This art history video discussion examines Petrus Christus' "Portrait of a Young Woman," c. 1470, oil on oak, 29 x 22.50 cm (Gemaldegalerie, Staatliche Museen zu Berlin).

This art history video discussion examines Cimabue's "Maesta of Santa Trinita," 1280-1290, tempera on panel, 151 1/2 x 87 3/4" (385 x 223 cm), Uffizi, Florence.

This art history video discussion examines Claes Oldenburg's "Floor Cake," Synthetic polymer paint and latex on canva filled with foam rubber and cardboard boxes, 58.375 x 114.25 x 58.375 in. (148.2 x 290.2 x 148.2 cm) 1962 (MoMA).

Cocaine afflicts many individuals and is potently addictive. Originally hailed as a wonder-drug in the late 19th century, cocaine is now considered an illegal substance. Cocaine’s addictive properties can be attributed to changes in the dopamine reward pathway of the Ventral Tegmental Area and Substantia Nigra, Prefrontal Cortex, Dorsal Striatum, Nucleus Accumbens, Amygdala, Globus Pallidus, and Hippocampus. This drug affects the brain in two processes: binge and crave. The binge process highlights cocaine’s ability to block dopamine reuptake from the synapse resulting in hyperstimulation of the postsynaptic neuron in the dopamine reward pathway. The crave process promotes drug-seeking behavior through conditional and contextual cues. Understanding the effects of cocaine in the brain may grant insight in creating future medication and therapies to treat individuals addicted to this drug.

This art history video discussion examines Thomas Cole's "Expulsion from the Garden of Eden," 1828, oil on canvas, 100.96 x 138.43 cm / 39-3/4 x 54-1/2 inches (Museum of Fine Arts, Boston).

This art history video discussion looks at the Colosseum (Amphitheatrum Flavium), c. 70-80 C.E., Rome.

This video features a Smarthistory conversation between Dr. Beth Harris and Dr. Steven Zucker in front of the Colossus of Constantine, c. 312-15 (the first Christian Emperor of Rome). Palazzo dei Conservatori, Musei Capitolini, Rome.

This art history video discussion examines the Column of Trajan, Carrara marble, completed 113 C.E., Rome. Dedicated to Emperor Trajan (Marcus Ulpius Nerva Traianus b. 53 , d. 117 C.E.) in honor of his victory over Dacia (now Romania) 101-02 and 105-06 C.E.

This concept-building module contains a variety of simulations for exploring factors that cause molecules to attract each other. It was developed to help secondary students understand both polar and non-polar covalent bonding. Users can manipulate models to see how the strength of attraction is affected by distance from one molecule to another, by heating the substance, and by mixing polar and non-polar substances. Part II of the activity is devoted to hydrogen bonds, and explores why water is one of the most important molecules for life's existence. This item is part of the Concord Consortium, a nonprofit research and development organization dedicated to transforming education through technology.

This interactive activity for grades 8-12 features eight models that explore atomic arrangements for gases, solids, and liquids. Highlight an atom and view its trajectory to see how the motion differs in each of the three primary phases. As the lesson progresses, students observe and manipulate differences in attractions among atoms in each state and experiment with adding energy to produce state changes. More advanced students can explore models of latent heat and evaporative cooling. This item is part of the Concord Consortium, a nonprofit research and development organization dedicated to transforming education through technology.

This art history video discussion examines John Constable"s "The Hay Wain", 1821. Oil on canvas, 51 1/4" x 73" (130.2 x 185.4 cm) (The National Gallery, London).

This art history video discussion examines the "Coronation Mantle" likely made for the Norman ruler Roger II in 1133/34 in the royal workshop in Palermo of fabric from Byzantium or Thebes, Samite, silk, gold, pearls, filigree, sapphires, garnets, glass, and cloisonne enamel.

This art history video discussion examines Correggio's "Jupiter and Io" 1532-33, oil on canvas 163.5 x 70.5 cm (Kunsthistorisches Museum, Vienna).

This art history video discussion examines Gustave Courbet's "The Artist's Studio; A real allegory summing up seven years of my artistic and moral life", oil on canvas, 1854-55 (Musee d'Orsay, Paris).

This art history video discussion looks at Thomas Couture's "Romans of the Decadence," 1847, oil on canvas. (Musée d’Orsay, Paris).

This art history video discussion examines Lucus Cranach the Elder's "Adam and Eve", 1526, oil on panel (Courtauld Gallery, London).

Precise modification of faulty genes for repair has been one of the most important goals in medicine. It is now finally within the realm of possibility thanks to the gene editing tool CRISPR. This microbial adaptive immune system can copy and cut specific DNA sequences. This animation provides a visual introduction of this revolutionary genetic tool.

This art history video discussion examines Salvador Dali's "Metamorphosis of Narcissus", 1937, oil on canvas, 51.1 x 78.1 cm (Tate Modern, London).

This art history video discussion examines Jacques-Louis David's "Oath of the Horatii", oil on canvas, 1784 (Musee du Louvre).

This art history video discussion examines Jacques-Louis David's "The Intervention of the Sabine Women", 1799, Oil on canvas, 12 feet, 8 inches x 17 feet and 3/4 of an inch or 3.85 x 5.22 m (Musee du Louvre, Paris).