Potentially Extreme Population Displacement and Concentration in the Tropics Under Non-Extreme Warming.

Evidence increasingly suggests that as climate warms, some plant, animal, and human populations may move to preserve their environmental temperature. The distances they must travel to do this depends on how much cooler nearby surfaces temperatures are. Because large-scale atmospheric dynamics constrain surface temperatures to be nearly uniform near the equator, these displacements can grow to extreme distances in the tropics, even under relatively mild warming scenarios. Here we show that in order to preserve their annual mean temperatures, tropical populations would have to travel distances greater than 1000 km over less than a century if global mean temperature rises by 2 °C over the same period. The disproportionately rapid evacuation of the tropics under such a scenario would cause migrants to concentrate in tropical margins and the subtropics, where population densities would increase 300% or more. These results may have critical consequences for ecosystem and human wellbeing in tropical contexts where alternatives to geographic displacement are limited

Baryogenesis in Lorentz-violating gravity theories

Lorentz-violating theories of gravity typically contain constrained vector fields. We show that the lowest-order coupling of such vectors to $\mathrm{U}(1)$-symmetric scalars can naturally give rise to baryogenesis in a manner akin to the Affleck-Dine mechanism. We calculate the cosmology of this new mechanism, demonstrating that a net $B-L$ can be generated in the early Universe, and that the resulting baryon-to-photon ratio matches that which is presently observed. We discuss constraints on the model using solar system and astrophysical tests of Lorentz violation in the gravity sector. Generic Lorentz-violating theories can give rise to the observed matter-antimatter asymmetry without violating any current bounds.Comment: Five pages, two figures, submitted to PL

A Novel Cooperative Intrusion Detection System for Mobile Ad Hoc Networks

Mobile ad hoc networks (MANETs) have experienced rapid growth in their use for various military, medical, and commercial scenarios. This is due to their dynamic nature that enables the deployment of such networks, in any target environment, without the need for a pre-existing infrastructure. On the other hand, the unique characteristics of MANETs, such as the lack of central networking points, limited wireless range, and constrained resources, have made the quest for securing such networks a challenging task. A large number of studies have focused on intrusion detection systems (IDSs) as a solid line of defense against various attacks targeting the vulnerable nature of MANETs. Since cooperation between nodes is mandatory to detect complex attacks in real time, various solutions have been proposed to provide cooperative IDSs (CIDSs) in efforts to improve detection efficiency. However, all of these solutions suffer from high rates of false alarms, and they violate the constrained-bandwidth nature of MANETs. To overcome these two problems, this research presented a novel CIDS utilizing the concept of social communities and the Dempster-Shafer theory (DST) of evidence. The concept of social communities was intended to establish reliable cooperative detection reporting while consuming minimal bandwidth. On the other hand, DST targeted decreasing false accusations through honoring partial/lack of evidence obtained solely from reliable sources. Experimental evaluation of the proposed CIDS resulted in consistently high detection rates, low false alarms rates, and low bandwidth consumption. The results of this research demonstrated the viability of applying the social communities concept combined with DST in achieving high detection accuracy and minimized bandwidth consumption throughout the detection process

STUDY OF THE RELATIONSHIP BETWEEN ECONOMIC GROWTH, VOLATILITY AND INNOVATION FOR THE EU-27 AND CEEC COUNTRIES

The present study applies, along general lines, the methodology used in Ramey&Ramey (1995), and Kroft, Lloyd-Ellis (2002), respectively, to analyze the dependencies between growth, volatility and innovation in the case of the EU-27 and CEEC (new member states from Central and Eastern Europe) countries, respectively. Unlike the above-mentioned papers, which use human capital as proxy for innovation, we use as indicator of innovation the Summary Innovation Index(SII), proposed by the European Innovation Scoreboard (EIS). Using the EVIEWS econometric software, we estimate regressions of the GDP growth rate on its total volatility, as well as on its partial volatilities, split with respect to the phases of the economic cycle. We also estimate regressions of the innovation rate on the GDP growth rate volatilities, as well as regressions of the GDP growth rate on the rate of innovation and the split volatility of the GDP growth rate. We find positive dependencies of the GDP growth rate on its own volatility, as well as on the innovation rate. The sources of the data are EUROSTAT, the National Statistical Institute of Romania (INS), and the European Innovation Scoreboard.growth, volatility, innovation