Two strains (NCm 9897 and 9898; strains A and B respectively) of a Pseudomonas· species have been shown to display antifungal and antibacterial activity on solid media. Biochemical tests indicate that the organisms may be two distinct strains of a new species. Cell morphology was studied using scanning electron microscopy. Chemically defined media, established for the organisms, indicate non-fastidous characteristics. Four liquid media, able to elicit antibiotic production from Strain A have been developed: a chemically defined medium (antibacterial), a chemically defined medium and a complex medium (antifungal) and a chemically defined medium (antibacterial and antifungal). Nitrogen and magnesium limitation significantly increased yields. Magnesium content in a medium (without a magnesium salt component) and in whole cell samples grown in the said medium were assessed using atomic absorption spectroscopy and elemental analysis respectively. Optimization experiments for antibacterial and antifungal activity, assessed by a disc diffusion assay, increased yields, in 250 ml conical flasks by a factor of X9 and 109% respectively. A 6 litre laboratory-scale fermentor was used for larger batch cultivations . Procedures for extraction of the active compounds from the biological matrices were . developed leading to the isolation of one antibacterial compound, ABl (yellow crystalline) and three antifungal compounds, AFl, AF2 and AF3 (pale yellow and amorphous). Structure determination of ABl, involving mass spectrometry, IR/UV spectroscopy, lH-NMR and x-ray diffraction, indicated it to be 1.6 dimethyl pyrimido[5,4-e ]-1,2,4- triazine-5,7(IH,6H)-dione (Xanthothricin; Toxoflavin), a toxic metabolite previously detected in foods contaminated with Ps. cocovenenans. Selective media, developed ' for Strain A and Strain B, did not support growth of Ps. cocovenenans. Preliminary structural analysis suggests that AFl may possess a mono-substituted ring system with CHz chain and a terminal hydroxyl group; that AF2 may belong to the polyene group of antifungal antibiotics and that AF3 may be an aliphatic ketone with hydroxyl group . Agar diffusion, minimum inhibitory concentration, assays for the compounds, indicate activity to be in the ~gml range for sensitive microorganisms. Antibiotic challenge against test microorganisms suggest bacteriostatic activity for ABl, fungistatic activity for AFl and AF3 and fungicidal activity for AF2.

Transport of sediment in coastal regions directly impacts mine countermeasure operations and naval construction efforts. Wave induced shear stress in the surf zone is responsible for entraining sediment particles into suspension within the combined wave and current boundary layer, where momentum is imparted through highly nonlinear processes. Therefore, a detailed understanding of sediment flux processes in the surf zone is essential to accurately model net sediment transport. This study examines the use of acoustic backscatter inversion as a means of measuring sediment concentration profiles. Measurements of sediment concentration and velocity profiles were made by a high frequency Doppler velocity profiler deployed on Blackâ s Beach during the Nearshore Canyon Experiment, NCEX. Profiles of sediment flux were compared with hourly mean current measurements from a cross-shore/long-shore array of PUV sensors and two-dimensional planner images of the morphological evolution provided by a three camera Argus video suite. Observations from a seven day period containing the development and evolution of a weak rip channel demonstrated that acoustic backscatter inversion techniques, when calibrated with in situ sediment samples, provide high spatial and temporal resolution estimates of sediment concentration and fluxes into the thin wave boundary layer. These sediment transport measurements were correlated with observed mean currents and rip channel evolution, and show a strong morphological response to the sediment flux.

Animal phyla vary dramatically in species richness (from one species to >1.2 million), but the causes of this variation remain largely unknown. Animals have also evolved striking variation in morphology and ecology, including sessile marine taxa lacking heads, eyes, limbs, and complex organs (e.g., sponges), parasitic worms (e.g., nematodes, platyhelminths), and taxa with eyes, skeletons, limbs, and complex organs that dominate terrestrial ecosystems (arthropods, chordates). Relating this remarkable variation in traits to the diversification and richness of animal phyla is a fundamental yet unresolved problem in biology. Here, we test the impacts of 18 traits (including morphology, ecology, reproduction, and development) on diversification and richness of extant animal phyla. Using phylogenetic multiple regression, the best-fitting model includes five traits that explain approximate to 74% of the variation in diversification rates (dioecy, parasitism, eyes/photoreceptors, a skeleton, nonmarine habitat). However, a model including just three (skeleton, parasitism, habitat) explains nearly as much variation (approximate to 67%). Diversification rates then largely explain richness patterns. Our results also identify many striking traits that have surprisingly little impact on diversification (e.g., head, limbs, and complex circulatory and digestive systems). Overall, our results reveal the key factors that shape large-scale patterns of diversification and richness across >80% of all extant, described species.

This thesis is a general description of the morphology and syntax of the Biak language. The Biak language belongs to the West New Guinea subgroup of the Austronesian language family and is spoken by around 50,000 to 70,000 speakers in West Papua in the northern part of the Geelvink Bay. The thesis consists of 7 main chapters that cover demographic and ethnographic information of the language, morphology, grammatical categories, basic constituent order, noun compounding and denominalization, relative clauses, and predicate nominal constructions. The main findings of the thesis are: • The Biak language is predominantly a head-initial language. • The Biak language has morphological variation from monomorphemic to polymorphemic with the polymorphemic being the dominant pattern in the language. • Inflectional patterns on verbal and prepositional predicates, demonstratives, and possessive pronouns are divided into two patterns: the consonantal pattern and the vocal pattern. • Biak has alienable and inalienable nouns. Alienability in Biak is a syntactic distinction, not exactly corresponding to the semantic distinction. • The basic constituent order is SVO or AVP. Variations occur with predicate nominal (OV) and internally headed relative clause which uses SOV pattern. • Three types of relative clauses were identified: (i) Post nominal relative clause; (ii) Headless relative clause; and, (iii) Internally headed relative clause. The Biak language allows stacked and nested relative clauses. Two kinds of predicate nominal constructions were identified: (i) copular clitics (clitic –ri, -s-, and free pronoun clitics) and (ii) copular verbs –iri and iso. The two kinds of predicate nominal constructions can be distinguished syntactically.

