RESUMEN
Both the MRTF-SRF and the YAP-TEAD transcriptional regulatory networks respond to extracellular signals and mechanical stimuli. We show that the MRTF-SRF pathway is activated in cancer-associated fibroblasts (CAFs). The MRTFs are required in addition to the YAP pathway for CAF contractile and proinvasive properties. We compared MRTF-SRF and YAP-TEAD target gene sets and identified genes directly regulated by one pathway, the other, or both. Nevertheless, the two pathways exhibit mutual dependence. In CAFs, expression of direct MRTF-SRF genomic targets is also dependent on YAP-TEAD activity, and, conversely, YAP-TEAD target gene expression is also dependent on MRTF-SRF signaling. In normal fibroblasts, expression of activated MRTF derivatives activates YAP, while activated YAP derivatives activate MRTF. Cross-talk between the pathways requires recruitment of MRTF and YAP to DNA via their respective DNA-binding partners (SRF and TEAD) and is therefore indirect, arising as a consequence of activation of their target genes. In both CAFs and normal fibroblasts, we found that YAP-TEAD activity is sensitive to MRTF-SRF-induced contractility, while MRTF-SRF signaling responds to YAP-TEAD-dependent TGFß signaling. Thus, the MRF-SRF and YAP-TEAD pathways interact indirectly through their ability to control cytoskeletal dynamics.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Fibroblastos Asociados al Cáncer/fisiología , Citoesqueleto/metabolismo , Proteínas de Unión al ADN/metabolismo , Neoplasias Mamarias Animales/fisiopatología , Fosfoproteínas/metabolismo , Transactivadores/metabolismo , Factores de Transcripción/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Animales , Proteínas de Ciclo Celular , Línea Celular Tumoral , Femenino , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Humanos , Ratones , Fosfoproteínas/genética , Transducción de Señal , Factores de Transcripción de Dominio TEA , Transactivadores/genética , Activación Transcripcional/genética , Factor de Crecimiento Transformador beta1/metabolismo , Proteínas Señalizadoras YAPRESUMEN
In this Letter, the western blot for LSD1 in the right panel of Fig. 2b ('TCP +') was inadvertently duplicated from the tubulin blot immediately below. The actual tubulin western blot shows the same result, with no significant change to the levels of tubulin (see Fig. 1 of this Amendment). In addition, the western blots for LSD1 and HDAC1 of Fig. 3b and c have been corrected to include vertical black lines to delineate the juxtaposition of lanes that were non-adjacent in the original blotting experiment (see Fig. 2 of this Amendment). Supplementary Figs. 4a, 6b and 9b have also been corrected to delineate non-adjacent lanes with vertical black lines (see Supplementary Information of this Amendment). The complete raw data images from these western blotting experiments can also be found in the Supplementary Information of this Amendment. The original Letter has not been corrected.
RESUMEN
The repeated evolution of the same traits in distantly related groups (convergent evolution) raises a key question in evolutionary biology: do the same genes underpin convergent phenotypes? Here, we explore one such trait, viviparity (live birth), which, qualitative studies suggest, may indeed have evolved via genetic convergence. There are >150 independent origins of live birth in vertebrates, providing a uniquely powerful system to test the mechanisms underpinning convergence in morphology, physiology, and/or gene recruitment during pregnancy. We compared transcriptomic data from eight vertebrates (lizards, mammals, sharks) that gestate embryos within the uterus. Since many previous studies detected qualitative similarities in gene use during independent origins of pregnancy, we expected to find significant overlap in gene use in viviparous taxa. However, we found no more overlap in uterine gene expression associated with viviparity than we would expect by chance alone. Each viviparous lineage exhibits the same core set of uterine physiological functions. Yet, contrary to prevailing assumptions about this trait, we find that none of the same genes are differentially expressed in all viviparous lineages, or even in all viviparous amniote lineages. Therefore, across distantly related vertebrates, different genes have been recruited to support the morphological and physiological changes required for successful pregnancy. We conclude that redundancies in gene function have enabled the repeated evolution of viviparity through recruitment of different genes from genomic "toolboxes", which are uniquely constrained by the ancestries of each lineage.
