Showing papers by "Stockholm University published in 1976"

Camping on Seesaws: Prescriptions for a Self-Designing Organization

Abstract: This article prescribes how an organization can meet social and technological changes and reap advantage from them. Long-term viability maximizes in a self-designing organization, in which those who perform activities take primary responsibility for learning and for inventing new methods, and in which nonparticipant designers restrict themselves to a catalytic role. Designers can form such an organization by putting together processes, the generators of behaviors. Although complex interactions among processes make designers’ forecasts unreliable, people can mitigate serious future problems by keeping processes dynamically balanced. Six aphorisms caricature the desired balance: Cooperation requires minimal consensus; Satisfaction rests upon minimal contentment; Wealth arises from minimal affluence; Goals merit minimal faith; Improvement depends on minimal consistency; Wisdom demands minimal rationality.

Underload and Overload in Working Life: Outline of a Multidisciplinary Approach

Abstract: A research project is outlined in which concepts and methods from social psychology and psychophysiology are integrated in the study of human adaptation to underload and overload related to technically advanced work processes. Attempts are made to identify aversive factors in the work process by studying acute stress reactions, e.g., catecholamine excretion, in the course of work and relating these to long term, negative effects on well-being, job satisfaction and health. Data from a pilot study of sawmill workers support the view that machine-paced work characterized by a short work cycle and lack of control over the work process constitutes a threat to health and well being.

Evaluation of genetic risks of alkylating agents. II. Haemoglobin as a dose monitor.

Abstract: The degree of alkylation of haemoglobin was determined at different times after treatment of mice with one directly active alkylating agent, ethylene oxide, and one agent that requires metabolic activation, dimethylnitrosamine. Because of the random alkylation of red blood cells of various ages and the stability of alkylated haemoglobin, the amount of alkylated amino acids in haemoglobin decreases linearly with time, reaching the value zero after about 40 days, the life-span of erythrocytes in the mouse. This provides a basis for the use of haemoglobin as a monitor for integral doses of genotoxic environmental chemicals.

Lacustrine Sediments and Tree-Limit Variations as Indicators of Holocene Climatic Fluctuations in Lappland, Northern Sweden

Abstract: In this paper Holocene climatic changes recorded in Lappland, northern Sweden, are described. Recorded changes are dated in three different ways: (1) moraines fronting alpine glaciers are dated lic...

Sex differences in sympathetic-adrenal medullary reactions induced by different stressors.

Abstract: Male and female university students were exposed to two different stressors in each of two 110-min sessions, i.e., a cognitive task (color-word conflict) and repeated venipuncture. Catecholamine excretion, heart rate, and subjective reactions were measured. Control values were obtained under conditions of relaxation in the laboratory. Subjects of both sexes responded to both stressors by increased heart rate and feelings of unpleasantness and distress. The pattern of adrenaline excretion, however, differed between sexes: in males both stressors induced a significant increase, whereas in females adrenaline excretion remained on the same level under the two stress conditions as during relaxation. Noradrenaline excretion was not systematically affected by either stressor in either sex group.

On decision rules and information processing strategies for choices among multiattribute alternatives

Abstract: .— It is suggested that a decision in a complex situation can be described as a sequential process in which different decision rules and information processing strategies can be used at different points in time. Examples of possible decision rules are presented in an approximate order of complexity. Two ways for processing the information in a decision situation, viz., breadth-first or depth-first strategies, are discussed and suggestions are made about their relationship to particular decision rules. Finally, it is proposed that the order of application of particular rules in a decision process is guided by a tendency to minimize cognitive effort.

