84 research outputs found

    Tensioactivos. XX. ω-Monoésteres grasos de ditioacetales de azúcares

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    The preparation of 5-O-lauroyl(myhstoyl, palmitoyl)-D-arabinose ethylendithioacetals, 6-O-lauroyl-D-glucose(D-galactose) ethylendithioacetals and 6-O-decanoyl(lauroyl)-D-mannose ethylendithioacetals is reported. The preparation of 5-O-octanoyl(decanoyl, lauroyl)-L-arabinose diethyldithioacetais is also reported. These compounds were obtained by monoesterification of aldosedithioacetals with the corresponding fatty acid chlorides in pyridine.Se describe la preparación de etilenditioacetales de la 5-O-lauroil(miristoil, palmitoil)- D-arabinosa, de la 6-O-lauroil-D-glucosa(D-galactosa) y de la 6-O-decanoil(lauroil)-D-manosa; y la preparación de dietilditioacetales de la 5-O-octanoil(decanoil, lauroil)-L-arabinosa. La síntesis de estos compuestos se ha realizado por monoesterificación de los ditioacetales de azúcares con los correspondientes cloruros de ácidos grasos en piridina

    Central America urgently needs to reduce the growing adaptation gap to climate change

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    Central America is highly impacted by current extreme events associated with climate variability and the adverse effects of climate change, showing high vulnerability compounded by its historical context and socioeconomic structure. In light of the important findings published by the WGII of the IPCC AR6 in 2022 on the adverse effects of climate change on the Central American region, there is still a clear need to improve data availability and to increase the number of studies on projections of changes in the climate, risks, impacts, vulnerability, and adaptation from the region to inform decision-makers and practitioners. The region has seen an increase in the number of adaptation projects implemented; however, there is limited information about their success or failure, and there are few case studies and reviews of lessons learned, highlighting an important gap in the implementation of effective adaptation measures. This article presents a current review of the literature on climatology, hydrology, impacts and vulnerability, mitigation and adaptation responses, action plans, and potential losses and damages in the region. It also proposes actionable recommendations based on the main gaps found and presents a case study of the Central American Dry Corridor, one of the climate change and underdevelopment hotspots of the region. We finish with a discussion highlighting the importance of considering system transitions perspectives and the need to plan and implement more transformational adaptation approaches to reduce further losses and damages and to further address adaptation gaps in Central America

    Cell identity and nucleo-mitochondrial genetic context modulate OXPHOS performance and determine somatic heteroplasmy dynamics

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    Heteroplasmy, multiple variants of mitochondrial DNA (mtDNA) in the same cytoplasm, may be naturally generated by mutations but is counteracted by a genetic mtDNA bottleneck during oocyte development. Engineered heteroplasmic mice with nonpathological mtDNA variants reveal a nonrandom tissue-specific mtDNA segregation pattern, with few tissues that do not show segregation. The driving force for this dynamic complex pattern has remained unexplained for decades, challenging our understanding of this fundamental biological problem and hindering clinical planning for inherited diseases. Here, we demonstrate that the nonrandom mtDNA segregation is an intracellular process based on organelle selection. This cell type-specific decision arises jointly from the impact of mtDNA haplotypes on the oxidative phosphorylation (OXPHOS) system and the cell metabolic requirements and is strongly sensitive to the nuclear context and to environmental cues

    Electrochemical degradation of surfactants in domestic wastewater using a DiaClean® cell equipped with a boron-doped diamond electrode

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    Treating domestic wastewater has become more and more complicated due to the high content of different types of detergents. In this context, advanced electro-oxidation (AEO) has become a powerful tool for complex wastewater remediation. The electrochemical degradation of surfactants present in domestic wastewater was carried out using a DiaClean® cell in a recirculation system equipped with boron-doped diamond (BDD) as the anode and stainless steel as the cathode. The effect of recirculation flow (1.5, 4.0 and 7.0 L min−1) and the applied current density (j = 7, 14, 20, 30, 40, and 50 mA cm−2) was studied. The degradation was followed by the concentration of surfactants, chemical oxygen demand (COD), and turbidity. pH value, conductivity, temperature, sulfates, nitrates, phosphates, and chlorides were also evaluated. Toxicity assays were studied through evaluating Chlorella sp. performance at 0, 3, and 7 h of treatment. Finally, the mineralization was followed by total organic carbon (TOC) under optimal operating conditions. The results showed that applying j = 14 mA cm−2 and a flow rate of 1.5 L min−1 during 7 h of electrolysis were the best conditions for the efficient mineralization of wastewater, achieving the removal of 64.7% of surfactants, 48.7% of COD, 24.9% of turbidity, and 44.9% of mineralization analyzed by the removal of TOC. The toxicity assays showed that Chlorella microalgae were unable to grow in AEO-treated wastewater (cellular density: 0 × 104 cells ml−1 after 3- and 7-h treatments). Finally, the energy consumption was analyzed, and the operating cost of 1.40 USD m−3 was calculated. Therefore, this technology allows for the degradation of complex and stable molecules such as surfactants in real and complex wastewater, if toxicity is not taken into account

    “Tourism, water, and gender”—An international review of an unexplored nexus

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    This international literature review of the tourism–water nexus identifies a gender gap. Tourism development can affect water supply both quantitatively and qualitatively. Many regions will face considerable problems of water availability and quality, affecting their tourism sector and increasing competition with local residents, and other industries especially agriculture. This international review of literature explores the tourism–water nexus, comparing and contrasting literature published in English, Chinese, and Spanish. Securing access to safe water for continued tourism development is a common theme and the vast majority of work has focused on hotels including water pricing, water-saving practices and innovative management methods. In all continents, struggles are apparent, and the unsustainability of tourism is having impacts on water quantity and quality. This article identifies significant gaps in the literature including climate change, the energy-water nexus, and the links with the Sustainable Development Goals. Furthermore, studies from a gendered perspective are minimal and the potential for areas of further gendered studies within the tourism–water nexus are highlighted including intersectionality, water insecurity and sanitation, tourism and gender based violence, and additional unpaid care work
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