1,057 research outputs found

    Asymptotic safety in the dark

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    We explore the Renormalization Group flow of massive uncharged fermions -- a candidate for dark matter -- coupled to a scalar field through a Higgs portal. We find that fermionic fluctuations can lower the bound on the scalar mass that arises from vacuum stability. Further, we discuss that despite the perturbative nonrenormalizability of the model, it could be ultraviolet complete at an asymptotically safe fixed point. In our approximation, this simple model exhibits two mechanisms for asymptotic safety: a balance of fermionic and bosonic fluctuations generates a fixed point in the scalar self-interaction; asymptotic safety in the portal coupling is triggered through a balance of canonical scaling and quantum fluctuations. As a consequence of asymptotic safety in the dark sector, the low-energy value of the portal coupling could become a function of the dark fermion mass and the scalar mass, thereby reducing the viable parameter space of the model.Comment: 16 pages plus appendix; 5 figure

    Politics on a Human Scale: The American Tradition of Decentralism (Book Review)

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    Reviewed Title: Politics on a Human Scale: The American Tradition of Decentralism. Lanham, Maryland: Lexington Books, 2013. 648 pp. ISBN 978-0-73918-67-49

    Tomato resistance to Alternaria stem canker: localization in host genotypes and functional expression compared to non-host resistance

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    The Alternaria stem canker resistance locus (Asc-locus), involved in resistance to the fungal pathogen Alternaria alternata f. sp. lycopersici and in insensitivity to host-specific toxins (AAL-toxins) produced by the pathogen, was genetically mapped on the tomato genome. Susceptibility and resistance were assayed by testing a segregating F2 population for sensitivity to AAL-toxins in leaf bioassays. Linkage was observed to phenotypic markers solanifolium and sunny, both on chromosome 3. For the Asc-locus, a distance of 18 centiMorgan to solanifolium was calculated, corresponding to position 93 on chromosome 3. This map position of the resistance locus turned out to be the same in three different resistant tomato accessions, one Dutch and two American, that are at least 40 years apart. AAL-toxin sensitivity in susceptible and resistant tomato genotypes was compared with AAL-toxin sensitivity in a non-host Nicotiana tabacum during different levels of plant cell development. In susceptible and resistant tomato genotypes, inhibitory effects were demonstrated at all levels, except for leaves of resistant genotypes. However, during pollen and root development, inhibitory effects on susceptible genotypes were larger than on resistant genotypes. In the non-host Nicotiana tabacum, hardly any effects of AAL-toxins were demonstrated. Apparently, a cellular target site is present in tomato, but not in Nicotiana tabacum. It was concluded that three levels of AAL-toxin sensitivity exist: (1) a susceptible host sensitivity, (2) a resistant host sensitivity, (3) a non-host sensitivity, and that the resistance mechanism operating in tomato is different from that operating in Nicotiana tabacum.

    Healthcare Costs in the U.S.

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    What are the ethical considerations regarding the price that pharmaceutical companies charge for medications, and how are those charges passed on to pharmacies and hospitals/clinics? Posting about advocating for cost-effective health care­­­­­­­­ from In All Things - an online hub committed to the claim that the life, death, and resurrection of Jesus Christ has implications for the entire world. http://inallthings.org/healthcare-costs-in-the-u-s

    Healthcare Costs in the U.S.

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    What are the ethical considerations regarding the price that pharmaceutical companies charge for medications, and how are those charges passed on to pharmacies and hospitals/clinics? Posting about advocating for cost-effective health care­­­­­­­­ from In All Things - an online hub committed to the claim that the life, death, and resurrection of Jesus Christ has implications for the entire world. http://inallthings.org/healthcare-costs-in-the-u-s

    Towards a generic compilation approach for quantum circuits through resynthesis

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    In this paper, we propose a generic quantum circuit resynthesis approach for compilation. We use an intermediate representation consisting of Paulistrings over {Z, I} and {X, I} called a ``mixed ZX-phase polynomial``. From this universal representation, we generate a completely new circuit such that all multi-qubit gates (CNOTs) are satisfying a given quantum architecture. Moreover, we attempt to minimize the amount of generated gates. The proposed algorithms generate fewer CNOTs than similar previous methods on different connectivity graphs ranging from 5-20 qubits. In most cases, the CNOT counts are also lower than Qiskit's. For large circuits, containing >= 100 Paulistrings, our proposed algorithms even generate fewer CNOTs than the TKET compiler. Additionally, we give insight into the trade-off between compilation time and final CNOT count.Comment: 10 pages including references. 2 tables, 1 figur

