Thesis (PH. D)--University of Chicago, 1934. / Published also without thesis note. Bibliography: p. [131]-148.

Issued also as thesis, Univ. of Chicago. / Bibliography: p. [131]-148.

Thesis (PhD)--Stellenbosch University, 1994. / ENGLISH ABSTRACT: Fifty nine species were studied in this taxonomic treatment of section Hoarea (Sweet) DC. of the genus Pelargonium L'Herit., which was last revised by Knuth in 1912. The majority of species occur in the winter rainfall area of the south-western Cape, but some species occur in the eastern Cape, a region of winter and summer rainfall. A few species also occur in the summer rainfall area in the central Karoo. Morphological, leaf anatomical, palynological and geographical data were studied in order to delimit the taxa and to determine their relationships. Eight new species were described and several name changes were made. Diagnostic features of the section are the regularly or turnip-shaped tubers with numerous dark brown peeling tunics or periderms and apically a short flattened stem from which the leaves and scape emerge. The zygomorphic flowers are almost sessile, because the pedicels are very short (0,5--1 mm) and the hypanthia long (6--100 mm). A large variation occurs in leaf form and floral structure, and the section is divided in 14 different floral groups, mainly based on the structure of the androecium and the tectum of the pollen grains, although petal form and size are also considered in clustering the species. Section Hoarea with its deciduous geophytes and sometimes extremely zygomorphic flowers, exhibits advanced morphological characters. Because of the large variation in the structure of the androecium, pollination biology was probably one of the major driving forces in the evolution of the section, and the annual rainfall plays an important role in the distribution patterns of the different species. / AFRIKAANSE OPSOMMING: Neen en vyftig spesies is bestudeer in hierdie taksonomiese ondersoek van seksie Hoarea (Sweet) DC. van die genus Pelargonium L'Herit., wat laas deur Knuth (1912) hersien is. Die meerderheid van die spesies kom in die winterreenstreek van die suidwes Kaap voor, maar sommige spesies word ook in die Oos-Kaap, wat 'n winter- en somerreenstreek is, aangetref. Enkele spesies kom in die somerreenstreek van die sentrale Karoo voor. Morfologiese, blaaranatomiese, palinologiese en geografiese data is bestudeer om die verskillende taksons af te baken, en terselfdertyd verwantskappe tussen die onderskeie spesies te bepaal. Agt nuwe spesies is beskryf en verskeie naamsveranderinge is gemaak. Diagnostiese kenmerke van die seksie is die reelmatiggevormde of raapvormige wortelknol met verskeie afskilferende donkerbruin periderms en apikaal 'n verkorte stingel waaruit blare en 'n bloeispil groei. Die sigomorfe blomme is byna sittend, aangesien die blomstele uiters kort is (0,5--1 mm) en die hipantiums relatief lank (6-- 100 mm). 'n Groot variasie in blaarvorm en blomstruktuur kom voor, en die seksie word in 14 verskillende blomvorms verdeel. Hierdie blomvorms is hoofsaaklik gebaseer op die struktuur van die andresium en tektum van die stuifmeelkorrels, alhoewel kroonblaarvorm en -grootte ook 'n rol gespeel het in die onderverdeling van die seksie. Seksie Hoarea met sy bladwisselende geofiete en soms uiters sigomorfe blomme, vertoon gevorderde morfologiese kenmerke. Die groot variasie in die struktuur van die andresium dui op 'n moontlike prominente rol wat die bestuiwingsbiologie gespeel het in die evolusie van die seksie, en die jaarlikse reenval speel 'n belangrike rol in die verspreidingspatrone van die verskillende spesies.

This study presents the first partial systematic revision of the speciose American seven-spined gobiid fish genus Chriolepis, which occurs in sublittoral reef-rock and rubble cryptobenthic habitats in tropical-subtropical, primarily insular, waters of the eastern Pacific and western Atlantic oceans. Although a few of the (more poorly known) western Atlantic species are briefly discussed or mentioned, this study focuses on eight eastern Pacific species, representing the majority of the known forms. These populations are disjunctively distributed in the Panamic Province from the Gulf of California, Mexico, southward to Costa Rican (Coco)-Colombian (Malpelo)-Equadorian (Galapagos) oceanic islands lying near or on the equator. This study offers a key to the species, diagnoses of the genus and two subgenera (Chriolepis and Eleotriculus), and diagnoses and descriptions of each species, including the type species and four new forms. The diagnoses and descriptions are based on external morphological study of all known specimens (including statistical analyses of several morphometric characters) and include data derived from recently collected material for the majority of the species. Also provided are illustrations of each species, their geographical and bathymetric distributions, discussions of their zoogeography and postulated evolutionary relationships, and notes on what little is known of their ecology. The highly sedentary behavior of these secretive fishes, coupled to habitat selection with small body size permitting tight-crevice and rock-interspace inhabitation, has favored morphological adaptation (e.g., loss of pelvic-fin fusion and head canal pores) as well as spatial isolation and genetic divergence within the sublittoral cryptobenthic ecotopes inhabited by these gobies in the eastern Pacific. Exploitation of such ecotopes evidently has produced a remarkable degree of convergent evolution between the American seven-spined genus Chriolepis (and its close allies) and several forms of six-spined gobiids found in similar habitats in the Old World.

