1,953 research outputs found
Prospects and Possibilities
After a long wait, we have the Trusts and Succession (Scotland) Bill to mull over. The proposed legislation will repeal the centenarian Trusts (Scotland) Act 1921 and replace many other provisions relating to trusts and succession. The Bill is largely the product of the Scottish Law Commissionâs extensive work in this area, beginning in 2003. This article will evaluate some of the most significant changes and updates to Scots trusts law proposed in the Bill. It will also discuss additional or alternative powers and provisions which have been proposed during the Delegated Powers and Law Reform Committeeâs Consultation period, in particular an express power for trustees to consider environmental, social and governance (âESGâ) aims in furtherance of the trust purposes, when making investment decisions
The geology, sedimentology, geochronology and palaeo-environmental reconstruction of the Heelbo hillslope deposit, Free State Province, South Africa
Thesis submitted in fulfillment of the requirements for the
Degree of Doctor of Philosophy
University of the Witwatersrand
South Africa
2015A multidisciplinary sedimentological, stratigraphic, mineralogical and geochronological analysis of a small, fossil-bearing, Holocene hillslope deposit, flanking a mesa, has enabled a reconstruction of the palaeo-environmental history of the region. The hillslope deposit, located on the farm Heelbo in the eastern Free State Povince, South Africa, overlies Jurassic mudrock and sandstone of the Elliot Formation, Karoo Supergroup. The deposit is located on a steep (~10°) slope and covers an area of ~7 km2 in two separate sections. It extends ~475 m downslope and reaches a maximum thickness of at least 6-8 m towards the base.
Mineralogy indicates the deposit is sourced from the mesa but its fine grain size and location on a steep slope position Heelbo outside the scope of traditionally described alluvial fans or colluvial deposits. The hillslope deposit is described as an alluvial slope based on the morphology of the deposit and the grain size distribution against the slope gradient. The deposit comprises fine-sand to silt- grain size, but is found on a steep (~10°) slope. The source of the sediment is shown to be the sediment of the mesa, rather than input from an aeolian source. The grains are described as sub-angular and poorly sorted which also suggests a local provenance for the sediment.
Microscopic and XRF analysis confirm the derivation of the sediment from the Elliot Formation, with the lithic fragments derived from subarkoses to arkoses of the underlying bedrock of the Upper Elliot Formation (UEF) in the Karoo Supergroup. Secondary calcite was visible in only two of the thin sections, thus it is likely due to a diagenetic overprint that is constrained by depth from the surface or time and not to specific layers.
The deposit is cut by several mature and continuous gully networks with V-shaped profiles in the proximal slope, and combined V- and U-shaped profiles in the medial and distal sections. Gully formation is linked to both the sodium adsorption ratio (SARs), and high soil clay content, which facilitates swelling and shrinking.
The Heelbo deposit comprises two palaeosols (BT1 and BT2) and four sediment (B1, B2, RB and TS) horizons. Through luminescence dating, the ages were found to be approximately 6390 ± 740 years BP for the oldest Brown (B1) horizon and 250 ± 170 years BP for the Red Brown (RB) horizon. The radiocarbon ages of the sediment were inconclusive, but the 14C ages of the fossil bones were in agreement with the luminescence ages. The multiple palaeosol horizons identified suggest two cycles of deposition, pedogenesis and erosion of the alluvial succession. The palaeosols and the presence of calcareous nodules and rhizocretions, and smectite and mixed-layer clay minerals, together with the total absence of illite and kaolinite, suggest protracted, dry periods with intermittent short
periods of high rainfall. This is a similar climate regime to what the region experiences currently.
Main findings: The Heelbo alluvial slope comprises locally derived sediment, rather than an aeolian source. Heelbo suggests that the hillslope deposits classification system needs to be re-evaluated and opens opportunities for wider study of Pleistocene-Holocene hillslope deposits in central / northern South Africa. This study also contributes to climate change debates in the Holocene
The geology, sedimentology, geochronology and palaeo-environmental reconstruction of the Heelbo hillslope deposit, Free State Province, South Africa
Thesis submitted in fulfillment of the requirements for the
Degree of Doctor of Philosophy
University of the Witwatersrand
South Africa
2015A multidisciplinary sedimentological, stratigraphic, mineralogical and geochronological analysis of a small, fossil-bearing, Holocene hillslope deposit, flanking a mesa, has enabled a reconstruction of the palaeo-environmental history of the region. The hillslope deposit, located on the farm Heelbo in the eastern Free State Povince, South Africa, overlies Jurassic mudrock and sandstone of the Elliot Formation, Karoo Supergroup. The deposit is located on a steep (~10°) slope and covers an area of ~7 km2 in two separate sections. It extends ~475 m downslope and reaches a maximum thickness of at least 6-8 m towards the base.
Mineralogy indicates the deposit is sourced from the mesa but its fine grain size and location on a steep slope position Heelbo outside the scope of traditionally described alluvial fans or colluvial deposits. The hillslope deposit is described as an alluvial slope based on the morphology of the deposit and the grain size distribution against the slope gradient. The deposit comprises fine-sand to silt- grain size, but is found on a steep (~10°) slope. The source of the sediment is shown to be the sediment of the mesa, rather than input from an aeolian source. The grains are described as sub-angular and poorly sorted which also suggests a local provenance for the sediment.
