A variational approach to Ising spin glasses in finite dimensions

We introduce a hierarchical class of approximations of the random Ising spin glass in $d$ dimensions. The attention is focused on finite clusters of spins where the action of the rest of the system is properly taken into account. At the lower level (cluster of a single spin) our approximation coincides with the SK model while at the highest level it coincides with the true $d$-dimensional system. The method is variational and it uses the replica approach to spin glasses and the Parisi ansatz for the order parameter. As a result we have rigorous bounds for the quenched free energy which become more and more precise when larger and larger clusters are considered.Comment: 16 pages, Plain TeX, uses Harvmac.tex, 4 ps figures, submitted to J. Phys. A: Math. Ge

Persistence Through Collaboration at Sea for Off-Shore and Coastal Operations

Collaboration (Bruzzone et al. 2013a, b, c, d, e, f) is often mentioned as an opportunity to develop new capabilities for autonomous systems; indeed this paper proposes a practical application where use this approach to enhance the autonomy of the systems during operations in coastal areas or around offshore platforms. The proposed case deals with developing a collaborative approach (Bruzzone et al. 2013a, b, c, d, e, f) among an USV (Unmanned Surface Vehicle) with several AUV (Autonomous Underwater Vehicles) to guarantee persistent surveillance over a marine area (Shkurti et al. 2012). Obviously, the proposed solution could be adopted also for defense and homeland security (Bruzzone et al. 2011a, b, 2010) as well as for archeological site protection in consistence with related cost analysis. The authors propose a technological solution as well as a simulation framework to validate and demonstrate the capabilities of this new approach as well as to quantify expected improvements

An investigation of the hidden structure of states in a mean field spin glass model

We study the geometrical structure of the states in the low temperature phase of a mean field model for generalized spin glasses, the p-spin spherical model. This structure cannot be revealed by the standard methods, mainly due to the presence of an exponentially high number of states, each one having a vanishing weight in the thermodynamic limit. Performing a purely entropic computation, based on the TAP equations for this model, we define a constrained complexity which gives the overlap distribution of the states. We find that this distribution is continuous, non-random and highly dependent on the energy range of the considered states. Furthermore, we show which is the geometrical shape of the threshold landscape, giving some insight into the role played by threshold states in the dynamical behaviour of the system.Comment: 18 pages, 8 PostScript figures, plain Te

Political conversations on Twitter in a disruptive scenario: The role of "party evangelists" during the 2015 Spanish general elections

