A Structural Split in the Human Genome

Background: Promoter-associated CpG islands (PCIs) mediate methylation-dependent gene silencing, yet tend to co-locate to transcriptionally active genes. To address this paradox, we used data mining to assess the behavior of PCI-positive (PCI+) genes in the human genome. Results: PCI+ genes exhibit a bimodal distribution: (1) a 'housekeeping-like' subset characterized by higher GC content and lower intron length/number, and (2) a 'pseudogene paralog' subset characterized by lower GC content and higher intron length/number (p<0.001). These subsets are functionally distinguishable, with the former gene group characterized by higher expression levels and lower evolutionary rate (p<0.001). PCI-negative (PCI-) genes exhibit higher evolutionary rate and narrower expression breadth than PCI+ genes (p<0.001), consistent with more frequent tissue-specific inactivation. Conclusions: Adaptive evolution of the human genome appears driven in part by declining transcription of a subset of PCI+ genes, predisposing to both CpG→TpA mutation and intron insertion. We propose a model of evolving biological complexity in which environmentally-selected gains or losses of PCI methylation respectively favor positive or negative selection, thus polarizing PCI+ gene structures around a genomic core of ancestral PCI- genes. © 2007 Tang, Epstein.published_or_final_versio

International technology innovation to accelerate energy transitions:The case of the international energy agency technology collaboration programmes

International cooperation in technology innovation can help accelerate energy transitions globally. If they are to promote global systemic change, partnerships need to move beyond nurturing niches and increase their geographical reach. Moving beyond niches brings challenges for such international partnerships traditionally focused on technological-hardware innovation in advanced countries. Based on an analytical framework rooted in innovation and transition studies, this paper explores how international technology innovation partnerships can help accelerate transitions globally by conducting a unique empirical study of the almost five decades-old IEA Technology Collaboration Programmes (TCPs). Results suggest that well-established networks for knowledge diffusion, growing compatibility of activities with climate change mitigation goals, and increased global participation currently enable TCPs to contribute to the energy transition. Improving outreach to non-scientific audiences, knowledge diffusion beyond technical knowledge, and cross-sectoral coordination, as well as ensuring equal-footing participation of developing countries, remain challenges to be addressed, especially as the transition accelerates

Can Green Hydrogen Exports Contribute to Regional Economic Development? Exploring Scenarios from the Dutch-Brazilian Green Hydrogen Corridor for the State of Ceará

To meet climate change mitigation targets, an exponential increase in global green hydrogen trade is expected. Countries rich in renewable energy resources would be in a favourable position to become exporters, potentially bringing opportunities for socio-economic development. The Brazilian state of Ceará is developing a large-scale green hydrogen hub, which is expected to provide one-fifth of European Union (EU) imports by 2030 via the green corridor between Ceará and The Netherlands. Located in what has historically been the least-developed Brazilian region, the green hydrogen hub could bring unique opportunities for regional development in Ceará. However, while empirical studies on economic impacts from other renewable energy projects in developing economies show limited localised benefits, the potential economic co-benefits from export-oriented green hydrogen projects remains uncertain. This study combines semi-structured interviews and input-output modelling to estimate impacts on valueadded, income and jobs (by gender) in Ceará according to four local content share scenarios and three renewable energy technologies (onshore wind, offshore wind and solar photovoltaics). By doing so, this study is the first to estimate the potential for economic co-benefits from export-oriented green hydrogen projects in a developing economy context, in a sub-national level, while accounting for technology- and project-specificity as well as impacts on gender inequality. Results suggest that highly internationalised scenarios, that is, with low local content shares and dominated by multinational companies, would not only present local benefits that are often an order of magnitude lower, but could, through distributional implications of employment types, also exacerbate existing income and gender inequalities

Can Green Hydrogen Exports Contribute to Regional Economic Development? Exploring Scenarios from the Dutch-Brazilian Green Hydrogen Corridor for the State of Ceará

To meet climate change mitigation targets, an exponential increase in global green hydrogen trade is expected. Countries rich in renewable energy resources would be in a favourable position to become exporters, potentially bringing opportunities for socio-economic development. The Brazilian state of Ceará is developing a large-scale green hydrogen hub, which is expected to provide one-fifth of European Union (EU) imports by 2030 via the green corridor between Ceará and The Netherlands. Located in what has historically been the least-developed Brazilian region, the green hydrogen hub could bring unique opportunities for regional development in Ceará. However, while empirical studies on economic impacts from other renewable energy projects in developing economies show limited localised benefits, the potential economic co-benefits from export-oriented green hydrogen projects remains uncertain. This study combines semi-structured interviews and input-output modelling to estimate impacts on valueadded, income and jobs (by gender) in Ceará according to four local content share scenarios and three renewable energy technologies (onshore wind, offshore wind and solar photovoltaics). By doing so, this study is the first to estimate the potential for economic co-benefits from export-oriented green hydrogen projects in a developing economy context, in a sub-national level, while accounting for technology- and project-specificity as well as impacts on gender inequality. Results suggest that highly internationalised scenarios, that is, with low local content shares and dominated by multinational companies, would not only present local benefits that are often an order of magnitude lower, but could, through distributional implications of employment types, also exacerbate existing income and gender inequalities