Surface code fidelity at finite temperatures

We study the dependence of the fidelity of the surface code in the presence of a single finite-temperature massless bosonic environment after a quantum error correction cycle. The three standard types of environment are considered: super-Ohmic, Ohmic, and sub-Ohmic. Our results show that, for regimes relevant to current experiments, quantum error correction works well even in the presence of environment-induced, long-range inter-qubit interactions. A threshold always exists at finite temperatures, although its temperature dependence is very sensitive to the type of environment. For the super-Ohmic case, the critical coupling constant separating high- from low-fidelity decreases with increasing temperature. For both Ohmic and super-Ohmic cases, the dependence of the critical coupling on temperature is weak. In all cases, the critical coupling is determined by microscopic parameters of the environment. For the sub-Ohmic case, it also depends strongly on the duration of the QEC cycle.Comment: 13 pages, 6 figure

Surface Code Threshold in the Presence of Correlated Errors

We study the fidelity of the surface code in the presence of correlated errors induced by the coupling of physical qubits to a bosonic environment. By mapping the time evolution of the system after one quantum error correction cycle onto a statistical spin model, we show that the existence of an error threshold is related to the appearance of an order-disorder phase transition in the statistical model in the thermodynamic limit. This allows us to relate the error threshold to bath parameters and to the spatial range of the correlated errors.Comment: 5 pages, 2 figure

A case study on the construction of application ontologies

Appropriate techniques for the development of application ontologies are needed and GAODT (“Goal-Oriented Application Ontology Development Technique”) technique described in this article contributes to this purpose. GAODT translates the goals and facts in natural language expressing the requirements of a knowledge-based system into rules and facts in first-order logic. Next, this knowledge base is mapped to an application ontology. GAODT was evaluated through the development of a case study on the construction of the application ontology of a knowledge-based System for the domain of Intestate Succession. A software tool to support the application of GAODT was also developed.This work is supported by CNPq, CAPES and FAPEMA

Evolution of optic nerve and retina alterations in a child with indirect traumatic neuropathy as assessed by optical coherence tomography

Herein, we describe the case of a 4-year-old child with indirect traumatic optic neuropathy and serial changes of the optic nerve head and retinal nerve fiber layer (RNFL) documented using optical coherence tomography (OCT). Visual acuity improved despite progressive RNFL thinning and optic disc pallor. We concluded that OCT may be useful for monitoring axonal loss but may not predict the final visual outcome.Univ Miami, Miller Sch Med, Bascom Palmer Eye Inst, Dept Ophthalmol, 900 NW 17th St, Miami, FL 33136 USAUniv Fed Sao Paulo, Dept Ophthalmol & Visual Sci, Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Dept Ophthalmol & Visual Sci, Sao Paulo, SP, BrazilWeb of Scienc

O manto litosférico subcontinental metassomatizado abaixo de Coyhaique, Patagônia Chlena : a geoquímica de rocha total, química mineral e isótopos de gases nobres e Sr-Nd