"This is an Accepted Manuscript of an article published by Taylor & Francis in The Communication Review on 2019, available online: https://www.tandfonline.com/doi/full/10.1080/10714421.2019.1599642"[EN] During election campaigns, candidates, parties, and media share their relevance on Twitter with a group of especially active users, aligned with a particular party. This paper introduces the profile of ¿party evangelists,¿ and explores the activity and effects these users had on the general political conversation during the 2015 Spanish general election. On that occasion, the electoral expectations were uncertain for the two major parties (PP and PSOE) because of the rise of two emerging parties that were disrupting the political status quo (Podemos and Ciudadanos). This was an ideal situation to assess the differences between the evangelists of established and emerging parties. The paper evaluates two aspects of the political conversation based on a corpus of 8.9 million tweets: the retweet- ing effectiveness, and the sentiment analysis of the overall conver- sation. We found that one of the emerging party¿s evangelists dominated message dissemination to a much greater extent.The present research was supported by the Ministerio de Economia y Competitividad [CSO2013-43960-R] [CSO2016-77331-C2-1-R]. The present research was supported by the Ministerio de Economia y Competitividad, Spain, under Grants CSO2013-43960-R ("2015-2016 Spanish political parties' online campaign strategies") and CSO2016-77331-C2-1-R ("Strategies, agendas and discourse in electoral cybercampaigns: media and citizens"). This work was possible thanks to help received from Emilio Giner in his task of extracting the corpus of tweets and from assistance provided by Mike Thelwall and David Vilares in the use of the SentiStrength application. We have benefited from valuable comments on drafts of this article from professors Joaquín Aldás, Amparo Baviera-Puig, Guillermo López-García, and especially Lidia Valera-Ordaz.Baviera, T.; Sampietro, A.; García-Ull, FJ. (2019). Political conversations on Twitter in a disruptive scenario: The role of "party evangelists" during the 2015 Spanish general elections. The Communication Review. 22(2):117-138. https://doi.org/10.1080/10714421.2019.1599642S117138222Alvarez, R., Garcia, D., Moreno, Y., & Schweitzer, F. (2015). Sentiment cascades in the 15M movement. EPJ Data Science, 4(1). doi:10.1140/epjds/s13688-015-0042-4Anduiza, E., Cristancho, C., & Sabucedo, J. M. (2013). Mobilization through online social networks: the political protest of theindignadosin Spain. Information, Communication & Society, 17(6), 750-764. doi:10.1080/1369118x.2013.808360Anstead, N., & O’Loughlin, B. (2011). The Emerging Viewertariat and BBC Question Time. The International Journal of Press/Politics, 16(4), 440-462. doi:10.1177/1940161211415519Barabási, A.-L., & Albert, R. (1999). Emergence of Scaling in Random Networks. Science, 286(5439), 509-512. doi:10.1126/science.286.5439.509Barberá, P. (2015). Birds of the Same Feather Tweet Together: Bayesian Ideal Point Estimation Using Twitter Data. Political Analysis, 23(1), 76-91. doi:10.1093/pan/mpu011Barberá, P., Jost, J. T., Nagler, J., Tucker, J. A., & Bonneau, R. (2015). Tweeting From Left to Right. Psychological Science, 26(10), 1531-1542. doi:10.1177/0956797615594620Barberá, P., & Rivero, G. (2014). Understanding the Political Representativeness of Twitter Users. Social Science Computer Review, 33(6), 712-729. doi:10.1177/0894439314558836Berger, J., & Milkman, K. L. (2012). What Makes Online Content Viral? Journal of Marketing Research, 49(2), 192-205. doi:10.1509/jmr.10.0353Bigonha, C., Cardoso, T. N. C., Moro, M. M., Gonçalves, M. A., & Almeida, V. A. F. (2011). Sentiment-based influence detection on Twitter. Journal of the Brazilian Computer Society, 18(3), 169-183. doi:10.1007/s13173-011-0051-5Blondel, V. D., Guillaume, J.