    Cnot circuit extraction for topologically-constrained quantum memories

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    Funding Information: We gratefully acknowledge support from the Unitary Fund (http://unitary.fund) for this work. We would also like to thank Will Zeng, Ross Duncan, and John van de Wetering for fruitful discussions about circuit mapping for NISQ as well as the authors of [22] for clarifying some points about their approach. Publisher Copyright: © Rinton Press.Many physical implementations of quantum computers impose stringent memory constraints in which 2-qubit operations can only be performed between qubits which are nearest neighbours in a lattice or graph structure. Hence, before a computation can be run on such a device, it must be mapped onto the physical architecture. That is, logical qubits must be assigned physical locations in the quantum memory, and the circuit must be replaced by an equivalent one containing only operations between nearest neighbours. In this paper, we give a new technique for quantum circuit mapping (a.k.a. routing), based on Gaussian elimination constrained to certain optimal spanning trees called Steiner trees. We give a reference implementation of the technique for CNOT circuits and show that it significantly out-performs general-purpose routines on CNOT circuits. We then comment on how the technique can be extended straightforwardly to the synthesis of CNOT+Rz circuits and as a modification to a recently-proposed circuit simplification/extraction procedure for generic circuits based on the ZX-calculus.Peer reviewe

    Cnot circuit extraction for topologically-constrained quantum memories

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    Funding Information: We gratefully acknowledge support from the Unitary Fund (http://unitary.fund) for this work. We would also like to thank Will Zeng, Ross Duncan, and John van de Wetering for fruitful discussions about circuit mapping for NISQ as well as the authors of [22] for clarifying some points about their approach. Publisher Copyright: © Rinton Press.Many physical implementations of quantum computers impose stringent memory constraints in which 2-qubit operations can only be performed between qubits which are nearest neighbours in a lattice or graph structure. Hence, before a computation can be run on such a device, it must be mapped onto the physical architecture. That is, logical qubits must be assigned physical locations in the quantum memory, and the circuit must be replaced by an equivalent one containing only operations between nearest neighbours. In this paper, we give a new technique for quantum circuit mapping (a.k.a. routing), based on Gaussian elimination constrained to certain optimal spanning trees called Steiner trees. We give a reference implementation of the technique for CNOT circuits and show that it significantly out-performs general-purpose routines on CNOT circuits. We then comment on how the technique can be extended straightforwardly to the synthesis of CNOT+Rz circuits and as a modification to a recently-proposed circuit simplification/extraction procedure for generic circuits based on the ZX-calculus.Peer reviewe

    The Effect of Hydrothermal Treatment on Olivine Nano-Silica

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    This paper provides an overview of the effects of ripening the olivine nano-silica to form particles with a lower specific surface area for optimal use in high performance concrete. The nano-silica was ripened using a hydrothermal treatment in a mixed batch reactor at 90 °C, pH ranging from 8 to 10 and a silica weight percentage of three and six percent. The specific surface area of the olivine nano-silica can be reduced by 62 percent by Ostwald ripening in 22 hours. This reduction corresponds to a 80 percent drop of the micropore surface area and a 57 percent drop of the external surface area. The different hydrothermal conditions did not affect the final specific surface area at the equilibrium. However, the use of a high energy mixer reduced the specific surface area by 52 percent in only five minutes. Despite the reduction in specific surface area, the aggregates of the original olivine nano-silica are not dissolved during the ripening process. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3491

    Het effect van toediening van calcium en borium aan de grond op de opbrengst, kwaliteit en minerale samenstelling van pootaardappelen

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    In het kader van het deelproject 'Nutriëntenvoorziening' van het deelcluster 'Innovatie Aardappelteelt' van Agrobiokon is onderzoek uitgevoerd naar de calciumvoorziening van pootgoed. Calcium speelt een belangrijke rol bij de kieming van pootgoed. Lage calciumgehaltes kunnen leiden tot een verminderde kiemkracht en afsterving van kiemen. Het doel van het onderzoek is na te gaan op welke wijze het calciumgehalte in pootaardappelen kan worden verhoogd. Hiertoe zijn in 1998 twee veldproeven aangelegd. Van deze veldproeven wordt in dit rapport verslag gedaan. De proef is aangelegd op twee locaties, namelijk Valthermond en Rold
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