| 1. |
- Atsawawaranunt, Kamolphat, et al.
(author)
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The SISAL database : a global resource to document oxygen and carbon isotope records from speleothems
- 2018
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In: Earth System Science Data. - : Copernicus GmbH. - 1866-3508 .- 1866-3516. ; 10:3, s. 1687-1713
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Journal article (peer-reviewed)abstract
- Stable isotope records from speleothems provide information on past climate changes, most particularly information that can be used to reconstruct past changes in precipitation and atmospheric circulation. These records are increasingly being used to provide "out-of-sample" evaluations of isotope-enabled climate models. SISAL (Speleothem Isotope Synthesis and Analysis) is an international working group of the Past Global Changes (PAGES) project. The working group aims to provide a comprehensive compilation of speleothem isotope records for climate reconstruction and model evaluation. The SISAL database contains data for individual speleothems, grouped by cave system. Stable isotopes of oxygen and carbon (delta O-18, delta C-13) measurements are referenced by distance from the top or bottom of the speleothem. Additional tables provide information on dating, including information on the dates used to construct the original age model and sufficient information to assess the quality of each data set and to erect a standardized chronology across different speleothems. The metadata table provides location information, information on the full range of measurements carried out on each speleothem and information on the cave system that is relevant to the interpretation of the records, as well as citations for both publications and archived data.
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| 2. |
- Bernal, Ximena E., et al.
(author)
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Empowering Latina scientists
- 2019
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In: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 363:6429, s. 825-826
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Journal article (other academic/artistic)
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| 3. |
- Bru, Samuel, et al.
(author)
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Polyphosphate is involved in cell cycle progression and genomic stability in Saccharomyces cerevisiae
- 2016
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In: Molecular Microbiology. - : Wiley. - 0950-382X .- 1365-2958. ; 101:3, s. 367-380
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Journal article (peer-reviewed)abstract
- Polyphosphate (polyP) is a linear chain of up to hundreds of inorganic phosphate residues that is necessary for many physiological functions in all living organisms. In some bacteria, polyP supplies material to molecules such as DNA, thus playing an important role in biosynthetic processes in prokaryotes. In the present study, we set out to gain further insight into the role of polyP in eukaryotic cells. We observed that polyP amounts are cyclically regulated in Saccharomyces cerevisiae, and those mutants that cannot synthesise (vtc4 Delta) or hydrolyse polyP (ppn1 Delta, ppx1 Delta) present impaired cell cycle progression. Further analysis revealed that polyP mutants show delayed nucleotide production and increased genomic instability. Based on these findings, we concluded that polyP not only maintains intracellular phosphate concentrations in response to fluctuations in extracellular phosphate levels, but also muffles internal cyclic phosphate fluctuations, such as those produced by the sudden demand of phosphate to synthetize deoxynucleotides just before and during DNA duplication. We propose that the presence of polyP in eukaryotic cells is required for the timely and accurate duplication of DNA.
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| 4. |
- Comas-Bru, Laia, et al.
(author)
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Evaluating model outputs using integrated global speleothem records of climate change since the last glacial
- 2019
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In: Climate of the Past. - : Copernicus GmbH. - 1814-9324 .- 1814-9332. ; 15:4, s. 1557-1579
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Journal article (peer-reviewed)abstract
- Although quantitative isotope data from speleothems has been used to evaluate isotope-enabled model simulations, currently no consensus exists regarding the most appropriate methodology through which to achieve this. A number of modelling groups will be running isotope-enabled palaeoclimate simulations in the framework of the Coupled Model Intercomparison Project Phase 6, so it is timely to evaluate different approaches to using the speleothem data for data-model comparisons. Here, we illustrate this using 456 globally distributed speleothem delta O-18 records from an updated version of the Speleothem Isotopes Synthesis and Analysis (SISAL) database and palaeoclimate simulations generated using the ECHAM5-wiso isotope-enabled atmospheric circulation model. We show that the SISAL records reproduce the first-order spatial patterns of isotopic variability in the modern day, strongly supporting the application of this dataset for evaluating model-derived isotope variability into the past. However, the discontinuous nature of many speleothem records complicates the process of procuring large numbers of records if data-model comparisons are made using the traditional approach of comparing anomalies between a control period and a given palaeoclimate experiment. To circumvent this issue, we illustrate techniques through which the absolute isotope values during any time period could be used for model evaluation. Specifically, we show that speleothem isotope records allow an assessment of a model's ability to simulate spatial isotopic trends. Our analyses provide a protocol for using speleothem isotope data for model evaluation, including screening the observations to take into account the impact of speleothem mineralogy on delta O-18 values, the optimum period for the modern observational baseline and the selection of an appropriate time window for creating means of the isotope data for palaeo-time-slices.
