'Network' is a heavily overloaded term, so that 'network analysis' means different things to different people. Specific forms of network analysis are used in the study of diverse structures such as ...the Internet, interlocking directorates, transportation systems, epidemic spreading, metabolic pathways, the Web graph, electrical circuits, project plans, and so on. There is, however, a broad methodological foundation which is quickly becoming a prerequisite for researchers and practitioners working with network models.
From a computer science perspective, network analysis is applied graph theory. Unlike standard graph theory books, the content of this book is organized according to methods for specific levels of analysis (element, group, network) rather than abstract concepts like paths, matchings, or spanning subgraphs. Its topics therefore range from vertex centrality to graph clustering and the evolution of scale-free networks.
In 15 coherent chapters, this monograph-like tutorial book introduces and surveys the concepts and methods that drive network analysis, and is thus the first book to do so from a methodological perspective independent of specific application areas.
Water frogs are involved in several hybridogenetic complexes. However, investigations in Southern and Western France produced evidence of new hybridization events between R. lessonae and R. perezi ...(some new hybrids tadpoles were discovered), and the existence of new assemblages R-G, L-P, R-P, P-R-G: (R, ridibunda; G, grafi; L, lessonae; P, perezi). In respect to hybridogenesis, these assemblages offer opportunities for both primary and secondary hybridizations. Such peculiarities may be explained either by introductions or by relic populations and may influence water frog evolution.
Neue Kontaktzonen und Gruppierungen bei Wasserfröschen in Südfrankreich
Wasserfrösche sind vielfach an der Bildung von hybridogenetischen Komplexen beteiligt. Unsere Untersuchungen in Süd‐ und Westfrankreich zeigten jedich neue Hybridisierungen zwischen Rana lessonae und Rana perezi (einige neue Hybride konnten im Kaulquappenstadium entdeckt werden) und das bestehen von neuen Komplex‐Gruppierungen R-G, L-P, R-P, P-R-G: (R, ridibunda; G, grafi; L, lessonae; P, perezi). In Bezug auf den Hybridogenese‐Mechanismus lassen diese Komplex‐Gruppierungen sowohl primäre als auch sekundäre Hybridisierungen zu. Diese Besonderheiten können entweder durch Introgression oder durch das Bestehen von Reliktpopulationen erklärt werden; sie könnten so die Evolution der Wasserfrösche merklich beeinflussen.
Everyone knows the small-world phenomenon: soon after meeting a stranger, we are surprised to discover that we have a mutual friend, or we are connected through a short chain of acquaintances. In his ...book, Duncan Watts uses this intriguing phenomenon--colloquially called "six degrees of separation"--as a prelude to a more general exploration: under what conditions can a small world arise in any kind of network? The networks of this story are everywhere: the brain is a network of neurons; organisations are people networks; the global economy is a network of national economies, which are networks of markets, which are in turn networks of interacting producers and consumers. Food webs, ecosystems, and the Internet can all be represented as networks, as can strategies for solving a problem, topics in a conversation, and even words in a language. Many of these networks, the author claims, will turn out to be small worlds. How do such networks matter? Simply put, local actions can have global consequences, and the relationship between local and global dynamics depends critically on the network's structure. Watts illustrates the subtleties of this relationship using a variety of simple models---the spread of infectious disease through a structured population; the evolution of cooperation in game theory; the computational capacity of cellular automata; and the sychronisation of coupled phase-oscillators. Watts's novel approach is relevant to many problems that deal with network connectivity and complex systems' behaviour in general: How do diseases (or rumours) spread through social networks? How does cooperation evolve in large groups? How do cascading failures propagate through large power grids, or financial systems? What is the most efficient architecture for an organisation, or for a communications network? This fascinating exploration will be fruitful in a remarkable variety of fields, including physics and mathematics, as well as sociology, economics, and biology.
The main goal of this study is to investigate the role of vascular graft thickness in wall stress gradient in anastomosis region. Atherosclerosis is a common heart disease causes high mortality rates ...every year. The gold standard treatment of atherosclerosis is replacing with autologous vein extracted from patient's body. Since proper autologous vein is limited, researchers have made efforts to achieve compliance engineered blood vessels. Mechanical stress has great effect on both smooth muscle cells and endothelial cells and it is considered as a stimulus in plaque formation. In this study, we evaluate the role of thickness in wall stress of anastomosis region. For this purpose, two anastomosis models have been provided in ADINA and FSI simulations have been performed during pulsatile flow. In addition, the sensitivity of compliancy to thickness and diameter has been investigated. The vascular graft used in the simulations is a synthetic graft made up PCL and PVA by our group. Results show that thickness is an important parameter and even if vascular graft is compliant, improper thickness leads to an increase of wall stress pressure in anastomosis region.
ABSTRACT
We studied flowering phenology at the level of individual branches within strangler fig trees to determine (1) whether branches bloomed asynchronously within trees and (2) whether ...asynchrony, if observed, could be ascribed to genetically different branches of mosaic trees (i.e., trees formed by spontaneous grafting of genetically different individuals) undergoing individual flowering cycles that were out of phase with each other. Although asynchrony was fairly common, it most often reflected individual branches failing to bloom during one flowering episode, then coming back to bloom in synchrony at the next episode. We detected fewer mosaic trees than expected, and found only a very weak suggestion that mosaic trees may show less within‐tree synchrony than simple trees.
