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2. Modelling Teacher Development through Open and Distance Learning: A Zimbabwean Experience

Author

Tarusikirwa, Moffat C.

Abstract

Historically, in Southern Rhodesia, now Zimbabwe, Standards 3, 4, 5 and 6 would teach during the school term and attend teacher training during the school holidays. This was mostly in Missionary institutions. Later, these organisations changed into full-time teacher training institutions. Then teacher training lasted two years. Students would spend time in college and in the field. Some teachers were certified because of good performance, without having attended any teacher development college. Some, for example holders of Primary Teacher Lower Course (P.T.L.) who passed the Cambridge General School Certificate, GCE were given an examination and upgraded to the Primary Teacher Higher Course (P.T.H.) qualification. Among the past models are the -3-3-3, the -3-3-3-3 and the ZINTEC (Zimbabwe Integrated Teacher Education Course) model of teacher development used in conventional colleges. Currently, conventional colleges use the 2-5-2 model. For the purpose of this paper, the Zimbabwe Open University ODL model of Teacher Development will be discussed. In this model, student teachers are continually teaching in schools, while at the same time undergoing teacher development. The purpose of this model is to make it cheaper to produce teachers as it has advantages of producing large numbers of teachers at the same time as they teach in the schools making it economic for the country.

Published
2016

3. Expanded Understanding of the Western Antarctic Peninsula Sea‐Ice Environment Through Local and Regional Observations at Palmer Station.

Author

Goodell, E., Stammerjohn, S., Meredith, M., Moffat, C., and Eveleth, R.

Subjects
SPRING, BIOGEOCHEMICAL cycles, SEAWATER, MARINE algae, STABLE isotopes, SEA ice
Abstract

The Western Antarctic Peninsula (WAP) has been experiencing rapid regional warming since at least the 1950s, however, the impacts of this warming at the local scale are variable and nuanced. Previous studies that have linked sea‐ice variability to biogeochemical cycles and food web dynamics often combine local‐scale biogeochemical data with coarse‐resolution regional satellite sea‐ice data, which may not adequately capture local sea‐ice conditions. In this study, we analyzed local‐scale in situ sea‐ice observations collected as part of a 28‐year record (1992–2020) from the Palmer Long‐Term Ecological Research site at Anvers Island, mid‐WAP, in conjunction with isotopically‐derived sea‐ice meltwater (SIM) fractions and satellite‐derived sea‐ice motion and concentration, to quantify the variability and long‐term trends in local sea‐ice behavior. In situ sea ice observations at Palmer Station displayed higher variability than satellite observations and showed no significant declines over this time, despite region‐wide declines identified in prior studies. Higher spring SIM fractions were attributed to strong northward sea‐ice motion throughout the winter. Applying these local‐scale sea‐ice insights to similarly scaled stratification and chlorophyll‐a measurements, we found that a longer‐lasting, more consistent sea‐ice pack led to greater water column stratification following the spring sea‐ice retreat. Greater sea‐ice persistence and stronger stratification led to larger peaks in chlorophyll‐a, though sea‐ice metrics did not explain the positive temporal trends in either stratification strength or chlorophyll‐a. Through this study, we identify how local sea‐ice observations and meltwater data can enhance satellite data to build an understanding of the intricate connections between ice, water column dynamics, and phytoplankton. Plain Language Summary: The western coast of the Antarctic Peninsula is one of the fastest‐warming places on the planet. The coastal ocean here is home to large amounts of marine algae (phytoplankton), which supports a rich ecosystem. Prior studies have noted that sea ice plays a role in determining how abundant phytoplankton are in the water, but these studies typically use sea‐ice measurements from regional‐scale satellites, which do not always provide details about how sea ice is behaving at the local scale. Here, we analyze a daily sea‐ice record that was acquired locally through visual observation, as well as local‐scale ocean water samples that detect how much sea‐ice meltwater is present. We found that, despite regional warming, high year‐to‐year variability masks long‐term trends in the local sea‐ice record, and that the movement of sea ice during winter influences how much sea ice melts in place when it retreats in the spring. We also found that years with greater winter sea‐ice coverage led to summers with more ideal conditions for phytoplankton growth (e.g., shallower and more stratified water), though sea ice does not appear to be the primary driver behind recent increases in phytoplankton. Key Points: Local‐scale sea‐ice measurements at Palmer Station show higher daily and interannual variability than satellite‐based measurementsNorthwestward winter ice movement typically preceded elevated spring sea‐ice meltwater near Palmer StationLocal sea‐ice retreat influences water column stratification and Chlorophyll‐a but does not explain increasing trends in these parameters [ABSTRACT FROM AUTHOR]

