Search

The article explores Chilean folk singer, Violeta Parra's relationship with Chilean popular poetry, particularly the tradition of religious-themed verses. It discusses how Violeta engaged with folk poetry and how her brother, Nicanor, played a crucial role in her exploration of the popular poetic traditions of Chile. It also delves into the spiritual aspects of Violeta's work, highlighting her complex relationship with religion and the church.

Abstract: Volumetrically minor microsyenites, alkali microgranite and related trachytic dykes intrude early Pliocene OIB-like alkali basaltic and basanitic flows of the Meseta del Lago Buenos Aires in Central Patagonia (47°S–71°30′W), and occur together with scarce trachytic lava flows. Whole-rock K–Ar ages between 3.98 and 3.08 Ma indicate that the emplacement of these felsic rocks occurred more or less synchronously with that of the post-plateau basaltic sequence that they intrude, during a bimodal mafic–felsic magmatic episode devoid of intermediate compositions. Chemically, these rocks have A1-type granitoid affinities and are characterized by high silica and alkali contents (60–68 wt.% SiO2; 8.7–10.8 wt.% Na2O+K2O), major and trace elements patterns evidencing evolution by low-pressure fractional crystallization, and Sr and Nd isotopic signatures similar to those of coeval basalts ((87Sr/86Sr)o =0.70488–0.70571; (143Nd/144Nd)o =0.512603–0.512645). Nevertheless, some of them have the most radiogenic Sr values ever reported for a magmatic rock in the Meseta and even in the whole Neogene Patagonian Plateau Lavas province ((87Sr/86Sr)o =0.70556–0.70571; (143Nd/144Nd)o =0.512603–0.512608). In addition, very high contents of strongly incompatible elements in the most evolved rocks, together with Sr isotopic ratios higher than those of coeval basalts, suggest the occurrence of open-system magmatic processes. Continuous fractional crystallization from a primitive basaltic source, similar to post-plateau coeval basalts, towards alkali granites combined with small rates of assimilation of host Jurassic tuffs (AFC) in a shallow magmatic reservoir, best explains the geochemical and petrographic features of the felsic rocks. Therefore, A1-type magmatic rocks can be generated by open-system crystallization of deep asthenospheric melts in back-arc tectonic settings. In Central Patagonia, these ∼3–4 Ma old alkaline intrusions occur aligned along a ∼N160–170 trending lineament, the Zeballos Fault Zone, stacking the morphotectonic front of one segment of the Patagonian Cordillera. Intrusion along this fault zone occurred during the onset of a new transtensional or extensional event in the area, related to major regional tectonics occurring in possible relation with the collision of one segment of the Chile Spreading Ridge with the trench. [Copyright &y& Elsevier]

Genetic algorithms allow solution of more complex, nonlinear civil, and environmental engineering problems than traditional gradient-based approaches, but they are more computationally intensive. One way to improve algorithm performance is through inclusion of local search, creating a hybrid genetic algorithm (HGA). The inclusion of local search helps to speed up the solution process and to make the solution technique more robust. This paper focuses on the effects of different local search algorithms on the performance of two different HGAs developed in previous phases of this research, the self-adaptive hybrid genetic algorithm (SAHGA) and the enhanced SAHGA. The algorithms are tested on eight test functions from the genetic and evolutionary computation literature and a groundwater remediation design case study. The results show that the selection of the local search algorithm to be combined with the simple genetic algorithm is critical to algorithm performance. The best local search algorithm varies for different problems, but can be selected prior to solving the problem by examining the reduction in fitness standard deviation associated with each local search algorithm, and the time distribution associated to the local search algorithm. [ABSTRACT FROM AUTHOR]

Abstract: The Meseta Chile Chico (MCC, 46.4°S) is the westernmost exposure of Eocene (lower basaltic sequence, LBS; 55–40 Ma, K–Ar ages) and Mio–Pliocene (upper basaltic sequence, UBS; 16–4 Ma, K–Ar ages) flood basalt volcanism in Patagonia. The MCC is located south of the Lago General Carrera-Buenos Aires (LGCBA), southeast from the present day Chile Triple Junction (CTJ), east of the actual volcanic gap between Southern South Volcanic Zone and Austral Volcanic Zone (SSVZ and AVZ, respectively) and just above the inferred location of the South Chile Ridge segment subducted at ∼6 Ma (SCR-1). Erupted products consist of mainly ne-normative olivine basalt with minor hy-normative tholeiites basalt, trachybasalt and basanite. MCC lavas are alkaline (42.7–53.1 wt.% SiO2, 3–8 wt.% Na2O+K2O) and relatively primitive (Ni: 133–360 ppm, Cr: 161–193 ppm, Co: 35–72 ppm, 4–16.5 MgO wt.%). They have a marked OIB-like signature, as shown by their isotopic compositions (87Sr/86Sro=0.70311–0.70414 and εNd=+4.7–+5.1) and their incompatible trace elements ratios (Ba/La=10–20, La/Nb=0.46–1.09, Ce/Pb=15.52–27.5, Sr/La<25), reflecting deep mantle origin. UBS-primitive lavas have characteristics similar to those of the Eocene LBS basalts, while UBS-intermediate lavas show geochemical imprints (La/Nb>1, Sr/La>25, low Ce/Pb, Nb/U) compatible with contamination by arc/slab-derived and/or crustal components. We propose that the genesis and extrusion of magmas is related to the opening of two slab windows due to the subduction of two active ridge segments beneath Patagonia during Eocene and Mio–Pliocene. [Copyright &y& Elsevier]

Optimal groundwater remediation design problems are often complex, nonlinear, and computationally intensive. Genetic algorithms allow solution of more complex nonlinear problems than traditional gradient-based approaches, but they are more computationally intensive. One way to improve performance is through inclusion of local search, creating a hybrid genetic algorithm (HGA). This paper presents a new self-adaptive HGA (SAHGA) and compares its performance to a nonadaptive hybrid genetic algorithm (NAHGA) and the simple genetic algorithm (SGA) on a groundwater remediation problem. Of the two hybrid algorithms, SAHGA is shown to be far more robust than NAHGA, providing fast convergence across a broad range of parameter settings. For the test problem, SAHGA needs 75% fewer function evaluations than SGA, even with an inefficient local search method. These findings demonstrate that SAHGA has substantial promise for enabling solution of larger-scale problems than was previously possible. [ABSTRACT FROM AUTHOR]

Background: Solid tumors such as glioblastoma (GBM) exhibit hypoxic zones that are associated with poor prognosis and immunosuppression through multiple cell intrinsic mechanisms. However, release of extracellular vesicles (EVs) has the potential to transmit molecular cargos between cells. If hypoxic cancer cells use EVs to suppress functions of macrophages under adequate oxygenation, this could be an important underlying mechanism contributing to the immunosuppressive and immunologically cold tumor microenvironment of tumors such as GBM. Methods: EVs were isolated by differential ultracentrifugation from GBM cell culture supernatant. EVs were thoroughly characterized by transmission and cryo-electron microscopy, nanoparticle tracking analysis (NTA), and EV marker expression by Western blot and fluorescent NTA. EV uptake by macrophage cells was observed using confocal microscopy. The transfer of miR-25/93 as an EV cargo to macrophages was confirmed by miRNA real-time qPCR. The impact of miR-25/93 on the polarization of recipient macrophages was shown by transcriptional analysis, cytokine secretion and functional assays using co-cultured T cells. Results: We show that indirect effects of hypoxia can have immunosuppressive consequences through an EV and microRNA dependent mechanism active in both murine and human tumor and immune cells. Hypoxia enhanced EV release from GBM cells and upregulated expression of miR-25/93 both in cells and in EV cargos. Hypoxic GBM-derived EVs were taken up by macrophages and the miR-25/93 cargo was transferred, leading to impaired cGAS-STING pathway activation revealed by reduced type I IFN expression and secretion by macrophages. The EV-treated macrophages downregulated expression of M1 polarization-associated genes Cxcl9, Cxcl10 and Il12b, and had reduced capacity to attract activated T cells and to reactivate them to release IFN-γ, key components of an efficacious anti-tumor immune response. Conclusions: Our findings suggest a mechanism by which immunosuppressive consequences of hypoxia mediated via miRNA-25/93 can be exported from hypoxic GBM cells to normoxic macrophages via EVs, thereby contributing to more widespread T-cell mediated immunosuppression in the tumor microenvironment. [ABSTRACT FROM AUTHOR]

