Multifactorial Design Research Articles

Gender differences in the use of an upper-extremity exoskeleton during physically and cognitively demanding tasks- a study protocol for a randomized experimental trial

BackgroundUpper limb exoskeletons are recommended to alleviate muscle fatigue, particularly in working conditions inducing musculoskeletal discomfort like overhead work. However, wearing an exoskeleton might introduce cognitive-motor interference, affecting performance. Understanding its neural impact and potential gender differences in design effects is crucial. Therefore, the aim of this study is to examine exoskeleton effects addressing cross-gender comparisons, and exploring the impact on cognitive and physical workload in real-world scenarios. The research questions address the impact of exoskeleton use on muscle synergies, upper body posture, cognitive resources, comfort/discomfort, acceptance and usability.MethodsThe cross-sectional study integrates a multifactorial mixed-measure design. Participants are grouped by gender (female vs. male) and working condition (with vs. without exoskeleton). Motor performance and underlying neuronal correlates (fNIRS) will be analyzed. Based on an a priori sample size calculation, 80 participants (40 female/40 male) will be recruited. Working performance will be assessed by 1. Physical Performance Task (PILE task) and 2. Precision Task (following the Fitts paradigm), while body postures will be monitored with an Xsens motion capture system. Brain activation will be captured with an fNIRS system comprising 32 active optodes. Postural comfort/discomfort, acceptance, and usability will be reported via standardized questionnaires.DiscussionThe study will gain insights into potential gender differences in exoskeleton use and will contribute to designing and optimizing the implementation of exoskeletons by considering muscle synergies, movement variability and cognitive resource allocation. Additionally, the study also highlights user discomfort, a crucial factor that could impede widespread adoption, particularly among females, in real-world scenarios.

A Study of the Influence of Ion-Ozonized Water on the Properties of Pasta Dough Made from Wheat Flour and Pumpkin Powder.

Water treated with ion ozone improves the technological qualities of food products. Therefore, ion-ozonated water was used in the work, and whole-grain flour from soft wheat of the Almaly variety and pumpkin powder were used as raw materials to improve the quality and nutritional value of the pasta. This study investigated the effects of ion-ozone concentration in ion-ozonated water Cio, water temperature tw, pumpkin powder content Cpp and drying temperature td on various characteristics affecting the quality of pasta, including its organoleptic physical, chemical, and rheological properties. These characteristics were assessed by conducting multiple experiments, a total of 25 indicators were determined, such as humidity, acidity, cooking properties, deformation, and other basic quality indicators. To reduce the number of experiments and obtain a reliable assessment of the influence of individual factors on the quality indicators of pasta, methods involving the multifactorial design of experiments were applied. Data processing and all necessary calculations were carried out using the PLAN sequential regression analysis program. Consequently, our findings indicate that minimizing dry water (DM) loss in cooking water requires a dual approach: increasing ion-ozone concentration and optimizing pasta composition and drying conditions, specifically by reducing pumpkin powder content and drying temperature. As a result, it was established that to obtain high-quality pasta from whole-grain flour with high quality and rheological properties, it is necessary to use the following optimal production modes: ion-ozone concentration in ion-ozonated water Cio = 2.5 × 10-6 mg/cm3, water temperature tw = 50 °C, pumpkin powder content Cpp = 3.0%, and pasta drying temperature td = 50 °C. The resulting pasta is an environmentally friendly product with a high content of biologically active substances.

Non-conventional endpoints show higher sulfoxaflor toxicity to Chironomus riparius than conventional endpoints in a multistress environment

