Computing the Skewness of the Phylogenetic Mean Pairwise Distance in Linear Time

The phylogenetic Mean Pairwise Distance (MPD) is one of the most popular measures for computing the phylogenetic distance between a given group of species. More specifically, for a phylogenetic tree T and for a set of species R represented by a subset of the leaf nodes of T, the MPD of R is equal to the average cost of all possible simple paths in T that connect pairs of nodes in R. Among other phylogenetic measures, the MPD is used as a tool for deciding if the species of a given group R are closely related. To do this, it is important to compute not only the value of the MPD for this group but also the expectation, the variance, and the skewness of this metric. Although efficient algorithms have been developed for computing the expectation and the variance the MPD, there has been no approach so far for computing the skewness of this measure. In the present work we describe how to compute the skewness of the MPD on a tree T optimally, in Theta(n) time; here n is the size of the tree T. So far this is the first result that leads to an exact, let alone efficient, computation of the skewness for any popular phylogenetic distance measure. Moreover, we show how we can compute in Theta(n) time several interesting quantities in T that can be possibly used as building blocks for computing efficiently the skewness of other phylogenetic measures.Comment: Peer-reviewed and presented as part of the 13th Workshop on Algorithms in Bioinformatics (WABI2013

CARTOGRAFIANDO EL SUMINISTRO: SOSPECHOSOS HABITUALES Y ANTIGÜEDADES IDENTIFICADAS EN ‘REPUTADAS’ CASAS DE SUBASTA EN 2013

The confiscation of the Medici, Becchina and Symes-Michaelides archives by the Italian authorities (with the cooperation of the French and Swiss) and Greek police and judicial authorities, has led to more than 250 repatriations of antiquities so far. Apart from these successful claims, the main contribution of the on-going research on the archives lies in revealing the fundamental role played by the main members of the international antiquities market (auction houses and galleries) in circulating illicit material after the 1970 UNESCO convention (against the illicit traffic in cultural material). It is telling for the current antiquities market, that despite the exposure of the wrongdoings of Sotheby’s, Christie’s, Bonhams, ‘Phoenix Ancient Art’, ‘Royal Athena Galleries’, etc., the same auction houses and galleries continue to rule this market and to sell material depicted in the confiscated archives. This article not only indicates and analyses the cases identified in 2013 in the most ‘reputable’ auction houses, but also reconstructs and maps the paths by which these antiquities reached and circulated in the market.La confiscación de los archivos de Medici, Becchina y Symes-Michaelides por las autoridades italianas (con la cooperación de las francesas y suizas) y la policía griega y autoridades judiciales, ha conducido a más de 250 repatriaciones de antigüedades hasta ahora. Aparte de estas exitosas reclamaciones, la principal contribución de la investigación en curso sobre los archivos es la revelación del fundamental papel jugado por los principales miembros del mercado internacional de antigüedades (casa de subasta y galerías) en la circulación del material ilícito tras la convención de 1970 de UNESCO (contra el tráfico ilícito de bienes culturales). Resulta llamativo que el actual mercado de antigüedades, a pesar de la revelación de malas prácticas de Sotheby’s, Christie’s, Bonhams, ‘Phoenix Ancient Art’, ‘Royal Athena Galleries’, etcétera, las mismas casas de subastas y galerías siguen controlando este mercado y vendiendo materiales incluidos en los archivos confiscados. Este artículo no solo indica y analiza los casos identificados en 2013 en las más ‘reputadas’ casas de subastas, sino también reconstruye y traza los caminos por los cuales estas antigüedades llegaron y circularon en el mercado

Implicit flow routing on terrains with applications to surface networks and drainage structures

Flow-related structures on terrains are defined in terms of paths of steepest descent (or ascent). A steepest descent path on a polyhedral terrain T with n vertices can have T(n^2) complexity. The watershed of a point p --- the set of points on T whose paths of steepest descent reach p --- can have complexity T(n^3). We present a technique for tracing a collection of n paths of steepest descent on T implicitly in O(n logn) time. We then derive O(n log n) time algorithms for: (i) computing for each local minimum p of T the triangles contained in the watershed of p and (ii) computing the surface network graph of T. We also present an O(n^2) time algorithm that computes the watershed area for each local minimum of T

Piecing together the story of a pair of Makron’s fragmented cups

In 2022, an Athenian red-figured cup attributed to Makron was returned to Italy by New York’s Metropolitan Museum of Art. The cup had been acquired in fragments, through purchase and gift, from multiple sources over several years, starting with two fragments from the restorer Fritz Bürki in 1978. A second cup, also attributed to Makron, was acquired in a parallel way. The sources for the fragments from both cups point to galleries collectors and donors – Summa Galleries, Frieda Tchachos, Elizabeth Hecht, and Dietrich von Bothmer – who have been associated with other material that has been repatriated to Italy in recent years. It is suggested that some of the incised ‘signatures’ by Hieron that are found on cups attributed to Makron may have been applied since antiquity

