El paisaje rural antropogénico de Aisén, Chile: Estructura y dinámica de la vegetación [The anthropogenic rural landscape of Aisen, Chile: Structure and vegetation dynamic]

We studied the dynamic of the vegetation degradation in a rural anthropogenic mosaic vegetal landscape of the Aisen Region, Chile to establish relations of origin in space and time between communities and propose series of degradation. With plant sociological methodology we make up 50 vegetation samples. The initial table was sorted using differential species in 7 communities: nire scrub (Anemone multifida-Nothofagus antarctica), silvipasture with nire, silvipasture with chacay, trebol-ballica prairie (Bromus catharticus-Trifolium repens), chepica-cadillo prairie (Acaena ovalifolia-Agrostis capillaris), cadillo-Aira prairie and cadillo steppe, which were compared in their systematic, biological and origin spectra. The initial table previously transformed into a data matrix was treated with multivariate statistical analysis of classification (cluster analysis) and ordination (principal components analysis). Finally using the Ellenberg community similarity coefficient were compared and distributed in a communities constellation. The flora of the initial plant sociological table consisted of 78 species with a predominance of annual and perennial herbaceous foreign species that indicated a large anthropic influence. The following vegetation dynamic of degradation was established: fire scrub is degraded by grazing in a nire silvipasture, which is transformed in a anthropogenic overgrazed trebol-ballica prairie this becomes a cadillo-Aira prairie, which by default ends in a cadillo steppe without human management possibility. We discussed the results and applicability of the using methods.Se estudió la dinámica de degradación de la vegetación en un mosaico vegetal antropogénico del paisaje rural de la Región de Aisén para establecer las posibles relaciones de origen tanto espacial como temporal entre las comunidades y proponer series de degradación. Se trabajó con metodología fitosociológica levantando 50 censos de vegetación. La tabla inicial fue ordenada usando especies diferenciales en 7 comunidades: matorral de ñire (Anemone multifida-Nothofagus antarctica), silvopastoreo con ñire, silvopastoreo con chacay, pradera de trébol-ballica (Bromus catharticus-Trifolium repens), pradera de chépica-cadillo (Acaena ovalifolia-Agrostis capillaris), pradera de cadillo-Aira y estepa de cadillo, las que se compararon en sus espectros sistemáticos, biológicos y de origen. Posteriormente, se realizaron análisis estadísticos multivariados de clasificación (conglomerados) y de ordenación (componentes principales) a la tabla inicial transformada previamente en una matriz de datos. Finalmente, utilizando el índice de Ellenberg se compararon las comunidades encontradas, las que se distribuyeron en una constelación de comunidades. La flora de la tabla inicial estuvo conformada por 78 especies con un predominio de plantas herbáceas perennes y anuales alóctonas que indican un alto grado de antropización. Se estableció la siguiente dinámica vegetacional de degradación: el matorral de ñire se degrada por pastoreo a un silvopastoreo con ñire, el cual se transforma en una pradera antropogénica, con sobrepastoreo ésta da origen a una pradera de cadillo-Aira, la que por abandono desemboca en una estepa de cadillo. Se discuten los resultados obtenidos y la aplicabilidad del método

Contrucción y ensayo de colectores solares calentadores de aire utilizando materiales no habituales

