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We investigate the anomalous energy change of the measurement apparatus when a qubit is measured in bases that do not commute with energy. We model two possible measurement implementations: one is a quantum clock model with a completely time-independent Hamiltonian, while the other is a Jaynes-Cummings model which is time-dependent but conserves the total excitation number. We look at the mean energy change of the measurement apparatus in both models, conditioned on the qubit post-selection, and find that this change can be much greater than the level spacing of the qubit, like an anomalous weak value. In the clock model, the expression for the apparatus energy shift explicitly contains the weak value of the qubit Hamiltonian. However, in our case, no explicit weak measurements are carried out. Our two models give different results, which we explain to be a consequence of the non-degenerate spectrum of the Jaynes-Cummings model. We compare our calculations in the Jaynes-Cummings model with the experimental data of [J. Stevens, et al, arXiv:2109.09648 (2021)] and find good agreement when the conditions of our derivation are valid., 23 pages, 6 figures

To perform scoping review of the existing literature available specific to child and adolescent mental health in Tanzania.An extensive literature search of PubMed, Scopus, MEDLINE and EMBASE was undertaken to identify studies that focussed specifically on mental illness in children and young people in Tanzania. This included neurological and functional disorders, affective disorders, psychosis, epidemiological, intervention and treatment-based studies. Qualitative analysis of the studies was then undertaken to assess what is currently known about the subject and how reliable this information is and to identify areas for further research.Of 23 studies were included in the final synthesis, which could be broadly split into studies focussing on the prevalence and incidence of child and adolescent mental illness, hypothesised causes and correlations, identified treatments and interventions and qualitative studies of human experience.There is a dearth of published research regarding child and adolescent mental health in Tanzania. Although some high-quality studies allow us good insight into the epidemiology of mental illness, interventional studies are often small and low-power, and significant correlational relationships are yet to be drawn. There is significant scope for further child and adolescent mental health research in Tanzania.Analyse de la portée de la littérature existante disponible spécifique à la santé mentale des enfants et des adolescents en Tanzanie. MÉTHODES: Une recherche documentaire approfondie de PubMed, Scopus, Medline et Embase a été entreprise pour identifier les études qui se concentraient spécifiquement sur la maladie mentale chez les enfants et les jeunes en Tanzanie. Cela comprenait des troubles neurologiques et fonctionnels, des troubles affectifs, des psychoses, des études épidémiologiques, d'intervention et basées sur le traitement. Une analyse qualitative des études a ensuite été entreprise pour évaluer ce que l'on sait actuellement sur le sujet, la fiabilité de ces informations et pour identifier des domaines pour des recherche plus approfondie. RÉSULTATS: 23 études ont été incluses dans la synthèse finale, qui pourrait être largement divisée en études axées sur la prévalence et l'incidence de la maladie mentale chez l'enfant et l'adolescent, les causes et corrélations hypothétiques, les traitements et interventions identifiés et les études qualitatives de l'expérience humaine.Il y a une pénurie de recherches publiées sur la santé mentale des enfants et des adolescents en Tanzanie. Bien que certaines études de haute qualité nous permettent de bien comprendre l'épidémiologie de la maladie mentale, les études interventionnelles sont souvent de petite taille et de faible puissance, et des relations de corrélation importantes doivent encore être établies. Il existe une marge de manœuvre importante pour plus de recherches sur la santé mentale des enfants et des adolescents en Tanzanie.

We introduce a two-qubit engine that is powered by entanglement and local measurements. Energy is extracted from the detuned qubits coherently exchanging a single excitation. Generalizing to an N-qubit chain, we show that the low energy of the first qubit can be up-converted to an arbitrarily high energy at the last qubit by successive neighbor swap operations and local measurements. We finally model the local measurement as the entanglement of a qubit with a meter, and we identify the fuel as the energetic cost to erase the correlations between the qubits. Our findings extend measurement-powered engines to composite working substances and provide a microscopic interpretation of the fueling mechanism.

The Wigner's friend paradox concerns one of the most puzzling problems of quantum mechanics: the consistent description of multiple nested observers. Recently, a variation of Wigner's gedankenexperiment, introduced by Frauchiger and Renner, has lead to new debates about the self-consistency of quantum mechanics. At the core of the paradox lies the description of an observer and the object it measures as a closed system obeying the Schr\"odinger equation. We revisit this assumption to derive a necessary condition on a quantum system to behave as an observer. We then propose a simple single-photon interferometric setup implementing Frauchiger and Renner's scenario, and use the derived condition to shed a new light on the assumptions leading to their paradox. From our description, we argue that the three apparently incompatible properties used to question the consistency of quantum mechanics correspond to two logically distinct contexts: either one assumes that Wigner has full control over his friends' lab, or conversely that some parts of the labs remain unaffected by Wigner's subsequent measurements. The first context may be seen as the quantum erasure of the memory of Wigner's friend. We further show these properties are associated with observables which do not commute, and therefore cannot take well-defined values simultaneously. Consequently, the three contradictory properties never hold simultaneously., Comment: 11 pages, 3 figures. Accepted in Quantum (24 June 2021)

