Climate causes correlations

Climate science has been getting some unwanted attention these days. Like the hoo-haa about HIV, in this case too, people are learning to be less sensationalist. When examining primary principles, one comes across quite a few studies that encourage us to pay heed to the need to be cautious lest one confuses correlations with causes. A recent paper by Sze Ling Ho and Thomas Laepple in Nature Geoscience is yet another in the series.

Surface temperatures of the seas and vast oceans of the planet play a big role in the climate change calculations. To model climate change, scientists use a proxy temperature index, TEX H 86, derived from the relationship between archaeal lipids and temperature. But use of this proxy in the climate model leads to unexplainable warm polar sea surface temperatures in Eocene - about 50 million years ago. This has been a bee in the bonnet for many climate scientists.

Now, this paper comes as a consolation and a cause for further worry. TEX may not be a good proxy for surface temperatures. But it is still very useful, since it is actually measuring subsurface temperatures.

If that does not worry climate researchers who insist that they see climate warming in the future, I see it only as a reflection of Tony Blair's "conviction" about weapons of mass destruction in Iraq.

Nature Geoscience 9, 606–610 (2016)doi:10.1038/ngeo2763

Climate causes correlations

Climate science has been getting some unwanted attention these days. Like the hoo-haa about HIV, in this case too, people are learning to be less sensationalist. When examining primary principles, one comes across quite a few studies that encourage us to pay heed to the need to be cautious lest one confuses correlations with causes. A recent paper by Sze Ling Ho and Thomas Laepple in Nature Geoscience is yet another in the series.

Surface temperatures of the seas and vast oceans of the planet play a big role in the climate change calculations. To model climate change, scientists use an proxy temperature index, TEX H 86 derived from the relationship between archaeal lipids and temperature. But use of this proxy in the climate model leads to unexplainable warm polar sea surface temperatures in Eocene - about 50 million year ago. This has been a bee in the bonnet of many climate scientists.

Now, the paper comes as a consolation and a cause for further worry. TEX may not be a good proxy for surface temperatures. But it is still very useful, since it is actually measuring subsurface temperatures.

If that does not cause worry to climate researchers who insist that they see climate warming in the future, I see it only as a a reflection of Tony Blair's "conviction" about weapons of mass destruction in Iraq.

Nature Geoscience 9, 606–610 (2016)doi:10.1038/ngeo2763

Sleep-Wake Cycles: Magnanimity of Magnesium

All of us know how the sleep-wake cycles work in us: behind our eyes, just below where the optic nerve from the eyes cross, there is the pituitary gland that has melatonin which increases and decreases in response to light and makes us sleepy or awake. Right?

Wrong. Circadian rhythms are found even in plants that do not have eyes or pituitary. Circa means about, dian refers to day. The clock that is inbuilt in living creatures has fascinated biologists and in the last few years we have seen discoveries of a large number of clock genes. So it is not the nervous system that is responsible for the daily cycles, but the clock genes, right?

Wrong. Says a paper in yesterday's Nature. Behind the evolution of clock genes, behind the evolution of pituitary, is the magic of magnesium.

The daily pendulum of human and algal cells, separated by more than a billion years of evolution, swing in response to intracellular magnesium. The element is needed in modest and meagre amounts, and is critical for life: magnesium is a cofactor in all ATP dependent processes. In other words, metabolic energy yo-yos with magnesium. And that sets the pattern for the evolution of clock genes, the evolution of the nervous system with a pituitary that releases melatonin...

The magnanimity of the modest magnesium!

Nature 532, 375–379 (21 April 2016)

Risk Takers Turn Risk Aversive:

We do not normally take risks. Yet, at times, we do. Scientists in Stanford University tell us why, in the recent issue of Nature. They have succeeded in turning risk taking rats into risk aversive ones by timely stimulation of dopamine type 2 receptors in some specific cells of the Nucleus accumbens.

The nucleus accumbens is generally considered the reward centre in the brain and is implicated in addiction. But given the results that are pouring in about the nucleus, perhaps it is more involved in decision making than in addiction.

Nature 531,642–646 (31 March 2016)

New method for dieting: Brain control

The sense of hunger and feeling of satiation after eating are mediated by cells in the lower part of the hypothalamus in the brain. Scientists have found ways to remotely activate and inhibit this region specifically without any surgical intervention. Genetically encoded nanoparticles that respond to radio signals of magnetic stimulation were used to activate glucose-sensing neurons in the ventromedial hypothalamus of live rats. This was found to increase plasma glucose and glucagon, lower insulin levels and stimulate feeding. Inhibition reduces blood glucose, raises insulin levels and suppresses feeding.

So, if you have been planning to diet and never got around to doing it yet, wait for some more time. The technique demonstrated in the lab might soon be around since there is enough demand.

Nature 531, 647–650 (31 March 2016)

Mobile Phones to Measure Tidal Forces

Many cell phones today have microelectromechanical systems that can detect acceleration. By tweaking the system a little, these devices can detect acceleration due to gravity, claims a paper in a recent issue of Nature.

The new device is sensitive enough to detect tidal forces on earth. From being a mere accelerometer, it becomes a gravimeter that can measure tidal forces.

Most present gravimeters are heavy. But this new device is so light that you can use it on a drone and let it survey the land. It will give you clues about underground reservoirs of oil, magma etc.

By putting the device into handphones, and crowdsourcing the data while people travel around, we will be able to map what lies underground.

Nature 531, 614–61(31 March 2016)

Unpunished corruption leads to more corruption

In our society, many cases of corruption go unpunished. Prevalence of rule violations (corruption, tax evasion etc.) tends to reduce intrinsic honesty in young people, says a recent paper in Nature.

More than 2500 young people from 23 countries took part in the experiment. Researchers conclude that

"weak institutions and cultural legacies that generate rule violations not only have direct adverse economic consequences, but might also impair individual intrinsic honesty that is crucial for the smooth functioning of society".

The message is clear: if you want to reduce corruption and tax evasion, punish the guilty and let the public know that economic offences will not be tolerated. This would have implications on lying and dishonest behaviour even in other realms of day-to-day life.