31. |
- McWhinney, Sean R, et al.
(författare)
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Diagnosis of bipolar disorders and body mass index predict clustering based on similarities in cortical thickness-ENIGMA study in 2436 individuals.
- 2022
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Ingår i: Bipolar disorders. - : Wiley. - 1399-5618 .- 1398-5647. ; 24:5, s. 509-520
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Tidskriftsartikel (refereegranskat)abstract
- Rates of obesity have reached epidemic proportions, especially among people with psychiatric disorders. While the effects of obesity on the brain are of major interest in medicine, they remain markedly under-researched in psychiatry.We obtained body mass index (BMI) and magnetic resonance imaging-derived regional cortical thickness, surface area from 836 bipolar disorders (BD) and 1600 control individuals from 14 sites within the ENIGMA-BD Working Group. We identified regionally specific profiles of cortical thickness using K-means clustering and studied clinical characteristics associated with individual cortical profiles.We detected two clusters based on similarities among participants in cortical thickness. The lower thickness cluster (46.8% of the sample) showed thinner cortex, especially in the frontal and temporal lobes and was associated with diagnosis of BD, higher BMI, and older age. BD individuals in the low thickness cluster were more likely to have the diagnosis of bipolar disorder I and less likely to be treated with lithium. In contrast, clustering based on similarities in the cortical surface area was unrelated to BD or BMI and only tracked age and sex.We provide evidence that both BD and obesity are associated with similar alterations in cortical thickness, but not surface area. The fact that obesity increased the chance of having low cortical thickness could explain differences in cortical measures among people with BD. The thinner cortex in individuals with higher BMI, which was additive and similar to the BD-associated alterations, may suggest that treating obesity could lower the extent of cortical thinning in BD.
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32. |
- Nerini, Francesco Fuso, et al.
(författare)
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Rural electrification options in the Brazilian Amazon A multi-criteria analysis
- 2014
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Ingår i: Energy for Sustainable Development. - : Elsevier BV. - 0973-0826 .- 2352-4669. ; 20:1, s. 36-48
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Tidskriftsartikel (refereegranskat)abstract
- Worldwide, approximately 1.2 billion people still lack access to electricity. Recognized by the Brazilian Government as a citizen's right, access to electricity was extended to almost 15 million people since 2003 as a result of the "Luz Para Todos" (Light for all - LPT) program. However, considerable parts of the Amazon region still lack access to electricity services, largely due to the long distances that need to be covered and to challenging topography. This paper explores electrification using selected renewable sources, both for new installations and for hybridization of existing diesel generators. We present results from a multi-criteria analysis that explores trade-offs associated with electrification options. Techno-economic, environmental, social and institutional criteria and attributes are explored. We find that renewable and hybrid systems present a number of advantages for application in isolated areas of the region.
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33. |
- Pena Balderrama, J. Gabriela, et al.
(författare)
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Incorporating high-resolution demand and techno-economic optimization to evaluate micro-grids into the Open Source Spatial Electrification Tool (OnSSET)
- 2020
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Ingår i: Energy for Sustainable Development. - : Elsevier. - 0973-0826 .- 2352-4669. ; 56, s. 98-118
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Tidskriftsartikel (refereegranskat)abstract
- For decades, electrification planning in the developing world has often focused on extending the national grid to increase electricity access. This article draws attention to the potential complementary role of decentralized alternatives – primarily micro-grids – to address universal electricity access targets. To this aim, we propose a methodology consisting of three steps to estimate the LCOE and to size micro-grids for large-scale geo-spatial electrification modelling. In the first step, stochastic load demand profiles are generated for a wide range of settlement archetypes using the open-source RAMP model. In the second step, stochastic optimization is carried by the open-source MicroGridsPy model for combinations of settlement size, load demand profiles and other important techno-economic parameters influencing the LCOE. In the third step, surrogate models are generated to automatically evaluate the LCOE using a multivariate regression of micro-grid optimization results as a function of influencing parameters defining each scenario instance. Our developments coupled to the OnSSET electrification tool reveal an important increase in the cost-competitiveness of micro-grids compared to previous analyses.
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34. |
- Pinto de Moura, G. N., et al.
(författare)
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South America power integration, Bolivian electricity export potential and bargaining power : An OSeMOSYS SAMBA approach
- 2017
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Ingår i: Energy Strategy Reviews. - : Elsevier. - 2211-467X .- 2211-4688. ; 17, s. 27-36
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Tidskriftsartikel (refereegranskat)abstract
- Bolivia has plenty of energy resources that can supply not only its own electricity demand but has also the potential to export surplus production to its neighbors in South America. This study presents a comparative analysis of the electricity export potential of Bolivia, considering modeling results carried out by the Bolivian government and those from OSeMOSYS SAMBA - South America Model Base. Four scenarios were modelled from different conceptions of strategic large hydropower combinations. The scenarios comparison highlights the cross-border potential trade between Bolivia and neighboring countries, mainly Brazil. Using a Cooperative Games approach, through the calculation of the Shapley value, the bargaining power of Bolivia was identified, reaching its higher value in the scenario where El Bala and Cachuela Esperanza dams are present. The cooperative games approach provides a better understanding of electricity trade opportunities to support policy makers in international negotiations, thus considerably reducing incentives to non-cooperative actions.
