Saturday 2 March 2024

Human tail, butterfly wings, & repetitive behaviour | Last Week in Science (3rd March 2024)

Tale of the tail

With the myriad functions the tail serves for organisms that have one, it is still a mystery as to why and how the common ancestor of apes and humans lost their tail.  One of the hypothesis for why our ancestor lost the tail is that the bipedal walking - walking on two limbs was easier without a tail. But a lot of animals have a tail and can still walk on two limbs. Certain AI models for robotics have even shown that a tail actually helps in stability while moving on two limbs. Although, we do not know the why but a group of scientists may have found the how.

Researchers in New York studied one of the genes - TBXT, which is involved in tail development in various species including mice and cats. They found that in apes including humans the TBXT gene is altered in a way that it forms a shorter RNA as compared to the RNA that gets formed from TBXT gene in other primates that have a tail. So, the code of the DNA is first transcribed into an RNA molecule which further forms a protein. A shorter RNA being formed means a shorter protein being formed in apes which could be the reason for loss of the tail. The scientists then introduced this altered TBXT gene of apes in mice to test whether the mice lost their tail. And they indeed lose their tails. I wonder now whether these mice can be trained to walk on two limbs like humans.

Reference: How humans lost their tails — and why the discovery took 2.5 years to publish 

Colors of butterfly wings

As soon as you read Biology in high school, you learn that the genes code for proteins which form via an intermediate molecule RNA. But then we now know that more number of genes code for RNA that never form proteins. This RNA must be doing something. The past few decades have shown that this RNA that is not coding for protein or non coding RNA plays an important role in deciding the formation of other proteins or as to say whether and when a specific gene is active to form the protein. When we talk about visible features and say that genes might be responsible then mostly it is the protein that is being formed from that gene is responsible. But that may not be true in the case of butterfly wing colors.

Who doesn't like looking at butterflies flapping their beautiful wings as they move from one flower to the other? Have you wondered what makes the butterfly have such colorful wings? By studying white butterflies, scientists found that it is not the protein but an RNA that decides whether the color pigments will form or not in the butterfly. This RNA molecule is a long non coding RNA or lncRNA. LncRNAs are known to be involved in many functions in the body and play important roles in the development of many diseases. But the current study is the first example where a visible trait is getting affected because of an lncRNA.

Reference: Surprise RNAs solve mystery of how butterfly wings get their colorful patterns

Beyond the role of glue

Half of the cells in the brain are not neurons but glia. The glial cells have been known to be the supporting cells for neurons till now. An increasing number of studies are showing that glia are much more than being the glue for neurons.

Repetitive behavior or doing an action again and again is present in disease conditions, like moving objects around to be in a specific order as seen in Obsessive Compulsive Disorder, repeated movement of limbs in Huntington's and Autism. A particular protein was found to be reduced in the brain of individuals with these conditions. In a surprising finding, the scientists found that this protein forms not in neurons but astrocytes - a type of glial cells. When they removed this protein from mice then repetitive behavior in the form of excessive self grooming, excessive licking of the water source in the cage, or excessive exploring of a familiar object stopped. Although, they still need to find how astrocytes are controlling neurons and thus the repetitive behavior, but this finding may soon lead to a better understanding of diseases like OCD and autism. 

Reference: Non-neuronal brain cells modulate behaviour

Sunday 25 February 2024

Male vs female brain, whale songs & human cooperation | Last Week in Science (25th Feb 2024)

Is the male and female brain really different?

Medically speaking, we know that some neuropsychiatric and neurological diseases affect women more than men. Hormones are/may be one of the reasons for this difference. But is the brain of a male individual different from a female's? 

Researchers at Stanford University used artificial intelligence to find it out. They trained the AI to identify MRI scans of females and males by showing it brain scans of both the sexes. When tested with 1500 brain scans taken from individuals across USA and EU, the AI could correctly identify the sex of the individual. This increased the confidence in the training as it could work on diverse populations. So, what do we do by identifying males and females just by looking at a brain scan?

The scientists digged into how the AI was identifying the sex of the individual. This process makes it an explainable artificial intelligence instead of a black box of mystery. What they observed was that the identification was happening by studying the organization of three different brain regions, default mode network - which helps in understanding of self, striatum - which plays a role in reward, and limbic network - which is involved in learning amongst its other functions. 

What makes their study useful according to the authors is - 1. The differences in the male and female brain organization that they have undercovered can help in research for neuropsychiatric and neurological diseases. 2. Their AI model will help in identifying the brain circuits responsible for any type of behaviour - like say for a learning disability.

Reference: Stanford Medicine study identifies distinct brain organization patterns in women and men

What makes you cooperate?

Helping your family or friend makes sense, although it may not to everyone, but helping someone whom you would never meet again or someone from whom you have nothing to gain, how do we explain that? The origin of these one time altruistic interactions are difficult to explain. What we know about human cooperation is that when two individuals will be meeting repeatedly then they would want to ensure they remain on good terms so they cooperate, again does not apply to all individuals and all interactions. But then this hypothesis cannot explain the one time interactions. Another hypothesis is 'group competition'. A group which has more cooperative individuals would be at an advantage than a group with selfish or non-cooperative (the terms can be used interchangeably in this context) individuals. But both the hypotheses are not sufficient to explain why 'cooperation' or to say 'altruism' as a trait evolved and remained in today's population (and society). 

