Gnidia L., variously estimated to contain 100–160 species, is the largest genus in the sub-cosmopolitan family Thymelaeaceae. Most species are shrubby, and occur in tropical and southern Africa, with one species reaching southern India and Sri Lanka, and 14 species endemic to Madagascar. Assorted segregate genera have been established using characters considered by some as too few, too trivial or unreliable. Generic limits have been contentious with authors following either a narrower concept of Gnidia or a broader circumscription within which segregate genera are placed in synonymy under Gnidia. Regional treatments for African and Madagascan floras have been published over the last century until very recently, but the genus was last revised in its entirety 153 years ago. Today, a broad-based concept of Gnidia is generally recognised, but there is no modern infrageneric classification, and species relationships are poorly understood. Homogenous groups of species are identified by their similarities of leaf length and width or bract length and width ratios. Species comprising the homogenous groups for leaf ratios differ to those comprising the homogenous groups based on bract ratios, and there is no correlation between leaf and bract length and width ratios. This suggests that the factors influencing leaf diversity differ from those influencing bract diversity. Bracts differ most from leaves in species with capitate inflorescences, and involucres of several layers of bracts likely protect reproductive organs (flowers) in heads. Previously overlooked morphological and micromorphological details, and morphometric analyses of leaf, bract and floral dimension data help define individual species, and clades of species derived from phylogenetic analyses of molecular data. Evidence from a phylogenetic analysis of nuclear ribosomal and plastid DNA sequence data confirms the polyphyly of Gnidia. Three lineages contain Gnidia species and species of genera from southern Africa, southern South America or Australia, while another lineage corresponds largely to the previously recognized genus Lasiosiphon. The genus Lasiosiphon is reinstated characterised by flowers mostly in heads, bracts different from the leaves, and the presence of smooth hairs; it now includes species with tetramerous flowers as well as ones with pentamerous flowers. Gynodioecy is recorded for the first time in a single species and represents the first documented example of sexual polymorphism involving unisexual flowers in Gnidia and sub- Saharan Thymelaeaceae. The findings of this thesis are discussed in terms of their phylogenetic value and contribution to our better understanding of the generic limits of Gnidia and its relationships with other southern hemisphere Thymelaeoideae. The circumscription and generic affinities of Gnidia as suggested by results presented in this thesis are compared to previous classification systems for congruence and dissimilarity. / Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2010.

Verbal extensions are well-known to play a most substantial role in the derivation and/or inflection of verbs in contemporary Zulu. Less well-known and less well investigated are a group of verbal derivatives which in former times played a significant role in derivation but which can no longer be freely attached to verbal stems: the non-productive verbal extensions (NPEs.) This thesis seeks to present and discuss all aspects of these NPEs from the perspective of their persisting roles in contemporary Zulu. This is undertaken on the basis of an extensive collection of currently-used verbs derived by means of NPEs, which is presented in the Appendix. Chapter 1 locates the study within the context of verbal extensions as a whole, and reviews the literature, which has focussed primarily on those verbal extensions which are still used productively today. Chapter 2 presents the theoretical framework for the investigation, considering issues such as productivity, derivation and inflection, and some relevant aspects of the theory of derivational morphology, currently under development. The following chapters focus in turn on the morphology of the NPEs, their current use in combination with productive extensions, the most salient aspect of their syntax, transitivity, and their meaning. NPEs have become fully integrated into Zulu vocabulary, and are used on a daily basis with no awareness of their earlier roles. Nevertheless, as this thesis demonstrates, a study of NPEs can explain both certain regularities and certain anomalies in word formation , in transitivity, and in the meaning of extended verbs in contemporary Zulu. / Thesis (M.A.)-University of Natal, Durban, 2001.

The consequences of toxigenic fungi associated with stored seed have stimulated these investigations aimed at developing treatments to minimise this mycoflora, without significantly reducing seed quality or viability. The effects of immersion in water at 55, 57 and 60 QC for durations of 5 to 60 min were assessed for maize (Zea mays L.) seed in terms of fungal status, water uptake, electrolyte leakage, germination and seedling establishment. These assessments were conducted immediately after treatment, after re-dehydration for 2 days in an ambient air stream, and following a 1 month storage period under either cold (4 QC) or ambient (25 QC) conditions (33% and 91% RH, respectively). In all cases, the results are compared with those of control seeds and seeds pre-imbibed for 4 h at ambient temperature. The level of internal contamination, represented almost entirely by Fusarium moniliforme Sheldon, declined significantly when assessed immediately after treatment, the efficacy of which increased with increasing temperature and duration of treatment. Seeds immersed in water at 55 QC for a duration of 15 min exhibited an 85% reduction in infection levels, when compared with those of the control, while those treated at 57 and 60 QC (same duration) were uninfected. Immersing seeds in hot water, however, resulted in a lag in germination rate and drop in germination totality, the degree of which was enhanced by increasing duration and temperature of treatment, suggesting the status of the manipulation to be an accelerated ageing treatment. The electrolyte leakage studies indicated that the reduced germination performance of these seeds was not due to plasmalemma disorganisation. These deleterious effects, however, were counter-balanced as seeds treated at 55, 57 and 60 QC for durations up to 60, 30 and 10 min, respectively, produced plants of superior quality than those of the control, which is ascribed to the reduction of systemically transmitted pathogens. The efficacy of the hot water treatment in reducing the levels of seed infection and improving seedling quality was enhanced by subsequent re-dehydration. The reduction in seed-associated mycoflora was maintained following storage for 1 month at both 4 QC (33% RH) and 25 QC (91% RH). However, both seed and seedling quality were adversely affected following storage even under cold, dry conditions, which may be a consequence of the pre-treatment history of the seeds, which had been cold-stored for two years prior to the experiments. Applied as a pre-sowing treatment, therefore, hot water treatment shows promise for producing a crop of superior quality, less prone to fusarial pathogenesis. This treatment may be of particular importance to Third-World subsistence communities. / Thesis (M.Sc.)-University of Natal, 1995.