Purification, Fractionation and Assay of Antibody‐Dependent Lymphocytic Effector Cells (K Cells) in Human Blood

Abstract: In this article we present methods for the purification and fractionation of human blood lymphocytes, which have been used in our laboratory to characterize antibody-dependent cytotoxic effector cells (K cells). The assay system consists of highly purified lymphocytes, 51Cr-labelled chicken erythrocytes (Ec) and IgG rabbit anti-Ec in high dilutions. Various ways of comparing K-cell potentials of different lymphocyte preparations in this system are discussed. When purified lymphocytes are partially depleted (60-85% depletion) of cells forming rosettes with sheep erythrocytes (E+ cells), the K-cell activity of the depleted fraction is increased, indicating the the majority of the E+ cells are inactive in this assay. Depletion of EAC-rosette-forming cells shows that most or all K cells have complement receptors. For depletion of B cells, the lymphocytes may be passed through glass bead columns, charg ed with F(ab')2 fragments of human IgG and F(ab')2 fragments of rabbit antibodies to the F(ab')2 part of human IgG. These columns give high yields of B-cell depleted fractions. These preparations are rich in E+ cells and contain approximately 80% of the Fc-receptor lymphocytes which form rosettes with bovine erythrocytes, coated with IgG antibodies. Their K-cell activity is unchanged or slightly elevated, indicating the mature B cells, i.e. SIg+ cells, have little or no K-cell activity. In contrast, passage of the lymphocytes through immune complex columns (ovalbumin/anti-ovalbumin) leads to approximately 70% depletion of Fc receptor-bearing cells, while most of the B cells (SIg+ cells) pass through the columns. The relative frequency of E+ cells in the passed fraction frequently shows a slight reduction. These preaparations have a very low K-cell activity, indicating that K cells are lymphocytes with Fc receptors of relatively strong avidity.

The Involvement of Cytochrome P‐450 in Hepatic Microsomal Steroid Hydroxylation Reactions Supported by Sodium Periodate, Sodium Chlorite, and Organic Hydroperoxides

Abstract: The mechanism of steroid hydroxylation in rat liver microsomes has been investigated by employing NaIO4, NaClO2, and various organic hydroperoxides as hydroxylating agents and comparing the reaction rates and steroid products formed with those of the NADPH-dependent reaction. Androstenedione, testosterone, progesterone, and 17β-estradiol were found to act as good substrates. NaIO4 was by far the most effective hydroxylating agent followed by cumene hydroperoxide, NADPH, NaClO2, pregnenolone 17α-hydroperoxide, tert-butyl hydroperoxide, and linoleic acid hydroperoxide. Androstenedione was chosen as the model substrate for inducer and inhibitor studies. The steroid was converted to its respective 6β-, 7α-, 15-, and 16α-hydroxy derivatives when incubated with microsomal fractions fortified with hydroxylating agent. Evidence for cytochrome P-450 involvement in androstenedione hydroxylation included a marked inhibition by substrates and modifiers of cytochrome P-450 and by reagents which convert cytochrome P-450 to cytochrome P-420. The ratios of the steroid products varied according to the type of hydroxylating agent used and were also modified by in vivo phenobarbital pretreatment. It was suggested that multiple forms of cytochrome P-450 exhibiting different affinities for hydroxylating agent are responsible for these different ratios. Horseradish peroxidase, catalase, and metmyoglobin could not catalyze androstenedione hydroxylation. Addition of NaIO4, NaClO2, cumene hydroperoxide and other organic hydroperoxides to microsomal suspensions resulted in the appearance of a transient spectral change in the difference spectrum characterized by a peak at about 440 nm and a trough at 420 nm. The efficiency of these oxidizing agents in promoting steroid hydroxylation in microsomes appeared to be related to their effectiveness in eliciting the spectral complex. Electron donors, substrates, and modifiers of cytochrome P-450 greatly diminished the magnitude of the spectral change. It is proposed that NaIO4, NaCIO2, and organic hydroperoxides promote steroid hydroxylation by forming a transient ferryl ion (compound I) of cytochrome P-450 which may be the common intermediate hydroxylating species involved in hydroxylations catalyzed by cytochrome P-450

Diethyl pyrocarbonate in nucleic acid research.

