103 research outputs found

    Palaeomagnetic and mineral magnetic analyses of the Deckenschotter of northern Switzerland and southern Germany

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    The Deckenschotter is a fluvial to glaciofluvial gravel unit in northern Switzerland and southern Germany. The deposits are considered the oldest preserved glacial to interglacial Quaternary deposits in the northern Alpine foreland and are thus important geomorphological markers for landscape evolution. Nevertheless, the age of the deposits is only approximately known and subject to controversial debates. This study presents the results of an extensive palaeomagnetic investigation carried out on intercalated fine-grained sediments at 11 sites of the Höhere Deckenschotter (HDS) and at 5 sites of the Tiefere Deckenschotter (TDS). The HDS show reversed and normal magnetisations, indicating deposition > 0.773 Ma, while the TDS exhibit only normal directions. Age constraints for the different sites are discussed in the light of evidence from other studies. The study therefore clearly supports the efforts to determine the age of the Deckenschotter. As data from previous palaeomagnetic studies on the HDS and TDS have not been published or preserved, this is in fact the only data-based palaeomagnetic study available

    Multi-Year Movements of Blacknose, Finetooth, & Sharpnose Sharks in the US South Atlantic Based on Monitoring Within a Regional-Scale Acoustic Telemetry Network

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    Despite their numerical abundance and economic value, the behavior of many small coastal sharks in the US South Atlantic has been only coarsely described. Here we present movement summaries for blacknose (Carcharhinus acronotus), finetooth (C. isodon), and Atlantic sharpnose shark (Rhizoprionodon terraenovae) as they travelled through a regional-scale acoustic telemetry network, offering direct comparisons of habitat utilization, site fidelity, and the extent and timing of coastal migrations. From 2013-2016, 165 total sharks were implanted with acoustic transmitters at Cape Canaveral, Florida, and tracked up to four years. While blacknose sharks were common off east Florida year-round, finetooth sharks were most abundant winter through early spring and sharpnose sharks summer through fall. Blacknose sharks also moved more slowly (mean 0.8 kilometers per hour) and had the broadest depth preferences, while finetooth sharks were strongly shore-associated and sharpnose preferred proportionally deeper waters. All species exhibited low site fidelity when at Cape Canaveral, remaining at the same site for more than 1 hour on average, even when associated with deeper hard-bottom sites. Most finetooth and many blacknose undertook spring migrations as far as Virginia and North Carolina, respectively, before returning to east Florida each winter. Sharpnose also made regular northward movements that were not as obviously seasonally-driven. Multiple individuals of all species, particularly females, returned briefly south to Cape Canaveral in mid-summer, illustrating that coastal migrations in these species are more akin to seasonal expansions of their geographic ranges as opposed to a synchronized shift of the entire population along the coast

    Florida Atlantic Coast Telemetry (FACT) Array: A Working Partnership

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    The Florida Atlantic Coast Telemetry (FACT) Array is a collaborative partnership of researchers from 24 different organizations using passive acoustic telemetry to document site fidelity, habitat preferences, seasonal migration patterns, and reproductive strategies of valuable sportfish, sharks, and marine turtles. FACT partners have found that by bundling resources, they can leverage a smaller investment to track highly mobile animals beyond a study area typically restrained in scale by funds and manpower. FACT is guided by several simple rules: use of the same type of equipment, locate receivers in areas that are beneficial to all researchers when feasible, maintain strong scientific ethics by recognizing that detection data on any receiver belongs to the tag owner, do not use other members detection data without permission and acknowledge FACT in publications. Partners have access to a network of 480 receivers deployed along a continuum of habitats from freshwater rivers to offshore reefs and covers 1100 km of coastline from the Dry Tortugas, Florida to South Carolina and extends to the Bahamas. Presently, 49 species, (25 covered by Fisheries Management Plans and five covered by the Endangered Species Act) have been tagged with 2736 tags in which 1767 tags are still active

    Heart Rate Response During Treadmill Exercise Test in Children and Adolescents With Congenital Heart Disease