<p>There continues to be a lack of agreement concerning the precise phylogenetic placement of Proconsul despite the wealth of fossil material and the extensiveness of its study. The difficulty in resolving the phylogenetic status of this important and well represented Miocene catarrhine is a consequence of its apparent basal position relative to crown catarrhines. This position complicates the inference of character polarities. This dissertation tests three previously proposed hypotheses concerning the phylogenetic position of Proconsul: (1) Proconsul is a stem catarrhine; (2) Proconsul is a stem hominoid; and (3) Proconsul is a basal hominid, most closely related to extant great apes and humans. A phylogenetic analysis based on 719 characters drawn from the skull, forelimb, pelvis and foot, and sampling a diversity of extant anthropoid taxa, offers no compelling support for a hominoid clade that includes Proconsul. The radiation of crown catarrhines involved rapid evolutionary changes from the ancestral catarrhine morphotype, resulting in stem catarrhines appearing much more similar to each other, even where there are key synapomorphies linking them with crown clades. As a result, systematic analyses alone are insufficient to confidently support a single optimal phylogenetic hypothesis. Further exploration of the data, by combining inferred ancestral morphotypes with phenetic visualizations of character evolution, demonstrated that inclusion of Proconsul among Hominoidea or Hominidae pushed the ancestral catarrhine morphotype closer to these clades, respectively. Given a more comprehensive analysis of character evolution under each hypothesis, this dissertation supports the hypothesis that Proconsul is a stem catarrhine. In addition to helping clarify the long-running debate about the phylogenetic status of Proconsul, the results offer fresh insights into the early stages of hominoid evolution and demonstrate the importance of comprehensive phylogenetic analyses in helping to resolve the relationships of problematic stem taxa.

This study was initiated after finding two chromosomal types of Peromyscus maniculatus north and south of the Red River in Texas and Oklahoma. The problem was to explain the chromosomal variations and their implications to the systematics of the grassland subspecies of P. maniculatus in this region.

This thesis describes the cloning and characterisation of two <I>Candida albicans</I> genes which were candidates for having a role in the phenotypic switching phenomenon of <I>C. albicans</I>. Phenotypic switching in <I>C. albicans</I> is a spontaneously occurring event whereby the surface morphology and several physiological processes of the <I>C. albicans</I> colony can change. These spontaneous switching events occur at high frequency and there are a range of up to fifteen different morphological forms that have been described. Switching is reversible and interconvertible (between the different phenotypes). The candidate genes chosen to investigate phenotypic switching were <I>RAD52</I>, a DNA double strand break repair gene and <I>H4</I>, a histone. <I>RAD52</I> was isolated following homologous probing of a <I>C. albicans</I> genomic library using a fragment of the gene sequence which was available on a public data base [http://alces.med.umn.edu/candida/html], as a probe. <I>H4</I> was isolated following PCR probing of a cosmid library. The switching repertoire of the <I>ura</I>- CAI4 strain of <I>C. albicans</I> was characterised. Attempts were also made to characterise switching frequencies. This strain was then used as the host for both knockout and overexpression studies of the candidate genes. The effect of overexpression of these genes on phenotypic switching was observed by recording growth rates, phenotypes and phenotypic switching frequencies. It was found that overexpression of <I>RAD52</I> affected the morphotype and growth of the yeast colonies compared the CAI4 parental strain. Overexpression of the H4 gene did not appear to affect growth, but a fourth morphological form named "root" appeared that had not arisen during characterisation of the CAI4 phenotypic switching repertoire. The degree to which the "root" phenotype was manifest appeared to correlate with the degree of overexpression of the <I>H4</I> gene. The effect of knocking out a single copy of <I>H4</I> was also observed. Growth was not affected. Observations of colony morphologies showed a preponderance of one particular morphology ("irregular wrinkle"). This data suggests that altering the wild type levels of expression of these genes can affect phenotypic switching in <I>C. albicans</I>.

Genus Frustulia was chosen for this work due to the continuity of the previous research of our phycological group. Using molecular techniques, it was found that a number of morphologically defined species of diatoms is cryptic species complex, which may have limited dispersal. The aim of this study was to: 1) evaluate the diversity of the genus Frustulia in northern Europe by molecular methods and classify found species in the phylogenetic context of related species; 2) find out if it possible to identify the isolated species in natural samples by using morphological characters. There have been analyzed 234 strains by molecular methods. Isolated ones were in four clades. 86 % of the strains belonged to a generic complex F. crassinervia-saxonica. Two strains were identified as species F. gaertnerae and F. septentrionalis. The last line was not described yet so it was labeled as F. sp. This line is closely related to the species F. maoriana, which is considered to be endemic in New Zealand. Phylogeny of the genus was created based on a dataset of four molecular markers. Published morphometric data were then compared with 264 cells photos taken by scanning electron microscope. There was done surveillance comparison of the results of the analysis of quantitative and qualitative characters with...

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Ph.D. / The declining marine fish catches and the increasing demand for farmed fresh water fishes are motivation for research and development of improved strains and techniques for the production of gynogenetic and triploid offspring of popular fresh water fishes ...