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Expression of gonadal immune genes during prepubertal sex change in spotty wrasse (Notolabrus celidotus)
(The University of Waikato, 2026) Longney, Jana; Muncaster, Simon; van der Burg, Chloé
Teleost fish display exceptional diversity in their reproductive strategies, including sequential hermaphroditism, in which individuals undergo complete functional sex change during adulthood (monandry) and in some cases, a second male morph can arise prior to puberty (diandry). While the endocrine and genetic mechanisms underlying sex change have been extensively studied, the contribution of the immune system to gonadal remodelling remains poorly understood. This thesis investigates the role of immune processes during female-tomale prepubertal sex change in initial-phase members of the New Zealand spotty wrasse (Notolabrus celidotus). This study integrates histological analysis with gene expression profiling to examine immune involvement across transitional stages of gonadal sex change. Histological examination revealed stage-dependent changes in gonadal leukocyte (eosinophilic granular cell) abundance and localisation, coinciding with ovarian degeneration and testicular development. Gene expression analyses demonstrated coordinated increases in immuneassociated markers (cd68, il-1β, and tnf-α), particularly during late transitional and male stages. Notably, immune activation was not confined to early degenerative phases but persisted into the male phase, suggesting roles beyond debris clearance, likely including tissue organisation and maintenance. Although inter-individual variability limited statistical significance for some markers, consistent directional trends across genes and concordance with histological observations support a biologically meaningful pattern of immune modulation during sex change. By building a body of evidence that links immune gene expression with histological evidence of leukocyte involvement, this study highlights a likely localised immune function response as a key mechanism associated with vertebrate sex change. Importantly, it identifies immune cells as active contributors to sex change rather than passive responders.
Verifying interoperability in evolving IoT systems
(SciTePress, 2026) Zhang, Hongming; Bowen, Judy; Turner, Jessica Dawn; König, Jemma Lynette
As IoT devices age they must be replaced to maintain reliability and performance. During upgrades, ensuring interoperability among new and existing devices is critical for preserving designated system behaviours. Existing formal verification approaches rely on system documentation or source code to build formal models or extract flat models from system logs. We propose a novel log-driven verification framework that automatically discovers executable Hierarchical Colored Petri Nets (HCPNs) from raw IoT system logs. The framework integrates model checking to verify cross-layer interoperability during IoT system evolution and device replacement. We demonstrate the effectiveness of our approach using a street lighting system study.
Synthesis and kinetics of isomerisation of 2',6'-dihydroxychalcones
(The University of Waikato, 1987) Miles, Christopher O.; Main, Lyndsay
The first-order rate constant, kₒbₛ, for the chalcone - flavanone isomerisation has been determined over the pH range 0-14 in water (μ = 1.0 mol 1⁻¹ with KC1) at 30°C for the following 2' ,6'-dihydroxychalcones: 2' ,6'-dihydroxychalcone (34); 2' ,6'-dihydroxy-4-methoxychalcone (38); 2' ,6'-dihydroxy-3,4-dimethoxychalcone (40); 2' ,6'-dihydroxy-3,4,5-trimethoxychalcone (42); 2' ,6'-dihydroxy-2,4,6-trimethoxychalcone (44); 4-chloro-2' ,6'-dihydroxychalcone (46); 2' ,6'-dihydroxy- 4,4'-dimethoxychalcone (32); 2' ,6'-dihydroxy-3,4,4'-trimethoxychalcone (36); and 2' ,4,6'-trihydroxy-4'-rhamnoglucosyloxychalcone (naringin-chalcone) (48). The pH-rate profiles have been analysed in terms of contributions to cyclisation and ring opening of the various ionised chalcone and flavanone species, and individual rate and equilibrium constants for all the contributing reactions have been determined. Rate measurements with D₂O as the solvent (for 32, 34, 36, 38, 40, 42, 44, 46) revealed a large (presumably primary) hydrogen kinetic isotope effect for one of the contributing reactions, the cyclisation of the chalcone mono-anion. Enthalpies and entropies of activation for the mono-anion cyclisation have also been determined for chalcones 34, 36, 38, 42, 44, and 46. ¹H n.m.r. studies of the product from the cyclisation of the mono-anion in D₂O for two chalcones (34, 38) showed little preference in protonation at the 3-position of the flavanone. Mass spectrometry allowed measurement of the preference for protonation over deuteriation at the 3-position of the flavanone during cyclisation of the mono-anions of 32 and 38, under kinetically-controlled conditions in H₂O - D₂O mixtures. The data obtained were not in accord with the those from kinetic isotope effect measurements. The above results were considered in terms of possible mechanisms for the various reactions involved in the isomerisation. Factors contributing to the specially high rate of cyclisation of 2' ,6'-dihydroxychalcones as compared to simple 2'-hydroxychalcones, and to the high stability of the 5-hydroxyflavanones as compared to simple flavanones (relative to their isomeric chalcones) were also considered. The low stability of the 2' ,6'-dihydroxychalcones, compared to the 2'-hydroxychalcones (relative to their flavanones) was found to be due to a highly reactive mono-anion form combined with a lower first pKₐ, and a greatly reduced susceptibility of the flavanone anions to base-catalysed ring opening. By utilising the above kinetic results, new and improved syntheses of 2' ,6'-dihydroxychalcones have been developed in the face of what are shown to be unreliable literature reports. The following compounds have been synthesised and characterised for the first time: (32); (34); (36); (38); 5-hydroxy-4' -methoxyflavanone (39); (40); 5-hydroxy-3' ,4'-dimethoxyflavanone (41); (42); 5-hydroxy-3' ,4' ,5'-trimethoxyflavanone (43); (44); 5-hydroxy-2' ,4' ,6'-trimethoxyflavanone (45); (46); 5-hydroxy-4'-chloroflavanone (47): 6-benzyl-7-benzyloxy-5-hydroxyflavanone (68); 6-benzyl-5,7-dihydroxyflavanone (69); 2 '-hydroxy-6 '-tetrahydropyrany loxy-3, 4, 5-trimethoxychalcone (70); 3'-benzyl-4' ,6'-dibenzyloxy-2'-hydroxychalcone (72); 2' ,3,4' ,6'-tetrahydroxy- 4-methoxychalcone (86); 2'-hydroxy-4' ,6'-dimethoxy-3'-methylchalcone (93). Two new routes to 2' ,6'-dihydroxychalcones were developed. The first involved base-catalysed condensation of acetophenones and benzaldehydes with free phenolic groups protected as their tetrahydro-pyranyl ethers, followed by deprotection at pH 2. The second involved reaction of flavanones with chlorosilanes, in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene, in which ring opening of the O-silylated flavanone was immediately followed by silylation of the resultant phenolate oxygen, thereby preventing recyclisation. The crystal structures of 5-hydroxy-4' ,7-dimethoxyflavanone (33) and 2' ,6'-dihydroxy-2,4,6-trimethoxychalcone (44) were determined by X-ray crystallography, 44 being the first 2' ,6'-dihydroxychalcone for which a crystal structure has been obtained. A computer programme was developed for the analysis of pH-rate data for 2'-hydroxy- and 2', 6'-dihydroxy-chalcones, but which is suitable for the analysis of pH-rate data for most mono- or di-acids in which the contributing reactions are (pseudo) first-order. The programme can also include second-order H⁺-catalysed reaction of the di-acid, and one second-order OH⁻-catalysed reaction, and calculates the concentrations of the various ionised species present on the basis that the two pKₐ values may not be well-separated. This programme has been used to successfully analyse the 2' ,4'-dihydroxychalcone - 7-hydroxyflavanone pH-rate profile previously reported, but not analysed, in the same way as for the 2' ,6'-dihydroxychalcones.
X-ray beam modelling in radiotherapy: the effect of lung inhomogeneities
(The University of Waikato, 1990) Metcalfe, Peter Edwin; Round, W. Howell
A lung phantom consisting of epoxy resin based analogs is developed in-house and a quality assurance method, which compares experimental CT numbers with theoretical CT numbers calculated from electronic cross sections, is described. Currently used photon beam inhomogeneity correction models and their inadequacies are discussed. The methods studied include Batho and Equivalent Tissue-Air-Ratio corrections. For a 10 MV high energy photon beam the mean difference in central axis depth dose in the lung phantom for these methods is 8.8% and 3.5%, respectively (for a 5 x 5 cm field). The differences in the beam profiles at an off-axis distance of 5 cm is 12.6% for both methods (for a 10 x 10 cm field). A unified three-dimensional superposition approach to dose calculations used in treatment planning of a polyenergetic 10 MV photon beam in radiotherapy is developed. This radiotherapy X-ray beam computation method involves an electron gamma shower (EGS) Monte Carlo generated surface polyenergetic dose spread array (PDSA), which describes the energy spread from a point interaction source. This is superposed with the relative reduction in polyenergetic total energy released per unit mass (TERMA) as the beam traverses tissue. By comparing primary PDSAs produced at different radiological depths, the effect of beam hardening on the PDSA has been quantified. Calculations show the mean electron range due to the surface 10 MV primary PDSA is 6.67 mm and the mean electron range of the beam hardened primary PDSA is 8.24 mm. In comparison a 3 MV primary monoenergetic dose spread array (MDSA) has a much smaller mean electron range of 4.81 mm. The effect of using a beam hardened PDSA for superposition is also studied. The mean percentage difference between depth dose curves obtained using superposition of a surface and a beam hardened PDSA is only 0.1 %. The mean percentage difference from experimental data for these superposition curves is 1.2% down to 20 cm in a homogeneous phantom. The superposition process is shown to be forgiving to spectral differences in the PDSA but sensitive to spectral changes in the TERMA. A method of scaling PDSAs to account for lung inhomogeneities is introduced which shows good agreement with experimental and Monte Carlo results in the lung phantom. The mean difference in central axis depth dose in the lung phantom for this method is 2.0% for a 5 x 5 cm field. The differences in lung for the beam profile at an off-axis distance of 5 cm is 4.3% for a 10 x 10 cm field.
The effect of voice input on information exchange in computer supported asynchronous group communication
(The University of Waikato, 1991) McQueen, Robert J.; Graham, Ian
Computer support for group communication in the business environment is examined. Study of group activities in videotaped business meetings identified information exchange as the most frequent communication task. Existing computer supported cooperative work (CSCW) systems for group communication are typically based on keyboard input, and this may limit their utility. A voice input prototype system for asynchronous (time separated transactions) group communication (AGC) with simulated conversion to text was developed and tested to determine if advantages over conventional keyboard input computer conferencing existed, and whether this method would have any effect on the information exchange task. An experiment utilizing 12 groups of 5 subjects compared the voice input prototype to an existing keyboard input computer conferencing system for an information exchange task, and over all test subjects, voice input resulted in an increase of the number of words contributed by 151 % and an increase in the information facts disclosed by 38%. For test subjects holding a high proportion of available facts, voice input resulted in increases of 204% in words and 39% for facts. Effective input speed was 150 words per minute for voice input. These results imply that for future asynchronous group communication systems supporting information exchange, incorporation of voice input capability, coupled with large vocabulary, connected word, speaker independent speech recognition should be considered.