Evidence grows that standard toxicity testing might underestimate the environmental risk of neurotoxic insecticides. Behavioural endpoints such as locomotion and mobility have been suggested as sensitive and ecologically relevant additions to the standard tested endpoints. Possible interactive effects of chemicals and additional stressors are typically overlooked in standardised testing. Therefore, we aimed to investigate how concurrent exposure to environmental stressors (increased temperature and predation cues) and a nicotinic acetylcholine receptor (nAChR)-modulating insecticide (‘sulfoxaflor’) impact Chironomus riparius across a range of conventional and non-conventional endpoints. We used a multifactorial experimental design encompassing three stressors, sulfoxaflor (2.0–110 µg/L), predation risk (presence/absence of predatory cues), and elevated temperature (20 °C and 23 °C), yielding a total of 24 distinct treatment conditions. Additional stressors did not change the sensitivity of C. riparius to sulfoxaflor. To assess potential additive effects, we applied an Independent Action (IA) model to predict the impact on eight endpoints, including conventional endpoints (growth, survival, total emergence, and emergence time) and less conventional endpoints (the size of the adults, swimming abilities and exploration behaviour). For the conventional endpoints, observed effects were either lower than expected or well-predicted by the IA model. In contrast, we found greater than predicted effects of predation cues and temperature in combination with sulfoxaflor on adult size, larval exploration, and swimming behaviour. However, in contrast to the non-conventional endpoints, no conventional endpoints detected interactive effects of the neurotoxic insecticide and the environmental stressors. Acknowledging these interactions, increasing ecological context of ecotoxicological test systems may, therefore, advance environmental risk analysis and interpretation as the safe environmental concentrations of neurotoxic insecticides depend on the context of both the test organism and its environment.

Ensiling conditions and changes of cannabinoid concentration in industrial hemp.

Hemp (Cannabis sativa L.) is an important source of fibre and seed oil and protein. By-products of industrial hemp fibre production, like hemp seeds and cakes, can be used as feed for all animal species as fat and protein source and the whole hemp plant (including stalk and leaves) might be a suitable fibre source for ruminants. However, a previous feeding experiment with leaf-flower-seed hemp silage, made from an industrial hemp variety, demonstrated detrimental effects on cow health parameters and a significant transfer of several cannabinoids, including the psychoactive tetrahydrocannabinol (∆9-THC), into cow's milk, posing a potential risk to the safety of consumers. Based on those observations, the present study tested the hypothesis that anaerobic fermentation, as during ensiling, increases the content of ∆9-THC in hemp. Therefore, silages of whole plants from the industrial hemp Cannabis sativa L. var. Ivory were prepared in a multifactorial design, with the four treatments 1) untreated control (CON), 2) addition of 10 mL per kg fresh weight homofermentative lactobacilli at 105 cfu/mL (LBAC), 3) addition of 10 mL per kg fresh weight homofermentative lactobacilli at 105 cfu/mL plus 30 g molasses (LBACmol) and 4) addition of propionic acid (10 mL/kg fresh weight) (PRO). Ultra high performance liquid chromatography coupled with tandem mass spectrometry with electrospray ionisation (UHPLC-MS/MS) was performed for analysis of cannabinoids in fresh hemp material and after 10 and 90 days of ensiling. The study revealed that ensiling decreased all acid forms of analysed cannabinoids in hemp at about 40-65% of the initial values after 90 days of storage, with the exception of cannabinolic acid (CBNA), and CBGA, the acidic form of cannabigerol (CBG). This decrease in most acidic forms was accompanied by an increase of the corresponding non-acidic forms of all cannabinoids, including the psychoactive ∆9-THC. Thus, although ensiling decreases the total cannabinoid content, psychoactive compounds like ∆9-THC can increase, enhancing the risk for animal health and a transfer of these substances into animal derived products.

Development of Edible Films Based on Nostoc and Modified Native Potato Starch and Their Physical, Mechanical, Thermal, and Microscopic Characterization.

Considering the potential of biopolymers from underutilized Andean sources in Peru to improve the characteristics of edible films, this work aimed to evaluate the formation of a polymeric matrix composed of Nostoc and modified potato starch for the formulation of edible films for food coating. The effects of polymer matrix ratio and drying temperature on films obtained by thermoforming were studied, determining the water vapor permeability and mechanical properties using a multifactorial design. Additionally, thermal properties were characterized by TGA and DSC, and structural properties by FT-IR and scanning electron microscopy. The results showed that the films exhibited lower solubility, lighter hues, better water vapor resistance, higher tensile strength, and improved thermal stability with increasing modified starch content. The formulation with higher Nostoc content exhibited a more homogeneous surface according to microscopy images, and no new chemical bonds were formed by adding modified starch and Nostoc to the polymer matrix, according to FT-IR spectra. These findings are promising and suggest using Nostoc for elaborating edible films composed of native and modified starch from native Andean potatoes as bio-based materials with potential application in the food industry.

