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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.

Taxonomies, knowledge and artifacts; interactivity in category learning

Hoff, Michael Unknown Date
No description available.

A Taxonomic and Ecological Study of Periphytic Cyanobacteria in Kaituna River and Its Tributaries, Banks Peninsula, New Zealand.

Merican, Faradina January 2013 (has links)
Most of the detailed studies on periphyton in New Zealand rivers and streams have focused on diatoms. Despite the recent rise of interest in potentially toxic cyanobacterial mats, knowledge of the diversity and ecology of these and other macroscopic growth forms is incomplete. A taxonomic survey was made on periphytic cyanobacteria at 100 locations along Kaituna River and a 1st to 3rd order tributary stream. Samples were taken from runs, riffles and pools in shaded and unshaded locations and from varied substrata from January to December 2011. Descriptions were made of all macroscopic growths. Fifty-six morphospecies were identified of which 29 are new records for New Zealand. Crust components were the most diverse with 23 morphospecies followed by mats (16), gelatinous colonies (5) and epiphytes (7). Five appeared only after growth in enrichment cultures. Twelve morphospecies were isolated into cultures for use in polyphasic assessment. In 16S rDNA phylogenies, Placoma regulare and Heteroleibleinia fontana did not cluster with other members of their traditional families. Nostoc sp. 2 was positioned distant from other Nostoc strains. Comparison of 16S – 23S rRNA internal transcribed spacer compositions for seven mat-forming oscillatorialean morphospecies confirmed their recognition as distinct morphospecies. Amplified fragment length polymorphisms were used to investigate genetic diversity of Nostoc verrucosum in relation to dispersal. This indicated that local dispersal is dominant while cross-catchment dispersal is probably infrequent. Light intensity, substratum type and water conductivity were significant factors influencing spatial patterns of distribution. Higher diversity of crusts, mats and gelatinous colonies was recorded in unshaded locations. Mats and gelatinous colonies were most diverse in Kaituna River and crusts in second to third order streams. Morphospecies in water with high conductivity were restricted to those locations. Spates had a major effect on temporal distribution. An increase in frequency and intensity of spates in spring and winter resulted in greater reduction in cover. Smaller spates caused partial removal followed by rapid regrowth within a week. Major spates caused complete removal of visible cover with re-colonization occurring within three to four weeks. This study has provided a first detailed account of cyanobacterial diversity and ecology in a New Zealand catchment. It provides a basis for long-term monitoring at this site of the effects of changes in climate and in human activities in the catchment.

A systematic study of the Leucanthemum - Chrysanthemum complex

Wilcox, B. H. January 1977 (has links)
No description available.

Conceptions of 'unity' in recent ecumenical discussion : a philosophical analysis

Harrison, Simon Ross January 1999 (has links)
No description available.

Aspects of the taxonomy and biology of Ceratodon Brid

Burley, J. S. January 1986 (has links)
No description available.

Taxonomic studies in the genus Gaultheria L. and related genera (Ericaceae)

Middleton, David J. January 1989 (has links)
The genera of the <i>Gaultheria</i> group of the tribe Andromedeae (Ericaceae) have been studied. These genera are <i>Gaultheria</i> L. (including <i>Chiogenes</i> Salis.), <i>Pernettya</i> Gaud., <i>Leucothoe</i> Don, <i>Zenobia</i> Don, <i>Diplycosia</i> Bl., <i>Pernettyopsis</i> King et Gamble and <i>Tepuia</i> Camp. Morphological, anatomical, chemical and cytological characters have been used to clarify generic limits and to construct a subgeneric classification of <i>Gaultheria</i>. Chemical and cytological characters were found to be of limited taxonomic use because of the unpredictable infraspecific variation of the former and the virtual absence of variation in the base chromosome number for the latter. <i>Chiogenes</i> and <i>Pernettya</i> are not sufficiently distinct from <i>Gaultheria</i> to be maintained as separate genera. Appropriate binomials have been proposed, within the genus <i>Gaultheria</i>, for all of the species of <i>Pernettya. Leucothoe</i> and <i>Zenobia</i>, although undoubtedly close to <i>Gaultheria</i>, are maintained as separate genera. The genus <i>Gaultheria</i> has been classified into ten sections (one with two subsections) and 22 series. Each taxon has been described and a diagnostic key to the sections and series has been provided. Field studies in Ecuador have highlighted aspects of the ecology of <i>Gaultheria</i> and <i>Pernettya</i>, particularly their preference for highly disturbed habitats. A previously undescribed hybrid between <i>Gaultheria reticulata</i> and <i>Pernettya prostrata</i> has been found. Closer study of the stamens and anthers of a number of species of <i>Gaultheria</i> has revealed a high incidence of male sterility indicating that gynodioecism may be more common in the genus than previously suspected. Previous studies and observations in the field suggest a high incidence of self-pollination.

