Harlequin frogs, a group of brightly colored, small-sized amphibians found in the rainforests of Central and South America, have a unique and intriguing relationship with fungi, particularly in the context of combating the devastating infectious disease known as chytridiomycosis. These frogs are known for their striking coloration, which serves as a warning signal to potential predators due to their toxic skin secretions. What makes their connection to fungi fascinating is that many species of Harlequin frogs rely on specialized skin bacteria that produce potent antifungal compounds. In the face of the deadly chytrid fungus (Batrachochytrium dendrobatidis), which has decimated amphibian populations worldwide, these frogs' skin microbiota, p ...

If you've ever experienced the sharp, intense sensation when consuming horseradish, you're not alone. This root vegetable, with its distinct pungent flavor, is notorious for its ability to ignite your senses and make your eyes water. But have you ever wondered why horseradish irritates the throat and the nose?

At the heart of horseradish's throat and nasal irritation lies a compound called allyl isothiocyanate (AITC, depicted below). When horseradish is cut, grated, or chewed, enzymes present in the plant cell walls break down a precursor compound, sinigrin, into AITC. It is this AITC that gives horseradish its characteristic heat.


Once ingested, AITC interacts with a group of sensory receptors in our bodies known as transient receptor poten ...

A Harvard researcher, Ellen Langer (1978), studied the effects of asking someone for a favor while giving them a reason for why it was needed. Langer had an accomplice approach a line of people waiting for a copy machine in a library. The accomplice made the request to jump to the front of the line in one of three ways. One request simply stated that the accomplice had only five pages to copy, so would it be okay if they went to the front of the line. Another request also stated that they had only five pages to copy, but it also included the accomplice saying that they needed to jump to the front of the line because they were in a rush. In response to the first request, only 60 percent of those waiting in line allowed the accomplice to jump ...

Infants are born with reflexes that support their survival. Newborns are making adjustments to living outside of the womb and do not have time to worry about survival. Fortunately, these reflexes support them in the first few months of life.

One reflex is the rooting reflex. This reflex occurs when the cheek or mouth is stroked and results in the baby turning its head toward the stroke. This reflex helps the baby find the nipple when it is time to eat. This reflex disappears around 4 months of age.

Another reflex is the sucking reflex. Whenever something touches the roof of the baby’s mouth, it will begin to suck. While this reflex is active before birth, babies that are born prematurely sometimes have difficulty coordinating their sucking ...

Human smell has often been characterized as being deficient when compared to the smell abilities of some lower organisms. Summarized below are four myths about human smell that have been contradicted by research.

Myth 1: Human smell is less sensitive than that of other animals.

Research indicates that the individual smell receptor cells in humans will respond to a single odorant molecule. The difference in overall sensitivity appears to be due to the fact that some lower organisms, such as dogs, have more smell receptors.

Myth 2: Humans have a relatively poor ability to detect changes in smell intensity.

Although earlier research indicated that the difference threshold for smell was the largest of all the senses, more recent research, carefully ...

Did you know that the Moon's rotation is locked to its orbit around Earth by a bulge of material under the Moon's surface? This material is denser than the rest of the Moon's surface material, and Earth's gravity pulls on it especially strongly. The side of the Moon containing the bulge always faces Earth. We call it the near side and we call the other side, which we never see from Earth, the far side. People often mistakenly use the term "dark side" when referring to the far side of the Moon, forgetting that the far side is fully illuminated by the Sun whenever we see a new moon from Earth.

If we were to look from high above the Earth-Moon system, we would see the Moon rotate once per month with respect to the stars. This is its sidereal ro ...

Rodents are mammals characterized by a pair of broad, sharp-edged, chisel-like incisor teeth that are firmly inserted in both jaws and are used in gnawing vegetation. The front surface of each incisor tooth is composed of enamel, and the hind surface is of soft dentine wears away during the process of gnawing so that the teeth are constantly kept sharp. Shown above is a beaver sporting bright orange teeth; the reason they are orange is because of an unusually high concentration of iron in the enamel.

Unlike human teeth, the incisors of rodents don't have roots, and they never stop growing! To keep these teeth from growing into their brains, rodents grind their teeth against each other. This friction is similar to using a grindstone to sharp ...

Birthmarks are congenital marks on the skin that appear at birth and occasionally disappears spontaneously. The term nevus refers to a benign cutaneous tumor consisting of blood capillaries. Such tumors, which rarely spread from their original site and are not dangerous, vary in color according to whether the capillaries composing them carry arterial or venous blood. The popularly termed cherry marks and port-wine stains (shown below) are nevi on a level with the surface of the skin. Certain other vascular nevi, commonly known as strawberry or raspberry marks (scientifically known as hemangiomas), are slightly elevated above the surface. These can appear anywhere on the body's surface, including the airway within the nose. The former Soviet ...