Ciencia y Tecnología

The Development of 'Pro-Life' NGOs in Argentina: Three strategic movements

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The Development of 'Pro-Life' NGOs in Argentina: Three strategic movements Moran Faundes, Jose Manuel Ferrucio In Latin America, the agenda of sexual and reproductive rights advocated by the feminist and LGBTI movements has challenged the hegemony of the sexual order held by traditionalist sectors, especially the hierarchy of the Catholic Church and conservative evangelical churches. These religious groups have reacted, in turn, to arrest the advance of feminist and LGBTI agendas. Beyond conservative Catholic and evangelical hierarchies, opposition activists also include religious academic institutions, politicians, Christian lay movements, and civil society groups, among others, all committed to a more restrictive view of sexuality. One important strategy of this "Pro-Life" activism in recent years has been the conformation of non-governmental organizations (NGOs). This article offers an analysis of the emergence and development of "Pro-Life" NGOs in Argentina. Using both quantitative and qualitative data, it examines three strategic movements made by these NGOs from the 1980s to the present: a state-political turn that favored strategies aimed to colonize the state and to impact sexual policies and the law; a blurring of religious identities; and a process of federalization and civil ecumenism.

Introduction: Christianity, Gender, Sexuality and the Law in Latin America

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Introduction: Christianity, Gender, Sexuality and the Law in Latin America Sáez, Macarena; Moran Faundes, Jose Manuel Ferrucio The issues of gender, sexuality and reproduction have gained a strong public presence in Latin America in recent years. Political agendas have begun gradually to include topics related to LGBTI rights and access of people "especially women " to reproductive justice. In some cases, these processes have generated policies, laws and judgments favorable to women and LGBTI movements?s demands. For example, in recent years, countries as diverse as Argentina, Uruguay, Mexico, Colombia and Brazil allowed same-sex marriage, whether through the adoption of laws or by favorable rulings, after broad political and social debates. Other countries, including Ecuador, Costa Rica and Chile, still do not recognize same-sex marriage, but have allowed civil unions. Argentina and Bolivia also adopted laws of gender identity which, among other things, guarantee the right to recognition of self-perceived identity over the one assigned at birth. Moreover, in recent years, Uruguay and the Federal District of Mexico have legalized abortion under a trimester-based system, while other countries have expanded the decriminalized grounds for terminating a pregnancy voluntarily, despite maintaining the illegality of abortion.However, the successful expansion of rights with respect to gender, sexuality and reproduction, is not a linear process or free from controversy and backlashes. In 1997, for example, El Salvador banned abortion without exception, a decision emulated by Nicaragua in 2007. In 2015, the Peruvian Congress rejected the adoption of a civil union law. In addition, since at least 1998 Latin America has seen a wave of litigation and legislative processes against emergency contraception (Peñas Defago and Morán Faúndes, 2014). Some of these have been reversed. In Chile, a law was passed in 2010 during Michelle Bachelet?s first administration (2006-2010) allowing the public health system to provide emergency contraception, which reversed an unfavorable ruling of the Constitutional Court in 2008. In Honduras and elsewhere, however, bans on emergency contraception remain.Considering the ongoing and often public controversy around these issues, it is necessary to develop and deepen the frames through which we understand how these dynamics unfold in the region. To this end, the contributors to this special issue understand gender and sexuality as public and political fields characterized by tensions, disputes and struggles over power, including state power.

¿Criadas o trabajadoras? Lenguajes, representaciones y estrategias frente a la justicia laboral (Buenos Aires, 1956-1970)

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¿Criadas o trabajadoras? Lenguajes, representaciones y estrategias frente a la justicia laboral (Buenos Aires, 1956-1970); Criadas or Workers? Languages, Representations and Strategies before Labor Justice (Buenos Aires, 1956-1970); Criadas ou travailleuses? Langages, représentations et stratégies face à la justice du travail (Buenos Aires, 1956-1970) Pérez, Inés A partir del análisis de expedientes iniciados ante el Tribunal del Trabajo Doméstico, creado en 1956, este artículo sostiene que la práctica de colocación de menores para el servicio –habitual desde tiempos coloniales– seguía siendo activa, en términos de la producción de sentidos sobre el servicio doméstico a mediados del siglo XX en Buenos Aires. El texto muestra que la “criada” era, en efecto, una de las figuras utilizadas en las contestaciones de los empleadores a las demandas iniciadas por sus empleadas, y señala algunas consecuencias de dicho uso en relación a la posibilidad de las trabajadoras de hacer efectivos los magros derechos que la ley les consagraba.; By analysing judicial files from the Tribunal of Domestic Work, created in 1956, this article argues that the practice of placing children for service –a customary practice since colonial times– remained alive regarding the production of meanings about domestic service in mid-twentieth-century Buenos Aires. The study shows that the “criada” (female child raised up for service) was one of the figures to which employers resorted in their opposing arguments to the claims initiated by their employees. The article points out some of the consequences of the use of this figure in relation to the workers‟ possibilities of making effective the meager rights that the law granted them.; En analysant les affaires judiciaires passées devant le Tribunal du Travail Domestique, créé en 1956, cet article soutient que la pratique de placement des enfants pour le service –habituelle depuis l‟époque coloniale– était toujours active, en termes de production de sens sur le service domestique au milieu du XXe siècle à Buenos Aires. Le texte montre que la “criada” était, en effet, l‟une des figures utilisées dans les contestations des employeurs aux requêtes de leurs employées. Il montre ainsi certaines conséquences de cet usage en rapport avec la possibilité pour les travailleuses de rendre effectifs les maigres droits que la loi leur octroyait.