Dissertação (mestrado)—Universidade de Brasília, Instituto de Geociências, Programa de Pós-Graduação em Geologia, 2020.Xenólitos mantélicos são comumente hospedados por lavas alcalinas na região de retro-arco patagônico. Os espinélio-lherzolitos de Coyhaique, região de Aysén, Chile (~46°S), estão entre as amostras mais próximas (~320 km) a Fossa do Chile e, portanto, sua composição geoquímica e isotópica podem registrar heterogeneidades do manto litosférico subcontinental (SCLM) causadas pela interação de componentes oriundos da zona de subducção atual e pretéritas. Neste trabalho apresentamos novos e detalhados dados de elementos maiores e traço de minerais (olivina, ortopiroxênio, clinopiroxênio e espinélio) e de rocha total juntamente com dados isotópicos de gases nobres (He, Ne, Ar) e de Sr-Nd de 16 espinélio-lherzolitos anidros. O processo de fusão parcial é evidenciado em rocha total e em minerais por correlações negativas de elementos basálticos (e.g., CaO, Al2O3, TiO2 e Na2O) vs. MgO. Todos os minerais silicáticos possuem padrão depletado de elementos terras raras leves (ETRL) com relação aos ETR- pesados (ETRP) (La/YbN <1), exceto por clinopiroxênios de quatro amostras (clinopiroxênio Tipo- 2; La/YbN = 1,35–3,48). Além disso, ETRP de rocha total e clinopiroxênios registram variados graus de fusão parcial (2–15% e 1-9%, respectivamente). Razões de Sr-Nd de rocha total e clinopiroxênios (87Sr/86Sr = 0,702347–0,703198; 143Nd/144Nd = 0,512940–0,513632; Nd = 5,89– 19,39) atestam o caráter depletado dos lherzolitos de Coyhaique. Dados geoquímicos sugerem metassomatismo críptico evidenciado por: 1) padrões enriquecidos de ETRL em rocha total e em clinopiroxênios do Tipo-2; 2) assinatura de elementos traço típica de arco caracterizada por pronunciadas anomalias negativas de elementos de alto potencial iônico (HFSE; Nb, Ta e Ti) somado ao enriquecimento de elementos litófilos de grande raio iônico (LILE) e de elementos calcófilos com relação a HFSE e ETRP em rocha total; 3) correlações positivas de Pb e U vs. La, e correlações negativas de Nb/Nb* e Ti/Ti* vs. La em clinopiroxênios; e 4) anomalias positivas de Li observadas em todos os silicatos. As diferenças entre as composições geoquímicas observadas entre rocha total e os minerais constituintes indicam enriquecimento seletivo da rocha total devido a componentes intergranulares ricos em LILE e ETRL. As razões radiogênicas de 3He/4He observadas nos lherzolitos de Coyhaique representam a primeira ocorrência para o SCLM patagônico (0,20–2,52 RA). A maioria das razões isotópicas de Ne analisadas não diferem da composição do ar, com exceção de algumas amostras que evidenciam um componente nucleogênico caracterizado pelo excesso de 21Ne (21Ne/22Ne = 0,0286–0,0308). As razões de 40Ar/36Ar (325–551) evidenciam forte contribuição de um componente atmosférico. Com base nos novos dados geoquímicos e isotópicos dos espinélio-lherzolitos de Coyhaique, identificamos um SCLM heterogêneo gerado a partir de variados e baixos graus de fusão parcial subsequentemente metassomatizado em decorrência da reciclagem de materiais derivados da subducção (melts e/ou fluidos provenientes de sedimentos e crosta oceânica subductados) no campo de estabilidade do espinélio (1,06–1,90 GPa e 886–1150 °C).Mantle xenoliths are commonly hosted by alkali lavas in the Patagonian back-arc region. The spinel-lherzolites from Coyhaique, Aysén Region, Chile (~46°S), are among the closest mantle samples (~320 km) to the Chile Trench and, therefore, their geochemical and isotopic compositions may record subcontinental lithospheric mantle (SCLM) heterogeneities caused by slab-derived components from current and/or ancient subduction zones. We present new detailed mineral (olivine, orthopyroxene, clinopyroxene and spinel) and whole-rock major and trace element analyses that are discussed together with noble gas (He, Ne, Ar) and Sr-Nd isotopic ratios from 16 selected anhydrous spinel-lherzolites. The xenoliths have experienced partial melting as evidenced by whole-rock and mineral negative correlations of basaltic elements (e.g., CaO, Al2O3, TiO2 and Na2O) vs. MgO. All silicate minerals show low light-rare earth element (LREE) over heavy-REE ratios (La/YbN <1), except four clinopyroxene samples that show some LREE enrichment (Type-2 clinopyroxene; La/YbN = 1.35–3.48). Additionally, whole-rock and clinopyroxenes HREE compositions record variables degrees of partial melting (2–15% and 1- 9%, respectively). Whole-rock and clinopyroxene Sr-Nd (87Sr/86Sr = 0.702347–0.703198; 143Nd/144Nd = 0.512940–0.513632; Nd = 5.89–19.39) data support the depleted character of Coyhaique lherzolite xenoliths. Our geochemical data suggest cryptic metasomatism that is evidenced by: 1) enriched LREE patterns in whole-rock and type-2 clinopyroxenes; 2) typical arc trace element signature characterized by pronounced negative anomalies of high field strength elements (HFSE; Nb, Ta and Ti) coupled with enrichment of large ion lithophile elements (LILE) and chalcophile elements in whole-rock samples; and 3) positive correlations of Pb and U vs. La, and negative correlations of Nb/Nb* and Ti/Ti* vs. La in clinopyroxene; and 4) Li positive anomalies observed in all silicates. The differences between whole-rock and mineral chemical compositions indicate a selective enrichment of the whole-rock samples due to LILE- and LREE- rich grain-boundary components. The 3He/4He ratios reported here are the first strongly radiogenic noble gas data for the Patagonian subcontinental lithospheric mantle (0.20–2.52 RA). Most measured Ne isotopic ratios are undistinguishable from air composition with few samples showing a nucleogenic component (21Ne/22Ne = 0.0286–0.0308). All 40Ar/36Ar ratios (325–551) were extensively affected by an atmospheric component. Based on the new geochemical and isotopic data of the Coyhaique spinel-lherzolite xenoliths, we identified a heterogeneous subcontinental lithospheric mantle affected by low but variable degrees of partial melting and subsequent enrichment by melts or fluids from recycled subduction-related materials (sediments and oceanic crust) in the spinel stability field (1.06–1.90 GPa and 886–1150 °C)

