Single observable concurrence measurement without simultaneous copies

We present a protocol that allows us to obtain the concurrence of any two qubit pure state by performing a minimal and optimal tomography of one of the subsystems through measuring a single observable of an ancillary four dimensional qudit. An implementation for a system of trapped ions is also proposed, which can be achieved with present day experimental techniques.Comment: 4 pages, 1 figur

Experimental Observation of Environment-induced Sudden Death of Entanglement

We demonstrate the difference between local, single-particle dynamics and global dynamics of entangled quantum systems coupled to independent environments. Using an all-optical experimental setup, we show that, while the environment-induced decay of each system is asymptotic, quantum entanglement may suddenly disappear. This "sudden death" constitutes yet another distinct and counter-intuitive trait of entanglement.Comment: 4 pages, 4 figure

Entropic Entanglement Criteria for Continuous Variables

We derive several entanglement criteria for bipartite continuous variable quantum systems based on the Shannon entropy. These criteria are more sensitive than those involving only second-order moments, and are equivalent to well-known variance product tests in the case of Gaussian states. Furthermore, they involve only a pair of quadrature measurements, and will thus should prove extremely useful the experimental identification of entanglement.Comment: 4 pages, 2 figure

Influência da artrite encefalite caprina na resposta superovulatória.

Resumo: Objetivando avaliar a resposta superovulatoria e a qualidade embrionaria pos-colheita em animais soropositivos para o virus da CAEV, foram utilizadas 18 cabras adultas da raca Saanen, sendo 12 soropositivas(G1) e seis soronegativas(G2). Nao se observou diferencas significativas(P>0,05) entre o G1 e G2 quanto a resposta do estro, 100,0% vs. 83,0%; ao inicio do estro(hora) em relacao ao momento da retirada das esponjas, 35,0+/-9,5 vs. 31,2+/-10,7; a duracao do estro(hora), 27,0+/-5,4 vs. 28,8+/-10,7; a taxa de ovulacao, 10,8+/-5,7 vs. 10,8+/-8,6; e a porcentagem de estruturas recuperadas, 72,0 vs. 67,0 e de embrioes viaveis 99,0 vs. 99,0 vs. 95,0, respectivamente. Considerando que a transferencia de embrioes e uma tecnica segura para o controle da CAEV e diante da resposta satisfatoria dos animais soropositivos, em especial, quanto as porcentagens de embrioes recuperados e viaveis, conclui-se que animais geneticamente superiores mesmo que soropositivos para a CAEV podem ser usados como doadores de embrioes. [The influence of caprine arthritis encephalitis on superovulatory response]. Abstract: The objectives of this work were to determine the ovulation rate and the embryo viability in seropositive animals to Caprine Arthritis Encephalitis Virus infection (CAEV). Eighteen goats of the Saanen breed were used, 12 CAEV-seropositives (G1) and six CAEV-seronegatives (G2). No statistical difference (P>0.05) was observed between groups (G1 and G2) in relation to estrus response, 100.0% vs. 83.0%; onset estrus (hours), 35.0+9,5 vs. 31.2+10.7; estrus duration (hours), 27.0+5.4 vs. 28.8+10.7; ovulation rate, 10.8+5.7 vs. 10.8+8.6; recovery rate of embryos, 72.0% vs. 67.0%; and viable embryos, 99.0% vs. 95.0%, respectively. Considering the embryo transfer is a safe technique for the control of CAEV and due to the fact that the seropositive female show a satisfatory response for embryo recovery rate and viability, we conclude that the CAEV-seropositive animals may be used as embryo donors

Flavonoids and other compounds from Ouratea ferruginea (Ochnaceae) as anticancer and chemopreventive agents.

The chemical study of the extracts from leaves and stems of Ouratea ferruginea allowed the identification of a new isoflavone, 5-hydroxy-7,3′4′5′-tetramethoxyisoflavone, and twenty two known compounds, including friedelin, 3β-friedelinol, lupeone, a mixture of sitosterol, stigmasterol and campesterol, sitosteryl- and stigmasteryl-3-O-b-D-glucopyranosides, 5,4′-dihydroxy-7,5′,3′-trimethoxyisoflavone, 5,4′-dihydroxy-7,3′-di-methoxyisoflavone (7,3′-di-O-methylorobol), 5,7,4′-trihydroxy-3′,5′-dimethoxyisoflavone (piscigenin), 2R,3R-epicatechin, syringic acid, 2,6-dimethoxybenzoquinone, 2,6-dimethoxyhydroquinone, syringic and ferulic aldehyde, a mixture of vanillic acid, 1-hydroxy-2-methoxy-4-(1E-3-hydroxy-1-propenyl)-benzene and 3,5-dimethoxy-4-hydroxy-dihydrocinamaldehyde, besides amenthoflavone and 7-O-methylamenthoflavone (sequoiaflavone) which are considered as chemotaxonomic markers of Ouratea. The structures were identified by IR, 1H- and 13C-NMR and GC-MS, HPLC-MS, besides comparison with literature data. The inhibitory effects of 5,4′-dihydroxy-7,5′,3′-trimethoxyisoflavone, 7,3′-di-O-methylorobol, piscigenin and 7-O-methylamenthoflavone on cytochrome P450-dependent 7-ethoxycoumarin O-deethylase (ECOD) and glutathione S-transferase (GST) were evaluated in vitro. The 5,4′-dihydroxy-7,5′,3′-trimethoxy-isoflavone was the best inhibitor, inhibiting almost 75% of GST activity. Sequoiaflavone was the most potent inhibitor, inhibiting ECOD assay in 75%. These activities allow us to consider both these flavonoids as potential anticancer and chemopreventive agents

