| 1. |
- Basalirwa, Daniel
(author)
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Low cost maize stover biochar as an alternative to inorganic fertilizer for improvement of soil chemical properties, growth and yield of tomatoes on degraded soil of Northern Uganda
- 2023
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In: BMC Plant Biology. - 1471-2229. ; 23
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Journal article (peer-reviewed)abstract
- Background Soil fertility decline due to nutrient mining coupled with low inorganic fertilizer usage is a major cause of low crop yields across sub-Saharan Africa. Recently, biochar potential to improve soil fertility has gained signifcant attention but there are limited studies on the use of biochar as an alternative to inorganic fertilizers. In this study, we determined the efect of maize stover biochar without inorganic fertilizers on soil chemical properties, growth and yield of tomatoes (Solanum lycopersicum L.). A feld experiment was conducted in 2022 for two consecutive seasons in Northern Uganda. The experiment included fve treatments; inorganic fertilizer (control), biochar applied at rates of 3.5, 6.9, 13.8 and 27.6 t ha−1. Results In this study, maize stover biochar improved all the soil chemical properties. Compared to the control, pH signifcantly increased by 27% in the 27.6 t ha−1 while total N increased by 35.6% in the 13.8 t ha−1. Although P was signifcantly low in the 3.5 t ha−1, 6.9 t ha−1 and 13.8 t ha−1, it increased by 3.9% in the 27.6 t ha−1. Exchangeable K was signifcantly increased by 42.7% and 56.7% in the 13.8 t ha−1 and 27.6 t ha−1 respectively. Exchangeable Ca and Mg were also higher in the biochar treatment than the control. Results also showed that plant height, shoot weight, and all yield parameters were signifcantly higher in the inorganic fertilizer treatment than in the 3.5, 6.9, and 13.8 t ha−1 treatments. Interestingly, maize stover biochar at 27. 6 t ha−1 increased fruit yield by 16.1% compared to the control suggesting it could be used as an alternative to inorganic fertilizer. Conclusions Maize stover biochar applied at 27.6 t ha−1 improved soil chemical properties especially pH, N, P and K promoting growth and yield of tomatoes. Therefore, maize stover biochar could be recommended as an alternative to expensive inorganic fertilizers for tomato production in Northern Uganda.
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| 2. |
- Calner, Mikael, et al.
(author)
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Geologiska råvaror; metanhydrater
- 2006
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In: Geobiosfären - en introduktion. - 9789144036700 ; , s. 497-498
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Book chapter (other academic/artistic)
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| 3. |
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| 4. |
- Euler, Chad W., et al.
(author)
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PlyKp104, a Novel Phage Lysin for the Treatment of Klebsiella pneumoniae, Pseudomonas aeruginosa, and Other Gram-Negative ESKAPE Pathogens
- 2023
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In: Antimicrobial Agents and Chemotherapy. - 0066-4804. ; 67:5
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Journal article (peer-reviewed)abstract
- Klebsiella pneumoniae and Pseudomonas aeruginosa are two leading causes of burn and wound infections, pneumonia, urinary tract infections, and more severe invasive diseases, which are often multidrug resistant (MDR) or extensively drug resistant. Due to this, it is critical to discover alternative antimicrobials, such as bacteriophage lysins, against these pathogens. Unfortunately, most lysins that target Gram-negative bacteria require additional modifications or outer membrane permeabilizing agents to be bactericidal. We identified four putative lysins through bioinformatic analysis of Pseudomonas and Klebsiella phage genomes in the NCBI database and then expressed and tested their intrinsic lytic activity in vitro. The most active lysin, PlyKp104, exhibited .5-log killing against K. pneumoniae, P. aeruginosa, and other Gram-negative representatives of the multidrug-resistant ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, K. pneumonia, Acinetobacter baumannii, P. aeruginosa, and Enterobacter species) without further modification. PlyKp104 displayed rapid killing and high activity over a wide pH range and in high concentrations of salt and urea. Additionally, pulmonary surfactants and low concentrations of human serum did not inhibit PlyKp104 activity in vitro. PlyKp104 also significantly reduced drug-resistant K. pneumoniae .2 logs in a murine skin infection model after one treatment of the wound, suggesting that this lysin could be used as a topical antimicrobial against K. pneumoniae and other MDR Gram-negative infections.
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| 5. |
- Euler, Elias, et al.
