Fast rate estimation of an unitary operation in SU(d)

We give an explicit procedure based on entangled input states for estimating a $SU(d)$ operation $U$ with rate of convergence $1/N^2$ when sending $N$ particles through the device. We prove that this rate is optimal. We also evaluate the constant $C$ such that the asymptotic risk is $C/N^2$. However other strategies might yield a better const ant $C$.Comment: 8 pages, 1 figure Rewritten version, accepted for publication in Phys. Rev. A. The introduction is richer, the "tool section" on group representations has been suppressed, and a section proving that the 1/N^2 rate is optimum has been adde

URBAN HOUSEHOLD DEMAND FOR MEAT AND MEAT PRODUCTS IN NIGERIA: AN ALMOST IDEAL DEMAND SYSTEM ANALYSIS

This study is based on micro level data on urban household food consumption and expenditure collected between 1999 and 2000 in three Nigerian cities. The LA/AIDS model, which allows the inclusion of demographic variables, was applied to a subset of the data on meat and meat products namely beef, mutton/goat, chicken, fish, eggs, and milk. Results indicate that urban demand for meat products will continue to increase as incomes improve, suggesting potential market opportunities especially for poultry. Intra-household demand patterns clearly indicate the importance of beef for children but contrary to expectations, there is a reduced demand for milk as the number of infants in urban households increase. The observed high income elasticity of demand for poultry products may have a positive impact on the derived demand for maize, a primary product in poultry feed. Encouraging poultry production will help restore the battered agricultural sector of Nigeria, increase farmer income, reduce unemployment, and conserve foreign exchange earnings.Urban households, Meat demand, Demand analysis, Nigeria, Demand and Price Analysis,

Convulsions on anaesthetic induction with sevoflurane in young children.

Increased worldwide use for paediatric anaesthesia of the volatile anaesthetic agent sevoflurane has mainly resulted from its low blood-gas partition coefficient and low airway irritability, providing smooth conditions for rapid induction of anaesthesia. Nevertheless, there are several clinical and experimental reports suggesting a correlation between exposure to sevoflurane and generalized clonic or tonic seizure activity. We report two clinical episodes of convulsions associated with the induction of sevoflurane anaesthesia in young children. Case 1: during induction of anaesthesia with sevoflurane by facemask in a 3-year-old healthy boy, there were symmetrical clonic seizure-like movements of the upper extremities for 60 s. Case 2: on re-induction of anaesthesia with sevoflurane because of profuse bleeding following nasal adenoidectomy in a 4-year-old healthy girl with a family history of epilepsy, there were symmetrical tonic and clonic seizure-like movements for 30-40 s in the upper and lower extremities. Both episodes ceased spontaneously. Although no EEG was recorded, it cannot be excluded that both episodes resulted from seizure activity within the CNS. Based on our observations and reports by others we suggest that, until further notice, sevoflurane should be avoided or at least used cautiously in patients where clinical epileptic activity has been verified or is strongly suspected

Mott insulator states of ultracold atoms in optical resonators

We study the low temperature physics of an ultracold atomic gas in the potential formed inside a pumped optical resonator. Here, the height of the cavity potential, and hence the quantum state of the gas, depends not only on the pump parameters, but also on the atomic density through a dynamical a.c.-Stark shift of the cavity resonance. We derive the Bose-Hubbard model in one dimension, and use the strong coupling expansion to determine the parameter regime in which the system is in the Mott-insulator state. We predict the existence of overlapping, competing Mott states, and bistable behavior in the vicinity of the shifted cavity resonance, controlled by the pump parameters. Outside these parameter regions, the state of the system is in most cases superfluid.Comment: 4 pages, 3 figures. Substantially revised version. To appear in Phys. Rev. Let

Political Ecology of REDD+ in Indonesia

Indonesia’s commitment to reducing land-based greenhouse gas emissions significantly includes the expansion of conservation areas, but these developments are not free of conflicts. This book provides a comprehensive analysis of agrarian conflicts in the context of the implementation of REDD+ (Reducing Emissions from Deforestation and Forest Degradation) and forest carbon offsetting in Indonesia, a country where deforestation is a major issue. The author analyzes new kinds of transnational agrarian conflicts which have strong implications for global environmental justice in the REDD+ pilot province of Jambi on the island of Sumatra. The chapters cover: the rescaling of the governance of forests; privatization of conservation; and the transnational dimensions of agrarian conflicts and peasants’ resistance in the context of REDD+. The book builds on an innovative conceptual approach linking political ecology, politics of scale and theories of power. It fills an important knowledge and research gap by focusing on the socially differentiated impacts of REDD+ and new forest carbon offsetting initiatives in Southeast Asia, providing a multi-scalar perspective. It is aimed at scholars in the areas of political ecology, human geography, climate change mitigation, forest and natural resource management, as well as environmental justice and agrarian studies

Temperature Dependence of Blue Phosphorescent Cyclometalated Ir(III) Complexes

The photophysical properties for a series of facial (fac) cyclometalated Ir(III) complexes (fac-Ir(C^N)_3 (C^N = 2-phenylpyridyl (ppy), 2-(4,6-difluorophenyl)pyridyl (F2ppy), 1-phenylpyrazolyl (ppz), 1-(2,4-difluorophenyl)pyrazolyl) (F2ppz), and 1-(2-(9,9′-dimethylfluorenyl))pyrazolyl (flz)), fac-Ir(C^N)_2(C^N′) (C^N = ppz or F2ppz and C^N′ = ppy or F2ppy), and fac-Ir(CC′)_3 (C^C′ = 1-phenyl-3-methylbenzimidazolyl (pmb)) have been studied in dilute 2-methyltetrahydrofuran (2-MeTHF) solution in a temperature range of 77−378 K. Photoluminescent quantum yields (Φ) for the 10 compounds at room temperature vary between near zero and unity, whereas all emit with high efficiency at low temperature (77 K). The quantum yield for fac-Ir(ppy)_3 (Φ = 0.97) is temperature-independent. For the other complexes, the temperature-dependent data indicates that the luminescent efficiency is primarily determined by thermal deactivation to a nonradiative state. Activation energies and rate constants for both radiative and nonradiative processes were obtained using a Boltzmann analysis of the temperature-dependent luminescent decay data. Activation energies to the nonradiative state are found to range between 1600 and 4800 cm^−1. The pre-exponential factors for deactivation are large for complexes with C^N ligands (1011−1013 s^−1) and significantly smaller for fac-Ir(pmb)_3 (109 s^−1). The kinetic parameters for decay and results from density functional theory (DFT) calculations of the triplet state are consistent with a nonradiative process involving Ir−N (Ir−C for fac-Ir(pmb)_3) bond rupture leading to a five-coordinate species that has triplet metal-centered (^3MC) character. Linear correlations are observed between the activation energy and the energy difference calculated for the emissive and ^3MC states. The energy level for the ^3MC state is estimated to lie between 21700 and 24000 cm^−1 for the fac-Ir(C^N)_3 complexes and at 28000 cm^−1 for fac-Ir(pmb)_3

Disorder induced metallicity in amorphous graphene

We predict a transition to metallicity when a sufficient amount of disorder is induced in graphene. Calculations were performed by means of a first principles stochastic quench method. The resulting amorphous graphene can be seen as nanopatches of graphene that are connected by a network of disordered small and large carbon rings. The buckling is minimal and we believe that it is a result of averaging of counteracting random in-plane stress forces. The linear response conductance is obtained by a model theory as function of lattice distortions. Such metallic behaviour is a much desired property for functionalisation of graphene to realize a transparent conductor, e.g. suitable for touch-screen devices