Microscopic and XRF analysis confirm the derivation of the sediment from the Elliot Formation, with the lithic fragments derived from subarkoses to arkoses of the underlying bedrock of the Upper Elliot Formation (UEF) in the Karoo Supergroup. Secondary calcite was visible in only two of the thin sections, thus it is likely due to a diagenetic overprint that is constrained by depth from the surface or time and not to specific layers.
The deposit is cut by several mature and continuous gully networks with V-shaped profiles in the proximal slope, and combined V- and U-shaped profiles in the medial and distal sections. Gully formation is linked to both the sodium adsorption ratio (SARs), and high soil clay content, which facilitates swelling and shrinking.
The Heelbo deposit comprises two palaeosols (BT1 and BT2) and four sediment (B1, B2, RB and TS) horizons. Through luminescence dating, the ages were found to be approximately 6390 ± 740 years BP for the oldest Brown (B1) horizon and 250 ± 170 years BP for the Red Brown (RB) horizon. The radiocarbon ages of the sediment were inconclusive, but the 14C ages of the fossil bones were in agreement with the luminescence ages. The multiple palaeosol horizons identified suggest two cycles of deposition, pedogenesis and erosion of the alluvial succession. The palaeosols and the presence of calcareous nodules and rhizocretions, and smectite and mixed-layer clay minerals, together with the total absence of illite and kaolinite, suggest protracted, dry periods with intermittent short
periods of high rainfall. This is a similar climate regime to what the region experiences currently.
Main findings: The Heelbo alluvial slope comprises locally derived sediment, rather than an aeolian source. Heelbo suggests that the hillslope deposits classification system needs to be re-evaluated and opens opportunities for wider study of Pleistocene-Holocene hillslope deposits in central / northern South Africa. This study also contributes to climate change debates in the Holocene
Developing the repository manager community
This paper describes activities which have taken place
within the UK institutional repository (IR) sector
focusing on developing a community of practice through
the sharing of experiences and best practice. This
includes work done by the UK Council of Research
Repositories (UKCoRR) and other bodies, together with
informal activities, such as sharing the experience of
organising Open Access Week events. The paper also
considers future work to be undertaken by UKCoRR to
continue developing the community
THE CONTRIBUTION OF LONG-RANGE TRANSPORT OF AIR POLLUTION TO THE SULPHUR BUDGET OF THE UNITED ARAB EMIRATES
Student Number :8701745W -
MSc research report -
Faculty of ScienceAn air chemistry study over the United Arab Emirates revealed a high
concentration of sulphur dioxide. SO2 and its resultant aerosols can have a
significant effect on the atmospheric processes. These aerosols could both
directly and indirectly affect the climate by scattering solar radiation and
increasing the albedo of the atmosphere or by altering the cloud formation
processes and characteristics. Sulphur dioxide and the resultant aerosols
also have a damaging effect on the environment and on human health.
Previous studies reviewed suggest that pollution can be transported for
hundreds of kilometres from the source of the emission and affect the air
chemistry of the receptor regions. The possibility that long-range transport of
pollution to the UAE may have contributed to these high concentrations was
also investigated. The possibility that the UAE is a receptor region of
pollution transported over long distances is investigated with the intention of
identifying the possible source regions of this pollution. In order to examine
the import of pollution to the UAE it was important to analyse the background
sulphur concentrations of the atmosphere over the UAE
Importance of the pleckstrin homology domain of dynamin in clathrin-mediated endocytosis
AbstractThe GTPase dynamin plays an essential role in clathrin-mediated endocytosis [1â3]. Substantial evidence suggests that dynamin oligomerisation around the necks of endocytosing vesicles and subsequent dynamin-catalysed GTP hydrolysis is responsible for membrane fission [4,5]. The pleckstrin homology (PH) domain of dynamin has previously been shown to interact with phosphoinositides, but it has not been determined whether this interaction is essential for dynamin's function in endocytosis [6â9]. In this study, we address the in vivo function of the PH domain of dynamin by assaying the effects of deletions and point mutations in this region on transferrin uptake in COS-7 fibroblasts. Overexpression of a dynamin construct lacking its entire PH domain potently blocked transferrin uptake, as did overexpression of a dynamin construct containing a mutation in the first variable loop of the PH domain. Structural modelling of this latter mutant suggested that the lysine residue at position 535 (Lys535) may be critical in the coordination of phosphoinositides, and indeed, the purified mutant no longer interacted with lipid nanotubes. Interestingly, the inhibitory phenotype of cells expressing this dynamin mutant was partially relieved by a second mutation in the carboxy-terminal proline-rich domain (PRD), one that prevents dynamin from binding to the Src homology 3 (SH3) domain of amphiphysin. These data demonstrate that dynamin's interaction with phosphoinositides through its PH domain is essential for endocytosis. These findings also support our hypothesis that PRDâSH3 domain interactions are important in the recruitment of dynamin to sites of endocytosis
Construction costs, chemical composition and payback time of high- and low-irradiance leaves
