Showing papers by "Stockholm University published in 1978"
745 citations
TL;DR: In this article, a model for nonconvective condensation processes is developed, which allows condensation to begin before relative humidity reaches 100% and the liquid water content of clouds is a prognostic variable of the model.
Abstract: A model for non-convective condensation processes has been developed. The model allows condensation to begin before relative humidity reaches 100%. The liquid water content of clouds is a prognostic variable of the model. The rate of condensation is a function of relative humidity and moisture flux convergence. The micro-physical processes involved in the formation of clouds and precipitation are parameterized by assuming that the rate of precipitation formation is a function of the amount of cloud water. Evaporation from falling rain is taken into account.
Quantitative tests with the model indicated that it yields reasonable evolution times and water content of clouds, and gives reasonable precipitation amounts.
505 citations
TL;DR: It is concluded that 1,2-dichloroethane is activated by conjugation to glutathione, which gives a weak direct mutagenic effect, which is enhanced by addition of the postmitochondrial liver fraction (S-9).
242 citations
TL;DR: It appears that the production of prostaglandins by tumor cells may constitute a means by which the tumor cells subvert the effect of a cellular immune response that is directed against them.
223 citations
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TL;DR: In this paper, the authors describe a series of phases of crisis response in organizations: at first, the organizations try to ignore the threatening situation, then they try to hide the problems by distorting reports of their performance, through both phases their executives make public statements that all is well.
Abstract: Crises are situations that threaten organizations' continued existence. Organizations encounter crises largely because they did not adapt sufficiently to changes in their social or technological environments. When organizations do face crises, their responses have a series of phases. At first, the organizations try to ignore the threatening situation -- perhaps it will go away. Next, they try to hide the problems by distorting reports of their performance. Through both phases their executives make public statements that all is well.Then the organizations try to address their problems by replacing top executives, but when they replace only one or two, the remaining executives continue to operate as they did in the past, so adaptations are inadequate. Finally, there is a realization that serious changes must take place, but by this time, workers have lost confidence in their bosses, many of the most skilled workers have left, and financial resources have been depleted.
222 citations
TL;DR: Male and female engineering students were studies under stress induced by a congnitive-conflict task and in a control condition spent in inactivity, showing sex differences on the subjective level were not reflected in actual performance.
Abstract: Male and female engineering students were studies under stress induced by a congnitive-conflict task and in a control condition spent in inactivity. The results showed that (a) in the control condition the sexes did not differ in adrenaline, noradrenaline or cortisol excretion, whereas heart rate was significantly higher in the females; (b) adrenaline excretion and heart rate increased significantly in both sexes during stress; (c) the rise in adrenaline excretion was more pronounced in the males, whereas the rise in heart rate was significantly greater in the females; (d) cortisol excretion increased significantly during stress in the male group only; and (e) self-estimates of effort and performance were consistently higher and increased more over time in the males than in the females, bu these sex differences on the subjective level were not reflected in actual performance. The interaction of biological and social factors in the development of sex differences in stress reactions is discussed.
178 citations
TL;DR: A spectrophotometric method for assaying cytochrome P -450 in microsomes contaminated with large amounts of hemoglobin and methemoglobin has been developed and it is necessary to add 0.25 m m ascorbic acid and 2.5 μ m PES (phenazine ethosulfate) to both cuvettes to balance the CO-hemoglobin peak.
174 citations
165 citations
TL;DR: In this paper, the authors investigated the common way of approximating multiple substitution effects by the unlinked cluster contribution based on the linked cluster theorem and developed a series expansion for the correction of a CI calculation, including double replacements only, for the erratic treatment of unlinked clusters.
158 citations
TL;DR: It appears that it is the low affinity binding site that is associated with muscarinic activation of cyclic GMP synthesis in cortical slices and in N1E 115 neuroblastoma cells.
147 citations
TL;DR: The results suggest that the combination of monotony and mental overload experienced by the high-risk group demands continuous mobilisation of biochemical adaptive resources which in the long run may prove harmful to the indiv...
Abstract: Social psychological theory on relations between production technology and work satisfaction was combined with arousal theory based on psychophysiological stress research in a study of workers in a highly mechanised production industry. A group of workers whose tasks were characterised by rcpetitiveness, physical constraint, machine-regulation of work pace and high demands for continuous attention (high-risk group) was compared to a control group who performed their work under less monotonous and more flexible conditions. Both groups were studied at work and during free hours with regard to urinary excretion of adrenaline and noradrenaline as well as self-ratings of mood and alertness. During work the high-risk group excreted significantly more catecholamines than the control group. The results suggest that the combination of monotony and mental overload experienced by the high-risk group demands continuous mobilisation of biochemical adaptive resources which in the long run may prove harmful to the indiv...
