Nootropics

Nootropics, aka, smart drugs, are supplements that enhance your cognitive functions like memory and creativity. Caffeine is one of the most common nootropic and it is found to increase alertness and attention. Another compound that is shown be psychoactive is L-Theanine. It is usually found in tea and has been shown to mitigate the negative effects of caffeine. L-Theanine seems to increase brain concentrations of serotonin and dopamine.

Unlike NZT from the movie Limitless, nootropics in real life have a much milder effect. And this comes with a catch. Most of these drugs have recorded side effect both short term and long term.

There are other drug-free options to achieve cognitive benefits. Exercising regularly, getting enough sleep, Blue light in the morning are some examples.

Genetically Engineered Products

All products that are aiming for a sizable market has to be generalized to some extent. To make it efficient to create, distribute and market the product it was essential that the product appealed to the masses. Having minimum variability was key to optimise the business as a whole. Take Apple for example, Back in the 2000’s they were successful partially because of their relatively small product line. Less options for the customers to choose from but why would they need options if the product was just so good.

On the other end of the spectrum are products that are bespoke to an individual. A good example are tailored outfits. By definition there is a need for the product to be unique and match a person’s style. Usually these kind of businesses rely on physical and more tangible parameters of a customer to make a customised product. With the reduced cost of doing a DNA test, there is a new vertical altogether that opens up a possibility for a business to create hyper-customized products.

23AndMe is a company that helps you map out your ancestral lineage using a sample of your DNA. As more and more customers use the service, the better their data and reach will become.

GenoPalate is a business that aims at creating a specialized diet plan based on your DNA. Based on the combination of genes that a person has, Genopalate can come up with an optimal nutritional plan. It can provide analysis on how our body digests various types of food and substances(caffeine, alcohol etc.).

Robots that can feel

Our skin has many types of neurons that allow us to feel upon touch. They are receptors of different kinds that are triggered by different stimuli but activate the same way upon triggering. Thermoreceptors trigger on change in temperature. Nociceptors trigger on pain. Mechanoreceptors trigger on mechanical stress. These receptors send signals to the spinal cord and the brain to register a touch.

A combination of these receptors spread across an area leads to a triggering in various nature depending on the stimuli. This is how we are able to distinguish textures and types of touch.

In general, robots are really good at predictable motions that can be broken down to a set of axis and have a known distribution of forces. This is why a robot is used for welding different parts of a vehicle body but a human operator is used to install an intricate wiring harness.

Tactile feedback would be a large improvement in the feedback loop for robots if they need even a fighting chance to learn more complex tasks. A new technology developed by a team at the University of Hong Kong allows robots to detect tactile inputs at a super-resolution.

The system uses a flexible magnetized film as the skin and a printed circuit board for the structure. The film creates a magnetic field within the device and the subtle changes in the field is sensed to determine the touch.

Bone Conduction Earphones

Ludwig van Beethoven is rumored to have invented this technology. The famous composer who was also deaf used to press one end of the rod on a piano while having the other end of the rod in his mouth. This would transmit the vibrations allowing him to hear. Rumor or not, but that is a gist of how bone conduction works.

Sound is perceived by our ears through the variation of pressure in air. The ear drum vibrates based on these pressure differences transmitting the vibrations to a set of small bones followed by a fluid filled cochlea.

Bone conduction used the bones of the skull to transmit the vibration to the cochlea directly. Bypassing the ear canal, ear drums and the set of bones in our ear. Bone conduction earphones usually sit on the cheekbones. The isolation and audio quality on these headphone are bad due to the fact that the ear is fully exposed. However, it provides people with hearing deficiencies and hearing loss another method to perceive sound.

Google Glass used bone conduction technology in it’s devices to transmit information to the wearer. X, Alphabet’s moonshot lab, is reportedly working on super hearing technology. They are working on technology that will allow the separation of voices of specific individuals from that of the group.

Thousand Brains Theory

Grid cells are special types of neurons that help us perceive position in a larger context. For example, to understand our position in the room we are sitting in. The cells themselves are arranged in a manner of a grid and fire based on our position. An array of such cells successfully encodes location, distance and direction. Grid cells are seen in the neocortex of the brain.

The neocortex is the part of the brain that is involved in higher-order brain functions such as cognition, spatial reasoning and language. A classical view on how a neocortex works is that it receives sensory inputs and is processed in a set of hierarchical steps. Where the sensory information is passed on from one region to another. It is assumed that a high-level object can be grasped when the information has passed through all the regions once.

This paper proposes a new theory. It starts by saying that there are more of grid cells in the neocortex. Arranged as columns and rows. Each column creates its own model of the objects based on sensory inputs. Each column would build a model based on slightly different inputs. These models than vote to reach a consensus on what it is sensing. As if, there are many tiny brains within our brain and what we sense and perceive is a weighted average of all the outputs.

