Evaluation of near-infrared spectroscopy in patients with acute coronary syndrome undergoing on and off-pump coronary artery bypass graft surgery

Thesis (M. Tech. (Clinical technology)) - Central University of technology, Free State, 2012The objective of this study was to investigate whether intra-operative regional cerebral tissue oxygen saturation (NIRS) and hemodynamic monitoring in patients with Acute Coronary syndrome (ACS) during coronary bypass graft surgery (CABG on-pump vs. off-pump) can predict clinical outcomes and complications. Data from 60 CABG patients (30 on-pump and 30 off-pump) were analyzed. The regional cerebral tissue oxygen saturation was monitored by using near-infrared spectroscopy (NIRS). The sensors were positioned in the middle of the patient's forehead and the cables were connected to the sensors and to the INVOS 5100C® Oximeter. According to NIRS values obtained, patients were subdivided into two groups. Patients in Group 1 had absolute NIRS values more than 50 or less than a 20% drop from the baseline value. Patients in Group 2 had absolute NIRS values of less than 50 or a drop of more than 20% from the baseline value. The lowest value recorded during the procedure was recorded for this purpose, irrespective of the time this value was obtained. Intra-operative hemodynamic monitoring was captured by a computer software program (Supplier Datex Ohmeda, South Africa). In order to describe surgical outcomes several parameters were analysed and compared. This included a Pre- and Post-operative Mini-Mental state examination that was performed to identify neurological outcomes or impairment. The NIRS values and trends in relation to renal function (U&E and creatinine, urine output, and urine electrolytes), as well as clinical outcomes were analyzed post-operatively for the different groups. Clinical outcomes were described using the Society of Thoracic Surgeons Database (STS database) data fields, and specifically the recording of complications. The overall clinical outcomes were analysed between the on-pump and off-pump groups as well as the NIRS results between the two groups. In order to elucidate the predictive role of NIRS the patients were divided into groups with either impaired /reduced NIRS values or acceptable NIRS values according to published results where a reduction of more than 20% from baseline or absolute values of less than 50 were associated with inferior outcomes. Finally, the predictive value of NIRS was evaluated within the on- and then the off-pump groups. In this analysis the outcomes of patients with reduced NIRS values was compared to those of patients with acceptable NIRS values. The study demonstrated that by far the majority of patients with reduced cerebral flow/oxygen delivery as reflected in cerebral NIRS, had on-pump CABG procedures (84% fell in risk group 2). It also showed that a NIRS reduction of more than 20 % from baseline and values of less than 50, has an impact on post–operative renal function. Monitoring of cerebral oximetry intra-operatively by using near-infrared spectroscopy during cardiac surgery (especially in on-pump cardiac surgery patients) allows the perfusionist and anaesthesiologist to detect cerebral desaturation and to intervene as necessary. This study also showed a tendency towards less renal function impairment in patients with absolute NIRS values > 50 or where there was < 20% drop from baseline. It is probably important to consider studying the time spend below 50 or a drop of more than 20% from baseline NIRS values, or the “area under the curve” as a specific factor contributing to the increased risk for post-operative complications applied on an increased study population. The study supports the routine use of NIRS as a non-invasive trend monitor of cerebral saturation and certainly initiated interventions by both anaesthetic and perfusion staff which contributed to excellent clinical outcomes in this research study

