107 research outputs found
Revitalisation of a historic building through performance evaluative research into workplace environmental conditions
Following the centennial celebrations of the University of the Free State in 2004, the need was identified to initiate a program according to which the image and future development of the university as a whole could be assessed. This included optimising the use of existing physical resources and prioritising on proposed new development. As part of this program, the historic Main Building was identified for revitalisation through an adaptive reuse program into office space for the executive management of the university. Completed in July 2005, the refurbished facility now provides an updated approach to the concept of workplace by providing a mix of private and open plan offices. In an attempt to introduce the concept of performance evaluative research in workplace environments to students of architecture at the University of the Free State, the revitalised Main Building workplace environment was regarded as a suitable example. Performance evaluative research in workplace environments is a form of evidence-based research which aims to assess the functionality and serviceability levels of a specific facility on the basis of its ability to support and facilitate diverse work styles, as well as the user-needs and -requirements associated with it. The evaluation process was conducted according to the principles of an Investigative-level Post-Occupancy Evaluation (POE) study, and aimed to assess the impact of stimuli from the workplace environment on the ability of users to optimally perform and accomplish work-related tasks. The methodology according to which information for this POE study was collected consisted of various surveys. This included an activity survey, an activity duration survey, a communication survey, and a movement survey. The POE study lasted one working day, with the various mapping surveys undertaken simultaneously in 15-minute periods with 5-minute rest and preparation intervals between them. Data collected in this manner thus provides a comprehensive view of all aspects pertaining to work performance and accomplishment in the specific office environment. The survey also included questionnaires distributed to all occupants of the workplace with a return rate of 86%. Conclusions drawn from results of this study have indicated the response of users to the new workplace environment in terms of their perception of the impact of the overall work environment on their ability to concentrate and perform work-related tasks. In this regard problems related to limited or inconvenient access to office resources and problems related to poor thermal comfort (specifically with regards to the penetration of direct sunlight and lack of control over air-conditioning) occurred with a similar frequency (N = 48; f = 0.15). Results of this study will:• serve as feedback for the continued alignment of the University’s physical resources with its dynamic resource management strategy — ; and• contribute to a database on work performance characteristics in South Africa
Die filosofie kan die teologie help om weg te beweeg van �n onhistoriese, sinkroniese interpretasie van tekste na �n historiese, diakroniese interpretasie van tekste
In the last few decades in South Africa, much emphasis has been placed on unhistorical, synchronistic interpretations of the text of the Old Testament. Very little effort has been made to look into the long historical development of the text from the sources to the present form. Sometimes the advocates of these synchronistic approaches even responded with hostility towards any approach that would, in their words, deny the authority of the text. Their search was for absolute truth, which they believed could be secured by their methods. The uncertainties of historical research were not attractive to them. In this article, we briefly look at Gerhard Von Rad�s Traditionsgeschichte [History of Traditions] and Hans-Georg Gadamer�s Wirkungsgeschichte [Reception History] and point out that mankind is rooted in history. We thus come to understanding through a process that is tied to our historical horisons. Furthermore, it will become clear that theology and philosophy can help one another in defining the process of understanding
Filosofie kan die teologie help om weg te beweeg van ‘n onhistoriese, sinkroniese interpretasie van tekste na ‘n historiese, diakroniese interpretasie van tekste
In the last few decades in South Africa, much emphasis has been placed on unhistorical,
synchronistic interpretations of the text of the Old Testament. Very little effort has been made to
look into the long historical development of the text from the sources to the present form.
