Quantum Fluctuation Theorems

Recent advances in experimental techniques allow one to measure and control systems at the level of single molecules and atoms. Here gaining information about fluctuating thermodynamic quantities is crucial for understanding nonequilibrium thermodynamic behavior of small systems. To achieve this aim, stochastic thermodynamics offers a theoretical framework, and nonequilibrium equalities such as Jarzynski equality and fluctuation theorems provide key information about the fluctuating thermodynamic quantities. We review the recent progress in quantum fluctuation theorems, including the studies of Maxwell's demon which plays a crucial role in connecting thermodynamics with information.Comment: As a chapter of: F. Binder, L. A. Correa, C. Gogolin, J. Anders, and G. Adesso (eds.), "Thermodynamics in the quantum regime - Fundamental Aspects and New Directions", (Springer International Publishing, 2018

Recomendações para o uso de coletores artificiais, para a captação, o manejo e o transporte de sementes de ostras nativas do gênero crassostrea em ambientes estuarinos da Costa Brasileira.

ODS 2, ODS 14

Second law, entropy production, and reversibility in thermodynamics of information

We present a pedagogical review of the fundamental concepts in thermodynamics of information, by focusing on the second law of thermodynamics and the entropy production. Especially, we discuss the relationship among thermodynamic reversibility, logical reversibility, and heat emission in the context of the Landauer principle and clarify that these three concepts are fundamentally distinct to each other. We also discuss thermodynamics of measurement and feedback control by Maxwell's demon. We clarify that the demon and the second law are indeed consistent in the measurement and the feedback processes individually, by including the mutual information to the entropy production.Comment: 43 pages, 10 figures. As a chapter of: G. Snider et al. (eds.), "Energy Limits in Computation: A Review of Landauer's Principle, Theory and Experiments

HIV-1 competition experiments in humanized mice show that APOBEC3H imposes selective pressure and promotes virus adaptation

APOBEC3 (A3) family proteins are DNA cytosine deaminases recognized for contributing to HIV-1 restriction and mutation. Prior studies have demonstrated that A3D, A3F, and A3G enzymes elicit a robust anti-HIV-1 effect in cell cultures and in humanized mouse models. Human A3H is polymorphic and can be categorized into three phenotypes: stable, intermediate, and unstable. However, the anti-viral effect of endogenous A3H in vivo has yet to be examined. Here we utilize a hematopoietic stem cell-transplanted humanized mouse model and demonstrate that stable A3H robustly affects HIV-1 fitness in vivo. In contrast, the selection pressure mediated by intermediate A3H is relaxed. Intriguingly, viral genomic RNA sequencing reveled that HIV-1 frequently adapts to better counteract stable A3H during replication in humanized mice. Molecular phylogenetic analyses and mathematical modeling suggest that stable A3H may be a critical factor in human-to-human viral transmission. Taken together, this study provides evidence that stable variants of A3H impose selective pressure on HIV-1

Protokół przetwarzania optymistycznego do multipleksowania w zewnętrznych sieciach komputerów osobistych

In external PC grids, it is difficult to protect data from falsifications and analyses because the data is processed by unspecified hosts. In the past, to resolve this problem a concealing method for processing purposes (CMPP) has been proposed. Although CMPP can detect falsifications with high probability, it takes much time to process the whole program due to the majority vote. This paper proposes an optimistic processing protocol for multiplexing. In the proposed protocol, each host starts to execute its segment based on a result of a previous segment from only one host even if the result is not decided by a majority vote. The majority vote is done after results of other hosts arrive. Through simulation experiments, we show that the proposed scheme can improve processing time of programs efficiently.W zewnętrznych sieciach komputerów osobistych trudno jest zabezpieczyć dane przed ich fałszowaniem i analizowaniem, ponieważ dane są przetwarzane przez bliżej nieokreślone serwery. W przeszłości do rozwiązania tego problemu była proponowana metoda ukrywania problemu przy przetwarzaniu (CMPP). Metoda CMPP polega na podzieleniu programu na wiele segmentów, a te segmenty są przetwarzane na różnych serwerach, aby zapobiec wykonaniu niepożądanej analizy programu. Co więcej, aby wykryć fałszerstwa, metoda CMPP zawiera schemat multipleksowania który wykonuje identyczne segmenty na różnych serwerach równolegle i decyduje o wyniku przetwarzania metodą głosowania większościowego. Chociaż CMPP może wykryć fałszerstwa z wysokim prawdopodobieństwem, to jednak głosowanie większościowe wymaga długiego czasu przetworzenia całego programu. W artykule jest zaproponowany protokół optymistycznego przetwarzania do multipleksowania. W zaproponowanym protokole każdy serwer zaczyna wykonywać własny segment w oparciu o wyniki poprzedniego segmentu z jednego z serwerów, nawet jeżeli wynik nie jest potwierdzony przez głosowanie większościowe. Głosowanie większościowe jest wykonywane po nadejściu wyników z innych serwerów. Za pomocą eksperymentów symulacyjnych wykazano, że proponowany schemat może efektywnie skrócić czas przetwarzania programów

Strong local passivity in finite quantum systems

Passive states of quantum systems are states from which no system energy can be extracted by any cyclic (unitary) process. Gibbs states of all temperatures are passive. Strong local (SL) passive states are defined to allow any general quantum operation, but the operation is required to be local, being applied only to a specific subsystem. Any mixture of eigenstates in a system-dependent neighborhood of a nondegenerate, entangled ground state is found to be SL passive. In particular, Gibbs states are SL passive with respect to a subsystem only at or below a critical, system-dependent temperature. SL passivity is associated in many-body systems with the presence of ground state entanglement in a way suggestive of collective quantum phenomena such as quantum phase transitions, superconductivity, and the quantum Hall effect. The presence of SL passivity is detailed for some simple spin systems where it is found that SL passivity is neither confined to systems of just a few particles nor limited to the near vicinity of the ground state.Comment: This newer version is longer and more detailed. Published 24 July 201