Gene Editing

The human genome is a complete set of nucleic acid sequences encoded as DNA within the 23 chromosome pairs in a cell nuclei. The complete set of human genome contains about 3 billion base pairs, amounting up to 750 megabytes of data. Some of the genes are protein coding genes. Each of these genes are responsible for several biological processes. All this data is stored in the nuclei of every cell in the human body. Gene editing is a method to edit the DNA of a living organism. Editing the DNA can lead to the changes in traits in the organism. CRISPR, a tool invented in 2009 has made it a lot easier to edit genes. Animals share a lot of genes. Mice and humans share about 85 percent of genes. Genes are changed on the mice and the effects are studied. This will help better predict the effect on humans. In this case, it has applications both in understanding a new disease or understanding the effect of a medicine. Gene therapies is a way to prevent and treat diseases in humans.

Protein Folding

Protein exists as a polypeptide chain consisting of amino acids linked by a peptide bond. These chains can be in random shapes. But what makes them biologically functional is the shape it takes up when they are acted upon by a ribosome. Ribosomes are found in all living cells and they perform protein synthesis. The exact folding of a protein is crucial for its function. There can be parts of the functional protein that still remains unfolded. From a physical point of view, the unfolded state has the highest entropy hence it’s natural state. There is a certain amount of energy that is required for the folding to happen and reduce its entropy. Folding can be triggered by hydrophobic reactions. Molecular chaperones are a class of proteins that aid in the correct folding of the protein. Neurogenerative diseases have been linked to the misfolding of proteins.

The process of protein folding is not stochastic. There are many variables build into this process that makes it really hard to predict the correct functional folding for a protein. It is estimated that a natural protein can have 10300 possible combinations. It is not truly random but rather a model that can replicate this process is still being developed. Understanding this fundamental biological process can help in developing new medicines and managing new environment.

Cambrian Explosion

The cambrian explosion was an evolutionary event that occurred around 541 m.y.a. (read as million years ago) where most of the animal phyla started appearing in fossil records. A phylum is a level of classification in biology that is one level below the kingdom. Almost all present animal phyla appeared during this period. The event lasted for about 20 to 25 million years. A leading theory for the cause of this event is the increase in oxygen levels in the atmosphere. Earth’s atmosphere did not contain free oxygen. The oxygen that is currently part of the atmosphere is the result of billions of years of photosynthesis. Metabolic functions may have been slowed down due to the lack of oxygen prior to the cambrian explosion. For example, the creation of the collagen tissue, which is required for hard exoskeletons. This also explain why there are very little fossils prior to this period.

In our times, there are some events that can be considered as an explosion of development. Maybe the technological cambrian explosion could be the invention of electricity or the transistor. One fundamental technological change that then had profound effects on all aspects of life. Probably writing is the cambrian explosion equivalent pre-technology times. That became the primary way in which we stored and transferred knowledge across generations. Leading to an advancement based on past experiences and mistakes.

How a Pulse Oximeter works

A pulse oximeter is used to measure the oxygen level in your blood using a non-invasive way. Haemoglobin are cells in the blood that carry oxygen. Hence they can occur in 2 states, either they are oxygenated or deoxygenated.

Principles involved

  1. Amount of light absorbed in directly proportional to the concentration of the light absorbing surface.
  2. Amount of light absorbed is directly proportional to the length of the path that the light has to take through the light absorbing surface.
  3. Oxygenated and Deoxygenated Haemoglobin absorb red light and infrared light differently.

The pulse oximeter basically passes red light and infrared light through the finger and measures it on the other side. Based on the ratio of the sensor readings from the red light and the infrared light the amount of oxygenated and deoxygenated haemoglobin can be calculated. Some limitations of this approach are, that the sensor has to be callibrated and light from ambient sources needs to be accounted for as well.

References

How Pulse Oximeter works

Pulse Oximetry Basic Principles and Interpretation

Brain Simulation

Brain simulation deals with creating a computer model of the brain. Such models can help in understanding diseases and reduce the need for animal experiments. The challenges in brain simulation are:

  1. Scale : The human brain contains about 86 billion neurons each with about 7000 connections. This pushes even the largest exascale computers to its limit. Exascale = quadrillion operations per second. Rat brains is the state of the art for now.
  2. Complexity : The exactly mimic a neuron and its molecular scale processes, each of these model neuron should have an unlimited set of parameters that need to be trained. Studies are ongoing to see what parts of these are important to achieve a better simulation and what parts can be left out.
  3. Speed : Learning and training in the brain occurs over years and the current technology limits us to run anything faster than real time. This puts a hard constraint on the depth to which we can train a model. This ability to model the speed and perhaps augment can open doors to better simulate the synapses.
  4. Integration : Our brain consists of different regions that handle different functions. To model this we need smaller models and combine them to achieve a brain wide function. This can lead to simulating aspects like consciousness and understanding.

Some interesting questions

  • Would such simulations lead to generation of more human aspects like consciousness and imagination?
  • Can such a model be used to augment the capabilities of the human brain?
  • Can we transfer information between such models in a more intrinsic way?


References

The four biggest challenges in brain simulation