Human Development and Human Rights: South African Country Study

human development, human rights

The virus and the vaccine: curatorship and the disciplinary outsider

In the various departments of a university, researchers, lecturers and students exercise limitations on the objects or subjects they study through the disciplinary categorisations and processes they apply. These methods, taught in the curricula of their undergraduate programmes, promote a particular way of looking and of understanding that privileges certain characteristics over others. As students become assimilated into their respective academic communities, they become naturalised to the resulting biases, habits, norms and conventions and, subsequently, are unaware of lurking blind spots. This process limits the kinds of knowledge these disciplinary ‘insiders' are exposed to, and I argue that it can lead to the occlusion of ethical considerations, hinder discovery and perpetuate negative aspects of the hegemonic Western foundations of many of these disciplines. To support these claims, I focus on an object housed in the University of Cape Town (UCT) library, a Tabloid medicine chest. This chest has been rendered invisible in the library because it exhibits characteristics that fall outside of those privileged by the library's categorisation systems and its search engines. By conducting an object-study that delivers a wide range of findings – most quite separate from the chest's original intended use – the object becomes a prompt and a provocation to examine where else in the institution knowledge has been rendered invisible by insiders and their methods. I survey objects and collections resident in the departments of the university and discuss two collections in detail: the M.R. Drennan anatomical collection, actively used in science curricula, and the Kirby collection of indigenous instruments, almost invisible in its host department. These case studies illustrate how limits imposed by their respective insiders curtail the explanatory power of objects, limiting an understanding of the social and political pressures brought to bear on a discipline and that shape its practice. The case studies, particularly of the Drennan collection, also illustrate that outsider perspectives can help expose disciplinary limitations. The next part of this enquiry considers the outsider perspective as championed by a particular form of curatorship and artmaking introduced by lecturers at the Michaelis School of Fine Art at UCT in the 1990s. The exhibition making format and curatorial strategies introduced by these individuals are shown to be effective in revealing limitations placed on objects, in surfacing blind spots within the university and its affiliated museums and in opening up collections and their disciplines to outside perspectives. The effects of such exhibitions are traced as they reverberate in the university and culminate in the introduction of an interdisciplinary initiative focused on examining the university's knowledge archives, the instatement of an honours programme in curatorship and various departmental installations. Lastly, to elucidate what is at stake when an object is limited by the constraints of its host department and to showcase the potential of artmaking and curatorship in combating these limitations, the invisible chest in the library is subjected to a range of my own artmaking and curatorial strategies. This process is conceptualised as a shift from object-as-virus to object-as-vaccine. The methods I employ celebrate a much wider resonance of the object and extend the results revealed by the object-study at the start of this thesis

Russia's Heroes 1941-45/Albert Axell

CITATION: Liebenberg, I. 2011. Russia's Heroes 1941-45/Albert Axell. Scientia Militaria, South African Journal of Military Studies, 39(2):152-159, doi:10.5787/39-2-118.The original publication is available at http://scientiamilitaria.journals.ac.za/pubIt is seldom that one comes across a work where history-writing and qualitative research meet succinctly. Add to this an author who communicates crisply and relates real-life narratives that capture and hold the reader’s attention. This is such a work. The author read history but did more than that. Since 1960, Axell has interviewed dozens of veterans of all genders, from soldiers to marshals, who took part in the battles on the Eastern Front. Through his reading of history, close acquaintanceship with the Soviet Union and Russian-speaking society, and multiple interviews, Axell brings the experience of the individual and group up close and personal.http://scientiamilitaria.journals.ac.za/pub/article/view/118Publisher's versio

Analyticity: Boghossian on Quine

Abstract Analyticity: Boghossian on Quine In the wake of scepticism over the lucidity of the analytic/synthetic distinction, Paul Boghossian defends the distinction, albeit, the distinction between those statements which are synthetic, and those statements which are analytic in a specific kind of way. Boghossian holds that analytic statements are either metaphysically analytic (where the meaning of the terms in the statement determine the truth of the statement), or epistemically analytic (where knowledge of the meaning of the terms in the statement justifies our knowledge of the truth of the statement). Boghossian’s claim is that Quine is ambiguous regarding which kind of analyticity is the target of his attack in “Two Dogmas of Empiricism”, and that his failure to draw a distinction between different types of analyticity leads to his erroneous dismissal of both kinds of analyticity and their concomitant theories. His thought is that Quine was correct to dismiss the metaphysical notion of analyticity, and thus the linguistic theory of necessary truth; but mistaken in dismissing the epistemic notion of analyticity, and hence the analytic theory of the a priori. Within this paper, I offer an exposition of Quine’s arguments, as well as Boghossian’s replies, before critically discussing Boghossian’s arguments against metaphysical analyticity, as well as purported separation of metaphysical and epistemic analyticity

Cytotaxonomic studies in Themeda triandra. I. Chromosome numbers and microsporogenesis

Metaphase I pairing associations and chiasmata, as well as anaphase I laggard and chromatid bridge data were collected from 53 collections of Themeda triandra Forsk. The distribution pattern of the diploids, tetraploids, pentaploids and hexaploids confirms that which was found by previous authors. Diploids occurred mainly in the eastern and southern coastal areas, hexaploids on the highveld and tetraploids in between, but with some overlap. The meiosis analysis suggests that the majority of the polyploids are segmental allopolyploids and that different homeologous genomes occur in this polyploid complex. It is likely that a certain amount of karyotype differentiation must have occurred between different diploid populations of this species