413 research outputs found

    A low complexity iterative channel estimation and equalisation scheme for (data-dependent) superimposed training

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    Channel estimation/symbol detection methods based on superimposed training (ST) are known to bemore bandwidth efficient than those based on traditional time-multiplexed training. In this paper we present an iterative version of the ST methodwhere the equalised symbols obtained via ST are used in a second step to improve the channel estimation, approaching the performance of the more recent (and improved) data dependent ST (DDST), but now with less complexity. This iterative ST method (IST) is then compared to a different iterative superimposed training method of Meng and Tugnait (LSST).We show via simulations that the BER of our IST algorithm is very close to that of the LSST but with a reduced computational burden of the order of the channel length. Furthermore, if the LSST iterative approach (originally based on ST) is now implemented using DDST, a faster convergence rate can be achieved for the MSE of the channel estimates

    Late Quaternary monogenetic volcanoes along Río Salado, Sothwest Mendoza Province, Argentina

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    On the eastem flank of the Andes, to the north of Río Salado in southwest Mendoza Province (35º07'S-35º10'S), there are 4 monogenetic cones with blocky lava flows. A western group of small volcanoes, Hoyada, Lagunita and Loma Negra, with a total volume of -0.2 km3, are composed of amphibole-bearing basaltic andesite, and the eastem, more voluminous Hoyo Colorado volcano, with 0.44 km3 is composed of olivine (+ oxidised amphibole) basaltic andesite. Although data indicate they were emitted through successive, strombolian eruptions, they are overall coeval and the youngest Late Pleistocene volcanoes located in an "extra-Andean" setting, -70 km east of the main volcanic front. The magmas of the westem group of monogenetic cones show petrographic and geochemical characteristics that support processes of crustal interaction during ascent. In contrast, the magmas of the Hoyo Colorado volcano had a more direct ascent. Structural characteristics of the basement rocks to the volcanoes and the current seismotectonic activity of the Andes at this latitude indicate that the monogenetic cones of Río Salado were emplaced in a dominantly compressive tectonic regime

    Synchronisation of the superimposed training method for channel estimation in the presence of DC-offset

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    The superimposed training method estimates the channel from the induced first-order cyclostationary statistics exhibited by the received signal. In this paper, using vector space decomposition, we show that the information needed for training sequence synchronisation, and for DC-offset estimation, can be extracted from the first-order cyclostationary statistics as well. Necessary and sufficient conditions for channel computation and equalisation are derived, when training sequence synchronisation and DC-offset removal are required. The computational burden of the practical implementation of the method presented here is much lighter than for existing algorithms. At the same time, simulation results show that the performance, in terms of the MSE of the channel estimates and BER, is not diminishedwhen compared to these existing algorithms

    Habilidades comunicativas dentro de la familia: una medida imprescincible contra el acoso escolar en La Rioja

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    En función del análisis de diferentes estudios que resaltan el importante papel del afecto y el diálogo intrafamiliar contra el mal comportamiento de los hijos en sociedad, nos planteamos qué opina la comunidad educativa respecto a esto y qué medidas proponen para erradicar el acoso escolar. Para obtener esta información, se ha llevado a cabo un estudio en la comunidad de La Rioja, a través de un cuestionario dirigido a 348 alumnos de ESO; entrevistas a treinta profesores, dos grupos de discusión entre padres, y otros dos entre alumnos de diferentes lugares y tipos de centro. La comunidad educativa riojana confi rma que un ambiente familiar carente de afecto y diálogo infl uye signifi cativa y positivamente en el comportamiento violento de los alumnos en la escuela, proponiendo como medida principal la formación de padres en habilidades comunicativas, opiniones menos claras en chicos y alumnos más jóvenes. Otras medidas propuestas son: que los padres pasen más tiempo con sus hijos, les aporten más afecto y una educación basada en valores, además de vigilar el consumo de violencia en los medios audiovisuales, denunciando más y estrechando su relación con la comunidad educativa y social para recibir ayuda. Based on the analysis of different studies that highlight the important role of affect and intrafamily dialogue against the misbehavior of children in society, we plan to know the opinion of the educational community about this and which ones measures they propose to eradicate bullying. To obtain this information, we carried out a study in the community of La Rioja, using a questionnaire in a sample of 348 middle-school students. Also, thirty teachers were interviewed; two focus groups with parents and two with students from different places and types of school. Rioja educational community confi rms that a family atmosphere devoid of affection and dialogue infl uences signifi cantly and positively in the violent behavior of students in the school, proposing as the primary measure parent training in communication skills, less clear opinions in boys and younger students. Other proposed measures are: that parents to spend more time with their children, provide them more affection and values-based education, in addition to monitor the consumption of violence in the media, denouncing more and by making close their relationship with the educational and social community to get help.