• GBM cells treated with radio-chemotherapy increase phagocytic activity of macrophages. • This increase correlates with the proportion of apoptotic GBM cells. • Macrophages up-regulate the efferocytosis receptor AXL. Immunotherapy is actively explored in glioblastoma (GBM) to improve patient prognosis. Tumor-associated macrophages (TAMs) are abundant in GBM and harnessing their function for anti-tumor immunity is of interest. They are plastic cells that are influenced by the tumor microenvironment, by radio-chemotherapy and by their own phagocytic activity. Indeed, the engulfment of necrotic cells promotes pro-inflammatory (and anti-tumoral) functions while the engulfment of apoptotic cells promotes anti-inflammatory (and pro-tumoral) functions through efferocytosis. To model the effect of radio-chemotherapy on the GBM microenvironment, we exposed human macrophages to supernatant of treated GBM cells in vitro. Macrophages were derived from human monocytes and GBM cells from patient-resected tumors. GBM cells were exposed to therapeutically relevant doses of irradiation and chemotherapy. Apoptosis and phagocytic activity were assessed by flow cytometry. The phagocytic activity of macrophages was increased, and it was correlated with the proportion of apoptotic GBM cells producing the supernatant. Whether uptake of apoptotic tumor cells could occur would depend upon the expression of efferocytosis-associated receptors. Indeed, we showed that efferocytosis-associated receptors, such as AXL , were upregulated. We showed that macrophage phagocytic activity increased when exposed to supernatant from GBM cells treated by radio-chemotherapy. However, as efferocytosis-associated receptors were up-regulated, this effect could be deleterious for the anti-GBM immune response. We speculate that by inducing GBM cell apoptosis in parallel to an increase in efferocytosis receptor expression, the impact of radio-chemotherapy on phagocytic activity could promote anti-inflammatory and pro-tumoral TAM functions. [ABSTRACT FROM AUTHOR]

Abstract: Aquifer heterogeneity (structure) and NAPL distribution (architecture) are described based on tracer data. An inverse modelling approach that estimates the hydraulic structure and NAPL architecture based on a Lagrangian stochastic model where the hydraulic structure is described by one or more populations of lognormally distributed travel times and the NAPL architecture is selected from eight possible assumed distributions. Optimization of the model parameters for each tested realization is based on the minimization of the sum of the square residuals between the log of measured tracer data and model predictions for the same temporal observation. For a given NAPL architecture the error is reduced with each added population. Model selection was based on a fitness which penalized models for increasing complexity. The technique is demonstrated under a range of hydrologic and contaminant settings using data from three small field-scale tracer tests: the first implementation at an LNAPL site using a line-drive flow pattern, the second at a DNAPL site with an inverted five-spot flow pattern, and the third at the same DNAPL site using a vertical circulation flow pattern. The Lagrangian model was capable of accurately duplicating experimentally derived tracer breakthrough curves, with a correlation coefficient of 0.97 or better. Furthermore, the model estimate of the NAPL volume is similar to the estimates based on moment analysis of field data. [Copyright &y& Elsevier]

Abstract: A Lagrangian stochastic model is proposed as a tool that can be utilized in forecasting remedial performance and estimating the benefits (in terms of flux and mass reduction) derived from a source zone remedial effort. The stochastic functional relationships that describe the hydraulic “structure” and non-aqueous phase liquid (NAPL) “architecture” have been described in a companion paper (Enfield, C.G., Wood, A.L., Espinoza, F.P., Brooks, M.C., Annable, M., Rao, P.S.C., this issue. Design of aquifer remediation systems: (1) describing hydraulic structure and NAPL architecture using tracers. J. Contam. Hydrol.). The previously defined functions were used along with the properties of the remedial fluids to describe remedial performance. There are two objectives for this paper. First, is to show that a simple analytic element model can be used to give a reasonable estimate of system performance. This is accomplished by comparing forecast performance to observed performance. The second objective is to display the model output in terms of change in mass flux and mass removal as a function of pore volumes of remedial fluid injected. The modelling results suggest that short term benefits are obtained and related to mass reduction at the sites where the model was tested. [Copyright &y& Elsevier]