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| 5. |
- Martínez-Hidalgo, Pilar, et al.
(author)
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Medicago root nodule microbiomes: insights into a complex ecosystem with potential candidates for plant growth promotion
- 2021
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In: Plant and Soil. - : Springer. - 0032-079X .- 1573-5036.
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Journal article (peer-reviewed)abstract
- Purpose: Studying the legume nodule microbiome is important for understanding the development and nutrition of the plants inhabited by the various microbes within and upon them. We analyzed the microbiomes of these underground organs from both an important crop plant (Medicago sativa) and a related legume (M. polymorpha) using metagenomic and culture-based techniques to identify the main cultivatable contributors to plant growth enhancement.Methods: Using high-throughput sequencing, culturing, and in planta techniques, we identified and analyzed a broad population of the bacterial taxa within Medicago nodules and the surrounding soil.Results: Fifty-one distinct bacterial strains were isolated and characterized from nodules of both Medicago species and their growth-promoting activities were studied. Sequencing of 16S rRNA gene amplicons showed that in addition to Ensifer, the dominant genus, a large number of Gram-positive bacteria belonging to the Firmicutes and Actinobacteria were also present. After performing ecological and plant growth-promoting trait analyses, selecting the most promising strains, and then performing in planta assays, we found that strains of Bacillus and Micromonospora among others could play important roles in supporting the growth, health, and productivity of the host plant.Conclusion: To our knowledge, the comparison of the biodiversity of the microbiota of undomesticated vs. cultivated Medicago roots and nodules is novel and shows the range of potential Plant Growth-Promoting Bacteria that could be used for plants of agricultural interest. These and other nodule-isolated microbes could also serve as inoculants with rhizobia with the goal of replacing synthetic fertilizers and pesticides for sustainable agriculture.
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| 6. |
- Wessén, Ella, et al.
(author)
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Spatial distribution of ammonia-oxidizing bacteria and archaea across a 44-hectare farm related to ecosystem functioning
- 2011
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In: Isme Journal. - : Springer Science and Business Media LLC. - 1751-7362 .- 1751-7370. ; 5:7, s. 1213-1225
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Journal article (peer-reviewed)abstract
- Characterization of spatial patterns of functional microbial communities could facilitate the understanding of the relationships between the ecology of microbial communities, the biogeochemical processes they perform and the corresponding ecosystem functions. Because of the important role the ammonia-oxidizing bacteria (AOB) and archaea (AOA) have in nitrogen cycling and nitrate leaching, we explored the spatial distribution of their activity, abundance and community composition across a 44-ha large farm divided into an organic and an integrated farming system. The spatial patterns were mapped by geostatistical modeling and correlations to soil properties and ecosystem functioning in terms of nitrate leaching were determined. All measured community components for both AOB and AOA exhibited spatial patterns at the hectare scale. The patchy patterns of community structures did not reflect the farming systems, but the AOB community was weakly related to differences in soil pH and moisture, whereas the AOA community to differences in soil pH and clay content. Soil properties related differently to the size of the communities, with soil organic carbon and total nitrogen correlating positively to AOB abundance, while clay content and pH showed a negative correlation to AOA abundance. Contrasting spatial patterns were observed for the abundance distributions of the two groups indicating that the AOB and AOA may occupy different niches in agro-ecosystems. In addition, the two communities correlated differently to community and ecosystem functions. Our results suggest that the AOA, not the AOB, were contributing to nitrate leaching at the site by providing substrate for the nitrite oxidizers. The ISME Journal (2011) 5, 1213-1225; doi:10.1038/ismej.2010.206; published online 13 January 2011 Subject Category: microbial ecology and functional diversity of natural habitats
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