Leptonic Decays at BABAR

We present recent results on leptonic B decays using data collected by the BaBar detector at the PEP-II asymmetric-energy e+e- collider at the Stanford Linear Accelerator Center. We report searches for the B -> tau nu decay, based on two statistically independent data samples.Comment: 4 pages, 3 eps figures, Submitted for the SUSY07 proceeding

Electoral rules and voter turnout

The paper investigates the effect of electoral rules on voter turnout. It focuses on Italian municipalities, where voting schemes are differentiated by the size of the city: a single ballot system applies to municipalities with less than 15,000 inhabitants, while a dual ballot system is in place above that threshold. By exploiting this discontinuity, the paper finds that the dual ballot increases participation at the local polls, with an estimated effect of about 1 percentage point. The increase in voter turnout is associated with wider political representation, politicians of higher quality, greater fiscal discipline, and more robust local development. Finally, we document that the higher political participation triggered by local electoral rules extends to nationwide voting contexts.voter turnout, electoral systems, regression discontinuity design

Local electoral rules and political participation

The paper investigates the effect of local electoral rules on the political participation of the residents, as reflected in voter turnout. It focuses on Italy, where municipal voting schemes are differentiated by the size of the city: a single ballot system applies to municipalities with less than 15,000 inhabitants, while a dual ballot system is in place above that threshold. By exploiting this discontinuity, the paper finds that the dual ballot increases political participation. The magnitude of the effect is estimated at between 1 and 3 percentage points.

Real time vibronic coupling dynamics in organic conjugated systems

In this work we show the potentialities of applying impulsive coherent vibrational spectroscopy to conjugated systems relevant for applications. We studied films of sexithiophene, a candidate for large area molecular electronics, poly-phenylene vinylene, a prototype electroluminescent material, and polydiacetylene, very promising for applications in photonic devices. These experiments demonstrate the possibility of studying coherent molecular dynamics in organic systems with extremely high time resolution

Dopamine D3 Receptor Antagonism Reverses the Escalation of Oxycodone Self-administration and Decreases Withdrawal-Induced Hyperalgesia and Irritability-Like Behavior in Oxycodone-Dependent Heterogeneous Stock Rats.

Prescription opioids, such as oxycodone, are highly effective analgesics for clinical pain management, but approximately 25% of patients who are prescribed opioids misuse them, and 5%-10% develop an opioid use disorder (OUD). Effective therapies for the prevention and treatment of opioid abuse and addiction need to be developed. The present study evaluated the effects of the highly selective dopamine D3 receptor antagonist VK4-116 ([R]-N-[4-(4-[3-chloro-5-ethyl-2-methoxyphenyl]piperazin-1-yl)-3-hydroxybutyl]-1H-indole-2-carboxamide) on oxycodone addictive-like behaviors. We used a model of extended access to oxycodone self-administration and tested the effects of VK4-116 on the escalation of oxycodone self-administration and withdrawal-induced hyperalgesia and irritability-like behavior in male and female rats. Pretreatment with VK4-116 (5-25 mg/kg, i.p.) dose-dependently decreased the escalation of oxycodone self-administration and reduced withdrawal-induced hyperalgesia and irritability-like behavior in opioid-dependent rats. These findings demonstrate a key role for D3 receptors in both the motivation to take opioids and negative emotional states that are associated with opioid withdrawal and suggest that D3 receptor antagonism may be a viable therapeutic approach for the treatment of OUD

Systemic and Intra-Habenular Activation of the Orphan G Protein-Coupled Receptor GPR139 Decreases Compulsive-Like Alcohol Drinking and Hyperalgesia in Alcohol-Dependent Rats.

GPR139 is an orphan G protein-coupled receptor (GPCR) that is expressed mainly in the brain, with the highest expression in the medial habenula. The modulation of GPR139 receptor function has been hypothesized to be beneficial in the treatment of some mental disorders, but behavioral studies have not yet provided causal evidence of the role of GPR139 in brain dysfunction. Because of the high expression of GPR139 in the habenula, a critical brain region in addiction, we hypothesized that GPR139 may play role in alcohol dependence. Thus, we tested the effect of GPR139 receptor activation using the selective, brain-penetrant receptor agonist JNJ-63533054 on addiction-like behaviors in alcohol-dependent male rats. Systemic administration of JNJ-63533054 (30 mg/kg but not 10 mg/kg, p.o.) reversed the escalation of alcohol self-administration in alcohol-dependent rats, without affecting water or saccharin intake in dependent rats or alcohol intake in nondependent rats. Moreover, systemic JNJ-63533054 administration decreased withdrawal-induced hyperalgesia, without affecting somatic signs of alcohol withdrawal. Further analysis demonstrated that JNJ-63533054 was effective only in a subgroup of dependent rats that exhibited compulsive-like alcohol drinking. Finally, site-specific microinjection of JNJ-63533054 in the habenula but not interpeduncular nucleus (IPN) reduced both alcohol self-administration and withdrawal-induced hyperalgesia in dependent rats. These results provide robust preclinical evidence that GPR139 receptor activation reverses key addiction-like behaviors in dependent animals, suggest that GPR139 may be a novel target for the treatment of alcohol use disorder, and demonstrate that GPR139 is functionally relevant in regulating mammalian behavior

Charge carrier generation in a conjugated polymer studied via ultrafast pump-push-probe experiments

Conjugated polymers find rapidly growing application in electroluminescent displays and are extensively studied for use in photovoltaics and laser diodes. For a wide range of conjugated materials ultrafast pump-probe experiments have revealed the excited state dynamics of singlet and triplet excitons as well as positively and negatively charged polarons. Charge carriers play a key role in all the above mentioned applications. However, there is yet no clear picture of the mechanisms which lead to their generation. Photocurrent excitation cross-correlation measurement on methyl-substituted ladder-type poly(para)phenyl (m-LPPP), a prototypical conjugated polymer with very appealing properties for the above mentioned applications, have suggested that charge carrier generation occurs preferentially from higher lying states during energy migration. Our approach to examining this mechanism consists of an innovative modification of the ultrafast time-resolved pump-probe technique