Barite formation in the ocean: Origin of amorphous and crystalline precipitates

We also thank editors and two anonymous reviewers for helpful comments that have significantly improved this contribution.Ocean export production is a key constituent in the global carbon cycle impacting climate. Past ocean export production is commonly estimated by means of barite and Barium proxies. However, the precise mechanisms underlying barite precipitation in the undersaturated marine water column are not fully understood. Here we present a detailed mineralogical and crystallographic analysis of barite from size-fractionated particulate material collected using multiple unit large volume in-situ filtration systems in the North Atlantic and the Southern Ocean. Our data suggest that marine barite forms from an initial amorphous phosphorus-rich phase that binds Ba, which evolves into barite crystals whereby phosphate groups are substituted by sulfate. Scanning electron microscopy observations also show the association of barite particles with organic matter aggregates and with extracellular polymeric substances (EPS). These results are consistent with experimental work showing that in bacterial biofilms Ba binds to phosphate groups in both cells and EPS, which promotes locally high concentrations of Ba leading to saturated microenvironments favoring barite precipitation. These results strongly suggest a similar precipitation mechanism in the ocean, which is consistent with the close link between bacterial production and abundance of Ba-rich particulates in the water column. We argue that EPS play a major role in mediating barite formation in the undersaturated oceanic water column; specifically, increased productivity and organic matter degradation in the mesopelagic zone would entail more extensive EPS production, thereby promoting Ba bioaccumulation and appropriate microenvironments for barite precipitation. This observation contributes toward better understanding of Ba proxies and their utility for reconstructing past ocean export productivity. This article is part of a special issue entitled: “Cycles of trace elements and isotopes in the ocean – GEOTRACES and beyond” - edited by Tim M. Conway, Tristan Horner, Yves Plancherel, and Aridane G. González.This study was supported by the European Regional Development Fund (ERDF) co-financed grants CGL2015-66830-R and CGL2017- 92600-EXP (MINECO Secretaría de Estado de Investigación, Desarrollo e Innovación, Spain), Research Group RNM-179 and BIO 103 (Consejería de Economía, Innovación, Ciencia y Empleo, Junta de Andalucía) and the University of Granada (Unidad Científica de Excelencia UCE-PP2016-05). We thank the Center for Scientific Instrumentation (CIC, University of Granada), the Warm Core Rings project, and NSF OCE- 0961660 for supporting sample collection during MV1101

Proyecto de construcción de una conservera y envasadora de garbanzos en el término municipal de Ayerbe (Huesca).

En el presente Trabajo de Final de Grado se describen las necesidades constructivas para la instalación y puesta en funcionamiento de una industria destinada al almacenamiento, selección, conserva y envasado de garbanzos. El proyecto está localizado en el municipio de Ayerbe (Huesca), dentro del Parque Industrial de Ayerbe. La producción anual de la planta de procesado es de 1.000 toneladas de producto terminado, de las cuales 750 toneladas son de conservas de garbanzos y 250 toneladas son de garbanzos secos. En primer lugar, se realiza un análisis del sector de las leguminosas y del garbanzo, (superficie del cultivo, producción, mercado interior y exterior, etc) y un estudio del entorno donde va a tener lugar el emplazamiento. A continuación, se describe el proceso productivo y el balance de materia, seguido de la maquinaria necesaria para su funcionamiento. Posteriormente, se establecen las zonas de la planta industrial y se realizan los cálculos estructurales y de las instalaciones (fontanería, saneamiento, eléctrica, etc), apoyadas con planos.Una vez obtenido el presupuesto de la obra civil, maquinaria y equipos, y seguridad y salud, se realiza el estudio de viabilidad económica. Finalmente, se ejecuta el pliego de condiciones y el estudio de seguridad y salud.<br /

Unique genetic profile of sporadic colorectal cancer liver metastasis versus primary tumors by SNP-Arrays

Trabajo presentado como póster al XXVI Congreso Nacional de Genética Humana y a la XIX Reunión Anual de la SEGCD celebradas en Murcia del 30 de marzo al 1 de abril del 2011.-- et al.Peer reviewe

Barium bioaccumulation by bacterial biofilms and implications for Ba cycling and use of Ba proxies

