Full Mode and Attribution Mode in Environmental Analysis

Several tools exist for the analysis of the environmental impacts of chains or networks of processes. These relatively simple tools include materials flow accounting (MFA), substance flow analysis (SFA), life-cycle assessment (LCA), energy analysis, and environmentally extended input-output analysis (IOA), all based on fixed input-output relations. They are characterized by the nature of their flow objects, such as products, materials, energy, substances, or money flows, and by their spatial and temporal characteristics. These characteristics are insufficient for their methodological characterization, and sometimes lead to inappropriate use. More clarity is desirable, both for clearer guidance of applications and for a more consistent methodology development. In addition to the nature of the flow object and to spatial and temporal characteristics, another key feature concerns the way in which processes are included in a system to be analyzed.
The inclusion of processes can be done in two fundamentally different ways: according to a full mode of analysis, with the inclusion of all flows and related processes to their full extent as present in a region in a specific period of time; and according to an attribution mode, taking processes into account insofar as these are required for a given social demand, function, or activity, in principle whenever and wherever these processes take place. This distinction, which cuts across families of tools that traditionally belong together, appears to have significant methodological and practical implications. Thus the distinction between the two modes of analysis, however crucial it may be, strengthens the idea of one coherent family of tools for environmental systems analysis.     

The Practical Mode—A Distinct Mode of Performance in Biology

Linnaeus' timely work was a major contribution to botany and is of interest to students of botany at all levels. This is a brief biographical outline with a version of his Flora's Clock which some might like to try.     

Kinship and Mode of Production

This article links the basic elements of kinship and marriage to the division of labor between the sexes. The concept of a mode of production is used to analyze the distinctive features of this organization of the labor process. These features include the categorization of persons by generation and sex and a specification of reciprocal rights and obligations. It is thus argued that kinship pertains to a particular form of production rather than to an irreducible and unchangeable human nature . [kinship, division of labor by sex, mode of production]     

Mode of Action of Lomofungin

Lomofungin inhibited the growth of some yeasts and mycelial fungi at concentrations between 5 and 10 μg/ml. At such concentrations, there was no decrease in endogenous and exogenous oxygen consumption, and even 50 μg of antibiotic per ml caused only slight decreases. The permeation of the cell membrane was changed so that leakage of ninhydrin-positive substances was reduced, and the uptake of ¹⁴C-labeled glucose, amino acids, uracil, and thymidine was decreased at concentrations as low as 4 μg/ml. Protein synthesis in whole cells of Saccharomyces cerevisiae was reduced 35% at 10 μg/ml. However, the antibiotic did not reduce the incorporation of phenylalanine-U-¹⁴C into polypeptides with cell-free systems of Rhizoctonia solani and S. cerevisiae. The synthesis of ribonucleic acid (RNA) and deoxyribonucleic acid (DNA) was inhibited even at concentrations of lomofungin of 4 μg/ml. Since RNA synthesis was inhibited at lower concentrations and earlier than DNA synthesis, the primary site of action of the antibiotic appears to be the synthesis of RNA.     

Mode of Action of Streptolydigin

Streptolydigin and rifamycin inhibit the catalytic function of ribonucleic acid (RNA) polymerase. Streptolydigin can inhibit polymerization after the reaction has started, whereas rifamycin is effective only if it is preincubated with RNA polymerase prior to the addition of substrates. The same relationships are observed with respect to these two antibiotics if the nucleoside triphosphate-pyrophosphate exchange reaction is used in the assay system. The inhibitory effect of streptolydigin is reversible by further addition of RNA polymerase but not by addition of deoxyribonucleic acid to the assay system.     

Mode of action of benzimidazoles

Benzimidazoles represent the only class of truly broad-spectrum anthelmintics, however, they also show activity against fungi and mammalian cells. This raises the question as to why benzimidazoles can selectively kill helminths and yet exhibit little or no mammalian toxicity. In this paper, Ernest Lacey examines this example of selectivity of drug action to the ubiquitous target of these drugs, the structural protein, tubulin.     

Mode of Action of Lomofungin

Lomofungin inhibited the growth of some yeasts and mycelial fungi at concentrations between 5 and 10 μg/ml. At such concentrations, there was no decrease in endogenous and exogenous oxygen consumption, and even 50 μg of antibiotic per ml caused only slight decreases. The permeation of the cell membrane was changed so that leakage of ninhydrin-positive substances was reduced, and the uptake of ¹⁴C-labeled glucose, amino acids, uracil, and thymidine was decreased at concentrations as low as 4 μg/ml. Protein synthesis in whole cells of Saccharomyces cerevisiae was reduced 35% at 10 μg/ml. However, the antibiotic did not reduce the incorporation of phenylalanine-U-¹⁴C into polypeptides with cell-free systems of Rhizoctonia solani and S. cerevisiae. The synthesis of ribonucleic acid (RNA) and deoxyribonucleic acid (DNA) was inhibited even at concentrations of lomofungin of 4 μg/ml. Since RNA synthesis was inhibited at lower concentrations and earlier than DNA synthesis, the primary site of action of the antibiotic appears to be the synthesis of RNA.     

