Recursos de colección

White Rose Research Online (80.987 recursos)

Este es el repositorio institucional de tres universidades del Reino Unido (York, Leeds y Sheffield), creado con el apoyo de SHERPA. Proporciona acceso a los artículos de investigación de las instituciones.

Institution = The University of Sheffield

Mostrando recursos 1 - 20 de 5.143

  1. Interaction of Ammonium Carbamate with Uranyl, Zirconium and Molybdate Containing PUREX Species

    Ogden, M.D.

  2. Tactile Language for a Head-Mounted Sensory Augmentation Device

    Kerdegari, H.; Kim, Y.; Prescott, T.
    Sensory augmentation is one of the most exciting domains for research in human-machine biohybridicity. The current paper presents the design of a 2nd generation vibrotactile helmet as a sensory augmentation prototype that is being developed to help users to navigate in low visibility environments. The paper outlines a study in which the user navigates along a virtual wall whilst the position and orientation of the user’s head is tracked by a motion capture system. Vibrotactile feedback is presented according to the user’s distance from the virtual wall and their head orientation. The research builds on our previous work by developing...

  3. Centralizing Bias and the Vibrotactile Funneling Illusion on the Forehead

    Kerdegari, H.; Kim, Y.; Stafford, T.; Prescott, T.J.
    This paper provides a novel psychophysical investigation of headmounted vibrotactile interfaces for sensory augmentation. A 1-by-7 headband vibrotactile display was used to provide stimuli on each participant’s forehead. Experiment I investigated the ability to identify the location of a vibrotactile stimulus presented to a single tactor in the display; results indicated that localization error is uniform but biased towards the forehead midline. In Experiment II, two tactors were activated simultaneously, and participants were asked to indicate whether they experienced one or two stimulus locations. Participants reported the funneling illusion—experiencing one stimulus when two tactors were activated—mainly for the shortest inter-tactor difference. We discuss the significance of these results for the...

  4. Transmission Rate performance of symmetric two-way full-duplex links at large antenna-array limit

    Riihonen, T.; Vehkaperä, M.; Wichman, R.; Wang, X.
    © 2015 IEEE. This paper concerns the performance of two-way point-to-point multiple-input multiple-output (MIMO) links. In particular, the system of interest comprises a pair of multiantenna full-duplex terminals that communicate with each other through a MIMO radio channel under residual self-interference from imperfect mitigation using joint decoding for reception. The new theoretical result underlying this study is to express asymptotic achievable rates in the system whose dimensions grow without bound when detection and decoding is mismatched due to the residual self-interference and spatial data streams are separately encoded using some practical digital modulation scheme, in contrast to ideal matched decoding...

  5. Extension of Nested Arrays with the Fourth-Order Difference Co-Array Enhancement

    Shen, Q.; Liu, W.; Cui, W.; Wu, S.L.
    To reach a higher number of degrees of freedom by exploiting the fourth-order difference co-array concept, an effective structure extension based on two-level nested arrays is proposed. It increases the number of consecutive lags in the fourth-order difference coarray, and a virtual uniform linear array (ULA) with more sensors and a larger aperture is then generated from the proposed structure, leading to a much higher number of distinguishable sources with a higher accuracy. Compressive sensing based approach is applied for direction-of-arrival (DOA) estimation by vectorizing the fourthorder cumulant matrix of the array, assuming non-Gaussian impinging signals.

  6. Development and Modification of Yield Line Patterns in Thin Slabs Subjected to Tensile Membrane Action

    Quichaud, F.; Burgess, I.W.; Huang, S-S
    It is widely recognized that composite floor slabs experiencing large displacement develop a central zone of hydrostatic membrane tension, surrounded and equilibrated by a ring of membrane compression around the periphery. This mechanism, known as tensile membrane action, can greatly enhance the load-bearing capacity of a slab compared with that defined by yield line analysis. This is a very useful effect in cases where large deflections can be accepted, particularly in fire-resistance design of composite slabs, since the strength enhancement permits some beams to be left unprotected. Studies of tensile membrane action in the 1960s led to the development of...

