290 research outputs found
Livestock production evolving to contribute to sustainable societies
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
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 identical qubits, there exists no
estimator which can perform better than the proposed estimator on a
neighborhood of size 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 , the statistical
model described by 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
. An essential result is that the neighborhood radius can be chosen
arbitrarily close to . This allows us to use a two steps procedure by
which we first localize the state within a smaller neighborhood of radius
, 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
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
A search for the decay
We search for the rare flavor-changing neutral-current decay in a data sample of 82 fb 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
at the 90% confidence level. In addition, by selecting for pions rather than
kaons, we obtain a limit of 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
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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