Private Standards and Employment Insecurity: GlobalGAP in the Senegalese Horticulture Export Sector

Crop Production/Industries, International Relations/Trade, Labor and Human Capital,

Clinical Studies in Scanning Laser Polarimetry

Glaucoma is the second leading cause of irreversible blindness worldwide. When left untreated, glaucoma results in visual field loss and eventually in blindness. In considering the diagnosis of glaucoma, the physician will evaluate the intraocular pressure, the optic nerve head and the visual field. This seems to be a straightforward diagnostic process, but, surprisingly, there is still no consensus on the criteria for the signs on which the diagnosis is based. Glaucoma is a progressive optic neuropathy characterized by death of retinal ganglion cells. The course of events that eventually leads to death of these cells is not exactly known, but the retinal nerve fiber layer, which is made up of the axons of the retinal ganglion cells, thins. Scanning laser polarimetry is an imaging technique that can detect glaucoma by assessing the thickness of the retinal nerve fiber layer. Scanning laser polarimetry came onto the market in 1993. The working principle is based on the fact that in the nerve fiber layer a phase shift occurs in polarized laser light that is sent through the nerve fiber layer. This so called retardation is thought to be linearly correlated with nerve fiber layer thickness. In the past, scanning laser polarimetry has shown to discriminate well between normal and glaucomatous eyes. The goal of this thesis was to investigate the clinical performance of the GDx (a revised version of the first scanning laser polarimeter, the Nerve Fiber Analyzer). In summary, the GDx provides fast, objective and quantitative data on nerve fiber layer thickness. The applicability and reproducibility of measurements are high and the image acquisition is user and patient friendly. The GDx yields useful sensitivity and specificity values for the detection of glaucoma, whereas its role in follow-up remains to be investigated. As it stands, the GDx holds insufficient validity to serve as a single test for glaucoma. It does, however, provide a very useful addition to the existing tests we run in patients to make the correct diagnosis

Dissimilatory nitrogen reduction in intertidal sediments of a temperate estuary: small scale heterogeneity and novel nitrate-to-ammonium reducers

The estuarine nitrogen cycle can be substantially altered due to anthropogenic activities resulting in increased amounts of inorganic nitrogen (mainly nitrate). In the past, denitrification was considered to be the main ecosystem process removing reactive nitrogen from the estuarine ecosystem. However, recent reports on the contribution of dissimilatory nitrate reduction to ammonium (DNRA) to nitrogen removal in these systems indicated a similar or higher importance, although the ratio between both processes remains ambiguous. Compared to denitrification, DNRA has been underexplored for the last decades and the key organisms carrying out the process in marine environments are largely unknown. Hence, as a first step to better understand the interplay between denitrification, DNRA and reduction of nitrate to nitrite in estuarine sediments, nitrogen reduction potentials were determined in sediments of the Paulina polder mudflat (Westerschelde estuary). We observed high variability in dominant nitrogen removing processes over a short distance (1.6m) with nitrous oxide, ammonium and nitrite production rates differing significantly between all sampling sites. Denitrification occurred at all sites, DNRA was either the dominant process (two out of five sites) or absent, while nitrate reduction to nitrite was observed in most sites but never dominant. In addition, novel nitrate-to-ammonium reducers assigned to Thalassospira, Celenbacter, and Halomonas, for which DNRA was thus far unreported, were isolated, with DNRA phenotype reconfirmed through nrfA gene amplification. This study demonstrates high small scale heterogeneity among dissimilatory nitrate reduction processes in estuarine sediments and provides novel marine DNRA organisms that represent valuable alternatives to the current model organisms

Book review. Simon Robertson. Nietzsche and contemporary ethics. Oxford: Oxford University press, 2020. 402 pp

[Excerpt] This new book by Simon Robertson reveals an impressive mastery of the subject. His previous research and his teaching as a lecturer at Cardiff University encompass contemporary ethical theories, theories of normativity and, perhaps paradoxically, Nietzsche’s thought. He was the co-editor, with Christopher Janaway, of Nietzsche, Naturalism, and Normativity, published in 2012 by Oxford University Press, an essay collection whose focus is to explain how Nietzsche’s naturalism can be integrated into a normative framework

Dispensing with truthfulness: truth and liberty in Rorty’s thought

Rorty saw the course of philosophy in the twentieth century as an effort to part from two major philosophical trends, namely historicism and naturalism, only to inevitably return at the end of a tortuous path to these very same tendencies. If we can concede without major objections (although perhaps with many objections of detail) Rorty’s diagnosis of the trends in contemporary continental and analytical philosophy, which seem to reveal the exhaustion of modern philosophy, based as it has been on epistemology, we must, on the other hand, examine carefully the three main questions that this diagnosis leaves open: (1) How does Rorty reconcile continental idealist subjectivism with materialistic behaviorism? (2) Is it really inevitable that philosophy (and philosophers) blinded by Geist are unable to question prevalent beliefs? (3) Finally, is the acceptance of a liberalism that is not able to give reasons for itself the most effective and pragmatic liberalism? In answering these questions, it may not be possible to avoid a non-dogmatic, but pragmatic, metaphysics: a vocabulary of vocabularies that allows Rorty (and us) to speak of the problems of justice in Plato and Rawls, of the soul in Aristotle and Descartes, of the dystopias in Moro and Orwell. On pragmatic terms, perhaps a modest version of a metaphysic’s “vocabulary” turns out to be as legitimate and practical as any other vocabulary