87 research outputs found

    The Oxfordian–Kimmeridgian transition in the Boulonnais (France) and the onset of organic-rich marine deposits in NW Europe: a climatic control?

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    International audienceWe characterised the organic matter content of marine deposits at the Oxfordian–Kimmeridgian transition in the Boulonnais (France). Organic rich deposits in platform environments are evidenced in the uppermost Cymodoce and lowermost Mutabilis Zone (early late Kimmeridgian), associated with enhanced planktonic palaeoproductivity and/or developing dysoxia/anoxia. Similar organic rich intervals in early late Kimmeridgian are also evidenced in platformdeposits in Normandy and Charentes in France, and in basinal deposits from Yorkshire and Dorset in UK. This refined onsetof the organic rich bands (ORB), as described in NW Europe during the late Jurassic, is coeval with seawater warming. We propose that this seawater warming was an important trigger of the onset of the late Jurassic ORB deposition system in NW Europe, which began at the Cymodoce–Mutabilis boundary during the early late Kimmeridgian and lasted until the middle part of the Tithonian, over a time span of 6.8Myr

    Mental Health Symptoms and Work-Related Stressors in Hospital Midwives and NICU Nurses: A Mixed Methods Study.

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    Hospital midwives and neonatal intensive care (NICU) nurses frequently encounter work-related stressors and are therefore vulnerable to developing mental health problems, such as secondary traumatic stress, burnout, anxiety, and depression. However, so far, the exact nature of these work-related stressors (traumatic vs. non-traumatic stressors) has not been investigated. This concurrent triangulation mixed methods cross-sectional study aimed to compare mental health symptoms in hospital midwives and NICU nurses, and to identify and compare work-related traumatic and non-traumatic stressors for both professional groups. 122 midwives and 91 NICU nurses of two Swiss university hospitals completed quantitative measures (Secondary Traumatic Stress Scale, STSS; Hospital Anxiety and Depression Scale, HADS; Maslach Burnout Inventory, MBI) and one qualitative question in an online survey. When controlling for socio-demographic variables, NICU nurses had a higher STSS total score and higher STSS subscales scores and less HADS anxiety subscale scores than hospital midwives. Work-related stressors were classified into five themes: "Working environment," "Nursing/midwifery care," "Dealing with death and dying," "Case management" and "Others." Forty-six (46.3%) percent of these were classified as traumatic work-related stressors. NICU nurses reported more traumatic stressors in their working environment but no other differences between professional groups regarding the total number of work-related traumatic vs. non-traumatic stressors were found. Measures, such as teaching strategies to amend the subjective appraisal of the traumatic stressors or providing time to recover in-between frequently occurring work-related traumatic stressors might not only improve the mental health of professionals but also decrease sick leave and improve the quality of patient care

    Associations de kystes de dinoflagellĂ©s des sĂ©ries du Jurassique supĂ©rieur (Oxfordien–Tithonien) du Rif externe (PrĂ©rif interne et MĂ©sorif, Maroc) et comparaisons rĂ©gionales = Dinoflagellate cyst assemblages of the Upper Jurassic (Oxfordian–Tithonian) from the External Rif Chain (Internal Prerif and Mesorif, Morocco) and regional comparisons

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    A biostratigraphic study of dinoflagellate cysts of the Upper Jurassic series from the eastern External Rif Chain, has been achieved for the first time on four outcrop sections : the DM section (Douar Marticha), the TB section (the Tarhchenna “Sof”), the KSD section (the Kef Mallou “Sof”) and the Y section (Douar Lamriene) among which three sections (TB, KSD and Y) are well-dated by ammonites and calpionellids fauna. The DM and TB sections are complementary in terms of stratigraphy and correspond respectively to the upper part of the “Ferrysch” Formation, a thick shaly–silty and sandy sequence assigned to the Callovian-Oxfordian stages and to the El Gouzat limestones Formation (Kimmeridgian - Lower Tithonian age) and to the Tarhchenna marly limestones Formation (Upper Tithonian age) from the EL Gouzat area (Mesorif). The KSD and Y sections are also complementary and correspond to the Kimmeridgian-Lower Tithonian Msila limestones Formation and to the overlying marly limestones Massif Formation of Upper Tithonian age, outcropping in the Msila region (Internal Prerif). These four sections have shown many dinocysts rich levels, which had allowed characterizing the Middle? and Upper Oxfordian substages in the DM section. In the other sections, the dinoflagellate cyst assemblages are nearly similar to those of the Kimmeridgian–Tithonian of many sections from the Boreal, Sub-boreal and North tethyan realms, particularily from England, Russia and South-East France basin. The results of the present work confirm once again, the important value of dinoflagellate cysts, for age dating of ammonites-lacking Mesozoic sedimentary sequences and for biostratigraphic correlations

    The life and scientific work of William R. Evitt (1923-2009)

