Using mLearning and MOOCs to understand chaos, emergence, and complexity in education deWaard, Inge; Abajian, Sean; Gallagher, Michael Sean; Hogue, Rebecca; Keskin, Nilgün; Koutropoulos, Apostolos; Rodriguez, Carlos Osvaldo In this paper, we look at how the massive open online course (MOOC) format developed by connectivist researchers and enthusiasts can help analyze the complexity, emergence, and chaos at work in the field of education today. We do this through the prism of a MobiMOOC, a six-week course focusing on mLearning that ran from April to May 2011. MobiMOOC embraced the core MOOC components of self-organization, connectedness, openness, complexity, and the resulting chaos, and, as such, serves as an interesting paradigm for new educational orders that are currently emerging in the field. We discuss the nature of participation in MobiMOOC, the use of mobile technology and social media, and how these factors contributed to a chaotic learning environment with emerging phenomena. These emerging phenomena resulted in a transformative educational paradigm.

Continental and oceanic crustal structure of the Pampean flat slab region, western Argentina, using receiver function analysis: New high-resolution results Gans, Christine R.; Beck, Susan L.; Zandt, George; Gilbert, Hersh; Alvarado, Patricia Monica; Anderson, Megan; Linkimer, Lepolt The Pampean flat slab of central Chile and Argentina (30°-32°S) has strongly influenced Cenozoic tectonics in western Argentina, which contains both the thick-skinned, basement-cored uplifts of the Sierras Pampeanas and the thin-skinned Andean Precordillera fold and thrust belt. In this region of South America, the Nazca Plate is subducting nearly horizontally beneath the South American Plate at ∼100km depth. To gain a better understanding of the deeper structure of this region, including the transition from flat to 'normal' subduction to the south, three IRIS-PASSCAL arrays of broad-band seismic stations have been deployed in central Argentina. Using the dense SIEMBRA array, combined with the broader CHARGE and ESP arrays, the flat slab is imaged for the first time in 3-D detail using receiver function (RF) analysis. A distinct pair of RF arrivals consisting of a negative pulse that marks the top of the oceanic crust, followed by a positive pulse, which indicates the base of the oceanic crust, can be used to map the slab's structure. Depths to Moho and oceanic crustal thicknesses estimated from RF results provide new, more detailed regional maps. An improved depth to continental Moho map shows depths of more than 70km in the main Cordillera and ∼50km in the western Sierras Pampeanas, that shallow to ∼35km in the eastern Sierras Pampeanas. Depth to Moho contours roughly follow terrane boundaries. Offshore, the hotspot seamount chain of the Juan Fernández Ridge (JFR) is thought to create overthickened oceanic crust, providing a mechanism for flat slab subduction. By comparing synthetic RFs, based on various structures, to the observed RF signal we determine that the thickness of the oceanic crust at the top of the slab averages at least ∼13-19km, supporting the idea of a moderately overthickened crust to provide the additional buoyancy for the slab to remain flat. The overthickened region is broader than the area directly aligned with the path of the JFR, however, and indicates, along with the slab earthquake locations, that the flat slab area is wider than the JFR volcanic chain observed in the offshore bathymetry. Further, RFs indicate that the subducted oceanic crust in the region directly along the path of the subducted ridge is broken by trench-parallel faults. One explanation for these faults is that they are older structures within the oceanic crust that were created when the slab subducted. Alternatively, it is possible that faults formed recently from tectonic underplating caused by increased interplate coupling in the flat slab region.

Cell Viability and Functionality of Probiotic Bacteria in Dairy Products Vinderola, Celso Gabriel; Binetti, Ana Griselda; Burns, Patricia Graciela; Reinheimer, Jorge Alberto Probiotic bacteria, according to the definition adopted by the World Health Organization in 2002, are live microorganisms, which when administered in adequate amounts confer a health benefit to the host. Recent studies show that the same probiotic strain produced and/or preserved under different storage conditions, may present different responses regarding their susceptibility to the adverse conditions of the gastrointestinal tract, its capacity to adhere to the intestinal epithelium, or its immunomodulating capacity, the functionality being affected without changes in cell viability. This could imply that the control of cell viability is not always enough to guarantee the functionality (probiotic capacity) of a strain. Therefore, a new challenge arises for food technologists and microbiologists when it comes to designing and monitoring probiotic food: to be able to monitor the functionality of a probiotic microorganism throughout all the stages the strain goes through from the moment it is produced and included in the food vehicle, until the moment of consumption. Conventional methodological tools or others still to be developed must be used. The application of cell membrane functionality markers, the use of tests of resistance to intestinal barriers, the study of surface properties and the application of in vivo models come together as complementary tools to assess the actual capacity of a probiotic organism in a specific food, to exert functional effects regardless of the number of viable cells present at the moment of consumption.

