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AI Magazine

The purpose of AI Magazine is to disseminate timely and informative articles that represent the current state of the art in AI and to keep its readers posted on AAAI-related matters. The articles are selected for appeal to readers engaged in research and


AI Magazine

AI Magazine

The purpose of AI Magazine is to disseminate timely and informative articles that represent the current state of the art in AI and to keep its readers posted on AAAI-related matters. The articles are selected for appeal to readers engaged in research and


Antonio Damasio Tells Us Why Pain Is Necessary - Issue 56: Perspective

Nautilus

Following Oliver Sacks, Antonio Damasio may be the neuroscientist whose popular books have done the most to inform readers about the biological machinery in our heads, how it generates thoughts and emotions, creates a self to cling to, and a sense of transcendence to escape by. But since he published Descartes' Error in 1994, Damasio has been concerned that a central thesis in his books, that brains don't define us, has been muted by research that states how much they do. To Damasio's dismay, the view of the human brain as a computer, the command center of the body, has become lodged in popular culture. In his new book, The Strange Order of Things, Damasio, a professor of neuroscience and the director of the Brain and Creativity Institute at the University of Southern California, mounts his boldest argument yet for the egalitarian role of the brain. In "Why Your Biology Runs on Feelings," another article in this chapter of Nautilus, drawn from his new book, Damasio tells us "mind and brain influence the body proper just as much as the body proper can influence the brain and the mind.


Toward dynamic structural biology: Two decades of single-molecule Förster resonance energy transfer

Science

FRET was first identified in the 1920s by Cario, Franck, and Perrin. In the late 1940s, Förster and Oppenheimer independently formulated a quantitative theory of the energy transfer between a pair of point dipoles. Stryer and Haugland verified this theory in the late 1960s and coined the term "spectroscopic ruler" for FRET. Simultaneously, Hirschfeld, and later Moerner and Orrit, pioneered optical single-molecule detection methods leading to the first demonstration of smFRET in 1996. This breakthrough made it possible to study heterogeneous systems, dynamic processes, and transient conformational changes on the nanometer scale.


A self-assembled nanoscale robotic arm controlled by electric fields

Science

The use of dynamic, self-assembled DNA nanostructures in the context of nanorobotics requires fast and reliable actuation mechanisms. We therefore created a 55-nanometer–by–55-nanometer DNA-based molecular platform with an integrated robotic arm of length 25 nanometers, which can be extended to more than 400 nanometers and actuated with externally applied electrical fields. Precise, computer-controlled switching of the arm between arbitrary positions on the platform can be achieved within milliseconds, as demonstrated with single-pair Förster resonance energy transfer experiments and fluorescence microscopy. The arm can be used for electrically driven transport of molecules or nanoparticles over tens of nanometers, which is useful for the control of photonic and plasmonic processes. Application of piconewton forces by the robot arm is demonstrated in force-induced DNA duplex melting experiments.


How Automation Could Worsen Racial Inequality

The Atlantic

All across the world, small projects demonstrating driverless buses and shuttles are cropping up: Las Vegas, Minnesota, Austin, Bavaria, Henan Province in China, Victoria in Australia. City governments are studying their implementation, too, from Toronto to Orlando to Ohio. And last week, the Federal Transit Administration of the Department of Transportation issued a "request for comments" on the topic of "Removing Barriers to Transit-Bus Automation." The document is fully in line with the approach that federal and state regulators have taken, which has promoted the adoption of autonomous vehicle technology as quickly as possible. Because most crashes are caused by human mistakes--and those crashes kill more than 30,000 Americans per year--self-driving-car proponents believe that the machines will eventually create much, much safer roads.


The Reality of Color Is Perception - Issue 56: Perspective

Nautilus

Philosophers have a bad reputation for casting unwarranted doubt on established facts. Little could be more certain than your belief that the cloudless sky, on a summer afternoon, is blue. Yet we may wonder in earnest, is it also blue for the birds who fly up there, who have different eyes from ours? And if you take an object that shares that color--like the flag of the United Nations--and place half in shadow and half in the full sun, one side will be a darker blue. You might ask, what is the real color of the flag?


Social place-cells in the bat hippocampus

Science

Social animals have to know the spatial positions of conspecifics. However, it is unknown how the position of others is represented in the brain. We designed a spatial observational-learning task, in which an observer bat mimicked a demonstrator bat while we recorded hippocampal dorsal-CA1 neurons from the observer bat. A neuronal subpopulation represented the position of the other bat, in allocentric coordinates. About half of these "social place-cells" represented also the observer's own position--that is, were place cells.


Spatial representations of self and other in the hippocampus

Science

An animal's awareness of its location in space depends on the activity of place cells in the hippocampus. How the brain encodes the spatial position of others has not yet been identified. We investigated neuronal representations of other animals' locations in the dorsal CA1 region of the hippocampus with an observational T-maze task in which one rat was required to observe another rat's trajectory to successfully retrieve a reward. Information reflecting the spatial location of both the self and the other was jointly and discretely encoded by CA1 pyramidal cells in the observer rat. A subset of CA1 pyramidal cells exhibited spatial receptive fields that were identical for the self and the other.


Taming the monsters of tomorrow

Science

In Mary Shelley's novel, the scientist Victor Frankenstein fears that creating a female companion to his unhappy monster could lead to a "race of devils" that could drive humanity extinct. Today, some scientists worry about scientific advances in the real world that could kill all of humanity, or at least end civilization as we know it. Some two dozen researchers at three academic centers are studying these "existential risks"--including labmade viruses, armies of nanobots, and artificial intelligence--and what can be done about them. But critics say their scenarios are far-fetched and distract from real existential dangers, including climate change and nuclear war.