introduction: herpes labialis is important in dentistry because of its high prevalence. herpes simplex virus (hsv) is responsive to treatment and infection control methods help protect patients and dental personnel. due to high levels of stress in the flight crew this study evaluated the prevalence of recurrent herpes labialis in the personnel of an airline company. materials and methods: in th...

A new positioning system is proposed that should give the surgeon the exact location and orientation of the instruments in the patient. The measuring system consists of markers placed on the instruments, outside of the human body. Two pairs of ultrasound markers placed on each instrument will suffice to measure both the position and orientation. The detection of marker positions is realized wit...

A traditional soccer ball is constructed using 32 pentagonal and hexagonal panels. In recent years, however, the likes of the Teamgeist and Jabulani balls, constructed from 14 and 8 panels, respectively, have entered the field, marking a significant departure from conventionality in terms of shape and design. Moreover, the recently introduced Brazuca ball features a new 6-panel design and has a...

in this paper a new guidance technique for ballistic missiles and launch vehicles is proposed. generally the lambert guidance is used to generate missile nominal (correlated) parameters through powered flight to put it in a ballistic flight path. because of uncertainties and undesired factors, the nominal position and velocity obtained by lambert technique need to be followed in actual flight. ...

With conventional time-of-flight sonar ranging systems, it is impossible to differentiate a reflection from a plane and from a rightangle corner reflector. A multitransducer pulse/echo ranging system is described that differentiates these two reflectors by exploiting the physical properties of sound propagation. The amplitudes and ranges of reflected signals for the different transmitter and re...

INTRODUCTION Helicopter overland navigation is a cognitively complex task that requires continuous monitoring of system and environment parameters and years of training. This study investigated potential improvements to training simulation by analyzing the influences of flight expertise on visual scan patterns. METHODS There were 12 military officers who varied in flight expertise as defined ...

Locomotion through structurally complex environments is fundamental to the life history of most flying animals, and the costs associated with movement through clutter have important consequences for the ecology and evolution of volant taxa. However, few studies have directly investigated how flying animals navigate through cluttered environments, or examined which aspects of flight performance ...

Ascending or descending locomotion involves a change in potential energy (PE) and a corresponding change in power requirement. We sought to test whether the mechanical power required for steady ascending or descending flight is a simple sum of the power required for level flight and the power necessary for potential energy change. Pigeons (Columba livia) were trained to fly at varying angles of...

Airflow conditions close to the Earth's surface are often complex, posing challenges to flight stability and control for volant taxa. Relatively little is known about how well flying animals can contend with complex, adverse air flows, or about the flight control mechanisms used by animals to mitigate wind disturbances. Several recent studies have examined flight in the unsteady von Kármán vort...