Abstract: Publisher Summary Interest in the biological and biochemical effects of diethyl pyrocarbonate, (EtOCO) 2 O, was initiated through the introduction of the compound as a cold sterilizer for beverages. The compound emerged in nucleic acid biochemistry through the demonstration of its nuclease-inhibiting property and through the suggestion of exploiting this property in the extraction of undegraded nucleic acids. Since the experimental verification of this suggestion and the elaboration of a method for the extraction of undegraded nucleic acids, based on its use as a nuclease inhibitor, the reagent was found to be useful in a number of laboratories for securing nuclease-free conditions. This chapter describes that (EtOCO) 2 O reacts with single-stranded nucleic acids and nucleic acid constituents. Such reactions were found to lead to a loss of the biological activity of RNA. This reactivity toward RNA has made some authors conclude that the use of this reagent in nucleic acid extraction might be impracticable. Since the reactions of diethyl pyrocarbonate with nucleophiles are not instantaneous, it is found practical with the purpose of systematizing data, to introduce the concept of “dose” of the electrophile ((EtOCO) 2 O. Fianlly, it concludes that (EtOCO) 2 O is not a unique compound, and not a specific enzyme inhibitor in a strict sense. The study of its interactions with biological materials is, therefore, of interest not only to the immediate, practical use of this compound in nucleic acid research, but it also exemplifies the general mechanisms and problems of concern in the confrontation of cell constituents with acylating agents and other electrophiles.

Dose response at low doses of X-irradiation and MMS on the induction of micronuclei in mouse erythroblasts.

Abstract: The test of induced micronuclei in erythrocytes of mammalian bone marrow constitutes, because of its high experimental resolution power, a suitable method for the screening of induced chromosomal lesions at very low dosages of chemicals or irradiations. This test was used for a comparative investigation of the effect of low dose levels of X-irradiation and of the alkylating agent methyl methanesulphonate (MMS). The dose-effect curve of X-irradiation indicated a deviation from linearity at 10 rad, showing a significantly stronger effect than expected on extrapolation from the control to 100 rad. This deviation from linarity, however, only appeared at a low dose rate (18 R/min), whereas a linear dose-effect relation was indicated with a high dose rate (95 R/min). Experiments at 10 rad with different dose rates at two different current potentials suggested that this effect of the dose rate is more pronounced with soft than with hard X-irradiation. The induction of micronuclei with MMS follows a drastically different dose-effect curve as compared with X-irradiation. The relative efficiency of the treatment is lowest at low concentrations, presumably as a result of the efficient repair process at such dose levels. Simultaneous treatment with X-rays and MMS at low dose levels only resulted in an additive effect. This suggests that X-irradiation does not interfere with the repair process operating with MMS. The difference in the dose-effect relations of X-irradiation as compared with MMS may be brought back to the fact that X-rays, in contrast with MMS, produce double-strand breaks.

The Low Lying Electronic States of SiO

Abstract: Perturbations in the A1Π state of the isotopic 28Si16O and 28Si18O molecules are analyzed. The perturbing states, d3Δr, e3Σ-, C1Σ-, and D1Δ, are identified and vibrationally assigned. Two independent methods of vibrationally numbering the perturbers, employing isotope shifts and vibrational variation of perturbation matrix elements, respectively, are described in detail and shown to be in complete agreement. Molecular constants for the eight lowest energy electronic states of SiO are presented. Semiempirical and isovalent relationships between spin-orbit and spin-spin constants are discussed.

Norepinephrine-induced shift in levels of adenosine 3':5'-monophosphate and ATP parallel to increased respiratory rate and lipolysis in isolated hamster brown-fat cells.

Abstract: 1. Isolated brown fat cells from hamster respond to added catecholamines with a temporary increase in respiratory rate and an extended lipolysis. 2. From experiments with catecholamines and alpha and beta-blockers, the receptors of these cells are classified as beta according to classical definition. 3. Norepinephrine induces a rapid increase in adenosine 3':5'-monophosphate levels which parallels in time the stimulated respiration. Maximal adenosine 3':5'-monophosphate levels are reached within 1-3 min and are followed by a continuous decline. 4. Parallel to the catecholamine-induced respiration and lipolysis there is a pronounced drop in ATP levels. This energy depletion could be reversed by addition within 5 min after norepinephrine of the beta-blocker propranolol. 5. The nucleotide pattern in isolated hamster brown fat cells after norepinephrine addition was mimicked in experiments with isolated hamster brown fat mitochondria. From these experiments it is concluded that a high ratio of AMP and ADP over ATP decreases the respiratory rate when endogenous free fatty acids are oxidized.

