MADISON, Wis. -- Su-Chun Zhang, a pioneer in developing neurons from stem cells at the University of Wisconsin-Madison, has created a specialized nerve cell that makes serotonin, a signaling chemical with a broad role in the brain.

Serotonin affects emotions, sleep, anxiety, depression, appetite, pulse and breathing. It also plays a role in serious psychiatric conditions like schizophrenia, bipolar disorder and depression.

"Serotonin essentially modulates every aspect of brain function, including movement," Zhang says. The transmitter is made by a small number of neurons localized on one structure at the back of the brain. Serotonin exerts its influence because the neurons that make it project to almost every part of the brain.

Our understanding of evolution can be enriched by adding fossil species to analyses of living animals, as shown by scientists from the University of Bristol.

Their paper, published today in Proceedings of the Royal Society B, investigates patterns of evolutionary change in a group of mammals known as Afrotheria. This charismatic group of mainly African mammals includes elephants, manatees, and elephant shrews. The team were interested in how body mass has evolved in Afrotheria, and how our interpretations differ when we take their extinct fossil relatives into account.

Having emerged late during evolution, seeds have transformed many plants into miniature travelers, contributing greatly to their colonization of terrestrial habitats. Researchers at the University of Geneva (UNIGE), Switzerland, have just discovered one of the keys to this success: the cuticle. Present as a thick waxy layer in the seed coat and composed of cutin -- a type of fatty acid --, the cuticle increases seeds' viability, their resistance to reactive oxygen species, and contributes to maintaining their dormant state. Seeds have thus recycled an ancient terrestrial plant protection mechanism that allows their leaves to be covered with an impermeable film preventing excessive transpiration. The results are published in the journal PLoS Genetics.

Their analysis revealed that the periods of Algol (2.85 days) and the Moon (29.6 days) strongly regulate the actions of deities in this calendar.

- Until now, there were only conjectures that many of the mythological texts of the Cairo Calendar describe astronomical phenomena. We can now unambiguously ascertain that throughout the whole year the actions of many deities in the Cairo Calendar are connected to the regular changes of Algol and the Moon, says Master of Science Sebastian Porceddu.

This research confirms that the first variable star, as well as its period, were discovered much earlier than was previously thought. These two "classical" milestones in the history of natural sciences need to be shifted three millennia backwards in time to 1244 - 1163 BC.

Not since 1977 has a full moon dawned in the skies on Christmas. But this year, a bright full moon will be an added gift for the holidays.

December's full moon, the last of the year, is called the Full Cold Moon because it occurs during the beginning of winter. The moon's peak this year will occur at 6:11 a.m. EST.

This rare event won't happen again until 2034. That's a long time to wait, so make sure to look up to the skies on Christmas Day.

How the moon will appear on Christmas, 2015. Credit: NASA/Goddard/Lunar Reconnaissance Orbiter

The anti-evolution movement, and specifically alternative beliefs to science like Intelligent Design, are wheezing their last, but because education is local in America, it can still happen in some school districts on education.

The most famous example of a legal opposition to teaching evolution began in the 1920s with the so-called Scopes Monkey Trial (science won) and the most famous recent example was the Kitzmiller
versus Dover case in 2005 (science won).

UW researchers working in collaboration with Kineta Inc. and the University of Texas at Galveston have shown that making a drug-like molecule to turn on innate immunity can induce genes to control infection in several -known viruses. The findings being published in the Journal of Virology Dec. 18 show promising evidence for creating a broad spectrum antiviral that can suppress a range of RNA viruses, including West Nile, dengue virus, hepatitis C, influenza A, respiratory syncytial, Nipah, Lassa and Ebola.

"Our study shows that our compound has an antiviral effect against all these viruses," said Michael Gale Jr., UW professor of immunology and director of the UW Center for Innate Immunity and Immune Disease.

Researchers reporting in the Cell Press journal Current Biology on December 17 have uncovered a direct link between the behavioral symptoms of people with autism and reduced action of an inhibitory neurotransmitter called GABA. GABA's primary responsibility is to dampen neural activity in the brain.

The findings suggest that drugs that increase brain concentrations of GABA might have potential for autism treatment, the researchers say.

"These findings mark the first empirical link between a specific neurotransmitter measured in the brains of individuals with autism and an autistic behavioral symptom," says Caroline Robertson of Harvard University and MIT's McGovern Institute for Brain Research.

FOR RELEASE from the UNIVERSITY OF TORONTO

TORONTO, ON - Long before kangaroos carried their joeys in their pouches and honey bees nurtured their young in hives, there was the 508-million-year-old Waptia. Little is known about the shrimp-like creature first discovered in the renowned Canadian Burgess Shale fossil deposit a century ago, but recent analysis by scientists from the University of Toronto, Royal Ontario Museum, and Centre national de la recherche scientifique has uncovered eggs with embryos preserved within the body of the animal. It is the oldest example of brood care in the fossil record.

Researchers say they have found the strongest evidence to date that human pluripotent stem cells -- cells that can give rise to all tissues of the body -- will develop normally once transplanted into an embryo.

Pluripotent stem cells for use in regenerative medicine or biomedical research come from two sources: embryonic stem cells, derived from fertilized egg cells; and induced pluripotent stem cells, where skin cells are 'reset' to their original form. The promise (bordering on hype in the case of human embryonic stem cells, with promises a decade ago of curing Alzheimer's if they just got more money) is that they might repair various organs and tissues, particularly those that have poor regenerative capacity, such as the heart, brain and pancreas.