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35. |
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36. |
- Siyal, Shahid Hussain, 1980-
(författare)
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Techno-economic assessment of wind energy for renewable hydrogen production in Sweden
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Wind energy deployment has been growing globally. The resource is expected to play an important role in achieving economic and environmental sustainability - depending on its level of availability, economics, and policy. Sweden has committed to have 20 TWh/year production of onshore wind energy in the national electricity sector by the year 2020. Further, Sweden has a target for a fossil fuel free transport sector by 2030. Local wind energy coupled to electrolysis-derived hydrogen fuel production offers a pathway for achieving both targets. The analysis of wind energy’s potential in this context necessitates a new type of approach, one that captures the complexities of wind turbine siting in relation to the build-up of hydrogen infrastructure, including refueling stations. In this thesis, high-resolution spatial assessments were performed to evaluate wind energy and wind-to-hydrogen energy potentials, including land use restrictions and techno-economic evaluations. The methodology combines analysis with Geographic Information System (GIS) data and the Hybrid Optimization Model for Multiple Energy Resources (HOMER) tool and includes key constraints with the purpose of improving the fidelity of the assessments.Overall, significant potentials for wind and hydrogen energy might be harnessed in Sweden. Wind-generated hydrogen can be produced cost-effectively at selected sites along existing roads. After applying a large array of land use restrictions, results show that around 31% of the total land area is viable for wind energy applications in the country. In total, 190 TWh/year wind electricity could be generated in areas within 30 km from the national electricity grid. Moreover, approximately 25580 kton/year of hydrogen fuel could be supplied by installing wind turbines on the viable land area. While considering standalone wind-powered hydrogen refueling stations, the cost of hydrogen lies in the range of 6-10 USD∕kg, depending on wind speed models employed and other factors. Note that this study does not evaluate how these new wind or hydrogen production potentials might be integrated into the energy sector.
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37. |
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38. |
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39. |
- Welsch, Manuel, et al.
(författare)
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Modelling elements of Smart Grids - Enhancing the OSeMOSYS (Open Source Energy Modelling System) code
- 2012
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Ingår i: Energy. - : Elsevier BV. - 0360-5442 .- 1873-6785. ; 46:1, s. 337-350
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Tidskriftsartikel (refereegranskat)abstract
- 'Smart Grids' are expected to help facilitate a better integration of distributed storage and demand response options into power systems and markets. Quantifying the associated system benefits may provide valuable design and policy insights. Yet many existing energy system models are not able to depict various critical features associated with Smart Grids in a single comprehensive framework. These features may for example include grid stability issues in a system with several flexible demand types and storage options to help balance a high penetration of renewable energy. Flexible and accessible tools have the potential to fill this niche. This paper expands on the Open Source Energy Modelling System (OSeMOSYS). It describes how 'blocks of functionality' may be added to represent variability in electricity generation, a prioritisation of demand types, shifting demand, and storage options. The paper demonstrates the flexibility and ease-of-use of OSeMOSYS with regard to modifications of its code. It may therefore serve as a useful test-bed for new functionality in tools with wide-spread use and larger applications, such as MESSAGE, TIMES, MARKAL, or LEAP. As with the core code of OSeMOSYS, the functional blocks described in this paper are available in the public domain.
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40. |
- Wierenga, Lara M., et al.
(författare)
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Greater male than female variability in regional brain structure across the lifespan
- 2022
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Ingår i: Human Brain Mapping. - : John Wiley & Sons. - 1065-9471 .- 1097-0193. ; 43:1, s. 470-499
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Tidskriftsartikel (refereegranskat)abstract
- For many traits, males show greater variability than females, with possible implications for understanding sex differences in health and disease. Here, the ENIGMA (Enhancing Neuro Imaging Genetics through Meta-Analysis) Consortium presents the largest-ever mega-analysis of sex differences in variability of brain structure, based on international data spanning nine decades of life. Subcortical volumes, cortical surface area and cortical thickness were assessed in MRI data of 16,683 healthy individuals 1-90 years old (47% females). We observed significant patterns of greater male than female between-subject variance for all subcortical volumetric measures, all cortical surface area measures, and 60% of cortical thickness measures. This pattern was stable across the lifespan for 50% of the subcortical structures, 70% of the regional area measures, and nearly all regions for thickness. Our findings that these sex differences are present in childhood implicate early life genetic or gene-environment interaction mechanisms. The findings highlight the importance of individual differences within the sexes, that may underpin sex-specific vulnerability to disorders.
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