Estado del sistema sociedad-naturaleza en el chaco argentino

La planificación y gestión de las actividades productivas y de protección de los servicios ecosistémicos requiere el conocimiento de las interacciones múltiples que determinan la dinámica del sistema sociedad-naturaleza. No resulta efectivo el manejo de las tierras desde la ecología, ni desde la sociología aisladamente, sino desde la comprensión del funcionamiento del sistema integrado, estudiado mediante un enfoque transdisciplinario que permita entender las asociaciones entre los factores sociales y físico-bióticos en cada jurisdicción política, especialmente en regiones tan heterogéneas como la chaqueña. En este trabajo se presentan los resultados del análisis integrado de conjuntos de datos ecológicos, del soporte físico de la producción, de producción agropecuaria y de variables sociales en 43 departamentos de la región chaqueña central, abarcando parte de las ecorregiones Chaco Seco y Chaco Húmedo. Se empleó el análisis de Procrustes Generalizado, el cual permite evaluar la consistencia entre conjunto de variables, partiendo de la hipótesis de que los cambios de uso de la tierra general situaciones de inestabilidad que afectan negativamente la resiliencia de los sistemas sociedad-naturaleza, con la consiguiente pérdida de sustentabilidad, y que este efecto se percibe a través de la consistencia entre los factores de los cuales depende la resiliencia. La predicción es que una asociación débil entre el soporte físico y el uso de la tierra implica un uso inadecuado de los recursos naturales que se reflejará en las condiciones sociales de los habitantes de la región. Los resultados muestran que la predicción se cumple en algunos de los departamentos pero no en otros. Se presentaron cuatro combinaciones posibles de concordancia entre soporte físico de la producción y uso de la tierra y su consecuencia sobre las condiciones sociales. El uso de la tierra se refleja en las condiciones sociales tanto como bienestar de la sociedad por un uso de la tierra consistente con su aptitud o como condiciones sociales adversas por un uso de la tierra no consistente con la aptitud natural de la tierra. Las otras dos combinaciones implican condiciones sociales adversas con uso adecuado de la tierra y condiciones de bienestar con un uso inadecuado de la tierra. En estos dos casos, el uso de la tierra no se refleja en las condiciones sociales. Se discuten las posibles razones de estos resultados y las consecuencias para la planificación y manejo de la tierra. La información producida será útil para el ordenamiento territorial.Fil: Matteucci, Silvia Diana. Universidad de Buenos Aires. Facultad de Arquitectura y Urbanismo. Grupo de Ecología del Paisaje y Medio Ambiente; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Silva, Mariana Elizabeth. Universidad de Buenos Aires. Facultad de Arquitectura y Urbanismo. Grupo de Ecología del Paisaje y Medio Ambiente; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rodriguez, Andrea F.. Universidad de Buenos Aires. Facultad de Arquitectura y Urbanismo. Grupo de Ecología del Paisaje y Medio Ambiente; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Quercetin enhances UVA-induced DNA damage in a rat fibroblast cell line

Ultraviolet A (UVA) radiation from sunlight induces the production of reactive oxygen species (ROS), affecting a variety of cellular targets including the DNA. Quercetin, a flavonol present in many fruits, vegetables and beverages has been reported as a powerful antioxidant with an important role in prevention of carcinogenesis. The use of this compound, in topical formulations, could be of benefit in the prevention of skin damage produced by sunlight exposure. We investigated the effect of quercetin on DNA damage induced by UVA radiation in the rat subcutaneous fibroblast cell line, L929. Cells were irradiated by UVA light for 1h, in the presence of quercetin and DNA damage assessed, in individual cells, by the alkaline single cell gel electrophoresis assay (Comet Assay). Our data showed that the combination of UVA with quercetin, at the three concentrations tested (20, 30 and 50 μM) enhances the level of DNA damage in a concentration-dependent manner. However, this effect seems not to be the same when cells are pre-incubated with quercetin, followed by irradiation, in the absence of the compound. We are investigating the mechanisms behind the observed harmful effect of quercetin together with UVA irradiation and trying to relate it, with the ROS levels, in both experimental conditions. The effect obtained suggests that, despite the well known antioxidant beneficial effects of quercetin in many different situations of oxidative stress, precautions should be taken if we think in the development of topical preparations with this compound, to be used on body areas exposed to sunlight.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/17174/200

