5,750 research outputs found

    Mars oxygen production system design

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    The design and construction phase is summarized of the Mars oxygen demonstration project. The basic hardware required to produce oxygen from simulated Mars atmosphere was assembled and tested. Some design problems still remain with the sample collection and storage system. In addition, design and development of computer compatible data acquisition and control instrumentation is ongoing

    Classical simulation of measurement-based quantum computation on higher-genus surface-code states

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    We consider the efficiency of classically simulating measurement-based quantum computation on surface-code states. We devise a method for calculating the elements of the probability distribution for the classical output of the quantum computation. The operational cost of this method is polynomial in the size of the surface-code state, but in the worst case scales as 22g2^{2g} in the genus gg of the surface embedding the code. However, there are states in the code space for which the simulation becomes efficient. In general, the simulation cost is exponential in the entanglement contained in a certain effective state, capturing the encoded state, the encoding and the local post-measurement states. The same efficiencies hold, with additional assumptions on the temporal order of measurements and on the tessellations of the code surfaces, for the harder task of sampling from the distribution of the computational output.Comment: 21 pages, 13 figure

    Aberrant right subclavian artery syndrome: A case of chronic cough1 1Competition of interest: none.

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    AbstractA young, otherwise healthy man had chronic cough of 16 months’ duration. Evaluation revealed an aberrant right subclavian artery. Kommerell’s diverticulum without aneurysmal degeneration was present. Imaging studies showed compression of the esophagus but not the trachea. Results of methacholine challenge test were negative for evidence of reactive airway disease, but suggested mild variable intrathoracic obstruction. While aberrant right subclavian artery syndrome most commonly involves dysphagia, our patient’s only symptom was cough. Right subclavian artery to right common carotid artery transposition was performed, with oversewing of the subclavian artery stump to the left of the esophagus through a right supraclavicular incision. This treatment was curative, with complete resolution of symptoms

    Off-diagonal Interactions, Hund's Rules and Pair-binding in Hubbard Molecules

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    We have studied the effect of including nearest-neighbor, electron-electron interactions, in particular the off-diagonal (non density-density) terms, on the spectra of truncated tetrahedral and icosahedral ``Hubbard molecules,'' focusing on the relevance of these systems to the physics of doped C60_{60}. Our perturbation theoretic and exact diagonalization results agree with previous work in that the density-density term suppresses pair-binding. However, we find that for the parameter values of interest for C60C_{60} the off-diagonal terms {\em enhance} pair-binding, though not enough to offset the suppression due to the density-density term. We also find that the critical interaction strengths for the Hund's rules violating level crossings in C60−2_{60}^{-2}, C60−3_{60}^{-3} and C60−4_{60}^{-4} are quite insensitive to the inclusion of these additional interactions.Comment: 20p + 5figs, Revtex 3.0, UIUC preprint P-94-10-08

    The phase diagram of the lattice Calogero-Sutherland model

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    We introduce a {\it lattice} version of the Calogero Sutherland model adapted to describe 1/d21/d^2 pairwise interacting steps with discrete positions on a vicinal surface. The configurational free energy is obtained within a transfer matrix method. The full phase diagram for attractive and for repulsive interaction is deduced. For attraction, critical temperatures of faceting transitions are found to depend on step density.Comment: latex PRBCalogSuth.tex, 6 files, 4 pages [SPEC-S00/900

    Healthy ageing education across Europe: a survey of ENPHE members

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    Background and Purpose Healthy ageing is an optimal status that people could achieve when they currently adapt their physical and psychological evolution that allow them to participate socially with a high level of autonomy. The process of becoming older is a personal process that can be very heterogeneous. This heterogeneity generates different approaches depending on the needs, capacities of adaptation and subject possibilities. Therefore, it is important that any kind of intervention should adapt specifically to each patient. Description With the goal to develop and offer updated education in Healthy Ageing, a group of five universities: Ecole d’Assas (France), Blanquerna-Universitat Ramón Lull (Spain), Univerzita Palackého v Olomouci (Czech Republic), Kolegji Heimerer (Kosovo) and Escola de Saúde do Alcoitão (Portugal) decided to set up a joint adventure as encouraged by ENPHE. Our first step is to benchmark and characterise within Europe the tendencies, the offers and models of best practices. Material / Methods An online questionnaire was developed and sent to all the ENPHE members between January and February of 2017. The survey was composed of twenty close and open questions related to the participant identification, course description and identification of institutional projects in healthy ageing Summary of Results From a population of 136 EMPHE member's we receive 39 complete responses (27%) and the main results are: 69% of the respondents offer courses about healthy ageing; 88% Integrated in the bachelor degree ; mainly for Physiotherapists students (92%); and with the most prevalent topics (above 80%) - Assessment and intervention of clients/populations, multidisciplinary issues and Prevention; the main pedagogical approaches used are lectures (88%), clinical training/field work (77%) and casebased learning (74%); being written or oral examination (81%) the main assessment strategies used. Importance It is very important to empower the individual to become autonomous in deciding how to manage their own ageing process in a healthy way. Any curricula should take in account this reality in order to transform the role of health care professionals and provide them competences to support individuals in this process.N/

    Methylation and protein expression of DNA repair genes: association with chemotherapy exposure and survival in sporadic ovarian and peritoneal carcinomas

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    <p>Abstract</p> <p>Background</p> <p>DNA repair genes critically regulate the cellular response to chemotherapy and epigenetic regulation of these genes may be influenced by chemotherapy exposure. Restoration of BRCA1 and BRCA2 mediates resistance to platinum chemotherapy in recurrent BRCA1 and BRCA2 mutated hereditary ovarian carcinomas. We evaluated BRCA1, BRCA2, and MLH1 protein expression in 115 sporadic primary ovarian carcinomas, of which 31 had paired recurrent neoplasms collected after chemotherapy. Additionally, we assessed whether promoter methylation of BRCA1, MLH1 or FANCF influenced response to chemotherapy or explained alterations in protein expression after chemotherapy exposure.</p> <p>Results</p> <p>Of 115 primary sporadic ovarian carcinomas, 39 (34%) had low BRCA1 protein and 49 (42%) had low BRCA2 expression. BRCA1 and BRCA2 protein expression were highly concordant (p < 0.0001). MLH1 protein loss occurred in 28/115 (24%) primary neoplasms. BRCA1 protein loss in primary neoplasms was associated with better survival (p = 0.02 Log Rank test) and remained significant after accounting for either stage or age in a multivariate model (p = 0.04, Cox proportional hazards). In paired specimens, BRCA1 protein expression increased in 13/21 (62%) and BRCA2 protein expression increased in 15/21 (71%) of recurrent carcinomas with low or intermediate protein in the paired primary. In contrast MLH1 expression was rarely decreased in recurrent carcinomas (1/33, 3%). Similar frequencies of MLH1, BRCA1, and FANCF promoter methylation occurred in primary carcinomas without previous chemotherapy, after neoadjuvant chemotherapy, or in recurrent neoplasms.</p> <p>Conclusion</p> <p>Low BRCA1 expression in primary sporadic ovarian carcinoma is associated with prolonged survival. Recurrent ovarian carcinomas commonly have increased BRCA1 and/or BRCA2 protein expression post chemotherapy exposure which could mediate resistance to platinum based therapies. However, alterations in expression of these proteins after chemotherapy are not commonly mediated by promoter methylation, and other regulatory mechanisms are likely to contribute to these alterations.</p
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