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Archive for the ‘biological’ category: Page 69

Jan 7, 2023

Interaction-free, single-pixel quantum imaging with undetected photons

Posted by in categories: biological, computing, quantum physics

Over the past few decades, several imaging protocols based on quantum technologies have been realized1,2, which have expanded the application capabilities of optical imaging. These include ghost imaging (GI)3,4, quantum imaging with undetected photons (QIUP)5, and interaction-free measurements (IFMs)6,7. The quantum GI scheme relies on the spatial correlations of entangled photon pairs and requires two-photon coincident measurements. Furthermore, ghost imaging can also be realized with classical intensity-fluctuation correlations8. Later, various single-pixel imaging (SPI) protocols were proposed9,10,11,12,13, where the spatial correlations are not between two photons but between one photon and a programmable mask held in a spatial light modulator (SLM).

In contrast to modern digital cameras employing array sensors to capture images, SPI use a sequence of masks to interrogate the scene along with the correlated intensity measurements by a single-pixel detector. The spatially resolved masks are usually generated by computer and displayed by SLM. Combined with compressive techniques10, the number of sampling measurements is fewer than the total number of pixels in the image. Thereby, SPI can reduce the data processing requirement, and shows potential capability for high dimensional sensing12. On the other hand, the modern single-photon detector is featured by improved detection efficiency, lower dark counts, and faster timing response14. Such enhancements have significance to applying SPI into weak signal detection scenarios, such as scattering medium imaging or long-range 3D imaging11.

The QIUP scheme is based on induced coherence (IC), which was first proposed by Zou, Wang, and Mandel15. They used two photon sources to generate photon pairs. By overlapping path of two sources for one photon (idler)15,16,17 and establishing the so-called path identity18,19, there is no information about the origin of the other photon (signal). Thus, the signal photon is in the superposition state of being created in either of the sources. The phase and transmissivity of the idler photon are encoded in the interference of the signal photon. Inserting one object onto the idler path between two sources, one can obtain images exclusively with the signal photons which have no interaction with the object5. In contrast to GI, QIUP does not involve the detection of the photon illuminating the object or any coincidence measurement. This is an advantage of QIUP, as the wavelength of the detected photon can be chosen independently from that of the photon interacting with the object5. This concept was further explored in infrared (IR) spectroscopy20, optical coherence tomography21,22, mid-IR imaging23,24,25, terahertz (THz) sensing26, biological microscopy27, and holography28. Recently, the related SU(1,1) interferometer has been investigated and employed in quantum-enhanced metrology29,30,31,32,33.

Jan 6, 2023

The top five telomere myths

Posted by in categories: biological, life extension

Let me assure you that my intent in this article is not to refute any empirical data or established theories about telomeres. Instead, I will explain why I believe that the historical course of scientific discoveries and an outdated paradigm about the biological cause of aging have led to the use of inaccurate language in describing the roles and functions of telomeres.

Jan 5, 2023

Dr. Stuart Minchin, Ph.D. — Sustainable Pacific Development Through Science, Knowledge & Innovation

Posted by in categories: biological, chemistry, education, food, health, science, sustainability

Is the Director General of the Pacific Community (SPC — https://www.spc.int/about-us/director-general) which is the largest intergovernmental organization in the Pacific and serves as a science and technology for development organization owned by the 26 Member countries and territories in the Pacific region.

SPC’s 650 member staff deliver services and scientific advice to the Pacific across the domains of Oceans, Islands and People, and has deep expertise in food security, water resources, fisheries, disasters, energy, maritime, health, statistics, education, human rights, social development and natural resources.

Continue reading “Dr. Stuart Minchin, Ph.D. — Sustainable Pacific Development Through Science, Knowledge & Innovation” »

Jan 5, 2023

Shrinking hydrogels enlarge nanofabrication options

Posted by in categories: biological, nanotechnology

Researchers from Carnegie Mellon University and the Chinese University of Hong Kong have developed a strategy for creating ultrahigh-resolution, complex 3D nanostructures out of various materials.

Carnegie Mellon University’s Yongxin (Leon) Zhao and the Chinese University of Hong Kong’s Shih-Chi Chen have a big idea for manufacturing nanodevices.