Biased Perceptions of Income Distribution and Preferences for Redistribution: Evidence from a Survey Experiment Cruces, Guillermo Antonio; Perez Truglia, Ricardo Nicolas; Tetaz, Martin Alberto Individual perceptions of income distribution play a vital role in political economy and public finance models, yet there is little evidence regarding their origins or accuracy. This study examines how individuals form these perceptions and posits that systematic biases arise from the extrapolation of information extracted from reference groups. A tailored household survey provides original evidence on the significant biases in individuals’ evaluations of their own relative position in the distribution. Furthermore, the data supports the hypothesis that the selection process into the reference groups is the source of those biases. Finally, this study also assesses the practical relevance of these biases by examining their impact on attitudes towards redistributive policies. An experimental design incorporated into the survey provides consistent information on the own ranking within the income distribution to a randomly selected group of respondents. Confronting agents’ biased perceptions with this information has a significant effect on their stated preferences for redistribution. Those who had overestimated their relative position and thought of themselves relatively richer than they were demand higher levels of redistribution when informed of their true ranking. This relationship between biased perceptions and political attitudes provides an alternative explanation for the relatively low degree of redistribution observed in modern democracies.

Optimal Contracts with Hidden Information: An Export Consortium Case Alderete, Maria Veronica This paper analyzes the creation of an export consortium among small and medium sized enterprises (SME) by the State. A hidden information principal agent model is introduced to explain the presence of SME export consortiums. The State (principal) can not observe the random realization of the firm’s (agent) disutility from effort. We introduce a setting where the informational asymmetry is post-contractual. The contract specifies the subsidy and effort levels that result from different announcements of the state by the firm. By means of the subsidy payments, the revelation of firms’ competitiveness can be achieved. The results obtained are that subsidies are ex post inefficient and they can constraint the participation of the less competitive firms to the export consortium.

Jasmonate-induced defenses: A tale of intelligence, collaborators and rascals Ballare, Carlos Luis Plants have sophisticated defense systems to protect their tissues against the attack of herbivorous organisms. Many of these defenses are orchestrated by the oxylipin jasmonate. A growing body of evidence indicates that the expression of jasmonate-induced responses is tightly regulated by the ecological context of the plant. Ecological information is provided by molecular signals that indicate the nature of the attacker, the value of the attacked organs, phytochrome status and thereby proximity of competing plants, association with beneficial organisms and history of plant interactions with pathogens and herbivores. This review discusses recent advances in this field and highlights the need to map the activities of informational modulators to specific control points within our emerging model of jasmonate signaling.

First record of Liolaemus lentus Gallardo, 1966 (Squamata, Iguania, Liolaemini) in Río Negro province, Argentina Perez, Cristian Hernan Fulvio; Avila, Luciano Javier Se da a conocer un nuevo registro de Liolaemus lentus. Además, se amplía el área de distribución de esta especie a la provincia de Río Negro, Patagonia Argentina.