-L., Lambiotte, R., & Lefebvre, E. (2008). Fast unfolding of communities in large networks. Journal of Statistical Mechanics: Theory and Experiment, 2008(10), P10008. doi:10.1088/1742-5468/2008/10/p10008Bravo-Marquez, F., Mendoza, M., & Poblete, B. (2014). Meta-level sentiment models for big social data analysis. Knowledge-Based Systems, 69, 86-99. doi:10.1016/j.knosys.2014.05.016Casero-Ripollés, A., Feenstra, R. A., & Tormey, S. (2016). Old and New Media Logics in an Electoral Campaign. The International Journal of Press/Politics, 21(3), 378-397. doi:10.1177/1940161216645340Ceron, A., Curini, L., Iacus, S. M., & Porro, G. (2013). Every tweet counts? How sentiment analysis of social media can improve our knowledge of citizens’ political preferences with an application to Italy and France. New Media & Society, 16(2), 340-358. doi:10.1177/1461444813480466Meeyoung Cha, Benevenuto, F., Haddadi, H., & Gummadi, K. (2012). The World of Connections and Information Flow in Twitter. IEEE Transactions on Systems, Man, and Cybernetics - Part A: Systems and Humans, 42(4), 991-998. doi:10.1109/tsmca.2012.2183359Chadwick, A. (2013). The Hybrid Media System. doi:10.1093/acprof:oso/9780199759477.001.0001Cogburn, D. L., & Espinoza-Vasquez, F. K. (2011). From Networked Nominee to Networked Nation: Examining the Impact of Web 2.0 and Social Media on Political Participation and Civic Engagement in the 2008 Obama Campaign. Journal of Political Marketing, 10(1-2), 189-213. doi:10.1080/15377857.2011.540224(2014). Journal of Communication, 64(2). doi:10.1111/jcom.2014.64.issue-2Conover, M. D., Gonçalves, B., Flammini, A., & Menczer, F. (2012). Partisan asymmetries in online political activity. EPJ Data Science, 1(1). doi:10.1140/epjds6Coviello, L., Sohn, Y., Kramer, A. D. I., Marlow, C., Franceschetti, M., Christakis, N. A., & Fowler, J. H. (2014). Detecting Emotional Contagion in Massive Social Networks. PLoS ONE, 9(3), e90315. doi:10.1371/journal.pone.0090315D’heer, E., & Verdegem, P. (2014). Conversations about the elections on Twitter: Towards a structural understanding of Twitter’s relation with the political and the media field. European Journal of Communication, 29(6), 720-734. doi:10.1177/0267323114544866Dang-Xuan, L., Stieglitz, S., Wladarsch, J., & Neuberger, C. (2013). AN INVESTIGATION OF INFLUENTIALS AND THE ROLE OF SENTIMENT IN POLITICAL COMMUNICATION ON TWITTER DURING ELECTION PERIODS. Information, Communication & Society, 16(5), 795-825. doi:10.1080/1369118x.2013.783608Díaz-Parra, I., & Jover-Báez, J. (2016). Social movements in crisis? From the 15-M movement to the electoral shift in Spain. International Journal of Sociology and Social Policy, 36(9/10), 680-694. doi:10.1108/ijssp-09-2015-0101Dubois, E., & Gaffney, D. (2014). The Multiple Facets of Influence. American Behavioral Scientist, 58(10), 1260-1277. doi:10.1177/0002764214527088Enli, G. (2017). Twitter as arena for the authentic outsider: exploring the social media campaigns of Trump and Clinton in the 2016 US presidential election. European Journal of Communication, 32(1), 50-61. doi:10.1177/0267323116682802Felt, M. (2016). Social media and the social sciences: How researchers employ Big Data analytics. Big Data & Society, 3(1), 205395171664582. doi:10.1177/2053951716645828Ferrara, E., & Yang, Z. (2015). Measuring Emotional Contagion in Social Media. PLOS ONE, 10(11), e0142390. doi:10.1371/journal.pone.0142390(2015). Journal of Communication, 65(5). doi:10.1111/jcom.2015.65.issue-5Guerrero-Solé, F. (2018). Interactive Behavior in Political Discussions on Twitter: Politicians, Media, and Citizens’ Patterns of Interaction in the 2015 and 2016 Electoral Campaigns in Spain. Social Media + Society, 4(4), 205630511880877. doi:10.1177/2056305118808776Guo, L., & Vargo, C. (2015). The Power of Message Networks: A Big-Data Analysis of the Network Agenda Setting Model and Issue Ownership. Mass Communication and Society, 18(5), 557-576. doi:10.1080/15205436.2015.1045300Himelboim, I., McCreery, S., & Smith, M. (2013). Birds of a Feather Tweet Together: Integrating Network and Content Analyses to Examine Cross-Ideology Exposure on Twitter. Journal of Computer-Mediated Communication, 18(2), 40-60. doi:10.1111/jcc4.12001Huckfeldt, R., Johnson, P. E., & Sprague, J. (2004). Political Disagreement. doi:10.1017/cbo9780511617102Brundidge, J. (2010). Encountering «Difference» in the Contemporary Public Sphere: The Contribution of the Internet to the Heterogeneity of Political Discussion Networks. Journal of Communication, 60(4), 680-700. doi:10.1111/j.1460-2466.2010.01509.xJungherr, A. (2015). Analyzing Political Communication with Digital Trace Data. Contributions to Political Science. doi:10.1007/978-3-319-20319-5Jungherr, A., Jürgens, P., & Schoen, H. (2011). Why the Pirate Party Won the German Election of 2009 or The Trouble With Predictions: A Response to