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1.
Nature ; 574(7776): 103-107, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31511700

RESUMO

The sequencing of ancient DNA has enabled the reconstruction of speciation, migration and admixture events for extinct taxa1. However, the irreversible post-mortem degradation2 of ancient DNA has so far limited its recovery-outside permafrost areas-to specimens that are not older than approximately 0.5 million years (Myr)3. By contrast, tandem mass spectrometry has enabled the sequencing of approximately 1.5-Myr-old collagen type I4, and suggested the presence of protein residues in fossils of the Cretaceous period5-although with limited phylogenetic use6. In the absence of molecular evidence, the speciation of several extinct species of the Early and Middle Pleistocene epoch remains contentious. Here we address the phylogenetic relationships of the Eurasian Rhinocerotidae of the Pleistocene epoch7-9, using the proteome of dental enamel from a Stephanorhinus tooth that is approximately 1.77-Myr old, recovered from the archaeological site of Dmanisi (South Caucasus, Georgia)10. Molecular phylogenetic analyses place this Stephanorhinus as a sister group to the clade formed by the woolly rhinoceros (Coelodonta antiquitatis) and Merck's rhinoceros (Stephanorhinus kirchbergensis). We show that Coelodonta evolved from an early Stephanorhinus lineage, and that this latter genus includes at least two distinct evolutionary lines. The genus Stephanorhinus is therefore currently paraphyletic, and its systematic revision is needed. We demonstrate that sequencing the proteome of Early Pleistocene dental enamel overcomes the limitations of phylogenetic inference based on ancient collagen or DNA. Our approach also provides additional information about the sex and taxonomic assignment of other specimens from Dmanisi. Our findings reveal that proteomic investigation of ancient dental enamel-which is the hardest tissue in vertebrates11, and is highly abundant in the fossil record-can push the reconstruction of molecular evolution further back into the Early Pleistocene epoch, beyond the currently known limits of ancient DNA preservation.


Assuntos
DNA Antigo/análise , Esmalte Dentário/metabolismo , Fósseis , Perissodáctilos/classificação , Perissodáctilos/genética , Filogenia , Proteoma/genética , Proteômica , Motivos de Aminoácidos , Sequência de Aminoácidos , Animais , Teorema de Bayes , História Antiga , Humanos , Masculino , Perissodáctilos/metabolismo , Fosforilação/genética , Proteoma/análise
2.
Proc Natl Acad Sci U S A ; 119(38): e2202338119, 2022 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-36099297

RESUMO

Understanding, prioritizing, and mitigating methane (CH4) emissions requires quantifying CH4 budgets from facility scales to regional scales with the ability to differentiate between source sectors. We deployed a tiered observing system for multiple basins in the United States (San Joaquin Valley, Uinta, Denver-Julesburg, Permian, Marcellus). We quantify strong point source emissions (>10 kg CH4 h-1) using airborne imaging spectrometers, attribute them to sectors, and assess their intermittency with multiple revisits. We compare these point source emissions to total basin CH4 fluxes derived from inversion of Sentinel-5p satellite CH4 observations. Across basins, point sources make up on average 40% of the regional flux. We sampled some basins several times across multiple months and years and find a distinct bimodal structure to emission timescales: the total point source budget is split nearly in half by short-lasting and long-lasting emission events. With the increasing airborne and satellite observing capabilities planned for the near future, tiered observing systems will more fully quantify and attribute CH4 emissions from facility to regional scales, which is needed to effectively and efficiently reduce methane emissions.


