Sunday 26 November 2023

Last Week in Science (26th Nov 2023)

The Head Tilt

Are you a dog parent or just that person who watches a lot of dog videos on Instagram. If the answer is yes, then this story is for you. As a dog parent you would have seen your dogs tilting their heads to one side and  would have wondered what they mean by it and whether it is another tactic to get to eat your food. You would have also searched the internet for what this behaviour could mean, and would have found answers. Now the answer has come from the researchers from the Eötvös Loránd University, Hungary, in Europe, who studies 'gifted dogs'. Yes, how can any dog be better than your dog, but let us just humor the researchers. These gifted dogs which were all border collies - could remember names of more than 10 toys and would bring them when told the name. Most dogs can remember no more than two. 

The interesting part comes when the researchers saw all these dogs tilting their heads just after hearing the word before they would go and search the toy which they know by that word. The researchers think that the dogs might be visualizing the toy on hearing the name or paying close attention during the head tilt. So, the next time you see your dog giving the head tilt, wonder what all can be happening inside that pup's brain. And no they haven't started any word training classes yet! 


Can we control our eating speed?

Have you wondered when you can't stop munching those chips what would be happening inside your body? Not a direct answer but a related answer has been found in a recent study. 

It has been shown that nerves in the gut convey the message to the brain and this helps you known when you are full. Such studies have been done in mice that were under anaesthesia so we don't know how their bodies will respond when they are being fed in an awake
state. Researchers at the University of California, San Francisco, studied mice in an awake state. What was special about these mice was that their brain region that receives the signal from the gut could be controlled - switched on or off by a method known as optogenetics, and also seen when the region is active. 

What the researchers found was the mice feed on a sweet and tasty liquid meal a specific neural circuit (made of PRLH neurons) switches on as the mice licks but shuts down the second the mice stops licking the meal. So, it switches on and off with the licking of the mice. While when the mice were given this sweet liquid directly in their stomach, the circuit switches on slowly and remains active until after feeding was stopped. This observation means that the brain can distinguish whether the signal is coming from the mouth or the gut. What was interesting this brain circuit did not switch on in the mice who cannot taste sweetness. Now, when this PRLH circuit was kept on the speed of the mice feeding/licking reduced.

A different brain circuit (GCG) was seen to be involved in giving the signal that the stomach is now full as they switch on minutes after the meal is consumed. It is interesting to see how different brain circuits control information coming from the mouth or the stomach and one is responsible for how fast you eat and the other for how much you eat. So, maybe if we keep that GCG circuit on maybe we can stop munching on those chips.


Greetings from far beyond

Cosmic rays are high energy particles, remember the dual nature of light and subatomic particles, that come in contact with Earth's atmosphere. The cosmic rays are formed by explosions, collisions and certain other physical phenomena that happen in space. It is a search ground for humans to discover new subatomic particles. Remember atom is further made up of subatomic particles like electrons and protons. 

The energy that is contained in these particles are measured in electron volts (eV). The typical energy levels of subatomic particles on Earth are close to Mega electron volts (100,000 electron volts). And the energy in the cosmic rays are close to 10 raise to power 18 (1 followed by 18 zeros) eV called as exa electron volts (EeV). It is rare that a subatomic particle that has an energy greater than 100 EeV comes to greet us. The last time it happened was in 1991 when the greatest high energy particle - which was named as 'Oh My God' particle was observed. It had an energy level of 320 EeV. 

We were greeted by an energy particle of 240 EeV this time, and the researchers at Osaka Metropolitan University in Japan who found it named it on a Sun goddess - Amaterasu. This doesn't mean that the particle came from the Sun. While the cosmic rays coming from the Sun were the first ones to be observed, we now can identify the origin of other cosmic rays coming from far beyond the Sun. But this time, it is not known where this particle came from. According to the researchers' calculation the particle seems to be coming from a space where there are hardly any galaxies. Astronomers think that it might be a new physical phenomenon that has created this particle and that could be the reason why they cannot find the origin of the Amaterasu particle. 


Sunday 19 November 2023

Last Week in Science (19th Nov 2023)


Penguins and Their Black Dots

Chirping and singing sparrows
Mark each other with their sounds
But penguins use their dots to find their marrows

Humans and other primates can recognize individuals of their species. But are there other organisms that can identify other members of their species. Many organisms ranging from whales to wasps are known to do so. While birds use sound to identify other birds, it is seen that other organisms can also visually recognize each other. So, how does this visual recognition occurs? We find an answer for one organism, which is African penguins. These penguins have black dots on their chest that is covered in white feathers and each penguin has a unique pattern of dots.

