Reshaping phenology: Grazing has stronger effects than climate on flowering and fruiting phenology in desert plants
Tadey, Mariana
Resources and climatic conditions impose bottom-up selective forces on flowering phenology, enabling flowering to occur when climatic conditions are the most suitable for reproduction. However, phenological rhythms also suffer from top-down forces imposed by herbivory, which may alter plant resources intake and allocation. I analysed the net effect of grazing and climate on phenological variables in an arid environment in northern Patagonia, using a hypothetical d-separation hierarchical path model, postulating two main pathways. One path analysed the effect of large exotic herbivores on flowering phenology and plant fitness, through plant damage. A second path estimated the effects of two main climatic variables (temperature and precipitation) on flowering phenology and plant fitness. Therefore, if climate has a stronger influence on flowering phenology than grazing, precipitation and/or temperature should show a stronger association with phenological variables than large herbivores’ density. I selected eight of the most common native plant species from seven independent rangelands located under the same environmental conditions but which differed in grazing intensity to study flowering phenology over four spring-summer seasons. I found that herbivore density had a stronger (negative) effect than climatic variables on flowering phenology affecting plant fitness. As grazing intensity increased, blooming started earlier, decreased in intensity, lasted for a shorter period of time leading to earlier fruiting. Temperature and precipitation had a positive effect on both flowering phenology and plant fitness, temperature having more influence than precipitation. My results suggest that grazing can impose top-down effects on the phenological variables and fitness of desert vegetation and that these are not counteracted by the bottom-up effects produced by climate. This illustrates a novel way through which exotic animals can affect ecosystem dynamics: by reshaping patterns of flowering phenology.
Core-corona effect in hadron collisions and muon production in air showers
Bauer, Sebastian; Dembinski, Hans; Perlin, Matias; Pierog, Tanguy; Ulrich, Ralf; Warner, Klaus
It is very well known that the fraction of energy in a hadron collision going into electromagnetic particles (electrons and photons, including those from decays) has a large impact on the number of muons produced in air shower cascades. Recent measurements at the LHC confirm features that can be linked to a mixture of different underlying particle production mechanisms such as a collective statistical hadronization (core) in addition to the expected string fragmentation (corona). Since the two mechanisms have a different electromagnetic energy fraction, we present a possible connection between statistical hadronization in hadron collisions and muon production in air showers. Using a novel approach, we demonstrate that the core-corona effect as observed at the LHC could be part of the solution for the lack of muon production in simulations of high energy cosmic rays. To probe this hypothesis, we study hadronization in high energy hadron collisions using calorimetric information over a large range of pseudorapidity in combination with the multiplicity of central tracks. As an experimental observable, we propose the production of energy in electromagnetic particles versus hadrons, as a function of pseudorapidity and central charged particle multiplicity.
Effect of crosslinking density on thermoresponsive nanogels: A study on the size control and the kinetics release of biomacromolecules
Navarro, Lucila; Theune, Loryn E.; Calderon, Marcelo
Thermoresponsive nanogels emerged as a robust and efficient platform for the delivery of a number of therapeutic agents. The need to deliver a wide range of biomolecules from different sizes requires a structural system with the ability to be tuned according to the specific applications. In this study, we design a library of nanogels using dendritic polyglycerol (dPG) as a crosslinker and poly (N-isopropyl acrylamide) as connecting thermoresponsive chains. Nanogels with diameters in a range of 70–210 nm were obtained by precipitation polymerization with low polydispersity. We provide a detailed study on how the flexibility of the network and size of the nanogels can be tuned by the modification of functionalities of the dPG, monomer feed and the size of the crosslinker. Additionally, we use different molecular weight proteins (6–66 kDa) as an indicator of the density of the structure by encapsulation and release experiments. We prove that the versatility of the system relays on the correct design of the nanogels and the careful selection of the starting materials and its final proportion in the reaction. By controlling the network density, a wider range of application can be achieved from a system with a short-term release triggered by temperature to a long-term release that could serve as reservoir platform.
