54 research outputs found
The intratracheal administration of endotoxin: X. Dexamethasone downregulates neutrophil emigration and cytokine expression in vivo
Intratracheal instillation of endotoxin (LPS) causes acute pulmonary inflammation characterized by the accumulation of plasma proteins and leukocytes within the pulmonary airways. The synthetic glucocorticoid dexamethasone 1) inhibits the LPS-initiated vascular leak of plasma proteins into the airspace, 2) inhibits the LPS-initiated emigration of neutrophils and lymphocytes into the airspace in a dose-dependent fashion, and 3) inhibits LPS-initiated mRNA and/or bronchoalveolar lavage protein expression of cytokines (TNF, IL-1 and IL-6) and chemokines (MIP-l Ī± , MIP-2 and MCP-1). In conclusion, dexamethasone inhibits both the vascular and cellular aspects of acute inflammation by downregulation of a broad spectrum of inflammatory cytokines and chemokines.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44515/1/10753_2005_Article_BF01487403.pd
Ozone co-exposure modifies cardiac responses to fine and ultrafine ambient particulate matter in mice: concordance of electrocardiogram and mechanical responses
Effects of Repeated Exposure to Nitric Acid Vapor and Ozone on Respiratory Tract Clearance in the Rat
Wireless Sensor Networking Applied to Swarms of Aquatic Drones
Aquatic Unmanned Surface Vehicles (USV) have potential in a variety of maritime activities such as environmental monitoring or sea-life tracking. They can be applied to military missions supĀ¬porting army in potentially dangerous situations such as reconnaissance or surveillance. USV are capable of many tasks due to technological progress and minimization of equipment in recent years. Size and price drop while reliability improved enables development of large scale multi-agent systems consisting of autonomous USVs.
Multi-agent system of aquatic autonomous USVs may act like a distributed sensing system imĀ¬proving the overall performance when compared to the performance of one unit of USV: more units in the system, larger monitored area. A promising approach inspired from nature is swarm intelligence, which can be found for instance in population of insects such as ants. SwarmbeĀ¬haviour is a motion of large number of units, where each one is autonomous but only as a group they are able to solve the problem. The exchange of information between units is essential for the success of the group. Wireless Sensor Networks (WSNs) have potential as communication architecture applied to swarms.
A scenario for the communication both with and within the swarm has been proposed. The challenges implied by tough environmental conditions call for heterogeneous approach such as the one proposed in this dissertation. A communication within the swarm is held using short-range communication technology such as XBee-PRO modules. All nodes acting as sensing agents are equipped with short-range communication technology. The communication with the swarm is held using nodes acting as gateways to the shore equipped with long-range technology, such as SX1272 modules from Semtech, called LoRa. The deployment of nodes acting as gateways to the shore, called buoys, with fixed localization has been proposed. Each node in the network is aware of the GPS coordinates of buoys, thus in case of communication loss, it can orient itself in the direction of the nearest buoy, increasing chances of successful communication with the base station.
The short-range communication XBee-PRO technology has been tested in order to determine communication range with and without Line of Sight (LoS). The objective is to improve the range of the communication link, which nowadays in held via Wi-Fi in the distance around 30
m. The results were promising for real-world implementation into swarms of aquatic surface drones.Os veĆculos nĆ£o-tripulados de superfĆcie aquĆ”tica (VNTSA) tem um enorme potencial para uma vasta gama de atividades marĆtimas, tais como a monitorizaĆ§Ć£o ambiental ou a amortizaĆ§Ć£o da vida marinha. Estes veĆculos podem ser tambĆ©m aplicados em miss6es militares de apoio ao exercito, em situaƧ6es potencialmente perigosas, tais como miss6es de reconhecimento ou de vigilĆ¢ncia. Os USVs (VNTSA) sĆ£o capazes de realizar diversas tarefas devido ao progresso tecnolĆ³gico e a reduĆ§Ć£o do tamanho dos equipamentos nos Ćŗltimos anos. A reduĆ§Ć£o do tamanho e preƧo, acompanhado pelo aumento da fiabilidade, permitiu o desenvolvimento de sistemas multi-agente em larga escala.