Assuntos
Poluentes Atmosféricos , Metano , Poluentes Atmosféricos/análise , Metano/análise , Estados Unidos
3.
Brief Bioinform ; 23(5)2022 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-36088548

RESUMO

A knowledge-based grouping of genes into pathways or functional units is essential for describing and understanding cellular complexity. However, it is not always clear a priori how and at what level of specificity functionally interconnected genes should be partitioned into pathways, for a given application. Here, we assess and compare nine existing and two conceptually novel functional classification systems, with respect to their discovery power and generality in gene set enrichment testing. We base our assessment on a collection of nearly 2000 functional genomics datasets provided by users of the STRING database. With these real-life and diverse queries, we assess which systems typically provide the most specific and complete enrichment results. We find many structural and performance differences between classification systems. Overall, the well-established, hierarchically organized pathway annotation systems yield the best enrichment performance, despite covering substantial parts of the human genome in general terms only. On the other hand, the more recent unsupervised annotation systems perform strongest in understudied areas and organisms, and in detecting more specific pathways, albeit with less informative labels.


Assuntos
Genômica , Software , Bases de Dados Factuais , Bases de Dados Genéticas , Genômica/métodos , Humanos
4.
Plant J ; 110(6): 1791-1810, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35411592

RESUMO

Wild relatives of tomato are a valuable source of natural variation in tomato breeding, as many can be hybridized to the cultivated species (Solanum lycopersicum). Several, including Solanum lycopersicoides, have been crossed to S. lycopersicum for the development of ordered introgression lines (ILs), facilitating breeding for desirable traits. Despite the utility of these wild relatives and their associated ILs, few finished genome sequences have been produced to aid genetic and genomic studies. Here we report a chromosome-scale genome assembly for S. lycopersicoides LA2951, which contains 37 938 predicted protein-coding genes. With the aid of this genome assembly, we have precisely delimited the boundaries of the S. lycopersicoides introgressions in a set of S. lycopersicum cv. VF36 × LA2951 ILs. We demonstrate the usefulness of the LA2951 genome by identifying several quantitative trait loci for phenolics and carotenoids, including underlying candidate genes, and by investigating the genome organization and immunity-associated function of the clustered Pto gene family. In addition, syntenic analysis of R2R3MYB genes sheds light on the identity of the Aubergine locus underlying anthocyanin production. The genome sequence and IL map provide valuable resources for studying fruit nutrient/quality traits, pathogen resistance, and environmental stress tolerance. We present a new genome resource for the wild species S. lycopersicoides, which we use to shed light on the Aubergine locus responsible for anthocyanin production. We also provide IL boundary mappings, which facilitated identifying novel carotenoid quantitative trait loci of which one was likely driven by an uncharacterized lycopene ß-cyclase whose function we demonstrate.


Assuntos
Solanum lycopersicum , Solanum , Antocianinas/genética , Cromossomos de Plantas/genética , Solanum lycopersicum/genética , Melhoramento Vegetal , Solanum/genética
5.
Nucleic Acids Res ; 49(D1): D605-D612, 2021 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-33237311

RESUMO

Cellular life depends on a complex web of functional associations between biomolecules. Among these associations, protein-protein interactions are particularly important due to their versatility, specificity and adaptability. The STRING database aims to integrate all known and predicted associations between proteins, including both physical interactions as well as functional associations. To achieve this, STRING collects and scores evidence from a number of sources: (i) automated text mining of the scientific literature, (ii) databases of interaction experiments and annotated complexes/pathways, (iii) computational interaction predictions from co-expression and from conserved genomic context and (iv) systematic transfers of interaction evidence from one organism to another. STRING aims for wide coverage; the upcoming version 11.5 of the resource will contain more than 14 000 organisms. In this update paper, we describe changes to the text-mining system, a new scoring-mode for physical interactions, as well as extensive user interface features for customizing, extending and sharing protein networks. In addition, we describe how to query STRING with genome-wide, experimental data, including the automated detection of enriched functionalities and potential biases in the user's query data. The STRING resource is available online, at https://string-db.org/.