Environmental aging influence on mechanical properties of additive manufactured polyamide parts: A statistical approach

AbstractThis study explores the influence of environmental factors and printing orientation on the aging of additive manufactured polyamide 12 (PA12). A multifactorial experimental design was employed to age specimens under controlled conditions. Analysis of variance revealed that temperature, irradiance, relative humidity, and time significantly impact the ultimate tensile strength (UTS) and Young's modulus (Y) of PA12. Applying multiple linear regression methods produced predictive models with R2 values of 0.9075 for the UTS and 0.5226 for the Y, indicating substantial explanatory power for the specimen's UTS. These models enhance understanding of PA12 aging, aiding in the design of more durable mechanical parts for applications exposed to environmental conditions, such as footwear, automotive components, and medical devices. As next steps, future research could empirically deploy these developed predictive models and explore longer time scales to further elucidate the long‐term aging behavior of additively manufactured PA12.

Automated multifactorial design of experiment and Bayesian optimisation algorithm approaches to method development for the green analysis by supercritical fluid chromatography of a pharmaceutical ingredient

During drug development, chromatography is frequently used for purity and stability testing of both drug substance and drug product. Reversed phase liquid chromatography (RPLC) is one of the most widely used methodologies due to its wide scope of application. In the later stages of drug development, the specified impurities and degradation products that define the critical quality attribute of the final API, also known as Key Predictive Sample Set (KPSS), are usually well defined and controlled. At this point, a method review enables selecting the most appropriate technique which should be the one providing optimal robustness (ICH-Q14[1]), with the support of Quality by Design (QbD) approaches. Supercritical Fluid Chromatography (SFC) is a preferred technique for its proven diversity in selectivity. The adoption of a technique which presents the most favourable environmental impact, such as, but not limited to, SFC, is also becoming increasingly important as laboratories strive to reduce carbon footprint. Re-developing a method requires high resource-demands in terms of staff, materials, and time. Any step of the process that can be automated can facilitate this approach, speeding up the delivery of the method whilst preserving robustness.In this article we describe how an SFC method was developed for the purity profiling of a late-stage oncology candidate, taking advantage of the superior selectivity of SFC towards structurally similar analytes, owed to the high orthogonality with R2 as low as 0.014 towards the KPSS. We describe two approaches to automate the method development. Firstly, a multifactorial design of experiments (DoE) and secondly, an optimization via a Bayesian algorithm, which was completed in one night, highlighting the potential and limitations, with an insight into the robustness. Both methods achieved baseline separation with varying levels of automation embedded into the process and a large reduction of the resource demands when compared to traditional optimisation methods. Finally, we describe the beneficial environmental impact that implementing SFC methods can yield, with a calculated green score reduced to a value between 17 and 30 % compared to RPLC, depending on the number of runs per sequence.

Polyploidy and environmental stress response: a comparative study of fern gametophytes.

Climate change is rapidly altering natural habitats and generating complex patterns of environmental stress. Ferns are major components of many forest understories and, given their independent gametophyte generation, may experience unique pressures in emerging temperature and drought regimes. Polyploidy is widespread in ferns and may provide a selective advantage in these rapidly changing environments. This work aimed to understand whether the gametophytes of allopolyploid ferns respond differently to climate-related physiological stress than their diploid parents. The experimental approach involved a multifactorial design with 27 treatment combinations including exposure to multiple levels of drought and temperature over three treatment durations, with recovery measured at multiple timepoints. We measured Chl fluorescence from over 2000 gametophytes to evaluate stress avoidance and tolerance in diploid and polyploid species. Polyploids generally showed a greater ability to avoid and/or tolerate a range of stress conditions compared with their diploid counterparts, suggesting that polyploidy may confer enhanced flexibility and resilience under climate stress. Overall, these results suggest that polyploidy may provide some resilience to climate change in mixed ploidy populations. However, all species remain susceptible to the impacts of extreme drought and heat stress.

Unraveling Eileen Chang’s stylistic multiverse: insights from multivariate analysis with multifactorial design

Abstract This study employs multivariate analysis within a multifactorial design to investigate the author-translator style of distinguished Chinese author Eileen Chang. Using principal component analysis (PCA) and linear discriminant analysis (LDA), it examines Chang’s stylistic multiverse across three literary types: original writing, self-translation, and regular translation of others’ works. The findings reveal diverse patterns of stylistic convergence and divergence among these literary types, analyzed using the metrics of the most frequent words: 200-MFW, 20-MFW, and 5-MFW. These patterns are shaped by the perspectives introduced by two explanatory factors, translation status (original versus translated) and translation type (self-translation versus regular translation), and influenced by Chang’s literary ambition, translation philosophy, and patronage. The study contributes methodologically to author-translator style research by demonstrating the effectiveness of multifactorial and multivariate approaches, which not only provide profound insights into datasets but facilitate methodological triangulation.