Sometimes the advocates of these synchronistic approaches even responded with hostility
towards any approach that would, in their words, deny the authority of the text. Their search
was for absolute truth, which they believed could be secured by their methods. The uncertainties
of historical research were not attractive to them. In this article, we briefly look at Gerhard Von
Rad’s Traditionsgeschichte [History of Traditions] and Hans-Georg Gadamer’s Wirkungsgeschichte
[Reception History] and point out that mankind is rooted in history. We thus come to
understanding through a process that is tied to our historical horisons. Furthermore, it will become
clear that theology and philosophy can help one another in defining the process of understanding.J.H.L.R. (Universiteit van Pretoria) was die promotor en
P.H.J.L. (Universiteit van Pretoria) het die navorsing gedoen
en die manuskrip geskryf.http://www.ve.org.zahttp://upetd.up.ac.za/thesis/available/etd-05122012-124456
Holocene Atmospheric Mercury Levels Reconstructed from Peat Bog Mercury Stable Isotopes
Environmental regulations on mercury (Hg)emissions and associated ecosystem restoration are closely linked to what Hg levels we consider natural. It is widely accepted that atmospheric Hg deposition has increased by a factor 3 ± 1 since preindustrial times. However, no long-term historical records of actual atmospheric gaseous elemental Hg (GEM) concentrations exist. In this study we report Hg stable isotope signatures in Pyrenean peat records (southwestern Europe) that are used as tracers of Hg deposition pathway (Δ200Hg, wet vs dry Hg deposition) and atmospheric Hg sources and cycling (δ202Hg, Δ199Hg). By anchoring peatderived GEM dry deposition to modern atmospheric GEM levels we are able to reconstruct the first millennial-scale atmospheric GEM concentration record. Reconstructed GEM levels from 1970 to 2010 agree with monitoring data, and maximum 20th century GEM levels of 3.9 ± 0.5 ng m−3 were 15 ± 4 times the natural Holocene background of 0.27 ± 0.11 ng m−3. We suggest that a −0.7‰ shift in δ202Hg during the medieval and Renaissance periods is caused by deforestation and associated biomass burning Hg emissions. Our findings suggest therefore that human impacts on the global mercury cycle are subtler and substantially larger than currently thought
Recent 210 Pb, 137 Cs and 241 Am accumulation in an ombrotrophic peatland from Amsterdam Island (Southern Indian Ocean)
Over the past 50 years, 210Pb, 137Cs and 241Am have been abundantly used in reconstructing recent sediment and peat chronologies. The study of global aerosol-climate interaction is also partially depending on our understanding of 222Rn-210Pb cycling, as radionuclides are useful aerosol tracers. However, in comparison with the Northern Hemisphere, few data are available for these radionuclides in the Southern Hemisphere, especially in the South Indian Ocean. A peat core was collected in an ombrotrophic peatland from the remote Amsterdam Island (AMS) and was analyzed for 210Pb, 137Cs and 241Am radionuclides using an underground ultra-low background gamma spectrometer. The 210Pb Constant Rate of Supply (CRS) model of peat accumulations is validated by peaks of artificial radionuclides (137Cs and 241Am) that are related to nuclear weapon tests. We compared the AMS 210Pb data with an updated 210Pb deposition database. The 210Pb flux of 98 ± 6 Bq·m−2·y−1 derived from the AMS core agrees with data from Madagascar and South Africa. The elevated flux observed at such a remote location may result from the enhanced 222Rn activity and frequent rainfall in AMS. This enhanced 222Rn activity itself may be explained by continental air masses passing over southern Africa and/or Madagascar. The 210Pb flux at AMS is higher than those derived from cores collected in coastal areas in Argentina and Chile, which are areas dominated by marine westerly winds with low 222Rn activities. We report a 137Cs inventory at AMS of 144 ± 13 Bq·m−2 (corrected to 1969). Our data thus contribute to the under-represented data coverage in the mid-latitudes of the Southern Hemisphere
MIKE-SHE integrated groundwater and surface water model used to simulate scenario hydrology for input to DRIFT-ARID: the Mokolo River case study