Supplementary Information accompanies this paper at https://doi.org/10.1038/s41467- 018-04069-z.Data availability. The datasets generated during the current study are available from the corresponding author.Ba proxies have been broadly used to reconstruct past oceanic export production. However, the precise mechanisms underlying barite precipitation in undersaturated seawater are not known. The link between bacterial production and particulate Ba in the ocean suggests that bacteria may play a role. Here we show that under experimental conditions marine bacterial biofilms, particularly extracellular polymeric substances (EPS), are capable of bioaccumulating Ba, providing adequate conditions for barite precipitation. An amorphous P-rich phase is formed at the initial stages of Ba bioaccumulation, which evolves into barite crystals. This supports that in high productivity regions where large amounts of organic matter are subjected to bacterial degradation, the abundant EPS would serve to bind the necessary Ba and form nucleation sites leading to barite precipitation. This also provides new insights into barite precipitation and opens an exciting field to explore the role of EPS in mineral precipitation in the ocean.This study was supported by the European Regional Development Fund (ERDF) cofinanced grant CGL2015-66830-R (MINECO Secretaría de Estado de Investigación, Desarrollo e Innovación, Spain), Research Groups BIO 103 and RNM-179 (Junta de Andalucía), and the University of Granada (Unidad Científica de Excelencia UCEPP2016-05)

Influence of hydrophobic matching on association of model transmembrane fragments containing a minimised glycophorin A dimerisation motif

The principles that govern the folding and packing of membrane proteins are still not completely understood. In the present work, we have revisited the glycophorin A (GpA) dimer- isation motif that mediates transmembrane (TM) helix associa- tion, one of the best-suited models of membrane protein oligomerisation. By using artificial polyleucine TM segments we have demonstrated in this study that a pattern of only five amino acids (GVxxGVxxT) promotes specific dimerisation. Fur- ther, we have used this minimised GpA motif to assess the influ- ence of hydrophobic matching on the TM helix packing process in detergent micelles and found that this factor modulates helix-helix association and/or dissociation between TM fragments

Unlocking the bentonite microbial diversity and its implications in selenium bioreduction and biotransformation: Advances in deep geological repositories

Selenium, 79Se, is one of the most critical radionuclides in radioactive waste disposed in future deep geological repositories (DGRs). Here, we investigate the impact of bentonite microbial communities on the allotropic transformation of Se(IV) bioreduction products under DGR relevant conditions. In addition, Se amendmentdependent shifts in the bentonite microbial populations are assessed. Microcosms of water-saturated bentonites were spiked with a bacterial consortium, treated with selenite and incubated anaerobically for six months. A combination of X-Ray Absorption Spectroscopy, Electron Microscopy, and Raman Spectroscopy was used to track the allotropic changes of the Se bioreduction products. Interestingly, the color of bentonite shifted from orange to black in the selenite-treated microcosms. In the orange layers, amorphous or monoclinic Se(0) were identified, whilst black precipitates consisted of stable trigonal Se(0) form. Illumina DNA sequencing indicated the distribution of strains with Se(IV) reducing and Se(0) allotropic biotransformation potential, like Pseudomonas, Stenotrophomonas, Desulfosporosinus, and unclassified-Desulfuromonadaceae. The archaea Methanosarcina decreased its abundance in the presence of Se(IV), probably caused by this oxyanion toxicity. These findings provide an understanding of the bentonite microbial strategies involved in the immobilization of Se(IV) by reduction processes, and prove their implication in the allotropic biotransformation from amorphous to trigonal Se(0) under DGR relevant conditions.Spanish Government RTI2018.101548.B.I00 FPU 14/0426

Spatio-temporal tumor heterogeneity in metastatic CRC tumors: A mutational-based approach

It is well known that activating mutations in the KRAS and NRAS genes are associated with poor response to anti-EGFR therapies in patients with metastatic colorectal cancer (mCRC). Approximately half of the patients with wild-type (WT) KRAS colorectal carcinoma do not respond to these therapies. This could be because the treatment decision is determined by the mutational profile of the primary tumor, regardless of the presence of small tumor subclones harboring RAS mutations in lymph nodes or liver metastases. We analyzed the mutational profile of the KRAS, NRAS, BRAF and PI3KCA genes using low-density microarray technology in samples of 26 paired primary tumors, 16 lymph nodes and 34 liver metastases from 26 untreated mCRC patients (n=76 samples). The most frequent mutations found in primary tumors were KRAS (15%) and PI3KCA (15%), followed by NRAS (8%) and BRAF (4%). The distribution of the mutations in the 16 lymph node metastases analyzed was as follows: 4 (25%) in KRAS gene, 3 (19%) in NRAS gene and 1 mutation each in PI3KCA and BRAF genes (6%). As expected, the most prevalent mutation in liver metastasis was in the KRAS gene (35%), followed by PI3KCA (9%) and BRAF (6%). Of the 26 cases studied, 15 (58%) displayed an overall concordance in the mutation status detected in the lymph node metastases and liver metastases compared with primary tumor, suggesting no clonal evolution. In contrast, the mutation profiles differed in the primary tumor and lymph node/metastases samples of the remaining 11 patients (48%), suggesting a spatial and temporal clonal evolution. We confirm the presence of different mutational profiles among primary tumors, lymph node metastases and liver metastases. Our results suggest the need to perform mutational analysis in all available tumor samples of patients before deciding to commence anti-EGFR treatment.This work has been partially supported by grants from the Instituto de Salud Carlos III (ISCIII; Ministerio de Sanidad y Consumo, Madrid, Spain) (PI18/00282), the Gerencia Regional de Salud de Castilla y León, Valladolid, Spain (GRS1302/A/16), the RTICC of the ISCIII (RD12/0020/0035-FEDER, RD12/0036/0048-FEDER) and CIBERONC (CB16/12/00400 and CB16/12/00233), the Fundación Memoria de Don Samuel Solórzano Barruso (Salamanca, Spain) and the Fundación Eugenio Rodríguez Pascual, (Madrid, Spain). JM Sayagués and ME Sarasquete are supported by grants (CES11/004 and CP13/00080) from the ISCIII, Ministerio de Ciencia e Innovación, Madrid, Spain

