208 research outputs found
Crosscutting cleavages and ethno-communal violence: Evidence from Indonesia in the post-Suharto era
Recent literature has shown that crosscutting social cleavages reduce the likelihood of civil war. This article argues that the same logic does not apply to lower-scale group violence such as riots, which differ in such a way that crosscutting social cleavages should often have the opposite effect, increasing both the frequency and scale of riots. We test this argument by analysing Muslim-Christian violence in the post-Suharto era, combining a new subnational data set of ethno-income and ethnogeographic crosscuttingness with a new and comprehensive subnational data set of violence in Indonesia. Our findings suggest that high ethno-income crosscuttingness, when combined with a high degree of urban anonymity and close living quarters, is a potent setting for inter-group communal violence. We conclude with a discussion of how context matters in understanding the effect of macrostructural variables such as crosscuttingness on violence
Tribology of swollen starch granule suspensions from maize and potato
The tribological properties of suspensions of cooked swollen starch granules are characterised for systems based on maize starch and potato starch. These systems are known as granule 'ghosts' due to the release (and removal) of polymer from their structure during cooking. Maize starch ghosts are less swollen than potato starch ghosts, resulting in a higher packing concentration and greater mechanical stability. In a soft-tribological contact, maize ghost suspensions reduce friction compared to the solvent (water), generate bell-shaped tribological profiles characteristic of particle entrainment and show a marked concentration dependence, whereas potato ghost suspensions exhibit lubrication behaviour similar to water. Microscopy analysis of the samples following tribological testing suggests that this is due to the rapid break-up of potato ghosts under the shear and rolling conditions within the tribological contact. A reduction in the small deformation moduli (associated with a weak gel structure) is also observed when the potato ghost suspensions are subjected to steady shear using parallel plate rheometry; both microscopy and particle size analysis show that this is accompanied by the partial shear-induced breakage of ghost particles. This interplay between particle microstructure and the resultant rheological and lubrication dynamics of starch ghost suspensions contributes to an enhanced mechanistic understanding of textural and other functional properties of cooked starches in food and other applications
Use of a Pulsed Radiofrequency Energy Device (PEAK Plasmablade™) in Neuromodulation Implant Revisions
BackgroundBattery replacement or revision surgery for neuromodulation implants is conventionally performed using sharp dissection. Meticulous dissection within thick scar tissue is vital to avoid damage to surrounding lead(s) which could result in more extensive revision surgery. Traditional electrosurgery devices are contraindicated as the emitted energy can be transferred to the hardware resulting in implant or tissue damage with severe consequent complications.ObjectiveWe report our experience and potential applications of a novel, pulsed monopolar radiofrequency energy device (PEAK PlasmaBlade™, Medtronic plc) which facilitates dissection around implants without the risk of damaging or transmitting energy through the system.MethodsA two-centre retrospective study to review the indications, safety and efficacy of the PlasmaBlade in 57 cases requiring either neuromodulation system replacement or revision. Deep brain stimulator (DBS) battery replacements were undertaken in 45 cases, 8 vagal nerve stimulator battery revisions, 2 intrathecal baclofen system revision, 1 DBS extension revision and 1 DBS scar revision around the cranial portion of the lead.ResultsAll cases proceeded without adverse event, damage to lead/generator and with a subjective and objective impression of significant time savings. Average operating times for battery replacements were reduced from 37 to 26 minutes (p=0.015).ConclusionIn our experience, the PlasmaBlade is safe to use in revising/replacing neuromodulation implants. We observed no damage or transmission of energy to the implants or leads; additional advantages of the system include reduced operating times, less damage to surrounding tissue and the potential to facilitate revision procedures in awake patients under local anaesthesia
Comparative gene expression profiling of ADAMs, MMPs, TIMPs, EMMPRIN, EGF-R and VEGFA in low grade meningioma
MMPs (matrix metalloproteinases), ADAMs (a disintegrin and metalloproteinase) and TIMPs (tissue inhibitors of metalloproteinases) are implicated in invasion and angiogenesis: both are tissue remodeling processes involving regulated proteolysis of the extracellular matrix, growth factors and their receptors. The expression of these three groups and their correlations with clinical behaviour has been reported in gliomas but a similar comprehensive study in meningiomas is lacking. In the present study, we aimed to evaluate the patterns of expression of 23 MMPs, 4 TIMPs, 8 ADAMs, selective growth factors and their receptors in 17 benign meningiomas using a quantitative real-time polymerase chain reaction (qPCR). Results indicated very high gene expression of 13 proteases, inhibitors and growth factors studied: MMP2 and MMP14, TIMP-1, -2 and -3, ADAM9, 10, 12, 15 and 17, EGF-R, EMMPRIN and VEGF-A, in almost every meningioma.