Assuntos
Bases de Dados de Proteínas , Mapeamento de Interação de Proteínas , Proteínas/genética , Interface Usuário-Computador
6.
Mo Med ; 119(4): 343-350, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36118816

RESUMO

Thyroid eye disease, although rare, is the most common inflammatory orbital disorder and is associated with autoimmune thyroid dysfunction. It is a progressive disorder with symptoms and signs that may cause significant facial disfigurement, visual disability, but rarely blindness. We will review the diagnostic criteria, immunologic basis, clinical course, and medical and surgical treatments for thyroid eye disease. Recent developments in the use of biologic agents to treat this disorder appear to be changing its progression curve and offer the first specific and preventative therapeutic options.


Assuntos
Oftalmopatia de Graves , Fatores Biológicos , Cegueira , Oftalmopatia de Graves/diagnóstico , Oftalmopatia de Graves/terapia , Humanos
7.
Environ Sci Technol ; 55(1): 581-592, 2021 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-33314919

RESUMO

In this study, a ground-based mobile measurement system was developed to provide rapid and cost-effective emission surveillance of both methane (CH4) and volatile organic compounds (VOCs) from oil and gas (O&G) production sites. After testing in several controlled release experiments, the system was deployed in a field campaign in the Eagle Ford basin, TX. We found fat-tail distributions for both methane and total VOC (C4-C12) emissions (e.g., the top 20% sites ranked according to methane and total VOC (C4-C12) emissions were responsible for ∼60 and ∼80% of total emissions, respectively) and a good correlation between them (Spearman's R = 0.74). This result suggests that emission controls targeting relatively large emitters may help significantly reduce both methane and VOCs in oil and wet gas basins, such as the Eagle Ford. A strong correlation (Spearman's R = 0.84) was found between total VOC (C4-C12) emissions estimated using SUMMA canisters and data reported from a local ambient air monitoring station. This finding suggests that this system has the potential for rapid emission surveillance targeting relatively large emitters, which can help achieve emission reductions for both greenhouse gas (GHG) and air toxics from O&G production well pads in a cost-effective way.


Assuntos
Poluentes Atmosféricos , Compostos Orgânicos Voláteis , Poluentes Atmosféricos/análise , Análise Custo-Benefício , Monitoramento Ambiental , Metano/análise , Compostos Orgânicos Voláteis/análise
8.
Nucleic Acids Res ; 47(D1): D607-D613, 2019 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-30476243

RESUMO

Proteins and their functional interactions form the backbone of the cellular machinery. Their connectivity network needs to be considered for the full understanding of biological phenomena, but the available information on protein-protein associations is incomplete and exhibits varying levels of annotation granularity and reliability. The STRING database aims to collect, score and integrate all publicly available sources of protein-protein interaction information, and to complement these with computational predictions. Its goal is to achieve a comprehensive and objective global network, including direct (physical) as well as indirect (functional) interactions. The latest version of STRING (11.0) more than doubles the number of organisms it covers, to 5090. The most important new feature is an option to upload entire, genome-wide datasets as input, allowing users to visualize subsets as interaction networks and to perform gene-set enrichment analysis on the entire input. For the enrichment analysis, STRING implements well-known classification systems such as Gene Ontology and KEGG, but also offers additional, new classification systems based on high-throughput text-mining as well as on a hierarchical clustering of the association network itself. The STRING resource is available online at https://string-db.org/.


Assuntos
Genômica/métodos , Mapeamento de Interação de Proteínas/métodos , Software , Animais , Bases de Dados Genéticas , Ontologia Genética , Humanos
9.
Ophthalmic Plast Reconstr Surg ; 37(3S): S140-S141, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32890121

RESUMO

This is a case report involving 3 siblings, ages 22, 21, and 3 years old, of consanguineous parents and Syrian descent with a particularly unique clinical phenotype and eyelid/gingival findings that have not been previously characterized. Full-thickness eyelid biopsies for 2 of the siblings were evaluated by ophthalmic pathology showed generalized fibrosis without any active destructive process or amyloid. Three of the 9 siblings were affected by this order with no familial history. Ophthalmic plastic surgeons should be aware of this new entity as genetic localization and further identification may help families affected by this disorder.


