The prevalence of cheating in National Standardised Assessments in South African schools : applying the Jacob and Levitt (2003) method to the Annual National Assessments of 2013

This paper builds on the underlying framework of Jacob and Levitt (2003) and further work by Gustafsson (2014) to determine the prevalence of cheating in South African schools using a nationally representative sample (Verification ANA) of the Annual National Assessments of 2013. This research forms part of a broader research project on 'binding constraints in education' promoted by the Programme to Support Pro-poor Policy Development (PSPPD), housed at Stellenbosch University. The adapted methodology is verified in order to ensure that the suspicious string indicators as discovered by Jacob and Levitt are indeed indicative of suspicious behaviour when applied to the South African ANA. At a national level, the data suggests that cheating or suspicious behaviour is likely to be prevalent in up to 10 percent of schools with respect to Mathematics and Language in Grades 3 and 6. The manner in which schools behave suspiciously varies significantly by province, subject and measure. As many as 37% of primary schools in the Eastern Cape, 26% of primary schools in KwaZulu-Natal and 24% of primary schools in Limpopo show some evidence of cheating in Grade 3 mathematics, compared to just 0% to 2% of primary schools in the Western Cape and Gauteng. Similar extremes are noted in the Grade 6 results. These results suggest that the mere act of assessment and measurement induces behavioural distortions such as gaming behaviour even in the absence of high-stakes

Immobilized photosensitizers for antimicrobial applications

Photodynamic antimicrobial chemotherapy (PACT) is a very promising alternative to conventional antibiotics for the efficient inactivation of pathogenic microorganisms; this is due to the fact that it is virtually impossible for resistant strains to develop due to the mode of action employed. PACT employs a photosensitizer, which preferentially associates with the microorganism, and is then activated with non-thermal visible light of appropriate wavelength(s) to generate high localized concentrations of reactive oxygen species (ROS), inactivating the microorganism. The concept of using photosensitizers immobilized on a surface for this purpose is intended to address a range of economic, ecological and public health issues. Photosensitising molecules that have been immobilized on solid support for PACT applications are described herein. Different supports have been analyzed as well as the target microorganism and the effectiveness of particular combinations of support and photosensitiser

Causal selection and the pathway concept

Causal selection has to do with a distinction between mere background conditions and the "true" cause or causes of some outcome of interest. Most philosophical work on this topic examines the selection of single causal factors and aims to clarify what grounds, if any, justify this selection. Such analyses overlook the fact that in scientific (and often ordinary life) contexts multiple factors are often selected as the important causes of some outcome. This analysis examines one such multicausal case where factors in causal pathways are selected in biological explanations. This work provides a novel analysis of the pathway concept, its role in causal selection, and the rationale behind this selection. It is argued that this rationale is guided by principled considerations, which have been overlooked in the extant literature

Causal selection in biochemistry: Making things by making things happen

Causal selection has to do with a distinction between mere background conditions and the "true" causes of some outcome of interest. Mainstream philosophical views claim that causal selection is "groundless" in the sense that it lacks any type of principled rationale (Schaffer 2016; Mill 1874; Lewis 1986). I argue against this position in the context of biochemistry where causal factors are selected in explanations of metabolic processes. These factors are selected on the basis of a principled rationale, which is best understood in terms of the causal control that they provide over an outcome of interest

Causal selection in biochemistry: Making things by making things happen

Causal selection has to do with a distinction between mere background conditions and the "true" causes of some outcome of interest. Mainstream philosophical views claim that causal selection is "groundless" in the sense that it lacks any type of principled rationale (Schaffer 2016; Mill 1874; Lewis 1986). I argue against this position in the context of biochemistry where causal factors are selected in explanations of metabolic processes. These factors are selected on the basis of a principled rationale, which is best understood in terms of the causal control that they provide over an outcome of interest

Distinguishing topological and causal explanation

Recent philosophical work has explored the distinction between causal and non-causal forms of explanation. In this literature, topological explanation is viewed as a clear example of the non- causal variety–it is claimed that topology lacks temporal information, which is necessary for causal structure (Pincock 2012; Huneman 2010). This paper explores the distinction between topological and causal forms of explanation and argues that this distinction is not as clear cut as the literature suggests. One reason for this is that some explanations involve both topological and causal information. In these “borderline” cases scientists explain some outcome by appealing to the causal topology of the system of interest. These cases help clarify a type of topological ex- planation that is genuinely causal, but that differs from standard topological and interventionist accounts of explanation (Woodward 2003)

The Doctrine of Specific Etiology

Modern medicine is often said to have originated with nineteenth century germ theory, which attributed diseases to bacterial contagions. The success of this theory is often associated with an underlying principle referred to as the “doctrine of specific etiology.” This doctrine refers to specificity at the level of disease causation or etiology. While the importance of this doctrine is frequently emphasized in the philosophical, historical, and medical literature, these sources lack a clear account of the types of specificity that it involves and why exactly they matter. This paper argues that the nineteenth century germ theory model involves two types of specificity at the level of etiology. One type receives significant attention in the literature, but its influence on modern medicine has been misunderstood. A second type is present in this model, but it has been completely overlooked in the extant literature. My analysis clarifies how these types of specificity led to a novel conception of etiology that continues to figure in medicine today