Tumasjan, A., Sprenger, T. O., Sander, P. G., & Welpe, I. M. «Predicting Elections With Twitter: What 140 Characters Reveal About Political Sentiment». Social Science Computer Review, 30(2), 229-234. doi:10.1177/0894439311404119Kaiser, H. F. (1960). The Application of Electronic Computers to Factor Analysis. Educational and Psychological Measurement, 20(1), 141-151. doi:10.1177/001316446002000116Klinger, U., & Svensson, J. (2014). The emergence of network media logic in political communication: A theoretical approach. New Media & Society, 17(8), 1241-1257. doi:10.1177/1461444814522952Lavezzolo, S., & Ramiro, L. (2017). Stealth democracy and the support for new and challenger parties. European Political Science Review, 10(2), 267-289. doi:10.1017/s1755773917000108McGregor, S. C., Mourão, R. R., & Molyneux, L. (2017). Twitter as a tool for and object of political and electoral activity: Considering electoral context and variance among actors. Journal of Information Technology & Politics, 14(2), 154-167. doi:10.1080/19331681.2017.1308289McPherson, M., Smith-Lovin, L., & Cook, J. M. (2001). Birds of a Feather: Homophily in Social Networks. Annual Review of Sociology, 27(1), 415-444. doi:10.1146/annurev.soc.27.1.415Medhat, W., Hassan, A., & Korashy, H. (2014). Sentiment analysis algorithms and applications: A survey. Ain Shams Engineering Journal, 5(4), 1093-1113. doi:10.1016/j.asej.2014.04.011Min, Y. (2004). News Coverage of Negative Political Campaigns. Harvard International Journal of Press/Politics, 9(4), 95-111. doi:10.1177/1081180x04271861Newman, M. (2010). Networks. doi:10.1093/acprof:oso/9780199206650.001.0001Orriols, L., & Cordero, G. (2016). The Breakdown of the Spanish Two-Party System: The Upsurge of Podemos and Ciudadanos in the 2015 General Election. South European Society and Politics, 21(4), 469-492. doi:10.1080/13608746.2016.1198454Park, C. S. (2013). Does Twitter motivate involvement in politics? Tweeting, opinion leadership, and political engagement. Computers in Human Behavior, 29(4), 1641-1648. doi:10.1016/j.chb.2013.01.044Riquelme, F., & González-Cantergiani, P. (2016). Measuring user influence on Twitter: A survey. Information Processing & Management, 52(5), 949-975. doi:10.1016/j.ipm.2016.04.003Robinson, J. P. (1976). Interpersonal Influence in Election Campaigns: Two Step-Flow Hypotheses. Public Opinion Quarterly, 40(3), 304. doi:10.1086/268307Robles, J. M., Díez, R., R. Castromil, A., Rodríguez, A., & Cruz, M. (2015). El movimiento 15-M en los medios y en las redes. Un análisis de sus estrategias comunicativas. Empiria. Revista de metodología de ciencias sociales, 0(32), 37. doi:10.5944/empiria.32.2015.15308Recerca. Revista de pensament i anàlisi. (s. f.). doi:10.6035/recercaSunstein, C. R. (2017). #Republic. doi:10.1515/9781400884711Thelwall, M., Buckley, K., Paltoglou, G., Cai, D., & Kappas, A. (2010). Sentiment strength detection in short informal text. Journal of the American Society for Information Science and Technology, 61(12), 2544-2558. doi:10.1002/asi.21416Vaccari, C., Chadwick, A., & O’Loughlin, B. (2015). Dual Screening the Political: Media Events, Social Media, and Citizen Engagement. Journal of Communication, 65(6), 1041-1061. doi:10.1111/jcom.12187Vergeer, M., & Hermans, L. (2013). Campaigning on Twitter: Microblogging and Online Social Networking as Campaign Tools in the 2010 General Elections in the Netherlands. Journal of Computer-Mediated Communication, 18(4), 399-419. doi:10.1111/jcc4.12023Vilares, D., Thelwall, M., & Alonso, M. A. (2015). The megaphone of the people? Spanish SentiStrength for real-time analysis of political tweets. Journal of Information Science, 41(6), 799-813. doi:10.1177/0165551515598926Weimann, G. (1991). The Influentials: Back to the Concept of Opinion Leaders? Public Opinion Quarterly, 55(2), 267. doi:10.1086/269257Wu, S., Hofman, J. M., Mason, W. A., & Watts, D. J. (2011). Who says what to whom on twitter. Proceedings of the 20th international conference on World wide web - WWW ’11. doi:10.1145/1963405.1963504Xu, W. W., Sang, Y., Blasiola, S., & Park, H. W. (2014). Predicting Opinion Leaders in Twitter Activism Networks. American Behavioral Scientist, 58(10), 1278-1293. doi:10.1177/0002764214527091Zollo, F., Novak, P. K., Del Vicario, M., Bessi, A., Mozetič, I., Scala, A., … Quattrociocchi, W. (2015). Emotional Dynamics in the Age of Misinformation. PLOS ONE, 10(9), e0138740. doi:10.1371/journal.pone.013874

