85 research outputs found
A remote secondary binding pocket promotes heteromultivalent targeting of DC-SIGN
Dendritic cells (DC) are antigen-presenting cells coordinating the interplay of the innate and the adaptive immune response. The endocytic C-type lectin receptors DC-SIGN and Langerin display expression profiles restricted to distinct DC subtypes and have emerged as prime targets for next-generation immunotherapies and anti-infectives. Using heteromultivalent liposomes copresenting mannosides bearing aromatic aglycones with natural glycan ligands, we serendipitously discovered striking cooperativity effects for DC-SIGN+ but not for Langerin+ cell lines. Mechanistic investigations combining NMR spectroscopy with molecular docking and molecular dynamics simulations led to the identification of a secondary binding pocket for the glycomimetics. This pocket, located remotely of DC-SIGN’s carbohydrate bindings site, can be leveraged by heteromultivalent avidity enhancement. We further present preliminary evidence that the aglycone allosterically activates glycan recognition and thereby contributes to DC-SIGN-specific cell targeting. Our findings have important implications for both translational and basic glycoscience, showcasing heteromultivalent targeting of DCs to improve specificity and supporting potential allosteric regulation of DC-SIGN and CLRs in general
Photon Exchange in Nucleus-Nucleus Collisions
The strong electromagnetic fields in peripheral heavy ion collisions give
rise to photon-photon and photon-nucleus interactions. I present a general
survey of the photon-photon and photon-hadron physics accessible in these
collisions. Among these processes I discuss the nuclear fragmentation through
the excitation of giant resonances, the Coulomb dissociation method for
application in nuclear astrophysics, and the production of particles.Comment: 51 pages, 16 figure
‘Not a country at all’: landscape and Wuthering Heights
This article explores the issue of women’s representational genealogies through an analysis of Andrea Arnold’s 2011 Wuthering Heights. Beginning with 1970s feminist arguments for a specifically female literary tradition, it argues that running through both these early attempts to construct an alternative female literary tradition and later work in feminist philosophy, cultural geography and film history is a concern with questions of ‘alternative landscapes’: of how to represent, and how to encounter, space differently. Adopting Mary Jacobus’ notion of intertextual ‘correspondence’ between women’s texts, and taking Arnold’s film as its case study, it seeks to trace some of the intertextual movements – the reframings, deframings and spatial reorderings – that link Andrea Arnold’s film to Emily Brontë’s original novel. Focusing on two elements of her treatment of landscape – her use of ‘unframed’ landscape and her focus on visceral textural detail – it points to correspondences in other women’s writing, photography and film-making. It argues that these intensely tactile close-up sequences which puncture an apparently realist narrative constitute an insistent presence beneath, or within, the ordered framing which is our more usual mode of viewing landscape. As the novel Wuthering Heights is unmade in Arnold’s adaptation and its framings ruptured, it is through this disturbance of hierarchies of time, space and landscape that we can trace the correspondences of an alternative genealogy
Evaluation of a high-resolution regional climate simulation over Greenland
A simulation of the 1991 summer has been performed over south Greenland with a coupled atmosphere–snow regional climate model (RCM) forced by the ECMWF re-analysis. The simulation is evaluated with in-situ coastal and ice-sheet atmospheric and glaciological observations. Modelled air temperature, specific humidity, wind speed and radiative fluxes are in good agreement with the available observations, although uncertainties in the radiative transfer scheme need further investigation to improve the model’s performance. In the sub-surface snow-ice model, surface albedo is calculated from the simulated snow grain shape and size, snow depth, meltwater accumulation, cloudiness and ice albedo. The use of snow metamorphism processes allows a realistic modelling of the temporal variations in the surface albedo during both melting periods and accumulation events. Concerning the surface albedo, the main finding is that an accurate albedo simulation during the melting season strongly depends on a proper initialization of the surface conditions which mainly result from winter accumulation processes. Furthermore, in a sensitivity experiment with a constant 0.8 albedo over the whole ice sheet, the average amount of melt decreased by more than 60%, which highlights the importance of a correctly simulated surface albedo. The use of this coupled atmosphere–snow RCM offers new perspectives in the study of the Greenland surface mass balance due to the represented feedback between the surface climate and the surface albedo, which is the most sensitive parameter in energy-balance-based ablation calculations.Peer reviewe
A mixed methods pilot study with a cluster randomized control trial to evaluate the impact of a leadership intervention on guideline implementation in home care nursing
Abstract
Background
Foot ulcers are a significant problem for people with diabetes. Comprehensive assessments of risk factors associated with diabetic foot ulcer are recommended in clinical guidelines to decrease complications such as prolonged healing, gangrene and amputations, and to promote effective management. However, the translation of clinical guidelines into nursing practice remains fragmented and inconsistent, and a recent homecare chart audit showed less than half the recommended risk factors for diabetic foot ulcers were assessed, and peripheral neuropathy (the most significant predictor of complications) was not assessed at all.
