290 research outputs found

    Livestock production evolving to contribute to sustainable societies

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    There is a hypothesis in the anthropological literature (e.g. Milton, 2003) that our complex human brains would not have developed without hominoids having routine access to foods of animal origin. In many countries, therefore, the consumption of animal source foods, and meat in particular, became part of a cultural identity, while in others (e.g. India) vegetarianism has long been part of the cultural/religious identity (approx. 30% of Indians are vegetarian, although the majority of those consume milk products). In the twenty first century, humans can, theoretically, have access to non animal- derived sources of nutrients required for brain development, so animal products are no longer as important for nutrition as they were for our ancestors. There are also other issues, however, associated with livestock production which impact on the consumption of animal products. Culture in many countries has evolved to give a higher priority to the welfare of farm animals and there are additional ethical issues associated with the negative environmental impacts of livestock production. We read a lot, therefore, about the rise of veganism, with calls for diets free of animal products, yet there is also evidence that the consumption of meat at a country level increases as the income of that country increases (FAO, 2009). The average global per capita meat consumption at over 40 kg, has, therefore, doubled from the consumption in 1960. However, the annual global rate of increase in both meat and milk consumption is projected (OECD/FAO, 2017) to decrease slightly in the decade from 2017-2026, to 1.5% per annum for meat and 1.9% per annum for milk

    Optimal estimation of qubit states with continuous time measurements

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    We propose an adaptive, two steps strategy, for the estimation of mixed qubit states. We show that the strategy is optimal in a local minimax sense for the trace norm distance as well as other locally quadratic figures of merit. Local minimax optimality means that given nn identical qubits, there exists no estimator which can perform better than the proposed estimator on a neighborhood of size n1/2n^{-1/2} of an arbitrary state. In particular, it is asymptotically Bayesian optimal for a large class of prior distributions. We present a physical implementation of the optimal estimation strategy based on continuous time measurements in a field that couples with the qubits. The crucial ingredient of the result is the concept of local asymptotic normality (or LAN) for qubits. This means that, for large nn, the statistical model described by nn identically prepared qubits is locally equivalent to a model with only a classical Gaussian distribution and a Gaussian state of a quantum harmonic oscillator. The term `local' refers to a shrinking neighborhood around a fixed state ρ0\rho_{0}. An essential result is that the neighborhood radius can be chosen arbitrarily close to n1/4n^{-1/4}. This allows us to use a two steps procedure by which we first localize the state within a smaller neighborhood of radius n1/2+ϵn^{-1/2+\epsilon}, and then use LAN to perform optimal estimation.Comment: 32 pages, 3 figures, to appear in Commun. Math. Phy

    Examination of the Nitric Oxide Production-Suppressing Component in Tinospora tuberculata

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    The component of aqueous Tinospora tuberculata extract that inhibits nitric oxide (NO) production was examined using macrophages activated by the addition of lipopolysaccharide. The aqueous extract was partitioned with ethyl acetate. The aqueous layer was fractionated with a Diaion column. The residue of the aqueous extract was extracted with methanol, and partitioned with ethyl acetate. The ethyl acetate layer was found to be associated with a distinct decrease in the NO level and inducible NO synthase. On further fractionation, the subfraction of E-3 showed high anti-NO activity. N-trans-Feruloyltyramine isolated from E-3 was identified as exhibiting strong anti-NO activity. This compound is the most active component of Tinospora tuberculata with respect to the suppression of NO production

    Protecting 30% of the planet for nature: costs, benefits, and economic implications:Working paper analysing the economic implications of the proposed 30% target for areal protection in the draft post-2020 Global Biodiversity Framework

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    Protecting 30% of the planet for nature: costs, benefits, and economic implications:Working paper analysing the economic implications of the proposed 30% target for areal protection in the draft post-2020 Global Biodiversity Framework

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    A search for the decay B+K+ννˉB^+ \to K^+ \nu \bar{\nu}

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    We search for the rare flavor-changing neutral-current decay B+K+ννˉB^+ \to K^+ \nu \bar{\nu} in a data sample of 82 fb1^{-1} collected with the {\sl BABAR} detector at the PEP-II B-factory. Signal events are selected by examining the properties of the system recoiling against either a reconstructed hadronic or semileptonic charged-B decay. Using these two independent samples we obtain a combined limit of B(B+K+ννˉ)<5.2×105{\mathcal B}(B^+ \to K^+ \nu \bar{\nu})<5.2 \times 10^{-5} at the 90% confidence level. In addition, by selecting for pions rather than kaons, we obtain a limit of B(B+π+ννˉ)<1.0×104{\mathcal B}(B^+ \to \pi^+ \nu \bar{\nu})<1.0 \times 10^{-4} using only the hadronic B reconstruction method.Comment: 7 pages, 8 postscript figures, submitted to Phys. Rev. Let

    High-reflectivity broadband distributed Bragg reflector lattice matched to ZnTe

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    We report on the realization of a high quality distributed Bragg reflector with both high and low refractive index layers lattice matched to ZnTe. Our structure is grown by molecular beam epitaxy and is based on binary compounds only. The high refractive index layer is made of ZnTe, while the low index material is made of a short period triple superlattice containing MgSe, MgTe, and ZnTe. The high refractive index step of Delta_n=0.5 in the structure results in a broad stopband and the reflectivity coefficient exceeding 99% for only 15 Bragg pairs.Comment: 4 pages, 3 figure
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