Bifurcation analysis of a model of the budding yeast cell cycle

We study the bifurcations of a set of nine nonlinear ordinary differential equations that describe the regulation of the cyclin-dependent kinase that triggers DNA synthesis and mitosis in the budding yeast, Saccharomyces cerevisiae. We show that Clb2-dependent kinase exhibits bistability (stable steady states of high or low kinase activity). The transition from low to high Clb2-dependent kinase activity is driven by transient activation of Cln2-dependent kinase, and the reverse transition is driven by transient activation of the Clb2 degradation machinery. We show that a four-variable model retains the main features of the nine-variable model. In a three-variable model exhibiting birhythmicity (two stable oscillatory states), we explore possible effects of extrinsic fluctuations on cell cycle progression.Comment: 31 pages,13 figure

Ecological Disaster & Jacques Ellul’s Theological Vision

This paper will focus Jacques Ellul’s insights onto the manner in which our modern technological society is deeply ingrained in the subordination of both humanity and nature to efficient use. Ellul maintains that our way of life is characterised by structural instrumentalism, which is in turn underpinned by a distorted theological outlook. The paper asserts that these aforementioned factors together form the key drivers that propel us towards environmental desolation. This paper asserts that no adequate fine tuning of our present way of life will be possible to address issues such as climate change. What is needed instead is the comprehensive sociological and theological conversion of our society. This paper will conclude by tentatively exploring ways in which the church might proclaim and embody a prophetic message of repentance and conversion in this and other socio-cultural matters

Costly and discrete communication: An experimental investigation

Language is an imperfect and uneven means of communicating information about a complex and nuanced world. We run an experimental investigation of a setting in which the messages available to the sender imperfectly describe the state of the world, however the sender can improve communication, at a cost, by increasing the complexity or elaborateness of the message. As is standard in the communication literature, the sender learns the state of the world then sends a message to the receiver. The receiver observes the message and provides a best guess about the state. The incentives of the players are aligned in the sense that both sender and receiver are paid an amount which is increasing in the accuracy of the receiver's guess. As would be expected, we find that larger communication costs are associated with worse outcomes for both sender and receiver. Consistent with the communication literature, albeit in very different setting, we find that there is overcommunication. For the receiver, there is a positive relationship between the payoffs relative to the equilibrium predictions and communication costs. This relationship is negative for the senders. We also find that the response time of both the sender and receiver are positively related to their payoffs.communication; cheap talk; overcommunication

Anton Kannemeyer's Tactics of Translation as Critical Lens

Anton Kannemeyer (b.1967) is a white Afrikaner artist whose work engages with translation: subject matter culled from historical archives, comics, and the mass media is transposed into different languages, artistic mediums, and styles. Kannemeyer's artworks use translation as a means of returning to and interrogating traumatic, historical events. The beholder is prompted to (re)engage painful aspects of the past, approached from the critical distance allowed by the deferral implicit in translation. By re-encountering history in the gallery, the viewer must confront her memory and reconcile or interrogate disjunctions proposed in the space of Kannemeyer's work. Thus, with the re-imagining of events as translations in a new language, there is the possibility for a renewed investigation of received histories and a working over of traumas of the past