The interaction of nonmitogenic and mitogenic lectins with T lymphocytes: association of cellular receptor sites.

Abstract: The relationship between the surface receptors on neuraminidase-treated human blood lymphocytes for the mitogenic lectins Phaseolus vulgaris leukoagglutinin (La), concanavalin A (Con A) and soy bean agglutinin (SBA) and the non-mitogenic lectin Helix pomatia A hemagglutinin (HP) was investigated. Two different techniques, co-capping with different fluorochrome-labeled lectins and cell binding-inhibition experiments with 125I-labeled lectins, were used. The results demonstrated that the nonmitogenic lectin HP and the mitogenic lectins SBA, La and Con A bind either to the same macromolecule (s) or to different but physically linked macromolecules on the surface of human T lymphocytes. In contrast, only part of beta2-microglobulin (beta2-m) or beta2-m-bearing complexes, appear to be physically linked to the lectin receptor complex(es). On the lectin-binding substance(s) at least two saccharide structures were recognized, one of which binds both HP and SBA and another which binds SBA and La (and probably also Con A) but not HP.

Sulphate-light scattering ratio as an index of the role of sulphur in tropospheric optics

Abstract: THE optical properties of the non-cloudy atmosphere are determined by a fixed component, the molecular gases, and a variable component, the aerosol particles. The optical effects of these two components have been subject to speculation and scientific investigation for many years. The major features of molecular and particle optics are reasonably well understood1–3 and instrumental techniques have been developed to measure extinction of light4, scattering phase function5,6 and the scattering component of extinction7. Few data or analyses have, however, been presented which consider the chemical nature of the aerosol in terms of its effects on radiative properties, although a few exceptions can be cited8–12. Experimental evidence quantitatively linking the chemical composition of aerosol particles with the macroscopic optical consequences is sparse, but here we mention one approach relating chemical and optical measurements on regional scale air masses and present preliminary data.

Organization of the Cone Cells in the Retinae of Salmon (Salmo salar) and Trout (Salmo trutta trutta) in Relation to Their Feeding Habits

Abstract: Regional variations of cone density, cone types and cone mosaic were investigated by light microscopy in yolk sac fry, parr and adults of salmon (Salmo salar) and trout (Salmo trutta trutta) and related to the feeding habits of different stages. The retinal organization of the two species is similar, as are their feeding habits. In parr and adults of both species a region with high cone density was found in the ventro-temporal part of the retina. The lowest values of cone density were found centrally in the dorsal half of the retina. An increase in cone density towards the ora serrata was noted in all retinae investigated. There is a good agreement between the density distribution of the cones in parr of salmon and trout and their feeding habits. The parr feed to a great extent on the invertebrate drift. Facing the current, the parr search the water region in front and above themselves for food organisms, thereby probably making use of the ventro-temporal area of high cone density. The connection between the cone density distribution and the feeding habits is less clear in adult salmon and trout, but the high cone density region is probably used when they feed on surface organisms and schooling prey. The ecological significance of cone types and cone mosaics is discussed. During growth there was a change of the cone mosaic from a regular square pattern in the fry towards a less regular square or row pattern in the adults. The position of regions with high and low cone density did not change during development in each species and had a similar distribution in the two species. On the other hand, the range of cone density values becomes relatively greater as the animal grows older. The cone density distribution seems to be more homogeneous in parr than in adults. Differences in the relative density distribution of the cones are influenced by recruitment at the retinal periphery and by spreading out of existing cells. In addition to the ora serrata, mitoses were also observed in more central parts of the retina having well-differentiated receptors and a cone mosaic. Mitoses were noted in all three nuclear layers but were most frequent in the outer nuclear layer, in which the resulting cells probably differentiate into rods. Undifferentiated zones similar to the peripheral growth zone of the retina were found on both sides of the falciform process in fry. In parr and adults an undifferentiated zone persisted only on the temporal side. It probably contributes to the high cone density in the ventro-temporal part of the retina by a delivery of new cells.

