882 research outputs found

    Critical systems heuristics

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    Critical systems heuristics (CSH) is a framework for reflective professional practice organised around the central tool of boundary critique. This paper, written jointly by the original developer, Werner Ulrich, and Martin Reynolds, an experienced practitioner of CSH, offers a systematic introduction to the idea and use of boundary critique. Its core concepts are explained in detail and their use is illustrated by means of two case studies from the domain of environmental planning and management. A particular focus is on working constructively with tensions between opposing perspectives as they arise in many situations of professional intervention. These include tensions such as ‘situation’ versus ‘system’, ‘is’ versus ‘ought’ judgements, concerns of ‘those involved’ versus ‘those affected but not involved’, stakeholders’ ‘stakes’ versus ‘stakeholding issues’, and others. Accordingly, boundary critique is presented as a participatory process of unfolding and questioning boundary judgements rather than as an expert-driven process of boundary setting. The paper concludes with a discussion of some essential skills and considerations regarding the practice of boundary critique. Parts of the account of the NRUA-Botswana study in Section 6.2 of the present paper are reproduced from an earlier publication by one of the authors (Reynolds 2007); we are grateful to the publishers of Edge Press, Point Reyes, CA, for granting us permission to reproduce this material. We do not need the systems concept at all if we are not interested in handling systems boundaries critically

    Ch. 6. Critical Systems Heuristics: The Idea and Practice of Boundary Critique

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    Critical systems heuristics (CSH) is a framework for reflective professional practice organised around the central tool of boundary critique. This chapter, written jointly by the original developer, Werner Ulrich, and Martin Reynolds, an experienced practitioner of CSH, offers a systematic introduction to the idea and use of boundary critique. Its core concepts are explained in detail and their use is illustrated by means of two case studies from the domain of environmental planning and management. A particular focus is on working constructively with tensions between opposing perspectives as they arise in many situations of professional intervention. These include tensions such as ‘situation’ versus ‘system’, ‘is’ versus ‘ought’ judgements, concerns of ‘those involved’ versus ‘those affected but not involved’, stakeholders’ ‘stakes’ versus ‘stakeholding issues’, and others. Accordingly, boundary critique is presented as a participatory process of unfolding and questioning boundary judgements rather than as an expert-driven process of boundary setting. The paper concludes with a discussion of some essential skills and considerations regarding the practice of boundary critique

    Recommendations for the surgical treatment of endometriosis—part 1: ovarian endometrioma

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    Study question: What does this document on the surgical treatment of endometriosis jointly prepared by the European Society for Gynaecological Endoscopy (ESGE), ESHRE, and the World Endometriosis Society (WES) provide? / Summary answer: This document provides recommendations covering technical aspects of different methods of surgery for endometriomas in women of reproductive age. / What is already known: Endometriomas (ovarian endometriotic cysts) are a commonly diagnosed form of endometriosis, owing to the relative ease and accuracy of ultrasound diagnosis. They frequently present a clinical dilemma as to whether and how to treat them when found during imaging or incidentally during surgery. Previously published guidelines have provided recommendations based on the best available evidence, but without technical details on the management of endometriosis. / Study design, size and duration: A working group of ESGE, ESHRE and WES collaborated on writing recommendations on the practical aspects of endometrioma surgery. / Participants/materials, setting and methods: This document focused on endometrioma surgery. Further documents in this series will provide recommendations for surgery of deep and peritoneal endometriosis. / Main results and the role of chance: The document presents general recommendations for surgery of endometrioma and specific recommendations for cystectomy, ablation by laser or by plasma energy, electrocoagulation and a combination of these techniques applied together or with an interval between them. / Limitations and reasons for caution: Owing to the limited evidence available, recommendations are mostly based on clinical expertise. / Wider implications of the findings: These recommendations complement previous guidelines on the management of endometriosis. / Study funding/competing interests: The meetings of the working group were funded by ESGE, ESHRE and WES. CB declares to be a member of the independent data monitoring committee for a clinical study by ObsEva and receiving research grants from Bayer, Roche Diagnostics, MDNA Life Sciences and Volition. ES received honoraria for provision of training to healthcare professionals from Ethicon, Olympus and Gedeon Richter. The other authors declare that they have no conflict of interest

    Walking through volcanic mud : the 2,100 year-old Acahualina footprints (Nicaragua) II: the Acahualina people, environmental conditions and motivation

