Dino J Levy and Paul W Glimcher - 2012-06

How do humans make choices between different types of rewards? Economists have long argued on theoretical grounds that humans typically make these choices as if the values of the options they consider have been mapped to a single common scale for comparison. Neuroimaging studies in humans have recently begun to suggest the existence of a small group of specific brain sites that appear to encode the subjective values of different types of rewards on a neural common scale, almost exactly as predicted by theory. We have conducted a meta analysis using data from thirteen different functional magnetic resonance imaging studies published in recent years and we show that the principle brain area associated with this common representation is a subregion of the ventromedial prefrontal cortex (vmPFC) / orbitofrontal cortex (OFC). The data available today suggest that this common valuation path is a core system that participates in day-to-day decision making suggesting both a neurobiological foundation for standard economic theory and a tool for measuring preferences neurobiologically. Perhaps even more exciting is the possibility that our emerging understanding of the neural mechanisms for valuation and choice may provide fundamental insights into pathological choice behaviors like addiction, obesity and gambling.

infinity-imagined:

Scanning electron micrographs of diatoms, microscopic algae that form the base of the food chain and produce 20% of Earth’s oxygen.

(via albanhouse)

postmodernmarvel:

This could be the beginning of a broad-spectrum cure for cancer.

calibornery:

kingcroacus:

fingers are weird??? like…… our arms just split into other smaller arms…………. ok

are we human or are we trees

(via hannahpoptarts)

about 10^31 viruses in the biosphere, all told

as in 10,000,000,000,000,000,000,000,000,000,000

The nervous system.

(via nellsays)

fuckyeahmolecularbiology:

T2 bacteriophage virus (seen in orange) attacking an Escherichia coli bacterium. Each phage consists of a large, DNA-containing head and a tail composed of a tube-like central sheath with several fibres. 

(via a-siren-singingyoutoshipwreck)

Clavelina moluccensis, the bluebell tunicate or blue sea squirt

normal sinus rhythm for a human heart

(from Wikipedia)

infinity-imagined:

A 6 week old human embryo.

(via pinkxdawn)

pretendy:

Protocells and Artificial Life

In this talk, Martin Hanczyc outlines a series of experiments where artificial protocells synthesised from oil and clay display primitive kinds of behaviour associated with life.

He begins by framing his working assumptions - that there exists a continuum between the living and the non-living - and identifies a few key features of a living system: a self-contained body, working metabolism, and inheritable information. The body coupled with metabolism allows an organism to move and interact with its environment, and all three together allow for replication and evolution.

While a cell might contain on the order of 1,000,000 different kinds of molecules, he was able to synthesise “life-like” protocells from just five. Oil disassociates with water and forms globules. These oil globules make up his protocell bodies, while a type of chemically active clay forms the basis of a metabolic system - extracting energy from the environment in order to “do something”. What can his protocells do? He shows us a few neat videos:

• A single protocell moves around its environment (a petri dish)
• It seek out ‘food’ 
• Multiple protocells interact with each other - “dance”.
• On a rare occasion, two cells of a different variety fuse, taking on qualities of both parent cells.
• Hybridised protocells are observed dividing.

These are really cool experiments. Though his humble artificial organisms are by no means Frankenstein’s monster, they go a long way to help us understand what questions we should be asking about what makes something living as opposed to non-living. They show that certain fundamental properties of the complex life we see around us can be observed in relatively simple chemical systems.