Vibration suppression and angle tracking of a fire-rescue ladder

This paper mainly considers vibration suppression and angle tracking of a fire-rescue ladder system. The dynamical model is regarded as a segmented Euler–Bernoulli beam with gravity and tip mass, described by a set of motion equations and boundary conditions. Based on the nonlinear Euler–Bernoulli beam model, two active boundary controllers are proposed to achieve the control objectives. The elastic deflection and the angular error in the closed-loop system are proven to converge exponentially to a small neighborhood of zero. Numerical simulations based on finite difference method verify the effectiveness and the ascendancy of active boundary controllers

Cannabinoid Agonists Inhibit Neuropathic Pain Induced by Brachial Plexus Avulsion in Mice by Affecting Glial Cells and MAP Kinases

Many studies have shown the antinociceptive effects of cannabinoid (CB) agonists in different models of pain. Herein, we have investigated their relevance in neuropathic pain induced by brachial plexus avulsion (BPA) in mice.Mice underwent BPA or sham surgery. The mRNA levels and protein expression of CB(1) and CB(2) receptors were assessed by RT-PCR and immunohistochemistry, respectively. The activation of glial cells, MAP kinases and transcription factors were evaluated by immunohistochemistry. The antinociceptive properties induced by cannabinoid agonists were assessed on the 5(th) and 30(th) days after surgery. We observed a marked increase in CB(1) and CB(2) receptor mRNA and protein expression in the spinal cord and dorsal root ganglion, either at the 5(th) or 30(th) day after surgery. BPA also induced a marked activation of p38 and JNK MAP kinases (on the 30(th) day), glial cells, such as microglia and astrocytes, and the transcription factors CREB and NF-κB (at the 5(th) and 30(th) days) in the spinal cord. Systemic treatment with cannabinoid agonists reduced mechanical allodynia on both the 5(th) and 30(th) days after surgery, but the greatest results were observed by using central routes of administration, especially at the 30(th) day. Treatment with WIN 55,212-2 prevented the activation of both glial cells and MAP kinases, associated with an enhancement of CREB and NF-κB activation.Our results indicate a relevant role for cannabinoid agonists in BPA, reinforcing their potential therapeutic relevance for the management of chronic pain states

Association of insularity and body condition to cloacal bacteria prevalence in a small shorebird

Do islands harbour less diverse disease communities than mainland? The island biogeography theory predicts more diverse communities on mainland than on islands due to more niches, more diverse habitats and availability of greater range of hosts. We compared bacteria prevalences ofCampylobacter,ChlamydiaandSalmonellain cloacal samples of a small shorebird, the Kentish plover (Charadrius alexandrinus) between two island populations of Macaronesia and two mainland locations in the Iberian Peninsula. Bacteria were found in all populations but, contrary to the expectations, prevalences did not differ between islands and mainland. Females had higher prevalences than males forSalmonellaand when three bacteria genera were pooled together. Bacteria infection was unrelated to bird's body condition but females from mainland were heavier than males and birds from mainland were heavier than those from islands. Abiotic variables consistent throughout breeding sites, like high salinity that is known to inhibit bacteria growth, could explain the lack of differences in the bacteria prevalence between areas. We argue about the possible drivers and implications of sex differences in bacteria prevalence in Kentish plovers