Subaqueous cryptodome eruption, hydrothermal activity and related seafloor morphologies on the andesitic North Su volcano

© The Author(s), 2016. This is the author's version of the work and is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Journal of Volcanology and Geothermal Research 323 (2016): 80-96, doi:10.1016/j.jvolgeores.2016.04.041.North Su is a double-peaked active andesite submarine volcano located in the eastern Manus Basin of the Bismarck Sea that reaches a depth of 1154 m. It hosts a vigorous and varied hydrothermal system with black and white smoker vents along with several areas of diffuse venting and deposits of native sulfur. Geologic mapping based on ROV observations from 2006 and 2011 combined with morphologic features identified from repeated bathymetric surveys in 2002 and 2011 document the emplacement of a volcanic cryptodome between 2006 and 2011. We use our observations and rock analyses to interpret an eruption scenario where highly viscous, crystal-rich andesitic magma erupted slowly into the water-saturated, gravel-dominated slope of North Su. An intense fragmentation process produced abundant blocky clasts of a heterogeneous magma (olivine crystals within a rhyolitic groundmass) that only rarely breached through the clastic cover onto the seafloor. Phreatic and phreatomagmatic explosions beneath the seafloor cause mixing of juvenile and pre-existing lithic clasts and produce a volcaniclastic deposit. This volcaniclastic deposit consists of blocky, non-altered clasts next, variably (1-100 %) altered clasts, hydrothermal precipitates and crystal fragments. The usually applied parameters to identify juvenile subaqueous lava fragments, i.e. fluidal shape or chilled margin, were not applicable to distinguish between pre-existing non-altered clasts and juvenile clasts. This deposit is updomed during further injection of magma and mechanical disruption. Gas-propelled turbulent clast-recycling causes clasts to develop variably rounded shapes. An abundance of blocky clasts and the lack of clasts typical for the contact of liquid lava with water is interpreted to be the result of a cooled, high-viscosity, crystal-rich magma that failed as a brittle solid upon stress. The high viscosity allows the lava to form blocky and short lobes. The pervasive volcaniclastic cover on North Su is partly cemented by hydrothermal precipitates. These hydrothermally-cemented breccias, crusts and single pillars show that hydrothermal circulation through a thick layer of volcaniclastic deposits can temporarily increase slope stability through precipitation and cementation.The RV Melville work was funded by a combination of the US National Science Foundation grant OCE-0327448 and a collaborative research funding grant from Nautilus Minerals for the ABE surveys. The RV Sonne research cruise was funded through the BMBF (Grant G03216a). Additional funding, including salary support for JT, was provided by the German DFG Research Centre/Excellence Cluster ―The Ocean in the Earth System‖. WB acknowledges support from DFG research grant BA1605/4-1.2018-05-1

Jet Propellant 8 versus Alternative Jet Fuels

The Air Force is the largest user of jet fuel in the Department of Defense DOD, consuming 2.4 billion gallons per year. In light of environmental impacts associated with using nonrenewable fuel sources and national security concerns regarding dependency on foreign oil, it is no surprise that the United States is paying more attention to alternative fuels. Both DOD and Air Force energy strategies address the need to develop and produce such fuels. The DOD has made a commitment to energy security, establishing an energy initiative that strives to modernize infrastructure, increase utility and energy conservation, enhance demand reduction, and improve energy flexibility, thereby saving taxpayer dollars and reducing emissions that contribute to air pollution and global climate change. This initiative has the following four goals 1. Maintain or enhance operational effectiveness while reducing total force energy demands 2. Increase energy strategic resilience by developing alternative assured fuels and energy 3. Enhance operational and business effectiveness by institutionalizing energy considerations and solutions in DoD planning business processes 4. Establish and monitor Department-wide energy metrics

An indole alkaloid from Strychnos erichsonii

Le premier alcaloïde indolique de type vobasine rencontré dans les #Loganiaceae a été isolé des écorces de #Strychnos erichsonii, récoltées en Guyane Française. Sa structure confirmée par cristallographie Rx. (Résumé d'auteur

Nuclear localization of Annexin A7 during murine brain development

BACKGROUND: Annexin A7 is a member of the annexin protein family, which is characterized by its ability to interact with phospholipids in the presence of Ca(2+)-ions and which is thought to function in Ca(2+)-homeostasis. Results from mutant mice showed altered Ca(2+)-wave propagation in astrocytes. As the appearance and distribution of Annexin A7 during brain development has not been investigated so far, we focused on the distribution of Annexin A7 protein during mouse embryogenesis in the developing central nervous system and in the adult mouse brain. RESULTS: Annexin A7 is expressed in cells of the developing brain where a change in its subcellular localization from cytoplasm to nucleus was observed. In the adult CNS, the subcellular distribution of Annexin A7 depends on the cell type. By immunohistochemistry analysis Annexin A7 was detected in the cytosol of undifferentiated cells at embryonic days E5–E8. At E11–E15 the protein is still present in the cytosol of cells predominantly located in the ventricular germinative zone surrounding the lateral ventricle. Later on, at embryonic day E16, Annexin A7 in cells of the intermediate and marginal zone of the neopallium translocates to the nucleus. Neuronal cells of all areas in the adult brain present Annexin A7 in the nucleus, whereas glial fibrillary acidic protein (GFAP)-positive astrocytes exhibit both, a cytoplasmic and nuclear staining. The presence of nuclear Annexin A7 was confirmed by extraction of the nucleoplasm from isolated nuclei obtained from neuronal and astroglial cell lines. CONCLUSION: We have demonstrated a translocation of Annexin A7 to nuclei of cells in early murine brain development and the presence of Annexin A7 in nuclei of neuronal cells in the adult animal. The role of Annexin A7 in nuclei of differentiating and mature neuronal cells remains elusive

