Principles of Antifragile Software

The goal of this paper is to study and define the concept of "antifragile software". For this, I start from Taleb's statement that antifragile systems love errors, and discuss whether traditional software dependability fits into this class. The answer is somewhat negative, although adaptive fault tolerance is antifragile: the system learns something when an error happens, and always imrpoves. Automatic runtime bug fixing is changing the code in response to errors, fault injection in production means injecting errors in business critical software. I claim that both correspond to antifragility. Finally, I hypothesize that antifragile development processes are better at producing antifragile software systems.Comment: see https://refuses.github.io

EMMIE and engineering: What works as evidence to improve decisions?

While written by a proponent of realism, this article argues in favour of a pragmatic approach to evaluation. It argues that multiple sources of evidence collected using diverse research methods can be useful in conducting informative evaluations of programmes, practices and policies. It argues in particular that methods, even if their assumptions appear incommensurable with one another, should be chosen to meet the evidence needs of decision-makers. These evidence needs are captured in the acronym, EMMIE, which refers to Effect size, Mechanism, Moderator (or context), Implementation and Economic impact. Finally the article questions evidence hierarchies that are inspired by clinical trials, and suggests instead that, notwithstanding the clear differences in the physical and social worlds, engineering may provide a superior model for evaluators to try to emulate. And engineering is, above all, a pragmatic field

Meritor brake assembly bench part setup process improvement

In partnership with Meritor\u27s Manning, South Carolina facility, this capstone project focuses on the changeover process of a drum brake assembly for industrial trucks. The changeover process is the downtime an operator spends preparing the workstation for the next set of brake orders. This team\u27s objective is to use process improvement techniques to reduce downtime in between brake orders. Once the customer needs were determined, the team developed concepts to increase the efficiency of the changeover process time. The concepts consisted of real world applications and the utilization of a discrete event simulation software called Arena. In addition to the Arena model, the team has begun testing individual concepts. With the results from these tested concepts, the team will be able to effectively develop solutions to reduce downtime of operators during the changeover process

Infrastructures of immobility: enabling international distance education students in Africa to <i>not</i> move

There is now a large literature discussing how mobilities are part of contemporary everyday power geometries and is a resource to which people have unequal access (Massey 1994; Sheller and Urry 2006). This body of work has, thus, valorised mobility as a desirable good. Why some people choose immobility and what has to be mobilised to enable this immobility has received much less attention. This paper draws on interviews with international distance education students in Namibia and Zimbabwe studying at the University of South Africa (UNISA) to explore the spatio-temporal underpinnings to why students choose to remain at home while studying abroad and how this is arranged. It outlines the infrastructures of reach that enable student immobility and how their incomplete nature means that students have to rely on extensive systems of mobilities of other people and objects to ensure that their study progresses without their own educational mobility. In doing so we move away from considering immobility as a result of limited access to mobility. Instead we set out a new research agenda on why and how the infrastructures of immobilities are important in mobility research

Super-Bridges Suspended Over Carbon Nanotube Cables

In this paper the new concept of super-bridges, i.e. kilometre-long bridges suspended over carbon nanotube cables, is introduced. The analysis shows that the use of realistic (thus defective) carbon nanotube bundles as suspension cables can enlarge the current limit main span by a factor of 3.Comment: 17 pages, 6 figures, 2 table

