Evoluzione eruttiva e geochimica dell'attivita storica del Piton de la Fournaise (1708-1939); focus sulla grande eruzione esplosiva del 1860.

Riassunto La ricostruzione della storia eruttiva di un vulcano è passo fondamentale e imprescindibile per comprendere i processi che hanno controllato e controlleranno le dinamiche eruttive di quel vulcano ed è una premessa fondamentale per la valutazione della sua pericolosità. Scopo di questa tesi è stata la dettagliata ricostruzione temporale del comportamento eruttivo del Piton de la Fournaise nell’isola de La Réunion, un grande vulcano attivo, a dominante attività effusiva. La ricerca si è focalizzata sul periodo 1708-1939, il meno conosciuto e studiato dell’attività storica, contraddistinto da una grande variabilità nella durata delle eruzioni e nella loro esplosività. Prima del 1900 l’attività del vulcano è stata caratterizzata da eruzioni effusive di lunga durata, presenza ripetuta di laghi di lava sommitali e frequenti eventi esplosivi; dopo il 1900 la situazione è cambiata drasticamente, con eruzioni effusive discrete, brevi, e attività esplosiva di minor intensità. Oltre che nella ricerca di documenti storici e nella loro interpretazione vulcanologica in chiave attuale, la tesi ha comportato un lavoro di campagna, nel corso del quale sono stati identificati e campionati, per la prima volta, depositi piroclastici relativi all’attività esplosiva storica del vulcano. Il più importante di questi livelli è composto principalmente di scorie basaltiche dense con subordinato materiale vetroso e vescicolato, cristalli anedrali di olivina, scorie dense, rossastre, alterate. E’ presente una frazione abbondante di litici densi e in minor misura di materiale intrusivo (gabbri). Lo studio dei nuovi campioni è stato integrato da 36 reperti provenienti da una collezioni storica (raccolti da Alfred Lacroix e conservati nel Muséum National d’Histoire Naturelle, Paris). Su una selezione dei campioni studiati sono state effettuate analisi chimiche (elementi maggiori e in tracce), isotopiche (Sr e Pb) e mineralogiche (olivine) per valutare un eventuale collegamento tra alimentazione magmatica e dinamica eruttiva. A livello di elementi maggiori, la maggior parte dei campioni studiati cade nel campo tipico degli “Steady State Basalts” (SSB), cioè dei magmi che hanno alimentato le eruzioni più recenti del Piton de la Fournaise (6-7 wt.% MgO, 10-12 wt.% CaO, 0.6-0.9 wt.% K2O); quattrodici campioni devono essere invece classificati come “Oceaniti” (basalti arricchiti in olivina) (MgO >8 e fino al 29%; CaO = 5-11%; K2O = 0.4-0.7%). Una dozzina di campioni della serie studiata risultano avere i maggiori rapporti CaO/Al2O3 registrati al Piton de la Fournaise fino ad oggi; è stata inoltre riscontrata una lineare diminuzione dell’indice di alcalinità (AI) col tempo. Riguardo ai rapporti isotopici dello Sr (87Sr/86Sr), di notevole interesse è che il periodo dal 1858 al 1863, di cui fa parte l’eruzione esplosiva del 1860 (la più grande in epoca storica), mostra un rapido cambiamento nei rapporti 87Sr/86Sr (variando da 0.704137 a 0.704249), mostrando quasi lo stesso range di variabilità riscontrato in tutta la serie di campioni disponibili dal 1700 ad oggi. Anche gli elementi in traccia mostrano la stessa ampia variabilità nella “serie 1860” aumentando anch’essi dal 1858 al 1863, con Ce/Yb = 19.77 - 23.13; La/Yb = 8.43 - 9.81; Nb/Zr = 0.095 - 0.120. Questi rapporti hanno quasi la stessa variabilità in tutto il periodo studiato (1708-1939): Ce/Yb = 18.59-24.13, La/Yb = 7.91-10.46 and Nb/Zr = 0.086-0.144. Vi è inoltre una correlazione lineare tra i rapporti degli elementi in traccia e il rapporto 87Sr/86Sr. I prodotti delle eruzioni esplosive, e anche quelli dell’evento del 1860, contengono olivine con una grande variabilità composizionale (Fo78-88), con una moda