1,245 research outputs found

    Water resources in Botswana with particular reference to the savanna regions

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    Production and development in the savanna regions of southern Africa are primarily determined by interactions between the limitations imposed by ecological determinants (such as rainfall and soil quality) and the management strategies of the specific region. Good planning, focussing on both the short and long-term effects of water use, is needed in water management strategies. Botswana is already experiencing so-called 'water stress' which is related to a number of factors such as rapidly increasing population leading to a sharp increase in water demand, low and variable rainfall, high rates of evaporation, and the high cost of exploiting existing water resources. At the current rates of abstraction, the lifetime of surface and groundwater resources is limited to decades. Botswana shares four river basins with its neighbouring countries. This results in a situation where 94% of the fresh water resources which Botswana can theoretically access originates outside its borders, making water resource management highly complex. Transnational sharing and management of water resources, therefore, plays a major role in securing sustainability of this precious resource

    The response of the two interrelated river components, geomorphology and riparian vegetation, to interbasin water transfers in the Orange-Fish-Sundays River Interbasin Transfer Scheme

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    The Skoenmakers River (located in the semi-arid Karoo region of the Eastern Cape) is being used as a transfer route for water transferred by the Orange-Fish-Sundays River Interbasin Transfer Scheme. The change in the hydrological regime of this once ephemeral stream to a much bigger perennial river led to dramatic changes to both the physical structure and riparian vegetation structure of the river system. These changes differ for each of the three river sections, the upper,middle and lower reaches. Qualitative, descriptive geomorphological data was gathered by means of field observations and this was then compared to the quantitative data collected by means of surveyed cross-sectional profiles at selected sites along the length of both the regulated Skoenmakers River and a nonregulated tributary of equivalent size, the Volkers River. Riparian vegetation data was gathered by means of plot sampling along belt transects at each site. A qualitative assessment of the vegetation conditions was also made at each site and then added to the quantitative data from the plot sampling. At each site the different morphological units were identified along the cross-section and changes in the vegetation and sediment composition were recorded. Aerial photographs were used as additional sources of data and observations made from these were compared to data gathered in the field. The pre-IBT channel in this river section was formed by low frequency flood flows but the hydrological regime has now been converted to base flows much higher than normal flood flows. Severe incision, erosion and degradation of both the channel bed and banks occurred. In the lower reaches, post-IBT base flows are lower than pre-IBT flood flows and, due to the increased catchment area, the impact of the IBT was better ā€˜absorbedā€™ by the river system. Aggradation and deposition increased for the regulated river in comparison to the non-regulated river due to more sediment introduced The IBT had the greatest impact in the upper reaches of the regulated river due to more sediment introduced at the top of the system

    Garden footprint area and water use of gated communities in South Africa

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    Gated community homes in South Africa are popular amongst property buyers in urban environments such as cities and metropoles due to the  increased security and lifestyle improvements offered. Garden design and layout requirements are prescribed in architectural guidelines compiled by the homeowners associations of these communities. Garden footprint area in gated community homes is of importance to researchers and planners, because of the influence on water use. This study used a quantitative approach to evaluate the spatial data of garden footprint area as a percentage of total plot area for 1 813 gated community homes in different regions of South Africa. The research reviewed how garden footprint area is prescribed and how it is applied in gated community homes. The impact of garden footprint area on water use was also analysed. The results were compared to relevant information lifted from specific architectural design guidelines developed for each gated community. Data from 11 gated communities were analysed and the average garden footprint area was found to be 36% of the total plot area. Gated community homes with a garden area smaller than 100 m2 were found to have limited influence on monthly water consumption, while the water use of gated community homes with a larger garden footprint area increased proportionally with garden footprint area. The seasonal fluctuation of water use is illustrative of garden irrigation and other outdoor water use. The results provided useful input for incorporation in outdoor water use modelling of gated  community homes Keywords: garden irrigation household water consumption plot are

    Seksuele teistering in die werkplek: ā€™n Suid-Afrikaanse perspektief

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    Sexual harassment in the workplace is a grave problem and it significantly impedes on a personā€™s entrance into many sectors of the wage labour market. The number of sexual harassment complaints increases dramatically every year, although researchers estimate that 80 to 90% of sexual harassment cases go unreported. Despite the high figures, few South African court cases and legal literature deal with sexual harassment. The reason for this is that few persons who are harassed report a case for fear that they will lose their jobs or that they will become sources of ridicule.Sexual harassment is an infringement upon a personā€™s personality and thus an iniurandi. The South African Constitution determines that there shall not be discriminated against any person and that includes a personā€™s right to work without harassment and discrimination. It is therefore necessary that all employers ensure a safe environment without discrimination for all employees. Employers must adopt a policy on sexual harassment, communicate it to all employees and ensure that the policy be adhered to. If harassment does take place, the procedure and disciplinary process prescribed in the policy must be enforced

