A Survey of Air-to-Ground Propagation Channel Modeling for Unmanned Aerial Vehicles

In recent years, there has been a dramatic increase in the use of unmanned aerial vehicles (UAVs), particularly for small UAVs, due to their affordable prices, ease of availability, and ease of operability. Existing and future applications of UAVs include remote surveillance and monitoring, relief operations, package delivery, and communication backhaul infrastructure. Additionally, UAVs are envisioned as an important component of 5G wireless technology and beyond. The unique application scenarios for UAVs necessitate accurate air-to-ground (AG) propagation channel models for designing and evaluating UAV communication links for control/non-payload as well as payload data transmissions. These AG propagation models have not been investigated in detail when compared to terrestrial propagation models. In this paper, a comprehensive survey is provided on available AG channel measurement campaigns, large and small scale fading channel models, their limitations, and future research directions for UAV communication scenarios

Management and Outcome of Cardiac and Endovascular Cystic Echinococcosis

Cardiac and vascular involvement are infrequent in classical cystic echinococcosis (CE), but when they occur they tend to present earlier and are associated with complications that may be life threatening. Cardiovascular CE usually requires complex surgery, so in low-income countries the outcome is frequently fatal. This case series describes the characteristics of cardiovascular CE in patients diagnosed and treated at a Tropical Medicine & Clinical Parasitology Center in Spain. A retrospective case series of 11 patients with cardiac and/or endovascular CE, followed-up over a period of 15 years (1995–2009) is reported. The main clinical manifestations included thoracic pain or dyspnea, although 2 patients were asymptomatic. The clinical picture and complications vary according to cyst location. Isolated cardiac CE may be cured after surgery, while endovascular extracardiac involvement is associated with severe chronic complications. CE should be included in the differential diagnosis of cardiovascular disease in patients from endemic areas. CE is a neglected disease and further studies are necessary in order to make more definite management recommendations for this rare and severe form of the disease. The authors propose a general approach based on cyst location: exclusively cardiac, endovascular or both

A unusual case of right lung and right atrio-inferiocaval injury caused by stabbing

PubMedID: 19670127Penetrating thoracic injuries can damage more than one intrathoracic structure and frequently require urgent surgical intervention due to life-threatening consequences. These injuries demand extreme awareness and emergency measures. This paper reports on an unusual case with right lung and right atrio-inferiocaval junction injury caused by a knife penetrating through the right paravertebral region of the thorax. The patient was treated by immediate surgical repair under partial cardiopulmonary bypass and discharged successfully. This case emphasizes the fact that right chest paravertebral penetrating injuries may require cardiopulmonary bypass, although this zone has less risk for cardiac injury. © Georg Thieme Verlag KG Stuttgart - New York

Malignant fibrous histiocytoma of the heart

PubMedID: 18427664[No abstract available

Left atrial extension of hepatoblastoma via left superior pulmonary vein

PubMedID: 24229501Hepatoblastoma is the most common malignant liver tumour in early childhood. The metastatic extension of hepatoblastoma into the left atrium via the pulmonary vein is rare. Reported lesions almost always involve a right-sided approach. Here we report the case of a 3-year-old girl with a recurrent hepatoblastoma at multiple sites, including the left atrium, brain, and lung. The patient was treated surgically for the prevention of further embolic complications and cardiac failure. © Cambridge University Press, 2013

Sternoclavicular joint dislocation with innominate artery injury

A 23-year-old man developed a incomplete injury of the innominate artery 15 days after blunt chest trauma. Sternoclavicular joint dislocation was caused injury of innominate artery. The patient had superior caval syndrome symptoms. We thought aort or arch's injured. The patient was managed with urgent surgical procedure and applied median sternotomy with femoro-femoral cardiopulmonary bypass. The patient was discharged without any problem

Aorto-cutaneous fistula: Complication of coronary artery bypass graft operation [3]

PubMedID: 16424851[No abstract available

The New Frontier in RAN Heterogeneity: Multi-Tier Drone-Cells

In cellular networks, the locations of the RAN elements are determined mainly based on the long-term traffic behavior. However, when the random and hard-to-predict spatio-temporal distribution of the traffic (load, demand) does not fully match the fixed locations of the RAN elements (supply), some performance degradation becomes inevitable. The concept of multi-tier cells (heterogeneous networks, Het-Nets) has been introduced in 4G networks to alleviate this mismatch. However, as the traffic distribution deviates more and more from the long-term average, even the HetNet architecture will have difficulty in coping with the erratic supply-demand mismatch, unless the RAN is grossly over-engineered (which is a financially non-viable solution). In this article, we study the opportunistic utilization of low-altitude unmanned aerial platforms equipped with BSs (i.e., drone-BSs) in future wireless networks. In particular, we envisage a multi-tier drone-cell network complementing the terrestrial HetNets. The variety of equipment and non-rigid placement options allow utilizing multi-tier drone-cell networks to serve diversified demands. Hence, drone-cells bring the supply to where the demand is, which sets new frontiers for the heterogeneity in 5G networks. We investigate the advancements promised by dronecells and discuss the challenges associated with their operation and management. We propose a drone-cell management framework (DMF) benefiting from the synergy among SDN, network functions virtualization, and cloud computing. We demonstrate DMF mechanisms via a case study, and numerically show that it can reduce the cost of utilizing drone-cells in multi-tenancy cellular networks