principale a Fo85-86, più magnesiaca delle tipiche olivine del PdF (Fo81-84) o dei prodotti post-1900. L’ampia variabilità negli elementi in traccia, isotopi e composizione delle olivine, permette di confrontare la “serie 1860” con le sequenze eruttive del 1998 e 2007 (le eruzioni più recenti a maggior volume), che sono ugualmente inusualmente eterogenee, suggerendo un’alimentazione di magma sia da serbatoi superficiali con magma già residente sia da parte di magmi più primitivi, profondi e potenzialmente ricchi in gas. Abstract The reconstruction of volcano eruptive history is one of the most important information to unravel the processes controlling past and future changes in eruptive dynamics and is a critical contribution to hazard assessment. The aim of this work is to provide a detailed reconstruction of the time evolution in eruptive behaviour of a dominantly effusive basaltic volcano: Piton de la Fournaise. Our research focuses on a very recent (1708-1939) period of activity marked by major changes in terms of eruption duration and degree of explosivity. Long lasting lava lake and effusive activity together with frequent explosive events represent the typical behaviour of pre-1900 activity, while discrete, effusive and relatively short lived effusive eruptions are the typical post-1900 activity. Our study has integrated both new sampling and 36 samples of the historical collection of Alfred Lacroix (Muséum National d’Histoire Naturelle, Paris). The field work permitted for the first time to identify the thin ash deposits related to the historical explosive activity of the volcano. We present a detailed dataset of chemical analysis (major elements, trace and isotopes, mineral composition) to assess whether the change in eruptive dynamics correlate with major evolution in the volcano plumbing system. The main ash layer is composed mostly of dense scoriae of olivine basalt and minor components are glassy vesciculated shards, free anhedral olivine crystals and altered reddish dense scoriae. This juvenile fraction is associated with an abundant dense lithic fraction and a lesser amount of intrusive material (gabbros). Bulk rock analyses show that all pre-1900 magmas fall in the typical field of Steady State Basalts (SSB) feeding the recent PdF eruptions (6-7 wt.% MgO, 10-12 wt.% CaO, 0.6-0.9 wt.% K2O). 14 samples fall in the Oceanite (olivine rich) field with higher MgO (8-29 wt.% MgO, 5-11 wt.% CaO, 0.4-0.7 wt.% K2O). 12 samples have the highest CaO/Al2O3 ratio recorded at Piton de la Fournaise until present. Moreover the Alkalinity Index (AI) show a decreasing trend with time since 1700. About the 87Sr/86Sr ratio, so interesting is the 1858 to 1863 period, bracketing the major 1860 eruption, that show rapid change in 87Sr/86Sr (from 0.704137 to 0.704249 ranges), almost the same range variability of the entire period from 1700 to present. Also trace elements shows the same large variability in the “1860 series”, increasing with time as the isotope ratios, with Ce/Yb = 19.77 - 23.13; La/Yb = 8.43 - 9.81; Nb/Zr = 0.095 - 0.120. Such ratios in the all studied period (1708-1939) have almost the same variability Ce/Yb = 18.59-24.13, La/Yb = 7.91-10.46 and Nb/Zr = 0.086-0.144. Furthermore trace elements ratios show a linear correlation with the 87Sr/86Sr ratio. Products of the most explosive eruptions contain olivines with a large compositional range (78-88 MgO), with a main mode at Fo 85-86, more magnesian than the typical olivines (Fo81-84) or post-1900 products. The wide variability in trace, isotopes and olivine compositions allows to compare the “1860 series” with the 1998 and 2007 sequences (which are the recent eruptions with largest volume), equally unusual heterogeneous, suggesting a magma supply either from shallow resident magmas and deep, more primitive, gas rich magmas

