Performance of Chlorella Vulgaris Exposed to Heavy Metal Mixtures: Linking Measured Endpoints and Mechanisms

Microalgae growth inhibition assays are candidates for referent ecotoxicology as a fundamental part of the strategy to reduce the use of fish and other animal models in aquatic toxicology. In the present work, the performance of Chlorella vulgaris exposed to heavy metals following standardized growth and photosynthesis inhibition assays was assessed in two different scenarios: (1) dilutions of single heavy metals and (2) an artificial mixture of heavy metals at similar levels as those found in natural rivers. Chemical speciation of heavy metals was estimated with Visual MINTEQ software; free heavy metal ion concentrations were used as input data, together with microalgae growth and photosynthesis inhibition, to compare different effects and explain possible toxicity mechanisms. The final goal was to assess the suitability of the ecotoxicological test based on the growth and photosynthesis inhibition of microalgae cultures, supported by mathematic models for regulatory and decision-making purposes. The C. vulgaris algae growth inhibition test was more sensitive for As, Zn, and Pb exposure whereas the photosynthesis inhibition test was more sensitive for Cu and Ni exposure. The effects on growth and photosynthesis were not related. C. vulgaris evidenced the formation of mucilaginous aggregations at lower copper concentrations. We found that the toxicity of a given heavy metal is not only determined by its chemical speciation; other chemical compounds (as nutrient loads) and biological interactions play an important role in the final toxicity. Predictive mixture effect models tend to overestimate the effects of metal mixtures in C. vulgaris for both growth and photosynthesis inhibition tests. Growth and photosynthesis inhibition tests give complementary information, and both are a fast, cheap, and sensitive alternative to animal testing. More research is needed to solve the challenge of complex pollutant mixtures as they are present in natural environments, where microalgae-based assays can be suitable monitoring tools for pollution management and regulatory purposes. Keywords: PAM; heavy metal mixtures; metals speciation; microalgae; toxicity

Energy consumption in sharp and non-sharp splits of ideal ternary mixtures

Most of the distillation processes deal with multicomponent mixtures, existing a great quantity of distillation sequences for this process. The sharp splits available for an ideal ternary mixture are the direct and the inverse distillation sequence scheme in which the compounds are separated in two different columns. There are nonsharp splits in which all the compounds are separated in a single distillation column that can incorporate a side column. Unfortunately, to choose non-sharp splits schemes, there is no heuristic that can provide information about the recommended cases, e.g. a single distillation column in which the intermediate boiling compound is collected by a side stream at the required purity or by other possibilities, such as the use of a side stripper or a side rectifier. The literature about this subject is very scarce, and many times when the non-sharp splits are used, no comparison with the sharp split alternatives is provided. Therefore, the cases for which the literature suggests the use of side columns are further studied, e.g. BTX (Benzene, Toluene, Xylene) mixtures separation. For many case studies, the results obtained show that the energy savings achieved, due to the use of side columns, are not significantly higher than the best sharp split process schemes. However, these results do not discard that for some other situations; the side column could be the most advantageous case. Usually, it is considered that when the desired purity of the main product in a stream is reached, the impurities proportion do not affect significantly the energy consumption, and for most of the systems, this is true. However, for a mixture with a molar composition of 10 % isopentane, 10 % pentane and 80 % hexane (mol), when split in the respective compounds at a purity of 95 % (mol), very different energy requirements are depicted depending on the proportion of isopentane and hexane, present in the pentane stream obtained in a direct sequence process . The rigorous simulation results illustrate that almost 60% of the energy required to separate the abovementioned mixture is saved when the pentane stream carries a mixture of isopentane and hexane. In addition, the environmental impact has been analyzed for each case studied, being reduced in the same way as the energy consumption doe

What burned the forest? Wildfires, climate change and human activity in the Mesolithic – Neolithic transition in SE Iberian Peninsula