Functional Diversity and Structural Disorder in the Human Ubiquitination Pathway

The ubiquitin-proteasome system plays a central role in cellular regulation and protein quality control (PQC). The system is built as a pyramid of increasing complexity, with two E1 (ubiquitin activating), few dozen E2 (ubiquitin conjugating) and several hundred E3 (ubiquitin ligase) enzymes. By collecting and analyzing E3 sequences from the KEGG BRITE database and literature, we assembled a coherent dataset of 563 human E3s and analyzed their various physical features. We found an increase in structural disorder of the system with multiple disorder predictors (IUPred - E1: 5.97%, E2: 17.74%, E3: 20.03%). E3s that can bind E2 and substrate simultaneously (single subunit E3, ssE3) have significantly higher disorder (22.98%) than E3s in which E2 binding (multi RING-finger, mRF, 0.62%), scaffolding (6.01%) and substrate binding (adaptor/substrate recognition subunits, 17.33%) functions are separated. In ssE3s, the disorder was localized in the substrate/adaptor binding domains, whereas the E2-binding RING/HECT-domains were structured. To demonstrate the involvement of disorder in E3 function, we applied normal modes and molecular dynamics analyses to show how a disordered and highly flexible linker in human CBL (an E3 that acts as a regulator of several tyrosine kinase-mediated signalling pathways) facilitates long-range conformational changes bringing substrate and E2-binding domains towards each other and thus assisting in ubiquitin transfer. E3s with multiple interaction partners (as evidenced by data in STRING) also possess elevated levels of disorder (hubs, 22.90% vs. non-hubs, 18.36%). Furthermore, a search in PDB uncovered 21 distinct human E3 interactions, in 7 of which the disordered region of E3s undergoes induced folding (or mutual induced folding) in the presence of the partner. In conclusion, our data highlights the primary role of structural disorder in the functions of E3 ligases that manifests itself in the substrate/adaptor binding functions as well as the mechanism of ubiquitin transfer by long-range conformational transitions. © 2013 Bhowmick et al

Decreased photosynthesis in the erect panicle 3 (ep3) mutant of rice is associated with reduced stomatal conductance and attenuated guard cell development

The ERECT PANICLE 3 gene of rice encodes a peptide that exhibits more than 50% sequence identity with the Arabidopsis F-box protein HAWAIIAN SKIRT (HWS). Ectopic expression of the Os02g15950 coding sequence, driven by the HWS (At3g61950) promoter, rescued the hws-1 flower phenotype in Arabidopsis confirming that EP3 is a functional orthologue of HWS. In addition to displaying an erect inflorescence phenotype, loss-of-function mutants of Os02g15950 exhibited a decrease in leaf photosynthetic capacity and stomatal conductance. Analysis of a range of physiological and anatomical features related to leaf photosynthesis revealed no alteration in Rubisco content and no notable changes in mesophyll size or arrangement. However, both ep3 mutant plants and transgenic lines that have a T-DNA insertion within the Os02g15950 (EP3) gene exhibit smaller stomatal guard cells compared with their wild-type controls. This anatomical characteristic may account for the observed decrease in leaf photosynthesis and provides evidence that EP3 plays a role in regulating stomatal guard cell development

The Cul3–KLHL21 E3 ubiquitin ligase targets Aurora B to midzone microtubules in anaphase and is required for cytokinesis

Selective ubiquitination of Aurora B by different Cul3 adaptors targets it at the correct time to the correct place during mitosis

Challenges of mainstreaming green infrastructure in built environment professions

© 2019, © 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. Green infrastructure (GI) has been identified as a promising approach to help cities adapt to climate change through the provision of multiple ecosystem services. However, GI contributions to urban resilience will not be realized until it is more fully mainstreamed in the built environment and design professions. Here, we interrogate five key challenges for the effective implementation of GI: (1) design standards; (2) regulatory pathways; (3) socio-economic considerations; (4) financeability; and (5) innovation. Methods include a literature review, case studies, and interviews with resilience managers. We propose a people-centred and context-dependent approach to advance effective implementation of GI in urban planning. We highlight two underlying currents that run across all of the challenges–(1) the role of political will as a pre-condition for tackling all challenges holistically; and (2) the role of stakeholder engagement in achieving public support, harnessing funding, and maintaining and monitoring GI in the long term. Highlights: • The effective implementation of GI is context-specific and should adhere to the basic principles of appropriate technology. • Continuous community engagement is needed to ensure the inclusivity and multi-functionality of GI. • Challenges to successful GI are intersectional and therefore cannot be addressed singly in isolation