La Neurología Infantil en su proyección profiláctico-social: Pediatría, Higiene Mental y Psicología en la Argentina (1934-1940); Child Neurology in its prophylactic-social projection: Pediatrics, Mental Hygiene and Psychology in Argentina (1934-1940); Neurologia Infantil em sua projeção profiláctica-social: Pediatria, Higiene Mental e Psicologia na Argentina (1934-1940)
Briolotti, Ana Soledad
Se analiza la propuesta de Aquiles Gareiso y Florencio Escardó en torno a la integración de la Neurología a la Pediatría. En momentos en los que la mayoría de los médicos concebían a la Neurología como una disciplina centrada en el diagnóstico, la propuesta de Gareiso y Escardó dialogaba con la Medicina Social, la Eugenesia y la Higiene Mental para proponer un enfoque dinámico, con potencialidades preventivas. Basada en el principio del paralelismo neuropsíquico, la Neuropediatría brindaba herramientas semiológicas para un diagnóstico temprano, hecho que excluía en principio los aportes de la Psicología. Posteriormente, dicho principio sería revisado a la luz de sus límites en la evaluación de niños a partir de los dos años de edad. Entre otros elementos, este hecho habría posibilitado una mayor apertura del campo pediátrico argentino a las técnicas de evaluación psicológica.; The article analyzes the proposal of Aquiles Gareiso and Florencio Escardó concerning the integration of Neurology into Pediatrics. In a period in which the majority of the physicians conceived Neurology as a discipline centered on diagnosis, Gareiso’s and Escardó’s proposal interacted with Social Medicine, Eugenics and Mental Hygiene to propose a dynamic focus, with preventive potentials. Based on the principle of neuropsychological parallelism, Neuropediatrics provided semiological tools for early diagnoses, excluding, initially, the contributions of Psychology. Subsequently, this principle was reviewed in light of its limits in the assessment of children aged two years and older. Among other elements, it is believed that this enabled a greater openness of the Argentinian pediatric field to psychological assessment techniques.; O artigo analisa a proposta de Aquiles Gareiso e Florencio Escardó sobre a integração da Neurologia na Pediatria. Em um período em que a maioria dos médicos concebeu a Neurologia como uma disciplina centrada no diagnóstico, a proposta de Gareiso e Escardó interagiu com a Medicina Social, Eugenia e Higiene Mental para propor um foco dinâmico, com potencialidades preventivas. Baseada no princípio do paralelismo neuropsicológico, a Neuropediatria forneceu ferramentas semiológicas para diagnósticos precoces, excluindo, inicialmente, as contribuições da Psicologia. Posteriormente, esse princípio foi revisado à luz de seus limites na avaliação de crianças com dois anos ou mais. Entre outros elementos, acredita-se que isso permitiu uma maior abertura do campo pediátrico argentino às técnicas de avaliação psicológica.
El debate acerca del desarrollo agropecuario argentino: la mirada de la intelectualidad trotskista; O debate sobre o desenvolvimento agrícola argentino: o olhar da intelectualidade de trotskist; The debate about argentine agricultural development: the look of trotskist intellectuality
Lissandrello, Guido Axel
A partir de la década de 1950 en toda América Latina y, con particular fuerza en la Argentina, se reactualizó el debate acerca del desarrollo y el subdesarrollo. Una página particular de esa discusión fue reservada a los problemas de la producción agropecuária y las trabas a su desarrollo. La bibliografía hasta ahora disponibles, se han concentrado en este debate privilegiando una serie de actores: los partidos políticos, las corporaciones rurales e industriales y los intelectuales que abordaron el problema en la etapa. Sin embargo, aún está pendiente un estudio acerca del tratamiento que esta problemática recibió en organizaciones e intelectuales filiados en las tradiciones políticas de izquierda. Intentando comenzar a subsanar ese déficit, nos proponemos abordar esta problemática acerca del desarrollo agrario argentino a partir de las interpretaciones elaboradas por un intelectual de izquierda filiado en la tradición del trotskismo: Milcíades Peña. En este sentido, nos interesa indagar si esta posición política radical lo llevó a elaborar una corriente que terciara entre las explicaciones liberales y agrarias, o si, por el contrario, quedó preso de alguna de ellas. Para ello, estudiamos los artículos escritos por este autor en su revista de debate intelectual, llamada Fichas.; A partir da década de 1950 em toda a América Latina e, com particular força na Argentina, o debate sobre desenvolvimento e subdesenvolvimento foi atualizado. Uma página específica dessa discussão foi reservada para os problemas da produção agrícola e os obstáculos ao seu desenvolvimento. A bibliografia disponível até o momento se concentrou nesse debate, privilegiando vários atores: partidos políticos, corporações rurais e industriais e intelectuais que abordaram o problema no estágio. No entanto, ainda está pendente um estudo sobre o tratamento que esse problema recebeu em organizações e intelectuais afiliados às tradições políticas de esquerda. Tentando