No description available.

The taxonomic affinities of the plants formerly-referred to Oncidium section Oncidium, (Orchidaceae) in the Caribbean Islands have been studied with respect to morphological, cytogenetical, biochemical and geographic data. The data was-examined employing numerical taxonomic methods. The study involved 57 taxa (28 taxa of the plants belonging to the orchid group studied and 29 related-species)-and a total of 63 attributes. The literature and all available herbarium specimens-concerning the plants studied were viewed critically. This resulted in the clarification of some problems of identification and taxonomy. The plants studied were reclassified into, the*genera Braasiella, Hispaniella, Olgasis and Tolumnia. For all but one species formerly referred to Oncidium section Oncidium, living material was obtained through purchase, donation or through personal collecting in the Caribbean Islands. Living plants were examined in respect to morphological and ultrastructural characters. For all but three taxa, the chromosome number (2n) was determined. The data obtained was compared with the data formerly reported. For nine taxa, the diploid chromosome numbers are reported for the first time. Field studies were performed in selected areas of Jamaica, Haiti and the Dominican Republic to determine some aspects of the pollination ecology, ecology and distribution of some of the taxa. -3- Leaf flavonoid fingerprinting was performed on material obtained from all 57 taxa studied, using two dimensional paper chromatography. All data obtained was collated using numerical taxonomic methods. It became apparent during this study that a number of previously described taxa needed clarification as far as their identity is concerned. Furthermore, it became apparent that the species formerly referred to, oncidium sect. Oncidium, differ from all other groups of the genus Oncidium sensu Garay and stacy, as well as from all genera within the Oncidiinae, in such a way as to warrant their separation as autonomous genera. These have been published by Rafinesque (1837), Braem (1980) and Braem et al. (1984). This work also shows the difficulty of gaining total objectivity in a systematic study. The main problems arise from the selection of attributes, and the difficulties experienced in the coding of the data.

No description available.

Many adult concepts can be represented in taxonomies hierarchical systems in which concepts are differentiated into varying levels of abstraction (e.g., musical instrument, wind instrument, flute) related by class inclusion (a flute is a wind instrument and a wind instrument is a musical instrument). Indeed, most natural kinds (e.g., whale, tree) and artifacts (e.g., flute, truck) are generally believed to fall within taxonomies. Moreover, in real world contexts, concepts are probably rarely learned as explicitly contrasting sets existing completely outside of known taxonomies (that is, one might not learn cats vs. dogs without also learning that both are types of animals, and that both include more specific subcategories). Surprisingly, relatively little research has been done on the learning of categories that are hierarchically structured. The present study began an investigation into how adults learned new concepts that are hierarchically structured. In Experiment 1, participants learned to classify items at one taxonomic level then at a later time classified items at either the same or a different level. The results suggested that people were unable to clearly detect the relationship among alternate levels of the hierarchy prior to exposure of those levels. However, results in Experiment 1 also suggested that learning multiple categories might lead to deeper understanding of how features transfer or generalize to higher taxonomic levels. The remaining experiments addressed more explicitly the influence of hierarchical structures on category learning by including prototype and control items, along with artificial and knowledge-based category labels. Results from these experiments indicated that, at least within the parameters of this study, prior experience cued by knowledge-based category labels interacted adversely with abstract materials and interfered with mapping of item information to categories. Moreover, when the relationship between categories and item information is unclear, generalization might be one important means by which people categorize.

Elatostema J.R.Forst. & G.Forst. (Urticaceae) is a taxonomically problematic genus of approximately 300 species that is widespread throughout the tropical, subtropical and sub-temperate regions of Africa through to SE Asia, Australasia to Polynesia. Morphological and molecular analyses were conducted to evaluate the infra-familial classification of the Urticaceae, to test the monophyly of Tribe Elatostemeae, to define generic limits of Elatostema and assess its relationship within the tribe, and to examine the current infrageneric grouping within Elatostema. Phylogenetic analyses based on choloroplast DNA sequences of rbcL and trnL-F do not provide support for the monophyly of Urticaceae, because of the position of Poikilospermum (currently Cecropiaceae) within the tribe Urticeae. Although the status of Cecropiaceae is equivocal, there is support for the inclusion of this family in the Urticaceae, with Cecropia and Coussapoa (Cecropiaceae) having close affinities to the Boehmerieae and Parietarieae. The phylogenetic position of Myriocarpa is unresolved, but is excluded from the Boehmerieae, as currently classified. The Elatostemeae is paraphyletic with Pilea placed sister to the Urticeae. Evaluation of the infrageneric classification of Elatostema, based on phylogenetic analyses of both morphological and molecular data (trn and ITS) does not support the current subgeneric classification as proposed by Schr??ter and Winkler (1935, 1936). The analyses support two main infrageneric grouping: (1) a group consisting of Elatostema subg. Pellionia and Procris, and (2) a group consisting of the remaining members of Elatostema (including E. griffithianum ??? subg. Pellionia). The molecular data are regarded as a more accurate estimate of the phylogeny than provided by morphology, with molecular data having a higher Rescaled Consistency Index on the most parsimonious trees, together with a much greater level of resolution and support than that of the morphological analyses.

