Software-Defined Networks (SDNs) represents an innovative approach in the area of computer networks, since they propose a new model to control forwarding and routing data packets that navigate the World Wide Web. Since research on this topic is still in progress, there are not many devices such as routers and switches that implement SDN functionalities; moreover, the existing ones are very expensive. Thus, in order to make researchers able to do experiments and to test novel features of this new paradigm in practice at a low financial cost, one solution is to use virtual network emulators. As a result, this paper focuses on study and evaluation of SDN emulation tool called Mininet. Initial tests suggested that the capacity of rapid and simplified prototyping, the ensuring applicability, the possibility of sharing results and tools at zero cost are positive factors that help scientists boost their researches despite the limitations of the tool in relation to the performance fidelity between the simulated and the real environment. After presenting some concepts of this paradigm, the purpose of its appearance, its elements and how it works, some net prototypes are created to better understand the Mininet tool and an evaluation is done to demonstrate its advantages and disadvantages.

Computer networks have evolved due to new trends in the society's needs since their emergence as a way of providing remote access and sharing of computational resources. The architecture inflexibility of the computer networks presents a challenge for researchers, since their experiments can hardly be evaluated in real networks. Thus, in general, tests of new technologies are conducted on network simulators, which imply in a streamline of the reality. The paradigm of Software Defined Networks (SDN) and OpenFlow architecture, offer a way for the implementation of a programmable network architecture, able to be implemented gradually in production networks, which offers the possibility of separating the control mechanisms of the many traffic flows served, so that a scientific experiment can be performed in a real network (adapted for SDN) without interfering with its operation. This paper contextualizes the existing problems in current computer networks, and presents the SDN network as one of the main proposals for the viability of the Internet of the Future. In this context, it is discussed the OpenFlow architecture, which allows the creation of applications for Software Defined Networks. Finally it is presented the network simulator SDN, the Mininet, which implements the OpenFlow interface in a network simulation scenario containing a controller POX with two components, one OpenFlow switch and three nodes. The main objective was to evaluate the communication and bandwidth between nodes.

The microbial infections involving the craniofacial skeleton, particularly maxilla and mandible, have direct relationship with the dental biofilm, with predominance of obligate anaerobes. In some patients, these infections may spread to bone marrow or facial soft tissues, producing severe and life-threatening septic conditions. In such cases, local treatment associated with systemic antimicrobials should be used in order to eradicate the sources of contamination. This paper discuss the possibility of spread of these infections and their clinical implications for dentistry, as well as their etiology and aspects related to microbial virulence and pathogenesis.

Bovine periodontitis is a progressive purulent infectious process associated with the presence of strictly and facultative anaerobic subgingival biofilm and epidemiologically related to soil management in large geographic areas of Brazil. This study aimed to detect species of the genera Porphyromonas and Prevotella, which occurr in periodontal pockets of cattle with lesions deeper than 5mm (n=26) and in gingival sulcus of animals considered periodontally healthy (n=25). Presence of the microorganisms was evaluated by independent-culture medium diagnostic method, using polymerase chain reaction (PCR) with specific primers of Porphyromonas asaccharolytica, P. endodontalis, P. gingivalis, P. gulae, Prevotella buccae, P. intermedia, P. loescheii, P. melaninogenica, P. nigrescens, P. oralis and P. tannerae. The species P. endodontalis (80.7%), P. melaninogenica (73.1%) and P. intermedia (61.5%) were the most predominant in samples of cattle with periodontitis. Regarding non-injured gingival sulcus of cattle, P. endodontalis (40%) and P. loeschei (40%) prevailed. Porphyromonas gingivalis, P. gulae and Prevotella tannerae were not detected in the 51 samples studied. Data evaluation by T test, enabled to verify that ocorrence of Porphyromonas asaccharolytica (p=0.000003), P. endodontalis (p=0.0023), Prevotella buccae (p=0.0017), P. intermedia (p=0.0020), P. melaninogenica (p=0.00006) and P. oralis (p=0.0028) is correlated with bovine periodontitis.