A Schmidt Decomposition Approach to Quantum Thermodynamics.

The development of a self-consistent thermodynamic theory of quantum systems is of fundamental importance for modern physics. Still, despite its essential role in quantum science and technology, there is no unifying formalism for characterizing the thermodynamics within general autonomous quantum systems, and many fundamental open questions remain unanswered. Along these lines, most current efforts and approaches restrict the analysis to particular scenarios of approximative descriptions and semi-classical regimes. Here, we propose a novel approach to describe the thermodynamics of arbitrary bipartite autonomous quantum systems based on the well-known Schmidt decomposition. This formalism provides a simple, exact, and symmetrical framework for expressing the energetics between interacting systems, including scenarios beyond the standard description regimes, such as strong coupling. We show that this procedure allows straightforward identification of local effective operators suitable for characterizing the physical local internal energies. We also demonstrate that these quantities naturally satisfy the usual thermodynamic notion of energy additivity.

Quality of malaria data in public health facilities in three provinces of Mozambique.

BACKGROUND: Malaria data reported through Mozambique's routine health information system are used to guide the implementation of prevention and control activities. Although previous studies have identified issues with the quality of aggregated data reported from public health facilities in the country, no studies have evaluated the quality of routine indicators recorded in health facility registries. This study addresses this issue by comparing indicators calculated from data from exit interviews and re-examinations of patients with data based on registry records from health facilities in order to measure the quality of registry data and data reporting in three provinces in Mozambique. METHODS: Data were collected from 1,840 outpatients from 117 health facilities in Maputo, Zambézia, and Cabo Delgado Provinces interviewed and examined as part of a malaria-specific health facility survey. Key indicators based on exit interview / re-examination data were compared to the same indicators based on records from health facility registries. Multivariable regression was performed to identify factors associated with indicators matching in re-examination / exit interview data and health facility registries. Aggregated indicators abstracted from facility registries were compared to those reported through the routine health management information system (HMIS) for the same time period. RESULTS: Sensitivity of exit interview / re-examination data compared with those recorded in facility registries was low for all indicators in all facilities. The lowest sensitivities were in Maputo, where the sensitivity for recording negative RDT results was 9.7%. The highest sensitivity was for recording positive RDT results in Cabo Delgado, at 75%. Multivariable analysis of factors associated with agreement between gold standard and registry data showed patients were less likely to be asked about having a fever in the triage ward in Maputo and Cabo Delgado (adjusted Odds Ratio 0.75 and 0.39 respectively), and in the outpatient ward in Cabo Delgado (aOR = 0.37), compared with the emergency department. Patients with positive RDT were also more likely to have RDT results recorded in all three provinces when patients had been managed according to national treatment guidelines during initial examination. Comparison of retrospective data abstracted from facility registries to HMIS data showed discrepancies in all three provinces. The proportion of outpatient cases with suspected and confirmed malaria were similar in registry and HMIS data across all provinces (a relatively low difference between registry and HMIS data of 3% in Maputo and Zambézia), though the total number of all-cause outpatient cases was consistently higher in the HMIS. The largest difference was in Maputo, where a total of 87,992 all-cause outpatient cases were reported in HMIS, compared with a total of 42,431 abstracted from facility registries. CONCLUSION: This study shows that care should be taken in interpreting trends based solely on routine data due to data quality issues, though the discrepancy in all-cause outpatient cases may be indicative that register availability and storage are important factors. As such, simple steps such as providing consistent access and storage of registers that include reporting of patient fever symptoms might improve the quality of routine data recorded at health facilities.

Validation of quantum adiabaticity through non-inertial frames and its trapped-ion realization.

Validity conditions for the adiabatic approximation are useful tools to understand and predict the quantum dynamics. Remarkably, the resonance phenomenon in oscillating quantum systems has challenged the adiabatic theorem. In this scenario, inconsistencies in the application of quantitative adiabatic conditions have led to a sequence of new approaches for adiabaticity. Here, by adopting a different strategy, we introduce a validation mechanism for the adiabatic approximation by driving the quantum system to a non-inertial reference frame. More specifically, we begin by considering several relevant adiabatic approximation conditions previously derived and show that all of them fail by introducing a suitable oscillating Hamiltonian for a single quantum bit (qubit). Then, by evaluating the adiabatic condition in a rotated non-inertial frame, we show that all of these conditions, including the standard adiabatic condition, can correctly describe the adiabatic dynamics in the original frame, either far from resonance or at a resonant point. Moreover, we prove that this validation mechanism can be extended for general multi-particle quantum systems, establishing the conditions for the equivalence of the adiabatic behavior as described in inertial or non-inertial frames. In order to experimentally investigate our method, we consider a hyperfine qubit through a single trapped Ytterbium ion 171Yb+, where the ion hyperfine energy levels are used as degrees of freedom of a two-level system. By monitoring the quantum evolution, we explicitly show the consistency of the adiabatic conditions in the non-inertial frame.

Probing the Unruh effect with an accelerated extended system.

It has been proved in the context of quantum fields in Minkowski spacetime that the vacuum state is a thermal state according to uniformly accelerated observers-a seminal result known as the Unruh effect. Recent claims, however, have challenged the validity of this result for extended systems, thus casting doubts on its physical reality. Here, we study the dynamics of an extended system, uniformly accelerated in the vacuum. We show that its reduced density matrix evolves to a Gibbs thermal state with local temperature given by the Unruh temperature [Formula: see text], where a is the system's spatial-dependent proper acceleration-c is the speed of light and kB and [Formula: see text] are the Boltzmann's and the reduced Planck's constants, respectively. This proves that the vacuum state does induce thermalization of an accelerated extended system-which is all one can expect of a legitimate thermal reservoir.