Asunto(s)
Lagartos , Viviparidad de Animales no Mamíferos , Animales , Evolución Biológica , Femenino , Genómica , Lagartos/genética , Mamíferos/fisiología , Placenta , Embarazo , Viviparidad de Animales no Mamíferos/genéticaRESUMEN
The parameterization of kinetic models requires measurement of fluxes and/or metabolite levels for a base strain and a few genetic perturbations thereof. Unlike stoichiometric models that are mostly invariant to the specific strain, it remains unclear whether kinetic models constructed for different strains of the same species have similar or significantly different kinetic parameters. This important question underpins the applicability range and prediction limits of kinetic reconstructions. To this end, herein we parameterize two separate large-scale kinetic models using K-FIT with genome-wide coverage corresponding to two distinct strains of Saccharomyces cerevisiae: CEN.PK 113-7D strain (model k-sacce306-CENPK), and growth-deficient BY4741 (isogenic to S288c; model k-sacce306-BY4741). The metabolic network for each model contains 306 reactions, 230 metabolites, and 119 substrate-level regulatory interactions. The two models (for CEN.PK and BY4741) recapitulate, within one standard deviation, 77% and 75% of the fitted dataset fluxes, respectively, determined by 13C metabolic flux analysis for wild-type and eight single-gene knockout mutants of each strain. Strain-specific kinetic parameterization results indicate that key enzymes in the TCA cycle, glycolysis, and arginine and proline metabolism drive the metabolic differences between these two strains of S. cerevisiae. Our results suggest that although kinetic models cannot be readily used across strains as stoichiometric models, they can capture species-specific information through the kinetic parameterization process.
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Análisis de Flujos Metabólicos , Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Cinética , Modelos BiológicosRESUMEN
The first dominant SARS-CoV-2 Omicron variant BA.1 harbours 35 mutations in its Spike protein from the original SARS-CoV-2 variant that emerged late 2019. Soon after its discovery, BA.1 rapidly emerged to become the dominant variant worldwide and has since evolved into several variants. Omicron is of major public health concern owing to its high infectivity and antibody evasion. This review article examines the theories that have been proposed on the evolution of Omicron including zoonotic spillage, infection in immunocompromised individuals and cryptic spread in the community without being diagnosed. Added to the complexity of Omicron's evolution are the multiple reports of recombination events occurring between co-circulating variants of Omicron with Delta and other variants such as XE. Current literature suggests that the combination of the novel mutations in Omicron has resulted in the variant having higher infectivity than the original Wuhan-Hu-1 and Delta variant. However, severity is believed to be less owing to the reduced syncytia formation and lower multiplication in the human lung tissue. Perhaps most challenging is that several studies indicate that the efficacy of the available vaccines have been reduced against Omicron variant (8-127 times reduction) as compared to the Wuhan-Hu-1 variant. The administration of booster vaccine, however, compensates with the reduction and improves the efficacy by 12-35 fold. Concerningly though, the broadly neutralising monoclonal antibodies, including those approved by FDA for therapeutic use against previous SARS-CoV-2 variants, are mostly ineffective against Omicron with the exception of Sotrovimab and recent reports suggest that the Omicron BA.2 is also resistant to Sotrovimab. Currently two new Omicron variants BA.4 and BA.5 are emerging and are reported to be more transmissible and resistant to immunity generated by previous variants including Omicron BA.1 and most monoclonal antibodies. As new variants of SARS-CoV-2 will likely continue to emerge it is important that the evolution, and biological consequences of new mutations, in existing variants be well understood.