Mode of action of nitrofurazone

When Escherichia coli strain B/r is exposed to 10 to 20 mug of nitrofurazone per ml, mutants with roughly threefold resistance are obtained. Treatment of these mutants with higher concentrations of nitrofurazone yields strains with six- to seven-fold resistance over strain B/r. Each of these steps toward nitrofurazone resistance is accompanied by loss of soluble nitrofurazone reductase activity. When sensitive bacteria are exposed to labeled nitrofurazone or labeled 2-nitrofuran, a considerable amount of radioactivity becomes bound to the cold trichloroacetic acid-insoluble fraction. Very little activity becomes bound in the mutants with six- to seven-fold resistance; mutants with intermediate resistance show intermediate levels of binding. Partially purified nitrofurazone reductase preparations catalyze the conversion of nitrofurazone to compounds which bind to protein and are not removed by prolonged dialysis against 8 m urea or by cold acid. Nitrofurazone reduced by xanthine oxidase or electrolytically reduced also yields compounds which react with protein to form stable derivatives.     

Mode of Action of Vibriocin

The mechanism of action of vibriocin, a bacteriocin produced by Vibrio comma, was investigated. Its lethal action (as defined by the loss in colony-forming ability) was reversed by tryptic digestion within 7 to 10 min after adsorption. The bacteriocin had a pronounced inhibitory effect on deoxyribonucleic acid (DNA) synthesis, whereas ribonucleic acid (RNA) and protein synthesis continued, although at a reduced rate. Chloramphenicol protected sensitive bacteria from the lethal action. Degradation of bacterial DNA prelabeled with (3)H-thymidine, as measured by changes in acid-precipitable radioactivity, occurred 10 min after treatment with vibriocin. The bacteriocin per se had no detectable deoxyribonuclease activity. Observation of vibriocin-treated cells by phase-contrast microscopy, measurement of ultraviolet light-absorbing capacity of extracellular fluid, and (42)K-efflux studies indicated a damaged bacterial membrane. This impairment of membrane function occurred in the presence of chloramphenicol and thus, unlike the lethal effect of vibriocin, was independent of protein synthesis.     

Mode of Action of Zorbamycin

Zorbamycin (U-30,604E) induces rapid degradation of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) in Bacillus subtilis cells. DNA degradation is initiated first and is closely followed by the degradation of RNA. No interaction between isolated DNA and zorbamycin is observed. Nucleic acid and protein syntheses are not inhibited by zorbamycin in cell-free systems. Since the initial effect of the antibiotic is expressed at the level of the cellular DNA fraction, we assume that zorbamycin somehow induces a change in the structure or function of the cellular DNA fraction which results in rapid breakdown of this fraction.     

Mode of Action of Streptozotocin

Streptozotocin induces rapid degradation of deoxyribonucleic acid (DNA) in actively dividing or resting Bacillus subtilis cells. Difference spectroscopy showed that the antibiotic interacts specifically with cytosine containing mononucleotides in vitro. This interference occurs only within the very narrow pH range of 5 to 5.5 and is reversed immediately upon lowering or increasing the pH. No measurable interaction was observed between isolated DNA and streptozotocin. The possibility is discussed that interaction of streptozotocin with cytosine residues in cellular DNA, although possibly taking place at a very low frequency, may constitute the primary step inducing DNA strand breakage.     

Mode of Action of Pesticin

The mode of action of pesticin, a bacteriocin produced by many strains of Pasturella pestis, was studied. Pesticin action on macromolecular synthesis of a sensitive strain of Escherichia coli, strain , was found to have features similar to those of colicin E2-317 acting on the same strain. After exposure to pesticin, deoxyribonucleic acid synthesis was arrested and ribonucleic acid was degraded, but little effect was observed on protein synthesis. Pesticin, like colicin E2-317, induced lysogenic E. coli (P1), but, unlike the colicin, was active in the presence of dinitrophenol. Trypsin was found to reverse pesticin action up to 15 min after its addition at 40 C to E. coli . Pesticin action was studied on three sensitive bacterial strains, P. pestis 2C, P. pseudotuberculosis, and E. coli strain , which vary widely in their optimal growth temperature. P. pestis grows best at 29 C, P. pseudotuberculosis at 37 C, and E. coli at 40 C. It was found that pesticin action on all three strains was optimal at 40 C. Whereas the titer of pesticin was the same on all three strains when determined on agar, E. coli was the most sensitive to pesticin action in broth. No action of pesticin in broth on P. pseudotuberculosis was observed unless Ca ions were added. The effect was not immediate; that is, the cells had to be grown in a medium containing Ca⁺⁺ before they displayed sensitivity to pesticin.     

浅谈性别决定方式

性别决定和分化机理的研究是生命科学的一个热点领域。结合中学教材上基因定位知识．从基因型和环境2方面总结了动物和植物性别决定的方式,并从染色体水平和基因水平对其进行了初步剖析。     

Mode of Action of Antirheumatic Drugs

The concentrations of free and protein-bound L-tryptophan were measured in sera from normal subjects, patients with rheumatoid arthritis, pregnant women, and patients with jaundice. In the patients with rheumatoid arthritis receiving treatment with one or more antirheumatic drugs the percentage of the amino-acid bound to the circulating proteins was significantly depressed and in one patient returned to normal when therapy was stopped. Pregnancy and jaundice were also associated with raised free tryptophan and decreased bound tryptophan concentrations and bilirubin displaced the amino-acid from its binding sites on human serum proteins in vitro. It is suggested the behaviour of tryptophan mimics that of certain peptides which protect susceptible tissues against chronic inflammatory insults.