Protected areas (PAs) are important tools for biodiversity conservation. In developing countries, incomplete information about the presence of non-native species makes it difficult to develop strategies to manage this threat to biodiversity. Although a list of non-native species for continental Ecuador has recently been published, information on the status of these species in PAs in terms of invasiveness and impacts is scarce. This study presents a method that proposes criteria to prioritize the management of non-native phanerogam plants and terrestrial vertebrate species in eight PAs in the coastal region of Ecuador, based on the minimal information available. The study area covers 79.6% of all coastal PAs. For the non-native species inventory, we collated information from global biodiversity databases, research papers, theses and project repositories from local private and public universities, public institutions, and management plans for the selected PAs. To categorize the monitoring priority of the non-native species from the selected PAs, we used a pipeline scheme based on species invasion risk principles. We registered 78 non-native species within the eight PAs, consisting of 64 phanerogam plants and 14 terrestrial vertebrates. The PA with the highest non-native plant species richness is Manglares Churute Ecological Reserve (ER) with 25 species (39.1%; n = 64). For terrestrial vertebrates, the highest non-native species richness was in Isla Santay National Recreation Area (NRA) (71.4%; n = 14). 15.6% of the phanerogam plants and 78.5% of the terrestrial vertebrates were classified in the high priority category. The majority of non-native plants are categorized as "more studies required", reflecting the state of art of invasion ecology in this country. This method allowed us to classify the species based on theoretical and occurrence data. It can potentially be replicated throughout the country and used as a rapid assessment method, complemented with specific invasion/impact studies on PAs in Ecuador. [ABSTRACT FROM AUTHOR]

To support the assessments of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), the IPBES Expert Group on Scenarios and Models is carrying out an intercomparison of biodiversity and ecosystem services models using harmonized scenarios (BES-SIM). The goals of BES-SIM are (1) to project the global impacts of land-use and climate change on biodiversity and ecosystem services (i.e., nature's contributions to people) over the coming decades, compared to the 20th century, using a set of common metrics at multiple scales, and (2) to identify model uncertainties and research gaps through the comparisons of projected biodiversity and ecosystem services across models. BES-SIM uses three scenarios combining specific Shared Socio-economic Pathways (SSPs) and Representative Concentration Pathways (RCPs) – SSP1xRCP2.6, SSP3xRCP6.0, SSP5xRCP8.6 – to explore a wide range of land-use change and climate change futures. This paper describes the rationale for scenario selection, the process of harmonizing input data for land use, based on the second phase of the Land Use Harmonization Project (LUH2), and climate, the biodiversity and ecosystem services models used, the core simulations carried out, the harmonization of the model output metrics, and the treatment of uncertainty. The results of this collaborative modeling project will support the ongoing global assessment of IPBES, strengthen ties between IPBES and the Intergovernmental Panel on Climate Change (IPCC) scenarios and modeling processes, advise the Convention on Biological Diversity (CBD) on its development of a post-2020 strategic plans and conservation goals, and inform the development of a new generation of nature-centred scenarios. [ABSTRACT FROM AUTHOR]

To support the assessments of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), the IPBES Expert Group on Scenarios and Models is carrying out an intercomparison of biodiversity and ecosystem services models using harmonized scenarios (BES-SIM). The goals of BES-SIM are (1) to project the global impacts of land use and climate change on biodiversity and ecosystem services (i.e. nature's contributions to people) over the coming decades, compared to the 20th century, using a set of common metrics at multiple scales, and (2) to identify model uncertainties and research gaps through the comparisons of projected biodiversity and ecosystem services across models. BES-SIM uses three scenarios combining specific Shared Socio-economic Pathways (SSPs) and Representative Concentration Pathways (RCPs) to explore a wide range of land-use change and climate change futures. This paper describes the rationale for scenarios selection, the process of harmonizing input data for land use, based on the second phase of the Land Use Harmonization Project (LUH2), and climate, the biodiversity and ecosystem service models used, the core simulations carried out, the harmonization of the model output metrics, and the treatment of uncertainty. The results of this collaborative modelling project will support the ongoing global assessment of IPBES, strengthen ties between IPBES and the Intergovernmental Panel on Climate Change (IPCC) scenarios and modelling processes, advise the Convention on Biological Diversity (CBD) on its development of a post-2020 strategic plans and conservation goals, and inform the development of a new generation of nature-centred scenarios. [ABSTRACT FROM AUTHOR]

