How much time does a measurement take?

We consider the problem of measurement using the Lindblad equation, which allows the introduction of time in the interaction between the measured system and the measurement apparatus. We use analytic results, valid for weak system-environment coupling, obtained for a two-level system in contact with a measurer (Markovian interaction) and a thermal bath (non-Markovian interaction), where the measured observable may or may not commute with the system-environment interaction. Analysing the behavior of the coherence, which tends to a value asymptotically close to zero, we obtain an expression for the time of measurement which depends only on the system-measurer coupling, and which does not depend on whether the observable commutes with the system-bath interaction. The behavior of the coherences in the case of strong system-environment coupling, found numerically, indicates that an increase in this coupling decreases the measurement time, thus allowing our expression to be considered the upper limit for the duration of the process.Comment: REVISED VERSION: 17 pages, 2 figure

Protecting a quantum state from environmental noise by an incompatible finite-time measurement

We show that measurements of finite duration performed on an open two-state system can protect the initial state from a phase-noisy environment, provided the measured observable does not commute with the perturbing interaction. When the measured observable commutes with the environmental interaction, the finite-duration measurement accelerates the rate of decoherence induced by the phase noise. For the description of the measurement of an observable that is incompatible with the interaction between system and environment, we have found an approximate analytical expression, valid at zero temperature and weak coupling with the measuring device. We have tested the validity of the analytical predictions against an exact numerical approach, based on the superoperator-splitting method, that confirms the protection of the initial state of the system. When the coupling between the system and the measuring apparatus increases beyond the range of validity of the analytical approximation, the initial state is still protected by the finite-time measurement, according with the exact numerical calculations.Comment: REVISED VERSION: 37 pages, 3 figure

Ensaios alelopáticos realizados com extratos obtidos do caule de Salácia impressifolia.

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Planting time for maximization of yield of vinegar plant calyx (Hibiscus sabdariffa L.)

Objetivou-se avaliar a produtividade de cálices de Hibiscus sabdariffa L., planta medicinal, em quatro épocas de plantio em Lavras M.G. Os tratamentos foram quatro épocas de plantio (18 de outubro; 15 de novembro; 18 de dezembro de 2001 e 15 de janeiro de 2002) e realizada uma colheita quando praticamente não existiam cálices em desenvolvimento, quase no final do ciclo da planta. Foram considerados os números de cálices por planta, as fitomassas frescas e secas dos cálices e a qualidade. Concluiu-se que a época de plantio influenciou o rendimento por planta e as fitomassas frescas e secas dos cálices, diferindo entre si pelo teste de Tukey a 5%. No plantio de outubro, houve maior rendimento (2.522 kg/ha), com produção de 5,24 vezes a mais em relação ao plantio do mês de janeiro (481 kg/ha). Os plantios nos meses de novembro e dezembro tiveram produções de 1.695 e 1.093 kg.ha-1 de cálices secos, respectivamente, e em relação ao mês de janeiro, a produção foi 3,52 e 2,27 vezes a mais.Deve-se realizar a colheita assim que os cálices estiverem maduros, a fim de preservar a qualidade

Análise de sujidades e matérias estranhas em méis (Apis mellifera L.) comercializadas na cidade de Belém-PA.

O objetivo deste trabalho foi avaliar a qualidade higiênica dos méis comercializados em feiras livres e supermercados de Belém, PA, Brasil, através da análise de matérias estranhas por microscopia. As amostras foram dissolvidas em água quente acidificada, filtradas e analisadas em estereomicroscópio. Nas amostras das feiras livres foram encontrados ácaros, cabelo, formigas, aranha e matéria orgânica carbonizada. Nos méis industrializados foram encontrados fragmentos de insetos. A presença de sujidades e matérias estranhas indicam que as amostras não estão em conformidade com a legislação vigente

An Intersectional Approach to Equity, Inequity, and Archaeology

The year 2020 was an awakening for some. For others, it reiterated the persistent social injustice in the United States. Compelled by these events, 30 diverse individuals came together from January to May 2021 for a semester-long seminar exploring inequity in archaeological practice. The seminar's discussions spotlighted the inequity and social injustices that are deeply embedded within the discipline. However, inequity in archaeology is often ignored or treated narrowly as discrete, if loosely bound, problems. A broad approach to inequity in archaeology revealed injustice to be intersectional, with compounding effects. Through the overarching themes of individual, community, theory, and practice, we (a subset of the seminar's participants) explore inequity and its role in various facets of archaeology, including North-South relations, publication, resource distribution, class differences, accessibility, inclusive theories, service to nonarchaeological communities, fieldwork, mentorship, and more. We focus on creating a roadmap for understanding the intersectionality of issues of inequity and suggesting avenues for continued education and direct engagement. We argue that community-building - by providing mutual support and building alliances - provides a pathway for realizing greater equity in our discipline.Fil: Rivera Prince, Jordi A.. University of Florida; Estados UnidosFil: Blackwood, Emily M.. University of Maine; Estados UnidosFil: Brough, Jason A.. University of Maine; Estados UnidosFil: Landázuri, Heather A.. University of Maine; Estados UnidosFil: Leclerc, Elizabeth L.. University of Maine; Estados UnidosFil: Barnes, Monica. American Museum of Natural History; Estados UnidosFil: Brasil, Kareen Kristina. Columbia University; Estados UnidosFil: Gutierrez, Maria Amelia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano. Universidad Nacional del Centro de la Provincia de Buenos Aires. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano; ArgentinaFil: Herr, Sarah. Desert Archaeology, Inc.; MéxicoFil: Maasch, Kirk A.. University of Maine; Estados UnidosFil: Sandweiss, Daniel H.. University of Maine; Estados Unido

