BOTDA Sensing Employing a Modified Brillouin Fiber Laser Probe Source

A theoretical and experimental study has been carried out on a tunable dual pump-probe optical source for distributed Brillouin optical time-domain analysis (BOTDA). The developed source exploits a modified Brillouin ring laser technology and is capable of a tuning range of ∼200 MHz without using phase-locked loop or optical sideband generation techniques, and exhibits a linewidth smaller than 2.5 MHz and ∼0.5 mW power. In BOTDA experiments, the proposed source has demonstrated to be an efficient solution enabling distributed sensing over 10 km single mode fiber with a spatial resolution of ∼4 m, and a strain and temperature resolutions of ∼10 μϵ and ∼0.5 °C respectively

Experimental Study on Mechanical and Electromagnetic Properties of Novel Silicon Photonic Devices

In this Thesis dissertation I have described the outcomes of an extensive set of simulative and experimental analyses carried out on strained-silicon micrometric and nanomentric structures and devices for photonic applications. The scope of this study was to perform a thorough analysis on the novel material properties, as well as to develop accurate and reliable simulative models for the design of photonic devices based on strained silicon technology, and assess the possible use of innovative experimental techniques for the strain measurement in photonic structures. In addition, this analysis allowed us to estimate the quality of the nanofabrication processes and techniques employed for the manufacturing of the devices

Sequential fissions of heavy nuclear systems

In Xe+Sn central collisions from 12 to 20 MeV/A measured with the INDRA 4$\pi$ multidetector, the three-fragment exit channel occurs with a significant cross section. In this contribution, we show that these fragments arise from two successive binary splittings of a heavy composite system. Strong Coulomb proximity effects are observed in the three-fragment final state. By comparison with Coulomb trajectory calculations, we show that the time scale between the consecutive break-ups decreases with increasing bombarding energy, becoming compatible with quasi-simultaneous multifragmentation above 18 MeV/A.Comment: 6 pages, 5 figures, contribution to conference proceedings of the Fifth International Workshop on Nuclear fission and Fission-Product Spectroscop

Organic farming enhances parasitoid diversity at the local and landscape scales

1. The magnitude of the benefits derived from organic farming within contrasting managed landscapes remains unclear and, in particular, the potential scale-dependent response of insect parasitoids is relatively unexplored. Identifying the scale at which parasitoids are affected by organic farming will be an important step to enhance their conservation. 2. We sampled tachinid parasitoids at the centre and margin of arable and grassland fields on paired organic and conventional farms located in landscapes with different proportions of organic land. A total of 192 fields were sampled in two biogeographical regions of the UK. 3. We found that the positive effect of organic farming on tachinid parasitoid diversity can be observed at multiple spatial scales. At the local scale, we found higher abundance and species richness of tachinid parasitoids on organic than on conventional farms and on field margins than on field centres. At the landscape scale, the diversity of tachinids was higher in landscapes with higher proportions of organic land. At both scales, the positive effect of organic farming was clear for arable fields, while it was almost neutral for grasslands. 4. Synthesis and applications. Any attempt to enhance parasitoid diversity in agricultural landscapes needs to consider the local management in relation to the habitat type, location within the field and agricultural management in the surrounding landscape. To restore parasitoid diversity, the promotion of organic agriculture should aim to increase both the total extent of organic farming and the connectivity of individual farms. As the benefits of organic farming to biodiversity clearly spread beyond individual farm boundaries, any assessment of organic farming should consider these positive externalities

