2,204 research outputs found

    Absolute absorption and fluorescence measurements over a dynamic range of 106^6 with cavity-enhanced laser-induced fluorescence

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    We describe a novel experimental setup that combines the advantages of both laser-induced fluorescence and cavity ring-down techniques. The simultaneous and correlated measurement of the ring-down and fluorescence signals yields absolute absorption coefficients for the fluorescence measurement. The combined measurement is conducted with the same sample in a single, pulsed laser beam. The fluorescence measurement extends the dynamic range of a stand-alone cavity ring-down setup from typically three to at least six orders of magnitude. The presence of the cavity improves the quality of the signal, in particular the signal-to-noise ratio. The methodology, dubbed cavity-enhanced laser-induced fluorescence (CELIF), is developed and rigorously tested against the spectroscopy of 1,4-bis(phenylethynyl)benzene in a molecular beam and density measurements in a cell. We outline how the method can be utilised to determine absolute quantities: absorption cross sections, sample densities and fluorescence quantum yields.Comment: 12 pages, 6 figures, submitted to J. Chem. Phy

    Transfer of a quantum state from a photonic qubit to a gate-defined quantum dot

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    Interconnecting well-functioning, scalable stationary qubits and photonic qubits could substantially advance quantum communication applications and serve to link future quantum processors. Here, we present two protocols for transferring the state of a photonic qubit to a single-spin and to a two-spin qubit hosted in gate-defined quantum dots (GDQD). Both protocols are based on using a localized exciton as intermediary between the photonic and the spin qubit. We use effective Hamiltonian models to describe the hybrid systems formed by the the exciton and the GDQDs and apply simple but realistic noise models to analyze the viability of the proposed protocols. Using realistic parameters, we find that the protocols can be completed with a success probability ranging between 85-97%

    RAPID THERMOCYCLER SYSTEM FOR RAPID AMPLIFICATION OF NUCLEIC ACIDS AND RELATED METHODS

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    A thermo cycling device and method of operating a thermocycler instrument, the instrument including a sample holder, at least one thermal cycling element, and at least one first and second temperature sensors, for causing the sample holder containing the at least one sample to undergo polymerase chain reaction amplification by repeated cycling between at least a denaturation heating stage and an aunealing cooling stage. The first temperature corresponding with the temperature of the sample holder is monitored using the at least one first temperature sensor, and a second temperature corresponding with the temperature external of the sample holder is monitored using the at least one second temperature sensor. Based upon the first temperature and the second temperature, the power that is delivered to the at least one thermal cycling element of the instrument is dynamically controlled

    Transport in the 3-dimensional Anderson model: an analysis of the dynamics on scales below the localization length

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    Single-particle transport in disordered potentials is investigated on scales below the localization length. The dynamics on those scales is concretely analyzed for the 3-dimensional Anderson model with Gaussian on-site disorder. This analysis particularly includes the dependence of characteristic transport quantities on the amount of disorder and the energy interval, e.g., the mean free path which separates ballistic and diffusive transport regimes. For these regimes mean velocities, respectively diffusion constants are quantitatively given. By the use of the Boltzmann equation in the limit of weak disorder we reveal the known energy-dependencies of transport quantities. By an application of the time-convolutionless (TCL) projection operator technique in the limit of strong disorder we find evidence for much less pronounced energy dependencies. All our results are partially confirmed by the numerically exact solution of the time-dependent Schroedinger equation or by approximative numerical integrators. A comparison with other findings in the literature is additionally provided.Comment: 23 pages, 10 figure

    Full regularity for a C*-algebra of the Canonical Commutation Relations. (Erratum added)

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    The Weyl algebra,- the usual C*-algebra employed to model the canonical commutation relations (CCRs), has a well-known defect in that it has a large number of representations which are not regular and these cannot model physical fields. Here, we construct explicitly a C*-algebra which can reproduce the CCRs of a countably dimensional symplectic space (S,B) and such that its representation set is exactly the full set of regular representations of the CCRs. This construction uses Blackadar's version of infinite tensor products of nonunital C*-algebras, and it produces a "host algebra" (i.e. a generalised group algebra, explained below) for the \sigma-representation theory of the abelian group S where \sigma(.,.):=e^{iB(.,.)/2}. As an easy application, it then follows that for every regular representation of the Weyl algebra of (S,B) on a separable Hilbert space, there is a direct integral decomposition of it into irreducible regular representations (a known result). An Erratum for this paper is added at the end.Comment: An erratum was added to the original pape

    IFNGR1 single nucleotide polymorphisms in rheumatoid arthritis

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    On the basis of their biological function, potential genetic candidates for susceptibility to rheumatoid arthritis can be postulated. IFNGR1, encoding the ligand-binding chain of the receptor for interferon gamma, IFNγR1, is one such gene because interferon gamma is involved in the pathogenesis of the disease. In the coding sequence of IFNGR1, two nucleotide positions have been described to be polymorphic in the Japanese population. We therefore investigated the association of those two IFNGR1 single nucleotide polymorphisms with rheumatoid arthritis in a case-control study in a central European population. Surprisingly, however, neither position was polymorphic in the 364 individuals examined, indicating that IFNGR1 does not contribute to susceptibility to rheumatoid arthritis, at least in Caucasians

    PENAMPILAN TINGKAH LAKU SEKSUAL SAPI PEJANTAN LIMOUSIN DAN SIMMENTAL DI BALAI INSEMINASI BUATAN LEMBANG

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    ABSTRACT SEXUAL BEHAVIOR OF LIMOUSIN AND SIMMENTAL BULL BREEDSAT THE LEMBANG ARTIFICIAL INSEMINATION CENTER. In order to provide the prominent bulls, the management process of animal selection was required for animal replacement stock. Animal selection was including the inspection of animal physical and sexual behavior.  Based on this criterion, study was conducted to observe the sexual behavior of Limousin and Simmental breed bulls at the artificial insemination center in Lembang, Bandung.  The objective of this study was to evaluate the characteristic of sexual behavior of the Limousin and Simmental breed bulls.  The amount of 80 bulls consisted of 40 Limousin and 40 Simmental bulls at the age of 6 to 9 years old were used in this study.  Data collections were conducted by focal animal sampling.  Sexual behavior was observed during ten days at the time from 07.00 to 11.00 West Indonesian Time.  Data collection were started at the period of bull was introduced into teaser.Based on t-test on sexual behavior of Limousin and Simmental bulls, the results showed that (1) The time need for courtship with teaser of Limousin bull was significantly shorter (P<0,01) compared with Simmental bull; (2) Time period use for the first time to start flehmen of Limousin bull was shorter significantly (P<0,01) compared with Simmental bull; (3) Flehmen frequency of Limousin and Simmental was non significantly.Based on the observation of sexual behavior, the Limousin bull need time of the 2,22 seconds to start courthip with teaser, while Simmental bull need time of 2,77 seconds to start courtship with teaser.  The Limousin bull need time of 222 seconds to start flehmen, while Simmental bull need time of 239 seconds to start flehmen. The time periods used for the first time to mount teaser by Limousin bull were 214,87 seconds, while those by Simmental bull were 302,02 seconds. The flehmen frequency of Limousin dan Simmental bulls was similar of only one time during sexual behavior.Key Words :Limousin, Simmental, Sexual behavior, Lembang Artificial Insemination Cente
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