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With the ever-increasing emphasis on climate change and sustainability, there is growing interest in using environmentally friendly coastal structures. In addition to engineering and cost factors, the construction global warming potential (GWP) can and should be an influencing factor in the selection and design of the structures. Therefore, knowledge of construction GWP facilitates informed decision-making in coastal projects to achieve climate goals. Considering the number of Icelandic-type berm breakwater (IceBB) structures worldwide, this structure's design method is commonly accepted in coastal protection projects. In this paper, the construction process of an IceBB was assessed for its GWP and compared with concrete armor unit protection of a conventional rubble mound breakwater (ConRMB). The assessment and comparison were made for constructing a breakwater to protect the port of Thorlakshofn in southwest Iceland. The life cycle assessment (LCA) methodology was applied to calculate the construction carbon footprint of the structures using GaBi software, version 10.6.1. Using the International Union for Conservation of Nature (IUCN) criteria for nature-based solutions (NBS) and based on the existing literature, the characteristics of IceBB were briefly explored. The results showed that the construction of IceBB has a lower GWP than ConRMB, mainly due to using natural rock armor instead of concrete armor units. Furthermore, the results indicated that IceBB characteristics meet the IUCN criteria for NBS and thus can be granted as a (hard) NBS coastal structure. Acknowledging the advantages of IceBB, adopting this structure in coastal protection projects could meaningfully contribute to climate change mitigating policies. [ABSTRACT FROM AUTHOR]

Objective: To determine the prevalence of hypnic headache.Background: The exact prevalence of hypnic headache is unknown since there are no published population-based prevalence studies.Methods: This study was a pilot for the SAGA cohort study, a population-based study on life stressors and various indices of health. Of 1398 invited adults, 921 (66%) participated; 402 men (average age 45.6 years, SD 13.2) and 519 women (52.6 years, SD 11.1). Subjects answered a headache questionnaire including a screening question for hypnic headache. "Do you have a headache that occurs only during sleep and causes wakening?". Diagnosis of hypnic headache was made by clinical interview using ICHD-3 criteria.Results: Among 921 participants, six screened positive for hypnic headache, of those two 0.22% (95% CI 0.06-0.79%) had probable hypnic headache and none had definite hypnic headache.Conclusion: Confirming that hypnic headache is rare, these data suggest a 0.22% prevalence of probable hypnic headache. [ABSTRACT FROM AUTHOR]

Objectives: The Icelandic Sagas are an important source of information on the way of life and diet habits in Iceland and possibly other Nordic countries 1000 years ago. Archaeological human skull material worldwide has revealed extensive tooth wear, with the main cause believed to be coarse diet. From a graveyard near volcano Hekla, 66 skeletons dated from before 1104 were excavated. The purpose of this study was to determine the main causes of tooth wear in Icelanders 1000 years ago.Materials and Methods: Forty-nine skulls were available for research. Two methods were used to evaluate tooth wear and seven for age estimation. An attempt was made to determine the main causes of tooth wear in the light of likely diet and beverage consumption according to a computer search on food and drink customs described in the Icelandic Sagas.Results: Tooth wear was extensive in all groups, increasing with age. The highest score was on first molars, with no difference between sexes. It had all the similarities seen in wear from coarse diet. In some instances it had similar characteristics to those seen in erosion in modern Icelanders consuming excessive amounts of soft drinks. According to the Sagas, acidic whey was a daily drink and used for preservation of food in Iceland until recently.Conclusions: Since acidic whey has considerably high dental erosive potential, it is postulated that consumption of acidic drinks and food, in addition to a coarse and rough diet, played a significant role in the dental wear of ancient Icelanders. [ABSTRACT FROM AUTHOR]