The effect of TP53 codon 72 and RNASEL codon 462 polymorphisms on the development of cervical cancer in Argentine women Barbisan, Gisela; Contreras, Anahí; Perez, Luis Orlando; Difranza, Leonardo; Golijow, Carlos Daniel Epidemiological evidence suggests that genetic factors, such as variants in cancer suppressor genes, may play an important role in the etiology of cervical carcinoma. . TP53 is an outstanding cell cycle regulator, mutated in most human cancers, and . RNASEL is thought to be involved in antiviral and apoptotic responses. To determine whether . TP53 Arg72Pro and . RNASEL Arg462Gln polymorphisms are associated with susceptibility to cervical cancer, a case-control study of 98 cancer patients and 123 healthy controls was conducted. Cervical samples were genotyped for both polymorphisms by pyrosequencing technology. The association between cervical cancer risk and the studied SNPs was evaluated by logistic regression, and potential gene-gene interactions were studied by Multifactor Dimensionality Reduction analysis. In the single-locus analysis, only the heterozygous . TP53 Arg72Pro genotype was significantly associated with the risk of developing a cervical carcinoma, while the . RNASEL polymorphism showed no association after age adjustment. In addition, the combination of both polymorphisms gives near-null information gain. Consequently, the effect provided by each single nucleotide polymorphism individually is considered higher than the effect resulting from the interaction between these two genes in cervical cancer risk. These results suggest that a heterozygous . TP53 Arg72Pro genotype may contribute to cervical cancer susceptibility.

Isolation of antibacterial components from infusion of Caesalpinia paraguariensis bark. A bio-guided phytochemical study Sgariglia, Melina Araceli; Soberon, Jose Rodolfo; Sampietro, Diego Alejandro; Quiroga, Emma Nelly; Vattuone, Marta Amelia The antimicrobial activities and toxicity of infusion, decoction and tincture of Caesalpinia paraguariensis Burk. bark (CPBEs) were investigated to validate its traditional use as drink additive and to identify microbicidal component(s). The minimum inhibitory concentrations (MIC) of CPBEs against aerobic bacteria (Gram-negative and Gram-positive species) were determined using standardised dilution methods. The LC 50 were determined by Brine Shrimp Test. CPBEs showed bacteriostatic and bactericidal activity against tested strains. The highest activity was observed for infusion (MIC:200 μg/mL) against Morganella morganii, Erwinia carotovora, Bacillus spp., Staphylococcus spp. and Enterococcus spp. The bacterial species were susceptible to CPBEs (MIC:200-1993 μg/mL) at lower concentration than sodium benzoate, a known food preservative. Two bioactive components were isolated from liophylised infusion by bio-guided chromatographic procedures; these were identified by spectrometric techniques as ellagic and 3-O-methylellagic acids. This study demonstrated that C. paraguariensis bark infusion it is safe for human consumption and a possible source of food natural preservatives.

La política latinoamericana en el Bicentenario: los avatares de la democracia Jensen, Silvina Inés A la luz de los debates en torno a los bicentenarios de la independencia, este artículo hace foco en la coyuntura de máxima impugnación democrática en la región, cuando bajo las dictaduras de la Doctrina de la Seguridad Nacional la oposición antidictatorial hizo de la defensa de los derechos más elementales de la persona su bandera de lucha y la piedra basal de la convivencia política deseada. En tal sentido analizaremos qué queda de esas luchas antidictatoriales y por la democracia de los años 1970 y 1980 de cara a ponderar qué se ha resignado y qué se ha conquistado, qué se ha consolidado y qué se ha abandonado y en qué medida los altos niveles de inequidad, pobreza y exclusión que acredita en la actualidad el subcontinente constituyen o no amenazas a la institucionalidad democrática.

The effect of economic variables over a biodiesel production plant Marchetti, Jorge Mario Biodiesel appears as one of the possible alternative renewable fuels to substitute diesel fuel derived from petroleum. Several researches have been done on the technical aspects of biodiesel production in an attempt to develop a better and cleaner alternative to the conventional process. Economic studies have been carried out to have a better understanding of the high costs and benefits of different technologies in the biodiesel industry. In this work it is studied the effect of the most important economic variables of a biodiesel production process over the general economy of a conventional plant which employs sodium methoxide as catalyst. It has been analyzed the effect of the oil price, the amount of free fatty acid, the biodiesel price, the cost of the glycerin, the effect due to the modification on the methanol price, the washing water price, and several others. Small variations on some of the major market variables would produce significant effects over the global economy of the plant, making it non profitable in some cases. © 2011 Elsevier Ltd. All rights reserved.

