557 research outputs found

    Distributed Binary Detection with Lossy Data Compression

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    Consider the problem where a statistician in a two-node system receives rate-limited information from a transmitter about marginal observations of a memoryless process generated from two possible distributions. Using its own observations, this receiver is required to first identify the legitimacy of its sender by declaring the joint distribution of the process, and then depending on such authentication it generates the adequate reconstruction of the observations satisfying an average per-letter distortion. The performance of this setup is investigated through the corresponding rate-error-distortion region describing the trade-off between: the communication rate, the error exponent induced by the detection and the distortion incurred by the source reconstruction. In the special case of testing against independence, where the alternative hypothesis implies that the sources are independent, the optimal rate-error-distortion region is characterized. An application example to binary symmetric sources is given subsequently and the explicit expression for the rate-error-distortion region is provided as well. The case of "general hypotheses" is also investigated. A new achievable rate-error-distortion region is derived based on the use of non-asymptotic binning, improving the quality of communicated descriptions. Further improvement of performance in the general case is shown to be possible when the requirement of source reconstruction is relaxed, which stands in contrast to the case of general hypotheses.Comment: to appear on IEEE Trans. Information Theor

    A Market-Based Environmental Policy Experiment in Chile

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    Despite the increasing interest in the use of emissions trading for pollution control, empirical evidence reduces to a few experiences in the US. This paper studies the “"emission-offsets trading program”" established since 1992 to control particulate in Santiago-Chile. While the program is doing well from an environmental perspective, thanks, in part, to the price-based introduction of natural gas, the market is poorly performing because of high transaction costs, uncertainty and low enforcement. However, the scarcity rents created by the allocation of grandfathered emission rights to incumbents have proved very effective for the completion of the emissions inventory.

    Emergentes de una propuesta didáctica en el marco de un aprendizaje colaborativo

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    Dada la importancia que tiene en la ingeniería civil las superficies regladas, en particular el paraboloide hiperbólico, hemos tomado esta superficie como objeto de aprendizaje para nuestros estudiantes de ingeniería. Les proponemos una actividad que propicia el reconocimiento del paraboloide hiperbólico como una superficie reglada. En el trabajo mostramos la actividad y las dificultades que emergieron durante el desarrollo de la misma. Consideramos que actividades como ésta deben ocupar mayor espacio en el aula por cuanto permiten explorar los razonamientos que ponen en juego los estudiantes, ofreciendo elementos para actuar didácticamente y generar líneas de acción para futuras prácticas educativas

    A market-based environmental policy experiment in Chile

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    Despite growing interest in the use of emissions trading for pollution control, empirical evidence for this regulatory instrument has been confined to a few experiences in the United States. This paper broadens the empirical base by examining the "Emission-Offsets Trading Program" that has been in place since 1992 to control airborne particulate emissions in Santiago, Chile. While the program is doing well from an environmental perspective, due in part to the price-based introduction of natural gas, the market is performing poorly because of high transaction costs, uncertainty, and poor enforcement. However, the scarcity rents created by allocating grandfathered emission rights to incumbents have proved to be a very effective tool for completing the emissions inventory.Supported by the MIT Center for Energy and Environmental Policy Research

    Geometría analítica con software

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    El objetivo esencial de la geometría analítica es la resolución de problemas geométricos mediante métodos algebraicos y la interpretación geométrica de los desarrollos algebraicos .A grandes rasgos podemos considerar que la geometría analítica se ocupa esencialmente de dos problemas: - dada la descripción geométrica de un conjunto de puntos, encontrar la ecuación algebraica que cumplen dichos puntos; - dada una expresión algebraica, describir en términos geométricos el lugar geométrico de los puntos que cumplen dicha expresión. Los cursos de geometría analítica, por lo general, por razones de tiempo y la complejidad de algunos desarrollos, tanto algebraicos como gráficos, tratan un número limitado de tales problemas. Nuestra propuesta para el taller es abordar una variada colección de problemas, en los que el uso de la herramienta computacional se convierte en un valioso recurso, no sólo para evitar cálculos que resultan tediosos cuando se realizan a mano, sino también, un medio facilitador de representaciones geométricas, a veces difícil o imposible de lograr de otra manera. Es así que el software se convierte en un valioso auxiliar para agilizar cálculos y facilitar la visualización de lugares geométricos. En el taller, en esta oportunidad, adoptamos el software Maple porque consideramos que no es complicado generar animaciones incluso en aquellos casos en los que se utilice el software por primera vez. En tal sentido, Bishop (1989) señala que, el poder generar y manipular imágenes en la computadora estimula las habilidades de visualización mental y la comprensión de ideas algebraicas. Son precisamente éstos algunos de nuestros propósitos de logro. Las propuestas se orientan a la resolución de problemas de la geometría lineal, del plano y del espacio, problemas de cónicas, superficies cuádricas y regladas como el conoide

