Survival of the Mýrdalsjökull ice cap through the Holocene thermal maximum: evidence from sulphur contents in Katla tephra layers (Iceland) from the last ∼8400 years

International audienceThe climate in Iceland was drier and warmer during the Holocene thermal maximum than it is today and it has been suggested that ice caps disappeared entirely. Katla, a volcano covered by the Mýrdalsjökull ice cap in southern Iceland, has erupted rather steadily throughout the Holocene. Preand post-eruption sulphur concentrations in its products have been determined in previous studies, through melt inclusions trapped in phenocrysts (pre-eruption mean values of 2155 ± 165 ppm) and fully degassed magmatic tephra (post-eruption mean values of 445 ± 130 ppm). The phreatomagmatic tephra has much more variable S contents (550-1775 ppm) and spans the compositional gap between magmatic tephra and melt inclusions. These variable sulphur values are attributed to arresting of degassing as the magma is quenched upon contact with external water in the shallow levels of the volcano conduit. Sulphur in Katla tephra can thus be used to evaluate whether Mýrdalsjökull survived the warm spells of the Holocene. In this study, sulphur concentrations in tephra layers representing the last ∼8400 years of the volcano's eruption history were measured, revealing concentrations in the phreatomagmatic range (600-1600 ppm). Hence, we conclude that over the last ∼8400 years, explosive activity at Katla has been dominated by phreatomagmatic eruptions, implying that the Mýrdalsjökull ice cap has been present throughout the Holocene

Imaging of penetrating thoracic trauma in a large Nordic trauma center

Background Penetrating trauma is rarely encountered in Nordic trauma centers, yet the incidence is increasing. Typical imaging findings in penetrating trauma should thus be familiar to all radiologists. Purpose To evaluate incidence and imaging findings of penetrating chest trauma, gunshot wound (GSW) and stab wound (SW) injury spectrum, imaging protocols, and outcome in a large trauma center. Material and Methods Trauma registry data from 2013-2016 was retrieved, and imaging accessed through hospital PACS. Retrieved variables included age, gender, injury severity scores, mechanism of injury, time to CT, and 30-day mortality. Depth of thoracic, pulmonary, abdominal and skeletal injury, active bleeding, and use of chest tubes were evaluated. Results Of 636 patients with penetrating injuries, 443 (69.7%) underwent imaging. Of these, 161 (36.3%) had penetrating thoracic injuries. Of 161 patients with penetrating chest trauma in imaging, 151 (93.8%) were men (mean age = 34.9 years) and 10 (6.2%) were women (mean age = 40.7 years). The majority of patients had SWs (138 SW vs. 15 GSW). Patients with GSWs were more severely injured (mean ISS 17.00 vs. 8.84 [P=0.0014] and ISS >= 16 in 53.3% vs. 16.7%) than SW patients. In CT, intrathoracic injuries were found in 49.4% (77/156) and active bleeding in 26.3% (41/156). Emergency surgery was performed in 6.2% (10/161) with postoperative CT imaging. Thirty-day mortality rate was 1.2% (2/161). Conclusion Penetrating thoracic trauma often violates intrathoracic structures and nearby compartments. Arterial phase whole-body CT is recommended as multiple injuries and active bleeding are common. CT after emergency surgery is warranted, especially to assess injuries outside the surgical field.Peer reviewe

Tephra in deglacial ocean sediments south of Iceland: Stratigraphy, geochemistry and oceanic reservoir ages

Icelandic tephra layers within deglacial ocean sediment cores from south of Iceland have been detected and their timing with respect to the climate shifts of the last deglaciation constrained. Geochemical analysis of the tephra allowed the likely source volcanic systems to be identified. The previously known Saksunarvatn ash and Vedde ash are recognised and described. Several other major tephra layers are examined: basaltic eruption(s) of Katla at ∼8.4 ka; a basaltic eruption of Katla at ∼12.6 ka; a rhyolitic eruption of Katla at ∼13.6 ka producing tephra similar in appearance and composition to the Vedde ash; a basaltic eruption of Katla at ∼14.0 ka; and two basaltic eruptions of Grímsvötn at ∼14.6 ka and ∼15.0 ka. Abundant rhyolitic ash with a similar appearance and chemistry to the Vedde ash is found throughout the deglacial interval, predating the Vedde ash by up to 3000 years, supporting previous suggestions that there were pre-Vedde ash eruptions of rhyolite that may have contributed to North Atlantic Ash Zone 1. / This study expands the tephro-stratigraphic framework of the North Atlantic and provides a marine archive in which the timing of tephra layers (useful as isochrons) can be directly compared to major ocean and climate events of the last deglaciation. Furthermore, by correlating tephra layers and abundance changes in the polar foraminifera, Neogloboquadrina pachyderma (sinistral), to equivalent tephra events and inferred abrupt cooling/warming in Greenland ice-cores, contemporaneous 14C-dated planktonic foraminifera have been used to estimate changes in the surface radiocarbon reservoir age south of Iceland. Consistent with previous studies, larger surface reservoir ages are calculated during late Heinrich Stadial 1 and the Younger Dryas (∼2000 years and ∼800–1900 years respectively)

