Streptomycin ototoxicity in the unborn child

The original publication is available at http://www.samj.org.zaStreptomycin has been used in pregnant patients for more than 30 years. Some doubt, however, still exists with regard to its effects on the ear of the unborn child. Thirty-three children whose mothers had received streptomycin during pregnancy were followed up and their hearing tested. A minor degree of hearing loss which could possibly be due to the action of streptomycin was found in only 2 children.Publishers' versio

Single photon production by rephased amplified spontaneous emission

The production of single photons using rephased amplified spontaneous emission is examined. This process produces single photons on demand with high efficiency by detecting the spontaneous emission from an atomic ensemble, then applying a population-inverting pulse to rephase the ensemble and produce a photon echo of the spontaneous emission events. The theoretical limits on the efficiency of the production are determined for several variants of the scheme. For an ensemble of uniform optical density, generating the initial spontaneous emission and its echo using transitions of different strengths is shown to produce single photons at 70% efficiency, limited by reabsorption. Tailoring the spatial and spectral density of the atomic ensemble is then shown to prevent reabsorption of the rephased photon, resulting in emission efficiency near unity

Non-classical photon streams using rephased amplified spontaneous emission

We present a fully quantum mechanical treatment of optically rephased photon echoes. These echoes exhibit noise due to amplified spontaneous emission, however this noise can be seen as a consequence of the entanglement between the atoms and the output light. With a rephasing pulse one can get an "echo" of the amplified spontaneous emission, leading to light with nonclassical correlations at points separated in time, which is of interest in the context of building wide bandwidth quantum repeaters. We also suggest a wideband version of DLCZ protocol based on the same ideas.Comment: 5 pages, 4 figures. Added section

Children’s resilience to sibling victimization: The role of family, peer, school, and neighborhood factors

Although common, little is known about the potential impacts of sibling victimization, and how best to ameliorate these. We explored longitudinal associations between sibling victimization and mental health and wellbeing outcomes, and promotive and risk factors that predicted better or worse outcomes following victimization. Data were from >12,000 participants in the Millennium Cohort Study, a longitudinal UK birth cohort, who reported on sibling victimization at age 11 and/or 14 years. We identified potential risk and promotive factors at family, peer, school, and neighborhood levels from age 14 data. Mental health and wellbeing outcomes (internalizing and externalizing problems, mental wellbeing, self-harm) were collected at age 17. Results suggested that over and above pre-existing individual and family level vulnerabilities, experiencing sibling victimization was associated with significantly worse mental health and wellbeing. Having no close friends was a risk factor for worse-than-expected outcomes following victimization. Higher levels of school motivation and engagement was a promotive factor for better-than-expected outcomes. This indicates that aspects of the school environment may offer both risk and promotive factors for children experiencing sibling victimization at home. We argue that effective sibling victimization interventions should be extended to include a focus on factors at the school level

Ultranarrow Optical Inhomogeneous Linewidth in a Stoichiometric Rare-Earth Crystal

We obtain a low optical inhomogeneous linewidth of 25 MHz in the stoichiometric rare-earth crystal EuCl3·6H2O by isotopically purifying the crystal in Cl35. With this linewidth, an important limit for stoichiometric rare-earth crystals is surpassed: the hyperfine structure of Eu153 is spectrally resolved, allowing the whole population of Eu1533+ ions to be prepared in the same hyperfine state using hole-burning techniques. This material also has a very high optical density, and can have long coherence times when deuterated. This combination of properties offers new prospects for quantum information applications. We consider two of these: quantum memories and quantum many-body studies. We detail the improvements in the performance of current memory protocols possible in these high optical depth crystals, and describe how certain memory protocols, such as off-resonant Raman memories, can be implemented for the first time in a solid-state system. We explain how the strong excitation-induced interactions observed in this material resemble those seen in Rydberg systems, and describe how these interactions can lead to quantum many-body states that could be observed using standard optical spectroscopy techniques

Quantum storage on subradiant states in an extended atomic ensemble

A scheme for coherent manipulation of collective atomic states is developed such that total subradiant states, in which spontaneous emission is suppressed into all directions due to destructive interference between neighbor atoms, can be created in an extended atomic ensemble. The optimal conditions for creation of such states and suitability of them for quantum storage are discussed. It is shown that in order to achieve the maximum signal-to-noise ratio the shape of a light pulse to be stored and reconstructed using a homogeneously broadened absorbtion line of an atomic system should be a time-reversed regular part of the response function of the system. In the limit of high optical density, such pulses allow one to prepare collective subradiant atomic states with near flat spatial distribution of the atomic excitation in the medium.Comment: V2: considerably revised (title, text). V3: minor changes - final version as published in PR