A PLL-based resampling technique for vibration analysis in variable-speed wind turbines with PMSG: A bearing fault case Pezzani, Carlos Martín; Bossio, Jose Maria; Castellino, Ariel Matías; Bossio, Guillermo Rubén; de Angelo, Cristian Hernan Condition monitoring in permanent magnet synchronous machines has gained interest due to the increasing use in applications such as electric traction and power generation. Particularly in wind power generation, non-invasive condition monitoring techniques are of great importance. Usually, in such applications the access to the generator is complex and costly, while unexpected breakdowns results in high repair costs. This paper presents a technique which allows using vibration analysis for bearing fault detection in permanent magnet synchronous generators used in wind turbines. Given that in wind power applications the generator rotational speed may vary during normal operation, it is necessary to use special sampling techniques to apply spectral analysis of mechanical vibrations. In this work, a resampling technique based on order tracking without measuring the rotor position is proposed. To synchronize sampling with rotor position, an estimation of the rotor position obtained from the angle of the voltage vector is proposed. This angle is obtained from a phase-locked loop synchronized with the generator voltages. The proposed strategy is validated by laboratory experimental results obtained from a permanent magnet synchronous generator. Results with single point defects in the outer race of a bearing under variable speed and load conditions are presented.

¿Heredada o construida? Diferentes perspectivas de análisis de la identidad étnica entre los descendientes de inmigrantes en Argentina; Inherited or Constructed? The Different Perspectives of Analysis of Ethnic Identity among Polish Immigrants’ Descendants in Argentina Porada, Katarzyna La comunidad polaca en Argentina es resultado de movimientos poblacionales a gran escala, iniciados en el siglo XIX y finalizados en la segunda mitad del XX. Han pasado ya varias décadas desde que prácticamente se detuvieron los procesos migratorios entre ambos países. Pese a la distancia temporal que separa la llegada del último grupo inmigrante, algunos de sus descendientes, que nacieron, crecieron y fueron educados en Argentina, siguen conservando, de una u otra forma, los lazos que les vinculan con el lugar de nacimiento de sus antepasados. El presente artículo analiza cómo, en el contexto actual, los descendientes de inmigrantes polacos perciben su identidad étnica, cuáles son las particularidades de los lazos, reales o simbólicas, que mantienen con el país de origen de sus antepasados y qué es lo que les motiva a lo hora de conservar esta vinculación.; The Polish community in Argentina is the result of large-scale population movements that began in the 19th century and completed in the second half of the 20th. Several decades have passed since that migration between the two countries stopped. Despite the time elapsed since the arrival of the last immigrant group, some of their descendants, who were born, grew up and were educated in Argentina, still maintain, in one way or anot-her, the ties that bind them to the birthplace of their ancestors. This article, using different theoretical perspectives, analyzes how, in the current context, the descendants of Polish immigrants perceive their ethnic identity, what the characteristics of the links, real or sym-bolic, they have with the country of their ancestors are and what motivates them to preserve this linkage.

El par cómico en la comedia temprana de Aristófanes y su pervivencia en Lisístrata; The comic couple in Aristophanes’ early comedy and its survival in Lisistrata Schere, María Jimena La noción de par cómico, definida como un par tópico compuesto por dos personajes opuestos y antagónicos, constituye una clave fundamental para comprender la comedia temprana de Aristófanes. Este esquema binario domina en las primeras comedias conservadas del autor y se vuelve a implementar en su forma más convencional en Lisístrata. Su utilización en Lisístrata se debe, entre otros motivos, al hecho de que esta pieza retoma la virulencia satírica de las primeras obras y la polémica a favor de la paz con Esparta, tema presente en todas las comedias tempranas conservadas.; A noção de par cómico, definida como um par tópico composto por duas personagens opostas e antagónicas, constitui uma chave fundamental para compreender a comédia inicial de Aristófanes. Este esquema binário domina nas primeiras comédias conservadas do autor e volta a implementar-se na sua forma mais convencional na Lisístrata: A sua utilização na Lisístrata deve-se, entre outros motivos, ao facto de esta peça retomar a virulência satírica das primeiras obras e a polémica a favor da paz com Esparta, tema presente em todas as comédias iniciais conservadas.; The notion of comic couple, understood as a conventional couple formed by two opposite and antagonistic characters, provides a fundamental key to understand Aristophanes’ early comedy. This binary scheme is prevalent in the author’s early extant comedies and will again be implemented in its more conventional form in Lisistrata. Its occurrence in Lisistrata is due, among other causes, to the fact that this play resumes the tone of satirical virulence present in the early plays and the controversy in favour of peace with Sparta, a theme which resonates in all of the author’s early extant plays.; La notion de duo comique, conçue comme un duo topique composé par deux personnages opposés et antagoniques, constitue une clé fondamentale pour comprendre la comédie initial d’Aristophane. Ce schéma binaire domine dans les premières comédies préservées de l’auteur et se remet en oeuvre dans sa forme la plus conventionnelle dans Lysistrata. Son utilisation dans Lysistrata est due, entre autre raison, au fait que cette pièce reprend la virulence satyrique des premières oeuvres et la polémique en faveur de la paix avec Sparte, thème présent dans toutes les comédies initiales préservées.

