Description: The first model of oxygenated haemoglobin is one of the iconic images of twentieth-century biology. Complete molecule of haemoglobin is made up of four subunits, each of which consists of one polypeptide chain and one haem.There are two kinds of subunit, designated alpha (white) and beta (black), which have different sequences of amino acid residues but similar three-dimensional structures. The beta chain also has one short extra helix. The four subunits are arranged at the vertices of a tetrahedron around an axis of two-fold symmetry. Each haem (gray) lies in a separate pocket at the surface of the molecule. Haemoglobin is the iron-containing oxygen-transport metalloprotein in the red blood cells of vertebrates.
Late Permian of Tanzania at the time of deposition of the Usili Formation.
Life restoration of Aenigmastropheus parringtoni (foreground), and herd of the dicynodont Endothiodon being pursued by a gorgonopsian. All these vertebrates were found together at the type locality of Aenigmastropheus parringtoni (locality B35). Drawing by Emilio López-Rolandi.
"Sensory model of the erupted male narwhal tusk showing, from bottom left, the introduction of water gradients penetrating cementum channels connected to patent dentinal tubules through the full thickness of the dentinal layer, connecting to odontoblastic processes and cells at the base of the tubules and at the periphery of the pulp, which stimulate nerve tissue connecting the base of tusk tissue to the maxillary branch of the fifth cranial nerve to the brain. Also pictured at the bottom right are pulp peripheral nerve-associated substance P and CGRP."
Habitus drawing of holotype female (SEMC F001019) of Borneomymar pankowskiorum, new species.
Abstract. A new fossil species of fairyfly (Hymenoptera: Chalcidoidea: Mymaridae) is described and figured from a well-preserved female in middle Eocene (Lutetian) Baltic amber as Borneomymar pankowskiorum Engel, McKellar, & Huber, new species. This species represents the fourth genus from Baltic amber whose extant species now occur only in southeastern Asia, Australia, and Madagascar.
"In a purpose-built dissection lab, Dr George McGavin is joined by leading anatomy experts to dissect a real hand, taking it apart layer by layer to reveal what makes it unique in the animal kingdom. We discover what gives our hands an unrivalled combination of power and precision, and meet people who use their hands in extraordinary ways - from magicians to rock climbers - to discover what gives them such astonishing abilities."
Myles Power created several excellent videos exposing the AIDS denialist film ‘House of Number’ To silence this criticism AIDS denialists have lodged a copyright claim against Myles but ignored the full length copies of 'House of number' on YouTube!
Some of the videos are currently down but you can view two of them: