| 1. |
- Ahlgren, Benjamin, et al.
(författare)
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A simplified model for linear correlation between annual yield and DNI for parabolic trough collectors
- 2018
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Ingår i: Energy Conversion and Management. - : Elsevier. - 0196-8904 .- 1879-2227. ; 174, s. 295-308
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Tidskriftsartikel (refereegranskat)abstract
- This paper proposes a simple method for estimating annual thermal performance of parabolic trough collectors (PTCs) based on a linear relation with annual DNI for a certain latitude. A case study with simulations for a novel concentrating solar collector in 316 locations for three operating temperature scenarios worldwide was carried out and showed promising results for the latitudes and continents investigated. For a certain latitude and mean operating temperature, the annual yield of a PTC was found to be linearly proportional to yearly DNI. The proposed method will serve as a simplified alternative to the steady-state and quasi-dynamic methods already used. Estimating performance based on yearly DNI can be used by design engineers to do quick preliminary planning of solar plants. Customers can also use this method to evaluate existing solar collector installations. A TRNSYS/TRNSED tool that uses a steady-state model has been developed to carry out the simulations and it has been validated against a PTC array at Technical University of Denmark (DTU). The results show that the simplified method can give reliable estimates of long-term performance of parabolic trough collectors.
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| 2. |
- Ahlgren, Johan, et al.
(författare)
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The influence of predator regime on the behaviour and mortality of a freshwater amphipod, Gammarus pulex
- 2011
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Ingår i: Hydrobiologia. - : Springer Science and Business Media LLC. - 0018-8158 .- 1573-5117. ; 671:1, s. 39-49
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Tidskriftsartikel (refereegranskat)abstract
- In species with restricted dispersal, traits may become genetically fixed leading to local adaptations. Therefore, predator avoidance in a prey species may differ between populations experiencing different predator regimes, but also between sexes within a population due to different vulnerability to predators. In this study we used male and female Gammarus pulex from two different predator regimes: fishless ponds, where invertebrates are the dominant predators and ponds with predatory fish. In the laboratory we examined refuge use, mortality, leaf decomposition rate and pair-formation in G. pulex when exposed to predator cues from either invertebrate predators or fish. Individuals from fish ponds spent more time in refuge and had a higher mortality than those from fishless ponds independent of predator cues. There was no effect of pond predator regime or predator cues on leaf decomposition rates. Further, fewer individuals formed pairs in G. pulex from fish ponds than from fishless ponds. Male G. pulex had a higher mortality and a higher decomposition rate than females independent of predator cues. However, there was no difference in refuge use between sexes. Our study shows that there are general differences in behaviour traits, both between predator regimes and sexes in G. pulex.
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| 3. |
- Ahlgren, Kajsa, 1996, et al.
(författare)
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New insights into the protein stabilizing effects of trehalose by comparing with sucrose
- 2023
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Ingår i: Physical Chemistry Chemical Physics. - : Royal Society of Chemistry (RSC). - 1463-9084 .- 1463-9076. ; 25:32, s. 21215-21226
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Tidskriftsartikel (refereegranskat)abstract
- Disaccharides are well known to be efficient stabilizers of proteins, for example in the case of lyophilization or cryopreservation. However, although all disaccharides seem to exhibit bioprotective and stabilizing properties, it is clear that trehalose is generally superior compared to other disaccharides. The aim of this study was to understand this by comparing how the structural and dynamical properties of aqueous trehalose and sucrose solutions influence the protein myoglobin (Mb). The structural studies were based on neutron and X-ray diffraction in combination with empirical potential structure refinement (EPSR) modeling, whereas the dynamical studies were based on quasielastic neutron scattering (QENS) and molecular dynamics (MD) simulations. The results show that the overall differences in the structure and dynamics of the two systems are small, but nevertheless there are some important differences which may explain the superior stabilizing effects of trehalose. It was found that in both systems the protein is preferentially hydrated by water, but that this effect is more pronounced for trehalose, i.e. trehalose forms less hydrogen bonds to the protein surface than sucrose. Furthermore, the rotational motion around dihedrals between the two glucose rings of trehalose is slower than in the case of the dihedrals between the glucose and fructose rings of sucrose. This leads to a less perturbed protein structure in the case of trehalose. The observations indicate that an aqueous environment closest to the protein molecules is beneficial for an efficient bioprotective solution.
