41 research outputs found

    Tmetoceratidae (Ammonitina) fauna from the Gerecse Mts (Hungary)

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    Abstract Taxonomic and stratigraphic problems of the family Tmetoceratidae and the genera Dumortieria, Catulloceras, Cotteswoldia, Pleydellia and Tmetoceras included in it are briefly discussed. Fifteen species of Tmetoceratidae are described and illustrated from the Upper Toarcian-Aalenian ammonite assemblages of the Gerecse Mts (NE Transdanubian Range, Hungary). The fauna described here is closely allied to the Mediterranean Province of the Mediterranean-Caucasian Realm

    First record of Rhabdoceras suessi (Ammonoidea, Late Triassic) from the Transylvanian Triassic Series of the Eastern Carpathians (Romania) and a review of its biochronology, paleobiogeography and paleoecology

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    Abstract The occurrence of the heteromorphic ammonoid Rhabdoceras suessi Hauer, 1860, is recorded for the first time in the Upper Triassic limestone of the Timon-Ciungi olistolith in the Rarău Syncline, Eastern Carpathians. A single specimen of Rhabdoceras suessi co-occurs with Monotis (Monotis) salinaria that constrains its occurrence here to the Upper Norian (Sevatian 1). It is the only known heteromorphic ammonoid in the Upper Triassic of the Romanian Carpathians. Rhabdoceras suessi is a cosmopolitan species widely recorded in low and mid-paleolatitude faunas. It ranges from the Late Norian to the Rhaetian and is suitable for high-resolution worldwide correlations only when it co-occurs with shorter-ranging choristoceratids, monotid bivalves, or the hydrozoan Heterastridium. Formerly considered as the index fossil for the Upper Norian (Sevatian) Suessi Zone, by the latest 1970s this species lost its key biochronologic status among Late Triassic ammonoids, and it generated a controversy in the 1980s concerning the status of the Rhaetian stage. New stratigraphic data from North America and Europe in the subsequent decades resulted in a revised ammonoid biostratigraphy for the uppermost Triassic, the Rhaetian being reinstalled as the topmost stage in the current standard timescale of the Triassic. The geographic distribution of Rhabdoceras is compiled from published worldwide records, and its paleobiogeography and paleoecology are discussed

    Communicating Information on Eruptions and Their Impacts from the Earliest Times Until the Late Twentieth Century

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    Volcanoes hold a fascination for human beings and, before they were recorded by literate observers, eruptions were portrayed in art, were recalled in legends and became incorporated into religious practices: being viewed as agents of punishment, bounty or intimidation depending upon their state of activity and the culture involved. In the Middle East the earliest depiction of an eruption is a wall painting dating from the Neolithic at Çatal Hüyük and the earliest record dates from the third millennium BCE. Knowledge of volcanoes increased over time. In some parts of the world knowledge of eruptions was passed down by oral transmission, but as far as written records were concerned, in the first century CE only 9 volcanoes in the Mediterranean region were recognised, together with Mount Cameroon in West Africa. In the next 1000 years the list grew by 17, some 14 of these volcanoes being in Japan. The first recorded eruptions in Indonesia occurred in 1000 and 1006, and volcanoes in newly settled Iceland increased the number to just 48 in 1380 CE. After this the list continued to increase, with important regions such as New Zealand and Hawaii only being added in the past 200 years. Only from 1900 did the rate of growth decline significantly (Simkin et al. 1981: 23; Simkin, 1993 Siebert et al. 2011; Simkin, 1993), but it is sobering to recall that in the twentieth century major eruptions have occurred from volcanoes that were considered inactive or extinct examples including: Mount Lamington - Papua New Guinea, 1951; Mount Arenal - Costa Rica, 1968 and Nyos - Cameroon, 1986. Although there are instances where the human impact of historical eruptions have been compiled - with examples including the 1883 eruption of Krakatau (Simkin and Fiske (1983) and 1943 -1952 eruption of Parícutin (Luhr and Simkin, 1993) - these are exceptions and there remains a significant gap in knowledge about both the short and long-term effects on societies of major eruptions which occurred before the 1980s. Following a broad review the chapter provides a discussion of the ways in which information has been collected, compiled and disseminated from the earliest times until the 1980s in two case study areas: the Azores Islands (Portugal) and southern Italy. In Italy information on eruptions stretches back to prehistoric times and has become progressively better known over more than 2,000 years of written history, yet even here there remain significant gaps in the record even for events that took place between 1900 and 1990. In contrast, located in the middle of the Atlantic, the Azores have been isolated for much of their history and illustrate the difficulties involved in using indigenous sources to compile, not only assessments of impact, but also at a more basic level a complete list of historical events with accurate dates

    First record of Rhabdoceras suessi

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    Follow-up immunologico di bambini con infezione asintomatica da HIV

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    In HIV infected children, CD45+CD4+ T lymph. reconstitution has been related to efficient thymopoiesis. Because human thymus undergoes spontaneous involution at a relatively young age, institution of antiretroviral therapy early in the course of infection has been recommended. 12 HIV vertically infected children aged 4-8 years were investigated T-cell subsets for four years. 7 children were naive for therapy (group NT); 5 experienced nucleoside analogues only (group T). CD45RA+ and CD45RO+ CD4+ values were compared to predicted values of healthy children. The two groups showed similar clinical and immunological baseline characteristics (CDC class N-A). Mean VL at t0 was 4.26 log10 (SD 0.71) in gr. NT and 4.01 log10 (SD 0.57) in gr. T; median CD4 T lymph values were 27% in gr. NT and 23.5% in gr. T. Median CD45RA+ values were 62.8% in gr. NT and 71.3% in gr. T. No differences in VL, CD4+ T lymph., CD45RA+, CD45RO+ were found in between groups or within each group at each time evaluation. Median CD45RA+ values were not different from predicted values of healthy children. None of the children changed CDC class during the study period. Although the number of subjects was small, our study evidenced the possibility of a normal immunological development in HIV-1 vertically infected asymptomatic children naive for HAART during the first decade, even in the presence of significant viremia

    [Immunological development in asymptomatic HIV infected children].

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    In HIV infected children, CD45+CD4+ T lymph. reconstitution has been related to efficient thymopoiesis. Because human thymus undergoes spontaneous involution at a relatively young age, institution of antiretroviral therapy early in the course of infection has been recommended. 12 HIV vertically infected children aged 4-8 years were investigated T-cell subsets for four years. 7 children were naive for therapy (group NT); 5 experienced nucleoside analogues only (group T). CD45RA+ and CD45RO+ CD4+ values were compared to predicted values of healthy children. The two groups showed similar clinical and immunological baseline characteristics (CDC class N-A). Mean VL at t0 was 4.26 log10 (SD 0.71) in gr. NT and 4.01 log10 (SD 0.57) in gr. T; median CD4 T lymph values were 27% in gr. NT and 23.5% in gr. T. Median CD45RA+ values were 62.8% in gr. NT and 71.3% in gr. T. No differences in VL, CD4+ T lymph., CD45RA+, CD45RO+ were found in between groups or within each group at each time evaluation. Median CD45RA+ values were not different from predicted values of healthy children. None of the children changed CDC class during the study period. Although the number of subjects was small, our study evidenced the possibility of a normal immunological development in HIV-1 vertically infected asymptomatic children naive for HAART during the first decade, even in the presence of significant viremia
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