Learning from, through and about Differences: A Multiple Case Study on Schools as Practice Grounds for Citizenship

Learning to relate to others that differ from you is one of the central aims of citizenship education. Schools can be understood as practice grounds for citizenship, where students’ citizenship is not only influenced by the formal curriculum, but also by their experiences in the context of teacher-student and student-student relations. In this article we therefore investigate: How is the practice of dealing with difference enacted in schools? Data were collected through an exploratory multiple case study in four secondary schools, combining interviews and focus groups. Despite the differences between the schools in terms of population and location, in all schools ‘being different’ was understood primarily in relation to other students within the school. Relevant differences for citizenship were confined to ‘ethnic and cultural diversity’. Furthermore, in all schools there was limited reflection on being different in relation to the broader community. This article calls for preparing teachers to consider a broader array of differences to practice dealing with differences with their students and to support students in reflecting on the societal implications of being different from each other

How to suppress undesired synchronization

It is delightful to observe the emergence of synchronization in the blinking of fireflies to attract partners and preys. Other charming examples of synchronization can also be found in a wide range of phenomena such as, e.g., neurons firing, lasers cascades, chemical reactions, and opinion formation. However, in many situations the formation of a coherent state is not pleasant and should be mitigated. For example, the onset of synchronization can be the root of epileptic seizures, traffic congestion in communication networks, and the collapse of constructions. Here we propose the use of contrarians to suppress undesired synchronization. We perform a comparative study of different strategies, either requiring local or total knowledge of the system, and show that the most efficient one solely requires local information. Our results also reveal that, even when the distribution of neighboring interactions is narrow, significant improvement in mitigation is observed when contrarians sit at the highly connected elements. The same qualitative results are obtained for artificially generated networks as well as two real ones, namely, the Routers of the Internet and a neuronal network

Making Sense Through Participation

In this chapter we discuss the issue of social differences in relation to learning. In theories on co-operative learning or collaborative learning social differences are treated as characteristics of individual learners. The focus on learning as a social process is primarily elaborated in terms of interaction between pupils and the combined construction of knowledge. Sociocultural theory (Vygotsky, Lave & Wenger), however, understands ‘social’ not only in terms of knowledge/meaning being constructed in interaction with others, but also in terms of the cultural practices/activities informing these interaction processes. Learning can be understood as increasing participating in communities of practice. As social differences are an intrinsic part of the culture in which students are learning to participate, these are also an inherent aspect of learning processes in schools. Students learn to participate in practices in different ways, depending on their social position, and thus develop distinguished cultural identities. In this chapter we elaborate on this tenet, using examples from various empirical research projects on learning in secondary education. We not only show how social differences in the cultural practices that underpin learning influence what is learned by whom, but also explore the consequences of this perspective for the pedagogical space of the school

A Mathematical model for Astrocytes mediated LTP at Single Hippocampal Synapses

Many contemporary studies have shown that astrocytes play a significant role in modulating both short and long form of synaptic plasticity. There are very few experimental models which elucidate the role of astrocyte over Long-term Potentiation (LTP). Recently, Perea & Araque (2007) demonstrated a role of astrocytes in induction of LTP at single hippocampal synapses. They suggested a purely pre-synaptic basis for induction of this N-methyl-D- Aspartate (NMDA) Receptor-independent LTP. Also, the mechanisms underlying this pre-synaptic induction were not investigated. Here, in this article, we propose a mathematical model for astrocyte modulated LTP which successfully emulates the experimental findings of Perea & Araque (2007). Our study suggests the role of retrograde messengers, possibly Nitric Oxide (NO), for this pre-synaptically modulated LTP.Comment: 51 pages, 15 figures, Journal of Computational Neuroscience (to appear

Gap Junctions and Epileptic Seizures – Two Sides of the Same Coin?

