Partial actions of monoids

We investigate partial monoid actions, in the sense of Megrelishvili and Schroeder [12]. These are equivalent to a class of premorphisms, which we call strong premorphisms. We describe two distinct methods for constructing a monoid action from a partial monoid action: the expansion method provides a generalisation of a result of Kellendonk and Lawson [10] in the group case, whilst the approach via globalisation extends results of both [12] and [10]

The transcriptional regulation of maspin : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Biochemistry at Massey University, Palmerston North, New Zealand

Maspin (mammary serine protease inhibitor) is a tumour suppressing member of the serpin superfamily. Maspin is expressed in normal breast and prostate cells, but reportedly down regulated during progression of cancer in these tissues. Maspin has been shown to inhibit cellular migration and invasion in vitro; while in vivo, maspin has been shown to inhibit tumour growth, metastasis, and angiogenesis. Maspin also plays a role in the sensitisation of cells to induced apoptosis. These functions of maspin are independent of serine protease inhibition; however the cellular mobility function is dependent on an intact reactive site loop. Despite this knowledge, the molecular mechanisms for all reported functions of maspin are currently unknown. Maspin is reported to be transcriptionally regulated: to date Ets, Ap1, and p53 transcription factors have been shown to activate transcription of maspin by binding directly to the promoter. Androgen is reported to be a negative regulator through the binding of the androgen receptor to a hormone response element within the promoter. This hormone response element is also responsible for an increase in maspin expression in response to tamoxifen, an anti-oestrogen drug. Transcriptional regulation of maspin has also been reported to be activated by other molecules, including gamma linolenic acid, manganese containing super-oxide dismutase, and nitric oxide, the mechanisms of regulation by these molecules is unknown. Loss of maspin expression in cancerous cells lines has been attributed to loss of one or more of the activating factors, and aberrant methylation of cytosine residues resulting in chromatin compaction. This study investigated the transcriptional regulation of maspin, with the aim of identifying transcriptional effectors important to the regulation of the gene. Identification of such factors may help identify a pathway in which maspin exerts its tumour suppressor functions. To this end, the maspin promoter was cloned and functional assays carried out. identifying several putative regions of the maspin promoter which may be important for the regulation of the gene. To date, the precise activator/repressor binding sites and the cognate proteins responsible for this regulation are unidentified

Extending the Ehresmann-Schein-Nambooripad Theorem

We extend the `join-premorphisms' part of the Ehresmann-Schein-Nambooripad Theorem to the case of two-sided restriction semigroups and inductive categories, following on from a result of Lawson (1991) for the `morphisms' part. However, it is so-called `meet-premorphisms' which have proved useful in recent years in the study of partial actions. We therefore obtain an Ehresmann-Schein-Nambooripad-type theorem for meet-premorphisms in the case of two-sided restriction semigroups and inductive categories. As a corollary, we obtain such a theorem in the inverse case.Comment: 23 pages; final section on Szendrei expansions removed; further reordering of materia

Reporting the Asian tsunami: Ethical issues

This article explores the ethical issues faced by New Zealand journalists reporting a disaster. Journalists who travelled to Asia to report on the 2004 tsunami were asked to complete an online survey containing a mixture of Likert scale and open-ended questions. Of the 20 journalists known to have travelled to Asia to cover the tsunami, 13, or 65 percent, took part in the survey. Many were confronted with ethical dilemmas. These problems were compared to the literature on reporting disasters, and triangulated through a one-on-one interview with a psychologist working with survivors of the tsunami. This comparison raised further issues not mentioned by the respondents. A second survey was sent out to elicit responses to these further issues. Four out of 20 replied, and their responses were compared to the literature and to the relevant codes of ethics. The results suggest New Zealand journalists have a strongly ethical approach but that there is a lack of awareness of some significant ethical issues. This indicates the level of support and training given to those covering such events needs revision. Further research on the issues raised would be fruitful

Developing Multimodal Spectroscopic Imaging Techniques to Study Metal Dyshomeostasis and Altered Brain Biochemistry During Ageing

