809 research outputs found

    Can implementation intentions and text messages promote brisk walking? A randomized trial.

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    Objective: To test the efficacy in promoting brisk walking of two theory-based interventions that incorporate implementation intentions and text message (Short Message Service; SMS) reminders directed at one’s walking-related plans or goals. Design: Participants (N = 149) were randomized to one of three conditions (implementation intention + SMS plan reminder, implementation intention + SMS goal reminder, control) before completing measures at baseline and follow-up 4 weeks later. At follow-up, the experimental groups were given a surprise recall task concerning their plans. All participants completed an equivalent goal recall task. Main Outcome Measures: Validated self-report measures of physical activity and measures of implementation intention and goal recall, weight, and waist-to-hip ratio. Results: Both intervention groups increased their brisk walking relative to the control group, without reducing other physical activity. The goal reminder group lost the most weight. The SMS plan reminder group recalled more of their plans than the SMS goal reminder group, but the latter were more successful in goal recall. Conclusion: Both interventions can promote brisk walking in sedentary populations. Text messages aid the recall of, and could enhance interventions that target, implementation intentions and goals

    Numerical modelling of centrifuge dynamic tests of circular tunnels in dry sand

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    This paper describes the numerical simulation of two dynamic centrifuge tests on reduced scale models of shallow tunnels in dry sand, carried out using both an advanced bounding surface plasticity constitutive soil model and a simple Mohr–Coulomb elastic-perfectly plastic model with embedded nonlinear and hysteretic behaviour. The predictive capabilities of the two constitutive models are assessed by comparing numerical predictions and experimental data in terms of accelerations at several positions in the model, and bending moment and hoop forces in the lining. Computed and recorded accelerations match well, and a quite good agreement is achieved also in terms of dynamic bending moments in the lining, while numerical and experimental values of the hoop force differ significantly with one another. The influence of the contact assumption between the tunnel and the soil is investigated by comparing the experimental data and the numerical results obtained with different interface conditions with the analytical solutions. The overall performance of the two models is very similar indicating that at least for dry sand, where shear-volumetric coupling is less relevant, even a simple model can provide an adequate representation of soil behaviour under dynamic condition

    Implementation of the Hydrographic Data Acquisition and Processing System (HDAPS) in the NOAA Fleet

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    The U.S. National Oceanic and Atmospheric Administration (NOAA) has developed an automated system for acquiring and processing hydrographic field data in support of its charting mission. The Hydrographic Data Acquisition and Processing System (HDAPS) addresses NOAA’s broad requirement to conduct hydrographic surveys in the coastal waters of the U.S. Systems have been successfully deployed on ships, launches, and small boats. Two types of HDAPS data acquisition systems (DAS) are presented. The first system, based on Hewlett-Packard (HP) hardware, is deployed on ships and launches. The second type is a small boat, 24-volt system, based on 1BM-PC compatible hardware. Both types of DAS are capable of conducting echo sounding and side scan sonar surveys. Data acquired by both systems are processed on an HP-based data processing system

    PV Cell Characteristic Extraction to Verify Power Transfer Efficiency in Indoor Harvesting System

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    A method is proposed to verify the efficiency of low-power harvesting systems based on Photovoltaic (PV) cells for indoor applications and a Fractional Open-Circuit Voltage (FOCV) technique to track the Maximum Power Point (MPP). It relies on an algorithm to reconstruct the PV cell Power versus Voltage (P-V) characteristic measuring the open circuit voltage and the voltage/current operating point but not the short-circuit current as required by state-of-the-art algorithms. This way the characteristic is reconstructed starting from the two values corresponding to standard operation modes of dc-dc converters implementing the FOCV Maximum Power Point Tracking (MPPT) technique. The method is applied to a prototype system: an external board is connected between the transducer and the dc-dc converter to measure the open circuit voltage and the voltage/current operating values. Experimental comparisons between the reconstructed and the measured P-V characteristics validate the reconstruction algorithm. Experimental results show the method is able to clearly identify the error between the transducer operating point and the one corresponding to the maximum power transfer, whilst also suggesting corrective action on the programmable factor of the FOCV technique. The proposed technique therefore provides a possible way of estimating MPPT efficiency without sampling the full P-V characteristic

    Money Walks: A Human-Centric Study on the Economics of Personal Mobile Data

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    In the context of a myriad of mobile apps which collect personally identifiable information (PII) and a prospective market place of personal data, we investigate a user-centric monetary valuation of mobile PII. During a 6-week long user study in a living lab deployment with 60 participants, we collected their daily valuations of 4 categories of mobile PII (communication, e.g. phonecalls made/received, applications, e.g. time spent on different apps, location and media, photos taken) at three levels of complexity (individual data points, aggregated statistics and processed, i.e. meaningful interpretations of the data). In order to obtain honest valuations, we employ a reverse second price auction mechanism. Our findings show that the most sensitive and valued category of personal information is location. We report statistically significant associations between actual mobile usage, personal dispositions, and bidding behavior. Finally, we outline key implications for the design of mobile services and future markets of personal data.Comment: 15 pages, 2 figures. To appear in ACM International Joint Conference on Pervasive and Ubiquitous Computing (Ubicomp 2014