Electrical synapses (gap junctions) play a pivotal role in the synchronization of neuronal ensembles which also makes them likely agonists of pathological brain activity. Although large body of experimental data and theoretical considerations indicate that coupling neurons by electrical synapses promotes synchronous activity (and thus is potentially epileptogenic), some recent evidence questions the hypothesis of gap junctions being among purely epileptogenic factors. In particular, an expression of inter-neuronal gap junctions is often found to be higher after the experimentally induced seizures than before. Here we used a computational modeling approach to address the role of neuronal gap junctions in shaping the stability of a network to perturbations that are often associated with the onset of epileptic seizures. We show that under some circumstances, the addition of gap junctions can increase the dynamical stability of a network and thus suppress the collective electrical activity associated with seizures. This implies that the experimentally observed post-seizure additions of gap junctions could serve to prevent further escalations, suggesting furthermore that they are a consequence of an adaptive response of the neuronal network to the pathological activity. However, if the seizures are strong and persistent, our model predicts the existence of a critical tipping point after which additional gap junctions no longer suppress but strongly facilitate the escalation of epileptic seizures. Our results thus reveal a complex role of electrical coupling in relation to epileptiform events. Which dynamic scenario (seizure suppression or seizure escalation) is ultimately adopted by the network depends critically on the strength and duration of seizures, in turn emphasizing the importance of temporal and causal aspects when linking gap junctions with epilepsy

Synchronous bursts on scale-free neuronal networks with attractive and repulsive coupling

This paper investigates the dependence of synchronization transitions of bursting oscillations on the information transmission delay over scale-free neuronal networks with attractive and repulsive coupling. It is shown that for both types of coupling, the delay always plays a subtle role in either promoting or impairing synchronization. In particular, depending on the inherent oscillation period of individual neurons, regions of irregular and regular propagating excitatory fronts appear intermittently as the delay increases. These delay-induced synchronization transitions are manifested as well-expressed minima in the measure for spatiotemporal synchrony. For attractive coupling, the minima appear at every integer multiple of the average oscillation period, while for the repulsive coupling, they appear at every odd multiple of the half of the average oscillation period. The obtained results are robust to the variations of the dynamics of individual neurons, the system size, and the neuronal firing type. Hence, they can be used to characterize attractively or repulsively coupled scale-free neuronal networks with delays.Comment: 15 pages, 9 figures; accepted for publication in PLoS ONE [related work available at http://arxiv.org/abs/0907.4961 and http://www.matjazperc.com/

Shunting Inhibition Controls the Gain Modulation Mediated by Asynchronous Neurotransmitter Release in Early Development

The sensitivity of a neuron to its input can be modulated in several ways. Changes in the slope of the neuronal input-output curve depend on factors such as shunting inhibition, background noise, frequency-dependent synaptic excitation, and balanced excitation and inhibition. However, in early development GABAergic interneurons are excitatory and other mechanisms such as asynchronous transmitter release might contribute to regulating neuronal sensitivity. We modeled both phasic and asynchronous synaptic transmission in early development to study the impact of activity-dependent noise and short-term plasticity on the synaptic gain. Asynchronous release decreased or increased the gain depending on the membrane conductance. In the high shunt regime, excitatory input due to asynchronous release was divisive, whereas in the low shunt regime it had a nearly multiplicative effect on the firing rate. In addition, sensitivity to correlated inputs was influenced by shunting and asynchronous release in opposite ways. Thus, asynchronous release can regulate the information flow at synapses and its impact can be flexibly modulated by the membrane conductance

Understanding Technology as Situated Practice: Everyday use of Voice User Interfaces Among Diverse Groups of Users in Urban India

Abstract: As smartphones have become ubiquitous across urban India, voice user interfaces (VUIs) are increasingly becoming part of diverse groups of users’ daily experiences. These technologies are now generally accessible as a result of improvements in mobile Internet access, [-8.5pc]Biography is Required. Please provide. introduction of low-cost smartphones and the ongoing process of their localisation into Indian languages. However, when people engage with technologies in their everyday lives, they not only enact the material attributes of the artifact but also draw on their skills, social positions, prior experience and societal norms and expectations to make use of the artifact. Drawing on Orlikowski’s analytical framework of “technologies-in-practice” we engage in an interview-based exploratory study among diverse groups of users in urban India to understand use of VUIs as situated practice. We identify three technologies-in-practice emerging through enactment of VUIs on users’ smartphones: looking up, learning and leisure. We argue that – instead of asking why and how users appropriate VUIs – identifying different kinds of enactments of VUIs present researchers and practitioners with a more nuanced understanding of existing and potential use of VUIs across varied contexts