Published
2024
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4. Widespread increase in discharge from West Antarctic Peninsula glaciers since 2018

Author

Davison, B.J., Hogg, A., Moffat, C., Meredith, M.P., Wallis, B.J., Davison, B.J., Hogg, A., Moffat, C., Meredith, M.P., and Wallis, B.J.

Abstract

Many glaciers on the Antarctic Peninsula have retreated and accelerated in recent decades. Here we show that there has been a widespread, quasi-synchronous, and sustained increase in grounding line discharge from glaciers on the west coast of the Antarctic Peninsula since 2018. Overall, the west Antarctic Peninsula discharge trends increased by over a factor of 3, from 50 Mt yr−2 during 2017 to 2020 up to 160 Mt yr−2 in the years following, leading to a 7.4 % increase in grounding line discharge since 2017. The acceleration in discharge was concentrated at glaciers connected to deep, cross-shelf troughs hosting warm-ocean waters, and the acceleration occurred during a period of anomalously high subsurface water temperatures on the continental shelf. Given that many of the affected glaciers have retreated over the past several decades in response to ocean warming, thereby highlighting their sensitivity to ocean forcing, we argue that the recent period of anomalously warm water was likely a key driver of the observed acceleration. However, the acceleration also occurred during a time of anomalously high atmospheric temperatures and glacier surface runoff, which could have contributed to speed-up by directly increasing basal water pressure and, by invigorating near-glacier ocean circulation, increasing submarine melt rates. The spatial pattern of glacier acceleration therefore provides an indication of glaciers that are exposed to warm-ocean water at depth and/or have active surface-to-bed hydrological connections; however, many stages in the chain of events leading to glacier acceleration, and how that response is affected by glacier-specific factors, remain insufficiently understood. Both atmospheric and ocean temperatures in this region and its surroundings are likely to increase further in the coming decades; therefore, there is a pressing need to improve our understanding of recent changes in Antarctic Peninsula glacier dynamics in response atmospheric and oceanic

Published
2024

9. Spatial demography of Calanus finmarchicus in the Irminger Sea

Author

Heath, M.R., Rasmussen, J., Ahmed, Y., Allen, J., Anderson, C.I.H., Brierley, A.S., Brown, L., Bunker, A., Cook, K., Davidson, R., Fielding, S., Gurney, W.S.C., Harris, R., Hay, S., Henson, S., Hirst, A.G., Holliday, N.P., Ingvarsdottir, A., Irigoien, X., Lindeque, P., Mayor, D.J., Montagnes, D., Moffat, C., Pollard, R., Richards, S., Saunders, R.A., Sidey, J., Smerdon, G., Speirs, D., Walsham, P., Waniek, J., Webster, L., and Wilson, D.

Published
2008
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10. Antiretroviral regimens in pregnancy and breast-feeding in Botswana

Author

Shapiro, R.L., Snowden, W., Martinez-Tristani, M., Mazhani, L., Essex, M., Souda, S., Lubega, E., Akhtar, M., Wester, C., Tuomola, R., Sharma, U., Handelsman, E., Mburu, K., Jayeoba, O., Moko, E., Leidner, J., Powis, K., Asmelash, A., Tumbare, E., Zwerski, S., Makhema, J., Moyo, S., Thior, I., McIntosh, K., van Widenfelt, E., Hughes, M.D., Ogwu, A., Kitch, D., Lockman, S., and Moffat, C.

