DA (IN)APLICABILIDADE DO CÓDIGO DE DEFESA DO CONSUMIDOR NOS TRANSPORTES MARÍTIMOS DE CARGAS

O Código Comercial (Lei n. 556, de 25 de junho de 1850) foi o primeiro diploma a regular o transporte no Direito Brasileiro, dispondo notadamente sobre o transporte marítimo. Por tempos o transporte foi regulado de forma superficial e casuística no ordenamento pátrio, mediante sucessivos decretos governamentais que tratavam mormente do transporte ferroviário. O Código Civil de 1916 não disciplinou a matéria, visto que o transporte era tido como contrato essencialmente mercantil. O Código Civil de 2002, pois, foi o primeiro diploma legal brasileiro a regular sistematicamente o contrato típico de transporte, estabelecendo princípios gerais e um regramento em consonância com a prática consolidada na doutrina e na jurisprudência. Alguns desafios exegéticos ainda subsistem para os juristas, em especial no tocante à responsabilidade civil do transportador. No tocante aos contratos de transporte marítimo de mercadorias, releva ainda discutir sobre a (in)aplicabilidade das normas de defesa do consumidor para fins de responsabilização do transportador. Tal questão envolve relevantes interesses conflitantes, tendo em vista que a aplicação da Lei Consumerista implica diversos reflexos mais favoráveis aos contratantes do serviço de transporte e, consequentemente, desvantajosos aos transportadores. A grande complexidade do sistema consumerista, que toca diretamente a problemática aqui retratada, diz respeito à definição do conceito de consumidor e, sobretudo, refere-se à exegese da expressão “destinatário final” constante do texto do art. 2º do Código de Defesa do Consumidor

A geometrical view of scalar modulation instability in optical fibers

Full models of scalar modulation instability (MI) in optical fibers available in the literature usually involve complex formulations. In this paper, we present a novel approach to the analysis of MI in optical fibers by means of a simple geometrical description in the power vs. frequency plane. This formulation allows to relate the shape of the MI gain to any arbitrary dispersion profile of the medium, thus providing a simple insight. As a result, we derive a straightforward explanation of the non-trivial dependence of the cutoff power on high-order dispersion and derive explicitly the power that maximizes the gain. Our approach puts forth a tool to synthesize a desired MI gain with the potential application to a number of parametric-amplification and supercontinuum-generation devices whose initial-stage dynamics rely upon modulation instability.Fil: Hernandez, Santiago Martin. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Fierens, Pablo Ignacio. Instituto Tecnológico de Buenos Aires; ArgentinaFil: Bonetti, Juan Ignacio. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Sánchez, Alfredo Daniel. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Grosz, Diego Fernando. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Instituto Tecnológico de Buenos Aires; Argentin

The 9-1-1 Complex Controls Mre11 Nuclease and Checkpoint Activation during Short-Range Resection of DNA Double-Strand Breaks.

Summary Homologous recombination is initiated by nucleolytic degradation (resection) of DNA double-strand breaks (DSBs). DSB resection is a two-step process in which an initial short-range step is catalyzed by the Mre11-Rad50-Xrs2 (MRX) complex and limited to the vicinity of the DSB end. Then the two long-range resection Exo1 and Dna2-Sgs1 nucleases extend the resected DNA tracts. How short-range resection is regulated and contributes to checkpoint activation remains to be determined. Here, we show that abrogation of long-range resection induces a checkpoint response that decreases DNA damage resistance. This checkpoint depends on the 9-1-1 complex, which recruits Dpb11 and Rad9 at damaged DNA. Furthermore, the 9-1-1 complex, independently of Dpb11 and Rad9, restricts short-range resection by negatively regulating Mre11 nuclease. We propose that 9-1-1, which is loaded at the leading edge of resection, plays a key function in regulating Mre11 nuclease and checkpoint activation once DSB resection is initiated

A higher-order perturbation analysis of the nonlinear Schrödinger equation

A well-known and thoroughly studied phenomenon in nonlinear wave propagation is that of modulation instability (MI). MI is usually approached as a perturbation to a pump, and its analysis is based on preserving only terms which are linear on the perturbation, discarding those of higher order. In this sense, the linear MI analysis is relevant to the understanding of the onset of many other nonlinear phenomena, such as supercontinuum generation, but it has limitations as it can only be applied to the propagation of the perturbation over short distances. In this work, we propose approximations to the propagation of a perturbation, consisting of additive white noise, that go beyond the linear modulation instability analysis, and show them to be in excellent agreement with numerical simulations and experimental measurements.Fil: Bonetti, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Hernandez, Santiago Martin. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Fierens, Pablo Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Tecnológico de Buenos Aires; ArgentinaFil: Grosz, Diego Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentin

The MRX Complex Plays Multiple Functions in Resection of Yku- and Rif2-Protected DNA Ends

The ends of both double-strand breaks (DSBs) and telomeres undergo tightly regulated 5′ to 3′ resection. Resection of DNA ends, which is specifically inhibited during the G1 cell cycle phase, requires the MRX complex, Sae2, Sgs1 and Exo1. Moreover, it is negatively regulated by the non-homologous end-joining component Yku and the telomeric protein Rif2. Here, we investigate the nuclease activities that are inhibited at DNA ends by Rif2 and Yku in G1 versus G2 by using an inducible short telomere assay. We show that, in the absence of the protective function of Rif2, resection in G1 depends primarily on MRX nuclease activity and Sae2, whereas Exo1 and Sgs1 bypass the requirement of MRX nuclease activity only if Yku is absent. In contrast, Yku-mediated inhibition is relieved in G2, where resection depends on Mre11 nuclease activity, Exo1 and, to a minor extent, Sgs1. Furthermore, Exo1 compensates for a defective MRX nuclease activity more efficiently in the absence than in the presence of Rif2, suggesting that Rif2 inhibits not only MRX but also Exo1. Notably, the presence of MRX, but not its nuclease activity, is required and sufficient to override Yku-mediated inhibition of Exo1 in G2, whereas it is required but not sufficient in G1. Finally, the integrity of MRX is also necessary to promote Exo1- and Sgs1-dependent resection, possibly by facilitating Exo1 and Sgs1 recruitment to DNA ends. Thus, resection of DNA ends that are protected by Yku and Rif2 involves multiple functions of the MRX complex that do not necessarily require its nuclease activity

Measuring self-steepening with the photon-conserving nonlinear Schrödinger equation

We propose an original, simple, and direct method to measure self-steepening (SS) in nonlinear waveguides. Our proposal is based on results derived from the recently introduced photon-conserving nonlinear Schrödinger equation (NLSE) and relies on the time shift experienced by soliton-like pulses due to SS upon propagation. In particular, a direct measurement of this time shift allows for a precise estimation of the SS parameter. Furthermore, we show that such an approach cannot be tackled by resorting to the NLSE. The proposed method is validated through numerical simulations, in excellent agreement with the analytical model, and results are presented for relevant spectral regions in the near infrared, the telecommunication band, and the mid infrared, and for realistic parameters of available laser sources and waveguides. Finally, we demonstrate the robustness of the proposed scheme against deviations expected in real-life experimental conditions, such as pulse shape, pulse peak power, pulsewidth, and/or higher-order linear and nonlinear dispersion.Fil: Linale, Nicolás Martín. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comision Nacional de Energia Atomica. Gerencia D/area Invest y Aplicaciones No Nucleares. Gerencia de Des. Tec. y Proyectos Especiales. Departamento de Ingenieria En Telecomunicaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Fierens, Pablo Ignacio. Instituto Tecnológico de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bonetti, Juan Ignacio. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comision Nacional de Energia Atomica. Gerencia D/area Invest y Aplicaciones No Nucleares. Gerencia de Des. Tec. y Proyectos Especiales. Departamento de Ingenieria En Telecomunicaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Sánchez, Alfredo Daniel. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comision Nacional de Energia Atomica. Gerencia D/area Invest y Aplicaciones No Nucleares. Gerencia de Des. Tec. y Proyectos Especiales. Departamento de Ingenieria En Telecomunicaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Hernandez, Santiago Martin. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Universidad Nacional de Cuyo; ArgentinaFil: Grosz, Diego Fernando. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Comision Nacional de Energia Atomica. Gerencia D/area Invest y Aplicaciones No Nucleares. Gerencia de Des. Tec. y Proyectos Especiales. Departamento de Ingenieria En Telecomunicaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentin

Processing of DNA Ends in the Maintenance of Genome Stability

DNA double-strand breaks (DSBs) are particularly hazardous lesions as their inappropriate repair can result in chromosome rearrangements, an important driving force of tumorigenesis. DSBs can be repaired by end joining mechanisms or by homologous recombination (HR). HR requires the action of several nucleases that preferentially remove the 5′-terminated strands at both DSB ends in a process called DNA end resection. The same nucleases are also involved in the processing of replication fork structures. Much of our understanding of these pathways has come from studies in the model organism Saccharomyces cerevisiae. Here, we review the current knowledge of the mechanism of resection at DNA DSBs and replication forks