A Base Nacional Comum Curricular e os Projetos Pedagógicos das Escolas Escolas Católicas: aproximações possíveis

Considering the normative character of the National Curricular Common Basis (BNCC) and, therefore, the inexorable implications of its propositions on the curricula of catholic schools, it is necessary to question the adaptation of the curricula of these schools to the postulates of Basis, ensuring that these institutions have coherence with their educational projects. Thus, this article, elaborated from a qualitative research, of exploratory nature, seeks to find approach points between the pedagogical conceptions underlying the BNCC and the Ecclesial Magisterium, through the study of the Basis itself and documents from the Congregation of Catholic Education. In view of the relevance given by these two instances of the humanizing meaning of education, it is concluded that both the BNCC and the Church Magisterium stress the need to broaden the notion of school education, reaching the idea of full human formation within the horizon of the characteristic of intentionality of a curriculum that is organized according to the competencies paradigm. Recebido em: 06/02/2020.Aprovado em: 15/05/2020.Considerando o caráter normativo da Base Nacional Comum Curricular (BNCC) e, por conseguinte, as inexoráveis implicações de suas proposições sobre os currículos das escolas católicas, impõe-se a exigência de se problematizar a adequação dos currículos desses estabelecimentos de ensino aos postulados da Base, assegurando, a essas instituições, coerência com seus projetos educativos. Assim, este artigo, elaborado a partir de uma pesquisa qualitativa, de natureza exploratória, procura encontrar pontos de aproximação entre as concepções pedagógicas subjacentes à BNCC e ao Magistério Eclesial, por meio do estudo comparativo entre a própria Base e documentos da Congregação para a Educação Católica. Tendo em vista a relevância outorgada por essas duas instâncias ao sentido humanizador da educação, conclui-se que tanto a BNCC quanto o Magistério da Igreja sublinham a necessidade de se alargar a noção de educação escolar, alcançando a ideia de formação humana plena, no horizonte da característica de intencionalidade de um currículo que se organiza segundo o paradigma das competências. Recebido em: 06/02/2020.Aprovado em: 15/05/2020