Researchers in University of Zurich created a model to understand this 'cooperative' human behavior. They then conducted a test on two different groups in Papua New Guinea. They paired individuals - once with a member of their own group (in-group) and then with a member of the other group (out-group). They asked the first member to give a certain amount of that individual's money to their partner following which they would give the double of that amount to their partner. They saw that in case of in-group partners the first member gave a higher sum and the second member gave back a much higher sum of money. While in the case of out-group pairings - the first member gave a smaller sum and the receiving individual gave a much lesser sum to the first one.

Now, when the researchers tested this result in their model then they found that such type of behaviour can explain the cooperation they saw in Papua New Guinea by a combination of both repeated interactions and group competition.

Reference: Why reciprocity is common in humans but rare in other animals

Eerie whale songs

Sailors would often tell stories of haunting sounds that could be heard in the ocean. It was only when the recordings of these songs became available to marine biologists that we understood that these sounds were whale songs. The mystery of how the songs were produced by the whales remained unexplainable for long because of the difficulty of studying these large marine mammals. But the researchers in Denmark might have found a piece of this puzzle that can help understand how whales are producing these sounds. The most interesting of the facts is that some of these whales can produce two different sounds at the same time. So, let us see what these scientists found.

Larynx the sound box has vocal cords or vocal folds present that is responsible for producing sound in mammals. As air passes through the larynx vocal cords - present on either side of the tube shaped larynx - vibrate to produce sound. The scientists studied the whale larynx dissected out from the dead bodies of whales. They passed air from the whales larynx to understand how sound is being produced. Now, the larynx in the whale has two different compartments unlike the larynx in land animals. A layer of fat - fat cushion, lines one side of the larynx creating a second compartment between fat cushion & vocal folds. Now, this creates two different surfaces - because of the presence of two vocal folds - lining next to the fat cushion that can vibrate as sound gets squeezed between the fat cushion and the vocal folds. Vibration of these two different surfaces can explain the production of two sounds at the same time. It also appears that the major sound production is via fat cushion- vocal fold instead of the air passing through the vocal folds.

This explanation still needs to be tested further in models where larynx is in an environment that still has the surrounding tissues intact. Another question that needs to be answered is how the sound is being produced underwater. And lastly, it would be interesting to see how some distinct and unusual whale sounds like - 'gunshot' and 'star wars' light-saber' like sounds are produced by whales.

Reference: An innovative way for whales to sing

Sunday 18 February 2024

Polar bears, joking apes, & predicting dementia | Last Week in Science (18th Feb 2024)

Will they survive?

With the global average temperature crossing the 1.5 degrees mark, the concern for animals in the Arctic and Antarctic has increased. Polar bears are one such organism that have been predicted to not survive the longer ice free days of the Arctic based on the studies done so far. Although, what these studies did not include were the differences in behavior, age, activity and thus energy expenditure of different bears. Researchers in Canada and USA studied polar bears in the Western Hudson bay to observe the differences between individuals.

Polar bears hunt and survive on seals exclusively. During the ice free period of summers they spend time on land - which has now increased to around 130 days and is expected to increase in the coming years based on the changes in the climate due to global warming. The scientists hypothesized that adult polar bears which have larger mass and more fat than females and younger bears would be able to hibernate and conserve energy when on land. While the younger bears would spend more time looking for and eating food sources that are available on the land in the absence of seals during that time of the year - with females foraging more as compared to younger adult males because of their smaller size - less fat and so more need for energy.

The scientists made these observations by making the bears wear GPS equipped cameras. They found that the age and size did not affect the hibernating or foraging behaviour of polar bears. Their energy expenditure based on their activity was dependent on the behaviour that had a high variation. Even though swimming is a high energy consuming activity, yet they found some of the bears, both males and females swimming. Polar bears were seen to lose body mass as the food available on land could not meet their energy needs. During hibernation, bears depend on the fat reserves in their body. But the scientists observed loss in lean muscle body mass instead of the depletion of fat reserves. It is another proof that the bears will not be to survive for long on the land for long because of eventual starvation. Although, it may be too complex to predict the overall behavior and adaptations of bears because of the high variations observed, the study still reiterated what we know.

Reference: Polar bear energetic and behavioral strategies on land with implications for surviving the ice-free period

Apes have a sense of humour

"Humor is mankind's greatest blessing." - Mark Twain

Humorous behaviour like joking and teasing (without harming the other individual) seems to increase bonding amongst individuals. Even infants as young as 8 months of age, who haven't even begun speaking show teasing behaviour like offering their toys and then pulling it back or taking something the moment you want to use it. 

Guess what, such behaviour is not just seen in humans but great apes like bonobos, gorillas, orangutans, and chimpanzees also show such teasing amongst themselves. Scientists in the University of California recorded these four different great ape species and got some 75 hours of video footage. They looked for signs of playful teasing, which is neither aggression nor play but one sided and involved one individual being targeted. This mostly involved poking, hitting, or pulling hair in the case of orangutans. This kind of behavior is also observed in human siblings and friends who are of the same age, but in the great apes the younger ones engaged with the adults to show such playful teasing.

But why study teasing in apes? Humour is a behaviour that utilises a lot of mental ability - judging of the situation, prediction of others' response and seems to be a way for bonding amongst individuals. Presence of this behaviour in apes who share a common ancestor with humans indicate that humourous behaviour evolved some 13 million years ago. So similar studies can help us in better understanding evolution of other behaviours and emotions. 

