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- Patching, Geoff
(författare)
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Applying Bayesian hierarchical modelling to assess the speed of goal side selection in a soccer related penalty shot task
- 2023
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Konferensbidrag (refereegranskat)abstract
- Traditionally, psychophysical data is modelled by fitting individual curves to each participant’s data and then by statistical analysis of the extracted parameters. A now viable alternative to this traditional two-stage approach is Bayesian hierarchical modelling (BHM). BHM allows for modelling all of the data and all of the parameters in one-step rather than two. Here, BHM is used to analyse the speed of participants’ binary goal side selections in a soccer related penalty shot task. Participants viewed realistic images of a soccer goal and goalkeeper, and chose which side of the goal to best score. Analogous to the visual line bisection task, we (Pereira & Patching, 2021, Perceptual and Motor Skills, 128, 2279-2303) systematically repositioned the goalkeeper from left to right along the goal line and, to simulate changes in the viewing position of the kicker, lateral position of the goalmouth in each image. Scaling response times in terms of signed response speed shows a close linear correspondence with log odds ratios (logit) of left goal side selection. Overall, participants tended to choose the left- over right-goal side, but both the speed and direction of this tendency depended on the goalkeeper’s position and lateral position of the goalmouth relative to participants’ body midline. Current analysis of signed response speed shows a similar pattern of results as binary response probability complementing our earlier analysis of binary goal side selection in the present penalty shot task.
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| 2. |
- Patel, Alok, Dr. 1989-, et al.
(författare)
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A comparative study on de novo and ex novo lipid fermentation by oleaginous yeast using glucose and sonicated waste cooking oil
- 2019
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Ingår i: Ultrasonics sonochemistry. - : Elsevier. - 1350-4177 .- 1873-2828. ; 52, s. 364-374
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Tidskriftsartikel (refereegranskat)abstract
- There are only a few reports available about the assimilation of hydrophobic substrates by microorganisms, however, it is well known that oleaginous microorganisms are capable of utilizing both hydrophilic and hydrophobic substrates and accumulate lipids via two different pathways namely de novo and ex novo lipid synthesis, respectively. In the present study, an oleaginous yeast, Cryptococcus curvatus, was investigated for its potentials to utilize a waste substrate of hydrophobic nature (waste cooking oil – WCO) and compared with its ability to utilize a hydrophilic carbon source (glucose). To facilitate the utilization of WCO by C. curvatus, the broth was sonicated to form a stable oil-in-water emulsion without adding any emulsifier, which was then compared with WCO samples without any ultrasound treatment (unsonicated) for the yeast cultivation. Ultrasonication reduces the size of hydrophobic substrates and improves their miscibility in an aqueous broth making them easily assimilated by oleaginous yeast. Under de novo lipid fermentation, the yeast synthesized 9.93 ± 0.84 g/L of cell dry weight and 5.23 ± 0.49 g/L lipids (lipid content of 52.66 ± 0.93% w/w) when cultivated on 40 g/L of glucose (C/N ratio of 40). The amount of cell dry weight, lipid concentration, and lipid content were considerably higher during the ex novo lipid synthesis. More specifically, the highest lipid content achieved was 70.13 ± 1.65% w/w with a corresponding dry cell weight and lipid concentration of 18.62 ± 0.76 g/L and 13.06 ± 0.92 g/L respectively, when grown on 20 g/L sonicated WCO. The highest lipid concentration, however, was observed when the yeast was cultivated on 40 g/L sonicated WCO. Under these conditions, 20.34 g/L lipids were produced with a lipid content of 57.05% w/w. On the other hand, lipid production with unsonicated WCO was significant lower, reaching 11.16 ± 1.02 g/L (69.14 ± 1.34% w/w of lipid content) and 12.21 ± 1.34 g/L (47.39 ± 1.67% w/w of lipid content) for 20 g/L and 40 g/L of WCO, respectively. This underpins the significance of the sonication treatment, especially at elevated WCO concentrations, to improve the accessibility of the yeast to the WCO. Sonication treatment that was used in this study assisted the utilization of WCO without the need to add emulsifiers, thus reducing the need for chemicals and in turn has a positive impact on the production costs. The microbial lipids produced presented a different fatty acid composition compared to the WCO, making them more suitable for biodiesel production as suggested by the theoretical estimation of the biodiesel properties.
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