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| 4. |
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| 5. |
- Ahlgren Ode, Kajsa, et al.
(författare)
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A business model pattern arrives … and then? A translation perspective on business model innovation in established firms
- 2024
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Ingår i: Strategic Organization. - : SAGE Publications. - 1476-1270 .- 1741-315X.
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Tidskriftsartikel (refereegranskat)abstract
- This study examines business model innovation in an established firm. We investigate the case of a Swedish utility company that adopted and implemented a business model pattern originating from outside the firm. We draw upon Scandinavian translation theory to understand the micro-level dynamics of how business model innovation unfolds. Our findings show that the business model pattern is disassembled into its constituent parts, that these are translated separately and, little by little, (re)assembled into a whole to form a new business model. This process involves several loops of translation activated by the interplay between five practices: formulating, engaging, resisting, anchoring, and energizing. On the basis of our findings, we develop a business model translation framework. We thereby contribute to a better understanding of the micro-level perspective on business model innovation initiated by the adoption of a business model pattern. We also reveal that business model innovation processes triggered by business model patterns from outside differ from those taking place when a new business model is entirely developed within a firm.
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| 6. |
- Ahlgren Ode, Kajsa, et al.
(författare)
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Business model translation—The case of spreading a business model for solar energy
- 2019
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Ingår i: Renewable Energy. - : Elsevier BV. - 0960-1481. ; 133, s. 23-31
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Tidskriftsartikel (refereegranskat)abstract
- Distributed solar photovoltaic systems are considered an important renewable energy source for meeting renewable energy targets and mitigating climate change. In several markets, emerging firms have established new business models to offer residential customers solar panel systems. In California, the third-party ownership business model has been successfully established during the last decade, and is currently spreading to other markets. Through a longitudinal case study, this paper explores how a startup firm in the Netherlands set up the third-party ownership business model on the Dutch market. The case shows that the process of bringing a business model to a new market is not sufficiently understood as a process of diffusion. Alternatively, it is a process of business model translation, in which the actors involved play a central role in adapting and successfully establishing the business model in a new market. The results have implications for both practitioners and policy makers, as well as the emerging literature on business models for sustainability.
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| 7. |
- Bäckström, Izabelle, et al.
(författare)
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Rigorous and Relevant – introducing a critical discourse analysis to the relevance debate
- 2018
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Ingår i: European Business Review. - 0955-534X. ; 30:2, s. 202-215
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: The purpose of this paper is to explore how the notion of “relevance” is produced, distributed and consumed in the field of management research by applying a critical discourse analysis (CDA) as a theoretical lens. A CDA perspective offers a way to scrutinize the power relations that emerge with journal rankings and how these influence how the relevance discourse develops. Design/methodology/approach: This paper illustrates how a CDA perspective can be fruitfully applied to the relevance literature, exemplifying such an application with two illustrative texts. The texts represent two distinct cases; one is a fictive story informally distributed among scholars, and the other is an extract of a published review on the relevance debate. Findings: A CDA lens sheds light on how academic power relations are maintained in the production, distribution and consumption of the “relevance” notion. It shows the importance of individual awareness among management researchers of how the discourse is shaped. Research limitations/implications: To increase the generalizability of the study, a CDA lens could be applied to a larger amount of texts in the relevance literature. The findings imply that the relevance literature would benefit from contributions bridging the gap between rigor and relevance, and questioning how power relations are maintained. Originality/value: CDA adds a new perspective to the relevance debate, revealing how academic power relations are maintained with management scholars’ adherence to journal norms and the implications of this act.
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| 8. |
- Hammarström, Anne, et al.