Διαχείριση αποβλήτων εκσκαφών, κατασκευών και κατεδαφίσεων (ΑΕΚΚ). Εθνικό και Ευρωπαϊκό θεσμικό πλαίσιο. Διεθνής πρακτική. Μελέτη Περίπτωσης: Πρόταση διαχείρισης ΑΕΚΚ στον Δήμο Αγρινίου σε περίπτωση καταστροφικού γεγονότος

Ένα από τα πλέον σημαντικά ρεύματα αποβλήτων στην Ευρωπαϊκή Ένωση και παγκόσμια είναι τα απόβλητα από εκσκαφές, κατασκευές και κατεδαφίσεις (ΑΕΚΚ). Η σημασία των ΑΕΚΚ έγκειται τόσο στην περιβαλλοντική όσο και στην οικονομική τους διάσταση, καθώς είναι σημαντικός ο όγκος που καταλαμβάνουν αλλά και οι δυνατότητες αξιοποίησής τους αντί της απλής απόρριψής τους μέσω υγειονομικής ταφής. Στην παρούσα εργασία παρουσιάζεται εκτενώς το θεσμικό πλαίσιο διαχείρισης των ΑΕΚΚ στην Ευρωπαϊκή Ένωση και την Ελλάδα. Παράλληλα, εξετάζεται ποιες είναι οι πρακτικές διαχείρισης ΑΕΚΚ που ακολουθούνται σε επιλεγμένα κράτη-μέλη της Ευρωπαϊκής Ένωσης σε περίοδο ηρεμίας, ποιες ήταν οι πρακτικές διαχείρισης των ΑΕΚΚ που προκλήθηκαν από μεγάλα καταστροφικά γεγονότα διεθνώς, καθώς και οι εμπειρίες που αντλούνται από αυτές. Ακολουθεί η παρουσίαση της υφιστάμενης κατάστασης και του στρατηγικού σχεδιασμού, όσον αφορά στη διαχείριση των ΑΕΚΚ, στη χώρα μας, την Περιφέρεια Δυτικής Ελλάδας και το Δήμο Αγρινίου, με ορίζοντα το έτος 2020. Παρουσιάζεται κατόπιν ο τρόπος με τον οποίο έγινε προσπάθεια διαχείρισης των ΑΕΚΚ που προκάλεσαν οι πρόσφατες πλημμύρες του Δεκεμβρίου 2017 στο Δήμο Αγρινίου και προτείνονται οι γενικές κατευθύνσεις για την εκπόνηση σχεδίου διαχείρισης ΑΕΚΚ στο Δήμο Αγρινίου, με την αξιοποίηση και της διεθνούς εμπειρίας. Τέλος, παρουσιάζονται τα συμπεράσματα και τα ζητήματα που αναδείχτηκαν από τη συγκεκριμένη διερεύνηση και γίνονται προτάσεις για ανάληψη πρωτοβουλιών για την εκπόνηση ή/και περαιτέρω βελτίωση του σχεδιασμού διαχείρισης των ΑΕΚΚ τόσο στο Δήμο Αγρινίου όσο και ευρύτερα στον ελλαδικό χώρο.One of the most important waste streams in the European Union and worldwide is excavation, construction and demolition waste (ECDW). Their importance lies both in their environmental and economic characteristic. This is because they occupy a substantial volume and possess many possibilities for their use [reuse – cyclical economy] rather than their simple disposal at the landfill. This paper presents the legislative framework for the management of ECDW in the European Union and Greece and examines the practices of their management in selected EU member states during regular “peaceful” periods. In addition, information are presented for the management practices of ECDW caused by large catastrophic events worldwide, as well as the experience gained from them. Specific information are given for the current situation in our country [Greece], the Region of Western Greece and more precisely the Municipality of Agrinio. All these based on the strategic planning, regarding the management of ECDW, with a view to 2020. It is noted that extreme floods took place in the Municipality of Agrinio during December 2017, and therefore an attempt is made to present the way that created ECDW were managed due to this catastrophic event. Since natural disasters are very possible to occur often, general directions are proposed, to prepare a management plan of the produced ECDW during these events in the Municipality of Agrinio, with the utilization of available international experience. Finally, the conclusions and issues raised by this study are presented, and proposals are made in order to assist initiatives for the preparation and / or further improvement of management planning of ECDW in both the Municipality of Agrinio and in Greece, especially after natural disasters

Comparative field studies of various traps and attractants for the Mediterranean fruit fly Ceratitis capitata (Diptera: Tephritidae) in fall

