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| 2. |
- Jones, G., et al.
(författare)
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Genome-wide meta-analysis of muscle weakness identifies 15 susceptibility loci in older men and women
- 2021
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Low muscle strength is an important heritable indicator of poor health linked to morbidity and mortality in older people. In a genome-wide association study meta-analysis of 256,523 Europeans aged 60 years and over from 22 cohorts we identify 15 loci associated with muscle weakness (European Working Group on Sarcopenia in Older People definition: n=48,596 cases, 18.9% of total), including 12 loci not implicated in previous analyses of continuous measures of grip strength. Loci include genes reportedly involved in autoimmune disease (HLA-DQA1p=4x10(-17)), arthritis (GDF5p=4x10(-13)), cell cycle control and cancer protection, regulation of transcription, and others involved in the development and maintenance of the musculoskeletal system. Using Mendelian randomization we report possible overlapping causal pathways, including diabetes susceptibility, haematological parameters, and the immune system. We conclude that muscle weakness in older adults has distinct mechanisms from continuous strength, including several pathways considered to be hallmarks of ageing. Muscle weakness has been associated with morbidity and mortality in older people. Here, the authors have investigated this trait further by performing a genome-wide meta-analysis of grip strength and Mendelian randomization to discover causal relationships between muscle weakness and other diseases.
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| 3. |
- Graham, E. K., et al.
(författare)
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Personality predicts mortality risk: An integrative data analysis of 15 international longitudinal studies
- 2017
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Ingår i: Journal of Research in Personality. - : Elsevier BV. - 0092-6566. ; 70, s. 174-186
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Tidskriftsartikel (refereegranskat)abstract
- This study examined the Big Five personality traits as predictors of mortality risk, and smoking as a mediator of that association. Replication was built into the fabric of our design: we used a Coordinated Analysis with 15 international datasets, representing 44,094 participants. We found that high neuroticism and low conscientiousness, extraversion, and agreeableness were consistent predictors of mortality across studies. Smoking had a small mediating effect for neuroticism. Country and baseline age explained variation in effects: studies with older baseline age showed a pattern of protective effects (HR < 1.00) for openness, and U.S. studies showed a pattern of protective effects for extraversion. This study demonstrated coordinated analysis as a powerful approach to enhance replicability and reproducibility, especially for aging-related longitudinal research. © 2017 Elsevier Inc.
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| 4. |
- Lee, James J, et al.
(författare)
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Gene discovery and polygenic prediction from a genome-wide association study of educational attainment in 1.1 million individuals.
- 2018
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Ingår i: Nature genetics. - : Springer Science and Business Media LLC. - 1546-1718 .- 1061-4036. ; 50:8, s. 1112-1121
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Tidskriftsartikel (refereegranskat)abstract
- Here we conducted a large-scale genetic association analysis of educational attainment in a sample of approximately 1.1 million individuals and identify 1,271 independent genome-wide-significant SNPs. For the SNPs taken together, we found evidence of heterogeneous effects across environments. The SNPs implicate genes involved in brain-development processes and neuron-to-neuron communication. In a separate analysis of the X chromosome, we identify 10 independent genome-wide-significant SNPs and estimate a SNP heritability of around 0.3% in both men and women, consistent with partial dosage compensation. A joint (multi-phenotype) analysis of educational attainment and three related cognitive phenotypes generates polygenic scores that explain 11-13% of the variance in educational attainment and 7-10% of the variance in cognitive performance. This prediction accuracy substantially increases the utility of polygenic scores as tools in research.
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| 5. |
- Becker, Joel, et al.
(författare)
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Resource profile and user guide of the Polygenic Index Repository
- 2021
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Ingår i: Nature Human Behaviour. - : Nature Research (part of Springer Nature). - 2397-3374. ; 51:6, s. 694-695
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Tidskriftsartikel (refereegranskat)abstract
- Polygenic indexes (PGIs) are DNA-based predictors. Their value for research in many scientific disciplines is growing rapidly. As a resource for researchers, we used a consistent methodology to construct PGIs for 47 phenotypes in 11 datasets. To maximize the PGIs’ prediction accuracies, we constructed them using genome-wide association studies—some not previously published—from multiple data sources, including 23andMe and UK Biobank. We present a theoretical framework to help interpret analyses involving PGIs. A key insight is that a PGI can be understood as an unbiased but noisy measure of a latent variable we call the ‘additive SNP factor’. Regressions in which the true regressor is this factor but the PGI is used as its proxy therefore suffer from errors-in-variables bias. We derive an estimator that corrects for the bias, illustrate the correction, and make a Python tool for implementing it publicly available. © 2021, The Author(s), under exclusive licence to Springer Nature Limited.
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| 6. |
- Sun, Vivian Z., et al.
