626 research outputs found

    Libor at crossroads: stochastic switching detection using information theory quantifiers

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    This paper studies the 28 time series of Libor rates, classified in seven maturities and four currencies), during the last 14 years. The analysis was performed using a novel technique in financial economics: the Complexity-Entropy Causality Plane. This planar representation allows the discrimination of different stochastic and chaotic regimes. Using a temporal analysis based on moving windows, this paper unveals an abnormal movement of Libor time series arround the period of the 2007 financial crisis. This alteration in the stochastic dynamics of Libor is contemporary of what press called "Libor scandal", i.e. the manipulation of interest rates carried out by several prime banks. We argue that our methodology is suitable as a market watch mechanism, as it makes visible the temporal redution in informational efficiency of the market.Comment: 17 pages, 9 figures. arXiv admin note: text overlap with arXiv:1508.04748, arXiv:1509.0021

    A permutation Information Theory tour through different interest rate maturities: the Libor case

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    This paper analyzes Libor interest rates for seven different maturities and referred to operations in British Pounds, Euro, Swiss Francs and Japanese Yen, during the period years 2001 to 2015. The analysis is performed by means of two quantifiers derived from Information Theory: the permutation Shannon entropy and the permutation Fisher information measure. An anomalous behavior in the Libor is detected in all currencies except Euro during the years 2006--2012. The stochastic switch is more severe in 1, 2 and 3 months maturities. Given the special mechanism of Libor setting, we conjecture that the behavior could have been produced by the manipulation that was uncovered by financial authorities. We argue that our methodology is pertinent as a market overseeing instrument.Comment: arXiv admin note: text overlap with arXiv:1304.039

    At last, it became a wasteland: the on-going story of Köpi Wasteland from noWHERE into nowHERE and back

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    This paper tells the story of Köpi Wasteland, a space in Berlin’s inner-city ring that was once part of the Berlin Wall. We bring to light the in-place-time stories that we found (Smithson, 1990) through a continuous field research conducted using a dialogical (Morin [1999] 2008; Bakhtin [1930s] 2001) method. This story exposes the dark side of Urban Regeneration processes directed by the urban planning discipline. Within the ostensibly good intentions of urban development for what are considered degraded areas – wastelands – urban policies end up creating real wastelands. Why and how does this happen? This is what the story of Köpi brings to light. Köpi now conceals what was once a vibrant and spontaneous environment. The lived experience in this place demonstrated the potential of neglected urban areas (Clement, 1984 & 2003), particularly the “Brachen” of Berlin depicted in Matthew Gandy’s (2017) Natura Urbana documentary, when inhabitants fully appropriate them by making the most of whatever they find there, transforming a space into a place of belonging. The term “wasteland” has been called into question as a result of the ongoing fieldwork in this place from February to October 2013. This investigation revealed that the term “wasteland” not only failed to define the specific characteristics and potential of this urban space, but it could also have a negative impact on the renewal process by ignoring what was already happening there. Regrettably, this is exactly what happened. As an outcome, it is clear that extreme caution should be used when labeling urban settings. The power of words (Weil, 1962) cannot be underestimated; they shape how we perceive and comprehend places, and thus how we modify them for better or worse. Unfortunately, Kopi’s present has been defined by an inaccurate story, and as a result, it has become a true wasteland

    SK2 channels are required for function and long-term survival of efferent synapses on mammalian outer hair cells

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    Cochlear hair cells use SK2 currents to shape responses to cholinergic efferent feedback from the brain. Using SK2-/- mice, we demonstrate that, in addition to their previously defined role in modulating hair cell membrane potentials, SK2 channels are necessary for long-term survival of olivocochlear fibers and synapses. Loss of the SK2 gene also results in loss of electrically driven olivocochlear effects in vivo, and down regulation of ryanodine receptors involved in calcium-induced calcium release, the main inducer of nAChR evoked SK2 activity. Generation of double-null mice lacking both the α10 nAChR gene, loss of which results in hypertrophied olivocochlear terminals, and the SK2 gene, recapitulates the SK2-/- synaptic phenotype and gene expression, and also leads to down regulation of α9 nAChR gene expression. The data suggest a hierarchy of activity necessary to maintain early olivocochlear synapses at their targets, with SK2 serving an epistatic, upstream, role to the nAChRs.Fil: Murthy, Vidya. Tufts University; Estados UnidosFil: Maison, Stéphane F.. Massachusetts Eye and Ear Infirmary; Estados Unidos. Harvard Medical School; Estados UnidosFil: Taranda, Julian. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. Tufts University; Estados UnidosFil: Haque, Nadeem. University of Notre Dame; Estados UnidosFil: Bond, Chris T.. Oregon Health Sciences University; Estados UnidosFil: Elgoyhen, Ana Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Adelman, John P.. Oregon Health Sciences University; Estados UnidosFil: Liberman, M. Charles. Massachusetts Eye and Ear Infirmary; Estados Unidos. Harvard Medical School; Estados UnidosFil: Vetter, Douglas E.. Tufts University; Estados Unido

