The evolution of Zoraptera

Zoraptera is one of the most enigmatic and least understood orders in insects. Based on a wide taxon sampling from all continents where the group is known, we applied a phylogenetic approach using multiple DNA sequences to elucidate species-level relationships. The resulting phylogeny shows that Zoraptera is divided into three major clades, and that two comprise species distributed on different continents. The monophyly of these clades is at least partly supported by shared derived morphological features. The divergence age estimation and ancestral distribution area reconstruction suggest an ancient origin and early radiation initiated in the Permian. Plate tectonics theory suggests that the present distribution of Zoraptera was mainly established by vicariance, rather than dispersal. The three major clades probably originated on the Pangaea supercontinent, or alternatively on the linked Gondwana and Laurasia supercontinents. Their ancient origin explains previously found conspicuous interspecific variation of the genital apparatus, sperm structure and mating behaviour, in striking contrast to a highly conserved general body morphology. We compiled data of available reproductive features and reconstructed the character evolution. Our analyses revealed repeated acquisitions and/or losses of a hyperelongated intromittent organ, mating hooks and tergal protuberances

Qualitative risk assessment of a Dual Fuel (LNG-Diesel) system for heavy-duty trucks

A Dual Fuel (LNG-Diesel) system can be applied to heavy-duty diesel trucks for achieving environmental benefits in comparison to existing diesel vehicles. Because of lack of reports about risk assessment of this technology, we performed a qualitative assessment based on a framework of some literature techniques for risk identification, analysis and evaluation. After constructing a Reliability Block Diagram (RBD) to establish the context, we conducted bow-tie analysis, Fault Tree Analysis (FTA), Failure Mode and Effects Analysis (FMEA), likelihood and consequence analysis, and used a risk matrix. We applied these methods and techniques qualitatively to identify causes (e.g. collisions), critical events (e.g. releases of natural gas), related consequences (e.g. fires and explosions), and different possible pathways from a specific cause to its consequence, and to assess some negative accident scenarios related to use and parking of the vehicle. The bow-tie analysis also allowed to make explicit barriers and controls that prevent critical events and/or mitigate consequences. Therefore, we identified a set of safety measures, including design, technical, management, and emergency actions, which shall be implemented in each step of the system's life cycle.Our risk assessment showed that the risk level of the Dual Fuel (LNG-Diesel) system is similar to the risk level of a traditional diesel system. Future research will overcome current lack of data and, therefore, permit a quantitative rating of the risk of the Dual Fuel (LNG-Diesel) system