Science 382, 1031–1035 (2023). DOI:10.1126/science.abo0233
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Astronomers have found a massive planet orbiting a small, cool star, and planet formation theories struggle to explain its existence.
More stable clocks could measure quantum phenomena, including the presence of dark matter.
The practice of keeping time relies on stable oscillations. In grandfather clocks, the length of a second is marked by a single swing of the pendulum. In digital watches, the vibrations of a quartz crystal mark much smaller fractions of time. And in atomic clocks, the world’s state-of-the-art timekeepers, the oscillations of a laser beam stimulate atoms to vibrate at 9.2 billion times per second. These smallest, most stable divisions of time set the timing for today’s satellite communications, GPS systems, and financial markets.
A clock’s stability depends on the noise in its environment. A slight wind can throw a pendulum’s swing out of sync. And heat can disrupt the oscillations of atoms in an atomic clock. Eliminating such environmental effects can improve a clock’s precision. But only by so much.
The field of supercapacitors consistently focuses on research and challenges to improve energy efficiency, capacitance, flexibility, and stability. Low-cost laser-induced graphene (LIG) offers a promising alternative to commercially available graphene for next-generation wearable and portable devices, thanks to its remarkable specific surface area, excellent mechanical flexibility, and exceptional electrical properties. We report on the development of LIG-based flexible supercapacitors with optimized geometries, which demonstrate high capacitance and energy density while maintaining flexibility and stability. Three-dimensional porous graphene films were synthesized, and devices with optimized parameters were fabricated and tested. One type of device utilized LIG, while two other types were fabricated on LIG by coating multi-walled carbon nanotubes (MWCNT) at varying concentrations.
Monolithic 3D integration of electronics based on fully 2D materials is demonstrated in the performance of artificial intelligence tasks.
An international team of researchers has used time-resolved ultrafast crystallography to follow the progress of DNA repair by a photolyase enzyme. The work is ‘the first structural characterisation of a full enzyme reaction cycle,’ says Manuel Maestre-Reyna, who led the research.
Photolyases repair DNA damage caused by ultraviolet light in bacteria, fungi, plants and some animals including marsupials. Humans and other mammals don’t contain these enzymes, but we too incur light-induced damage. One common outcome is the formation of cyclobutane pyrimidine dimers (CPDs), where two adjacent pyrimidine bases (thymine or cytosine) fuse together via a four-membered cyclobutane ring. ‘CPD formation is the main cause of skin cancer, and sunburnt skin always contains CPD lesions’, says Maestre-Reyna, a biochemist at the Institute of Biological Chemistry in Taipei, Taiwan.
A new study, published in PLOS ONE, has uncovered a remarkable connection between individuals’ musical preferences and their moral values, shedding new light on the profound influence that music can have on our moral compass.
The research, conducted by a team of scientists at Queen Mary University of London and ISI Foundation in Turin, Italy, employed machine learning techniques to analyze the lyrics and audio features of individuals’ favorite songs, revealing a complex interplay between music and morality.
“Our study provides compelling evidence that music preferences can serve as a window into an individual’s moral values,” stated Dr. Charalampos Saitis, one of the senior authors of the study and Lecturer in Digital Music Processing at Queen Mary University of London’s School of Electronic Engineering and Computer Science.
If we lived in a cosmic area with below average density, it would explain recent contradictory measurements of the universe’s expansion.
BMIs using intracortical electrodes, such as Utah arrays, are particularly adept at sensing fast changing (millisecond-scale) neural activity from spatially localized regions (1 cm) during behavior or stimulation that is correlated to activity in such spatially specific regions, for example, M1 for motor and V1 for vision. Intracortical electrodes, however, struggle to track individual neurons over longer periods of time, for example, between subsequent recording sessions15,16. Consequently, decoders are typically retrained every day15. A similar neural population identification problem is also present with an ultrasound device, including from shifts in the field of view between experiment sessions. In the current study, we demonstrated an alignment method that stabilizes image-based BMIs across more than a month and decodes from the same neurovascular populations with minimal, if any, retraining. This is a critical development that enables easy alignment of a previous days’ models to a new day’s data and allows decoding to begin with minimal to no new training data. Much effort has focused on ways to recalibrate intracortical BMIs across days that do not require extensive new data18,19,20,21,22,23. Most of these methods require identification of manifolds and/or latent dynamical parameters and collecting new neural and behavioral data to align to these manifolds/parameters. These techniques are, to date, tailored to each research group’s specific applications with varying requirements, such as hyperparameter tuning of the model23 or a consistent temporal structure of data22. They are also susceptible to changes in function in addition to anatomy. For example, ‘out-of-manifold’ learning/plasticity alters the manifold24 in ways that many alignment techniques struggle to address. Finally, some of the algorithms are computationally expensive and/or difficult to implement in online use22.
Contrasting these manifold-based methods, our decoder alignment algorithm leverages the intrinsic spatial resolution and field of view provided by fUS neuroimaging to perform decoder stabilization in a way that is intuitive, repeatable and performant. We used a single fUS frame (∼ 500 ms) to generate an image of the current session’s anatomy and aligned a previous session’s field of view to this single image. Notably, this did not require any additional behavior for the alignment. Because we only relied upon the anatomy, our decoder alignment is robust, can use any off-the-shelf alignment tool and is a valid technique so long as the anatomy and mesoscopic encoding of relevant variables do not change drastically between sessions.
It remains an open question as to how much the precise positioning of the ultrasound transducer during each session matters for decoder performance, especially out-of-plane shifts or rotations. In these current experiments, we used linear decoders that assumed a given image pixel is the same brain voxel across all aligned data sessions. To minimize disruptions to this pixel–voxel relationship, we performed image alignment within the 2D plane. As we could only image a 2D recording plane, we did not correct for any out-of-plane brain shifts between sessions that would have disrupted the pixel–voxel mapping assumption. Future fUS-BMI decoders may benefit from three-dimensional (3D) models of the neurovasculature, such as registering the 2D field of view to a 3D volume25,26,27 to better maintain a consistent pixel–voxel mapping.