começar a corrigir esse déficit, propomos abordar esse problema sobre o desenvolvimento agrícola argentino a partir das interpretações elaboradas por um intelectual de esquerda filmado na tradição do trotskismo: Milcíades Peña. Nesse sentido, estamos interessados em indagar se essa posição política radical o levou a elaborar uma corrente terciária entre explicações liberais e agrárias, ou se, pelo contrário, ele estava preso em uma delas. Para isso, estudamos os artigos escritos por esse autor em sua revista de debate intelectual, chamada Fichas.; From the 1950s throughout Latin America and, with particular strength in Argentina, the debate about development and underdevelopment was updated. A particular page of that discussion was reserved for the problems of agricultural production and the obstacles to its development. The bibliography so far available, have focused on this debate by privileging a number of actors: political parties, rural and industrial corporations and intellectuals who addressed the problem at the stage. However, a study is still pending on the treatment that this problem received in organizations and intellectuals affiliated with left-wing political traditions. Trying to begin to correct this deficit, we propose to address this problem about the Argentine agricultural development from the interpretations elaborated by a leftist intellectual filmed in the tradition of Trotskyism: Milcíades Peña. In this sense, we are interested in inquiring whether this radical political position led him to elaborate a current that tertiary between liberal and agrarian explanations, or if, on the contrary, he was imprisoned in one of them. To do this, we study the articles written by this author in his intellectual debate magazine, called Fichas.
An event of simultaneous activity of atmospheric gravity waves and meteotsunami in the inner continental shelf of the Buenos Aires Province, Argentina
Perez, Iael; Dragani, Walter Cesar; Saucedo, Marcos Adolfo; Godoy, Alejandro Anibal; Cerne, Silvia Bibiana
The aim of this paper is to investigate an event of simultaneous activity of atmospheric gravity waves (AGW) and meteotsunami recorded on December 1–2, 2013, in the inner continental shelf of Buenos Aires Province, Argentina. The Weather Research and Forecasting (WRF) model was implemented to simulate high-frequency atmospheric disturbances. WRF outputs were used to drive an oceanic model (Tide And Wind Induced Circulation, TAWIC) to reproduce the observed meteotsunami. WRF model was validated using twenty-five data series of atmospheric pressure, and a high-resolution atmospheric pressure data series observed at Mar del Plata. TAWIC model was validated using a high-resolution sea-level data series recorded at Mar del Plata. WRF model was able to capture the main synoptic and mesoscale features during the simulated period. Wavelet and cross-wavelet analysis showed that the spectral structures of the AGW and meteotsunami were satisfactorily simulated. AGW propagated following the storm track, and its activity area was mainly bounded between Mar del Plata and Punta Médanos. Numerical simulations showed that the meteotsunami was practically negligible westwards Quequén Port and at the Río de la Plata mouth, and that it was amplified when the AGW propagated along the coast. Numerical results suggest that the meteotsunami can be seen like an ocean edge wave propagating along the coast of the Buenos Aires Province.
Effects of Fusarium graminearum and Fusarium poae on disease parameters, grain quality and mycotoxin contamination in barley (Part II)
Martínez, Mauro; Ramirez Alburquerque, Lady D.; Dinolfo, María Inés; Biganzoli, Fernando; Fernández Pinto, Virginia; Stenglein, Sebastian Alberto
Barley is one of the most important winter crops in the world, withmultiple uses such as human consumption, animal feed and for the malting industry. This crop is affected by different diseases, such as Fusarium Head Blight (FHB), that causes losses in yield and quality. In the last years F. graminearum and F. poae were two of the most frequently isolated species in barley grains, so the aim of this study was to evaluate the interaction between these Fusarium species and the effects on disease parameters, grain quality and mycotoxin contamination on five barley genotypes under field conditions.RESULTS: Statistical differences between Fusarium treatments for some parametersdepending mainly on the year/genotype were found. The results showed that germination process was affected by both Fusarium species. As to grain quality and the different hordein fractions, it was observed that F. graminearum affects preferentially D and Chordeins Different concentrations of nivalenol, deoxynivalenol and their acetylated derivatives (3-ADON and 15-ADON) were detected.CONCLUSIONS: In the present work, no evidence of synergism between F.graminearum and F. poae were found regarding disease parameters and mycotoxincontamination. However, at least in the years with favorable climatic conditions to FHB development and depending on the barley genotype, a continuous monitoring is deemed necessary to prevent the negative impact on protein composition and germinative parameters.