    O157:H7 Shiga Toxin-Producing Escherichia coli Strains Associated with Sporadic Cases of Diarrhea in São Paulo, Brazil

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    Inst Adolfo Lutz Registro, Sao Paulo, BrazilLab Anal Clin Dr Joao Antonio Vozza, Campinas, SP, BrazilUniv Fed Sao Paulo, Escola Paulista Med, Sao Paulo, BrazilUniv Fed Sao Paulo, Escola Paulista Med, Sao Paulo, BrazilWeb of Scienc

    Amplifying actions for food system transformation: Insights from the Stockholm region

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    Food is essential to people and is one of the main ways in which people are connected to the world’s ecosystems. However, food systems often cause ecosystem degradation and produce ill-health, which has generated increasing calls to transform food systems to be more sustainable. The Swedish food system is currently undergoing substantial change. A varied set of local actors have created alternative sustainability initiatives that enact new ways of doing, thinking, and organizing. These actors can increase the transformative impact of their initiatives through multiple actions and a variety of amplification processes. We analyzed the actions adopted by 29 food initiatives active in the Stockholm region using information available online. We conducted 11 interviews to better understand the amplification processes of speeding up (i.e., accelerating impact), scaling up (i.e., influencing higher institutional levels), and scaling deep (i.e., changing values and mind-sets). Our results indicated that the initiatives mainly seek to stabilize and grow their impact while changing the awareness, values, and mind-sets of people concerning the food they consume (scaling deep). However, these approaches raise new questions about whether these actions subvert or reinforce current unsustainable and inequitable system dynamics. We suggest there are distinct steps that local and regional governments could take to support these local actors via collaborations with coordinated forms of initiatives, and fostering changes at the municipality level, but these steps require ongoing, adaptive approaches given the highly complex nature of transformative change and the risks of reinforcing current system dynamics

    Impact of a Tutored Theoretical-Practical Training to Develop Undergraduate Students’ Skills for the Detection of Caries Lesions: Study Protocol for a Multicenter Controlled Randomized Study

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    Background: Tutored laboratorial activities could be a manner of improving the competency development of students. However, its impact over conventional theoretical classes has not yet been tested. Additionally, different university contexts could influence this issue and should be explored. Objective: To assess the impact of a tutored theoretical-practical training for teaching undergraduate students to detect caries lesions as compared with theoretical teaching activities. The impact of these teaching/learning activities will be assessed in terms of efficacy, cost/benefit, retention of knowledge/acquired competences, and student acceptability. Methods: Sixteen centers (7 centers from Brazil and 9 centers from other countries throughout the world) are involved in the inclusion of subjects for this protocol. A randomized controlled study with parallel groups will be conducted. One group (control) will be exposed to a 60- to 90-minute conventional theoretical class and the other group (test) will be exposed to the same theoretical class and also a 90-minute laboratory class, including exercises and discussions based on the evaluation of a pool of images and extracted teeth. The mentioned outcomes will be evaluated immediately after the teaching activities and also in medium- and long-term analyses. To compare the long-term outcomes, students who enrolled in the university before the participating students will be interviewed for data collection and these data will be used as a control and compared with the trained group. This stage will be a nonrandomized phase of this study, nested in the main study. Appropriate statistical analysis will be performed according to the aims of this study. Variables related to the centers will also be analyzed and used to model adjustment as possible sources of variability among results. Results: This ongoing study is funded by a Brazilian national funding agency (CNPq- 400736/2014-4). We expect that the tutored theoretical-practical training will improve the undergraduate students’ performance in the detection of caries lesions and subsequent treatment decisions, mainly in terms of long-term retention of knowledge. Our hypothesis is that tutored theoretical-practical training is a more cost-effective option for teaching undergraduate students to detect caries lesions. Conclusions: If our hypothesis is confirmed, the use of laboratory training in conjunction with theoretical classes could be used as an educational strategy in Cariology to improve the development of undergraduate students’ skills in the detection of caries lesions and clinical decision-making

    Anisotropic flow of charged hadrons, pions and (anti-)protons measured at high transverse momentum in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}}=2.76 TeV

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    The elliptic, v2v_2, triangular, v3v_3, and quadrangular, v4v_4, azimuthal anisotropic flow coefficients are measured for unidentified charged particles, pions and (anti-)protons in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}} = 2.76 TeV with the ALICE detector at the Large Hadron Collider. Results obtained with the event plane and four-particle cumulant methods are reported for the pseudo-rapidity range η<0.8|\eta|<0.8 at different collision centralities and as a function of transverse momentum, pTp_{\rm T}, out to pT=20p_{\rm T}=20 GeV/cc. The observed non-zero elliptic and triangular flow depends only weakly on transverse momentum for pT>8p_{\rm T}>8 GeV/cc. The small pTp_{\rm T} dependence of the difference between elliptic flow results obtained from the event plane and four-particle cumulant methods suggests a common origin of flow fluctuations up to pT=8p_{\rm T}=8 GeV/cc. The magnitude of the (anti-)proton elliptic and triangular flow is larger than that of pions out to at least pT=8p_{\rm T}=8 GeV/cc indicating that the particle type dependence persists out to high pTp_{\rm T}.Comment: 16 pages, 5 captioned figures, authors from page 11, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/186
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