73 research outputs found

    Protein disulfide-isomerase interacts with a substrate protein at all stages along its folding pathway

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    In contrast to molecular chaperones that couple protein folding to ATP hydrolysis, protein disulfide-isomerase (PDI) catalyzes protein folding coupled to formation of disulfide bonds (oxidative folding). However, we do not know how PDI distinguishes folded, partly-folded and unfolded protein substrates. As a model intermediate in an oxidative folding pathway, we prepared a two-disulfide mutant of basic pancreatic trypsin inhibitor (BPTI) and showed by NMR that it is partly-folded and highly dynamic. NMR studies show that it binds to PDI at the same site that binds peptide ligands, with rapid binding and dissociation kinetics; surface plasmon resonance shows its interaction with PDI has a Kd of ca. 10−5 M. For comparison, we characterized the interactions of PDI with native BPTI and fully-unfolded BPTI. Interestingly, PDI does bind native BPTI, but binding is quantitatively weaker than with partly-folded and unfolded BPTI. Hence PDI recognizes and binds substrates via permanently or transiently unfolded regions. This is the first study of PDI's interaction with a partly-folded protein, and the first to analyze this folding catalyst's changing interactions with substrates along an oxidative folding pathway. We have identified key features that make PDI an effective catalyst of oxidative protein folding – differential affinity, rapid ligand exchange and conformational flexibility

    Embracing open innovation to acquire external ideas and technologies and to transfer internal ideas and technologies outside

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    The objective of this dissertation is to increase understanding of how organizations can embrace open innovation in order to acquire external ideas and technologies from outside the organization, and to transfer internal ideas and technologies to outside the organization. The objective encompasses six sub-objectives, each addressed in one or more substudies. Altogether, the dissertation consists of nine substudies and a compendium summarizing the substudies. An extensive literature review was conducted on open innovation and crowdsourcing literature (substudies 1–4). In the subsequent empirical substudies, both qualitative research methods (substudies 5–7) and quantitative research methods (substudies 8–9) were applied. The four literature review substudies provided insights on the body of knowledge on open innovation and crowdsourcing. These substudies unveiled most of the influential articles, authors, and journals of open innovation and crowdsourcing disciplines. Moreover, they identified research gaps in the current literature. The empirical substudies offer several insightful findings. Substudy 5 shows how non-core ideas and technologies of a large firm can become valuable, especially for small firms. Intermediary platforms can find solutions to many pressing problems of large organizations by engaging renowned scientists from all over world (substudy 6). Intermediary platforms can also bring breakthrough innovations with novel mechanisms (substudy 7). Large firms are not only able to garner ideas by engaging their customers through crowdsourcing but they can also build long-lasting relations with their customers (substudies 8 and 9). Embracing open innovation brings challenges for firms too. Firms need to change their organizational structures in order to be able to fully benefit from open innovation. When crowdsourcing is successful, it produces a very large number of new ideas. This has the consequence that firms need to allocate a significant amount of resources in order to identify the most promising ideas. In an idea contest, customarily, only one or a few best ideas are rewarded (substudy 7). Sometimes, no reward is provided for the selected idea (substudies 8 and 9). Most of the ideas that are received are not implemented in practice

    A Deep Insight into the Sialotranscriptome of the Gulf Coast Tick, Amblyomma maculatum

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    Background: Saliva of blood sucking arthropods contains compounds that antagonize their hosts ’ hemostasis, which include platelet aggregation, vasoconstriction and blood clotting; saliva of these organisms also has anti-inflammatory and immunomodullatory properties. Perhaps because hosts mount an active immune response against these compounds, the diversity of these compounds is large even among related blood sucking species. Because of these properties, saliva helps blood feeding as well as help the establishment of pathogens that can be transmitted during blood feeding. Methodology/Principal Findings: We have obtained 1,626,969 reads by pyrosequencing a salivary gland cDNA library from adult females Amblyomma maculatum ticks at different times of feeding. Assembly of this data produced 72,441 sequences larger than 149 nucleotides from which 15,914 coding sequences were extracted. Of these, 5,353 had.75 % coverage to their best match in the non-redundant database from the National Center for Biotechnology information, allowing for the deposition of 4,850 sequences to GenBank. The annotated data sets are available as hyperlinked spreadsheets. Putative secreted proteins were classified in 133 families, most of which have no known function. Conclusions/Significance: This data set of proteins constitutes a mining platform for novel pharmacologically activ