Reference: Spontaneous playful teasing in four great ape species 

Blood tests for early diagnosis of dementia

Dementia is a condition that is associated with memory loss and gradual decline of brain functioning. It is a condition seen in many neurodegenerative disease. It is usually too late by the time the disease is diagnosed because of the absence of diagnostic tests. Brain scans are done only after a substantial decline in mental functioning is seen, which shows the damage inside the brain. Scientists have been looking for blood tests that can help in the diagnosis of diseases that cause dementia before the symptoms appear.

Scientists at Fudan University, China have now found a blood test that can diagnose dementia as early as 15 years before the symptoms start to appear. They looked at some 52,000 human samples (taken from UK Biobank) and identified 1400 individuals that had developed dementia when followed up after 14 years. Using this data, they could find four different proteins in the blood that were found to have increased in individuals that developed dementia 14 years before they developed dementia.

We can hope for a blood test to be available once this study is tested and repeated again for consistency and robustness.

Reference: Plasma proteomic profiles predict future dementia in healthy adults

Sunday 11 February 2024

Firefly petunia, fighting cancer using its trick, & solar farms to bring rains | Last Week in Science (11th Feb 2024)

Firefly petunia that glows in the dark

Glowing green colored petunia plant leaves in dark
Credit: Light Bio

Who doesn't get mesmerized by the flickering light coming from the glowing fireflies in the dark? Imagine having a plant that would glow in the dark without needing any extra effort on your part, but just the regular and usual care that all plants need. I would definitely want one for myself and especially when you can get it for just under Rs 2500 ($29). Sounds like a cool Valentine's gift!

Firefly petunia are now open for pre booking on Light Bio's website  - the makers of bioluminescent plants - but for now they are only available in the USA. Fireflies have an enzyme - luciferase that generates light via a chemical reaction. Luciferase has been used in molecular biology research to answer various research questions ranging from whether a certain gene is on or not to measuring levels of different proteins. Plant biologists have also used it for similar purposes. So, we already had the technique and tools to genetically engineer such plants since 1980s. But the glow in such plants was faint and would require special chemicals to be supplied to the plants for them to luminescence. So, what is different in firefly petunias is the luciferase enzyme that has been taken from a mushroom. It glows constantly with an intensity as bright as the moon light and does not require any extra chemicals. The white flowers in the day time are visible with this soft green glow at night.   

While the concern for genetically engineered plants to be spreading their artificially introduced genes in other plants remain. The researchers and the founders have assured that petunia being a non invasive species do not pose any such risk. What makes this an achievement is the potential use of this gene editing technology to produce plants that can glow when stressed or infected and signal to farmers that they need attention. And yes, sensitising people about the benefits of genetic engineering by such beautiful plants is a bonus.

Source: Glow way! Bioluminescent houseplant hits US market for first 

Fighting cancer using its trick

You must have come across the news of the first patient who got cancer free after using CAR-T cell therapy that was approved last year and is developed by ImmunoACT - an Indian company. It is a huge achievement for the country. The treatment cost 42 lakhs which would have been 4 crores had it been taken in the USA or EU.

Let us see what CAR-T cells are. T cells are one of the immune cells of the body that can identify and destroy cancer cells in the body. But they fail at times and this is where gene editing can help. T- cells from the patients can be taken, edited and equipped with CAR (chimeric antigen receptor) that can help the CAR-T cell to recognize and kill the cancer cells in the body. The limitation of this therapy is - besides being super expensive that it can be used only to treat blood cancers. How can we tinker with the CAR-T cells to make them reach cancers in other places like breast or lungs? Scientists that co-founded Moonlight Bio have the answer. They used one of the mutations that helps cancer cells to spread through the body to make CAR-T cells reach tumors present inside organs. The therapy has been tested in mics so far but they are going to bring it out for humans and get the clinical trials started in the next 2-3 years. 

The concern of these modified CAR-T cells carrying a mutation that is present in the cancer cells itself which can cause cancer developing from the CAR-T cells has been addressed as the therapy has been found to be not just effective but also safe in mice. We can hope for more efficient and less expensive cancer therapies to be coming out soon.

Source: Cancer’s power harnessed — lymphoma mutations supercharge T cells

Solar farms to bring rain storms

We have a technology to artificially produce rain by seeding clouds. Remember when there were plans by the government to use it to mitigate air pollution in Delhi! Cloud seeding is regularly used in desert areas like in the UAE. But there is another way to produce rain.

In 2020, scientists modeled and predicted if there is a solar farm as large as the size of 1/3rd the size of India then it can cause rainfall in that area by hot air rising above leading to cloud formation and rainfall. Producing a solar farm this large is not possible and it would also impact the monsoon in other nearby regions. In a new modeling study, scientists discovered that if the solar panels are dark that completely absorb all the light without reflecting any then a smaller sized solar farm - as large as the Indira Gandhi International airport can bring about rainfall in that area. Now this is something that can be tried out in deserts!

Source: massive-solar-farms-could-provoke-rainclouds-desert

Sunday 4 February 2024

X chromosome, training AI, anti-obesity drugs for AD & PD | Last Week in Science (4th Feb 2024)

Is X making you sick?

Auto immunity is when your immune system starts attacking your own body. Two thirds of the cases of autoimmune diseases are seen in females. Sex hormones are thought to cause this higher susceptibility of females to develop autoimmune diseases like rheumatoid arthritis. X chromosome is also seems to be a probable culprit for development of autoimmunity.