  7. A qualitative study evaluating experiences of a lifestyle intervention in men with prostate cancer undergoing androgen suppression therapy

    Bourke, L.; Sohanpal, R.; Nanton, V.; Crank, H.; Rosario, D.J.; Saxton, J.M.
    Background: The severe iatrogenic hypogonadal state induced by medical castration used for treatment of prostate cancer is associated with adverse effects including fatigue, increased fracture risk, and a decrease in skeletal muscle function, which negatively impact quality of life. We have previously reported beneficial changes in healthy lifestyle behaviors, physical function and fatigue as a result of a novel combined exercise and dietary advice intervention (a lifestyle intervention) in men with prostate cancer on androgen suppression therapy (AST). The aim of this research was to conduct a qualitative evaluation of the lifestyle intervention in these men with advanced prostate cancer receiving androgen suppression therapy (AST). Methods: Twelve...

  8. A profile of enzalutamide for the treatment of advanced castration resistant prostate cancer.

    Greasley, R.; Khabazhaitajer, M.; Rosario, D.J.
    Recent advances in understanding the mechanisms underlying the development and progression of castration resistant prostate cancer from androgen-sensitive prostate cancer have provided new avenues exploring efficacious therapies in a disease which is the second leading cause of cancer deaths among men in the western world. In the evolution of second generation anti-androgens, enzalutamide, a novel androgen-receptor signaling inhibitor, has emerged targeting multiple steps within the androgenic stimulation pathway. This review discusses what is currently known of the mechanisms surrounding castration resistant prostate cancer development and the current human clinical trials to determine whether enzalutamide presents a new hope for men...

  9. A pragmatic, multicentre, randomised controlled trial comparing stapled haemorrhoidopexy to traditional excisional surgery for haemorrhoidal disease (eTHoS): study protocol for a randomised controlled trial

    Watson, A.J.M.; Bruhn, H.; MacLeod, K.; McDonald, A.; McPherson, G.; Kilonzo, M.; Norrie, J.; Loudon, M.A.; McCormack, K.; Buckley, B.; Brown, S.; Curran, F.; Jayne, D.; Rajagopal, R.; Cook, J.A.; eTHoS study group,
    Background: Current interventions for haemorrhoidal disease include traditional haemorrhoidectomy (TH) and stapled haemorrhoidopexy (SH) surgery. However, uncertainty remains as to how they compare from a clinical, quality of life (QoL) and economic perspective. The study is therefore designed to determine whether SH is more effective and more cost-effective, compared with TH. Methods/Design: eTHoS (either Traditional Haemorrhoidectomy or Stapled Haemorrhoidopexy for Haemorrhoidal Disease) is a pragmatic, multicentre, randomised controlled trial. Currently, 29 secondary care centres are open to recruitment. Patients, aged 18 year or older, with circumferential haemorrhoids grade II to IV, are eligible to take part. The primary clinical and economic outcomes are QoL profile (area under...

  10. Circular polarization in a non-magnetic resonant tunneling device

    dos Santos, L.F.; Gobato, Y.G.; Teodoro, M.D.; Lopez-Richard, V.; Marques, G.E.; Brasil, M.J.S.P.; Orlita, M.; Kunc, J.; Maude, D.K.; Henini, M.; Airey, R.J.
    We have investigated the polarization-resolved photoluminescence (PL) in an asymmetric n-type GaAs/AlAs/GaAlAs resonant tunneling diode under magnetic field parallel to the tunnel current. The quantum well (QW) PL presents strong circular polarization (values up to -70% at 19 T). The optical emission from GaAs contact layers shows evidence of highly spin-polarized two-dimensional electron and hole gases which affects the spin polarization of carriers in the QW. However, the circular polarization degree in the QW also depends on various other parameters, including the g-factors of the different layers, the density of carriers along the structure, and the Zeeman and Rashba effects.