Preparation and characterization of micro-nano engineered targets for high-power laser experiments

[EN] The continuous development of ultra-fast high-power lasers (HPL) technology with the ability of working at unprecedented repetition rates, between 1 and 10 Hz, is raising the target needs for experiments in the different areas of interest to the HPL community. Many target designs can be conceived according to specific scientific issues, however to guarantee manufacturing abilities that enable large number production and still allow for versatility in the design is the main barrier in the exploitation of these high repetition rate facilities. Here, we have applied MEMS based manufacturing processes for this purpose. In particular, we have focused on the fabrication and characterization of submicrometric conductive membranes embedded in a silicon frame. These kinds of solid targets are used for laser-driven particle acceleration through the so-called Target Normal Sheath Acceleration mechanism (TNSA). They were obtained by top-down fabrication alternating pattern transfer, atomic layer deposition, and selective material etching. The adaptability of the approach is then analyzed and discussed by evaluating different properties of targets for use in laser-driven particle acceleration experiments. These characteristics include the surface properties of membranes after fabrication and the high density of the target array. Finally, we were able to show their efficiency for laser-driven proton acceleration in a series of experiments with a 3 TW table-top laser facility, achieving stable proton acceleration up to 2 MeV.The authors highly appreciate the collaboration of Radosys (Budapest) which provided CR-39 detector material, etching bath, and readout equipment. This project has been financed by the Spanish Ministry for Economy and Competitiveness within the Retos-Colaboracion 2015 initiative, ref. RTC-2015-3278-1. P. Mur has received a grant of the Garantia Juvenil 2015 program. This work has made use of the Spanish ICTS Network MICRONANOFABS partially supported by MEINCOM.Zaffino, R.; Seimetz, M.; Quirión, D.; Ruiz-De La Cruz, A.; Sánchez, I.; Mur, P.; Benlliure, J.... (2018). Preparation and characterization of micro-nano engineered targets for high-power laser experiments. Microelectronic Engineering. 194:67-70. https://doi.org/10.1016/j.mee.2018.03.011S677019