Os sistemas multi-agente dos USVs autĆ³nomos aquĆ”ticos podem agir como um sistema de senĀ¬sores distribuĆdos, melhorando o desempenho global, quando comparado com o desempenho de uma unidade de USV isolado, ou seja, quantos mais unidades no sistema, maior Ć”rea monitorĀ¬izada. Uma abordagem promissora, inspirada na natureza, e inteligĆŖncia de cardume (swarm intelligence), que pode ser observada na populaĆ§Ć£o de insetos, como por exemplo nas formigas. O comportamento do cardume (swarm) e um movimento de um grande numero de elementos, em que cada ume autĆ³nomo, porem sĆ³ em grupo sĆ£o capazes de resolver tarefas complexas. A troca de informaƧ6es entre as unidades e essencial para o sucesso do grupo. A arquitectura de comunicaĆ§Ć£o aplicada a cardume pode ser suportada pelas Redes de Sensores Sem Fios (RSSF).
Nesta dissertaĆ§Ć£o, foi proposto um cenĆ”rio para a comunicaĆ§Ć£o "com" e "dentro" do cardume. Os desafios decorrentes das condiƧ6es ambientais difĆceis exigem uma abordagem heterogĆ©nea, tal como o proposto nesta dissertaĆ§Ć£o. A comunicaĆ§Ć£o dentro do cardume e realizada utiĀ¬lizando tecnologia de comunicaĆ§Ć£o de curto alcance, tais como os mĆ³dulos XBee-PRO. Todos os nos atuam como agentes de deteĆ§Ć£o, que estĆ£o equipados com tecnologia de comunicaĆ§Ć£o de curto alcance. A comunicaĆ§Ć£o com o cardume e concretizada usando os nos que funcionam como portas de comunicaĆ§Ć£o (gateways) para a estaĆ§Ć£o de base equipada com tecnologia de longo alcance, tais como os mĆ³dulos SX1272 de Semtech, chamados LoRa. Foi ainda proposto, implementar nos, atuando como portas de comunicaĆ§Ć£o (gateways) para a estaĆ§Ć£o de base, designados de boias, com localizaĆ§Ć£o fixa. Cada no na rede tem conhecimento das coordenadas de GPS das boias, assim, em caso de perda de comunicaĆ§Ć£o, podem (re)orientar-se na direĆ§Ć£o da boia mais prĆ³xima, aumentando a probabilidade de sucesso de comunicaĆ§Ć£o com a estaĆ§Ć£o de base.
A tecnologia de comunicaĆ§Ć£o de curto alcance XBee-PRO foi testada, a fim de determinar o alcance da comunicaĆ§Ć£o com linha de vista e sem linha de vista. O objetivo foi melhorar o alcance da ligaĆ§Ć£o (link) de comunicaĆ§Ć£o, que hoje em dia e realizado via Wi-Fi, a distancias de aproximamente 30 m. Os resultados revelam potencial para a implementaĆ§Ć£o no mundo real dos drones aquĆ”ticos de superfĆcie
The āFishing Licenseā method for analyzing the time course of effects in repeated measurements.
