483 research outputs found

    Interaction of light with a single atom in the strong focusing regime

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    We consider the near-resonant interaction between a single atom and a focused light mode, where a single atom localized at the focus of a lens can scatter a significant fraction of light. Complementary to previous experiments on extinction and phase shift effects of a single atom, we report here on the measurement of coherently backscattered light. The strength of the observed effect suggests combining strong focusing with the well-established methods of cavity QED. We consider theoretically a nearly concentric cavity, which should allow for a strongly focused optical mode. Simple estimates show that in a such case one can expect a significant single photon Rabi frequency. This opens new perspectives and a possibility to scale up the system consisting of many atom+cavity nodes for quantum networking due to a significant technical simplification of the atom--light interfaces.Comment: 7 pages, 6 figures, followup of workshop "Single photon technologies" in Boulder, CO, 200

    Generalized Weyl solutions in d=5 Einstein-Gauss-Bonnet theory: the static black ring

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    We argue that the Weyl coordinates and the rod-structure employed to construct static axisymmetric solutions in higher dimensional Einstein gravity can be generalized to the Einstein-Gauss-Bonnet theory. As a concrete application of the general formalism, we present numerical evidence for the existence of static black ring solutions in Einstein-Gauss-Bonnet theory in five spacetime dimensions. They approach asymptotically the Minkowski background and are supported against collapse by a conical singularity in the form of a disk. An interesting feature of these solutions is that the Gauss-Bonnet term reduces the conical excess of the static black rings. Analogous to the Einstein-Gauss-Bonnet black strings, for a given mass the static black rings exist up to a maximal value of the Gauss-Bonnet coupling constant α\alpha'. Moreover, in the limit of large ring radius, the suitably rescaled black ring maximal value of α\alpha' and the black string maximal value of α\alpha' agree.Comment: 43 pages, 14 figure

    Characterizing bird-keeping user-groups on Java reveals distinct behaviours, profiles and potential for change

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    Over 70 million cage‐birds are kept across 12 million households on the island of Java, Indonesia, fuelling serious concerns for the health of regional wild bird populations. Understanding the behaviours, preferences and demographic profiles of bird‐keepers will guide attempts to reduce demand for wild birds and hence the impact of trade on wild populations and their host ecosystems. We profile three songbird‐keeping user‐groups based on interviews of nearly one thousand people across Java: hobbyists, who own birds primarily as pets; contestants, who own birds to enter in singing contests; and breeders, who own birds to breed and train for resale or as a pastime. User‐groups diverged in their bird‐keeping habits and preferences. Hobbyists tended to own small numbers of inexpensive and typically native birds, while contestants and breeders owned larger numbers of often valuable birds. Hobbyists were far less likely to consider origin when buying a bird, owned a larger proportion of both potentially wild‐caught and globally threatened birds, but showed no preference for any taxon. By contrast, owning relatively large numbers of lovebirds Agapornis spp. and Zebra Doves Geopelia striata were key characteristics of contestants, while breeders owned the largest number of birds and species, in particular White‐rumped Shamas Kittacincla malabarica. Within a 2‐year period, user‐group membership was fluid, with much transitioning between non‐bird ownership and hobbyists, recruitment of non‐bird owners to contestants and movement both in and out of the breeder group. Our study provides behavioural change efforts with demographic and geographic profiles to target bird‐keepers, who tended to be more affluent and urban and to live in the eastern provinces. Among bird‐keepers, hobbyists tended to be middle‐aged and lived in the western provinces, contestants were younger urban bird‐keepers employed in business and breeders were commoner in the eastern provinces, reflecting the cultural importance of bird‐keeping among the Javanese. Efforts to increase the sustainability of bird‐keeping in Java should focus on emphasizing the importance of captive‐bred birds, in particular to hobbyists, the largest user‐group, whose bird‐keeping behaviour poses the biggest threat to wild bird populations, whilst also incentivizing legitimate breeding enterprises among contestants and breeders

    A fatal case of oral intoxication by mustard gas

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    Opisan je slučaj peroralne intosikacije iperitom u namjeri samoubojstva i iznesen obdukcioni nalaz. Ukratko su izneseni neki toksikološki pogledi na otrovanje iperifom, te klinički simptomi i patomorfološke promjene kod intoksikacije ovim otrovom.A case is presented of a man aged 27 who swallowed 50 g of mustard gas (dichlor-diethylsulphide) in order to commit suicide. Although immediately treated at the Internal Clinic of the Medical Faculty, he died 8 hours and 20 minutes after taking the poison. A postmortem examination carried out 19 hours after death, as well as histological findings showed congestion and oedema of the brain, fragmentation of cardiac muscle, oedema of mucous membranes of the upper part of gastrointestinal tract, oedema of larynx and epiglotis, oedema of the liver, and congestion of the spleen, adrenal glands, and kidneys. A microscopic examination of the lung tissue revealed hemorrhages probably due to the irritative effect of the poison

    Identifying Modules of Coexpressed Transcript Units and Their Organization of Saccharopolyspora erythraea from Time Series Gene Expression Profiles