Ostracods of the family Cylindroleberididae are speciose, widespread, and well-defined by morphological features including the possession of gills. Despite the family having been divided into three subfamilies, five tribes, 32 genera, and more than 200 species, the relationships between its species have never been analysed phylogenetically. Twenty-five of the 32 genera are not defined by unique features but rather combinations of characters, and may therefore be historical constructions rather than evolutionary groups. The classification is of limited functional and predictive use, and requires a systematic revision. (For complete abstract open document)

Squids in the family Onychoteuthidae Gray, 1847 have been reported from every ocean but the Arctic, are taken frequently in deep-sea fisheries by catch, and are ecologically important in the diets of many marine predators including cetaceans, pinnipeds, sharks, and seabirds. However, the diversity and systematic of the family have remained poorly understood. Of the 60+ nominal species, 12–14 have generally been accepted in recent studies. Challenges to clarity include insufficient species descriptions, original descriptions published in eight languages and often based solely on early life stages, non-designation or subsequent loss of type material, and the existence of several unresolved species complexes. In light of the general systematic disarray of the Onychoteuthidae, a global revision of the family follows, based on ~1500 specimens examined from 19 repositories. Type material has been examined wherever possible; for some species, photographs of type specimens, original illustrations, and/or the original descriptions have provided the only information available. It has not been possible to fully disambiguate taxa in some cases (e.g. Gen. nov. 2), given the limited material and information available, but for all species treated in this revision (25 out of 26 species; no material was available for Kondakovia nigmatullini), descriptions and illustrations are provided to a consistent standard that will enable their reidentification. External and internal morphological characters and states are described for sub adult to adult stages of most species, with external characters reported through ontogeny as permitted by available material. Historically important characters are treated (general external morphology, body proportions, tentacle clubs, photophores, gladius, lower beak, radula), augmented by several more recently recognised characters (palatine teeth, detailed morphology of the tentacular hooks in adults, tentacular suckers in paralarvae, chromatophore patterns). The systematic value of both historical and new morphological characters at the generic and species levels are discussed; at all ontogenetic stages, tentacular club and hook morphology are considered the most valuable characters, although body proportions and gladius also prove useful. Partial disambiguation of the Onychoteuthis banksii complex has been possible in the Pacific and Atlantic Oceans, resulting in the resurrection of Onychoteuthis bergii Lichtenstein, 1818 and Onychoteuthis aequimanus Gabb, 1868, the description of two new species, Onychoteuthis lacrima and Onychoteuthis prolata (in press), and the expansion of one species’ recognised distribution (Onychoteuthis compacta) to include the Atlantic Ocean. The genus Moroteuthis Verrill, 1881 is considered a junior synonym of Onykia Lesueur, 1821, in accordance with the findings of several earlier authors. However, morphological differences in the species ‘Moroteuthis’ ingens necessitate the resurrection of the subgenus Moroteuthopsis Pfeffer, 1908b, with all other Onykia species placed into a new subgenus, Onykia (Onykia). Sexual dimorphism is reported in the beaks of Onykia (Moroteuthopsis) ingens (new comb.), and revised sex-specific equations are given for estimating this species’ biomass based on LRL. Morphological and historical genetic data suggest a more distant relationship between Onykia and the species ‘Moroteuthis’ knipovitchi Filippova, 1972 than was suggested by earlier classifications. This species is therefore considered to represent an undescribed genus, herein referred to as Gen. Nov. 1, which cannot be more fully diagnosed and described at present due to limited material. The generic position of ‘Onykia’ rancureli (Okutani, 1981) is also uncertain; it may be allied to Walvisteuthis virilis Nesis & Nikitina, 1986 (family Walvisteuthidae Nesis & Nikitina, 1986), but confirmation is impossible without examining type material of W. virilis. A second new genus, Gen. Nov. 2, is therefore described for ‘Onykia’ rancureli and several morphological variants reported from the Pacific and Atlantic Oceans. Given that the majority of available onychoteuthid material was collected after 1950, resulting in the descriptions of over half of the generally accepted genera and species since 1960, ongoing collection programmes are necessary to further resolve onychoteuthid systematic.

