Katherine Unger Baillie

In small plastic tubs lining the shelves of a basement laboratory at the University of Pennsylvania, a million organisms live in complex societies.

In small plastic tubs lining the shelves of a basement laboratory at the University of Pennsylvania, a million organisms live in complex societies.

Just as the brain forms memories of familiar faces, the immune system remembers pathogens it has encountered in the past. T cells with these memories circulate in the blood stream looking for sites of new infection.

Elephant ivory, rhinoceros horn, tiger skin: all are illegally traded products from wildlife species that are in danger of extinction. Government and private agencies have channeled millions of dollars, hours, and advanced technology into efforts to prevent this banned trade, but the problem is complex and not easily solved.

The human genome encodes roughly 20,000 genes, only a few thousand more than fruit flies. The complexity of the human body, therefore, comes from far more than just the sequence of nucleotides that comprise our DNA, it arises from modifications that occur at the level of gene, RNA and protein.

Cancer cells defy the rules by which normal cells abide. They can divide without cease, invade distant tissues and consume glucose at abnormal rates.

Lyme disease cases are on the rise, with diagnoses occurring in areas that were historically Lyme-free. Scientists attribute the spread to the fact that populations of blacklegged ticks, which carry the bacteria that causes the disease, now flourish in areas once thought to be devoid of ticks.

Point-of-care glucose meters, or glucometers, have revolutionized the landscape for diabetics and practitioners. Using only a small drop of blood to measure blood glucose in an instant, they make it easier for people with diabetes to maintain their levels in a healthy range. Pet owners, too, sometimes rely on glucometers to monitor their diabetic animals.

In the most severe form of male infertility, men do not make any measurable levels of sperm. This condition, called azoospermia, affects approximately 1 percent of the male population and is responsible for about a sixth of cases of male infertility.

Social networks affect every aspect of our lives, from the jobs we get and the technologies we adopt to the partners we choose and the healthiness of our lifestyles. But where do they come from?