Magnetic properties and geochemistry of the active oxidation front and the youngest sapropel in the eastern Mediterranean Sea

Magnetic properties (IRM, ARM, xin, S-ratio at 0.3 T, room temperature (RT) hysteresis and thermomagnetic curves) and geochemical data (Fe, S, Mn, Al, Ti, organic C) were studied in two eastern Mediterranean boxcores (ABC26 and BC19) at a resolution of 3-5 mm. The boxcores contain sapropel S1 (9-6 kyr BP) at a few decimetres below seafloor. The magnetic fraction consists predominantly of single-domain (SD) to pseudo-singledomain (PSD) magnetite in the entire cores. The original input of magnetic grains comes from two sources: aeolian dust (both cores) and volcanic ash from the Minoan eruption of Santorini (core BC19 only). Non-steady-state diagenesis has changed the magnetic mineralogy considerably in these alternating organic-rich/organic-poor sediments. During deposition of sapropel S1, reductive diagenesis and pyritization in and just below the sapropel caused lower magnetic intensities, coarser magnetic grain sizes and partial maghemitization. In thermomagnetic curves two types of pyrite can be identified: one oxidizes below 450 uC and the other above 450 uC. The higher oxidation temperature is predominantly found below the sapropel. This may be related to the microtexture of pyrite, which is euhedral below sapropels and mainly framboidal within sapropels. Since the end of sapropel deposition a downward moving oxidation front has oxidized the upper half (c. 5 cm) of the sapropel. The oxidized part of the sapropel is enriched in diagenetically formed Fe oxides with relatively high coercivity and ARM. The maximum coercivity is found in a distinct layer between the present-day Mn- and Fe-redox boundaries at the top of the unoxidized sapropel. The freshly precipitated Fe oxides in this centimetre-thick layer contain a mixture of superparamagnetic (SP) grains and high-coercivity SD magnetite. Higher in the oxidized zone the freshly precipitated Fe oxides have aged into generally slightly lower-coercivity SD grains, with relatively high ARM. In addition to the diagenetic formation of Fe oxides at the top of the sapropel, formation of a ferrimagnetic Fe monosulphide may have occurred within the sapropel during later stages of diagenesis, which may have enhanced the ARM signal in the organic-rich interval in particular

Using benthic foraminifera to reconstruct the benthic environment during sapropel formation

Date du colloque : 03/2008International audienc

Mental Condition and Ventricular Size in Arrested Hydrocephalus: an Analysis of 29 Shunt‐independent Children

Measurement of the diameter of the ventricular system, in a series of 29 patients with arrested hydrocephalus who had become shunt‐independent, showed that enlargement of the ventricles does not necessarily play a part in the arrest of hydrocephalus, for in many of these cases the ventricles were normal or only slightly enlarged. A study was made of the relationship between ventricular width and intelligence. Although children with the lowest IQS usually had a very wide ventricular system and those with the highest IQS a ventricular system of normal size, normal intelligence was compatible with ventricles of any size. It is concluded from these findings, and from the fact that removal of the drainage system did not appear to increase the size of the ventricles, that shunt independence in these children did not result in diminished intelligence. Etat mental et dimension ventriculaire dans les hydrocéphalies stabilisées La mesure du diamètre du système ventriculaire chez 29 sujets avec hydrocéphalic stabilisée, devenus autonomes de shunts, a montré que l'élargissement des ventricules ne joue pas nécessairement un r̂ole dans l'évolution de l'hydrocéphalie, car dans de nombreux cas les ventricules étaient normaux ou tres légèrement élargis. Une étude a été faite de la relation existant entre la dimension ventriculaire et Intelligence. En général, les enfants avec les plus bas QI avaient un système ventriculaire très élargi tandis que celui‐ci était de taille normale dans les cas de QI élevé; cependant, une intelligence correcte peut s'observer avec un système ventriculaire de n'importe quelle dimension. A partir de ces données et du fait que la suppression du drain décroit plus qu'elle n'accroit la taille des ventricules, les auteurs concluent que l'autonomie de shunt chez ces enfants ne risque pas de diminuer l'intelligence. Geistige Verfassung und Ventrikelgröβe bei versperrtem Hydrocephalus In einer Serie von 29 Patienten mit versperrtem Hydrocephalus, die vom Shunt unabhängig geworden waren, zeigte die Messung des Durchmessers im Ventrikelsystem, daß die Vergrößerung der Ventrikel nicht unbedingt bei der Versperrung des Hydrocephalus eine Rolle spielen muß, da in vielen Fällen die Ventrikel normal oder nur gering vergrößert waren. Uber die Beziehung zwischen der Weite der Ventrikel und der Intelligenz wurde eine Studie durchgeführt. Obwohl die Kinder mit den niedrigsten IQS gewöhnlich ein sehr weites Ventrikelsystem haben, die mit den höchsten IQS ein Ventrikelsystem von normaler Größe, kann die Intelligenz doch bei alien Ventrikelgrößen festgestellt werden. Aus diesen Befunden und aus der Tatsache, daß die Entfernung des Drainagesystems die Ventrikel eher zu verengen als zu erweitern schien, wurde abgeleitet, daß die Shunt‐Unabhängigkeit bei diesen Kindern nicht eine Verringerung der Intelligenz bewirkte. Estado mental y tamaño ventricular en la hidrocefalia detenida La medición del diámetro del sistema ventricular en una serie de 29 pacientes con hidrocefalia detenida y que se habían convertido en independientes del shunt, mostró que el aumento de volumen de los ventriculos no juega necesariamente una parte en la detentión de la hidrocefalia, ya que en muchos de estos casos los ventriculos eran normales o solo ligeramente aumentados. Se estudió la relacion entre la anchura ventricular y la inteligencia. Aunque los niños con c.i. más bajo generalmente tenian un sistema ventricular muy grande y los de c.i. más alto poseian un sistema ventricular de tamaño normal, la inteligencia era compatible con cualquier tamaño ventricular. Se concluye de estos hallazgos y del hecho de que al eliminar el sistema de drenaje disminuía más bien que aumentaba el tamaño de los ventriculos, que la independencia del shunt en estos niños no daba lugar a una inteligencia disminuida. Copyrigh

