Molecular approaches to smart materials via interface recognition and conformationally switchable cavitands

In this thesis the molecular level design of functional materials and systems is reported. In the first part, tetraphosphonate cavitand (Tiiii) recognition properties towards amino acids are studied both in the solid state, through single crystal X-ray diffraction, and in solution, via NMR and ITC experiments. The complexation ability of these supramolecular receptors is then applied to the detection of biologically remarkable N-methylated amino acids and peptides using complex dynamic emulsions-based sensing platforms. In the second part, a general supramolecular approach for surface decoration with single-molecule magnets (SMMs) is presented. The self-assembly of SMMs is achieved through the formation of a multiple hydrogen bonds architecture (UPy-NaPy complexation). Finally we explore the possibility to impart auxetic behavior to polymeric material through the introduction of conformationally switchable monomers, namely tetraquinoxaline cavitands (QxCav). Their interconversion from a closed vase conformation to an extended kite form is studied first in solution, then in polymeric matrixes via pH and tensile stimuli by UV-Vis spectroscopy.

Expert Approaches to Mental Toughness Development in the High Risk Sport of Diving

Research focusing on mental toughness development and high risk sport is limited to one examination of elite gymnasts' perceptions. Coaches have acknowledged that mental toughness is important to performance success, while admitting they do not know effective development strategies. The aim of the current research is to address both these concerns by employing a grounded theory approach to ascertain elite diving coaches perceptions of mental toughness development and what mental toughness is. Seven diving coaches volunteered and were interviewed for an average of 49 minutes. They all coached an athlete that participated either in the world championships or Olympic games since 2008. Participants reported that mental toughness was the ability of a diver to perform a movement in a crucial moment that requires focus, extending beyond their comfort zone, overcoming fear, and never giving up. Mentaltoughness may not be the appropriate term due to its lack of multicultural sensitivity. Participants felt that dealing with adversity was something divers would have to constantly process. Mental toughness can be developed by the coach, the environment, or individual athlete. Unique attributes specific to divers were an awareness of self and a distinct level of knowing what the athlete was going to do. More research needs to be conducted to determine if these concepts can be generalized to other high risk sports. Future research could help establish a valid quantitative measure of mental toughness development.

Computational approaches to subjectivity and sentiment analysis: Present and envisaged methods and applications

Recent years have witnessed a surge of interest in computational methods for affect, ranging from opinion mining, to subjectivity detection, to sentiment and emotion analysis. This article presents a brief overview of the latest trends in the field and describes the manner in which the articles contained in the special issue contribute to the advancement of the area. Finally, we comment on the current challenges and envisaged developments of the subjectivity and sentiment analysis fields, as well as their application to other Natural Language Processing tasks and related domains.

Using new scanning electron microscopy (SEM) approaches to elucidate bacterial biofilm architecture

Healthcare-associated infections (HAI) are a major public health problem being Klebsiella pneumoniae and nontuberculous mycobacteria, both with high antibiotic resistance rates, among their etiological agent. Since biofilme assembly is pointed as one of the mechanisms involved in emergence of antibiotic resistance understanding bacteria organization within the biofilm and the identification of differences between planktonic and sessile forms of bacteria will be a step forward to fight HAI. In the present work we used SEM as a tool to characterize the internal structure of biofilm assembled on different surfaces. For SEM analysis, biofilms were allowed to form either on six-well cell culture plates, silicon or metallic disks placed inside the wells for different incubation periods at 37 °C. The biofilm assembled on the cell culture dish was for both secondary and backscattered electron analysis as described before. Biofilms assembled on silicon disks instead of being sectioned were prepared as metallographic samples, by grinding with grit SIC paper and polishing with diamond particles. Samples were cleaned (70% ethanol), dried with hot air, further coated and analysed. A preliminary study using FIB-SEM has been performed to access the ultrastructure of biofilms assembled on metallic surfaces. The results obtained showed that the same bacteria assembled biofilms with different ratios of biomass and extracellular matrix depending on the surface. SEM performed on thin sections of biofilms is a powerful tool to elucidate biofilm structure allowing the quantification of the major components. FIB-SEM is also a promising tool in this field.

Classic and new approaches to evaluate risk assessment for public health related to exposure to Halogenated Polycyclic Aromatic Hydrocarbons present in ludic waters

Risk assessment for public health related to exposure to Halogenated Polycyclic Aromatic Hydrocarbons present in ludic waters