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Jan 3, 2023

Prof. IRINA RISH — AGI, Complex Systems, Transhumanism #NeurIPS

Posted by in categories: biological, chemistry, ethics, information science, mathematics, neuroscience, robotics/AI, transhumanism

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Irina Rish is a world-renowned professor of computer science and operations research at the Université de Montréal and a core member of the prestigious Mila organisation. She is a Canada CIFAR AI Chair and the Canadian Excellence Research Chair in Autonomous AI. Irina holds an MSc and PhD in AI from the University of California, Irvine as well as an MSc in Applied Mathematics from the Moscow Gubkin Institute. Her research focuses on machine learning, neural data analysis, and neuroscience-inspired AI. In particular, she is exploring continual lifelong learning, optimization algorithms for deep neural networks, sparse modelling and probabilistic inference, dialog generation, biologically plausible reinforcement learning, and dynamical systems approaches to brain imaging analysis. Prof. Rish holds 64 patents, has published over 80 research papers, several book chapters, three edited books, and a monograph on Sparse Modelling. She has served as a Senior Area Chair for NeurIPS and ICML. Irina’s research is focussed on taking us closer to the holy grail of Artificial General Intelligence. She continues to push the boundaries of machine learning, continually striving to make advancements in neuroscience-inspired AI.

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Jan 1, 2023

Microscopic Animal Brought Back To Life After 24,000 Years Frozen In Siberian Permafrost

Posted by in categories: biological, chemistry, life extension

Tardigrades have competition in the realm of microscopic and incredibly sturdy beasties. Like tardigrades, Bdelloid rotifers can also survive drying, freezing, starving, and even low-oxygen conditions. Now, scientists report that they revived some of these rotifers after having been frozen in Siberian permafrost for at least 24,000 years.

The incredible observations are reported in the journal Current Biology. The researchers took samples of permafrost about 3.5 meters (11.5 feet) deep and slowly warmed the sample, which led to the resurrection of several microscopic organisms including these tiny little animals.

“Our report is the hardest proof as of today that multicellular animals could withstand tens of thousands of years in cryptobiosis, the state of almost completely arrested metabolism,” co-author Stas Malavin of the Soil Cryology Laboratory at the Institute of Physicochemical and Biological Problems in Soil Science in Pushchino, Russia, said in a statement.

Jan 1, 2023

Scientists Uncover a Gut-Brain Connection for Social Development

Posted by in categories: biological, neuroscience

To learn to socialize, zebrafish need to trust their gut.

Gut microbes encourage specialized cells to prune back extra connections in brain circuits that control social behavior, new University of Oregon research in zebrafish shows. The pruning is essential for the development of normal social behavior.

The researchers also found that these ‘social’ neurons are similar in zebrafish and mice. That suggests the findings might translate between species — and could possibly point the way to treatments for a range of neurodevelopmental conditions.

Dec 31, 2022

Why Do We Like What We Like? The Neuroscience Behind the Objects That Please Us

Posted by in categories: biological, neuroscience

Summary: Researchers say hedonic value isn’t simply a biological and psychological mechanism, it’s also vital for our survival.

Source: The Conversation.

We humans, like other cognitive systems, are sensitive to our environment. We use sensory information to guide our behavior. To be in the world.

Dec 31, 2022

Trillions of tiny, self-replicating satellites could unlock interstellar travel

Posted by in categories: biological, chemistry, genetics, satellites

Alpha Centauri, here we come.


However, while technology has indeed advanced a long way since the 1940s, it still seems like we are still a long way from having a fully functional von Neumann machine. That is unless you turn to biology. Even simple biological systems can perform absolutely mind-blowing feats of chemical synthesis. And there are few people in the world today who know that better than George Church. The geneticist from Harvard has been at the forefront of a revolution in the biological sciences over the last 30 years. Now, he’s published a new paper in Astrobiology musing about how biology could aid in creating a pico-scale system that could potentially explore other star systems at next to no cost.

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Dec 31, 2022

New research reveals how the brain holds information in mind

Posted by in categories: biological, computing, neuroscience

MIT neuroscientists have published a key new insight on how working memory functions, in a study published in PLOS Computational Biology.

The researchers at The Picower Institute for Learning and Memory compared measurements of brain cell activity in an animal performing a working memory task with the output of various computer models representing two theories on the underlying mechanism for holding information in mind.

The results favored the newer theory that a network of neurons stores information by making short-lived changes in the connections, or synapses, between them, rather than the traditional theory that memory is maintained by neurons remaining persistently active.

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