Showing papers by "University of Iceland published in 1985"
TL;DR: In this paper, the results of five gas geothermometers are presented, three of which used CO2, H2S and H2 concentrations in fumarole steam, respectively.
212 citations
TL;DR: In this article, a new carbonate-silica mixing model is proposed which is useful in distinguishing boiled and non-boiled geothermal waters, which can also be used to estimate underground temperatures using data from warm springs.
160 citations
TL;DR: With few exceptions the upper mode fish smoltified and showed no gonadal maturation in June/July of the second year, following the segregation, while the lower mode fish did not smoltify and had a high incidence of mature males.
97 citations
01 Jan 1985
67 citations
TL;DR: Thermophilic obligately autotrophic hydrogen-oxidizing bacteria were isolated from several alkaline hot springs in Iceland and were very sensitive to common antibiotics.
Abstract: Thermophilic obligately autotrophic hydrogen-oxidizing bacteria were isolated from several alkaline hot springs in Iceland. The bacteria were Gram negative rods, 0.4–0.5 μm in diameter and 3–4 μm long but 6–7 μm long cells without septa were often seen. Long and short laments are formed. Spores, flagella or lipid granules were not observed. Strains H1 and H12 grew optimally at 70° C and pH 6.5 under mixture of air plus 0.6 atm H2 and 0.1 atm CO2. The cells contained cytochromes and carotenoid-like pigments. They would not grow on agar or silicia gel plates. The cells would not grow heterotrophically on organic substrates and were inhibited by most of these same organic compounds and agar in low concentrations. They were very sensitive to common antibiotics. The role of these bacteria in the hot spring ecosystem is discussed.
55 citations
TL;DR: In this article, the authors looked at the relationship between suggestibility and personality as measured by the EPQ, perceptual defensiveness and belief in extraordinary and religious phenomena in Iceland.
43 citations
TL;DR: In this article, the authors extended the efforts of Kristjansson & McDougall to obtain a semi-quantitative description of various long-term (0.1-10 Myr) properties of the geomagnetic field in Iceland.
Abstract: Summary. This paper extends the efforts of Kristjansson & McDougall to obtain a semi-quantitative description of various long-term (0.1–10 Myr) properties of the geomagnetic field in Iceland. Due to the long time intervals between eruptions of the lavas recording the field, local average and stochastic properties are emphasized, rather than detailed aspects such as pole paths. These properties can be represented by smooth functions of virtual-pole latitude. It is possible to describe both the frequency distribution of virtual poles in latitude and the estimated frequency of geomagnetic reversals, by a simple process of random walk of the pole. This is also in agreement with the observed long-term symmetry of the reversal process, and demonstrates that memory effects are unnecessary to account for the behaviour of the field. The average transition time for the field isofthe order of 5—6000yr. Right-handedness is a pervasive property of the field in Iceland, apparently increasing with age. It is demonstrated that the size of palaeomagnetic collections in lava sequences has to be much larger than 20 units in order to yield consistent values of statistical parameters for mean palaeofield directions.
36 citations
TL;DR: Three populations in South- and North-Thingeyjarsýslas, Northeast Iceland, were surveyed for the presence of torus palatinus, and prevalence and size were affected by age and population but not by sex.
Abstract: Three populations in South- and North-Thingeyjarsýslas, Northeast Iceland, were surveyed for the presence of torus palatinus. A total of 987 schoolchildren (489 male and 487 female) were examined. A statistically significant difference was noted between the prevalence in South-Thingeyjarsýsla (33.3%) and North-Thingeyjarsýsla (14.6%). Prevalence and size were affected by age and population but not by sex. An association between torus palatinus and torus mandibularis was not found. Secular changes in the occurrence of torus palatinus in Icelanders emphasize the importance of environmental etiological factors and diminish the value of torus palatinus as a racial trait.
30 citations
TL;DR: The utilization of other compounds was variable and indicated a high degree of nutritional diversity among strains of Thermus, which were isolated from hot springs in Iceland.
28 citations
TL;DR: In this paper, the partial pressures of CO2, H2S and H2 in geothermal reservoir waters are fixed by temperature-dependent mineral equilibria, where the dissolved gases have a significant effect at which depth the rising hot waters start to boil, if their temperature exceeds 250°C and particularly when it exceeds 300°C.
21 citations
TL;DR: ED visits were found to predict hospital care utilization in a 5-year follow-up of a 10% population sample and the utilization of medical specialties differed most in psychiatry, where those with 4 or more ED visits had nearly 17 times more admissions per 100 personyears than non-visitors.
TL;DR: In this article, a generalized model of planar random surfaces with a curvature term in the action was introduced, and the authors established the basic thermodynamic properties of the model, proved reflection positivity of the two-loop function and verified tree bounds.
TL;DR: Serological responses of Icelandic sheep experimentally infected with visna virus were contrasted with responses in American Targhee sheep naturally infected with progressive pneumonia virus, suggesting important biological differences between the lytic fibroblast-tropic virus strains used for experimental infection and the nonlytic macrophage- Tropic strains of PPV circulating in nature.