Assuntos
Irmãos , Fibrose , Humanos , Fenótipo , Síndrome
10.
Bioinformatics ; 35(20): 4147-4155, 2019 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-30903186

RESUMO

MOTIVATION: Modern genomic breeding methods rely heavily on very large amounts of phenotyping and genotyping data, presenting new challenges in effective data management and integration. Recently, the size and complexity of datasets have increased significantly, with the result that data are often stored on multiple systems. As analyses of interest increasingly require aggregation of datasets from diverse sources, data exchange between disparate systems becomes a challenge. RESULTS: To facilitate interoperability among breeding applications, we present the public plant Breeding Application Programming Interface (BrAPI). BrAPI is a standardized web service API specification. The development of BrAPI is a collaborative, community-based initiative involving a growing global community of over a hundred participants representing several dozen institutions and companies. Development of such a standard is recognized as critical to a number of important large breeding system initiatives as a foundational technology. The focus of the first version of the API is on providing services for connecting systems and retrieving basic breeding data including germplasm, study, observation, and marker data. A number of BrAPI-enabled applications, termed BrAPPs, have been written, that take advantage of the emerging support of BrAPI by many databases. AVAILABILITY AND IMPLEMENTATION: More information on BrAPI, including links to the specification, test suites, BrAPPs, and sample implementations is available at https://brapi.org/. The BrAPI specification and the developer tools are provided as free and open source.


Assuntos
Melhoramento Vegetal , Software , Interface Usuário-Computador , Genômica
11.
Environ Sci Technol ; 54(21): 13926-13934, 2020 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-33058723

RESUMO

Methane emission fluxes were estimated for 71 oil and gas well pads in the western Permian Basin (Delaware Basin), using a mobile laboratory and an inverse Gaussian dispersion method (OTM 33A). Sites with emissions that were below detection limit (BDL) for OTM 33A were recorded and included in the sample. Average emission rate per site was estimated by bootstrapping and by maximum likelihood best log-normal fit. Sites had to be split into "complex" (sites with liquid storage tanks and/or compressors) and "simple" (sites with only wellheads/pump jacks/separators) categories to achieve acceptable log-normal fits. For complex sites, the log-normal fit depends heavily on the number of BDL sites included. As more BDL sites are included, the log-normal distribution fit to the data is falsely widened, overestimating the mean, highlighting the importance of correctly characterizing low end emissions when using log-normal fits. Basin-wide methane emission rates were estimated for the production sector of the New Mexico portion of the Permian and range from ∼520 000 tons per year, TPY (bootstrapping, 95% CI: 300 000-790 000) to ∼610 000 TPY (log-normal fit method, 95% CI: 330 000-1 000 000). These estimates are a factor of 5.5-9.0 times greater than EPA National Emission Inventory (NEI) estimates for the region.


Assuntos
Poluentes Atmosféricos , Metano , Poluentes Atmosféricos/análise , Laboratórios , Metano/análise , Gás Natural/análise , New Mexico
12.
J Neurosci ; 38(50): 10709-10724, 2018 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-30396913

