1.Bees can see the direction of plane polarized light and use it to navigate. [Nature, Rossel et al 1986] From the abstract: "The mechanism involves the transformation of polarization information into modulations of perceived brightness while the bee scans the sky by rotating its field of view." Some invertebrates are able to detect the plane of polarized light because they have polarization-sensitive photoreceptors, where pigment molecules (i.e rhodopsin) are oriented parallel to the vector of incident light. In vertebrates, like lowly humans, our rhodopsin molecules are oriented randomly in all our photoreceptors (womp womp). In bees, there is a patch of retina containing polarization-sensitive photoreceptors that are aligned in a graded manner. The angle of polarization of light from the sun is (generally) perpendicular to the plane containing the sun. So bees can sweep their eyes across the sky and turn around its vertical axis, and when the vectors of incident sunlight match up with the orientation of their eyes, the light will be brightest, allowing them to discern cardinal directions.
2. Mantis shrimp can see circularly-polarized light, and even differentiate R vs L handed circularly-polarized light: excerpt from a summary in [Cell: Current Biology by Michael Land] on a paper authored by Chiou et al in the same journal. "Circularly polarised light is not directly identifiable by oriented rhodopsin molecules, because the electric vector is not confined to one plane, but rotates continuously… circularly polarised light can be converted back to plane polarised light by passing it through a quarter-wave plate so that the delay between the two orthogonal components is eliminated… This, according to Chiou et al is exactly what happens in the eyes of stomatopods... Running through the centre of each eye is a band of six rows of special ommatidia. Four of these constitute a remarkable colour vision system, containing a total of 12 different visual pigments; the two further rows appear, from the arrangement of the microvilli, to be concerned with the analysis of polarised light. The receptors in these ommatidia are in two tiers. Seven of the eight receptors have their microvilli arranged at right angles in alternating blocks, so that they have the capability to respond differentially to incident light polarised in different planes. Above these, in the light path, is an eighth cell containing a single block of parallel microvilli, all aligned the same way. As Chiou et al.[3] show ...en bloc they introduce a quarter wavelength phase difference into the light passing through. Consequently, they convert circularly polarised light into plane polarised light, which the underlying seven receptors are then able to detect. Interestingly, the eighth cell microvilli are orthogonal to each other in the two ommatidial rows, meaning that they introduce orthogonal retardations into circularly polarised beams. Referring back to Figure 1C, this means that one will produce plane polarised light from a right-hand helix, and the other from a left-hand helix. This accounts for the animals' ability to distinguish right-hand and left-hand polarised light."
3. Some speculation as to why it may be useful to be able to see circularly polarized light, again from Chiou et al: light may become circularly polarized in turbid water, so being able to differentiate R from L handed circularly polarized light may enhance contrast and allow the shrimp to see better. Additionally, certain materials (such as arthropod exoskeletons, most notably scarab beetles) have the ability to circularly polarize light. Apparently, male mantis shrimp (but not females) have patches of exoskeleton that are able to do this, so perhaps they use them in communication or for behavior displays.
4. Scarab beetle shells reflect L-handed circularly polarized light. According to a paper in [Biol Rev], this occurs because the exoskeleton proteins (chitins) are organized in a helical manner. What this means is that there are many layers of microfibril protein. Each layer is composed of proteins that are oriented parallel to each other; below that, there is an identical layer of proteins that are all parallel to each other but oriented at an angle relative to the layer above them. And so on, so forth, many layers.
5. Cuttlefish can see polarized light, and use it to see through the camouflage of silvery fish (pun intended). Many fish employ radiance-matching camouflage, whereby silvery darker scales on their back and lighter scales on their bellies make it such that if they're seen from above or below, they blend in with their background. As reported by a paper in [Vision Research by Shashar et al], this reflected light is partially polarized, and cuttlefish (and some other cephalopods) can see polarized light (by the aforementioned mechanism-- pigment proteins oriented parallel to vector of incident light) and thus take advantage of this fact to hunt their prey. This paper reported findings that cuttlefish preferentially chose polarized-light reflecting fish to prey on. Also mentioned in this paper is the intriguing fact that some species of fish have evolved scales that only reflect light polarized to a small-degree, adding a second layer of camouflage.
6. Squid are able to detect transparent prey via polarization-sensitive vision. In another paper by Shashar et al in [Nature], it was found that while the bodies of many zooplankton are transparent, some tissues within them do polarize light, notably muscle fibers and ironically, rhabdomeric photoreceptors, and squid predators are able to see this light and use it to catch prey.
7. There is some evidence that humans have a preferred chewing side. One paper out of Japan found that the preferred chewing side was influenced by subclinical displacement of the articular disk in the TMJ, but only for hard food; (chewing on one side places an increased load on the contralateral TMJ). Another paper out of China found that chew-side preference may be related to the dominant brain hemisphere.
8. An extract of an african tree root used in traditional medicine for pain relief has been found to contain a compound that is identical in structure to Tramadol (Nature) The tree in question is the pincushion tree (Nauclea latifolia)
9. Eating whole fruit is associated with a slightly lower risk of diabetes, but drinking fruit juice is associated with a slightly higher risk, according to a paper in BMJ. In the form of HR(95% CI) for developing type 2 diabetes-- "0.74 (0.66 to 0.83) for blueberries, 0.88 (0.83 to 0.93) for grapes and raisins, 0.89 (0.79 to 1.01) for prunes, 0.93 (0.90 to 0.96) for apples and pears, 0.95 (0.91 to 0.98) for bananas, 0.95 (0.91 to 0.99) for grapefruit." The 95% CI for stone fruits (peaches, plums, apricots), oranges, strawberries and cantaloupe crossed 1.0; drinking fruit juice had a HR of 1.08 (1.05-1.11).
10. Naegleria fowleri found in municipal drinking water in Louisiana. (NPR)