Effect of thiosulfate on pitting corrosion of Ni-Cr-Fe alloys in chloride solutions

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Effect of thiosulfate on pitting corrosion of Ni-Cr-Fe alloys in chloride solutions Becerra Araneda, Abraham Alexis; Kappes, Mariano Alberto; Rodríguez, Martín Alejandro; Carranza, Ricardo Mario Pitting corrosion of Alloys 600, 690, and 800 (UNS N06600, N06690, and N08800) was studied in 1 M NaCl solution with different concentrations of thiosulfate (S2O2 3 −). Alloys exhibited vastly different electrochemical behavior, depending on the S2O2 3 − concentration and chromium content of the alloy. Alloy 600 exhibited a breakdown and repassivation potential that decreased with decreasing S2O2 3 − concentration, in the range from 1 M to 10−4 M. Breakdown and repassivation potentials decreased about 300 mV and 600 mV, respectively, when 10−4 M S2O2 3 − was added to a 1 M NaCl solution. For Alloys 690 and 800, additions of S2O2 3 − in the range of 1 M to 0.01 M caused a decrease in the breakdown and repassivation potentials. Dilute solutions were more aggressive, and a 0.01 M addition of S2O2 3 − to a 1 M NaCl solution caused a decrease in breakdown and repassivation potentials of about 300 mV. In a solution containing 0.001 M Na2S2O3 + 1 M NaCl, Alloys 690 and 800 showed two different submodes of pitting, each one of them existing at a different range of potential. Chloride pitting corrosion was observed at high potentials and was characterized by pits with a lacy cover. The stable pit initiation potential associated with this process in both alloys was near 300 mVAg/AgCl and was preceded by frequent metastable events. Chloride plus S2O2 3 − pitting was observed at low potentials (near −225 mVAg/AgCl) and was characterized by hemispherical pits. In potentiodynamic curves, this submode of pitting showed a characteristic anodic peak of approximately 120 mV width and a maximum current density of 10 μA/cm2 for both alloys. Potentiostatic tests at potentials within this anodic peak led to stable pit growth. Those pits could be repassivated by scanning the potential either in noble or active directions. Low-potential and high-potential pitting submodes were separated by a stable passivity range, as determined by potentiodynamic curves. Upon a further decrease in S2O2 3 − concentration down to 10−4 M, only high-potential pitting corrosion was observed, with pitting and repassivation potentials similar than those in 1 M NaCl solution.

Influence of the spatial distribution of border traps in the capacitance frequency dispersion of Al2O3/InGaAs

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Influence of the spatial distribution of border traps in the capacitance frequency dispersion of Al2O3/InGaAs Palumbo, Félix Roberto Mario; Aguirre, Fernando Leonel; Pazos, Sebastián Matías; Krylov, Igor; Winter, Roy; Eizenberg, Moshe In this paper, the capacitance frequency dispersion in strong accumulation of capacitance voltage curves has been studied for different high-k dielectric layers in MOS stacks. By studying experimental data at low (77 K) and room temperature (300 K), in oxides with different density of defects, it was possible reflect the spatial distribution of the defects in the capacitance frequency dispersion. The experimental data show that while at room temperature, the capacitance dispersion is dominated by the exchange of carriers from the semiconductor into oxide traps far away from the interface, at low temperature the oxide traps near the Al2O3/InGaAs interface are responsible for the frequency dispersion. The results indicate that the capacitance dispersion in strong accumulation reflect the spatial distribution of traps within the oxide, and that dielectric/semiconductor conduction band offset is a critical parameter for determining the capacitance dispersion for Al2O3/InGaAs based gate stacks.

