Calculations of the effect of catalyst size and structure on the electrocatalytic reduction of CO2 on Cu nanoclusters.

The structure and catalytic properties of Cu nanoclusters of sizes between 55 and 147 atoms were examined to understand if small Cu clusters could provide enhancement over traditional catalysts for the electrocatalysis of CO2 to CO and carbon-based fuels, such as CH4 and CH3OH, compared to bulk Cu surfaces and large Cu nanoparticles. Clusters studied included Cu55, Cu78, Cu101, Cu124, and Cu147, the structures of which were determined using global optimisation. The majority of Cu clusters examined were icosahedral, including the perfect closed-shell, partial-shell, elongated and distorted icosahedral clusters. Free energy diagrams for the reduction of CO2 showed the potential required for the formation of CO is notably smaller for all cluster sizes considered, relative to Cu(111). Less variation is observed for the limiting potential for the formation of CH4 and CH3OH. However, it was found that clusters that are either a distorted motif or contain vacancy defects yielded the best activity and provide an interesting synthesis target for future experiments.

How a Scoville aneurysm clip fought in the Cold War and helped to establish neurosurgery in Iceland.

It can be said that the specialty of neurosurgery in Iceland had its beginnings on November 30, 1971, with the arrival of a huge American C-130 Hercules aircraft. It was carrying a small package containing Scoville aneurysm clips. They were sent to the late Bjarni Hannesson (1938-2013), who had received his neurosurgical training in 1967-1971 at the Dartmouth-Hitchcock Medical Center (then known as Mary Hitchcock Memorial Hospital and located in Hanover, New Hampshire). He used one to clip the right posterior communicating artery aneurysm of a 34-year-old fisherman, who recovered well. The apparent reason for the use of such a huge aircraft for such a small payload is to be found in the sociocultural politics of the Cold War. It involved the continued presence of the American base at Keflavík, where the C-130 landed. The base was under pressure to be closed by Iceland's left-leaning, nominally communist government. The C-130's arrival generated welcome publicity for the continued operation of the American base, which is still there.

The distribution and diversity of eukaryotic phytoplankton in the Icelandic marine environment.

Phytoplankton play a crucial role in the marine food web and are sensitive indicators of environmental change. Iceland is at the center of a contrasting hydrography, with cold Arctic water coming in from the north and warmer Atlantic water from the south, making this geographical location very sensitive to climate change. We used DNA metabarcoding to determine the biogeography of phytoplankton in this area of accelerating change. Seawater samples were collected in spring (2012-2018), summer (2017) and winter (2018) together with corresponding physico-chemical metadata around Iceland. Amplicon sequencing of the V4 region of the 18S rRNA gene indicates that eukaryotic phytoplankton community composition is different between the northern and southern water masses, with some genera completely absent from Polar Water masses. Emiliania was more dominant in the Atlantic-influenced waters and in summer, and Phaeocystis was more dominant in the colder, northern waters and in winter. The Chlorophyta picophytoplankton genus, Micromonas, was similarly dominant to the dominant diatom genus, Chaetoceros. This study presents an extensive dataset which can be linked with other 18s rRNA datasets for further investigation into the diversity and biogeography of marine protists in the North Atlantic.

Observational evidence linking ocean sulfur compounds to atmospheric dimethyl sulfide during Icelandic Sea phytoplankton blooms.

In two Icelandic Sea spring blooms (May 2018 and 2019) in the North Atlantic Ocean (62.9-68.0°N, 9.0-28.0°W), chlorophyll-a and dimethylsulfoniopropionate (DMSP) concentrations and DMSP lyase activity (the DMSP-to-dimethyl sulfide (DMS) conversion efficiency) were measured at 67 stations, and the hourly atmospheric DMS mixing ratios were concurrently measured only in May 2019 at Storhofdi on Heimaey Island, located south of Iceland (63.4°N, 20.3°W). The ocean parameters for biology (i.e., chlorophyll-a, DMSP, and DMSP lyase activity) were broadly associated in distribution; however, the statistical significance of the association differed among four ocean domains and also between 2018 and 2019. Specifically, the widespread dominance of Phaeocystis, coccolithophores, and dinoflagellates (all rich in DMSP and high in DMSP lyase activity) across the study area is a compelling indication that variations in DMSP-rich phytoplankton were likely a main cause of the variations in statistical significance. For all the ocean domains defined here, we found that the DMS production capacity (calculated using the exposures of air masses to ocean biology prior to their arrivals at Heimaey and the atmospheric DMS mixing ratios of those air masses at Heimaey) was surprisingly consistent with in situ ocean S data (i.e., DMSP and DMSP lyase activity). Our study shows that the proposed computational approach enabled the detection of changes in DMS production and emission in association with changes in ocean primary producers.

The Current State of Neurosurgery in Iceland.