The word pun is one of the figures of speech that people employ in everyday communication and especially in literary works in order to advance intricate aspects of meaning that may not be easy to express using 'plain' language. The word pun generally provides a speaker with an opportunity to mean more while saying less instead of saying more while meaning less. Considering the facts that people primarily communicate in order to exchange meaning, and that meaning can be very elusive and controversial, there are two questions about the use of the word pun. Can people understand the meaning in word puns? And, if they can, how do they do so? These questions are especially relevant in the case of literary works because the author is far removed from the audience. As such, there is no room for the negotiation of meaning. The current study probes these two questions by considering two types of word pun, Chiasmus and Metathesis, which are composed through the transposition of the morphological and or syntactic order of expressions. At a theoretical level, the study explores and explains the common underlying processes that guide the comprehension of the word puns. Further than that, it demonstrates through a case study that people are able to understand the word puns by using what the study proposes to be the reverse principle. Ultimately, the study illustrates how people derive meaning of utterances through interplay of the different subsystems of the language system. The word puns in this study present a good context in which to explore interfaces between semantics and other language fields by linking insights drawn from different fields of linguistic enquiry to the concept of meaning and demonstrating how aspects of all these come together in explaining the processing of word puns that involve morphological and syntactic transposition. Additionally, the study demonstrates that people understand the world by relating concepts to one another because of the underlying relationships existing between concepts and by virtue of the relationships that hold between and among words or word parts. / Thesis (M.A.)-University of KwaZulu-Natal, 2007.

Gasterosteus aculeatus (threespine stickleback) is a well-known model for behavioral and evolutionary studies. Rapid evolutionary radiations in postglacial timeframes have promoted distinct local populations with remarkable variation in biological characteristics. This study examines genetic and morphological variation among populations from the Thlewiaza watershed, specifically an isolated freshwater population in Nueltin Lake. Statistically significant genetic differences were observed using 11 microsatellite loci; FST values ranged from 0.29 (within watershed) to 0.48 (between watersheds) in comparison with the Nueltin Lake population. Gene flow between populations was likely inhibited due to isostatic rebound following the recent deglaciation of North America, 8.5 kya. In comparison with similar freshwater populations, the retention of defensive structures in G. aculeatus from Nueltin Lake was unexpected, and may reflect strong piscivorous predation pressures. Levels of differentiation, both genetic and morphological, observed in the Nueltin Lake population are highly significant, and should be recognised as a Designatable Unit (DU).

No description available.

With a generally conserved function for locomotion, paired fins have an extensive evolutionary history that has resulted in highly disparate morphologies in a wide diversity of taxa. Two-dimensional geometric morphometrics offers a means to quantitatively describe disparity and changes in the shape of pectoral fins. Actinopterygians lend themselves well to a study of this nature due to their prolific diversity and prevalence in the fossil record. As a result of changes in skeletal fin structures and the lack of homologous elements throughout the group, three morphological modules are used as the unit of comparison rather than individual elements of the fin. Ordination plots from thin plate spline analyses, including fossil and extant taxa, show correspondence with the actinopterygian phylogeny as trends become apparent through the group. Basal actinopterygians and basal teleosts tend to have a narrow, elongate fin shape. Following a shift in morphospace, derived teleosts have a wider fin base, with an elongate anterior margin of the fin relative to the posterior trailing edge. Linear and squared-change parsimony reconstructions of continuous data allow the phylogeny to be traced through morphospace to approximate the path of pectoral fin evolution. The shift in morphospace occurs at Acanthomorpha, and is correlated with the evolution of a physoclistous swim bladder and a change in the position and orientation of pectoral fins. As a result of these changes, new swimming modes are made available, and the expansion of locomotory modes of Acanthomorpha is here hypothesized to be associated with a sharp increase in pectoral fin disparity.