A fully integrated, physically-based MIKE SHE/MIKE11 model was developed for the Mokolo River basin flow system to simulate key hydraulic and hydrologic indicator inputs to the Downstream Response to Imposed Flow Transformation for Arid Rivers (DRIFT-ARID) decision support system (DSS). The DRIFT-ARID tool is used in this study to define environmental water requirements (EWR) for non-perennial river flow systems in South Africa to facilitate ecosystembased management of water resources as required by the National Water Act (Act No. 36 of 1998). Fifty years of distributed daily climate data (1950 to 2000) were used to calibrate the model against decades of daily discharge data at various gauges, measurements of Mokolo Dam stage levels, and one-time groundwater level measurements at hundreds of wells throughout the basin. Though the calibrated model captures much of the seasonal and post-event stream discharge response characteristics, lack of sub-daily climate and stream discharge data limits the ability to calibrate the model to event-level system response (i.e. peak flows). In addition, lack of basic subsurface hydrogeologic characterisation and transient groundwater level data limits the ability to calibrate the groundwater flow model, and therefore baseflow response, to a high level. Despite these limitations, the calibrated model was used to simulate changes in hydrologic and hydraulic indicators at five study sites within the basin for five 50-year land-use change scenarios, including a present-day (with dam), natural conditions (no development/irrigation), and conversion of present-day irrigation to game farm, mine/city expansion, and a combination of the last two. Challenges and recommendations for simulating the range of non-perennial systems are presented.Keywords: hydrology, non-perennial, MIKE SHE, integrated surface and groundwater modellin
DRIFT-ARID: A method for assessing environmental water requirements (EWRs) for non-perennial rivers
Environmental water requirement (EWR) assessment methods, for ascertaining how much water should be retained in rivers to sustain ecological functioning and desired levels of biodiversity, have mostly been developed for perennial rivers. Despite non-perennial rivers comprising about 30–50% of the world’s freshwater systems, data on their hydrology, biota and ecological functioning are sparse. Current EWR assessments require hydrological and other data that may not be available for such rivers and some adaptation in the methods used seems necessary. DRIFT is an EWR method for perennial (or near-perennial) rivers that has been developed in South Africa over the past two decades and is now widely applied nationally and internationally. When applied to the semi-permanent Mokolo River, challenges particular to, or accentuated by, non-perennial rivers included the reliable simulation of hydrological data, the extent of acceptable extrapolation of data, difficulties in predicting surface-water connectivity along the river, and the location and resilience of pools, as well as whether it was possible to identify a reference (natural) condition. DRIFT-ARID, reported on here, is an adaptation of the DRIFT approach to begin addressing these and other issues. It consists of 11 phases containing 29 activities.Keywords: EWR, non-perennial, DRIFT, DS
Novel S-adenosyl-L-methionine decarboxylase inhibitors as potent antiproliferative agents against intraerythrocytic Plasmodium falciparum parasites
S-adenosyl-L-methionine decarboxylase (AdoMetDC) in the polyamine biosynthesis pathway has been
identified as a suitable drug target in Plasmodium falciparum parasites, which causes the most lethal form
of malaria. Derivatives of an irreversible inhibitor of this enzyme, 50-{[(Z)-4-amino-2-butenyl]methylamino}-
50-deoxyadenosine (MDL73811), have been developed with improved pharmacokinetic profiles
and activity against related parasites, Trypanosoma brucei. Here, these derivatives were assayed for
inhibition of AdoMetDC from P. falciparum parasites and the methylated derivative, 8-methyl-50-{[(Z)-
4-aminobut-2-enyl]methylamino}-50-deoxyadenosine (Genz-644131) was shown to be the most active.
The in vitro efficacy of Genz-644131 was markedly increased by nanoencapsulation in immunoliposomes,
which specifically targeted intraerythrocytic P. falciparum parasites.Department of Science and Technology through the South African Malaria Initiative, the University of Pretoria, the South African National Research Foundation and by grant BIO2011-25039 from the Ministerio de Economía y Competitividad, Spain, which
included FEDER funds, and 2009SGR-760 from the Generalitat de Catalunya, Spainhttp://www.elsevier.com/locate/ijpddrhb201
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