Mapping a gene on wheat chromosome 4BL involved in a complementary interaction with adult plant leaf rust resistance gene LrSV2

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Mapping a gene on wheat chromosome 4BL involved in a complementary interaction with adult plant leaf rust resistance gene LrSV2 Dieguez, Maria Jose; Petignat, Camila; Ferella, Luciana; Fiorentino, Gabriela; Silva, Martha; Dabove, Marisol Alicia; Rosero Yánez, Gustavo Ivan; López, Micaela; Pergolesi, María Fernanda; Ingala, Lorena Romina; Cuyeu, Alba Romina; Sacco, Francisco Key message: A complementary gene toLrSV2for specific adult plant leaf rust resistance in wheat was mapped on chromosome 4BL, tightly linked toLr12/31. Abstract: LrSV2 is a race-specific adult plant leaf rust (Puccinia triticina) resistance gene on subdistal chromosome 3BS detected in the cross of the traditional Argentinean wheat (Triticum aestivum) variety Sinvalocho MA and the experimental line Gama6. The analysis of the cross of R46 [recombinant inbred line (RIL) derived from Sinvalocho MA carrying LrSV2 gene and the complementary gene Lrc-SV2 identified in the current paper] and the commercial variety Relmo Siriri (not carrying neither of these two genes) allowed the detection of the unlinked complementary gene Lrc-SV2 because the presence of one dominant allele of both is necessary to express the LrSV2-specific adult plant resistance. Lrc-SV2 was mapped within a 1-cM interval on chromosome 4BL using 100 RILs from the cross Sinvalocho MA × Purple Straw. This genetic system resembles the Lr27+31 seedling resistance reported in the Australian varieties Gatcher and Timgalen where interacting genes map at similar chromosomal positions. However, in high-resolution maps, Lr27 and LrSV2 were already mapped to adjacent intervals on 3BS and Lrc-SV2 map position on 4BL is distal to the reported Lr12/31-flanking microsatellites.

Two Rieske Fe/S Proteins and TAT System in Mesorhizobium loti MAFF303099: Differential Regulation and Roles on Nodulation

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Two Rieske Fe/S Proteins and TAT System in Mesorhizobium loti MAFF303099: Differential Regulation and Roles on Nodulation Basile, Laura Ana; Zalguizuri, Andrés; Briones, Carlos Gabriel; Lepek, Viviana Claudia Mesorhizobium loti MAFF303099 is a rhizobial strain that nodulates Lotus spp. A M. loti MAFF303099 mutant strain affected in the tatC gene was generated. This strain presented an altered protein secretion level to the culture supernatant and also a higher sensitivity to SDS. Its nodulation phenotype on Lotus showed the induction of small and colorless nodules, and in a larger number than those induced by the wild-type strain. In addition, these nodules presented defects in the degree of occupation by rhizobia. Two Rieske Fe/S proteins, encoded by the mll2707 and mlr0970 genes, were predicted as potential Tat substrates in M. loti MAFF303099. The transcriptional expression of mll2707 and mlr0970 genes was analyzed under different oxygen growth conditions. The mll2707 gene was expressed constitutively, while the expression of the mlr0970 gene was only detected under anaerobic and microaerophilic in vitro conditions. Both genes were down-regulated in the tatC mutant strain. mll2707 and mlr0970 mRNAs from the wild-type strain were detected in nodules. Using a translational reporter peptide fusion, we found that the Mll2707 protein was only detectable in the wild-type strain. On the other hand, although Mlr0970 protein was detected in wild-type and tatC mutant strains, its association with the membrane was favored in the wild-type strain. The tatC and the mll2707 mutant strains were affected in the cytochrome c oxidase activity. These results confirm that Mll2707 is required for cytochrome c-dependent respiration and that Tat functionality is required for the correct activity of Mll2707. The mll2707 mutant strain showed a nodulation phenotype similar to the tatC mutant strain, although it presented only a slight difference in comparison with wild-type strain in terms of nodule occupation. No defective phenotype was observed in the nodulation with the mlr0970 mutant strain. These results indicate that, of the two Rieske Fe/S proteins coded by M. loti MAFF303099, only Mll2707 expression is required for the induction of effective nodules, and that the functionality of the Tat system is necessary not only for the correct function of this protein, but also for some other protein required in an earlier stage of the nodulation process.

