The ability of “target tracking,” i.e., keeping a target object in sight, is essential for various activities and has improved in animals and machines through the evolution of life and technology, respectively. Because most sensing systems are inevitably subject to a certain degree of delay caused by information processing, many studies have addressed the challenge of overcoming this delay constraint for more accurate target tracking. At this point, studying animals’ sophisticated tracking behavior would bring a significant breakthrough against this fundamental problem.

Taking advantage of free-moving bats chasing moths as a realistic model of target tracking, a team consisting of researchers from the National Institute for Basic Biology of Japan and Doshisha University found that bats used the four key tactics and organized them effectively to track prey accurately. The team also proposed a possible operational rule enabling bats to exercise this strategy efficiently.

“This research was conducted by 3D motion analysis and computer simulations on previously recorded bat-moth interactions, where 3D trajectories and ultrasounds of bats (Rhinolophus nippon) during encounters with prey moths were observed in an experiment chamber, using two high-speed cameras and many microphones on the walls of the chamber,” explains Dr. Nozomi Nishiumi of the National Institute for Basic Biology, corresponding author of the report published in Current Biology.

The research team first demonstrated that bats simultaneously deploy the following four tactical elements:

1. Prediction of the target direction
2. Adjustment of the sensing rate
3. Adjustment of the sensing angular range
4. Stabilization of the target direction by counter maneuvers

In addition, the results from computer simulations demonstrated that the combination of the above tactics greatly and robustly improves the tracking accuracy over a wide range of the delay constraint.

The team also showed that control of those tactics can be explained by a concise rule based on the angular velocity of the target direction, which suggests that bats successfully reduce the burden of multitasking management. Summarizing these findings, the team proposed our conceptual framework for orchestrating several tactics for efficient target tracking.

“Although we used active-sensing bats as subjects, the problem of delay in target tracking and the countermeasures against it are common in various active/passive-sensing animals and devices,” explains Dr. Nishiumi.

Through the demonstration of the sophisticated strategy used by bats, their findings would provide insights into the understanding and development of a wide range of objects that engage in target tracking.

A trio of security experts at Stanford University has found that millions of people are running an infected version of Chrome web browser due to extensions installed from the Google Chrome Web Store (GCWS). Sheryl Hsu, Manda Tran and Aurore Fass have posted a paper to the arXiv preprint server describing their findings after studying thousands of extensions on GCWS.

To get the most out of web browsers, such as Google’s Chrome, users download extensions from popular extension sites. One of the most popular and well-known such sites is GCWS—it hosts extensions for the Chrome web browser that have been written by third-party programmers.

Two of the main problems with downloading and using extensions written by third parties is the uneven level of quality and the possibility of malware. In this new effort, the researchers have looked at the latter issue, and the scale of risk for people using extensions downloaded from GCWS.

The researchers took two approaches to determine how many of the thousands of extensions hosted on GCWS have what they describe as security-noteworthy extensions (SNEs)—those that violate GCWS policy or contain malware or vulnerable code.

The first involved analyzing data from past research efforts into security issues with Chrome web extensions. The second involved downloading all extensions (approximately 125,000) that were available on the site between July 2020 and February 2023 and then analyzing the code that was used when they were written, looking for telltale signs of malware infection.

They also analyzed the site’s download history and the longevity of extensions on the site.

The research team found that approximately 346 million users had downloaded a SNE from GCWS during the two-year period under study—280 million of which involved SNEs with malware. They note that Google claims that less than 1% of extensions hosted by the store have malware—the company also claims to vet all extensions hosted on the site.

The researchers also found that SNEs differ widely in how long they are available on GCWS, from months to years, and that users very seldom report an extension as being problematic.

© 2024 Science X Network