    Complete moduli of cubic threefolds and their intermediate Jacobians

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    The intermediate Jacobian map, which associates to a smooth cubic threefold its intermediate Jacobian, does not extend to the GIT compactification of the space of cubic threefolds, not even as a map to the Satake compactification of the moduli space of principally polarized abelian fivefolds. A much better "wonderful" compactification of the space of cubic threefolds was constructed by the first and fourth authors --- it has a modular interpretation, and divisorial normal crossing boundary. We prove that the intermediate Jacobian map extends to a morphism from the wonderful compactification to the second Voronoi toroidal compactification of the moduli of principally polarized abelian fivefolds --- the first and fourth author previously showed that it extends to the Satake compactification. Since the second Voronoi compactification has a modular interpretation, our extended intermediate Jacobian map encodes all of the geometric information about the degenerations of intermediate Jacobians, and allows for the study of the geometry of cubic threefolds via degeneration techniques. As one application we give a complete classification of all degenerations of intermediate Jacobians of cubic threefolds of torus rank 1 and 2.Comment: 56 pages; v2: multiple updates and clarification in response to detailed referee's comment

    A Multidimensional Approach to Pain Assessment in Critically Ill Infants During a Painful Procedure

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    Objectives: Inferring the pain level of a critically ill infant is complex. The ability to accurately extract the appropriate pain cues from observations is often jeopardized when heavy sedation and muscular blocking agents are administered. Near-infrared spectroscopy is a noninvasive method that may provide the bridge between behavioral observational indicators and cortical pain processing. We aimed to describe regional cerebral and systemic hemodynamic changes, as well as behavioral reactions in critically ill infants with congenital heart defects during chest-drain removal after cardiac surgery. Methods: Our sample included 20 critically ill infants with congenital heart defects, less than 12 months of age, admitted to the cardiac intensive care unit after surgery. Results: Cerebral deoxygenated hemoglobin concentrations significantly differed across the epochs (ie, baseline, tactile stimulus, noxious stimulus) (P=0.01). Physiological systemic responses and Face Leg Activity Cry Consolability (FLACC) pain scores differed significantly across the events (P<0.01). The 3 outcome measures were not found to be associated with each other. Mean FLACC pain scores during the painful procedure was 7/10 despite administration of morphine. Midazolam administration accounted for 36% of the variance in pain scores. Discussion: We demonstrated with a multidimensional pain assessment approach that significant cerebral, physiological, and behavioral activity was present in response to a noxious procedure in critically ill infants despite the administration of analgesic treatment. Considering that the sedating agent significantly dampened pain behaviors, assessment of cerebral hemodynamic in the context of pain seems to be an important addition.National Institutes of Health (U.S.) (Grant R01EB001659)National Institutes of Health (U.S.) (Grant K24NS057568)National Institutes of Health (U.S.) (Grant R21HD056009)National Institute for Biomedical Imaging and Bioengineering (U.S.)National Institute of Neurological Disorders and Stroke (U.S.)Eunice Kennedy Shriver National Institute of Child Health and Human Development (U.S.

    New age constraints on metamorphism, metasomatism and gold mineralisation at Plutonic Gold Mine, Marymia Inlier, Western Australia