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, in fulfillment of the requirements for the degree of Master of Science. 2014. / No abstract provided.

Thesis (Ph.D.)Soil Science)--University of Pretoria, 2000. / Includes bibliographical references.

A long overdue taxonomic revision is performed on the family Euretidae (Hexactinellida). World literature is compiled, world type material is gathered, prepared, re-examined, measured, described and illustrated, taxonomic histories and world species distributions are provided. A generic key to the Euretidae is also provided. Of the 19 generic names associated with the Euretidae at one time or another, 16 are recognised here (Bathyxiphus, Calyptorete, Chonelasma, Conorete, Endorete, Eurete, Gymnorete, Heterorete, Iphiteon, Myliusia, Pararete, Periphragella, Pleurochorium, Ptychodesia, Lefroyella and Verrucocoeloidea). Syringidium is put into synonymy with Lefroyella; Joanella and Margaritella are synonymized with Iphiteon; two subspecies and one form are elevated to species status; three new species combinations are presented and two new species are named. Phylogenetic analysis suggests the majority of morphological euretid characters are prone to homoplasy and are not useful for phylogenetic classification. Subfamilies based on channelization and the presence or absence of key spicules are designated.

La thèse concerne la transformation de données textuelles non structurées en données structurées et exploitables par des systèmes de recommandation. Deux grandes catégories d'informations sont utilisées dans le domaine des moteurs de recommandation : les données descriptives de contenus comme les méta-données ou les tags (filtrage thématique), et les données d'usages qui peuvent être des notes ou encore des pages Web visitées par exemple (filtrage collaboratif). D'autres données sont présentes sur le Web et ne sont pas encore réellement exploitées. Avec l'émergence du Web 2.0, les internautes sont de plus en plus amenés à partager leurs sentiments, opinions, expériences sur des produits, personnalités, films, musiques, etc. Les données textuelles produites par les utilisateurs représentent potentiellement des sources riches d'informations qui peuvent être complémentaires des données exploitées actuellement par les moteurs de recommandation et peuvent donc ouvrir de nouvelles voies d'études dans ce domaine en plein essor. Notre objectif dans le cadre de la thèse est de produire, à partir de commentaires issus de sites communautaires (blogs ou forums), des matrices d'entrées pertinentes pour les systèmes de recommandation. L'idée sous-jacente est de pouvoir enrichir un système pour un service débutant, qui possède encore peu d'utilisateurs propres, et donc peu de données d'usages, par des données issues d'autres utilisateurs. Nous faisons tout d'abord un état de l'art de la recommandation automatique. Nous présentons ensuite le moteur ainsi que les données utilisées pour les expérimentations. Le chapitre suivant décrit les premières expérimentations en mode thématique. Nous faisons ensuite un nouvel état de l'art sur la classification d'opinion. Pour finir, nous décrivons les expérimentations menées pour l'approche collaborative à l'aide de la classification d'opinion. / The thesis is about the transformation of unstructured textual data in structured data in order to be used by a recommender system. Recommender systems can operate on two main types of data: content descriptors as metadata or tags (content-based filtering), and usage data as rates or visited Web pages for example (collaborative filtering). Other data exist on the Web which are not used yet. With the emergence of the Web 2.0, users share their feelings, opinions, experiences on products, personalities, movies, music, etc. (through comments for example). This textual data generated by users potentially represent rich sources of information which can supplement data exploited by recommender systems. The exploitation of this kind of data could open new paths in this burgeoning field. Our objective in this thesis is to generate matrices relevant for recommender systems. The underlying idea is to enrich a system for a beginner service, which has still few own users, then too little usage data, by information on other users on the Web. The thesis begins with a state of the art of automatic recommendation. Then, we present the recommender systems and the textual corpus used for experiments. The next chapter presents first experiments with the content-based filtering approach. The next part contains the state of the art of opinion mining. Finally, we describe experiments done with collaborative filtering approach using opinion classification.

No description available.

Comparative morphological and anatomical studies of the dispersal mechanisms characterizing the wheat complex (Triticum L. and Aegilops L.) have documented patterns of adaptive radiation which may have significance for evolutionary relationships. These patterns, which form an array of diverse types of diaspores among the diploid taxa, appear conceptually to have a starting point in the dimorphic inflorescence of Ae. speltoides. Separate dispersal trends, centered primarily in features of rachis disarticulation, lead in the direction of novel diaspore types for Aegilops and in the direction of domestication for Triticum. With respect to the taxonomy, this structural evidence supports the traditional Linnaean generic circumscriptions and suggests a need for a monographic revision of Triticum. In documenting the dispersal mechanisms, these studies have clarified conventional interpretations and have offered new insights on the developmental relationships linking the wild and domesticated taxa of the wheat complex. Although genetic studies were not encompassed within this research, a consideration of the genetic explanations for rachis disarticulation and glume closure suggests that the phenotypic traits typically used in genetic studies are not well understood. Given that the reticulate nature of genomic relationships in the wheats is coupled with intergrading variation and polymorphic species, a proposal is made for a broader evolutionary view than is found in the strict cladistic concept. This proposal emphasizes the need of an improved understanding of fundamental structural traits and an inclusion of these traits in evolutionary analyses. / Graduation date: 1995