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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.
21

Dendrochronology in Big Bend National Park, Texas

Schulman, Edmund 01 1900 (has links)
No description available.
22

Note on the Durango Dates

Morris, Earl H. 04 1900 (has links)
No description available.
23

Spruce Samples from the Copper River Drainage, Alaska

Oswalt, Wendell 07 1900 (has links)
No description available.
24

Rio Grande Chronologies

Schulman, Edmund 04 1900 (has links)
No description available.
25

The Origin of Driftwood on Nunivak Island, Alaska

Van Stone, James W. 12 1900 (has links)
No description available.
26

Systematic revision of the golden mole genera : Amblysomus, Chlorotalpa and Calcochloris (Insectivora : Chrysochloromorpha ; Chrysochloridae)

Bronner, Gary N. January 1995 (has links)
Patterns of variation in hyoid morphology, chromosomal properties and craniodental characteristics among ten chrysochlorid species from South Africa were studied to clarify generic relationships among taxa assigned variably to Amblysomus, Chlorotalpa and Calcochloris by previous authors. Intra-specific variation in hyoid morphology was negligible, but inter-specific differences were marked. Similarly, intra-specific karyotypic variation was negligible, except in A. hottentotus, which displayed three cytotypes. These data supported the recognition of Chlorotalpa, Calcochloris and Neamblysomus as taxa distinct from Amblysomus. Only one (presence/absence of M3) of the seven dental traits used by previous authors was consistent enough within species to be taxonomically useful in this work. Dental variability within species appeared to arise from the morphological differences between deciduous and permanent teeth, which may occur together in the same toothrow. Intra-specific craniometric variation in most species involved pronounced sexual size dimorphism, but negligible age-related variation. In the more widespread species, patterns of geographic variation were dominated by divergence in overall size, although subtle differences in cranial shape were also evident. Multivariate analyses confirmed the validity of subspecies in Chlorotalpa sclateri and Calcochloris obtusirostris, and showed that A. hottentotus (as traditionally recognized) includes: four cryptic species; five subspecies (including A. h. iris); and several populations that should be relegated to A. corriae. Inter-specific morphometric variation was dominated by overall size. The species fell into two size groups, and eight phena that differed mainly in skull width, palatal shape, rostrum breadth and claw size. Inter-specific relationships suggested by phenetic analyses of metric and mixed-mode data were, however, incongruent owing to discordance between different data suites. Evolutionary relationships inferred by integrating data suites, using either equal or differential weights, indicated that a strong phylogenetic signal was present in the data. Phylogenetic analyses showed that the differentially weighted treatment was more consilient with character-state distributions. A phylogram based on the differential-weights cladogram was used to derive a revised phylogenetic classification for the Chrysochloridae. Unlike previous treatments, this classification affords Carpitalpa and Neamblysomus generic rank, and assigns C. leucorhina from equatorial Africa to Calcochloris, rather than to Chlorotalpa. / Thesis (Ph.D.)-University of Natal, 1995.
27

The ecological implications of sea-level rise and storms for sandy beaches in KwaZulu-Natal.

January 2008 (has links)
The aesthetic appeal of beaches has made coastal properties prime sites for development. However, this development has been mismanaged and is within the littoral active zone. Beaches retreat landwards as sea levels rise, but with current development trends, beaches are trapped in a coastal squeeze. Climate-change predictions include an increase in frequency and heightened intensity of storms, which can cause significant erosion. This study aimed to determine the ecological implications of sea-level rise and storms for beaches in KwaZulu-Natal (KZN), using geographic information systems (GIS) and beach sampling methods. The beaches were mapped in terms of physical and biological attributes. Spatial trends in these attributes showed that the coastline can be split into three – the northern, central and southern regions. Although 25 % of the coastline is protected by marine reserves, these are located in the Delagoa bioregion: 28 macrofauna species in the Natal bioregion are not protected. Storm impacts for beaches can be heterogeneous, depending on local coastal features, e.g., nearshore reef and sand dunes, and represented a temporary disturbance to macrofauna communities. A GIS-based coastal recession model was derived from Bruun’s rule, and applied for different scenarios of sea-level rise and coastal development. Coastal squeeze is concern, particularly in the southern region. Further, the 10-m elevation contour was not completely effective as a setback line, even for a low sea-level rise scenario. The coastal recession model was validated using data from a real event in KZN, where sea level rose temporarily by ~1.0 m. The model performed well, although the calibration possibly did not span a wide enough range of beach morphodynamic types, and under-predicted retreat for dissipative beaches. It was concluded that the Natal bioregion needs marine reserves, and that higher resolution spatial data are required for accurate beach modeling and the south coast railway line should be relocated proactively. Guidelines for sandy beach systematic conservation planning were outlined, and seated in a conceptual framework of managing beaches for resilience. Application of the proposed recommendations and frameworks could aid in determining a way forward in integrated coastal zone management for KZN, in the face of the uncertainties associated with climate change. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2008.
28

