Morris Jesup Spur and Rise north of Greenland – exploring present seabed features, the history of sediment deposition, volcanism and tectonic deformation at a Late Cretaceous/early Cenozoic triple junction in the Arctic Ocean

The narrow Morris Jesup Spur and an adjacent broader western rise extend 220 km into the Eurasia Basin from the shelf edge north of Greenland. We have used a hovercraft platform drifting with the sea to collect the first seismic reflection transect across an area postulated to be a former triple junction between the Greenland, Eurasian and North American plates. The narrow, flat-topped Morris Jesup Spur is a succession of west-dipping (? 3°) sediments overlying a basal volcanic unit truncated at the top by an unconformity. The Morris Jesup Rise is formed by intensely deformed sediments and volcanic rocks with a deformation front to the northwest. The basin between theMorris Jesup Rise and the Lomonosov Ridge has a sediment thickness of >3 km with a large submarine channel/levee complex in the upper part and repeated volcanic units present in the deeper stratigraphy below 1.0 sec. sub-bottom. Volcanism on the Morris Jesup Spur is considered to be Late Cretaceous–early Cenozoic in age, and continued into the late Miocene on the Morris Jesup Rise and possibly into early Oligocene in the SW Amundsen Basin. The western slope of the Morris Jesup Spur represented the continental slope north of Svalbard in the Late Cretaceous. A block which included the Morris Jesup Spur and Yermak Plateau rifted off during the initial opening of the Eurasia Basin and moved as part of Greenland until about Chron 22. The architecture of the Morris Jesup Rise is a result of plate convergence possibly including a former extensional plate boundary segment which connected the Gakkel spreading centre to the Hornsund Fault between Chron 22 and Chron 13. The Morris Jesup Rise may be a northern tectonic outlier of a more extensive Eurekan tectonic domain hidden below the Lincoln Sea continental shelf. The Morris Jesup Spur remained subaerial until latest Miocene and submergence of the spur most likely intensified the East Greenland Current.publishedVersio

Sediment deformation atop the Lomonosov Ridge, central Arctic Ocean: Evidence for gas-charged sediment mobilization

We have used a hovercraft platform drifting with the sea ice to acquire the first digitally recorded seismic reflection data transects across the Canada/Greenland (89°N-85°N) section of the Lomonosov Ridge, central Arctic Ocean. The flat-lying, laterally uniform Cenozoic sediment package on top of the ridge at 87°N, 60° W shows at least four sites with local seismic amplitude anomalies. The common feature is a column (<600 m wide) of partly discontinuous or chaotic bright reflection events at the center of a <1.5 km wide dome (amplitude <25 m) terminating at the seabed in a 8–12 m deep depression. The amplitude anomalies are interpreted as gas-charged fluid escape pipes marked by a pockmark at the seabed. Gas and fluids introduced from below have mobilized the overlying high porosity, low density Eocene bio-siliceous ooze causing the doming. The gas and fluids appear to originate from the top of rotated fault blocks and sub-basalt sediments of Mesozoic or older age deposited when the Lomonosov Ridge was part of the pre-Late Cretaceous continental margin north of Franz Josef Land.publishedVersio

Basilar Artery Occlusion Thrombectomy Technique: An International Survey of Practice Patterns

Background: Two recent trials demonstrated a benefit for endovascular therapy (EVT) in the treatment of basilar artery occlusion (BAO). In light of the expected increase in the use of EVT for BAO, we sought to understand the technique preferences of neurointerventionalists performing EVT for BAO. Methods: We conducted an international online survey of physician opinions on the use of EVT in BAO between January and March 2022. The survey was distributed through stroke and neurointerventional organizations. Survey questions examined selection of patients for the procedure and the techniques currently used for EVT in BAO. Responses from neurointerventionalists were analyzed. Results: More than 3000 participants were invited yielding 1245 respondents, of whom 543 were classified as neurointerventionalists across 52 countries and included in this analysis. Most neurointerventionalists would proceed to EVT for occlusions of the V4 segment, the basilar artery, or the posterior cerebral artery, without regard for prior intravenous thrombolysis. For BAO of embolic etiology, aspiration only thrombectomy was the preferred method of 50.3% of neurointerventionalists. For BAO of intracranial atherosclerotic disease etiology, combined stent retriever and aspiration thrombectomy was the preferred method of 40.5% of neurointerventionalists. The majority of neurointerventionalists (88.0%) would proceed to stenting after 3 or fewer failed passes for patients with BAO of intracranial atherosclerotic disease etiology. In patients undergoing stenting, aspirin and clopidogrel was the most common antiplatelet regime (52.4%). Conclusions:Among the surveyed neurointerventionalists, the most common techniques for EVT of patients with BAO were contact aspiration or combined stent retriever with aspiration thrombectomy. For patients with BAO due to intracranial atherosclerotic disease, the majority of neurointerventionalists were willing to stent and do so most often after 3 or fewer failed passes and with the use of dual antiplatelet medications. Further study is needed to determine the optimal technique for EVT of BAO with or without intracranial atherosclerotic disease

