Programming microbes to treat superbug infection

Superbug infection is one of the greatest public health threat with grave implications across all levels of society. Towards a new solution to combat infection by multi-drug resistant bacteria, this thesis presents an engineering framework and genetic tools applied to repurpose commensal bacteria into “micro-robots” for the treatment of superbug infection. Specifically, a prototype of designer probiotic was developed using the human commensal bacteria Escherichia coli. The engineered commensal was reprogrammed with user-specified functions to sense superbug, produced pathogen-specific killing molecules and released the killing molecules via a lytic mechanism. The engineered commensal was effective in suppressing ~99% of planktonic Pseudomonas and preventing ~ 90% of biofilm formation. To enhance the sensing capabilities of engineered commensal, genetic interfaces comprising orthogonal AND & OR logic devices were developed to mediate the integration and interpretation of binary input signals. Finally, AND, OR and NOT logic gates were networked to generate a myriad of cellular logic operations including half adder and half subtractor. The creation of half adder logic represents a significant advancement of engineering human commensal to be biological equivalent of microprocessor chips in programmable computer with the ability to process input signals into diversified actions. Importantly, this thesis provides exemplary case studies to the attenuation of cellular and genetic context dependent effects through principles elucidated herein, thereby advancing our capability to engineer commensal bacteria.Open Acces

Performance monitoring of Kuantan-Gambang (FR 2) and Gambang toll plaza (FR 222)-Muadzam (FR 12) cross junction using Malaysian intelligent traffic system (MITS)

Nowadays, traffic monitoring using Supervisory Control And Data Acquisition (SCADA) system is more efficient and accurate. The objective of this project is to come up as a user manual for the engineers and also the users. There are so many engineers that are still using manual counting and also lack of know how to use SCADA system as a traffic monitoring tools in real life. In this project will show the step by step of collecting the traffic data using the Malaysian Intelligent Traffic System (MITS), it is one of the SCADA system. There are so many different types of data, such as traffic volume, vehicle classification, reporting errors, setting time, traffic queueing, green time, junction time setting and also live view of the junction. MITS could be a great SCADA system for traffic monitoring in Malaysia and also helps the engineers for collecting information and data in the future

Engineering microbes to sense and eradicate Pseudomonas aeruginosa, a human pathogen

A synthetic genetic system is designed and characterized that allows Escherichia coli to sense and eradicate Pseudomonas aeruginosa, providing a novel antimicrobial strategy that could potentially be applied to fighting infectious pathogens

Interethnic differences in neuroimaging markers and cognition in Asians, a population-based study

We examined interethnic differences in the prevalence of neuroimaging markers of cerebrovascular and neurodegenerative disease in 3 major Asian ethnicities (Chinese, Malays, and Indians), as well as their role in cognitive impairment. 3T MRI brain scans were acquired from 792 subjects (mean age: 70.0 ± 6.5years, 52.1% women) in the multi-ethnic Epidemiology of Dementia In Singapore study. Markers of cerebrovascular disease and neurodegeneration were identified. Cognitive performance was evaluated using Mini Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), and a neuropsychological assessment. Compared to Chinese, Malays had a higher burden of intracranial stenosis (OR: 2.28. 95%CI: 1.23-4.20) and cortical atrophy (β: -0.60. 95%CI: -0.78, -0.41), while Indians had a higher burden of subcortical atrophy (β: -0.23. 95%CI: -0.40, -0.06). Moreover, Malay and Indian ethnicities were likely to be cognitively impaired (OR for Malays: 3.79. 95%CI: 2.29-6.26; OR for Indians: 2.87. 95%CI: 1.74-4.74) and showed worse performance in global cognition (β for Malays: -0.51. 95%CI: -0.66, -0.37; and Indians: -0.32. 95%CI: -0.47, -0.17). A higher burden of cerebrovascular and neurodegenerative markers were found in Malays and Indians when compared to Chinese. Further research is required to fully elucidate the factors and pathways that contribute to these observed differences

Anti-windup PI controller, SIPIC for Motor Position Control

Control system plays a major role in the industry nowadays as it simplifies workload and reduce manpower. Among all the controlled applicable field, control system is heavily used in motor speed and motor position controls. Although there are various types of controllers available in the market, PID controller remains as one of the most used controller due to its simplicity. Unfortunately, PID controller experiences windup phenomenon which affects the controller’s performance. This paper proposes a new type of anti-windup PI controller, SIPIC for motor position control application and aims to validate the performance of this controller as compared to conventional PI controller. To test the ability of the controllers, both controllers were experimented using hardware testing. The settings conditions of with and without loadings were used under two different inputs of 0° to 90° and 270° to 90°. The results obtained show that under without loadings, both controller showed favourable performances. Though, SIPIC controller slightly outperforms PI controller by having lower overshoot and shorter settling time for a wider range of gains. The rise time of both controllers are similar as it is the lowest possible rise time due to hardware limitations. Experiment results with loading condition, for both inputs and when Kp is 1 and Ki is 15, PI controller shows unstable performance by having large amount of oscillations and overshoots. The settling time was unable to be determined as the controller did not settle within the given step time. On the other hand, at the same gain, SIPIC controller still shows acceptable performance. This shows that SIPIC controller is more favourable by having better stable performance for a wider range of gains while PI controller needs to be finely tuned to a specific gain to obtain desired results.