(author)
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A student-generated embodied metaphor for binary star interactions
- 2018
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Conference paper (other academic/artistic)abstract
- In this presentation, we present an example of a student-generated metaphor for celestial motion in the form of an embodied dance. We examine how this dance played a part in the students’ reasoning about astronomy, paying particular attention to how the students coordinated the movements of their bodies to communicate with one another about the centrality and reciprocity of the interactions between binary stars. We also consider how an open-ended, technology-rich learning environment made such a metaphorical, embodied representation possible, and review how the process of unpacking such metaphors can be embraced by teachers in potentially fruitful ways.
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| 6. |
- Euler, Elias, et al.
(author)
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Discovering variation: learning physics in a creative digital environment
- 2018
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Conference paper (peer-reviewed)abstract
- In this paper, we investigate the ways in which an open-ended software can support the learning of physics through a case study of a pair of students using Algodoo, a creativity-based 2D Newtonian physics environment which, in contrast to the majority of educational simulations, is not targeted for the investigation of a specific phenomenon (or subset of phenomena). Specifically, we explore how open-ended software such as Algodoo supports the learning of physics by (1) allowing users to experience the variation of physical parameters and, importantly, by (2) requiring users to discern those parameters which are relevant to the learning situation at hand.
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| 7. |
- Euler, Elias, et al.
(author)
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Embodiment in physics learning : A social-semiotic look
- 2019
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In: Physical Review Physics Education Research. - 2469-9896. ; 15:1
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Journal article (peer-reviewed)abstract
- In this paper, we present a case study of a pair of students as they use nondisciplinary communicative practices to mechanistically reason about binary star dynamics. To do so, we first review and bring together the theoretical perspectives of social semiotics and embodied cognition, therein developing a new methodological approach for analyzing student interactions during the learning of physics (particularly for those interactions involving students’ bodies). Through the use of our new approach, we are able to show how students combine a diverse range of meaning-making resources into complex, enacted analogies, thus forming explanatory models that are grounded in embodied intuition. We reflect on how meaning-making resources—even when not physically persistent—can act as coordinating hubs for other resources as well as how we might further nuance the academic conversation around the role of the body in physics learning.
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| 8. |
- Euler, Elias, et al.
(author)
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Embodying the abstract or abstracting from the body
- 2018
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Conference paper (other academic/artistic)abstract
- Some discussions of kinesthetic learning activities include a distinction between (1) activities which involve students’ bodies as symbolic representations and (2) activities which incorporate students’ bodies as sensors for experiencing things such as forces and torques. In this poster, we go beyond this binary distinction to propose a theoretical interpretation of how the body can be included in physics learning. We then use our interpretation in discussing an example from a learning activity where a pair of students spontaneously recruited an embodied metaphor as part of their reasoning about binary stars.
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| 9. |
- Euler, Elias, et al.
(author)
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Experiencing Variation and Discerning Relevant Aspects Through Playful Inquiry in Algodoo
- 2017
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Conference paper (peer-reviewed)abstract
- Educational simulations in physics tend to be designed to help students learn selected concepts and thus are typically limited in their potential for open-ended and creative exploration. We are interested in the educational potential of a simulation environment, Algodoo, which does not address any one specific physics phenomenon, but rather provides a creative platform for users to design their own simulations using basic building blocks (e.g. massless springs, rigid bodies). In this study, we investigate the ways in which the Algodoo software supports the learning of physics concepts when it is used as an open environment for students’ inquiry through a case study of a pair of students using Algodoo for the first time. Our study suggests that Algodoo promotes learning in two main ways. First, not unlike more traditional educational simulations, it makes purposeful variation of relevant physics parameters possible and allows the user to experience variation in multiple ways. Second, in contrast to traditional educational simulations (and more like ‘messy’ real experiments), it requires the user to discern the relevant parameters to be varied.
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| 10. |
- Euler, Elias, et al.
(author)
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Exploring how physics students use a sandbox software to move between the physical and the formal
- 2017
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In: PERC Proceedings. - Cincinnati, OH : American Association of Physics Teachers. ; , s. 128-131
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Conference paper (peer-reviewed)abstract
- In this paper, we present a theoretical framework based on Hestenes's discussion of modeling in physics and diSessa's early theories on creativity-based digital learning environments. We use this framework to formulate new understandings of how a pair of students work with an open-ended physics sandbox software, Algodoo, alongside a physical laboratory setup. Algodoo is a digital environment that makes it possible for students to create simple, two-dimensional models of physical phenomena. We identify Algodoo's role as that of a semi-formalism, whereby the students made use of the software in their process of modeling as a means of moving between the physical, experimental context and the formal, mathematical representations associated with that context. We propose a hypothesis to be tested in future research and suggest further avenues for exploration in relation to the proposed theoretical framework.
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