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This article investigates the decentralized formation tracking problem for complex multiagent systems in finite settling time, subjected to output constraints and external disturbances. The barrier Lyapunov function is used to constrain the output of each agent. Therefore, starting inside a closed boundary, the agents are guaranteed to remain inside it for all future time. Under directed communication topology, decentralized time-varying formation tracking is achieved in finite time. Furthermore, in the proposed work, the linear sliding manifold is employed to mitigate the singularity problem that occurs in the conventional robust finite-time methods, i.e., terminal sliding mode-based control schemes. The stability properties of the proposed framework are established through the Lyapunov method which not only ensures the finite-time formation tracking of nonlinear multiagent systems under directed communication but also guarantees that for all time the agents remain inside a closed boundary if they are initially inside it. Consequently, the uniqueness of this article is that it presents a novel formation tracking control framework for multiagent systems that simultaneously considers three performance metrics of robustness, finite-time convergence, and output constraints while mitigating the singularity problem. The proposed topology is validated by implementing the numerical examples in MATLAB/SIMULINK. [ABSTRACT FROM AUTHOR]

In this paper, we propose a methodology for implementing an output feedback control (OFC) strategy for a two-time-scale nonlinear system. A permanent-magnet DC motor model is utilized. We estimated the states using a high-gain observer for a two-time-scale nonlinear system. The results demonstrate the robustness and efficacy of the suggested OFC technique. Furthermore, the output feedback control approach exhibits robustness to parametric uncertainties, thereby making it feasible for practical implementation in a two-time-scale nonlinear system. [ABSTRACT FROM AUTHOR]

OBJECTIVE OF STUDY: To determine if two punctures in fine needle aspiration biopsies are sufficient for cytological analysis of thyroid nodules. MATERIALS AND METHODS: A cross-sectional study was carried out with the emphasis towards a diagnosis. The sample size for the study was taken conveniently form a total of 172 patients who reported at the healthcare facility for ultrasound guided FNAB. The study was carried out for a period of 1 year and 8 months. For the procedure to be carried out an aspiration puncture technique was used with a gauge size of 22. Results of the biopsy were entered into SPSS version 19.0. Continuous variables were reported in the form of mean and standard deviation while categorical variables were reported in the form of frequency and percentages. RESULTS: The mean age of the study participants was 44 ± 13.4 years. Out of the 172 patients, 65 (75.6%) were women. With the utilization of two punctures, the correct analysis was obtained for 97.6% of the patients. The most commonly reported cytological finding was of Nodular goiter (41.9%) followed by Cystic Colloid Goiter (18.6%). CONCLUSION: The study concludes that administration of two fine needle aspiration punctures allows correct analysis and identification of thyroid nodules in 97.6% of the cases. This study thus suggests that multiple punctures are not required for a safe and appropriate diagnosis of thyroid nodules. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To evaluate different features of ganglion cyst by using ultrasound and its exact localization in relation to adjacent tendons, ligaments, arteries and joints. METHODOLOGY: A cross sectional study was conducted in Department of Radiology, Dallah Hospital, Riyadh. Study duration was 1 year (1st August 2016 to 31st July 2017). A sample size of 89 patients was achieved using simple random sampling (Lottery Method). Patients diagnosed with ganglion cysts based on USG findings using MRI as gold standard, both genders and age greater than 18 years were included. Superficial ultrasound with high frequency transducer was performed in all patients, probe frequency ranging from 12 to 18 MHz. Ethical approval was taken from ethical review board of Dallah Hospital and consent was taken from patients. Data was analyzed using SPSS Software version 20. Chi-square test was applied for observing association between different variables. RESULTS: Total 89 patients were included in study. There were 25 (28%) males and 64 (72%) females. Mean age of patients was 43.6 ± 14.8 SD. Most common location of ganglion cyst in relation to joint, ligament, tendon & artery was anterior to scapholunate ligament 9 (10.1%) and around scapholunate joint dorsal aspect of wrist 18 (20.1%), volar surface 10 (11.2%) and medial to radial artery 2 (1.1%) respectively. A significant association was reported between limb & anatomical side (p=0.03), margins & echogenicity (p=0.03). CONCLUSION: Ultrasound is the primary imaging modality for evaluation and localization of ganglion cysts. Majority of ganglion cysts appear anechoic, have smooth margins and demonstrate clear internal content with no septation or echoes. Moreover, ganglion cysts occur most commonly adjacent to scapholunate ligament on dorsal surface of wrist. Although diagnosis of ganglion cysts is rarely a problem, we believe ultrasound allows accurate evaluation of ganglion cysts even as small as 2 mm, which are difficult to appreciate clinically or on MR imaging. [ABSTRACT FROM AUTHOR]

Anterior cruciate ligament injuries are very commonly encountered during routine MRI reporting and various signs have been described for their identification. However, the diagnosis of isolated bundle tears is difficult using MRI, thus can be easily overlooked, especially isolated tear of posterolateral bundle. We present a case of a young male with "Gap" and "Footprint" signs on MRI knee joint, which are considered highly specific of posterolateral ACL bundle tear.

Alexander disease, less commoniy known as fibrinoid leukodystrophy is an extremely rare, non- familial, progressive, lethal leukodystrophy which is characterized predominantly by abnormalities of white matter in bilateral frontal regions. It usually presents early within first 2 years of life with clinical features of macrocephaly, recurrent seizures and psychomotor retardation. Diagnosis of this white matter disorder is possible with certain features seen on magnetic resonance imaging (MRI), even without the need for histological confirmation. Our case is a one year old male infant who presented with repeated episodes of focal seizures to the paediatrician. He was referred for an MRI and subsequently based on typical MRI findings the diagnosis of Alexander disease was made.