Selecting β-glucosidases to support cellulases in cellulose saccharification

BACKGROUND: Enzyme end-product inhibition is a major challenge in the hydrolysis of lignocellulose at a high dry matter consistency. β-glucosidases (BGs) hydrolyze cellobiose into two molecules of glucose, thereby relieving the product inhibition of cellobiohydrolases (CBHs). However, BG inhibition by glucose will eventually lead to the accumulation of cellobiose and the inhibition of CBHs. Therefore, the kinetic properties of candidate BGs must meet the requirements determined by both the kinetic properties of CBHs and the set-up of the hydrolysis process. RESULTS: The kinetics of cellobiose hydrolysis and glucose inhibition of thermostable BGs from Acremonium thermophilum (AtBG3) and Thermoascus aurantiacus (TaBG3) was studied and compared to Aspergillus sp. BG purified from Novozyme®188 (N188BG). The most efficient cellobiose hydrolysis was achieved with TaBG3, followed by AtBG3 and N188BG, whereas the enzyme most sensitive to glucose inhibition was AtBG3, followed by TaBG3 and N188BG. The use of higher temperatures had an advantage in both increasing the catalytic efficiency and relieving the product inhibition of the enzymes. Our data, together with data from a literature survey, revealed a trade-off between the strength of glucose inhibition and the affinity for cellobiose; therefore, glucose-tolerant BGs tend to have low specificity constants for cellobiose hydrolysis. However, although a high specificity constant is always an advantage, in separate hydrolysis and fermentation, the priority may be given to a higher tolerance to glucose inhibition. CONCLUSIONS: The specificity constant for cellobiose hydrolysis and the inhibition constant for glucose are the most important kinetic parameters in selecting BGs to support cellulases in cellulose hydrolysis

Altering one's body-perception through e-textiles and haptic metaphors

Tajadura-Jiménez A, Väljamäe A and Kuusk K (2020) Altering One's Body-Perception Through E-Textiles and Haptic Metaphors. Front. Robot. AI 7:7.Technologies change rapidly our perception of reality, moving from augmented to virtual to magical. While e-textiles are a key component in exergame or space suits, the transformative potential of the internal side of garments to create embodied experiences still remains largely unexplored. This paper is the result from an art-science collaborative project that combines recent neuroscience findings, body-centered design principles and 2D vibrotactile array-based fabrics to alter one's body perception. We describe an iterative design process intertwined with two user studies on the effects on body-perceptions and emotional responses of various vibration patterns within textile that were designed as spatial haptic metaphors. Our results show potential in considering materials (e.g., rocks) as sensations to design for body perceptions (e.g., being heavy, strong) and emotional responses. We discuss these results in terms of sensory effects on body perception and synergetic impact to research on embodiment in virtual environments, human-computer interaction, and e-textile design. The work brings a new perspective to the sensorial design of embodied experiences which is based on "material perception" and haptic metaphors, and highlights potential opportunities opened by haptic clothing to change body-perception.This work was partially supported by PSI2016-79004-R Magic Shoes project grant (AEI/FEDER, UE), from Ministerio de Economía, Industria y Competitividad of Spain and the Magic Lining VERTIGO project as part of the STARTS program of the European Commission, based on technological elements from the project Magic Shoes. AT-J was supported by RYC- 2014–15421 grant from the Ministerio de Economía, Industria y Competitividad of Spain and AV was supported by the Estonian Research Council grant PUT1518

Altering One's Body-Perception Through E-Textiles and Haptic Metaphors

Technologies change rapidly our perception of reality, moving from augmented to virtual to magical. While e-textiles are a key component in exergame or space suits, the transformative potential of the internal side of garments to create embodied experiences still remains largely unexplored. This paper is the result from an art-science collaborative project that combines recent neuroscience findings, body-centered design principles and 2D vibrotactile array-based fabrics to alter one's body perception. We describe an iterative design process intertwined with two user studies on the effects on body-perceptions and emotional responses of various vibration patterns within textile that were designed as spatial haptic metaphors. Our results show potential in considering materials (e.g., rocks) as sensations to design for body perceptions (e.g., being heavy, strong) and emotional responses. We discuss these results in terms of sensory effects on body perception and synergetic impact to research on embodiment in virtual environments, human-computer interaction, and e-textile design. The work brings a new perspective to the sensorial design of embodied experiences which is based on “material perception” and haptic metaphors, and highlights potential opportunities opened by haptic clothing to change body-perception