Quality of malaria services offered in public health facilities in three provinces of Mozambique: a cross-sectional study.

BACKGROUND: Fever associated with malaria is the leading cause of health care-seeking in Mozambique, yet there is limited evidence on the quality of malaria case management. This study evaluated the quality of malaria service provision offered in public health facilities in Mozambique. METHODS: A cross-sectional assessment was conducted in April-May 2018 in three provinces of Mozambique: Maputo Province (low malaria burden), Cabo Delgado (high), and Zambézia (high). The study included all secondary and tertiary facilities and a random sample of primary facilities in each province. Data collection included exit interviews and re-examinations of 20 randomly selected outpatient service patients, interviews with up to five health care providers and the health facility director, a stockroom inventory and routine data abstraction. RESULTS: A total of 319 health care providers and 1840 patients from 117 health facilities were included. Of these, 1325 patients (72%) had suspected malaria (fever/history of fever) and 550 (30%) had febrile, confirmed malaria with the highest burden in Cabo Delgado (43%), followed by Zambézia (34%) and Maputo Province (2%). Appropriate management of malaria cases, defined as testing malaria suspects and treating confirmed cases with the correct dose of anti-malarial, was highest in Zambézia and Cabo Delgado where 52% (95% CI 42-62) and 49% (42-57) of febrile malaria cases were appropriately managed, respectively. Only 14% (5-34) of febrile cases in Maputo Province were appropriately managed. The biggest gap in the malaria case management pathway was failure to test febrile patients, with only 46% of patients with this indication tested for malaria in Maputo Province. Additionally, anti-malarial treatment of patients with a negative malaria test result was common, ranging from 8% (2-23) in Maputo Province to 22% (14-32) of patients with a negative test in Zambézia. Only 58-62% of patients prescribed an anti-malarial correctly recited dosing instructions. Provider training and malaria knowledge was low outside of Zambézia and supervision rates were low in all provinces. Factors associated with correct case management varied by province and included patient age, facility type, treatment and testing availability, supervision, and training. CONCLUSION: These findings underscore the need to strengthen provider testing of all patients with fever, provider adherence to negative test results, and effective counselling of patients across epidemiological settings in Mozambique.

Non-Thermal Quantum Engine in Transmon Qubits.

The design and implementation of quantum technologies necessitates the understanding of thermodynamic processes in the quantum domain. In stark contrast to macroscopic thermodynamics, at the quantum scale processes generically operate far from equilibrium and are governed by fluctuations. Thus, experimental insight and empirical findings are indispensable in developing a comprehensive framework. To this end, we theoretically propose an experimentally realistic quantum engine that uses transmon qubits as working substance. We solve the dynamics analytically and calculate its efficiency.

An extensive reef system at the Amazon River mouth.

Large rivers create major gaps in reef distribution along tropical shelves. The Amazon River represents 20% of the global riverine discharge to the ocean, generating up to a 1.3 × 10(6)-km(2) plume, and extensive muddy bottoms in the equatorial margin of South America. As a result, a wide area of the tropical North Atlantic is heavily affected in terms of salinity, pH, light penetration, and sedimentation. Such unfavorable conditions were thought to imprint a major gap in Western Atlantic reefs. We present an extensive carbonate system off the Amazon mouth, underneath the river plume. Significant carbonate sedimentation occurred during lowstand sea level, and still occurs in the outer shelf, resulting in complex hard-bottom topography. A permanent near-bottom wedge of ocean water, together with the seasonal nature of the plume's eastward retroflection, conditions the existence of this extensive (~9500 km(2)) hard-bottom mosaic. The Amazon reefs transition from accretive to erosional structures and encompass extensive rhodolith beds. Carbonate structures function as a connectivity corridor for wide depth-ranging reef-associated species, being heavily colonized by large sponges and other structure-forming filter feeders that dwell under low light and high levels of particulates. The oxycline between the plume and subplume is associated with chemoautotrophic and anaerobic microbial metabolisms. The system described here provides several insights about the responses of tropical reefs to suboptimal and marginal reef-building conditions, which are accelerating worldwide due to global changes.

Quantum information storage using tunable flux qubits.

We present details and results for a superconducting quantum bit (qubit) design in which a tunable flux qubit is coupled strongly to a transmission line. Quantum information storage in the transmission line is demonstrated with a dephasing time of T(2)∼ 2.5 µs. However, energy lifetimes of the qubit are found to be short (∼ 10 ns) and not consistent with predictions. Several design and material changes do not affect qubit coherence times. In order to determine the cause of these short coherence times, we fabricated standard flux qubits based on a design which was previously successfully used by others. Initial results show significantly improved coherence times, possibly implicating losses associated with the large size of our qubit.

Reflexões sobre a Federação brasileira / Reflections about the Brazilian Federation

Aborda a questão do pacto federativo e seus respectivos desdobramentos. Destaca as discussões relativas às desigualdades sócio-econômicas inter-regionais e a atual estrutura de distribuição de recursos entre as esferas de governo e seus impactos sobre os entes federados