Indistinguishability right from the start in standard quantum mechanics

We discuss a reconstruction of standard quantum mechanics assuming indistinguishability right from the start, by appealing to quasi-set theory. After recalling the fundamental aspects of the construction and introducing some improvements in the original formulation, we extract some conclusions for the interpretation of quantum theory

Security Principles of Smart Grid Networks

Increased power consumption and power supply variability require implementation of modern tools for intelligent management and control of grid networks. One of the most promising advancements in technology is the Smart Grid network. Unfortunately, this technology is still rapidly evolving and at this point contains many security issues. As recent attacks have shown, only some of these issues are known. This paper is using a systematic approach to detect these issues and to analyze all types of attacks on the Smart Grid networks. The last part of the paper proposes solution models for securing Smart Grid networks against found vulnerabilities

Ministers in rural churches of Missouri

Cover title.Digitized 2007 AES MoU.Includes bibliographical references

A Comparison of rural churches and ministers in Missouri over a 15 year period

Cover title.Digitized 2007 AES MoU.Includes bibliographical references (page 26)

On the connection between Complementarity and Uncertainty Principles in the Mach-Zehnder interferometric setting

We revisit, in the framework of Mach-Zehnder interferometry, the connection between the complementarity and uncertainty principles of quantum mechanics. Specifically, we show that, for a pair of suitably chosen observables, the trade-off relation between the complementary path information and fringe visibility is equivalent to the uncertainty relation given by Schr\"odinger and Robertson, and to the one provided by Landau and Pollak as well. We also employ entropic uncertainty relations (based on R\'enyi entropic measures) and study their meaning for different values of the entropic parameter. We show that these different values define regimes which yield qualitatively different information concerning the system, in agreement with findings of [A. Luis, Phys. Rev. A 84, 034101 (2011)]. We find that there exists a regime for which the entropic uncertinty relations can be used as criteria to pinpoint non trivial states of minimum uncertainty.Comment: 7 pages, 2 figure

A quantum logical and geometrical approach to the study of improper mixtures

We study improper mixtures from a quantum logical and geometrical point of view. Taking into account the fact that improper mixtures do not admit an ignorance interpretation and must be considered as states in their own right, we do not follow the standard approach which considers improper mixtures as measures over the algebra of projections. Instead of it, we use the convex set of states in order to construct a new lattice whose atoms are all physical states: pure states and improper mixtures. This is done in order to overcome one of the problems which appear in the standard quantum logical formalism, namely, that for a subsystem of a larger system in an entangled state, the conjunction of all actual properties of the subsystem does not yield its actual state. In fact, its state is an improper mixture and cannot be represented in the von Neumann lattice as a minimal property which determines all other properties as is the case for pure states or classical systems. The new lattice also contains all propositions of the von Neumann lattice. We argue that this extension expresses in an algebraic form the fact that -alike the classical case- quantum interactions produce non trivial correlations between the systems. Finally, we study the maps which can be defined between the extended lattice of a compound system and the lattices of its subsystems.Comment: submitted to the Journal of Mathematical Physic

Distinct Secondary Structures of the Leucine-Rich Repeat Proteoglycans Decorin and Biglycan: Glycosylation-Dependent Conformational Stability

Biglycan and decorin, closely related small leucine-rich repeat proteoglycans, have been overexpressed in eukaryotic cers and two major glycoforms isolated under native conditions: a proteoglycan substituted with glycosaminoglycan chains; and a core protein form secreted devoid of glycosaminoglycans. A comparative biophysical study of these glycoforms has revealed that the overall secondary structures of biglycan and decorin are different. Far-UV Circular Dichroism (CD) spectroscopy of decorin and biglycan proteoglycans indicates that, although they are predominantly Beta-sheet, biglycan has a significantly higher content of alpha-helical structure. Decorin proteoglycan and core protein are very similar, whereas the biglycan core protein exhibits closer similarity to the decorin glycoforms than to. the biglycan proteoglycan form. However, enzymatic removal of the chondroitin sulfate chains from biglycan proteoglycan does not induce a shift to the core protein structure, suggesting that the fmal form is influenced by polysaccharide addition only during biosynthesis. Fluorescence emission spectroscopy demonstrated that the single tryptophan residue, which is at a conserved position at the C-terminal domain of both biglycan and decorin, is found in similar microenvironments. This indicates that at least in this specific domain, the different glycoforms do exhibit apparent conservation of structure. Exposure of decorin and biglycan to 10 M urea resulted in an increase in fluorescent intensity, which indicates that the emission from tryptophan in the native state is quenched. Comparison of urea-induced protein unfolding curves provided further evidence that decorin and biglycan assume different structures in solution. Decorin proteoglycan and core protein unfold in a manner similar to a classic two-state model, in which there is a steep transition to an unfolded state between 1-2 M urea. The biglycan core protein also shows a similar steep transition. However, biglycan proteoglycan shows a broad unfolding transition between 1-6 M urea, probably indicating the presence of stable unfolding intermediates

RNA polymerase mapping during stress responses reveals widespread nonproductive transcription in yeast

BACKGROUND: The use of genome-wide RNA abundance profiling by microarrays and deep sequencing has spurred a revolution in our understanding of transcriptional control. However, changes in mRNA abundance reflect the combined effect of changes in RNA production, processing, and degradation, and thus, mRNA levels provide an occluded view of transcriptional regulation. RESULTS: To partially disentangle these issues, we carry out genome-wide RNA polymerase II (PolII) localization profiling in budding yeast in two different stress response time courses. While mRNA changes largely reflect changes in transcription, there remains a great deal of variation in mRNA levels that is not accounted for by changes in PolII abundance. We find that genes exhibiting \u27excess\u27 mRNA produced per PolII are enriched for those with overlapping cryptic transcripts, indicating a pervasive role for nonproductive or regulatory transcription in control of gene expression. Finally, we characterize changes in PolII localization when PolII is genetically inactivated using the rpb1-1 temperature-sensitive mutation. We find that PolII is lost from chromatin after roughly an hour at the restrictive temperature, and that there is a great deal of variability in the rate of PolII loss at different loci. CONCLUSIONS: Together, these results provide a global perspective on the relationship between PolII and mRNA production in budding yeast

Indistinguishability and the origins of contextuality in physics

In this work, we discuss a formal way of dealing with the properties of contextual systems. Our approach is to assume that properties describing the same physical quantity, but belonging to different measurement contexts, are indistinguishable in a strong sense. To construct the formal theoretical structure, we develop a description using quasi-set theory, which is a settheoretical framework built to describe collections of elements that violate Leibnitz’s principle of identity of indiscernibles. This framework allows us to consider a new ontology in order to study the properties of quantum systems. This article is part of the theme issue ‘Contextuality and probability in quantum mechanics and beyond’.Facultad de Ciencias Exacta