Se determinó el efecto tóxico de extractos metanólicos, hexánicos, y de acetato de etilo de semilla y hoja de higuerilla, Ricinus communis, en la inhibición de crecimiento y desarrollo de larvas del mosquito Culex quinquefasciatus (Say). El extracto hexánico de hoja afectó el desarrollo de larvas con una concentración efectiva (CE) media CE50 = 176.1 ppm y el acetato de etilo de hoja eliminó 100% de las larvas a los 1.7 días. Los tratamientos con menores índices de inhibición de desarrollo (IID); tres de hoja: el acetato de etilo con 1, 250, y 625 ppm con formación de 0.0 y 1.3 de pupas y sin adultos y 625 ppm acortó la duración larval en 2.3 días, seguido del hexánico con 625 ppm con formación de 12.5 de pupas y 0 de adultos disminuyó el periodo larval en 2.8 días, con IID de 0.000, 0.013, y 0.063, y tres de semilla: a 1, 250, 625, y 312.5 ppm de acetato de etilo, hexano, y metanol que afectaron las viabilidades y el hexánico a 1, 250, y 312.5 ppm aumentó el periodo pupal en 1.5 y 1.6 días, la primer concentración de los tres disolventes con valores de IID de 0.250, 0.331, y 0.338. El hexánico de hoja a 1, 250, y 312.5 ppm y metanol a 1, 250 ppm afectaron la viabilidad obteniendo IID´s subsecuentes de 0.081 y 0.169, y 0.113, con 0, 5 y 10 de adultos formados y con el metanólico a 1, 250 ppm con el mínimo número de adultos. El estudio demostró que el acetato de etilo, hexano y metanol de hoja y semilla de Ricinus communis inhibieron 50% el desarrollo de la población de larvas de Cx. quinquefasciatus, afectaron la duración y viabilidad larval y pupal al grado de evitar la formación de pupas y emergencia de adultos. The toxic effect of methanolic, hexane, and ethyl acetate extracts of seed and leaf of Ricinus communis on the inhibition of growth and development of Culex quinquefasciatus (Say) mosquitoes was determined. The hexane leaf extract affected the development of larvae with a mean effective concentration (EC) EC50 = 176.1 ppm, and leaf ethyl acetate eliminated 100% of the larvae at 1.7 days. Treatments with lower development inhibition index (DII) were three of leaf: ethyl acetate with 1, 250, and 625 ppm with formation of 0.0 and 1.3 of pupae and without adults and 625 ppm shortened the larval duration in 2.3 days, followed by hexane with 625 ppm with formation of 12.5 of pupae and 0 adults decreased the larval period in 2.8 days, with DII of 0.000, 0.013, and 0.063, and three of seed: at 1, 250, 625, and 312.5 ppm of ethyl acetate, hexane, and methanol that affected the viabilities and the hexanic at 1, 250, y 312.5 ppm increased the pupal period in 1.5 and 1.6 days, the first concentration of the three solvents with DII values of 0.250, 0.331, and 0.338. The leaf hexanic at 1, 250, and 312.5 ppm and methanol at 1, 250 ppm affected the viability, resulting in subsequent DII's of 0.081 and 0.169, and 0.113, with 0, 5, and 10 adults formed and with methanolic at 1, 250 ppm with the minimum number of adults. The study showed that the extracts ethyl acetate, hexane, and methanol of leaf of R. communis inhibited 50% the development of the population of larvae of IV instar early of Cx. quinquefasciatus with 272.82, 176.06, and 924.58 ppm and those of seed with 677.37, 652.33, and 705.53 ppm, which affected larval and pupal duration and viability to the extent of avoiding the formation of pupae and adult emergency. These results demonstrate the potential of leaf and seed extracts of this plant species to be included as an alternative to the control of Cx. quinquefasciatus. [ABSTRACT FROM AUTHOR]

In this study, a camera to infrared diode (IRED) distance estimation problem was analyzed. The main objective was to define an alternative to measures depth only using the information extracted from pixel grey levels of the IRED image to estimate the distance between the camera and the IRED. In this paper, the standard deviation of the pixel grey level in the region of interest containing the IRED image is proposed as an empirical parameter to define a model for estimating camera to emitter distance. This model includes the camera exposure time, IRED radiant intensity and the distance between the camera and the IRED. An expression for the standard deviation model related to these magnitudes was also derived and calibrated using different images taken under different conditions. From this analysis, we determined the optimum parameters to ensure the best accuracy provided by this alternative. Once the model calibration had been carried out, a differential method to estimate the distance between the camera and the IRED was defined and applied, considering that the camera was aligned with the IRED. The results indicate that this method represents a useful alternative for determining the depth information. [ABSTRACT FROM AUTHOR]