RESUMO

To combat retinal degeneration, healthy fetal retinal sheets have been successfully transplanted into both rodent models and humans, with synaptic connectivity between transplant and degenerated host retina having been confirmed. In rodent studies, transplants have been shown to restore responses to flashes of light in a region of the superior colliculus corresponding to the location of the transplant in the host retina. To determine the quality and detail of visual information provided by the transplant, visual responsivity was studied here at the level of visual cortex where higher visual perception is processed. For our model, we used the transgenic Rho-S334ter line-3 rat (both sexes), which loses photoreceptors at an early age and is effectively blind at postnatal day 30. These rats received fetal retinal sheet transplants in one eye between 24 and 40 d of age. Three to 10 months following surgery, visually responsive neurons were found in regions of primary visual cortex matching the transplanted region of the retina that were as highly selective as normal rat to stimulus orientation, size, contrast, and spatial and temporal frequencies. Conversely, we found that selective response properties were largely absent in nontransplanted line-3 rats. Our data show that fetal retinal sheet transplants can result in remarkably normal visual function in visual cortex of rats with a degenerated host retina and represents a critical step toward developing an effective remedy for the visually impaired human population.SIGNIFICANCE STATEMENT Age-related macular degeneration and retinitis pigmentosa lead to profound vision loss in millions of people worldwide. Many patients lose both retinal pigment epithelium and photoreceptors. Hence, there is a great demand for the development of efficient techniques that allow for long-term vision restoration. In this study, we transplanted dissected fetal retinal sheets, which can differentiate into photoreceptors and integrate with the host retina of rats with severe retinal degeneration. Remarkably, we show that transplants generated visual responses in cortex similar in quality to normal rats. Furthermore, transplants preserved connectivity within visual cortex and the retinal relay from the lateral geniculate nucleus to visual cortex, supporting their potential application in curing vision loss associated with retinal degeneration.


Assuntos
Potenciais Evocados Visuais/fisiologia , Retina/transplante , Degeneração Retiniana/fisiopatologia , Degeneração Retiniana/terapia , Índice de Gravidade de Doença , Córtex Visual/fisiologia , Animais , Feminino , Humanos , Masculino , Estimulação Luminosa/métodos , Ratos , Ratos Long-Evans , Ratos Transgênicos , Degeneração Retiniana/patologia
13.
Biotechnol Bioeng ; 116(9): 2223-2235, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31062870

RESUMO

Biomanufacturing exhibits inherent variability that can lead to variation in performance attributes and batch failure. To help ensure process consistency and product quality the development of predictive models and integrated control strategies is a promising approach. In this study, a feedback controller was developed to limit excessive lactate production, a widespread metabolic phenomenon that is negatively associated with culture performance and product quality. The controller was developed by applying machine learning strategies to historical process development data, resulting in a forecast model that could identify whether a run would result in lactate consumption or accumulation. In addition, this exercise identified a correlation between increased amino acid consumption and low observed lactate production leading to the mechanistic hypothesis that there is a deficiency in the link between glycolysis and the tricarboxylic acid cycle. Using the correlative process parameters to build mechanistic insight and applying this to predictive models of lactate concentration, a dynamic model predictive controller (MPC) for lactate was designed. This MPC was implemented experimentally on a process known to exhibit high lactate accumulation and successfully drove the cell cultures towards a lactate consuming state. In addition, an increase in specific titer productivity was observed when compared with non-MPC controlled reactors.


Assuntos
Ciclo do Ácido Cítrico , Glicólise , Ácido Láctico/metabolismo , Modelos Biológicos , Animais , Células CHO , Cricetinae , Cricetulus , Previsões
14.
Environ Sci Technol ; 53(15): 8976-8984, 2019 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-31283190

RESUMO

Current research efforts on the atmospheric impacts of natural gas (NG) have focused heavily on the production, storage/transmission, and processing sectors, with less attention paid to the distribution and end use sectors. This work discusses 23 flights at 14 natural gas-fired power plants (NGPPs) using an aircraft-based mass balance technique and methane/carbon dioxide enhancement ratios (ΔCH4/ΔCO2) measured from stack plumes to quantify the unburned fuel. By comparing the ΔCH4/ΔCO2 ratio measured in stack plumes to that measured downwind, we determined that, within uncertainty of the measurement, all observed CH4 emissions were stack-based, that is, uncombusted NG from the stack rather than fugitive sources. Measured CH4 emission rates (ER) ranged from 8 (±5) to 135 (±27) kg CH4/h (±1σ), with the fractional CH4 throughput lost (loss rate) ranging from -0.039% (±0.076%) to 0.204% (±0.054%). We attribute negative values to partial combustion of ambient CH4 in the power plant. The average calculated emission factor (EF) of 5.4 (+10/-5.4) g CH4/million British thermal units (MMBTU) is within uncertainty of the Environmental Protection Agency (EPA) EFs. However, one facility measured during startup exhibited substantially larger stack emissions with an EF of 440 (+660/-440) g CH4/MMBTU and a loss rate of 2.5% (+3.8/-2.5%).


