Pharmacological iron-chelation as an assisted nutritional immunity strategy against Piscirickettsia salmonis infection

Indexación ScopusSalmonid Rickettsial Septicaemia (SRS), caused by Piscirickettsia salmonis, is a severe bacterial disease in the Chilean salmon farming industry. Vaccines and antibiotics are the current strategies to fight SRS; however, the high frequency of new epizootic events confirms the need to develop new strategies to combat this disease. An innovative opportunity is perturbing the host pathways used by the microorganisms to replicate inside host cells through host-directed antimicrobial drugs (HDAD). Iron is a critical nutrient for P. salmonis infection; hence, the use of iron-chelators becomes an excellent alternative to be used as HDAD. The aim of this work was to use the iron chelator Deferiprone (DFP) as HDAD to treat SRS. Here, we describe the protective effect of the iron chelator DFP over P. salmonis infections at non-antibiotic concentrations, in bacterial challenges both in vitro and in vivo. At the cellular level, our results indicate that DFP reduced the intracellular iron content by 33.1% and P. salmonis relative load during bacterial infections by 78%. These findings were recapitulated in fish, where DFP reduced the mortality of rainbow trout challenged with P. salmonis in 34.9% compared to the non-treated group. This is the first report of the protective capacity of an iron chelator against infection in fish, becoming a potential effective host-directed therapy for SRS and other animals against ferrophilic pathogens. © 2020, The Author(s).https://veterinaryresearch.biomedcentral.com/articles/10.1186/s13567-020-00845-

Testing the stress gradient hypothesis in soil bacterial communities associated with vegetation belts in the Andean Atacama Desert

17 Pág.Soil microorganisms are in constant interaction with plants, and these interactions shape the composition of soil bacterial communities by modifying their environment. However, little is known about the relationship between microorganisms and native plants present in extreme environments that are not affected by human intervention. Using high-throughput sequencing in combination with random forest and co-occurrence network analyses, we compared soil bacterial communities inhabiting the rhizosphere surrounding soil (RSS) and the corresponding bulk soil (BS) of 21 native plant species organized into three vegetation belts along the altitudinal gradient (2400-4500 m a.s.l.) of the Talabre-Lejía transect (TLT) in the slopes of the Andes in the Atacama Desert. We assessed how each plant community influenced the taxa, potential functions, and ecological interactions of the soil bacterial communities in this extreme natural ecosystem. We tested the ability of the stress gradient hypothesis, which predicts that positive species interactions become increasingly important as stressful conditions increase, to explain the interactions among members of TLT soil microbial communities.This study was funded by ANID FONDECYT Grants 1201278 to MG, 11200319 to DM, 3190194 to JM and 1211893 to VC, and ANID-MILENIO-CN2021-044. LAC was supported by ANID FB21006 and ACT210038. AG was supported by ANID Ph.D. Fellowship 21210808. Research was supported by the "Severo Ochoa Program for Centers of Excellence in R&D" from the Agencia Estatal de Investigación of Spain (Grant SEV-2016-0672 (2017-2021)) to the CBGP. BG-J was supported by a Postdoctoral contract associated to the Severo Ochoa Program. In addition, this research was partially supported by the supercomputing infrastructure of the NLHPC (ECM-02) (Powered@NLHPC).Peer reviewe

: Edificios Colectivos de la Caja del Seguro Obrero Obligatorio de Tocopilla, 1939-41. Movimiento moderno, solución social. Ediciones Retruecanosinversos, Tocopilla

Edificios Colectivos de la Caja del Seguro Obrero Obligatorio de Tocopilla, 1939-41. Movimiento moderno, solución social. Ediciones Retruecanosinversos, TocopillaInternational audienceEdificios Colectivos de la Caja del Seguro Obrero Obligatorio de Tocopilla, 1939-41. Movimiento moderno, solución social. Ediciones Retruecanosinversos, Tocopill

Edificios máquinas: Arquitectura Moderna y disciplinaria del Frente Popular Tocopilla

International audienceMachinery Buildings: Disciplinary and Modern Architecture of the Popular Front in Tocopilla 1 RESUMEN/ En el presente artículo se caracteriza un proceso de producción arquitectónica sustentada en el Movimiento Moderno en la ciudad de Tocopilla, durante el gobierno del Frente Popular. Se examinan las dimensiones urbana, social, arquitectónica y biopolítica como horizontes ideológicos que activaron la reacción gubernamental frente a una crisis socioeconómica. ABSTRACT/ This article describes an architecture production process supported by the Modern Movement in the city of Tocopilla during the Popular Front's administration. Urban, social, architectural and biopolitical aspects are discussed as ideological horizons that triggered governmental action facing a socioeconomic crisis. Palabras clave/ Arquitectura moderna, biopolítica, Frente Popular, Luciano Kulczewski

Tele-production of miningscapes in the open-pit era: The case of low-grade copper, Bingham Canyon, US and Chuquicamata, Chile (1903–1923)

International audienceIn 1906, the Guggenheim Exploration Company (GUGGENEX), financed the low-grade copper project that Daniel Cowen Jackling had started three years earlier at Bingham Canyon (Utah, US). With GUGGENEX's investment, the exploitation of copper entered into the open-pit mining era. Nine years later, the Guggenheims applied the industrial experience acquired in Bingham Canyon in the opening of the Chuquicamata Mine (northern Chile). In both cases, all the crucial decisions about the mining were made in Manhattan, New York, while the local territories faced these projects' outcomes. From a geohistorical standpoint, and through the analysis of several archives, in this paper, we explore how the extractive territories associated with these mines were remotely produced, transformed, and redefined; becoming “teleconnected miningscapes”. We aimed to visualize how the cross-sector partnership between large economic groups—GUGGENEX—and scientific personalities was essential in the emergence of open-pit copper mining. We argue that the miningscapes produced in Bingham Canyon and Chuquicamata mines are an entanglement of scientific discourses, research (geology and metallurgy), materialities (capital and technology), human bodies (workers) and nature (copper porphyries, water, air, etc.) that were unevenly and remotely produced from the headquarters of GUGGENEX

