title: Modelling external light transmission through to the human fetus

authors: Isaac, Zac

subjects: fetal vision

abstract: Little is known about the visual experience of human fetuses within the womb. For many years, the uterus was assumed to be a dark environment, limited only to illumination under intense radiation. Recent research, however, shows that the human fetus exhibits brain activity when presented with visual stimuli and displays a preference for face-like stimuli presented via laser diode application to the maternal abdominal exterior. Despite growing evidence to support the notion of a visually engaged fetus during gestation, there has been minimal research undertaken to determine the extent to which the human uterus is illuminated by external light sources. Beyond aiding with experimental research in fetal vision, an understanding of uterine illumination begins to reveal the impact of varying environmental conditions on the fetal visual experience, with direct relevance to ongoing research across fields such as fetal vision, photoacoustics, and ectogenesis. This thesis outlines a mathematical model developed for the purposes of simulating the propagation of light sources through maternal tissue to the human fetus, with applications exploring the effect of adipose on transdermal monochromatic stimuli, the degree of uterine illumination imposed by natural light, and an extension to the illumination of a full maternal abdomen via a model that can account for curvature, varying tissue layer thicknesses, and the temporal aspects of pregnancy.

text: Modelling external light transmission through to the human fetus Little is known about the visual experience of human fetuses within the womb. For many years, the uterus was assumed to be a dark environment, limited only to illumination under intense radiation. Recent research, however, shows that the human fetus exhibits brain activity when presented with visual stimuli and displays a preference for face-like stimuli presented via laser diode application to the maternal abdominal exterior. Despite growing evidence to support the notion of a visually engaged fetus during gestation, there has been minimal research undertaken to determine the extent to which the human uterus is illuminated by external light sources. Beyond aiding with experimental research in fetal vision, an understanding of uterine illumination begins to reveal the impact of varying environmental conditions on the fetal visual experience, with direct relevance to ongoing research across fields such as fetal vision, photoacoustics, and ectogenesis. This thesis outlines a mathematical model developed for the purposes of simulating the propagation of light sources through maternal tissue to the human fetus, with applications exploring the effect of adipose on transdermal monochromatic stimuli, the degree of uterine illumination imposed by natural light, and an extension to the illumination of a full maternal abdomen via a model that can account for curvature, varying tissue layer thicknesses, and the temporal aspects of pregnancy.

year: 2024

title: Portimine: a bioactive metabolite from the benthic dinoflagellate Vulcanodinium rugosum

authors: Selwood, Andrew I.

subjects: pinnatoxin

abstract: Portimine, a new polycyclic ether toxin containing a cyclic imine moiety, was isolated from the marine benthic dinoflagellate Vulcanodinium rugosum collected from Northland, New Zealand. The structure of portimine, including the relative configurations, was elucidated by spectroscopic analyses. The cyclic imine moiety consists of an unprecedented five-membered ring with a spiro-link to a cyclohexene ring. This is the only structural similarity to the pinnatoxin group of polycyclic ethers also produced by V. rugosum, which all contain a six-membered cyclic imine ring. The LD50 of portimine to mice by intraperitoneal injection was 1570 μg/kg, indicating a much lower toxicity than many other cyclic imine shellfish toxins. In contrast, portimine was highly toxic to mammalian cells in vitro with an LC50 to P388 cells of 2.7 nM, and activation of caspases indicating apoptotic activity.

text: Portimine: a bioactive metabolite from the benthic dinoflagellate Vulcanodinium rugosum Portimine, a new polycyclic ether toxin containing a cyclic imine moiety, was isolated from the marine benthic dinoflagellate Vulcanodinium rugosum collected from Northland, New Zealand. The structure of portimine, including the relative configurations, was elucidated by spectroscopic analyses. The cyclic imine moiety consists of an unprecedented five-membered ring with a spiro-link to a cyclohexene ring. This is the only structural similarity to the pinnatoxin group of polycyclic ethers also produced by V. rugosum, which all contain a six-membered cyclic imine ring. The LD50 of portimine to mice by intraperitoneal injection was 1570 μg/kg, indicating a much lower toxicity than many other cyclic imine shellfish toxins. In contrast, portimine was highly toxic to mammalian cells in vitro with an LC50 to P388 cells of 2.7 nM, and activation of caspases indicating apoptotic activity.

year: 2013

title: A critical race analysis of Māori representation in university strategic documents in Aotearoa New Zealand

authors: Waitoki, Waikaremoana

subjects: critical race theory

abstract: Following the recent claims lodged at two universities in Aotearoa New Zealand alleging the existence of racism, there has been scepticism towards the professed commitments by universities to create an inclusive and safe environment for Indigenous Māori. As a Kaupapa Māori-informed study, we (a group of Māori and Tauiwi scholars) employed tenets of Critical Race Theory to examine how the representation of Māori is racialised and subordinated in university strategic documents. We located five predominant discourses portraying different mechanisms that reify whiteness in university practices such as the selective interpretation of Te Tiriti articles, targeted recruitment of Māori, framing of Māori as dependent on the Crown to succeed, commodification of mātauranga Māori, and avoidance of conversations about structural racism, colonisation, and racial equity. Our findings suggest that university strategic goal statements need to incorporate a critical race analysis, or else risk perpetuating practices that fall short of challenging the status quo.

text: A critical race analysis of Māori representation in university strategic documents in Aotearoa New Zealand Following the recent claims lodged at two universities in Aotearoa New Zealand alleging the existence of racism, there has been scepticism towards the professed commitments by universities to create an inclusive and safe environment for Indigenous Māori. As a Kaupapa Māori-informed study, we (a group of Māori and Tauiwi scholars) employed tenets of Critical Race Theory to examine how the representation of Māori is racialised and subordinated in university strategic documents. We located five predominant discourses portraying different mechanisms that reify whiteness in university practices such as the selective interpretation of Te Tiriti articles, targeted recruitment of Māori, framing of Māori as dependent on the Crown to succeed, commodification of mātauranga Māori, and avoidance of conversations about structural racism, colonisation, and racial equity. Our findings suggest that university strategic goal statements need to incorporate a critical race analysis, or else risk perpetuating practices that fall short of challenging the status quo.

year: 2024