Optimization of β-cyclodextrin-based extraction of antioxidant and anti-browning activities from thyme leaves by response surface methodology

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Optimization of β-cyclodextrin-based extraction of antioxidant and anti-browning activities from thyme leaves by response surface methodology Favre, Leonardo Cristian; dos Santos, Cristina; Lopez Fernandez, Maria Paula; Mazzobre, Maria Florencia; Buera, Maria del Pilar Thyme (Thymus vulgaris) has been demonstrated to extend the shelf-life of food products, being also a potential source of bioactive compounds. The aim of this research was to optimize the ultrasound assisted extraction employing β-cyclodextrin aqueous solutions as no-contaminant technology and Response Surface Methodology to obtain thyme extracts with the maximum antioxidant capacity. The optimal extraction conditions were: a solution of β-ciclodextrin 15 mM, an ultrasonic treatment time of 5.9 min at a temperature of 36.6 °C. They resulted in an extract with a polyphenolic content of 189.3 mg GAE/mL, an antioxidant activity (DPPH[rad]) of 14.8 mg GAE/mL, and ferric reducing/antioxidant power (FRAP) of 3.3 mg GAE/mL. Interestingly, the extract demonstrated to inhibit the production of Maillard browning products and can be considered a potential antiglycant agent. The obtained data is important for developing eco-friendly technologies in order to obtain natural antioxidant extracts with a potential inhibitory capacity of Maillard glycation reaction.

Amyloid oligomerization of the Parkinson's disease related protein α-synuclein impacts on its curvature-membrane sensitivity

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Amyloid oligomerization of the Parkinson's disease related protein α-synuclein impacts on its curvature-membrane sensitivity Gallea, Jose Ignacio; Ambroggio, Ernesto Esteban; Vilcaes, Aldo Alejandro; James, Nicholas G.; Jameson, David M.; Celej, Maria Soledad The amyloid aggregation of the presynaptic protein α-synuclein (AS) is pathognomonic of Parkinson's disease and other neurodegenerative disorders. Physiologically, AS contributes to synaptic homeostasis by participating in vesicle maintenance, trafficking, and release. Its avidity for highly curved acidic membranes has been related to the distinct chemistry of the N-terminal amphipathic helix adopted upon binding to appropriated lipid interfaces. Pathologically, AS populate a myriad of toxic aggregates ranging from soluble oligomers to insoluble amyloid fibrils. Different gain-of-toxic function mechanisms are linked to prefibrillar oligomers which are considered as the most neurotoxic species. Here, we investigated if amyloid oligomerization could hamper AS function as a membrane curvature sensor. We used fluorescence correlation spectroscopy to quantitatively evaluate the interaction of oligomeric species, produced using a popular method based on lyophilization and rehydration, to lipid vesicles of different curvatures and compositions. We found that AS oligomerization has a profound impact on protein-lipid interaction, altering binding affinity and/or curvature sensitivity depending on membrane composition. Our work provides novel insights into how the formation of prefibrillar intermediate species could contribute to neurodegeneration due to a loss-of-function mechanism.

Resightings of Two-banded Plovers (Charadrius falklandicus) during the breeding season in coastal Chubut, Patagonia, Argentina

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Resightings of Two-banded Plovers (Charadrius falklandicus) during the breeding season in coastal Chubut, Patagonia, Argentina; Avistamientos de Chorlos Doble Collar (Charadrius falklandicus) durante el período reproductivo en la costa de Chubut, Patagonia, Argentina Hevia, Glenda Denise; Dallas Jordan, Fredrick; Terorde, Noé; Bertellotti, Néstor Marcelo; D'amico, Veronica Laura Presentamos avistamientos de Chorlos Doble Collar (Charadrius falklandicus) anillados en dos playas de la provincia de Chubut, Argentina: Playas Blancas (Península Valdés) y Playa Paraná (Puerto Madryn) separadas entre si aproximadamente 65 km en línea recta. En la temporada 2016, se capturaron y anillaron 24 individuos adultos durante la incubación. La mayoría de ellos (19, ca. 80%) fueron avistados en la temporada 2017, 17 en el mismo sitio donde fueron anillados y 2 en el otro sitio de estudio. El 32% se observó anidando mientras que, el 68% restante, se observó en el área descansando o alimentádose en forma solitaria o en bandadas mixtas con otras especies de aves playeras. Entre los individuos reproductores en 2017, dos anidaron con parejas también anilladas aunque diferentes al año anterior. Los reproductores restantes se observaron con parejas no marcadas, por lo que no se pudo evaluar si estaban apareados con el mismo individuo que en la temporada anterior. Estos resultados aportan nuevos datos sobre la biología reproductiva de esta especie que se suman a los estudios previos en la zona, sugiriendo que los Chorlos Doble Collar muestran fidelidad al sitio reproductivo.; We report resightings of individually-marked Two-banded Plovers (Charadrius falklandicus) breeding in northern Patagonia across two consecutive seasons in two beaches separated by approximately 65 km in a straight line: Playas Blancas (Península Valdés) and Playa Paraná (Puerto Madryn), Chubut province, Argentina. We captured and banded 24 adults at the nest while incubating during 2016. Nineteen banded individuals (ca. 80%) were resighted in 2017, 17 on the same site where they were banded, while 2 moved between survey sites. Only 32% were found breeding again while the remaining 68% were resighted resting or foraging, solitarily or in mixed flocks with other shorebird species. Among the resighted breeders, two adults were found paired with a different banded partner as in the previous year. The remaining breeders were paired with unbanded partners, and hence mate fidelity could not be assessed. Our findings add information to the scarce data on the breeding biology of this species suggesting that Two-banded Plovers exhibit site fidelity.

