Fracturing and tectonic stress drive ultrarapid magma flow into dikes

Many examples of exposed giant dike swarms can be found where lateral magma flow has exceeded hundreds of kilometers. We show that massive magma flow into dikes can be established with only modest overpressure in a magma body if a large enough pathway opens at its boundary and gradual buildup of high tensile stress has occurred along the dike pathway prior to the onset of diking. This explains rapid initial magma flow rates, modeled up to about 7400 cubic meters per second into a dike ~15-kilometers long, which propagated under the town of Grindavík, Southwest Iceland, in November 2023. Such high flow rates provide insight into the formation of major dikes and imply a serious hazard potential for high-flow rate intrusions that propagate to the surface and transition into eruptions.

Metabolite Profile Characterization of Cyanobacterial Strains with Bioactivity on Lipid Metabolism Using In Vivo and In Vitro Approaches

Cyanobacteria have demonstrated their therapeutic potential for many human diseases. In this work, cyanobacterial extracts were screened for lipid reducing activity in zebrafish larvae and in fatty-acid-overloaded human hepatocytes, as well as for glucose uptake in human hepatocytes and ucp1 mRNA induction in murine brown adipocytes. A total of 39 cyanobacteria strains were grown and their biomass fractionated, resulting in 117 chemical fractions. Reduction of neutral lipids in zebrafish larvae was observed for 12 fractions and in the human hepatocyte steatosis cell model for five fractions. The induction of ucp1 expression in murine brown adipocytes was observed in six fractions, resulting in a total of 23 bioactive non-toxic fractions. All extracts were analyzed by untargeted UPLC-Q-TOF-MS mass spectrometry followed by multivariate statistical analysis to prioritize bioactive strains. The metabolite profiling led to the identification of two markers with lipid reducing activity in zebrafish larvae. Putative compound identification using mass spectrometry databases identified them as phosphatidic acid and aromatic polyketides derivatives-two compound classes, which were previously associated with effects on metabolic disorders. In summary, we have identified cyanobacterial strains with promising lipid reducing activity, whose bioactive compounds needs to be identified in the future.

Deformation and seismicity decline before the 2021 Fagradalsfjall eruption

Increased rates of deformation and seismicity are well-established precursors to volcanic eruptions, and their interpretation forms the basis for eruption warnings worldwide. Rates of ground displacement and the number of earthquakes escalate before many eruptions^1-3, as magma forces its way towards the surface. However, the pre-eruptive patterns of deformation and seismicity vary widely. Here we show how an eruption beginning on 19 March 2021 at Fagradalsfjall, Iceland, was preceded by a period of tectonic stress release ending with a decline in deformation and seismicity over several days preceding the eruption onset. High rates of deformation and seismicity occurred from 24 February to mid-March in relation to gradual emplacement of an approximately 9-km-long magma-filled dyke, between the surface and 8 km depth (volume approximately 34 × 10⁶ m³), as well as the triggering of strike-slip earthquakes up to magnitude M_W 5.64. As stored tectonic stress was systematically released, there was less lateral migration of magma and a reduction in both the deformation rates and seismicity. Weaker crust near the surface may also have contributed to reduced seismicity, as the depth of active magma emplacement progressively shallowed. This demonstrates that the interaction between volcanoes and tectonic stress as well as crustal layering need to be fully considered when forecasting eruptions.

Unexpected large eruptions from buoyant magma bodies within viscoelastic crust

Large volume effusive eruptions with relatively minor observed precursory signals are at odds with widely used models to interpret volcano deformation. Here we propose a new modelling framework that resolves this discrepancy by accounting for magma buoyancy, viscoelastic crustal properties, and sustained magma channels. At low magma accumulation rates, the stability of deep magma bodies is governed by the magma-host rock density contrast and the magma body thickness. During eruptions, inelastic processes including magma mush erosion and thermal effects, can form a sustained channel that supports magma flow, driven by the pressure difference between the magma body and surface vents. At failure onset, it may be difficult to forecast the final eruption volume; pressure in a magma body may drop well below the lithostatic load, create under-pressure and initiate a caldera collapse, despite only modest precursors.