Abstract: During the time period of the eruption of the Icelandic volcano Eyjafjallajökull in April/May 2010 the Duesseldorf University of Applied Sciences has performed 14 research flights in situations with and without the volcanic ash plume over Germany. In parallel to the research flights in Germany three measurement flights have been performed by the University of Iceland in May 2010 over the western part of Iceland. During two of these flights the outskirts of the eruption plume were entered directly, delivering most direct measurements within the eruption plume during this eruptive event. For all the measurement flights reported here, light durable piston-motor driven aircrafts were used, which were equipped with optical particle counters for in-situ measurements. Real-time monitoring of the particle concentrations was possible during the flights. As different types of optical particle counters have been used in Iceland and Germany, the optical particle counters have been re-calibrated after the flights to the same standard using gravimetric reference methods and original Eyjafjallajökull volcanic ash samples. In-situ measurement results with high spatial resolution, directly from the eruption plume in Iceland as well as from the dispersed and several days old plume over Germany, are therefore presented here for the first time. They are normalized to the same ash concentration calibration standard. Moreover, airborne particles could be sampled directly out of the eruption plume in Iceland as well as during the flights over Germany. During the research flights over Iceland from 9 May 2011 to 11 May 2011 the ash emitted from the vent of the volcano turned out to be concentrated in a narrow well-defined plume of about 10 km width at a distance of 45–60 km away from the vent. Outside this plume the airborne ash concentrations could be proved to be below 50 μg m−3 over western Iceland. However, by entering the outskirts of the plume directly the research aircraft could detect ash concentrations of up to 2000 μg m−3. On the other hand, the ash plume, which was analysed by research flights over Germany several thousand km away from the eruption vent, appeared to be significantly structured in horizontal and vertical directions. Different sub-plumes could be found. Peak concentrations of more than 330 μg m−3 could be detected. The results of the measurements within the ash plume over Germany were compared with the predictions of the London VAAC model. The range of ash concentrations found by the research aircraft in Germany were not in conflict with the calculations of concentration regimes by the London VAAC model. However, the in-situ measurements performed by the research aircraft were able to deliver information about the structure and composition of the ash plume, which could not be covered by the dispersion model. Therefore, light piston-motor driven aircrafts equipped with optical particle counters proved to be a very versatile tool for the real-time in-situ determination of the spatial extension of volcanic ash plumes, the ash particle size distributions and the particle mass concentrations. Moreover, all these parameters could be measured with a high horizontal and vertical spatial resolution. Therefore, these kinds of measurements can deliver immediate data for the validation and verification of dispersion models and can give direct in-situ information additional to LIDAR measurements and satellite observations. As the piston-motor driven aircrafts are able to operate even at elevated volcanic ash concentrations they can provide valuable ash concentration results for air traffic safety. [Copyright &y& Elsevier]

Arnadottir IB, Holbrook WP, Eggertsson H, Gudmundsdottir H, Jonsson SH, Gudlaugsson JO, Saemundsson SR, Eliasson ST, Agustsdottir H. Prevalence of dental erosion in children: a national survey. Community Dent Oral Epidemiol 2010; 38: 521-526. © 2010 John Wiley & Sons A/S To measure the prevalence of dental erosion in permanent teeth in Iceland as part of the National Oral Health Survey. A representative, nationwide sample of 2251 Icelandic children, 20% of those aged 6, 12 and 15 year, was examined. Dental erosion was recorded for all erupted permanent teeth and graded using the modified scale of Lussi. Erosion was not seen in the permanent teeth of six-year-olds, but was present in 15.7% of 12-year-olds, more frequently in boys than girls (19.9% boys, 11.0% girls; P < 0.001). Among 15-year-olds, dental erosion was seen among 30.7% of subjects (38.3% boys, 22.7% girls; P < 0.001). Severity of erosion was mostly scored as grade I, with only 5.5% of 15-year-olds scored as grade II, mostly on tooth 46 (4.3%) and 36 (4.2%). For 12-year-olds, 0.9% had erosion scores of grade II mostly on tooth 46 (0.8%) and 36 (0.7%). No subjects had erosion of grade III. The most common clinical manifestation of erosion was the appearance of cup-like lesions on the cusps of lower first molars. Dental erosion was frequently present by the age of 12; the prevalence doubled by age 15 and was seen almost twice as often among boys than girls. Teeth most frequently showing signs of erosion were the lower first molars. The rapidly growing prevalence of erosion demonstrated by this nationwide survey emphasizes the need for further research into the aetiology of erosion and possible methods of preventing and treating this emerging dental problem. [ABSTRACT FROM AUTHOR]