  11. Spin injection in n-type resonant tunneling diodes

    Gordo, V.O.; Herval, L.K.S.; Galeti, H.V.A.; Gobato, Y.G.; Brasil, M.J.S.P.; Marques, G.E.; Henini, M.; Airey, R.J.
    We have studied the polarized resolved photoluminescence of n-type GaAs/AlAs/GaAlAs resonant tunneling diodes under magnetic field parallel to the tunnel current. Under resonant tunneling conditions, we have observed two emission lines attributed to neutral (X) and negatively charged excitons (X− ). We have observed a voltage-controlled circular polarization degree from the quantum well emission for both lines, with values up to −88% at 15 T at low voltages which are ascribed to an efficient spin injection from the 2D gases formed at the accumulation layers.

  12. Photoluminescence upconversion at interfaces driven by a sequential two-photon absorption mechanism

    Hylton, N.P.; Hinrichsen, T.F.; Vaquero-Stainer, A.R.; Yoshida, M.; Pusch, A.; Hopkinson, M.; Hess, O.; Phillips, C.C.; Ekins-Daukes, N.J.
    This paper reports on the results of an investigation into the nature of photoluminescence upconversion at GaAs/InGaP2 interfaces. Using a dual-beam excitation experiment, we demonstrate that the upconversion in our sample proceeds via a sequential two-photon optical absorption mechanism. Measurements of photoluminescence and upconversion photoluminescence revealed evidence of the spatial localization of carriers in the InGaP2 material, arising from partial ordering of the InGaP2. We also observed the excitation of a two-dimensional electron gas at the GaAs/InGaP2 heterojunction that manifests as a high-energy shoulder in the GaAs photoluminescence spectrum. Furthermore, the results of upconversion photoluminescence excitation spectroscopy demonstrate that the photon energy onset of upconversion luminescence coincides...

  13. Metaflammasome components in the human brain: a role in dementia with alzheimer's pathology?

    Taga, M.; Minett, T.; Classey, J.; Matthews, F.E.; Brayne, C.; Ince, P.G.; Nicoll, J.A.R.; Hugon, J.; Boche, D.
    Epidemiological and genetic studies have identified metabolic disorders and inflammation as risk factors for Alzheimer's disease (AD). Evidence in obesity and type-2 diabetes suggests a role for a metabolic inflammasome (“metaflammasome”) in mediating chronic inflammation in peripheral organs implicating IKKβ (inhibitor of nuclear factor kappa-B kinase subunit beta), IRS1 (insulin receptor substrate 1), JNK (c-jun N-terminal kinase), and PKR (double-stranded RNA protein kinase). We hypothesized that these proteins are expressed in the brain in response to metabolic risk factors in AD. Neocortex from 299 participants from the MRC Cognitive Function and Ageing Studies was analysed by immunohistochemistry for the expression...

  14. Evidence of positive selection associated with placental loss in tiger sharks

    Swift, D.G.; Dunning, L.T.; Igea, J.; Brooks, E.J.; Jones, C.S.; Noble, L.R.; Ciezarek, A.; Humble, E.; Savolainen, V.
    Background: All vertebrates initially feed their offspring using yolk reserves. In some live-bearing species these yolk reserves may be supplemented with extra nutrition via a placenta. Sharks belonging to the Carcharhinidae family are all live-bearing, and with the exception of the tiger shark (Galeocerdo cuvier), develop placental connections after exhausting yolk reserves. Phylogenetic relationships suggest the lack of placenta in tiger sharks is due to secondary loss. This represents a dramatic shift in reproductive strategy, and is likely to have left a molecular footprint of positive selection within the genome. Results: We sequenced the transcriptome of the tiger shark and eight other live-bearing shark species. From...

  15. Evidence for Fast Electron Transfer between the High-Spin Haems in Cytochrome bd-I from Escherichia coli

    Siletsky, S.A.; Rappaport, F.; Poole, R.K.; Borisov, V.B.
    Cytochrome bd-I is one of the three proton motive force-generating quinol oxidases in the O2-dependent respiratory chain of Escherichia coli. It contains one low-spin haem (b558) and the two high-spin haems (b595 and d) as the redox-active cofactors. In order to examine the flash-induced intraprotein reverse electron transfer (the so-called ''electron backflow''), CO was photolyzed from the ferrous haem d in one-electron reduced (b558 3+b595 3+d2+-CO) cytochrome bd-I, and the fully reduced (b5582+b5952+d2+-CO) oxidase as a control. In contrast to the fully reduced cytochrome bd-I, the transient spectrum of one-electron reduced oxidase at a delay time of 1.5 μs is clearly different from that at a delay time of...