The workers of a zoo in Italy use this pattern to identify individual penguins. Researchers at the University of Turin, Italy used the animals that were housed at this zoo to see whether  the penguins themselves use the same pattern for identification. They performed some interesting experiments, where a penguin was shown photos of their mate and another penguin. The penguin could easily recognize their mate's photo as it stared at it for long. Now, when the black dots were digitally removed from the photos, the penguin failed to identify its mate. 

The beauty of these findings is how both humans and penguins identify penguins using the same black dots. It would be interesting to see if other birds and animals can also identify individuals of other species.

~ ____________ ~ ___________ ~

The Cooperative Bonobos

Together we walk, hand in hand
Taking the humanity ahead
Is that something which the bonobos planned?

Identification of individuals within a group of a specific species is necessary for cooperation amongst individuals of a group. Why do individuals need to cooperate? The reason is similar to why humans need to cooperate, i.e. for food, shelter and reproduction. But we do not know how and when this cooperative behaviour evolved. 

To answer this question, another interesting question was posed by the researchers at Harvard University, Max Planck institute, Leipzig and German Primate Center, Gottingen - whether bonobos, primates that are much more closely related to humans than Chimpanzees, can cooperate with individuals of different groups. They found that yes, bonobos indeed can cooperate outside their groups. This cooperation was seen for food sharing and grooming. They also saw that the individuals that cooperated more within their own groups (equivalent of human families), cooperated more with other groups also. It was interesting to see that this was something that was not rare and wasn't being used for any personal benefit of a bonobo. Do we humans have something more to learn from bonobos that our ancestors missed?  

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Breakthrough gene therapy approved in UK

Red blood cells (RBCs) are one of the major components of blood. They contain haemoglobin that helps in transporting oxygen, which is required by all the cells of the body. What will happen if this hemoglobin (Hb) is not formed properly? Anemia, which can also happen due to dietary deficiency occurs in that case. But unlike anemia in which dietary supplements can help, here they do not help and requires blood transfusion.

The instructions to form hemoglobin is present in our DNA. At times, one or more of the letters of DNA coding for Hb changes and that causes the cell to form defective Hb. In a disease called as Sickle Cell Anemia, because of the presence of defective Hb the RBCs change their shape and become like a sickle in shape, as molecules of Hb clump together. The sickle shaped RBCs cannot pass from narrow blood vessels and capillaries thus leading to blockage. The blockage causes pain in whichever body part doesn't receive blood and therefore oxygen due to blockage. There is another disease where regular blood transfusions are needed, known as thalassemia. In this disease also Hb does not form because of a defect in the DNA that codes for Hb. Individuals with Sickle Cell or Thalassemia suffer pain and emergency hospital visits frequently. 

Many researchers have been trying to cure the disease by correcting the instruction code i.e., the defective DNA present in the patients that codes for Hb. Recent advances in editing DNA uses a breakthrough technology known as CRISPR-Cas (that won the 2020 Nobel Prize in medicine) has make this correction of DNA possible. 

Now a recent clinical trial has shown that patients who were given gene therapy known as Casgevy did not require any blood transfusion or faced painful episodes for over a year. Looking at these promising rules UK has approved gene therapy as a treatment for Sickle Cell Anemia and a type of Thalassemia known as β-thalassemia. Although, the current gene therapy is expensive but we do hope that new and inexpensive gene therapy is on its way for patients who have been suffering from such debilitating genetic diseases where the change in DNA that causes the diseases is known.


Saturday 11 November 2023

Last Week in Science (12th Nov 2023)

And he could walk again!

Tremors and freezing gait,
do not pass as you wait,
but it is no more your fate.

Parkinson's disease is a condition where neurons of the brain region that controls and coordinates movement start dying. It begins with hand tremors, where the hand shakes uncontrollably, and as the disease progresses other complications follow. One of the symptoms that is seen in the later stages of the disease is difficulty in walking, freezing gate - sudden stopping of muscle movement while walking. This can lead to falls and makes the individual incapacitated. 

A recent case study reports how by providing a neuroprosthesis, an implant in the spinal cord could help an individual with Parkinson's disease to walk without falling. The signals to leg muscle for movement come from the brain via the spinal cord. The researchers had the expertise in controlling these muscle movements via electrical stimulation in the spinal cord controlled by a device that is implanted under the skin and is tuned to provide electric currents to the spinal cord. They had been using this technique to treat paralysed individuals to walk again. The study has been done in a single individual so far but there are plans to initiate a clinical trial to see whether an electrical stimulation in the spinal cord can help other individuals with Parkinson's disease.