Genetically human females and males are different because of the presence of two X chromosomes in females and one X and one Y chromosome in males. To compensate for the double dose of genes on the X chromosome in females, one of the chromosomes is made inactive. This process coats the chromosome with RNA and proteins. Xist is the RNA that wraps around one of the X chromosomes in the cells of human females.

In a recent study, it was found that auto antibodies are formed in the body that attack the proteins associated with Xist. Now, since all the cells of human females have Xist so it puts them at a higher risk of developing such auto antibodies and in turn autoimmune disease. Individuals that had auto immune diseases also had these auto antibodies present in their blood. Using this information the scientists will now be developing tests for early detection of autoimmune diseases. These auto antibodies can also be used for developing new treatment methods.

Anti-obesity drugs can treat Alzheimer's and Parkinson's Disease

The bestseller anti obesity drug of 2023 - semaglutide suppresses appetite and makes the brain believe you are full. It is used to treat diabetes and it also causes weight loss. It has recently found to decrease the risk of heart disease. And this drug has also shown to suppress inflammation - a process that happens when the immune cells are in the fight mode either attacking and/or clearing up the dead cells and the collateral damage after the attack is over. There are many diseases where the inflammation is either the cause or the effect. And semaglutide like drugs seem to reduce inflammation everywhere in the body.

There is brain inflammation in neurodegenerative diseases like Alzheimer's and Parkinson's Disease - where there is memory loss or individuals lose control of their motor function leading to tremors and falls. Currently, drugs similar to semaglutide are being tested as a medicine for AD and PD. And it is showing promising results, improving symptoms of these neurodegenerative diseases.

Training AI with the eyes of a toddler

Is language inherent or acquired? We all learn language when we are young. Can we train an AI by providing the same kind of experience? And if yes, then what will we gain out of this experiment?

Researchers at New York University made a toddler wear a camera on his head for 1 hour per week from the age of six months to two years. This footage was then used to train an AI algorithm. The audio was given as the transcript - thus the algorithm could associate words with the images in the video. This algorithm was not trained any language and it could still identify some of the words by the image and word association like crib and ball. This experiment challenges the view that language is inherent because the computer program could learn it without having no prior information of how language works.

Sunday 28 January 2024

Ants & lions, immune system & ageing, stress & bacteria in the intestine | Last Week in Science (28th Jan 2024)

The ants and the lions

The old moral story of how small ants can fight off an animal as huge as an elephant was true in the forests of Kenya until big headed ants started showing up. Scientists observed that the big head ants started to kill the native acacia ants which would have saved the acacia trees from being eaten up by the elephants.

You must be wondering how elephants getting more food to eat can affect the lions.

These acacia trees provide hiding spots to lions for hunting zebras. The absence of acacia ants, increased grazing of acacia trees by elephants that decreased the tree cover. Scientists at Wyoming University studied number of zebras in areas where big head ants had invaded comparing it to areas where they had not invaded. They also looked at how many zebras got killed in these two different regions. They also tracked the movement of lionesses in these different regions by bugging them with GPS.

After three years of tracking, the result was as the trees started getting less dense, creating more open space, the lions had trouble in hunting zebras. So, the lions started hunting buffaloes. But how can that be a big deal? For one it takes lions more energy to hunt buffaloes and at times the lions get killed in the process. Second, the increase in zebras could cause unexpected changes to the existing ecosystem of the forests in Kenya.

This study is a beautiful example of how one small change in the ecosystem can have big effects. 

Can we use the immune system to slow ageing?

Our immune system have a specific type of cells called as the T cells which are trained to recognize specific cell types - pathogens or infected cells. With the recent advances, these T cells can be trained outside the body to recognize other types of cells - like cancer cells. These trained cells are called as CAR-T cells for chimeric antigen receptor T - cell. These T cells recognize specific molecules that are present on the surface of a specific cell type.

The aged and defective cells are called as senescent cells are the ones that have stopped growing and dividing because of damage. These cells usually release signals to call immune system to destroy them and are important for preventing cancer and causing healing after injury. The senescent cells increase in different tissues as we age. Their removal becomes less effective because of the decline in the immune system as we age. In the recent study, scientists at Cold Spring Harbor Lab generated CAR-T cells to recognize aged cells of mice. What they found was when these CAR-T cells were introduced in aged mice then they prevented some of the diseases that come with ageing or because of consumption of high fat diet. These mice were also physically more active after this one time treatment.

But it still remains to be seen whether it can prolong life and whether we can use such an approach in humans.

Stress and the bacteria in the intestine

We all have heard examples of how stress can upset one's stomach. In severe cases, a disease called as Inflammatory Bowel Disease (IBD) is seen with stress that persists for a long time - called as chronic stress, which causes swelling of the intestines, stomach pain, and diarrhea. 

In the recent study, scientists at China Pharmaceutical University found that when mice were given chronic stress, for 2 weeks, they could not produce enough cells in their intestines to protect from infections and so causing swelling or inflammation. A specific type of bacteria of the Lactobacillus genus was found to be increased in their gut. These bacteria produced a chemical - indole-3-acetate (IAA). This chemical did not let the stem cells of the intestine to form the cells that would have protected the gut from infections.

What is interesting is scientists also found Lactobacillus and IAA in feces of humans who have depression. The scientists could treat the mice by giving a chemical called as alpha ketoglutarate. But it will still take time to see whether the same treatment would work in individuals suffering from inflammatory bowel disease or not. 

The scientists are still seeking answers to how the brain affects the bacteria in the intestines. These answers will help in understanding and treating many diseases that happen because of stress.

