The interactions among plants and insects in a field turns out to be a good measure of the impact of global warming, and the outlook is not promising. Things looked good early on in a field study of grasslands that simulated coming climate change. For two years production and diversity increased. But after five years the grass took over and plant diversity fell by half. Flowering plants in particular were suppressed, leaving insects with far less food.

Collaborative tagging sites like del.icio.us are examples of systems that harvest crowd intelligence. The collective behavior of thousands of people acting independently produces a solution.

It turns out that even though people are acting intelligently and independently, collaborative tagging behavior follows two simple rules: the rich get richer, i.e. more popular tags get more popular, and recent tags are picked more frequently than older tags.

Hmm. If something can be modeled it can often be reverse-engineered. So what happens when someone comes up with an algorithm that does “collaborative” tagging automatically?

It turns out that subliminal distractions throw off your game more than the consciously annoying kind. A study found that subliminal visual distractions impaired task performance more than visual distractions that subjects consciously perceived. It looks like subliminal visual distractions get past the parts of the brain that filter out visual noise.

Some animals hunt cooperatively, but usually the teamwork involves the same species. Scientists have found an example of cross-species cooperative hunting in the Red Sea — groupers and giant moray eels.

Groupers hunt in open water and moray eels hunt in coral reefs. Prey fish fleeing groupers often take shelter in coral reefs and prey fish fleeing moray eels often take to open water. This sets the stage for a strategic partnership.

The scientists saw groupers signaling moray eels by approaching the eels and shaking their heads from side to side. The eels then followed the groupers and they hunted together. Sometimes during the hunt, groupers stood on their heads to signal that prey was hiding in particular crevices.

The theory is the partnership works because groupers and moray eels swallow their prey in a single bite so there is no fighting over carcasses to sour the relationship.

A NASA study shows that global warming decreases the amount of phytoplankton, the microscopic plants that underpin the ocean food chain. This delivers a double blow. It decreases marine populations, including fish stocks. It also contributes to global warming because phytoplankton absorb carbon dioxide from the atmosphere.

Your mind and your brain aren’t always on the same page. An experiment using a magic trick shows that the success of the illusion depends on social cues. The magician’s gaze and head movements convince us that a ball vanishes in the air, even though our eyes are not looking where we think we see the ball disappear. The research supports the notion that perception and vision are separate systems.

They say that people who get rich tend to forget where they came from. It looks like this is a scientifically valid observation. A series of experiments shows that money makes people less helpful and makes them prefer to play and work alone and keep their physical distance.

A climate data analysis shows that global carbon emissions grew by 3.2 percent per year between 2000 and 2005, up dramatically from 0.8 percent per year between 1990 and 1999. The study also found that sea levels are rising at 1.5 to 2 millimeters per year and the rate is accelerating.

A computer model that examines the interaction between carbon dioxide doubling and land-use shows that soil moisture is a key variable for global warming. Drought increases the effects of carbon dioxide changes on crops and other vegetation, while high soil moisture decreases the effects.

A second computer model shows that phytoplankton blooms in the ocean increase cloud cover in the areas of the blooms. This implies that, in addition to being the foundation of the ocean food chain, the microscopic organisms play a role in moderating the effects of global warming.

The caffeine hit that leaves coffee drinkers wide-eyed and alert isn’t the only way to get the brain revved up. It turns out that electrical brain stimulation also boosts cognitive function.

Cranking the central thalamus of rat brains with low-power, high-frequency electrical current boosted the critters’ object recognition memory, exploratory behavior and grooming, indicating heightened cognitive performance.

The technique, which boosts neural activity and related gene expression involved in maintaining an alert state, could be a treatment for some cognitive disabilities.

Turning theory into practice — or at least a demo — scientists have created an invisibility cloak. The shield, a set of metamaterial concentric rings, bends microwaves around objects. The device only works in a narrow band of frequencies, only in two dimensions and not perfectly, but it shows that the concept is, well, more than just theory.