(författare)
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Central gender theoretical concepts in health research : the state of the art
- 2014
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Ingår i: Journal of Epidemiology and Community Health. - : BMJ Publishing Group Ltd. - 0143-005X .- 1470-2738. ; 68:2, s. 185-190
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Tidskriftsartikel (refereegranskat)abstract
- Despite increasing awareness of the importance of gender perspectives in health science, there is conceptual confusion regarding the meaning and the use of central gender theoretical concepts. We argue that it is essential to clarify how central concepts are used within gender theory and how to apply them to health research. We identify six gender theoretical concepts as central and interlinked-but problematic and ambiguous in health science: sex, gender, intersectionality, embodiment, gender equity and gender equality. Our recommendations are that: the concepts sex and gender can benefit from a gender relational theoretical approach (ie, a focus on social processes and structures) but with additional attention to the interrelations between sex and gender; intersectionality should go beyond additive analyses to study complex intersections between the major factors which potentially influence health and ensure that gendered power relations and social context are included; we need to be aware of the various meanings given to embodiment, which achieve an integration of gender and health and attend to different levels of analyses to varying degrees; and appreciate that gender equality concerns absence of discrimination between women and men while gender equity focuses on women's and men's health needs, whether similar or different. We conclude that there is a constant need to justify and clarify our use of these concepts in order to advance gender theoretical development. Our analysis is an invitation for dialogue but also a call to make more effective use of the knowledge base which has already developed among gender theorists in health sciences in the manner proposed in this paper.
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| 9. |
- Stepulane, Annija, 1994, et al.
(författare)
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Lyotropic liquid crystal elastomers for drug delivery
- 2023
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Ingår i: Colloids and Surfaces B: Biointerfaces. - 0927-7765 .- 1873-4367. ; 226
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Tidskriftsartikel (refereegranskat)abstract
- Silicone elastomers like polydimethylsiloxane (PDMS) possess a combination of attractive material and biological properties motivating their widespread use in biomedical applications. Development of elastomers with capacity to deliver active therapeutic substances in the form of drugs is of particular interest to produce medical devices with added functionality. In this work, silicone-based lyotropic liquid crystal elastomers with drug-eluting functionality were developed using PDMS and triblock copolymer (diacrylated Pluronic F127, DA-F127). Various ternary PDMS–DA-F127–H2O compositions were explored and evaluated. Three compositions were found to have specific properties of interest and were further investigated for their nanostructure, mechanical properties, water retention capacity, and morphology. The ability of the elastomers to encapsulate and release polar and nonpolar substances was demonstrated using vancomycin and ibuprofen as model drugs. It was shown that the materials could deliver both types of drugs with a sustained release profile for up to 6 and 5 days for vancomycin and ibuprofen, respectively. This works demonstrates a lyotropic liquid crystal, silicone-based elastomer with tailorable mechanical properties, water retention capacity and ability to host and release polar and nonpolar active substances.
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| 10. |
- Storlazzi, Clelia T, et al.
(författare)
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Identification of a commonly amplified 4.3 Mb region with overexpression of C8FW, but not MYC in MYC-containing double minutes in myeloid malignancies
- 2004
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Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 13:14, s. 1479-1485
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Tidskriftsartikel (refereegranskat)abstract
- Double minutes (dmin), the cytogenetic hallmark of genomic amplification, are found in ∼1% of karyotypically abnormal acute myelold leukemias (AML) and myelodysplastic syndromes (MDS). The MYC gene at 8q24 has been reported to be amplified in the majority of the cases, and generally it has been assumed that MYC is the target gene. However, only a few studies have focused on the extent of the amplicon or on the expression patterns of the amplified genes. We have studied six cases (five AML and one MDS) with MYC-containing dmin. Detailed fluorescence in situ hybridization analyses identified a common 4.3 Mb amplicon, with clustered proximal and distal breakpoints, harboring eight known genes (C8FW, NSE2, POU5FLC20, MYC, PVT1, AK093424, MGC27434 and MLZE). The corresponding region was deleted in one of the chromosome 8 homologues in five of the six cases, suggesting that the dmin originated through extra replication (or loop-formation)-excision-amplification. Northern blot analysis revealed that MYC was not overexpressed. Instead, the C8FW gene, encoding a phosphoprotein regulated by mitogenic pathways, displayed increased expression. These results exclude MYC as the target gene and indicate that overexpression of C8FW may be the functionally important consequence of 8q24 amplicons in AML and MDS. © Oxford University Press 2004, all rights reserved.
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