10 research outputs found

    Effektivare dokumentering av ÄTA-arbeten

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    Att undersöka om en effektivare arbetsmetod för hantering av ÄTA-arbeten skulle kunna användas samtidigt som det ger en bättre transparens mellan beställare och entreprenör

    Autenticering i peer-to-peer system

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    In the environment of the 3:rd generation Internet based on peer-to-peer architecture, well-trusted methods must exist to establish a secure environment. One main issue is the possibility to verify that a node actually is who it claims to be (authentication). Establishment of authentication between nodes in a peer-to-peer environment where nodes are exchanging information directly with each other requires more planning than in a typical client-server environment where the authentication methods are server-based. The peer-to-peer applications described in this report use authentication methods based on central authorities as well as solutions without central authorities. Lack of standards in the way peer-to-peer systems should communicate and apply security lead to a variety of “local” communication and security solutions. These local solutions make different applications incompatible with each other, meaning that a peer using one application will not be able to communicate and exchange information with other peers using some other application

    The increased trend of non-drinking alcohol among adolescents : what role do internet activities have?

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    Background: Recently, an increased trend toward non-drinking among adolescents has been observed in several countries. The aim of the present study is to evaluate a common suggestion in literature, that adolescents do not drink alcohol because they spend more time on the internet, monitored at home, by examining associations between internet activities (social media/chatting and computer gaming) and non-drinking. Methods: A health questionnaire was distributed to all 9th graders (1516 years) in a mid-sized Swedish county in 2008, 2010 and 2012. In total, 7089 students returned the questionnaire. Results: In contrast to the suggestion, no association was found between total time spent on computers and non-drinking. Social media/chatting was robustly associated with a decreased probability of non-drinking across the three survey years. On the other hand, computer gaming during weekends only (OR = 1.74, CI = 1.132.69) or both on weekdays and weekends increased the probability of non-drinking (OR = 1.82, CI = 1.312.54) in 2012 only. However, neither social media/chatting nor computer gaming was associated with the increased trend of non-drinking from 2008 to 2012. Conclusions: Internet activities were in general not associated with non-drinking among adolescents aged 1516 years in Sweden. Although, a weak positive association between computer gaming and non-drinking was found in 2012, this effect benefited the vast majority of the boys. The larger alcohol use among those with extensive social media use/chatting may indicate that these online platforms are arenas where adolescents are exposed for positive alcohol preferences and alcohol advertising without parental supervision

    Superresolution imaging of amyloid fibrils with binding-activated probes

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    Protein misfolding into amyloid-like aggregates underlies many neurodegenerative diseases. Thus, insights into the structure and function of these amyloids will provide valuable information on the pathological mechanisms involved and aid in the design of improved drugs for treating amyloid-based disorders. However, determining the structure of endogenous amyloids at high resolution has been difficult. Here we employ binding-activated localization microscopy (BALM) to acquire superresolution images of α-synuclein amyloid fibrils with unprecedented optical resolution. We propose that BALM imaging can be extended to study the structure of other amyloids, for differential diagnosis of amyloid-related diseases and for discovery of drugs that perturb amyloid structure for therapy

    Proteins behaving badly. Substoichiometric molecular control and amplification of the initiation and nature of amyloid fibril formation: lessons from and for blood clotting1.

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    AbstractThe chief and largely terminal element of normal blood clotting is considered to involve the polymerisation of the mainly α-helical fibrinogen to fibrin, with a binding mechanism involving ‘knobs and holes’ but with otherwise little change in protein secondary structure. We recognise, however, that extremely unusual mutations or mechanical stressing can cause fibrinogen to adopt a conformation containing extensive β-sheets. Similarly, prions can change morphology from a largely α-helical to largely β-sheet conformation, and the latter catalyses both the transition and the self-organising polymerisation of the β-sheet structures. Many other proteins can also do this, where it is known as amyloidogenesis. When fibrin is formed in samples from patients harbouring different diseases it can have widely varying diameters and morphologies. We here develop the idea, and summarise the evidence, that in many cases the anomalous fibrin fibre formation seen in such diseases actually amounts to amyloidogenesis. In particular, fibrin can interact with the amyloid-β (Aβ) protein that is misfolded in Alzheimer's disease. Seeing these unusual fibrin morphologies as true amyloids explains a great deal about fibrin(ogen) biology that was previously opaque, and provides novel strategies for treating such coagulopathies. The literature on blood clotting can usefully both inform and be informed by that on prions and on the many other widely recognised (β-)amyloid proteins. A preprint has been lodged in bioRxiv (Kell and Pretorius, 2016)

    Proteins behaving badly. Substoichiometric molecular control and amplification of the initiation and nature of amyloid fibril formation: lessons from and for blood clotting

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