Thalamic inputs to dorsomedial striatum are involved in inhibitory control: evidence from the five-choice serial reaction time task in rats

Rationale Corticostriatal circuits are widely implicated in the top-down control of attention including inhibitory control and behavioural flexibility. However, recent neurophysiological evidence also suggests a role for thalamic inputs to striatum in behaviours related to salient, reward-paired cues. Objectives Here, we used designer receptors exclusively activated by designer drugs (DREADDs) to investigate the role of parafascicular (Pf) thalamic inputs to the dorsomedial striatum (DMS) using the five-choice serial reaction time task (5CSRTT) in rats. Methods The 5CSRTT requires sustained attention in order to detect spatially and temporally distributed visual cues and provides measures of inhibitory control related to impulsivity (premature responses) and compulsivity (perseverative responses). Rats underwent bilateral Pf injections of the DREADD vector, AAV2-CaMKIIa-HA-hM4D(Gi)-IRES-mCitrine. The DREADD agonist, clozapine N-oxide (CNO; 1 μl bilateral; 3 μM) or vehicle, was injected into DMS 1 h before behavioural testing. Task parameters were manipulated to increase attention load or reduce stimulus predictability respectively. Results We found that inhibition of the Pf-DMS projection significantly increased perseverative responses when stimulus predictability was reduced but had no effect on premature responses or response accuracy, even under increased attentional load. Control experiments showed no effects on locomotor activity in an open field. Conclusions These results complement previous lesion work in which the DMS and orbitofrontal cortex were similarly implicated in perseverative responses and suggest a specific role for thalamostriatal inputs in inhibitory control

TOF studies for dedicated PET with open geometries

[EN] Recently, two novel PET devices have been developed with open geometries, namely: breast and prostate-dedicated scanners. The breast-dedicated system comprises two detector rings of twelve modules with a field of view of 170 mm x 170 mm x 94 mm. Each module consists of a continuous trapezoidal LYSO crystal and a PSPMT. The system has the capability to vary the opening of the rings up to 60 mm in order to allow the insertion of a needle to perform a biopsy procedure. The prostate system has an open geometry consisting on two parallel plates separated 28 cm. One panel includes 18 detectors organized in a 6 x 3 matrix while the second one comprises 6 detectors organized in a 3 x 2 matrix. All detectors are formed by continuous LYSO crystals of 50 mm x 50 mm x15 mm, and a SiPM array of 12 x 12 individual photo-detectors. The system geometry is asymmetric maximizing the sensitivity of the system at the prostate location, located at about 2/3 in the abdomen-anus distance. The reconstructed images for PET scanners with open geometries present severe artifacts due to this peculiarity. These artifacts can be minimized using Time Of Flight information (TOF). In this work we present a TOF resolution study for open geometries. With this aim, the dedicated breast and prostate systems have been simulated using GATE (8.1 version) with different TOF resolutions in order to determine the image quality improvements that can be achieved with the existing TOF-dedicated electronics currently present in the market. The images have been reconstructed using the LMOS algorithm including TOF modeling in the calculation of the voxel-Line Of Response emission probabilities.This work was supported in part by the Spanish Government Grants TEC2016-79884-C2 and RTC-2016-5186-1 and by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (Grant Agreement No. 695536).Moliner, L.; Ilisie, V.; González Martínez, AJ.; Oliver-Gil, S.; Gonzalez, A.; Giménez-Alventosa, V.; Cañizares, G.... (2019). TOF studies for dedicated PET with open geometries. Journal of Instrumentation. 14:1-8. https://doi.org/10.1088/1748-0221/14/02/C02006S181

Wafer-scale fabrication of target arrays for stable generation of proton beams by laser-plasma interaction