The effect of irradiance on leaf construction costs, chemical composition, and on the payback time of leaves was investigated. To enable more generalized conclusions, three different systems were studied: top and the most-shaded leaves of 10 adult tree species in a European mixed forest, top leaves of sub-dominant trees of two evergreen species growing in small gaps or below the canopy in an Amazonian rainforest, and plants of six herbaceous and four woody species grown hydroponically at low or high irradiance in growth cabinets. Daily photon irradiance varied 3-6-fold between low- and high-light leaves. Specific leaf area (SLA) was 30-130% higher at low light. Construction costs, on the other hand, were 1-5% lower for low-irradiance leaves, mainly because low-irradiance leaves had lower concentrations of soluble phenolics. Photosynthetic capacity and respiration, expressed per unit leaf mass, were hardly different for the low- and high-light leaves. Estimates of payback times of the high-irradiance leaves ranged from 2-4 d in the growth cabinets, to 15-20 d for the adult tree species in the European forest. Low-irradiance leaves had payback times that were 2-3 times larger, ranging from 4 d in the growth cabinets to 20-80 d at the most shaded part of the canopy of the mixed forest. In all cases, estimated payback times were less than half the life span of the leaves, suggesting that even at time-integrated irradiances lower than 5% of the total seasonal value, investment in leaves is still fruitful from a carbon-economy point of view. A sensitivity analysis showed that increased SLA of low-irradiance leaves was the main factor constraining payback times. Acclimation in the other five factors determining payback time, namely construction costs, photosynthetic capacity per unit leaf mass, respiration per unit leaf mass, apparent quantum yield, and curvature of the photosynthetic light-response-curve, were unimportant when the observed variation in each factor was examine
Human Tear Fluid Reduces Culturability of Contact Lens-Associated Pseudomonas aeruginosa Biofilms but Induces Expression of the Virulence-Associated Type III Secretion System
Purpose The type III secretion system (T3SS) is a significant virulence determinant for Pseudomonas aeruginosa. Using a rodent model, we found that contact lens(CL)-related corneal infections were associated with lens surface biofilms. Here, we studied the impact of human tear fluid on CL-associated biofilm growth and T3SS expression. Methods P. aeruginosa biofilms were formed on contact lenses for up to 7 days with or without human tear fluid, then exposed to tear fluid for 5 or 24 h. Biofilms were imaged using confocal microscopy. Bacterial culturability was quantified by viable counts, and T3SS gene expression measured by RT-qPCR. Controls included trypticase soy broth, PBS and planktonic bacteria. Results With or without tear fluid, biofilms grew to âŒ108 CFU viable bacteria by 24 h. Exposing biofilms to tear fluid after they had formed without it on lenses reduced bacterial culturability âŒ180-fold (P\u3c.001). CL growth increased T3SS gene expression versus planktonic bacteria [5.46 ± 0.24-fold for T3SS transcriptional activitor exsA (P=.02), and 3.76 ± 0.36-fold for T3SS effector toxin exoS(P=.01)]. Tear fluid further enhanced exsA and exoS expression in CL-grown biofilms, but not planktonic bacteria, by 2.09 ± 0.38-fold (P=.04) and 1.89 ± 0.26-fold (P\u3c.001), respectively. Conclusions Considering the pivitol role of the T3SS in P. aeruginosa infections, its induction in CL-grown P. aeruginosa biofilms by tear fluid might contribute to the pathogenesis of CL-related P. aeruginosa keratitis
DataMoves:Entangling data and movement to support computer science education
In the domain of computing education for children, much work has been done to devise creative and engaging methods of teaching about programming. However, there are many other fundamental aspects of computing that have so far received relatively less attention. This work explores how the topics of number systems and data representation can be taught in a way that piques curiosity and captures learnersâ imaginations. Specifically, we present the design of two interactive physical computing artefacts, which we collectively call DataMoves, that enable students, 12-14 years old, to explore number systems and data through embodied movement and dance. Our evaluation of DataMoves, used in tandem with other pedagogical methods, demonstrates that the form of embodied, exploration-based learning adopted has much potential for deepening studentsâ understandings of computing topics, as well as for shaping positive perceptions of topics that are traditionally considered boring and dull
Pathfinders: Realizing Reconciliation Through Lessons Learned
In 2016, a group of Indigenous and non-Indigenous scholars came together to imagine a better world through a bold approach to education at the Werklund School of Education. This imagining took the form of a newly designed graduate pathway program which focused on meaningfully and actively responding to Canadaâs Truth and Reconciliation Commissionâs (TRC) (2015) 94 Calls to Action. Central to the design of our program is the inclusion of a capstone service-learning project that asks graduate students to bring together Indigenous and non-Indigenous groups in designing and delivering projects of mutual benefit. In sharing insights from their respective learning journeys, our students reveal the complexities and challenges of reconciliatory work but also its many rewards. Further, in sharing these courageous acts, we hope to inspire others to take action
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