ZF_4_18 — Deep Ocean Microplastics

Deep ocean microplastics — synthetic polymer particles smaller than 5 mm that have infiltrated the deepest marine environments on Earth — represent one of the most alarming and poorly understood dimensions of global plas

ZF_4_15 — Ocean Sediments: Deep-Sea Cores, Proxy Records, and Paleoclimate

Ocean sediments are the Earth's most comprehensive climate archive — a continuous record of planetary conditions extending back over 200 million years, slowly accumulated grain by grain on the deep seafloor at rates of m

ZF_4_05 — Marine Pharmacology and Drug Discovery

Marine pharmacology explores the ocean's vast biodiversity as a source of bioactive compounds for drug development — a field that has yielded several approved drugs and thousands of promising leads since the pioneering w

Z_5_00 — Modern Genomics Technologies: Subfolder Summary

Z_5_05 — Proteomics: The Global Study of Proteins

Proteomics — the large-scale study of the complete set of proteins (proteome) expressed by a cell, tissue, or organism at a given time — bridges the gap between the genome (static DNA sequence) and the phenotype (observa

Z_5_18 — Gut-Brain Axis: The Microbiome-Nervous System Connection

The gut-brain axis — the bidirectional communication network between the gastrointestinal tract and the central nervous system — has emerged as one of the most transformative concepts in modern biology and medicine. The

Z_5_03 — Metabolomics: The Small-Molecule Landscape of Life

Metabolomics — the comprehensive study of all small-molecule metabolites (<~1,500 Da) present in a biological sample (cell, tissue, organ, biofluid, organism) — is the newest of the major "-omics" disciplines (after geno

Z_4_13 — Membrane Biology: Lipid Bilayers, Rafts, and Cellular Boundaries

Biological membranes — the lipid bilayer structures that define cells and compartmentalize their interiors — are fundamental to all life on Earth. Every cell is bounded by a plasma membrane that separates the interior (c

Z_4_18 — Protein Misfolding and Prion Diseases

Prion diseases — transmissible spongiform encephalopathies (TSEs) — are fatal neurodegenerative disorders caused by the misfolding and self-propagating aggregation of a normal cellular protein (PrPᶜ) into a pathological

Z_4_00 — RNA Protein Cell Biology: Subfolder Summary

Z_4_10 — Signal Transduction: How Cells Communicate

Signal transduction — the molecular mechanisms by which cells detect, interpret, and respond to external signals (hormones, growth factors, neurotransmitters, cytokines, environmental cues) — is one of the central organi

Z_0_00 — Molecular Biology & Genomics: Section Summary

E_2_13 — Paleocene-Eocene Thermal Maximum

The Paleocene-Eocene Thermal Maximum (PETM) — approximately 55.8 million years ago — was the most extreme rapid warming event of the past 66 million years and is widely studied as a deep-time analog for modern anthropoge

E_2_12 — Great Oxygenation Event

The Great Oxygenation Event (GOE) — approximately 2.4–2.1 billion years ago — was one of the most transformative events in Earth's history: the first permanent rise of free molecular oxygen (O₂) in the atmosphere, from n

E_4_21 — Oxygen Isotope Stages: Marine Isotope Record and Climate Cycles

The marine oxygen isotope record — constructed from measurements of the ratio of oxygen-18 to oxygen-16 (δ¹⁸O) in the calcium carbonate (CaCO₃) shells of foraminifera (single-celled marine organisms) preserved in deep-se

E_4_13 — Milankovitch Cycles and Orbital Forcing

Milankovitch cycles are periodic variations in Earth's orbital geometry that modulate the distribution and intensity of solar radiation reaching Earth's surface, driving the glacial-interglacial cycles that have dominate

E_4_26 — Younger Dryas Impact Evidence: A Comprehensive Review

The Younger Dryas Impact Hypothesis (YDIH) proposes that one or more extraterrestrial objects (comet or asteroid fragments) struck or exploded over the Earth approximately 12,900 years ago (12.9 ka BP), triggering the Yo

E_4_27 — Chicxulub Impact and the K-Pg Mass Extinction

The Chicxulub impact was a catastrophic asteroid strike that occurred approximately 66.043 ± 0.011 million years ago at what is now the Yucatan Peninsula, Mexico, marking the boundary between the Cretaceous and Paleogene

E_1_14 — Supernovae in Human History: Crab Nebula, SN 1006, Vela

Supernovae — the catastrophic explosions of massive stars (core-collapse, Type II/Ib/Ic) or white dwarfs exceeding the Chandrasekhar mass limit (thermonuclear, Type Ia) — are among the most energetic events in the univer

J_0_00 — Ancient Technology: Section Summary