Exploring the interplay of emotional intelligence, psychological resilience, perceived stress, and life satisfaction: A cross-sectional study in the Turkish context

BackgroundEmotional intelligence and life satisfaction are essential components for good psychological well-being. Studies examining the elements contributing to emotional intelligence and its relationships with different psychological constructs are likely to positively contribute to mental health. Therefore, the present study examined the mediating roles of perceived stress and psychological resilience in the relationship between emotional intelligence and life satisfaction.MethodsThe study sample comprised 780 university students (62.3% females) studying at universities in different regions of Türkiye. An online survey included the Emotional Intelligence Scale, Satisfaction with Life Scale, Psychological Resilience Scale, and Perceived Stress Scale. A multifactorial complex predictive correlational design was used.ResultsThe results showed that emotional intelligence was (i) positively correlated with life satisfaction and psychological resilience, and (ii) negatively correlated with perceived stress. In the final model, perceived stress and psychological resilience played a mediating role in the relationship between emotional intelligence and life satisfaction. The findings suggest that higher emotional intelligence may lower perceived stress and appears to have a positive effect in relation to life satisfaction and psychological resilience.ConclusionIndividuals working in the field of mental health need to help individuals increase their level of EI, which may help reduce the level of perceived stress and increase psychological resilience and life satisfaction.

Guide for Optimization of Olive Leaf Extraction and Silver Nanoparticles Biosynthesis as an Initial Step for Pilot Plant Design.

This account presents the results of two successful optimization processes. First, a polyphenol-rich aqueous olive extract was obtained and then silver nanoparticles (AgNPs) synthesized with high efficiency. Selected parameters for both processes were optimized based on the procedure of the Box-Behnken multifactorial design. The independent variables in the extraction process were the biomass/water ratio, temperature, and time. For AgNPs synthesis, the independent variables were the volume of olive extract, temperature, and process duration. The relationship between the process parameters was visualized graphically by using the response surface methodology. A high fit of the experimental data with the predicted models was shown. The regression coefficients were high, 0.9936 for extraction and 0.9757 for AgNPs biosynthesis. The extraction efficiency under its optimal conditions was as follows: biomass/solvent ratio 0.016, temperature 80 °C for 80 min, and yield 160.67 [μg GAE (gallic acid equivalent)/mL]. The highest yield of AgNPs synthesis, equal to 1.955, was obtained when it was carried out for 50 min at 75 °C with the application of 11 mL of extract. Studies on the AgNPs suspension's stability depending on the extract amount were demonstrated. A physicochemical analysis using dynamic light scattering, transmission electron microscopy images, and Fourier transform infrared spectroscopy for AgNPs obtained under optimal conditions was shown. Finally, a pilot-scale biosynthesis of AgNPs was designed.

Experimental manipulation of food availability and macroparasite prevalence reveal differential effects on space use in wild rodents.

Research Highlight: Mistrick, J., Veitch, J. S. M., Kitchen, S. M., Clague, S., Newman, B. C., Hall, R. J., Budischak, S. A., Forbes, K. M., & Craft, M. E. (2024). Effects of food supplementation and helminth removal on space use and spatial overlap in wild rodent populations. Journal of Animal Ecology. http://doi.org/10.1111/1365-2656.14067. The spread of pathogens has been of long-standing interest, even before dramatic outbreaks of avian influenza and the coronavirus pandemic spiked broad public interest. However, the dynamics of pathogen spread in wild populations are complex, with multiple effects shaping where animals go (their space use), population density and, more fundamentally, the resultant patterns of contacts (direct or indirect) among individuals. Thus, experimental studies exploring the dynamics of contact under different sets of conditions are needed. In the current field study, Mistrick etal. (2024) used a multifactorial experimental design, manipulating food availability and individual pathogen infection state in wild bank voles (Clethrionomys glareolus). They found that while food availability, individual traits and seasonality can affect how far individual voles moved, the degree of overlap between individual voles remained largely the same despite a high variation in population density-which itself was affected by food availability. These results highlight how biotic and abiotic factors can shape patterns of space use and balance the level of spatial overlap through multiple pathways.