Assuntos
Poluentes Atmosféricos , Gás Natural , Dióxido de Carbono , Metano , Centrais Elétricas
15.
Mol Cell Proteomics ; 16(5): 759-769, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28254776

RESUMO

Lysine acetylation is a protein posttranslational modification (PTM) that occurs on thousands of lysine residues in diverse organisms from bacteria to humans. Accurate measurement of acetylation stoichiometry on a proteome-wide scale remains challenging. Most methods employ a comparison of chemically acetylated peptides to native acetylated peptides, however, the potentially large differences in abundance between these peptides presents a challenge for accurate quantification. Stable isotope labeling by amino acids in cell culture (SILAC)-based mass spectrometry (MS) is one of the most widely used quantitative proteomic methods. Here we show that serial dilution of SILAC-labeled peptides (SD-SILAC) can be used to identify accurately quantified peptides and to estimate the quantification error rate. We applied SD-SILAC to determine absolute acetylation stoichiometry in exponentially-growing and stationary-phase wild-type and Sirtuin deacetylase CobB-deficient cells. To further analyze CobB-regulated sites under conditions of globally increased or decreased acetylation, we measured stoichiometry in phophotransacetylase (ptaΔ) and acetate kinase (ackAΔ) mutant strains in the presence and absence of the Sirtuin inhibitor nicotinamide. We measured acetylation stoichiometry at 3,669 unique sites and found that the vast majority of acetylation occurred at a low stoichiometry. Manipulations that cause increased nonenzymatic acetylation by acetyl-phosphate (AcP), such as stationary-phase arrest and deletion of ackA, resulted in globally increased acetylation stoichiometry. Comparison to relative quantification under the same conditions validated our stoichiometry estimates at hundreds of sites, demonstrating the accuracy of our method. Similar to Sirtuin deacetylase 3 (SIRT3) in mitochondria, CobB suppressed acetylation to lower than median stoichiometry in WT, ptaΔ, and ackAΔ cells. Together, our results provide a detailed view of acetylation stoichiometry in E. coli and suggest an evolutionarily conserved function of Sirtuin deacetylases in suppressing low stoichiometry acetylation.


Assuntos
Proteínas de Escherichia coli/metabolismo , Escherichia coli/metabolismo , Proteoma/metabolismo , Sirtuínas/metabolismo , Acetilação , Marcação por Isótopo
16.
Environ Sci Technol ; 52(15): 8947-8953, 2018 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-29989804

RESUMO

We performed an infrared optical gas imaging (OGI) survey by helicopter of hydrocarbon emissions in the Bakken formation of North Dakota. One year after an earlier survey of 682 well pads in September of 2014, the same helicopter crew resurveyed 353 well pads in 2015 to examine the persistence of emissions. Twenty-one newly producing well pads were added in the same sampling blocks. An instrumented aircraft was also used to quantify emissions from 33 plumes identified by aerial OGI. Well pads emitting methane and ethane in 2014 were far more likely to be emitting in 2015 than would be expected by chance; Monte Carlo simulations suggest >5σ deviation ( p < 0.0001) from random assignment of detectable emissions between survey years. Scaled up using basin-wide leakage estimates, the emissions quantified by aircraft are sufficient to explain previously observed basin-wide emissions of methane and ethane.


