ScienceIQ.com

Butterflies In Your Brain

The idea behind chaos theory is that complex systems have an inherent element of unpredictability. The human brain certainly qualifies as a complex system. It is also a chaotic system. It does not behave in completely predictable ways, partly because it is always restructuring itself in response to environmental input. It is a constantly moving ...

Continue reading...

ButterfliesInYourBrain
Biology

Sex and the Sea Slug

The sea slug, Aplysia. Now there's an expert on sex. Equipped with both male and female sex organs, this shell-less, subtidal mollusk lives alone most of the year. It loses its self-sufficiency, ... Continue reading

SexSeaSlug
Physics

Ultraviolet Light

Ultraviolet light is a form of radiation which is not visible to the human eye. It's in an invisible part of the 'electromagnetic spectrum'. Radiated energy, or radiation, is given off by many ... Continue reading

UltravioletLight
Physics

Get the Point?

The discus and javelin first appeared in ancient game competitions in 708 B.C. Javelin events included both target throwing and distance throwing using a sling. By 1780, the javelin was adopted as an ... Continue reading

DiscusJavelin
Medicine

What Is Sickle Cell Anemia?

Sickle cell anemia is an inherited blood disease. That means you are born with it and it lasts a lifetime. Sickle cell anemia affects the red blood cells. Normal red blood cells are smooth and round ... Continue reading

WhatIsSickleCellAnemia

Resistance is NOT Futile!

ResistanceisNOTFutileMaybe if you are a Star Trek heroine up against the Borg, 'resistance is futile.' But if you are a germ that makes people sick, resistance - to antibiotics - is not futile at all.

When penicillin began to be widely used over fifty years ago, it could kill most of the bacteria that made us sick. Such bacteria are called 'pathogens,' to distinguish them from the many bacteria that are harmless or even useful. Nowadays, many pathogens are 'resistant' to a lot of the antibiotics we use to combat them. They have evolved the ability to fight off the effects of the drugs, so the drugs cannot cure you. This can be very dangerous in hospitals, where drug-resistant pathogens can spread rapidly and kill many people.

How can bacteria evolve drug resistance so quickly? The genes for drug resistance are usually not carried as part of the regular chromosome, but on extra rings of DNA called plasmids. These can be passed on to the bacterial cell's descendants, and can also sometimes be passed around to any other bacteria that happen to be in the area, even those of other species. If a drug kills all the susceptible bacteria, any few that are resistant will be free to multiply without competition and take over the population. So we are involved in an 'arms race' between biologists and chemists inventing new antibiotics, and pathogens inventing new ways to resist them.