Evaluating Opportunities When People are Uncertainty Averse

We consider the problem of ranking sets of alternatives. Standard approaches to this problem regard the addition of an alternative to a set containing one element as enhancing choice. We argue that this monotonicity axiom may not be desirable when an agent is uncertain as to the value of this additional alternative. We replace monotonicity with an uncertainty aversion axiom, and also introduce an axiom that produces lexicographic behaviour. These axioms, in conjunction with an independence axiom, enable us to prove a characterisation theorem. This theorem says that sets are ranked in terms of the number of uncertain elements that they contain, the fewer the better. This is the only ranking rule that satisfies our axioms.

U.S Presidential Elections and the Referendum Paradox*

In the United States, the president is elected by the Electoral Col- lege (EC) and not directly by individual voters. This can give rise to a so-called referendum paradox in which one candidate receives more popular votes than any other, but this candidate is not elected. The 2000 election is an example of this phenomenon. Can the EC be reformed so that a referendum paradox never arises? We consider vary- ing three natural parameters. First, we consider changing the method of apportioning seats in the House of Representatives to states. Sec- ond, we consider changing the total number of seats in the House. Intuition suggests that as the number of seats approaches the number

The size of the House of Representatives, not the American people, can determine the outcome of presidential elections

After the 2000 presidential election, in which Al Gore won the majority of the popular vote, but not the election, there have been perennial discussions of the merit of using the Electoral College to elect the President. Fabrice Barthélémy, Mathieu Martin, and Ashley Piggins examine the so-called “referendum paradox” that resulted in the Bush victory and its effect on other presidential elections. They show that because of the Electoral College, the arbitrary size of the House of Representatives, not the voters, can determine the outcome of a presidential election

Ferguson shows us that in contemporary America, black citizenship is not comparable to that of others and life is not secure or guaranteed

Late on Friday evening, a Grand Jury in Ferguson Missouri reached a decision not to indict police officer Darren Wilson in the killing of a black teenager, Mike Brown, in August. Shana Redmond writes that the decision is another example of the system acting to preserve itself at the expense of black communities. In the aftermath of the decision, which has seen widespread protests, state officials and police have reacted by asserting their commitment to the protection of property, rather than engaging with the protestors or their concerns. With protests spreading to other cities, she argues that for many, the events in Ferguson have become a symbol of the daily brutality of racism in America

Even without ‘Senate’ electoral votes, the size of the U.S. House of Representatives could still determine the outcome of presidential elections

Earlier this year on this blog, Fabrice Barthélémy, Mathieu Martin, and Ashley Piggins showed that under the Electoral College system, the arbitrary size of the House of Representatives, not the voters, can determine the outcome of a presidential election. They referred to work by Nicholas R. Miller to explain this ‘House size effect.’ Here he further explores the issue and writes that, even without ‘Senate’ electoral votes, the winner of the electoral vote could still depend on the size of the House

Dietary fat and corticosterone levels are contributing factors to meal anticipation

Daily restricted access to food leads to the development of food anticipatory activity and metabolism, which depends upon an as yet unidentified food-entrainable oscillator(s). A premeal anticipatory peak in circulating hormones, including corticosterone is also elicited by daily restricted feeding. High-fat feeding is associated with elevated levels of corticosterone with disrupted circadian rhythms and a failure to develop robust meal anticipation. It is not clear whether the disrupted corticosterone rhythm, resulting from high-fat feeding contributes to attenuated meal anticipation in high-fat fed rats. Our aim was to better characterize meal anticipation in rats fed a low- or high-fat diet, and to better understand the role of corticosterone in this process. To this end, we utilized behavioral observations, hypothalamic c-Fos expression, and indirect calorimetry to assess meal entrainment. We also used the glucocorticoid receptor antagonist, RU486, to dissect out the role of corticosterone in meal anticipation in rats given daily access to a meal with different fat content. Restricted access to a low-fat diet led to robust meal anticipation, as well as entrainment of hypothalamic c-Fos expression, metabolism, and circulating corticosterone. These measures were significantly attenuated in response to a high-fat diet, and animals on this diet exhibited a postanticipatory rise in corticosterone. Interestingly, antagonism of glucocorticoid activity using RU486 attenuated meal anticipation in low-fat fed rats, but promoted meal anticipation in high-fat-fed rats. These findings suggest an important role for corticosterone in the regulation of meal anticipation in a manner dependent upon dietary fat content

Vertex importance extension of betweenness centrality algorithm

Variety of real-life structures can be simplified by a graph. Such simplification emphasizes the structure represented by vertices connected via edges. A common method for the analysis of the vertices importance in a network is betweenness centrality. The centrality is computed using the information about the shortest paths that exist in a graph. This approach puts the importance on the edges that connect the vertices. However, not all vertices are equal. Some of them might be more important than others or have more significant influence on the behavior of the network. Therefore, we introduce the modification of the betweenness centrality algorithm that takes into account the vertex importance. This approach allows the further refinement of the betweenness centrality score to fulfill the needs of the network better. We show this idea on an example of the real traffic network. We test the performance of the algorithm on the traffic network data from the city of Bratislava, Slovakia to prove that the inclusion of the modification does not hinder the original algorithm much. We also provide a visualization of the traffic network of the city of Ostrava, the Czech Republic to show the effect of the vertex importance adjustment. The algorithm was parallelized by MPI (http://www.mpi-forum.org/) and was tested on the supercomputer Salomon (https://docs.it4i.cz/) at IT4Innovations National Supercomputing Center, the Czech Republic.808726

Powering Rural Transformation: Solar PV in Rural Uganda.

