Omni-directional L-band antenna for mobile communications

The principle and design of an L-band omni-directional mobile communication antenna are discussed. The antenna is a circular wave guide aperture with hybrid circuits attached to higher order mode excitation. It produces polarized and symmetric two split beams in elevation. The circular waveguide is fed by eight probes with a 90 degree phase shift between their inputs. Radiation pattern characteristics are controlled by adjusting the aperture diameter and mode excitation. This antenna satisfies gain requirements as well as withstanding the harsh environment

Low Temperature Susceptibility of the Noncentrosymmetric Superconductor CePt_3Si

We report ac susceptibility measurements of polycrystalline CePt_3Si down to 60 mK and in applied fields up to 9 T. In zero field, a full Meissner state emerges at temperatures T/Tc < 0.3, where Tc=0.65 K is the onset transition temperature. Though transport measurements show a relatively high upper critical field Bc2 ~ 4-5 T, the low temperature susceptibility, \chi', is quite fragile to applied field, with \chi' diminishing rapidly in fields of a few kG. Interestingly, the field dependence of \chi' is well described by the power law, 4\pi\chi'=(B/B_c)^{1/2}, where Bc is the field at which the onset of resistance is observed in transport measurements.Comment: 5 figure

Labeling of endothelial cells with magnetic microbeads by angiophagy

Objectives Attachment of magnetic particles to cells is needed for a variety of applications but is not always possible or efficient. Simpler and more convenient methods are thus desirable. In this study, we tested the hypothesis that endothelial cells (EC) can be loaded with micron-size magnetic beads by the phagocytosis-like mechanism ‘angiophagy’. To this end, human umbilical vein EC (HUVEC) were incubated with magnetic beads conjugated or not (control) with an anti-VEGF receptor 2 antibody, either in suspension, or in culture followed by re-suspension using trypsinization. Results In all conditions tested, HUVEC incubation with beads induced their uptake by angiophagy, which was confirmed by (i) increased cell granularity assessed by flow cytometry, and (ii) the presence of an F-actin rich layer around many of the intracellular beads, visualized by confocal microscopy. For confluent cultures, the average number of beads per cell was 4.4 and 4.2, with and without the presence of the anti-VEGFR2 antibody, respectively. However, while the actively dividing cells took up 2.9 unconjugated beads on average, this number increased to 5.2 if binding was mediated by the antibody. Magnetic pulldown increased the cell density of beads-loaded cells in porous electrospun poly-capro-lactone scaffolds by a factor of 4.5 after 5 min, as compared to gravitational settling (p < 0.0001). Conclusion We demonstrated that EC can be readily loaded by angiophagy with micron-sized beads while attached in monolayer culture, then dispersed in single-cell suspensions for pulldown in porous scaffolds and for other applications

Direct detection of electron backscatter diffraction patterns.

We report the first use of direct detection for recording electron backscatter diffraction patterns. We demonstrate the following advantages of direct detection: the resolution in the patterns is such that higher order features are visible; patterns can be recorded at beam energies below those at which conventional detectors usefully operate; high precision in cross-correlation based pattern shift measurements needed for high resolution electron backscatter diffraction strain mapping can be obtained. We also show that the physics underlying direct detection is sufficiently well understood at low primary electron energies such that simulated patterns can be generated to verify our experimental data

Laser-based three-dimensional manufacturing technologies for rechargeable batteries.

Laser three-dimensional (3D) manufacturing technologies have gained substantial attention to fabricate 3D structured electrochemical rechargeable batteries. Laser 3D manufacturing techniques offer excellent 3D microstructure controllability, good design flexibility, process simplicity, and high energy and cost efficiencies, which are beneficial for rechargeable battery cell manufacturing. In this review, notable progress in development of the rechargeable battery cells via laser 3D manufacturing techniques is introduced and discussed. The basic concepts and remarkable achievements of four representative laser 3D manufacturing techniques such as selective laser sintering (or melting) techniques, direct laser writing for graphene-based electrodes, laser-induced forward transfer technique and laser ablation subtractive manufacturing are highlighted. Finally, major challenges and prospects of the laser 3D manufacturing technologies for battery cell manufacturing will be provided

A Heuristic Computational Model of Basic Cellular Processes and Oxygenation during Spheroid-Dependent Biofabrication

