1,514 research outputs found

    Lie bialgebras of generalized Witt type

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    In a paper by Michaelis a class of infinite-dimensional Lie bialgebras containing the Virasoro algebra was presented. This type of Lie bialgebras was classified by Ng and Taft. In this paper, all Lie bialgebra structures on the Lie algebras of generalized Witt type are classified. It is proved that, for any Lie algebra WW of generalized Witt type, all Lie bialgebras on WW are coboundary triangular Lie bialgebras. As a by-product, it is also proved that the first cohomology group H1(W,W⊗W)H^1(W,W \otimes W) is trivial.Comment: 14 page

    Emergency contraception in Australia: The desired source of information versus the actual source of information

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    Objective: To determine long-term trends in emergency contraception (EC) management by general practitioners in Australia. Design, setting and participants: Data from April 2000 to March 2012 were drawn from the BEACH (Bettering the Evaluation and Care of Health) program, a continuous cross-sectional survey of GP activity. We analysed consultations involving EC management, unwanted pregnancy management and emergency contraceptive pill (ECP) prescribing per 1000 GP encounters with women aged 14-54 years. Summary statistics were calculated with 95% confidence intervals. Results: In 2000-2001, GPs managed EC problems at a rate of 5.50 per 1000 encounters (95% CI, 4.37-6.63). From 2004, after the ECP became available over the counter (OTC) in pharmacies, EC management, which includes ECP prescription, progressively declined. By 2011-2012, only 1.43 EC problems were managed per 1000 encounters (95% CI, 0.84-2.02) and only 0.48 ECP prescriptions were provided per 1000 encounters (95% CI, 0.14-0.82). Yet the management rate of unwanted pregnancy problems stayed relatively constant (rate in 2000-2001, 0.95 per 1000 encounters; 95% CI, 0.40-1.50; rate in 2011-2012, 0.88 per 1000 encounters; 95% CI, 0.41-1.36). Conclusion: Low rates of EC management by GPs since ECP became available OTC suggest that women may be obtaining information on EC elsewhere. Further investigation is needed to uncover the sources of this information and its acceptability and application by Australian women

    Current contraceptive management in Australian general practice: An analysis of BEACH data

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    Objective: To determine current contraceptive management by general practitioners in Australia. Design, setting and participants: Analysis of data from a random sample of 3910 Australian GPs who participated in the Bettering the Evaluation and Care of Health (BEACH) survey, a continuous cross-sectional survey of GP activity, between April 2007 and March 2011. Consultations with female patients aged 12-54 years that involved all forms of contraception were analysed. Main outcome measures: GP and patient characteristics associated with the management of contraception; types of contraception used; rates of encounters involving emergency contraception. Results: Increased age, ethnicity, Indigenous status and holding a Commonwealth Health Care Card were significantly associated with low rates of encounters involving management of contraception. The combined oral contraceptive pill was the most frequently prescribed method of contraception, with moderate prescription of long-acting reversible contraception (LARC), especially among women aged 34-54 years. Rates of consultations concerned with emergency contraception were low, but involved high rates of counselling, advice or education (48%) compared with encounters for general contraception (> 20%). Conclusion: A shift towards prescribing LARC, as recommended in clinical guidelines, has yet to occur in Australian general practice. Better understanding of patient and GP perspectives on contraceptive choices could lead to more effective contraceptive use

    Hamiltonian type Lie bialgebras

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    We first prove that, for any generalized Hamiltonian type Lie algebra LL, the first cohomology group H1(L,L⊗L)H^1(L,L \otimes L) is trivial. We then show that all Lie bialgebra structures on LL are triangular.Comment: LaTeX, 16 page

    Model Exact Low-Lying States and Spin Dynamics in Ferric Wheels; Fe6_6 to Fe12_{12}

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    Using an efficient numerical scheme that exploits spatial symmetries and spin-parity, we have obtained the exact low-lying eigenstates of exchange Hamiltonians for ferric wheels up to Fe12_{12}. The largest calculation involves the Fe12_{12} ring which spans a Hilbert space dimension of about 145 million for Ms_s=0 subspace. Our calculated gaps from the singlet ground state to the excited triplet state agrees well with the experimentally measured values. Study of the static structure factor shows that the ground state is spontaneously dimerized for ferric wheels. Spin states of ferric wheels can be viewed as quantized states of a rigid rotor with the gap between the ground and the first excited state defining the inverse of moment of inertia. We have studied the quantum dynamics of Fe10_{10} as a representative of ferric wheels. We use the low-lying states of Fe10_{10} to solve exactly the time-dependent Schr\"odinger equation and find the magnetization of the molecule in the presence of an alternating magnetic field at zero temperature. We observe a nontrivial oscillation of magnetization which is dependent on the amplitude of the {\it ac} field. We have also studied the torque response of Fe12_{12} as a function of magnetic field, which clearly shows spin-state crossover.Comment: Revtex, 24 pages, 8 eps figure

    Rotational modes in molecular magnets with antiferromagnetic Heisenberg exchange

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    In an effort to understand the low temperature behavior of recently synthesized molecular magnets we present numerical evidence for the existence of a rotational band in systems of quantum spins interacting with nearest-neighbor antiferromagnetic Heisenberg exchange. While this result has previously been noted for ring arrays with an even number of spin sites, we find that it also applies for rings with an odd number of sites as well as for all of the polytope configurations we have investigated (tetrahedron, cube, octahedron, icosahedron, triangular prism, and axially truncated icosahedron). It is demonstrated how the rotational band levels can in many cases be accurately predicted using the underlying sublattice structure of the spin array. We illustrate how the characteristics of the rotational band can provide valuable estimates for the low temperature magnetic susceptibility.Comment: 14 pages, 7 figures, to be published in Phys. Rev.

