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The evidence presented by Boldrini et al2 was considered resilient and convincing because the authors ensured that the samples were taken from healthy individuals using more biological parameters, such as angiogenesis and change in volume of DG, for a suitable comparison. They also employed unbiased stereology, which is the gold standard for counting number of neurons.2

The contrary results presented by the Sorrels study and Boldrini study highlight the existing ambiguity regarding the concept of neurogenesis in adult humans. Both studies employed reasonably similar immunohistological methods and included many of the same neurogenesis markers, yet contrasting results were observed. The study by Boldrini et al examined samples from humans aged 14 to 79 years, finding more than a thousand cells in each part of the DG, which was in stark contrast to what was observed by Sorrells et al, who found very few cells in the neurogenic niche of subjects in the same age range. Even if we consider that some discrepancies in numbers might arise due to the difference in counting methods (or subjective reasons), such marked and obvious disparity is perplexing. Sorrels et al justified their findings, noting the limitation that relying solely on the presence of markers might cause glial lineage cells to be identified as neuronal lineage cells. However, the authors stated that they used additional methods for confirmation, including transmission electron microscopy (TEM)-immunogold and in-situ hybridization. The relative paucity of any type of progenitor or immature cells, including glia in the neurogenic niche of DG in their study, remains unexplained.

Kempermann et al7 expressed skepticism regarding the negative findings of Sorrells et al, naming the postmortem interval, the lack of known status regarding neuropsychiatric disease or chronic ailment, and using patients with epilepsy as key factors of concern.7 Kempermann et al argued that, in severe epilepsy, destruction of the neurogenic niche is an explicit possibility, and that, in some cases, epilepsy could be the reason for the lack of neurogenesis.7 Additionally, Kempermann et al also criticized the use of 10% formalin in some of the samples due its potential to mask the expression of proteins.7 However, Sorrells et al clearly mentioned that they performed appropriate antigen retrieval for the selected sections.1 Kempermann et al7 suggested that dependence on the protein markers to denote neurogenesis could be an erroneous approach and that some of the markers, such as DCX, are known for fast degradation. Additionally, the presence of DCX-negative immature neurons and high inter-individual variation in expression of DCX in humans, which was also reflected in the data presented by Boldrini et al, are not unusual.7 The use of fluorescence markers also was presented as a caveat by Kempermann et al7 because it is prone to fade away and might give rise to false negative impression.

Scientists from the National University of Singapore (NUS) have developed a highly effective and general molecular design that enables an enhancement in radioluminescence within organometallic scintillators by more than three orders of magnitude. This enhancement harnesses X-ray-induced triplet exciton recycling within lanthanide metal complexes.

Detection of ionizing radiation is crucial in diverse fields, such as medical radiography, and astronomy. As a result, significant efforts have been dedicated to the development of luminescent materials that respond to X-rays.

However, current high-performance scintillators are almost exclusively limited to ceramic and perovskite materials, which face issues such as complex manufacturing processes, environmental toxicity, self-absorption and stability problems.

A new artificial intelligence (AI) model has just achieved human-level results on a test designed to measure “general intelligence.”

On December 20, OpenAI’s o3 system scored 85% on the ARC-AGI benchmark, well above the previous AI best score of 55% and on par with the average human score. It also scored well on a very difficult mathematics test.

Creating artificial , or AGI, is the stated goal of all the major AI research labs. At first glance, OpenAI appears to have at least made a significant step towards this goal.

Northwestern University engineers are the first to successfully demonstrate quantum teleportation over a fiber optic cable already carrying Internet traffic.

The discovery, published in the journal Optica, introduces the new possibility of combining quantum communication with existing Internet cables — greatly simplifying the infrastructure required for for advanced sensing technologies or quantum computing applications.

The company behind Oreo cookies has, by its own admission, been quietly creating new flavors using machine learning.

As the Wall Street Journal reports, Mondelez — the processed food behemoth that manufactures Oreos, Chips Ahoy, Clif Bars, and other popular snacks — has developed a new AI tool to dream up new flavors for its brands.

Used in more than 70 of the company’s products, the company says the machine learning tool is different from generative AI tools like ChatGPT and more akin to the drug discovery algorithms used by pharmaceutical companies to find and test new medications rapidly. Thus far the tool, created with the help of the software consultant Fourkind, has created products like the “Gluten Free Golden Oreo” and updated Chips Ahoy’s classic recipe, per the WSJ.

Andrew Cassy had spent his working life in a telecommunications research department until a diagnosis of Parkinson’s disease in 2010 pushed him into early retirement. Curious about his illness, which he came to think of as an engineering problem, he decided to volunteer for clinical trials.

“I had time, something of value that I could give to the process of understanding the disease and finding good treatments,” he says.

In 2024, he was accepted into a radical trial. That October, surgeons in Lund, Sweden, placed neurons that were derived from human embryonic stem (ES) cells into his brain. The hope is that they will eventually replace some of his damaged tissue.

The study is one of more than 100 clinical trials exploring the potential of stem cells to replace or supplement tissues in debilitating or life-threatening diseases, including cancer, diabetes, epilepsy, heart failure and some eye diseases. It’s a different approach from the unapproved therapies peddled by many shady clinics, which use types of stem cell that do not turn into new tissue.