Levosimendan increases brain tissue oxygen levels after cardiopulmonary resuscitation independent of cardiac function and cerebral perfusion

Prompt reperfusion is important to rescue ischemic tissue; however, the process itself presents a key pathomechanism that contributes to a poor outcome following cardiac arrest. Experimental data have suggested the use of levosimendan to limit ischemia–reperfusion injury by improving cerebral microcirculation. However, recent studies have questioned this effect. The present study aimed to investigate the influence on hemodynamic parameters, cerebral perfusion and oxygenation following cardiac arrest by ventricular fibrillation in juvenile male pigs. Following the return of spontaneous circulation (ROSC), animals were randomly assigned to levosimendan (12 µg/kg, followed by 0.3 µg/kg/min) or vehicle treatment for 6 h. Levosimendan-treated animals showed significantly higher brain PbtO(2) levels. This effect was not accompanied by changes in cardiac output, preload and afterload, arterial blood pressure, or cerebral microcirculation indicating a local effect. Cerebral oxygenation is key to minimizing damage, and thus, current concepts are aimed at improving impaired cardiac output or cerebral perfusion. In the present study, we showed that NIRS does not reliably detect low PbtO(2) levels and that levosimendan increases brain oxygen content. Thus, levosimendan may present a promising therapeutic approach to rescue brain tissue at risk following cardiac arrest or ischemic events such as stroke or traumatic brain injury

The results of arthroscopic anterior stabilisation of the shoulder using the bioknotless anchor system

<p>Abstract</p> <p>Background</p> <p>Shoulder instability is a common condition, particularly affecting a young, active population. Open capsulolabral repair is effective in the majority of cases, however arthroscopic techniques, particularly using suture anchors, are being used with increasing success.</p> <p>Methods</p> <p>15 patients with shoulder instability were operated on by a single surgeon (VK) using BioKnotless anchors (DePuy Mitek, Raynham, MA). The average length of follow-up was 21 months (17 to 31) with none lost to follow-up. Constant scores in both arms, patient satisfaction, activity levels and recurrence of instability was recorded.</p> <p>Results</p> <p>80% of patients were satisfied with their surgery. 1 patient suffered a further dislocation and another had recurrent symptomatic instability. The average constant score returned to 84% of that measured in the opposite (unaffected) shoulder. There were no specific post-operative complications encountered.</p> <p>Conclusion</p> <p>In terms of recurrence of symptoms, our results show success rates comparable to other methods of shoulder stabilisation. This technique is safe and surgeons familiar with shoulder arthroscopy will not encounter a steep learning curve. Shoulder function at approximately 2 years post repair was good or excellent in the majority of patients and it was observed that patient satisfaction was correlated more with return to usual activities than recurrence of symptoms.</p

Human iPSC-derived astrocytes transplanted into the mouse brain undergo morphological changes in response to amyloid-beta plaques

BACKGROUND: Increasing evidence for a direct contribution of astrocytes to neuroinflammatory and neurodegenerative processes causing Alzheimer’s disease comes from molecular and functional studies in rodent models. However, these models may not fully recapitulate human disease as human and rodent astrocytes differ considerably in morphology, functionality, and gene expression. RESULTS: To address these challenges, we established an approach to study human astrocytes within the mouse brain by transplanting human induced pluripotent stem cell (hiPSC)-derived astrocyte progenitors into neonatal brains. Xenografted hiPSC-derived astrocyte progenitors differentiated into astrocytes that integrated functionally within the mouse host brain and matured in a cell-autonomous way retaining human-specific morphologies, unique features, and physiological properties. In Alzheimer´s chimeric brains, transplanted hiPSC-derived astrocytes responded to the presence of amyloid plaques undergoing morphological changes that seemed independent of the APOE allelic background. CONCLUSIONS: In sum, we describe here a promising approach that consist of transplanting patient-derived and genetically modified astrocytes into the mouse brain to study human astrocyte pathophysiology in the context of Alzheimer´s disease

Xenon improves neurologic outcome and reduces secondary injury following trauma in an in vivo model of traumatic brain injury

Objectives: To determine the neuroprotective efficacy of the inert gas xenon following traumatic brain injury and to determine whether application of xenon has a clinically relevant therapeutic time window. Design: Controlled animal study. Setting: University research laboratory. Subjects: Male C57BL/6N mice (n = 196). Interventions: Seventy-five percent xenon, 50% xenon, or 30% xenon, with 25% oxygen (balance nitrogen) treatment following mechanical brain lesion by controlled cortical impact. Measurements and Main Results: Outcome following trauma was measured using 1) functional neurologic outcome score, 2) histological measurement of contusion volume, and 3) analysis of locomotor function and gait. Our study shows that xenon treatment improves outcome following traumatic brain injury. Neurologic outcome scores were significantly (p < 0.05) better in xenon-treated groups in the early phase (24 hr) and up to 4 days after injury. Contusion volume was significantly (p < 0.05) reduced in the xenon-treated groups. Xenon treatment significantly (p < 0.05) reduced contusion volume when xenon was given 15 minutes after injury or when treatment was delayed 1 or 3 hours after injury. Neurologic outcome was significantly (p < 0.05) improved when xenon treatment was given 15 minutes or 1 hour after injury. Improvements in locomotor function (p < 0.05) were observed in the xenon-treated group, 1 month after trauma. Conclusions: These results show for the first time that xenon improves neurologic outcome and reduces contusion volume following traumatic brain injury in mice. In this model, xenon application has a therapeutic time window of up to at least 3 hours. These findings support the idea that xenon may be of benefit as a neuroprotective treatment in patients with brain trauma