Για την επιλογή της πλέον αποτελεσματικής παγίδας και ελκυστικού μεταξύ ορισμένων από τους τύπους παγίδων και ελκυστικών ουσιών που χρησιμοποιούνται σήμερα για την παρακολούθηση και καταπολέμηση της μύγας της Μεσογείου, Ceratitis capitata, (Wiedemann) (Diptera: Tephritidae), συγκρίθηκαν σε πορτοκαλεώνες επτά τύποι παγίδων (δύο τύπου MePhail, Υαλοπλαστική, χάρτινο-δίπτυχο, χάρτινος φάκελος-χαρτοπλαστική, διαφανής πλαστική φιάλη, παγίδα ξηρού τύπου), τέσσερα τροφικά ελκυστικά ( Dacus bait 100, Entomela 12SL, όξινο ανθρακικό αμμώνιο και το με κωδικό ZI), ένα ελκυστικό φύλου (Trimedlure) και ένας συνδυασμός τροφικού και ελκυστικού φύλου (Όξινο ανθρακικό αμμώνιο+Trimedlure). Τα αποτελέσματα έδειξαν ότι μεταξύ των παγίδων τύπου MePhail δεν υπάρχουν σημαντικές διαφορές.Η παγίδα τύπου πλαστικής φιάλης απεδείχθη πολύ αποτελεσματική όταν πληρούται με το ZI (πρωτεϊνικό τροφικό ελκυστικό). Από τα δοκιμασθέντα ελκυστικά , τα πλέον αποτελεσματικά ήταν το ZI και το Entomela. Ο συνδυασμός ελκυστικών τροφής και φύλου δεν έδειξε σημαντική συνεργιστική δράση στην αποτελεσματικότητα της παγίδας. Τα αποτελέσματα επιτρέπουν μια καλύτερη επιλογή μεταξύ των παραπάνω τύπων παγίδων και ελκυστικών, για παρακολούθηση και καταπολέμηση της μύγας της Μεσογείου.To clarify questions regarding the effectiveness of the many different types of traps and semiochemicals used for the monitoring and the control of the Mediterranean Fruit Fly, Ceratitis capitata (Wiedemann) (Diptera: Τephrititae), seven trap types, four food attractants, one sex attractant and a combination of food and sex attractant, were evaluated under field conditions in orange orchards in fall. No major differences were observed between trap designs resembling the original McPhail glass trap. The plastic bottle trap of 1,5L volume, with four side openings for one-way fly entrance, proved very efficient when filled with a proteinaceous food attractant Ζ1. From the attractants, two of them, Ζ1 and Entomela showed the best performance. The combination of food and a sex attractant showed no significant synergistic effects on trap efficiency. The findings allow a better choice among trap types and attractants, available today in the market, for Medfly monitoring and control

REDESIGN AND TOPOLOGY OPTIMIZATION OF AN INDUSTRIAL ROBOT LINK FOR ADDITIVE MANUFACTURING

Design optimization for Additive Manufacturing is demonstrated by the example of an industrial robot link. The part is first redesigned so that its shape details are compatible with the requirements of the Selective Laser Sintering technique. Subsequently, the SIMP method of topology optimization is utilized on commercially available software in order to obtain the optimum design of the part with restrictions applicable to Additive Manufacturing, namely member thickness, symmetry and avoidance of cavities and undercuts. Mass and strain energy are the design responses. The volume was constrained by a fraction of the initial mass. The desired minimization of maximum strain energy is expressed as an objective function. A 7% reduction in the mass of the part was achieved while its strength and stiffness remained unchanged. The process is supported by topology optimization software but it also involves some trial-and-error depending on the designer’s experience

Electric Car Chassis for Shell Eco Marathon Competition: Design, Modelling and Finite Element Analysis

The increasing demand for energy efficient electric cars, in the automotive sector, entails the need for improvement of their structures, especially the chassis, because of its multifaceted role on the vehicle dynamic behaviour. The major criteria for the development of electric car chassis are the stiffness and strength enhancement subject to mass reduction as well as cost and time elimination. Towards this direction, this work indicates an integrated methodology of developing an electric car chassis considering the modeling and simulation concurrently. The chassis has been designed in compliance with the regulations of Shell Eco Marathon competition. This methodology is implemented both by the use of our chassis load calculator (CLC) model, which automatically calculates the total loads applied on the vehicle&rsquo s chassis and by the determination of a worst case stress scenario. Under this extreme stress scenario, the model&rsquo s output was evaluated for the chassis design and the FEA method was performed by the pre-processor ANSA and the solver Ansys. This method could be characterized as an accurate ultrafast and cost-efficient method. Document type: Articl