Antonio Augusto de Aragão Rocha

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BitTorrent, the immensely popular file swarming system, suffers a fundamental problem: unavailability. Although swarming scales well to tolerate flash crowds for popular content, it is less useful for unpopular or rare files as peers arriving after the initial rush find the content unavailable. Our primary contribution is a model to quantify content(More)
— The deployment of wireless LANs (WLANs) has been steadily increasing over the years and estimating the actual bit rate of a WLAN device is important for management and applications such as those that can adapt their transmission rates according to the network characteristics. We propose a simple and accurate active measurement technique to infer the bit(More)
Peer-to-peer swarming is one of the de facto solutions for distributed content dissemination in today's Internet. By leveraging resources provided by clients, swarming systems reduce the load on and costs to publishers. However, there is a limit to how much cost savings can be gained from swarming; for example, for unpopular content peers will always depend(More)
A large number of performance evaluation tools have been developed over the years to support the analyst in the difficult task of model building. As systems increase in complexity, the need is critical for tools that are able to help the user throughout the whole modeling cycle, from model building to model solution and experimentation. In this work we(More)
High glucose concentration in the airway surface liquid (ASL) is an important feature of diabetes that predisposes to respiratory infections. We investigated the role of alveolar epithelial SGLT1 activity on ASL glucose concentration and bacterial proliferation. Non-diabetic and diabetic rats were intranasally treated with saline, isoproterenol (to increase(More)
BACKGROUND Paracoccidioides brasiliensis is a thermo-dimorphic fungus that causes paracoccidiodomycosis (PCM). Glycoprotein gp43 is the fungal main diagnostic antigen, which can also protect against murine PCM and interact with extracellular matrix proteins. It is structurally related to glucanases, however not active, and whose expression varies(More)
Modeling and understanding BitTorrent (BT) dynamics is a recurrent research topic mainly due to its high complexity and tremendous practical efficiency. Over the years, different models have uncovered various phenomena exhibited by the system, many of which have direct impact on its performance. In this paper we identify and characterize a phenomenon that(More)