Expression pattern analysis showed several positive correlations between MMPs, ADAMs, TIMPs and growth factors. Furthermore, our findings suggest that expression of MMP14, ADAM9, 10, 12, 15 and 17, TIMP-2, EGF-R and EMMPRIN reflects histological subtype of meningioma such that fibroblastic subtype had the highest mRNA expression, transitional subtype was intermediate and meningothelial type had the lowest expression. In conclusion, this is the first comprehensive study characterizing gene expression of ADAMs in meningiomas. These neoplasms, although by histological definition benign, have invasive potential. Taken together, the selected elevated gene expression pattern may serve to identify targets for therapeutic intervention or indicators of biological progression and recurrence
Influence of fluid viscosity and wetting on multiscale viscoelastic lubrication in soft tribological contacts
Friction (and lubrication) between soft contacts is prevalent in many natural and engineered systems and plays a crucial role in determining their functionality. The contribution of viscoelastic hysteresis losses to friction in these systems has been well-established and defined for dry contacts; however, the influence of fluid viscosity and wetting on these components of friction has largely been overlooked. We provide systematic experimental evidence of the influence of lubricant viscosity and wetting on lubrication across multiple regimes within a viscoelastic contact. These effects are investigated for comparatively smooth and rough elastomeric contacts (PTFE-PDMS and PDMS-PDMS) lubricated by a series of Newtonian fluids with systematically controlled viscosity and static wetting properties, using a ball-on-disc tribometer. The distinct tribological behaviour, characterised generally by a decrease in the friction coefficient with increasing fluid viscosity and wettability, is explained in terms of lubricant dewetting and squeeze-out dynamics and their impact on multi-scale viscoelastic dissipation mechanisms at the bulk-, asperity-, sub-asperity- and molecular-scale. It is proposed that lubrication within the (non-molecularly) smooth contact is governed by localised fluid entrapment and molecular-scale (interfacial) viscoelastic effects, while additional rubber hysteresis stimulated by fluid-asperity interactions, combined with rapid fluid drainage at low speeds within the rough contact, alter the general shape of the Stribeck curve. This fluid viscosity effect is in some agreement with theoretical predictions. Conventional methods for analysing and interpreting tribological data, which typically involve scaling sliding velocity with lubricant viscosity, need to be revised for viscoelastic contacts with consideration of these indirect viscosity effects
Surface-wave imaging of the weakly-extended Malawi Rift from ambient-noise and teleseismic Rayleigh waves from onshore and lake-bottom seismometers
Located at the southernmost sector of the Western Branch of the East African Rift System, the Malawi Rift exemplifies an active, magma-poor, weakly extended continental rift. To investigate the controls on rifting, we image crustal and uppermost mantle structure beneath the region using ambient-noise and teleseismic Rayleigh-wave phase velocities between 9 and 100 s period. Our study includes six lake-bottom seismometers located in Lake Malawi (Nyasa), the first time seismometers have been deployed in any of the African rift lakes. Noise-levels in the lake are lower than that of shallow oceanic environments and allow successful application of compliance corrections and instrument orientation determination. Resulting phase-velocity maps reveal slow velocities primarily confined to Lake Malawi at short periods (T 25 s) a prominent low-velocity anomaly exists beneath the Rungwe Volcanic Province at the northern terminus of the rift basin. Estimates of phase-velocity sensitivity indicates these low velocities occur within the lithospheric mantle and potentially uppermost asthenosphere, suggesting that mantle processes may control the association of volcanic centers and the localization of magmatism. Beneath the main portion of the Malawi Rift, a modest reduction in velocity is also observed at periods sensitive to the crust and upper mantle, but these velocities are much higher than those observed beneath Rungwe