Gradual caldera collapse at Bárdarbunga volcano, Iceland, regulated by lateral magma outflow

Large volcanic eruptions on Earth commonly occur with a collapse of the roof of a crustal magma reservoir, forming a caldera. Only a few such collapses occur per century, and the lack of detailed observations has obscured insight into the mechanical interplay between collapse and eruption. We use multiparameter geophysical and geochemical data to show that the 110-square-kilometer and 65-meter-deep collapse of Bárdarbunga caldera in 2014-2015 was initiated through withdrawal of magma, and lateral migration through a 48-kilometers-long dike, from a 12-kilometers deep reservoir. Interaction between the pressure exerted by the subsiding reservoir roof and the physical properties of the subsurface flow path explain the gradual, near-exponential decline of both collapse rate and the intensity of the 180-day-long eruption.

Monitoring, alarm, and data visualization service on sample preparing and sample storing devices in biobanks

An important feature in "Good Biobanking Practices" is to monitor and log conditions of sample storing devices. The Institute of Laboratory Medicine at Landspitali University Hospital in Reykjavik, Iceland, has installed a temperature monitoring and alarm system for freezers, incubators, and refrigerators as a part of its quality program. This paper describes the key features of the system, how it works, and what has been learned.

[Quinolone resistance in Gram negative rods in Iceland and association with antibiotic use]

OBJECTIVE

Fluoroquinolones are bacteriocidal drugs that are widely used to treat severe urinary and respiratory tract infections. Studies show that resistance to fluoroquinolones is continuously increasing both in Europe and the United States. The purpose of this study was to measure the frequency of fluoroquinolone resistance in the most prevalent Gram negative rods and look at the correlation with fluoroquinolone use over the last 8 years.

MATERIALS AND METHODS

All strains of Escherichia coli, Klebsiella sp., Proteus sp. and Pseudomonas aeruginosa identified from clinical specimens at the Department of Clinical Microbiology at the Landspitali University Hospital (LUH) during the time period 1.11.2006 to 31.1.2007. Antibiotic susceptibility testing was performed by disc diffusion tests and all strains were tested for ciprofloxacin susceptibility. Antibiotic resistance data for the last years were collected from the reports of the Department of Clinical Microbiology, but ciprofloxacin susceptibility was usually only tested for specimens from hospitalised patients and when there was resistance to two or more antimicrobial agents. Data on antibiotic use/sales was obtained from the State Epidemiologist at the Directorate of Health.

RESULTS

Of the 1861 strains tested, 104 fluoroquinolone resistant strains were identified during the study period, including 91 E. coli (87%), 8 Klebsiella sp. (8%) and 5 P. aeruginosa (5%). No fluoroquinolone resistant Proteus sp. was identified. There was a significant positive correlation between fluoroquinolone use and the frequency of resistant strains of E. coli and Enterobacteriaceae. The frequency of resistant E. coli strains was 6% and it differed significantly between age groups (p >0.001) and sex, 6% for females and 11% for males (p = 0.015). The ratio of fluoroquinolone resistant E. coli was highest in the LUH and homes for the elderly.

CONCLUSION

The frequency of fluoroquinolone resistance is increasing fast in Iceland but is still one of the lowest compared to the other European countries. The frequency is highest in the oldest age groups where the use of the quinolones is the greatest and there was a significant correlation between the quinolone use and the frequency of resistance in E. coli and Enterobacteriaceae. The results highlight the importance of prudent fluoroquinolone use and the need to monitor fluoroquinolone use and resistance.

The molecular epidemiology of genital Chlamydia trachomatis in the greater Reykjavik area, Iceland

BACKGROUND

The diversity in MOMP (major outer membrane protein) of Chlamydia trachomatis is thought to be necessary for the bacteria to survive in its environment. The rate of change in the omp1 gene (coding for MOMP) is not known. Iceland offers a good opportunity to study the epidemiology of chlamydial infections because the population is small (280,000) and geographically well defined.

GOAL

The goal was to determine the number and distribution of genotypes in a population attending the STD clinic in Reykjavík and to assess changes in omp1 sequences over a period of 2 years.

STUDY DESIGN

Three-hundred thirty isolates of C trachomatis collected periodically from January 1999 to January 2001 were omp1 genotyped with nested PCR and sequencing.