    Understanding similarities and differences in land use visions for Scotland

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    The successful transition towards a global society that can live within planetary boundaries is one of the greatest challenges for the twenty-first century. Sustainable land use and land management will be essential to ensure the continued delivery of the ecosystem goods and services needed to support a rapidly growing global population. To support the transition towards sustainable development, decision-makers need to better understand how land use change affects people and the environment. However, these insights are of limited use without societal agreement on future land uses. Understanding synergies and differences between land use visions forms a first step in assessing and comparing alternative pathways towards a sustainable future. This thesis uses a range of methods to understand visions of future land use amongst professional land use stakeholders, society at large, and young people in Scotland. Twenty semi-structured interviews were held with policy experts from the Scottish land use sectors. A nationwide statistically representative web-based survey provided insight into the visions of the Scottish population. And finally, a novel visual interview methodology was used to interview 26 pupils from two high schools in Perthshire. Inductive content analysis and descriptive statistics were used to analyse the results and understand and compare the land use visions of these different groups. As expected, different groups had different visions of future land use. There was, however, general agreement on certain themes, in particular the desire for a more sustainable lifestyle and the importance of a healthy environment. The sectoral stakeholders would like to see more partnerships, dialogue and collaboration; a society that is more engaged and aware about land use; resilient local economies; and short-, medium-, and long-term policies that help to achieve these goals. One of the key challenges for these groups will be how to translate abstract concepts such as ‘healthy ecosystem’ and ‘dialogue and partnerships’ into practice. This clearly requires a shared understanding of what a ‘healthy ecosystem’ means to different stakeholders, as well as appreciation of what true dialogue means and how this can be used to co-create solutions – potentially a radical change from the traditional top-down approaches. The research also identified divisions in Scottish society between those who want to continue a ‘status quo’ lifestyle, and those – in particular younger people (who spent time in the natural environment, through either school or home life) and those from a higher socio-economic background – who want a more sustainable lifestyle and to be more connected with the natural environment. These results are important, as policy makers need to be able to identify the factors that have successfully engaged certain groups and to promote these factors. Programmes that provide access to the natural environment (such as the Duke of Edinburgh’s Award) need to ensure equal opportunities by targeting disadvantaged groups. Simultaneously, it needs to be explored how to encourage those who would like to continue a ‘status quo’ lifestyle into a more sustainable one. Past research has shown how preferences can be influenced and how changes can be initiated by incentives and restrictions in order to promote desired behaviours. The power of the media should be leveraged: programmes such as BBC’s ‘Blue Planet’ highlight how our lifestyle choices impact on the natural environment and can provide the motivation for change. The current issues surrounding Brexit and Climate Change require a national conversation; using methods such as those presented in the thesis to elicit land use visions can help identify the commonalties and differences between stakeholders’ views. This can provide a starting point for dialogue and critical reflection on current instruments and objectives, and how they might be adapted to better reflect Scottish preferences and conditions

    Crowdsourcing: A new tool for policy-making?

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    Crowdsourcing is rapidly evolving and applied in situations where ideas, labour, opinion or expertise of large groups of people are used. Crowdsourcing is now used in various policy-making initiatives; however, this use has usually focused on open collaboration platforms and specific stages of the policy process, such as agenda-setting and policy evaluations. Other forms of crowdsourcing have been neglected in policy-making, with a few exceptions. This article examines crowdsourcing as a tool for policy-making, and explores the nuances of the technology and its use and implications for different stages of the policy process. The article addresses questions surrounding the role of crowdsourcing and whether it can be considered as a policy tool or as a technological enabler and investigates the current trends and future directions of crowdsourcing. Keywords: Crowdsourcing, Public Policy, Policy Instrument, Policy Tool, Policy Process, Policy Cycle, Open Collaboration, Virtual Labour Markets, Tournaments, Competition

    Proc. Natl. Acad. Sci. U. S. A.

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