Pathogenic role of inflammatory response during Shiga toxin-associated hemolytic uremic syndrome (HUS)

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Pathogenic role of inflammatory response during Shiga toxin-associated hemolytic uremic syndrome (HUS) Exeni, Ramon Alfonso; Fernández Brando, Romina Jimena; Santiago, Adriana Patricia; Fiorentino, Gabriela Alejandra; Exeni, Andrea Mariana; Ramos, Maria Victoria; Palermo, Marina Sandra Hemolytic uremic syndrome (HUS) is defined as a triad of noninmune microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury. The most frequent presentation is secondary to Shiga toxin (Stx)-producing Escherichia coli (STEC) infections, which is termed postdiarrheal, epidemiologic or Stx-HUS, considering that Stx is the necessary etiological factor. After ingestion, STEC colonize the intestine and produce Stx, which translocates across the intestinal epithelium. Once Stx enters the bloodstream, it interacts with renal endothelial and epithelial cells, and leukocytes. This review summarizes the current evidence about the involvement of inflammatory components as central pathogenic factors that could determine outcome of STEC infections. Intestinal inflammation may favor epithelial leakage and subsequent passage of Stx to the systemic circulation. Vascular damage triggered by Stx promotes not only release of thrombin and increased fibrin concentration but also production of cytokines and chemokines by endothelial cells. Recent evidence from animal models and patients strongly indicate that several immune cells types may participate in HUS physiopathology: neutrophils, through release of proteases and reactive oxygen species (ROS); monocytes/macrophages through secretion of cytokines and chemokines. In addition, high levels of Bb factor and soluble C5b-9 (sC5b-9) in plasma as well as complement factors adhered to platelet-leukocyte complexes, microparticles and microvesicles, suggest activation of the alternative pathway of complement. Thus, acute immune response secondary to STEC infection, the Stx stimulatory effect on different immune cells, and inflammatory stimulus secondary to endothelial damage all together converge to define a strong inflammatory status that worsens Stx toxicity and disease.

Processing, structural, and biological evaluations of zirconia scaffolds coated by fluorapatite

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Processing, structural, and biological evaluations of zirconia scaffolds coated by fluorapatite León, Laura Beltina; Albano, Maria Patricia; Garrido, Liliana Beatriz; Ferraz, Emanuela; Rosa, Adalberto; Oliveira, Paulo Tambasco de Highly porous zirconia (ZrO2) scaffolds fabricated by the replication method were coated with fluorapatite (FA). The FA coating was obtained by dipping the ZrO2 scaffolds into stabilized aqueous FA slips having different viscosity values (≤5.0 mPa.s). The influence of the FA slip viscosity and the immersion time on the reduction in the scaffold porosity and microstructure of the coated scaffolds were investigated. Cell spreading and survival of bone marrow-derived stromal cells (BMSC) and pre-osteoblastic MC3T3-E1 cells on the uncoated and coated scaffolds were examined using fluorescence and SEM microscopy, and MTT assay.The FA slip with the lowest viscosity value did not lead to a continuous film along the strut network and the macropores remained uncoated. The slips with the highest viscosity value produced a partial blocking of macropores. The porous structure obtained after coating with slips of 2.2 mPa.s viscosity for 2 seconds exhibited a low reduction in porosity and pore size (400-420 μm), due to the formation of the FA layer, and a continuous film distributed along the strut surfaces. Morphology, spreading, and survival of BMSC and MC3T3-E1 cells over a 7-day culture period evidenced good biocompatibility of FA-coated ZrO2 scaffolds processed by dip coating.

Influencia de los cambios en el uso del suelo y la precipitación sobre la dinámica hídrica de una cuenca de llanura extensa. Caso de estudio: Cuenca del Río Salado, Buenos Aires, Argentina

