198 research outputs found

    The development potential of Kwazulu-Natal aquifers for rural water supply

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    The supply of water to 'disadvantaged' areas of KwaZulu-Natal has in the past received low priority. Local government is now faced with supplying water to large, sometimes dispersed, rural populations. Groundwater has been utilised informally as a water supply for some years, but the impetus provided by the Department of Water Affairs and Forestry's White Paper has compelled those responsible for water supply to seriously consider groundwater as a sustainable option. The development potential or success of groundwater in its role as a reliable water supply is dependent on acceptance of the resource by the communities, appropriate level of service, yield sustainability and safe quality. Apart from the social aspects, the yield and groundwater quality characteristics of the aquifers under consideration must be used to determine the best hydrogeological features to target during exploration. A total of 993 borehole records, from a recent government drought relief programme, were used to compare the yield, water quality and best geophysical exploration and drilling techniques of the main hydrolithologies in rural KwaZulu-Natal. The results of comparative analysis shows that the competent rocks of the Natal Group and Natal Metamorphic Province and the karstic Uloa Formation of the Maputaland Group have the best overall potential for water supply. The unconsolidated sediments of the Maputaland Group also have good potential, but have some salinity problems. The Karoo Supergroup sediments and volcanics have moderate potential, with the argillaceous rocks having the worst potential of the Karoo rocks. The contacts between the Ecca Group shales and sandstone have the best potential of the Karoo Supergroup sedimentary hydrolithologies. Fractures clearly enhance the groundwater potential of most hydrolithologies, with fractured Dwyka Group tillites rated as having one of the best development potentials of all the hydrogeological targets in KwaZulu-Natal, despite the hydrolithology's poor water-bearing characteristics. Dolerite contacts with sedimentary rocks are commonly targeted features in groundwater development. However, the results from this research showed that, apart from the Natal Group's contact with dolerite, these targets have poor development potential. In general, contacts between different hydro lithologies. Health related quality was found to be adversely affected in argillaceous hydrolithologies, such as the majority of Karoo rocks which had high levels of sodium and chloride and Natal Metamorphic Province schists which had elevated sodium, chloride and fluoride. Crystalline and arenaceous hydrolithologies generally exhibited good quality groundwater. A comparison between the different geophysical methods for each target feature indicates that there are appropriate methods to use to detect anomalies related to water-bearing features. The large number of dry boreholes drilled in locations with recorded geophysical anomalies can be either a function of the water-bearing characteristics of the formation, human error or background noise. The cost of using the different geophysical methods vary considerably. The order of increasing cost is magnetics, VLF, EM-34, electrical resistivity profiling followed by vertical electrical sounding. Drilling has a large influence on the development potential of certain aquifers due to the high costs involved. Most of the secondary aquifers will require percussion drilling which is the cheapest method of drilling commonly used. Some very unstable formations within fractured or highly weathered rock may need ODEX drilling to enable drilling to advance. ODEX drilling in these conditions is very costly and can double the cost of drilling compared to air percussion. The unconsolidated sediments of the Maputaland Group can only be drilled by mud rotary or ODEX techniques. The relative costs of these two methods arer very similar with ODEX being slightly cheaper. Because of the high expense of drilling in the sands it is recommended that alternative sources, possibly from shallow hand-dug wells, be considered as appropriate methods of accessing groundwater. The aspects of groundwater yield and quality of aquifers, appropriate geophysical siting and drilling methods, together with social considerations will all contribute to the success of groundwater development in rural KwaZulu-Natal

    Innovations in (U–Th)/He, Fission Track, and Trapped Charge Thermochronometry with Applications to Earthquakes, Weathering, Surface‐Mantle Connections, and the Growth and Decay of Mountains

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    A transformative advance in Earth science is the development of low‐temperature thermochronometry to date Earth surface processes or quantify the thermal evolution of rocks through time. Grand challenges and new directions in low‐temperature thermochronometry involve pushing the boundaries of these techniques to decipher thermal histories operative over seconds to hundreds of millions of years, in recent or deep geologic time and from the perspective of atoms to mountain belts. Here we highlight innovation in bedrock and detrital fission track, (U–Th)/He, and trapped charge thermochronometry, as well as thermal history modeling that enable fresh perspectives on Earth science problems. These developments connect low‐temperature thermochronometry tools with new users across Earth science disciplines to enable transdisciplinary research. Method advances include radiation damage and crystal chemistry influences on fission track and (U–Th)/He systematics, atomistic calculations of He diffusion, measurement protocols and numerical modeling routines in trapped charge systematics, development of 4He/3He and new (U–Th)/He thermochronometers, and multimethod approaches. New applications leverage method developments and include quantifying landscape evolution at variable temporal scales, changes to Earth\u27s surface in deep geologic time and connections to mantle processes, the spectrum of fault processes from paleoearthquakes to slow slip and fluid flow, and paleoclimate and past critical zone evolution. These research avenues have societal implications for modern climate change, groundwater flow paths, mineral resource and petroleum systems science, and earthquake hazards