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COVID-19 , SARS-CoV-2 , Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Monoclonales Humanizados , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Humanos , SARS-CoV-2/genéticaRESUMEN
Clostridium thermocellum is a promising candidate for consolidated bioprocessing because it can directly ferment cellulose to ethanol. Despite significant efforts, achieved yields and titers fall below industrially relevant targets. This implies that there still exist unknown enzymatic, regulatory, and/or possibly thermodynamic bottlenecks that can throttle back metabolic flow. By (i) elucidating internal metabolic fluxes in wild-type C. thermocellum grown on cellobiose via 13C-metabolic flux analysis (13C-MFA), (ii) parameterizing a core kinetic model, and (iii) subsequently deploying an ensemble-docking workflow for discovering substrate-level regulations, this paper aims to reveal some of these factors and expand our knowledgebase governing C. thermocellum metabolism. Generated 13C labeling data were used with 13C-MFA to generate a wild-type flux distribution for the metabolic network. Notably, flux elucidation through MFA alluded to serine generation via the mercaptopyruvate pathway. Using the elucidated flux distributions in conjunction with batch fermentation process yield data for various mutant strains, we constructed a kinetic model of C. thermocellum core metabolism (i.e. k-ctherm138). Subsequently, we used the parameterized kinetic model to explore the effect of removing substrate-level regulations on ethanol yield and titer. Upon exploring all possible simultaneous (up to four) regulation removals we identified combinations that lead to many-fold model predicted improvement in ethanol titer. In addition, by coupling a systematic method for identifying putative competitive inhibitory mechanisms using K-FIT kinetic parameterization with the ensemble-docking workflow, we flagged 67 putative substrate-level inhibition mechanisms across central carbon metabolism supported by both kinetic formalism and docking analysis.
Asunto(s)
Clostridium thermocellum , Celobiosa/metabolismo , Clostridium thermocellum/genética , Clostridium thermocellum/metabolismo , Etanol/metabolismo , Fermentación , CinéticaRESUMEN
The atypical glycolysis of Clostridium thermocellum is characterized by the use of pyrophosphate (PPi) as a phosphoryl donor for phosphofructokinase (Pfk) and pyruvate phosphate dikinase (Ppdk) reactions. Previously, biosynthetic PPi was calculated to be stoichiometrically insufficient to drive glycolysis. This study investigates the role of a H+-pumping membrane-bound pyrophosphatase, glycogen cycling, a predicted Ppdk-malate shunt cycle, and acetate cycling in generating PPi. Knockout studies and enzyme assays confirmed that clo1313_0823 encodes a membrane-bound pyrophosphatase. Additionally, clo1313_0717-0718 was confirmed to encode ADP-glucose synthase by knockouts, glycogen measurements in C. thermocellum, and heterologous expression in Escherichia coli. Unexpectedly, individually targeted gene deletions of the four putative PPi sources did not have a significant phenotypic effect. Although combinatorial deletion of all four putative PPi sources reduced the growth rate by 22% (0.30 ± 0.01 h-1) and the biomass yield by 38% (0.18 ± 0.00 gbiomass gsubstrate-1), this change was much smaller than what would be expected for stoichiometrically essential PPi-supplying mechanisms. Growth-arrested cells of the quadruple knockout readily fermented cellobiose, indicating that the unknown PPi-supplying mechanisms are independent of biosynthesis. An alternative hypothesis that ATP-dependent Pfk activity circumvents a need for PPi altogether was falsified by enzyme assays, heterologous expression of candidate genes, and whole-genome sequencing. As a secondary outcome, enzymatic assays confirmed functional annotation of clo1313_1832 as ATP- and GTP-dependent fructokinase. These results indicate that the four investigated PPi sources individually and combined play no significant PPi-supplying role, and the true source(s) of PPi, or alternative phosphorylating mechanisms, that drive(s) glycolysis in C. thermocellum remain(s) elusive. IMPORTANCE Increased understanding of the central metabolism of C. thermocellum is important from a fundamental as well as from a sustainability and industrial perspective. In addition to showing that H+-pumping membrane-bound PPase, glycogen cycling, a Ppdk-malate shunt cycle, and acetate cycling are not significant sources of PPi supply, this study adds functional annotation of four genes and availability of an updated PPi stoichiometry from biosynthesis to the scientific domain. Together, this aids future metabolic engineering attempts aimed to improve C. thermocellum as a cell factory for sustainable and efficient production of ethanol from lignocellulosic material through consolidated bioprocessing with minimal pretreatment. Getting closer to elucidating the elusive source of PPi, or alternative phosphorylating mechanisms, for the atypical glycolysis is itself of fundamental importance. Additionally, the findings of this study directly contribute to investigations into trade-offs between thermodynamic driving force versus energy yield of PPi- and ATP-dependent glycolysis.