RISK ANALYSIS AND MACHINE PROTECTION OF SIS100

Abstract To ensure safe functionality and reduce unnecessary shutdowns, a risk analysis of the main driver accelerator for the FAIR project SIS100, has been done. The analysis includes all major technical systems and was done accordingly to EN 61508. Results of the analysis and appropriate countermeasures for detection and/or mitigation of the failures are presented. Furthermore, an estimation of the accelerator's availability is given

Ashes of the Anthropocene:Carbon Omissions and Toxic Stratigraphy in Tocopilla (Chile)

This article offers a transdisciplinary critique of “carbon neutrality”. We present a situated analysis of energy production for large-scale copper and lithium mining in the city of Tocopilla (northern Chile). Examining the social and material transformations triggered by the production of energy for large-scale mining during the 20th century, this article problematizes carbon neutrality by demonstrating how large-scale mining corporations in Chile claim emissions reduction by producing carbon omissions, most notably by ignoring the toxic sediments of fuel combustion. We see these residuesas the ashes of the Anthropocene. To render them visible, we experiment with a situated toxic stratigraphy, aimed at visualizing the historical processes that preceded the accumulation of ash on the Quaternary sediments of the coastal bluff. This visualization also explores the current and future effects of the interaction between stratigraphic layers. Ultimately, our analysis of Tocopilla shows how the carbon neutrality claimed by the mining industry functions as a capitalist abstraction, one that can onlysucceed by omitting the material and toxic transformations triggered by the so-called energy transition, which in the material world is actually a mining transition

Testing the stress gradient hypothesis in soil bacterial communities associated with vegetation belts in the Andean Atacama Desert

Abstract Background Soil microorganisms are in constant interaction with plants, and these interactions shape the composition of soil bacterial communities by modifying their environment. However, little is known about the relationship between microorganisms and native plants present in extreme environments that are not affected by human intervention. Using high-throughput sequencing in combination with random forest and co-occurrence network analyses, we compared soil bacterial communities inhabiting the rhizosphere surrounding soil (RSS) and the corresponding bulk soil (BS) of 21 native plant species organized into three vegetation belts along the altitudinal gradient (2400–4500 m a.s.l.) of the Talabre–Lejía transect (TLT) in the slopes of the Andes in the Atacama Desert. We assessed how each plant community influenced the taxa, potential functions, and ecological interactions of the soil bacterial communities in this extreme natural ecosystem. We tested the ability of the stress gradient hypothesis, which predicts that positive species interactions become increasingly important as stressful conditions increase, to explain the interactions among members of TLT soil microbial communities. Results Our comparison of RSS and BS compartments along the TLT provided evidence of plant-specific microbial community composition in the RSS and showed that bacterial communities modify their ecological interactions, in particular, their positive:negative connection ratios in the presence of plant roots at each vegetation belt. We also identified the taxa driving the transition of the BS to the RSS, which appear to be indicators of key host-microbial relationships in the rhizosphere of plants in response to different abiotic conditions. Finally, the potential functions of the bacterial communities also diverge between the BS and the RSS compartments, particularly in the extreme and harshest belts of the TLT. Conclusions In this study, we identified taxa of bacterial communities that establish species-specific relationships with native plants and showed that over a gradient of changing abiotic conditions, these relationships may also be plant community specific. These findings also reveal that the interactions among members of the soil microbial communities do not support the stress gradient hypothesis. However, through the RSS compartment, each plant community appears to moderate the abiotic stress gradient and increase the efficiency of the soil microbial community, suggesting that positive interactions may be context dependent. </jats:sec

Effects of sustainable agricultural practices on soil microbial diversity, composition, and functions

Soil microorganisms can provide multiple benefits to agroecosystems, which are assumed to be promoted by sustainable agricultural practices. However, the mechanisms that explain this relationship have not been clearly elucidated. Although studies have reported that sustainable agricultural practices promote microbial biomass, the broader implications for soil microbial composition and functions remain uncertain. Accordingly, we searched field experiments worldwide contrasting soil microbial communities under conventional and sustainable agricultural practices. We analysed 924 results of relative abundance of bacteria or fungi (using 16 S and ITS rRNA amplicon sequencing, respectively) at the Family taxonomic level obtained from 46 articles. We found higher soil bacterial richness and higher abundance of copiotrophic bacteria under sustainable agricultural practices. Organic fertilisation promoted the abundance of bacteria involved in C and N cycling, while conservation tillage decreased those involved in the decomposition of plant residue. While sustainable agricultural practices had a minor effect on the overall fungal structure, they led to increases in symbiotic fungi abundance (e.g., Geoglossaceae). Additionally, we observed a slight increase in arbuscular mycorrhizal fungi and a slight reduction in pathogenic fungi associated with plant disease (e.g., Botryosphaeriaceae). Higher soil microbial taxonomic diversity did not lead to increased soil multifunctionality; however, it could safeguard resilience for soil functions via the diversity insurance effect. This study establishes that sustainable agricultural practices can significantly influence microbial communities, leading to compositional and structural changes, as well as promoting relevant functions for agroecosystems. Altogether, these results highlight the importance of integrating concepts of community ecology into agricultural management practices for reaching sustainable agricultural systems