Legislative Bargaining Under Weighted Voting

Organizations often distribute resources through weighted voting. We analyze this setting using a noncooperative bargaining game based on the Baron-Ferejohn (1989) model. Unlike analyses derived from cooperative game theory, we find that each voter’s expected payoff is proportional to her voting weight. An exception occurs when many high-weight voters exist, as low-weight voters may expect disproportionately high payoffs due to proposal power. The model also predicts that, ex post, the coalition formateur (the party chosen to form a coalition) will receive a disproportionately high payoff. Using data from coalition governments from 1946 to 2001, we find strong evidence of such formateur effects. (JEL D7, D72) Collective decision-making frequently in-volves situations in which actors have different numbers of votes. Some institutions assign un-equal voting weights explicitly. Examples in-clude important political bodies, such as th

An Informational Rationale for Political Parties

This article studies a model of political parties as informative "brands" to voters. Voters across a large number of constituencies are assumed to be risk averse and incompletely informed about candidate ideal policies, and candidates are unable to commit to a declared policy platform. In this environment, parties can play a critical role by aggregating ideologically similar candidates and signaling their preferences to voters. This signaling is effective because party membership imposes costs, which screen out candidates whose preferences are not sufficiently close to the party's platform. We find that when party labels are very informative, the parties' platforms converge. When party labels are less informative, however, platforms diverge, because taking an extreme position allows a party to reduce the variance of its members' preferences. As parties become less able to impose costs on their members, or less able to screen out certain types of candidates, their platforms move further apart

INTEREST GROUPS AND THE ELECTORAL CONTROL OF POLITICIANS 1

Abstract We develop a model of interest group influence in the presence of repeated electoral competition. In each period of the game, an interest group attempts to "buy" an incumbent's policy choice, and a voter chooses whether to replace the incumbent with an unknown challenger. The voter faces a tension between retaining good politician types and rewarding past performance. The model predicts that "above average" incumbents face little discipline, but others are disciplined increasingly-and re-elected at a higher rate-as the interest group becomes more extreme. Extensions of the model consider term limits, long-lived groups, and multiple groups. JEL D7

Noncommutative D-Brane in Non-Constant NS-NS B Field Background

We show that when the field strength H of the NS-NS B field does not vanish, the coordinates X and momenta P of an open string endpoints satisfy a set of mixed commutation relations among themselves. Identifying X and P with the coordinates and derivatives of the D-brane world volume, we find a new type of noncommutative spaces which is very different from those associated with a constant B field background.Comment: 11 pages, Latex, minor modification

Widespread contribution of transposable elements to the innovation of gene regulatory networks

Transposable elements (TEs) have been shown to contain functional binding sites for certain transcription factors (TFs). However, the extent to which TEs contribute to the evolution of TF binding sites is not well known. We comprehensively mapped binding sites for 26 pairs of orthologous TFs in two pairs of human and mouse cell lines (representing two cell lineages), along with epigenomic profiles, including DNA methylation and six histone modifications. Overall, we found that 20% of binding sites were embedded within TEs. This number varied across different TFs, ranging from 2% to 40%. We further identified 710 TF–TE relationships in which genomic copies of a TE subfamily contributed a significant number of binding peaks for a TF, and we found that LTR elements dominated these relationships in human. Importantly, TE-derived binding peaks were strongly associated with open and active chromatin signatures, including reduced DNA methylation and increased enhancer-associated histone marks. On average, 66% of TE-derived binding events were cell type-specific with a cell type-specific epigenetic landscape. Most of the binding sites contributed by TEs were species-specific, but we also identified binding sites conserved between human and mouse, the functional relevance of which was supported by a signature of purifying selection on DNA sequences of these TEs. Interestingly, several TFs had significantly expanded binding site landscapes only in one species, which were linked to species-specific gene functions, suggesting that TEs are an important driving force for regulatory innovation. Taken together, our data suggest that TEs have significantly and continuously shaped gene regulatory networks during mammalian evolution

Force dysmetria in spinocerebellar ataxia 6 correlates with functional capacity

Spinocerebellar ataxia type 6 (SCA6) is a genetic disease that causes pure cerebellar degeneration affecting walking, balance, and coordination. One of the main symptoms of SCA6 is dysmetria. The magnitude of dysmetria and its relation to functional capacity in SCA6 has not been studied. Our purpose was to quantify dysmetria and determine the relation between dysmetria and functional capacity in SCA6. Ten individuals diagnosed and genetically confirmed with SCA6 (63.7 ± 7.02yrs) and nine age-matched healthy controls (65.9 ± 8.5yrs) performed goal-directed isometric contractions with the ankle joint. Dysmetria was quantified as the force and time error during goal-directed contractions. SCA6 functional capacity was determined by ICARS and SARA clinical assessments. We found that SCA6 participants exhibited greater force dysmetria than healthy controls (P < 0.05), and reduced time dysmetria than healthy controls (P < 0.05). Only force dysmetria was significantly related to SCA6 functional capacity, as measured with ICARS kinetic score (R2 = 0.63), ICARS total score (R2 = 0.43), and SARA total score (R2 = 0.46). Our findings demonstrate that SCA6 exhibit force dysmetria and that force dysmetria is associated to SCA6 functional capacity. Quantifying force and time dysmetria in individuals with SCA6 could provide a more objective evaluation of the functional capacity and disease state in SCA6

Altered ATP release and metabolism in dorsal root ganglia of neuropathic rats

<p>Abstract</p> <p>Background</p> <p>Adenosine 5'-triphosphate (ATP) has a ubiquitous role in metabolism and a major role in pain responses after tissue injury. We investigated the changes in basal and KCl-evoked ATP release from rat dorsal root ganglia (DRG) after peripheral neuropathy induction by unilateral sciatic nerve entrapment (SNE).</p> <p>Results</p> <p>After SNE, rats develop long-lasting decreases in ipsilateral hindpaw withdrawal thresholds to mechanical and thermal stimulation. At 15–21 days after neuropathy induction, excised ipsilateral L4-L5 DRG display significantly elevated basal extracellular ATP levels compared to contralateral or control (naive) DRG. However, KCl-evoked ATP release is no longer observed in ipsilateral DRG. We hypothesized that the differential SNE effects on basal and evoked ATP release could result from the conversion of extracellular ATP to adenosine with subsequent activation of adenosine A1 receptors (A1Rs) on DRG neurons. Adding the selective A1R agonist, 2-chloro-N⁶-cyclopentyladenosine (100 nM) significantly decreased basal and evoked ATP release in DRG from naïve rats, indicating functional A1R activation. In DRG ipsilateral to SNE, adding a selective A1R antagonist, 8-cyclopentyl-1,3-dipropylxanthine (30 nM), further increased basal ATP levels and relieved the blockade of KCl-evoked ATP release suggesting that increased A1R activation attenuates evoked ATP release in neurons ipsilateral to SNE. To determine if altered ATP release was a consequence of altered DRG metabolism we compared O₂consumption between control and neuropathic DRG. DRG ipsilateral to SNE consumed O₂at a higher rate than control or contralateral DRG.</p> <p>Conclusion</p> <p>These data suggest that peripheral nerve entrapment increases DRG metabolism and ATP release, which in turn is modulated by increased A1R activation.</p