BACKGROUND: Although surgical conditions account for 32% of the global burden of diseases, approximately 5 billion people worldwide lack access to timely and affordable, surgical and anesthetic services. Disparities in access to surgical care are most evident in low- and middle-income countries, often resulting from a lack of surgical infrastructure. However, the establishment of surgical infrastructure, particularly for specialty surgical services including neurosurgery, is challenging in countries with small populations, irrespective of income classification, due to the distribution of high costs among a lesser number of individuals. One such nation is Iceland. Despite high-income status, high quality of life, literacy, and educational attainment, the population of Iceland has often lacked access to local neurosurgical care, with the establishment of the domestic neurosurgical system in 1971 and continued externalization of complex neurosurgical procedures to neighboring nations and neurosurgeons. METHODS: A narrative review was conducted. RESULTS: This article provides the first-ever examination of neurosurgery in Iceland. We discussed the history and the social, political, and economical contexts in Iceland. We examined the history of neurosurgery in Iceland, which provided brief biographic sketches of pioneers who have catalyzed the establishment of neurosurgical care and training in Iceland, and characterize the current state of neurosurgery in Iceland. CONCLUSIONS: Recommendations derived from the experiences of Icelandic neurosurgeons may guide the international community in future initiatives.

A multi-method autonomous assessment of primary productivity and export efficiency in the springtime North Atlantic.

Fixation of organic carbon by phytoplankton is the foundation of nearly all open-ocean ecosystems and a critical part of the global carbon cycle. But quantification and validation of ocean primary productivity at large scale remains a major challenge, due to limited coverage of ship-based measurements and the difficulty of validating diverse measurement techniques. Accurate primary productivity measurements from autonomous platforms would be highly desirable, due to much greater potential coverage. In pursuit of this goal we estimate gross primary productivity over two months in the springtime North Atlantic from an autonomous Lagrangian float using diel cycles of particulate organic carbon derived from optical beam attenuation. We test method precision and accuracy by comparison against entirely independent estimates from a locally parameterized model based on chlorophyll a and light measurements from the same float. During nutrient replete conditions (80% of the study period), we obtain strong relative agreement between the independent methods across an order of magnitude of productivities (r2=0.97), with slight under-estimation by the diel cycles method (-19±5 %). At the end of the diatom bloom, this relative difference increases to -58 % for a six-day period, likely a response to SiO4 limitation, which is not included in the model. In addition, we estimate gross oxygen productivity from O2 diel cycles and find strong correlation with diel cycles-based gross primary productivity over the entire deployment, providing further qualitative support to both methods. Finally, simultaneous estimates of net community productivity, carbon export and particle size suggest that bloom growth is halted by a combination of reduced productivity due to SiO4 limitation and increased export efficiency due to rapid aggregation. After the diatom bloom, high chlorophyll a normalized productivity indicates that low net growth during this period is due to increased heterotrophic respiration and not nutrient limitation. These findings represent a significant advance in the accuracy and completeness of upper ocean carbon cycle measurements from an autonomous platform.

The prognostic value of injury severity, location of event, and age at injury in pediatric traumatic head injuries.

AIMS: To estimate the prognostic value of injury severity, location of event, and demographic parameters, for symptoms of pediatric traumatic head injury (THI) 4 years later. METHODS: Data were collected prospectively from Reykjavik City Hospital on all patients age 0-19 years, diagnosed with THI (n = 408) during one year. Information was collected on patient demographics, location of traumatic event, cause of injury, injury severity, and ICD-9 diagnosis. Injury severity was estimated according to the Head Injury Severity Scale (HISS). Four years post-injury, a questionnaire on late symptoms attributed to the THI was sent. RESULTS: Symptoms reported were more common among patients with moderate/severe THI than among others (p < 0.001). The event location had prognostic value (p < 0.05). Overall, 72% of patients with moderate/severe motor vehicle-related THI reported symptoms. There was a curvilinear age effect (p < 0.05). Symptoms were least frequent in the youngest age group, 0-4 years, and most frequent in the age group 5-14 years. Gender and urban/rural residence were not significantly related to symptoms. CONCLUSIONS: Motor vehicle related moderate/severe THI resulted in a high rate of late symptoms. Location had a prognostic value. Patients with motor vehicle-related THI need special consideration regardless of injury severity.

Urban-rural differences in pediatric traumatic head injuries: A prospective nationwide study.

AIMS: To estimate differences in the incidence of recorded traumatic head injuries by gender, age, severity, and geographical area. METHODS: The study was prospective and nationwide. Data were collected from all hospitals, emergency units and healthcare centers in Iceland regarding all Icelandic children and adolescents 0-19 years old consecutively diagnosed with traumatic head injuries (N = 550) during a one-year period. RESULTS: Annual incidence of minimal, mild, moderate/severe, and fatal head injuries (ICD-9 850-854) was 6.41 per 1000, with 95% confidence interval (CI) 5.9, 7.0. Annual incidence of minimal head injuries (ICD-9 850) treated at emergency units was 4.65 (CI 4.2, 5.1) per 1000, mild head injuries admitted to hospital (ICD-9 850) was 1.50 (CI 1.3, 1.8) per 1000, and moderate/severe nonfatal injuries (ICD-9 851-854) was 0.21 (CI 0.1, 0.3) per 1000. Death rate was 0.05 (CI 0.0, 0.1) per 1000. Young children were at greater risk of sustaining minimal head injuries than older ones. Boys were at greater risk than girls were. In rural areas, incidence of recorded minimal head injuries was low. CONCLUSIONS: Use of nationwide estimate of the incidence of pediatric head injury shows important differences between urban and rural areas as well as between different age groups.