Methylated BSA Mimics Amyloid-Related Proteins and Triggers Inflammation

The mechanistic study of inflammatory or autoimmune diseases requires the generation of mouse models that reproduce the alterations in immune responses observed in patients. Methylated bovine serum albumin (mBSA) has been widely used to induce antigen-specific inflammation in targeted organs or in combination with single stranded DNA (ssDNA) to generate anti-nucleic acids antibodies in vivo. However, the mechanism by which this modified protein triggers inflammation is poorly understood. By analyzing the biochemical properties of mBSA, we found that mBSA exhibits features of an intermediate of protein misfolding pathway. mBSA readily interact with a list of dyes that have binding specificity towards amyloid fibrils. Intriguingly, mBSA displayed cytotoxic activity and its binding to ssDNA further enhanced formation of beta-sheet rich amyloid fibrils. Moreover, mBSA is recognized by the serum amyloid P, a protein unanimously associated with amyloid plaques in vivo. In macrophages, we observed that mBSA disrupted the lysosomal compartment, signaled along the NLRP3 inflammasome pathway, and activated caspase 1, which led to the production of IL-1β. In vivo, mBSA triggered rapid and prominent immune cell infiltration that is dependent on IL-1β induction. Taken together, these data demonstrate that by mimicking amyloidogenic proteins mBSA exhibits strong innate immune functions and serves as a potent adjuvant. These findings advance our understanding on the underlying mechanism of how aberrant immune responses lead to autoimmune reactions

Continuous free-crab gaits for hexapod robots on a natural terrain with forbidden zones: An application to humanitarian demining

Autonomous robots are leaving the laboratories to master new outdoor applications, and walking robots in particular have already shown their potential advantages in these environments, especially on a natural terrain. Gait generation is the key to success in the negotiation of natural terrain with legged robots; however, most of the algorithms devised for hexapods have been tested under laboratory conditions. This paper presents the development of crab and turning gaits for hexapod robots on a natural terrain characterized by containing uneven ground and forbidden zones. The gaits we have developed rely on two empirical rules that derive three control modules that have been tested both under simulation and by experiment. The geometrical model of the SILO-6 walking robot has been used for simulation purposes, while the real SILO-6 walking robot has been used in the experiments. This robot was built as a mobile platform for a sensory system to detect and locate antipersonnel landmines in humanitarian demining missions.Funding for this paper was provided by CICYT under Grant DPI2001-1595 and DPI2004-05824.Peer reviewe

Location of legged robots in outdoor environments

Knowledge of a robot's position with an accuracy of within a few centimeters is required for potential applications for legged robots, such as humanitarian de-mining tasks. Individual sensors are unable to provide such accuracy. Thus information from various sources must be used to accomplish the tasks. Following this trend, this paper describes the method developed for estimating the position of legged robots in outdoor environments. The proposed method factors in the specific features of legged robots and combines dead-reckoning estimation with data provided by a Differential Global Positioning System through an extended Kalman filter algorithm. This localization system permits accurate trajectory tracking of legged robots during critical activities such as humanitarian de-mining tasks. Preliminary experiments carried out with the SILO4 system have shown adequate performance using this localization system. © 2007 Elsevier B.V. All rights reserved.Peer Reviewe

Accurate tracking of legged robots on natural terrain

Statically stable walking locomotion research has focused mainly on robot design and gait generation. However, there is a need to expand robots’ capabilities so that walking machines can accomplish the kinds of real tasks for which they are eminently suited. Many such tasks demand trajectory tracking, but researchers have traditionally ignored this subject. This article focuses on the tracking of predefined trajectories with hexapod robots walking on natural terrain with forbidden zones. The method presented herein, which relies on gait algorithms defined elsewhere, describes certain localization strategies and control techniques that have been employed to follow trajectories accurately and have been implemented in a real walking hexapod. Several experimental examples are included to assess the proposed algorithms.Funding for this work was provided by the Spanish Ministry of Science and Technology under Grants DPI2001-1595 and DPI2004-05824.Peer reviewe

La vegetación del Ventisquero de la Condesa (Sierra de Guadarrama, Madrid) y sus condicionantes termo-nivales

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