scholarly journals Real time genetic compensation operationally defines the dynamic demands of feedback control

2018 ◽  
Author(s):  
Patrick Harrigan ◽  
Hiten D. Madhani ◽  
Hana El-Samad

SUMMARYBiological signaling networks use feedback control to dynamically adjust their operation in real time. Traditional static genetic methods such as gene knockouts or rescue experiments often can identify the existence of feedback interactions, yet are unable to determine what feedback dynamics are required. Here, we implement a new strategy, closed loop optogenetic compensation (CLOC), to address this problem. Using a custom-built hardware and software infrastructure, CLOC monitors in real time the output of a pathway deleted for a feedback regulator. A minimal model uses these measurements to calculate and deliver—on the fly—an optogenetically-enabled transcriptional input designed to compensate for the effects of the feedback deletion. Application of CLOC to the yeast pheromone response pathway revealed surprisingly distinct dynamic requirements for three well-studied feedback regulators. CLOC, a marriage of control theory and traditional genetics, presents a broadly applicable methodology for defining the dynamic function of biological feedback regulators.

Cell ◽  
2018 ◽  
Vol 175 (3) ◽  
pp. 877-886.e10 ◽  
Author(s):  
Patrick Harrigan ◽  
Hiten D. Madhani ◽  
Hana El-Samad

2020 ◽  
Vol 5 (6) ◽  
pp. 1156-1162
Author(s):  
Anirudh Gautam ◽  
Jason A. Brant ◽  
Michael J. Ruckenstein ◽  
Steven J. Eliades

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 3955
Author(s):  
Jung-Cheng Yang ◽  
Chun-Jung Lin ◽  
Bing-Yuan You ◽  
Yin-Long Yan ◽  
Teng-Hu Cheng

Most UAVs rely on GPS for localization in an outdoor environment. However, in GPS-denied environment, other sources of localization are required for UAVs to conduct feedback control and navigation. LiDAR has been used for indoor localization, but the sampling rate is usually too low for feedback control of UAVs. To compensate this drawback, IMU sensors are usually fused to generate high-frequency odometry, with only few extra computation resources. To achieve this goal, a real-time LiDAR inertial odometer system (RTLIO) is developed in this work to generate high-precision and high-frequency odometry for the feedback control of UAVs in an indoor environment, and this is achieved by solving cost functions that consist of the LiDAR and IMU residuals. Compared to the traditional LIO approach, the initialization process of the developed RTLIO can be achieved, even when the device is stationary. To further reduce the accumulated pose errors, loop closure and pose-graph optimization are also developed in RTLIO. To demonstrate the efficacy of the developed RTLIO, experiments with long-range trajectory are conducted, and the results indicate that the RTLIO can outperform LIO with a smaller drift. Experiments with odometry benchmark dataset (i.e., KITTI) are also conducted to compare the performance with other methods, and the results show that the RTLIO can outperform ALOAM and LOAM in terms of exhibiting a smaller time delay and greater position accuracy.


2021 ◽  
Vol 165 ◽  
pp. 112218
Author(s):  
Rohit Kumar ◽  
Pramila Gautam ◽  
Shivam Gupta ◽  
R.L. Tanna ◽  
Praveenlal Edappala ◽  
...  

2020 ◽  
Vol 53 (2) ◽  
pp. 8519-8524
Author(s):  
G. Hassan ◽  
A. Chemori ◽  
L. Chikh ◽  
P.E. Hervé ◽  
M. El Rafei ◽  
...  

2017 ◽  
Vol 53 (68) ◽  
pp. 9470-9473 ◽  
Author(s):  
Krishna Kalyani Behara ◽  
Y. Rajesh ◽  
Yarra Venkatesh ◽  
Bhaskar Rao Pinninti ◽  
Mahitosh Mandal ◽  
...  

We report a new strategy, viz. cascade photocaging, for protecting diethylamine diazeniumdiolate (O2-position), a light sensitive molecule.


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