Singular features of trypanosomatids' phosphotransferases involved in cell energy management Pereira, Claudio Alejandro; Bouvier, León Alberto; Camara, María de los Milagros; Miranda, Mariana Reneé Trypanosomatids are responsible for economically important veterinary affections and severe human diseases. In Africa, Trypanosoma brucei causes sleeping sickness or African trypanosomiasis, while in America, Trypanosoma cruzi is the etiological agent of Chagas disease. These parasites have complex life cycles which involve a wide variety of environments with very different compositions, physicochemical properties, and availability of metabolites. As the environment changes there is a need to maintain the nucleoside homeostasis, requiring a quick and regulated response. Most of the enzymes required for energy management are phosphotransferases. These enzymes present a nitrogenous group or a phosphate as acceptors, and the most clear examples are arginine kinase, nucleoside diphosphate kinase, and adenylate kinase. Trypanosoma and Leishmania have the largest number of phosphotransferase isoforms ever found in a single cell; some of them are absent in mammals, suggesting that these enzymes are required in many cellular compartments associated to different biological processes. The presence of such number of phosphotransferases support the hypothesis of the existence of an intracellular enzymatic phosphotransfer network that communicates the spatially separated intracellular ATP consumption and production processes. All these unique features make phosphotransferases a promising start point for rational drug design for the treatment of human trypanosomiasis. © 2011 Claudio A. Pereira et al.

Characterization of the regulatory subunit of Yarrowia lipolytica cAMP-dependent protein kinase. Evidences of a monomeric protein Kronberg, Maria Florencia; Giacometti, Romina; Ruiz Herrera, Jose; Passeron, Susana cAMP-dependent protein kinase (PKA) catalytic (C) and regulatory (R) subunits from Yarrowia lipolytica are encoded by single genes, TPK1 and RKA1, respectively. Here we performed the heterologous expression, purification and characterization of the R subunit from Y. lipolytica yeast cells, and explored the main biochemical features of the PKA. The purified recombinant R, active and capable to interact with C subunit was used to prepare highly specific polyclonal antiserum. Sucrose-gradient centrifugation and gel filtration analysis of both recombinant and native R revealed the monomeric nature of this subunit. Hydrodynamic parameters of the holoenzyme indicated that Y. lipolytica PKA is a dimer of 90 kDa composed of an R subunit of 42 kDa and a C subunit of 39 kDa. The identification of the N-terminal sequence was carried out by mass spectrometry analysis of the purified native R subunit. The differences between N-terminal sequences of R subunits from Y. lipolytica and other organisms, particularly a short linker that spans the inhibitory site, were discussed as the possible cause of the lack of dimerization. R was identified as a type II subunit since our results indicated that it was phosphorylated in vivo by C at S124 identified by anti-phospho-PKA substrate (RRXS/T) antibody.

Hidrogenación de anhídrido maleico en fase gas sobre catalizadores soportados de Cu y Ni: efecto del soporte y del método de preparación Meyer, Camilo Ignacio; Regenhardt, Silvina Andrea; Bertone, Matías Ezequiel; Marchi, Alberto Julio; Garetto, Teresita Francisca Se estudió la hidrogenación de anhídrido maleico en fase gas empleando catalizadores de Cu y/o Ni, soportados sobre SiO2 y SiO2-Al2O3, preparados por impregnación a humedad incipiente y precipitación-deposición. La carga metálica total fue del orden del 10% en todos los casos. Las muestras fueron caracterizadas por DRX, RTP y quimisorción de H2. Los ensayos de actividad catalítica se llevaron a cabo en fase gas, a presión atmosférica y a temperaturas entre 170-220 ºC. Se encontró que tanto el método de preparación como el soporte influyen sobre las propiedades fisicoquímicas y la actividad catalítica de los sólidos preparados. Como consecuencia, es posible obtener catalizadores de Ni con diferente capacidad hidrogenolítica. Los catalizadores bimetálicos Cu-Ni resultaron más selectivos en la hidrogenólisis del anhídrido succínico a γ-butirolactona. Esto se atribuyo a la formación de una fase bimetálica de Cu-Ni, la cual se puede obtener más fácilmente por el método de precipitación-deposición.

