326 research outputs found

    Middle to Late Holocene vegetation history of the Upper Engadine (Swiss Alps): the role of man and fire

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    To reconstruct the vegetation and fire history of the Upper Engadine, two continuous sediment cores from Lej da Champfèr and Lej da San Murezzan (Upper Engadine Valley, southeastern Switzerland) were analysed for pollen, plant macrofossils, charcoal and kerogen. The chronologies of the cores are based on 38 radiocarbon dates. Pollen and macrofossil data suggest a rapid afforestation with Betula, Pinus sylvestris, Pinus cembra, and Larix decidua after the retreat of the glaciers from the lake catchments 11,000cal years ago. This vegetation type persisted until ca. 7300cal b.p. (5350b.c.) when Picea replaced Pinus cembra. Pollen indicative of human impact suggests that in this high-mountain region of the central Alps strong anthropogenic activities began during the Early Bronze Age (3900cal b.p., 1950b.c.). Local human settlements led to vegetational changes, promoting the expansion of Larix decidua and Alnus viridis. In the case of Larix, continuing land use and especially grazing after fire led to the formation of Larix meadows. The expansion of Alnus viridis was directly induced by fire, as evidenced by time-series analysis. Subsequently, the process of forest conversion into open landscapes continued for millennia and reached its maximum at the end of the Middle Ages at around 500cal b.p. (a.d.1450

    Climatic cycles recorded in the Middle Eocene hemipelagites from a Dinaric foreland basin of Istria (Croatia)

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    Middle Eocene hemipelagic marls from the Pazin-Trieste Basin, a foreland basin of the Croatian Dinarides, display repetitive alternations of two types of marls with different resistance to weathering. This study focuses on the chemical composition, stable isotopes, and palynomorph content of these marls in order to better understand the nature of their cyclic deposition and to identify possible paleoenvironmental drivers responsible for their formation. The less resistant marls (LRM) have consistently lower carbonate content, lower δ18O and δ13C values, and more abundant dinoflagellate cysts than the more resistant marls (MRM). We interpret these differences between the two marl types to be a result of climatic variations, likely related to Milankovitch oscillations. Periods with wetter climate, associated with increased continental runoff, detrital and nutrient influx produced the LRM. Higher nutrient supply sparked higher dinoflagellate productivity during these times, while reduced salinity and stratification of the water column may have hampered the productivity of calcareous nannoplankton and/or planktonic foraminifera. In contrast, the MRM formed during dryer periods which favoured higher carbonate accumulation rates. This study provides new information about the sedimentary record of short-scale climate variations reflected in wet-dry cycles during an overall warm, greenhouse Earth

    Kundensegmente im Agrotourismus

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    Voraussetzung für eine marktorientierte Ausgestaltung eines touristischen Angebots sind Kenntnisse der Gästebedürfnisse. Mittels einer Clusteranalyse wurden erstmals Gästesegmente (Cluster) aufgrund individueller Bedürfnisse für den Agrotourismus in der Schweiz identifiziert. Die Abgrenzung der sechs Cluster basiert auf einer Befragung von 655 potenziellen Gästen von Agrotourismusbetrieben. Die sechs Gästesegmente weisen vor allem hinsichtlich der Freizeitaktivitäten auf dem Bauernhof und in der Region klare Präferenzen auf. In Bezug auf Übernachtungs- sowie Verpflegungsangebote sind die Unterschiede zwischen den Cluster hingegen weniger markant

    An End-to-End Approach for Recognition of Modern and Historical Handwritten Numeral Strings

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    An end-to-end solution for handwritten numeral string recognition is proposed, in which the numeral string is considered as composed of objects automatically detected and recognized by a YoLo-based model. The main contribution of this paper is to avoid heuristic-based methods for string preprocessing and segmentation, the need for task-oriented classifiers, and also the use of specific constraints related to the string length. A robust experimental protocol based on several numeral string datasets, including one composed of historical documents, has shown that the proposed method is a feasible end-to-end solution for numeral string recognition. Besides, it reduces the complexity of the string recognition task considerably since it drops out classical steps, in special preprocessing, segmentation, and a set of classifiers devoted to strings with a specific length

    Is the natural history of Sydney so camouflaged that it will not survive?