The crystal structure of PknI from Mycobacterium tuberculosis shows an inactive, pseudokinase-like conformation Lisa, María Natalia; Wagner, Tristan; Alexandre, Matthieu; Barilone, Nathalie; Raynal, Bertrand; Alzari, Pedro M.; Bellinzoni, Marco Eukaryotic-like Ser/Thr protein kinases (ePKs) have been identified in many bacterial species, where they are known to mediate signalling mechanisms that share several features with their eukaryotic counterparts. In Mycobacterium tuberculosis, PknI is one of the 11 predicted ePKs and it has been related to bacterial virulence. In order to better understand the molecular basis of its role in mycobacterial signalling, we solved the crystal structure of the PknI cytoplasmic domain. We found that even though PknI possesses most conserved elements characteristic of Hanks-type kinases, it is degraded in several motifs that are essential for the ePKs catalytic activity. Most notably, PknI presents a remarkably short activation segment lacking a peptide–substrate binding site. Consistent with this observation and similar to earlier findings for eukaryotic pseudokinases, no kinase activity was detected for the catalytic domain of PknI, against different substrates and in various experimental conditions. Based on these results, we conclude that PknI may rely on unconventional mechanism(s) for kinase activity and/or it could play alternative role(s) in mycobacterial signalling. Database: Atomic coordinates and structure factors for the catalytic domain of M. tuberculosis PknI are in the Protein Data Bank under the accession codes 5M06 (wild-type PknI + ADP), 5M07 (PknI_C20A), 5M08 (PknI_C20A_R136A) and 5M09 (PknI_C20A_R136N).

Species at Risk (SPEAR) index indicates effects of insecticides on stream invertebrate communities in soy production regions of the Argentine Pampas Hunt, Lisa; Bonetto, Carlos Alberto; Marrochi, María Natalia; Scalise, Ana Maria; Fanelli, Silvia Laura; Liess, M.; Lydy, Michael J.; Chiu, M. C.; Resh, Vincent H. We investigated relationships among insecticides and aquatic invertebrate communities in 22 streams of two soy production regions of the Argentine Pampas over three growing seasons. Chlorpyrifos, endosulfan, cypermethrin, and lambda-cyhalothrin were the insecticides most frequently detected in stream sediments. The Species at Risk (SPEAR) pesticide bioassessment index (SPEARpesticides) was adapted and applied to evaluate relationships between sediment insecticide toxic units (TUs) and invertebrate communities associated with both benthic habitats and emergent vegetation habitats. SPEARpesticides was the only response metric that was significantly correlated with total insecticide TU values for all three averaged data sets, consistently showing a trend of decreasing values with increasing TU values (r2 = 0.35 to 0.42, p-value = 0.001 to 0.03). Although pyrethroids were the insecticides that contributed the highest TU values, toxicity calculated based on all insecticides was better at predicting changes in invertebrate communities than toxicity of pyrethroids alone. Crustaceans, particularly the amphipod Hyalella spp., which are relatively sensitive to pesticides, played a large role in the performance of SPEARpesticides, and the relative abundance of all crustaceans also showed a significant decreasing trend with increasing insecticide TUs for two of three data sets (r2 = 0.30 to 0.57, p-value = 0.003 to 0.04) examined. For all data sets, total insecticide TU was the most important variable in explaining variance in the SPEARpesticides index. The present study was the first application of the SPEAR index in South America, and the first one to use it to evaluate effects of pesticides on invertebrate communities associated with aquatic vegetation. Although the SPEAR index was developed in Europe, it performed well in the Argentine Pampas with only minor modifications, and would likely improve in performance as more data are obtained on traits of South American taxa, such as pesticide sensitivity and generation time.