Objective: To assess the evolution of anticoagulation with single dose of unfractionated heparin (UFH) in patients undergoing hemodialysis. Material and methods: We evaluated 31 patients undergoing chronic hemodialysis received one dose of UFH 30UI/Kg/hr, and got blood samples at 0, 5, 60, 120 minutes and at the end of the hemodialysis to measure the activated tromboplastin time (aTPT) to monitor the anticoagulation. Results: The aTPT ratio at time 0 was 1.22 ± 0.49, from these, 13 patients (41.94%) started the hemodialysis with abnormal aTPT ratio. At 5'and 60', all the patients showed values of aTPT ratio higher than 6.9 (aTPT > 300 seconds); at 120' eleven of these (35.8%) had aTPT ratio higher than 6.9 and 20 patients (64.52%) showed an aTPT ratio of 5.59 ± 1.35; all of them over the recommended interval. At the end of the procedure, the mean of the aTPT ratio was 2.17 ± 0.75 and only 3 patients showed aTPT ratio under the anticoagulation interval. We observed two cases of macroscopic bleeding without complications, and there were no contraindications for the reuse of the dializers. Conclusion: The use of UFH in one bolus dose during hemodialysis showed anticoagulation levels higher than the upper limit of the therapeutic range, which persist up to the end of the procedure. It is recommended to stop the practice of this method. [ABSTRACT FROM AUTHOR]

Recent field work and review of radiometric data obtained from Neogene lavas and plutonic rocks exposed in the Eastern Central Patagonian Cordillera (46–48ºS), which overlie subducted segments of the South Chile Ridge, suggest important Late Miocene to Pleistocene morphological changes in relation to base level variations and/or tectonic events. We present new field observations from a region south of Lago General Carrera-Buenos Aires, between the main Cordillera and the Meseta del Lago Buenos Aires, demonstrating that normal faulting controlled valley incisions and occurred during lava emplacement at 5–4 Ma and after 3 Ma. We also show that the 12 Ma basaltic flows of the Meseta del Lago Buenos Aires (∼2000 m a.s.l.) have been subjected to deep incision, with younger lavas dated at 1.2 Ma partially filling the valleys. These incisions are thought to reflect progressive eastward tilting of the entire meseta. Our new observations, together with additional features from Central Patagonia, strongly suggest that tectonic events led to a regional widespread morphological change after 5 Ma. The coincidence in time and space between the subduction of segments of the South Chile Ridge at 6 and 3 Ma causing opening of a slab window, and strong base level variations in the studied area, suggests a cause-and-effect relationship. In Central Patagonia, compressional tectonics ended well before extensional events reported here. Causes of uplift and further extension are probably completely disconnected. The uplift is purely tectonic in origin and occurred prior to the subduction of the South Chile Ridge. Extension should be a consequence of this subduction. [ABSTRACT FROM AUTHOR]

In the measurement systems of three-dimensional (3-D) positions using active vision (e.g., laser and camera), it is necessary to know the precise rotation angles of the camera and the laser with respect to the object on which the 3-D coordinate measures are desired. A small variation of these angles can result in substantial errors of measurement. In this work, we present a novel solution to measure the rotation-angle variations of the elements that form the measurement system under vibration. In our case, the objective is to determine these angles for a 3-D-coordinate measurement system of the wires that feed the electric trains (contact wires). The measurement system must go onboard a measurement car. The 3-D-coordinate measurements are done by triangulation, from a digital camera and a laser that emits a plane of structured light incident on contact wires. In order to measure the angle variations, which result from the vibrations that take place in the measurement system, two line scan cameras and two artificial marks are used. In this paper, the procedure that allows the measurement of the rotation angles of the camera and the laser, the proposed models, and the results obtained in the simulations are shown. [ABSTRACT FROM AUTHOR]