Agustsdottir H, Gudmundsdottir H, Eggertsson H, Jonsson SH, Gudlaugsson JO, Saemundsson SR, Eliasson ST, Arnadottir IB, Holbrook WP. Caries prevalence of permanent teeth: a national survey of children in Iceland using ICDAS. Community Dent Oral Epidemiol 2010; 38: 299–309. © John Wiley & Sons A/S Objectives: The Icelandic Oral Health Survey aimed to obtain new national data on the oral health of Icelandic children and teenagers. Methods: A representative stratified random cluster sample of 2251 Icelandic children in first, seventh and 10th grade, aged approximately 6-, 12- and 15-years old was examined for caries prevalence using the ICDAS criteria. Bite-wing digital radiographs were obtained for the children in 7th and 10th grade. Results: D3MFT scores by visual examination of 6-, 12- and 15-year olds were 0.12, 1.43 and 2.78 respectively but when including radiographs, the D3MFT rose to 2.11 at 12 years and 4.25 at 15 years. The Significant Caries Index, SiC, by visual examination for 12 and 15 y was 3.7 and 6.7 respectively but was 4.7 for 12 y and 8.9 for 15 y with radiographs. In all age groups and at most disease levels, caries was active in the majority of the lesions (58–100%). The percentage of children with no visually detectable caries at D3/D1 level was 93%/74% for 6 years, 48%/22% for 12 years and 35%/16% for 15 years. When radiographs were included the percentage reduced to 34%/15% for 12 years and 20%/6% for 15 years. Approximately 80% of 12- and 15-year-olds had at least one of their first molars sealed, with the mean number of sealed first molars being 2.2 among 12 y and 2.0 among 15 y. Conclusions: Caries levels were higher than expected in this national survey and further away from the goals of the National Health Plan for 2010 than anticipated. Caries distribution was skewed with more than half of the children having low caries scores but a wide distribution of caries experience was seen among the remaining population. [ABSTRACT FROM AUTHOR]

Precipitation simulations on an 8×8 km grid using the PSU/NCAR Mesoscale Model MM5 are used to estimate the M5 and Ci statistical parameters in order to support the M5 map used for flood estimates by Icelandic engineers. It is known a priori that especially wind anomalies occur on a considerably smaller scale than 8 km. The simulation period used is 1962-2005 and 73 meteorological stations have records long enough in this period to provide a validation data set. Of these only one station is in the central highlands, so the highland values of the existing M5 map are estimates. A comparison between the simulated values and values based on station observations set shows an M5 average difference (observed-simulated) of -5 mm/24 h with a standard deviation of 17 mm, 3 outliers excluded. This is within expected limits, computational and observational errors considered. A suggested correction procedure brings these values down to 4mm and 11 mm, respectively. [ABSTRACT FROM AUTHOR]

The heat loss theory and the hydraulic theory for the analysis of the development of wide channel ice jams are discussed and shown. The heat loss theory has been used in Iceland for a long time, while the hydraulic theory largely follows the classical ice-jam build-up theories used in known CFD models. The results are combined in a new method to calculate the maximum thickness and the extent of an ice jam. The results compare favorably to the HEC-RAS model for the development of a very large ice jam in Thjorsa River in Iceland, and have been found in good agreement with historical data, collected where a hydroelectric dam project, Urridafoss, is being planned in the Thjorsa River. [ABSTRACT FROM AUTHOR]

Hálslón reservoir is the main reservoir of the Kárahnjúkar hydropower project in the eastern highlands of Iceland. Studies for the environmental impact assessment for the hydropower project showed that sediment will fill the reservoir in about 500 years based on the present sediment transport rate. The main source of the sediment is the Brüarjökull outlet glacier which is a part of the Vatnajökull ice cap. Recent studies of the influence of climate warming on glaciers in Iceland show that they will decrease significantly and, in some cases, completely disappear during the nest few hundred years. In this study, a glacier melt model for the Brúarjökull outlet glacier is constructed to predict how fast the glacier will retreat in response to accepted climate warming scenarios. The results from the glacier model are then used as input to a sediment transport mass balance model for the Hálslón reservoir, which predicts the influence of the retreat of the glacier on the sedimentation in the reservoir. The modeling shows that, instead of the reservoir being completely full of sediment in 500 years, the Hálslón reservoir will at that time still have about 50-60% of its original volume as the sediment yield will decrease as a result of the decreasing glacier size. [ABSTRACT FROM AUTHOR]