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Influencia de los cambios en el uso del suelo y la precipitación sobre la dinámica hídrica de una cuenca de llanura extensa. Caso de estudio: Cuenca del Río Salado, Buenos Aires, Argentina; Influence of land use and rainfall changes on the water dynamics of a plain, an extensive flat river basin. Case study: The Salado River Basin, Buenos Aires, Argentina Garcia, Pablo Ezequiel; Badano, Nicolás Diego; Menendez, Angel Nicolas; Bert, Federico; García, Guillermo Ariel; Podestá, Guillermo; Rovere, Santiago; Verdin, Andrew; Rajagopalan, Balaji; Arora, Poonam La región pampeana de la República Argentina, una de las mayores llanuras del mundo, ha registrado en los últimos 50 años un fuerte ascenso en los niveles freáticos, con el consecuente aumento en la frecuencia de inundaciones. Esta dinámica tiene origen en dos procesos que se desarrollaron en ese período. En primer lugar, la zona presentó una tendencia hacia del aumento en las precipitaciones anuales. En segundo lugar se produjo un fuerte aumento del área dedicada a la agricultura, desplazando zonas con pasturas y pastizales, es decir, hubo un cambio en el uso del suelo. A través de ensayos numéricos con un modelo hidrológico (distribuido en el espacio y continuo en el tiempo, debidamente calibrado y verificado), se muestra en este trabajo que el aumento de las precipitaciones es el fenómeno que explica en mayor medida el incremento observado en los niveles freáticos, pero que la vegetación también juega un rol altamente significativo. Más aún, se pone de manifiesto la no linealidad de la respuesta del sistema hidrológico a los cambios en la precipitación y el uso del suelo, ya que la combinación de ambos efectos produce un resultado bastante inferior a la suma de cada uno de los efectos por separado. Adicionalmente, el modelo indica que existe una relación exponencial entre la profundidad de la napa y las áreas inundadas, estableciéndose una profundidad freática de 2 metros como el valor umbral a partir de la cual las áreas inundadas crecen significativamente.; The Argentine Pampas, one of the largest plains in the world, has experienced during the last 50 years a strong rise in its water table level, with a consequent increase in the frequency of floods. This dynamics is associated with two processes that took place in this zone during this period. First, the annual rainfall has shown a positive trend; and secondly, change over to field crops has expanded throughout the Pampas, displacing grasslands and pastures, so there has been a land use change. Based on numerical simulations with a properly calibrated and verified hydrological model, distributed in space and continuous in time, this paper shows that the increase in rainfall is the prime phenomenon explaining the increase in groundwater levels, but that vegetation has also played a very significant role. Moreover, the non-linear response of this hydrological system to changes in precipitation and land use was put into evidence, as the combination of both effects produces a result that is much less intense than the sum of each of the individual effects. In addition, the model indicates that there is an exponential relationship between water table depth and the flooded areas, identifying a value of 2 meters for the water table depth as a threshold below which the flooded area grows significantly.

Chemical taphonomy and preservation modes of Jurassic spinicaudatans from Patagonia: A chemometric approach

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Chemical taphonomy and preservation modes of Jurassic spinicaudatans from Patagonia: A chemometric approach Monferran, Mateo Daniel; D`angelo, José Alejandro; Cabaleri, Nora Graciela; Gallego, Oscar Florencio; Garban Gonzalez, Grony José Spinicaudatans ('clam shrimps') are small branchiopod crustaceans enclosed in a chitinous bivalved carapace that is often the only preserved element in the fossil record. However, few studies have analyzed the preservation of these carapaces, which have been found in continental facies from the Devonian to the present. The aim of this study was to contribute to a better understanding of the chemical preservation of fossil spinicaudatan carapaces, and it focused on spinicaudatan carapaces of the Cañadón Asfalto Formation from the Jurassic of Argentina. Semiquantitative energy-dispersive X-ray spectrometry (EDS) analysis provided elemental composition data that were interpreted using principal component analysis (PCA). The results showed a complex chemical mode of preservation for spinicaudatan carapaces. In some parts, EDS spectra of the specimens exhibit peaks of calcium, phosphorous, aluminum, and fluorine, representing the retention of original carapace material with some diagenetic recrystallization. Certain zones of the carapace show low-intensity peaks of the elements mentioned, while silicon and oxygen peaks (from the rock matrix) become the dominant spectral signals. These modes of preservation modify the interpretations and observations of the ornamentation of the carapace, which are used as taxonomic features. Our results suggest that specific diagenetic processes play a fundamental role in the preservation of spinicaudatans.

Implementation of standard penalty procedures for the solution of incompressible Navier–Stokes equations, employing the element-free Galerkin method

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Implementation of standard penalty procedures for the solution of incompressible Navier–Stokes equations, employing the element-free Galerkin method Álvarez Hostos, Juan Carlos; Fachinotti, Victor Daniel; Sarache Piña, Alirio Johan; Bencomo, Alfonso Daniel; Puchi Cabrera, Eli S. The present work introduces an alternative implementation of the element-free Galerkin method (EFGM) for the steady incompressible Navier-Stokes equations. The linear momentum balance and mass conservation equations have been developed on the basis of this global weak formulation. The weak forms of both equations have been coupled by means of two standard penalty procedures, which have been previously formulated and successfully employed in mesh-based numerical techniques such as the finite element method (FEM). These include the consistent penalty method (CPM) and reduced integration penalty method (RIPM). A detailed explanation concerning the characteristics inherent to the implementation of both penalty procedures in the EFGM based solutions for the incompressible Navier-Stokes equations, has also been provided. The resulting systems of equations have been adapted to the solution of different well-known incompressible flow benchmark problems. The feasibility and reliability of extending the implementation of these penalty procedures to the EFGM based solutions has been verified by comparison with the numerical techniques proposed and the results reported by other researchers. Results have revealed that this technique could be successfully used in the solution of Newtonian incompressible flow problems under the aforementioned penalty approaches.