An emerging approach in biofabrication is the creation of 3D tissue constructs through scaffold-free, cell spheroid-only methods. The basic mechanism in this technology is spheroid fusion, which is driven by the minimization of energy, the same biophysical mechanism that governs spheroid formation. However, other factors such as oxygen and metabolite accessibility within spheroids impact on spheroid properties and their ability to form larger-scale structures. The goal of our work is to develop a simulation platform eventually capable of predicting the conditions that minimize metabolism-related cell loss within spheroids. To describe the behavior and dynamic properties of the cells in response to their neighbors and to transient nutrient concentration fields, we developed a hybrid discrete-continuous heuristic model, combining a cellular Potts-type approach with field equations applied to a randomly populated spheroid cross-section of prescribed cell-type constituency. This model allows for the description of: (i) cellular adhesiveness and motility; (ii) interactions with concentration fields, including diffusivity and oxygen consumption; and (iii) concentration-dependent, stochastic cell dynamics, driven by metabolite-dependent cell death. Our model readily captured the basic steps of spheroid-based biofabrication (as specifically dedicated to scaffold-free bioprinting), including intra-spheroid cell sorting (both in 2D and 3D implementations), spheroid defect closure, and inter-spheroid fusion. Moreover, we found that when hypoxia occurring at the core of the spheroid was set to trigger cell death, this was amplified upon spheroid fusion, but could be mitigated by external oxygen supplementation. In conclusion, optimization and further development of scaffold-free bioprinting techniques could benefit from our computational model which is able to simultaneously account for both cellular dynamics and metabolism in constructs obtained by scaffold-free biofabrication

Voice-QA: evaluating the impact of misrecognized words on passage retrieval

Question Answering is an Information Retrieval task where the query is posed using natural language and the expected result is a concise answer. Voice-activated Question Answering systems represent an interesting application, where the question is formulated by speech. In these systems, an Automatic Speech Recognition module can be used to transcribe the question. Thus, recognition errors may be introduced, producing a significant effect on the answer retrieval process. In this work we study the relationship between some features of misrecognized words and the retrieval results. The features considered are the redundancy of a word in the result set and its inverse document frequency calculated over the collection. The results show that the redundancy of a word may be an important clue on whether an error on it would deteriorate the retrieval results, at least if a closed model is used for speech recognition.This work was carried out in the framework of TextEnterprise (TIN2009-13391-C04-03), Timpano (TIN2011-28169-C05-01), WIQEI IRSES (grant no. 269180) within the FP 7 Marie Curie People, FPU Grant AP2010-4193 from the Spanish Ministerio de Educaci´on (first author), and the Microcluster VLC/Campus on Multimodal Intelligent Systems (third author)Calvo Lance, M.; Buscaldi, D.; Rosso, P. (2012). Voice-QA: evaluating the impact of misrecognized words on passage retrieval. En Advances in Artificial Intelligence - IBERAMIA 2012. Springer Verlag (Germany). 462-471. https://doi.org/10.1007/978-3-642-34654-5_47S462471Buscaldi, D., Gómez, J.M., Rosso, P., Sanchis, E.: N-Gram vs. Keyword-Based Passage Retrieval for Question Answering. In: Peters, C., Clough, P., Gey, F.C., Karlgren, J., Magnini, B., Oard, D.W., de Rijke, M., Stempfhuber, M. (eds.) CLEF 2006. LNCS, vol. 4730, pp. 377–384. Springer, Heidelberg (2007)Harabagiu, S., Moldovan, D., Picone, J.: Open-Domain Voice-Activated Question Answering. In: 19th International Conference on Computational Linguistics (COLING 2002), pp. 1–7 (2002)Jones, K.: Index Term Weighting. Information Storage and Retrieval 9(11), 619–633 (1973)Moldovan, D., Paşca, M., Harabagiu, S., Surdeanu, M.: Performance Issues and Error Analysis in an Open-Domain Question Answering System. ACM Transactions on Information Systems (TOIS) 21(2), 133–154 (2003)Rosso, P., Hurtado, L.F., Segarra, E., Sanchis, E.: On the Voice-Activated Question Answering. IEEE Transactions on Systems, Man, and Cybernetics, Part C: Applications and Reviews 42(1), 75–85 (2012)Sanderson, M., Paramita, M.L., Clough, P., Kanoulas, E.: Do User Preferences and Evaluation Measures Line Up? In: 33rd International ACM SIGIR Conference on Research and Development in Information Retrieval (SIGIR 2010), pp. 555–562. ACM, New York (2010)Turmo, J., Comas, P., Rosset, S., Galibert, O., Moreau, N., Mostefa, D., Rosso, P., Buscaldi, D.: Overview of QAST 2009. In: Peters, C., Di Nunzio, G.M., Kurimo, M., Mandl, T., Mostefa, D., Peñas, A., Roda, G. (eds.) CLEF 2009. LNCS, vol. 6241, pp. 197–211. Springer, Heidelberg (2010