Category 5 Hurricane Michael made landfall near Mexico Beach, Florida on October 9, 2018, with measured high water marks (HWMs) reaching 7.2 m NAVD88. The town itself received great damage, with many areas destroyed down to the foundations. In this study, we document the storm and its effects on the greater Mexico Beach area: hazard, structural damage, and their relationships. Wave and surge damage was nearly total for low-lying properties, but damage decreased greatly with increasing elevation. Major wave and surge damage was noted in Federal Emergency Management Agency (FEMA) X zones, which are out of the 100-year floodplain, and it is suggested that the 100-year storm is a deficient measure for categorizing flood risk. This work is made available under the terms of the Creative Commons Attribution 4.0 International license, https://creativecommons.org/licenses/by/4.0/ National Science FoundationNational Science Foundation (NSF) [1661015, 1822307, 1841667]; National Institute of Standards and TechnologyNational Institute of Standards & Technology (NIST) - USA; Florida Division of Emergency Management Project [B0021 DEM-HL-00004]; Joint Airborne Lidar Bathymetry Technical Center of Expertise; Applied Technology Council This work was performed with funding from the National Science Foundation (Grant Nos. 1661015, 1822307, and 1841667), the National Institute of Standards and Technology, financial support from the Florida Division of Emergency Management Project No. B0021 DEM-HL-00004, the Joint Airborne Lidar Bathymetry Technical Center of Expertise, and the Applied Technology Council. Their support is gratefully acknowledged.

Colloidal semiconductor nanocrystals (NCs) represent a promising class of nanomaterials for lasing applications. Currently, one of the key challenges facing the development of high-performance NC optical gain media lies in enhancing the lifetime of biexciton populations. This usually requires the employment of charge-delocalizing particle architectures, such as core/shell NCs, nanorods, and nanoplatelets. Here, we report on a two-dimensional nanoshell quantum dot (QD) morphology that enables a strong delocalization of photoinduced charges, leading to enhanced biexciton lifetimes and low lasing thresholds. A unique combination of a large exciton volume and a smoothed potential gradient across interfaces of the reported CdSbulk/CdSe/CdSshell (core/shell/shell) nanoshell QDs results in strong suppression of Auger processes, which was manifested in this work though the observation of stable amplified stimulated emission (ASE) at low pump fluences. An extensive charge delocalization in nanoshell QDs was confirmed by transient absorption measurements, showing that the presence of a bulk-size core in CdSbulk/CdSe/CdSshell QDs reduces exciton-exciton interactions. Overall, present findings demonstrate unique advantages of the nanoshell QD architecture as a promising optical gain medium in solid-state lighting and lasing applications.

We introduce diffraction-based interaction-free measurements. In contrast with previous work where a set of discrete paths is engaged, good quality interaction-free measurements can be realized with a continuous set of paths, as is typical of optical propagation. If a bomb is present in a given spatial region -- so sensitive that a single photon will set it off -- its presence can still be detected without exploding it. This is possible because, by not absorbing the photon, the bomb causes the single photon to diffract around it. The resulting diffraction pattern can then be statistically distinguished from the bomb-free case. We work out the case of single- versus double- slit in detail, where the double-slit arises because of a bomb excluding the middle region., Comment: 8 pages, 4 figures

The visualization of distinct molecular species represents an important challenge of bio-imaging research. In past decades, the development of multicolor fluorescent (FL) labels has greatly improved our ability to track biological analytes, paving the way for important advances in understanding the cell dynamics. It remains challenging, however, to visualize a large number of different fluorephores simultaneously. Owing to a spectrally broad absorption of fluorescent dyes, only up to five color categories can be resolved at once. Here, we demonstrate a general strategy for distinguishing between multiple fluorescent targets in acquired microscopy images with improved accuracy. The present strategy is enabled through spectral shaping of the excitation light with an optical filter that uniquely attenuates the light absorption of each fluorophore in the investigated sample. The resulting emission changes, induced by such excitation modulation, are therefore target-specific and can be used for identifying various fluorescent species. The technique is demonstrated through an accurate identification of 8 different CdSe dyes with absorption maxima spanning the 520-620 spectral range. It is subsequently applied for accurate measurements of the pH balance in buffers emulating a metabolism of tumor cells.

Posthurricane Ike surveys for almost 2,000 individual wood-framed houses were combined with high resolution numerical hindcasts to investigate the collapse limit state arising from overland waves and surge. For this storm, freeboard above wave crests, wave height, current velocity, and construction date were found to be the most important factors determining survival. Regressions show considerable skill in predicting collapse fragilities and will prove useful in assessing vulnerability. The relatively small range of wind speeds available in the data set did not allow accurate assessments of wind effects on collapse. Several ASCE and FEMA force estimates showed relatively low skill in modeling fragility, in large part because their breaking wave assumption was not accurate over much of the range. However, the use of best-estimate wave heights in force modeling greatly improved accuracy of fragility estimates. Despite the positive results of this study, numerous questions remain. It proved impossibl...

