6,345 research outputs found
Clinical and biomarker changes in premanifest Huntington disease show trial feasibility: A decade of the PREDICT-HD study
Dynamic virtual simulation of the occurrence and severity of edge loading in hip replacements associated with variation in the rotational and translational surgical position
Variation in the surgical positioning of total hip replacement can result in edge loading of the femoral head on the rim of the acetabular cup. Previous work has reported the effect of edge loading on the wear of hip replacement bearings with a fixed level of dynamic biomechanical hip separation. Variations in both rotational and translational surgical positioning of the hip joint replacement combine to influence both the biomechanics and the tribology including the severity of edge loading, the amount of dynamic separation, the force acting on the rim of the cup and the resultant wear and torque acting on the cup. In this study, a virtual model of a hip joint simulator has been developed to predict the effect of variations in some surgical positioning (inclination and medial-lateral offset) on the level of dynamic separation and the contact force of the head acting on the rim as a measure of severity of edge loading. The level of dynamic separation and force acting on the rim increased with increased translational mismatch between the centres of the femoral head and the acetabular cup from 0 to 4 mm and with increased cup inclination angle from 45° to 65°. The virtual model closely replicated the dynamics of the experimental hip simulator previously reported, which showed similar dynamic biomechanical trends, with the highest level of separation being found with a mismatch of 4 mm between the centres of the femoral head and acetabular cup and 65° cup inclination angle
Probing the Higgs Field Using Massive Particles as Sources and Detectors
In the Standard Model, all massive elementary particles acquire their masses
by coupling to a background Higgs field with a non-zero vacuum expectation
value. What is often overlooked is that each massive particle is also a source
of the Higgs field. A given particle can in principle shift the mass of a
neighboring particle. The mass shift effect goes beyond the usual perturbative
Feynman diagram calculations which implicitly assume that the mass of each
particle is rigidly fixed. Local mass shifts offer a unique handle on Higgs
physics since they do not require the production of on-shell Higgs bosons. We
provide theoretical estimates showing that the mass shift effect can be large
and measurable, especially near pair threshold, at both the Tevatron and the
LHC.Comment: 6 pages, no figures; Version 2 corrects some typographical errors of
factors of 2 in equations 14, 17, 18 and 19 (all of the same origin) and
mentions a linear collider as an interesting place to test the results of
this pape
On the alpha activity of natural tungsten isotopes
The indication for the alpha decay of 180-W with a half-life
T1/2=1.1+0.8-0.4(stat)+-0.3(syst)x10^18 yr has been observed for the first time
with the help of the super-low background 116-CdWO_4 crystal scintillators. In
conservative approach the lower limit on half-life of 180-W has been
established as T1/2>0.7x10^18 yr at 90% C.L. Besides, new T1/2 bounds were set
for alpha decay of 182-W, 183-W, 184-W and 186-W at the level of 10^20 yr.Comment: 16 pages, 8 figures, accepted in Phys. Rev.
Improving contemporary approaches to the master planning process.
Master-planning has had a strong revival in recent years. However, significant demographic and social changes are on-going amidst the constraints of the current economic stagnation, the policy of reduced public spending and the drive to respond to environmental imperatives. These conditions challenge the feasibility of the application of past master-planning practice. The way we conceive of master-planning now requires re-visiting. The traditional perspective of master-planning as a design-led activity concerned with the architectural form of buildings, spaces and infrastructures is out-dated and inadequate to coordinating the plural processes of negotiating sustainable place development which, in addition to realising a visually pleasing townscape, critically satisfies social, functional, economic and environmental requirements. Masterplanning requires both a business planning component, without which there is no delivery, and a governance component, without which the physical strategy has no legitimacy. A more adaptive master-planning approach is required. The paper proposes how a flexible master-planning process can provide a basis of a suitable approach for the development of sustainable settlements. Published in Proceedings of the ICE - Urban Design and Planning, Vol 167, Issue 1, October 2013. Permission is granted by ICE Publishing to print one copy for personal use. Any other use of this PDF file is subject to reprint fees.</p
Compositionally tunable ternary Bi2(Se1-xTex)3 and (Bi1-ySby)2Te3 thin films via low pressure chemical vapor deposition
The inherently rapid ligand substitution kinetics associated with the novel and chemically compatible precursors, [MCl3(EnBu2)3] (M = Sb, Bi; E = Se, Te), enable CVD growth of ternary Bi2(Se1−xTex)3 and (Bi1−ySby)2Te3 thin films with very good compositional, structural and morphological control, for the first time. X-ray diffraction data follow Vegard's law and Raman bands shift linearly with the atom substitutions, indicating very well-distributed solid solutions
Knee orthoses for treating patellofemoral pain syndrome
