Tag Archives: functionality

Bird Retinas: How Scientists Discovered Their Oxygen-Free Functionality

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Zebra finches study

Research on Zebra Finches’ Eyes Reveals Unique Mechanisms

Ger Bosma/Alamy

The anatomy of zebra finches’ eyes is distinct from known vertebrate tissues. Their retinas, responsible for light detection, utilize an unusual energy source by absorbing glucose instead of the typical oxygen.

This groundbreaking discovery addresses a 400-year-old question regarding avian eye physiology. Christian Damsgaard from Aarhus University in Denmark notes, “This is compelling evidence that certain neurons can operate without oxygen, notably in common garden birds.”

The retina sends light signals to the brain, demanding considerable energy supplied by oxygen and nutrients through blood vessels. However, the thick avascular retina in zebra finches raises the question of how these essential nerve cells sustain life.

Damsgaard and his research team investigated zebra finches, or Teniopygia guttata, in the lab. By attaching oxygen sensors to their eyes, they discovered that the inner retinal layer does not receive oxygen.


“Oxygen enters through the back of the eye, but it cannot permeate the retina,” explains Damsgaard.

Analyzing metabolic gene activity in various retinal layers revealed frequent reliance on glycolysis in areas devoid of oxygen. Although this process is less efficient, it serves the retina’s energy needs.

“This method requires 15 times more glucose for equivalent energy output,” states Damsgaard. So, where does all this sugar come from?

The answer lies in the pecten, a structure of rake-shaped blood vessels found in avian eyes. Previously thought to transport oxygen, recent findings show that the pecten instead inundates the retina with glucose—four times what brain cells absorb—fueling its high-energy requirements.

According to Luke Tyrrell, researchers at the State University of New York at Plattsburgh are astonished that birds have evolved to depend on such a less efficient method for vision. “The avian retina is among the most energy-intensive tissues in the animal kingdom,” he adds.

This specialized, blood vessel-free retina may provide superior vision in birds, with the pecten sugar supply being a crucial evolutionary adaptation. An oxygen-independent retina could also contribute to their capabilities for high-altitude migratory flights.

For Pavel Niemec, findings from Charles University in Prague, Czech Republic, illustrate that evolution can yield counterintuitive solutions to physical challenges.

Damsgaard and his colleagues believe there may be future applications for modifying human cells to allow greater resilience under low-oxygen conditions, such as after a stroke.

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Source: www.newscientist.com

Transplanting Pig Livers into Living Humans Achieves Near-Normal Functionality

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Surgeons carry out a pig liver transplant at the First Affiliated Hospital of Anhui Medical University in China in May 2024.

Lu Xianfu

Transplants of organs from non-human animals to human recipients could transform medicine and potentially save countless lives each year as many die awaiting transplants. Past experiments have seen pig hearts and kidneys transplanted into humans, but this marks the first instance of an animal liver being transplanted into a living person.

“This is truly groundbreaking,” remarks Heiner Wedemeyer from Hannover Medical School in Germany, who was not involved in the procedure. “The patient was critically ill, but thanks to the transplant, he survived for six months.”

The complexities of the liver have prevented previous surgeries of this kind. Earlier studies were conducted on brain-dead individuals, but indications of success were observed. “The heart acts merely as a muscle for pumping blood,” Wedemeyer explains. “Kidneys are simpler as they filter waste. The liver, however, is unique as it synthesizes a variety of proteins essential for numerous metabolic functions.”

Similar early successes were noted in heart and kidney transplants, although subsequent complications arose. In the realm of heart transplantation, risks potentially include the spread of swine viruses.

Recently, Hokujo Taiyo and colleagues at Anhui Medical University reported a pig liver transplant performed on a 71-year-old man. His liver was deemed too damaged for a traditional transplant due to severe tumor growth and significant scarring from hepatitis B. Thousands perish annually awaiting liver transplants, so each surgical case must be meticulously justified, according to Sun.