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    BACKGROUND: The Saccharopolyspora erythraea genome sequence was released in 2007. In order to look at the gene regulations at whole transcriptome level, an expression microarray was specifically designed on the S. erythraea strain NRRL 2338 genome sequence. Based on these data, we set out to investigate the potential transcriptional regulatory networks and their organization. METHODOLOGY/PRINCIPAL FINDINGS: In view of the hierarchical structure of bacterial transcriptional regulation, we constructed a hierarchical coexpression network at whole transcriptome level. A total of 27 modules were identified from 1255 differentially expressed transcript units (TUs) across time course, which were further classified in to four groups. Functional enrichment analysis indicated the biological significance of our hierarchical network. It was indicated that primary metabolism is activated in the first rapid growth phase (phase A), and secondary metabolism is induced when the growth is slowed down (phase B). Among the 27 modules, two are highly correlated to erythromycin production. One contains all genes in the erythromycin-biosynthetic (ery) gene cluster and the other seems to be associated with erythromycin production by sharing common intermediate metabolites. Non-concomitant correlation between production and expression regulation was observed. Especially, by calculating the partial correlation coefficients and building the network based on Gaussian graphical model, intrinsic associations between modules were found, and the association between those two erythromycin production-correlated modules was included as expected. CONCLUSIONS: This work created a hierarchical model clustering transcriptome data into coordinated modules, and modules into groups across the time course, giving insight into the concerted transcriptional regulations especially the regulation corresponding to erythromycin production of S. erythraea. This strategy may be extendable to studies on other prokaryotic microorganisms

    Hot Halos and Galactic Glasses

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    We initiate a systematic study of the state space of non-extremal, stationary black hole bound states in four-dimensional N = 2 supergravity. Specifically, we show that an exponential multitude of classically stable "halo" bound states can be formed between large finite temperature D4-D0 black hole cores and much smaller, arbitrarily charged black holes at the same temperature. We map out in full the regions of existence for thermodynamically stable and metastable bound states in terms of the core's charges and temperature, as well as the region of stability of the core itself. Several features of these systems, such as a macroscopic configurational entropy and exponential relaxation timescales, are similar to those of the extended family of glasses. We draw parallels between the two with a view toward understanding complex systems in fundamental physics.Comment: 29 pages, 5 figures, v2: typos corrected, references adde

    How European Fans in Training (EuroFIT), a lifestyle change program for men delivered in football clubs, achieved its effect : a mixed methods process evaluation embedded in a randomised controlled trial

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    Funding This project has received funding from the European Union’s Seventh Framework Program for research, technological development, and demonstration under grant agreement number 602170. The Health Services Research Unit, University of Aberdeen, receives core funding from the Chief Scientist Office of the Scottish Government Health Directorates. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Acknowledgements We are grateful to participants who took part in the research, coaches and club managers at fifteen football clubs and UEFA’s Football and Social Responsibility department for supporting the proposal at bidding stage. Ciaran Clissman of Pintail Ltd managed the project and provided invaluable editorial input into the funding application and delivery of the program. Prof Nanette Mutrie was substantially involved in the development of the EuroFIT program. Dr Lisa Macauley administered the UK data collection in the UK and Alan Pollok supported some UK data collection. Dr Mattias Rost and Prof Mathew Chalmers were substantially involved in the development of MatchFIT and Drs Douglas Maxwell and Nikos Mourselas of PAL Technologies in the technical development of the SitFIT. Views and opinions expressed are those of the authors and do not necessarily reflect those of the European Union.Peer reviewedPublisher PD

    IgE sensitisation in relation to flow-independent nitric oxide exchange parameters

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    BACKGROUND: A positive association between IgE sensitisation and exhaled NO levels has been found in several studies, but there are no reports on the compartment of the lung that is responsible for the increase in exhaled NO levels seen in IgE-sensitised subjects. METHODS: The present study comprised 288 adult subjects from the European Community Respiratory Health Survey II who were investigated in terms of lung function, IgE sensitisation (sum of specific IgE), smoking history and presence of rhinitis and asthma. Mean airway tissue concentration of NO (Caw(NO)), airway transfer factor for NO (Daw(NO)), mean alveolar concentration of NO (Calv(NO)) and fractional exhaled concentration of NO at a flow rate of 50 mL s(-1 )(FE(NO 0.05)) were determined using the extended NO analysis. RESULTS: IgE-sensitised subjects had higher levels (geometric mean) of FE(NO 0.05 )(24.9 vs. 17.3 ppb) (p < 0.001), Daw(NO )(10.5 vs. 8 mL s(-1)) (p = 0.02) and Caw(NO )(124 vs. 107 ppb) (p < 0.001) and positive correlations were found between the sum of specific IgE and FE(NO 0.05), Caw(NO )and Daw(NO )levels (p < 0.001 for all correlations). Sensitisation to cat allergen was the major determinant of exhaled NO when adjusting for type of sensitisation. Rhinitis and asthma were not associated with the increase in exhaled NO variables after adjusting for the degree of IgE sensitisation. CONCLUSION: The presence of IgE sensitisation and the degree of allergic sensitisation were related to the increase in airway NO transfer factor and the increase in NO concentration in the airway wall. Sensitisation to cat allergen was related to the highest increases in exhaled NO parameters. Our data suggest that exhaled NO is more a specific marker of allergic inflammation than a marker of asthma or rhinitis
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