Shared territorial defence in the suboscine Aphrastura spinicauda Ippi, Silvina Graciela; Dongen, Walter van; Lazzoni, I.; Vasquez, Rodrigo A. Territorial behaviour is an active and typically aggressive behaviour used to defend resources. Here, we investigated the presence of shared territorial defence behaviour during conspecific intrusions in the Thorn-tailed Rayadito (Aphrastura spinicauda), a suboscine species that generally does not maintain long-term pair bonds. We found that, compared to females, males displayed more alarm calling during their response, approached closer and were also more physically aggressive towards conspecific intruders. Despite these differences, the defence behaviour ofmales and females was highly correlated during territorial responses to simulated intruders. To our knowledge, this is the first report of coordinated or joint territorial defence in a South American suboscine that generally only maintains short-term pair bonds.

Metals as chemical tracers to discriminate ecological populations of threatened Franciscana dolphins (Pontoporia blainvillei) from Argentina Romero, María Belén; Polizzi, Paula Sabrina; Chiodi Boudet, Leila Natalia; Robles, Alicia Daniela; Das, Kalyan; Gerpe, Marcela Silvia Franciscana dolphins are the most impacted small cetacean in the Southwestern Atlantic Ocean, classified as Vulnerable A3d by IUCN. Essential (Fe, Mo, Mn, Cr, Ni, Co) and non-essential (Ag, Pb, Sn) trace elements (TEs) were measured in liver, kidney, and brain samples of by-catch Franciscana dolphins that were living in estuarine (n = 21) and marine (n = 21) habitats (1) to assess whether TEs posed a threat and (2) to evaluate the suitability of TEs for discriminating ecological populations of this species in Argentinean waters. Essential TEs showed little variation in tissues from both groups in agreement with levels reported for other cetaceans and suggesting that these concentrations correspond to normal physiological levels. Non-essential TEs were higher in estuarine juveniles and adults dolphins than in marine specimens. These results suggest anthropogenic sources associated with estuarine area and that Franciscana dolphins are good sentinels of the impact of the environment. The difference in the concentrations of TEs beetwen ecological populations appeared to be related to distinct exposures in both geographical areas, and it is suggested that Ag and Sn concentrations in adults are good chemical tracers of anthropogenic input of TEs. These results provide additional information for improved management and regulatory policy.

Celpe-Bras y el libro didáctico de Portugués Lengua Extranjera Ariet, Andrea; Martins, María Elisa; Olavarriaga, Martín El Certificado de Língua Portuguesa para Estrangeiros (Celpe-Bras) representa un examen de proficiencia considerado de alto impacto ya que los resultados tienen un correlato con decisiones que interfieren en la vida de muchos individuos. Poder ejercer la profesión de médico en territorio brasileño siendo extranjero, cursar ciertas carreras de posgrado stricto senso en universidades brasileñas, ingresar a la carrera diplomática, etc.; son algunas de las acciones que dependen del resultado del Celpe-Bras. El crecimiento exponencial de candidatos, cuyo número superó los 10 mil en 2015, lo ubica en el centro de cualquier programa y planificación de la enseñanza formal de portugués como lengua extranjera. En este contexto, la elección del material didáctico merece un interés especial puesto que los libros de enseñanza de portugués son escasos y anteriores o contemporáneos al surgimiento del Celpe-Bras. Este trabajo secentrará en el análisis de los libros Avenida Brasil (LIMA, 1991) y Bem-vindo: a língua portuguesa no mundo da comunicação (PONCE et al, 1997), teniendo en cuenta el constructo del Celpe-Bras.