    Isolation and Characterisation of a Uniquely Regulated Threonine, Tyrosine Phosphatase (TYP 1) Which Inactivates Mitogen-Activated Protein Kinases

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    The recent discovery of the vaccinia virus protein phosphatase VH1, and its mammalian counterparts has highlighted a novel subfamily of protein phosphatases that exhibit dual specificity towards phosphotyrosine- and phosphoserine/threonine- residues. The aim of this thesis was to isolate and characterise further members of this phosphatase subfamily. Employing the technique of polymerase chain reaction (PCR), degenerate PCR primers, designed from amino acid sequences conserved between two members of this dual specificity phosphatase family, were used to amplify related sequences from poly (A)+ RNA isolated from the human squamous cell line A431. Screening cDNA libraries with probes derived from the PCR analysis resulted in the isolation of five novel genes, which show significant homology to the catalytic domain of the dual specificity phosphatases, such as the human phosphatase CL100. Two of these, TYP 1 and TYP 2 (threonine-tyrosine phosphatase), have been analysed further. Interestingly, whilst TYP 2 expression is regulated with similar kinetics to CL100, TYP 1 differs dramatically in its regulation. The TYP 1 gene is not expressed in human fibroblasts unlike other CL100-like genes. Furthermore, northern analysis has demonstrated that following mitogenic stimulation of squamous cells, induction of TYP 1 mRNA reaches its maximal levels after four hours, in contrast to the immediate-early CL100-like genes. Both TYP 1 and CL100 mRNAs are induced upon transforming growth factor- beta treatment of squamous cell lines sensitive to the growth factors antiproliferative effects. Investigations were undertaken to determine if TYP 1 demonstrated substrate specificity towards the mitogen-activated protein kinases, a function peculiar to the other CL100-like phosphatases. Indeed, transient transfection of TYP 1 into COS-1 cells resulted in the inhibition of both ERK2 and p54JNK MAP kinase isoforms. In addition, purified TYP 1 protein efficiently inactivates recombinant ERK2 in vitro by the concomitant dephosphorylation of both the phosphothreonine and -tyrosine residues. The subcellular localisation of TYP 1 was investigated, and shown to encode a nuclear protein. Interestingly, the mitogenic induction of TYP 1 results in an increase in the half-life of the protein. The results presented in this thesis suggest that the dual specificity phosphatases are an expanding family, some members of which are differentially regulated, therefore providing alternative mechanisms for the control of cellular responses to different ligands in different cell types. As discussed, TYP 1 is particularly exciting as its kinetics of induction and cell specificity of expression make it unique in terms of its possible roles

    Potential impacts of chemical weathering on feldspar luminescence dating properties

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    Chemical weathering alters the chemical composition of mineral grains. As a result, trapped-charge dating signals of primary silicates may be progressively modified. In this study, we treated three feldspar specimens to understand the effect of proton- and ligand-promoted dissolution on their luminescence properties. We conducted kinetic experiments over 720 h using two solutions: (1) oxalic acid (pH 3, 20 ∘C), an organic acid with chelating abilities, and (2) aqua regia (pH < 1, 40 ∘C), a mixture of strong acids creating aggressive acid hydrolysis conditions. These two solutions were chosen to provoke, on laboratory timescales, some of the changes that may occur on geological timescales as minerals weather in nature. The effect of the extracting solutions on mineral dissolution was investigated by monitoring the concentration of dissolved elements, while changes in feldspar surface morphology were assessed by scanning electron microscopy (SEM). Subsequent changes in feldspar luminescence in the near-UV (∌ 340 nm) and blue (∌ 410 nm) thermoluminescence (TL) and infrared stimulated luminescence (IRSL) emission bands were assessed at the multi- and/or single-grain levels to gain insight into the emission spectra, dose response, saturation, and anomalous fading characteristics of the feldspars. In all experiments, only minor feldspar dissolution was observed after 720 h. In general, aqua regia, the more chemically aggressive solution, had a larger effect on feldspar dissolution compared to that of oxalic acid. Additionally, our results showed that although the TL and IRSL intensities changed slightly with increasing artificial weathering time, the feldspar luminescence properties were otherwise unmodified. This suggests that chemical alteration of feldspar surfaces may not affect luminescence dating signals obtained from natural samples

    Dementia Care Mapping and Patient-Centred Care in Australian residential homes: An economic evaluation of the CARE Study, CHERE Working Paper 2008/4

