The Self-Selection of Democracies into Treaty Design: Insights from International Environmental Agreements

Generally, democratic regime type is positively associated with participating in international environmental agreements. In this context, this study focuses on the legal nature of an agreement, which is linked to audience costs primarily at the domestic level that occur in case of non-compliance and are felt especially by democracies. Eventually, more legalized (\hard-law") treaties make compliance potentially more challenging and democratic leaders may anticipate the corresponding audience costs, which decreases the likelihood that democracies select themselves into such treaties. The empirical implication of our theory follows that environmental agreements with a larger share of democratic members are less likely to be characterized by hard law. This claim is tested using quantitative data on global environmental treaties. The results strongly support our argument, shed new light on the relationship between participation in international agreements and the form of government, and also have implications for the \words-deeds" debate in international environmental policy-making

The Dramatic Size and Kinematic Evolution of Massive Early-type Galaxies

We aim to provide a holistic view on the typical size and kinematic evolution of massive early-type galaxies (ETGs) that encompasses their high-z star-forming progenitors, their high-z quiescent counterparts, and their configurations in the local Universe. Our investigation covers the main processes playing a relevant role in the cosmic evolution of ETGs. Specifically, their early fast evolution comprises biased collapse of the low angular momentum gaseous baryons located in the inner regions of the host dark matter halo; cooling, fragmentation, and infall of the gas down to the radius set by the centrifugal barrier; further rapid compaction via clump/gas migration toward the galaxy center, where strong heavily dust-enshrouded star formation takes place and most of the stellar mass is accumulated; and ejection of substantial gas amount from the inner regions by feedback processes, which causes a dramatic puffing-up of the stellar component. In the late slow evolution, passive aging of stellar populations and mass additions by dry merger events occur. We describe these processes relying on prescriptions inspired by basic physical arguments and by numerical simulations to derive new analytical estimates of the relevant sizes, timescales, and kinematic properties for individual galaxies along their evolution. Then we obtain quantitative results as a function of galaxy mass and redshift, and compare them to recent observational constraints on half-light size Re, on the ratio v/\u3c3 between rotation velocity and velocity dispersion (for gas and stars) and on the specific angular momentum j 17of the stellar component; we find good consistency with the available multiband data in average values and dispersion, both for local ETGs and for their z 3c 1-2 star-forming and quiescent progenitors. The outcomes of our analysis can provide hints to gauge sub-grid recipes implemented in simulations, to tune numerical experiments focused on specific processes, and to plan future multiband, high-resolution observations on high-redshift star-forming and quiescent galaxies with next-generation facilities

SIPA1L2 controls trafficking and local signaling of TrkB-containing amphisomes at presynaptic terminals

Amphisomes are organelles of the autophagy pathway that result from the fusion of autophagosomes with late endosomes. While biogenesis of autophagosomes and late endosomes occurs continuously at axon terminals, non-degradative roles of autophagy at boutons are barely described. Here, we show that in neurons BDNF/TrkB traffick in amphisomes that signal locally at presynaptic boutons during retrograde transport to the soma. This is orchestrated by the Rap GTPase-activating (RapGAP) protein SIPA1L2, which connects TrkB amphisomes to a dynein motor. The autophagosomal protein LC3 regulates RapGAP activity of SIPA1L2 and controls retrograde trafficking and local signaling of TrkB. Following induction of presynaptic plasticity, amphisomes dissociate from dynein at boutons enabling local signaling and promoting transmitter release. Accordingly, sipa1l2 knockout mice show impaired BDNF-dependent presynaptic plasticity. Taken together, the data suggest that in hippocampal neurons, TrkB-signaling endosomes are in fact amphisomes that during retrograde transport have local signaling capacity in the context of presynaptic plasticity