Climate variability such as higher or lower temperatures, changing precipitation patterns, shifts in plant communities and other climate-related changes have particularly affected areas with Mediterranean-type climates. A multi-proxy analysis including pollen, sedimentary charcoal, mineralogy and Summed Probability Distributions (SPD) of archaeological 14C dates, allowed the reconstruction of landscape change, geomorphological evolution and fire history at the Laguna de Villena, in the southeastern Iberian Peninsula, during the Mesolithic-Neolithic transition. The Villena paleolake was sensitive to Early Holocene and Middle Holocene regional climatic variability that included several arid phases (around 8.2 ka cal BP, 6.8 ka cal BP and 5.9 ka cal BP) according to geochemical and pollen data. During this period, landscape dynamics show the degradation of oak forests and expansion of pyrophytic pine forests and shrublands, as well as open spaces predominated by grasses. The charcoal record shows a decreasing trend of biomass burned from 8.5 ka cal BP onwards, although fire peaks occurred recurrently during the Early and Middle Holocene. The most intense phase of fire activity was experienced in the last millennia of the Early Holocene, with five fire episodes from 9.1 to 8.4 ka cal BP, coinciding with a phase of higher archaeological evidence in the area. A decrease in archaeological evidence coincides with a gap in fire episodes during the Early Holocene-Middle Holocene transition, suggesting an effect of the abrupt 8.2 ka cal BP event on human activity and on landscape dynamics. After 8.0 ka cal BP, lowerer biomass burned is explained by the configuration of a more open landscape due to the combination of climate (increasing aridity) and increasing human activities in the region. The mineralogical and palynological data highlighted the interaction between human activities, climate and fire dynamics. The sedimentary charcoal record evidenced how most of the fire peaks did not occur in the context of dry episodes, as often assumed, deriving on an anthropogenic explanation related to Early and Late Mesolithic burning practices during a phase of higher archaeological evidence in the Villena paleolake surroundings. Afterwards, combined agropastoral activities from the Early Neolithic onwards and increasing aridity during the Middle Holocene maintained the forest clearances, in the context of fire episodes characterised by decreased biomass burned. This study shows how Middle Holocene palaeoecological records reflect complex histories blending climate and anthropogenic processes that derived in major landscape changes explaining the origin of current landscapes.This research has received funding from the European Research Council (ERC) under the Horizon 2020 research and innovation programme (Grant agreement No. 683018) to JFLdP. Additional analyses on the pollen data sets have been produced in the context of the research project PID2020-113664RB-100 supported by the Spanish Ministry of Science and Innovation. JFLdP is additionally supported by the Plan Gen-T program (Ref. CIDEGENT-18/040) of the Generalitat Valenciana. CSG is currently supported by a Margarita Salas fellowship (ref. MARSALAS21-22) funded by the European Union-Next Generation EU, the Spanish Ministry of Universities and the University of Alicante. JR, IE and FB are members of the research group GAPS (2017 SGR 836). JR acknowledges postdoctoral fellowship support from the Spanish “Juan de la Cierva Incorporación (IJC2020)” program (MICINN, Spain). The Institut Català de Paleoecologia Humana I Evolució Social (IPHES-CERCA) has received financial support from the Spanish Ministry of Science and Innovation through the “María de Maeztu'' program for Units of Excellence (CEX2019-000945-M). LS is granted by the ICREA Academia Program

La carta fundacional

Una declaració d'intencions

Identification of HIV-reservoir cells with reduced susceptibility to antibody-dependent immune response

HIV; Infectious disease; ReservoirVIH; Malalties infeccioses; ReservoriVIH; Enfermedades infecciosas; ReservorioHuman immunodeficiency virus (HIV) establishes a persistent infection in heterogeneous cell reservoirs, which can be maintained by different mechanisms including cellular proliferation, and represent the main obstacle to curing the infection. The expression of the Fcγ receptor CD32 has been identified as a marker of the active cell reservoirs in people on antiretroviral therapy (ART), but if its expression has any role in conferring advantage for viral persistence is unknown. Here, we report that HIV-infected cells expressing CD32 have reduced susceptibility to natural killer (NK) antibody-dependent cell cytotoxicity (ADCC) by a mechanism compatible with the suboptimal binding of HIV-specific antibodies. Infected CD32 cells have increased proliferative capacity in the presence of immune complexes, and are more resistant to strategies directed to potentiate NK function. Remarkably, reactivation of the latent reservoir from antiretroviral-treated people living with HIV increases the pool of infected CD32 cells, which are largely resistant to the ADCC immune mechanism. Thus, we report the existence of reservoir cells that evade part of the NK immune response through the expression of CD32.This study was supported by the Spanish Secretariat of Science and Innovation and FEDER funds (grants SAF2015-67334-R and RTI2018-101082-B-I00 [MINECO/FEDER]), the Spanish “Ministerio de Economia y Competitividad, Instituto de Salud Carlos III” (ISCIII, PI17/01470), GeSIDA and the Spanish AIDS network Red Temática Cooperativa de Investigación en SIDA (RD16/0025/0007), the Fundació La Marató TV3 (grants 201805-10FMTV3 and 201814-10FMTV3) and the Gilead fellowships GLD19/00084 and GLD18/00008. M.B is supported by the Miguel Servet program funded by the Spanish Health Institute Carlos III (CP17/00179). A.A-G is supported by the Spanish Secretariat of Science and Innovation Ph.D. fellowship (BES-2016–076382). The funders had no role in study design, data collection, and analysis, the decision to publish, or preparation of the manuscript

CNApp, a tool for the quantification of copy number alterations and integrative analysis revealing clinical implications.

