2,378 research outputs found

    Graphical Methods in Device-Independent Quantum Cryptography

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    We introduce a framework for graphical security proofs in device-independent quantum cryptography using the methods of categorical quantum mechanics. We are optimistic that this approach will make some of the highly complex proofs in quantum cryptography more accessible, facilitate the discovery of new proofs, and enable automated proof verification. As an example of our framework, we reprove a previous result from device-independent quantum cryptography: any linear randomness expansion protocol can be converted into an unbounded randomness expansion protocol. We give a graphical proof of this result, and implement part of it in the Globular proof assistant.Comment: Publishable version. Diagrams have been polished, minor revisions to the text, and an appendix added with supplementary proof

    A Two-Coordinate Nickel Imido Complex That Effects C−H Amination

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    An exceptionally low coordinate nickel imido complex, (IPr*)Ni═N(dmp) (2) (dmp = 2,6-dimesitylphenyl), has been prepared by the elimination of N_2 from a bulky aryl azide in its reaction with (IPr*)Ni(η^6-C_7H_8) (1). The solid-state structure of 2 features two-coordinate nickel with a linear C−Ni−N core and a short Ni−N distance, both indicative of multiple-bond character. Computational studies using density functional theory showed a Ni═N bond dominated by Ni(dπ)−N(pπ) interactions, resulting in two nearly degenerate singly occupied molecular orbitals (SOMOs) that are Ni−N π* in character. Reaction of 2 with CO resulted in nitrene-group transfer to form (dmp)NCO and (IPr*)Ni(CO)_3 (3). Net C−H insertion was observed in the reaction of 2 with ethene, forming the vinylamine (dmp)NH(CH═CH_2) (5) via an azanickelacyclobutane intermediate, (IPr*)Ni{N,C:κ^2-N(dmp)CH_2CH_2} (4)

    In defence of global egalitarianism

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    This essay argues that David Miller's criticisms of global egalitarianism do not undermine the view where it is stated in one of its stronger, luck egalitarian forms. The claim that global egalitarianism cannot specify a metric of justice which is broad enough to exclude spurious claims for redistribution, but precise enough to appropriately value different kinds of advantage, implicitly assumes that cultural understandings are the only legitimate way of identifying what counts as advantage. But that is an assumption always or almost always rejected by global egalitarianism. The claim that global egalitarianism demands either too little redistribution, leaving the unborn and dissenters burdened with their societies' imprudent choices, or too much redistribution, creating perverse incentives by punishing prudent decisions, only presents a problem for global luck egalitarianism on the assumption that nations can legitimately inherit assets from earlier generations – again, an assumption very much at odds with global egalitarian assumptions

    Synthesis, structures and cytotoxicity studies of p-sulfonatocalix[4]arene lanthanide complexes

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    A number of p-sulfonatocalix[4]arene complexes of the lanthanides (Tb, Gd, and Eu) have been prepared, some in the presence of tetraazamacrocycle 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid (DO3A), and fully characterised. Crystal structure determinations reveal lanthanide coordination at the sulfonate group, bridging several calixarene units, giving coordination polymers. All complexes in this study have been determined to be relatively non-toxic using in vitro cell assays with CC₅₀ values in the range 30–170 μM

    INTELLIGENT MODULAR TOOL FOR EMERGENCY SURGICAL TREATMENT DURING PAYLOADCRITICAL MISSIONS

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    During any extended mission to an extreme environment (i.e. the International Space Station, a lunar base or a manned mission to Mars) the chances of an otherwise minor mJury becoming life threatening grow to be significant. In order to address these concerns, equipment must be provided to diagnose and treat a wide range of possible afflictions while direct contact with Earth-based physicians is impossible. Minimally invasive surgery (MIS) is an excellent treatment option due to its history of decreasing trauma in patients and speeding recovery. In an effort to provide the maximum functionality for any given MIS procedure, an intelligent modular surgical system has been designed and is being further refined to assist surgeons and other practitioners during medical procedures without necessitating the inclusion of many different instruments. The overall design approach was to identify the functions of existing technology and then to design a device that combined functionalities whenever possible to minimize the overall complexity of the design. The intelligence in the design is intended to make finding instruments easier for the individual performing the surgical procedure rather than replace humans in the operating theater. This paper presents analysis quantifying the payload reduction achieved by the new modular design as it pertains to extended missions to extreme environments. In addition to assisting surgeons, this system will take approximately 25% less space than the current equivalent MIS tools