However, Sun indicated that the man required some form of transplant as there was a risk of the tumor rupturing, which could be life-threatening. With the patient’s consent, Sun and his team replaced the affected portion of the liver with one harvested from an 11-month-old minipig in May 2024. During a five-hour procedure, they connected the blood vessels of the pig liver to those of the left side of the recipient’s own liver.

To mitigate the risk of rejection by the immune system, three pig genes were disabled while seven human genes were introduced, enhancing compatibility. The patient was also administered immunosuppressants while the team diligently examined his liver to ensure it was free from swine viruses.

Almost immediately post-surgery, the new liver began to produce bile. Bile is crucial for the digestion of fats. Within weeks, levels of bile and albumin (a protein that retains fluid within blood vessels) in the patient rose to healthy ranges, as reported by Sun.

Nevertheless, about a month post-transplant, a life-threatening blood clot formed in a blood vessel, necessitating the removal of the graft. This complication likely stemmed from an overactive immune response, leading to abnormal blood-clotting protein levels—a challenge that may be common in pig transplants given the biological differences between species.

The patient lived for roughly five additional months with only the left side of his liver remaining before succumbing to gastrointestinal bleeding, a frequent issue associated with liver scarring, according to Sun. Both Sun and Wedemeyer believe this bleeding was probably not related to the transplant.

Despite the outcome, the operation is seen as a partial success because the patient would likely have died very soon after the tumor’s removal, noted Wedemeyer. Furthermore, he added that the patient’s liver may have partially regenerated during the successful functioning of the transplant, enabling survival for several months after the graft removal.

Wedemeyer emphasized that this procedure enhanced the understanding of xenotransplantation and opened up the possibility of pig livers providing temporary solutions for patients awaiting human transplants. There may even be a chance that the remaining liver tissue could grow sufficiently to negate the need for further treatment, indicated Sun.

However, Sun cautioned that it may take at least ten years before pig livers can replace human livers permanently. He stressed the need to minimize potential complications through further genetic advancements.

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Source: www.newscientist.com

Brain Structure Mapping Alone Fails to Capture Its Functionality

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The human brain contains trillions of connections

Sherbrooke Connectivity Imaging Lab/Connect Images/Alamy

Is it possible to fully comprehend brain function if we can accurately map its structures? Researchers aim to develop a wiring diagram, or connectome, of our neural pathways, yet the task of unveiling the brain’s mysteries is proving to be complex.

The Connectome serves as a roadmap for nerve signal pathways, but Sophie Dovari from Princeton University and her team have found notable gaps in these pathways.

Researchers analyzed the connectome of the nematode worm, Caenorhabditis elegans, and compared it to recorded neural signals. They accomplished this by stimulating each neuron and observing how signals flowed through the connectome. This method is feasible with nematodes due to their relatively simple nervous system, composed of roughly 300 neurons.

Nematode worms are significantly simpler than humans, with approximately 300 neurons depicted in green

Heiti Paves / Alamy Stock Photo

By viewing these two datasets as mathematical networks, researchers can ascertain whether closely connected groups of neurons manifest a high frequency of signal exchanges. They uncovered that this correlation is not always evident.

Dvali notes instances of substantial connection density and overlapping signal exchanges, like how worms eat or the groups of neurons that correspond well. However, even in cases where they appeared significantly connected, a gap remained in understanding their respective functionalities across both networks. Overall, these findings suggest that the biological connectome is insufficient to predict all neural behaviors.

Team member Andrew Leifer, also from Princeton University, points out that signals do not always follow the shortest paths between neurons; some may communicate beyond their direct connections. “While we typically leverage connectomes for research, the multitude of useful connections calls for deeper comprehension,” he explains.

According to Albert Laslo Barabasi at Northeastern University, Massachusetts, criticism surrounding connectomics often revolves around its inability to provide action-oriented insights from structural data. This new paper seeks to address that challenge.

Looking forward, researchers aim to delve deeper into how signals disseminate through the connectome when multiple neurons are activated simultaneously, with aspirations to study more complex organisms, such as fruit fly larvae, recognized for their intricate neural networks. “We are on the verge of a revolution in brain mapping,” Barabasi concludes.