European Collaboration in Ocean Cores Science: roots, highlights, off-springs and vision

July 4th, 1947, exactly 75 years after the legendary cruise of H.M.S. Challenger and at a time when ocean science seemed to definitively shift to the shores of Massachusetts and California, the Swedish 5-masted schooner and school-ship Albatross set sail from Göteborg for a 15-months ambitious voyage of circumnavigation of the world oceans. Staffed with cadets and scientists and headed by Hans Pettersson, the Albatross had on board a revolutionary tool: Kullenberg’s piston corer, a 30m-long device which had already allowed the recovery of a 20m-long sediment core. Previously, the Meteor had recovered cores of a maximal length of 0.90m (1925), while in the thirties C.S. Piggot of the Carnegie Institution had “shot” cores up to 3m length in the North-Atlantic with a gun-like device. Sedimentological, geochemical, mineralogical, micropalaeontological analyses and radio-active dating would be carried out not only in Swedish institutes, but also in Vienna, Göttingen, Hanover, Wageningen, Ghent, Paris, London and La Jolla, in the true spirit of the data exploitation scheme which had shaped the success of the cruise of the Challenger. The stage was set for palaeo-environmental research on long sediment cores, archives of past climate and oceans.In the mid-sixties, ocean cores science takes a giant leap with the Deep Sea Drilling Program (DSDP). 20 years after the Albatross, in the fall of 1968, the Glomar Challenger sails from Dakar for the South Atlantic to verify the hypothesis of seafloor spreading and plate tectonics. Europe would join the Ocean Drilling Program (ODP), which set sail in 1984, subsequent to the International Phase of Ocean Drilling (IPOD, 1975-1983). For the first time, the European Science Foundation moves in, providing to numerous smaller European partners a platform of participation in ODP through ECOD, the European Consortium for Ocean Drilling.Some 50 years after the Albatross, the ‘Calypso’ piston corer on board of R/V Marion Dufresne would set the record of piston coring length, with an unrivaled core of over 64m length. The IMAGES programme would boost palaeoclimate research worldwide.At the turn of the century, ECORD - an off-spring of ECOD which had left the parental house - took the lead of the Mission Specific Platform (MSP) scheme in the Integrated Ocean Drilling Program (IODP), pushing frontiers of ocean drilling to extreme environments such as the poles and coral reefs. While not directly involved in the operational aspects, ESF soon took a prominent place in the supporting science, not the least through the EUROCORES programme and research networks.At the onset of the 21st century, while IODP and the international ocean drilling and coring community define a new strategy for post-2013 ocean coring science, Europe moves in with a new revolutionary tool, the MeBo (Meeresboden Bohrgerät), a remotely operated seabed drilling tool capable of drilling and coring from a variety of large vessels. EUROFLEETS provides new opportunities for coordinated naval operations for ocean science. And in parallel, Europe develops the plans for an ambitious drilling platform for the Arctic: Aurora Borealis.Any lucid vision on the future of Ocean Cores Science, which plays a key role in the unraveling of the dynamics of our planet, will build upon the lessons of the past, reflect upon the strengths and weaknesses of the present, and ride upon the excitement of Europe’s young generation, driver of the future

High-resolution study of planktic foraminifera from the eastern Mediterranean over the last 13 cal ka BP