    Functionalisation of methacrylated gellan gum hydrogels by anti-angiogenic dendrons

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    The regeneration of cartilage in the intervertebral disc nucleus pulposus and joints is impaired by the formation of fibrocartilage that is caused by the invasion of the tissue by blood vessels. Peptides have been identified by phage display technique which are able to bind VEGF thus inhibiting angiogenesis. The present works focusses on the synthesis of poly(epsilon-lysine) dendrons of three branching generations in which the molecular root of the dendron bears a di-phenylalanine sequence to promote hydrophobic interactions with material surfaces and the uppermost molecular branches are functionalised with the amino acid sequenceWHLPFKC that is known to block VEGF. These biofunctionalised dendrons were entrapped in methacrylated Gellan Gum (GG-MA) hydrogels and tested for their ability to inhibit endothelial cell sprouting by both a 3D in vitro cell models and an in ovo model. The results show that when GG-MA is functionalised with the dendronised VEGF blockers, a regression of angiogenesis takes place around the hydrogel boundary. The in ovo study supports these findings as the GG-MA functionalised with the dendronised VEGF blockers did not elicit any acute inflammatory response, and decrease the number of converging macroscopic blood vessels as compared to positive controls. Moreover, the hydrogels prevented the infiltration of blood vessels, after 4 days of implantation.Fundação para a Ciência e TecnologiaEU 7th Framework ProgrammeMICINNJunta de Castilla y LeónCIBER-BBNFundo Social EuropeuPrograma Operacional Potencial Human

    Anti-angiogenic potential of VEGF blocker dendron-laden gellan gum hydrogels for tissue engineering applications

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    Damage of non-vascularised tissues such as cartilage and cornea can result in healing processes accompanied by a non-physiological angiogenesis. Peptidic aptamers have recently been reported to block the vascular endothelial growth factor (VEGF). However, the therapeutic applications of these aptamers is limited due to their short half-life in vivo. In this work, an enhanced stability and bioavailability of a known VEGF blocker aptamer sequence (WHLPFKC) was pursued through its tethering of molecular scaffolds based on hyperbranched peptides, the poly(É -lysine) dendrons, bearing three branching generations. The proposed design allowed simultaneous and orderly-spaced exposure of sixteen aptamers per dendrimer to the surrounding biological microenvironent, as well as a relatively hydrophobic core based on di-phenylalanine aiming to promote an hydrophobic interaction with the hydrophobic moieties of ionically-crosslinked metacrylated gellan gum (iGG-MA) hydrogels. The VEGF blocker dendrons were entrapped in iGG-MA hydrogels and their capacity to prevent endothelial cell sprouting was assessed qualitatively and quantitatively using 3D in vitro models and the in vivo chick chorioallantoic membrane (CAM) assay. The data demonstrate that at nanoscale concentrations, the dendronised structures were able to enhance control of the biological actvity of WHLPFKC at the material/tissue interface and hence the anti-angiogenic capacity of iGG-MA hydrogels not only preventing blood vessel invasion, but also inducing their regression at the tissue/iGG-MA interface. The in ovo study confirmed that iGG-MA functionalised with the dendron VEGF blockers do inhibit angiogenesis by controlling both size and ramifications of blood vessels in proximity of the implanted gel surface.This work was mainly supported by the EC FP7 project Disc Regeneration (Contract No NMP3-LA-2008-213904). This study was also funded by the EC FP7 Programme contract agreement no REGPOT-CT2012-316331-POLARIS

    CD81 controls sustained T cell activation signaling and defines the maturation stages of cognate immunological synapses