A Penicillin Derivative Exerts an Anti-Metastatic Activity in Melanoma Cells Through the Downregulation of Integrin αvβ3 and Wnt/β-Catenin Pathway
Barrionuevo, Alejandra Elizabeth; Cayrol, Maria Florencia; Cremaschi, Graciela Alicia; Cornier, Patricia Griselda; Boggian, Dora Bernarda; Delpiccolo, Carina Maria Lujan; Mata, Ernesto Gabino; Roguin, Leonor Patricia; Blank, Viviana Claudia
The synthetic triazolylpeptidyl penicillin derivative, named TAP7f, has been previously characterized as an effective antitumor agent in vitro and in vivo against B16-F0 melanoma cells. In this study, we investigated the anti-metastatic potential of this compound on highly metastatic murine B16-F10 and human A375 melanoma cells. We found that TAP7f inhibited cell adhesion, migration and invasion in a dose-dependent manner. Additionally, we demonstrated that TAP7f downregulated integrin αvβ3 expression and Wnt/β-catenin pathway, a signaling cascade commonly related to tumor invasion and metastasis. Thus, TAP7f reduced both the enzymatic activity and the expression levels of matrix-metalloproteinases-2 and -9 in a time dependent manner. Moreover, TAP7f inhibited the expression of the transcription factor Snail and the mesenchymal markers vimentin, and N-cadherin, and up-regulated the expression of the epithelial marker E-cadherin, suggesting that the penicillin derivative affects epithelial–mesenchymal transition. Results obtained in vitro were supported by those obtained in a B16-F10-bearing mice metastatic model, that showed a significant TAP7f inhibition of lung metastasis. These findings suggest the potential of TAP7f as a chemotherapeutic agent for the treatment of metastatic melanoma.
Assessment of high-frequency steady-state visual evoked potentials from below-the-hairline areas for a brain-computer interface based on Depth-of-Field
Floriano, Alan; Delisle Rodriguez, Denis; Diez, Pablo Federico; Bastos Filho, Teodiano Freire
Background and Objective: Recently, a promising Brain-Computer Interface based on Steady-State Visual Evoked Potential (SSVEP-BCI) was proposed, which composed of two stimuli presented together in the center of the subject's field of view, but at different depth planes (Depth-of-Field setup). Thus, users were easily able to select one of them by shifting their eye focus. However, in that work, EEG signals were collected through electrodes placed on occipital and parietal regions (hair-covered areas), which demanded a long preparation time. Also, that work used low-frequency stimuli, which can produce visual fatigue and increase the risk of photosensitive epileptic seizures. In order to improve the practicality and visual comfort, this work proposes a BCI based on Depth-of-Field using the high-frequency SSVEP response measured from below-the-hairline areas (behind-the-ears). Methods: Two high-frequency stimuli (31 Hz and 32 Hz) were used in a Depth-of-Field setup to study the SSVEP response from behind-the-ears (TP9 and TP10). Multivariate Spectral F-test (MSFT) method was used to verify the elicited response. Afterwards, a BCI was proposed to command a mobile robot in a virtual reality environment. The commands were recognized through Temporally Local Multivariate Synchronization Index (TMSI) method. Results: The data analysis reveal that the focused stimuli elicit distinguishable SSVEP response when measured from hairless areas, in spite of the fact that the non-focused stimulus is also present in the field of view. Also, our BCI shows a satisfactory result, reaching average accuracy of 91.6% and Information Transfer Rate (ITR) of 5.3 bits/min. Conclusion: These findings contribute to the development of more safe and practical BCI.
