No description available.

No description available.

A turkey prolactin (PRL) cDNA, encoding a 199 amino acid turkey PRL (tPRL), was cloned from a pituitary library. The mature PRL shared about 70% homology with mammalian PRLs and about 30% with fish PRLs. Areas of highest homology to other PRLs were located in the carboxyl terminus of the tPRL. Prolactin mRNA analyses, during the reproductive life of the turkey hen, confirmed that the high pituitary and plasma levels of PRL measured during the incubation phase are due to enhanced transcription of the PRL gene. Furthermore, tPRL mRNA levels were highly correlated with pituitary levels of tPRL. Recombinant tPRL (rctPRL), biologically and immunologically similar to pituitary tPRL, was purified from Escherichia coli cultures hosting an expression vector carrying the tPRL cDNA. Polyclonal antibodies raised against purified rctPRL behaved similar as antibodies raised against pituitary derived tPRL, in immunoblotting and immunocytochemistry experiments. Three tPRL isoforms (with estimated molecular weights of 27 kDa, 25 kDa and 24 kDa) were identified in turkey pituitary extracts. The relative proportion of the 27 kDa isoform increased while that of the 25 kDa decreased with increasing levels of total pituitary tPRL, during the reproductive life of the turkey hen. The partition of the immunoreactivity of tPRL into the three isoforms perhaps provides an additional control of the multitude functions of PRL.

The corresponding isoperoxidases from the flax genotrophs L and S have different molecular weights. Since further structural analysis will rely on knowledge of the primary structures of these molecules, the isolation of a molecular clone of this enzyme was attempted. Probing a cDNA library with a synthetic oligonucleotide was not successful, but a partial cDNA sequence was isolated by probing an S genotroph stem $ lambda$gt11 library with polyclonal antibodies raised against anionic plant peroxidases. Its longest reading frame sequence is divergent from those of other peroxidases, but contains some related segments. Genomic Southern analysis of the clone is presented, along with a study of the expression of its corresponding mRNA in plant tissues. A study on the effects of IAA, ABA and kinetin levels on the expression of peroxidase and of the putative peroxidase cloned mRNA is also presented.

<p>Metagenomics has been successfully used to discover novel enzymes from uncultured microorganisms in the environment. In this study, metagenomic DNA from a Malawian hot spring soil sample was used to construct a fosmid library. This metagenomic library comprised of more than 10000 clones with an average insert size of 30 kb, representing more than 3.0 x 108 bp of metagenomic DNA (equivalent to approximately 100 bacterial genomes). The library was screened for cellulase activity using a Congo red plate assay to detect zones of carboxymethylcellulose hydrolysis. This yielded 15 positive fosmid clones, of which five were further characterised for activity and thermostability using the 3, 5-dinitrosalicylic assay. Two of the five fosmids (XP008C2 and XP026G5) were selected for DNA pyrosequencing. The full sequence of the XP008C2 (29800bp) fosmid insert is presented in this study and genes thereon were chosen for further study.</p>

No description available.

No description available.

Behavioural cloning is a simple and effective technique for automatically and non-intrusively producing comprehensible and implementable models of human control skill. Behavioural cloning applies machine learning techniques to behavioural trace data, in a transparent manner, and has been very successful in a wide range of domains. The limitations of early behavioural cloning work are: that the clones lack goal-structure, are not robust to variation, are sensitive to the nature of the training data and often produce complicated models of the control skill. Recent behavioural cloning work has sought to address these limitations by adopting goal-structured task decompositions and combining control engineering representations with more sophisticated machine learning algorithms. These approaches have had some success but by compromising either transparency or robustness. This thesis addresses these limitations by investigating: new behavioural cloning representations, control structures, data processing techniques, machine learning algorithms, and performance estimation and testing techniques. First a novel hierarchical decomposition of control is developed, where goal settings and the control skill to achieve them are learnt. This decomposition allows feedback control mechanisms to be combined with modular goal-achievement. Data processing limitations are addressed by developing data-driven, correlative and sampling techniques, that also inform the development of the learning algorithm. The behavioural cloning process is developed by performing experiments on simulated aircraft piloting tasks, and then the generality of the process is tested by performing experiments on simulated gantry-crane control tasks. The performance of the behavioural cloning process was compared to existing techniques, and demonstrated a marked improvement over these methods. The system is capable of handling novel goal-settings and task structure, under high noise conditions. The ability to produce successful controllers was greatly improved by using the developed control representation, data processing and learning techniques. The models produced are compact but tend to abstract the originating control behaviour. In conclusion, the control representation and cloning process address current limitations of behavioural cloning, and produce reliable, reusable and readable clones.

Bibliography: leaves 139-158. / vii, 158, [44] leaves, [33] leaves of plates : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Hypothesises that p160 and p67 proteins repress the functional activities of c-Myb . Their ability to interact with the c-jun basic-leucine zipper (bZIP region) and their existence amongst the murine cell lines is examined. The complete cloning of cDNA encoding both p160 and p67, and the characterisation of these proteins, including the determination of their relationship is described. / Thesis (Ph.D.)--University of Adelaide, Dept. of Genetics, 1998?

Copies of author's previously published articles inserted. / Errata pasted onto front end-paper. / Bibliography: leaves 111-139. / xii, 139, [34] leaves, [25] leaves of plates : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Defines the origin of ring extra structurally abnormal chromosomes (ESACs), relates the genetic content of different ring ESACs derived from the same chromosome with the patient's pheuotype, generates probes for diagnostic use and refines the critical region of Wolf-Hirschhorn syndrome. / Thesis (Ph.D.)--University of Adelaide, Dept. of Paediatrics, 1998