Unravelling the magma feeding system of a young basaltic oceanic volcano

A multidisciplinary approach combining petrological, geochemical, and fluid-inclusion studies with seismic monitoring data was used to build a model of the magma feeding system of Pico volcano (Azores islands, North Atlantic Ocean). We explore how magma has ascended to the surface in the last 10 ka and how this ascent is associated with the selective activation of the three tectonic systems intersecting the volcano. The deepest and most important ponding level for all ascending magmas is located at 17.3–17.7 km and corresponds to the Moho Transition Zone (MTZ), which marks the transition from mantle rocks to ultramafic cumulates. At shallower depth ascending magmas carry >30 vol% of clinopyroxene and olivine. Each magma ascent followed a distinct path and ponded often for a limited period. Ponding levels common to all feeding systems are present at 16.3–16.7 km, 12.1–14.5 km, 9.4–9.8 km, and 7.7–8.1 km. These depths mark important discontinuities where magmas formed stacked sills and evolved through fractional crystallisation. Dense and un-decrepitated fluid inclusions show rapid ascent from the MTZ along the Lomba do Fogo-São João fault (N150° system) and along the N120° regional transtensive system, despite multiple intrusions. Magma ponding at 5.6–6.8 km occurs where the N150° and N60° tectonic systems intersect each other. Here magma evolves towards plagioclase-rich and is only erupted at the summit crater and subterminal vents. This region is the source of the frequent microseismicity recorded at 4 to 7 km beneath the southern flank of Pico volcano, which might be associated with the early stages of formation of a more complex magma reservoir. The local and regional tectonics are of paramount importance in the activation of the different magma feeding systems over time. This new information is fundamental to improve the knowledge on the future eruptive behaviour of Pico volcano and can have significant implications on the mitigation of volcanic risk. This multidisciplinary approach can be applied not only to other volcanoes of the Azores but also to poorly monitored oceanic volcanoes, where magma ascent strongly depends on the activation of tectonic systems

Hurdles and opportunities in implementing marine biosecurity systems in data-poor regions

Managing marine nonindigenous species (mNIS) is challenging, because marine environments are highly connected, allowing the dispersal of species across large spatial scales, including geopolitical borders. Cross-border inconsistencies in biosecurity management can promote the spread of mNIS across geopolitical borders, and incursions often go unnoticed or unreported. Collaborative surveillance programs can enhance the early detection of mNIS, when response may still be possible, and can foster capacity building around a common threat. Regional or international databases curated for mNIS can inform local monitoring programs and can foster real-time information exchange on mNIS of concern. When combined, local species reference libraries, publicly available mNIS databases, and predictive modeling can facilitate the development of biosecurity programs in regions lacking baseline data. Biosecurity programs should be practical, feasible, cost-effective, mainly focused on prevention and early detection, and be built on the collaboration and coordination of government, nongovernment organizations, stakeholders, and local citizens for a rapid response.This work resulted from a workshop organized at the King Abdul- lah University of Science and Technology and sponsored under the Support for Conferences and Workshops Program. We would like to thank the admin support of the Red Sea Research Cen- ter team, IT, and teachers and students from the KAUST schools who participated in some outreach activities. We thank Ana Bi- gio for the artwork presented in this article (figures 1–4). GS was supported by the European Social Fund, under project no 09.3.3- LMT-K-712, the “Development of Competences of Scientists, other Researchers and Students through Practical Research Activities” measure, grant agreement no. 09.3.3-LMT-K-712–19-0083

Genetic Variation and Population Substructure in Outbred CD-1 Mice: Implications for Genome-Wide Association Studies

Outbred laboratory mouse populations are widely used in biomedical research. Since little is known about the degree of genetic variation present in these populations, they are not widely used for genetic studies. Commercially available outbred CD-1 mice are drawn from an extremely large breeding population that has accumulated many recombination events, which is desirable for genome-wide association studies. We therefore examined the degree of genome-wide variation within CD-1 mice to investigate their suitability for genetic studies. The CD-1 mouse genome displays patterns of linkage disequilibrium and heterogeneity similar to wild-caught mice. Population substructure and phenotypic differences were observed among CD-1 mice obtained from different breeding facilities. Differences in genetic variation among CD-1 mice from distinct facilities were similar to genetic differences detected between closely related human populations, consistent with a founder effect. This first large-scale genetic analysis of the outbred CD-1 mouse strain provides important considerations for the design and analysis of genetic studies in CD-1 mice

New arrivals: An indicator for non-indigenous species introductions at different geographical scales

Several legal and administrative instruments aimed to reduce the spread of non-indigenous species, that may pose harm to the environment, economy and/or human health, were developed in recent years at international and national levels, such as the International Convention for the Control and Management of Ship's Ballast Water and Sediments, the International Council for the Exploration of the Sea Code of Practice on the Introductions and Transfers of Marine Organisms, the EU Regulation on Invasive Alien Species and the Marine Strategy Framework Directive, the US Invasive Species Act, the Biosecurity Act of New Zealand, etc. The effectiveness of these instruments can only be measured by successes in the prevention of new introductions. We propose an indicator, the arrival of new non-indigenous species (nNIS), which helps to assess introduction rates, especially in relation to pathways and vectors of introduction, and is aimed to support management. The technical precondition for the calculation of nNIS is the availability of a global, continuously updated and verified source of information on aquatic non-indigenous species. Such a database is needed, because the indicator should be calculated at different geographical scales: (1) for a particular area, such as port or coast of a country within a Large Marine Ecosystem (LME); (2) for a whole LME; and (3) for a larger biogeographical region, including two or more neighboring LMEs. The geographical scale of nNIS helps to distinguish between a primary introduction and secondary spread, which may involve different pathways and vectors. This, in turn, determines the availability of management options, because it is more feasible to prevent a primary introduction than to stop subsequent secondary spread. The definition of environmental target, size of assessment unit and possible limitations of the indicator are also discussed