Turning discarded blue shark (Prionace glauca) skin into a valuable nutraceutical resource: An enzymatic collagen hydrolysate

Marine-derived collagen, particularly from blue shark (Prionace glauca) skin, represents a sustainable resource for the nutraceutical industry, yet its effective utilization remains underexplored. This study aims to optimise the enzymatic hydrolysis of blue shark skin collagen using alcalase and bromelain to enhance the bioactive properties of the resultant hydrolysates. We employed a multifactorial experimental design to determine the optimal hydrolysis conditions, assessing factors including enzyme concentration, pH, and temperature. The alcalase-treated hydrolysates demonstrated superior antioxidant and anti-inflammatory activities compared to those treated with bromelain, with increased solubilised proteins and a higher degree of hydrolysis. Notably, peptide profiles indicated that alcalase hydrolysates favoured the production of smaller peptides, suggesting enhanced bioavailability and digestive stability. In vitro gastrointestinal simulations demonstrated the functional stability of these peptides, indicating that while they undergo structural changes during digestion, their potential for gastrointestinal health remains significant. Our findings highlight the feasibility of converting blue shark skin, a commonly discarded by-product, into valuable nutraceutical ingredients, thus contributing to marine sustainability and waste reduction This research advances the biotechnological application of marine collagen and opens avenues for developing functional foods and pharmaceuticals.

Effects of Wind Exposure and Deficit Irrigation on Vegetative Growth, Yield Components and Berry Composition of Malbec and Cabernet Sauvignon.

The impact of global warming on Argentine viticulture may result in a geographical shift, with wine-growing regions potentially moving towards the southwest, known as one of the windiest regions in the world. Deficit irrigation is a widely used strategy to control the shoot growth and improve fruit quality attributes, such as berry skin polyphenols. The present study aimed to assess the effects of different wind intensities and irrigation levels, as well as their interactions, on field-grown Vitis vinifera L. cvs. Malbec and Cabernet Sauvignon. The experiment was conducted during two growing seasons with two wind treatments (sheltered and exposed) and two irrigation treatments (well-watered and moderate deficit irrigation) in a multifactorial design. Vegetative growth, stomatal conductance, shoot biomass partition, fruit yield components and berry skin phenolics were evaluated. Our study found that, generally, wind exposure reduced vegetative growth, and deficit irrigation increased the proportion of smaller berries within the bunches. Meanwhile, deficit irrigation and wind exposure additively increased the concentration of berry skin phenolics. Combined stressful conditions enhance biomass partition across the shoot to fruits in Malbec, increasing the weight of bunches and the number of berries. Our findings offer practical implications for vineyard managers in windy regions, providing actionable insights to optimize grapevine cultivation and enhance wine quality.

Green ecofriendly enhancement of cellulase productivity using agricultural wastes by Aspergillus terreus MN901491: statistical designs and detergent ability on cotton fabrics

BackgroundCellulase is considered a group member of the hydrolytic enzymes, responsible for catalyzing the hydrolysis of cellulose and has various industrial applications. Agricultural wastes are used as an inexpensive source for several utilizable products throughout the world. So, searching for cellulase enzymes from fungal strains capable of utilizing agricultural wastes to increase productivity, reduce costs and overcome waste accumulation in the environment is very important to evaluate its potency as a bio-additive to detergent agents.ResultsIn the current study, the previously identified fungal strain Aspergillus terreus MN901491 was screened and selected for cellulase production. Medium parameters were optimized using one-factor-at-a-time (OFAT) and multi-factorial (Plackett-Burman and Box-Behnken) design methods. OFAT showed the ability of the fungal strain to utilize agricultural wastes (corn cob and rice straw) as a substrate. Also, yeast extract was the best nitrogen source for enhancing cellulase productivity. The most significant variables were determined by Plackett-Burman Design (PBD) and their concentrations were optimized by Response Surface Methodology (RSM) using Box-Behnken Design (BBD). Among eleven independent variables screened by PBD, malt extract, (NH4)2SO4, and KCl were the most significant ones followed by rice straw which affected cellulase production positively. The ANOVA results particularly the R2-value of PBD (0.9879) and BBD (0.9883) confirmed the model efficiency and provided a good interpretation of the experiments. PBD and BBD improved cellulase productivity by 6.1-fold greater than that obtained from OFAT. Medium optimization using OFAT and statistical models increased cellulase production from A. terreus MN901491 by 9.3-fold compared to the non-optimized medium. Moreover, the efficiency of cellulase activity on cotton fabrics as a bio-additive detergent was evaluated and estimated using whiteness and scanning electron microscope (SEM) that affirmed its potential effect and remarkable detergent ability to improve whiteness by 200% in comparison with non-washed fabric and by 190% in comparison with fabric washed by water.ConclusionThe presented work was stabilized as a multi-efficiency in which wastes were used to produce cellulase enzyme from the fungal strain, Aspergillus terreus MN901491 as a bio-additive to detergent applications that involved ecofriendly and green processes.

