatic cellular ultrastructural changes take place. This probably signifies a “change of guards” during which the gametophyte is freed from part of the controls by the ultrastructural units of the mother plant, preparing the ground after fertilization for a new, genetically independent sporophyte.
- Upon closer examination, the seemingly simple processes of fertilization and embryogenesis, as described in textbooks, turn out to be very complex and full of problems. Is the role each male nucleus plays preordained or is it left to chance which male nucleus goes where? What causes the degeneration of the synergids and of the vegetative nucleus, and what protects the other two male nuclei from a similar fate? Which ultrastructural organelles are carried by the generative nuclei into their respective receptor cells and what is their role in them? Why do zygotes in some species develop after fertilization immediately into an embryo whereas in other species the zygote remains dormant for some time? What causes the polarity of the egg cell which, after fertilization, divides into one developmentally most active apical cell (giving rise to the embryo) and into another “lazy” basal cell which develops into the suspensor of “unknown function?”
- In the source-sink relationship between photosynthesizing organs and the maturing seed there is one point at which the photosynthates pass from symplast to apoplast to symplast. The mechanism involved is largely unknown as well as the effect which environmental conditions have on this transport.
16.
C. A. Hainfeld S. L. Boatright-Horowitz S. S. Boatright-Horowitz A. Megela Simmons 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1996,179(1):75-87
- Male bullfrogs at two different natural calling sites were presented with playbacks of synthetic advertisement calls differing in phase spectra. Sounds were presented in a ABA design to analyze the ability of the animals to perceive changes in repeated series of stimuli.
- The number of individual croaks in an answering call significantly increased over repeated presentations of two of the three stimulus phase types in condition A1. There were significantly fewer croaks to the third stimulus. These data suggest that two stimuli were perceived in a similar manner.
- Latency of calling to stimuli presented in conditions A and B changed in response to shifts in phase spectrum at a low density calling site. These differences were significant when comparing latency to playbacks where shifts in the phase spectrum changed the temporal fine-structure and waveform periodicity of the stimulus.
- The increase in number of croaks and decrease in response latency across condition A1 and the increase in latency in condition B suggest that discrimination may take the form of stimulus-specific sensitization. In this context, sensitization might reflect an increase in arousal due to repeated presentation of a salient stimulus.
- The operation of a hypothetical ‘mating call detector,’ based on linear summation of temporal responses from the eighth nerve, provides output similar to the behavioral results.
17.
Supply and turnover of phosphorus was studied in an acidified lake ecosystem, Lake Gårdsjön, located in southwestern Sweden. This study included transport and budget calculations combined with field and laboratory experimental work on abiotic phosphorus chemistry and biological utilization of phosphorus. The main conclusions presented in this paper are: - The acidification process in inland waters resulting from acid atmospheric deposition is accompanied by ‘oligotrophication’ because of reduced input of phosphorus from the drainage area, possibly due to efficient fixation of phosphorus to aluminium complexes in the B-horizon of podzol soils - Primary productivity in acidified lakes is limited mainly by low phosphorus supply - Algal utilization of phosphorus in acidified lakes is impaired, yielding lower biomass than could be expected from ambient phosphorus concentrations. One possible reason for this could be that enzymatic recycling of organic phosphates is prevented by high levels of aluminium in lake water. 相似文献
18.
I. Walker 《Hydrobiologia》1985,122(2):137-152
A method was developed to sample the microfauna in open stream water and to observe its food habits over long periods in the laboratory. Evaluation of the material leads to the following conclusions:
- The microfauna is primarily associated with submerged leaf litter. Its density in the open water is a function of water current and hence, of rainfall,
- A considerable quantity of living and detritus-biomass is swept down-stream with each heavy rain,
- The foodweb starts essentially with decomposing fungi and detritus, and to a much lesser extent with algae and bacteria. Protozoa and Rhabdocoela are an insignificant input into the foodweb of higher invertebrates, but their role for maintenance of water quality may be important. Prey of fishes and shrimps depends primarily on ‘primary input’, i.e. on detritus, fungi and to some extent on algae and bacteria. The role of biomass transport from forest streams into larger rivers is discussed in relation to the fauna of the periodically inundated forest (igapó).
19.
Most of the 33 fungal metabolites tested provoke:
- Bacterial growth inhibition of Bacillus thuringiensis similar to lethal effect of antibiotics.
- Positive response in the ‘Rec’ assay using strains of Bacillus subtilis; this fact shows that these toxins are DNA modifying agents.
- Enlargement of cell volume in the first bacteria species; this cell-abnormality induction resembles those obtained with mitomycin C.
20.
Kenneth M. Towe 《Origins of life and evolution of the biosphere》1985,15(4):235-250
In the absence of direct evidence concerning the nature of the early Earth environments, it is acceptable under the uniformitarian principle to attempt to define primitive habitats from modern procaryotic physiology. Combining the rock and fossil record with present phylogenetic reconstuctions, application of this paleoecological approach to the evolutionary biochemistry and physiology of nitrogen fixation and photosynthesis leads to several inferences about the nature of Archean environments:
- To stimulate nitrogenase evolution and avoid its repression, the activity of the NH 4 + ion was less than 10?3, and probably lower.
- To be consistent with a moderately protective ozone screen, while not also repressing nitrogenase activity, incursions of abiotic dissolved oxygen at levels in the range 10?1.2?10?3.5 PAL would have been acceptable.
- To induce the formation and activity of RuBP carboxylase, the pCO2 was less than 100 PAL.
- To support Photosystem I activity, sulfide concentrations of at least 10?4 M were present in the photic zone.
- To avoid a too-rapid oxidation of sulfide, the pH was probably between 6–7, where H2S exceeds HS?.
- Lowering the sulfide to < 10?4 M to inhibit Photosystem I.
- Raising the pH above neutral (HS? > H2S), to mediate more rapid oxidation of HS?.
- Maintaining either an illumination below 300–400 lux (to avoid photosynthetic O2 self-repression of nitrogen fixation), or an adequate local source of combined nitrogen (aNH 4 + > 10?4) to repress nitrogen fixation entirely.