Identification and characterization of the gene expression profiles for protein coding and non-coding RNAs of pancreatic ductal adenocarcinomas

This is an open-access article distributed under the terms of the Creative Commons Attribution License.Significant advances have been achieved in recent years in the identification of the genetic and the molecular alterations of pancreatic ductal adenocarcinoma (PDAC). Despite this, at present the understanding of the precise mechanisms involved in the development and malignant transformation of PDAC remain relatively limited. Here, we evaluated for the first time, the molecular heterogeneity of PDAC tumors, through simultaneous assessment of the gene expression profile (GEP) for both coding and non-coding genes of tumor samples from 27 consecutive PDAC patients. Overall, we identified a common GEP for all PDAC tumors, characterized by an increased expression of genes involved in PDAC cell proliferation, local invasion and metastatic capacity, together with a significant alteration of the early steps of the cellular immune response. At the same time, we confirm and extend on previous observations about the genetic complexity of PDAC tumors as revealed by the demonstration of two clearly distinct and unique GEPs (e.g. epithelial-like vs. mesenchymal-like) reflecting the alteration of different signaling pathways involved in the oncogenesis and progression of these tumors. Our results also highlight the potential role of the immune system microenvironment in these tumors, with potential diagnostic and therapeutic implications.This work has been partially supported by grants from the Gerencia Regional de Salud de Castilla y León, Valladolid, Spain (GRS861/A/13), RTICC from the Instituto de Salud Carlos III, Ministerio de Sanidad y Consumo, Madrid, Spain (RD06/0020/0035-FEDER; RD12/0036/0048-FEDER), Fundación Memoria de Don Samuel Solórzano Barruso, Salamanca, Spain (FS/13-2012 and FS/16-2013). JM Sayagués is supported by grant CP05/00321 from the Ministerio de Ciencia e Innovación, Madrid, Spain.Peer Reviewe

Nonuniversality of front fluctuations for compact colonies of nonmotile bacteria

The front of a compact bacterial colony growing on a Petri dish is a paradigmatic instance of non-equilibrium f luctuations in the celebrated Eden, or Kardar-Parisi-Zhang (KPZ), universality class. While in many experiments the scaling exponents crucially differ from the expected KPZ values, the source of this disagreement has remained poorly understood. We have performed growth experiments with B. subtilis 168 and E. coli ATCC 25922 under conditions leading to compact colonies in the classically alleged Eden regime, where individual motility is suppressed. Non-KPZ scaling is indeed observed for all accessible times, KPZ asymptotics being ruled out for our experiments due to the monotonic increase of front branching with time. Simulations of an effective model suggest the occurrence of transient nonuniversal scaling due to diffusive morphological instabilities, agreeing with expectations from detailed models of the relevant biological reaction-diffusion processe

Nonuniversality of front fluctuations for compact colonies of nonmotile bacteria

The front of a compact bacterial colony growing on a Petri dish is a paradigmatic instance of non-equilibrium fluctuations in the celebrated Eden, or Kardar-Parisi-Zhang (KPZ), universality class. While in many experiments the scaling exponents crucially differ from the expected KPZ values, the source of this disagreement has remained poorly understood. We have performed growth experiments with B. subtilis 168 and E. coli ATCC 25922 under conditions leading to compact colonies in the classically alleged Eden regime, where individual motility is suppressed. Non-KPZ scaling is indeed observed for all accessible times, KPZ asymptotics being ruled out for our experiments due to the monotonic increase of front branching with time. Simulations of an effective model suggest the occurrence of transient nonuniversal scaling due to diffusive morphological instabilities, agreeing with expectations from detailed models of the relevant biological reaction-diffusion processes.This work has been supported by Ministerio de Economía y Competitividad, Agencia Estatal de Investigación, and Fondo Europeo de Desarrollo Regional (Spain and European Union) through Grants No. FIS2015- 66020-C2-1-P, FIS2015-69167-C2-1-P, FIS2015-73337-JIN, and BIO2016-79618-R, and by Comunidad Autónoma de Madrid (Spain) Grant No. NANOAVANSENS S2013/MIT302