A transdisciplinary collaborative journey leading to sensorial clothing

Recent science funding initiatives have enabled participants from a diverse array of disciplines to engage in common spaces for developing solutions for new wearables. These initiatives include collaborations between the arts and sciences, fields which have traditionally contributed very different forms of knowledge, methodology, and results. However, many such collaborations often turn out as science communication and dissemination activities that make no concrete contribution to technological innovation. Magic Lining, a transdisciplinary collaborative project involving artistic and scientific partners working in the fields of e-textile design, cognitive neuroscience and human-computer interaction, creates a shared experiential knowledge space. This article focuses on the research question of how a transdisciplinary collaborative design processinvolving material explorations, prototyping, first-person-perspective and user studies, can lead to the creation of a garment that invites various perceptual and emotional responses in its wearer. The article reflects on the design journey, highlighting the transdisciplinary team's research through design experience and shared language for knowledge exchange. This process has revealed new research paths for an emerging field of 'sensorial clothing', combining the various team members' fields of expertise and resulting in a wearable prototype.This work was partially supported by the VERTIGO project as part of the STARTS program of the European Commission, based on technological elements from the project Magic Shoes (grant PSI2016-79004-R, Ministerio de Economía, Industria y Competitividad of Spain, AEI/FEDER). The work was also supported by the project Magic outFIT, funded by the Spanish Agencia Estatal de Investigación (PID2019-105579RB-I00/AEI/10.13039/501100011033). Aleksander Väljamäe’s work was supported by the Estonian Research Council grant PUT1518; and Ana Tajadura-Jiménez’s work was supported by RYC-2014–15421 grant, Ministerio de Economía, Industria y Competitividad of Spain

Evaluation of Psychoacoustic Sound Parameters for Sonification

Sonification designers have little theory or experimental evidence to guide the design of data-to-sound mappings. Many mappings use acoustic representations of data values which do not correspond with the listener's perception of how that data value should sound during sonification. This research evaluates data-to-sound mappings that are based on psychoacoustic sensations, in an attempt to move towards using data-to-sound mappings that are aligned with the listener's perception of the data value's auditory connotations. Multiple psychoacoustic parameters were evaluated over two experiments, which were designed in the context of a domain-specific problem - detecting the level of focus of an astronomical image through auditory display. Recommendations for designing sonification systems with psychoacoustic sound parameters are presented based on our results

Prototyping a method for the assessment of real-time EEG sonifications

This paper presents a first step in the development of a methodology to compare the ability of different sonifications to convey the fine temporal detail of the Electroencephalography (EEG) brainwave signal in real time. In EEG neurofeedback a person‟s EEG activity is monitored and presented back to them, to help them to learn how to modify their brain activity. Learning theory suggests that the more rapidly and accurately the feedback follows behaviour the more efficient the learning will be. Therefore a critical issue is how to assess the ability of a sonification to convey rapid and temporally complex EEG data for neurofeedback. To allow for replication, this study used sonifications of pre-recorded EEG data and asked participants to try and track aspects of the signal in real time using a mouse. This study showed that, although imperfect, this approach is a practical way to compare the suitability of EEG sonifications for tracking detailed EEG signals in real time and that the combination of quantitative and qualitative data helped characterise the relative efficacy of different sonifications

Investigating Perceptual Congruence Between Data and Display Dimensions in Sonification

The relationships between sounds and their perceived meaning and connotations are complex, making auditory perception an important factor to consider when designing sonification systems. Listeners often have a mental model of how a data variable should sound during sonification and this model is not considered in most data:sound mappings. This can lead to mappings that are difficult to use and can cause confusion. To investigate this issue, we conducted a magnitude estimation experiment to map how roughness, noise and pitch relate to the perceived magnitude of stress, error and danger. These parameters were chosen due to previous findings which suggest perceptual congruency between these auditory sensations and conceptual variables. Results from this experiment show that polarity and scaling preference are dependent on the data:sound mapping. This work provides polarity and scaling values that may be directly utilised by sonification designers to improve auditory displays in areas such as accessible and mobile computing, process-monitoring and biofeedback

Designing a gesture-sound wearable system to motivate physical activity by altering body perception

People, through their bodily actions, engage in sensorimotor loops that connect them to the world and to their own bodies. People's brains integrate the incoming sensory information to form mental representations of their body appearance and capabilities. Technology provides exceptional opportunities to tweak sensorimotor loops and provide people with different experiences of their bodies. We recently showed that real-time sound feedback on one's movement (sonic avatar) can be used for sensory alteration of people's body perception, and in turn provoke enhanced motor behaviour, confidence and motivation for physical activity (PA) in people while increasing their positive emotions towards their own bodies. Here we describe the design process of a wearable prototype that aims to investigate how we can overcome known body-perception-related psychological barriers to PA by employing action-sound loops. The prototype consists of sensors that capture people's bodily actions and a gesture-sound palette that allows different action-sound mappings. Grounded in neuroscientific, clinical and sports psychology studies on body perception and PA, the ultimate design aim is to enhance PA in inactive populations by provoking changes on their bodily experience

From presence to consciousness through virtual reality

Immersive virtual environments can break the deep, everyday connection between where our senses tell us we are and where we are actually located and whom we are with. The concept of 'presence' refers to the phenomenon of behaving and feeling as if we are in the virtual world created by computer displays. In this article, we argue that presence is worthy of study by neuroscientists, and that it might aid the study of perception and consciousness