TL;DR: In this article, the total transmission as well as the transmission into various angular and energy intervals of electrons from different depths in a CEMS 57 Fe absorber has been computed, mainly by means of the Monte Carlo method.
TL;DR: Methods of measuring subjective difficulty, effort and other aspects of work-load which have been developed by the author and his colleagues are described and the use of these methods as means of distinguishing between individuals, and their relationships to psychometric measures are discussed.
Abstract: Methods of measuring subjective difficulty, effort and other aspects of work-load which have been developed by the author and his colleagues are described, and the use of these methods as means of distinguishing between individuals, and their relationships to psychometric measures, are discussed. Applications are noted to both physical and mental work.
TL;DR: Benzo( a )pyrene quinones and 3-OH-BP are the metabolites preferentially converted to glucuronyl conjugates when BP is metabolized by microsomes from 3-methyl-cholanthrene (MC)-treated rats in the presence of NADPH, O 2 , and UDP-glucuronic acid.
TL;DR: A sensitive method, especially suitable for clinical laboratories, for the routine determination of cholinesterase activities in whole blood is presented, based on the hydrolysis of propionylthiocholine and the spectrophotometric determination of the thiocholine produced by reaction with 4,4'-dithiodipyridine.
TL;DR: Effects of personal control over noise intensity were studied in experimental situations where subjects performed mental arithmetic under noise exposure, and mean measures of catecholamine and cortisol excretion, and of heart rate and subjective effort and discomfort showed that subjects were more aroused in the yoked situation.
TL;DR: The structures of the O-antigens of all known serotypes and subserotypes of Shigella flexneri have been reinvestigated and support the assumption that these antigens are composed of a basic tetrasaccharide repeating unit.
Abstract: The structures of the O-antigens of all known serotypes and subserotypes of Shigella flexneri have been reinvestigated. The results support the assumption that these antigens are composed of a basic tetrasaccharide repeating unit (1), to which alpha-D-glucopyranosyl and/or O-acetyl groups are attached at different positions. Leads to 3)-beta-D-GlcNAcp-(1 leads to 2)-alpha-L-Rhap-(1 leads to 2)-alpha-L-Rhap-(1 leads to 3)-alpha-L-Rhap-(1 leads to The immunological determinants responsible for O-factors I, II, IV, V and 7, 8 contain alpha-D-gluco-pyranosyl groups, the locations of which have been determined. O-Factor 6 is due to O-acetyl groups, linked to O-2 of the 3-substituted alpha-L-rhamnopyranosyl residue in unit 1 and O-factor III seems to be due to the same groups. The chemical natures of the determinants responsible for O-factors 4 and 3, 4 are still obscure. The structural studies indicate that the immunological classification of Sh. flexneri serotypes and subserotypes, as regards these O-factors, may need revision.
TL;DR: Evidence supports the suggestion of a mechanism in which tumor cells may prevent the effect of a cellular immune response by producing inhibitory levels of prostaglandins and suggests that manipulation of this mechanism can enhance the effectiveness of the lymphocyte response.
TL;DR: Glyoxalase I from human and porcine erythrocytes, rat liver, and yeast was shown to contain zinc in a stoichiometry of about 1 mole per mole of enzyme subunit.
TL;DR: In erythrocytes from mouse bone marrow the time schedule of micronucleus formation in relation to the last DNA synthesis was investigate by [3H]thymidine labelling in the autoradiographic technique, suggesting that micron nuclei can be produced both in the G 2 and S periods by X-irradiation.
Abstract: In erythrocytes from mouse bone marrow the time schedule of micronucleus formation in relation to the last DNA synthesis was investigated by [ 3 H]thymidine labelling in the autoradiographic technique. The results suggest that micronuclei can be produced both in the G 2 and S periods by X-irradiation. Furthermore, X-rays had a delaying effect on the cell cycle leading to a pronounced under-estimation of the dose—effect curve at higher dosages. Even when the cells were harvested as late as 30 h after irradiation, the full effect had most likely not yet appeared at dosages over 100 rad. Combined treatment with caffeine did not influence the dose—effect curve of X-rays, indicating no influence of a caffeine-sensitive repair mechanism. The induction of micronuclei by MMS, in contrast with the effect of X-rays, seems to have been restricted, at least predominantly, to the period of DNA synthesis. The dose—effect relation of MMS was characterized by a threshold giving a weaker effect than expected at low doses. Pretreatment with caffeine enhanced the effect of MMS at high but not at low doses, suggesting an error-free repair process operating at low doses and an error-prone and caffeine-sensitive repair at higher doses. The extent of alkylation in the bone-marrow cells was linear with respect to injected dose of MMS both in the presence and absence of caffeine. Pretreatment with phenobarbital reduced the effect of MMS sixfold, which can be explained by a reduction of alkylation found in the bone marrow. This result is in agreement with the enhanced excretion of MMS or its metabolites into urine and bile after pretreatment of the mice with phenobarbital. DMN had no measurable effect on the frequency of micronuclei. However, in the presence of caffeine a significant effect was observed, which was roughly of the same magnitude for the two dosages used. Pretreatment with phenobarbital also indicated a synergistic effect between DMN and phenobarbital. The treatment with DMN, phenobarbital and caffeine together gave a frequency of micronuclei not different from the control level, suggesting some antagonistic action between phenobarbital and caffeine. The indication that DMN is caffeine-sensitive at low dosages, whereas MMS is not, might be related to the difference in the alkylating properties of these chemicals.