The following morphological structures of the ovipositor of Homolobus truncator (Say) (Hymenoptera : Braconidae) are described and hypotheses of their functions are proposed: a series of sharp ridges on the distal surface of the notch helps maintain a grip on the inner surface of the host cuticle; the sperone directs eggs away from the inner surface of the ventral valves; a flap-like structure on each ventral valve covers the portal through which eggs pass; the valvillus maintains position of the egg within the ovipositor and acts against the egg to force it out; ctenidia on the inner surface of the ventral valves move eggs along the basal half of the egg canal; recurved barbs at the apex of each ventral valve hook into the inner surface of the host cuticle to maintain purchase while the thick dorsal valve is inserted into the host. The tribe Maxfischeriini (Hymenoptera : Braconidae) is emended to subfamily status based on morphological and biological evidence. A novel egg morphology is described for Maxfischeria, representing a new life history strategy among Braconidae. Based on egg and ovipositor morphology, I suggest that Maxfischeria is a proovigenic, koinobiont ectoparasitoid. Five new species of Maxfischeria are described (M. ameliae sp. nov., M. anic sp. nov. M. briggsi sp. nov., M. folkertsorum sp. nov., and M. ovumancora sp. nov.). A phylogenetic analysis of morphological and molecular characters for the braconid subfamily Euphorinae is presented. The results imply a revised classification that recognizes 9 tribes and 44 genera. Proposed changes include: Meteorus and Zele are recognized as Meteorinae. Planitorus and Mannokeraia are included among Euphorinae and comprise the tribe Planitorini. Cosmophorini, Euphorini, Helorimorphini, Perilitini, Leiophron, and Perilitus are redefined. The following synonyms are proposed: Cryptoxilonini and Dinocampini with Cosmophorini; Myiocephalini and Proclithrophorini with Perilitini; Myiocephalus with Microctonus; Bracteodes, Falcosyntretus, Sculptosyntretus, Syntretellus, Syntretomorpha, and Syntretoriana with Syntretus and are recognized as subgenera; Perilitus (Townesilitus) with Microctonus and are recognized as a subgenus. Transitions in host associations are examined with ancestral state reconstruction. Some ambiguous nodes in the reconstruction are reconciled by examining the overlap in host associations.

This dissertation investigates interactions between gender and number and gender and evaluative morphology in a sample of 100 African languages, and provides a method for assessing the role that these interactions play in the grammatical complexity of gender systems. The dissertation is organised around three research foci. First, the dissertation surveys patterns of interaction between gender and number along the following dimensions: exponence, syncretism, indexation, correlations in type of marking, and gender assignment. The study provides evidence for the possibility that nominal features are organised in a relevance hierarchy. In addition, the study shows that animacy and lexical plurality play a crucial role in the distribution of special patterns of plural indexation. The study also shows that pervasive indexation systems in the language sample always involve both gender and number. Finally, the study shows how gender assignment can be used as a means for encoding variation in the countability properties of nouns and noun phrases. Second, the dissertation surveys patterns of interaction between gender and evaluative morphology in the languages of the sample. Two types of interactions are found. The study shows that the distribution of the two types depends on three factors: the type of gender system, the number of gender distinctions and the possibility of assigning a noun to more than one gender. Third, the dissertation investigates the role that interactions of gender and number and gender and evaluative morphology play in the absolute complexity of gender. The study proposes a metric for gender complexity and uses this metric to compute complexity scores for the languages of the sample. The results suggest that the gender systems of the language sample lean toward high complexity, that genealogically related languages have the same or similar complexity scores, and that the distribution of the outliers can often be understood as the result of language contact.

In this thesis, the morphological changes of the anode surface in lithium sulphur cell, during early cycling, were simulated using symmetrical lithium electrode cells with dissolved polysulphides (PS) in the electrolyte. Electron microscopy (SEM) was used as the principal investigation technique to study and record the morphological changes. The resulting images from the SEM were analysed and discussed. The initial surface structure of the lithium anode largely influenced the ensuing morphological changes taking place through lithium dissolution (pits) and lithium deposition (dendrites) during discharge and charge respectively. The rate of lithium dissolution and deposition was found to be linearly proportional to the current density applied to the cell and the effect of cycling on the anode was proportional to the total charge of the cell in general in agreement with the expected reaction. The effect of self-discharge on the anode was also studied using photoelectron spectroscopy (XPS) in tandem with SEM. The results indicated that self-discharge, occurring in the form of corrosion of the anode SEI by PS reduction, was influenced by the altered morphology of the cell after cycling. The findings presented in this project can be understood as a preliminary description for the morphological changes in the anode and their influence in the performance of lithium sulphur battery, which can be further investigated by more advanced methods. / <p>Joint collaboration project between Scania CV AB and Uppsala University.</p>