(författare)
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Overview and Results From the Mars 2020 Perseverance Rover's First Science Campaign on the Jezero Crater Floor
- 2023
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Ingår i: Journal of Geophysical Research: Planets. - : John Wiley and Sons Inc. - 2169-9097 .- 2169-9100. ; 128:6
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Tidskriftsartikel (refereegranskat)abstract
- The Mars 2020 Perseverance rover landed in Jezero crater on 18 February 2021. After a 100-sol period of commissioning and the Ingenuity Helicopter technology demonstration, Perseverance began its first science campaign to explore the enigmatic Jezero crater floor, whose igneous or sedimentary origins have been much debated in the scientific community. This paper describes the campaign plan developed to explore the crater floor's Máaz and Séítah formations and summarizes the results of the campaign between sols 100–379. By the end of the campaign, Perseverance had traversed more than 5 km, created seven abrasion patches, and sealed nine samples and a witness tube. Analysis of remote and proximity science observations show that the Máaz and Séítah formations are igneous in origin and composed of five and two geologic members, respectively. The Séítah formation represents the olivine-rich cumulate formed from differentiation of a slowly cooling melt or magma body, and the Máaz formation likely represents a separate series of lava flows emplaced after Séítah. The Máaz and Séítah rocks also preserve evidence of multiple episodes of aqueous alteration in secondary minerals like carbonate, Fe/Mg phyllosilicates, sulfates, and perchlorate, and surficial coatings. Post-emplacement processes tilted the rocks near the Máaz-Séítah contact and substantial erosion modified the crater floor rocks to their present-day expressions. Results from this crater floor campaign, including those obtained upon return of the collected samples, will help to build the geologic history of events that occurred in Jezero crater and provide time constraints on the formation of the Jezero delta.
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| 7. |
- Bellucci, J. J., et al.
(författare)
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Insights into the chemical diversity of the martian mantle from the Pb isotope systematics of shergottite Northwest Africa 8159
- 2020
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Ingår i: Chemical Geology. - : Elsevier BV. - 0009-2541 .- 1872-6836. ; 545
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Tidskriftsartikel (refereegranskat)abstract
- Shergottite Northwest Africa (NWA) 8159 is a basaltic rock derived from a mantle source with chemical characteristics that are unique in the martian meteorite suite. To further investigate this source reservoir, the Pb isotope compositions of plagioclase/maskelynite, pyroxene, phosphates, and shock melt-glass in NWA 8159 have been measured in situ by Secondary Ion Mass Spectrometry (SIMS). Due to the limited spread in Pb isotope data, these Pb isotope compositions have been used to calculate an imprecise PbPb isochron age of 3.4 ± 2.1 Ga (2σ), which is broadly consistent with the crystallization age of 2.37 ± 0.25 Ga determined previously by 147Sm143Nd. The lack of radiogenic in-growth within individual minerals since 2.4 Ga means that this sample is depleted in U, which is in agreement with NWA 8159's positive initial ε143Nd. An initial Pb composition was calculated using an x-y weighted average of the least radiogenic Pb isotope population measured in the sample. This initial Pb composition is not consistent with the model for Pb growth in the shergottite mantle at 2.4 Ga. This composition is, however, consistent with the model for the Nakhla-Chassigny mantle. Using the latter model, a source μ (238U/204Pb) of 2.6 ± 0.6 has been calculated. This μ-value is in contrast with the other depleted shergottites (1.4-1.5) and falls significantly off the array of source ε143Nd vs. μ defined by the rest of the martian meteorite suite and thus, necessitates a differentiation history distinct from the other martian meteorites. Sequestering Pb in sulphides during differentiation is the only mechanism to fractionate U from Pb and create a low-μ reservoir. Consequently, the relatively high μ-value of the source of NWA 8159 is in contrast with the positive initial ε143Nd and indicates that its mantle source region likely lacked significant sulphur. This is consistent with the lack of sulphides in the sample itself and could have played a role in its complicated oxidation history.
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| 8. |
- Steele, A., et al.
(författare)
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A Reduced Organic Carbon Component in Martian Basalts
- 2012
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 337:6091, s. 212-215
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Tidskriftsartikel (refereegranskat)abstract
- The source and nature of carbon on Mars have been a subject of intense speculation. We report the results of confocal Raman imaging spectroscopy on 11 martian meteorites, spanning about 4.2 billion years of martian history. Ten of the meteorites contain abiotic macromolecular carbon (MMC) phases detected in association with small oxide grains included within high-temperature minerals. Polycyclic aromatic hydrocarbons were detected along with MMC phases in Dar al Gani 476. The association of organic carbon within magmatic minerals indicates that martian magmas favored precipitation of reduced carbon species during crystallization. The ubiquitous distribution of abiotic organic carbon in martian igneous rocks is important for understanding the martian carbon cycle and has implications for future missions to detect possible past martian life.
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