Subjects
Highly active antiretroviral therapy -- Health aspects, HIV infection -- Drug therapy, HIV infection -- Prevention, Disease transmission -- Risk factors, Disease transmission -- Patient outcomes, Pregnancy -- Health aspects, Breast feeding -- Health aspects, HIV infection in pregnancy -- Drug therapy, HIV infection in pregnancy -- Prevention
Abstract

The study attempts to evaluate the most effective and safe highly active antiretroviral therapy (HAART) in preventing human immunedeficiency virus type -1 (HIV-1) transmission during pregnancy and breast-feeding. The results indicate that all regimes of HAART had positive outcomes in reducing HIV-1 transmission, with a overall rate of 1.1% between mother and infant.

Published
2010

11. Chapter 11: Changes in liquid and atmospheric inputs to the marine environment from land (including through groundwater), ships and offshore installations

Author

Ebinghaus, R., Grøsvik, B., Hassellöv, I., Moffat, C., Simcock, A., Sonesten, L., Vlahos, P., Achterberg, E., Alo, B., Andrade, C., Bebianno, M., Caetano, M., Gnandi, K., Hong, G., Kim, S., Lohmann, R., Stankiewicz, M., and Wang, J.

Abstract

Chemical production has continued to in-crease and change since 2003. The potential geographic impact of the chemical industry continued to change from the Atlantic Ocean to the Pacific Ocean, where almost 70 per cent of the industry is expected to operate by 2030, while new products are continually being devel-oped, thus adding to the mixture of chemicals to which biota in the ocean is being exposed.Different lists of hazardous substances have been identified by international organizations, although there is still no agreed single global list of substances that are of concern. The present chapter contains an assessment of the changes since the first Assessment in wa-ter and airborne inputs to the marine environ-ment from land (including groundwater), ships and offshore installations. In addition, the information in the present chapter builds upon the assessment of the list of hazardous sub-stances used in the first Assessment, namely, POPs, metals, hydrocarbons and radioactive substances. It includes new information on rare earth elements, PPCPs and airborne in-puts of nitrogen oxides and sulfur oxides that were not included in the first Assessment.

Published
2021

16. Synthesis, characterisation and applications of chemically modified heparins

Author

Moffat, C. F.

Subjects
572, Heparins' biosynthesis
Abstract

Heparin is a highly sulphated glycosaminoglycan. Approximately 70% of the polymer structure is represented by the disaccharide repeat unit (IdA-2S→GlcNS-6S). Variations with respect to the degree of sulphation, acetylation of the amino group and configuration of the uronic acid introduces extensive microheterogeneity within the polymer primary sequence. Heparin is not just a blood anticoagulant but has a wide ranging capability to interact with inorganic ions, proteins and drugs. Such interactions have been increasingly studied with specific reference to structure-function relationships. Heparin was subjected to a variety of chemical modifications including de-N-sulphation, de-N/O-sulphation, N-acetylation, N-propionylation, N-sulphation and carboxyl reduction. Partially modified polymers were synthesised using either less stringent solvolytic conditions or hydrochloric acid. The modified polymers were characterised using high-resolution ^1 3 C-NMR spectroscopy, Ir spectroscopy and acid-base titrations. Prior analysis of native heparin provided a set of reference spectra and titration profiles. Specific ion replacement and polarimetry were employed to study the interactions between heparin and cations. Polarimetry was further utilised to investigate the effect of polymer modification on the interaction with calcium and copper (II) ions. A study was conducted on the ability of the modified polymers to potentiate antithrombin inhibition of the cleavage of synthetic substrates by Factor Xa and thrombin. In addition, the influence of the modified heparin on capillary vessel growth in the chick CAM was investigated. Heparin and the chemically modified heparins were subjected to the bacterial enzymes heparinase II and heparinase III. Analysis of the degradation products was conducted using molecular exclusion chromatography and HPLC. The substrate specificity of the two lyases was assessed together with the potential of employing the enzymes, in conjunction with HPLC, to characterise heparins from various sources. The major conclusion are: 1) The interaction of calcium and copper (II) ions with modified polymers are fundamentally different with the amino group playing an important role in the copper (II) interaction. 2) Polysaccharide-catalysed inhibition of thrombin by antithrombin is more pronounced than for Factor AXa. The polysaccharides appear to play a subsidiary role through the formation of a simple electrostatic interaction with thrombin and antithrombin, thus bringing the protease and inhibitor together. 3) Heparinase II is active against a wide range of heparin-like polymers producing a variety of disaccharides and tetrasaccharides. Two specific glycosidic linkages are, however, resistant to the action of the enzyme. 4) Heparinase III catalyses the degradation of heparin-like polymers that are N-sulphated or N-acetylated but is inactive in those parts of the molecule in which a 2-0-sulphated uronic acid is present. 5) Enzyme-catalysed degradation followed by HPLC analysis is a viable method of characterising the disaccaride composition of heparins and heparin-like polymers.

