87 research outputs found

    The Pine Woods along the sea shoreline: a natural defence of the north italian Adriatic coastal zone.

    Get PDF
    Considering the importance of the pine woods in the Adriatic costal zone, like a natural defence against the attack of the storm waves tending to produce the regression of the shoreline, this study is a preliminary attempt for a more detailed investigation that will try to correlate geological, lithological, climatological and paleobotanical parameters to obtain a better knowledge of the evolutional trend of the different environments in different times of the North Italian Adriatic coastal zone

    Deep Tree Models for 'Big' Biological Data

    Get PDF
    The identification of useful temporal dependence structure in discrete time series data is an important component of algorithms applied to many tasks in statistical inference and machine learning, and used in a wide variety of problems across the spectrum of biological studies. Most of the early statistical approaches were ineffective in practice, because the amount of data required for reliable modelling grew exponentially with memory length. On the other hand, many of the more modern methodological approaches that make use of more flexible and parsimonious models result in algorithms that do not scale well and are computationally ineffective for larger data sets. In this paper we describe a class of novel methodological tools for effective Bayesian inference for general discrete time series, motivated primarily by questions regarding data originating from studies in genetics and neuroscience. Our starting point is the development of a rich class of Bayesian hierarchical models for variable-memory Markov chains. The particular prior structure we adopt makes it possible to design effective, linear-time algorithms that can compute most of the important features of the relevant posterior and predictive distributions without resorting to Markov chain Monte Carlo simulation. The origin of some of these algorithms can be traced to the family of Context Tree Weighting (CTW) algorithms developed for data compression since the mid-1990s. We have used the resulting methodological tools in numerous application-specific tasks (including prediction, segmentation, classification, anomaly detection, entropy estimation, and causality testing) on data from different areas of application. The results obtained compare quite favourably with those obtained using earlier approaches, such as Probabilistic Suffix Trees (PST), Variable-Length Markov Chains (VLMC), and the class of Markov Transition Distributions (MTD)

    Works for the diversion of bed of rivers and torrents and their impact to the environmental of the Lagoons of Greece and Italy

    Get PDF
    This work deals with the comparative account and evaluation of the impact to the environment and especially with the alterations to the geomorphological structure and the hydro-geomorphological processes caused by the works for the diversion of the beds and the flow of rivers and torrents in the greater area of the "Katafourko lagoon" in Greece and of the "Venice lagoon" in Italy. Human intervention in the study areas, was of different aims in each location, but it all resulted in the alteration of the dynamic evolution of the hydro-geomorphological processes which has led to the creation of an "artificial" environment, controlled to a great extend by human power and which in turn, in the long term re-strengthens and reenforces the possibility of environmental destabilization

    Methods & Techniques for the Anti-erosion and anti-flooding protection in mountainous drainage basins in evrytania (Greece)

    Get PDF
    The object of this study is to depict and evaluate the methods and techniques implemented or scheduled for the anti-erosion - anti-flooding protection in mountainous drainage basins in Evrytania, which exhibit intense erosion phenomena and constitute a danger of flooding for the downstream areas. Among these areas are also inhabited areas, such the town of Karpenisi, and for this reason the optimum way of management of these drainage basins constitutes an important element for the development of the town and also for the "sustainability" of the greater area (Evrytania, Greece)

    The "new diverted bed" of the Sperchios river and the new National Road Athina-Lamia in the area of the "Alamana Bridge" and the impact to the environment to the coastal area of the Maliakos Gulf and the Delta (Fthiotida-Greece)

    Get PDF
    The purpose of this work is to depict and evaluate the alterations in the geomorphological characteristics and the hydro-geomorphological processes as well as the effects to the environment of the coastal area of the Maliakos gulf and the delta of the Sperchios river, as a result of the construction of the "new bed" of the new diverted bed of Sperchios river, the "New Alamana Bridge" and the construction of the long embankments which are constructed in order to facilitate the road works for the New National Road Athina-Lamia in the section Thermopylae - Lamia (Fthiotida-Greece)

    Multisource noninvasive genetics of brown bears (Ursus arctos) in Greece reveals a highly structured population and a new matrilineal contact zone in southern Europe

    Get PDF
    In human‐dominated landscapes, connectivity is crucial for maintaining demographically stable mammalian populations. Here, we provide a comprehensive noninvasive genetic study for the brown bear population in the Hellenic Peninsula. We analyze its population structuring and connectivity, estimate its population size throughout its distribution, and describe its phylogeography in detail for the first time. Our results, based on 150 multilocus genotypes and on 244‐bp sequences of the mtDNA control region, show the population is comprised by three highly differentiated genetic clusters, consistent with geographical populations of Pindos, Peristeri, and Rhodope. By detecting two male bears with Rhodopean ancestry in the western demes, we provide strong evidence for the ongoing genetic connectivity of the geographically fragmented eastern and western distributions, which suggests connectivity of the larger East Balkan and Pindos‐Dinara populations. Total effective population size (Ne) was estimated to be 199 individuals, and total combined population size (NC) was 499, with each cluster showing a relatively high level of genetic variability, suggesting that migration has been sufficient to counteract genetic erosion. The mtNDA results were congruent with the microsatellite data, and the three genetic clusters were matched predominantly with an equal number of mtDNA haplotypes that belong to the brown bear Western mitochondrial lineage (Clade 1), with two haplotypes being globally new and endemic. The detection of a fourth haplotype that belongs to the Eastern lineage (Clade 3a1) in three bears from the western distribution places the southernmost secondary contact zone between the Eastern and Western lineages in Greece and generates new hypotheses about postglacial maxima migration routes. This work indicates that the genetic composition and diversity of Europe's low‐latitude fringe population are the outcome of ancient and historical events and highlight its importance for the connectivity and long‐term persistence of the species in the Balkans
    corecore