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Clostridium thermocellum , Clostridium thermocellum/metabolismo , Difosfatos/metabolismo , Glucosa-1-Fosfato Adenililtransferasa/metabolismo , Pirofosfatasa Inorgánica/metabolismo , Fosfatos/metabolismo , Piruvato Ortofosfato Diquinasa/genética , Piruvato Ortofosfato Diquinasa/metabolismo , Ácido Pirúvico/metabolismoRESUMEN
Evolution leaves heterogeneous patterns of nucleotide variation across the genome, with different loci subject to varying degrees of mutation, selection, and drift. In phylogenetics, the potential impacts of partitioning sequence data for the assignment of substitution models are well appreciated. In contrast, the treatment of branch lengths has received far less attention. In this study, we examined the effects of linking and unlinking branch-length parameters across loci or subsets of loci. By analyzing a range of empirical data sets, we find consistent support for a model in which branch lengths are proportionate between subsets of loci: gene trees share the same pattern of branch lengths, but form subsets that vary in their overall tree lengths. These models had substantially better statistical support than models that assume identical branch lengths across gene trees, or those in which genes form subsets with distinct branch-length patterns. We show using simulations and empirical data that the complexity of the branch-length model with the highest support depends on the length of the sequence alignment and on the numbers of taxa and loci in the data set. Our findings suggest that models in which branch lengths are proportionate between subsets have the highest statistical support under the conditions that are most commonly seen in practice. The results of our study have implications for model selection, computational efficiency, and experimental design in phylogenomics.
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Modelos Genéticos , Filogenia , Simulación por ComputadorRESUMEN
Understanding the governing principles behind organisms' metabolism and growth underpins their effective deployment as bioproduction chassis. A central objective of metabolic modeling is predicting how metabolism and growth are affected by both external environmental factors and internal genotypic perturbations. The fundamental concepts of reaction stoichiometry, thermodynamics, and mass action kinetics have emerged as the foundational principles of many modeling frameworks designed to describe how and why organisms allocate resources towards both growth and bioproduction. This review focuses on the latest algorithmic advancements that have integrated these foundational principles into increasingly sophisticated quantitative frameworks.
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Aprendizaje Automático , Modelos Biológicos , Estudios de Factibilidad , Cinética , TermodinámicaRESUMEN
Establishing an accurate evolutionary timescale for green plants (Viridiplantae) is essential to understanding their interaction and coevolution with the Earth's climate and the many organisms that rely on green plants. Despite being the focus of numerous studies, the timing of the origin of green plants and the divergence of major clades within this group remain highly controversial. Here, we infer the evolutionary timescale of green plants by analyzing 81 protein-coding genes from 99 chloroplast genomes, using a core set of 21 fossil calibrations. We test the sensitivity of our divergence-time estimates to various components of Bayesian molecular dating, including the tree topology, clock models, clock-partitioning schemes, rate priors, and fossil calibrations. We find that the choice of clock model affects date estimation and that the independent-rates model provides a better fit to the data than the autocorrelated-rates model. Varying the rate prior and tree topology had little impact on age estimates, with far greater differences observed among calibration choices and clock-partitioning schemes. Our analyses yield date estimates ranging from the Paleoproterozoic to Mesoproterozoic for crown-group green plants, and from the Ediacaran to Middle Ordovician for crown-group land plants. We present divergence-time estimates of the major groups of green plants that take into account various sources of uncertainty. Our proposed timeline lays the foundation for further investigations into how green plants shaped the global climate and ecosystems, and how embryophytes became dominant in terrestrial environments.
Asunto(s)
Evolución Biológica , Clasificación/métodos , Fósiles , Viridiplantae/clasificación , Genoma del Cloroplasto/genética , Tiempo , Viridiplantae/genéticaRESUMEN
The question a judge has to ask in deciding whether or not life-sustaining treatment should be withdrawn is whether the continued treatment is lawful. It will be lawful if it is in the patient's best interests. Identifying this question gives no guidance about how to approach the assessment of best interests. It merely identifies the judge's job. The presumption in favour of the maintenance of life is part of the job that follows the identification of the question.The presumption is best regarded as a presumption of law. It has long been recognised as part of the way in which the English law discharges its obligations under Article 2 of the European Convention on Human Rights (the right to life). But even if it is a 'mere' evidential presumption it cannot, on the facts of most cases involving applications for the withdrawal of life-sustaining treatment from patients in prolonged disorders of consciousness, be rebutted.