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    In this study, we investigated the dynamics of the molecular interactions of tetraspanin CD81 in T lymphocytes, and we show that CD81 controls the organization of the immune synapse (IS) and T cell activation. Using quantitative microscopy, including fluorescence recovery after photobleaching (FRAP), phasor fluorescence lifetime imaging microscopy-Föster resonance energy transfer (phasorFLIM-FRET), and total internal reflection fluorescence microscopy (TIRFM), we demonstrate that CD81 interacts with ICAM-1 and CD3 during conjugation between T cells and antigen-presenting cells (APCs). CD81 and ICAM-1 exhibit distinct mobilities in central and peripheral areas of early and late T cell-APC contacts. Moreover, CD81-ICAM-1 and CD81- CD3 dynamic interactions increase over the time course of IS formation, as these molecules redistribute throughout the contact area. Therefore, CD81 associations unexpectedly define novel sequential steps of IS maturation. Our results indicate that CD81 controls the temporal progression of the IS and the permanence of CD3 in the membrane contact area, contributing to sustained T cell receptor (TCR)-CD3-mediated signaling. Accordingly, we find that CD81 is required for proper T cell activation, regulating CD3ζ, ZAP-70, LAT, and extracellular signal-regulated kinase (ERK) phosphorylation; CD69 surface expression; and interleukin- 2 (IL-2) secretion. Our data demonstrate the important role of CD81 in the molecular organization and dynamics of the IS architecture that sets the signaling threshold in T cell activationThis work was supported by SAF2011-25834 from the Spanish Ministry of Science and Innovation, INDISNET-S2011/BMD-2332 from the Comunidad de Madrid, Cardiovascular Network RD12-0042-0056 from the Instituto Salud Carlos III, and ERC-2011-AdG 294340-GENTRI

    A Generative Programming Approach to Interactive Information Retrieval:Insights and Experiences

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    Abstract. We describe the application of generative programming to a problem in interactive information retrieval. The particular interactive information retrieval problem we study is the support for ‘out of turn interaction ’ with a website – how a user can communicate input to a website when the site is not soliciting such information on the current page, but will do so on a subsequent page. Our solution approach makes generous use of program transformations (partial evaluation, currying, and slicing) to delay the site’s current solicitation for input until after the user’s out-of-turn input is processed. We illustrate how studying out-of-turn interaction through a generative lens leads to several valuable in-sights: (i) the concept of a web dialog, (ii) an improved understanding of web taxonomies, and (iii) new web interaction techniques and interfaces. These notions allow us to cast the design of interactive (and responsive) websites in terms of the underlying dialog structure and, further, suggest a simple implementation strategy with a clean separation of concerns. We also highlight new research directions opened up by the generative pro-gramming approach to interactive information retrieval such as the idea of web interaction axioms.

    Eruption dynamics of the 22–23 April 2015 calbuco volcano (Southern Chile): Analyses of tephra fall deposits

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    After 54 years since its last major eruption in 1961, Calbuco Volcano (Ensenada, Southern Chile) reawakened with few hours of warning on 22 April 2015 at 18:05 local time. The main explosive eruption consisted of two eruption pulses (lasting ~1.5 and 6 h each one) on 22 and 23 April, producing stratospheric (>15 km height) eruption columns. The erupted materials correspond to porphyritic basaltic andesite (~55 wt.% of SiO2). The tephra fall affected mainly the area northeast of the volcano and the finest ash was deposited over Southern Chile and Patagonia Argentina. We studied the tephra fall deposits of both pulses in terms of stratigraphy, distribution, volume, emplacement dynamics and eruption source parameters. Here, we show field observations that have been made 5-470 km downwind and distinguish five layers (Layers A, B, B1, C and D) representing different stages of the eruption evolution: eruption onset (Layer A; pulse 1), followed by the first paroxysmal event (Layer B; pulse 1), in some places interbedded by layer B1, tentatively representing the sedimentation of a secondary plume during the end of pulse 1. We recognized a second paroxysm (Layer C; pulse 2) followed by the waning of the eruption (Layer D; pulse 2). The total calculated bulk tephra fall deposit volume is 0.27 ± 0.007 km3 (0.11-0.13 km3 dense rock equivalent), 38% of which was erupted during the first phase and 62% during the second pulse. This eruption was a magnitude 4.45 event (VEI 4 eruption) of subPlinian type.Fil: Romero, J. E.. Universidad de Atacama; ChileFil: Morgavi, D.. Università di Perugia; ItaliaFil: Arzilli, F.. University of Manchester; Reino UnidoFil: Daga, Romina Betiana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; ArgentinaFil: Caselli, Alberto Tomás. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Río Negro; ArgentinaFil: Reckziegel, Florencia Mabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones en Energía no Convencional. Universidad Nacional de Salta. Facultad de Ciencias Exactas. Departamento de Física. Instituto de Investigaciones en Energía no Convencional; ArgentinaFil: Viramonte, Jose German. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Investigaciones en Energía no Convencional. Universidad Nacional de Salta. Facultad de Ciencias Exactas. Departamento de Física. Instituto de Investigaciones en Energía no Convencional; ArgentinaFil: Díaz Alvarado, J.. Universidad de Atacama; ChileFil: Polacci, M.. University of Manchester; Reino UnidoFil: Burton, M.. University of Manchester; Reino UnidoFil: Perugini, D.. Università di Perugia; Itali
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