Douala as a “hybrid space” : comparing online and offline representations of a sub-Saharan city

This study investigates the complex relationship between the physical and digital spaces of the city of Douala, Cameroon by comparing its online representation with the social representations emerging orally by locals. Using the results of two existing studies reporting on the online image of the city, we investigate the social representations foreigners and locally relevant people have of Douala and uncover similarities and discrepancies of the two resulting representations. Outcomes from the analysis permit reflection on the implications of these and show an unripe, intermediate stage of the “hybrid Douala,” where the virtual space seems still not to be affecting the way the physical space is experienced, as well as where the gaps in the digital divide are perpetuated. At the same time, strong local ownership of certain digital activities suggests how the online image of the city is in the process of being constructed and developed locally. As the spaces of the city start appearing online, the process of hybridization between physical and digital Douala is slowly taking place and offline and online narratives, now rather separated, will possibly communicate a different image of the city to global online narratives

Social hotspots life cycle assessment: A case study on social risks of an antimicrobial keyboard cover

This article explores the application of social life cycle assessment (S-LCA) to products or technologies in their earliest developing phase. Indeed, it would be beneficial to have an overview of the social risks generated by novel products and understand what their potential supply chain would be like. To this end, this study presents a S-LCA study for identifying hotspots linked to a novel product: an antimicrobial keyboard cover integrating gold nanoparticles. Firstly, countries which could supply Europe with the input materials required in the system were identified, then by following the S-LCA methodology working hours and working functional hours were estimated. Ultimately, social risks were calculated by combining working functional hours with social risk levels and weights, concerning the relative importance of each category and sub-category. The analysis helped to determine which countries could supply the materials needed and hence become part of the potential supply chain of antimicrobial keyboard covers integrating gold nanoparticles. Furthermore, it led to the identification of main social hotspots linked to each material used. In general, results show that the stakeholders most at risk of adverse social impacts across different sectors and countries are workers. Indeed, they may be affected on both their rights and work conditions, health and safety. The process of gold mining highlights the difference in terms of social risks between more developed countries, such as Australia and Sweden, and developing countries, such as South Africa. The production of chemicals presents a homogeneity in terms of risk hours associated to the considered European countries

The life-cycle environmental performance of producing formate via electrochemical reduction of CO_{2} in ionic liquid

Carbon capture and utilisation provide a means to mitigate climate change caused by anthropogenic greenhouse gas emissions by delaying carbon emissions via temporary storage in goods. This article presents a comprehensive Life Cycle Assessment (LCA) study of a novel process that generates formate via electrochemical reduction of CO_{2} in ionic liquid. We performed a scenario analysis, covering uncertain parameters like the recycling rate of unreacted reagents and the market price of CO_{2}, and compared the environmental performance of the carbon utilisation system with that of the conventional process, which relies on fossil sources. Inventory data is obtained from a mix of literature sources and commercial LCA databases. Our analysis indicates that (i) the system needs to attain a 99.9% recycling rate to be competitive with the conventional process; (ii) a future negative market price of CO_{2} would substantially reduce the environmental impacts associated with formate; (iii) there are significant environmental trade-offs between the carbon utilisation system and the conventional process, with the former outperforming the latter in 6/8 out of the 14 impact categories investigated. It should be noted that our results are conservative because inventory data for the electrochemical reduction process is obtained from laboratory experiments

Can the use of captured CO2 lower the environmental impacts of formate production?

The majority of bulk chemicals (e.g. olefins and alcohols) are organic compounds that are almost exclusively produced from fossil feedstocks such as natural gas. Utilisation of carbon dioxide captured from anthropogenic sources, which are both inexpensive and abundantly available, represents an alternative pathway that is drawing increasing attention, mainly for its potential to decreasing emissions of greenhouse gases and resource depletion of chemicals production. Notably, carbon utilisation does not represent an approach to CO2 mitigation because it only delays its emissions rather than removing it over a long timescale; hence, the relevant question that we aim to address is: "Can captured CO2 be used as feedstock to reduce the environmental impacts of chemicals' production?". As a case study, this work focuses on the production of formate and presents a prospective comparative life cycle assessment (LCA) between the conventional fossil-based pathway and an innovative, CO2-based process, that involves the electro-catalytic reduction of CO2 using an ionic liquid as solvent. CO2 is assumed to originate from a natural gas-fired power plant and captured after combustion, through a conventional monoethanolamine absorption system. Ionic liquids are used to enanche the reduction of CO2 and its conversion to formate. The study adopts a cradle-to-gate perspective and analyses multiple impact categories including, but not limited to, global warming and resources depletion

A disulfide bond in the membrane protein IgaA is essential for repression of the RcsCDB system