Comparison between the continuum threshold and the Polyakov loop as deconfinement order parameters Carlomagno, Juan Pablo; Loewe, Marcelo We study the relation between the continuum threshold s0 within finite energy sum rules and the trace of the Polyakov loop Φ in the framework of a nonlocal SU(2) chiral quark model, establishing a contact between both deconfinement order parameters at finite temperature T and chemical potential μ. In our analysis, we also include the order parameter for the chiral symmetry restoration, the chiral quark condensate. We found that s0 and Φ provide us with the same information for the deconfinement transition, both for the zero and finite chemical potential cases. At zero density, the critical temperatures for both quantities coincide exactly and, at finite μ both order parameters provide evidence for the appearance of a quarkyonic phase.

An inside look at the sensory biology of triatomines Barrozo, Romina; Reisenman, Carolina Esther; Guerenstein, Pablo Gustavo; Lazzari, Claudio Ricardo; Lorenzo, Marcelo Gustavo Although kissing bugs (Triatominae: Reduviidae) are perhaps best known as vectors of Chagas disease, they are important experimental models in studies of insect sensory physiology, pioneered by the seminal studies of Wigglesworth and Gillet more than eighty years ago. Since then, many investigations have revealed that the thermal, hygric, visual and olfactory senses play critical roles in the orientation of these blood-sucking insects towards hosts. Here we review the current knowledge about the role of these sensory systems, focussing on relevant stimuli, sensory structures, receptor physiology and the molecular players involved in the complex and cryptic behavioural repertoire of these nocturnal insects. Odours are particularly relevant, as they are involved in host search and are used for sexual, aggregation and alarm communication. Tastants are critical for a proper recognition of hosts, food and conspecifics. Heat and relative humidity mediate orientation towards hosts and are also important for the selection of resting places. Vision, which mediates negative phototaxis and flight dispersion, is also critical for modulating shelter use and mediating escape responses. The molecular bases underlying the detection of sensory stimuli started to be uncovered by means of functional genetics due to both the recent publication of the genome sequence of Rhodnius prolixus and the availability of modern genome editing techniques.

Adsorption dynamics of molecular nitrogen at an Fe(111) surface Nosir, M. A.; Martin Gondre, L.; Bocan, Gisela Anahí; Díez Muiño, R. We present an extensive theoretical study of N2 adsorption mechanisms on an Fe(111) surface. We combine the static analysis of a six-dimensional potential energy surface (6D-PES), based on ab initio density functional theory (DFT) calculations for the system, with quasi-classical trajectory (QCT) calculations to simulate the adsorption dynamics. There are four molecular adsorption states, usually called γ, δ, α, and ε, arising from our DFT calculations. We find that N2 adsorption in the γ-state is non-activated, while the threshold energy is associated with the entrance channel for the other three adsorption states. Our QCT calculations confirm that there are activated and nonactivated paths for the adsorption of N2 on the Fe(111) surface, which is in agreement with previous experimental investigations. Molecular dynamics at a surface temperature Ts = 300 K and impact energies Ei in the 0-5 eV range show the relative occupancy of the γ, δ, α, and ε states. The δ-state, however, is only marginally populated despite its adsorption energy being very similar to that of the γ-state. Our QCT calculations trace the dependence of molecular trapping on the surface temperature Ts and initial impact energy Ei and quantify the rates of the different competitive channels that eventually lead to molecular adsorption.

Hydriding kinetics of Mg[sbnd]TiH2 fine dispersions obtained by mechanosynthesis Biasetti, Andrés Tobías; Meyer, Marcos; Mendoza Zélis, Luis Alejandro Mg80[sbnd]Ti20 hydride systems were prepared via reactive ball milling following two different procedures: grinding Mg with Ti or TiH2, in both cases under H2 atmosphere. Such systems were subjected to several cycles of hydrogen uptake and release in volumetric Sieverts apparatus under different pressure and temperature conditions. A structural characterization from SEM images and XRD patterns reveals no essential microstructural differences between the samples obtained by different routes, although a growth in domain size with temperature is observed. Also, the slowing of the kinetics when the temperature goes down is more pronounced in the specimen fabricated by the second route. The influence of the transformed and untransformed phase fractions on the absorption kinetics can be well described using a double Hill function. Such complex function takes into account two distinguishable processes, with and without nucleation, that differentiate themselves as temperature increases. The first one may be related to surface absorption and the second tentatively ascribed to reactions at grain boundaries, dislocations and other extended defects. The fitted values may then be associated to physical constants of the processes occurring during hydrogen absorption in both regions.

