The application of image processing for Human-Computer Interface (HCI) using the Eye

The field of Human-Computer Interaction (HCI) has been developing tremendously since the past decade. The existence of smartphones or modern computers is already a norm in society these days which utilizes touch, voice and typing as a means for input. To further increase the variety of interaction, human eyes are set to be a good candidate for another form of HCI. The amount of information which the human eyes contain are extremely useful, hence, various methods and algorithm for eye gaze tracking are implemented in multiple sectors. However, some eye-tracking method requires infrared rays to be projected into the eye of the user which could potentially cause enzyme denaturation when the eye is subjected to those rays under extreme exposure. Therefore, to avoid potential harm from the eye-tracking method that utilizes infrared rays, this paper proposes an image-based eye tracking system using the Viola-Jones algorithm and Circular Hough Transform (CHT) algorithm. The proposed method uses visible light instead of infrared rays to control the mouse pointer using the eye gaze of the user. This research aims to implement the proposed algorithm for people with hand disability to interact with computers using their eye gaze.

The Effect of High Temperature on α-Amylase Enzyme Activity in the Germination of Several Rice Varieties (Oryza sativa L.)

High temperatures can affect plant morphophysiological changes and enzyme denaturation that can interfere with the germination process. This research aims to study the effect of temperature changes on the α-amylase enzyme activity of several rice varieties germination. The research applies Factorial Experiment in Completely Random Design, where the first factor is four levels of rice varieties, Anak Daro, Batang Piaman, Cisokan, and Inpari 30. The second factor is temperature level, 28 0C, 32 0C, 36 0C, 40 0C, 44 0C and 48 0C. Results showed that the activity of the α -amylase enzymes of the four varieties increased when the temperature increased to reach the optimal temperature, and denaturation began to occur above that temperature. The highest enzyme activity of α-amylase of Anak Daro, Cisokan and Inpari 30 varieties at 48 0C is 0,14 micromol, 0,365 micromol dan 0,191 micromol. In contrast the optimum enzyme activity of α-amylase of Batang Piaman variety at a temperature of 40 0C is 0,237 micromol and when the temperature rises to 48 0C a decrease in the activity of the α-amylation enzyme is 0,138 micromol. The variation in the activity of α-amylase enzymes in the four varieties is probably due to genetic differences and sucrose content. The Batang Piaman and Cisokan varieties can only germinate up to 36 0C, while the Daro and Inpari 30 varieties can germinate up to 40 0C.

Features of Solubilizing Effect of Amphiphilic Compounds during Pulp Deresination

The necessity to improve the existing technology of pulp deresination, in particular, to reduce the surfactants consumption and decrease the environmental load, led to a combination of existing methods of resin removal with the use of enzymatic treatment. The basis of the pulp deresination mechanism by amphiphilic compounds is the solubilization of resinous substances. Thus, the establishment of the patterns of this process and its control predetermines the success of implementation of the selected technology. The features of solubilization of triolein and rosin in the lipase-based systems of individual nonionic surfactants, the enzyme, as well as their synergistic mixtures with the determination of solubilization capacities of micelles and the possible mechanism of solubilizate incorporation into them were studied using spectrophotometry, pH measurement and dynamic light scattering. It was found that synthamide-5 has a low deresination capability in spite of the high solubilization capacity of its micelles and the production of aggregates with a hydrodynamic radius up to 98 nm after diffusion of rosin into them. It is likely that compact micellar structures with a developed surface, which are implemented in mixed systems of amphiphilic compounds, including the presence of synthamide-5 in them, are more preferable for successful deresination of pulp semi-finished products. The addition of lipase leads to an increased solubilization capacity of mixed aggregates and an increase in the intensity of solubilizate molecules incorporation. Thus, depending on the nature of the amphiphilic compound, there is a different mechanism for solubilizate incorporation into micelles. Determination of the size of associates in mixed systems showed the absence of enzyme denaturation, which predicts the successful application of such cooperative systems for deresination of fiber semi-finished products. It is found that the solubilizing capability of the studied systems on resin modeling objects correlates with their deresination capability with respect to different fiber semi-finished products.

Effect of temperature, pH and storage time on the stability of an extracellular fructosyltransferase from Aspergillus oryzae IPT-301

In this work, it was determined the influence of temperature, pH and storage time on the enzymatic activity and stability of an extracellular fructosyltransferase (FTase E.C.2.4.1.9) from Aspergillus oryzae IPT-301 produced by submerged fermentation. The thermodynamic parameters showed a tendency for increasing enzyme denaturation with the rise in temperature. The maximum transfructosylation activity was obtained at the incubation pH 5.5. During storage at 4 °C, the transfructosylation activity decreased, whereas the hydrolytic activity increased, especially in the first nine hours, a time in which the enzyme presented 45.6% of its initial transfructosylation activity. These results contributed to the improvement of the conditions of storage, immobilization and use of the soluble fructosyltransferases (FTase) in fructooligosaccharide (FOS) production.

Mechanistic insights into the dual activities of the single active site of l-lysine oxidase/monooxygenase from Pseudomonas sp. AIU 813

l-Lysine oxidase/monooxygenase (l-LOX/MOG) from Pseudomonas sp. AIU 813 catalyzes the mixed bioconversion of l-amino acids, particularly l-lysine, yielding an amide and carbon dioxide by an oxidative decarboxylation (i.e. apparent monooxygenation), as well as oxidative deamination (hydrolysis of oxidized product), resulting in α-keto acid, hydrogen peroxide (H2O2), and ammonia. Here, using high-resolution MS and monitoring transient reaction kinetics with stopped-flow spectrophotometry, we identified the products from the reactions of l-lysine and l-ornithine, indicating that besides decarboxylating imino acids (i.e. 5-aminopentanamide from l-lysine), l-LOX/MOG also decarboxylates keto acids (5-aminopentanoic acid from l-lysine and 4-aminobutanoic acid from l-ornithine). The reaction of reduced enzyme and oxygen generated an imino acid and H2O2, with no detectable C4a-hydroperoxyflavin. Single-turnover reactions in which l-LOX/MOG was first reduced by l-lysine to form imino acid before mixing with various compounds revealed that under anaerobic conditions, only hydrolysis products are present. Similar results were obtained upon H2O2 addition after enzyme denaturation. H2O2 addition to active l-LOX/MOG resulted in formation of more 5-aminopentanoic acid, but not 5-aminopentamide, suggesting that H2O2 generated from l-LOX/MOG in situ can result in decarboxylation of the imino acid, yielding an amide product, and extra H2O2 resulted in decarboxylation only of keto acids. Molecular dynamics simulations and detection of charge transfer species suggested that interactions between the substrate and its binding site on l-LOX/MOG are important for imino acid decarboxylation. Structural analysis indicated that the flavoenzyme oxidases catalyzing decarboxylation of an imino acid all share a common plug loop configuration that may facilitate this decarboxylation.