Se presentan los resultados del diseño, construcción, ensayo y comparación de colectores solares para calentamiento de aire de bajo costo. Se compararon seis prototipos con un área expuesta nominal de 1 m². Las superficies absorbedoras han sido construidas con materiales no habituales y/o reciclados: chapa ondulada de acero galvanizado, chapa plana galvanizada perforada, latas de aluminio, viruta metálica. La cubierta, de film de polietileno transparente de 200 micrones. Se presentan las ventajas y desventajas con relación al diseño, los procesos y factibilidades constructivas acordes al medio social en el cuál serán transferidos (comunidad de escasos recursos). Se analizan los niveles térmicos alcanzados en el aire de entrada y salida de cada colector y en un recinto de 1 m3 adosado a cada uno de ellos como área a climatizar. La medición se realizó en los meses de julio y agosto de 2010. Como conclusiones se identifican los sistemas que han presentado las mejores prestaciones.This work exposes the results of designing, construction, testing and comparison of low cost air heating solar collector. Six prototypes were compared with a nominal surface area of 1 m2 . Absorber surfaces have been built with unusual and / or recycled materials: corrugated metal, galvanized steel, aluminum cans, metal shavings. The cover is a 200 microns transparent polyethylene sheet. Advantages and disadvantages related to designing, processes and feasibility constructive related to social location in which will be transferred, is presented. Achieved thermal levels from input and output air collector and a 1 m3 air container connected to each of them, were analyzed. Measurement was realized in July and August 2010. As a result, systems that have presented the best performance were identified.Fil: San Juan, Gustavo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de la Plata. Facultad de Arquitectura y Urbanismo. Instituto de Inv y Politica del Ambiente Construido; ArgentinaFil: Viegas, Graciela Melisa. Universidad Nacional de la Plata. Facultad de Arquitectura y Urbanismo. Instituto de Inv y Politica del Ambiente Construido; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Discoli, Carlos Alberto. Universidad Nacional de la Plata. Facultad de Arquitectura y Urbanismo. Instituto de Inv y Politica del Ambiente Construido; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Perez, Federico. Universidad Nacional de la Plata. Facultad de Arquitectura y Urbanismo. Instituto de Inv y Politica del Ambiente Construido; ArgentinaFil: Lamonica, Martin. Universidad Nacional de la Plata. Facultad de Arquitectura y Urbanismo. Instituto de Inv y Politica del Ambiente Construido; ArgentinaFil: Ruótolo, Carla. No especifica;Fil: Güimil, Ana. No especifica

Mutation Analysis in Regulator DNA-Binding Regions for Antimicrobial Efflux Pumps in 17,000 Pseudomonas aeruginosa Genomes

Mutations leading to upregulation of efflux pumps can produce multiple drug resistance in the pathogen Pseudomonas aeruginosa. Changes in their DNA binding regions, i.e., palindromic operators, can compromise pump depression and subsequently enhance resistance against several antibacterials and biocides. Here, we have identified (pseudo)palindromic repeats close to promoters of genes encoding 13 core drug-efflux pumps of P. aeruginosa. This framework was applied to detect mutations in these repeats in 17,292 genomes. Eighty-nine percent of isolates carried at least one mutation. Eight binary genetic properties potentially related to expression were calculated for mutations. These included palindromicity reduction, mutation type, positioning within the repeat and DNA-bending shift. High-risk ST298, ST308 and ST357 clones commonly carried four conserved mutations while ST175 and the cystic fibrosis-linked ST649 clones showed none. Remarkably, a T-to-C transition in the fourth position of the upstream repeat for mexEF-oprN was nearly exclusive of the high-risk ST111 clone. Other mutations were associated with high-risk sublineages using sample geotemporal metadata. Moreover, 1.5% of isolates carried five or more mutations suggesting they undergo an alternative program for regulation of their effluxome. Overall, P. aeruginosa shows a wide range of operator mutations with a potential effect on efflux pump expression and antibiotic resistance.This research was funded by Acción Estratégica en Salud from the ISCIII, grant MPY 509/19. This research was also supported by Personalized and Precision Medicine grant from the Instituto de Salud Carlos III (MePRAM Project, PMP22/00092), Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación and Unión Europea-NextGenerationEU.S

Extracellular microRNAs exhibit sequence-dependent stability and cellular release kinetics

Multiple studies have described extracellular microRNAs (ex-miRNAs) as being remarkably stable despite the hostile extracellular environment, when stored at 4oC or lower. Here we show that many ex-miRNAs are rapidly degraded when incubated at 37oC in the presence of serum (thereby simulating physiologically relevant conditions). Stability varied widely between miRNAs, with half-lives ranging from similar to 1.5 hours to more than 13 hours. Notably, ex-miRNA half-lives calculated in two different biofluids (murine serum and C2C12 mouse myotube conditioned medium) were highly similar, suggesting that intrinsic sequence properties are a determining factor in miRNA stability. By contrast, ex-miRNAs associated with extracellular vesicles (isolated by size exclusion chromatography) were highly stable. The release of ex-miRNAs from C2C12 myotubes was measured over time, and mathematical modelling revealed miRNA-specific release kinetics. While some ex-miRNAs reached the steady state in cell culture medium within 24 hours, the extracellular level of miR-16 did not reach equilibrium, even after 3 days in culture. These findings are indicative of miRNA-specific release and degradation kinetics with implications for the utility of ex-miRNAs as biomarkers, and for the potential of ex-miRNAs to transfer gene regulatory information between cells

