Quantum Entanglement and the Lorentz Group

International audienceThe Lorentz metric represented by the diagonal matrix G = diag(1,-1,-1,-1) acts on Minkowski space-time quadrivectors. In the language of Quantum Information the operator G can be viewed as an entangling gate this because it acts in a similar way as the Controlled-Z gate on the computational basis of a 2-qubit separable quantum vector. The entangling power corresponds to the fact that the resulting vector, considered as a 2-qubit vector, cannot be put into a Kronecker product of two 1-qubit vectors.One can represent the generators of the Lorentz group by 4x4 matrices. An example is given by the Lorentz rotation considered as a controlled 2-qubit gate structure similar to the Control-NOT logical quantum gate.The Minkowski metric, according to the positive energy theorem in General Relativity, represents the ground state of the metric field, its maximally entangled character analogous to the singlet Bell state suggests that entanglement and hyperbolic space are intimately interconnected.Quantum Information associated with the logic linear algebraic structures, as proposed in Eigenlogic, could provide a new tool to revisit the geometric structures (rotational and hyperbolic) of the Lorentz group linking Quantum Mechanics and Relativity Theory

Compras públicas ambientalmente sustentáveis em um contexto de green supply chain management: um survey sobre o papel do treinamento ambiental, empowerment dos funcionários e fatores influenciadores externos

The objective of this study is to investigate the level of influence of environmental training and empowerment of employees to adopt environmentally sustainable procurement in public universities in Brazil. For this, a theoretical grounding was held to discuss issues relating to existing legal instruments in Brazil for environmentally sustainable public procurement, environmental criteria that can be used in public procurement, the profile of those responsible for public procurement department, and identify drivers and barriers to the environmentally sustainable procurement. This theoretical grounding supported the develpment of an empirical research, which was collected from 52 procurement department, for further analysis and processing by using descriptive statistics and correlation. The result show: (a) the departments of the sample indicate that many practices/ initiative are being implemented to enable the sustainable procurement are receiving training and have autonomy to pursue sustainable procurement; (c) Environmental Laws has become more demanding, however, they are still very insufficient according to the view of those responsible for purchasing, unable to generate awareness in the population; (d) while the green supply chain management in the private sector is already showing good results, the public sector has shown incipient, highlighting a state with much difficulty creating synergy with its suppliers and consumers. The originality of this research is the fact, to date, has not been found similar research on environmental training, empowerment, external factors and adopting sustainable procurement practices in the Brazilian context. Both managers and stakeholders can learn from this work and plain strategies to assist the achievement of sustainable resultsO objetivo deste estudo é analisar o nível de adoção de treinamento ambiental e empowerment ambiental dos funcionários para a adoção de compras ambientalmente sustentáveis no setor público brasileiro (universidades públicas do Brasil). Para tanto, realizou-se uma fundamentação conceitual onde são discutidos questões relativas aos instrumentos legais existentes no Brasil para as compras públicas ambientalmente sustentáveis, os critérios ambientais que podem ser utilizados nas compras públicas, além de identificar facilitadores e barreiras às compras ambientalmente sustentáveis. Esta fundamentação teórica apoiou o desenvolvimento de uma pesquisa empírica, onde foram coletados junto a 52 setores de compras, para posterior análise e processamento atravé de técnicas estatísticas descritivas e de correlação. Os resultados permitem constatar que: (a) os setores da amostra estudada indicam que muitas práticas/iniciativas estão sendo implementadas para viabilizar as compras sustentáveis; (b) os responsáveis pelos setores de compras estão recebendo treinamento e possuem autonomia para buscar as compras sustentáveis; (c) as Leis Ambientais vem se tornando mais exigentes, no entanto, ainda continuam muito insuficientes na visão dos responsáveis pelos setores de compras, incapazes de gerar consciência na população de u m modo geral; (d) enquanto o green supply chain management no setor privado já apresenta resultados satisfatórios, no setor público tem se mostrado incipiente, evidenciando um Estado com muita dificuldade em criar sinergia com seus fornecedores e consumidores. A originalidade deste trabalho reside no fato de, até o momento, não ter sido encontrada pesquisa similar sobre treinamento ambiental, empowerment, fatores externos e adoção de práticas de compras públicas sustentáveis no contexto brasileiro. Tanto gestores como stakeholders podem retirar ensinamentos deste trabalho e traduzir em ações..

Temperature- and pressure-dependence of the hydrogen bond network in plastic ice VII

We model, via classical molecular dynamics simulations, the plastic phase of ice VII across a wide range of the phase diagram of interest for planetary investigations. Although structural and dynamical properties of plastic ice VII are mostly independent on the thermodynamic conditions, the hydrogen bond network (HBN) acquires a diverse spectrum of topologies distinctly different from that of liquid water and of ice VII simulated at the same pressure. We observe that the HBN topology of plastic ice carries some degree of similarity with the crystal phase, stronger at thermodynamic conditions proximal to ice VII, and gradually lessening when approaching the liquid state. Our results enrich our understanding of the properties of water at high pressure and high temperature and may help in rationalizing the geology of water-rich planets. Published under an exclusive license by AIP Publishing

Computational pipeline to probe NaV1.7 gain-of-function variants in neuropathic painful syndromes

Applications of machine learning and graph theory techniques to neuroscience have witnessed an increased interest in the last decade due to the large data availability and unprecedented technology developments. Their employment to investigate the effect of mutational changes in genes encoding for proteins modulating the membrane of excitable cells, whose biological correlates are assessed at electrophysiological level, could provide useful predictive clues. We apply this concept to the analysis of variants in sodium channel NaV1.7 subunit found in patients with chronic painful syndromes, by the implementation of a dedicated computational pipeline empowering different and complementary techniques including homology modeling, network theory, and machine learning. By testing three templates of different origin and sequence identities, we provide an optimal condition for its use. Our findings reveal the usefulness of our computational pipeline in supporting the selection of candidates for cell electrophysiology assay and with potential clinical applications

Development of the CMS detector for the CERN LHC Run 3

International audienceSince the initial data taking of the CERN LHC, the CMS experiment has undergone substantial upgrades and improvements. This paper discusses the CMS detector as it is configured for the third data-taking period of the CERN LHC, Run 3, which started in 2022. The entire silicon pixel tracking detector was replaced. A new powering system for the superconducting solenoid was installed. The electronics of the hadron calorimeter was upgraded. All the muon electronic systems were upgraded, and new muon detector stations were added, including a gas electron multiplier detector. The precision proton spectrometer was upgraded. The dedicated luminosity detectors and the beam loss monitor were refurbished. Substantial improvements to the trigger, data acquisition, software, and computing systems were also implemented, including a new hybrid CPU/GPU farm for the high-level trigger

Development of the CMS detector for the CERN LHC Run 3

International audienceSince the initial data taking of the CERN LHC, the CMS experiment has undergone substantial upgrades and improvements. This paper discusses the CMS detector as it is configured for the third data-taking period of the CERN LHC, Run 3, which started in 2022. The entire silicon pixel tracking detector was replaced. A new powering system for the superconducting solenoid was installed. The electronics of the hadron calorimeter was upgraded. All the muon electronic systems were upgraded, and new muon detector stations were added, including a gas electron multiplier detector. The precision proton spectrometer was upgraded. The dedicated luminosity detectors and the beam loss monitor were refurbished. Substantial improvements to the trigger, data acquisition, software, and computing systems were also implemented, including a new hybrid CPU/GPU farm for the high-level trigger