Efectos de un programa de intervención para aumentar la reflexividad y la planificación en un ámbito escolar de alto riesgo por pobreza; Effects of a training program to increase reflexivity and planning in a school area at risk due to poverty Arán Filippetti, Vanessa; Richaud, Maria Cristina El propósito de este estudio fue analizar las diferencias en el estilo cognitivo reflexividad-impulsividad (R-I) y en la capacidad de planificación según el riesgo social, y poner a prueba la eficacia de un programa de intervención integrado a la tarea curricular áulica en un contexto de pobreza. Se trabajó con una muestra de 110 niños de 6 años de edad: experimental (N = 47) y control (N = 22) en riesgo por pobreza y un grupo control sin riesgo (N = 41) pertenecientes a Entre Ríos, Argentina. Los resultados indican claras diferencias en el patrón de respuestas R-I y en la planificación según el riesgo social, lo que apunta al papel de la experiencia en el desarrollo de estas funciones. Además brindan apoyo a la hipótesis que supone la posibilidad de aumentar la disposición reflexiva mediante un entrenamiento sistematizado.; The aim of this paper was to analyze the differences Reflexivity-Impulsivity in cognitive style and planning as regards social risk and to test the efficacy of a reflexivity training program integrated to the curriculum in a poverty context. We have worked with a sample of 110 6-year-old children: an experimental group (N = 47) a control group (N = 22) at risk and a control group not at risk (N = 41). All of them live in Entre Ríos, Argentina. The results indicate differences in R-I response patterns and planning in terms of social risk and emphasize the role of experience in the development of these functions. Besides, they support the hypothesis which holds the possibility to improve the reflexive disposition after program training.

Vibrio cholerae in waters of the Sunderban mangrove: relationship with biogeochemical parameters and chitin in seston size fractions Lara, Ruben Jose; Neogi, Sucharit B.; Islam, Mohammad Sirajul; Mahmud, Zahid H.; Islam, Shafiqul; Paul, Debasish; Demoz, Biniam; Yamasaki, Shinji; Nair, Gopinath B.; Kattner, Gerhard Wetland dynamics are probably linked to cholera endemicity in South Asia. We focus on links between Vibrio cholerae abundance, chitin content and suspended particle load in size fractions of suspended particulate matter (SPM) along the salinity gradient of Sunderban mangrove waters. SPM decreased downstream, while salinity increased from 0.2 to 4. Particulate organic carbon (90 ± 25 lM) and nitrogen (9.1 ± 3.3 lM) highly correlated with SPM and turbidity, suggesting a significant contribution of fine particles to organic matter. Total chitin ranged 1–2 mg/l and decreased downstream. The distribution among size fractions of SPM, chitin and V. cholerae O1 (the bacterial serogroup mainly associated with cholera epidemics) was similar, with *98% of the total in the fraction \20 lm. In comparison, the number of V. cholerae O1 attached to zooplankton and microplankton size classes [20 lm was almost negligible, in contrast to usual assumptions. Thus, microdetritus, nanoplankton and fungal cells in size classes \20 lm represent a chitinaceous substrate on which V. cholerae can grow and survive. Total bacteria, cultivable vibrios and V. cholera O1 increased 5–10 times downstream, together with salinity and nitrite concentration. Overall, nitrate and silicate concentrations were relatively constant ([22 lM N and 100 lM Si). However, nitrite increased *9 times in the outer sector, reaching *1.2 lM N, probably as a result of increased abundance of nitrate-reducing vibrios. A characterization of Vibrio habitats that takes account of the presence of nitrate-reducing bacteria could improve the understanding of both mangrove nitrogen cycling and cholera seasonality.