[EN] Large-scale fabrication of targets for laser-driven acceleration of ion beams is a prerequisite to establish suitable applications, and to keep up with the challenge of increasing repetition rate of currently available high-power lasers. Here we present manufacturing and test results of large arrays of solid targets for TNSA laser-driven ion acceleration. By applying micro-electro-mechanical-system (MEMS) based methods allowing for parallel processing of thousands of targets on a single Si wafer, sub-micrometric, thin-layer metallic membranes were fabricated by combining photolithography, physical and chemical vapor deposition, selective etching, and Si micromachining. These structures were characterized by using optical and atomic force microscopy. Their performance for the production of laser-driven proton beams was tested on a purpose-made table-top Ti:Sapphire laser system running at 3 TW peak power with a contrast over ASE of 108. We have performed several test series achieving maximum proton energy values around 2 MeV.This work has made use of the Spanish ICTS Network MICRONANOFABS partially supported by MEINCOM. This project has been financed by the Spanish Ministry for Economy and Competitiveness within the Retos- Colaboración 2015 initiative, ref. RTC-2015-3278-1. P. Mur has received a grant of the Garantía Juvenil 2015 program.Zaffino, R.; Seimetz, M.; Ruiz-De La Cruz, A.; Sánchez, I.; Mur, P.; Bellido-Millán, PJ.; Lera, R.... (2018). Wafer-scale fabrication of target arrays for stable generation of proton beams by laser-plasma interaction. Journal of Physics: Conference Series (Online). 1079. https://doi.org/10.1088/1742-6596/1079/1/012007S0120071079Abedi, S., Dorranian, D., Abari, M. E., & Shokri, B. (2011). Relativistic effects in the interaction of high intensity ultra-short laser pulse with collisional underdense plasma. Physics of Plasmas, 18(9), 093108. doi:10.1063/1.3633529Antici, P., Fuchs, J., d’ Humières, E., Lefebvre, E., Borghesi, M., Brambrink, E., … Pépin, H. (2007). Energetic protons generated by ultrahigh contrast laser pulses interacting with ultrathin targets. Physics of Plasmas, 14(3), 030701. doi:10.1063/1.2480610Ceccotti, T., Lévy, A., Popescu, H., Réau, F., D’Oliveira, P., Monot, P., … Martin, P. (2007). Proton Acceleration with High-Intensity Ultrahigh-Contrast Laser Pulses. Physical Review Letters, 99(18). doi:10.1103/physrevlett.99.18500

Efficient proton acceleration from a 3 TW table-top laser interacting with submicrometric mass-produced solid targets

[EN] Thin layer membranes with controllable features and material arrangements are often used as target materials for laser driven particle accelerators. Reduced cost, large scale fabrication of such membranes with high reproducibility, and good stability are central for the efficient production of proton beams. These characteristics are of growing importance in the context of advanced laser light sources where increased repetition rates boost the need for consumable targets with design and properties adjusted to study the different phenomena arising in ultra-intense laser-plasma interaction. Wepresent the fabrication of sub-micrometric thin-layer gold or aluminum membranes in a silicon wafer frame by using nano/micro-electro-mechanical-system (N/MEMS) processing which are suitable for rapid patterning and machining of many samples at the same time and allowing for high-throughput production of targets for laser-driven acceleration. Obtained targets were tested for laserproton acceleration through the Target Normal Sheath Acceleration mechanism (TNSA) in a series of experiments carried out on a purpose-made table-top Ti:Sa running at 3 TW peak power and 10 Hz diode pump rate with a contrast over ASE of 10(8)The authors highly appreciate the collaboration of Radosys (Budapest) which provided CR-39 detector material, etching bath, and readout equipment. This project has been financed by the Spanish Ministry for Economy and Competitiveness within the Retos-Colaboracion 2015 initiative, ref. RTC-2015-3278-1. P Mur has received a grant of the Garantia Juvenil 2015 program. This work has made use of the Spanish ICTS Network MICRONANOFABS partially supported by MEINCOM.Zaffino, R.; Seimetz, M.; Ruiz-De La Cruz, A.; Sánchez, I.; Mur, P.; Quirión, D.; Bellido-Millán, PJ.... (2018). Efficient proton acceleration from a 3 TW table-top laser interacting with submicrometric mass-produced solid targets. Journal of Physics Communications. 2(4):1-6. https://doi.org/10.1088/2399-6528/aabc25S1624Borghesi, M., Campbell, D. H., Schiavi, A., Haines, M. G., Willi, O., MacKinnon, A. J., … Bulanov, S. (2002). Electric field detection in laser-plasma interaction experiments via the proton imaging technique. Physics of Plasmas, 9(5), 2214-2220. doi:10.1063/1.1459457Ledingham, K., Bolton, P., Shikazono, N., & Ma, C.-M. (2014). Towards Laser Driven Hadron Cancer Radiotherapy: A Review of Progress. Applied Sciences, 4(3), 402-443. doi:10.3390/app4030402Spindloe, C., Arthur, G., Hall, F., Tomlinson, S., Potter, R., Kar, S., … Tolley, M. K. (2016). High volume fabrication of laser targets using MEMS techniques. Journal of Physics: Conference Series, 713, 012002. doi:10.1088/1742-6596/713/1/012002Schomburg, W. K. (2011). Thin Films. RWTHedition, 9-20. doi:10.1007/978-3-642-19489-4_4Bellido, P., Lera, R., Seimetz, M., Cruz, A. R. la, Torres-Peirò, S., Galán, M., … Benlloch, J. M. (2017). Characterization of protons accelerated from a 3 TW table-top laser system. Journal of Instrumentation, 12(05), T05001-T05001. doi:10.1088/1748-0221/12/05/t05001Mayer, M. (1999). SIMNRA, a simulation program for the analysis of NRA, RBS and ERDA. AIP Conference Proceedings. doi:10.1063/1.59188Ceccotti, T., Lévy, A., Popescu, H., Réau, F., D’Oliveira, P., Monot, P., … Martin, P. (2007). Proton Acceleration with High-Intensity Ultrahigh-Contrast Laser Pulses. Physical Review Letters, 99(18). doi:10.1103/physrevlett.99.185002Dollar, F., Reed, S. A., Matsuoka, T., Bulanov, S. S., Chvykov, V., Kalintchenko, G., … Maksimchuk, A. (2013). High-intensity laser-driven proton acceleration enhancement from hydrogen containing ultrathin targets. Applied Physics Letters, 103(14), 141117. doi:10.1063/1.4824361Neely, D., Foster, P., Robinson, A., Lindau, F., Lundh, O., Persson, A., … McKenna, P. (2006). Enhanced proton beams from ultrathin targets driven by high contrast laser pulses. Applied Physics Letters, 89(2), 021502. doi:10.1063/1.2220011Green, J. S., Carroll, D. C., Brenner, C., Dromey, B., Foster, P. S., Kar, S., … Zepf, M. (2010). Enhanced proton flux in the MeV range by defocused laser irradiation. New Journal of Physics, 12(8), 085012. doi:10.1088/1367-2630/12/8/085012Giuffrida, L., Svensson, K., Psikal, J., Dalui, M., Ekerfelt, H., Gallardo Gonzalez, I., … Margarone, D. (2017). Manipulation of laser-accelerated proton beam profiles by nanostructured and microstructured targets. Physical Review Accelerators and Beams, 20(8). doi:10.1103/physrevaccelbeams.20.08130

