301 research outputs found

    Measuring the effectiveness of neurological rehabilitation.

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    Neurological rehabilitation aims to reduce the restrictions on an individual's participation in society. Psychometrically rigorous and clinically relevant outcome measures, used appropriately, enhance the evidence base of rehabilitation. This Thesis assesses routinely used outcome measures at three time points: inpatient, outpatient, and longer-term follow-up. First, a retrospective analysis of the inpatient database of the Neurorehabilitation Unit was carried out to assess the Barthel index (BI) and Functional Independence Measure (FIM). Second, a prospective study examined the impact of rehabilitation on physical function and emotional wellbeing. Five measures were completed on admission, discharge and three months post-discharge: the BI (clinician and patient scored versions), FIM, General Health Questionnaire and Hospital Anxiety and Depression Scale. Finally, the effect of multiple sclerosis (MS) on work retention was assessed in a cross- sectional study using a newly developed outcome measure, the Impact on Work Questionnaire. In the first study, the responsiveness of the Bl and FIM total scores ranged from moderate to large. But item level analyses indicated differential item performance, with effect sizes varying from very low to large, associated with large floor and ceiling effects. The second study demonstrated the significant improvements in physical and psychological functioning in patients undergoing rehabilitation. Physical gains persisted after discharge, however, emotional wellbeing deteriorated. The last study revealed that a combination of MS-related problems, environmental restrictions and poor vocational support impact on work retention in people with MS. Following patients through the rehabilitation process, in the form of three distinct studies, has afforded a unique view of the effect of rehabilitation in neurological conditions. Furthermore, the examination of routinely used measures has provided guidance on the application of these in future research. Choosing the most appropriate measures and analytical techniques provides richer data, facilitates accurate evaluation of rehabilitation interventions, and ultimately improves patient care

    Solid immersion lens applications for nanophotonic devices

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    Solid immersion lens (SIL) microscopy combines the advantages of conventional microscopy with those of near-field techniques, and is being increasingly adopted across a diverse range of technologies and applications. A comprehensive overview of the state-of-the-art in this rapidly expanding subject is therefore increasingly relevant. Important benefits are enabled by SIL-focusing, including an improved lateral and axial spatial profiling resolution when a SIL is used in laser-scanning microscopy or excitation, and an improved collection efficiency when a SIL is used in a light-collection mode, for example in fluorescence micro-spectroscopy. These advantages arise from the increase in numerical aperture (NA) that is provided by a SIL. Other SIL-enhanced improvements, for example spherical-aberration-free sub-surface imaging, are a fundamental consequence of the aplanatic imaging condition that results from the spherical geometry of the SIL. Beginning with an introduction to the theory of SIL imaging, the unique properties of SILs are exposed to provide advantages in applications involving the interrogation of photonic and electronic nanostructures. Such applications range from the sub-surface examination of the complex three-dimensional microstructures fabricated in silicon integrated circuits, to quantum photoluminescence and transmission measurements in semiconductor quantum dot nanostructures

    Searches for Stable Strangelets in Ordinary Matter: Overview and a Recent Example

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    Our knowledge on the possible existence in nature of stable exotic particles depends solely upon experimental observation. Guided by this general principle and motivated by theoretical hypotheses on the existence of stable particles of strange quark matter, a variety of experimental searches have been performed. We provide an introduction to the theoretical hypotheses, an overview of the past searches, and a more detailed description of a recent search for helium-like strangelets in the Earth's atmosphere using a sensitive laser spectroscopy method

    Theory of finite temperature crossovers near quantum critical points close to, or above, their upper-critical dimension