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Estado de Conciencia , Cuidados para Prolongación de la Vida , Toma de Decisiones , Derechos Humanos , Humanos , Valor de la Vida , Privación de TratamientoRESUMEN
We designed and tested a protocol for measuring the performance of individuals in small-sided soccer games. We tested our protocol on three different groups of youth players from elite Brazilian football academies. Players in each group played a series of 3v3 games, in which individuals were randomly assigned into new teams and against new opponents for each game. We calculated each individual's average individual goals scored, goals scored by teammates, goals conceded, and net team goals per game. Our protocol was consistent across days and repeatable across groups, with intraclass correlation coefficients (ICCs) of 0.57-0.69 for average net goals per game across testing days. Players could achieve high success by scoring goals or ensuring their team concede few goals. We also calculated the first and second dimension of a principal component analysis based on each player's number of goals scored, goals scored by teammates, and number of goals conceded per game. Players that were overall high performers had higher PC1 scores, while PC2 scores represented the type of contribution made by a player to overall performance. Positive PC2 values were indicative of high number of individual goals while negative values were associated with more goals from teammates and fewer conceded goals. Our design allows coaches and scouts to easily collect a robust metric of individual performance using randomly designed, small-sided games. We also provide simulations that allow one to apply our methodology for individual talent identification to other small-sided games in any team sport.
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Atletas/estadística & datos numéricos , Rendimiento Atlético/fisiología , Rendimiento Atlético/estadística & datos numéricos , Fútbol/fisiología , Fútbol/estadística & datos numéricos , Aptitud , Niño , Prueba de Esfuerzo , Humanos , Reproducibilidad de los ResultadosRESUMEN
Australia is an excellent setting to explore relationships between climate change and diversification dynamics. Aridification since the Eocene has resulted in spectacular radiations within one or more Australian biomes. Acacia is the largest plant genus on the Australian continent, with around 1000 species, and is present in all biomes. We investigated the macroevolutionary dynamics of Acacia within climate space. We analysed phylogenetic and climatic data for 503 Acacia species to estimate a time-calibrated phylogeny and central climatic tendencies for BioClim layers from 132 000 herbarium specimens. Diversification rate heterogeneity and rates of climate space exploration were tested. We inferred two diversification rate increases, both associated with significantly higher rates of climate space exploration. Observed spikes in climate disparity within the Pleistocene correspond with onset of Pleistocene glacial-interglacial cycling. Positive time dependency in environmental disparity applies in the basal grade of Acacia, though climate space exploration rates were lower. Incongruence between rates of climate space exploration and disparity suggests different Acacia lineages have experienced different macroevolutionary processes. The second diversification rate increase is associated with a south-east Australian mesic lineage, suggesting adaptations to progressively aridifying environments and ability to transition into mesic environments contributed to Acacia's dominance across Australia.
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Acacia , Vuelo Espacial , Australia , Ecosistema , FilogeniaRESUMEN
Our understanding of the evolution of complex biological traits is greatly advanced by examining taxa with intermediate phenotypes. The transition from oviparity (egg-laying) to viviparity (live-bearing) has occurred independently in many animal lineages, but there are few phenotypic intermediates. The lizard Saiphos equalis exhibits bimodal reproduction, with some viviparous populations, and other oviparous populations with long egg-retention, a rare trait where most of embryonic development occurs inside the mother prior to late ovipositioning. We posit that oviparous S. equalis represent an intermediate form between "true" oviparity and viviparity. We used transcriptomics to compare uterine gene expression in these two phenotypes, and provide a molecular model for the genetic control and evolution of reproductive mode. Many genes are differentially expressed throughout the reproductive cycle of both phenotypes, which have clearly different gene expression profiles overall. The differentially expressed genes within oviparous and viviparous individuals have broadly similar biological functions putatively important for sustaining embryos, including uterine remodelling, respiratory gas and water exchange, and immune regulation. These functional similarities indicate either that long egg-retention is an exaptation for viviparity, or might reflect parallel evolution of similar gravidity-related changes in gene expression in long egg-retention oviparity. In contrast, gene expression changes across the reproductive cycle of long egg-retaining oviparous S. equalis are dramatically different from those of "true" oviparous skinks (such as Lampropholis guichenoti), supporting our assertion that oviparous S. equalis exhibit an intermediate phenotype between "true" oviparity and viviparity.