Characteristics of 24 SARS-CoV-2-Sequenced Reinfection Cases in a Tertiary Hospital in Spain

SARS-CoV-2; Clinical features; ReinfectionSARS-CoV-2; Características clínicas; ReinfecciónSARS-CoV-2; Característiques clíniques; ReinfeccióBackground: Since the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the main concern is whether reinfections are possible, and which are the associated risk factors. This study aims to describe the clinical and molecular characteristics of 24 sequence-confirmed reinfection SARS-CoV-2 cases over 1 year in Barcelona (Catalonia, Spain). Methods: Patients with > 45 days between two positive PCR tests regardless of symptoms and negative tests between episodes were initially considered as suspected reinfection cases from November 2020 to May 2021. Whole-genome sequencing (WGS) was performed to confirm genetic differences between consensus sequences and for phylogenetic studies based on PANGOLIN nomenclature. Reinfections were confirmed by the number of mutations, change in lineage, or epidemiological criteria. Results: From 39 reported suspected reinfection cases, complete viral genomes could be sequenced from both episodes of 24 patients, all were confirmed as true reinfections. With a median age of 44 years (interquartile range [IQR] 32–65), 66% were women and 58% were healthcare workers (HCWs). The median days between episodes were 122 (IQR 72–199), occurring one-third within 3 months. Reinfection episodes were frequently asymptomatic and less severe than primary infections. The absence of seroconversion was associated with symptomatic reinfections. Only one case was reinfected with a variant of concern (VOC). Conclusion: Severe acute respiratory syndrome coronavirus 2 reinfections can occur in a shorter time than previously reported and are mainly found in immunocompetent patients. Surveillance through WGS is useful to identify viral mutations associated with immune evasion.This research was supported by CIBER -Consorcio Centro de Investigación Biomédica en Red- (CB 2021), Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación and Unión Europea – NextGenerationEU

A year living with SARS-CoV-2: an epidemiological overview of viral lineage circulation by whole-genome sequencing in Barcelona city (Catalonia, Spain)

Catalonia; SARS-CoV-2; Molecular epidemiologyCataluña; SARS-CoV-2; Epidemiología molecularCatalunya; SARS-CoV-2; Epidemiologia molecularHerein, we describe the genetic diversity of circulating SARS-CoV-2 viruses by whole-genome sequencing (WGS) in Barcelona city (Catalonia, Spain) throughout the first four pandemic waves. From weeks 11/2020–24/2021, SARS-CoV-2-positive respiratory samples were randomly selected per clinical setting (80% from primary care or 20% from the hospital), age group, and week. WGS was performed following the ARTICv3 protocol on MiSeq or NextSeq2000 Illumina platforms. Nearly complete consensus sequences were used for genetic characterization based on GISAID and PANGOLIN nomenclatures. From 2475 samples, 2166 (87%) were fully sequenced (78% from primary care and 22% from hospital settings). Multiple genetic lineages were co-circulating, but four were predominant at different periods. While B.1.5 (50.68%) and B.1.1 (32.88%) were the major lineages during the first pandemic wave, B.1.177 (66.85%) and B.1.1.7 (83.80%) were predominant during the second, third, and fourth waves, respectively. Almost all (96.4%) were carrying D614G mutation in the S protein, with additional mutations that define lineages or variants. But some mutations of concern, such as E484K from B.1.351 and P.1 lineages are currently under monitoring, together with those observed in the receptor-binding domain or N-terminal domain, such as L452R and T478K from B.1.617.2 lineage. The fact that a predominant lineage was observed in each pandemic wave suggests advantageous properties over other contemporary co-circulating variants. This genetic variability should be monitored, especially when a massive vaccination campaign is ongoing because the potential selection and emergence of novel antigenic SARS-CoV-2 strains related to immunological escapement events.This work was supported by Spanish Network for the Research in Infectious Diseases: [Grant Number REIPI RD16/0016/0003]; Centro para el Desarrollo Tecnológico Industrial (CDTI) from the Spanish Ministry of Economy and Business [Grant Number IDI-20200297]; Direcció General de Recerca i Innovació en Salut (DGRIS); European Development Regional Fund (ERDF) “A way to achieve Europe” by Spanish Network for Research in Infectious Diseases [REIPI RD16/0016/0003]