Acciones didácticas en el desarrollo de un recorrido de estudio y de investigación que involucra a la matemática y a la física en la escuela secundaria.; Didactic Actions in the Development os a Study and Research Path That Involves Mathematics and Physics in Secondary School
Gazzola Bascougnet, María Paz; Otero, Maria Rita; Llanos, Viviana Carolina
En este trabajo se presentan resultados sobre el desarrollo de un Recorrido de Estudio y de Investigación (REI) que involucra a la Matemática y a la Física, a partir de las acciones o gestos didácticos propuestos por la Teoría Antropológica de lo Didáctico (TAD) como propios de un REI, llamados dialécticas (Chevallard, 2013a). El REI fue implementado en cinco cursos de Matemática en escuelas secundarias con N=116 estudiantes en total. Se emplean técnicas cualitativas de análisis y metaanálisis de datos para construir una categorización inductiva conforme al uso de técnicas cuantitativas de estadística multivariada. Los resultados muestran las dificultades del desarrollo de estos gestos en el aula y permiten interpretar la existencia de un funcionamiento conjunto de ciertas dialécticas, puesto que el aumento de frecuencia de ocurrencia de algunas se corresponde con el aumento de las otras.; This paper presents results on the development of a Study and Research Path (SRP) that involves mathematics and physics, from the didactic actions or gestures proposed by the Anthropological Theory of the Didactic (ATD) as typical of a SRP, called dialectics (Chevallard, 2013a). The SRP was implemented in five secondary school math courses with N=116 students in total. Qualitative techniques for data analysis and meta-analysis are used to construct an inductive categorization according to the use of multivariate quantitative techniques. The results show the difficulties of the development of these gestures in the classroom and allow to interpret the existence of a joint operation of certain dialectics, since the increase in the frequency of occurrence of some corresponds to the increase in the others.
La mégafaune: splendeur et décadence
Boivin, Myriam; Pujos, François Roger Francis; Antoine, Pierre Olivier
Le gigantisme est l'un des traits les plus inattendus de la faune disparue des néotropiques. Tortues et chinchillas semblent tout autant pris de démesure que le célèbre paresseux géant. Éteints il ny a que quelques milliers d'nnées, ces géants ont côtoyé lhomme
Virulence and pCM1 plasmid carriage are related to BOX-PCR fingerprint type in strains of Clavibacter michiganensis subsp. michiganensis that cause bacterial wilt and canker of tomato in Argentina
Wassermann, Eliana; Montecchia, Marcela Susana; Garaventa, Valeria Soledad; Correa, Olga Susana; Romero, Ana María
Clavibacter michiganensis subsp. michiganensis (Cmm) causes bacterial wilt and canker in tomato, producing important economic losses worldwide. Its virulence has been related to several putative virulence factors present on a chromosomal pathogenicity island and on plasmids pCM1 and pCM2, in strain NCPPB382. We genotypically characterized a collection of Cmm isolates from the main greenhouse tomato-producing areas of Argentina by BOX-PCR fingerprinting and screened for the presence of genes and plasmids involved in pathogenicity by PCR. In addition, we evaluated in vitro cellulolytic activity and virulence in planta of selected strains. BOX-PCR fingerprinting clustered strains into four groups. Group II was dominant and included the most virulent strains, while Group III was the smallest and had the least virulent strains. All local strains exhibited similar cellulolytic activity. Most of the examined strains carry two plasmids of similar size to those of NCPPB382, although there were strains with one or three plasmids. By PCR amplification of repA, pCM1 was detected only in strains belonging to Group III, which includes local strains closely related to reference strain NCPPB382. All analysed pathogenicity genes were widespread among strains, and so in strains belonging to Groups I and II, celA found on pCM1 in NCPPB382 could be found in the chromosome or in plasmids other than pCM1. This study contributes to a better understanding of the diversity of Cmm genetic profiles and virulence of strains present in Argentina. Such information could be useful for the selection of strains for screening of host resistance and development of resistant tomato varieties.