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Lagartos/genética , Lagartos/fisiología , Oviparidad/genética , Viviparidad de Animales no Mamíferos/genética , Animales , Evolución Biológica , Femenino , Regulación del Desarrollo de la Expresión Génica , Modelos Genéticos , Nueva Gales del Sur , TranscriptomaRESUMEN
The Kinship Theory of Genomic Imprinting (KTGI) posits that, in species where females mate with multiple males, there is selection for a male to enhance the reproductive success of his offspring at the expense of other males and his mating partner. Reciprocal crosses between honey bee subspecies show parent-of-origin effects for reproductive traits, suggesting that males modify the expression of genes related to female function in their female offspring. This effect is likely to be greater in the Cape honey bee (Apis mellifera capensis), because a male's daughters have the unique ability to produce female offspring that can develop into reproductive workers or the next queen without mating. We generated reciprocal crosses between Capensis and another subspecies and used RNA-seq to identify transcripts that are over- or underexpressed in the embryos, depending on the parental origin of the gene. As predicted, 21 genes showed expression bias towards the Capensis father's allele in colonies with a Capensis father, with no such bias in the reciprocal cross. A further six genes showed a consistent bias towards expression of the father's allele across all eight colonies examined, regardless of the direction of the cross. Consistent with predictions of the KTGI, six of the 21 genes are associated with female reproduction. No gene consistently showed overexpression of the maternal allele.
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Impresión Genómica , Reproducción , Alelos , Animales , Abejas/genética , Femenino , Expresión Génica , Masculino , FenotipoRESUMEN
Kinetic models of metabolic networks offer the promise of quantitative phenotype prediction. The mechanistic characterization of enzyme catalyzed reactions allows for tracing the effect of perturbations in metabolite concentrations and reaction fluxes in response to genetic and environmental perturbation that are beyond the scope of stoichiometric models. In this study, we develop a two-step computational pipeline for the rapid parameterization of kinetic models of metabolic networks using a curated metabolic model and available 13C-labeling distributions under multiple genetic and environmental perturbations. The first step involves the elucidation of all intracellular fluxes in a core model of E. coli containing 74 reactions and 61 metabolites using 13C-Metabolic Flux Analysis (13C-MFA). Here, fluxes corresponding to the mid-exponential growth phase are elucidated for seven single gene deletion mutants from upper glycolysis, pentose phosphate pathway and the Entner-Doudoroff pathway. The computed flux ranges are then used to parameterize the same (i.e., k-ecoli74) core kinetic model for E. coli with 55 substrate-level regulations using the newly developed K-FIT parameterization algorithm. The K-FIT algorithm employs a combination of equation decomposition and iterative solution techniques to evaluate steady-state fluxes in response to genetic perturbations. k-ecoli74 predicted 86% of flux values for strains used during fitting within a single standard deviation of 13C-MFA estimated values. By performing both tasks using the same network, errors associated with lack of congruity between the two networks are avoided, allowing for seamless integration of data with model building. Product yield predictions and comparison with previously developed kinetic models indicate shifts in flux ranges and the presence or absence of mutant strains delivering flux towards pathways of interest from training data significantly impact predictive capabilities. Using this workflow, the impact of completeness of fluxomic datasets and the importance of specific genetic perturbations on uncertainties in kinetic parameter estimation are evaluated.