Melt inclusion constraints on the magma source of Eyjafjallajökull 2010 flank eruption

International audienc

Subsidiary roles as determinants of subsidiary technology sourcing: empirical evidence from China

Emerging economies have become new destinations for knowledge sourcing, forcing Multinational Enterprises (MNEs) to reconfigure their global innovation strategies and structure. While foreign subsidiaries located in emerging economies were conventionally viewed as having market or efficiency seeking roles, they have started to evolve towards knowledge-seeking roles. We argue that the conventional wisdom shall be reassessed considering this recent shift. We empirically investigate 129 manufacturing MNE subsidiaries of Fortune 500 companies in China, in terms of their roles and sources of technology. Our results indicate that market and knowledge seeking subsidiaries located in China tend to have a positive impact on the generation of new knowledge, either through locally established MNE R&D laboratories or through collaborations with local firms and scientific institutions

Holocene volcanic activity at Grímsvötn, Bárdarbunga and Kverkfjöll subglacial centres beneath Vatnajökull, Iceland

International audienc

Holocene eruption history and magmatic evolution of the subglacial volcanoes, Grimsvötn, Bárdarbunga and Kverkfjöll beneath Vatnajökull, Iceland

Dans le but d'étudier l'activité volcanique et l'évolution magmatique des volcans sous-glaciaires de Grimsvötn, Bárdarbunga et Kverkfjöll, des téphras ont été systématiquement échantillonnés au sein de profils établis dans les sols autour du glacier de Vatnajökull en Islande. La composition en éléments majeurs de 921 échantillons de téphra a été analysée par microsonde, ce qui a permis, par comparaison avec la composition chimique des différents produits émis par ces systèmes volcaniques, de déterminer leur provenance. Les nouveaux résultats indiquent 3 groupes de composition distincts, présentant chacun des variations cohérentes avec une évolution cotectique. Si l'identification de ces groupes améliore la distinction compositionnelle entre les produits émis par les 3 systèmes volcaniques étudiés, une légère superposition des compositions demeure néanmoins entre ces différents groupes. L'analyse in situ des teneurs en éléments traces par ICP-MS à ablation laser permet toutefois d'affiner leur distinction. Ensemble, l'analyse des teneurs en éléments majeurs et traces permet d'améliorer significativement l'identification de la provenance des téphras basaltiques holocène qui peuvent avoir des compositions en éléments majeurs similaires autour de Vatnajökull. Régionalement, les profils étudiés dans les sols sont corrélés les uns avec les autres en utilisant des niveaux de téphras marqueurs clefs, et les unités intermédiaires sont corrélées grâce à des outils stratigraphiques et à leur composition chimique. Approximativement, 70% des couches de téphras viennent de Grimsvötn, Bárdarbunga ou Kverkfjöll. La fréquence éruptive de Grimsvötn indique que c'est le système volcanique le plus actif, suivi de Bárdabunga. En revanche, Kverkfjöll présente une activité épisodique avec des périodes de repos supérieures au millier d'années. La diminution de la fréquence éruptive observée il y a 2000-5000 ans dans les 3 systèmes volcaniques, est liée à une diminution de l'activité volcanique et non à des facteurs environnementaux. Pendant la préhistoire, une différence d'âge de 1000-3000 ans a été observée entre les pics d'activité à l'aplomb du panache mantellique (Grimsvötn et Bardarbunga) et les pics d'activité des volcans localisés au sud-ouest, dans la partie hors-rift de la Zone Volcanique Est (ZVE ; e.g. Kalta). Ceci suggère qu'une importante augmentation de l'activité volcanique dans cette partie du ZVE est attendue dans un futur proche car la fréquence éruptive maximum a été observée il y a 1000-2000 ans à Grimsvötn et Bárdarbung. L'évolution magmatique des 3 systèmes volcaniques étudiés est contrôlée par les processus de cristallisation fractionnée et de contamination crustale. Les teneurs en éléments traces indiquent des minéralogies similaires dans les différentes sources magmatiques sous les 3 volcans. Ceci permet alors d'accéder aux conditions relatives de fusion partielle du manteau source : Bárdarbunga à l'aplomb du centre du panache mantellique islandais produit des basaltes issus de plus forts degrés de fusion alors que les plus faibles degrés de fusion sont atteints sous Kverkfjöll, plus loin du centre du panache. Une source magmatique profonde semble avoir joué un rôle important dans l'activité de Grimsvötn et Bárdarbunga, avec un système de sills et dykes plus actif sous le système volcanique de Grimsvötn pendant la période de plus forte fréquence éruptive. Ce système a évolué en chambre magmatique il y a environ 1000 ans, ce qui explique les plus faibles fréquences éruptives observées à cette période. Un lien direct semble lié la fréquence éruptive à l'architecture de la chambre magmatique. Les variations de composition des basaltes issus de Grimsvötn et Bárdarbunga sont consistantes avec la présence d'une chambre magmatique active en profondeurCLERMONT FD-BCIU Sci.et Tech. (630142101) / SudocSudocFranceF