Arterial lactate as a risk factor for death in respiratory failure related to coronavirus disease 2019: an observational study

Background: Arterial lactate is a recognized biomarker associated with death in critically ill patients. The prognostic role of arterial lactate in acute respiratory failure due to the novel coronavirus disease 2019 (COVID-19) is unclear. Objectives: We aimed to investigate the prognostic role of arterial lactate levels at admission in patients with COVID-19-related acute respiratory failure. Design and methods: Cohorts of consecutive patients admitted to nonintensive care units (ICU) at study centers for COVID-19-related respiratory failure were merged into a collaborative database. The prognostic role of lactate levels at admission was assessed for continuous values and values ⩾2.0 mmol/l, and lactate clearance at 24 h through delta-lactate (ΔLac). The study outcome was 30-day in-hospital death. Cox proportional regression model was used to assess independent predictors of the study outcome. Results: At admission, 14.6% of patients had lactate levels ⩾2 mmol/l. In-hospital death at 30 days occurred in 57 out of 206 patients; 22.3% and 56.7% with normal or ⩾ 2 mmol/l lactate at admission, respectively. The median lactate level was 1.0 [interquartile range (IQR) 0.8-1.3] mmol/l and 1.3 (IQR 1.0-2.1) mmol/l in survivors and nonsurvivors, respectively (p-value < 0.001). After adjusting for age, relevant comorbidities, acidemia, and the severity of respiratory failure, lactate ⩾2.0 mmol/l was associated with in-hospital death (HR 2.53, 95% CI 1.29-4.95, p-value 0.0066), while Δ Lac ⩾0 was not (HR 1.37, 95% CI 0.42-4.49). These results were confirmed in patients with a pO2/FiO2-ratio (P/F ratio) ⩽300 mmHg. Conclusions: In our study, increased arterial lactate at admission was independently associated with in-hospital death at 30 days in non-ICU patients with acute respiratory failure related to COVID-19