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    Background: Impaired exercise capacity is a common feature of congenital heart disease (CHD). In adults with CHD, it has been shown that impaired heart rate response during exercise may contribute to exercise limitation. Systematic data in children and adolescents on this topic is limited. We therefore purposed to assess heart rate response during treadmill exercise testing in children and adolescents with CHD compared to healthy controls.Methods: One hundred and sixty three children and adolescents (103 with CHD, median age 15 years and 60 age-matched controls) performed cardiopulmonary exercise testing and were included in this study. Beyond peak oxygen consumption, increase in heart rate from resting level to peak exercise (heart rate reserve) and decrease of heart rate after peak exercise (heart rate recovery) were measured. Chronotropic index was defined as percentage of age predicted maximal heart rate reserve. According to data from adults on bicycle exercise, chronotropic incompetence was assumed for chronotropic index below 0.8.Results: While resting heart rate was similar between both groups, peak heart rate, heart rate reserve as well as chronotropic index were lower in the CHD group than in controls. Chronotropic index was lowest in patients with single ventricle hemodynamics and correlated with peak oxygen consumption. Heart rate recovery was impaired in the CHD group 1 and 2 min after peak exercise compared to controls and correlated with peak oxygen consumption. Chronotropic index below 0.8 was a relatively frequent finding even in the control group suggesting that the threshold of 0.8 appears inadequate for the identification of chronotropic incompetence using treadmill exercise testing in children. After normalizing to the 2.5th chronotropic index percentile of the control group we obtained a chronotropic incompetence threshold of 0.69.Conclusion: As an adjunct to measurement of peak oxygen consumption, heart rate response to exercise appears to be a physiologically important diagnostic parameter in children and adolescents with CHD. However, interpretation of heart rate response needs to consider specific age characteristics and the mode of exercise test. Our data may help future studies on chronotropic incompetence using treadmill ergometer protocols in children and adolescents

    The selection and definition of indicators in public health monitoring for the 65+ age group in Germany

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    Selecting relevant indicators is an important step in the development of public health monitoring for older people. Indicators can be used to combine information comprehensively from various data sources and enable recurring, comparable findings to be made about the health of older people. Indicators were systematically compiled from existing international monitoring systems. An indicator set on health in old age was developed using a multistage, structured consensus-based process together with an interdisciplinary panel of experts. The resulting 18 indicators were assigned to three health areas: (1) environmental factors, (2) activities and participation, and (3) personal factors. Data sources that can be used for the indicators are the health surveys within the framework of the Robert Koch Institute’s (RKI) health monitoring system, as well as surveys from other research institutes and official statistics. In the future, the indicator set is to be developed further and integrated into an overall approach that is geared towards health reporting and the monitoring of chronic diseases in all phases of life

    A 68 ka precipitation record from the hyperarid core of the Atacama Desert in northern Chile

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    [Abstract] The Atacama Desert in northern Chile is one of the driest deserts on Earth. Hyperaridity persists at least since the Miocene and was punctuated by pluvial phases. However, very little is known about the timing, regional spread and intensities of precipitation changes. Here, we present a new precipitation record from a sedimentary sequence recovered in a tectonically blocked endorheic basin that is located in the hyperarid core of the Atacama Desert. The chronostratigraphic framework of the record is given by a multi-disciplinary dating approach, suggesting an age of ca. 68 ka BP for the core base. The sequence consists of three sediment types, whose sedimentological and geochemical characteristics suggest different depositional processes that reflect different degrees in humidity. First, particularly fine-grained sediments with high clastic but low calcium sulfate and carbonate contents reflect a particularly dry climate with only sporadic precipitation events and fluvial supply via channel systems. Second, more coarse-grained sediments with lower clastic and higher calcium sulfate and carbonate contents reflect more moist conditions with stronger precipitation events that lead to fluvial activity not restricted to the channels but involving the slopes and plains in the catchment. Third, normally graded layers with an equally high proportion of calcium sulfate and carbonate reflect occasional high-precipitation events that caused sediment supply also from most distant parts of the catchment via severe flash floods. The sedimentary succession suggests that precipitation changes took place on orbital but also on millennial time scales. Rather moist periods occurred during most of MIS 2, several shorter periods within MIS 3 and parts of MIS 4. Comparison of the findings from the Huara record with selected climate records from continental and marine sites in South America suggests a strong precipitation heterogeneity across the Atacama. This heterogeneity is caused by pronounced differences in the dominating climate patterns and a shift from predominant summer rain in the north to winter rain in the south. Precipitation supply to the Huara clay plan is controlled by the atmospheric circulation rather than the surface temperature of the adjacent ocean