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    Occasionally (and fortunately), circumstances and timing combine to allow an individual, almost singlehandedly, to generate a paradigm shift in his or her chosen field of inquiry. William R. (‘Bill’) Evitt (1923-2009) was such a person. During his career as a palaeontologist, Bill Evitt made lasting and profound contributions to the study of both dinoflagellates and trilobites. He had a distinguished, long and varied career, researching first trilobites and techniques in palaeontology before moving on to marine palynomorphs. Bill is undoubtedly best known for his work on dinoflagellates, especially their resting cysts. He worked at three major US universities and spent a highly significant period in the oil industry. Bill's early profound interest in the natural sciences was actively encouraged both by his parents and at school. His alma mater was Johns Hopkins University where, commencing in 1940, he studied chemistry and geology as an undergraduate. He quickly developed a strong vocation in the earth sciences, and became fascinated by the fossiliferous Lower Palaeozoic strata of the northwestern United States. Bill commenced a PhD project on silicified Middle Ordovician trilobites from Virginia in 1943. His doctoral research was interrupted by military service during World War II; Bill served as an aerial photograph interpreter in China in 1944 and 1945, and received the Bronze Star for his excellent work. Upon demobilisation from the US Army Air Force, he resumed work on his PhD and was given significant teaching duties at Johns Hopkins, which he thoroughly enjoyed. He accepted his first professional position, as an instructor in sedimentary geology, at the University of Rochester in late 1948. Here Bill supervised his first two graduate students, and shared a great cameraderie with a highly motivated student body which largely comprised World War II veterans. At Rochester, Bill continued his trilobite research, and was the editor of the Journal of Paleontology between 1953 and 1956. Seeking a new challenge, he joined the Carter Oil Company in Tulsa, Oklahoma, during 1956. This brought about an irrevocable realignment of his research interests from trilobites to marine palynology. He undertook basic research on aquatic palynomorphs in a very well-resourced laboratory under the direction of one of his most influential mentors, William S. ‘Bill’ Hoffmeister. Bill Evitt visited the influential European palynologists Georges Deflandre and Alfred Eisenack during late 1959 and, while in Tulsa, first developed several groundbreaking hypotheses. He soon realised that the distinctive morphology of certain fossil dinoflagellates, notably the archaeopyle, meant that they represent the resting cyst stage of the life cycle. The archaeopyle clearly allows the excystment of the cell contents, and comprises one or more plate areas. Bill also concluded that spine-bearing palynomorphs, then called hystrichospheres, could be divided into two groups. The largely Palaeozoic spine-bearing palynomorphs are of uncertain biological affinity, and these were termed acritarchs. Moreover, he determined that unequivocal dinoflagellate cysts are all Mesozoic or younger, and that the fossil record of dinoflagellates is highly selective. Bill was always an academic at heart and he joined Stanford University in 1962, where he remained until retiring in 1988. Bill enjoyed getting back into teaching after his six years in industry. During his 26-year tenure at Stanford, Bill continued to revolutionise our understanding of dinoflagellate cysts. He produced many highly influential papers and two major textbooks. The highlights include defining the acritarchs and comprehensively documenting the archaeopyle, together with highly detailed work on the morphology of Nannoceratopsis and Palaeoperidinium pyrophorum using the scanning electron microscope. Bill supervised 11 graduate students while at Stanford University. He organised the Penrose Conference on Modern and Fossil Dinoflagellates in 1978, which was so successful that similar meetings have been held about every four years since that inaugural symposium. Bill also taught many short courses on dinoflagellate cysts aimed at the professional community. Unlike many eminent geologists, Bill actually retired from actively working in the earth sciences. His full retirement was in 1988; after this he worked on only a small number of dinoflagellate cyst projects, including an extensive paper on the genus Palaeoperidinium

    Étude sĂ©dimentologique et palĂ©ontologique d'une coupe tardiglaciaire des environs de Morat (Fribourg, Suisse)

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    Le but de cette note est de donner une base stratigraphique à des études limnogéologiques entreprises sur les sédiments pléistocÚnes supérieurs et holocÚnes du lac de Morat (Suiisse). La palynologie permet de dater des sédiments tardiglaciaires du Bölling au Dryas récent. Les alternances tempérées et froides observées par la palynologie sont confirmées par la variation de la répartition spécifique et du nombre des ostracodes, des mollusques et des characées.</p

    Specific needs based design of a housing and real estate observatory at the local level ::a conceptual framework

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    To respond to the problem of matching housing supply and demand, a research project was conducted to assess the utility and finality of a housing and real estate observatory for the canton of Fribourg (Switzerland) as well as to propose potential directions for its design. At the end of the day, the observatory should meet the needs and expectations of the various stakeholders. The main challenge of this service delivery lies in the identification,collection, analysis and aggregation of relevant and useful information for action. The aim of this paper is to present key dimensions to be considered when designing a housing and real estate observatory dedicated to a local market and to the specific needs of its users/providers

    Purbeck beds (Late Jurassic) in the Phare de Chassiron section (Île d'OlĂ©ron, NW Aquitaine Basin, France): refined age-assignment and long-term depositional sequences.

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    15 pagesInternational audienceIn western european basins, lowering of relative sea-level during the Late Jurassic-Early Cretaceous led to the widespread deposition in numerous basins of so-called Purbeck facies. Age-assignment and longdistance correlations are difficult to establish in such shallow marine to continental deposits, where ammonites are generally lacking. This paper aims to present new biostratigraphical and sedimentological data from the Phare de Chassiron section, located at the western part of the Aquitaine Basin (SW France), where Purbeck beds crop out. Marine bands, interfingered within the Purbeck beds, allow refining the age-assignment of these beds using dinoflagellate cysts, calcareous nannofossils and magnetostratigraphy. Most of the Purbeck beds appear to have a Tithonian age. Uppermost beds of the section, although not precisely dated, are not younger than the Early Berriasian. Field sedimentology, palynofacies and trace-element data (strontium) on carbonates, allow depositional environments to be characterized and a sequence-stratigraphy scheme to be established. This section provides an unique, continuous record, within the Aquitaine Basin, of the final exposure, during the Tithonian, of the former Late Kimmeridgian open-marine platform. The Phare de Chassiron may be considered as one of the most important exposures of Purbeck facies of Tithonian age in Europe
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