Measurement events relative to temporal quantum reference frames

The Page-Wootters formalism is a proposal for reconciling the background-dependent, quantum-mechanical notion of time with the background independence of general relativity. However, there has been much discussion regarding the physical meaning of the framework. In this work, we compare two consistent approaches to the Page-Wootters formalism to clarify the operational meaning of evolution and measurements with respect to a quantum temporal reference frame. The so-called "twirled observable" approach implements measurements as operators that are invariant with respect to the Hamiltonian constraint. The "purified measurement" approach instead models measurements dynamically by modifying the constraint itself. While both approaches agree in the limit of ideal clocks, a natural generalization of the purified measurement approach to the case of non-ideal, finite-resource clocks yields a radically different picture. We discuss the physical origin of this discrepancy and argue that they describe operationally distinct situations. Moreover, we show that, for non-ideal clocks, the purified measurement approach yields time non-local, non-unitary evolution and implies a fundamental limitation to the operational definition of the temporal order of events. Nevertheless, unitarity and definite temporal order can be restored if we assume that time is discrete

Thecamoeba aesculea n. sp. (Amoebozoa, Thecamoebidae), a Terrestrial Amoeba with Affinities to Th. sphaeronucleolus (Greeff, 1891)

Thecamoeba aesculea n. sp. was isolated and described from the surface of the bark of Aesculus hippocastanum and from terrestrial mosses growing on it. This amoeba is superficially similar to Thecamoeba sphaeronucleolus, but comparison of the newly isolated strain with the photographs and video records of the type strain of this species reveals differences which show that the two strains do not belong to the same morphospecies. The data obtained indicate the necessity of further comparative studies on the diversity of thecamoebian ‘morphospecies’ to outline clearer borders between them

Description of Paramoeba atlantica n. sp. (Amoebozoa, Dactylopodida) – a Marine Amoeba from the Eastern Atlantic, with Emendation of the Dactylopodid Families

A strain of marine amoeba has been isolated and studied from the bottom sediments of the Great Meteor Seamount (Atlantic Ocean, 29°36.29′N; 28°59.12′W; 267.4 m deep). This amoeba has a typical dactylopodiid morphotype, a coat of delicate, boat-shaped scales, and a Perkinsela-like organism (PLO), an obligatory, deeply-specialized kinetoplastid symbiont near the nucleus. These characters allow us to include this species into the genus Paramoeba. However, it differs from its only described species, P. eilhardi, in the structure of scales. P. atlantica n. sp. is established therefore to accommodate the studied strain. SSU rRNA gene sequence analysis suggests that P. atlantica belongs to the Dactylopodida, and is sister to a monophyletic clade of P. eilhardi and all Neoparamoeba spp., branching separately from P. eilhardi. Therefore, the genera Paramoeba and Neoparamoeba, currently defined based on the cell surface ultrastructure, might be paraphyletic and probably should be synonymized, as further evidence is accumulated. Based on the data available we emend the families Vexilliferidae and Paramoebidae to make them more consistent with the current phylogenetic schemes

The Atlas of Economic Complexity

Maps capture data expressing the economic complexity of countries from Albania to Zimbabwe, offering current economic measures and as well as a guide to achieving prosperity Why do some countries grow and others do not? The authors of The Atlas of Economic Complexity offer readers an explanation based on "Economic Complexity," a measure of a society's productive knowledge. Prosperous societies are those that have the knowledge to make a larger variety of more complex products.The Atlas of Economic Complexity attempts to measure the amount of productive knowledge countries hold and how they can move to accumulate more of it by making more complex products. Through the graphical representation of the "Product Space," the authors are able to identify each country's "adjacent possible," or potential new products, making it easier to find paths to economic diversification and growth. In addition, they argue that a country's economic complexity and its position in the product space are better predictors of economic growth than many other well-known development indicators, including measures of competitiveness, governance, finance, and schooling. Using innovative visualizations, the book locates each country in the product space, provides complexity and growth potential rankings for 128 countries, and offers individual country pages with detailed information about a country's current capabilities and its diversification options. The maps and visualizations included in the Atlas can be used to find more viable paths to greater productive knowledge and prosperity

Requirements for interoperable Intelligent Transport Systems in South East Europe

Transport integration in South East Europe (SEE) is a fundamental pre-requisite for regional cohesion and development. Intelligent Transport Systems (ITS) applications can play an important role in transport infrastructure management and traveler information provision throughout the SEE area. This paper presents the results of study focused on the identification and description of the requirements for interoperable ITS for integrated traffic management and ITS deployment. The key outcome of the study is the identification of the requirements for interoperable ITS along regional, national an urban transport networks