Cognitive decline and neurodegenerative diseases such as Alzheimer’s disease, pose significant concerns for the ageing population. Increased understanding of the biochemical processes that occur during ageing, may help to reveal pathways for prevention or treatment. There has been interest in the potential role that metal dis-homeostasis plays during ageing and cognitive decline, so this thesis has focussed on developing and applying spectroscopic methods to study metal dis-homeostasis and concomitant biochemical changes during ageing

The northwestern extent of Sandy Lake ware : a Canadian perspective

Sandy Lake ware, a late precontact to early postcontact archaeological manifestation, was first identified in central Minnesota by Cooper and Johnson (1964). Since then, few studies about this ware have been completed. It is considered to be part of the Psinomani culture and occurs across a large area of central North America, where it persisted from about A.D. 1000 to 1750. Archaeological sites with Psinomani components often occur in regions where wild rice grows. It is likely that the people who left behind Sandy Lake ware were ancestral to the Eastern Dakota in central Minnesota and the Assiniboine in southern Canada. The Psinomani and Selkirk composite likely represent the material remains of an early Assiniboine and Cree alliance. Three problems related to Sandy Lake ware were identified, including classification uncertainties, associated cultural questions and its northwestern extent; the latter had never been fully assessed. By studying this ware and comparing it to other pottery, some classification complications were simplified. A synthesis of present information about the Psinomani culture was also completed. Collections from sites across a large area in south central Canada were examined to determine the northwest extent of Sandy Lake ware. One of the first inventories of shell tempered pottery, likely Sandy Lake ware, was compiled for the study area. The Stamped type is now known to have been recovered several 100 km farther northwest into Canada than previously determined

Geochemistry in the Uchi subprovince, northern Superior Province : an evaluation of the geodynamic evolution of the northern margin of the Superior Province ocean basin

Older assemblages of the Uchi subprovince, northern Superior Province, Canada, ranging in age from 2.9 to 3.0 Ga, are dominated by an association of komatiite-tholeiite sequences intercalated with felsic volcanic rocks. Komatiites vary from weakly LREE enriched to strongly depleted. The majority of ultramafic rocks display the conjunction of negative Nb anomalies with trends of increasing SiO2 and La/Smn, indicative of contamination by a felsic component. Many of the komatiites and komatiitic basalts are characterised by high V/Yb and Sc/Yb ratios which are unique amongst Archean komatiites. Tholeiitic flows intercalated with the komatiites typically display flat REE patterns with variable Nb anomalies, consistent with minor degrees of contamination. Two suites of felsic volcanic rocks are intercalated with the komatiite-tholeiite sequences of the older assemblages. Both types display pronounced LREE enrichment and negative Nb and Ti anomalies, but Type 1 has strongly fractionated HREE patterns, whereas Type 2 HREE are generally flat in conjunction with elevated compatible element contents. Collectively, the geochemical, geochronological and stratigraphic evidence from the northern Superior Province greenstone belts provide evidence for both a spatial and temporal association of mantle plumes and subduction zones during generation of the proto-continent nucleus to the Superior Province. The 2.8-2.9 Ga assemblages of the Uchi subprovince comprise mafic tholeiites characterised by predominantly flat REE, along with volumetrically significant units of felsic to intermediate volcanic rocks, that display enriched LREE and moderately fractionated HREE in conjunction with pronounced negative Nb anomalies. The geochemistry and geochronology of these assemblages is consistent with the formation of ocean plateau fragments which were accreted to the Uchi paleo continental margin where they subsequently formed the basement for a subduction related arc complex. Five distinct suites have been recognised in the ~2.7 Ga Confederation assemblage: (1) tholeiitic basalts with flat to smoothly depleted REE; (2) tholeiites with flat to weakly depleted LREE in conjunction with pronounced negative Nb anomalies; (3) Fe-rich basalts with elevated Ti and P contents, enriched LREE and fractionated HREE; (4) LREE enriched basalts and andesites with negative Nb anomalies; and (5) dacites and rhyolites with variably enriched LREE, moderately fractionated HREE and variable HFSE anomalies. The occurrence of this varied range of rocks in a single assemblage is comparable to modern back arc basins