TL;DR: In this paper, the Fermi contact parameters of the b3Σ+-a3II and c3-it+a3i systems of AlF have been analysed in detail, using a computer program to simulate the profiles by calculating the frequencies and intensities of individual hyperfine transitions.
Abstract: Lines in the b3Σ+-a3II and c3Σ+-a3II systems of AlF show partially resolved hyperfine structure. This structure has been attributed to magnetic interactions involving the 27Al nucleus for which I = 5/2. About twenty unblended lines from the (0, 0) bands of the two systems have been analysed in detail, using a computer programme to simulate the profiles by calculating the frequencies and intensities of individual hyperfine transitions. For low values of the rotational quantum number, the lines show a simple triplet structure, which reflects the case (bβS) coupling in the 3Σ states. Analysis of these lines gives values for the Fermi contact parameters in the two states involved (bF = 0.049 cm-1 and 0.057 cm-1 in the b3Σ+ and c3Σ+ states respectively). As the rotational quantum number increases, the hyperfine patterns become less regular, indicating a departure from case (bβS) coupling in the 3Σ states and from case (aβ) coupling in the 3II state. By reproducing the details of these line-shapes, it has also proved possible to determine values for the electron spin-spin and spin-rotation parameters in the two 3Σ states: b3Σ+ λ = -0.025(10)cm-1 γ = 0.0000(3)cm-1 c3Σ+ λ = 0.00(1)cm-1 γ = 0.0015(10)cm-1 The experimental values for the Fermi contact parameter of AlF in the a3II and b3Σ+ states are well produced by a simple single configuration molecular orbital calculation but the value for the c3Σ state is rather larger than expected on this basis.
TL;DR: The present study explores the possibilities of using specific amino acids in haemoglobin for tissue dosimetry of alkylating agents and demonstrates a stability of these alkylated products, which is fundamental to their use as integral dose monitors.
Abstract: The present study explores the possibilities of using specific amino acids in haemoglobin for tissue dosimetry of alkylating agents. The well-known directly alkylating compound methyl methanesulfonate has been used as a model compound. In one experiment 3 H-labelled methyl methanesulfonate was given to mice intraperitoneally at three dose levels. The degree of alkylation of haemoglobin exhibited a linear dependence on the quantity of methyl methanesulfonate injected. The degree of alkylation of guanine- N -7 in DNA indicated a slight positive deviation from linearity at high doses. After a single injection the degree of alkylation of cysteine- S and histidine- N -3 in haemoglobin decreased linearly with time reaching the value zero after about 40 days (the life-time of the erythrocytes in the mouse). This demonstrates a stability of these alkylated products, which is fundamental to their use as integral dose monitors. In a second experiment mice were treated with methyl methanesulfonate once a week over a period of 8 weeks. The experiment demonstrated an accumulation of alkylated groups in haemoglobin in agreement with expectation. A method for the quantitative determination of S -methylcysteine in a protein hydrolysate by gas chromatography was developed.
TL;DR: It was found that treatment of intact microsomes with ammonia breaks down their permeability barrier but also removes significant amounts of microsomal phospholipid and inactivates a number ofmicrosomal enzymes.
Abstract: 1
Protease and diazobenzene sulfonate have been used to probe the transverse topology of the microsomal glucose-6-phosphatase system.
2
Treatment of intact microsomes with these reagents under the conditions used here did not affect the permeability of the membrane to mannose 6-phosphate, nucleoside diphosphatase, or dextran of 70 000 molecular weight. Nor did these treatments inactivate the hydrolytic site of glucose-6-phosphatase, a finding in agreement with earlier conclusions that this site is on the inside of the membrane.
3
On the other hand, treatment of intact microsomes with diazobenzene sulfonate or proteases does inactivate (or increase the apparent Km of) some other component which is rate-limiting for glucose-6-phosphatase activity in intact but not in disrupted microsomes. The simplest explanation for this phenomenon is that there is a protein carrier in the microsomal membrane which transports glucose 6-phosphate from the medium to the lumen, where it is hydrolyzed, and that diazobenzene sulfonate and proteases attack this carrier.
