Investigating the nature of epistemological access afforded by a first-year chemistry intervention programme : towards a pedagogy of possibility!

This paper describes a study motivated by a general concern to capture innovative and effective practice in higher education, supporting a move towards a ‘pedagogy of possibility’, ‘understanding who we are and what we do’, opening up ‘new ways of being in the university’ (Boughey, 2010). The research seeks to investigate the nature of epistemological access afforded by a first-year chemistry intervention programme, with an ultimate aim of contributing to the development of effective spaces for learning in higher education. The study is regarded as dynamic in terms of its emergence from, and its intended contribution to, practice. The outcome of this somewhat emergent process not only suggests relevant and useful insights into educational practice in higher education but also offers an appropriate and meaningful model for conducting research in higher education. This research contributes to the field both pedagogically as well as methodologically

An analysis of the influence of question design on pupils' approaches to number pattern generalisation tasks

This study is based on a qualitative investigation framed within an interpretive paradigm, and aims to investigate the extent to which question design affects the solution strategies adopted by children when solving linear number pattern generalisation tasks presented in pictorial and numeric contexts. The research tool comprised a series of 22 pencil and paper exercises based on linear generalisation tasks set in both numeric and 2-dimensional pictorial contexts. The responses to these linear generalisation questions were classified by means of stage descriptors as well as stage modifiers. The method or strategy adopted was carefully analysed and classified into one of seven categories. A meta-analysis focused on the formula derived for the nth term in conjunction with its justification. The process of justification proved to be a critical factor in being able to accurately interpret the origin of the sub-structure evident in many of these responses. From a theoretical perspective, the central role of justification/proof within the context of this study is seen as communication of mathematical understanding, and the process of justification/proof proved to be highly successful in providing a window of understanding into each pupil’s cognitive reasoning. The results of this study strongly support the notion that question design can play a critical role in influencing pupils’ choice of strategy and level of attainment when solving pattern generalisation tasks. Furthermore, this study identified a diverse range of visually motivated strategies and mechanisms of visualisation. An awareness and appreciation for such a diversity of visualisation strategies, as well as an understanding of the importance of appropriate question design, has direct pedagogical application within the context of the mathematics classroom

The heuristic significance of enacted visualisation

This study is centred on an analysis of pupils' lived experience while engaged in the generalisation of linear sequences/progressions presented in a pictorial context. The study is oriented within the conceptual framework of qualitative research, and is anchored within an interpretive paradigm. A case study methodological strategy was adopted, the research participants being the members of a mixed gender, high ability Grade 9 class of 23 pupils at an independent school in South Africa. The analytical framework is structured around a combination of complementary multiple perspectives provided by three theoretical ideas, enactivism, figural apprehension, and knowledge objectification. An important aspect of this analytical framework is the sensitivity it shows to the visual, phenomenological and semiotic aspects of figural pattern generalisation. It is the central thesis of this study that the combined complementary multiple perspectives of enactivism, figural apprehension and knowledge objectification provide a powerful depth of analysis to the exploration of the inter-relationship between the embodied processes of pattern generalisation and the visualisation of pictorial cues. The richly textured tapestry of activity captured through a multi-systemic semiotic analysis of participants' generalisation activity stands testament to this central thesis. Insights gleaned from this study are presented as practical strategies which support and encourage a multiple representational approach to pattern generalisation in the pedagogical context of the classroom

Interacting Frobenius Algebras are Hopf

Theories featuring the interaction between a Frobenius algebra and a Hopf algebra have recently appeared in several areas in computer science: concurrent programming, control theory, and quantum computing, among others. Bonchi, Sobocinski, and Zanasi (2014) have shown that, given a suitable distributive law, a pair of Hopf algebras forms two Frobenius algebras. Here we take the opposite approach, and show that interacting Frobenius algebras form Hopf algebras. We generalise (BSZ 2014) by including non-trivial dynamics of the underlying object---the so-called phase group---and investigate the effects of finite dimensionality of the underlying model. We recover the system of Bonchi et al as a subtheory in the prime power dimensional case, but the more general theory does not arise from a distributive law.Comment: 32 pages; submitte

Imaging memory in temporal lobe epilepsy: predicting the effects of temporal lobe resection

