The region’s enormous herbivores, some weighing more than 1 ton, were no match for this prehistoric beast
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The Turtle in Your Bloodstream
This week on Heliox, we trace the science from a rigorous long COVID symptom meta-analysis, through the structural biology of the “turtle” variant, to why a proven diagnostic test still isn’t in your local lab — and why clean air might be the fastest fix we actually have.
Podcast Episode · Heliox: Where Evidence Meets Empathy 🇨🇦 · September 2 · 17m.
Scientists may have detected the 1st direct evidence of dark matter
As LUX-ZEPPLIN continues to gather the largest dataset in dark matter science, the team will determine if this event has grown in significance or if its significance fades.
One definite positive is the fact that WIMP/ matter interactions are so rare that it wouldn’t take many detections such as this to confirm the existence of WIMP dark matter, thus solving the puzzle of what the universe’s most mysterious stuff actually is composed of.
“We expect dark matter events to be extremely rare, so only a handful could mark the first detection of WIMP dark matter,” Eriksen said.
Robust inference and correlates from genetic associations with personality
Among participants with EUR-like genomes, SNP heritability (h2SNP) estimated for the Big Five traits using linkage disequilibrium score regression (LDSC)34 ranged from 4.8% (s.e. = 0.2%) for agreeableness to 9.3% (s.e. = 0.3%) for extraversion (Table 1, Supplementary Table 4 and Supplementary Note 3). Importantly, these SNP heritability estimates from GWAS meta-analysis index genetic effects that are consistent across contributing cohorts. To allow for variability in genetic effects across cohorts, we conducted a random effects meta-analysis of cohort-specific h2SNP estimates, which indicated an average h2SNP of 8.6% (s.e. = 0.6%) across traits (ranging from 7.4% for agreeableness to 10.6% for extraversion; Table 1 and Supplementary Table 21), with significant variability across cohorts (mean τ = 3.6%). Random response error by the participants cannot systematically relate to their genome35,36. Accordingly, we found that personality measures with greater reliability (lower random response error) tended to be more heritable (b = 6.7%, s.e. = 0.7%; Extended Data Fig. 2). In this analysis, the expected h2SNP for a measure of typical (median) reliability (α = 0.81) ranged from 9.3% for agreeableness (s.e. = 0.6%) to 13.3% for extraversion (s.e. = 0.6%), and h2SNP completely disattenuated for measurement error ranged from 10.8% for agreeableness (s.e. = 0.9%) to 15.8% for extraversion (s.e. = 0.9%; Table 1).
To further characterize the generalizability of genetic associations with personality, we examined the concordance of genetic signal across geography, age, veteran status, measurement instrument and reporter perspective (Table 1 and Extended Data Fig. 3). Genetic effects were similar but not identical across four western country clusters (USA, continental Europe, Nordic and UK–Australia, mean rg = 0.86, mean s.e. = 0.15), three age groups (young (≤25 years), middle (25–64 years) and older (65 years and older), mean rg = 0.80, mean s.e. = 0.18), between the Million Veteran Program and other, primarily non-veteran cohorts (mean rg = 0.82, mean s.e. = 0.04), and across five personality measurement instruments (mean rg = 0.85, mean s.e. = 0.07). Additional characterization of genetic architecture across measurement instruments using genomic structural equation modelling37 confirmed that genetic effects plausibly operate at the level of broad cross-instrument latent factors, with only one locus showing significantly heterogenous effects across measurement instruments (Supplementary Tables 22 – 24 and Extended Data Fig. 4). Notably, genetic associations with agreeableness were less consistent across cohorts (Table 1), explaining in part why agreeableness exhibited lower heritability than other traits in the meta-analytic GWAS. In the Estonian Biobank, in which the personality of the participants was assessed both by their self-report (n = 73,983) and by reports by close others (n = 20,269), we found strong genetic overlap between rater perspectives (mean rg = 0.84, mean s.e. = 0.12), indicating that the genetic architecture of personality is not an epiphenomenon of self-perception. In sex-stratified analyses of neuroticism in the UK Biobank cohort, X-chromosome-linked h2SNP did not differ between male individuals (n = 168,989; h2SNP, X = 0.23%; s.e. = 0.04%) and female individuals (n = 198,139; h2SNP, X = 0.18%; s.e. = 0.03%; Pdifference = 0.33). The dosage compensation ratio (\(\hat{{m{\gamma }}}\) = 1.26, s.e. = 0.30) was intermediate between no compensation (0.5) and full compensation (2.0) but was estimated relatively imprecisely. Genetic effects were correlated near-unity across sex (rg = 0.96; 95% confidence interval (CI) = 0.81–1.10).
Biological follow-up of GWAS signals indicated that enriched gene sets intersected across the Big Five (mean enrichment rank-order ρ = 0.72; Extended Data Fig. 5), providing evidence for trait-overlapping molecular and cellular systems in personality neurobiology despite only modest genetic correlations (Fig. 1f). Consistent with theories of personality development that emphasize the prefrontal cortex38,39, genetic associations for each Big Five trait, except for agreeableness, were enriched in genes expressed in the prefrontal cortex (among these, top lead SNPs implicate RCE1, FOXP2 and SEMA6D, indicated in Fig. 1; Supplementary Tables 25–34). All traits demonstrated strong enrichment in protein-truncating variant-intolerant gene sets specifically expressed in neurons (such as ARNTL, TCF4 and NEGR1; Fig. 1).
Less-intensive drug combination is more effective in treating acute myeloid leukemia, clinical trial finds
Investigators from the Mass General Brigham Cancer Institute have found that adults with newly diagnosed acute myeloid leukemia (AML) receiving a less-intensive combination of azacitidine and venetoclax had more than twice as much time before treatment failed, the leukemia returned or worsened, or they died, compared with patients receiving intensive chemotherapy. Published in the New England Journal of Medicine, the findings could change the initial treatment approach for many patients with AML.
“Less-intensive treatment does not necessarily mean less-effective treatment,” said lead author Amir T. Fathi, MD, director of the Leukemia Program at the Mass General Brigham Cancer Institute. “Our goal is to optimally treat acute myeloid leukemia while reducing serious complications and the amount of time patients spend in the hospital.”
The less-intensive combination is already used in older patients or those unable to tolerate intensive chemotherapy. The PARADIGM trial tested whether it could work as well—or better—for patients who could receive intensive chemotherapy, including younger patients.
When we eat helps set the liver’s metabolic rhythms
When we think about metabolism, we usually ask, “What did I eat? How much sugar, fat or protein was in the meal?” But through our research, we have become interested in another question: “When did I eat it?” This matters because metabolism does not work at the same pace throughout the day.
The liver, one of our main metabolic organs, follows daily rhythms that help coordinate how nutrients are processed, stored and used. These rhythms are controlled partly by the molecular circadian clock, present in virtually all body cells, but eating also provides an important signal.
In our recent study published in Cell Reports, we set out to understand how the timing of food intake influences these daily metabolic rhythms. What we found points to a mitochondrial enzyme, ACSF3, as a potential link between feeding time and the temporal organization of liver metabolism.
2 spacecraft headed to Mercury are about to begin their longawaited arrival for Europe and Japan live on Sept. 3
The BepiColombo mission’s two science orbiters will separate from their transfer module at around 8 a.m. EDT on Thursday (Sept. 3).