Search results for "Tree"
showing 10 items of 1841 documents
Monumental chestnut trees: source of genetic diversity, cultural and landscape value
2019
The mtonumental trees are unique individuals tof venerable age and ctonsiderable size, which represent a heritage tof inestimable histtorical, cultural, landscape, and scientific value ftor the territtory. They alsto ctonstitute a stource tof genetic diversity which ctonfers them ltongevity and ability tto adapt tto climate and envirtonmental changes. In this ctontext, studies ton centennial trees can be useful ftor interpretatiton tof species histtory as migratiton events, selectiton and anthrtoptogenic actiton. The aim tof this research was tto evaluate the genetic variability tof ancient Castanea sativa trees and relate them tto actual natural/naturalized ptopulatitons and varieties in t…
Art for Change
2021
Una serie di documentari brevi (26 minuti ad episodio) che racconta quattro progetti di design per il sociale tra Italia e Spagna. Quando l’arte entra nelle aree marginali delle nostre città produce concrete trasformazioni: la street art del progetto di Borgo Vecchio Factory a Palermo, l’Accademia del Cinema dei Ragazzi di Enziteto a Bari, il Museo dell’Altro e dell’Altrove nelle ex fabbriche Fiorucci di Roma, la comunità di Puerta del Angel a Madrid.
Reguły działania a argumentacja
2016
Argumentacja niemonotoniczna ma być blisko rozumowań praktycznych i zdroworozsądkowych: wykonawcy czynności (agenci) opracowują plany działań i starają się plany te wykonać; często jednak są pozbawieni pełnego opisu sytuacji, ich wiedza jest cząstkowa, czynią założenia i podejmują decyzje oraz działania, w tym działania słowne, polegając na własnym doświadczeniu i nawykach. Powstające formalne struktury obejmują tzw. cyrkumskrypcje (circumscriptions), logikę domyśleń (default logic), logikę autoepistemiczną (autoepistemic logic), konsekwencje kumulatywne (cumulative consequences) i szereg innych. Można wyodrębnić dwa główne typy systemów rozumowań niemonotonicznych: systemy defi niowalne po…
La pré-structure diégétique et le théâtre de la plénitude amoureuse ou deux visions de l'arbre dans la série romanesque d'Émile Zola, "Les Rougon-Mac…
2020
Artykuł analizuje dwie formy, jakie przybiera motyw drzewa w cyklu powieściowym Émile’a Zoli Rougon-Macquartowie. Pierwszą z nich, którą można nazwać „społeczną”, jest drzewo genealogiczne postaci tworzących powieściową rodzinę; sporządzenie tego drzewa i przygotowanie szczegółowych informacji na temat każdego bohatera i jego losów poprzedziło rozpoczęcie pracy nad cyklem, co czyni z niego rodzaj pra-struktury całej serii. Drugą formą, w jakiej drzewo pojawia się w analizowanych tekstach, jest forma „naturalna”, związana z przyrodą (drzewo jako roślina) i nasycona symboliką dotykającą miłości i płodności. Obie formy łączy odniesienie do życia jako nadrzędnej wartości i podstawowego tematu l…
DAE-GP
2020
Estimation of distribution genetic programming (EDA-GP) algorithms are metaheuristics where sampling new solutions from a learned probabilistic model replaces the standard mutation and recombination operators of genetic programming (GP). This paper presents DAE-GP, a new EDA-GP which uses denoising autoencoder long short-term memory networks (DAE-LSTMs) as probabilistic model. DAE-LSTMs are artificial neural networks that first learn the properties of a parent population by mapping promising candidate solutions to a latent space and reconstructing the candidate solutions from the latent space. The trained model is then used to sample new offspring solutions. We show on a generalization of t…
Hartree - Fock simulation of the Ag/MgO interface structure
1996
The atomic and electronic structure of the Ag/MgO interface are calculated using an ab initio Hartree - Fock computer code and a supercell model of a silver monolayer atop three layers of MgO substrate. The band structure, electronic density distribution and densities of states are analysed in detail for isolated and interacting slabs of a metal and MgO. The energetically most favoured adsorption position for Ag atoms is found to be above the O atoms, with the binding energy of 0.20 eV and the equilibrium Ag - O distance of 2.64 A. Neither appreciable charge transfer in the interfacial region, nor considerable population of bonds between the silver monolayer and the insulating substrate tak…
Evolution of Complex Acoustic Signals in Drosophila Species
2009
species produce complex acous-tic cues, so-called courtship songs, while pursuing a female.In most of the over 100 species studied so far (see thelist of these species in Hoikkala, 2005), such cues areproduced by wing vibration. Other mechanisms of songproduction include abdomen purring (Hoy, Hoikkala, &Kaneshiro, 1988) and rapid vibrations of the whole body(Ritchie & Gleason, 1995). The carrier frequency of songsproduced through any of these actions ranges from 150 to500Hz. A hitherto unknown mechanism enables males ofsome Hawaiian species to generate songs of up to 15,000Hz(Hoikkala, Hoy, & Kaneshiro, 1989).The structure of the courtship songs of closely relatedspecies often reflects phylo…
Molecular phylogeny of treecreepers (Certhia) detects hidden diversity†
2006
We sequenced a part of the mitochondrial cytochrome-b gene from the seven treecreeper species, including 18 subspecies, to reconstruct the phylogeny of the genus Certhia. Species status of all seven species could be affirmed. Certhia discolor, C. himalayana, C. nipalensis, and C. tianquanensis, the species with relatively small distribution ranges in southeast Asia and simple territorial song, are found at the base of all phylogenetic trees, although without good support. A comparatively recent sister species of C. tianquanensis is C. nipalensis, replacing C. discolor as closest relative. Certhia familiaris, C. brachydactyla and C. americana form a derived set of species (again only weak su…
Seed dispersal, braeding system, tree density and the spatial pattern of trees – a simulation approach
2002
Summary Tropical tree populations with low densities and with clumped spatial distributions are at risk in the face of fragmentation. It is therefore important to understand factors driving spatial patterns of tree populations. An important set of factors which may influence the spatial pattern of plants, could be the spatial distribution of possible seed sources such as the breeding system (monoecious, dioecious), tree density and the spatial pattern of the parent population. Another set of important factors might be dispersal of seeds away from the parent plants characterised by the mean dispersal distance and by the distribution of dispersal distances (either negative exponential or logn…
A geometrical framework for f –statistics
2020
AbstractA detailed derivation of the f–statistics formalism is made from a geometrical framework. It is shown that the f–statistics appear when a genetic distance matrix is constrained to describe a four population phylogenetic tree. The choice of genetic metric is crucial and plays an outstanding role as regards the tree–like–ness criterion. The case of lack of treeness is interpreted in the formalism as presence of population admixture. In this respect, four formulas are given to estimate the admixture proportions. One of them is the so–called f4–ratio estimate and we show that a second one is related to a known result developed in terms of the fixation index FST. An illustrative numerica…