Background: Patellofemoral pain syndrome (PFPS) is a painful musculoskeletal condition, which is characterised by knee pain located in the anterior aspect (front) and retropatellar region (behind) of the knee joint. Various non-operative interventions are suggested for the treatment of this condition. Knee orthoses (knee braces, sleeves, straps or bandages) are worn over the knee and are thought to help reduce knee pain. They can be used in isolation or in addition to other treatments such as exercise or non-steroidal anti-inflammatory medications. Objectives: To assess the effects (benefits and harms) of knee orthoses (knee braces, sleeves, straps or bandages) for treating PFPS. Search methods: We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (11 May 2015), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2015 Issue 5), MEDLINE (1946 to 8 May 2015), EMBASE (1980 to 2015 Week 18), SPORTDiscus (1985 to 11 May 2015), AMED (1985 to 8 May 2015), CINAHL (1937 to 11 May 2015), PEDro (1929 to June 2015), trial registries and conference proceedings. Selection criteria: Randomised and quasi-randomised controlled clinical trials evaluating knee orthoses for treating people with PFPS. Our primary outcomes were pain and function. Data collection and analysis: Two review authors independently assessed studies for eligibility, assessed study risk of bias and extracted data. We calculated mean differences (MD) or, where pooling data from different scales, standardised mean differences (SMD) with 95% confidence intervals (CI) for continuous outcomes and risk ratios (RR) with 95% CIs for binary outcomes. We pooled data using the fixed-effect model. Main results: We included five trials (one of which was quasi-randomised) that reported results for 368 people who had PFPS. Participants were recruited from health clinics in three trials and were military recruits undergoing training in the other two trials. Although no trials recruited participants who were categorised as elite or professional athletes, military training does comprise intensive exercise regimens. All five trials were at high risk of bias, including performance bias reflecting the logistical problems in these trials of blinding of participants and care providers. As assessed using the GRADE approach, the available evidence for all reported outcomes is 'very low' quality. This means that we are very uncertain about the results. The trials covered three different types of comparison: knee orthosis and exercises versus exercises alone; one type of orthosis versus another; and knee orthosis versus exercises. No trials assessed the mode of knee orthosis use, such as whether the orthosis was worn all day or only during physical activity. Two trials had two groups; two trials had three groups; and one trial had four groups. All five trials compared a knee orthosis (knee sleeve, knee brace, or patellar strap) versus a 'no treatment' control group, with all participants receiving exercises, either through a military training programme or a home-based exercise programme. There is very low quality evidence of no clinically important differences between the two groups in short-term (2 to 12 weeks follow-up) knee pain based on the visual analogue scale (0 to 10 points; higher scores mean worse pain): MD -0.46 favouring knee orthoses, 95% CI -1.16 to 0.24; P = 0.19; 234 participants, 3 trials). A similar lack of clinically important difference was found for knee function (183 participants, 2 trials). None of the trials reported on quality of life measures, resource use or participant satisfaction. Although two trials reported on the impact on sporting or occupational participation, one trial (35 participants) did not provide data split by treatment group on the resumption of sport activity and the other reported only on abandonment of military training due to knee pain (both cases were allocated a knee orthosis). One trial (59 participants, 84 affected knees) recording only adverse events in the two knee orthoses (both were knee sleeves) groups, reported 16 knees (36% of 44 knees) had discomfort or skin abrasion. Three trials provided very low quality evidence on single comparisons of different types of knee orthoses: a knee brace versus a knee sleeve (63 participants), a patella strap with a knee sleeve (31 participants), and a knee sleeve with a patellar ring versus a knee sleeve only (44 knees). None of three trials found an important difference between the two types of knee orthosis in pain. One trial found no clinically important difference in function between a knee brace and a knee sleeve. None of the three trials reported on quality of life, resource use or participant satisfaction. One trial comparing a patella strap with a knee sleeve reported that both participants quitting military training due to knee pain were allocated a knee sleeve. One poorly reported trial found three times as many knees with adverse effects (discomfort or skin abrasion) in those given knee sleeves with a patella ring than those given knee sleeves only. One trial compared a knee orthosis (knee brace) with exercise (66 participants). It found very low quality evidence of no clinically important difference between the two intervention groups in pain or knee function. The trial did not report on quality of life, impact on sporting or occupational participation, resource use, participant satisfaction or complications. Authors' conclusions: Overall, this review has found a lack of evidence to inform on the use of knee orthoses for treating PFPS. There is, however, very low quality evidence from clinically heterogeneous trials using different types of knee orthoses (knee brace, sleeve and strap) that using a knee orthosis did not reduce knee pain or improve knee function in the short term (under three months) in adults who were also undergoing an exercise programme for treating PFPS. This points to the need for good-quality clinically-relevant research to inform on the use of commonly-available knee orthoses for treating PFPS
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ADC Nonlinearity Correction for the Majorana Demonstrator
Imperfections in analog-to-digital conversion (ADC) cannot be ignored when signal digitization requirements demand both wide dynamic range and high resolution, as is the case for the Majorana Demonstrator 76Ge neutrinoless double-beta decay search. Enabling the experiment's high-resolution spectral analysis and efficient pulse shape discrimination required careful measurement and correction of ADC nonlinearities. A simple measurement protocol was developed that did not require sophisticated equipment or lengthy data-taking campaigns. A slope-dependent hysteresis was observed and characterized. A correction applied to digitized waveforms prior to signal processing reduced the differential and integral nonlinearities by an order of magnitude, eliminating these as dominant contributions to the systematic energy uncertainty at the double-beta decay Q value
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