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Source: www.newscientist.com

Kosmik: A Visual Canvas Equipped with PDF Reader and Web Browser Functionality

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In recent years, tools like Figma, TLDraw, Apple’s Freeform, and the Easel feature in the Arc browser have tried to sell the idea of ​​using an “infinite canvas” to capture and share ideas.french startup cosmic builds on that general concept with knowledge acquisition tools that don’t require users to switch between different windows or apps to retrieve information.

Kosmik was founded in 2018 by Paul Rony and Christophe Van Deputte. Prior to that, Ronnie worked as a junior his director at a video production company, but instead of files and folders on which he could place videos, PDFs, websites, notes, and drawings, Ronnie used a single whiteboard as his type of canvas. was needed. And that’s when he started building his Kosmic, Ronnie told his TechCrunch. He draws on his background in the history and philosophy of computing.

“It took us almost three years to create a working product that included baseline features like data encryption, offline-first mode, and built a spatial canvas-based UI,” Rony explained. “We built all of this on top of his IPFS, so when the two of us collaborate, everything is peer-to-peer instead of relying on a server-based architecture.”

Image credits: cosmic

Kosmik offers an infinite canvas interface where you can insert text, images, videos, PDFs, and links, which can be opened and previewed in the side panel. It also has a built-in browser, so users no longer have to switch between windows to find relevant links on his website. Additionally, the platform also features a PDF reader that allows users to extract elements such as images and text.

This tool helps designers, architects, consultants, and students to build information boards for various projects. This tool is useful because it doesn’t require you to open numerous Chrome tabs and enter details in documents. Documents are a less visual medium for many different types of media. Some retail investors use apps to monitor stock prices, and consultants use apps for project boards.

Image credits: cosmic

Ronnie emphasized that bringing these different tools together in one place is a core selling point for Kosmik.

“I think it all revolves around the idea that we don’t have the best web browser or text editor or the best thing. It’s a PDF reader,” Ronnie said. “But being able to have them exist together in the same place, and being able to drag and drop items between them, makes this tool very powerful.”

Available via the web, Mac, and Windows, Kosmik comes with a basic free tier, which has a limit of 50 MB of files and 5 GB of storage with 500 canvas “elements.” For more storage and unlimited elements, the company offers a monthly subscription of $5.99, and eventually he offers a “one-time” subscription for those who only want to use the software on one device. We are planning to offer a “pay-as-you-go” model.

double down

Cosmic also announced today that it has raised funds. $3.7 million in seed round of funding led by Creandum. Alven, Kima Ventures, Betaworks, Replit and Quizlet founders participated.

Hanel Baveja, a principal at Creandum, told TechCrunch that the company decided to invest in Kosmik because Kosmik is a bit like Notion or Miro, and the potential to build something that completely changes an organization’s workflow. He said this is because there is. But Babeja said that like any consumer tool in this space, the startup needs to create immediate value for users.

“The time to value for any product must be immediate. Especially if it aims to become a commodity, you only have one chance to attract users,” Babeja said. “Finding a balance between a rich feature set and ease of deployment is certainly one of the challenges and is an area where the Kosmik team continues to strive.”

This cash injection is also timely given the product iterations in the pipeline.As expected of Cosmic is consolidating its codebases and Kosmik 2.0 will bring feature parity. The new app will be web-based and the desktop client will essentially be a wrapper app.

Additionally, the new version includes features such as multiplayer collaboration and AI-powered automatic tagging of items in images.

Ronnie said that in multiplayer mode, you can collaborate with someone on just a portion of the canvas using “cards,” which are like folders with objects dropped into them, rather than sharing the entire board. .

Kosmik opened to users in March and currently claims to have around 8,000 daily users, but the product can work completely offline, making it difficult to determine exactly how many people are actively using it. said it was difficult.

It’s worth noting that Kosmik isn’t the only startup active in the personal whiteboard space. Berlin-based Deta is building a new cloud OS for this problem and solution. sanity Building a social knowledge sharing platform. These companies must compete in some way to capture users’ attention and persuade them to try new paradigms for acquiring knowledge.

Source: techcrunch.com