Marcadores de formación y resorción ósea y su utilidad para determinar el final del periodo de aposición ósea; Bone formation and resorption markers to evaluate the end of bone apposition Seijo, Mariana; Oliveri, María Beatriz; Deferrari, Juan Mariano; Casco, Cristina; Zeni, Susana Noemi El pico de masa ósea (PMO) se alcanza entre los 20 y 35 años, pero la aposición ósea continúa hasta alcanzar el pico de fortaleza ósea (PFO). Se crea así una ventana entre ambos picos que podría ser evaluada mediante marcadores bioquímicos de recambio óseo, ya que durante dicho período la densidad mineral permanece constante. El objetivo fue determinar el final de la aposición ósea mediante marcadores bioquímicos óseos. Se evaluaron por décadas entre 20 y 49 años de edad 139 sujetos sanos de ambos sexos (69 hombres y 70 mujeres), determinando fosfatasa alcalina ósea (FAO), osteocalcina (OC), propéptido amino terminal del colágeno tipo 1 (P1NP) y telopéptido C-terminal del colágeno tipo 1 (CTX). Los marcadores correlacionan negativamente con la edad (OC: r= -0,3; p<0,01; P1NP: r= -0,4; p< 0,01 y CTX: r= -0,4; p< 0,01), exceptuando FAO. En hombres de 20-29 años, P1NP y el CTX fueron significativamente mayores vs. 30-39 años (p<0,05 y p<0,001, respectivamente), y entre 30-39 años vs. de 40-49 años en P1NP y CTX (p<0,05; p<0,001, respectivamente). En mujeres de 20-29 años, P1NP y CTX fueron significativamente mayores vs. 30-39 años (p<0,0001 y p<0,01, respectivamente). Conclusión: los marcadores de remodelado óseo más sensibles y específicos permitirían determinar bioquímicamente el fin de la aposición ósea que se produce entre el PMO y el PFO. Si bien es necesario ampliar el número de sujetos evaluados, los datos que surgen de la presente investigación sentarían las bases para futuros estudios epidemiológicos referidos al fin de la aposición ósea.; Peak bone mass is achieved between 20- 35 years; however bone apposition continues to reach an optimal skeleton strength. The window between peak bone mass and peak bone apposition may be evaluated by biochemical bone turnover markers. The objective of this study was to determine the end of bone apposition through biochemical bone markers in both sexes. A total of 139 subjects (69 men and 70 women) were divided by decades between 20 and 49 years of age. Bone alkaline phosphatase (BAL), osteocalcin (OC), type I collagen propeptide (P1NP) and type I collagen C-terminal telopeptide (CTX) were evaluated. Except BAL, the other bone markers negatively correlated with the age [OC (r= -0.3; p<0.01); P1NP (r= -0.4; p<0.01) and CTX (r= -0.4; p<0.01)]. Regarding men aged 20 to 29 years, P1NP and CTX were significantly higher vs. 30-39 years (p<0.05 y p<0.001, respectively) and. vs. 40-49 years (p<0.05; p<0.001, respectively). In women, the results were similar. Regarding 20-29 years, P1NP and CTX were higher vs. 30-39 years (p<0.001 y p<0.01, respectively). Bone remodeling rate decreases after the third decade, suggesting the end of the apposition period of peak bone mass. Conclusion: The most specific and sensitive bone markers would biochemically determine the end of bone apposition that extends between the peak of bone mass and the peak of bone strength. Although it is necessary to increase the number of subjects evaluated, the data that emerge from the present study would establish the bases for future epidemiological studies referring to the end of bone apposition.