listening to what matters for the patients and health professionals

Funding Information: The authors would like to acknowledge the members of the medical and patient committees for the input, advice and experiences shared for the guidance of this study. Namely, to AM, SP, JP, LR, MC, RF, TR and JB for being part of the patient committee and to JJ, EM, LB, DCo, DCa, CTL, RA, CL and AE for integrating the medical committee. We also want to acknowledge the volunteers from the NOVA Sci & Tech Volunteer program that helped with the organisation of this project. Funding Information: This work was supported by the CDG & Allies—Professionals and Patient Associations International Network (CDG&Allies-PPAIN) and by national funds from FCT—Fundação para a Ciência e a Tecnologia, I.P., in the scope of the Project UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular Biosciences—UCIBIO, the Project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy—i4HB C.P. and R.F. were funded by Fundação para a Ciência e Tecnologia with the Grants SFRH/BD/138647/2018 and (SFRH/BD/124326/2016) respectively. Publisher Copyright: © 2022, The Author(s).Background: Congenital disorders of glycosylation (CDG) are a growing group of rare genetic disorders. The most common CDG is phosphomannomutase 2 (PMM2)-CDG which often has a severe clinical presentation and life-limiting consequences. There are no approved therapies for this condition. Also, there are no validated disease-specific quality of life (QoL) scales to assess the heterogeneous clinical burden of PMM2-CDG which presents a challenge for the assessment of the disease severity and the impact of a certain treatment on the course of the disease. Aim and methods: This study aimed to identify the most impactful clinical signs and symptoms of PMM2-CDG, and specific patient and observer reported outcome measures (PROMs and ObsROMs, respectively) that can adequately measure such impact on patients’ QoL. The most burdensome signs and symptoms were identified through input from the CDG community using a survey targeting PMM2-CDG families and experts, followed by family interviews to understand the real burden of these symptoms in daily life. The list of signs and symptoms was then verified and refined by patient representatives and medical experts in the field. Finally, a literature search for PROMs and ObsROMs used in other rare or common diseases with similar signs and symptoms to those of PMM2-CDG was performed. Results: Twenty-four signs/symptoms were identified as the most impactful throughout PMM2-CDG patients’ lifetime. We found 239 articles that included tools to measure those community-selected PMM2-CDG symptoms. Among them, we identified 80 QoL scales that address those signs and symptoms and, subsequently, their psychometric quality was analysed. These scales could be applied directly to the PMM2-CDG population or adapted to create the first PMM2-CDG-specific QoL questionnaire. Conclusion: Identifying the impactful clinical manifestations of PMM2-CDG, along with the collection of PROMs/ObsROMs assessing QoL using a creative and community-centric methodology are the first step towards the development of a new, tailored, and specific PMM2-CDG QoL questionnaire. These findings can be used to fill a gap in PMM2-CDG clinical development. Importantly, this methodology is transferable to other CDG and rare diseases with multiple signs and symptoms.publishersversionpublishe

Enhancement of carrier lifetimes in type-II quantum dot/quantum well hybrid structures

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORWe investigate optical transitions and carrier dynamics in hybrid structures containing type-I GaAs/AlGaAs quantum wells (QWs) and type-II GaSb/AlGaAs quantum dots (QDs). We show that the optical recombination of photocreated electrons confined in the QWs with holes in the QDs and wetting layer can be modified according to the QW/QD spatial separation. In particular, for low spacer thicknesses, the QW optical emission can be suppressed due to the transference of holes from the QW to the GaSb layer, favoring the optical recombination of spatially separated carriers, which can be useful for optical memory and solar cell applications. Time-resolved photoluminescence (PL) measurements reveal non-exponential recombination dynamics. We demonstrate that the PL transients can only be quantitatively described by considering both linear and quadratic terms of the carrier density in the bimolecular recombination approximation for type-II semiconductor nanostructures. We extract long exciton lifetimes from 700 ns to 5 mu s for QDs depending on the spacer layer thickness. Published by AIP Publishing.We investigate optical transitions and carrier dynamics in hybrid structures containing type-I GaAs/AlGaAs quantum wells (QWs) and type-II GaSb/AlGaAs quantum dots (QDs). We show that the optical recombination of photocreated electrons confined in the QWs with holes in the QDs and wetting layer can be modified according to the QW/QD spatial separation. In particular, for low spacer thicknesses, the QW optical emission can be suppressed due to the transference of holes from the QW to the GaSb layer, favoring the optical recombination of spatially separated carriers, which can be useful for optical memory and solar cell applications. Time-resolved photoluminescence (PL) measurements reveal non-exponential recombination dynamics. We demonstrate that the PL transients can only be quantitatively described by considering both linear and quadratic terms of the carrier density in the bimolecular recombination approximation for type-II semiconductor nanostructures. We extract long exciton lifetimes from 700 ns to 5 mu s for QDs depending on the spacer layer thickness.120817FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR2012/11382-9 , 2014/17141-9Sem informaçãoSem informaçã

Valence-band splitting energies in wurtzite InP nanowires : Photoluminescence spectroscopy and ab initio calculations

We investigated experimentally and theoretically the valence-band structure of wurtzite InP nanowires. The wurtzite phase, which usually is not stable for III-V phosphide compounds, has been observed in InP nanowires. We present results on the electronic properties of these nanowires using the photoluminescence excitation technique. Spectra from an ensemble of nanowires show three clear absorption edges separated by 44 meV and 143 meV, respectively. The band edges are attributed to excitonic absorptions involving three distinct valence-bands labeled: A, B, and C. Theoretical results based on"ab initio" calculation gives corresponding valence-band energy separations of 50 meV and 200 meV, respectively, which are in good agreement with the experimental results