Influência da artrite encefalite caprina na resposta superovulatória.

Resumo: Objetivando avaliar a resposta superovulatória e a qualidade embrionária pós-colheita em animais soropositivos para o vírus da Artrite Encefalite Caprina (CAEV), foram utilizadas 18 cabras adultas da raça Saanen, sendo 12 soropositivas (G1) e seis soronegativas (G2).Não se observou diferenças significativas (P>0,05) entre o G1 e G2 quanto à resposta do estro, 100,0% vs. 83,0%; ao início do estro (hora) em relação ao momento da retirada das esponjas, 35,0±9,5 vs. 31,2±10,7; à duração do estro (hora), 27,0± 5,4 vs. 28,8±10,7; à taxa de ovulação, 10,8±5,7 vs. 10,8±8,6; e à porcentagem de estruturas recuperadas, 72,0 vs. 67,0 e de embriões viáveis 99,0 vs. 95,0, respectivamente. Considerando que a transferência de embriões é uma técnica segura para o controle da CAEV e diante da resposta satisfatória dos animais soropositivos, em especial, quanto as porcentagens de embriões recuperados e viáveis, concluí-se que animais geneticamente superiores mesmo que soropositivos para a CAEV podem ser usados como doadores de embriões. [The influence of caprine arthritis encephalitis on superovulatory response]. Abstract: The objectives of this work were to determine the ovulation rate and the embryo viability in seropositive animals to Caprine Arthritis Encephalitis Virus infection (CAEV). Eighteen goats of the Saanen breed were used, 12 CAEV-seropositives (G1) and six CAEV-seronegatives (G2). No statistical difference (P>0.05) was observed between groups (G1 and G2) in relation to estrus response, 100.0% vs. 83.0%; onset estrus (hours), 35.0+9,5 vs. 31.2+10.7; estrus duration (hours), 27.0+5.4 vs. 28.8+10.7; ovulation rate, 10.8+5.7 vs. 10.8+8.6; recovery rate of embryos, 72.0% vs. 67.0%; and viable embryos, 99.0% vs. 95.0%, respectively. Considering the embryo transfer is a safe technique for the control of CAEV and due to the fact that the seropositive female show a satisfatory response for embryo recovery rate and viability, we conclude that the CAEV-seropositive animals may be used as embryo donor

Experimental investigation of the dynamics of entanglement: Sudden death, complementarity, and continuous monitoring of the environment

We report on an experimental investigation of the dynamics of entanglement between a single qubit and its environment, as well as for pairs of qubits interacting independently with individual environments, using photons obtained from parametric down-conversion. The qubits are encoded in the polarizations of single photons, while the interaction with the environment is implemented by coupling the polarization of each photon with its momentum. A convenient Sagnac interferometer allows for the implementation of several decoherence channels and for the continuous monitoring of the environment. For an initially-entangled photon pair, one observes the vanishing of entanglement before coherence disappears. For a single qubit interacting with an environment, the dynamics of complementarity relations connecting single-qubit properties and its entanglement with the environment is experimentally determined. The evolution of a single qubit under continuous monitoring of the environment is investigated, demonstrating that a qubit may decay even when the environment is found in the unexcited state. This implies that entanglement can be increased by local continuous monitoring, which is equivalent to entanglement distillation. We also present a detailed analysis of the transfer of entanglement from the two-qubit system to the two corresponding environments, between which entanglement may suddenly appear, and show instances for which no entanglement is created between dephasing environments, nor between each of them and the corresponding qubit: the initial two-qubit entanglement gets transformed into legitimate multiqubit entanglement of the Greenberger-Horne-Zeilinger (GHZ) type.Comment: 15 pages, 14 figures; only .ps was working, now .pdf is also availabl