Saturday 20 January 2024

The tail wag, the sick chimps, reversing memory loss | Last Week in Science (21st Jan 2024)

The tail wag

Can't get enough of your dancing dog with their tail wagging on seeing you? Do you wonder why they wag their tails?

In a recent compilation of existing studies, researchers have made some interesting findings. Tail wagging is seen in many other animals like wolves for communicating. In the wild, wolves may show a sign of submission to a more aggressive wolf by tugging their tails between their legs or moving it slowly, which is also true for dogs. Dogs not only wag their tails more often than wolves but also show an asymmetry when it comes to their preference towards the object that they are wagging their tail after looking at. When they want to approach towards an object then their tail wags more towards the right side while it is towards the left when they want to move away from the object. The speed of their tail movement does help in distinguishing whether they are happy or aggressive.

But we still do not have clear answers to whether they feel happy and so less stressed after they dance with their tails wagging fervently, how does their brain control the movement of their tails and is this a behaviour that they can control voluntarily.

The sick chimps

It's not only animals who transfer disease causing microbes to humans but the reverse is also true. Remember how you were asked to stay away from your pets if you caught COVID-19. The cases of cheetah and deers getting affected of COVID-19 were also reported, which created a fear of SARS-COV2 evolving in these animals into more deadly forms. What we overlook is how we can affect the different species especially of apes like chimpanzees and gorillas who are closely related to us. There have been disease outbreaks in the wilderness of sanctuaries because of microbes that may not harm humans that much but have been deadly for the apes. The situation is more pertinent because many of these species have such low numbers that we cannot afford to lose them to such infections. 59% of deaths of these apes which had a known cause were because of infections coming from humans.

Transmission from tourists who do not follow safety guidelines of wearing masks and not going close to the animals are one of the causes.

A study that was conducted in Kibale National Park, Uganda traced the transmission from scientists working at the Park who had young children studying in schools. By testing children, their parents and the chimpanzees' stool samples the link was established. This brought to light the unhygienic conditions of the schools where these kids used to study and the initiation of Happy Children Happy Apes program with measures like creating awareness about infections in children. It is hoped that making scientist, tourists, Park officials, and nearby residents aware would help in keeping the apes safe. 

Reversing memory loss

Athletes like football players often get hit by the football on their heads. Multiple mild hits on the head can cause memory loss or what is known as amnesia. It was earlier thought that such a memory loss is because of the death of neurons in the brain, an event that cannot be reversed. But in a recent study scientists have shown that this isn't true. 

They gave multiple mild head injuries to mice to see the effects on its memory. These mice had neurons tagged in a manner that the scientists can switch them on and off. What they discovered was it is the connections between the neurons that are responsible for remembering a memory get affected and when the scientists switched on the specific neurons they could reverse the memory loss seen after the head injuries.

Although, we are still too far from using this finding in humans but what gives hope is the possibility of reversing memory loss in instances of mild brain injuries.

Sunday 14 January 2024

The lost great apes, EU ancestors and human fetal brain organoids | Last Week in Science (14th Jan 2024)

The lost great apes

Gigantopithecus blacki
 are the largest apes known that went extinct 210,000 years ago. They would weigh 200-300 kgs and would be as tall as 3 meters or more than 9 feet.

What changed in this ape's environment that made it extinct? To answer this question, researchers studied teeth excavated from caves in China, these apes were native to China. They found that older teeth samples indicated a healthy and balanced diet being taken by G blacki but in the teeth samples which were more recent the diet seemed to be less balanced.

By dating - finding how old the teeth samples are and comparing it with how the environment would have been at that time the researchers found further clues.

Around 3.2 million years back, G blacki were living in surroundings that were covered with dense forests mixed with open grasslands. But this environment changed in to a less dense and more open grasslands at around the time the great apes went extinct. 

The researchers are looking out for more fossils because so far they could only find teeth, especially the thigh bones so that they can better understand what made these giants apes go extinct.

Reference: Why did the world’s biggest ape go extinct?

The European ancestors

When it comes to study ancestry and human migration around the globe, researchers study the genetic material that they extract from fossils of humans. In a recent study that looked at 1000 different European ancestors, the researchers found that the current day European Union has had three different waves of human migration. The earliest coming from hunter gatherers from Asia 45,000 years ago followed by farmers from Middle East, 11,000 years ago and the most recent being the animal herders that came from Western Aisa some 5,000 years ago. 

There is a mixing of these populations but there are also clear distinctions between northern and southern Europe. This was because the animal herders mostly settled in the northern part of the Europe while the farmers went to the southern and western parts.

The northern population being at high risk of diabetes and Alzheimer's while the southern population being at high risk of developing a neurological condition known as multiple sclerosis can be explained by the ancestors being different in two geographically different regions of the EU.

Multiple Sclerosis is a disease where the body's immune system starts to attack the nerves of the body. As the animal herder started to settle in the northern regions the instances of disease would have increased because of the microbes being introduced by the animals in the environment. Individuals with an overactive immune system would be at an advantage in this change in the environment. This would explain why the northern population have more individuals that have an over active immune system and increasing the chances of developing auto immune disease like Multiple Sclerosis.

The study also revealed that in certain places like in Denmark the migrants completely replaced the existing local population by killing them. I wonder if an in depth analysis might be able to reveal more about the evolution of the killer instinct of humans as we advanced towards the modern world. 

