On quantum teleportation with beam-splitter-generated entanglement

Following the lead of Cochrane, Milburn, and Munro [Phys. Rev. A {\bf 62}, 062307 (2000)], we investigate theoretically quantum teleportation by means of the number-sum and phase-difference variables. We study Fock-state entanglement generated by a beam splitter and show that two-mode Fock-state inputs can be entangled by a beam splitter into close approximations of maximally entangled eigenstates of the phase difference and the photon-number sum (Einstein-Podolsky-Rosen -- EPR -- states). Such states could be experimentally feasible with on-demand single-photon sources. We show that the teleportation fidelity can reach near unity when such ``quasi-EPR'' states are used as the quantum channel.Comment: 7 pages (two-column), 7 figures, submitted to Phys. Rev. A. Text unmodified, postscript error correcte

Diversity, distribution and threats of the Juglandaceae in Vietnam

Vietnam is one of the main centers of generic diversity for Juglandaceae worldwide. In this study, we present for the first time a province-wide distribution of all 3 subfamilies, 7 genera, and 11 Vietnamese species, and give an update on the habitats of all Vietnamese Juglandaceae species, their uses, and current threats. Juglandaceae are found throughout Vietnam. However, most species occur predominantly in the north- ern part of the country between 600 and 1200 m. Some taxa range is found extensively from sea level up to 2,500 meters above sea level. According to the IUCN Red List, Rhoiptelea chiliantha, Carya sinensis, and Pterocarya tonkinensis are threatened while Engelhardia spicata, E. serrata, Alfaropsis roxburghiana, Pterocarya stenoptera are classified as least concerned (Carya tonkinensis is threatened locally, and Engelhardia spicata var. colebrookiana and Platycarya strobilacea merit “threatened” designation in Vietnam’s Red Data Book. The most frequent threats are logging, land-use change, and habitat destruction due to artificial wood planta- tions or road construction. Until now, no conservation measures have been applied for any of the species in Vietnam, although some species occur in national parks. Our study gives an important update on the current diversity and distribution of Juglandaceae in Vietnam. We point out the need for a correct assessment of the threat status of various species on a national and international scale to protect the rarest and most endangered of them. Further research, the use of various forms of protection of individual taxa and/or their habitats, and drawing the attention of an international group of researchers to the urgent need to work together to protect biodiversity in Vietnam hot spots are necessary

Antimicrobial susceptibility of indicator bacteria isolated from chickens in Southeast Asian countries (Vietnam, Indonesia, and Thailand)

To determine the prevalence of indicator bacteria resistant to antimicrobials among poultry in three Southeast Asian countries (Vietnam, Indonesia and Thailand), we examined the antimicrobial susceptibilities of commensal bacteria isolated from chickens. In total, 125, 117 and 180 isolates of Escherichia coli, Enterococcus faecalis and Enterococcus faecium, respectively, were used to test for antimicrobial susceptibility. Bacterial resistance to antimicrobial treatment was most frequently observed with oxytetracycline with a prevalence of 73.6% (E. coli), 69.2% (E. faecalis) and 92.2% (E. faecium). Resistance to fluoroquinolones, which are critically important medicines, was also frequently observed in E. coli (48.8%), E. faecalis (17.9%) and E. faecium (82.8%). The prevalence of indicator bacteria resistant to most of the antimicrobials tested in these countries was higher than those for developed countries. The factors underlying antimicrobial resistance may include inappropriate and/or excessive use of antimicrobials. These results highlight the need for monitoring the emergence and prevalence of antimicrobial resistance in developing countries