    A point mutation in the hair cell nicotinic cholinergic receptor prolongs cochlear inhibition and enhances noise protection

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    The transduction of sound in the auditory periphery, the cochlea, is inhibited by efferent cholinergic neurons projecting from the brainstem and synapsing directly on mechanosensory hair cells. One fundamental question in auditory neuroscience is what role(s) this feedback plays in our ability to hear. In the present study, we have engineered a genetically modified mouse model in which the magnitude and duration of efferent cholinergic effects are increased, and we assess the consequences of this manipulation on cochlear function. We generated the Chrna9L9′T of knockin mice with a threonine for leucine change (L9′T) at position 9′ of the second transmembrane domain of the α9 nicotinic cholinergic subunit, rendering α9-containing receptors that were hypersensitive to acetylcholine and had slower desensitization kinetics. The Chrna9L9′T allele produced a 3-fold prolongation of efferent synaptic currents in vitro. In vivo, Chrna9L9′T mice had baseline elevation of cochlear thresholds and efferent-mediated inhibition of cochlear responses was dramatically enhanced and lengthened: both effects were reversed by strychnine blockade of the α9α10 hair cell nicotinic receptor. Importantly, relative to their wild-type littermates, Chrna9L9′T/L9′T mice showed less permanent hearing loss following exposure to intense noise. Thus, a point mutation designed to alter α9α10 receptor gating has provided an animal model in which not only is efferent inhibition more powerful, but also one in which sound-induced hearing loss can be restrained, indicating the ability of efferent feedback to ameliorate sound trauma.Fil: Taranda, Julian. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. Tufts University School of Medicine; Estados UnidosFil: Maison, Stéphane F.. Massachusetts Eye and Ear Infirmary; Estados UnidosFil: Ballestero, Jimena Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Katz, Eleonora. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Savino, Jessica. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Vetter, Douglas E.. Tufts University School of Medicine; Estados UnidosFil: Boulter, Jim. University of California at Los Angeles; Estados UnidosFil: Liberman, M. Charles. Massachusetts Eye and Ear Infirmary; Estados UnidosFil: Fuchs, Paul A.. The Johns Hopkins University School of Medicine; Estados UnidosFil: Elgoyhen, Ana Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Farmacología; Argentin

    Rammed earth walls in Mediterranean climate: material characterization and thermal behaviour

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    Rammed earth is considered a very sustainable construction system due to its low embodied energy, long service life and high recyclability. However, authors found that there is a lack of experimental results at real scale regarding rammed earth thermal behaviour. For this reason, this paper is first focused on the characterization of two different types of earth in order to check the suitability of being used in rammed earth walls. After the characterization, two experimental cubicle-shape buildings were built in Barcelona and Puigverd de Lleida (Spain) in order to test the thermal behaviour of their walls in two different climatic conditions. Temperature profiles inside walls have been monitored using thermocouples and temperature profile of southern walls was analysed in free floating conditions during summer and winter periods of 2013. Results show that thermal amplitude from outside to inside temperatures are decreased by rammed earth walls, achieving constant temperatures in inner surface of southern walls.The work was partially funded by the Spanish government (ENE2015-64117-C5-1-R (MINECO/FEDER)), in collaboration with the City Hall of Puigverd de Lleida. The authors would like to thank the Catalan Government for the quality accreditation given to their research group (2014 SGR 123). This project has received funding from the European Commission Seventh Framework Programme (FP/2007-2013) under Grant agreement Nº PIRSES-GA-2013-610692 (INNOSTORAGE) and from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 657466 (INPATH-TES). Barcelona cubicle has been conducted under the direction of the company Casa S-Low, with the collaboration of Luis Allepuz y Cristian Poza in their final degree project at EPSEB (UPC)