  16. Engaging Terminally Ill Patients in End of Life Talk: How Experienced Palliative Medicine Doctors Navigate the Dilemma of Promoting Discussions about Dying

    Pino, M.; Parry, R.; Land, V.; Faull, C.; Feathers, L.; Seymour, J.
    Objective To examine how palliative medicine doctors engage patients in end-of-life (hereon, EoL) talk. To examine whether the practice of “eliciting and responding to cues”, which has been widely advocated in the EoL care literature, promotes EoL talk. Design Conversation analysis of video- and audio-recorded consultations. Participants Unselected terminally ill patients and their companions in consultation with experienced palliative medicine doctors. Setting Outpatient clinic, day therapy clinic, and inpatient unit of a single English hospice. Results Doctors most commonly promoted EoL talk through open elaboration solicitations; these created opportunities for patients to introduce–then later further articulate–EoL considerations in such a way that doctors did not overtly ask about EoL matters. Importantly, the wording of elaboration...

  17. Efficacy and Safety of Radium-223 Dichloride in Symptomatic Castration-resistant Prostate Cancer Patients With or Without Baseline Opioid Use From the Phase 3 ALSYMPCA Trial

    Parker, C.; Finkelstein, S.E.; Michalski, J.M.; O'Sullivan, J.M.; Bruland, Ø.; Vogelzang, N.J.; Coleman, R.E.; Nilsson, S.; Sartor, O.; Li, R.; Seger, M.A.; Bottomley, D.
    Background: The phase 3 ALSYMPCA trial enrolled metastatic castration-resistant prostate cancer patients with or without baseline opioid use. Objective: To assess the efficacy and safety of radium-223 dichloride (radium-223) versus placebo in ALSYMPCA patients by baseline opioid use. Design, setting, and participants: Nine hundred and twenty one patients enrolled at 136 centers globally. Intervention: Radium-223 (50 kBq/kg, intravenous injection) every 4 wk for six cycles or matching placebo, each plus best standard of care. Outcome measurements and statistical analysis: Primary endpoint (overall survival [OS]), main secondary efficacy endpoints, and safety were evaluated by baseline opioid use. Additional analyses included time to first opioid use, time to first external beam radiation therapy...

  18. Cancer-associated fibroblasts – Not-so-innocent bystanders in metastasis to bone?

    Prajapati, P.; Lambert, D.W.

  19. Analysis of primary visual cortex in dementia with Lewy bodies indicates GABAergic involvement associated with recurrent complex visual hallucinations

    Khundakar, A.A.; Hanson, P.S.; Erskine, D.; Lax, N.Z.; Roscamp, J.; Karyka, E.; Tsefou, E.; Singh, P.; Cockell, S.J.; Gribben, A.; Ramsay, L.; Blain, P.G.; Mosimann, U.P.; Lett, D.J.; Elstner, M.; Turnbull, D.M.; Xiang, C.C.; Brownstein, M.J.; O’Brien, J.T.; Taylor, J-P.; Attems, J.; Thomas, A.J.; McKeith, I.G.; Morris, C.M.
    Dementia with Lewy bodies (DLB) patients frequently experience well formed recurrent complex visual hallucinations (RCVH). This is associated with reduced blood flow or hypometabolism on imaging of the primary visual cortex. To understand these associations in DLB we used pathological and biochemical analysis of the primary visual cortex to identify changes that could underpin RCVH. Alpha-synuclein or neurofibrillary tangle pathology in primary visual cortex was essentially absent. Neurone density or volume within the primary visual cortex in DLB was also unchanged using unbiased stereology. Microarray analysis, however, demonstrated changes in neuropeptide gene expression and other markers, indicating altered GABAergic neuronal...

  20. Air Pollution and Subtypes, Severity and Vulnerability to Ischemic Stroke—A Population Based Case-Crossover Study

    Maheswaran, R.; Pearson, T.; Beevers, S.D.; Campbell, M.J.; Wolfe, C.D.

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