Skip to main content

Posts

An Evolutionarily-conserved Wnt3/β-catenin/Sp5 Feedback Loop Restricts Head Organizer Activity in Hydra

Penelitian - The freshwater Hydra is able to regenerate any part of its body to rebuild an entire individual. The small polyp has a development organizer center located at the head level, and another located in the foot.

The head organizer performs two opposite activities, one activating, which causes the head to differentiate, and the other inhibiting, which prevents the formation of supernumerary heads.


Researchers at the University of Geneva (UNIGE), Switzerland, have discovered the identity of the inhibitor, a protein called Sp5, and deciphered the dialogue between these two antagonistic activities, which helps maintain a single-headed adult body and organize an appropriate regenerative response.

Published in the Nature Communications, their study points out that this mechanism has been conserved throughout evolution, both in Hydra and in humans. Sp5 could therefore be an excellent candidate to be tested as an inhibitor of human tumors in which the activator pathway is the motor o…
Recent posts

Learning Ambidextrous Robot Grasping Policies

Penelitian - E-commerce continues to expand and achieved new levels during the recent holiday season. To rapidly fulfill the enormous volume and variety of orders, companies such as Amazon, Walmart, and Alibaba are investing heavily in new warehouses.

To address the shortage of workers, many companies are considering robots. However, reliably grasping a diverse range of products remains a Grand Challenge for robotics.


In a paper published Wednesday, Jan. 16, in Science Robotics, engineers at the University of California, Berkeley present a novel, "ambidextrous" approach to grasping a diverse range of object shapes without training.

"Any single gripper cannot handle all objects. For example, a suction cup cannot create a seal on porous objects such as clothing and parallel-jaw grippers may not be able to reach both sides of some tools and toys," said Jeff Mahler of the UC Berkeley.

Mahler works in the lab of Ken Goldberg, a UC Berkeley professor with joint appointme…

Body Camera Footage Leads to Lower Judgments of Intent than Dash Camera Footage

Penelitian - A team of researchers at Northwestern University has found that people serving as mock jurors tend to view police officer intent differently when viewing events captured using body cams versus dash cams.

In their paper published in Proceedings of the National Academy of Sciences, the group describes their study, in which they used volunteers as stand-ins for jurors watching either real or staged police action video events.


The use of body cams by police officers has become routine in the U.S.—their use is based on the idea that video footage of encounters between police and the public will make police officers more accountable for their actions.

Many jurisdictions have passed laws requiring their use after multiple instances in which questions were raised about the intent of the officers involved and their subsequent actions, particularly in cases when the victim was unarmed.

In this new effort, the researchers have sought to determine if the existence of body cam video d…

Neuroinspired Unsupervised Learning and Pruning with Subquantum CBRAM Arrays

Penelitian - A team led by the University of California San Diego has developed a neuroinspired hardware-software co-design approach that could make neural network training more energy-efficient and faster.

Their work could one day make it possible to train neural networks on low-power devices such as smartphones, laptops and embedded devices. The advance is described in a paper published recently in Nature Communications.


Training neural networks to perform tasks like recognize objects, navigate self-driving cars or play games eats up a lot of computing power and time. Large computers with hundreds to thousands of processors are typically required to learn these tasks, and training times can take anywhere from weeks to months.

That's because doing these computations involves transferring data back and forth between two separate units--the memory and the processor--and this consumes most of the energy and time during neural network training, said senior author Duygu Kuzum, a profe…

Reversible Conductivity Recovery of Highly Sensitive Flexible Devices by Water Vapor

Penelitian - Wearable electronic devices are susceptible to degradation or fatigue fracture, but now the aged electrodes of the devices can be healed by simple water vapor treatment.

A group of international researchers led by Lifeng Cui from Dongguan University of Technology, China designs repairable microfiber-based network electrodes with high conductivity, high transparency and ultra-flexibility.


The electrodes consist of polycaprolactone microfibers as healing agents and a thin conducting layer coating such as gold. The electrodes can recover the conductivity and mechanical strength after tensile failure or even cutting, which can be attributed to the adhesion and capillary force at the interface of gold and polymer.

Upon embedding in PDMS elastomer, the electrodes show excellent durability of up to 1000 cycles and can be used in wearable pressure and strain sensing devices.



Journal : Yuting Wang et al. Reversible conductivity recovery of highly sensitive flexible devices by water…

Eye Blinks Are Perceived as Communicative Signals in Human Face-to-face Interaction

Penelitian - Blinking may feel like an unconscious activity, but new research by Paul Hömke and colleagues at the Max Planck Institute for Psycholinguistics, suggests that humans unknowingly perceive eye blinks as nonverbal cues when engaging in conversation.

Humans blink about 13,500 times a day -- much more frequently than is necessary for lubricating the eyeballs. Additionally, studies have shown that blinks often occur at natural pauses in conversation. Hömke wondered whether a movement as tiny and subliminal as blinking could act as conversational feedback, just like nodding one's head.


To test this idea, the researchers developed a new, virtual reality-based experimental set-up where humans talk with an avatar that acts as a "virtual listener." Volunteers answered questions such as "How was your weekend?" while researchers controlled the avatar's nonverbal responses, using short and long blinks that each lasted less than a second.

The experiments show…

Full-field Interferometric Imaging of Propagating Action Potentials

Penelitian - A promising non-invasive technique for measuring electrical activity in neurons and other cells works by observing how cells deform in response to changes in their electric potential. Existing methods for analyzing cells’ electrical activity are invasive and may affect natural cell behavior.

Now, Tong Ling and co-workers from Daniel Palanker’s lab at Stanford University in the US demonstrated a method that monitors changes in cell shapes during electrical spikes – or ‘action potentials’ - using quantitative phase microscopy.


Action potential occurs when the negatively-charged cell interior depolarizes due to a stimulus, triggering a rapid voltage change across the cell membrane. Ling’s team demonstrated that cells deform in response to these relatively large (0.1 V) voltage shifts, revealing exactly when action potentials occur. Their technique may facilitate non-invasive analysis of neuronal networks and other cellular activities.



Journal : Tong Ling et al. Full-field int…

Mechanical Loading of Desmosomes Depends on the Magnitude and Orientation of External Stress

Penelitian - Cell biologists at the University of Münster have developed a new method for measuring how mechanical forces in cells are processed. The results have been published in the journal Nature Communications.

The skin is our largest organ, and, among other things, it provides protection against mechanical impacts. To ensure this protection, skin cells have to be connected to one another especially closely. Exactly how this mechanical stability is provided on the molecular level was unclear for a long time.


Researchers are now able to demonstrate how mechanical stress on specialized adhesion points, so-called desmosomes, is processed. They designed a mini-measuring device, which can determine forces along individual components of the desmosomes. They show how mechanical forces propagate along these structures.

Our skin acts as a protective shield against external influences and has to withstand very different stresses. It has to be able to stretch but must not tear when exposed …