Assuntos
Poluentes Atmosféricos , Metano , Etano , Gás Natural , North Dakota
17.
Mol Cell Proteomics ; 15(6): 1921-37, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27001437

RESUMO

Climate change in conjunction with population growth necessitates a systems biology approach to characterize plant drought acclimation as well as a more thorough understanding of the molecular mechanisms of stress recovery. Plants are exposed to a continuously changing environment. Extremes such as several weeks of drought are followed by rain. This requires a molecular plasticity of the plant enabling drought acclimation and the necessity of deacclimation processes for recovery and continuous growth.During drought stress and subsequent recovery, the metabolome and proteome are regulated through a sequence of molecular processes including synthesis and degradation and molecular interaction networks are part of this regulatory process. In order to study this complex regulatory network, a comprehensive analysis is presented for the first time, investigating protein turnover and regulatory classes of proteins and metabolites during a stress recovery scenario in the model legume Medicago truncatula The data give novel insights into the molecular capacity and differential processes required for acclimation and deacclimation of severe drought stressed plants.Functional cluster and network analyses unraveled independent regulatory mechanisms for stress and recovery with different dynamic phases that during the course of recovery define the plants deacclimation from stress. The combination of relative abundance levels and turnover analysis revealed an early transition phase that seems key for recovery initiation through water resupply and is independent from renutrition. Thus, a first indication for a metabolite and protein-based load capacity was observed necessary for the recovery from drought, an important but thus far ignored possible feature toward tolerance. The data indicate that apart from the plants molecular stress response mechanisms, plasticity may be related to the nutritional status of the plant prior to stress initiation. A new perspective and possible new targets as well as metabolic mechanisms for future plant-bioengineering toward enhanced drought stress tolerance are presented.


Assuntos
Medicago truncatula/crescimento & desenvolvimento , Medicago truncatula/fisiologia , Metabolômica/métodos , Proteínas de Plantas/metabolismo , Proteômica/métodos , Estresse Fisiológico , Cromatografia Líquida/métodos , Secas , Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes , Medicago truncatula/genética , Biologia de Sistemas , Espectrometria de Massas em Tandem
19.
Proc Natl Acad Sci U S A ; 112(51): 15597-602, 2015 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-26644584

RESUMO

Published estimates of methane emissions from atmospheric data (top-down approaches) exceed those from source-based inventories (bottom-up approaches), leading to conflicting claims about the climate implications of fuel switching from coal or petroleum to natural gas. Based on data from a coordinated campaign in the Barnett Shale oil and gas-producing region of Texas, we find that top-down and bottom-up estimates of both total and fossil methane emissions agree within statistical confidence intervals (relative differences are 10% for fossil methane and 0.1% for total methane). We reduced uncertainty in top-down estimates by using repeated mass balance measurements, as well as ethane as a fingerprint for source attribution. Similarly, our bottom-up estimate incorporates a more complete count of facilities than past inventories, which omitted a significant number of major sources, and more effectively accounts for the influence of large emission sources using a statistical estimator that integrates observations from multiple ground-based measurement datasets. Two percent of oil and gas facilities in the Barnett accounts for half of methane emissions at any given time, and high-emitting facilities appear to be spatiotemporally variable. Measured oil and gas methane emissions are 90% larger than estimates based on the US Environmental Protection Agency's Greenhouse Gas Inventory and correspond to 1.5% of natural gas production. This rate of methane loss increases the 20-y climate impacts of natural gas consumed in the region by roughly 50%.

20.
Angew Chem Int Ed Engl ; 57(25): 7369-7374, 2018 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-29603563

RESUMO

Ahead of display, a non-original layer was observed on the surface of a fragment of a wall painting by Ambrogio Lorenzetti (active 1319, died 1348/9). FTIR analysis suggested proteinaceous content. Mass spectrometry was used to better characterise this layer and revealed two protein components: sheep and cow glue and chicken and duck egg white. Analysis of post-translational modifications detected several photo-oxidation products, which suggest that the egg experienced prolonged exposure to UV light and was likely applied long before the glue layer. Additionally, glycation products detected may indicate naturally occurring glycoprotein degradation or reaction with a carbohydrate material such as starch, identified by ATR-FTIR in a cross-section of a sample taken from the painting. Palaeoproteomics is shown to provide detailed characterisation of organic layers associated with mural paintings and therefore aids reconstruction of the conservation history of these objects.

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