An Oral Abscess as the Entrance Leading to Endocarditis: A Sexual Behavior Role

The risk factors for infective endocarditis (IE) in the population are changing: the reported worldwide increase in the incidence of IE has been associated with the widespread use of medical devices and procedures responsible of heath care associated infection. Endocarditis incurred by Streptococcus agalactiae inadults (nonpregnant females and men) has increased in recent years, even though the source of infection due to this bacterium and the portal of entry are unclear and not often well documented.

 
Concerning the possible sexual port of entry in the cause of endocarditis, this mode of transmission should be suspected in a search of clinical history, especially in recurrent endocarditis.

Linearization of Power Amplifier using the Modified Feed Forward Method

The use of high power amplifiers with high linearity for mobile and satellite communications systems is essential. For example, in second and third generation mobile systems, GSM (Global System Mobile), 3GPP (third Generation Partnership Project), a large number of signals with different frequencies are transmitted from BS (Base Station) by high power amplifiers at the same time. To avoid interference of these amplified signals, the amplifier must operate linear and that linearization is not possible by classical methods. Since the amplitude of intermodulation signals at the output of the amplifiers depends on the size of the input signals, input signals with large amplitude limit the performance of the amplifier. 

If the connection between an amplifier input and output signals display as transformation function that is extended in the form of a series (for example Taylor’s series), we see that for the larger signal, the role of higher degrees of expression is more and more important, that is, the behavior of amplifiers is no longer linear and amplifier operates in saturation (non-linear) region. The saturation region, due to high output power and resulting high efficiency in mobile communications and satellite systems play an important role.