A unique high-resolution record from the Nile prodelta has been investigated in order to study past hydrological and climatic changes in the southeastern Levantine region over the last 13 cal ka BP. To this end, we used planktic foraminifera (accumulation rates, diversity, assemblages and size properties) as bioindicators of the ecological characteristics of the water column (temperature, salinity, primary production and hydrology). These characteristics were mainly connected to Nile discharges and thermohaline circulation which in turn were controlled by various global and regional climatic forcing factors (e.g., orbital forcing, African and Indian Monsoon, North Atlantic Oscillation (NAO)). Our data showed seven main climatic periods: 1) from 13.0 to 11.5 cal ka BP encompassing the Younger Dryas and characterized by rather cold productive and mixed waters; 2) from 11.5 to 10.1 cal ka BP matching the start of the Holocene and the onset of the African Humid Period (AHP). This period was defined by surface water warming and increasing stratification due to increased river outflow; 3) from 10.1 to 6.4 cal ka BP encompassing the Sapropel deposit (S1) and matching the maximum of the AHP with drastic ecological conditions and maximum water stratification. During this period, the dominant warm taxon Globigerinoides ruber increased significantly in size and accumulation rate marking an opportunistic behavior and a total adaptation to the less saline and stratified waters. After 8.8 cal ka BP, the increase in diversity marked a progressive return to normal conditions; 4) from 6.4 to 2.9 cal ka BP, a progressive aridification period was recorded and the planktic ecosystem returned progressively to equilibrium conditions due to the recovery of thermohaline circulation after S1 and the decrease in Nile runoff; 5) from 2.9 to 1.1 cal ka BP, particular dry conditions were recorded leading to a severe drop in planktic diversity. These conditions seemed to be connected to a negative state of the NAO marking the Roman Humid Period in the western Mediterranean and being anti-phased with the southeastern Mediterranean; 6) from 1.1 to 0.54 cal ka BP, a humid period was recorded matching the Medieval Warm Anomaly and this time connected to a positive NAO. The highest foraminiferal diversity was recorded and the increase in proportions of deep dwellers and eutrophic taxa marked highly productive and mixed waters; 7) from 0.54 cal ka BP to modern time encompassing the Little Ice Age and recorded in our data by a general aridity and surface water warming

Науково-практичний семінар “Архівна україніка: пошук, реєстрація та комплектування архівів”

28 жовтня 2010 р. у Державному комітеті архівів України відбувся науково-практичний семінар “Архівна україніка: пошук, реєстрація та комплектування архівів”, організований Державним комітетом спільно з Центральним державним архівом зарубіжної україніки (ЦДАЗ У) і Українським науково-дослідним інститутом архівної справи та документознавства (УНДІА СД) на виконання Указу Президента України від 13.10.2006 № 875/2006 “Про національну концепцію співпраці із закордонними українцями, державної програми співпраці із закордонним українством та галузевої програми “Зарубіжна україніка”

The concept of quality of life in dementia in the different stages of the disease

In order to conceptually define quality of life (QOL) in dementia, the literature on QOL in the elderly population, in chronic disease and in dementia was studied. Dementia is a progressive, age-related, chronic condition and to avoid omissions within the dementia-specific concept of QOL, a broad orientation was the preferred approach in this literature study. Adaptation is a major outcome in studies investigating interventions aimed at improving QOL in chronic conditions, but to date, it has not been used in the definition of QOL. It is argued that adaptation is an important indication of QOL in people with chronic diseases and therefore also in dementia. Some crucial issues in assessing dementia-related QOL that are relevant to clarify the continuing debate on whether QOL, particularly in dementia, can be measured at all, are discussed. Then the following conceptual definition is offered: dementia-specific QOL is the multidimensional evaluation of the person-environment system of the individual, in terms of adaptation to the perceived consequences of the dementi

Thirteen thousand years of southeastern Mediterranean climate variability inferred from an integrative planktic foraminiferal-based approach

Over the past 13 ka, the hydrology for the southeastern Mediterranean was mainly regulated by Nile River runoff, which in turn was controlled by climate forcing. Being affected by orbital forcing, and the position of the Intertropical Convergence Zone (ITCZ), planktic foraminiferal data (assemblages, stable isotopes, and size properties) indicate three major periods. (1) From 13.0 to 11.5 ka, the upper water column was well-mixed, cold, and productive. (2) From 11.5 to 6.4 ka, hydrology and foraminifers were affected by intensified monsoonal circulation. The enhanced size of Globigerinoides ruber is interpreted as a response to environmental stress caused by low-saline waters. (3) After 6.4 ka, the southward retreat of the ITCZ caused a decrease in freshwater discharge and hence a return to ecological equilibrium. A drop in foraminifer diversity from 2.9 to 1.1 ka was related to more arid conditions, and limited supply of nutrients from the Nile River. We suggest a link to a negative North Atlantic Oscillation (NAO) marking the Roman Humid Period in the western Mediterranean, and in anti-phase with the southeastern Mediterranean aridity. Because Nile River runoff exerted major control on surface hydrology, a connection to Indian and Pacific climate systems partially controlling precipitation over the Nile catchment area is hypothesized. From 1.1 to 0.54 ka, high foraminifer diversity indicates humid conditions synchronous to the Medieval Climate Anomaly under a positive NAO state. Over the past 0.54 ka encompassing the Little Ice Age, another arid period is indicated by a drop in foraminifer diversity