β-Cyclodextrins as affordable antivirals to treat coronavirus infection

The SARS-CoV-2 pandemic made evident that there are only a few drugs against coronavirus. Here we aimed to identify a cost-effective antiviral with broad spectrum activity and high safety profile. Starting from a list of 116 drug candidates, we used molecular modelling tools to rank the 44 most promising inhibitors. Next, we tested their efficacy as antivirals against α and β coronaviruses, such as the HCoV-229E and SARS-CoV-2 variants. Four drugs, OSW-1, U18666A, hydroxypropyl-β-cyclodextrin (HβCD) and phytol, showed in vitro antiviral activity against HCoV-229E and SARS-CoV-2. The mechanism of action of these compounds was studied by transmission electron microscopy and by fusion assays measuring SARS-CoV-2 pseudoviral entry into target cells. Entry was inhibited by HβCD and U18666A, yet only HβCD inhibited SARS-CoV-2 replication in the pulmonary Calu-3 cells. Compared to the other cyclodextrins, β-cyclodextrins were the most potent inhibitors, which interfered with viral fusion via cholesterol depletion. β-cyclodextrins also prevented infection in a human nasal epithelium model ex vivo and had a prophylactic effect in the nasal epithelium of hamsters in vivo. All accumulated data point to β-cyclodextrins as promising broad-spectrum antivirals against different SARS-CoV-2 variants and distant alphacoronaviruses. Given the wide use of β-cyclodextrins for drug encapsulation and their high safety profile in humans, our results support their clinical testing as prophylactic antivirals

β-Cyclodextrins as affordable antivirals to treat coronavirus infection

The SARS-CoV-2 pandemic made evident that there are only a few drugs against coronavirus. Here we aimed to identify a cost-effective antiviral with broad spectrum activity and high safety profile. Starting from a list of 116 drug candidates, we used molecular modelling tools to rank the 44 most promising inhibitors. Next, we tested their efficacy as antivirals against α and β coronaviruses, such as the HCoV-229E and SARS-CoV-2 variants. Four drugs, OSW-1, U18666A, hydroxypropyl-β-cyclodextrin (HβCD) and phytol, showed in vitro antiviral activity against HCoV-229E and SARS-CoV-2. The mechanism of action of these compounds was studied by transmission electron microscopy and by fusion assays measuring SARS-CoV-2 pseudoviral entry into target cells. Entry was inhibited by HβCD and U18666A, yet only HβCD inhibited SARS-CoV-2 replication in the pulmonary Calu-3 cells. Compared to the other cyclodextrins, β-cyclodextrins were the most potent inhibitors, which interfered with viral fusion via cholesterol depletion. β-cyclodextrins also prevented infection in a human nasal epithelium model ex vivo and had a prophylactic effect in the nasal epithelium of hamsters in vivo. All accumulated data point to β-cyclodextrins as promising broad-spectrum antivirals against different SARS-CoV-2 variants and distant alphacoronaviruses. Given the wide use of β-cyclodextrins for drug encapsulation and their high safety profile in humans, our results support their clinical testing as prophylactic antivirals.This work has been funded by grant RTI2018-094445-B100 (MCIU/AEI/FEDER, UE) from the Ministry of Science and Innovation of Spain (C.R.), by Palex Medical S.A., Sika S.A.U. and 7 more companies, and by Ms. Raquel Casaus Alvarez, Mr. Miguel Pardo Gil, Mr. Jacques Noguès and a total of 2916 citizens through the Precipita crowdfunding platform of Fecyt (Fundación Española para la Ciencia y la Tecnología). NI-U is supported by the Spanish Ministry of Science and Innovation (grant PID2020-117145RB-I00), EU HORIZON-HLTH-2021-CORONA-01 (grant 101046118) and by institutional funding of Grifols, Pharma Mar, HIPRA, Amassence and Palobiofarma. This work used the computational resources of the Centro de Supercomputación de Galicia (CESGA) supported by the Partnership for Advanced Computing in Europe (PRACE) COVID-19 Fast Track Call for Proposals – Allocation Decision – Proposal COVID19-85.info:eu-repo/semantics/publishedVersio