Track analysis of the Mexican species of Cerambycidae (Insecta, Coleoptera)

A track analysis of 221 species belonging to 68 genera of Mexican Cerambycidae was undertaken in order to identify their main distributional patterns. Based on the comparison of the individual tracks, fifteen generalized tracks were obtained: six are placed in the Neotropical region, seven are shared by the Neotropical region and the Mexican Transition Zone, one is situated in the Mexican Transition Zone, and one is shared by the Nearctic region and the Mexican Transition Zone. Eight nodes were found in the intersection of these generalized tracks, five of them located in the Neotropical region and three in the Mexican Transition Zone. Distributional patterns of Mexican Cerambycidae show two basic patterns: one mostly Neotropical, in the Mesoamerican dominion (Mexican Pacific Coast and Mexican Gulf biogeographic provinces) and another in the Mexican Transition Zone (Transmexican Volcanic Belt and Balsas Basin biogeographic provinces).

Track analysis of the Neotropical Entimini (Coleoptera: Curculionidae: Entiminae)

Track analysis of the Neotropical Entimini (Coleoptera, Curculionidae, Entiminae). Distributional patterns of the species belonging to the tribe Entimini from the Neotropical region were analyzed. Based on a track analysis of 22 species of Entimus, Rhigus, and Phaedropus, for which distributional data were available, two generalized tracks were found. One is located in northern Brazil, corresponding to the Amazonian subregion, and is determined by Phaedropus candidus and Rhigus speciosus. The other is located in southern Brazil, corresponding to the Parana subregion, and is determined by Entimus imperialis, E. excelsus, Phaedropus togatus, Rhigus dejeanii, R. faldermanni, R. horridus, R. lateritus, R. nigrosparsus, and R. tribuloides. The development of the Chacoan subregion is hypothesized to have been the dynamic vicariant event that fragmented the former Amazonian-Parana forest.

Effect of hyperbaric oxygen on the regeneration of experimental crush injuries of nerves

Hyperbaric oxygen has been successfully used on treatment of acute ischemic injuries involving soft tissues and chronic injuries. In nerve crush injuries, the mechanisms involved are very similar to those found in ischemic injuries. Consequently, it is logical to hypothesize that hyperbaric oxygen should improve nerve repair, which is a critical step on functional recovery. In the present study, we created standard nerve crush injuries on sciatic nerves of rats, which underwent treatment with hyperbaric oxygen. Results were assessed by functional evaluation using walking-track analysis. The functional recovery indexes observed did not differ from control group. We concluded that hyperbaric oxygen therapy, in the schedule used, had no influence on functional recovery after nerve crush injuries.

Distributional patterns of the Neotropical genus Thecomyia Perty (Diptera, Sciomyzidae) and phylogenetic support

Distributional patterns of the Neotropical genus Thecomyia Perty (Diptera, Sciomyzidae) and phylogenetic support. The distributional pattern of the genus Thecomyia Perty, 1833 was defined using panbiogeographic tools, and analyzed based on the phylogeny of the group. This study sought to establish biogeographical homologies in the Neotropical region between different species of the genus, based on their distribution pattern and later corroboration through its phylogeny. Eight individual tracks and 16 generalized tracks were identified, established along nearly the entire swath of the Neotropics. Individual tracks are the basic units of a panbiogeographic study, and correspond to the hypothesis of minimum distribution of the organisms involved. The generalized tracks, obtained from the spatial congruence between two or more individual tracks, are important in the identification of smaller areas of endemism. Thus, we found evidence from the generalized tracks in support of previous classification for the Neotropical region. The Amazon domain is indicated as an area of outstanding importance in the diversification of the group, by the confluence of generalized tracks and biogeographic nodes in the region. Most of the generalized tracks and biogeographical nodes were congruent with the phylogenetic hypothesis of the genus, indicating support of the primary biogeographical homologies originally defined by the track analysis.

Analysis of emergency braking performance with particular consideration of temperature effects on brakes

During vehicle deceleration due to braking there is friction between the lining surface and the brake drum or disc. In this process the kinetic energy of vehicle is turned into thermal energy that raises temperature of the components. The heating of the brake system in the course of braking is a great problem, because besides damaging the system, it may also affect the wheel and tire, which can cause accidents. In search of the best configuration that considers the true conditions of use, without passing the safety limits, models and formulations are presented with respect to the brake system, considering different braking conditions and kinds of brakes. Some modeling was analyzed using well-known methods. The flat plate model considering energy conservation was applied to a bus, using for this a computer program. The vehicle is simulated to undergo an emergency braking, considering the change of temperature on the lining-drum. The results include deceleration, braking efficiency, wheel resistance, normal reaction on the tires and the coefficient of adhesion. Some of the results were compared with dynamometer tests made by FRAS-LE and others were compared with track tests made by Mercedes-Benz. The convergence between the results and the tests is sufficient to validate the mathematical model. The computer program makes it possible to simulate the brake system performance in the vehicle. It assists the designer during the development phase and reduces track tests.