Science Sunday: Wrap-up of recent advancements in science from EurekAlert!

Tears reveal some of their deepest secrets to researchers:
It's no secret why we shed tears. But exactly what our tears are made of has remained a mystery to scientists. A new study sheds some light on the complex design of tears. What we think of as tears, scientists call tear film, which is made up of three distinct, microscopic layers.

Researchers create new class of compounds:
Researchers have synthesized new aluminum-hydrogen compounds with a unique chemistry that could lead to the development of more powerful solid rocket fuel and may also, in time, be useful for hydrogen-powered vehicles or other energy applications.

The hitchhiker's guide to altruism -- Study explains how costly traits evolve:
Darwin explained how beneficial traits accumulate in natural populations, but how do costly traits evolve? A new study by researchers from Oxford University and the University of Edinburgh explains how kin selection can be seen as a special form of genetic hitchhiking.

A new language barrier -- Why learning a new language may make you forget your old one:
Traveling abroad presents an ideal opportunity to master a foreign language. While the immersion process facilitates communication in a diverse world, people are often surprised to find they have difficulty returning to their native language. This phenomenon is referred to as first-language attrition and has University of Oregon psychologist Benjamin Levy wondering how it is possible to forget, even momentarily, words used fluently throughout one's life.

Buckyballs used as 'passkey' into cancer cells:
Rice University chemists and Baylor College of Medicine pediatric scientists have discovered how to use buckyballs as passkeys that allows drugs to enter cancer cells. Research in the January 21 issue of the journal Organic and Biomolecular Chemistry, describes how the researchers mimicked the techniques used by some viruses to introduce non-toxic bits of buckyball-containing protein into both neuroblastoma and liver cancer cells.

Walking molecule now carries packages:
A research team, led by UC Riverside's Ludwig Bartels, was the first to design a molecule that can move in a straight line on a flat surface. Now this team has found a way to attach cargo: two CO2 molecules, making the nano-walker a molecule carrier.

Parasite infection may benefit MS patients:
The first study examining the relationship between parasite infections and MS in humans suggests that such infections may affect the immune response in a way that alters the course of MS.

Study looks to bring the high properties of metallic glass materials to bulk production:
Metallic glasses are a relatively new type of material with astounding properties that have lead to them being called the wonder materials of the future.

Dark energy may be vacuum:
Researchers at the University of Copenhagen's Dark Cosmology Centre at the Niels Bohr Institute have brought us one step closer to understanding what the universe is made of. The new data shows that vacuum energy is the most likely cause and the expansion history of the universe can be explained by simply adding this constant background of acceleration into the normal theory of gravity.

Researchers discover surprising drug that blocks malaria:
Northwestern University researchers have uncovered how malaria parasites break into red blood cells and how to block the invading parasites with a commonly prescribed high-blood pressure medication. This opens the door for important new drugs to which the parasites are much less likely to become resistant. Malaria is surging worldwide because of drug resistance and the lack of an effective vaccine. Jamaica, which had eradicated the disease for 50 years, recently reported an outbreak.