Late Window Imaging Selection for Endovascular Therapy of Large Vessel Occlusion Stroke: An International Survey

Background - Current stroke guidelines recommend advanced imaging (computed tomography [CT] perfusion or magnetic resonance imaging) prior to endovascular therapy (EVT) in patients with late presentation of large vessel occlusion. Adherence to guidelines may be constrained by resources or timely access to imaging. We sought to understand the factors which influence late window imaging selection for EVT candidates with large vessel occlusion. Methods - We conducted an international survey from January to May 2022. The questions aimed to identify advanced imaging and treatment decisions based on access to imaging, time delays, and simulated patient scenarios. Results - There were 3000 invited participants and 1506 respondents, the majority (89.6%) from comprehensive stroke centers in high‐income countries. Neurointerventionalists comprised 31.8% and noninterventionalists 68.2% of respondents. Overall, 70.7% reported routine use of advanced imaging for late EVT selection, and 63.6% reported its usage in every case. There was greater availability of advanced imaging in comprehensive stroke centers versus primary stroke centers (67.0% versus 33.7%; P Conclusion - Current guidelines for imaging late window EVT candidates are inconsistent with imaging decisions by physicians. Most respondents consider an imaging delay of greater than 20 minutes unacceptable. Access to advanced imaging was greater in comprehensive stroke centers and high‐income countries. In the case of limited access most respondents would consider EVT based on CT only

Two Novel Lyso-Ornithine Lipids Isolated from an Arctic Marine Lacinutrix sp. Bacterium

The Lacinutrix genus was discovered in 2005 and includes 12 Gram-negative bacterial species. To the best of our knowledge, the secondary metabolite production potential of this genus has not been explored before, and examination of Lacinutrix species may reveal novel chemistry. As part of a screening project of Arctic marine bacteria, the Lacinutrix sp. strain M09B143 was cultivated, extracted, fractionated and tested for antibacterial and cytotoxic activities. One fraction had antibacterial activity and was subjected to mass spectrometry analysis, which revealed two compounds with elemental composition that did not match any known compounds in databases. This resulted in the identification and isolation of two novel isobranched lyso-ornithine lipids, whose structures were elucidated by mass spectrometry and NMR spectroscopy. Lyso-ornithine lipids consist of a 3-hydroxy fatty acid linked to the alpha amino group of an ornithine amino acid through an amide bond. The fatty acid chains were determined to be iso-C15:0 (1) and iso-C16:0 (2). Compound 1 was active against the Gram-positive S. agalactiae, while 2 showed cytotoxic activity against A2058 human melanoma cells

The Norwegian PraksisNett: a nationwide practice-based research network with a novel IT infrastructure