RESULTS

The serotypes found, in descending order of prevalence, were E, D, J, F, K, G, H, and I. Eighteen distinctive genotypes were found. During the study period no significant changes in frequency of genotypes were noted, and introduction of new or changed genotypes was not observed.

CONCLUSION

The results indicate a relatively stable situation of genotypes and suggest an ecological advantage of serotype E.

Listeriosis in Iceland, 1978-2000: a description of cases and molecular epidemiology

The purpose of our study was to review all cases of listeriosis in Iceland during the period 1978-2000 and to analyse the genetic relatedness of their isolates. Case records of all patients in Iceland with listeriosis during the period were reviewed and the isolates compared using serotyping and pulsed-field gel electrophoresis (PFGE) using SmaI, AseI and ApaI restriction enzymes. Forty cases of listeriosis were diagnosed during the period, resulting in a mean annual incidence of 6.9 cases per million and a case fatality rate of 33%. In the first 5 y of the study only serotype 4b was observed; subsequently serotypes 1/2a and 1/2b appeared and serotype 4b declined in prevalence. PFGE yielded 24 different genotypes with 7 clusters of indistinguishable genotypes, each comprising 2-6 cases. During 1992-95 the annual incidence of listeriosis in Iceland rose to 15 cases per million. This was largely due to 2 clusters, 1 of 3 cases and the other of 6. No cases of listeriosis were diagnosed during 1998-2000. Our data show an increased number of cases within clusters in the latter half of the period. At the same time, food processing and distribution has become increasingly centralized in Iceland, suggesting an increased risk of listeriosis outbreaks.

Transvaginal hydrolaparoscopy: a new diagnostic tool in infertility investigation

BACKGROUND

To establish the value of a new technique called transvaginal hydrolaparoscopy for exploration of the tubo-ovarian structures in the management of patients with unexplained infertility.

METHODS

A total of 120 women with primary or secondary infertility, and without obvious pelvic pathology, were included in the study. The first 14 patients received general anesthesia and underwent transvaginal laparoscopy immediately before standard laparoscopy. The remaining 106 patients had transvaginal laparoscopy performed under local anesthesia, with standard laparoscopy performed only on those with pathology, which required operative intervention. Information on pathology, complications, and successful access to the pouch of Douglas were recorded.

RESULTS

The successful rate of access was 93%. Pathology was found in 29 patients, of whom 15 required operative laparoscopy. Also, out of 19 patients with adhesions, 11 (58%) had normal dye test bilateral, and only two (11%) had bilateral occlusion of the tubes. No complications were observed.

CONCLUSION

Transvaginal hydrolaparoscopy is a safe and well-tolerated method for investigating the tubo-ovarian structures in unexplained infertility. It is superior to hysterosalpingography for diagnosis of adhesions.

Comparison of Roche Cobas Amplicor and Abbott LCx for the rapid detection of Chlamydia trachomatis in specimens from high-risk patients

OBJECTIVE

To evaluate two automated amplification systems for the detection of Chlamydia trachomatis in urogenital specimens, the Cobas Amplicor (Roche Diagnostic Systems, Branchburg, NJ) and the LCx (Abbott Laboratories, Abbott Park, IL).

STUDY DESIGN

The two systems were compared testing specimens from 302 high-risk patients, including 98 female cervical swab specimens and 204 male urine specimens. The patients attended the state STD clinic in Reykjavik, Iceland, either because of symptoms or as a result of contract tracing.

RESULTS

The prevalence of C. trachomatis infection was 15.3% in women and 13.2% in men. For the male urine specimens, the sensitivity and specificity were 100% and 99.4% for the Cobas Amplicor and 74.1% and 100% for the LCx. In the cervical swabs, both systems detected all 15 true-positive specimens. The internal control used with the Cobas Amplicor detected inhibition in 2% of the male urine and 20% female cervical swabs, respectively.

CONCLUSION

The Cobas Amplicor demonstrated slightly better sensitivity than LCx in male urine specimens. Both systems offer the benefits of automation for routine diagnostic testing.

Reduced prevalence of cervical Chlamydia infection among women requesting termination

BACKGROUND

The prevalence and pattern of Chlamydia trachomatis infection among women requesting induced abortion in the three year period 1992-95 was evaluated and compared to the results of a previous study in 1982-84, where the prevalence of chlamydial infection had been 13.5%.