4
The lack of effect of these reagents on microsomal inorganic pyrophosphatase activity suggests that the glucose-6-phosphate carrier cannot transport pyrophosphate.
5
Finally, it was found that treatment of microsomes with ammonia breaks down their permeability barrier but also removes significant amounts of microsomal phospholipid and inactivates a number of microsomal enzymes. We do not recommend it as a general approach to altering microsomal permeability.
TL;DR: In this paper, a review of previous estimates of atmospheric sulfur budgets of scales ranging from global down to about 100 km is presented, with particular emphasis on the implied turnover times (i.e. average residence times) for the different sulfur compounds.
TL;DR: Human and mouse lymphocytes were surface‐labeled by lactoperoxidasecatalyzed iodination, or by galactose oxidase oxidation followed by reduction with tritiated sodium borohydride to produce pomatia A hemagglutinin.
Abstract: Human and mouse lymphocytes were surface-labeled by lactoperoxidasecatalyzed iodination, or by galactose oxidase oxidation followed by reduction with tritiated sodium borohydride. The labeled cells were lysed with Nonidet P-40. Proteins binding to Helix pomatia A hemagglutinin (HP) were isolated by affinity chromatography on HP-Sepharose and analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis and autoradiography.
A major cell surface glycoprotein (apparent mol. wt. 150000, using reducing conditions) on human lymphocytes was responsible for almost all binding of HP. This protein was present on normal and malignant thymus-derived lymphocytes, e.g. thymocytes, blood T cells and T leukemia cell lines. It was also found on chronic lymphocytic leukemia cells, one null cell leukemia line, one unidentified leukemia line, one lymphoblastoid cell line of B origin and on one stem cell lymphoma line. In contrast, this protein was not found on various B cells at different steps of differentiation, e.g. four B lymphoma lines or one myeloma line. It was also absent from a histiocytic leukemia line. However, two of the four B lymphoma lines and the myeloma line had another HP-binding surface glycoprotein (mol. wt. 200000) instead of the 150000 protein.
Studies of mouse lymphocytes similarly showed that thymus-derived lymphocytes (normal and malignant) but not normal adult B cells expressed a major HP-binding surface glycoprotein of apparent mol. wt. 130000 (reducing conditions).
TL;DR: In this article, a detailed discussion of the relationship between sulfur concentration and amount of precipitation is presented, and the results from a large number of additional sampling sites around and between the regular network sampling sites are most helpful in this regard.
TL;DR: A review of the literature indicates that men with Kartagener's syndrome are usually infertile, whereas the women are not as mentioned in this paper, and this fact and the data presented herein constitute strong evidence that ciliary motility is not essential for female fertility.
TL;DR: In this paper, the authors tested the relative plausibility of three main theories and hypotheses concerning the relationship between intolerance of ambiguity and socio-politico ideology: (a) authoritarian personality theory, (b) the extremism hypothesis and (c) the context hypothesis.
Abstract: This study tested the relative plausibility of three, main theories and/or hypotheses concerning the relationship between intolerance of ambiguity and socio-politico ideology: (a) authoritarian personality theory, (b) the extremism hypothesis and (c) the context hypothesis. The sample consisted of 195 Swedish high school students randomly selected from five different high schools from greater Stockholm in the spring of 1974. Separate factor analyses of the Budner Intolerance of Ambiguity Scale and the S4 Conservatism Scale generated seven factors of ambiguity intolerance and five factors of socio-politico ideology, Scattergram, correlation and trend analyses disclosed a number of statistically significant relationships between the various dimensions of ambiguity intolerance and socio-politico ideology. The main trend of the results tended to confirm authoritarian personality theory concerning the relationship between intolerance of ambiguity and racism or ethnic prejudice. Furthermore, some support was found for the context hypothesis, with regards to the relationship between general intolerance of ambiguity and general conservatism, among other things. No support could be found for the extremism hypothesis.
TL;DR: A ring detector positron camera system for brain metabolism studies is being constructed at the Institute of Physics, University of Stockholm, in collaboration with the Departments of Neuroradiology and clinical Neurophysiology.
Abstract: A ring detector positron camera system for brain metabolism studies is being constructed at the Institute of Physics, University of Stockholm, in collaboration with the Departments of Neuroradiology and clinical Neurophysiology, Karolinska Sjukhuset, Stockholm, Sweden. The instrument utilizes 95 NaI(Tl) detectors and will simultaneously record coincidences from 1900 detector combinations. Each detector is coupled in coincidence with forty detectors on the opposite side of the ring. In the conventional stationary mode of operation the experimental system resolution is 10.5 mm. A new sampling technique has been developed to reduce the system resolution. Based on this technique, an experimental system resolution of 7 mm has been obtained.