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Isótopos de Carbono/metabolismo , Biología Computacional/métodos , Escherichia coli , Redes y Vías Metabólicas , Modelos Biológicos , Algoritmos , Metabolismo de los Hidratos de Carbono , Escherichia coli/genética , Escherichia coli/metabolismo , Cinética , Redes y Vías Metabólicas/genética , Redes y Vías Metabólicas/fisiología , Mutación/genética , Mutación/fisiologíaRESUMEN
BACKGROUND: Adults spend a majority of their time outside the workplace being sedentary. Large amounts of sedentary behaviour increase the risk of type 2 diabetes, cardiovascular disease, and both all-cause and cardiovascular disease mortality. OBJECTIVES: Primary ⢠To assess effects on sedentary time of non-occupational interventions for reducing sedentary behaviour in adults under 60 years of age Secondary ⢠To describe other health effects and adverse events or unintended consequences of these interventions ⢠To determine whether specific components of interventions are associated with changes in sedentary behaviour ⢠To identify if there are any differential effects of interventions based on health inequalities (e.g. age, sex, income, employment) SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, Cochrane Database of Systematic Reviews, CINAHL, PsycINFO, SportDiscus, and ClinicalTrials.gov on 14 April 2020. We checked references of included studies, conducted forward citation searching, and contacted authors in the field to identify additional studies. SELECTION CRITERIA: We included randomised controlled trials (RCTs) and cluster RCTs of interventions outside the workplace for community-dwelling adults aged 18 to 59 years. We included studies only when the intervention had a specific aim or component to change sedentary behaviour. DATA COLLECTION AND ANALYSIS: Two review authors independently screened titles/abstracts and full-text articles for study eligibility. Two review authors independently extracted data and assessed risk of bias. We contacted trial authors for additional information or data when required. We examined the following primary outcomes: device-measured sedentary time, self-report sitting time, self-report TV viewing time, and breaks in sedentary time. MAIN RESULTS: We included 13 trials involving 1770 participants, all undertaken in high-income countries. Ten were RCTs and three were cluster RCTs. The mean age of study participants ranged from 20 to 41 years. A majority of participants were female. All interventions were delivered at the individual level. Intervention components included personal monitoring devices, information or education, counselling, and prompts to reduce sedentary behaviour. We judged no study to be at low risk of bias across all domains. Seven studies were at high risk of bias for blinding of outcome assessment due to use of self-report outcomes measures. Primary outcomes Interventions outside the workplace probably show little or no difference in device-measured sedentary time in the short term (mean difference (MD) -8.36 min/d, 95% confidence interval (CI) -27.12 to 10.40; 4 studies; I² = 0%; moderate-certainty evidence). We are uncertain whether interventions reduce device-measured sedentary time in the medium term (MD -51.37 min/d, 95% CI -126.34 to 23.59; 3 studies; I² = 84%; very low-certainty evidence) We are uncertain whether interventions outside the workplace reduce self-report sitting time in the short term (MD -64.12 min/d, 95% CI -260.91 to 132.67; I² = 86%; very low-certainty evidence). Interventions outside the workplace may show little or no difference in self-report TV viewing time in the medium term (MD -12.45 min/d, 95% CI -50.40 to 25.49; 2 studies; I² = 86%; low-certainty evidence) or in the long term (MD 0.30 min/d, 95% CI -0.63 to 1.23; 2 studies; I² = 0%; low-certainty evidence). It was not possible to pool the five studies that reported breaks in sedentary time given the variation in definitions used. Secondary outcomes Interventions outside the workplace probably have little or no difference on body mass index in the medium term (MD -0.25 kg/m², 95% CI -0.48 to -0.01; 3 studies; I² = 0%; moderate-certainty evidence). Interventions may have little or no difference in waist circumference in the medium term (MD -2.04 cm, 95% CI -9.06 to 4.98; 2 studies; I² = 65%; low-certainty evidence). Interventions probably have little or no difference on glucose in the short term (MD -0.18 mmol/L, 95% CI -0.30 to -0.06; 2 studies; I² = 0%; moderate-certainty evidence) and medium term (MD -0.08 mmol/L, 95% CI -0.21 to 0.05; 2 studies, I² = 0%; moderate-certainty evidence) Interventions outside the workplace may have little or no difference in device-measured MVPA in the short term (MD 1.99 min/d, 95% CI -4.27 to 8.25; 4 studies; I² = 23%; low-certainty evidence). We are uncertain whether interventions improve device-measured MVPA in the medium term (MD 6.59 min/d, 95% CI -7.35 to 20.53; 3 studies; I² = 70%; very low-certainty evidence). We are uncertain whether interventions outside the workplace improve self-reported light-intensity PA in the short-term (MD 156.32 min/d, 95% CI 34.34 to 278.31; 2 studies; I² = 79%; very low-certainty evidence). Interventions may have little or no difference on step count in the short-term (MD 226.90 steps/day, 95% CI -519.78 to 973.59; 3 studies; I² = 0%; low-certainty evidence) No data on adverse events or symptoms were reported in the included studies. AUTHORS' CONCLUSIONS: Interventions outside the workplace to reduce sedentary behaviour probably lead to little or no difference in device-measured sedentary time in the short term, and we are uncertain if they reduce device-measured sedentary time in the medium term. We are uncertain whether interventions outside the workplace reduce self-reported sitting time in the short term. Interventions outside the workplace may result in little or no difference in self-report TV viewing time in the medium or long term. The certainty of evidence is moderate to very low, mainly due to concerns about risk of bias, inconsistent findings, and imprecise results. Future studies should be of longer duration; should recruit participants from varying age, socioeconomic, or ethnic groups; and should gather quality of life, cost-effectiveness, and adverse event data. We strongly recommend that standard methods of data preparation and analysis are adopted to allow comparison of the effects of interventions to reduce sedentary behaviour.
