The Effects of Truck Platoons on Steel Bridge Load Ratings

Platooning is the use of vehicle-to-vehicle communications and sensors, such as cameras and radars, to allow two or more trucks to drive as a single unit, and automatically accelerate and brake together, allowing them to travel at closer distances. With the world moving closer towards a more environmental-friendly approach to everyday decisions, it is not a surprise that the concept of truck platooning is gaining momentum, as it reduces CO2 emissions by lowering fuel consumption. However, studies need to be performed to confirm that bridges already in existence will be able to handle platoons, even though they were not designed for them, or, restrict platoon activity on the ones that show poor results. The scope of this research is to study the effects of truck platooning on, steel girder bridges of single, two, and three-spans. Several truck-to-truck distances were selected and tested with a different number of trucks, per platoon, while varying spans lengths, or girder spacings. The AASHTO design and legal load ratings were calculated for each platoon case and were then used to examine the effects of truck platooning on bridge load ratings, and thus the adequacy of current bridges to carry platoons. The overall findings of the study include the following observations. Bridges previously designed using Allowable Stress Design may be inadequate for truck platoons in the positive moment region for medium to long-spans. In addition, they may be inadequate in the negative moment region for short spans. Bridges previously designed using Load Factor Design will likely be adequate for truck platoons in the positive moment region. However, issues may arise in the negative moment region for medium span lengths. Bridges previously designed using Load and Resistance Factor Design may be inadequate for truck platoons in the positive moment region for long-spans. However, there will likely not be any issues in the negative moment region. The number of trucks with in a platoon and the spacing between trucks inside a platoon are the most influential parameters on their load ratings. The adequacy of existing bridges will hinge on the quantities of these variables

A Journey Under the Sea: The Quest for Marine Anti-Cancer Alkaloids

The alarming increase in the global cancer death toll has fueled the quest for new effective anti-tumor drugs thorough biological screening of both terrestrial and marine organisms. Several plant-derived alkaloids are leading drugs in the treatment of different types of cancer and many are now being tested in various phases of clinical trials. Recently, marine-derived alkaloids, isolated from aquatic fungi, cyanobacteria, sponges, algae, and tunicates, have been found to also exhibit various anti-cancer activities including anti-angiogenic, anti-proliferative, inhibition of topoisomerase activities and tubulin polymerization, and induction of apoptosis and cytotoxicity. Two tunicate-derived alkaloids, aplidin and trabectedin, offer promising drug profiles, and are currently in phase II clinical trials against several solid and hematologic tumors. This review sheds light on the rich array of anti-cancer alkaloids in the marine ecosystem and introduces the most investigated compounds and their mechanisms of action

Differential Growth Inhibitory Effects of Highly Oxygenated Guaianolides Isolated from the Middle Eastern Indigenous Plant Achillea falcata in HCT-116 Colorectal Cancer Cells

Medicinal plants play a crucial role in traditional medicine and in the maintenance of human health worldwide. Sesquiterpene lactones represent an interesting group of plant-derived compounds that are currently being tested as lead drugs in cancer clinical trials. Achillea falcata is a medicinal plant indigenous to the Middle Eastern region and belongs to the Asteraceae family, which is known to be rich in sesquiterpene lactones. We subjected Achillea falcata extracts to bioassay-guided fractionation against the growth of HCT-116 colorectal cancer cells and identified four secotanapartholides, namely 3-β-methoxy- isosecotanapartholide (1), isosecotanapartholide (2), tanaphallin (3), and 8-hydroxy-3-methoxyisosecotanapartholide (4). Three highly oxygenated guaianolides were isolated for the first time from Achillea falcata, namely rupin A (5), chrysartemin B (6), and 1β, 2β-epoxy- 3β,4α,10α-trihydroxyguaian- 6α,12-olide (7). These sesquiterpene lactones showed no or minor cytotoxicity while exhibiting promising anticancer effects against HCT-116 cells. Further structure-activity relationship studies related the bioactivity of the tested compounds to their skeleton, their lipophilicity, and to the type of functional groups neighboring the main alkylating center of the molecule

Comment saisir et comprendre la marche en ville ?: Introduction à l’usage de l’eye tracker dans une rue de Beyrouth

International audienceÀ partir d’une recherche menée dans deux rues proches du centre-ville de Beyrouth, une équipe pluridisciplinaire composée d’anthropologues, de géographes et de sociologues, s’interroge sur la complexité de la marche dans une ville considérée comme chaotique et saturée par la circulation automobile. Dans la perspective des approches relationnistes et afin de comprendre comment s’établit une écologie de la perception, une méthodologie fondée sur la captation du regard et du cheminement avec un eye tracker (oculomètre) est mise en œuvre. Cet instrument permet, entre autres, d’envisager la dimension du « corps en acte », y compris dans l’explicitation par les personnes participantes des matériaux visuels et sonores recueillis