IMA Commission on New Minerals, Nomenclature and Classification (CNMNC), Newsletter 53: IMA No. 2019-085
Biglia, Marco Esteban; Cooper, Mark A.; Grew, Edward S.; Sfragulla, Jorge Alberto; Márquez Zavalía, María Florencia; Guereschi, Alina Beatriz; Yates, Martin G.; Galliski, Miguel Angel
Liraite NaCa2Mn2+ 2 [Fe3+Fe2+]Mn2+ 2 (PO4)6(H2O)2 Ceferino Namuncurá pegmatite, Pocho Department, Córdoba Province, Argentina (31◦370 4500 S, 65◦150 0300 W)
How to explicitly calculate Feynman and Wheeler propagators in the ADS/CFT https://ri.conicet.gov.ar/admin/static/img/broom.pngcorrespondence
Plastino, Ángel Luis; Rocca, Mario Carlos
We discuss, giving all necessary details, the boundary-bulk propagators. We do it for a scalar field, with and without mass, for both the Feynman and the Wheeler cases. Contrary to standard procedure, we do not need here to appeal to any unfounded conjecture (as done by other authors). Emphasize that we do not try to modify standard ADS/CFT procedures, but use them to evaluate the corresponding Feynman and Wheeler propagators. Our present calculations are original in the sense of being the first ones undertaken explicitly using distributions theory (DT). They are carried out in two instances: 1) when the boundary is a Euclidean space and 2) when it is of Minkowskian nature. In this last case we compute also three propagators: Feynman’s, Anti-Feynman’s, and Wheeler’s (half advanced plus half retarded). For an operator corresponding to a scalar field we explicitly obtain, for the first time ever, the two points’ correlations functions in the three instances above mentioned. To repeat, it is not our intention here to improve on ADS/CFT theory but only to employ it for evaluating the corresponding Wheeler’s propagators.
Toward the detection of permafrost using land-surface temperature mapping
Batbaatar, Jigjidsurengiin; Gillespie , Alan R.; Sletten, Ronald S.; Mushkin , Amit; Amit, Rivka; Trombotto, Dario Tomas; Liu , Lu; Petrie, Gregg
Permafrost is degrading under current warming conditions, disrupting infrastructure, releasing carbon from soils, and altering seasonal water availability. Therefore, it is important to quantitatively map the change in the extent and depth of permafrost. We used satellite images of land-surface temperature to recognize and map the zero curtain, i.e., the isothermal period of ground temperature during seasonal freeze and thaw, as a precursor for delineating permafrost boundaries from remotely sensed thermal-infrared data. The phase transition of moisture in the ground allows the zero curtain to occur when near-surface soil moisture thaws or freezes, and also when ice-rich permafrost thaws or freezes. We propose that mapping the zero curtain is a precursor to mapping permafrost at shallow depths. We used ASTER and a MODIS-Aqua daily afternoon land-surface temperature (LST) timeseries to recognize the zero curtain at the 1-km scale as a "proof of concept. " Our regional mapping of the zero curtain over an area around the 7000 m high volcano Ojos del Salado in Chile suggests that the zero curtain can be mapped over arid regions of the world. It also indicates that surface heterogeneity, snow cover, and cloud cover can hinder the effectiveness of our approach. To be of practical use in many areas, it may be helpful to reduce the topographic and compositional heterogeneity in order to increase the LST accuracy. The necessary finer spatial resolution to reduce these problems is provided by ASTER (90 m).
Relationship between Formulation, Gelation Kinetics, Micro/Nanostructure and Rheological Properties of Sodium Caseinate Nanoemulsion-Based Acid Gels for Food Applications
Montes de Oca Avalos, Juan Manuel; Borroni, Maria Virginia; Huck Iriart, Cristián; Navarro, Alba Sofia del Rosario; Candal, Roberto Jorge; Herrera, Maria Lidia
Legislation and concerns about health effects of trans and saturated fatty acids have led to elimination or reduction of them in foods formulation. One of the alternatives for structuring food with healthy ingredients is using food-grade biopolymers such as proteins or polysaccharides to formulate hydrogels. The aim of the present work was to study the relationship among formulation, gelation kinetics, structure, and rheological properties of sodium caseinate (NaCas)/sunflower oil hydrogels prepared from nanoemulsions. NaCas was used as stabilizer in concentrations of 1, 2, 3, or 4 wt.%. Sucrose was also added in 2, 4, 6, or 8 wt.% to the 4-wt.% nanoemulsion. Gelation kinetics was studied by two methods: oscillatory rheometry and Turbiscan. Although gelation time values were significantly different between methods, tendencies were similar: values decreased with increasing protein and sucrose contents. However, the most influential factor on gelation time was the ratio glucono-delta-lactone (GDL)/NaCas. Structure was analyzed by confocal laser scanning microscopy and synchrotron X-ray microtomography. Low-protein content hydrogels (1 or 2 wt.%) had an inhomogeneous structure containing nano- and conventional-size droplets while the 4-wt.% hydrogel kept the initial structural characteristics: homogeneity in dispersed phase distribution and non-aggregated nanodroplets. Sucrose improved structure in terms of homogeneity. Analyses of X-ray microtomoghraphy data showed that while the porosity diminished, the wall width increased with increasing protein and sucrose contents. The hydrogel formulated with 4 wt.% NaCas and 8 wt.% sucrose showed a structure with nanodroplets evenly distributed and the highest G′∞ values of all hydrogels.