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    A systematic method for the computation of finite temperature (TT) crossover functions near quantum critical points close to, or above, their upper-critical dimension is devised. We describe the physics of the various regions in the TT and critical tuning parameter (tt) plane. The quantum critical point is at T=0T=0, t=0t=0, and in many cases there is a line of finite temperature transitions at T=Tc(t)T = T_c (t), t<0t < 0 with Tc(0)=0T_c (0) = 0. For the relativistic, nn-component ϕ4\phi^4 continuum quantum field theory (which describes lattice quantum rotor (n≄2n \geq 2) and transverse field Ising (n=1n=1) models) the upper critical dimension is d=3d=3, and for d<3d<3, Ï”=3−d\epsilon=3-d is the control parameter over the entire phase diagram. In the region ∣T−Tc(t)∣â‰ȘTc(t)|T - T_c (t)| \ll T_c (t), we obtain an Ï”\epsilon expansion for coupling constants which then are input as arguments of known {\em classical, tricritical,} crossover functions. In the high TT region of the continuum theory, an expansion in integer powers of Ï”\sqrt{\epsilon}, modulo powers of lnâĄÏ”\ln \epsilon, holds for all thermodynamic observables, static correlators, and dynamic properties at all Matsubara frequencies; for the imaginary part of correlators at real frequencies (ω\omega), the perturbative Ï”\sqrt{\epsilon} expansion describes quantum relaxation at ℏω∌kBT\hbar \omega \sim k_B T or larger, but fails for ℏω∌ϔkBT\hbar \omega \sim \sqrt{\epsilon} k_B T or smaller. An important principle, underlying the whole calculation, is the analyticity of all observables as functions of tt at t=0t=0, for T>0T>0; indeed, analytic continuation in tt is used to obtain results in a portion of the phase diagram. Our method also applies to a large class of other quantum critical points and their associated continuum quantum field theories.Comment: 36 pages, 4 eps figure

    Reconstruction and subsurface lattice distortions in the (2 × 1)O-Ni(110) structure: A LEED analysis

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    LEED analysis of the reconstructed (2 × 1)O-Ni(110) system clearly favors the “missing row” structure over the “saw-tooth” and “buckled row” models. By using a novel computational procedure 8 structural parameters could be refined simultaneously, leading to excellent R-factors (RZJ = 0.09, RP = 0.18). The adsorbed O atoms are located 0.2 Å above the long bridge sites in [001] direction, presumably with a slight displacement ( 0.1 Å) in [1 0] direction to an asymmetric adsorption site. The nearest-neighbor Ni---O bond lengths (1.77 Å) are rather short. The separation between the topmost two Ni layers is expanded to 1.30 Å (bulk value 1.25 Å), while that between the second and third layer is slightly contracted to 1.23 Å. The third layer is, in addition, slightly buckled (±0.05 Å). The results are discussed on the basis of our present general knowledge about the structure of adsorbate covered metallic surfaces

    GLIPR1L1 is an IZUMO-binding protein required for optimal fertilization in the mouse

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    Background: The sperm protein IZUMO1 (Izumo sperm-egg fusion 1) and its recently identified binding partner on the oolemma, IZUMO1R, are among the first ligand-receptor pairs shown to be essential for gamete recognition and adhesion. However, the IZUMO1-IZUMO1R interaction does not appear to be directly responsible for promoting the fusion of the gamete membranes, suggesting that this critical phase of the fertilization cascade requires the concerted action of alternative fusogenic machinery. It has therefore been proposed that IZUMO1 may play a secondary role in the organization and/or stabilization of higher-order heteromeric complexes in spermatozoa that are required for membrane fusion. Results: Here, we show that fertilization-competent (acrosome reacted) mouse spermatozoa harbor several high molecular weight protein complexes, a subset of which are readily able to adhere to solubilized oolemmal proteins. At least two of these complexes contain IZUMO1 in partnership with GLI pathogenesis-related 1 like 1 (GLIPR1L1). This interaction is associated with lipid rafts and is dynamically remodeled upon the induction of acrosomal exocytosis in preparation for sperm adhesion to the oolemma. Accordingly, the selective ablation of GLIPR1L1 leads to compromised sperm function characterized by a reduced ability to undergo the acrosome reaction and a failure of IZUMO1 redistribution. Conclusions: Collectively, this study characterizes multimeric protein complexes on the sperm surface and identifies GLIPRL1L1 as a physiologically relevant regulator of IZUMO1 function and the fertilization process.Avinash S. Gaikwad, Amanda L. Anderson, D. Jo Merriner, Anne E. O’Connor, Brendan J. Houston, R. John Aitken, Moira K. O’Bryan, and Brett Nixo