    The Hasli Formation of the Irchel Plateau – A key record for older Early Pleistocene interglacial sediments in northern Switzerland

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    In the Alpine region of Central Europe, terrestrial Early Pleistocene deposits with preserved faunal and botanical remains are rare. The predominantly gravelly Höhere Deckenschotter (HDS) deposits of northern Switzerland and adjoining south-western Germany are considered the oldest Quaternary sediments in the northern Alpine Foreland, linked with the first extensive Quaternary Alpine glaciations. This multidisciplinary study investigates the Hasli Formation (HF), a unique silty unit with well-preserved biological remains within an HDS sequence at the Irchel Plateau north of Zürich, providing new climatic and environmental data for these exceptional deposits, as well as crucial information about their age. Systematic mapping of the HF, in addition to the underlying and covering gravel units, has been coupled with sedimentary logging and biostratigraphic analysis at several sites. The HF is present over an area c.4 by up to 1.4 km, and where studied is 1.6–6.2 m thick. The sediments and biological material are indicative of overbank deposits accumulating within the damp floodplain of a large meandering river. The recovered small mammal remains are from eight arvicolid species or genera, including Mimomys pliocaenicus, M. reidi/tigliensis and Clethrionomys cf. kretzoii, which became extinct c.1.8 Ma, and Pliomys episcopalis/simplicior, which first appeared c.2 Ma ago. The over 75k identified molluscs, include c.72k coming from 89 terrestrial species and over 3k from 28 aquatic taxa. The molluscan faunas from all locations where the HF has been studied share important biostratigraphic marker species, and indicate analogous climatic and environmental conditions. The marker species include several that became extinct during the Early Pleistocene, of which Clausilia stranzendorfensis and Cochlostoma salomoni, present throughout the HF, are the most important as they disappeared c.1.8 Ma. Many marker species have modern or palaeo-distributions that lie far to the west, south and east of the Swiss Plateau, showing that the climate was much warmer than today, typical for the Tiglian warm stage. The alluvial floodplain was covered by rather dense, mature woodland. Amino acid (AA) analysis shows that molluscan remains from the HF are among the oldest of the Quaternary shell material studied from across the Swiss Plateau. Palaeomagnetic data shows a change from reversed to normal polarity within the upper part of the HF. When combined, the small mammal and molluscan remains, palaeomagnetic measurements, AA geochronology and sedimentary data, suggest an age of 2.1–1.8 Ma for the HF. Recently produced cosmogenic dates bracket the age of the HDS gravels beneath the HF to depositional periods between 2.6 and 0.9 Ma, with the youngest ages being in disagreement with our findings. The abundance and diversity of the molluscs from the Irchel Plateau, with several rare extinct species, together with a notable small mammal assemblage, make this a key palaeontological site and an important reference point for European Quaternary biostratigraphy

    Fucino palaeo-lake: Towards the Palaeoenvironmental history of the last 430 Ka

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    © 2010 AIQUA - Associazione Italiana per lo Studio del Quaternario e EMMEVI - Servizio Congressi SPA. The sedimentary succession deposited in Fucino palaeo-lake potentially records the environmental history of the Central Mediterranean Region continuously since the early Pleistocene and up to recent historical times. Fucino palaeo-lake sediments are interbedded with numerous volcanic ash layers which allow the reconstruction a robust and independent chronological framework of past environment changes. This framework is a fundamental tool to synchronise different archives at a regional and extra-regional scale and to better understand the spatio-temporal climate variability in the Quaternary at the orbital and millennial-scales. Here we present new preliminary data for the last five glacial to interglacial cycles
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