Las exportaciones del litoral argentino al puerto de Buenos Aires entre 1783 y 1850

Editada en la Fundación Empresa PúblicaEn este trabajo estudiamos la dinámica de las exportaciones del Litoral argentino con el puerto de Buenos Aires entre los años de 1783 a 1850. A partir del análisis cuantitativo del comercio litoraleño evaluamos su comportamiento y composición, lo que nos permite sostener que las exportaciones crecieron más rápidamente después de la independencia que durante el período colonial, y por tanto también el conjunto de la economía litoraleña. Así, esta región habría experimentado una transición económica relativamente exitosa entre el período colonial y la etapa independiente.This article studies the dynamics of exports from the Argentine Litoral to Buenos Aires between 1783 and 1850. A quantitative analysis of the litoral's commerce enables us to state that exports grew faster after independence than during the colonial period, as did the «litoraleña» economy as a whole. As a result, die región experienced a successful transition from the colonial period to independence.Publicad

Redox-active metal-organic frameworks for the removal of contaminants of emerging concern

The pollution due to the presence of contaminants of emerging concern (CECs) is a major cause for concern because of the serious threat it supposes to human health and ecosystem functions. Many efforts have been geared toward their removal to guarantee safer freshwater. Metal-organic frameworks (MOFs) are crystalline hybrid materials with high surface area and flexible rational design, which allows the incorporation of different active sites into a particular framework, thereby emerging as a potentially excellent candidate for water and wastewater treatment. Benefiting from the unique redox-active properties of MOFs, this review surveys literature update on their application for the removal of CECs. The underlaying electron transfer mechanism and strategies for incorporating redox-active sites into MOFs are comprehensively discussed. Different components of MOFs that are redox-active are further highlighted. This study elaborates the application of MOFs for Fenton-type and other advanced oxidation processes (AOPs) for removing emerging contaminants. AOPs generate highly reactive strong oxidants like hydroxyl and sulfate radicals that are efficient for degrading emerging pollutants with high mineralization rates. MOFs display semiconductor-like properties. Their photocatalytic use for the removal of dissolved emerging pollutants is detailed in the discussion. This review also provides an overview of the most promising directions for future research

Política comercial, flujos mercantiles y negocios: Buenos Aires y Montevideo frente al comercio exterior rioplatense en el siglo XIX

The aim of this article is to analyze the export growth rate in the Río de la Plata as well as the trading competence between the seaports of Buenos Aires and Montevideo in their endeavours to homogenize the commercial fluxes. By means of quantitative and qualitative analyses of the traffic and the trading policies implemented between 1830 and 1850, new evidence is offered which reasertains the advantages and disadvantages of business in the Río de la Plata ambits as from mid 19th Century.Este trabajo tiene como objetivo analizar el ritmo de crecimiento de las exportaciones rioplatenses y la competencia mercantil de los puertos de Buenos Aires y Montevideo en pos de hegemonizar el flujo comercial. A partir del estudio cuantitativo y cualitativo del tráfico y las políticas comerciales implementadas entre 1830 y 1850, presentamos nuevas evidencias que replantean las ventajas y desventajas que tuvieron los negocios en el espacio rioplatense desde mediados del siglo XIX

Nanoplastic toxicity towards freshwater organisms

The fragmentation of plastic litter into smaller fragments, known as microplastics and nanoplastics, as well as their toxicity and environmental distribution have become issues of high concern. Furthermore, the popularization of bioplastics as a greener substitute of conventional plastics represents a challenge for the scientific community in view of the limited information concerning their potential environmental impact. Here, we systematically review the recent knowledge on the environmental fate and toxicity of nanoplastics in freshwater environments, discuss the results obtained thus far, and identify several knowledge gaps. The sources and environmental behaviors of nanoplastics are presented considering in vitro, in vivo, and in silico studies with a focus on real exposure scenarios. Their effects on organisms are classified based on their impact on primary producers, primary consumers, and secondary consumers. This review covers the main results published in the last four years, including all relevant experimental details and highlighting the most sensitive toxicity endpoints assessed in every study. We also include more recent results on the potential environmental impact of biodegradable plastics, a type of material belonging to the category of bioplastics for which there are still scarce data. This review identifies a need to perform studies using secondary nanoplastics rather than synthetic commercial materials as well as to include other polymers apart from polystyrene. There is also an urgent need to assess the possible risk of nanoplastics at environmentally realistic concentrations using sublethal endpoints and long-term assay

Use of cyanobacterial luminescent bioreporters to report on the environmental impact of metallic nanoparticles

Due to their ecological relevance, low cost, and easy maintenance, cyanobacteria have been used for bioreporter development. In this study, a battery of cyanobacterial bioreporters has been used to assess the ecotoxicity of four highly used metallic nanoparticles (NPs). The toxicity of these NPs was tested using the bioreporter Nostoc CPB4337 (Anabaena CPB4337). As oxidative stress is a primary toxic mechanism of metallic NPs, cyanobacterial reactive oxygen species (ROS)-detecting bioreporters were used. Metallic NPs release metal ions, which contribute to their toxic effect and the formation of ROS, so a metal-detecting bioreporter was also used to detect the bioavailable metals. The results confirm that ROS production by NPs was due to the NPs per se and not by released free-ions, which in fact were almost undetectable. Although the metal-detecting bioreporter could not detect the dissolved metal ions, it was able to detect the metallic NPs themselves, indicating that this bioreporter may be useful to detect them in the environment. ROS production varied depending on the growth medium or environmental matrices conditions and on the NP type. This work demonstrated the different levels of ROS production by metallic NPs and the importance of nanotoxicology studies in real matricesThis research was funded by MINECO, grant number CTM2013-45775-C2-1/2-R and CTM2016-74927-C2-1/2-