Somatic copy number alterations (CNAs) are a hallmark of cancer, but their role in tumorigenesis and clinical relevance remain largely unclear. Here, we developed CNApp, a web-based tool that allows a comprehensive exploration of CNAs by using purity-corrected segmented data from multiple genomic platforms. CNApp generates genome-wide profiles, computes CNA scores for broad, focal and global CNA burdens, and uses machine learning-based predictions to classify samples. We applied CNApp to the TCGA pan-cancer dataset of 10,635 genomes showing that CNAs classify cancer types according to their tissue-of-origin, and that each cancer type shows specific ranges of broad and focal CNA scores. Moreover, CNApp reproduces recurrent CNAs in hepatocellular carcinoma and predicts colon cancer molecular subtypes and microsatellite instability based on broad CNA scores and discrete genomic imbalances. In summary, CNApp facilitates CNA-driven research by providing a unique framework to identify relevant clinical implications. CNApp is hosted at https://tools.idibaps.org/CNApp/

The landscape of genomic copy number alterations in colorectal cancer and their consequences on gene expression levels and disease outcome

This work has been supported by the Instituto de Salud Carlos III and co-funded by the European Regional Development Fund (ERDF) [CP13/00160, PI14/00783, PI17/01304 to JC]; the Agència de Gestió d'Ajuts Universitaris i de Recerca, Generalitat de Catalunya [2017 SGR 1035]; PERIS Generalitat de Catalunya [SLT002/16/00398 to JC]; Fundación Científica de la Asociación Española Contra el Cáncer [GCB13131592CAST]; the intramural program of the National Institutes of Health. CIBEREHD is funded by the Instituto de Salud Carlos III. This article is based upon work from COST Action [CA17118], supported by COST (European Cooperation in Science and Technology). RB is supported by a REACH HIGH Scholars Programme-PostDoctoral Grants. The grant is part-financed by the EU, Operational Programme II-Cohesion Policy 2014–2020 investing in human capital to create more opportunities and promote the wellbeing of society-European Social Fund.Aneuploidy, the unbalanced state of the chromosome content, represents a hallmark of most solid tumors, including colorectal cancer. Such aneuploidies result in tumor specific genomic imbalances, which emerge in premalignant precursor lesions. Moreover, increasing levels of chromosomal instability have been observed in adenocarcinomas and are maintained in distant metastases. A number of studies have systematically integrated copy number alterations with gene expression changes in primary carcinomas, cell lines, and experimental models of aneuploidy. In fact, chromosomal aneuploidies target a number of genes conferring a selective advantage for the metabolism of the cancer cell. Copy number alterations not only have a positive correlation with expression changes of the majority of genes on the altered genomic segment, but also have effects on the transcriptional levels of genes genome-wide. Finally, copy number alterations have been associated with disease outcome; nevertheless, the translational applicability in clinical practice requires further studies. Here, we (i) review the spectrum of genetic alterations that lead to colorectal cancer, (ii) describe the most frequent copy number alterations at different stages of colorectal carcinogenesis, (iii) exemplify their positive correlation with gene expression levels, and (iv) discuss copy number alterations that are potentially involved in disease outcome of individual patients.Publisher PDFPeer reviewe

La geografia a les aules: quin és el seu espai?

L'ensenyament de la geografia a les aules, tant a primària com a secundària, topa amb una sèrie de contradiccions que en fan necessari un profund replantejament. La formació del professorat i els màsters de formació, la predominança dels historiadors entre els professors de geografia, el seguiment dels llibres de text, la visió de la geografia com a ciència descriptiva, la pèrdua de continguts de la matèria al batxillerat i de pes específic a les PAU, el propi examen de les PAU, la lluita de les universitats per no perdre estudiants dels graus de geografia, els currículums i el nou model competencial... són els temes que aborda aquesta taula rodona a través de diferents visions, des de mestres de primària a coordinadors de la formació del professorat de secundària, passant per la percepció dels alumnes.Teaching geography in the classrooms, both in primary and secondary education, clashes with a series of contradictions that require a profound rethinking. Those are: teacher training and teacher training masters; the overwhelming predominance of historians among professors of geography; textbooks and the predominant vision of geography as a descriptive science; the reduction of geography contents in secondary education and its specific weight in the PAU (university access exams), or the PAU exam itself, the struggle of the universities not to lose students in geography degrees, the curricula and the new competence model… This paper summarizes the results of a round table around all these topics with contribution of different views from primary teachers to coordinators of secondary school teacher training, including the perception of students.La enseñanza de la geografía en las aulas, tanto en primaria como en secundaria, choca con una serie de contradicciones que hacen necesario un profundo replanteamiento. La formación del profesorado y los másters de formación, el predominio de los historiadores entre los profesores de geografía, el seguimiento de los libros de texto, la visión de la geografía como una ciencia descriptiva, la pérdida de contenidos de la materia en bachillerato y de peso específico en las PAU, el propio examen de las PAU, la lucha de las universidades para no perder estudiantes en los grados de geografía, los currículums i el nuevo modelo competencial… son los temas que aborda esta mesa redonda a través de diferentes visiones, desde maestros de primaria a coordinadores de la formación del profesorado de secundaria, pasando por la percepción de los alumnos