Detecting parasites loads in urine diversion toilets.

Hawksworth, David James. January 2009 (has links)
In an attempt to supply sanitation to the growing communities in rural and peri-urban areas around Durban, the eThekweni Municipality has installed urine diversion (UD) toilets which have been modified to suit local conditions . These toilets are based on the ecological sanitation (EcoSan) system. The future aims are to reuse waste as a composting medium and minimize the use of water but the presence of microorganisms in the faecal waste poses a potential health risk to people in contact with it. Currently the Municipality has not deemed the waste safe for re-use but has suggested that after a one year standing period it should be free of all potential pathogens including Ascaris lumbricoiodes (human roundworm) ova. This study reports on the development of the AMBIC protocol for the recovery of Ascaris ova from the standing vaults of UD toilets. The protocol has been shown to consistently recover over 70% of Ascaris ova and has the added advantage of recovering the ova of other helminth species (Trichuris trichiura and Taenia sp.) present in a UD standing vault sample. Recoveries of Ascaris ova and ova of other parasite species, namely Trichuris and Taenia sp., are reported from waste which has been standing for one year. This is cause for concern as it shows one year is not a sufficient standing period to render the waste free of all microorganisms. Sampling from 124 UD toilet vaults that were in use, showed a high prevalence of both helminth (Ascaris lumbricoiodes, Trichuris trichiura and Taenia sp.) and protozoan (Giardia and Cryptosporidium) parasites. / Thesis (M.Sc.)-University of KwaZulu-Natal, 2009.
29

The relative influence of local and landscape processes on the structure of insectivorous bat ensembles in urban nature reserves.

Moonsamy, Shivani. January 2012 (has links)
Urbanization is arguably the most damaging and rapidly expanding threat to biodiversity. The process of urbanization results in the fragmentation of natural habitat into patches that are disjunct and isolated from one another. Biogeography theory predicts that landscape processes, including fragment size and isolation, should predominate in species assembly. However, these predictions have not been tested on African bats in urban landscapes. Bats are important models for urban studies because they comprise more than a fifth of all mammals, and play vital roles as primary, secondary and tertiary consumers that support human-dominated ecosystems. Furthermore, there is evidence that local, biotic processes specifically competition and prey defences are important determinants of species composition patterns. In this study, I investigated the relative influence of local and landscape processes on the species composition patterns of insectivorous bat ensembles in Durban. Using active capture methods and passive monitoring, I sampled the insectivorous bat ensembles of eight nature reserves in Durban between 2008 and 2010. I used multivariate analyses to test predictions from biogeographic and climate hypotheses, and I used null model analyses to test predictions from competition and nestedness hypotheses to determine whether the bat richness patterns were significantly different from patterns expected by chance. Species richness estimators indicated that species inventories for ensembles were fairly complete (i.e. estimated species richness was not much larger than observed species richness). Multiple regression analyses showed that there was a significant parabolic relationship between species evenness and daily maximum temperature, and there was a significant negative relationship between relative activity and reserve shape. However, I found no evidence that competition influenced species composition patterns. Conversely, I found support for the nestedness hypothesis: species in species-poor ensembles were subsets of species in species-rich ensembles. Spearman rank correlation indicated that the degree of nestedness was significantly correlated with maximum temperature. My results suggest that in urban landscapes, abiotic processes operating at the landscape scale may be more important determinants of composition patterns of insectivorous bat species than biotic factors operating at a local scale. Furthermore, bat species that forage in cluttered habitats may not be able to persist in urban landscapes. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2012.
30

The Value of Tree-Ring Analysis in Engineering

Lassetter, Roy 10 1900 (has links)
No description available.

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