Memory and brain cancer

Brain uses a specific type of signalling to learn and store memories. It is because of this signalling that uses growth factors like BDNF, to name one, that connection between brain cells can be modified making learning possible. The neurons and connections that are used more makes the connections stronger by releasing growth factors.

In a surprising and interesting finding, it was reported that cancer cells in the brain, for example glioma also use the same growth factors and signalling to grow and spread (metastasize) inside the brain. What makes this finding important is that if we can stop this signalling between cancer cells, it can help in treating cancers like glioma.

Written (not) by ChatGPT

After the popularity of chatGPT, a large language model trained on existing text data available online, the biggest challenge was to identify whether a certain piece of text has been written by ChatGPT or not. While the makers of such AI tools came up with their own algorithms and and models to find ChatGPT / other AI generated text - so called AI detectors like ZeroGPT, the detection rate was 35 - 65%, i.e it can correctly identify a text piece written by AI only 3 - 6 times out of 10. 

The current study reports an AI detector with a detection rate of 98 - 100%. So, what was different this time? The authors of the study used a specialized text, Chemistry journal articles to train their AI detector to learn. We hope similar tools would be created in the future to reduce instances of cheating and plagiarism. 

Sunday 5 November 2023

Last Week in Science (5th Nov 2023)


The imagining brain of rats

Brain has the power to relive,
Places that were visited in the past.
As long as the rewards they give.

Do you know that the London taxi drivers need to remember a map of 25,000 streets to get their licence? This shows the immense capacity of the human brain to remember maps. We can visualise these maps in our heads. But is it a capability that is restricted to the human brain? There are so many animals that are master navigators, for example rats but can they also imagine the world like we do? 

A recent study answers these questions, where rats were made to run on a spherical treadmill in a virtual reality created space by giving them rewards for reaching specific spots in that VR space. This movement created a pattern of brain activity. Next the rats were taken off the treadmill but shown the same VR space, although they were not moving physically but their brain created the same pattern of activity as when they reached out to various objects while on the treadmill. Although, it is not easy to imagine what the rats would have been imagining but this does qualify as imagination of a route by creating a mental map.

And in another set of experiments - called as the Jedi experiments - the brain activity of the rats could move a box on a screen in this VR space. The study offers possibilities of understanding how we navigate our surroundings and aiding individuals with sensory deficits to move around safely.

~ ____________~ ____________ ~

Opening the lid 

Photo: NASA/Erika Blumenfeld & Joseph Aebersold

It took 7 years to bring back a part of the rock,
that has been around since the formation of our solar system,
but now we are struggling to open its lock.

Asteroids are fragments of matter that was left out of becoming a planet as our solar system formed. A lot of information can thus be gathered by investigating what these asteroids are made up of. They are referred to minor planets at times as they can also have their own moons and they revolve around the sun just like the planets. 

Asteroid Bennu, 4.5 billion years old passes the Earth every 6 years. NASA's OSIRIS-REx mission which was sent 6 years back to the asteroid, brought back a sample from the surface of Bennu in this September. It was surprising that when the sample collector touched the surface, dust particles enveloped the OSIRIS, showing that the asteroid's surface is not rocky as it was thought. Now the only trouble is that the team at NASA is not able to open the capsule that brought back the sample. Nature (the journal) has also asked their readers to send in suggestions of how they stop their hiccups so as to help the team at NASA. You will have to read more on your own if you want to find out how hiccups and the OSIRIS-REx mission capsule have in common.

Symbology Alert: The name Bennu comes from Egyptian mythology, where Bennu is a bird similar to the Greek phoenix that symbolises rebirth, and is said to be present at the time of the creation, in this case referring to the creation of the solar system. It is also associated another Egyptian mythological God called Osiris (which is the name of the NASA mission) that symbolises life, creation and resurrection. We are hopeful of getting information about the formation of the solar system from these pieces of asteroid Bennu.  

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AI and humans

With the rise of Artificial Intelligence, in addition to the threat of many jobs becoming obsolete, the dangers of development of warfare and bioweapons is hanging on our heads. Another threat is of not getting meaningful information or worse misleading information from AI models. It becomes imperative in scenarios of weather prediction of disease prediction. 

Recent high profile summits in US and UK, initiatives by Joe Biden and Rishi Sunak, respectively brought forth the conversation of how innovation is needed in the AI space. There was no mention of regulatory framework development, which was the topic of discussion in a parallel AI fringe event conducted by individual researchers. They have put forth the need for transparency in using and sharing of how the information has been generated by AI along with the representation of social scientists, who can bring in the need for ethics,  in the discussions on AI.


Intro sound for the podcast; interval sound for the podcast