← Biology and medicine this week · 26 October 2026 · 5 min read
Biology and medicine this week
From motion sickness in commercial astronauts to AI-guided molecular discovery, this week’s preprints explore how living systems adapt—and how researchers can learn to intervene.
How to check the findings and keep reading? Illustrated guide
Space travel’s unsettled stomach #
For commercial astronauts, adjusting to weightlessness can be a decidedly physical ordeal. A study of eight crew members on the Polaris Dawn and Fram2 missions found that seven experienced space motion sickness and five vomited. In two participants, symptoms persisted for at least three days in orbit. After returning to Earth, four experienced readaptation motion sickness, although it was significantly less severe and tended to be shorter-lived than sickness in space.
The cohort is small, but the researchers used a standardized reporting method to track symptoms rather than relying mainly on recollections after landing. This preprint offers a baseline for understanding an operationally disruptive problem as commercial spaceflight expands. It does not establish how representative these eight flyers are of future passengers.
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Spaceflight-associated Motion Sickness in Commercial Crew Astronauts
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AI molecular designers meet the laboratory #
Can AI agents improve molecular designs by learning from experiments rather than merely submitting a final prediction for testing? Researchers explored that question with aptamers, short nucleic-acid molecules that can bind proteins. Across three design-and-test rounds involving roughly 4,400 constructs, agentic pipelines sought binders for two targets, thrombin and myoglobin. Among new candidates, measured on-target hit rates rose from zero to 42.1% for thrombin, and from 10.2% to 33.5% for myoglobin, although the latter initially fell in the second round.
The details temper the headline. The strongest measured thrombin binding came from agent-engineered versions of motifs already known in the literature; newly devised scaffolds bound more weakly. The myoglobin experiments also exposed a loss of specificity that the pipelines subsequently worked to reverse. The preprint’s most useful lesson may be that experimental feedback helps agents identify misleading assay signals and revise their strategies—something computational stand-ins alone did less well.
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Aptamers as a sandbox for lab-in-the-loop agentic molecular discovery
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Designing a smaller blocker of inflammation #
Another molecular-design preprint targets IL-23, a signaling protein involved in inflammatory bowel disease and psoriasis. Existing antibodies against its p19 component are effective medicines, but the researchers are exploring much smaller proteins designed to obstruct the same receptor-binding surface. A conventional computational pipeline produced no reliably predicted interfaces among 972 designs. An interface-optimized method, BindCraft, performed substantially better on the researchers’ prediction metrics, yielding five lead candidates for closer analysis.
This is a computational result, not evidence of a new treatment. None of the candidates has yet been experimentally shown to bind or neutralize IL-23. The study also highlights a practical difficulty in protein engineering: apparently reassuring scores can reflect protein length or quirks of the prediction setup rather than a convincing molecular interface. Better scoring can improve the shortlist, but laboratory tests remain essential.
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Computational De Novo Design of Miniprotein Candidate Neutralizers Targeting the IL-23 Cytokine Subunit p19
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How the immune system might budget its attention #
The gut contains an interacting community of microbes, making immune control more complicated than simply attacking one unwanted species. Reanalyzing experiments in mice colonized with a defined microbial community, researchers found that T-cell recognition of particular strains was associated with changes in those strains’ abundance. Recognition was sparse overall, while some individual T-cell clones recognized multiple, taxonomically diverse strains.
To interpret that pattern, the team developed a model in which the immune system balances the harm microbes cause against the cost of maintaining a response. Competition among T cells for microbial antigens could produce the resulting allocation of immune attention. The model also supplies an important qualification: interactions between microbes can interfere with immune control of their abundance. This is a quantitative framework grounded in a controlled mouse system, not yet a general account of how human gut communities are managed.
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Rational T cell repertoire allocation to control the gut microbiota
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Different languages, related maps of meaning #
A multilingual brain-decoding study analyzed recordings from 227 participants spanning Chinese, English and French. The researchers report that relationships among cortical representations of meaning were consistent across both languages and individuals. In other words, although words and sentence structures differ, the relative arrangement of meanings in the measured brain representations showed common patterns.
That consistency increased from regions associated with sensation and movement toward higher-order association cortex, following a major gradient of brain organization. The preprint suggests a shared neural structure underlying some semantic commonalities across languages. It does not imply that languages produce identical brain activity, or that a decoder can read arbitrary thoughts.
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Multilingual Brain Decoding Reveals Shared Cortical Semantic Geometry
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A Bayesian argument about COVID-19’s origins #
One preprint applies Bayesian reasoning to compare a broadly defined zoonotic origin of COVID-19 with a specific research-related scenario based on prior work and grant proposals. Drawing on observations including the outbreak’s location, the absence of known prior hosts, early viral evolution and sequence features, the author reports odds strongly favoring the research-related scenario, including when allowing uncertainty in prior odds.
That conclusion is the paper’s inference, not a newly established fact about the pandemic’s origin. Bayesian comparisons depend on which hypotheses are included and how likely the evidence is judged to be under each one; allowing uncertainty in starting odds does not by itself resolve those other choices. This not-yet-peer-reviewed analysis should therefore be read as an argument built from selected evidence and modeling assumptions, rather than as direct evidence of a research-related origin.
These six preprints, drawn from 147 papers announced in biology and medicine this week, share a concern with turning observations into useful explanations or interventions. Their evidential foundations differ: astronaut symptom reports, laboratory binding measurements, mouse experiments, brain recordings and computational models answer different kinds of questions. Reading them together underscores a recurring distinction in science: a promising pattern or persuasive model is a starting point, while testing how well it survives new measurements is what gives it lasting value.
Rising in this field
- Blood clues to sudden confusion in hospital medRxiv · ×9.1 compared with usual · 7 papers from 7 teams
- 3D printing living tissues bioRxiv · ×11.5 compared with usual · 6 papers from 6 teams
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Written by AI from the 147 papers of the week in this field. Most are preprints, not yet peer reviewed: the text says what their authors report.
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