Abstract: Miocene to Quaternary large basaltic plateaus occur in the back-arc domain of the Andean chain in Patagonia. They are thought to result from the ascent of subslab asthenospheric magmas through slab windows generated from subducted segments of the South Chile Ridge (SCR). We have investigated three volcanic centres from the Lago General Carrera–Buenos Aires area (46–47°S) located above the inferred position of the slab window corresponding to a segment subducted 6 Ma ago. (1) The Quaternary Río Murta transitional basalts display major, trace elements, and Sr and Nd isotopic features similar to those of oceanic basalts from the SCR and from the Chile Triple Junction near Taitao Peninsula (e.g., (87Sr/86Sr)o =0.70396–0.70346 and εNd=+5.5−+3.0). We consider them as derived from the melting of a Chile Ridge asthenospheric mantle source containing a weak subduction component. (2) The Plio-Quaternary (<3.3 Ma) post-plateau basanites from Meseta del Lago Buenos Aires (MLBA), Argentina, likely derive from small degrees of melting of OIB-type mantle sources involving the subslab asthenosphere and the enriched subcontinental lithospheric mantle. (3) The main plateau basaltic volcanism in this region is represented by the 12.4–3.3-Ma-old MLBA basalts and the 8.2–4.4-Ma-old basalts from Meseta Chile Chico (MCC), Chile. Two groups can be distinguished among these main plateau basalts. The first group includes alkali basalts and trachybasalts displaying typical OIB signatures and thought to derive from predominantly asthenospheric mantle sources similar to those of the post-plateau MLBA basalts, but through slightly larger degrees of melting. The second one, although still dominantly alkalic, displays incompatible element signatures intermediate between those of OIB and arc magmas (e.g., La/Nb>1 and TiO2 <2 wt.%). These intermediate basalts differ from their strictly alkalic equivalents by having lower High Field Strength Element (HFSE) and higher εNd (up to +5.4). These features are consistent with their derivation from an enriched mantle source contaminated by ca. 10% rutile-bearing restite of altered oceanic crust. The petrogenesis of the studied Mio-Pliocene basalts from MLBA and MCC is consistent with contributions of the subslab asthenosphere, the South American subcontinental lithospheric mantle and the subducted Pacific oceanic crust to their sources. However, their chronology of emplacement is not consistent with an ascent through an asthenospheric window opened as a consequence of the subduction of segment SCR-1, which entered the trench at 6 Ma. Indeed, magmatic activity was already important between 12 and 8 Ma in MLBA and MCC as well as in southernmost plateaus, i.e., 6 Ma before the subduction of the SCR-1 segment. We propose a geodynamic model in which OIB and intermediate magmas derived from deep subslab asthenospheric mantle did uprise through a tear-in-the-slab, which formed when the southernmost segments of the SCR collided with the Chile Trench around 15 Ma. During their ascent, they interacted with the Patagonian supraslab mantle and, locally, with slivers of subducted Pacific oceanic crust that contributed to the geochemical signature of the intermediate basalts. [Copyright &y& Elsevier]

Recombinant vaccines have low-cost manufacturing, regulatory requirements, and reduced side effects compared to attenuated or inactivated vaccines. In the porcine industry, post-weaning multisystemic disease syndrome generates economic losses, characterized by progressive weight loss and weakness in piglets, and it is caused by porcine circovirus type 2 (PCV2). We designed a chimeric antigen (Qm1) to assemble the main exposed epitopes of the Cap-PCV2 protein on the capsid protein of the tobacco necrosis virus (TNV). This design was based on the Cap-N-terminal of an isolated PCV2 virus obtained in Chile. The virus was characterized, and the sequence was clustered within the PCV2 genotype b clade. This chimeric protein was expressed as inclusion bodies in both monomeric and multimeric forms, suggesting a high-molecular-weight aggregate formation. Pigs immunized with Qm1 elicited a strong and specific antibody response, which reduced the viral loads after the PCV2 challenge. In conclusion, the implemented design allowed for the generation of an effective vaccine candidate. Our proposal could be used to express the domains or fragments of antigenic proteins, whose structural complexity does not allow for low-cost production in Escherichia coli. Hence, other antigen domains could be integrated into the TNV backbone for suitable antigenicity and immunogenicity. This work represents new biotechnological strategies, with a reduction in the costs associated with vaccine development. [ABSTRACT FROM AUTHOR]