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    The Plutonic Well Greenstone Belt (PWGB) is located in the Marymia Inlier between the Yilgarn and Pilbara cratons in Western Australia, and hosts a series of major Au deposits. The main episode of Au mineralisation in the PWGB was previously interpreted to have either accompanied, or shortly followed, peak metamorphism in the late Archean at ca 2650 Ma with a later, minor, event associated with the Capricorn Orogeny. Here we present new Pb isotope model ages for sulfides and Rbā€“Sr ages for mica, as well as a new 207Pbā€“206Pb age for titanite for samples from the Plutonic Gold Mine (Plutonic) at the southern end of the PWGB. The majority of the sulfides record Proterozoic Pb isotope model ages (2300ā€“2100 Ma), constraining a significant Au mineralising event at Plutonic that occurred >300 Myr later than previously thought. A Rbā€“Sr age of 2296 Ā± 99 Ma from muscovite in an Au-bearing sample records resetting or closure of the Rbā€“Sr system in muscovite at about the same time. A younger Rbā€“Sr age of 1779 Ā± 46 Ma from biotite from the same sample may record further cooling, or resetting during a late-stage episode of metasomatism in the PWGB. This could have been associated with the 1820ā€“1770 Ma Capricorn Orogeny, or a late-stage hydrothermal event potentially constrained by a new 207Pbā€“206Pb age of 1725 Ā± 26 Ma for titanite in a chloriteā€“carbonate vein. This titanite age correlates with a pre-existing age for a metasomatic event dated at 1719 Ā± 14 Ma by Uā€“Pb ages of zircon overgrowths in a sample from the Marymia Deposit. Based on the Pb-isotope data presented here, Au mineralising events in the PWGB are inferred to have occurred at ca 2630, 2300ā€“2100 Ma, during the Glenburgh and Capricorn orogenies, and 1730ā€“1660 Ma. The 2300ā€“2100 Ma event, which appears to have been significant based on the amount of sulfide of this age, correlates with the inferred age for rifting of the Marymia Inlier from the northern margin of the Yilgarn Craton. The texturally-later visible Au may have been deposited during the Glenburgh and Capricorn orogenies

    Berg adder (Bitis atropos): An unusual case of acute poisoning

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    A 5-year-old boy presented to hospital with mild local cytotoxic and severe neurotoxic symptoms. The neurotoxic symptoms included ptosis, fixed dilated pupils and flaccid paralysis with respiratory failure. Mild hyponatraemia was also a clinical feature. After various unsuccessful treatment options were followed, the Tygerberg Poison Information Centre was contacted and a diagnosis of berg adder bite was made. Berg adder bites are uncommon and therefore not usually considered in the differential diagnosis of a patient presenting with an unexplained clinical picture. A timeous poison information helpline consultation is recommended in this situation

    The management side of talent : causal implications for the retention of generation Y employees

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    Organisations are facing significant challenges to retain Generation Y employees. Research shows that, once these individuals are employed, they are not likely to remain in that position for very long. Organisations therefore need to find innovative solutions to retain this group of employees. The purpose of this research was to determine the causal relationship between management support towards talent management and the impact thereof on the turnover intentions of Generation Y employees. The Human Capital Index, Perceived Organisational Support Questionnaire, Perceived Organisational Support and Intention to Quit questionnaires were administered among a convenience sample of generation Y employees (N=135). The results showed that Perceived Organisational Support is significantly related to Talent management practices, Perceived Supervisor Support and Intention to Quit. Perceived Supervisor Support is significantly related to Talent management practices and Intention to Quit. Talent management practices are significantly related to intention to quit. Recommendations are made.http://www.cluteinstitute.com/journals/journal-of-applied-business-research-jabram2016Human Resource Managemen

    Baseline adjustment methodology in a shared water savings contract under serious drought conditions

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    CITATION: Jacobs, H. E. et al. 2020. Baseline adjustment methodology in a shared water savings contract under serious drought conditions. Water SA, 46(1):22-29, doi:10.17159/wsa/2020.v46.i1.7874.The original publication is available at: http://www.scielo.org.zaENGLISH ABSTRACT: Baselines are often employed in shared water saving contracts for estimating water savings after some type of intervention by the water service company. An adjustment to the baseline may become necessary under certain conditions. Earlier work has described a number of relatively complex methods for baseline determination and adjustment, but application in regions faced with relatively limited data becomes problematic. If the adjustment were determined before finalising the contractual matters, it would be possible to gather the required data in order to determine the adjustment. However, in cases where no adjustment was fixed prior to the contract, a method is required to determine an adjustment mid-contract based on whatever data are available at the time. This paper presents a methodology for baseline adjustment in an existing shared water savings contract and explains how adjustment could be determined mid-contract, under conditions of limited data. The adjustment compensates for expected reduced water consumption due to external influences induced by serious water restrictions, typically introduced during periods of drought. The fundamental principle underpinning the baseline adjustment methodology presented in this paper involved segregating real water losses from the actual consumption of end-users, preferably by analysing the minimum night flow. In the absence of recorded night flows, an alternative procedure involving the minimum monthly consumption pre- and post-baseline was employed. The baseline adjustment method was subsequently applied in a South African case study, reported on separately. This technique is helpful because adjustments could be determined without adding unnecessary complexity or cost, and provides a means to resolve disputes in cases where unexpected savings occur mid-contract.Publisher's versio
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