Hydrogen photo-production by mixotrophic cultivation of chlamydomonas reinhardtii: Interaction between organic carbon and nitrogen

Hydrogen photo-production by a wild type and two engineered strains of Chlamydomonas reinhardtii was investigated. Growth rate values and hydrogen yields attained as the concentration of acetate and nitrogen vary were compared. In the analysis of microalgal growth, the interaction between organic carbon (acetate) and nitrogen (nitrate) was investigated by recourse to an experimental factorial design. This analysis evidenced the existence of a statistically significant interaction between organic carbon and nitrate. Hydrogen production was attained by cultivating microalgae previously grown in mixotrophic regime with sulphur deprived medium. The influence of varying the photobioreactor headspace on hydrogen production was investigated. This analysis revealed an increase in the hydrogen produced per unit volume of culture of about one order of magnitude when the headspace volume is modified from 100 to 350 mL. This result provides valuable indications on how to design and operate photobioreactors for hydrogen production optimization and was thoroughly discussed in terms of the metabolic pathways activated by sulphur depletion. ©2014, AIDIC Servizi S.r.l

Supporting ethnographic studies of ubiquitous computing in the wild

Ethnography has become a staple feature of IT research over the last twenty years, shaping our understanding of the social character of computing systems and informing their design in a wide variety of settings. The emergence of ubiquitous computing raises new challenges for ethnography however, distributing interaction across a burgeoning array of small, mobile devices and online environments which exploit invisible sensing systems. Understanding interaction requires ethnographers to reconcile interactions that are, for example, distributed across devices on the street with online interactions in order to assemble coherent understandings of the social character and purchase of ubiquitous computing systems. We draw upon four recent studies to show how ethnographers are replaying system recordings of interaction alongside existing resources such as video recordings to do this and identify key challenges that need to be met to support ethnographic study of ubiquitous computing in the wild

The Crystal Structure of Monovalent Streptavidin.

The strong interaction between streptavidin (SA) and biotin is widely utilized in biotechnological applications. A SA variant, monovalent SA, was developed with a single and high affinity biotin-binding site within the intact tetramer. However, its structural characterization remains undetermined. Here, we seek to determine the crystal structure of monovalent SA at 1.7-Å resolution. We show that, in contrast to its 'close-state' in the only wild-type subunit, the L3,4 loops of three Dead SA subunits are free from crystal packing and remain in an 'open state', stabilized by a consistent H-bonding network involving S52. This H-bonding network also applies to the previously reported open state of the wild-type apo-SA. These results suggest that specific substitutions (N23A/S27D/S45A) at biotin-binding sites stabilize the open state of SA L3,4 loop, thereby further reducing biotin-binding affinity. The general features of the 'open state' SA among different SA variants may facilitate its rational design. The structural information of monovalent SA will be valuable for its applications across a wide range of biotechnological areas

An In silico Based Comparison of Drug Interactions in Wild and Mutant Human HIV-1 RT through Docking Studies

The aim of this research is to compare the drug interactions between wild-type and mutant forms of human HIV-1 reverse transcriptase (RT) using in silico docking studies Materials and methods: Extract the crystal structures of wild-type HIV-1 RT (PDB ID: 6CQJ) and K103N/Y181C mutant RT (PDB ID: 6COR) from Protein Data Bank, antiviral drugs were downloaded from Pubchem server. Docking was carried out by HEX docking server and interaction was analyzed using Docking energy. Discussion: The findings of this research could contribute to the development of more effective antiretroviral therapies tailored to specific mutations and aid in the design of novel drugs targeting drug-resistant HIV-1 strains. Ultimately, this research may contribute to improving the treatment outcomes and quality of life for individuals living with HIV-1 infection. Conclusion: From the analysis the drug of Zidovudine has shown in Wild type Structure whereas Didanosine the drug which was shown in highest interaction of Mutant type structure

Mobslinger: The Fastest Mobile in the West.

Whilst there is a number of location sensing games emerging for mobile phones, from both commercial and academic sectors, there are few examples of social proximity based games that are effectively position independent. Bluetooth would seem an obvious choice for proximity based games, although the majority of games produced to-date simply uses it to provide a quasi peer to peer connection between users of multiplayer games. This is no-doubt due to the fact that proximity can often be implied from other location sensing technologies and that Bluetooth is often perceived as difficult to employ. In this paper we will show that Bluetooth can provide exciting game scenarios that can enable spontaneous stimulated social interaction using only proximity information. We illustrate this through the design rationale and subsequent implementation of ‘mobslinger’ which is a wild west, quick draw, ‘shoot-em-up’ game using mobile phones

