High-Performance Testbed for Vision-Aided Autonomous Navigation for Quadrotor UAVs in Cluttered Environments

This thesis presents the development of an aerial robotic testbed based on Robot Operating System (ROS). The purpose of this high-performance testbed is to develop a system capable of performing robust navigation tasks using vision tools such as a stereo camera. While ensuring the computation of robot odometery, the system is also capable of sensing the environment using the same stereo camera. Hence, all the navigation tasks are performed using a stereo camera and an inertial measurement unit (IMU) as the main sensor suite. ROS is used as a framework for software integration due to its capabilities to provide efficient communication and sensor interfaces. Moreover, it also allows us to use C++ which is efficient in performance especially on embedded platforms. Combining together ROS and C++ provides the necessary computation efficiency and tools to handle fast, real-time image processing and planning which are the vital parts of navigation and obstacle avoidance on such scale. The main application of this work revolves around proposing a real-time and efficient way to demonstrate vision-based navigation in UAVs. The proposed approach is developed for a quadrotor UAV which is capable of performing defensive maneuvers in case any obstacles are in its way, while constantly moving towards a user-defined final destination. Stereo depth computation adds a third axis to a two dimensional image coordinate frame. This can be referred to as the depth image space or depth image coordinate frame. The idea of planning in this frame of reference is utilized along with certain precomputed action primitives. The formulation of these action primitives leads to a hybrid control law for feasible trajectory generation. Further, a proof of stability of this system is also presented. The proposed approach keeps in view the fact that while performing fast maneuvers and obstacle avoidance simultaneously, many of the standard optimization approaches might not work in real-time on-board due to time and resource limitations. This leads to a need for the development of real-time techniques for vision-based autonomous navigation

Penile Fracture: Experience from a Third World Country

Aim. To ascertain the clinical presentation, commonest age group affected, and treatment of patients diagnosed to have penis fracture. Materials and Methods. We performed a retrospective study carried at a tertiary care hospital from January 2005 to January 2011. All the 36 patients diagnosed to have penile fracture were enrolled in the study group. The diagnosis was made based on the clinical findings in the patients. All, except two patients, were managed by a standard surgical procedure, same for all the patients, on the day of presentation to the hospital. All the data pertaining to the presentation, management, and followup of these patients were studied and scrutinized thoroughly. Results. Thirty-four patients were operated while 2 refused surgery. Most of our patients were between 16 and 30 years (55.6%) of age. The commonest presenting complaints were penile swelling and detumescence during sexual intercourse or an erection. All except two of our patients were managed with immediate surgical repair which had excellent results even in the presence of associated urethral injury. Conclusion. Fracture of the penis is a surgical emergency which can be best managed by immediate surgical repair with excellent results even in the presence of urethral injury

Thermoelectric Generator Scheme For IOT

In the recent year Thermoelectric Modules (TEM) are widely used for cooling of different electronic devices. Thermoelectric module allows obtaining the additional and dropping of device temperature. The different way for manufacturing array of thermoelectric model by using integrated circuit technology are presented, So the fundamental dependent parameter of the thermoelectric model are thermal conductance, electrical resistance and seebeck coefficient, among the other factors. Paper introduces a method for calculating parameter from observable variables, which can be obtained from temperature, voltage, and electric current measurements made on a working TE device. The parameters are plotted against the temperature between the hot and cold side of the module

Flexible Supervised Autonomy for Exploration in Subterranean Environments

While the capabilities of autonomous systems have been steadily improving in recent years, these systems still struggle to rapidly explore previously unknown environments without the aid of GPS-assisted navigation. The DARPA Subterranean (SubT) Challenge aimed to fast track the development of autonomous exploration systems by evaluating their performance in real-world underground search-and-rescue scenarios. Subterranean environments present a plethora of challenges for robotic systems, such as limited communications, complex topology, visually-degraded sensing, and harsh terrain. The presented solution enables long-term autonomy with minimal human supervision by combining a powerful and independent single-agent autonomy stack, with higher level mission management operating over a flexible mesh network. The autonomy suite deployed on quadruped and wheeled robots was fully independent, freeing the human supervision to loosely supervise the mission and make high-impact strategic decisions. We also discuss lessons learned from fielding our system at the SubT Final Event, relating to vehicle versatility, system adaptability, and re-configurable communications.Comment: Field Robotics special issue: DARPA Subterranean Challenge, Advancement and Lessons Learned from the Final

Bioluminescence

Microcosm describes a miniature representation of a living or non-living thing. For example, there are miniature buildings, cars, furniture, dolls, mushrooms, flowers and plants. Microcosm bioluminescent mushrooms are miniatures of real mushrooms that produce light which is visible in the dark as a result of a biochemical reaction

Efficacy of different doses of dexmedetomidine as an adjuvant to bupivacaine in sub-arachnoid block for patients undergoing lower limb surgeries