Conformational diversity analysis reveals three functional mechanisms in proteins Monzón, Alexander; Zea, Diego Javier; Fornasari, Maria Silvina; Saldaño, Tadeo Enrique; Fernández Alberti, Sebastián; Tosatto, Silvio C. E.; Parisi, Gustavo Daniel Protein motions are a key feature to understand biological function. Recently, a large-scale analysis of protein conformational diversity showed a positively skewed distribution with a peak at 0.5 Å C-alpha root-mean-square-deviation (RMSD). To understand this distribution in terms of structure-function relationships, we studied a well curated and large dataset of ~5,000 proteins with experimentally determined conformational diversity. We searched for global behaviour patterns studying how structure-based features change among the available conformer population for each protein. This procedure allowed us to describe the RMSD distribution in terms of three main protein classes sharing given properties. The largest of these protein subsets (~60%), which we call "rigid" (average RMSD = 0.83 Å), has no disordered regions, shows low conformational diversity, the largest tunnels and smaller and buried cavities. The two additional subsets contain disordered regions, but with differential sequence composition and behaviour. Partially disordered proteins have on average 67% of their conformers with disordered regions, average RMSD = 1.1 Å, the highest number of hinges and the longest disordered regions. In contrast, malleable proteins have on average only 25% of disordered conformers and average RMSD = 1.3 Å, flexible cavities affected in size by the presence of disordered regions and show the highest diversity of cognate ligands. Proteins in each set are mostly non-homologous to each other, share no given fold class, nor functional similarity but do share features derived from their conformer population. These shared features could represent conformational mechanisms related with biological functions.

Optimum PR Control applied to LCL filters with Low Resonance Frequency Fantino, Roberto Armin; Busada, Claudio; Solsona, Jorge Alberto A control strategy for LCL Grid-connected voltage source inverters is proposed. Using the injected grid current measurement exclusively, the proposal allows the use of the proportional plus resonant regulator (PR) optimum design, regardless of the filter resonance frequency. Simulation and experimental results that demonstrate the validity and effectiveness of the proposal for different LCL filter resonance frequency values are presented. Also its superiority compared to a control methodrecently proposed in the literature is shown.

El Fondo Tecnológico Argentino (FONTAR) anuncia los resultados del proceso de evaluación para la ventanilla ANR INT 3500 mediante Resolución de Directorio N° 028/17.

El Fondo Tecnológico Argentino (FONTAR) anuncia los resultados del proceso de evaluación para la convocatoria ANR 2200 2015 C2 mediante Resolución de Directorio N° 031/17.

El Fondo Tecnológico Argentino (FONTAR) anuncia los resultados del proceso de reconsideración para la convocatoria ANR 1700 2015 C1 mediante Resolución de Directorio N° 032/17.

El Fondo Tecnológico Argentino (FONTAR) anuncia los resultados del proceso de evaluación para la convocatoria ANR 3500 2016 C1 mediante Resolución de Directorio N° 035/17.

NiNbO Catalyst Deposited on Anodized Aluminum Monoliths for the Oxidative Dehydrogenation of Ethane Santander, José Anibal; Boldrini, Diego Emmanuel; Pedernera, Marisa Noemi; Tonetto, Gabriela Marta Aluminum monoliths were used as substrates to prepare structured catalysts. A rough alumina layer was generated on the surface of the substrates by anodizing followed by hydrothermal treatments. The dip-coating technique was used for coating the monolithic substrates. Aqueous suspensions with 0.15 and 0.30 g/g of Ni-Nb mixed oxides catalysts were prepared for that purpose. Colloidal SiO2 was added as a binder in order to obtain homogeneous and adherent coatings. The samples were characterized by SEM, TPR, XPS, XRD, and N2 adsorption and tested in the oxidative dehydrogenation (ODH) of ethane to ethylene. The silica particles produced a drop in catalytic activity without affecting ethylene selectivity. The former effect was attributed mainly to a decrease in surface nickel concentration and an increase in reduction temperature. The presence of anodized aluminum substrates in the reaction environment did not have a significant influence on catalytic activity and product distribution, as observed for the coated monoliths used in this work, thus being a useful material to prepare structured catalysts for low-temperature ethane ODH.