TL;DR: Molybdenite has not been found in active geothermal systems in Iceland but is known to occur in some New Zealand geothermal system and it has been identified in hydrothermally altered Tertiary basalt formations at Reydarartindur in southeast Iceland.
Abstract: Molybdenum concentrations in Icelandic geothermal waters lie in the range 1–70 ppb. Warm waters and dilute high-temperature waters which contain high concentrations of sulphide are lowest in molybdenum. No correlation is otherwise observed between molybdenum concentrations and temperature. Surface waters and cold ground waters do not contain detectable molybdenum (<1 ppb). It seems likely that leaching rate is the prime factor in limiting molybdenum levels in these waters. Within individual geothermal fields molybdenum concentrations are either approximately constant or they vary regularly across the field. This regular variation may often be correlated with variations in other solute concentrations and subsurface temperatures and is taken to indicate a control of molybdenum mobility by a temperature dependent equilibrium. The evidence suggests that the solubility of molybdenite is responsible. Molybdenite has not been found in active geothermal systems in Iceland but is known to occur in some New Zealand geothermal systems and it has been identified in hydrothermally altered Tertiary basalt formations at Reydarartindur in southeast Iceland. Boiling and mixing with cold water leads to molybdenite undersaturation and thus these processes favour leaching of molybdenum from the rock. On the other hand, conductive cooling leads to supersaturation which favours removal of molybdenum from solution.
TL;DR: It appears that the CMI‐MR errs in the direction of false negatives when the symptoms are recent and related to situational stress, but the GHQ has a tendency to miss cases with symptoms of long standing.
Abstract: This study compares the 30-item version of the General Health Questionnaire (GHQ) and the psychiatric section of the Cornell Medical Index Health Questionnaire (CMI-MR) using normative data from a sample of the general population and data from general practice patients where clinical assessment by a psychiatrist is used as a criterion of psychiatric caseness. In this study the CMI-MR has a slightly better overall performance as a screening test. It appears that the CMI-MR errs in the direction of false negatives when the symptoms are recent and related to situational stress, but the GHQ has a tendency to miss cases with symptoms of long standing.
TL;DR: Systematic screening of women and teenage girls, with vaccination of seronegative persons, was more cost-effective than vaccination of all children, and use of rubella vaccine in combined vaccines proved the most expensive strategy.
Abstract: Cost-benefit analyses show that prevention of congenital rubella infection is cost-effective. Before selection of a strategy, local epidemiologic and social factors need examination. Analyzing these factors may lead to considerable cost reduction, especially if results from preexisting screening programs are available. The cost-effectiveness of different strategies are compared in Iceland. Systematic screening of women and teenage girls, with vaccination of seronegative persons, was more cost-effective than vaccination of all children. Previously unscreened females aged 12-40 years were screened and seronegative females were vaccinated for one-third the cost of vaccinating all children aged two to 12 years. Continuation of this program by vaccinating 12-year-old girls was two to three times more cost-effective than vaccination of all two-year-old children. Use of rubella vaccine in combined vaccines proved the most expensive strategy, with or without revaccination of teenagers.
TL;DR: A few of the solvents and drugs that cause flushing as well as Rovsing syndrome, cold urticaria, and hereditary vibratory angioedema are discussed, which were excluded in the previous review.
Abstract: lushing has many causes and is triggered by various F mechanisms; these are covered in a recent comprehensive review of the mechanisms and consequences of flushing reactions’ and are not covered in depth in this article. I do, however, discuss a few of the solvents and drugs that cause flushing as well as Rovsing syndrome, cold urticaria, and hereditary vibratory angioedema, which were excluded in the previous review. Transient erythema, called flushing, usually appears on the face but can include other areas-the neck (most frequent), the upper chest, and the abdomen. Because flushing is associated with so many conditions, it is perhaps simplest, when confronted with a patient complaining of flushing, to begin by categorizing the syndrome according to its associated or mediating factors (Tables 1-8). Once the syndrome has been categorized, it can be decided whether further laboratory evaluation i s necessary.
TL;DR: The fertility problems of dairy cows on problem farms in southern Iceland were late ovulations, low conception rate, probably in part, due to luteal phase inseminations, and a high frequency of ketosis which could be caused by low quality feedstuff.