Clinical research in primary care is relatively scarce. Practice-based research networks (PBRNs) are research infrastructures to overcome hurdles associated with conducting studies in primary care. In Norway, almost all 5.4 million inhabitants have access to a general practitioner (GP) through a patient-list system. This gives opportunity for a PBRN with reliable information about the general population. The aim of the current paper is to describe the establishment, organization and function of PraksisNett (the Norwegian Primary Care Research Network). Materials and Methods We describe the development, funding and logistics of PraksisNett as a nationwide PBRN. Results PraksisNett received funding from the Research Council of Norway for an establishment period of five years (2018–2022). It is comprised of two parts; a human infrastructure (employees, including academic GPs) organized as four regional nodes and a coordinating node and an IT infrastructure comprised by the Snow system in conjunction with the Medrave M4 system. The core of the infrastructure is the 92 general practices that are contractually linked to PraksisNett. These include 492 GPs, serving almost 520,000 patients. Practices were recruited during 2019–2020 and comprise a representative mix of rural and urban settings spread throughout all regions of Norway. Conclusion Norway has established a nationwide PBRN to reduce hurdles for conducting clinical studies in primary care. Improved infrastructure for clinical studies in primary care is expected to increase the attractiveness for studies on the management of disorders and diseases in primary care and facilitate international research collaboration. This will benefit both patients, GPs and society in terms of improved quality of care.publishedVersio

A novel totivirus and piscine reovirus (PRV) in Atlantic salmon (Salmo salar) with cardiomyopathy syndrome (CMS)

<p>Abstract</p> <p>Background</p> <p>Cardiomyopathy syndrome (CMS) is a severe disease affecting large farmed Atlantic salmon. Mortality often appears without prior clinical signs, typically shortly prior to slaughter. We recently reported the finding and the complete genomic sequence of a novel piscine reovirus (PRV), which is associated with another cardiac disease in Atlantic salmon; heart and skeletal muscle inflammation (HSMI). In the present work we have studied whether PRV or other infectious agents may be involved in the etiology of CMS.</p> <p>Results</p> <p>Using high throughput sequencing on heart samples from natural outbreaks of CMS and from fish experimentally challenged with material from fish diagnosed with CMS a high number of sequence reads identical to the PRV genome were identified. In addition, a sequence contig from a novel totivirus could also be constructed. Using RT-qPCR, levels of PRV in tissue samples were quantified and the totivirus was detected in all samples tested from CMS fish but not in controls. <it>In situ </it>hybridization supported this pattern indicating a possible association between CMS and the novel piscine totivirus.</p> <p>Conclusions</p> <p>Although causality for CMS in Atlantic salmon could not be proven for either of the two viruses, our results are compatible with a hypothesis where, in the experimental challenge studied, PRV behaves as an opportunist whereas the totivirus might be more directly linked with the development of CMS.</p

Pseudochelin A, a siderophore of Pseudoalteromonas piscicida S2040

A new siderophore containing a 4,5-dihydroimidazole moiety was isolated from Pseudoalteromonas piscicida S2040 together with myxochelins A and B, alteramide A and its cycloaddition product, and bromo- and dibromoalterochromides. The structure of pseudochelin A was established by spectroscopic techniques including 2D NMR and MS/MS fragmentation data. In bioassays selected fractions of the crude extract of S2040 inhibited the opportunistic pathogen Pseudomonas aeruginosa. Pseudochelin A displayed siderophore activity in the chrome azurol S assay at concentrations higher than 50 μM, and showed weak activity against the fungus Aspergillus fumigatus, but did not display antibacterial, anti-inflammatory or anticonvulsant activity

Heart and Skeletal Muscle Inflammation of Farmed Salmon Is Associated with Infection with a Novel Reovirus

Atlantic salmon (Salmo salar L.) mariculture has been associated with epidemics of infectious diseases that threaten not only local production, but also wild fish coming into close proximity to marine pens and fish escaping from them. Heart and skeletal muscle inflammation (HSMI) is a frequently fatal disease of farmed Atlantic salmon. First recognized in one farm in Norway in 1999[1], HSMI was subsequently implicated in outbreaks in other farms in Norway and the United Kingdom[2]. Although pathology and disease transmission studies indicated an infectious basis, efforts to identify an agent were unsuccessful. Here we provide evidence that HSMI is associated with infection with piscine reovirus (PRV). PRV is a novel reovirus identified by unbiased high throughput DNA sequencing and a bioinformatics program focused on nucleotide frequency as well as sequence alignment and motif analyses. Formal implication of PRV in HSMI will require isolation in cell culture and fulfillment of Koch's postulates, or prevention or modification of disease through use of specific drugs or vaccines. Nonetheless, as our data indicate that a causal relationship is plausible, measures must be taken to control PRV not only because it threatens domestic salmon production but also due to the potential for transmission to wild salmon populations