Impact of Nb and Al content in arc evaporation targets on Ti1−x−yAlxNbyN coating properties

Titanium-based physical vapor deposition (PVD) coatings, such as titanium nitride (TiN) and titanium niobium nitride (TiNbN), are common solutions for surface modifications in medical applications. Ex vivo studies of retrieved knee implants indicate the demand for increased scratch and abrasion resistance of PVD coatings in clinical applications. Based on the promising mechanical performance of titanium aluminum nitride (TiAlN) as a coating for tools, the aim of this study was to evaluate the impact of the chemical composition of titanium-based nitride coatings with aluminum (Al) and niobium (Nb). Nine titanium aluminum niobium nitride (Ti1−x−yAlxNbyN) coatings with 0.4 ≤ x < 0.7 and 0 ≤ y ≤ 0.18, as well as commercial TiN and TiNbN, were coated in an industrial scale arc PVD process, following a randomized, multifactorial response surface design. The deposition rate, the scratch resistance, and the hardness were measured following standardized protocols. The microstructure of the coating was analyzed by SEM and XRD. In addition, the surface roughness was determined by laser scanning microscopy. A quadratic regression was performed to determine the impact of the chemical composition on coating properties. Experimental results and regression analyses revealed the significant impact of the chemical composition of Ti1−x−yAlxNbyN on the coating microstructure, mechanics, and morphology. Scratch resistance for initial crack formation and cohesive failure could be increased decisively, compared to TiN.

Technical note: An autonomous flow-through salinity and temperature perturbation mesocosm system for multi-stressor experiments

Abstract. The rapid environmental changes in aquatic systems as a result of anthropogenic forcings are creating a multitude of challenging conditions for organisms and communities. The need to better understand the interaction of environmental stressors now, and in the future, is fundamental to determining the response of ecosystems to these perturbations. This work describes an automated ex situ mesocosm perturbation system that can manipulate several variables of aquatic media in a controlled setting. This perturbation system was deployed in Kongsfjorden (Svalbard); within this system, ambient water from the fjord was heated and mixed with freshwater in a multifactorial design to investigate the response of mixed-kelp communities in mesocosms to projected future Arctic conditions. The system employed an automated dynamic offset scenario in which a nominal temperature increase was programmed as a set value above real-time ambient conditions in order to simulate future warming. A freshening component was applied in a similar manner: a decrease in salinity was coupled to track the temperature offset based on a temperature–salinity relationship in the fjord. The system functioned as an automated mixing manifold that adjusted flow rates of warmed and chilled ambient seawater, with unmanipulated ambient seawater and freshwater delivered as a single source of mixed media to individual mesocosms. These conditions were maintained via continuously measured temperature and salinity in 12 mesocosms (1 control and 3 treatments, all in triplicate) for 54 d. System regulation was robust, as median deviations from nominal conditions were < 0.15 for both temperature (∘C) and salinity across the three replicates per treatment. Regulation further improved during a second deployment that mimicked three marine heat wave scenarios in which a dynamic temperature regulation held median deviations to < 0.036 ∘C from the nominal value for all treatment conditions and replicates. This perturbation system has the potential to be implemented across a wide range of conditions to test single or multi-stressor drivers (e.g., increased temperature, freshening, and high CO2) while maintaining natural variability. The automated and independent control for each experimental unit (if desired) provides a large breadth of versatility with respect to experimental design.

Investigating the Effects of Avatarization and Interaction Techniques on Near-field Mixed Reality Interactions with Physical Components.