    Eureka and beyond: mining's impact on African urbanisation

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    This collection brings separate literatures on mining and urbanisation together at a time when both artisanal and large-scale mining are expanding in many African economies. While much has been written about contestation over land and mineral rights, the impact of mining on settlement, notably its catalytic and fluctuating effects on migration and urban growth, has been largely ignored. African nation-states’ urbanisation trends have shown considerable variation over the past half century. The current surge in ‘new’ mining countries and the slow-down in ‘old’ mining countries are generating some remarkable settlement patterns and welfare outcomes. Presently, the African continent is a laboratory of national mining experiences. This special issue on African mining and urbanisation encompasses a wide cross-section of country case studies: beginning with the historical experiences of mining in Southern Africa (South Africa, Zambia, Zimbabwe), followed by more recent mineralizing trends in comparatively new mineral-producing countries (Tanzania) and an established West African gold producer (Ghana), before turning to the influence of conflict minerals (Angola, the Democratic Republic of Congo and Sierra Leone)

    HEART Rate Variability Biofeedback for LOng COVID Dysautonomia (HEARTLOC): Results of a Feasibility Study

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    Introduction: Post-COVID-19 syndrome, or Long Covid (LC) refers to symptoms persisting 12 weeks after the COVID-19 infection. LC comprises a wide range of dysautonomia symptoms, including fatigue, breathlessness, palpitations, dizziness, pain and brain fog. This study tested the feasibility and estimated the efficacy, of a Heart Rate Variability Biofeedback (HRV-B) programme via a standardised slow diaphragmatic breathing technique in individuals with LC. Methods: LC patients underwent a 4-week HRV-B intervention for 10 minutes twice daily for 4 weeks using the Polar H10 ECG (Electrocardiogram) chest strap and Elite HRV phone application. Outcome measures C19-YRSm (Yorkshire Rehabilitation Scale modified), Composite Autonomic Symptom Score (COMPASS-31), WHO Disability Assessment Schedule (WHODAS), EQ5D-5L (EuroQol 5 Dimensions) and Root Mean Square of Successive Differences between heartbeats (RMSSD) using a Fitbit device were recorded before and after the intervention. The study was pre-registered at clinicaltrials.gov NCT05228665. Results: A total of 13 participants (54% female, 46% male) completed the study with high levels of independent use of technology, data completeness and intervention adherence. There was a statistically significant improvement in C19YRS-m (P = .001), COMPASS-31 (P = .007), RMSSD (P = .047), WHODAS (P = .02) and EQ5D Global Health Score (P = .009). Qualitative feedback suggested participants could use it independently, were satisfied with the intervention and reported beneficial effects from the intervention. Conclusion: HRV-B using diaphragmatic breathing is a feasible intervention for LC. The small sample size limits generalisability. HRV-B in LC warrants further exploration in a larger randomised controlled study

    Numerical simulations of a non-commutative theory: the scalar model on the fuzzy sphere

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    We address a detailed non-perturbative numerical study of the scalar theory on the fuzzy sphere. We use a novel algorithm which strongly reduces the correlation problems in the matrix update process, and allows the investigation of different regimes of the model in a precise and reliable way. We study the modes associated to different momenta and the role they play in the ``striped phase'', pointing out a consistent interpretation which is corroborated by our data, and which sheds further light on the results obtained in some previous works. Next, we test a quantitative, non-trivial theoretical prediction for this model, which has been formulated in the literature: The existence of an eigenvalue sector characterised by a precise probability density, and the emergence of the phase transition associated with the opening of a gap around the origin in the eigenvalue distribution. The theoretical predictions are confirmed by our numerical results. Finally, we propose a possible method to detect numerically the non-commutative anomaly predicted in a one-loop perturbative analysis of the model, which is expected to induce a distortion of the dispersion relation on the fuzzy sphere.Comment: 1+36 pages, 18 figures; v2: 1+55 pages, 38 figures: added the study of the eigenvalue distribution, added figures, tables and references, typos corrected; v3: 1+20 pages, 10 eps figures, new results, plots and references added, technical details about the tests at small matrix size skipped, version published in JHE
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