Task demand as reflected in catecholamine excretion and heart rate.

Abstract: Immediate effects and aftereffects of exposure to a color-word conflict task were studied in two groups of subjects, one of which performed the task without auditory interference („single conflict”), the other with auditory interference („double conflict”). Physiological arousal indices were more susceptible than performance measures to the level of task demand. Thus, the higher demand imposed by the double-conflict task was reflected in relatively larger increases of adrenaline excretion and heart rate, both during the conflict task and during the subsequent arithmetic task, whereas the performance measures remained unaffected.

Vyredox — In Situ Purification of Ground Water

Abstract: The abundance and relative purity of ground water guarantees its increase in usage. In some localities, the content of iron and manganese in ground water is so high that these metals must be removed before the water can be used for drinking or industrial purposes. Iron occurs in two states of oxidation in nature–the divalent (ferrous) and trivalent (ferric) forms. The Vyredox method developed in Finland and used now also in Sweden and some other countries oxidizes the ferrous ion, which is soluble in water, to the ferric ion, which is insoluble, before the water enters the well. The Vyredox method achieves a high degree of oxidation in the strata around the well. The method makes use of iron-oxidizing bacteria and aeration wells. A number of aeration wells are placed in a ring around the supply well. Water is forced down the aeration wells but first it is degassed and then enriched with oxygen. The oxygen-rich water provides a suitable habitat for the iron-oxidizing bacteria which assist in the oxidation of ferrous iron. The process must be repeated at specific time intervals to avoid further increases of iron content. The process of precipitating iron in the aquifer has only a slight effect on aquifer permeability. Cloggage of the aquifer surrounding the well should not occur for a period many times longer than the life span of a typical well.

Prognostic factors in mammary carcinoma.

Abstract: The simultaneous prognostic influence of multiple clinical and microscopic features of mammary carcinoma was analysed in 581 women with radical mastectomy. The most important of these features were connected with the extent of the disease in the axillary lymph nodes. In substantial groups of patients, however, a favourable outcome could be predicted from microscopic features of the primary tumour, viz. tubule formation, mitotic frequency and elastosis.

The person and the situation in an international model of behavior

Abstract: — The report deals with two main problems: (a) cross-situational consistency of person variables, which is discussed on the basis of a critical analysis of empirical research on cross-situational stability of actual behavior, and (b) the role of the momentary situation in models of behavior, and the consequences of an interactional view for theorizing and research on situations The analyses and discussions are based on two distinctions, namely (a) a distinction between consistency in terms of actual behavior and consistency in terms of mediating processes, and (b) a distinction between personality theories and measurement models Three different senses of consistency in terms of reactions are distinguished

Error structure of enzyme kinetic experiments. Implications for weighting in regression analysis of experimental data.

Abstract: Knowledge of the error structure of a given set of experimental data is a necessary prerequisite for incisive analysis and for discrimination between alternative mathematical models of the data set. A reaction system consisting of glutathione S-transferase A (glutathione S-aryltransferase), glutathione, and 3,4-dichloro-l-nitrobenzene was investigated under steady-state conditions. It was found that the experimental error increased with initial velocity, ν, and that the variance (estimated by replicates) could be described by a polynomial in ν Var(ν)=K0+K1.ν+K2.ν2 or by a power function Var (ν)=K0+K1oνK2. These equations were good approximations irrespective of whether different ν values were generated by changing substrate or enzyme concentrations. The selection of these models was based mainly on experiments involving varying enzyme concentration, which, unlike ν, is not considered a stochastic variable. Different models of the variance, expressed as functions of enzyme concentration, were examined by regression analysis, and the models could then be transformed to functions in which velocity is substituted for enzyme concentration owing to the proportionality between these variables. Thus, neither the absolute nor. the relative error was independent of velocity, a result previously obtained for glutathione reductase in this laboratory [BioSystems 7, 101–119 (1975)]. If the experimental errors or velocities were standardized by division with their corresponding mean velocity value they showed a normal (Gaussian) distribution provided that the coefficient of variation was approximately constant for the data considered. Furthermore, it was established that the errors in the independent variables (enzyme and substrate concentrations) were small in comparison with the error in the velocity determinations. For weighting in regression analysis the inverted value of the local variance in each experimental point should be used. It was found that the assumption of proportionality between variance and ν (where a is an empirically determined exponent) was a good approximation for the weighting. The value of α was 1.6 in the present case. The weight function was tested in the fitting of a rate equation to a kinetic-data set involving variable substrate concentrations. Recommendations are given regarding the establishment of the error structure in a general case and its application in regression analysis.