Feeding the Coffee Habit: A Longitudinal Study of a Robo-Barista

Studying Human-Robot Interaction over time can provide insights into what really happens when a robot becomes part of people's everyday lives. "In the Wild" studies inform the design of social robots, such as for the service industry, to enable them to remain engaging and useful beyond the novelty effect and initial adoption. This paper presents an "In the Wild" experiment where we explored the evolution of interaction between users and a Robo-Barista. We show that perceived trust and prior attitudes are both important factors associated with the usefulness, adaptability and likeability of the Robo-Barista. A combination of interaction features and user attributes are used to predict user satisfaction. Qualitative insights illuminated users' Robo-Barista experience and contribute to a number of lessons learned for future long-term studies.Comment: Author Accepted Manuscript, 8 pages, RO-MAN'23, 32nd IEEE International Conference on Robot and Human Interactive Communication (RO-MAN), August 2023, Busan, South Kore

Exhaustive mutagenesis of six secondary active-site residues in Escherichia coli chorismate mutase shows the importance of hydrophobic side chains and a helix N-capping position for stability and catalysis

Secondary active-site residues in enzymes, including hydrophobic amino acids, may contribute to catalysis through critical interactions that position the reacting molecule, organize hydrogen-bonding residues, and define the electrostatic environment of the active site. To ascertain the tolerance of an important model enzyme to mutation of active-site residues that do not directly hydrogen bond with the reacting molecule, all 19 possible amino acid substitutions were investigated in six positions of the engineered chorismate mutase domain of the Escherichia coli chorismate mutase-prephenate dehydratase. The six secondary active-site residues were selected to clarify results of a previous test of computational enzyme design procedures. Five of the positions encode hydrophobic side chains in the wild-type enzyme, and one forms a helix N-capping interaction as well as a salt bridge with a catalytically essential residue. Each mutant was evaluated for its ability to complement an auxotrophic chorismate mutase deletion strain. Kinetic parameters and thermal stabilities were measured for variants with in vivo activity. Altogether, we find that the enzyme tolerated 34% of the 114 possible substitutions, with a few mutations leading to increases in the catalytic efficiency of the enzyme. The results show the importance of secondary amino acid residues in determining enzymatic activity, and they point to strengths and weaknesses in current computational enzyme design procedures

Social Robots to enhance therapy and interaction for children: From the design to the implementation "in the wild"