Functional magnetic resonance imaging can demonstrate the functional anatomy of cognitive processes. In patients with refractory temporal lobe epilepsy, evaluation of preoperative verbal and visual memory function is important as anterior temporal lobe resections may result in material specific memory impairment, typically verbal memory decline following left and visual memory decline after right anterior temporal lobe resection. This study aimed to investigate reorganization of memory functions in temporal lobe epilepsy and to determine whether preoperative memory functional magnetic resonance imaging may predict memory changes following anterior temporal lobe resection. We studied 72 patients with unilateral medial temporal lobe epilepsy (41 left) and 20 healthy controls. A functional magnetic resonance imaging memory encoding paradigm for pictures, words and faces was used testing verbal and visual memory in a single scanning session on a 3T magnetic resonance imaging scanner. Fifty-four patients subsequently underwent left (29) or right (25) anterior temporal lobe resection. Verbal and design learning were assessed before and 4 months after surgery. Event-related functional magnetic resonance imaging analysis revealed that in left temporal lobe epilepsy, greater left hippocampal activation for word encoding correlated with better verbal memory. In right temporal lobe epilepsy, greater right hippocampal activation for face encoding correlated with better visual memory. In left temporal lobe epilepsy, greater left than right anterior hippocampal activation on word encoding correlated with greater verbal memory decline after left anterior temporal lobe resection, while greater left than right posterior hippocampal activation correlated with better postoperative verbal memory outcome. In right temporal lobe epilepsy, greater right than left anterior hippocampal functional magnetic resonance imaging activation on face encoding predicted greater visual memory decline after right anterior temporal lobe resection, while greater right than left posterior hippocampal activation correlated with better visual memory outcome. Stepwise linear regression identified asymmetry of activation for encoding words and faces in the ipsilateral anterior medial temporal lobe as strongest predictors for postoperative verbal and visual memory decline. Activation asymmetry, language lateralization and performance on preoperative neuropsychological tests predicted clinically significant verbal memory decline in all patients who underwent left anterior temporal lobe resection, but were less able to predict visual memory decline after right anterior temporal lobe resection. Preoperative memory functional magnetic resonance imaging was the strongest predictor of verbal and visual memory decline following anterior temporal lobe resection. Preoperatively, verbal and visual memory function utilized the damaged, ipsilateral hippocampus and also the contralateral hippocampus. Memory function in the ipsilateral posterior hippocampus may contribute to better preservation of memory after surgery

Memory reorganization following anterior temporal lobe resection: a longitudinal functional MRI study

Anterior temporal lobe resection controls seizures in 50-60% of patients with intractable temporal lobe epilepsy but may impair memory function, typically verbal memory following left, and visual memory following right anterior temporal lobe resection. Functional reorganization can occur within the ipsilateral and contralateral hemispheres. We investigated the reorganization of memory function in patients with temporal lobe epilepsy before and after left or right anterior temporal lobe resection and the efficiency of postoperative memory networks. We studied 46 patients with unilateral medial temporal lobe epilepsy (25/26 left hippocampal sclerosis, 16/20 right hippocampal sclerosis) before and after anterior temporal lobe resection on a 3 T General Electric magnetic resonance imaging scanner. All subjects had neuropsychological testing and performed a functional magnetic resonance imaging memory encoding paradigm for words, pictures and faces, testing verbal and visual memory in a single scanning session, preoperatively and again 4 months after surgery. Event-related analysis revealed that patients with left temporal lobe epilepsy had greater activation in the left posterior medial temporal lobe when successfully encoding words postoperatively than preoperatively. Greater pre- than postoperative activation in the ipsilateral posterior medial temporal lobe for encoding words correlated with better verbal memory outcome after left anterior temporal lobe resection. In contrast, greater postoperative than preoperative activation in the ipsilateral posterior medial temporal lobe correlated with worse postoperative verbal memory performance. These postoperative effects were not observed for visual memory function after right anterior temporal lobe resection. Our findings provide evidence for effective preoperative reorganization of verbal memory function to the ipsilateral posterior medial temporal lobe due to the underlying disease, suggesting that it is the capacity of the posterior remnant of the ipsilateral hippocampus rather than the functional reserve of the contralateral hippocampus that is important for maintaining verbal memory function after anterior temporal lobe resection. Early postoperative reorganization to ipsilateral posterior or contralateral medial temporal lobe structures does not underpin better performance. Additionally our results suggest that visual memory function in right temporal lobe epilepsy is affected differently by right anterior temporal lobe resection than verbal memory in left temporal lobe epilepsy