Strategic complexity and global expansion: an empirical study of newcomer multinational corporations from small economies

The purpose of this paper is to analyse the determinants of global expansion strategies of newcomer Multinational Corporations (MNCs) by focusing on Iceland, Israel and Ireland. We argue that newcomer MNCs from small open economies pursue complex global expansion strategies (CGES). We distinguish four different types of global expansion strategies, namely, horizontal, vertical, lateral integration, and risk diversification. Building upon the traditions of Caves and Dunning and applying a multinomial logistic approach, we model CGES as a function of firm and country specific factors. The empirical evidence suggests that newcomer MNCs move away from simplistic dualities in the formulation of their strategic choices towards more complex options as a means of maintaining and enhancing their global competitiveness

Cluster analysis of personality traits in psychiatric patients with borderline personality disorder

Background: Though the heterogeneous expression of symptoms of borderline personality disorder (BPD) is well-known, it is far from fully understood. Hybrid models combining dimensional and categorical ways of diagnosing BPD have been suggested to better handle this heterogeneity, but more research is needed. The aim of this study was to identify potential clusters in BPD, and evaluate if these clusters differed in diagnostic composition, severity, psychiatric symptoms, emotion regulation and control, or sociodemographic features. Methods: Clusters were based on personality traits measured with the Swedish universities Scales of Personality (SSP) in 141 psychiatric patients diagnosed with BPD. Hierarchical cluster analysis was performed using Ward's method. We used one-way analysis of variance to explore the different clusters' properties. Effect sizes were calculated using partial eta squared. Results: We found three distinct clusters: the lower psychopathology cluster (N = 67), the externalizing cluster (N = 28), and the internalizing cluster (N = 46). The clusters differed regarding trait composition, severity, and emotion regulation and control. Conclusions: Our findings support hybrid models for diagnosing BPD by showing that clusters differed in terms of both severity (lower and higher psychopathology) and personality traits/style (internalizing and externalizing). Assessment of personality traits may be a feasible way to differentiate between clusters. In the future, this knowledge might be used to personalize treatment

Strategic complexity and global expansion: an empirical study of newcomer multinational corporations from small economies

The purpose of this paper is to analyse the determinants of global expansion strategies of newcomer Multinational Corporations (MNCs) by focusing on Iceland, Israel and Ireland. We argue that newcomer MNCs from small open economies pursue complex global expansion strategies (CGES). We distinguish four different types of global expansion strategies, namely, horizontal, vertical, lateral integration, and risk diversification. Building upon the traditions of Caves and Dunning and applying a multinomial logistic approach, we model CGES as a function of firm and country specific factors. The empirical evidence suggests that newcomer MNCs move away from simplistic dualities in the formulation of their strategic choices towards more complex options as a means of maintaining and enhancing their global competitiveness