4,211 research outputs found

    A note on the history of the Faculty of Law of the University of the Free State — NUNC PRO TUNC

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    From text: The year 2004 is the centenary of the University of the Free State. For any university to have survived for a century is nothing new in Europe or in North Africa, but in Sub-Saharan Africa it is a very impressive feat

    Complex maps without invariant densities

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    We consider complex polynomials f(z)=zℓ+c1f(z) = z^\ell+c_1 for ℓ∈2N\ell \in 2\N and c1∈Rc_1 \in \R, and find some combinatorial types and values of ℓ\ell such that there is no invariant probability measure equivalent to conformal measure on the Julia set. This holds for particular Fibonacci-like and Feigenbaum combinatorial types when ℓ\ell sufficiently large and also for a class of `long-branched' maps of any critical order.Comment: Typos corrected, minor changes, principally to Section

    Equilibrium states for potentials with \sup\phi - \inf\phi < \htop(f)

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    In the context of smooth interval maps, we study an inducing scheme approach to prove existence and uniqueness of equilibrium states for potentials Ï•\phi with he `bounded range' condition \sup \phi - \inf \phi < \htop, first used by Hofbauer and Keller. We compare our results to Hofbauer and Keller's use of Perron-Frobenius operators. We demonstrate that this `bounded range' condition on the potential is important even if the potential is H\"older continuous. We also prove analyticity of the pressure in this context.Comment: Added Lemma 6 to deal with the disparity between leading eigenvalues and operator norms. Added extra references and corrected some typo

    Seksuele teistering in die werkplek: ’n Suid-Afrikaanse perspektief

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    Sexual harassment in the workplace is a grave problem and it significantly impedes on a person’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 person’s personality and thus an iniurandi. The South African Constitution determines that there shall not be discriminated against any person and that includes a person’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

    Public perceptions of how to reduce carbon footprints of consumer food choices

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    Carbon footprints – the greenhouse gas (GHG) emissions associated with consumer food choices –substantially contribute to climate change. Life cycle analyses from climate and environmental sciences have identified effective rules for reducing these food-related carbon footprints, including eating seasonal produce and replacing dairy and red meat with plant-based products. In a national UK survey, we studied how many and which rules our participants generated for reducing GHG emissions of produce, dairy, and protein-rich products. We also asked participants to estimate GHG emission reductions associated with pre-selected rules, expressed in either grams or percentages. We found that participants generated few and relatively less effective rules, including ambiguous ones like 'Buy local'. Furthermore, participants' numerical estimates of pre-selected rules were less accurate when they assessed GHG emission reductions in grams rather than in percentages. Findings suggest a need for communicating fewer rules in percentages, for informing consumers about reducing food-related GHG emissions

    Checklists improve experts' diagnostic decisions

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    Context Checklists are commonly proposed tools to reduce error. However, when applied by experts, checklists have the potential to increase cognitive load and result in expertise reversal'. One potential solution is to use checklists in the verification stage, rather than in the initial interpretation stage of diagnostic decisions. This may avoid expertise reversal by preserving the experts' initial approach. Whether checklist use during the verification stage of diagnostic decision making improves experts' diagnostic decisions is unknown. Methods Fifteen experts interpreted 18 electrocardiograms (ECGs) in four different conditions: undirected interpretation; verification without a checklist; verification with a checklist, and interpretation combined with verification with a checklist. Outcomes included the number of errors, cognitive load, interpretation time and interpretation length. Outcomes were compared in two analyses: (i) a comparison of verification conditions with and without a checklist, and (ii) a comparison of all four conditions. Standardised scores for each outcome were used to calculate the efficiency of a checklist and to weigh its relative benefit against its relative cost in terms of cognitive load imposed, interpretation time and interpretation length. Results In both analyses, checklist use was found to reduce error (more errors were corrected in verification conditions with checklists [0.29 +/- 0.77 versus 0.03 +/- 0.61 errors per ECG], and fewer net errors occurred in all conditions with checklists [0.39 +/- 1.14 versus 1.04 +/- 1.49 errors per ECG];

    Comparison of large aperture scintillometer and eddy covariance measurements: Can thermal infrared data be used to capture footprint-induced differences?

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    Eddy covariance (EC) and large aperture scintillometer (LAS) measurements were collected over an irrigated olive orchard near Marrakech, Morocco. The tall, sparse vegetation in the experimental site was relatively homogeneous, but during irrigation events spatial variability in soil humidity was large. This heterogeneity caused large differences between the source area characteristics of the EC system and the LAS, resulting in a large scatter when comparing sensible heat fluxes obtained from LAS and EC. Radiative surface temperatures were retrieved from thermal infrared satellite images from the Landsat Enhanced Thematical Mapper and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellites. Using these images in combination with an analytical footprint model, footprint-weighted radiative surface temperatures for the footprints of the LAS and the EC system were calculated. Comparisons between the difference in measured sensible heat fluxes and the difference in footprint-weighted radiative surface temperature showed that for differences between the footprint-weighted radiative surface temperatures larger than 0.5 K, correlations with the difference in measured sensible heat flux were good. It was found that radiative surface temperatures, obtained from thermal infrared satellite imagery, can provide a good indication of the spatial variability of soil humidity, and can be used to identify differences between LAS and EC measurements of sensible heat fluxes resulting from this variability
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