    Caracterización del movimiento fuerte en el emplazamiento de la presa de Itoiz

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    Se presenta en este trabajo una nueva caracterización del movimiento del suelo en la presa de Itoiz, consistente con la peligrosidad sísmica del emplazamiento. En primer lugar, proponemos una metodología con tres niveles de aproximación al movimiento esperado, que es después aplicada considerando las características particulares de la presa y su emplazamiento. Los cálculos de peligrosidad se realizan siguiendo la línea metodológica conocida como PSHA, con un método probabilista zonificado y formulando un árbol lógico que combina diferentes zonificaciones sísmicas y modelos de movimiento fuerte. La peligrosidad se representa en términos de la aceleración pico PGA y de las aceleraciones espectrales para periodos coincidentes con los de vibración de la presa, considerando dos estados de la misma correspondientes a presa vacía (T=0.1s) y presa con capacidad máxima de llenado (T=0.22 s). Se caracterizan los correspondientes movimientos para dos periodos de retorno, 975 años y 4975 años, asociados al sismo de proyecto y al sismo extremo, respectivamente. El efecto de sitio en el emplazamiento de la presa también fue tenido en cuenta. La metodología propuesta conduce a caracterizar el movimiento con tres niveles de detalle. En una primera etapa se obtienen los espectros de respuesta uniforme (UHS) para los dos niveles de movimiento referidos. Seguidamente se desarrolla un análisis de desagregación para obtener los sismos de control que previsiblemente pueden afectar mas a la presa. Estos se identifican como los que más contribuyen a los movimientos objeto dados por las aceleraciones espectrales de los dos periodos característicos, SA (0,1 s) y SA (0.22 s) y para los dos periodos de retorno de 975 y 4975 años asociados a lo sismos de proyecto y extremo. De ahí se obtienen los espectros de respuesta específicos para las cuatro combinaciones resultantes. Finalmente, se realiza una simulación del movimiento en el dominio del tiempo, obteniendo acelerogramas sintéticos mediante el método de número de onda discreto. Las simulaciones se realizaron considerando fuentes finitas en diferentes posiciones y evaluando el efecto de la directividad en las posibles fuentes consideradas. Se concluye destacando la importancia del efecto de directividad, en la caracterización del emplazamiento de la presa

    Assessing Latrine Use in Rural India: A Cross-Sectional Study Comparing Reported Use and Passive Latrine Use Monitors.

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    Although large-scale programs, like India's Total Sanitation Campaign (TSC), have improved latrine coverage in rural settings, evidence suggests that actual use is suboptimal. However, the reliability of methods to assess latrine use is uncertain. We assessed the reliability of reported use, the standard method, by comparing survey-based responses against passive latrine use monitors (PLUMs) through a cross-sectional study among 292 households in 25 villages in rural Odisha, India, which recently received individual household latrines under the TSC. PLUMs were installed for 2 weeks and householders responded to surveys about their latrine use behavior. Reported use was compared with PLUM results using Bland-Altman (BA) plots and concordance statistics. Reported use was higher than corresponding PLUM-recorded events across the range of comparisons. The mean reported "usual" daily events per household (7.09, 95% confidence interval [CI] = 6.51, 7.68) was nearly twice that of the PLUM-recorded daily average (3.62, 95% CI = 3.29, 3.94). There was poor agreement between "usual" daily latrine use and the average daily PLUM-recorded events (ρc = 0.331, 95% CI = 0.242, 0.427). Moderate agreement (ρc = 0.598, 95% CI = 0.497, 0.683) was obtained when comparing daily reported use during the previous 48 hours with the average daily PLUM count. Reported latrine use, though already suggesting suboptimal adoption, likely exaggerates the actual level of uptake of latrines constructed under the program. Where reliance on self-reports is used, survey questions should focus on the 48 hours prior to the date of the survey rather than asking about "usual" latrine use behavior
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