Reference: Ancient DNA reveals origins of multiple sclerosis in Europe 

Mini brains from human fetus

Brain organoids are mini brains grown in the lab that help scientists to study how the brain develops or what goes wrong in diseases where the brain is not able to develop properly.

Till now, scientists have grown brain organoids from stem cells that can be created in the lab by taking cells from adult humans. While these brain organoids do help in understanding how different brain cells form but further development and forming of connections between different brain regions cannot be studied. This is where tissue from fetus can help. But using human fetal tissue especially the brain is banned in many countries like the USA. The current research happened in the EU where there is no ban. The researchers also ensured that the mini brains were not conscious or feeling pain, an ethical concern that surrounds research around growing mini brains in the lab.

The researchers used brain tissue from 12 to 15 week old aborted fetuses. They could grow different parts of the brain in a dish by taking slices from the fetal brain. These formed balls of cells that resembled the different parts of the brain. They tested drugs for brain cancer on these mini fetal brain organoids after creating cancerous cells in them and the drugs were found to be effective. The researchers now plan to use these mini brains for screening new drugs to treat brain cancer along with better studying the development of brain. 

Sunday 31 December 2023

Last Year in Science 2023

The weight loss drug of 2023

Obesity is the risk factor for type 2 diabetes, hypertension, and heart disease. Achieving weight loss before these diseases take you in their grip is the best case scenario but even if you develop one of these diseases, weight loss remains as one of the treatment goals. 

Wegovy or semaglutide is the weight loss drug was a hype online in 2023. It was approved for use in 2017 for diabetes, and then later in 2021 for obesity. Since then it is being hailed as the best weight loss drug ever known to humans. 

Wegovy or semaglutide increases insulin release, slows down stomach emptying, and signals the brain that the stomach is full. It is owned by Novo Nordisk and their recent clinical trial results show that not only is the drug effective in causing weight loss but also reduces the risk of heart disease by 20%. 

The sales for the drug are expected to go as high as billions of dollars in the next year. It does feel like a miracle drug but before you think of going to the nearby pharmacy to buy it, hear the downside. It needs to be injected weekly and once you go off this medicine, the lost weight is gained back. 

There are many more weight loss drugs on their way to the market in 2024 and some of them are going to focus on burning fat instead of reducing sugar levels and your appetite.

A sweet protein that can replace artificial sweetener

Why not remove one of the major culprits of weight gain, obesity and type 2 diabetes? I am talking about sugar. There are artificial sweeteners in the market but many of them have been shown to affect the microbes inside your gut, reducing the good gut bacteria and leading to health complications including eventual weight gain. 

Now, we have a new sweetener - which is a protein and is 3000 times sweeter than sugar. The protein is monellin and was discovered in serendipity berries, a type of tropical berry. Amai Proteins is going to synthetically produce this protein - and have named it sweelin,  which can withstand the high temperatures of cooking unlike the naturally occurring protein monellin. They claim that sweelin will reduce the percentage of sugar by 50 - 70% in chocolates and ketchup.

Chandrayaan-3 moon landing

I reached my destination and you too!' was the first message from Chandrayaan-3 after landing on the south pole of the moon on 23rd August 2023. 

The whole world was watching as the Chandrayaan 3 spacecraft was launched on 14th July. With an indigenous propulsion module, lander (Vikram lander) and rover, the mission life was of 14 earth days or one lunar day. The main purpose of this mission was to demonstrate the technological readiness of India for conducting inter planetary missions. 

After the soft landing, the rover explored the surface of the moon's south pole, conducting experiments that measured temperatures at different depths from the surface of moon, looked for the different elements that are present on the pole to see if it is different from other regions of the moon. It found Sulfur along with other elements like - Al, Ca, Fe, Mn, Si which are present in other areas of the moon as well.

Now the world is waiting for the results from ISRO's solar mission Aditya L1.

AI boom with ChatGPT

Artificial Intelligence was another biggest hype of 2023. Tools that can generate text, art, and code with a simple or a detailed text prompt were being rolled out throughout the last year. ChatGPT by OpenAI was the first one to be made open to the public. ChatGPT did not only pass the Turing test but was found to be clearing exams like the pre medical entrance, law and engineering.

Since then there have been debates and polls on whether to use text generating tools like ChatGPT or not. Articles and videos describing how best to use AI started doing the rounds on the internet. Talks about job loss and the AI taking over the world continued.

And then ChatGPT was found to be making up information that did not exist. The concerns over intellectual property infringement and plagiarism were soon brought to attention. Tools to detect content generated by AI started coming out. As ChatGPT or similar tools are computer programs that are trained using a large amount of language data available on the internet. They generate text by predicting what the next word could be based on the information that they were trained on. This not only is breach of intellectual property but also reinforces the existing biases. ChatGPT does not understand language - the way we do has been said repeatedly by linguists like Noam Chomsky. 

It seems the pandora's box has been opened but we shall come up with solutions as we always do. 

Hottest year on record

Even though we have a solution for the epidemics, we still are struggling to save our planet Earth. 

2023 is the hottest year on record, taking up the position of 2016 which is now the second hottest year in the human recorded history. The average global temperature was 1.4 degree Celsius higher than the pre industrial 1850 - 1900 average global temperature, i.e just 0.1 degrees less than the crossing over the 1.5 degrees mark of irreversible damage. Levels of greenhouse gases - carbon dioxide, methane and nitrous oxide, sea surface temperature and sea level rise are also the highest so far in the recorded history.

And to make it all worse, 2024 could beat all the records of 2023.