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    Our answer, to the question: Is the natural history of Sydney so camouflaged that it will not survive? is “yes”. Harry Recher, an active participant in the plenary session, took the view that as the ecosystems around us decline, there will be even less native fauna in the city. There exists a strong case for knowing what is native, and not just pushing on with restoration, or setting aside green spaces without knowing what is there, and what will occupy the new habitats. That case is the subject of this paper. Knowing the natural history of Sydney is one element of living in a civilised society, which includes caring about the past, knowing your local plants and animals, and managing for future generations. All the papers in this book are linked thematically around the idea that Sydney has its own rich natural history that is worthy of sustained study and conservation. We comment on the way that historians have looked at Sydney, and where native animals have fitted into the history of Australia, and Sydney in particular. In our view, that subject is only now taking hold, but it will be one that will yield many new insights, and in turn it will merge with ecological thinking and contribute to the new disciple of ecological history. Paul Adam, in his paper, shows the merit of reference back to Britain for our understanding of how and why the colony took the course it did with respect to natural history. He is dismayed that natural history no longer has any prominence, yet it is the foundation stone upon which so many of the specialist disciplines rest. More importantly, it is a guiding light for any major conservation effort. We present one glimpse of the natural history of Sydney, invite others to enjoy its diversity, to support its conservation, and then integrate those views into your city life

    The Carnian Humid Episode of the late Triassic: a review

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    From 1989 to 1994 a series of papers outlined evidence for a brief episode of climate change from arid to humid, and then back to arid, during the Carnian Stage of the late Triassic Epoch. This time of climate change was compared to marine and terrestrial biotic changes, mainly extinction and then radiation of flora and fauna. Subsequently termed, albeit incorrectly, the Carnian Pluvial Event (CPE) by successive authors, interest in this episode of climatic change has increased steadily, with new evidence being published as well as several challenges to the theory. The exact nature of this humid episode, whether reflecting widespread precipitation or more local effects, as well as its ultimate cause, remains equivocal. Bed-by-bed sampling of the Carnian in the Southern Alps (Dolomites) shows the episode began with a negative carbon isotope excursion that lasted for only part of one ammonoid zone (A. austriacum). However, that the Carnian Humid Episode represents a significantly longer period, both environmentally and biotically, is irrefutable. The evidence is strongest in the European, Middle Eastern, Himalayan, North American and Japanese successions, but not always so clear in South America, Antarctica and Australia. The eruption of the Wrangellia Large Igneous Province and global warming (causing increased evaporation in the Tethyan and Panthalassic oceans) are suggested as causes for the humid episode

    Cross-sectional observational study of 208 patients with non-classical urea cycle disorders.

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    Urea cycle disorders (UCDs) are inherited disorders of ammonia detoxification often regarded as mainly of relevance to pediatricians. Based on an increasing number of case studies it has become obvious that a significant number of UCD patients are affected by their disease in a non-classical way: presenting outside the newborn period, following a mild course, presenting with unusual clinical features, or asymptomatic patients with only biochemical signs of a UCD. These patients are surviving into adolescence and adulthood, rendering this group of diseases clinically relevant to adult physicians as well as pediatricians. In preparation for an international workshop we collected data on all patients with non-classical UCDs treated by the participants in 20 European metabolic centres. Information was collected on a cohort of 208 patients 50% of which were ≥ 16 years old. The largest subgroup (121 patients) had X-linked ornithine transcarbamylase deficiency (OTCD) of whom 83 were female and 29% of these were asymptomatic. In index patients, there was a mean delay from first symptoms to diagnosis of 1.6 years. Cognitive impairment was present in 36% of all patients including female OTCD patients (in 31%) and those 41 patients identified presymptomatically following positive newborn screening (in 12%). In conclusion, UCD patients with non-classical clinical presentations require the interest and care of adult physicians and have a high risk of neurological complications. To improve the outcome of UCDs, a greater awareness by health professionals of the importance of hyperammonemia and UCDs, and ultimately avoidance of the still long delay to correctly diagnose the patients, is crucial

    The natural history of classic galactosemia: lessons from the GalNet registry.

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    BACKGROUND Classic galactosemia is a rare inborn error of carbohydrate metabolism, caused by a severe deficiency of the enzyme galactose-1-phosphate uridylyltransferase (GALT). A galactose-restricted diet has proven to be very effective to treat the neonatal life-threatening manifestations and has been the cornerstone of treatment for this severe disease. However, burdensome complications occur despite a lifelong diet. For rare diseases, a patient disease specific registry is fundamental to monitor the lifespan pathology and to evaluate the safety and efficacy of potential therapies. In 2014, the international Galactosemias Network (GalNet) developed a web-based patient registry for this disease, the GalNet Registry. The aim was to delineate the natural history of classic galactosemia based on a large dataset of patients. METHODS Observational data derived from 15 countries and 32 centers including 509 patients were acquired between December 2014 and July 2018. RESULTS Most affected patients experienced neonatal manifestations (79.8%) and despite following a diet developed brain impairments (85.0%), primary ovarian insufficiency (79.7%) and a diminished bone mineral density (26.5%). Newborn screening, age at onset of dietary treatment, strictness of the galactose-restricted diet, p.Gln188Arg mutation and GALT enzyme activity influenced the clinical picture. Detection by newborn screening and commencement of diet in the first week of life were associated with a more favorable outcome. A homozygous p.Gln188Arg mutation, GALT enzyme activity of ≤ 1% and strict galactose restriction were associated with a less favorable outcome. CONCLUSION This study describes the natural history of classic galactosemia based on the hitherto largest data set
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