A multimethod research investigation of consumer involvement in Australian health service accreditation programmes: The ACCREDIT-SCI study protocol

Introduction: Health service accreditation programmes are a regulatory mechanism adopted to drive improvements inpatient safety and quality. Research investigating the benefits or limitations, of consumer involvement in accreditation programmes is negligible. To develop our knowledge in this area the ACCREDIT collaboration (Accreditation Collaborative for the Conduct of Research, Evaluation and Designated Investigations through Teamwork) has developed a research plan, known as the ACCREDIT-SCI (Standards of Consumer Involvement) study protocol. Two complementary studies have been designed: one, to examine the effectiveness of a standard for consumer participation and two, to explore how patient experiences vary across a range of settings with differing accreditation results. Methods and design: The research setting is the Australian healthcare system, and the two studies focus on three accreditation programmes in the primary, acute and aged care domains. The studies will use multimethods: document analysis; interviews and surveys. Participants will be stakeholders across the three domains including: policy officers; frontline healthcare professionals; accreditation agency personnel, including surveyors and healthcare consumers. Drawing on previous experience, the research team has developed purpose-designed tools. Data will be analysed using thematic, narrative and statistical (descriptive and inferential) procedures. Ethics and dissemination: The University of New South Wales Human Research Ethics Committee has approved the two studies (HREC 10274). Findings will be disseminated through seminars, conference presentations, academic publications and research partner websites. The findings will be formulated to facilitate uptake by policy and accreditation agency professionals, researchers and academics, and consumers, nationally and internationally

Direct determination of Pb isotope ratios in archaeological materials by coupling liquid chromatography to multicollector ICP-MS

A procedure for the determination of Pb isotope ratios by coupling liquid chromatography to a multicollector ICP-MS has been developed. The procedure allows the direct injection of samples after dissolution without resorting to time-consuming off-line separation procedures. The separation of Pb from concomitant elements is carried out by anionic exchange as ethylenediamine tetraacetic acid (EDTA) chelates using EDTA and ammonium nitrate as a mobile phase. A flow injection system allows the injection of NIST 981 Pb isotopic standard, before and after the Pb peak from the sample, and the on-line addition of Tl for mass bias correction and bracketing. The procedure was validated by injecting NIST 981 into the chromatographic system and by comparing the results for real samples with the classical off-line separation procedure using Pb spec resins. The optimised procedure was applied to archaeological samples containing different concentrations of Pb. It was observed that the only limitation to the accuracy of the procedure was the concentration of Pb in the samples as no preconcentration is performed. Solid archaeological samples containing at least 500 μg g−1 of Pb can be studied using the proposed procedure

Evaluation of current Australian health service accreditation processes (ACCREDIT-CAP): Protocol for a mixed-method research project

Introduction: Accreditation programmes aim to improve the quality and safety of health services, and have been widely implemented. However, there is conflicting evidence regarding the outcomes of existing programmes. The Accreditation Collaborative for the Conduct of Research, Evaluation and Designated Investigations through Teamwork-Current Accreditation Processes (ACCREDIT-CAP) project is designed to address key gaps in the literature by evaluating the current processes of three accreditation programmes used across Australian acute, primary and aged care services. Methods and design: The project comprises three mixed-method studies involving documentary analyses, surveys, focus groups and individual interviews. Study samples will comprise stakeholders from across the Australian healthcare system: accreditation agencies; federal and state government departments; consumer advocates; professional colleges and associations; and staff of acute, primary and aged care services. Sample sizes have been determined to ensure results allow robust conclusions. Qualitative information will be thematically analysed, supported by the use of textual grouping software. Quantitative data will be subjected to a variety of analytical procedures, including descriptive and comparative statistics. The results are designed to inform health system policy and planning decisions in Australia and internationally. Ethics and dissemination: The project has been approved by the University of New South Wales Human Research Ethics Committee (approval number HREC 10274). Results will be reported to partner organisations, healthcare consumers and other stakeholders via peer-reviewed publications, conference and seminar presentations, and a publicly accessible website