[[sponsorship]]ēµ±čØē§åøē ē©¶ę[[note]]å·²åŗē;[SCI];ęåÆ©ę„å¶åŗ¦;å
·ä»£č”Øę§[[note]]http://gateway.isiknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=Drexel&SrcApp=hagerty_opac&KeyRecord=0277-6715&DestApp=JCR&RQ=IF_CAT_BOXPLO
Recommended from our members
Effect of nitric acid vapor on the response to inhaled ozone
Studies concerned with the adverse health effects of acidic atmospheres have focused primarily on sulfuric acid aerosols and other acid sulfates. Little information is available on the health effects of nitric acid (HNO3), an important atmospheric pollutant in southern California. The purpose of this study was to investigate the effects of exposure to nitric acid vapor, alone and in combination with ozone (O3), on the rat lung. Groups of rats were exposed once for 4 h to purified air, 0.6 ppm O3, 7.0 mg/m3 HNO3 or 0.6 ppm O3 plus 1.0 mg/m3 HNO3. Other rats were exposed for 4 days, 4 h/day to purified air, 0.15 ppm O3 0.25 mg/m3 HNO3, or 0.15 ppm O3 plus 0.25 mg/m3 HNO3 The animals were lavaged 18 h after exposure, and cells and fluid were assayed for changes in lavage cell population and lavage fluid protein content, pulmonary macrophage respiratory burst activity and leuko-triene production, and elastase inhibitory capacity of lavage fluid. A separate series of rats was lavaged 2 h after exposure to high concentration atmospheres for measurement of lavage fluid pH and PCO2 and macrophage intracellular pH. Exposure to 0.25 mg/m3 HNO3 alone decreased spontaneous and PMA-stimulated respiratory burst activity in freshly isolated macrophages, while the high concentration mixed atmosphere was also found to cause a significant decrease in respiratory burst activity in freshly isolated macrophages, while the high concentration mixed atmosphere was also found to cause a significant decrease in respiratory burst activity of macrophages maintained overnight in culture. HNO, at both concentrations resulted in a modest but significant increase in elastase inhibitory capacity of lung lavage fluid. Exposure to 0.6 ppm O3 resulted in an increased number of neutrophils in the lavage cell population as well as in increased lavage fluid protein content and elastase inhibitory capacity These changes were also observed following exposure to 1.0 mg/m3 HNO3 plus 0.6 ppm O3 although not to the same extent as following O3 alone. Linear regression analysis indicated that an antagonistic interaction occurs between HNO3 and O3 for changes in lavage cell population, lavage fluid protein content, and elastase inhibitory capacity. Ā© 1992 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted
Recommended from our members
Effect of nitric acid vapor on the response to inhaled ozone
Studies concerned with the adverse health effects of acidic atmospheres have focused primarily on sulfuric acid aerosols and other acid sulfates. Little information is available on the health effects of nitric acid (HNO ), an important atmospheric pollutant in southern California. The purpose of this study was to investigate the effects of exposure to nitric acid vapor, alone and in combination with ozone (O ), on the rat lung. Groups of rats were exposed once for 4 h to purified air, 0.6 ppm O , 7.0 mg/m HNO or 0.6 ppm O plus 1.0 mg/m HNO . Other rats were exposed for 4 days, 4 h/day to purified air, 0.15 ppm O 0.25 mg/m HNO , or 0.15 ppm O plus 0.25 mg/m HNO The animals were lavaged 18 h after exposure, and cells and fluid were assayed for changes in lavage cell population and lavage fluid protein content, pulmonary macrophage respiratory burst activity and leuko-triene production, and elastase inhibitory capacity of lavage fluid. A separate series of rats was lavaged 2 h after exposure to high concentration atmospheres for measurement of lavage fluid pH and PCO and macrophage intracellular pH. Exposure to 0.25 mg/m HNO alone decreased spontaneous and PMA-stimulated respiratory burst activity in freshly isolated macrophages, while the high concentration mixed atmosphere was also found to cause a significant decrease in respiratory burst activity in freshly isolated macrophages, while the high concentration mixed atmosphere was also found to cause a significant decrease in respiratory burst activity of macrophages maintained overnight in culture. HNO, at both concentrations resulted in a modest but significant increase in elastase inhibitory capacity of lung lavage fluid. Exposure to 0.6 ppm O resulted in an increased number of neutrophils in the lavage cell population as well as in increased lavage fluid protein content and elastase inhibitory capacity These changes were also observed following exposure to 1.0 mg/m HNO plus 0.6 ppm O although not to the same extent as following O alone. Linear regression analysis indicated that an antagonistic interaction occurs between HNO and O for changes in lavage cell population, lavage fluid protein content, and elastase inhibitory capacity. Ā© 1992 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted. 3 3 3 3 3 3 3 3 3 3 2 3 3 3 3 3 3 3 3 3 3 3 3
Susceptibility to pulmonary hypertension in inbred strains of mice exposed to cigarette smoke
- ā¦