METHODS

A total of 1995 women requested termination, 1855 (93%) of whom were tested for Chlamydia and were included in the study. Two types of tests for chlamydial infection, ELISA and PCR, were used in two consecutive periods. In addition cultures for gonorrhea were done in each case. Information on age, marital status, parity, gestational age and the results of chlamydia and gonorrhea tests of the women and sexual partners were recorded.

RESULTS

Chlamydia trachomatis positive women were 149 (8.0%), a significant reduction from the previous 1982-84 study (p<0.001). Women with positive tests were significantly younger (80% < or = 25 years of age; p<0.001) and more frequently single (86.6%; p<0.001), than those with negative tests, as in the previous period. Of the partners, 80.4% were contacted, and 52.1% presented for investigation. Of those tested 42.1% were Chlamydia positive. Four women (0.2%) had Neisseria gonorrhea but none of the partners.

CONCLUSIONS

The prevalence of Chlamydia trachomatis is receding among women coming for termination of pregnancy. As treatment before or at operation has repeatedly been shown to be of benefit and since the prevalence is still considerable, continued screening of these women is justified.

Life-threatening Haemophilus influenzae infections in Scandinavia: a five-country analysis of the incidence and the main clinical and bacteriologic characteristics

The five countries of Scandinavia (Denmark, Finland, Iceland, Norway, and Sweden) comprise 22.6 million inhabitants and rather homogeneous socioeconomic conditions. A survey of systemic Haemophilus influenzae diseases over the last decades revealed that the reported incidence of H. influenzae disease is increasing. In recent years, the overall incidence has been 3.5 cases per 100,000 people each year (800 cases annually); in children less than 5 years of age, the annual incidence has been 49 cases per 100,000. Meningitis represents only 52% of all systemic H. influenzae diseases, but lack of reliable data may obscure the importance of other entities. Few strains (less than 5%) are beta-lactamase-positive, and the case fatality rate is 3%. Analysis of seasonal variation shows peaks in June and September-October. If the efficacy of the H. influenzae conjugate vaccines were as high as that of a conjugate vaccine used in Finland during 1986-1987 (approximately 85% efficacy), then at least an 80% reduction in life-threatening H. influenzae infections would be achieved annually by routine immunization before or at the age of 6 months.

Meningococcal serotypes and serogroup B disease in north-west Europe

Examination of the trends of meningococcal infection in Norway, Iceland, Faroe Islands, Denmark, England and Wales, and the Netherlands, has shown that Neisseria meningitidis B:2b:P1.2 and/or B:2a:P1.2 phenotypes were associated with peaks of infection in the Netherlands in 1966, in Iceland 1976-77, and in England and Wales in 1973-75. These strains were present in all six countries in the decade 1970-80 but their prevalence is now practically negligible. In contrast the prevalence of the B:15:P1.16 phenotype has risen. In the Faroe Islands and northern Norway this change in serotype prevalence has been followed by rises in incidence of meningococcal disease; the same is happening in England and Wales but not yet in the other countries.

Meningococcal disease in Scandinavia

Scandinavia (Denmark, Finland, Iceland, Norway, and Sweden) comprises with mutual borders and 22.3 million inhabitants an area where the socioeconomic and cultural conditions are similar. Epidemic diseases, such as meningococcal infection, might therefore be expected to be uniformly distributed. An epidemiological study in the 10-year period 1970-9 shows, however, remarkable differences in the incidence, age, and serogroup and type distribution, as well as in the general dynamics of the disease. Three epidemics, two caused by different serotypes of group B (Norway and Iceland) and one by group A (Finland) occurred within the observation period. The annual overall incidence was generally around 3/100 000 but increased from fivefold (Finland) to eightfold (northern Norway) during epidemics. The epidemic strains caused infection in over 3000 patients and the loss of at least 250 lives. The overall case fatality rate was 8.6% (range 4.1-13.7%). Men were more susceptible and had a worse prognosis than women of the same age group. The group A epidemic in Finland was influenced by a large vaccination campaign, but this possibility was not feasible in the two other epidemics.