The intent of this study was to understand the role that solar PV plays in the process of rural electrification, what barriers exist in the PV market, and how the Rural Electrification Agency is bringing down those barriers. Moreover, I sought to understand solar PV’s development impact in rural areas and how people in rural regions of Uganda are using the technology, especially those at the bottom of the economic pyramid. Additionally, I sought to understand if PV is a financially viable option for the rural poor or if it is only obtainable by the rural upper and middle class. Consequently, I interned with the Rural Electrification Agency (REA) in the ERT program, specifically with the solar PV department. While at REA, I interviewed people from many departments in order to understand the bigger picture of RE and what role PV plays in the process. I also took part in an end-user audit induction and worked with a team of end-user auditors on an audit journey to the West Nile region. Additionally, as part of my internship, I sat in on meetings, looked over previous audit reports and reviewed REA policy documents. I discovered that PV plays a subsidiary role in the process of RE. I also discovered that the subsidy program for solar PV run by REA has been largely ineffective at meeting its goals. Likewise, PV has struggled to reach people at the bottom of the pyramid and caters mostly to the rural upper and middle classes. The systems advanced by REA are often not well marketed and are too expensive for the rural poor

Circadian Disruptions in the Myshkin Mouse Model of Mania are Independent of Deficits in Suprachiasmatic Molecular Clock Function

Background Alterations in environmental light and intrinsic circadian function have strong associations with mood disorders. The neural origins underpinning these changes remain unclear, although genetic deficits in the molecular clock regularly render mice with altered mood-associated phenotypes. Methods A detailed circadian and light-associated behavioral characterization of the Na+/K+-ATPase (NKA) α3 Myshkin (Myk/+) mouse model of mania was performed. NKA α3 does not reside within the core circadian molecular clockwork, but Myk/+ mice exhibit concomitant disruption in circadian rhythms and mood. The neural basis of this phenotype was investigated through molecular and electrophysiological dissection of the master circadian pacemaker, the suprachiasmatic nuclei (SCN). Light input and glutamatergic signalling to the SCN were concomitantly assessed through behavioral assays and calcium imaging. Results In vivo assays revealed several circadian abnormalities including lengthened period and instability of behavioral rhythms, and elevated metabolic rate. Grossly aberrant responses to light included accentuated resetting, accelerated re-entrainment and an absence of locomotor suppression. Bioluminescent recording of circadian clock protein (PER2) output from ex vivo SCN revealed no deficits in Myk/+ molecular clock function. Optic-nerve crush rescued the circadian period of Myk/+ behavior, highlighting that afferent inputs are critical upstream mediators. Electrophysiological and calcium imaging SCN recordings demonstrated changes in response to glutamatergic stimulation as well as electrical output indicative of altered retinal input processing. Conclusions The Myshkin model demonstrates profound circadian and light-responsive behavioral alterations independent of molecular clock disruption. Afferent light-signaling drives behavioral changes and raises new mechanistic implications for circadian disruption in affective disorders

Global parameter search reveals design principles of the mammalian circadian clock

Background: Virtually all living organisms have evolved a circadian (~24 hour) clock that controls physiological and behavioural processes with exquisite precision throughout the day/night cycle. The suprachiasmatic nucleus (SCN), which generates these ~24 h rhythms in mammals, consists of several thousand neurons. Each neuron contains a gene-regulatory network generating molecular oscillations, and the individual neuron oscillations are synchronised by intercellular coupling, presumably via neurotransmitters. Although this basic mechanism is currently accepted and has been recapitulated in mathematical models, several fundamental questions about the design principles of the SCN remain little understood. For example, a remarkable property of the SCN is that the phase of the SCN rhythm resets rapidly after a 'jet lag' type experiment, i.e. when the light/ dark (LD) cycle is abruptly advanced or delayed by several hours. Results: Here, we describe an extensive parameter optimization of a previously constructed simplified model of the SCN in order to further understand its design principles. By examining the top 50 solutions from the parameter optimization, we show that the neurotransmitters' role in generating the molecular circadian rhythms is extremely important. In addition, we show that when a neurotransmitter drives the rhythm of a system of coupled damped oscillators, it exhibits very robust synchronization and is much more easily entrained to light/dark cycles. We were also able to recreate in our simulations the fast rhythm resetting seen after a 'jet lag' type experiment. Conclusion: Our work shows that a careful exploration of parameter space for even an extremely simplified model of the mammalian clock can reveal unexpected behaviours and non-trivial predictions. Our results suggest that the neurotransmitter feedback loop plays a crucial role in the robustness and phase resetting properties of the mammalian clock, even at the single neuron level