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    Background: As the population ages, the incidence of dementia and its burden on society will increase. The economic costs of dementia are high, particularly for persons in the mid and late stages of the disease, when formal care arrangements such as nursing home placement are required. The need for care is often precipitated by the development of behavioural and psychological symptoms of dementia (BPSD) which also severely affect the quality of life of affected persons and their carers The Caring for Aged-Care REsident Study (CARES), the first randomised controlled trial to evaluate Dementia Care Mapping (DCM) and Person Centred Care (PCC), demonstrated that either of the two interventions improved outcomes compared to Usual Care (UC) on the primary outcome measure, the Cohen-Mansfield Agitation Inventory (CMAI). This study reports the results of an economic evaluation which was undertaken in conjunction with the trial. This information will provide additional information to assist policy makers in making choices between competing options. Methods: Fifteen nursing homes were randomised to one of three conditions: DCM, PCC or Usual Care (UC). The sample consisted of 360 residents with dementia. Data were collected at baseline, three months, and eight months by assessors blind to group assignment. In addition to the CMAI, data were collected about the use and costs of health care resources and pharmacological interventions. Total costs associated with each of the interventions were estimated, which were contrasted with the outcomes using standard health economics methodology. Results: Over one year, the cost per residential setting of implementing DCM and PCC relative to UC was 10,034and10,034 and 2,250 respectively. The additional cost per resident-level unit improvement in CMAI post-intervention (at follow-up) relative to UC was 48.95(48.95 (46.89) for DCM and 8.01(8.01 (6.43) for PCC. Compared to DCM, PCC produced a greater reduction in anxiety and agitation at a lower cost. Therefore, DCM was dominated by PCC and removed from the economic evaluation. Sensitivity analysis suggests this result is robust to changing model parameters. Conclusions: PCC provides a greater decrease in agitation and related behavioural and psychological symptoms of dementia, compared with DCM, at a lower cost and is the preferred option for cost-effectiveness. While there is no existing standard for a reasonable cost for a point improvement in CMAI, the cost per unit under PCC seems acceptable.Dementia, patient centred care

    DRAC:Dose Rate and Age Calculator for trapped charge dating

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    Accurate calculation of the environmental radiation dose rate (ᾊ) is an essential part of trapped charge dating methods, such as luminescence and electron spin resonance dating. Although the calculation of ᾊ is not mathematically complex, the incorporation of multiple variables and the propagation of uncertainties can be challenging. The Dose Rate and Age Calculator (DRAC) is an open access, web-based program which enables rapid ᾊ calculation for trapped charge dating applications. Users can select from recently published attenuation and conversion factors to make mathematically robust, reproducible ᾊ calculations. Comparison of DRAC calculated ᾊ values against the published ᾊ determinations of 422 samples from 32 studies results in a reproducibility ratio of 1.01 ± 0.05. It is anticipated that DRAC will facilitate easier inter-laboratory comparisons and will provide greater transparency for ᾊ calculations. DRAC will be updated to reflect the latest advances in ᾊ calculation and is freely accessible at www.aber.ac.uk/alrl/drac. The code for DRAC is available from github at https://github.com/DRAC-calculator/DRAC-calculator

    Project initiation workflow for research involving personal data

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    This document outlines the preferred process for initiating a research project involving personal data at the University of Glasgow. It includes a summary workflow diagram, a full workflow diagram with links to relevant resources, and a list of key contacts. Version 2.0, 2020-08-19

    Preserving Nature in New York City: NYC Parks’ Forever Wild Program

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    Urban biodiversity has increasingly been recognized as providing multiple local, regional, and even global benefits. In New York City (NYC), conservation and planning professionals in the Department of Parks and Recreation (NYC Parks) pursued biodiversity protection through the creation of a “Forever Wild” program in 2001, which designated and aimed to protect 8,700 acres of the largest, most ecologically valuable natural areas across City parkland. In 2018-2020, NYC Parks’ Natural Resources Group (NRG) expanded the program’s extent, resulting in 2,500 acres added to the Forever Wild program, for a total of over 12,300 acres. These additions reflect new acquisitions to the Parks system as well as an acknowledgment of the ecological importance of smaller patches of habitat. By prioritizing the conservation of habitat at the scale of the Parks system, the Forever Wild program enabled tackling some of the scale mismatches that often challenge urban ecosystem management. Over the past two decades, this program has highlighted the value of habitat conservation within NYC Parks, enabled the reduction of natural resource impacts from construction projects in or near Forever Wild areas, and included hundreds of acres of ecological restoration. At the same time, the program has faced constraints and challenges due to competing priorities for limited public land in NYC. Because the program does not confer any regulatory or statutory power, its effectiveness has waxed and waned under different administrations, each with their own priorities. To meet this challenge, NRG has aimed to make information about Forever Wild areas, the program, and its intent widely available within the agency and to the public. NRG has worked to coordinate with other parts of the agency to anticipate and better manage conflicts while protecting biodiversity. Still, upholding the program’s conservation goals in the face of continued threats remains an ongoing challenge. More recently, the need for outdoor recreation during the COVID pandemic has given new visibility to natural areas in NYC. NYC Parks will continue to rely on the Forever Wild program to care for these areas while also facilitating their appropriate use
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