Published
1987

22. Variability and change in the west Antarctic Peninsula marine system: Research priorities and opportunities

Author

Henley, S.F., Schofield, O.M.E., Hendry, K.R., Schloss, I.R., Steinberg, D.K., Moffat, C., Peck, L.S., Costa, D.P., Bakker, D.C.E., Hughes, C., Rozema, P.D., Ducklow, H.W., Abele, D., Stefels, J., van Leeuwe, M.A., Brussaard, C.P.D., Buma, A.G.J., Kohut, J., Sahade, R., Friedlaender, A.S., Stammerjohn, S.E., Venables, H.J., Meredith, M.P., Henley, S.F., Schofield, O.M.E., Hendry, K.R., Schloss, I.R., Steinberg, D.K., Moffat, C., Peck, L.S., Costa, D.P., Bakker, D.C.E., Hughes, C., Rozema, P.D., Ducklow, H.W., Abele, D., Stefels, J., van Leeuwe, M.A., Brussaard, C.P.D., Buma, A.G.J., Kohut, J., Sahade, R., Friedlaender, A.S., Stammerjohn, S.E., Venables, H.J., and Meredith, M.P.

Abstract

The west Antarctic Peninsula (WAP) region has undergone significant changes in temperature and seasonal ice dynamics since the mid-twentieth century, with strong impacts on the regional ecosystem, ocean chemistry and hydrographic properties. Changes to these long-term trends of warming and sea ice decline have been observed in the 21st century, but their consequences for ocean physics, chemistry and the ecology of the high-productivity shelf ecosystem are yet to be fully established. The WAP shelf is important for regional krill stocks and higher trophic levels, whilst the degree of variability and change in the physical environment and documented biological and biogeochemical responses make this a model system for how climate and sea ice changes might restructure high-latitude ecosystems. Although this region is arguably the best-measured and best-understood shelf region around Antarctica, significant gaps remain in spatial and temporal data capable of resolving the atmosphere-ice-ocean-ecosystem feedbacks that control the dynamics and evolution of this complex polar system. Here we summarise the current state of knowledge regarding the key mechanisms and interactions regulating the physical, biogeochemical and biological processes at work, the ways in which the shelf environment is changing, and the ecosystem response to the changes underway. We outline the overarching cross-disciplinary priorities for future research, as well as the most important discipline-specific objectives. Underpinning these priorities and objectives is the need to better define the causes, magnitude and timescales of variability and change at all levels of the system. A combination of traditional and innovative approaches will be critical to addressing these priorities and developing a co-ordinated observing system for the WAP shelf, which is required to detect and elucidate change into the future.

Published
2019

23. Highly-Parallel, Highly-Compact Computing Structures Implemented in Nanotechnology

Author

Crawley, D. G, Duff, M. J. B, Fountain, T. J, Moffat, C. D, and Tomlinson, C. D

Subjects
Computer Operations And Hardware
Abstract

In this paper, we describe work in which we are evaluating how the evolving properties of nano-electronic devices could best be utilized in highly parallel computing structures. Because of their combination of high performance, low power, and extreme compactness, such structures would have obvious applications in spaceborne environments, both for general mission control and for on-board data analysis. However, the anticipated properties of nano-devices mean that the optimum architecture for such systems is by no means certain. Candidates include single instruction multiple datastream (SIMD) arrays, neural networks, and multiple instruction multiple datastream (MIMD) assemblies.

Published
1995

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