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    We analyzed bare human footprints in Holocene tuff preserved in two pits in the Acahualinca barrio in the northern outskirts of Managua (Nicaragua). Lithology, volcanology, and age of the deposits are discussed in a companion paper (Schmincke et al. Bull Volcanol doi: 10.1007/s00445-008-0235-9, 2008). The footprint layer occurs within a series of rapidly accumulated basaltic–andesitic tephra that is regionally correlated to the Masaya Triple Layer Tephra. The people were probably trying to escape from a powerful volcanic eruption at Masaya Caldera 20 km farther south that occurred at 2.1 ka BP. We subdivided the swath of footprints, up to 5.6 m wide, in the northern pit (Pit I) into (1) a central group of footprints made by about six individuals, the total number being difficult to determine because people walked in each other’s footsteps one behind the other and (2) two marginal groups on either side of the central group with more widely spaced tracks. The western band comprises tracks of three adjacent individuals and an isolated single footprint farther out. The eastern marginal area comprises an inner band of deep footprints made by three individuals and, farther out, three clearly separated individuals. We estimate the total number of people as 15–16. In the southern narrow and smaller pit (Pit II), we recognize tracks of ca. 12 individuals, no doubt made by the same group. The group represented in both pits probably comprised male and female adults, teenagers and children based on differences in length of footprints and of strides and depth of footprints made in the soft wet ash. The smallest footprints (probably made by children) occur in the central group, where protection was most effective. The footprint layer is composed of a lower 5–15-cm thick, coarse-grained vesicle tuff capped by a medium to fine-grained tuff up to 3 cm thick. The surface on which the people walked was muddy, and the soft ash was squeezed up on the sides of the foot imprints and between toes. Especially, deep footprints are mainly due to local thickening of the water-rich ash, multiple track use, and differences in weight of individuals. The excellent preservation of the footprints, ubiquitous mudcracks, sharp and well-preserved squeeze-ups along the margins of the tracks and toe imprints, and the absence of raindrop impressions all suggest that the eruption occurred during the dry season. The people walked at a brisk pace, as judged from the tight orientation of the swath and the length of the strides. The directions of a major erosional channel in the overlying deposits that probably debouched into Lake Managua and the band of footprints are strictly parallel, indicating that people walked together in stride along the eastern margin of a channel straight toward the lake shore, possibly a site with huts and/or boats for protection and/or escape

    Discovering the constrained NMSSM with tau leptons at the LHC

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    The constrained Next-to-Minimal Supersymmetric Standard Model (cNMSSM) with mSugra-like boundary conditions at the GUT scale implies a singlino-like LSP with a mass just a few GeV below a stau NLSP. Hence, most of the squark/gluino decay cascades contain two tau leptons. The gluino mass >~ 1.2 TeV is somewhat larger than the squark masses of >~ 1 TeV. We simulate signal and background events for such a scenario at the LHC, and propose cuts on the transverse momenta of two jets, the missing transverse energy and the transverse momentum of a hadronically decaying tau lepton. This dedicated analysis allows to improve on the results of generic supersymmetry searches for a large part of the parameter space of the cNMSSM. The distribution of the effective mass and the signal rate provide sensitivity to distinguish the cNMSSM from the constrained Minimal Supersymmetric Standard Model in the stau-coannihilation region.Comment: 18 pages, 3 Figure

    Progression and Forecast of a Curated Web-of-Trust: A Study on the Debian Project's Cryptographic Keyring

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    The Debian project is one of the largest free software undertakings worldwide. It is geographically distributed, and participation in the project is done on a voluntary basis, without a single formal employee or directly funded person. As we will explain, due to the nature of the project, its authentication needs are very strict — User/password schemes are way surpassed, and centralized trust management schemes such as PKI are not compatible with its distributed and flat organization; fully decentralized schemes such as the PGP Web of Trust are insuficient by themselves. The Debian project has solved this need by using what we termed a ``curated Web of Trust''. We will explain some lessons learned from a massive key migration process that was triggered in 2014. We will present the social insight we have found from examining the relationships expressed as signatures in this curated Web of Trust, some recommendations on personal key-signing policies, and a statistical study and forecast on aging, refreshment and survival of project participants stemming from an analysis on their key-handling

    Spirometry reference equations for central European populations from school age to old age.

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    Spirometry reference values are important for the interpretation of spirometry results. Reference values should be updated regularly, derived from a population as similar to the population for which they are to be used and span across all ages. Such spirometry reference equations are currently lacking for central European populations. To develop spirometry reference equations for central European populations between 8 and 90 years of age. We used data collected between January 1993 and December 2010 from a central European population. The data was modelled using "Generalized Additive Models for Location, Scale and Shape" (GAMLSS). The spirometry reference equations were derived from 118'891 individuals consisting of 60'624 (51%) females and 58'267 (49%) males. Altogether, there were 18'211 (15.3%) children under the age of 18 years. We developed spirometry reference equations for a central European population between 8 and 90 years of age that can be implemented in a wide range of clinical settings

    Virtual screening for inhibitors of the human TSLP:TSLPR interaction

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    The pro-inflammatory cytokine thymic stromal lymphopoietin (TSLP) plays a pivotal role in the pathophysiology of various allergy disorders that are mediated by type 2 helper T cell (Th2) responses, such as asthma and atopic dermatitis. TSLP forms a ternary complex with the TSLP receptor (TSLPR) and the interleukin-7-receptor subunit alpha (IL-7Ra), thereby activating a signaling cascade that culminates in the release of pro-inflammatory mediators. In this study, we conducted an in silico characterization of the TSLP: TSLPR complex to investigate the drugability of this complex. Two commercially available fragment libraries were screened computationally for possible inhibitors and a selection of fragments was subsequently tested in vitro. The screening setup consisted of two orthogonal assays measuring TSLP binding to TSLPR: a BLI-based assay and a biochemical assay based on a TSLP: alkaline phosphatase fusion protein. Four fragments pertaining to diverse chemical classes were identified to reduce TSLP: TSLPR complex formation to less than 75% in millimolar concentrations. We have used unbiased molecular dynamics simulations to develop a Markov state model that characterized the binding pathway of the most interesting compound. This work provides a proof-ofprinciple for use of fragments in the inhibition of TSLP: TSLPR complexation
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