Comparing computed tomography (CT) angiography versus digital subtraction angiography for the screening of traumatic pseudoaneurysms in transcranial stab injuries

Introduction: Transcranial stab injuries among the civilian population in South Africa are more common than in the West. In a study conducted in Durban, South Africa, in 1992, transcranial stab injuries accounted for 6% of all head injuries admitted to the neurosurgical unit. Digital subtraction angiography (DSA) has been the gold standard for diagnosing traumatic pseudoaneurysms. Its use as a screening tool is, however, limited and carries risks of neurological deficits. We postulate that the newer generation computed tomography (CT) scanner would serve as a better screening tool for traumatic pseudoaneurysms following transcranial stab injuries with the blade removed, provided the image quality is good. Methods: All patients admitted with a stab to the head with total calvarial penetration from September 2014 to January 2016 were included in the study. Those with a retained metallic fragment, incomplete imaging protocols, no penetration of the blade into the brain parenchyma or other causes of penetrating head injury were not included in the study. A retrospective chart review was then done on a prospectively recruited patient cohort. All CT angiograms were performed using a dual source CT scanner. Results: A total of 26 patients met the inclusion criteria. There were seven vascular injuries identified on DSA: three traumatic pseudoaneurysms and four vessel cut-offs. One traumatic pseudoaneurysm was missed on computed tomography angiography (CTA) because of a poor quality scan. The average sensitivity and specificity of CTA compared with DSA was 67% and 95.5%, respectively. Negative predictive value for CTA was 99.5%. Conclusion: A good quality CTA carried out on the newer generation CT scanners allows for use of CTA as a screening tool for patients with a transcranial stab injury and no retained blade or metallic foreign bodies

Ethanol down regulates the expression of myelin proteolipid protein in the rat hippocampus

It is well known that chronic ethanol treatment affects the synthesis of RNA and protein in the brain and the maintenance and function of nervous system. The changes in myelination-related genes are most prominent in human alcoholics. Previously, our cDNA microarray study showed altered Proteolipid protein (PLP), a major protein of central myelin. The present study aimed to gain more understanding of the expression of PLP after chronic ethanol treatment. Male Sprague-Dawley rats were daily treated with ethanol (15% in saline, 3 g/kg, i.p.) or saline for 14 days. Messenger RNAs from hippocampus of each group were subjected to cDNA expression array hybridization to determine the differential gene expressions. Among many ethanol responsive genes, PLP was negatively regulated by ethanol treatment, which is one of the most abundant proteins in the CNS and has an important role in the stabilization of myelin sheath. Using northern blot and immunohistochemical analysis, we showed the change in expression level of PLP mRNA and protein after ethanol treatment. PLP mRNA and protein were decreased in hippocampus of rat with chronic ethanol exposure, suggesting that ethanol may affect the stabilization of myelin sheath through the modulation of PLP expression and induce the pathophysiology of alcoholic brain

Categories of Quantum and Classical Channels (extended abstract)

We introduce the CP*-construction on a dagger compact closed category as a generalisation of Selinger's CPM-construction. While the latter takes a dagger compact closed category and forms its category of "abstract matrix algebras" and completely positive maps, the CP*-construction forms its category of "abstract C*-algebras" and completely positive maps. This analogy is justified by the case of finite-dimensional Hilbert spaces, where the CP*-construction yields the category of finite-dimensional C*-algebras and completely positive maps. The CP*-construction fully embeds Selinger's CPM-construction in such a way that the objects in the image of the embedding can be thought of as "purely quantum" state spaces. It also embeds the category of classical stochastic maps, whose image consists of "purely classical" state spaces. By allowing classical and quantum data to coexist, this provides elegant abstract notions of preparation, measurement, and more general quantum channels.Comment: In Proceedings QPL 2012, arXiv:1407.842