Study of the antitumour effects and the modulation of immune response by histamine in breast cancer
Nicoud, Melisa Beatriz; Sterle, Helena Andrea; Massari, Noelia Andrea; Táquez Delgado, Mónica Alejandra; Formoso, Karina; Herrero Ducloux, María Verónica; Martinel Lamas, Diego José; Cremaschi, Graciela Alicia; Medina, Vanina Araceli
Background: The aim of this work was to improve the knowledge of the role of histamine in breast cancer by assessing the therapeutic efficacy of histamine and histamine H4 receptor (H4R) ligands in a triple-negative breast cancer (TNBC) model developed in immunocompetent hosts. By using publicly available genomic data, we further investigated whether histidine decarboxylase (HDC) could be a potential biomarker. Methods: Tumours of 4T1 TNBC cells were orthotopically established in BALB/c mice. Treatments employed (mg kg−1): histamine (1 and 5), JNJ28610244 (H4R agonist, 1 and 5) and JNJ7777120 (H4R antagonist, 10). Results: Increased HDC gene expression is associated with better relapse-free and overall survival in breast cancer patients. Histamine treatment (5 mg kg−1) of 4T1 tumour-bearing mice reduced tumour growth and increased apoptosis. Although no immunomodulatory effects were observed in wild-type mice, significant correlations between tumour weight and cytotoxic lymphocyte infiltration were detected in H4R knockout mice. H4R agonist or antagonist differentially modulated tumour growth and immunity in 4T1 tumour-bearing mice. Conclusions: Histamine plays a complex role and stands out as a promising drug for TNBC treatment, which deserves to be tested in clinical settings. HDC expression level is associated with clinicopathological characteristics, suggesting a prognostic value in breast cancer.
Analysis of mitochondrial enzymatic activity in blood lymphomonocyte fractions during infection with different Trypanosoma cruzi strains
Báez, Alejandra Lidia; Lo Presti, Maria Silvina; Bazán, Paola Carolina; Strauss, Mariana; Velázquez López, Daniela Alejandra; Miler, Noemí del Carmen; Rivarola, Hector Walter; Paglini, Patricia Adriana
Proinflammatory and inflammatory mediators induced by Trypanosoma cruzi infection increase the oxidative stress, generating toxicity for cells targeting mitochondria of different tissues. We studied the activity of citrate synthase and complexes I-IV of respiratory chain in mitochondria of blood lymphomonocyte fraction, from albino Swiss mice infected with different isolates of T. cruzi, during Chagas disease evolution. Complexes I-IV were modified in infected groups (p<0.05) in all the stages, and an inflammatory process of different magnitudes was detected in the heart and skeletal muscle according to the isolate. The citrate synthase activity presented modifications in the SGO Z12 and the Tulahuen group (p<0.05). Hearts showed fiber fragmentation and fibrosis; skeletal muscle presented inflammatory infiltrates and in the Tulahuen infected group, there were also amastigote nests. The inflammatory processes produced an oxidative stress that induced different alterations of mitochondrial enzymes activities in the lymphomonocyte fraction that can be detected by a simple blood extraction, suggesting that they could be used as disease markers, especially in the indeterminate phase of Chagas disease.