POLÍTICAS PÚBLICAS DE MITIGAÇÃO DA EMISSÃO DE GASES DE EFEITO ESTUFA NA AGRICULTURA: UMA ANÁLISE DO PROGRAMA ABC

O objetivo do trabalho foi analisar o Programa ABC em termos de concessão de crédito rural “verde”, visando à sustentabilidade do sistema produtivo e a redução das emissões de gases de efeito estufa (GEE) na agricultura. Mais especificamente, analisa-se em que tecnologias e regiões estão sendo investidos os recursos e se estes desembolsos estão adequados com as áreas prioritárias e as demandas ambientais regionais (Macrorregiões e Estados). Em termos metodológicos, o trabalho usa dados quantitativos do MCTIC, IMAFLORA, Programa ABC, Banco Central do Brasil (BCB) (mais especificamente do SICOR e do PROAGRO) e da FGV. Os resultados e conclusões evidenciam que o Programa ABC elegeu as tecnologias adequadas e recomendadas para a redução das emissões de GEE, sendo que a recuperação de áreas de pastagens degradadas é aquela em que são aplicados mais da metade dos recursos. Além disso, os dados de uso dos recursos quando espacializados por regiões e estados brasileiros mostram que estão bem alocados territorialmente em termos de combater os GEE nos locais em que suas taxas são mais elevadas, entretanto, a sua principal rubrica de uso dos recursos que é a recuperação de pastagens degradadas está parcialmente adequada em relação às regiões e estados em que esta tecnologia seria mais necessária à mitigação dos GEE

Hybrid Biomaterials Based on Calcium Carbonate and Polyaniline Nanoparticles for Application in Photothermal Therapy

Inorganic materials contain remarkable properties for drug delivery, such as a large surface area and nanoporous structure. Among these materials, CaCO3 microparticles (CMPs) exhibit a high encapsulation efficiency and solubility in acidic media. The extracellular pH of tumor neoplastic tissue is significantly lower than the extracellular pH of normal tissue facilitating the release of drug-encapsulating CMPs in this area. Conducting polyaniline (PANI) absorbs light energy and transforms it into localized heat to produce cell death. This work aimed to generate hybrid CMPs loaded with PANI for photothermal therapy (PTT). The hybrid nanomaterial was synthesized with CaCO3 and carboxymethyl cellulose in a simple, reproducible manner. The CMP-PANI-Cys particles were developed for the first time and represent a novel type of hybrid biomaterial. Resultant nanoparticles were characterized utilizing scanning electron microscopy, dynamic light scattering, zeta potential, UV-vis, FTIR and Raman spectroscopy. In vitro HeLa cells in dark and irradiated conditions showed that CMP-PANI-Cys and PANI-Cys are nontoxic at the assayed concentrations. Hybrid biomaterials displayed high efficiency for potential PTT compared with PANI-Cys. In summary, hierarchical hybrid biomaterials composed of CMPs and PANI-Cys combined with near infrared irradiation represents a useful alternative in PTT.Fil: Neira Carrillo, Andrónico. Universidad de Chile; ChileFil: Yslas, Edith Inés. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Biología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Marini, Yazmin Amar. Universidad de Chile; ChileFil: Vásquez Quitral, Patricio. Universidad de Chile; ChileFil: Sánchez, Marianela. Universidad de Chile; ChileFil: Riveros, Ana. Universidad de Chile; ChileFil: Yáñez, Diego. Universidad de Chile; ChileFil: Cavallo, Pablo César. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Kogan, Marcelo Javier. Universidad de Chile; ChileFil: Acevedo, Diego Fernando. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentin

Dualities of Latin America

Determining whether the current situation of Latin America is better described as "post-neoliberalism" or as "commodities consensus" requires an analysis of recent changes in the region. Capitalism has expanded in agriculture and mining, accentuating the preeminence of basic exports. Traditional industry is declining, and remittances and tourism have increased in importance. Local capitalists associated with foreign corporations have replaced the national bourgeoisie, while the exodus of peasants consolidates labor precariousness, poverty, and inequality. At the same time, the United States is deploying troops to reorganize its domination. The South American rebellions have limited neoliberal aggression and achieved unusual victories in other parts of the world. The concept of post-neoliberalism emphasizes the region's political turn toward autonomy but overlooks the persistence of the economic model generated during the previous phase. The opposing concept, commodities consensus, highlights the extractivism prevailing throughout the region but plays down the extreme divergences among right-wing, center-left, and radical governments in all other areas. Both concepts contain part of the truth, but neither fully explains the regional scenario.Para determinar si la situación actual de Latinoamérica es mejor descrita como “postneoliberalismo” o como un “consenso de los commodities” hay que hacer un análisis de los cambios recientes en la región. El capitalismo se ha expandido en la agricultura y la minería, acrecentando la preeminencia de las exportaciones básicas. La industria tradicional ha disminuido, y la importancia del turismo y las remesas ha aumentado. Los capitalistas locales asociados con empresas extranjeras han reemplazado a la burguesía nacional, mientras que el éxodo de los campesinos ha consolidado la precariedad laboral, la pobreza y la desigualdad. Al mismo tiempo, Estados Unidos despliega tropas para reorganizar su dominio. Las rebeliones en América del Sur han puesto barreras a la agresión neoliberal y logrado victorias inusuales en otras partes del mundo. El concepto del postneoliberalismo destaca el giro político de la región hacia la autonomía pero con una tendencia a la persistencia del modelo económico generado durante la fase anterior. El otro concepto, el consenso de las commodities, destaca el extractivismo que prevalece en toda la región pero minoriza las divergencias entre los gobiernos de derecha, centro-izquierda y radicales en todas las demás áreas. Ambos conceptos son parcialmente ciertos, pero no explican totalmente el escenario regional.Fil: Katz, Claudio Isaac. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Distribution of Engraulis encrasicolus eggs and larvae in relation to coastal oceanographic conditions (the South-western Adriatic Sea case study)

Identification of potential spawning and nursery areas of European anchovy (Engraulis encrasicolus) represents an essential step in the management of a resource which is of fundamental importance both for fishery and pelagic trophic web. Egg and larvae occurrence from ichthyoplankton surveys (2012 - 2015) in the South Western Adriatic Sea were examined to understand the mechanisms that control their distribution. Egg and larvae densities varied through the years with the highest values recorded in 2012 and the lowest in 2014. Positive correlations between eggs and larvae with zooplankton were observed. When quotient analysis was used to find relations with environmental and biological variables, the results pointed out an egg preference for depth between 91 and 120 m and an avoidance between 11 and 30 m. Moreover, egg avoidances for high values of chlorophyll-a (> 0.52 mg m-3) and low values of zooplankton biomass ( 151 m; preference for high zooplankton biomass (> 1000 mg m-2) and avoidance for low biomass (< 299 mg m-2). These correlations and the quotient values suggest that egg and larvae distribution in the South-Western Adriatic Sea is mainly driven by food availability and depth

Functional characterization of the Mycobacterium tuberculosis zinc metallopeptidase Zmp1 and identification of potential substrates

Zinc metallopeptidases of bacterial pathogens are widely distributed virulence factors and represent promising pharmacological targets. In this work, we have characterized Zmp1, a zinc metallopeptidase identified as a virulence factor of Mycobacterium tuberculosis and belonging to the neprilysin (NEP; M13) family, whose X-ray structure has been recently solved. Interestingly, this enzyme shows an optimum activity toward a fluorogenic substrate at moderately acidic pH values (i.e., 6.3), which corresponds to those reported for the Mtb phagosome where this enzyme should exert its pathological activity. Substrate specificity of Zmp1 was investigated by screening a peptide library. Several sequences derived from biologically relevant proteins were identified as possible substrates, including the neuropeptides bradykinin, neurotensin, and neuropeptide FF. Further, subsequences of other small bioactive peptides were found among most frequently cleaved sites, e.g., apelin-13 and substance P. We determined the specific cleavage site within neuropeptides by mass spectrometry, observing that hydrophobic amino acids, mainly phenylalanine and isoleucine, are overrepresented at position P1′. In addition, the enzymatic mechanism of Zmp1 toward these neuropeptides has been characterized, displaying some differences with respect to the synthetic fluorogenic substrate and indicating that the enzyme adapts its enzymatic action to different substrate