Del reformismo colonial borbónico al librecomercio: las exportaciones pecuarias del Río de la Plata (1768-1854)

Fil: Rosal, Miguel A.Universidad de Buenos Aires .Facultad de Filosofía y Letras; Argentina.Fil: Schmit, Roberto. Universidad de Buenos Aires. Facultad de Filosofía y Letras; Argentina

Early and differential bacterial colonization on microplastics deployed into the effluents of wastewater treatment plants

Título del Post Print: Early and differential bacterial colonization on microplasticsMicrobial colonization of microplastics (MPs) in aquatic ecosystems is a well-known phenomenon; however, there is insufficient knowledge of the early colonization phase. Wastewater treatment plant (WWTP) effluents have been proposed as important pathways for MPs entry and transport in aquatic environments and are hotspots of bacterial pathogens and antibiotic resistance genes (ARGs). This study aimed at characterizing bacterial communities in the early stage of biofilm formation on seven different types of MPs deployed in two different WWTPs effluents as well as measuring the relative abundance of two ARGs (sulI and tetM) on the tested MPs. Illumina Miseq sequencing of the 16S rRNA showed significant higher diversity of bacteria on MPs in comparison with free-living bacteria in the WWTP effluents. β-diversity analysis showed that the in situ environment (sampling site) and hydrophobicity, to a lesser extent, had a role in the early bacterial colonization phase. An early colonization phase MPs-core microbiome could be identified. Furthermore, specific core microbiomes for each type of polymer suggested that each type might select early attachment of bacteria. Although the tested WWTP effluent waters contained antibiotic resistant bacteria (ARBs) harboring the sulI and tetM ARGs, MPs concentrated ARBs harboring the sulI gene but not tetM. These results highlight the relevance of the early attachment phase in the development of bacterial biofilms on different types of MP polymers and the role that different types of polymers might have facilitating the attachment of specific bacteria, some of which might carry ARGsFinancial support was provided by the Spanish Ministry of Economy and Competitiveness (CTM2016-74927-C2-1/2-R

Effects of petroleum-based and biopolymer-based nanoplastics on aquatic organisms: A case study with mechanically degraded pristine polymers

Mismanaged plastic litter submitted to environmental conditions may breakdown into smaller fragments, eventually reaching nano-scale particles (nanoplastics, NPLs). In this study, pristine beads of four different types of polymers, three oil-based (polypropylene, PP; polystyrene, PS; and low-density polyethylene, LDPE) and one bio-based (polylactic acid, PLA) were mechanically broken down to obtain more environmentally realistic NPLs and its toxicity to two freshwater secondary consumers was assessed. Thus, effects on the cnidarian Hydra viridissima (mortality, morphology, regeneration ability, and feeding behavior) and the fish Danio rerio (mortality, morphological alterations, and swimming behavior) were tested at NPLs concentrations in the 0.001 to 100 mg/L range. Mortality and several morphological alterations were observed on hydras exposed to 10 and 100 mg/L PP and 100 mg/L LDPE, whilst regeneration capacity was overall accelerated. The locomotory activity of D. rerio larvae was affected by NPLs (decreased swimming time, distance or turning frequency) at environmentally realistic concentrations (as low as 0.001 mg/L). Overall, petroleum- and bio-based NPLs elicited pernicious effects on tested model organisms, especially PP, LDPE and PLA. Data allowed the estimation of NPLs effective concentrations and showed that biopolymers may also induce relevant toxic effectsThe authors acknowledge the financial support provided by the Spanish Government (Ministerio de Ciencia e Innovación): PID2020-113769RBC21/22, PLEC2021-007693 and the Thematic Network of Micro- and Nanoplastics in the Environment (RED2018-102345-T, EnviroPlaNet Network) and by the Portuguese Government: Project NanoPlanet (2022.02340.PTDC) and financial support to CESAM (UIDP/ 50017/ 2020+UIDB/50017/2020+LA/P/0094/2020), through FCT/MCTES. MTB is the recipient of a FPU (FPU17/01789) pre-doctoral contract by the Spanish Ministerio de Ciencia, Innovación y Universidade

Combined toxicity of graphite-diamond nanoparticles and thiabendazole to Daphnia magna

Carbon-based nanomaterials exhibit unique properties that make them suitable for a wide variety of industrial and biomedical applications. In this work, we studied the acute toxicity of graphite-diamond nanoparticles (GDN) combined with the fungicide thiabendazole (TBZ) to the immobilization of the cladoceran Daphnia magna in the presence and absence of the micro green algae Raphidocelis subcapitata, supplied as food source. The toxicity of GDN to D. magna decreased in the presence of R. subcapitata, while that of TBZ increased, the latter suggesting a carrier effect to TBZ. GDN-TBZ mixtures were fitted to the most common conceptual models applied to mixture toxicity: Concentration Addition (CA), Independent Action (IA) and Combination Index (CI). For GDN-TBZ mixtures in the absence of food the best fit was obtained with dose ratio deviation from CA model, while in the presence of food, dose level deviation from CA gave a better fit. The binary mixtures of GDN and TBZ showed synergistic toxic interactions at low concentrations, which could be attributed to the increased bioavailability of TBZ adsorbed on GDN. For higher concentrations of GDN, the binary mixtures turned antagonistic due to particle agglomeration. Our study provides evidence that deviations from additivity are dose dependent and relevant for the risk assessment of mixtures of nanoparticles with other chemical pollutants.publishe