Concepções da Igreja Católica Apostólica Romana sobre educação

Este artigo encerra um estudo teórico, elaborado segundo uma investigação qualitativa, por meio de pesquisas do tipo bibliográfica e documental, sustentando a tese de que o Magistério Eclesial, desenvolvido desde a celebração do Concílio Ecumênico Vaticano II (1962-1965), qualificaria a Igreja Católica Apostólica Romana como importante interlocutora junto às instâncias que discutem a realidade educacional hodierna. Assim, no âmbito deste trabalho, tendo em vista o conteúdo da convocação proferida pelo Papa Francisco, em 12 de setembro de 2019, para a afirmação de um pacto educativo global, pretende-se evidenciar a preocupação do Magistério Eclesial em resgatar a dimensão humanizadora da educação. Conclui-se que, para a Igreja, a educação compreende um processo de formação humana plena, o qual, recuperando a intrínseca vocação relacional dos sujeitos à experiência da alteridade e da transcendência, deve formá-los para o exercício do humanismo solidário

Resilient Quantum Computation in Correlated Environments: A Quantum Phase Transition Perspective

We analyze the problem of a quantum computer in a correlated environment protected from decoherence by QEC using a perturbative renormalization group approach. The scaling equation obtained reflects the competition between the dimension of the computer and the scaling dimension of the correlations. For an irrelevant flow, the error probability is reduced to a stochastic form for long time and/or large number of qubits; thus, the traditional derivation of the threshold theorem holds for these error models. In this way, the ``threshold theorem'' of quantum computing is rephrased as a dimensional criterion.Comment: 4.1 pages, minor correction and an improved discussion of Eqs. (4) and (14

Artificial intelligence tools for student learning assessment in professional schools

The necessity to maximize the learning success of the students as well as to produce professionals with the right skills to fulfil the market requirements, raises the question of closely following and assessing the learning paths of the students of Professional Schools. To solve at once problems and difficulties that arise during the learning process, we need to develop technologies and tools that allow the monitoring of those paths, if not in real time, at least periodically. Supported on a knowledge base of student features, also called a Student Model, a Student Assessment System must be able to produce diagnosis of student’s learning paths. Given the wide range of students’ learning experiences and behaviours, which implies a wide range of points and values in students’ models, such a tool should have some sort of intelligence. Moreover, that tool must rely on a formal methodology for problem solving to estimate a measure of the quality-ofinformation that branches out from students’ profiles, before trying to diagnose their learning problems. Indeed, this paper presents an approach to design a Diagnosis Module for a Student Assessment System, which is, in fact, a reasoner, in the sense that, presented with a new problem description (a student outline) it produces a solved problem, i.e., a diagnostic of the student learning state. We undertook the problem by selecting the attributes that are meaningful to produce a diagnosis, i.e., biographical, social, economical and cultural data, as well as skills so far achieved, which may drive, as constraints or invariants, the acquisition of new knowledge. Next, we selected the metrics that would allow us to infer the quality of the ongoing learning, i.e., the degree of expertise on the currently attended learning domains. To collect these indicators we used the Moodle e-Learning System. Both, attributes and metrics, make the student model. Finally, we designed a reasoner based on Artificial Intelligence techniques that rely on the Quality-of-Information quantification valuations to foster a Multi-Valued Extended Logic Programming language, a key element in order to produce diagnosis of the student learning paths. Confronted with a new case, i.e., a student model, the reasoner evaluates it in terms of its QI and outputs a diagnostic

Patient monitoring under an ambient intelligence setting

Springer - Series Advances in Intelligent and Soft Computing, vol. 72In recent years there has been a growing interest in developing Ambient Intelligence based systems in order to create smart environments for user and environmental monitoring. In fact, higher-level monitoring systems with vital information about the user and the environment around him/her represents an improvement of the quality of care provided. In this paper, we propose an architecture that implements a multi-agent user-profile based system for patient monitoring aimed to improve the assistance and health care provided. This system mixes logical based reasoning mechanisms with context-aware technologies. It is also presented a case based on a scenario developed at a major Portuguese healthcare institution