Strong leadership is consistently described as significant to successfully transfer guidelines into practice. Limited research exists however regarding which leadership behaviours facilitate and support implementation in nursing.
The purpose of this pilot study is to evaluate the impact of a leadership intervention in community nursing on implementing recommendations from a clinical guideline on the nursing assessment and management of diabetic foot ulcers.
Methods
Two phase mixed methods design is proposed (ISRCTN 12345678). Phase I: Descriptive qualitative to understand barriers to implementing the guideline recommendations, and to inform the intervention. Phase II: Matched pair cluster randomized controlled trial (n = 4 centers) will evaluate differences in outcomes between two implementation strategies. Primary outcome: Nursing assessments of client risk factors, a composite score of 8 items based on Diabetes/Foot Ulcer guideline recommendations.
Intervention: In addition to the organization's 'usual' implementation strategy, a 12 week leadership strategy will be offered to managerial and clinical leaders consisting of: a) printed materials, b) one day interactive workshop to develop a leadership action plan tailored to barriers to support implementation; c) three post-workshop teleconferences.
Discussion
This study will provide vital information on which leadership strategies are well received to facilitate and support guideline implementation. The anticipated outcomes will provide information to assist with effective management of foot ulcers for people with diabetes.
By tracking clinical outcomes associated with guideline implementation, health care administrators will be better informed to influence organizational and policy decision-making to support evidence-based quality care. Findings will be useful to inform the design of future multi-centered trials on various clinical topics to enhance knowledge translation for positive outcomes.
Trial Registration
Current Control Trials ISRCTN0691089
Improvement to numerical predictions of aerodynamic flows using experimental data assimilation
No abstract available
Damage Tolerance and Fail Safety of Welded Aircraft Wing Panels
An investigation is presented on fatigue crack growth behavior and fail safety
of integral stringer panels typified by welded aircraft fabrications. The
stringer panel is made of aluminum alloy 2024-T351 and fabricated by the
variable-polarity plasma-arc welding process. The sample simulates a part of the
lower-wing skin structures. Based on the linear elastic fracture mechanics,
numerical simulations are performed for two configurations, two-stringer and
nine-stringer panels, and three damage scenarios, in which welding-induced
longitudinal residual stresses are taken into account. A typical load spectrum
for large transport aircraft is employed for the analysis. For the two-stringer
panel life predictions have a reasonably good correlation with the test results.
Based on this validation, large-scale nine-stringer panels with three
manufacture options, that is, riveted, integrally machined, and welded integral,
are simulated for a skin crack under a broken central stringer propagating to
two-bay length. Useful comparisons are made among the three variants. Finally,
remedies to improve damage tolerance and fail safety of integral stringer panels
are explored. The incorporation of crack retarder straps bonded to the inner
surface of an integral panel has greatly improved the fail safety behavior of
the component with dramatically increased crack growth live
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