Conformational sampling of the intrinsically disordered dsRBD-1 domain from: Arabidopsis thaliana DCL1

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Conformational sampling of the intrinsically disordered dsRBD-1 domain from: Arabidopsis thaliana DCL1 Suarez, Irina Paula; Gauto, Diego Fernando; Hails, Guillermo; Mascali, Florencia Carla; Crespo, Roberta; Zhao, Lingzi; Wang, Jin; Rasia, Rodolfo Maximiliano DCL1 is the ribonuclease that carries out miRNA biogenesis in plants. Substrate pri-miRNA recognition by DCL1 requires two double stranded RNA binding domains located at the C-terminus of the protein. We have previously shown that the first of these domains, DCL1-A, is intrinsically disordered and folds upon binding pri-miRNA. Integrating NMR and SAXS data, we study here the conformational landscape of free DCL1-A through an ensemble description. Our results reveal that secondary structure elements, corresponding to the folded form of the protein, are transiently populated in the unbound state. The conformation of one of the dsRNA binding regions in the free protein shows that, at a local level, RNA recognition proceeds through a conformational selection mechanism. We further explored the stability of the preformed structural elements via temperature and urea destabilization. The C-terminal helix is halfway on the folding pathway in free DCL1-A, constituting a potential nucleation site for the final folding of the protein. In contrast, the N-terminal helix adopts stable non-native structures that could hinder the correct folding of the protein in the absence of RNA. This description of the unfolded form allows us to understand details of the mechanism of binding-induced folding of the protein.

Elementos territoriales claves para la gestión del fuego en el Paraná medio

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Elementos territoriales claves para la gestión del fuego en el Paraná medio Castro Diaz, Ivan Ricardo; Zamboni, Lisandra Pamela; Sione, Walter Fabian; Aceñolaza, Pablo Gilberto Yogüin es la palabra Chaná para denominar el fuego: principio activo de la relación entre la ganadería y el suelo en la región. Las implicaciones ambientales de su uso afectan directamente los recursos naturales y los servicios ambientales provistos por los ecosistemas del río Paraná en su tramo medio, en donde las afectaciones por la acelerada apropiación de la tierra para la ganadería dan paso a la configuración de diversas relaciones socioterritoriales productivas, culturales y ambientales isleñas. Este artículo presenta una serie de elementos efectivos para la planificación estratégica, siendo claves para la comprensión de la problemática desde la perspectiva del desarrollo sustentable. A partir de la definición del papel del fuego en la región, se explicitan los actores territoriales involucrados en la causalidad sistémica y variables asociadas a procesos de pampeanización presentes en la dinámica del lugar.

Mechanism of Tetramer Dissociation, Unfolding, and Oligomer Assembly of Pneumovirus M2-1 Transcription Antiterminators

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Mechanism of Tetramer Dissociation, Unfolding, and Oligomer Assembly of Pneumovirus M2-1 Transcription Antiterminators Esperante, Sebastian; Álvarez Paggi, Damián Jorge; Salgueiro, Mariano; de Prat Gay, Gonzalo Among Mononegavirales, the Pneumovirus family stands out by its RNA polymerase processivity that relies on a transcription antiterminator, the M2-1 protein, which also plays a key role in viral particle assembly. Biophysical and structural evidence shows that this RNA-binding tetramer is strongly modulated by a CCCH Zn2+ binding motif. We show that while the global dissociation/unfolding free energy is 10 kcal mol-1, more stable for the respiratory syncytial virus M2-1, the human metapneumovirus (HMPV) counterpart shows a 7 kcal mol-1 higher intersubunit affinity. Removal of Zn2+ from both homologues leads to an apo-monomer of identical secondary structure that further undergoes a slow irreversible oligomerization. Mutation of the histidine residue of the Zn2+ motif to cysteine or alanine leads directly to large oligomers, strongly suggesting that metal coordination has an exquisite precision for modulating the quaternary arrangement. Zn2+ removal is very slow and requires subdenaturing concentrations of guanidine chloride, suggesting a likely local folding energy barrier. Exploring a broad combination of denaturant and ethylenediaminetetraacetic acid conditions, we showed that the metapneumovirus protein has to overcome a higher energy barrier to trigger Zn2+ removal-driven dissociation, in concordance with a slower dissociation kinetics. In silico modeling of open and close conformations for both M2-1 tetramers together with interaction energy calculations reveals that the gradual opening of protomers decreases the number of intersubunit contacts. Half of the interaction energy holding each protomer in the tetramer comes from the CCCH motif, while HMPV-M2-1 harbors additional contacts between the CCCH motif of one subunit and the core domain of a protomer located in trans, allowing the rationalization of the experimental data obtained. Overall, the evidence points at a key role of the CCCH motif in switching between structural and consequently functional alternatives of the M2-1 protein.