IgaA is an integral inner membrane protein that was discovered as repressor of the RcsCDB phosphorelay system in the intracellular pathogen Salmonella enterica serovar Typhimurium. The RcsCDB system, conserved in many members of the family Enterobacteriaceae, regulates expression of varied processes including motility, biofilm formation, virulence and response to envelope stress. IgaA is an essential protein to which, in response to envelope perturbation, the outer membrane lipoprotein RcsF has been proposed to bind in order to activate the RcsCDB phosphorelay. Envelope stress has also been reported to be sensed by a surface exposed domain of RcsF. These observations support a tight control of the RcsCDB system by RcsF and IgaA via mechanisms that, however, remain unknown. Interestingly, RcsF and IgaA have four conserved cysteine residues in loops exposed to the periplasmic space. Two non-consecutive disulfide bonds were shown to be required for RcsF function. Here, we report mutagenesis studies supporting the presence of one disulfide bond (C404-C425) in the major periplasmic loop of IgaA that is essential for repression of the RcsCDB phosphorelay. Our data therefore suggest that the redox state of the periplasm may be critical for the control of the RcsCDB system by its two upstream regulators, RcsF and IgaA.Work in our laboratory is supported by grants BIO2016-77639-P (AEI/FEDER, UE) and PCIN-2016-082 (to FG-dP) from the Spanish Ministry of Economy and Competitiveness and European Regional Development Funds (FEDER)

Contribution of sortase A to the regulation of Listeria monocytogenes LPXTG surface proteins

Gram-positive bacteria of the genus Listeria contain many surface proteins covalently bound to the peptidoglycan. In the pathogenic species Listeria monocytogenes, some of these surface proteins mediate adhesion and entry into host cells. Specialized enzymes called sortases anchor these proteins to the cell wall by a mechanism involving processing and covalent linkage to the peptidoglycan. How bacteria coordinate the production of sortases and their respective protein substrates is currently unknown. The present work investigated whether the functional status of the sortase influences the level at which its cognate substrates are produced. The relative amounts of surface proteins containing an LPXTG sorting motif recognized by sortase A (StrA) were determined in isogenic wild-type and ΔsrtA strains of L. monocytogenes. The possibility of regulation at the transcriptional level was also examined. The results showed that the absence of SrtA did not affect the expression of any of the genes encoding LPXTG proteins. However, marked differences were found at the protein level for some substrates depending on the presence/absence of SrtA. In addition to the known mis-sorting of some LPXTG proteins caused by the absence of SrtA, the total amount of certain LPXTG protein species was lower in the ΔsrtA mutant. These data suggested that the rate of synthesis and/or the stability of a subset of LPXTG proteins could be regulated post-transcriptionally depending on the functionality of SrtA. For some LPXTG proteins, the absence of SrtA resulted in only a partial loss of the protein that remained bound to the peptidoglycan, thus providing support for additional modes of cell-wall association in some members of the LPXTG surface protein familyThis study was funded by grant BIO2010-18962 of the Spanish Ministry of Economy and Competitiveness to M.G.P

Recent Advances in Understanding the Protein Corona of Nanoparticles and in the Formulation of “Stealthy” Nanomaterials

In the last decades, the staggering progress in nanotechnology brought around a wide and heterogeneous range of nanoparticle-based platforms for the diagnosis and treatment of many diseases. Most of these systems are designed to be administered intravenously. This administration route allows the nanoparticles (NPs) to widely distribute in the body and reach deep organs without invasive techniques. When these nanovectors encounter the biological environment of systemic circulation, a dynamic interplay occurs between the circulating proteins and the NPs, themselves. The set of proteins that bind to the NP surface is referred to as the protein corona (PC). PC has a critical role in making the particles easily recognized by the innate immune system, causing their quick clearance by phagocytic cells located in organs such as the lungs, liver, and spleen. For the same reason, PC defines the immunogenicity of NPs by priming the immune response to them and, ultimately, their immunological toxicity. Furthermore, the protein corona can cause the physical destabilization and agglomeration of particles. These problems induced to consider the PC only as a biological barrier to overcome in order to achieve efficient NP-based targeting. This review will discuss the latest advances in the characterization of PC, development of stealthy NP formulations, as well as the manipulation and employment of PC as an alternative resource for prolonging NP half-life, as well as its use in diagnostic applications

“I found myself alone” – A phenomenological study of the home care workers' experience during the COVID-19 pandemic

Home care workers (HCWs) are a highly heterogeneous population in Italy in terms of their professional qualifications. HCWs play an important role in helping patients affected by chronic diseases and their families. Although many investigators have studied the lived experiences of family caregivers, few have been conducted "to give a voice" to HCWs and even fewer have examined the experiences of HCWs during the present COVID-19 pandemic. We investigated the lived experiences of HCWs during the first wave of the pandemic in Italy. Cohen's phenomenological research approach was used to conduct this study. In our study, we enrolled and interviewed 19 HCWs who were female, and most were married, with an average age of 52 years. The participants were enrolled from September 2020 to November 2020, after the first COVID-19 wave in Italy. Four main themes emerged from the analysis of the data: (1) "I found myself alone"; (2) from invisibility to visibility; (3) a fear of getting sick and infecting others; and (4) "Health or work? That is the question." Understanding HCWs' lived experiences, especially those related to the COVID-19 pandemic, is a first step in giving a voice to this important but vulnerable population in the healthcare workforce