Abstract: The purpose of this survey was to evaluate the reproductive performance of dairy cows on problem farms in southern Iceland. In all 229 cows on 6 farms were studied. The animals were examined clinically by rectal palpation, once a month. Blood samples were taken 2–5 and 7–10 weeks after calving. The blood samples were analysed for the contents of glucose, urea, inorganic phosphate, calcium and magnesium. Milk samples for progesterone profiles were taken, by the farmer, every 4th day from day 10 postpartum until first oestrus. Because of this sampling method, 128 cows had no rise in progesterone levels, when milk sampling was stopped. These 128 animals were excluded from the study. The results are based on 101 animals. There was a large variation between cows in postpartum reproductive performance. In the total material 1st ovulation occurred later than reported in many other countries. Fifty percent of the cows had ovulated 35 days after calving and 90 percent 70 days after calving. The first luteal phase was short in about 60 % of the cows. The progesterone values assayed from those short cycles were lower than the values assayed from the following cycle. First artificial insemination (ai) was on the average 77 days postpartum (pp). The conception rate to first service was 49 %. Of 100 milk samples taken at the time of ai, 20 had high progesterone value. This indicates a high frequency of luteal phase inseminations. Clinical ketosis was diagnosed in 35 cows. Of these, 31 had a low glucose value. Cows with clinical ketosis ovulated, on the average, later than other animals and 24 ovulated later than 40 days pp. The results indicated that the fertility problems of these cows studied were late ovulations, low conception rate, probably in part, due to luteal phase inseminations, and a high frequency of ketosis which could be caused by low quality feedstuff.
TL;DR: In the majority of cases campylobacteriosis presented as a mild disease, some patients however were severely ill and 22 were hospitalized and 22 (32.8%) were hospitalized.
Abstract: During a 2-year period, 67 isolates of Campylobacter ssp. were cultured from 7213 stool specimens submitted for culture from 4019 individuals (1.7%). In the same period considerably more strains of Salmonella were isolated, 164 (4.1%). In the majority of cases campylobacteriosis presented as a mild disease. Some patients however were severely ill and 22 (32.8%) were hospitalized. Clinical resemblance to ulcerative colitis caused diagnostic difficulties in several patients. Two thirds of the patients contracted their disease domestically. There was a marked seasonal variation with peak incidence during the summer months.
TL;DR: In the classical macroeconomic system, real wages were supposed to clear the labor market. Yet real wage rates were only slightly reduced by the massive and persistent unemployment during the depression as discussed by the authors.
Abstract: Ever since the days of Keynes, economists have been puzzled by the behavior of wages. In the classical macroeconomic system, real wages were supposed to clear the labor market. Yet real wage rates were only slightly reduced by the massive and persistent unemployment during the depression. It is true that nominal wage rates fell, but prices fell in roughly the same proportion.
01 Jan 1985
TL;DR: Stress is considered one of the pathogenic factors in development of coronary artery disease and increased sympathetic activity and elevated plasma levels of catecholamines influence markedly cardiac function and myocardial metabolism.
Abstract: Stress is considered one of the pathogenic factors in development of coronary artery disease. Increased sympathetic activity and elevated plasma levels of catecholamines influence markedly cardiac function and myocardial metabolism. Changes in function of the heart induced by exogenous or endogenous catecholamines during stress or significant changes in living conditions could modify composition of membrane lipids during the process of adaptation. Catecholamines have been shown to affect various aspects of glycerolipid metabolism (1).
TL;DR: The Nordic nuclear-weapons-free status date back to the 1950s and are still very much alive as mentioned in this paper, and the positions of the superpowers and domestic political dynamics could be the deciding factors.
Abstract: Proposals to formalize the Nordic nuclear-weapons-free status date back to the 1950s and are still very much alive. The positions of the superpowers and domestic political dynamics could be the deciding factors.
TL;DR: In this article, a temperature modulation technique has been developed for magnetic measurements in solids, and the basic principles of the method and the construction of apparatus for measurements of metals are described.
Abstract: A temperature modulation technique has been developed for magnetic measurements in solids. The paper outlines the basic principles of the method and the construction of apparatus for measurements of metals. Measurements of the temperature derivative of the magnetisation of the weak itinerant ferromagnet Ni 3 Al are reported. The field dependence of the temperature derivative of the magnetisation shows that the collapse of the magnetisation in Ni 3 Al with increasing temperature can be attributed to spin fluctuations.
TL;DR: In this article, the authors present a theoretical framework for assessing the consequences of an income policy in a unionised economy and present a model to capture relevant features of the wage formation process.
Abstract: Until quite recently there has been a dearth of interesting models which capture relevant features of the wage formation process in a unionised economy and which enable appropriate intervention policies to be analysed. There has been, for example, virtually no theoretical framework for assessing the consequences of an incomes policy. However, recent years have seen developments in this area; although we still have a long way to go before we reach an adequate understanding of some of these matters, there have been some significant advances in the last few years and the paper by Richard Jackman is an important contribution to the literature.
01 Jan 1985
TL;DR: The detection of microbial antigens by immunological methods has proven to be a clinically relevant and reliable method for the rapid diagnosis of infectious disease.
Abstract: The detection of microbial antigens by immunological methods has proven to be a clinically relevant and reliable method for the rapid diagnosis of infectious disease. Traditionally, the laboratory has isolated the microorganism from clinical specimens, and, if necessary, determined its antibiotic susceptibility profile. If cultural microbiology was either unsuccessful or beyond the competence of the routine laboratory, then patients were tested for specific antibody response. While important, this process is time-consuming, requiring specimens submitted 2–3 weeks apart unless an increase in IgM antibody can be observed.