    Development and Application of a Thermistor Current Meter

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    This report provides details for the construction of a hot-bead thermistor current meter which is capable of measuring water velocities on a millimeter spatial scale and for the construction of a compact and accurate calibration system. Hot-bead thermistor current meters can be built with response times of 200 ms capable of measuring velocities between 0.1 and 80 cm s-1. The construction of a sturdy probe for application in lotic systems such as high gradient Hawaiian streams was achieved by the use of heavy-duty acrylic tubing, small stainless steel gas-chromatography tubing, and flexible Tygon spaghetti tubing. An acrylic handle anchors the electrical cable at one end and the thermistors at the other. The following criteria were central to the development of the calibration system a accurate calibration b compact unit for storage and use in limited laboratory space c leak-proof system d inexpensive design requirement for readily available materials and e construction requirements for the use of hand tools. The thermistor current meter has been used to measure velocities in the water column and around various substrate features in riverine habitats. More detailed spatial velocity measurements were made in streams by dividing a habitat into small grid cells. With fine spatial scales e.g., grid sizes of 200 to 300 cm 2 or less and repetitive sampling under varying water flow conditions, insights into relationships between various spatial and temporal characteristics of microhabitat velocities were made. The current meter has been used to determine ambient velocity profiles around a variety of benthic stream

    Vector competence experiments with Rocio virus and three mosquito species from the epidemic zone in Brazil

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    First-generation progeny of field-collected Psorophora ferox, Aedes scapularis, and Aedes serratus from the Rocio encephalitis epidemic zone in S.Paulo State, Brazil, were tested for vector competency in the laboratory. Psorophora ferox and Ae. scapularis are susceptible to per os infection with Rocio virus and can transmit the virus by bite following a suitable incubation period. Oral ID50S for the two species (10(4.1) and 10(4.3) Vero cell plaque forming units, respectively) did not differ significantly. Infection rates in Ae. serratus never exceeded 36%, and, consequently, an ID50 could not be calculated for this species. It is unlikely that Ae. serratus is an epidemiologically important vector of Rocio virus. The utility of an in vitro feeding technique for demonstrating virus transmission by infected mosquitoes and difficulties encountered in working with uncolonized progeny of field-collected mosquitoes are discussed.Em condições de laboratório procedeu-se a ensaios visando testar a capacidade vetora para o virus Rocio, da primeira geração de Psorophora ferox, Aedes scapularis e Aedes serratus obtida a partir de especimens coletados na região epidêmica do Estado de São Paulo, Brasil. Psorophora ferox e Aedes scapularis revelaram-se suscetíveis à infecção por via oral e capazes de transmitir o vírus mediante a picada após período adequado de incubação. Para as duas espécies, as ID50 orais não diferiram significativamente. Em Ae. serratus as taxas de infecção nunca ultrapassaram os 36,0% o que impossibilitou o cálculo da ID50 para essa espécie. É improvável que Ae. serratus seja vetor epidemiológicamente importante do vírus Rocio. Discute-se a utilidade da técnica de alimentação "in vitro" para demonstrar a transmissão por mosquitos infectados, e também as dificuldades encontradas ao trabalhar com gerações não colonizadas originárias de especimens coletados no campo

    The Importance of Background in the Detection and Identification of Gas Plumes Using Emissive Infrared Hyperspectral Sensing

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    Using a Fourier transform infrared field spectrometer, spectral infrared radiance measurements were made of several generated gas plumes against both a uniform sky and terrestrial background. Background temperature, spectral complexity, and physical homogeneity each influenced the success of emissive infrared spectral sensing technology in detecting and identifying the presence of a gas plume and its component constituents. As expected, high temperature contrast and uniform backgrounds provided the best conditions for detectability and diagnostic identification. This report will summarize some of SITAC’s findings concerning plume detectability, including the importance of plume cooling, plumes in emission and absorption, the effects of optical thickness, and the effects of condensing plumes on gas detection

    Matrix Pencils and Entanglement Classification

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    In this paper, we study pure state entanglement in systems of dimension 2mn2\otimes m\otimes n. Two states are considered equivalent if they can be reversibly converted from one to the other with a nonzero probability using only local quantum resources and classical communication (SLOCC). We introduce a connection between entanglement manipulations in these systems and the well-studied theory of matrix pencils. All previous attempts to study general SLOCC equivalence in such systems have relied on somewhat contrived techniques which fail to reveal the elegant structure of the problem that can be seen from the matrix pencil approach. Based on this method, we report the first polynomial-time algorithm for deciding when two 2mn2\otimes m\otimes n states are SLOCC equivalent. Besides recovering the previously known 26 distinct SLOCC equivalence classes in 23n2\otimes 3\otimes n systems, we also determine the hierarchy between these classes
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