Mixed reality (MR) interactions feature users interacting with a combination of virtual and physical components. Inspired by research investigating aspects associated with near-field interactions in augmented and virtual reality (AR & VR), we investigated how avatarization, the physicality of the interacting components, and the interaction technique used to manipulate a virtual object affected performance and perceptions of user experience in a mixed reality fundamentals of laparoscopic peg-transfer task wherein users had to transfer a virtual ring from one peg to another for a number of trials. We employed a 3 (Physicality of pegs) X 3 (Augmented Avatar Representation) X 2 (Interaction Technique) multi-factorial design, manipulating the physicality of the pegs as a between-subjects factor, the type of augmented self-avatar representation, and the type of interaction technique used for object-manipulation as within-subjects factors. Results indicated that users were significantly more accurate when the pegs were virtual rather than physical because of the increased salience of the task-relevant visual information. From an avatar perspective, providing users with a reach envelope-extending representation, though useful, was found to worsen performance, while co-located avatarization significantly improved performance. Choosing an interaction technique to manipulate objects depends on whether accuracy or efficiency is a priority. Finally, the relationship between the avatar representation and interaction technique dictates just how usable mixed reality interactions are deemed to be.

Development and characterization of a novel poly(N-isopropylacrylamide)-based thermoresponsive photoink and its applications in DLP bioprinting.

The field of 3-dimensional (3D) bioprinting has significantly expanded capabilities in producing precision-engineered hydrogel constructs, and recent years have seen the development of various stimuli-responsive bio- and photoinks. There is, however, a distinct lack of digital light processing (DLP)-compatible photoinks with thermoresponsivity. To remedy this, this work focuses on formulating and optimizing a versatile ink for DLP printing of thermoresponsive hydrogels, with numerous potential applications in tissue engineering, drug delivery, and adjacent biomedical fields. Photoink optimization was carried out using a multifactorial study design. The optimized photoink yielded crosslinked hydrogels with strong variations in hydrophobicity (contact angles of 44.4° <LCST, 71.0° >LCST), indicating marked thermoresponsivity. Mechanical- and rheological characterization of the printed hydrogels showed significant changes above the LCST: storage- and loss moduli both increased and loss tangent and compressive modulus decreased above this temperature (P ≤ 0.01). The highly cytocompatible hydrogel microwell arrays yielded both single- and multilayer spheroids with human dermal fibroblasts (HDFs) and HeLa cells successfully. Evaluation of the release of encapsulated model macro- (bovine serum albumin, BSA) and small molecule (rhodamine B) drugs in a buffer solution showed an interestingly inverted thermoresponsive release profile with >80% release at room temperature and about 50-60% release above the gels' LCST. All told, the optimized ink holds great promise for multiple biomedical applications including precise and high-resolution fabrication of complex tissue structures, development of smart drug delivery systems and 3D cell culture.

Valorization of chicken feather waste using recombinant bacillus subtilis cells by solid-state fermentation for soluble proteins and serine alkaline protease production

Feather waste, a by-product of the poultry industry, is rich in proteins, peptides, and amino acids. Improper disposal of feathers can cause environmental pollution. Solid-state fermentation (SSF) is a viable alternative to submerged fermentation due to its simplicity, productivity, and lower cost. The study goal is a biorefinery of chicken feather waste supplemented with wheat bran using a recombinant Bacillus subtilis strain to produce soluble proteins and a serine alkaline protease. Plackett-Burman Design and Central Composite Design were utilized in a statistical-mathematical model to optimize the process. Multi-factorial design optimization resulted in 80 % substrate degradation efficiency, an alkaline protease with dual activities (1423 proteolytic units and 190 keratinolytic units), 214 mg soluble proteins/g substrate, and 87 % model validation. Scaling up the SSF process to 50 g of substrate significantly enhanced the end products of feather biodegradation to 1616 proteolytic units, 2844 keratinolytic units, and 127 mg soluble proteins/g substrate. Aim and scope of the manuscriptThe aim of the present study is to utilize chicken feather waste (alone or supplemented with other materials) through recombinant Bacillus subtilis cells using solid state fermentation (SSF) at a laboratory scale. The plan study provides a promising waste management in the environmental field concerning biodegradation of such recalcitrant keratinous wastes supplemented with agricultural residues via recombinant microorganism. On semi-pilot scale, high production and quality of soluble protein, protease, and keratinase activity were produced according to the statistically optimised first stage fermentation in the laboratory scale. The bioconversion process took place as a major goal to obtain valuable products, with low utilities and energy requirements. Therefore, this will consider as an economically feasible and environmentally friendly alternative. Moreover, this study is considered as first step fermentation for feather waste to pave the road for directing it to a second step fermentation for biogas production and bioenergy generation through bio-electrochemical systems (Manuscript under publication).