Centromedian thalamic nuclei deep brain stimulation and Anakinra treatment for FIRES - Two different outcomes
Febrile infection-related epilepsy syndrome (FIRES) is a severe epilepsy disorder that affects previously healthy children. It carries high likelihood of unfavourable outcome and putative aetiology relates to an auto-inflammatory process. Standard antiepileptic drug therapies including intravenous anaesthetic agents are largely ineffective in controlling status epilepticus in FIRES. Deep brain stimulation of the centromedian thalamic nuclei (CMN-DBS) has been previously used in refractory status epilepticus in only a few cases. The use of Anakinra (a recombinant version of the human interleukin-1 receptor antagonist) has been reported in one case with FIRES with good outcome. Here we describe two male paediatric patients with FIRES unresponsive to multiple anti-epileptic drugs, first-line immune modulation, ketogenic diet and cannabidiol. They both received Anakinra and underwent CMN-DBS. The primary aim for CMN-DBS therapy was to reduce generalized seizures. CMN-DBS abolished generalized seizures in both cases and Anakinra had a positive effect in one. This patient had a favourable outcome whereas the other did not. These are the first reported cases of FIRES where CMN-DBS has been used
Potential predictive value of repetitive transcranial magnetic stimulation before chronic cortical stimulation for epilepsia partialis continua
Formation and tribology of fucoidan/chitosan polyelectrolyte multilayers on PDMS substrates
Polysaccharide polyelectrolyte multilayers (PEMs) based on fucoidan and chitosan were formed by Layer-by-Layer (LbL) assembly on polydimethylsiloxane (PDMS) substrates. The surface and aqueous lubrication properties of the PEM films are evaluated for two types of fucoidan extracted from separate seaweed species (Fucus vesiculosus – FV and Undaria pinnatifida – UP). Zeta potential and atomic force microscopy (AFM) imaging reveal that the PEM layers are formed with consistent charge reversal as each polysaccharide layer is adsorbed to the PDMS substrate, and that there is an associated increase in thickness of the multilayer. The multilayers containing FV fucoidan are found to be thicker than those containing UP fucoidan. Soft tribology measurements using matching PDMS tribo-pairs are used to show that the films are robust under rolling/sliding contacts and effective under aqueous lubricating conditions. The friction in the boundary lubrication regime is substantially decreased (relative to native hydrophobic PDMS) by the presence of the multilayers, with some dependence on whether fucoidan or chitosan is in the outer layer (5 or 5.5 bilayers) for FV fucoidan. The lowest friction coefficient is obtained for the multilayer with the thickest (and likely most hydrated) coating – the (FV/chitosan) 5.5 bilayer system. The results suggest that PEMs involving naturally derived polysaccharides such as fucoidan, which has notable antimicrobial properties and is resistant to enzymatic degradation, may provide opportunities in surface coating design in biomaterials applications for friction reduction
Home Office Fingerprint Source Book
The Fingerprint Source Book is primarily intended to provide the background and validation for the techniques currently (up to 2016) recommended by the Home Office Centre for Applied
Science and Technology (CAST), and to publish, in some cases for the first time, data collected over 45 years of research. It will therefore often present information in an ‘CASTcentric’ way, emphasising research that was carried out at Sandridge or Horseferry House, possibly sometimes at the expense of research carried out elsewhere. It is not the intention of
the authors to ignore the significant contributions made by other research groups and apologies are made in advance if this sometimes appears to be the case. The document is
also aimed at providing the UK Forensic Science Regulator and the United Kingdom Accreditation Service (UKAS), which has carried out ISO 17025 accreditation in the UK, with the background evidence behind the advice given in the Fingermark Visualisation Manual
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