Can yield potential be increased by manipulation of reproductive partitioning in quinoa (Chenopodium quinoa)? Evidence from Gibberellic Acid synthesis inhibition using Paclobutrazol Gómez, María Belén; Aguirre Castro, P.; Mignone, C.; Bertero, Hector Daniel One factor conditioning quinoa (Chenopodium quinoa Willd.) adoption is the need to increase yield. This paper analyses the effect that Paclobutrazol, a GA synthesis inhibitor, produces on yield, biomass, partitioning, seed number and weight in quinoa. Two experiments were conducted under field conditions: one compared a tall genotype (2-Want) with a shorter genotype (NL-6); while the other analysed seed yield and its components using the 2-Want genotype. As a consequence of Paclobutrazol application in the one-genotype experiment, plant height decreased from 197 to 138 cm, yield increased from 517 to 791 g m–2, seed numbers rose from 308 000 to 432 000 seeds per m2, and the harvest index increased from 0.282 to 0.398 g g–1. Biomass accumulation and seed weight were not affected. The leaf area index was reduced by Paclobutrazol but radiation interception was only marginally reduced; soil plant analysis development (SPAD) values and specific leaf weight were increased, but radiation use efficiency was not affected by treatments. Root biomass and lateral roots tended to increase under Paclobutrazol treatment. Genotypes were compared until the end of flowering and similar responses were obtained. Higher yields could be obtained in quinoa if reproductive partitioning was increased, turning it into a good candidate in the search for high quality protein sources.

An extension of the Green-Ampt model to decreasing flooding depth conditions, with efficient dimensionless parametric solution Barrera, Daniel Florencio; Masuelli, Sergio The theoretical formulation of the Green-Ampt infiltration model has been extended to conditions of decreasing flooding depth in an isolated system. By defining dimensionless variables of flooding depth s and time τ, an implicit dimensionless equation τ(s) was obtained, which contains a single fundamental dimensionless parameter γ controlling the process, named “infiltration delay parameter”. The characteristics and functional behaviour of γ were analysed, and its physical meaning discussed. A parametric expression s(τ) has been obtained, which uses a unique descriptive parameter a, which in turn depends only on γ and on four generic coefficients valid for a wide range of soil properties and conditions occurring in nature. By means of numerical simulations using different values of soil parameters and initial flooding depths, it was proved that the proposed parametric function generates similar infiltration rates and cumulative storages to those that are obtained starting from Darcy's equation in the extended Green-Ampt scheme.

Diverse stages of sex-chromosome differentiation in tinamid birds: evidence from crossover analysis in Eudromia elegans and Crypturellus tataupa Pigozzi, Maria Ines All extant birds share the same sex-chromosome system: ZZ males and ZW females with striking differences in the stages of sex-chromosome differentiation between the primitive palaeognathus ratites and the large majority of avian species grouped within neognaths. Evolutionarily close to ratites is the neotropical order Tinamiformes that has been scarcely explored regarding their ZW pair morphology and constitution. Tinamous, when compared to ratites, constitute a large group among Palaeognathae, therefore, exploring the extent of homology between the Z and W chromosomes in this group might reveal key features on the evolution of the avian sex chromosomes. We mapped MLH1 foci that are crossover markers on pachytene bivalents to determine the size and localization of the homologous region shared by the Z and W chromosomes in two tinamous: Eudromia elegans and Crypturellus tataupa. We found that the homologous (pseudoautosomal) region differ significantly in size between these two species. They both have a single recombination event on the long arm of the acrocentric Z and W chromosomes. However, in E. elegans the pseudoautosomal region occupies one-fourth of the W chromosome, while in C. tataupa it is restricted to the tip of the long arm of the W. The W chromosomes in these two species differ in their heterochromatin content: in E. elegans it shows a terminal euchromatic segment and in C. tataupa is completely heterochromatic. These results show that tinamous have ZW pairs with more diversified stages of differentiation compared to ratites. Finally, the idea that the avian proto-sex chromosomes started to diverge from the end of the long arm towards the centromere of an acrocentric pair is discussed.

Vicenin-2, a potential anti-inflammatory constituent of Urtica circularis Marrassini, Carla; Davicino, Roberto Carlos; Acevedo, Cristina; Anesini, Claudia Alejandra; Gorzalczany, Susana; Ferraro, Graciela Ester Vicenin-2, a flavonoid glycoside, was isolated and identified from an ethanol extract of the aerial parts of Urtica circularis. This crude extract was found to possess significant anti-inflammatory activity in a carrageenan-induced rat hind paw edema model (41.5% inhibition at a dose of 300 mg/kg; ip). The effects of 1 on several inflammatory mediators were investigated. In cultured murine macrophages, this compound modified LPS-induced total nitrite and TNF-R production, in addition to the LPS-induced translocation of the nuclear factor NF-kB.