The Bolivar Peninsula in Texas was severely impacted by Hurricane Ike with strong winds, large waves, widespread inundation, and severe damage. This paper examines the wave and surge climate on Bolivar during the storm and the consequent survival and destruction of buildings. Emphasis is placed on differences between buildings that survived (with varying degrees of damage) and buildings that were completely destroyed. Building elevations are found to be the primary indicator of survival for areas with large waves. Here, buildings that were sufficiently elevated above waves and surge suffered relatively little structural damage, while houses at lower elevations were impacted by large waves and generally completely destroyed. In many areas, the transition from destruction to survival was over a very small elevation range of around 0.5 m. In areas where waves were smaller, survival was possible at much lower elevations. Higher houses that were not inundated still survived, but well-built houses at lower elevations could also survive as the waves were not large enough to cause structural damage. However, the transition height where waves became damaging could not be determined from this study.

Hurricane Ike made landfall on the U.S. Gulf of Mexico coast on September 13, 2008 over the Galveston Bay Entrance in Texas (Edge, 2013). The Bolivar Peninsula is a barrier island/peninsula on the east side of the Entrance that received peak overland storm surge and wave heights in the right front quadrant of the hurricane. Prior to the storm Bolivar had been developed with 6000+ buildings, primarily low-density, single-family houses elevated on piling foundations. Over 2000 buildings were destroyed during the storm.

Hurricane Ike was a large storm as it crossed the Gulf of Mexico. When it entered into Texas it caused a storm surge of up to 4 m and substantial waves with high winds represented by a Category 2 hurricane. The storm caused extensive flooding and erosion which led to significant property damage on Boliver Peninsula and on Galveston Island. COPRI (Coasts, Oceans, Ports and Rivers Institute) of the ASCE (American Society of Civil Engineers) sponsored a team of engineers and scientists to observe the coast and collect perishable data approximately one month after the storm. One of the main conclusions from the inspection of buildings was that elevation was a key determinant for survival. Members of the team returned for another visit approximately one year later to observe how the recovery had progressed. Those observations show some redevelopment but also some serious flaws in the coastal management implementation.

Hurricane Ike was the third costliest hurricane to hit the United States, causing almost $30 billion in damage after making landfall on the Bolivar Peninsula, Texas, in September, 2008. Following the disaster, a case study of the peninsula was conducted to evaluate hurricane-generated wave and water level effects on wood framed, pile-elevated coastal residences. This study provided information about the structural characteristics most influential to the survival of these homes and may be used to validate future wave force prediction and fragility models for elevated coastal residences. A total of 1922 homes on the Bolivar Peninsula were sampled, and hindcasts of significant wave heights and water levels during the storm were run to relate environmental factors and structural attributes to a home’s probability of survival. Freeboard, calculated as the difference between the elevation of the lowest horizontal structural member and the combined wave crest and storm surge elevation, was shown to play a critical role in determining survival: survey data indicated that a positive freeboard resulted in a near 100% survival rate for homes subjected to significant wave heights above 3.5 ft (1.07 m). Survival was also strongly influenced by maximum significant wave height itself; below significant wave heights of approximately 3.5 ft, the freeboard requirement for survival dropped sharply. Uncertainty of numerical hindcasts of significant wave heights was considered when evaluating survival as a function of wave height; however, these estimations were considered more accurate than assuming depth-limited breaking waves at each house location. Homes experienced much larger survival rates in areas subject to small significant wave height conditions than in locations affected by larger waves. This analysis was the first step in accurately determining expected damage resulting from specific wave and water level loadings. A more generalized analysis will mitigate possible effects of construction techniques, survey bias, debris impact, and environment-specific wave height estimations on quantitative survival criteria.

The results of damage assessments following recent hurricane events suggest that predictions of wave transformation across barrier islands during overtopping events are unreliable and, even worse, inaccurate. In many cases, inaccurate model predictions of wave heights in high hazard areas are translating into improper standards for “lowest structural member” elevations on residential and commercial structures. The substantive result of which is increased cost of construction, whether initial or replacement costs. The purpose of this research is to improve guidance on building elevations in high hazard flood plain areas where wave action is the primary structural damage mechanism. A number of novel, autonomous wave gauges will be temporarily mounted to fixed structures on Dauphin Island, Alabama, in advance of an overtopping event during future hurricane seasons. Measured wave heights and water levels will provide an opportunity to characterize wave transformation across the barrier island. When combined with surveyed building elevations and a detailed inventory of structural and foundation characteristics, the measured waves and water levels will provide an opportunity to identify critical building elevations that delineate survival and destruction, as well as determine the adequacy of structural connections and foundations.