¿Hacia la regulación postburocrática de los sistemas educativos latinoamericanos?: Un análisis del discurso de los organismos multilaterales de la región en el período 2012-2018; Rumo à regulação pós-burocrática dos sistemas educacionais latino-americanos?: Uma análise do discurso dos organismos multilaterais da região no período 2012-2018; Towards post-bureaucratic regulation of Latin American educational systems?: Analizing the discourse of regional multilateral organizations in the 2012-2018 period
Gorostiaga, Jorge Manuel
El objetivo de este artículo es analizar de qué manera y en qué medida la retórica de los organismos multilaterales se alinea con la promoción de los modelos de regulación postburocráticos de la educación en el contexto latinoamericano. Enmarcado en la teoría de la regulación y en la noción de campo global de política educativa, este artículo busca contribuir a comprender el componente discursivo de la regulación transnacional. Se analizan documentos auspiciados por tres organismos multilaterales de nivel regional publicados entre 2012 y 2018: la Oficina Regional de Educación para América Latina y el Caribe de la Organización de las Naciones Unidas para la Educación, la Ciencia y la Cultura (OREALC/UNESCO), el Banco Interamericano de Desarrollo (BID) y la Organización de Estados Iberoamericanos para la Educación, la Ciencia y la Cultura (OEI). El foco está puesto en comprender cómo se articula el discurso de estas agencias sobre el gobierno de la educación, así como sus vinculaciones con el contexto de producción y su carácter político, en el sentido de que expresa recomendaciones basadas en valores y no meramente técnicas. Se busca identificar los temas y enfoques dominantes, pero también las contradicciones, las variaciones, diferentes énfasis y planteos alternativos.; O objetivo deste artigo é analisar como e em que medida a retórica das organizações multilaterais se alinha com a promoção de modelos de regulação pós-burocrática da educação no contexto latino-americano. Enquadrado na teoria da regulação e da noção de campo global da política educacional, este artigo pretende contribuir para a compreensão do componente discursivo da regulação transnacional. Analizan-se documentos patrocinados por três agências multilaterais da região publicados entre 2012 e 2018: a Oficina Regional de Educação para a América Latina e o Caribe da Organização das Nações Unidas para a Educação, a Ciência e a Cultura (OREALC/UNESCO), o Banco Interamericano de Desenvolvimento (BID) e a Organização dos Estados Ibero-Americanos para a Educação, a Ciência e a Cultura (OEI). O foco é sobre a compreensão de como se articula o discurso dessas agências sobre o governo da educação, suas ligações com o contexto de produção e seu caráter político, no sentido que expressa recomendações com base em valores e não apenas técnicas. Procura-se identificar os temas e abordagens dominantes, e também as contradições, variações, ênfases diferentes e abordagens alternativas.; The objective of this article is to analyze how and to what extent the rhetoric of multilateral organizations are aligned with the promotion of models of post-bureaucratic regulation of education in the Latin American context. Framed in the theory of regulation and in the notion of a global field of educational policy, this article seeks to contribute to the understanding of the discursive component of transnational regulation. Documents sponsored by three regional multilateral organizations published between 2012 and 2018 are analyzed: the Regional Bureau for Education in Latin America and the Caribbean (OREALC/UNESCO), the Inter-American Development Bank (IDB) and the Organization of Ibero-American States for Education, Science and Culture (OEI). The focus is on understanding how the discourse of these agencies is articulated on the government of education, as well as its links with the production context and its political character, in the sense that it expresses recommendations based on values and not merely techniques. It seeks to identify the dominant themes and approaches, and also the contradictions, variations, different emphases and alternative views.
Understanding atmospheric methane sub-seasonal variability over India
Tiwari, Yogesh K.; Guha, Tania; Valsala, Vinu; Saiz López, Alfonso; Cuevas, Carlos; Fernandez, Rafael Pedro; Mahajan, Anoop S.
Atmospheric methane (CH4) is considered to be one of the most important greenhouse gases due to its increasing atmospheric concentrations and the fact that it has a warming potential 28 times that of atmospheric carbon dioxide (CO2). Over the Indian sub-continent, fluxes and transport both contribute towards CH4 seasonal variability. Its intra-seasonal variability however is more complex as it is additionally influenced by monsoonal activity during the Asian Summer Monsoon (ASM) period. In this study, the intra-seasonal variability of atmospheric CH4 is examined using ground-based observations at two sites located in the Southern Indian Peninsula, Sinhagad (SNG) and Cape Rama (CRI); and outputs from three different model simulations. Both, the ground based observations and multi-model simulations show that the dominant spectral variability of CH4 is coherent with 20–90 day oscillations in the dynamics of the monsoon (termed hereafter as Intra-Seasonal Oscillations, ISOs). The multi-model analysis revealed that CH4 is heavily influenced by advection due to this intra-seasonal variability. The simulations also display a clear northward propagation of CH4 anomalies over India. The coevolution of CH4, outgoing long wave radiation (to represent convection) and OH radicals (proxy to CH4 sinks) is presented. The study quantifies CH4 variability at intra-seasonal timescales and also its spatial extent. The results suggest that the effect of ISOs on CH4 needs to be considered along with the corresponding observations for future inverse modeling.