Interrogating pollution sources in a mangrove food web using multiple stable isotopes

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Interrogating pollution sources in a mangrove food web using multiple stable isotopes Souza, Iara da C.; Arrivabene, Hiulana P.; Craig, Carol-Ann; Midwood, Andrew J.; Thornton, Barry; Matsumoto, Silvia T.; Elliott, Michael; Wunderlin, Daniel Alberto; Monferran, Magdalena Victoria; Fernandes, Marisa N. Anthropogenic activities including metal contamination create well-known problems in coastal mangrove ecosystems but understanding and linking specific pollution sources to distinct trophic levels within these environments is challenging. This study evaluated anthropogenic impacts on two contrasting mangrove food webs, by using stable isotopes (δ13C, δ15N, 87Sr/86Sr, 206Pb/207Pb and 208Pb/207Pb) measured in sediments, mangrove trees (Rhizophora mangle, Laguncularia racemosa, Avicennia schaueriana), plankton, shrimps (Macrobranchium sp.), crabs (Aratus sp.), oysters (Crassostrea rhizophorae) and fish (Centropomus parallelus) from both areas. Strontium and Pb isotopes were also analysed in water and atmospheric particulate matter (PM). δ15N indicated that crab, shrimp and oyster are at intermediate levels within the local food web and fish, in this case C. parallelus, was confirmed at the highest trophic level. δ15N also indicates different anthropogenic pressures between both estuaries; Vitória Bay, close to intensive human activities, showed higher δ15N across the food web, apparently influenced by sewage. The ratio87Sr/86Sr showed the primary influence of marine water throughout the entire food web. Pb isotope ratios suggest that PM is primarily influenced by metallurgical activities, with some secondary influence on mangrove plants and crabs sampled in the area adjacent to the smelting works. To our knowledge, this is the first demonstration of the effect of anthropogenic pollution (probable sewage pollution) on the isotopic fingerprint of estuarine-mangrove systems located close to a city compared to less impacted estuarine mangroves. The influence of industrial metallurgical activity detected using Pb isotopic analysis of PM and mangrove plants close to such an impacted area is also notable and illustrates the value of isotopic analysis in tracing the impact and species affected by atmospheric pollution.

Biogeographic shell shape variation in trophon Geversianus (gastropoda: muricidae) along the Southwestern Atlantic coast

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Biogeographic shell shape variation in trophon Geversianus (gastropoda: muricidae) along the Southwestern Atlantic coast Malvé, Mariano Ezequiel; Rivadeneira Valenzuela, Marcelo Michel; Gordillo, Sandra Broad-scale latitudinal morphological trends in gastropods along the southwestern Atlantic coast are scant, since the majority of studies have focused on local scales. Here, we evaluate biogeographic shell shape variation in the marine gastropod Trophon geversianus across most of its distributional range, covering 14 degrees of latitude. Samples come from death assemblages which have the potential to unveil biogeographic patterns along spatio-temporal scales and are not affected by short-term volatility in comparison with living assemblages. We performed morphometric analyses on shells from death assemblages, and compared shape variation between mid-Holocene and modern shells from one southern site. Multivariate analyses identified two morphotypes matching the biogeographic regions of the Argentine Sea that segregates a warm-temperate from a cold-temperate zone. The Magellan province morphotype is characterized by a larger shell, lower spire height, and higher aperture length than the Argentinean province morphotype. This change in shell shape is significantly correlated to sea surface temperature, even after accounting for spatial autocorrelation, which could be indirectly influencing intraspecific morphoclines via shifts in growth rates. On the other side, shell size and shape variations were also detected (size increase over recent geological time) between mid-Holocene and modern specimens at the Beagle Channel, which could be attributed to paleoenvironmental changes and to shifts in predator-prey relationships. Our study illustrates the usefulness of death assemblages for revealing large-scale patterns of shell-shape variability in mollusk species, and highlights the spatial coincidence of intraspecific morphological differentiation with the transition zone between biogeographic provinces of the Argentine Sea.

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