The multidimensionality of state and trait anxiety.

Abstract: .— The two major problems investigated were (a) the multidimensionality of trait (A-Trait) and state (A-State) anxiety, and (b) the relationship between A-Trait and A-State under neutral conditions, using two measures of A-Trait (SR-GTA and STAI-T) and two measures of A-State (BRQ and STAI-S). These scales were administered to a sample of Swedish university students (54 males and 105 females). Factor analyses of the GTA situational scales yielded an interpersonal ego threat A-Trait factor and a physical danger A-Trait factor. Factor analyses of the GTA reaction scales and STAI-T reaction scales yielded, respectively, two and three factors providing evidence for the multidimensionality of A-Trait. Results of variance components analyses of the GTA scales provided further evidence for the multidimensionality of A-Trait. Factor analyses of the BRQand STAI-S measures yielded four and three factors, respectively, indicating the multidimensionality of A-State. The correlations between trait and state measures were higher than the correlations between the two state measures, and a factor analysis of the trait and state scales did not yield separate state and trait factors, questioning the proposition that A-Trait and A-State are distinct concepts. Via latent profile analysis, it was possible to compare A-State differences for different A-Trait profiles. Problems for further research were discussed.

The Pneumococcal Polysaccharides: A Re-Examination

Abstract: Publisher Summary The pneumococcal polysaccharides and their antisera are used in the immunological characterization of other polysaccharides. Structural studies of these polysaccharides are of special importance, and this chapter summarizes the results of such studies. Studies of a great number of extracellular polysaccharides from Gram-positive and Gram-negative bacteria indicate that they are composed of oligosaccharide repeating-units. The synthesis of a bacterial polysaccharide requires a considerable number of highly specific enzymes, increasing in number with the complexity of the repeating unit. The purification of a pneumococcal polysaccharide may be difficult, and the polysaccharide material is sometimes contaminated by a cell-wall component known as the “C-substance.” The methods for structural analysis of polysaccharides are not always adequate, especially when results of quantitative significance are needed. Sometimes, it may even be difficult to obtain satisfactory, quantitative analysis of the component sugars. Furthermore, considering the importance of these compounds in immunochemistry further work in this field is needed.

SCF-CI studies of the equilibrium structure and the proton transfer barrier H3O 2 −

Abstract: Large-scale configuration interaction (CI) calculations have been performed in order to study the effect of the correlation energy on the equilibrium geometrical structure, the stability, and on the energy barrier of the proton transfer reaction in the hydrogen bonded system HO− · HOH. An extended Gaussian basis set including polarization functions on each nuclear centre has been employed to approximate the molecular Orbitals. All possible single and double replacements resulting from a single determinant Hartree-Fock reference state have been taken into account in the CI wavefunction. Compared to the SCF results the equilibrium oxygen/oxygen distance has been obtained from the CI calculations to be smaller by about 0.08 A and the correlation energy has been found to stabilize the composed system by 3.6 kcal/mole. An almost symmetric equilibrium structure with the hydrogen bonding H-atom midway between the two oxygen centres has been obtained in the CI treatment, whereas SCF calculations yield an asymmetric geometrical configuration with a small energy barrier of 1.4 kcal/mole for the proton transfer process.