Abstract: Water resources are economically important and environmentally extremely vulnerable. The electrical power system in Iceland is hydropower based and due to the country’s isolation, power import is not an option as elsewhere in Europe. In the hydropower system, a water shortage is met by flow augmentation from reservoirs. The management of these reservoirs are a human intervention in a natural flow and therefore necessarily limited by environmental regulations. During a heavy drought, the available water storage in the reservoir may not be sufficient to cater for the demand and consequently there will be a shortage of electrical power. This is politically acceptable as long as it only touches heavy industries but not power deliveries to the common market. Empty or near empty reservoirs cause power shortage that will be felt by homeowners and businesses, until spring thaw sets in and inflow to the reservoirs begins. If such a power shortage event occurs, it will cause heavy social problems and a political decision making will follow. It is commonly agreed, that management methods leading to such a disastrous event as a general power shortage in the whole country, are not acceptable. It is therefore very important to have mathematical tools to estimate the risk of water shortage in the system when searching for the best management method. In view of the fact that the subject is to estimate the risk of events that have to be very rare, i.e. with large recurrence time, stochastic simulation is used to produce synthetically run-off records with adequate length, in order to estimate very rare droughts. The method chosen is to make the run-off series stationary in the mean and the variance and simulating the resulting stationary process. When this method is chosen, future trends in the run-off from climate change and glacier reduction can easily be incorporated in the model. The probabilities of extreme droughts are calculated and their frequencies are compared to theoretical distributions. [Copyright &y& Elsevier]

Ninety-one Icelandic practicing dentists (51% response rate) provided information related to the reasons for placement and replacement of 8,395 restorations and 741 sealants in 5,997 patients. Information included the patients' gender and age, clinician's gender and experience and years since graduation, the defined criteria for placement of restorations, the estimated past use of material in five-year increments and the records of 100 consecutively placed restorations. The material used includes composite (52.7%), amalgam (29.2%), glass ionomer (9.5%), resin-modified glass ionomer (7.1%), and other materials (1.4%). Although material selection was independent of the clinician's gender, female patients received more composite and fewer amalgam restorations than their male counterparts. Reasons for placing restorations comprised placement of failed restorations (47.2%), primary caries (45.3%) and non-caries defects (7.5%). Secondary caries was the main reason for replacement for all types of restorations. Chi square analysis related to the dependence between the reasons for replacement and clinicians experience showed that more experienced clinicians recorded a lower frequency of secondary caries than less experienced ones (p<0.0001), while the diagnosis of discoloration and fracture of restorations increased with the clinicians' experience (p<0.0001). [ABSTRACT FROM AUTHOR]

A random sample of 1023 people 52-79 yr of age out of a group participating in a longitudinal study at the Heart Preventive Clinic of the Icelandic Heart Association in Reykjavik, Iceland, was examined. The examination was carried Out in 1985-7. The results on the number of remaining teeth and total edentulousness were compared to information regarding smoking habits and social status. Total edentulousness was more common among women. Total and partial edentulousness was more frequent in the lower "employment" classes while no statistical difference was found for smoking in this respect. This, however, did not affect the significance of tobacco smoking as a factor in the loss of teeth. In general smokers had fewer remaining teeth and were more often edentulous than ex-smokers, smoking time not considered, who again suffered more tooth loss than those who had never smoked. Therefore it is concluded that tobacco smoking may be a major single independent risk factor in the loss of teeth. [ABSTRACT FROM AUTHOR]

The article discusses a study which investigated the association between migraine with aura and increased mortality from cardiovascular disease, other causes, and all causes. The prospective cohort study involved 18,725 men and women, who were born from 1907 to 1935 and are living in Reykjavik, Iceland. The authors concluded that people with migraine with aura have higher risk of all cause mortality.

Relative permeabilities of water and steam were calculated, by applying the Shinohara method, using data from geothermal wells in Iceland. This method does not require that the local water saturation of the two phase mixture is known, but requires production history of mass flow and enthalpy from each well. The results were compared to relative permeability curves found in literature and to values from laboratory measurements and revealed that wells within the same field can follow different relative permeability curves. This method enabled us to get relative permeability values for geothermal wells with production history. [ABSTRACT FROM AUTHOR]