Other references-

Sunday 24 December 2023

Last Week in Science (24th Dec 2023)

Those dark brown eyes

What secrets do those dark brown eyes hold.
Are we the ones who had the dogs mold?

Dogs melt our hearts with their puppy eyes. Have you wondered if there is a reason why most dogs have brown eyes? Scientists at Teikyo University of Science might have found the answer. The scientists showed photos of dogs with brown and light colored eyes to individuals and asked them to rate the dogs based on whether looked aggressiveness, friendliness and intelligence. They found that the dogs with dark eyes were seen as friendlier and non aggressive and also less intelligent - exactly how a puppy would be like.

Light colored eyes, as present in wolves are advantageous for communication in the wild because of the ease of picking up cues from a dark colored pupil on a light background of the iris. And we all know how scary a wolf is. So, the dark eyed dogs might have been selected by humans during the domestication of dogs. One reason could be that the pupils look larger in dark colored eyes and humans prefered those dogs as larger pupil appears to be a sign of friendliness and also babies have a larger pupil.

But more studies need to be done as how can we forget the drama queen - siberian huskies who have blue colored eyes and are still loved around the world? But no wonder they do look scary as a wolf!


Talk, talk and talk

Could not stop yourself from talking to your toddler? Guess what, it helps the toddler as well. Recent research at Harvard University shows that the more the parents talk to their kids, the more the kids talk and have larger vocabularies. 

The scientists made the kids wear a small recording device, not to spy on them, but to record how much are they speaking or blabbering and how much of the talking is happening in their environment. They made these recordings in 12 different countries from 1001 kids to get 40,000 hours of recording from 2865 days. They also found that there were no differences in how much a kid talked because of the socio-economic status of the parents - mother being less educated or the family being poor.

The sleepy reindeers

Eat, sleep and repeat - is not the only mantra.
Sleep while you eat - says the Santa.

What do you like the most after a fulfilling meal? Sleep, right? What if you could eat and sleep at the same time? That will definitely save some time for those slow eaters. Researchers at University of Zurich, Switzerland have found that reindeers show sleep like brain activity while they ruminate - an activity that is similar to what cows do i.e, chewing the food stored in stomach long after they have eaten it.

What makes this study interesting is the following! When the reindeers were kept awake for 2 hours longer than their regular active time by making loud sounds or giving them tasty treats, then their need to sleep during their active team increased. But if the reindeer had ruminated and were disturbed thereafter, then the need for sleep during active time was not seen. 

The reindeers eat as much as possible during the summers so as to bulk up for the coming winters when the food would be scarce. So, spending the maximum time eating by reducing their need to sleep separately lets them optimize their time. The reindeers thus save up time on sleeping because they can multitask.


Sunday 17 December 2023

Last Week in Science (17th Dec 2023)

The social life of snakes

By Wilson44691 - Own work, Public Domain,

How many friends do you have? Two? Three? I am not asking about the ones on Facebook/Instagram. It would definitely not as high as 46. This is the maximum number of friends that garter snakes, that are found in the United States and Canada, can have. 

Researchers in Queen's University in Canada made this interesting finding while studying garter snakes that were being relocated due to some road construction work. The ecologists were tracking some 3000 snakes for 12 years to ensure they are happy in their new environment. This data was then looked at by researchers of Queen's University. They found that they would catch the same group of snakes hanging together each time they were caught. Another interesting finding was that these groups were led by female snakes, and the younger females would follow the older ones. While the males were found to become aloof as they aged. I wonder whether the older females would be giving tips the younger ones on how to find that perfect mate.

Nuclear fusion is here to stay

Nuclear fusion happens inside the Sun and happens to be the source of all energy for the Earth. Scientists have been working on generating energy from nuclear fusion reactions in a lab bu each time they would get lesser energy output than they would provide for the reaction as the input. Unfortunately, such energy equations do not matter when making a hydrogen bomb that uses the same nuclear fusion reaction. 

Last year in December, a breakthrough was made when scientists at US National Ignition Facility managed to produce more energy than they had supplied to carry out the nuclear fusion reaction. But in the world of science you need to repeat any experiments to be certain that it wasn't a fluke. Now, the laser facility at Lawrence Livermore National Laboratory in California has repeated this feat four times which is a reason to rejoice. There is still a long away from creating fusion power plants because the amounts of input energy are less so as to ensure that the Sun like environment does not blow up the lab but experiments are underway, including the ones for nuclear weapons, to keep increasing the input so that we may eventually be able to generate enough clean energy to sustain our daily activities on this planet.

Don't blame the fetus for that morning sickness 

Pregnancy comes with its own challenges and nausea and vomiting is one of them. In some 0.3- 3% of pregnancies, the frequency of vomiting is so high that the pregnant women need to be hospitalized and it often leads to either abortion or the death of the mother. The cause for this condition, which is known as hyperemesis gravidarum (HG) hasn't been known for long. 

In the study carried out at the University of California, the researchers found that a specific gene - GDF 15 (growth differentiation factor 15) increases the chances of a woman developing HG. The researchers found that there were two forms of this gene. GDF 15 gene produces a hormone that circulates in the blood. One of the forms that is known as H202D causes the non pregnant women to have low levels of GDF 15 in their blood. The researchers also found that GDF 15 in the blood during pregnancy comes from the fetus.