En les últimes dues dècades els robots socials s'han convertit en un camp emergent en el qual encara hi ha molt per fer. Aquest camp requereix coneixements en mecànica, control, intel·ligència artificial, sistemes, etc., però també en psicologia, disseny, ètica, etc. El nostre grup de recerca de perfil interdisciplinari ha estat treballant en el disseny de robots socials en diferents aplicacions per a nens amb necessitats especials. L'objectiu d'aquesta tesi és investigar diferents escenaris en teràpia o educació on els robots socials podrien ser una eina útil per als nens. Es van realitzar 4 estudis amb diferents propòsits: (1) dissenyar activitats amb robòtica de LEGO per avaluar el comportament social dels nens amb trastorn de l'espectre autista (TEA) (entre companys i amb adults) i analitzar la seva efectivitat, (2) dissenyar un robot social per recuperar les funcionalitats més afectades a causa de traumatismes cranioencefàlics (TCE) en nens i veure l'eficàcia del tractament, (3) proporcionar un robot mascota per alleujar els sentiments d'ansietat, solitud i estrès en nens hospitalitzats, i (4) comprovar com un robot amb comportament social i amb una personalització versus robots sense aquestes característiques mostra diferències en termes d'interacció amb nens i, per tant, pot ajudar en l'efectivitat de diferents tractaments com hem esmentat anteriorment. Els resultats van revelar diferents resultats depenent de l'aplicació: (1) efectivitat amb la plataforma robòtica social que vam dissenyar en el tractament neuropsicològic per a aquells nens afectats per TCE, (2) eficàcia amb les activitats de robòtica de LEGO dissenyades per un grup de terapeutes en termes de millora d'habilitats socials (3) un efecte positiu entre els mediadors i facilitadors de la interacció i les relacions entre els diferents agents involucrats en el procés de la cura: pacients hospitalitzats, familiars, voluntaris i personal clínic, i (4) una interacció diferent, en termes de temps, entre els dos grups durant període de dues setmanes.En las últimas dos décadas los robots sociales se han convertido en un campo emergente en el que todavía hay mucho por hacer. Este campo requiere conocimientos en mecánica, control, inteligencia artificial, sistemas, etc., pero también en psicología, diseño, ética, etc. Nuestro grupo de investigación de perfil interdisciplinar ha estado trabajando en el diseño de robots sociales en diferentes aplicaciones para niños con necesidades especiales. El objetivo de esta tesis es investigar diferentes escenarios en terapia o educación donde los robots sociales podrían ser una herramienta útil para los niños. Se realizaron 4 estudios con diferentes propósitos: (1) diseñar actividades con robótica de LEGO para evaluar el comportamiento social de los niños con trastorno del espectro autista (TEA) (entre compañeros y con adultos) y analizar su efectividad, (2) diseñar un robot social para recuperar las funcionalidades más afectadas a causa de traumatismos craneoencefálicos (TCE) en niños y ver la eficacia del tratamiento, (3) proporcionar un robot mascota para aliviar los sentimientos de ansiedad, soledad y estrés en niños hospitalizados, y (4) comprobar como un robot con comportamiento social y con una personalización versus robots sin esas características muestra diferencias en términos de interacción con niños y, por tanto, puede ayudar en la efectividad de diferentes tratamientos como mencionamos anteriormente. Los resultados revelaron diferentes resultados dependiendo de la aplicación: (1) efectividad con la plataforma robótica social que diseñamos en el tratamiento neuropsicológico para aquellos niños afectadas por TCE, (2) eficacia con las actividades de robótica de LEGO diseñadas por un grupo de terapeutas en términos de mejora de habilidades sociales (3) un efecto positivo entre los mediadores y facilitadores de la interacción y las relaciones entre los diferentes agentes involucrados en el proceso del cuidado: pacientes hospitalizados, familiares, voluntarios y personal clínico, y (4) una interacción diferente, en términos de tiempo, entre ambos grupos en el promedio de un período de dos semanas.Over the past two decades social robots have become an emerging field where there are many things still to work on. This field not only requires knowledge in mechanics, control, artificial intelligence, systems, etc., but also in psychology, design, ethics, etc. Our multidisciplinary research group has been working on designing social robotic platforms in different applications for children with special needs. The aim of this thesis is to investigate different scenarios in therapy or education where social robots could be a useful tool for children. We ran 4 studies with different purposes: (1) to design activities with LEGO robotics to assess children with autism spectrum disorder (ASD) social behaviour (between peers and with adults) and to analyze the effectiveness, (2) to design a social robotic platform to recover the functionalities most affected by traumatic brain injuries (TBI) in children and see the effectiveness of the treatment, (3) to provide a pet robot to alleviate feelings of anxiety, loneliness and stress of long-term children inpatient and their bystanders, and (4) to verify how a robot with social behaviour and personalization verses those robots without, shows differences in terms of interaction with children and thus, helps the effectiveness of different treatments as we mention above. The results revealed different outcomes depending on the application: (1) effectiveness with the social robotic platform that we designed in neuropsychological treatment in those areas affected by TBI, (2) effectiveness with the LEGO robotics activities designed by a group of therapists in terms of improvement of the social skills and engagement, (3) a positive effect within mediators and facilitators of interaction and relationships between the different agents involved in the caring process: in-patients, relatives, volunteers and clinical staff (4) slight evidence towards a different interaction, in terms of time, between both groups in the average of a two-week period

A Budding-Defective M2 Mutant Exhibits Reduced Membrane Interaction, Insensitivity To Cholesterol, And Perturbed Interdomain Coupling

Influenza A M2 is a membrane-associated protein with a C-terminal amphipathic helix that plays a cholesterol-dependent role in viral budding. An M2 mutant with alanine substitutions in the C-terminal amphipathic helix is deficient in viral scission. With the goal of providing atomic-level understanding of how the wild-type protein functions, we used a multipronged site-directed spin labeling electron paramagnetic resonance spectroscopy (SDSL-EPR) approach to characterize the conformational properties of the alanine mutant. We spin-labeled sites in the transmembrane (TM) domain and the C-terminal amphipathic helix (AH) of wild-type (WT) and mutant M2, and collected information on line shapes, relaxation rates, membrane topology, and distances within the homotetramer in membranes with and without cholesterol. Our results identify marked differences in the conformation and dynamics between the WT and the alanine mutant. Compared to WT, the dominant population of the mutant AH is more dynamic, shallower in the membrane, and has altered quaternary arrangement of the C-terminal domain. While the AH becomes more dynamic, the dominant population of the TM domain of the mutant is immobilized. The presence of cholesterol changes the conformation and dynamics of the WT protein, while the alanine mutant is insensitive to cholesterol. These findings provide new insight into how M2 may facilitate budding. We propose the AH–membrane interaction modulates the arrangement of the TM helices, effectively stabilizing a conformational state that enables M2 to facilitate viral budding. Antagonizing the properties of the AH that enable interdomain coupling within M2 may therefore present a novel strategy for anti-influenza drug design