Anti-windup PI controller, SIPIC For Motor Position Control

Control system plays a major role in the industry nowadays as it simplifies workload and reduce manpower. Among all the controlled applicable field, control system is heavily used in motor speed and motor position controls. Although there are various types of controllers available in the market, PID controller remains as one of the most used controller due to its simplicity. Unfortunately, PID controller experiences windup phenomenon which affects the controller’s performance. This paper proposes a new type of anti-windup PI controller, SIPIC for motor position control application and aims to validate the performance of this controller as compared to conventional PI controller. To test the ability of the controllers, both controllers were experimented using hardware testing. The settings conditions of with and without loadings were used under two different inputs of 0° to 90° and 270° to 90°. The results obtained show that under without loadings, both controller showed favourable performances. Though, SIPIC controller slightly outperforms PI controller by having lower overshoot and shorter settling time for a wider range of gains. The rise time of both controllers are similar as it is the lowest possible rise time due to hardware limitations. Experiment results with loading condition, for both inputs and when Kp is 1 and Ki is 15, PI controller shows unstable performance by having large amount of oscillations and overshoots. The settling time was unable to be determined as the controller did not settle within the given step time. On the other hand, at the same gain, SIPIC controller still shows acceptable performance. This shows that SIPIC controller is more favourable by having better stable performance for a wider range of gains while PI controller needs to be finely tuned to a specific gain to obtain desired results.

Evaluation of SIPIC01 and SIPIC02 on Motor Speed Control

Due to its simplicity, Proportional-Integral (PI) controller still remains as the widely used controller for motor speed control system. However, PI controller exhibits windup phenomenon when the motor operates in a saturated state, which may cause degradation to the control system. In order to overcome the windup phenomenon, many researches have introduced various types of anti-windup methods such as the Conditioning Technique (CI), Tracking Back Calculation (TBC), Integral State Prediction (ISP), Steady-state Integral Proportional Integral Controller-01 (SIPIC01) and Steady-state Integral Proportional Integral Controller-02 (SIPIC02). These are anti-windup techniques with integral control switching mechanism, coupling of proportional gain, kp, and integral gain, ki. Due to the coupled kp and ki, tuning motor performance is a difficult task with short settling time without experiencing overshoot. SIPIC01 and SIPIC02 are robust anti-windup methods without a switching mechanism and exhibit decoupling feature. SIPIC01 and SIPIC02 have shown better dynamic performance compared to CI, TBC and ISP. However, SIPIC01 has not been compared to SIPIC02 in terms of their decoupling effect flexibility and dynamic performance. The decoupling effect was verified using MATLAB simulation, while the performance analysis was verified through hardware simulation and testing by using Scilab. The results obtained from the simulation showed that both SIPIC01 and SIPIC02 consist of decoupling features that allow a performance with coexistence of zero or minimum overshoot with short settling time. However, SIPIC02 consists of longer rise and settling time as compared to SIPIC01. Therefore, it can be concluded that SIPIC01 is better than SIPIC02 in term of dynamic performance

Evaluation of SIPIC01 and SIPIC02 on Motor Speed Control

Due to its simplicity, Proportional-Integral (PI) controller still remains as the widely used controller for motor speed control system. However, PI controller exhibits windup phenomenon when the motor operates in a saturated state, which may cause degradation to the control system. In order to overcome the windup phenomenon, many researches have introduced various types of anti-windup methods such as the Conditioning Technique (CI), Tracking Back Calculation (TBC), Integral State Prediction (ISP), Steady-state Integral Proportional Integral Controller-01 (SIPIC01) and Steady-state Integral Proportional Integral Controller-02 (SIPIC02). These are anti-windup techniques with integral control switching mechanism, coupling of proportional gain, kp, and integral gain, ki. Due to the coupled kp and ki, tuning motor performance is a difficult task with short settling time without experiencing overshoot. SIPIC01 and SIPIC02 are robust anti-windup methods without a switching mechanism and exhibit decoupling feature. SIPIC01 and SIPIC02 have shown better dynamic performance compared to CI, TBC and ISP. However, SIPIC01 has not been compared to SIPIC02 in terms of their decoupling effect flexibility and dynamic performance. The decoupling effect was verified using MATLAB simulation, while the performance analysis was verified through hardware simulation and testing by using Scilab. The results obtained from the simulation showed that both SIPIC01 and SIPIC02 consist of decoupling features that allow a performance with coexistence of zero or minimum overshoot with short settling time. However, SIPIC02 consists of longer rise and settling time as compared to SIPIC01. Therefore, it can be concluded that SIPIC01 is better than SIPIC02 in term of dynamic performance

Extended Dijkstra Algorithm in Path Planning for Vision Based Patrol Robot

In the recent years, Global positioning system (GPS) has worked with Global Navigation Satellite System (GNSS) to provide higher accuracy quality of locating a device. However, this localization service doesn't reach indoor facility. For an indoor type vision based patrol robot, the problem would encounter in path planning that allows the patrol robot to find the optimum path to reach the destination and return to home position. In this paper, an extended Dijkstra algorithm is proposed for path planning to the vision based patrol robot for surveillance purposes. This design used visual type sensor, range sensor and IMU system to instantaneously update the map data according to the current path of the vision robot and apply the path planning feature to perform obstacle avoidance and re-routing process based on the obstacle type faced by the robot. The result shown by this approach indeed capable to complete multiple cycles of testing with positive result