RESUMEN
La fenología de floración de cinco especies de ficus extranguladodres fue estudiada a nivel de ramas individuales dentro de un mismo írbol. El propósito del estudio fue determinar: (1) si las ramas de un mismo írbol producían flores en asincronía, y (2) si la asincronía, de presentarse, podía estar relacionada a la existencia de un mosaico genético en las ramas de un mismo írbol (e.i., írboles formados por la fusión de individuos genéticamente diferentes) donde cada genotipo presenta un ciclo fenológico independienre de los otros genotipos. Aunque los eventos de floración asincrónica heron comunes, en la mayoría de los casos las ramas que estaban des‐sincronizadas en un episodio de floración se unieron al resto de las ramas en el siguiente episodio. El número de írboles “mosaico” encontrados fue mucho menor que lo esperado y sólo se encontró una pequeña evidencia de que estos írboles muestran menos sincronía en floración que los írboles genéticamente uniformes.
On a identifi é 70 graffi tis historiques, réalisés dans les murs originaux de deux maisons à Granada (Espagne).
Les bâtiments sont situés au quartier historique du Realejo, prés d où étaient les ...vieux murs médiévaux, à côté de
la porte du Poisson, au Sud de la ville et déjà disparu. La chronologie des édifi ces est au début du XIXe siècle. Les graffi tis
sont d une grande variété de thèmes; étant les représentations les plus nombreuses des navires, des fi gures féminines qui
portent crinolines, des cercles décoratif et des éléments des comptes, mais il y a aussi des croix, des éléments architecturaux,
d écriture, des coeurs, etc.
Se han identifi cado un total de 70 grafi tos1 históricos, realizados en el revoco original de dos casas del
Barrio del Realejo de Granada. Los inmuebles están situados en el entorno de la antigua muralla medieval, junto a la
desaparecida Puerta del Pescado, ubicada al sur de la Medina. La cronología del edifi cio es de principios del s.XIX. Los
grafi tos son de una gran variedad temática, siendo los más numerosos las representaciones de barcos, fi guras femeninas
con miriñaques, círculos trazados a compás y elementos de cuentas; aunque también hay cruces, elementos arquitectónicos,
escritura, corazones, etc.
Artiklen refererer til erfaringer fra et konkret aktionsforskningsprojekt, hvor 12 børn mellem 4 og 6 år med mentale handicap blev inviteret til at fotografere. Samtidig sættes fokus på en række af ...de etiske problemstillinger og di- lemmaer som børneforskeren er konfronteret med, når man inviterer børn til at deltage i et sådan projekt. Deltagelse og etik er derfor artiklens nøglebegreber, og sigtet er at besvare tre spørgsmål:
Hvad betyder deltagelse og hvilke etiske dilemmaer rejser børns deltagelse?
Er der særlige etiske problemer og dilem- maer forbundet med at forske med “sær- lige” børn?
Kræver studier, der benytter sig af visuelle metoder, en særlig forskningsetik?
Artiklen konkluderer, at man må indstille sig på at tackle forskerens etiske dilemmaer si- tueret/situationsbestemt og hen ad vejen. Det konkluderes også, at etikken i et projekt, der inviterer børn med særlige behov til at deltage, ikke er anderledes end etikken i alle andre børneprojekter: børn har ret til at deltage og børn har ret til omsorg og beskyttelse. Måden at praktisere den på vil dog ofte opleves an-derledes, da kommunikationen med børn, der er mentalt handicappede, kan kræve andre former (tegn-til-tale, tegnsprog, totalkommu- nikation, o.lign.) Endelig konkluderes det, at forskeren, der benytter visuelle metoder, må undersøge hvilke love og regler, der gælder de steder, hvor et projekt finder sted og skaffe sig den tilladelse, der er nødvendig, for at undgå at skabe problemer for såvel børn som for forskningsprojektet.
The article refers to the experiences of a con- crete action research project in which 12 chil- dren between 4 and 6 years with mental dis- abilities were invited to photograph everyday life. At the same time the article highlights a number of ethical issues and dilemmas the re- searcher is confronted with, when he/she invite children to participate. Participation and ethics in such a project. This is done in order to an- swer three questions:
– What does participation mean and what are the ethical dilemmas about children’s participation?
– Require research with special children spe- cial ethics?
– Requires a study using visual methods a special research ethics?
The article concludes that participation stu- dies always will raise ethical dilemmas and the researcher must be prepared to solve these “situated”: It also conclude that the ethics of a project that invites children with special needs to participate, should not differ from the ethics in any other research project: all children have right to participate and all need care and protection simultaneously. Finally it is recommended that the researcher examines the laws and rules governing the places where research takes place and that the researcher obtains the permits necessary to avoid creating problems for both children as informants, as for the research.