Business opportunities analysis using GIS: the retail distribution sector

[EN] The retail distribution sector is facing a difficult time as the current landscape is characterized by ever-increasing competition. In these conditions, the search for an appropriate location strategy has the potential to become a differentiating and competitive factor. Although, in theory, an increasing level of importance is placed on geography because of its key role in understanding the success of a business, this is not the case in practice. For this reason, the process outlined in this paper has been specifically developed to detect new business locations. The methodology consists of a range of analyzes with Geographical Information Systems (GISs) from a marketing point of view. This new approach is called geomarketing. First, geodemand and geocompetition are located on two separate digital maps using spatial and non-spatial databases. Second, a third map is obtained by matching this information with the demand not dealt with properly by the current commercial offer. Third, the Kernel density allows users to visualize results, thus facilitating decision-making by managers, regardless of their professional background. The advantage of this methodology is the capacity of GIS to handle large amounts of information, both spatial and non-spatial. A practical application is performed in Murcia (Spain) with 100 supermarkets and data at a city block level, which is the highest possible level of detail. This detection process can be used in any commercial distribution company, so it can be generalized and considered a global solution for retailers.Roig Tierno, H.; Baviera-Puig, A.; Buitrago Vera, JM. (2013). Business opportunities analysis using GIS: the retail distribution sector. Global Business Perspectives. 1(3):226-238. doi:10.1007/s40196-013-0015-6S22623813Alarcón, S. (2011). The trade credit in the Spanish agrofood industry. Mediterranean Journal of Economics, Agriculture and Environment (New Medit), 10(2), 51–57.Alcaide, J. C., Calero, R., & Hernández, R. (2012). Geomarketing. Marketing territorial para vender y fidelizar más. Madrid: ESIC.Applebaum, W., & Cohen, S. B. (1961). The dynamics of store trading areas and market equilibrium. Annals of the Association of American Geographers, 51(1), 73–101.Baviera-Puig, A., Buitrago-Vera, J. M., Escriba, C., & Clemente, J. S. (2009). Geomarketing: Aplicación de los sistemas de información geográfica al marketing. Paper presented at the Octava Conferencia Iberoamericana en Sistemas, Cibernética e Informática, Orlando, FL.Baviera-Puig, A., Buitrago-Vera, J. M., & Mas-Verdú, F. (2012). Trade areas and knowledge-intensive services: The case of a technology centre. Management Decision, 50(8), 1412–1424.Baviera-Puig, A., Buitrago-Vera, J. M., & Rodríguez-Barrio, J. E. (2013). Un modelo de geomarketing para la localización de supermercados: Diseño y aplicación práctica. Documentos de Trabajo de la Cátedra Fundación Ramón Areces de Distribución Comercial (DOCFRADIS), 1, 1–27.Berumen, S. A., & Llamazares, F. (2007). La utilidad los métodos de decisión multicriterio (como el AHP) en un entorno de competitividad creciente. Cuadernos de administración, 20(34), 65–87.Birkin, M., Clarke, G., & Clarke, M. (2002). Retail geography and intelligent network planning. Chichester: Wiley.Chasco, C. (2003). El geomarketing y la distribución commercial. Investigación y Márketing, 79, 6–13.Chen, R. J. C. (2007). Significance and variety of geographic information system (GIS) applications in retail, hospitality, tourism, and consumer services. Journal of Retailing and Consumer Services, 14, 247–248.Church, R. L. (2002). Geographical information systems and location science. Computers and Operations Research, 29, 541–562.Church, R. L., & Murray, A. T. (2009). Business site selection, location analysis and GIS. Hoboken, NJ: Wiley.Clarke, G. (1998). Changing methods of location planning for retail companies. GeoJournal, 45, 289–298.Clarkson, R. M., Clarke-Hill, C. M., & Robinson, T. (1996). UK supermarket location assessment. International Journal of Retail and Distribution Management, 24(6), 22–33.Davis, P. (2006). Spatial competition in retail markets: Movie theaters. The RAND Journal of Economics, 37(4), 964–982.Ghosh, A., & McLafferty, S. L. (1982). Locating stores in uncertain environments: A scenario planning approach. Journal of Retailing, 58(4), 5–22.Härdle, W. (1991). Smoothing techniques with implementation in S. Nueva York, NY: Springer.Harris, B., & Batty, M. (1993). Locational models, geographical information, and planning support systems. Journal of Planning Education and Research, 12, 184–198.Hernandez, T. (2007). Enhancing retail location decision support: The development and application of geovisualization. Journal of Retailing and Consumer Services, 14, 249–258.Hernandez, T., & Bennison, D. (2000). The art and science of retail location decisions. International Journal of Retail and Distribution Management, 28(8), 357–367.Huff, D. (1963). Defining and estimating a trade area. Journal of Marketing, 28, 34–38.Instituto Nacional de Estadística (INE). (2011). Padrón de habitantes 2011. http://www.ine.es . Accessed 9 Oct 2012.Kelly, J. P., Freeman, D. C., & Emlen, J. M. (1993). Competitive impact model for site selection: The impact of competition, sales generators and own store cannibalization. The International Review of Retail, Distribution and Consumer Research, 3, 237–259.Latour, P., & Le Floc’h, J. (2001). Géomarketing: Principes, méthodes et applications. París: Éditions d’Organisation.Mendes, A. B., & Themido, I. H. (2004). Multi-outlet retail site location assessment. International Transactions in Operational Research, 11, 1–18.Moreno, A. (1991). Modelización cartográfica de densidades mediante estimadores Kernel. Treballs de la Societat Catalana de Geografia, 6(30), 155–170.Moreno, A. (2007). Obtención de capas raster de densidad. In A. Moreno (Coord.), Sistemas y Análisis de la información Geográfica. Manual de autoaprendizaje con ArcGIS (pp. 685–691). Madrid: Editorial RA-MA.Murad, A. A. (2003). Creating a GIS application for retail centers in Jeddah City. International Journal of Applied Earth Observation and Geoinformation, 4, 329–338.Murad, A. A. (2007). Using GIS for retail planning in Jeddah City. American Journal of Applied Sciences, 4(10), 820–826.Musyoka, S. M., Mutyauvyu, S. M., Kiema, J. B. K., Karanja, F. N., & Siriba, D. N. (2007). Market segmentation using geographic information systems (GIS). A case study of the soft drink industry in Kenya. Marketing Intelligence and Planning, 25(6), 632–642.Nielsen Database. (2012). Retailers Database. http://www.nielsen.com/global/en.html . Accessed 12 Oct 2012.Ozimec, A. M., Natter, M., & Reutterer, T. (2010). Geographical information systems-based marketing decisions: Effects of alternative visualizations on decision quality. Journal of Marketing, 74, 94–110.Reilly, W. J. (1931). The law of retail gravitation. New York: Knickerbocker Press.Rob, M. A. (2003). Some challenges of integrating spatial and non-spatial datasets using a geographical information system. Information Technology for Development, 10, 171–178.Rosenblatt, M. (1956). Remarks on some nonparametric estimates of a density functions. Annals of Mathematical Statistic, 27, 832–837.Sede Electrónica del Catastro. (2012). Datos Catastrales. https://www.sedecatastro.gob.es . Accessed 10 Oct 2012.Silverman, B. W. (1986). Density estimation for statistics and data analysis. London: Chapman and Hall.Sleight, P., Harris, R., & Webber, R. (2005). Geodemographics, GIS and neighbourhood targeting. Chichester: Wiley.Suárez-Vega, R., Santos-Peñate, D. R., & Dorta-González, P. (2012). Location models and GIS tools for retail site location. Applied Geography, 35, 12–22.Thaler, R. (1986). The psychology and economics conference handbook: Comments on Simon, on Einhorn and Hogarth, and on Tversky and Kahneman. The Journal of Business, 59(4), 279–284.Wood, S., & Reynolds, J. (2012). Leveraging locational insights within retail store development? Assessing the use of location planners’ knowledge in retail marketing. Geoforum, 43, 1076–1087