    Upstream ORFs influence translation efficiency in the parasite Trypanosoma cruzi

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    It is generally accepted that the presence of ORFs in the 5′ untranslated region of eukaryotic transcripts modulates the production of proteins by controlling the translation initiation rate of the main CDS. In trypanosomatid parasites, which almost exclusively depend on post-transcriptional mechanisms to regulate gene expression, translation has been identified as a key step. However, the mechanisms of control of translation are not fully understood. In the present work, we have annotated the 5′UTRs of the Trypanosoma cruzi genome both in epimastigotes and metacyclic trypomastigotes and, using a stringent classification approach, we identified putative regulatory uORFs in about 9% of the analyzed 5′UTRs. The translation efficiency (TE) and translational levels of transcripts containing putative repressive uORFs were found to be significantly reduced. These findings are supported by the fact that proteomic methods only identify a low number of proteins coded by transcripts containing repressive uORF. We additionally show that AUG is the main translation initiator codon of repressive uORFs in T. cruzi. Interestingly, the decrease in TE is more pronounced when the uORFs overlaps the main CDS. In conclusion, we show that the presence of the uORF and features such as initiation codon and/or location of the uORFs may be acting to fine tune translation levels in these parasites

    A pharmacoeconomic analysis of the use of single MMC instillation in low risk NMIBC in Italy

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    BACKGROUND: Bladder cancer accounts for 5-10% of all cancers in Europe and up to 85% patients presents a noninvasive tumor, whose treatment of choice is the transurethral bladder resection (TURB) paired with adjuvant intravesical chemotherapy or immunotherapy. Despite several clinical trials showed that this treatment is safe and decreases recurrences by 17% to 44% this practice is limited for many reasons. The study objective is to analyze the economical advantages of the single immediate post operative Mitomycin C instillation in Non Muscle-invasive Bladder Cancer (NMIBC) low-risk patients.METHODS: A cost-benefit analysis was performed evaluating the economical gain that would raised from a scenario with a single immediate post operative mitomycin C instillation in each low-risk NMIBC patient who underwent to TURB. Net present value and cost-benefit ratio were calculated and sensitivity analyses were performed. Base case analysis was performed considering tumor recurrence rate reduction of 11.7% and a TURB costs of 2,167.0 €, while sensitivity analyses were performed using a recurrence rate reduction of 19.2% and 15.0% and a TURB cost of 2,472.93 €. The discount rate was 2%.RESULTS: The single immediate post operative instillation of mitomycin C resulted to be cost-beneficial with a cost-benefit ratio that goes from 0.48 to 0.79 when compared to TURB alone raising a Net Present Value that goes from 660,284.39 € to 2,650,530.79 €.CONCLUSION: This study demonstrates that even assuming conservative parameters for recurrence rates reduction, a single immediate post operative mitomycin C instillation in low risk NMIBC patients would lower not only the recurrence rate but also the caring cost for bladder cancer

    Musashi mediates translational repression of the Drosophila hypoxia inducible factor.

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    Adaptation to hypoxia depends on a conserved α/β heterodimeric transcription factor called Hypoxia Inducible Factor (HIF), whose α-subunit is regulated by oxygen through different concurrent mechanisms. In this study, we have identified the RNA binding protein dMusashi, as a negative regulator of the fly HIF homologue Sima. Genetic interaction assays suggested that dMusashi participates of the HIF pathway, and molecular studies carried out in Drosophila cell cultures showed that dMusashi recognizes a Musashi Binding Element in the 3' UTR of the HIFα transcript, thereby mediating its translational repression in normoxia. In hypoxic conditions dMusashi is downregulated, lifting HIFα repression and contributing to trigger HIF-dependent gene expression. Analysis performed in mouse brains revealed that murine Msi1 protein physically interacts with HIF-1α transcript, suggesting that the regulation of HIF by Msi might be conserved in mammalian systems. Thus, Musashi is a novel regulator of HIF that inhibits responses to hypoxia specifically when oxygen is available.Fil: Bertolin, Agustina Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Katz, Maximiliano Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Yano, Masato. Niigata University; JapónFil: Pozzi, María Berta. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisiología, Biología Molecular y Celular; ArgentinaFil: Acevedo, Julieta María. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Blanco Obregón, Dalmiro Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Gándara, Lautaro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Sorianello, Eleonora Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Kanda, Hiroshi. Keio University School of Medicine; JapónFil: Okano, Hideyuki. Keio University School of Medicine; JapónFil: Srebrow, Anabella. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisiología, Biología Molecular y Celular; ArgentinaFil: Wappner, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Fisiología, Biología Molecular y Celular; Argentin
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