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Ejercicio Físico , Conducta Sedentaria , Adulto , Sesgo , Intervalos de Confianza , Consejo , Femenino , Monitores de Ejercicio , Educación en Salud , Humanos , Vida Independiente , Masculino , Persona de Mediana Edad , Ensayos Clínicos Controlados Aleatorios como Asunto , Autoinforme , Sedestación , Televisión/estadística & datos numéricos , Factores de Tiempo , Adulto JovenRESUMEN
âRosamond Rhodes contends, by reference to seven examples, that medical ethics is distinctly different from non-medical ethics. Each of those examples, on proper examination, illustrates precisely the opposite contention. It is clear not only that medical ethics relies on the same principles as non-medical (and indeed non-professional) ethics, but that it should so rely. A distinctively medical ethics would be dangerous: it would divorce ethical medical decision-making from the patients whom medicine exists to serve.
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Principios Morales , Médicos , Ética Médica , HumanosRESUMEN
There is a strong presumption in favour of the maintenance of life. Given sufficient evidence, it can be rebutted. But the epistemic uncertainties about the best interests of patients in prolonged disorders of consciousness ('PDOC') and the wishes that they should be presumed to have are such that, in most PDOC cases, the presumption cannot be rebutted. It is conventional and wrong (or at least unsupported by the evidence) to assume that PDOC patients have no interest in continued existence. Treatment withdrawal/continuation decisions should focus on the patient as he or she actually is, and should not unjustifiably assume that the premorbid patient continues to exist unchanged, and that the actual patient has the same interests as the premorbid patient and would make the same decisions in relation to treatment as the premorbid patient would have done.
Asunto(s)
Ética Médica , Privación de Tratamiento/ética , Humanos , Cuidados para Prolongación de la Vida/ética , Estado Vegetativo Persistente/terapia , IncertidumbreRESUMEN
In English law there is a strong (though rebuttable) presumption that life should be maintained. This article contends that this presumption means that it is always unlawful to withdraw life-sustaining treatment from patients in permanent vegetative state (PVS) and minimally conscious state (MCS), and that the reasons for this being the correct legal analysis mean also that such withdrawal will always be ethically unacceptable. There are two reasons for this conclusion. First, the medical uncertainties inherent in the definition and diagnosis of PVS/MCS are such that, as a matter of medical fact, it can never be established, with the degree of certainty necessary to rebut the presumption, that it is not in the patient's best interest to remain alive. And second (and more controversially and repercussively), that even if permanent unconsciousness can be unequivocally demonstrated, the presumption is not rebutted. This is because there is plainly more to human existence than consciousness (or consciousness the markers of which can ever be demonstrated by medical investigations). It can never be said that the identity of the patient whose best interests are at stake evaporates (so eliminating the legal or ethical subject) when that person ceases to be conscious. Nor can it be said that the best interests of an unconscious person do not mandate continued biological existence. We simply cannot know. That uncertainty is legally conclusive, and (subject to resource allocation questions and views about the relevance of family wishes and the previously expressed wishes of the patient) should be ethically conclusive.