Unexpected large eruptions from buoyant magma bodies within viscoelastic crust

Large volume effusive eruptions with relatively minor observed precursory signals are at odds with widely used models to interpret volcano deformation. Here we propose a new modelling framework that resolves this discrepancy by accounting for magma buoyancy, viscoelastic crustal properties, and sustained magma channels. At low magma accumulation rates, the stability of deep magma bodies is governed by the magma-host rock density contrast and the magma body thickness. During eruptions, inelastic processes including magma mush erosion and thermal effects, can form a sustained channel that supports magma flow, driven by the pressure difference between the magma body and surface vents. At failure onset, it may be difficult to forecast the final eruption volume; pressure in a magma body may drop well below the lithostatic load, create under-pressure and initiate a caldera collapse, despite only modest precursors

Controls on explosive-effusive volcanic eruption styles

One of the biggest challenges in volcanic hazard assessment is to understand how and why eruptive style changes within the same eruptive period or even from one eruption to the next at a given volcano. This review evaluates the competing processes that lead to explosive and effusive eruptions of silicic magmas. Eruptive style depends on a set of feedbacks involving interrelated magmatic properties and processes. Foremost of these are magma viscosity, gas loss, and external properties such as conduit geometry. Ultimately, these parameters control the speed at which magmas ascend, decompress and outgas en route to the surface, and thus determine eruptive style and evolution

Koppel Fraenkel and his descendants : The fate of a Geman-Jewish family.

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Monitoring an effusive eruption at Piton de la Fournaise using radar and thermal infrared remote sensing data: insights into the October 2010 eruption and its lava flows

The figures give the data processing of the post-eruptive radar images

Post-glacial fluvial response and landform development in the upper Muskegon River valley in North-Central Lower Michigan, U.S.A.

This study focuses on the upper part of the Muskegon River system in north-central Lower Michigan and is the first to reconstruct the post-glacial history of fluvial landform development in the core of North America's Great Lakes region. Results indicate that the upper Muskegon River valley contains four alluvial terraces and numerous paleomeanders. Radiocarbon dating of peats within these old channels provides a good chronology for stream behavior and landform development. The T-4 terrace is a paired Pleistocene outwash/lacustrine surface that probably formed about 12,500 years ago. The T-3 terrace is a fill-strath surface that was cut between about 12,000 and perhaps 9500 years ago. The geometry of macromeanders on this surface suggests that stream discharge was ∼ 8 times greater than during the Holocene. The Pleistocene/Holocene transition is marked by a major period of downcutting that likely began as the climate warmed/dried and sediment yield diminished. This period of downcutting potentially lasted through the drier middle Holocene, creating a 6-m-high escarpment in the valley. The Muskegon River then began to aggrade when the climate became wetter. Subsequently the river again incised, creating the paired T-2 terrace, about 3400 years ago when the climate became still wetter. T-2 paleomeanders indicate that stream discharge at this time was consistent with the modern river. In the past 2500 years, the stream has constructed a poorly defined complex of T-1 terraces. These surfaces likely formed due to complex response associated with more variable climate. This study demonstrates that the upper Muskegon River has a similar post-glacial history as streams on deglacial and periglacial landscapes elsewhere in the world

Survival analysis of HIV patients undergoing antiretroviral therapy at Centre Hospitalier Universitaire Sylvanus Olympio of Lomé, Togo

L’infection par le VIH reste l'une des principales causes de mortalité dans le monde, malgré les efforts contre la pandémie et la région subsaharienne africaine reste la plus infectée. Une bonne connaissance de l’issue de la maladie implique de connaître l'impact de certaines caractéristiques socio-démographiques et physiques sous la thérapie sur la survie des patients.Objectif : Le but de ce travail était d'analyser et de comparer la survie et d'identifier les facteurs pronostiques de base qui affectent de manière significative la survie des patients sous traitement antirétroviral au Centre Hospitalier Universitaire Sylavanus Olympio de Lomé, Togo. Patients et méthodes : Les données proviennent de la cohorte de suivi ambulatoire des patients infectés par le VIH du 1er janvier 2007 au 31 décembre 2014. Au total, 1284 patients ont été inclus dans l'étude. Les méthodes non paramétriques de test de Kaplan- Meier ont été utilisées pour analyser et comparer respectivement les courbes de survie et le modèle des risques proportionnels de Cox a été utilisé pour évaluer l'effet de facteurs significatifs sur la survie des patients inscrits. Résultats : Dans un intervalle de temps médian de 20,9 (intervalle interquartile (IQR): 8,9 - 38) mois, nous avons enregistré 81 (6,3%) décès. Il y avait 441 (34,3%) hommes et 843 (65,6%) femmes. L'âge à l'entrée de l'étude, le sexe, le poids de base, le nombre de cellules CD4 de base et le taux d'hémoglobine affectent significativement la survie des patients. Conclusion : La mortalité chez les patients atteints du VIH / SIDA diffère par de nombreuses caractéristiques et les décès par TAR ont diminué. Il faut s’accorder à traiter tôt les patients infectés pour espérer augmenter la survie globale. Mots clés : modèle de régression de Cox, VIH / SIDA, facteurs, thérapie antirétrovirale, CHU Sylvanus Olympio de Lomé.   Background: HIV/AIDS still be one of leading worldwide causes of mortality despite efforts against the pandemic and the Africa sub-saharan region is the most infected. A good knowledge of prevalence needs to know effect of some socio-demographic and medical characteristics on the survival of the HIV- patients.Objective: The aim of this work was to estimate and compare the survival and identify the baseline prognostic factors that significantly affect the survival of patients undergoing antiretroviral therapy at Centre Hospitalier Universitaire Sylavanus Olympio in Lome, Togo.Methods: The data came from a retrospective cohort study of HIV-patients from January 1, 2007 to December 31, 2014. 1284 patients were enrolled in the study with exclusions of patients who did not have complete baseline characteristics (based on the first clinic visit), age more than 60 years and pregnancy. The Kaplan-Meier and log rank test nonparametric methods were used to respectively estimate and compare survival curves and the Cox proportional hazards model was used to assess the effect of significant factors on survival of enrolled patients.Results: In the median time of 20.9 (Interquartile range (IQR): 8.9 - 38) months, we recorded 81 (6.3 %) deaths. There were 441 (34.3 %) men and 843 (65.6 %) women. Age at the entry of the study, sex, baseline weight, baseline CD4 cell counts and haemoglobin level significantly affect the survival of patients.Conclusions: Mortality among HIV/AIDS-patients differs by many characteristics and ART reduced deaths. More care should be given to the  treatment to definitively eradicate the pandemic. Keywords: Cox regression model, HIV/AIDS, factors, antiretroviral therapy, CHU Sylvanus Olympio of Lome. &nbsp

Monitoring an effusive eruption at Piton de la Fournaise using radar and thermal infrared remote sensing data: insights into the October 2010 eruption and its lava flows

Table A3 gives the parameters used for the calculation of the effusion rates

Monitoring an effusive eruption at Piton de la Fournaise using radar and thermal infrared remote sensing data: insights into the October 2010 eruption and its lava flows

Tables A1 and A2 give satellite images used in this study

Exosomes as bioactive messengers in a critical time for preimplantation embryos n an ultrastructural study

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