Geometric Entanglement of Symmetric States and the Majorana Representation

Permutation-symmetric quantum states appear in a variety of physical situations, and they have been proposed for quantum information tasks. This article builds upon the results of [New J. Phys. 12, 073025 (2010)], where the maximally entangled symmetric states of up to twelve qubits were explored, and their amount of geometric entanglement determined by numeric and analytic means. For this the Majorana representation, a generalization of the Bloch sphere representation, can be employed to represent symmetric n qubit states by n points on the surface of a unit sphere. Symmetries of this point distribution simplify the determination of the entanglement, and enable the study of quantum states in novel ways. Here it is shown that the duality relationship of Platonic solids has a counterpart in the Majorana representation, and that in general maximally entangled symmetric states neither correspond to anticoherent spin states nor to spherical designs. The usability of symmetric states as resources for measurement-based quantum computing is also discussed.Comment: 10 pages, 8 figures; submitted to Lecture Notes in Computer Science (LNCS

COVID-19: Rapid antigen detection for SARS-CoV-2 by lateral flow assay: A national systematic evaluation of sensitivity and specificity for mass-testing

Background Lateral flow device (LFD) viral antigen immunoassays have been developed around the world as diagnostic tests for SARS-CoV-2 infection. They have been proposed to deliver an infrastructure-light, cost-economical solution giving results within half an hour. Methods LFDs were initially reviewed by a Department of Health and Social Care team, part of the UK government, from which 64 were selected for further evaluation from 1st August to 15th December 2020. Standardised laboratory evaluations, and for those that met the published criteria, field testing in the Falcon-C19 research study and UK pilots were performed (UK COVID-19 testing centres, hospital, schools, armed forces). Findings 4/64 LFDs so far have desirable performance characteristics (orient Gene, Deepblue, Abbott and Innova SARS-CoV-2 Antigen Rapid Qualitative Test). All these LFDs have a viral antigen detection of >90% at 100,000 RNA copies/ml. 8951 Innova LFD tests were performed with a kit failure rate of 5.6% (502/8951, 95% CI: 5.1–6.1), false positive rate of 0.32% (22/6954, 95% CI: 0.20–0.48). Viral antigen detection/sensitivity across the sampling cohort when performed by laboratory scientists was 78.8% (156/198, 95% CI 72.4–84.3). Interpretation Our results suggest LFDs have promising performance characteristics for mass population testing and can be used to identify infectious positive individuals. The Innova LFD shows good viral antigen detection/sensitivity with excellent specificity, although kit failure rates and the impact of training are potential issues. These results support the expanded evaluation of LFDs, and assessment of greater access to testing on COVID-19 transmission. Funding Department of Health and Social Care. University of Oxford. Public Health England Porton Down, Manchester University NHS Foundation Trust, National Institute of Health Research

Primary Liver Cancer Rate and Mlatoxin Intake in a High Cancer Area

Data have been accumulating in various parts of the world which suggest that there might be some relationship be~een the level of aflatoxin intake by certain populations and their primary liver cancer rate. The object of this work was to examine this relationship in the highest known liver cancer incidence area in the world, namely the Inhambane district of Mozambique. It was therefore necessary to obtain an estimate of the primary liver cancer rate for the total population which wc:s more reliable than existing data, and to sample prepared meals throughout the district for aflatoxin analysis. The age and sex distribution of the disease was obtained by means of a hospital registration programme and data on the absolute occurrence of the disease extracted from the health records of gold-miners originating from the study area. Tile two sets of data were used to calculate the specific cancer rates according to age and sex, in addition to' the over-all cancer rate for the population. Values for the 1964 to 1968 and lS69 to 1971 periods were 35,5 and 25,4 per 100000 per year, the disease occurring more than twice as commonly in males than in females. The extent of aflatoxin contamination of prepared food consumed by the population was ascertained by means of the chemical assay of 880 meals collected at random. The mycotoxin was found in 9,3% of all samples, resulting in a mean contamination of all prepared food of 7,8 p.g/ kg wet food, and a mean daily per capita consumption of 222,4 ng/kg bodyweight (15 p.g/adult/day). The pooling of these data with similar studies in lower incidence areas elsewhere revealed a significant correlation between the level of aflatoxin consumption and the liver cancer rate. The results obtained represent both the highest primary liver cancer rate reported and the highest known aflatoxin intake

Fabrication and optoelectronic characterisation of ZnO photonic structures

Zinc oxide (ZnO) is recognised as a potential II–VI photonic semiconductor and wavelength-scale ordered patterning of such material helps favourably in tailoring the photonic properties. Here we present two novel approaches for fabricating ZnO photonic structures, namely, via a synthetic route and via electrochemical deposition. We demonstrate fabrication of well-ordered mesa and microphotonic structures from self-assembly of template-assisted electrochemical deposition. We have explored various aspects of the fabrication techniques for achieving an optimized performance. Several optical, electrical and structural techniques are used to highlight the potential utility of these ZnO photonic structures. Our results suggest that these structures show promise in many novel photonic applications.<br/

Optical properties of mesoporous II-VI semiconductor compound films

Direct liquid crystal templating from non-ionic polyoxyethylene surfactants has been utilised to produce well-defined birefringent films of nanostructured cadmium telluride films which displayed good optical properties as evidenced by UV/ VIS reflectance spectroscopy

Nanoporous semiconductor-based metamaterials

Growth of periodic nanoporous CdTe and ZnO metamaterials is developed and characterised. We model the induced birefringence and measure the charge transport and density of surface states in the films

Nutritional intervention during gestation alters growth, body composition and gene expression patterns in skeletal muscle of pig offspring

peer-reviewedVariations in maternal nutrition during gestation can influence foetal growth, foetal development and permanently ‘programme’ offspring for postnatal life. The objective of this study was to analyse the effect of increased maternal nutrition during different gestation time windows on offspring growth, carcass quality, meat quality and gene expression in skeletal muscle. A total of 64 sows were assigned to the following feeding treatments: a standard control diet at a feed allocation of 2.3 kg/day throughout gestation, increased feed allowance of 4.6 kg/day from 25 to 50 days of gestation (dg), from 50 to 80 dg and from 25 to 80 dg. At weaning, Light, Medium and Heavy pigs of the same gender, within litter, were selected based on birth weight, individually penned and monitored until slaughter at 130 days post weaning. Carcass and meat quality traits of the semimembranosus (SM) muscle were recorded post mortem. A cross section of the semitendinosus (ST) muscle encompassing the deep and superficial regions were harvested from pigs (n518 per treatment) for RNA extraction and quantification of gene expression by real-time PCR. The results showed that doubling the feed intake from 25 to 50 dg reduced offspring growth, carcass weight, intramuscular fat content and increased drip loss of the SM muscle. Interestingly, protein phosphatase 3 catalytic subunit – a-isoform, which codes for the transcription factor calcineurin, was upregulated in the ST muscle of offspring whose mothers received increased feed allowance from 25 to 50 dg. This may provide an explanation for the previous observed increases in Type IIa muscle fibres of these offspring. Increasing the maternal feed intake from 50 to 80 dg negatively impacted pig growth and carcass weight, but produced leaner male pigs. Extending the increased maternal feed intake from 25 to 80 dg had no effect on offspring over the standard control gestation diet. Although intra-litter variation in pig weight is a problem for pig producers, increased maternal feeding offered no improvement throughout life to the lighter birth weight littermates in our study. Indeed, increased maternal nutrition at the three-gestation time windows selected provided no major benefits to the offspring.Teagasc, under the National Development Plan; Teagasc Walsh Fellowship; Short Term Scientific Mission (STSM) fund, COST925