Now, when both the mother and fetus have the some form of GDF 15 then the mother does not develop HG. But when the mother has H202D GDF 15 and the fetus has the other form then the women develop HG. This study will help in finding a cure for HG and also will support research for other diseases that occur during pregnancy. An interesting question that still remains unanswered is why are humans the only species that have morning sickness during pregnancy? 

Sunday 10 December 2023

Last Week in Science (10th Dec 2023)


The Honey Hunters and their companions

Honey hunters in Africa, people who look for honey bee nests to extract honey use a special guide - the honey guide birds. What makes this cooperation interesting? The honey hunters use a special sounds to call the birds to lead them to honey bee nests. The birds get wax and bee larvae in return. And at times it is the bird that calls upon these humans to go honey hunting.

People in different regions of Africa use different sounds to call birds of that region. What makes it unique is that the birds are genetically same but have learnt to recognize different sounds. The study was carried out by researchers of Cambridge university. They say that that cultural practices of these birds and honey hunters are affecting each other. The sounds that are being used by the hunters are passed on from generation to generation. But if that is the same for the honey guide birds still needs to be studied.   

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Predicting disease by looking at your blood

We hear all the time that age is just a number and now we have scientific evidence to back that. 

There have been studies that predicted the biological age of a person by looking at the condition of the body using various tests, but they haven't looked at individual organs. The existing tests for various organs tell us about the status of a disease condition. What if we get to know in advance that one of our organs is at risk of developing a disease, would it not help us by taking timely precautions?

Researchers at Stanford University have taken a step in that direction. They found after looking at the blood samples of 5000 individuals that different organs age differently in an individual and amongst different individuals by identifying proteins - molecules that make an organ function, coming from different organs. They used machine learning to predict the age of an organ and found that 20 out of 100 individuals in those 5000 people that they studied, had an organ that was ageing faster than what it would have been like in most individuals of their age. This increases their chance of developing disease in that organ and increased the chances of early death. 
The blood tests need to be tested in more individuals before it will become available to know the age of your different organs. 

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A sense of relief

Do you remember feeling a sense of relief after that stressful interview was over or after coming out of the examination hall? Although, we still don't know why it happens but the researchers at Zhejiang University, China have found an important application for this behaviour. 

This feeling of relief is seen because the reward centres in the brain become activated as the stress ends.
The researchers show that this feeling of relief after stress helps in preventing depression. They tested depressed mice by giving them stress - a foot shock or by keeping them immobile - and then gave them a reward like a chocolate. They found that these mice showed less of depressed behaviour but this did not happen in mice that were not given the reward. 

The researchers suggest that providing reward within two hours after the stressful situation is over could help in alleviating symptoms of depression. 

We now know why that ice cream/chocolate or shopping after a stressful situation feels so good.

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Sunday 3 December 2023

Last Week in Science (3rd Dec 2023)

10,000 naps

Have you experienced a power nap? Can you remember the shortest nap you had? It might have lasted at least a few minutes. The naps of chinstrap penguins lasts from 4 to 32 seconds. What is interesting is they survive on thousands of such naps that they take during a day, including night times. The naps that they take amounts to some 11 hours of sleep in a day and this is all they need to survive. Think of taking 600 naps in an hour.

Scientists from Neuroscience Research Center of Lyon in Bron, France implanted electrodes in chinstrap penguins housed in King George Island, Antarctica to record sleep pattern of the penguins over a duration of 10 days. The scientists were intrigued by this finding and are now hoping to understand how and whether other organisms use such microsleep or naps to stay alert. Would you exchange your 6-8 hours of sleep for 10,000 micro naps?



Robots made of human cells

Kids often wonder whether there are humanoid robots inside our bodies that perform the functions that help us survive. While that is not the reality but what may be a reality soon is scientists sending robots (not humanoid but made of human cells) inside the human body. 

In this cool experiment, scientists at  University of Pennsylvania in Philadelphia created tiny robots made of human cells- called as 'anthrobots', each one made of 100s of cells. These robots were created in a dish and were found to be moving in circles, straight line or haphazardly. Next they created a layer of neurons and then made a scratch on it. When the tiny robots were added to this layer, they could repair the layer by causing formation of more neurons. The scientists are hoping that if we can make anthrobots from a person's body cells then they can be used in repair processes, like clearing of an artery (that may have caused a heart attack if not cleared) or deliver medicines inside the body. 



Attack on the brain due to stress

As the cases of depression increase a need to understand what causes depression becomes imperative. While many individuals with depression respond to medication, one thirds of the patients do not respond. So, there is also a need to develop new treatment options. 

It has been seen in individuals with major depressive disorder (MDD) - who have a chronic form of depression - that incidence of autoimmune diseases are high. Immune system that helps in defense of the body when starts attacking itself that is when autoimmune diseases happen. It is known that after facing chronic stressful conditions, immune cells of the body (like neutrophils and monocytes) can start to attack the brain in individuals who have MDD. It is not known whether it is a cause of depression and whether it can affect the severity of the disease.

A recent study was performed to study the effect on immune system using mice that were made depressed by creating social stress; these mice were kept together with an aggressive mice for 1 hour/ day for a total of 10 days. The aggressive mice fight and defeat the non-aggressive mice. Such social defeat stress causes depression in mice. It was found that the depressed mice had antibodies against brain tissue. Antibodies are created by B cells of the body to fight invading pathogens and cause their destruction. What was interesting was that the mice who had low B cell counts did not get affected by the social defeat stress. So, can we use targeting of antibody producing cells to treat depression? It will take a while to find that answer so till then keep yourselves away from stress as much as possible.