Doctor of Philosophy / The genus Poltys C.L. Koch is revised for Australia and partly examined for the wider Australasian region. Five of the ten species originally described from Australia are found to be synonymous with South East Asian species, a further three are synonymous with an Australian species and four which were previously overlooked are newly described, resulting in a total of eight current species recorded from Australia. Poltys coronatus Keyserling, P. keyserlingi Keyserling, P. multituberculatus Rainbow and P. penicillatus Rainbow are synonymised with P. illepidus C.L. Koch; P. microtuberculatus Rainbow is synonymised with P. stygius Thorell; P. bimaculatus Keyserling, P. mammeatus Keyserling and P. salebrosus Rainbow are synonymised with P. laciniosus Keyserling; P. sigillatus Chrysanthus from New Guinea is synonymised with P. frenchi Hogg. Five new species are described, four from Australia, P. grayi sp.nov., P. jujorum sp.nov., P. milledgei sp.nov. and P. noblei sp.nov., and P. timmeh sp.nov. from New Caledonia. A checklist of all Poltys types described from the region, including illustrations, is included. The delimitation of the Australian species is aided and confirmed by DNA sequencing. Sequences from two genes and morphological characters are used to reconstruct a phylogeny of the Australian species. The generic relationships of Poltys are examined in the context of the putative tribe Poltyini (Simon, 1895). No firm conclusions about the relationships of Poltys can be made, however the results indicate that the Poltyini is polyphyletic. The results of field studies are presented; these indicate that P. noblei is less likely to move between web sites than diurnal taxa referenced from other studies. Specimens were shown to sometimes occupy the same, or a closely adjacent web site, for over eight months. Spiders most often move during spring and summer but often remain in the same site throughout winter. Specimens of Poltys noblei are also shown to be unevenly distributed on trees and bushes in respect to aspect and position. It is suggested that these observations indicate the importance of camouflage to deter wasp and bird predators. Specimens of several Poltys species were reared from egg sacs, confirming male–female identification and showing the variation in abdominal shape between siblings. Growth data indicate that sibling males and females cannot normally interbreed; males mature after 2–4 moults, females after 8–11 moults. Field and cage observations of general aspects of Poltys biology are presented including preferred habitat, prey capture and handling, courtship and mating, competition and web construction.

Στις μέρες μας οι χρήστες εκτός από 'καταναλωτές' πληροφορίας στο διαδίκτυο είναι και 'παραγωγοί' και διαχειριστές της. Μια συνήθης πρακτική είναι η σήμανση του περιεχομένου που διαμοιράζονται με ετικέτες (tags) και η χρήση των ετικετών αυτών σε διαδικασίες αναζήτησης ή εύρεσης περιεχομένου με παρόμοια χαρακτηριστικά. Ένα από τα εργαλεία που ευρέως χρησιμοποιούνται στις διαδικασίες αυτές είναι οι ταξονομίες (taxonomies). Οι ταξονομίες είναι δενδρικές δομές που συνίστανται από κόμβους, καθένας από τους οποίους αντιπροσωπεύει μια κατηγορία-ένοια και συνδέεται με τα παιδιά και τον γονέα του με σχέσεις 'IS-A'. Δημιουργούνται κατά βάση χειρωνακτικά, από ειδικούς, ενώ η ανανέωση και επέκτασή τους είναι αρκετά χρονοβόρες ενέργειες. Στην εργασία αυτή ασχολούμαστε με την αυτόματη εξαγωγή ταξονομίας από είσοδο που προέρχεται από μια κοινότητα χρηστών. Θεωρούμε πως οι χρήστες μας είναι ικανοί να παρέχουν σχέσεις ετικετών που περιγράφουν καταστάσεις υπερκατηγορίας-υποκατηγορίας μεταξύ θεματικών κόμβων και προσπαθούμε να τις συγκεράσουμε ώστε να προκύψει μια ταξονομία. Η τελική ταξονομία είναι συμβατή με τα 'κβάντα' πληροφορίας που έχουμε στη διάθεσή μας, επιλύει αντικρουόμενες απόψεις χρηστών όσον αφορά την τελική της δομή και αποτυπώνει την ικανότητα της κοινότητας στη διακριτοποίηση εννοιών. Προτείνουμε έναν αλγόριθμο κατασκευής μιας ταξονομίας και θα αξιολογήσουμε την απόδοσή του, χρησιμοποιώντας τόσο συνθετικά, όσο και πραγματικά δεδομένα. Γίνεται επίσης προσαρμογή και μελέτη του συστήματος σε crowdsourcing περιβάλλοντα, περιβάλλοντα δηλαδή όπου ένας μεγάλος αριθμός από χρήστες χρησιμοποιείται για την περάτωση μικρών εργασιών που χαρακτηριστικό τους είναι η αδυναμία εκτέλεσης τους από υπολογιστικά συστήματα. / Taxonomies are a useful mechanism to organize, evaluate, and search web content. As such, many popular classes of web applications, utilize them. However, their manual generation and maintenance by experts is a timecostly procedure, often resulting in platform dependent and static vocabularies. We propose a new approach for constructing taxonomies. Our idea is based on the proven, increased human involvement and desire to annotate web content (e.g., in social media and product categorization applications). We define the required input from humans in the form of explicit structural, e.g., supertype-subtype relationships between concepts. In this way, we harvest, via common annotation practices, the collective wisdom of users with respect to the (categorization of) web content they share and access. We further define the principles upon which crowdsourced taxonomy construction algorithms should be based. We show that the resulting problem is NP-Hard. We provide heuristic algorithms that aggregate human input, resolving conflicting input, and produce taxonomies. We evaluate our algorithms with real world crowdsourcing experiments and on real world taxonomies.

No description available.