Nanomineralogy of evaporative precipitation of efflorescent compounds from coal mine drainage

Efflorescent nanophases (NPs) are found as a transitory accumulation of potentially hazardous elements (PHEs), particularly in tropical climates. The central objective of this study was to investigate the distribution of PHEs with NPs through the evaporative formation structures (EFS) of enormously PHEs-rich coal-mine drainages (CMD). The EFS were studied in natural coal mine drainage for five months in order to determine their geochemical and ecological structures and to assess their position in the reduction of PHEs in nature. The largest coal-fired power plant in South America, located in south Brazil, is used as an example of such a problem. In this work, a novel methodology for the analysis of PHEs in CMD precipitates is proposed for this affected coal area. The analytical method, combining X-Ray Diffraction (XRD) and advanced electron microscopies, shows the importance of nanomineralogy in understanding different circumstances of coal contamination. Several ultrafine-nanoparticles (UNPs) were identified in the sampled soils and river sediments together with the PHEs. A decrease in PHEs was identified in association with UNPs. However, further investigations are required with regard to the mobility of PHEs in water, atmosphere, soils, and sediments. The EPS was thoroughly studied, acquiring suitable understanding with investigational facts for Ca and Fe-sulphates, pickeringite, and several amorphous phases

Fluoxetine and Nutrients Removal from Aqueous Solutions by Phycoremediation

The tertiary treatment using microalgae offers an attractive alternative to the removal of low but relevant concentrations of pharmaceuticals from domestic wastewaters. The removal of fluoxetine from aqueous solutions by living and non-living (lyophilized) Chlorella vulgaris was assessed. The determination of the pH at the point of zero charge, Fourier transmittance infrared analysis, and scanning electron microscopy were performed to characterize the microalgae biomass. Kinetic and equilibrium experiments were performed. The pseudo-second-order model described the kinetics of fluoxetine. The corresponding kinetic constants indicated that biosorption was faster onto non-living biomass than onto living biomass. The equilibrium results showed that the systems followed the Langmuir isotherm model. The maximum capacity of living microalgae (1.9 ± 0.1 mg·g−1) was slightly higher than the non-living microalgae (1.6 ± 0.2 mg·g−1). Living Chlorella vulgaris, free and immobilized in calcium-alginate, were also used to remove fluoxetine and nutrients (nitrogen and phosphorus) from treated municipal wastewater in a batch system. In both experiments, fluoxetine was completely removed within six days. The total phosphorus (TP) and total nitrogen (TN) removal efficiencies achieved for free and immobilized cells were, null and 65.0 ± 0.1%, and 86.2 ± 0.1% and 81.8 ± 3.1, respectivelyThis research was funded by the Associate Laboratory for Green Chemistry-LAQV, which received financial support from UIDB/50006/2020, UIDP/50006/2020, and LA/P/0008/2020 by the Fundação para a Ciência e a Tecnologia (FCT)/Ministério da Ciência, Tecnologia e En sino Superior (MCTES) through national funds. This research was also funded by the EU and FCT/UEFISCDI/FORMAS, in the frame of the collaborative international consortium REWATER— “Sustainable and safe water management in agriculture: increasing the efficiency of water reuse for crop growth while protecting ecosystems, services and citizens’ welfare” (WaterJPI/0007/2016), which was financed under the ERA-NET Co-fund WaterWorks2015 Call, as an integral part of the 2016 Joint Activities developed by the Water Challenges for a Changing World Joint Program Initiative (Water JPI). The research was funded also by FCT and BiodivRestore Joint Call 2020–2021-European Union’s Horizon 2020 research and innovation program under grant agreement No. 101003777- BiodivRestore-406/DivRestore/0002/2020-BioReset-“Biodiversity restoration and conservation of inland water ecosystems for environmental and human well-being”. A.D.M. Silva would like to thank FCT for her Ph.D. Grant SFRH/BD/138/780/2018. The authors are greatly indebted to all financing sources. The authors are grateful to Materials Centre of the University of Porto (CEMUP), Porto, Portugal, for expert assistance with SEM/EDSinfo:eu-repo/semantics/publishedVersio