    The Wicked Machinery of Government: Malta and the Problems of Continuity under the New Model Administration

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    This is a study focused on the early years of British rule in Malta (1800-1813). It explores the application to the island of the “new model” of colonial government, one based on direct rule from London mediated by the continuation of existing laws and institutions. Systemic deficiencies are identified. These tended to undermine the effectiveness of direct British rule. This study also reveals, in the context of legal and constitutional continuity, unresolved tensions between modernity and tradition. The political stability of the island was damaged and the possibility of continued British possession was threatened

    Proton NMR for Measuring Quantum-Level Crossing in the Magnetic Molecular Ring Fe10

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    The proton nuclear spin-lattice relaxation rate 1/T1 has been measured as a function of temperature and magnetic field (up to 15 T) in the molecular magnetic ring Fe10. Striking enhancement of 1/T1 is observed around magnetic field values corresponding to a crossing between the ground state and the excited states of the molecule. We propose that this is due to a cross-relaxation effect between the nuclear Zeeman reservoir and the reservoir of the Zeeman levels of the molecule. This effect provides a powerful tool to investigate quantum dynamical phenomena at level crossing.Comment: Four pages, to appear in Phys.Rev.Let

    Masked suffix priming and morpheme positional constraints

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    Although masked stem priming (e.g., dealer\u2013DEAL) is one of the most established effects in visual word identification (e.g., Grainger et al., 1991), it is less clear whether primes and targets sharing a suffix (e.g., kindness\u2013WILDNESS) also yield facilitation (Giraudo & Grainger, 2003; Du\uf1abeitia et al., 2008). In a new take on this issue, we show that prime nonwords facilitate lexical decisions to target words ending with the same suffix (sheeter\uac\u2013TEACHER) compared to a condition where the critical suffix was substituted by another one (sheetal\u2013TEACHER) or by an unrelated non\u2013morphological ending (sheetub\u2013 TEACHER). We also show that this effect is genuinely morphological, as no priming emerged in non\u2013complex items with the same orthographic characteristics (sportel\u2013BROTHEL vs. sportic\u2013BROTHEL vs. sportur\u2013BROTHEL). In a further experiment, we took advantage of these results to assess whether suffixes are recognized in a position\u2013specific fashion. Masked suffix priming did not emerge when the relative order of stems and suffixes was reversed in the prime nonwords\u2014ersheet did not yield any time saving in the identification of teacher as compared to either alsheet or obsheet. We take these results to show that \u2013er was not identified as a morpheme in ersheet, thus indicating that suffix identification is position specific. This conclusion is in line with data on interference effects in nonword rejection (Crepaldi, Rastle, & Davis, 2010), and strongly constrains theoretical proposals on how complex words are identified. In particular, because these findings were reported in a masked priming paradigm, they suggest that positional constraints operate early, most likely at a pre\u2013lexical level of morpho\u2013orthographic analysi

    Extragenic suppressor mutations in ΔripA disrupt stability and function of LpxA

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    Abstract Background Francisella tularensis is a Gram-negative bacterium that infects hundreds of species including humans, and has evolved to grow efficiently within a plethora of cell types. RipA is a conserved membrane protein of F. tularensis, which is required for growth inside host cells. As a means to determine RipA function we isolated and mapped independent extragenic suppressor mutants in ∆ripA that restored growth in host cells. Each suppressor mutation mapped to one of two essential genes, lpxA or glmU, which are involved in lipid A synthesis. We repaired the suppressor mutation in lpxA (S102, LpxA T36N) and the mutation in glmU (S103, GlmU E57D), and demonstrated that each mutation was responsible for the suppressor phenotype in their respective strains. We hypothesize that the mutation in S102 altered the stability of LpxA, which can provide a clue to RipA function. LpxA is an UDP-N-acetylglucosamine acyltransferase that catalyzes the transfer of an acyl chain from acyl carrier protein (ACP) to UDP-N-acetylglucosamine (UDP-GlcNAc) to begin lipid A synthesis. Results LpxA was more abundant in the presence of RipA. Induced expression of lpxA in the ΔripA strain stopped bacterial division. The LpxA T36N S102 protein was less stable and therefore less abundant than wild type LpxA protein. Conclusion These data suggest RipA functions to modulate lipid A synthesis in F. tularensis as a way to adapt to the host cell environment by interacting with LpxA.http://deepblue.lib.umich.edu/bitstream/2027.42/110509/1/12866_2014_Article_336.pd
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