Tetramic and Tetronic Acids as Scaffolds in Bioinorganic and Bioorganic Chemistry

Tetramic and tetronic acids are naturally occurring molecules with a variety of biological activities. In this review article, we present the general strategies for the synthesis of these compounds and we reveal the functionalized groups that are responsible for their properties. We also set out their coordinating modes with up-to-date bibliographical references

The role of environmental context in dementia

A role for contextual information is invariably assumed in theories of episodic memory function. Extensive research has been conducted on behavioural and neuroimaging measures focusing on participants’ retrieval of contextual information and on associative memory. Much evidence suggests that memory for context and associative memory start to decline early in AD. Consequently, the assumption is made that AD patients could not benefit from the incidental reinstatement of contextual information. Here, the case is made that a more thorough differentiation needs to be made between memory for context and the influence of incidental context reinstatement. Such a distinction would suggest the possibility that AD patients could benefit from the reinstatement of contextual information is worth exploring further

Strategic Utilization of the VR and AR Technologies for the African Cultural Heritage Promotion and Management

The importance and purpose of heritage preservation have been extensively discussed in tourism research and has also been linked with regional and national development strategies. Because of time degradation, human activities, and the overcrowding effect, heritage preservation and reconstruction efforts are becoming critical to ensure the sustainability of heritage sites and disseminate the history and the potential of a region or a country. Virtual reality (VR) and augmented reality (AR) offer useful applications in heritage preservation. This study aims to explore the potential of these interactive technologies to be applied in heritage preservation in Africa, introduce strategies and applications developed Egypt and Tunis but also from Oman, and Finland, and highlight their impact in regional and national socio-economic development. As members of the Time Machine Europe this paper analyzes previous experiences in global scale and aim is to contribute in large-scale digitalization projects in Europe but also world-wide

Improved shaping approach to the preliminary design of low-thrust trajectories

This paper presents a general framework for the development of shape-based approaches to low-thrust trajectory design. A novel shaping method, based on a three-dimensional description of the trajectory in spherical coordinates, is developed within this general framework. Both the exponential sinusoid and the inverse polynomial shaping are demonstrated to be particular two-dimensional cases of the spherical one. The pseudoequinoctial shaping is revisited within the new framework, and the nonosculating nature of the pseudoequinoctial elements is analyzed. A two step approach is introduced to solve the time of flight constraint, related to the design of low-thrust arcs with boundary constraints for both spherical and pseudoequinoctial shaping. The solution derived from the shaping approach is improved with a feedback linear-quadratic controller and compared against a direct collocation method based on finite elements in time. The new shaping approach and the combination of shaping and linear-quadratic controller are tested on three case studies: a mission to Mars, a mission to asteroid 1989ML, a mission to comet Tempel-1, and a mission to Neptune