Taxonomic studies in the family Asclepiadaceae

Rahman, M. A. January 1990 (has links)
1. The taxonomic history and currently accepted classification of the family Asclepiadaceae is presented and discussed. The evolutionary relationship with nearest families, overall geographical distribution and a brief note on economic importance of asclepiads are provided in a general account of the family. 2. A complete taxonomic account of the family for the Flora of Bangladesh is prepared for the first time after a comprehensive survey of the existing taxa. 56 species and 4 varieties from 25 genera are recognized from the area. A dichotomous key to the genera, based on field characters, is provided, and suprageneric, infrageneric and infraspecific classifications are given. A nomenclatural and typification note is provided with a proposal for 16 lectotypes and 3 topotypes according to ICBN. A few nomenclatural changes in some species are made and a full attention is paid to synonymy which results in a number of reductions. Wallich's asclepiad material from Bangladesh held at K-W and other major herbaria have been examined critically, and an index has been prepared with nomenclatural notes and current taxonomic status. There are 7 species and 2 varieties recorded new to the flora of Bangladesh. 2 new varieties, <i>Gymnema acuminatum</i> var. <i>glabrum</i> and <i>Tylophora indica</i> var. <i>intermedia</i>, have been described from Bangladesh. Some investigations on pollinaria, seed morphology and leaf flavonoids have been done. A comparative account of the morphology of the pollinaria of 50 species from 25 genera is prepared with a dichotomous key for the <i>Flora of Bangladesh</i>. Seed morphology under SEM for 14 species from 11 genera provides diagnostic features which may prove useful for supra- and infra-generic classifications. Flavonoid distribution in asclepiads is not taxonomically useful at any level of the taxonomic hierarchy. 3. Two genera, <i>Calotropis</i> and <i>Pentasacme</i>, have been revised for the first time with notes on their taxonomic history, distribution, ecology and synonymy. 3 species of <i>Calotropis</i> and 4 in <i>Pentasacme</i> are recognized. <i>C. procera</i> ssp. <i>hamiltonii</i> (Wight) Ali is reduced to <i>C. procera</i> (Aiton) R. Br. Two sections in the genus <i>Pentasacme</i> are recognized: sect. <i>Pentasacme</i> and sect. <i>Wallichiana</i> (sect. nov.). <i>Pentasacme championii</i> Benth. is considered as a synonym of <i>P. caudatum</i> Wall. ex Wight.

Characterisation of arthrobacters by pyrolysis mass spectrometry

Bovonsombut, Sakunnee January 2000 (has links)
No description available.

A study of the taxonomic status of some bacteria currently assigned to the genus Aeromonas

McCarthy, D. H. January 1978 (has links)
No description available.

Middle Jurassic ostracoda from southern England and northern France

Sheppard, Lesley Margaret January 1981 (has links)
A taxonomic and biostratigraphic study of Middle Jurassic (mainly Bathonian) ostracods from southern England and northern France is here presented. A fauna of 111 species of 55 genera, belonging to the Order Podocopida, is described. Thirty four species, 3 genera, Strictocythere, Angliaecytheridea and Konarocythereis and 1 subgenus, Blanoacanthocythere, are new; a further 11 species are left under open nomenclature owing to lack of material. The biostratigraphic application of the ostracods is a continuation of the work of Bate (1978) in constructing a zonation scheme based on ostracods for the correlation of the English Bathonian. Such a zonation is necessary because of the rarity, and often absence, of ammonites within the Stage and because of the highly complex interfingering of facies belts, making correlation on lithologies very tenuous. The Zones are named, fully defined and applied to a much wider geographical area than before. These are the rimosa, confossa, polonica, blakeana, and falcata Zones, the lowermost rimosa Zone (commencing in the topmost Bajocian) being sub-divided into the rimosa, batei, and postangusta Subzones. Considered as time Zones they are shown to be highly reliable in dating sediments of varying facies and to permit a direct correlation of the beds in southern England with those of northern France. On the basis of the zonation two lithostratigraphic units in the French succession, the Calcaire de Reviers and the Caillasse de Fontaine-Henry are no longer considered valid as discrete units and are regarded as being equivalent to the Calcaire de Blainville and the Caillasse de Blainville respectively. Certain discrepancies in the ostracod faunas are seen between the areas sampled and these are used to construct a slightly modified palaeogeographic interpretation to that currently accepted.

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