Chitosan/alginate based multilayers to control drug release fromophthalmic lens

In this study we investigated the possibility of using layer-by-layer deposition, based in natural polymers (chitosan and alginate), to control the release of different ophthalmic drugs from three types of lens materials: a silicone-based hydrogel recently proposed by our group as drug releasing soft contact lens (SCL) material and two commercially available materials: CI26Y for intraocular lens (IOLs) and Definitive 50 for SCLs. The optimised coating, consisting in one double layer of (alginate – CaCl2)/(chitosan + glyoxal) topped with a final alginate-CaCl2 layer to avoid chitosan degradation by tear fluid proteins, proved to have excellent features to control the release of the anti-inflammatory, diclofenac, while keeping or improving the physical properties of the lenses. The coating leads to a controlled release of diclofenac from SCL and IOL materials for, at least, one week. Due to its high hydrophilicity (water contact angle ≈ 0) and biocompatibility, it should avoid the use of further surface treatments to enhance the useŕs comfort. However, the barrier effect of this coating is specific for diclofenac, giving evidence to the need of optimizing the chemical composition of the layers in view of the desired drug.info:eu-repo/semantics/publishedVersio

Donepezil-based hybrids as multifunctional anti-Alzheimer's disease chelating agents: Effect of positional isomerization

The intricate and multifactorial nature of Alzheimer's disease (AD) requires the development of compounds able to hit different pathophysiological targets, such as cholinergic dysfunction, deposits of amyloid beta (A beta) peptide and metal dyshomeostasis. In order to continue the search for new anti-AD drugs, a design strategy was once more followed based on repositioning donepezil (DNP) drug, by ortho-attaching a benzylpiperidine mimetic of DNP moiety to a hydroxyphenyl-benzimidazole (BIM) chelating unit (compound 1). Herein, compound 1 and a positional isomer 2 are compared in terms of their potential multiple properties: both present good acetylcholinesterase (AChE) inhibition (low mu molar range) and are moderate/good inhibitors of A beta self- and Cu-mediated aggregation, the inhibition process being mainly due to ligand intercalation between the p-sheets of the fibrils; compound 1 has a higher chelating capacity towards Cu2+ and Zn2+ (pCu = 14.3, pZn = 6.4, pH 7.4, C-I/C-M = 10, C-M = 10(-6) M) than 2 (pCu = 10.7, pZn = 6.3), attributed to its ability to establish a tridentate (N,O,O) coordination to the metal ion. Both compounds are eligible as drug candidates for oral administration but compound 1 shows improved neuroprotective role by completely preventing Ali-induced cell toxicity

Adverse reactions and dietary supplements

Over the last years, the use of dietary supplements has increased substantially. Although these products are considered as safe and can be beneficial, there are risks associated with some. Manufacturers are not required to demonstrate their safety and efficacy, so it is essential that consumers have good knowledge about dietary supplements. The attribution of injury to a specific supplement can be challenging, especially because of the multiple ingredients, the variability in quality and content, as well as the vast underreporting of adverse reactions.info:eu-repo/semantics/publishedVersio

Mitochondria at the Base of Neuronal Innate Immunity in Alzheimer’s and Parkinson’s Diseases

Mitochondria are exceptionally primed to play a key role in neuronal cell survival since they are involved in energy production and function as the metabolic center of cells. Several findings provide evidence for the role of mitochondria in neurodegeneration associated with Alzheimer’s and Parkinson’s diseases (AD and PD). Recent data highlight the role of mitochondrial proteins and mitochondrial reactive oxygen species in the intracellular signaling that regulates innate immunity and inflammation. In this chapter, we will discuss the relevance of the interplay between mitochondria and innate immunity, focusing on mitochondrial damage-associated molecular patterns (DAMPs) and how they can activate innate immunity and elicit AD and PD neurodegenerative process