Electromagnetic quarkonium decays at order v^7

We compute S-wave and P-wave electromagnetic quarkonium decays at order v^7 in the heavy-quark velocity expansion. In the S-wave case, our calculation confirms and completes previous findings. In the P-wave case, our results are in disagreement with previous ones; in particular, we find that two matrix elements less are needed. The cancellation of infrared singularities in the matching procedure is discussed.Comment: Eq. (A.1) and following comment corrected, rest of the paper unchange

Training and Product Quality in Unionized Oligopolies

In this paper we analyze the private and public incentives towards skill acquisition when the skill level of workers determines the quality level of goods, and both labor and product markets are non competitive. We delve into the mechanisms that determine the equilibrium skill acquisition outcomes and show that both "pure" (training set by either firms or unions only) and "mixed" (training set by firms and unions) training scenarios may emerge at equilibrium. We show that firms have generally greater training incentives than unions, resulting in a higher product quality. In line with empirical evidence, we also find that the wage differential between high-skill workers and low-skill workers is lower when the training levels of the workforce are selected by unions than by firms. Finally, we analyze the optimal public training skill levels and demonstrate that both unions and firms under-invest in training in comparison with the social optimum. Yet, in this case the skill premium is the lowest

Location in a vertically differentiated industry

We analyze a two-stage game in a vertically differentiated duopoly with two regions which can differ for the willingness to pay of their consumers or for the market size; firms sequentially choose to settle in one region and then simultaneously compete in prices, selling their products both on the local market and on the foreigner one by exporting them at a fixed cost. We study how strategic interaction influences firms’ location choices and we show that the decision whether to agglomerate or not crucially depends on the extent of regions’ asymmetries, but, counter intuitively, there are parametric regions in which the model predicts that the leader (the first firm choosing location) settles either in the poorer or in the smaller region, leaving the other one to the follower. Welfare analysis completes the paper

Measuring neuromuscular junction functionality

Neuromuscular junction (NMJ) functionality plays a pivotal role when studying diseases in which the communication between motor neuron and muscle is impaired, such as aging and amyotrophic lateral sclerosis (ALS). Here we describe an experimental protocol that can be used to measure NMJ functionality by combining two types of electrical stimulation: direct muscle membrane stimulation and the stimulation through the nerve. The comparison of the muscle response to these two different stimulations can help to define, at the functional level, potential alterations in the NMJ that lead to functional decline in muscle. Ex vivo preparations are suited to well-controlled studies. Here we describe an intensive protocol to measure several parameters of muscle and NMJ functionality for the soleus-sciatic nerve preparation and for the diaphragm-phrenic nerve preparation. The protocol lasts approximately 60 min and is conducted uninterruptedly by means of a custom-made software that measures the twitch kinetics properties, the force-frequency relationship for both muscle and nerve stimulations, and two parameters specific to NMJ functionality, i.e. neurotransmission failure and intratetanic fatigue. This methodology was used to detect damages in soleus and diaphragm muscle-nerve preparations by using SOD1G93A transgenic mouse, an experimental model of ALS that ubiquitously overexpresses the mutant antioxidant enzyme superoxide dismutase 1 (SOD1)

Training and Product Quality in Unionized Oligopolies

In this paper we analyse the private and public incentives towards skill acquisition when the skill level of workers determines the quality level of goods, and both labour and product markets are non-competitive. We show that both ‘pure’ (set by either firms or unions only) and ‘mixed’ (set by firms and unions) training scenarios may emerge at equilibrium. We show that firms have generally greater training incentives than unions, resulting in a higher product quality. Our welfare analysis shows that both unions and firms underinvest in training in comparison with the social optimum