Objective: To determine the difference in efficacy of bupivacaine as adjuvant to 5 µg& 10 µg of dexmedetomidine respectively during intrathecal administration in prolongation of duration of sensory block (as a main primary variable) in lower limb orthopedic surgery. Setting: Department of anesthesia, MTI-HMC, Peshawar. Study design: Randomized controlled trails. Duration of study: From 1st Feb 2021 to 30th July 2021. Subjects & Methods: Each patient enrolled in study after proper consent in written form and counselling was subjected to complete medical history, clinical examination. Spinal column was the primary focus of examination. All standard vitals monitoring equipment attahed. Baseline readings obtained and noted. Double i/v line was secured. Patients were preloaded with 10ml/ kg of Ringer Lactate. Spinal injection of anesthetic. Conclusion: Results obtained from this study showed that adding 10 micro gram of dexmeditomidine in comparison to 5 micro gram to spinal anesthetic for lower limb traumatic orthopedic surgery significantly prolongs the sensory block, analgesia, decreased onset time for block, early rehabilitaion and ambulation of patients which has various socioecnomic advantages

CT Findings of Patients Treated with Irreversible Electroporation for Locally Advanced Pancreatic Cancer

Introduction. In patients with locally advanced pancreatic cancer (LAPC), IRE has been shown to be safe for local disease control and palliation. As IRE continues to gain acceptance it is important to characterize the expected imaging findings. Materials and Methods. A review of our prospective soft tissue ablation registry from July 2010 to June 2013 was performed on patients who had undergone IRE for LAPC. Five masses treated with intraoperative IRE ablation for pancreatic tumors that underwent CT imaging before and after ablation were reviewed. Results and Discussion. Following IRE, the postablation bed is larger than the original ablated tumor. This ablation zone may get smaller in size (due to decreased edema and hyperemia) in the following months and more importantly remains stable provided there is no recurrence. In cases of recurrent disease there is increased size of the ablation bed, mass effect, and new or worsening vascular encasement or occlusion. Conclusion. CT imaging remains the best current imaging modality to assess post-IRE ablation changes. Serial imaging over at least 2–6 months must be employed to detect recurrence by comparing with prior studies in conjunction with clinical and serum studies. Larger imaging studies are underway to evaluate a more ideal imaging modality for this unique patient population

A Comprehensive Review on Metallic Trace Elements Toxicity in Fishes and Potential Remedial Measures

Metallic trace elements toxicity has been associated with a wide range of morphological abnormalities in fish, both in natural aquatic ecosystems and controlled environments. The bioaccumulation of metallic trace elements can have devastating effects on several aspects of fish health, encompassing physiological, reproductive, behavioural, and developmental functions. Considering the significant risks posed by metallic trace elements-induced toxicity to fish populations, this review aims to investigate the deleterious effects of prevalent metallic trace elements toxicants, such as mercury (Hg), cadmium (Cd), chromium (Cr), lead (Pb), arsenic (As), and copper (Cu), on the neurological, reproductive, embryonic, and tissue systems of fish. Employing diverse search engines and relevant keywords, an extensive review of in vitro and in vivo studies pertaining to metallic trace elements toxicity and its adverse consequences on fish and their organs was conducted. The findings indicate that Cd was the most prevalent metallic trace elements in aquatic environments, exerting the most severe impacts on various fish organs and systems, followed by Cu and Pb. Moreover, it was observed that different metals exhibited varying degrees and types of effects on fish. Given the profound adverse effects of metallic trace elements contamination in water, immediate measures need to be taken to mitigate water pollution stemming from the discharge of waste containing metallic trace elements from agricultural, industrial, and domestic water usage. This study also compares the most common methods for treating metallic trace elements contamination in water

The first Middle East and North Africa expert consensus recommendations for management of advanced gastric cancer

Gastric cancer (GC) ranks as the fifth most prevalent cancer and the fourth deadliest cancer worldwide. In the Middle East and North Africa (MENA) region, GC represents about 4.8% of cancer cases with more than 35,000 new cases in 2020. To strengthen and improve the management of this cancer in the region, a group of MENA experts in the field of GC developed the first MENA consensus recommendations for the management of advanced GC. A total of 28 statements were drafted, discussed and voted on, using a modified Delphi process, during a virtual consensus meeting. The statements addressed the areas of epidemiology, biomarkers and treatment

The first Middle East and North Africa expert consensus recommendations for management of advanced gastric cancer

Gastric cancer (GC) ranks as the fifth most prevalent cancer and the fourth deadliest cancer worldwide. In the Middle East and North Africa (MENA) region, GC represents about 4.8% of cancer cases with more than 35,000 new cases in 2020. To strengthen and improve the management of this cancer in the region, a group of MENA experts in the field of GC developed the first MENA consensus recommendations for the management of advanced GC. A total of 28 statements were drafted, discussed and voted on, using a modified Delphi process, during a virtual consensus meeting. The statements addressed the areas of epidemiology, biomarkers and treatment