Late Toarcian marine gastropods from the Cleveland Basin, UK: systematics, palaeobiogeography and contribution to biotic recovery from the early Toarcian extinction event

As part of a study to evaluate the recovery from the early Toarcian extinction event in the Cleveland Basin, 477 new gastropod specimens were collected from mid-late Toarcian rocks of the Ravenscar section, North Yorkshire, UK. The gastropods were preserved in two modes: 1) specimens preserved with recrystallized shells, mainly in the Whitby Mudstone Formation, but also some in the Blea Wyke Sandstone Formation; 2) specimens preserved as external moulds in mineralized patches of shells in the Yellow Sandstone Member.Fil: Ferrari, Silvia Mariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico de Geología y Paleontología; ArgentinaFil: Little, Crispin. University of Leeds; Reino UnidoFil: Atkinson, Jed W.. University of Leeds; Reino Unido3rd International Workshop Toarcian Oceanic Anoxic Event: Impact on marine organisms and ecosystemsErlangenAlemaniaGeoZentru

Surface Acoustic Wave Single-Electron Interferometry

We propose an experiment to observe interference of a single electron as it is transported along two parallel quasi-one-dimensional channels trapped in a single minimum of a travelling periodic electric field. The experimental device is a modification of the surface acoustic wave (SAW) based quantum processor. Interference is achieved by creating a superposition of spatial wavefunctions between the two channels and inducing a relative phase shift via either a transverse electric field or a magnetic field. The interference can be used to estimate the decoherence time of an electron in this type of solid-state device

Vitamin A Supplementation and Stunting Levels Among Two Year Olds in Kenya: Evidence from the 2008-09 Kenya Demographic and Health Survey

Background: High levels of undernutrition, particularly stunting, have persisted in Kenya, like in other developing countries. The relationship betweeen vitamin A supplementation and growth of children in Kenya has not been established, while there are context-specific variations on the relationship. This study explores this relationship in the Kenyan context. Methods: The study uses data from the 2008-09 Kenya Demographic and Health Survey, involving children aged 24-35 months, a weighted sample of 1029 children. Descriptive and logistic regression analyses were conducted. The outcome variable of interest is stunting, while the exposure variable of interest is ever receiving a dose of vitamin A supplement. Secondary outcomes include underweight and wasting status. Results: The prevalence of stunting in the study group was 46%; underweight 20%; and wasting 6%. The prevalence of ever receiving vitamin A supplement was 78%. Receiving vitamin A supplement was significantly negatively associated with stunting and underweight status, adjusting for other co-risk factors. The odds of stunting were 50% higher (p=0.038), while for underweight were 75% higher (p=0.013) among children who did not receive Vitamin A supplement compared with those who did. Conclusion: This study demonstrates that receiving vitamin A supplement may be beneficial to growth of young children in Kenya. However, though freely offered through immunization services to children 6-59 months, some children do not receive it, particularly after completing the immunization schedule. There is need to establish innovative and effective ways of maximizing utilization of this intervention, particularly for children who have completed their immunization schedule

Harnessing post-translational modifications for next-generation HIV immunogens

The extensive post-translational modifications of the envelope spikes of the human immunodeficiency virus (HIV) present considerable challenges and opportunities for HIV vaccine design. These oligomeric glycoproteins typically have over 30 disulfide bonds and around a 100 N-linked glycosylation sites, and are functionally dependent on protease cleavage within the secretory system. The resulting mature structure adopts a compact fold with the vast majority of its surface obscured by a protective shield of glycans which can be targeted by broadly neutralizing antibodies (bnAbs). Despite the notorious heterogeneity of glycosylation, rare B-cell lineages can evolve to utilize and cope with viral glycan diversity, and these structures therefore present promising targets for vaccine design. The latest generation of recombinant envelope spike mimetics contains re-engineered post-translational modifications to present stable antigens to guide the development of bnAbs by vaccination

Charge qubits based on ultra-thin topological insulator films

We study how to use the surface states in a Bi$_{2}$Se$_{3}$ topological insulator ultra-thin film that are affected by finite size effects for the purpose of quantum computing. We demonstrate that: (i) surface states under the finite size effect can effectively form a two-level system where their energy levels lie in between the bulk energy gap and a logic qubit can be constructed, (ii) the qubit can be initialized and manipulated using electric pulses of simple forms, (iii) two-qubit entanglement is achieved through a $\sqrt{\text{SWAP}}$ operation when the two qubits are in a parallel setup, and (iv) alternatively, a Floquet state can be exploited to construct a qubit and two Floquet qubits can be entangled through a Controlled-NOT operation. The Floquet qubit offers robustness to background noise since there is always an oscillating electric field applied, and the single qubit operations are controlled by amplitude modulation of the oscillating field, which is convenient experimentally.Comment: 12 pages, 9 figures, submitted to the journal Frontiers of Physic