Vascular risk factors in glaucoma: The results of a national survey

Graefe's Archive for Clinical and Experimental Ophthalmology Volume 245, Issue 6, 1 June 2007, Pages 795-802 Vascular risk factors in glaucoma: The results of a national survey (Article) Orzalesi, N.a , Rossetti, L.a, Omboni, S.b, Sborgia, C.c, Vetrugno, M.c, Cantatore, F.c, Campos, E.d, Baldi, A.d, Quaranta, L.e, Serra, A.f, Zucca, I.f, Mura, M.f, Malocci, M.f, Uva, M.g, Longo, A.g, Lombardo, A.g, Scorcia, G.h, Moschettini, R.h, Gallenga, P.E.i, Mastropasqua, L.i, Ciancaglini, M.i, Carpineto, P.i, Lobefalo, L.i, Perri, P.j, Paduano, B.j, Alfieri, G.k, Menchini, U.k, Campana, F.k, Giansanti, F.k, Delle Noci, N.l, Balducci, F.l, Calabria, G.m, Saccà, S.m, Sanna, G.m, Camicione, P.m, Mastromarino, A.m, Balestrazzi, E.n, Di Staso, S.n, Ferreri, G.o, D’Andrea, A.o, Orzalesi, N.p, Rossetti, L.p, Fogagnolo, P.p, Mazzolani, F.p, Brancato, R.q, Carassa, R.q, Bettin, P.q, Fiori, M.q, Guerra, R.r, Martini, E.r, Scarale, G.r, Campi, L.r, Bonavolontà, G.s, Rinaldi, E.s, Di Meo, A.s, Fusco, R.s, Dorigo, M.T.t, Doro, D.t, Grgic, V.t, Lodato, G.u, Morreale Bubella, D.u, Signorelli, F.u, Gandolfi, S.v, Trimarchi, F.w, Milano, G.w, Fiore, C.x, De Carolis, A.x, Sbordone, G.x, Nardi, M.y, Bartolomei, M.P.y, Figus, M.y, Guidi, G.y, Scullica, L.z, Salgarello, T.z, Colotto, A.z, Bucci, M.G.aa, Cerulli, L.aa, Manni, G.L.aa, Centofanti, M.aa, Parravano, M.aa, Scuderi, G.aa, Nucci, C.aa, Carta, F.ab, Pinna, A.ab, Caporossi, A.ac, Frezzotti, P.ac, Grignolo, F.ad, Brogliatti, B.ad, Rolle, T.ad, Ravalico, G.ae, Vattovani, O.ae, Tritto, D.ae, Canziani, T.ae, Marchini, G.af, Marraffa, M.af, OPTIME Study Group (Osservatorio sulla Patologia glaucomatosa, Indagine Medico Epidemiologica)ag, CONPROSO (Collegio Nazionale dei Professori Ordinari di Scienze Oftalmologiche)ah Hide additional authors a Department of Medicine, Surgery and Odontology, University of Milan, San Paolo Hospital, Milan, Italy b Docleader Srl, Somma Lombardo, VA, Italy c University of Bari, Italy View additional affiliations View references (52) Abstract Background The role of vascular risk factors in glaucoma is still being debated. To assess the importance of vascular risk factors in patients with primary open-angle glaucoma (POAG), data from the medical history of 2,879 POAG patients and 973 age-matched controls were collected and analyzed. Methods Design: observational survey. Setting: 35 Italian academic centers. Study population: POAG patients and age-matched controls. In order to reduce bias consecutive patients were included. Observation procedures: data concerning vascular risk factors were collected for all patients with a detailed questionnaire. A complete ophthalmological examination with assessment of intraocular pressure (IOP), visual field, optic disc, and systemic blood pressure was performed. Main outcome measures: the ESH-ESC (European Society of Hypertension-European Society of Cardiology) guidelines were used to calculate the level of cardiovascular risk. Crude and adjusted estimates of the odds ratios (OR) were calculated for all cardiovascular risk factors in POAG and controls. Results The study included 2,879 POAG patients and 973 controls. POAG cases had a significantly higher systolic and diastolic blood pressure (p=0.001) and systolic perfusion pressure (p=0.02) as compared with controls. Also mean IOP was significantly higher in the POAG group (p=0.01), while diastolic perfusion pressure was not significantly different in the two groups. Myopia was more prevalent in the POAG group (23 vs 18%, p=0.005) as well as a positive family history for glaucoma (26 vs 12%, p= 0.004). POAG patients tended to have a higher cardiovascular risk than controls: 63% of glaucoma cases vs 55% of controls (OR: 1.38, p=0.005) had a “high” or “very high” cardiovascular risk. Conclusions The level of cardiovascular risk was significantly higher in glaucoma patients than in controls. © Springer-Verlag 2006

A global-scale screening of non-native aquatic organisms to identify potentially invasive species under current and future climate conditions

The threat posed by invasive non-native species worldwide requires a global approach to identify which introduced species are likely to pose an elevated risk of impact to native species and ecosystems. To inform policy, stakeholders and management decisions on global threats to aquatic ecosystems, 195 assessors representing 120 risk assessment areas across all six inhabited continents screened 819 non-native species from 15 groups of aquatic organisms (freshwater, brackish, marine plants and animals) using the Aquatic Species Invasiveness Screening Kit. This multi-lingual decision-support tool for the risk screening of aquatic organisms provides assessors with risk scores for a species under current and future climate change conditions that, following a statistically based calibration, permits the accurate classification of species into high-, medium- and low-risk categories under current and predicted climate conditions. The 1730 screenings undertaken encompassed wide geographical areas (regions, political entities, parts thereof, water bodies, river basins, lake drainage basins, and marine regions), which permitted thresholds to be identified for almost all aquatic organismal groups screened as well as for tropical, temperate and continental climate classes, and for tropical and temperate marine ecoregions. In total, 33 species were identified as posing a ‘very high risk’ of being or becoming invasive, and the scores of several of these species under current climate increased under future climate conditions, primarily due to their wide thermal tolerances. The risk thresholds determined for taxonomic groups and climate zones provide a basis against which area-specific or climate-based calibrated thresholds may be interpreted. In turn, the risk rankings help decision-makers identify which species require an immediate ‘rapid’ management action (e.g. eradication, control) to avoid or mitigate adverse impacts, which require a full risk assessment, and which are to be restricted or banned with regard to importation and/or sale as ornamental or aquarium/fishery enhancement