Search

Adjoint waveform tomography (AWT) sits at the cutting edge of seismic tomography on local, regional, and global scales. However, the choice in starting model may have a significant impact on the final inversion results. In this paper, we present 3 AWT models of California that are based on different starting models. We chose three models that were inverted at different scales: SPiRaL, a global travel-time tomography model (Simmons et al., 2021, 10.1093/gji/ggab277), CSEM_NA, a regional adjoint tomography model of North America and the North Atlantic (Krischer et al., 2018, 10.1029/2017JB015289), and WUS256, a regional adjoint tomography model of the western US (Rodgers et al., 2022, https://doi.org/10.1029/2022JB024549). We then inverted three AWT models using the same source and receiver set. We ran each model over three period bands: 30–100 s, 25–100 s, and 20–80 s. Once the iterations were finalized, we used five methods of testing model similarity in both the model and data space. We conclude that the choice of starting model has a minimal impact on long wavelength models if an appropriate multi-scale inversion approach is used.

We report a new model (WUS256) of radially anisotropic seismic wavespeeds of the crust and upper mantle of the western United States (WUS) obtained from adjoint waveform tomography for the purpose of improving synthetic waveform fits to observed data. WUS256 is based on inversion of over 94,000 waveforms from 72 earthquakes recorded by nearly 3,400 stations. We started with the SPiRaL global model (Simmons et al., 2021, https://doi.org/10.1093/gji/ggab277) and waveforms in the period band of 50–120 s. We followed a conservative multiscale inversion approach with eight stages and 256 total inversion iterations which enabled monotonic misfit reduction to 20-s minimum-period waves. WUS256 relied on time-frequency (TF) phase misfits and a trust region limited memory Broyden–Fletcher–Goldfarb–Shanno (L-BFGS) optimization. Hessian-vector products were used to qualitatively assess model resolution. Results indicate that WUS256 has good coverage of the continental regions to depths of about 150 km and is able to resolve features on lateral scales of about 200 km. We quantify waveform fits by the reduction in TF and normalized amplitude difference misfits between WUS256 and the SPiRaL starting model. WUS256 significantly improves waveform fits with misfit reduction (Formula presented.) 64% for both inversion and validation data sets compared to the SPiRaL starting model and shows even better fits compared to other models. Waveform fits illustrate that WUS256 reproduces body-waves, fundamental mode surface waves as well as late arriving dispersed and/or scattered short period surface waves. The improvement in waveform fit indicates that WUS256 can be used to reproduce path effects on regional complete waveforms and moment tensor inversions.

We report a new model of radially anisotropic crustal and upper mantle structure of the western United States (WUS324) obtained from full waveform inversion of earthquake data. We ran three multiscale inversion stages beyond model WUS256 (Rodgers et al., 2022, https://doi.org/10.1029/2022jb024549) allowing them to approach convergence to fit a larger data set to a shorter minimum period of 16 s. WUS324 is based on 324 total iterations from its starting model, significantly more (16 times) than previous studies. Waveform misfit reductions are 66%–70% for both the inversion data and an independent validation data set providing confidence in the predictive power of the model. WUS324 provides much better fits and reveals shear wavespeed, vS, structure of this large region with more detail than previous waveform tomography models. We show representative images demonstrating the resolution of diverse seismic structure across this highly heterogeneous region including oceanic lithosphere, subducting slabs and continental magmatism. Plain Language Summary: Seismic tomography allows seismologists to infer properties of the inaccessible solid Earth through interpretations of seismic waves measured at the surface. Full waveform inversion tomography uses three‐dimensional (3D) wave propagation simulations to image subsurface structure as well as improve physical models for numerical modeling of seismograms. This study used powerful high‐performance computers to run many simulations of a large set of earthquake waveforms sampling the western United States to create a new model of seismic wavespeeds. The model spans the volume from the surface through the crust to the upper mantle from the Pacific Ocean to the Great Plains and from Mexico to Canada. By running many more inversion iterations and fitting shorter periods and wavelengths this study resulted in better waveform fits and imaged more detail compared to previous waveform tomography studies. The new model can be used for better understanding of the thermal and compositional state of the region or to improve simulations of new events, say to characterize ground motions or sources. Key Points: A new seismic model of the western US (WUS324) is obtained from full waveform inversion where stages are iterated to approach convergenceThe model is based on significantly more multiscaleiterations and fits waveforms with periods 16–100 s much better than previous modelsWUS324 images diverse seismic heterogeneity across a large region including subducting slabs and continental magmatism [ABSTRACT FROM AUTHOR]

Background: Acceptance and Commitment Therapy (ACT) is a type of Cognitive Behavioural Therapy, which has demonstrated positive outcomes in individuals with chronic pain. The purpose of this study was to compare the effect of an 8‐week programme combining Exercise with Acceptance and Commitment Therapy (ExACT) with a standalone supervised exercise programme at 1‐year follow‐up. Methods: One hundred and seventy‐five people with chronic pain were randomly assigned to ExACT or supervised exercise only. The primary outcome was pain interference measured with the Brief Pain Inventory‐Interference Scale. Secondary and treatment process outcomes included pain severity, depression, anxiety, pain catastrophizing, pain self‐efficacy, fear avoidance, pain acceptance, committed action, healthcare utilization, patient satisfaction, and global impression of change. Estimates of treatment effects at 1‐year follow‐up were based on intention‐to‐treat analyses, implemented using a linear mixed‐effects model. Results: Eighty‐three participants (47.4%) returned the outcome measures at 1‐year follow‐up. No significant difference was observed between the groups for the primary outcome, pain interference. There was a statistically significant difference between the groups, in favour of ExACT for pain catastrophizing. Within group improvements that were observed within both groups at earlier timepoints were maintained at 1‐year follow‐up for many of the secondary and treatment process outcomes. ExACT group participants reported higher levels of satisfaction with treatment and global perceived change. Conclusions: The study results showed no significant difference between the two groups for the primary outcome pain interference at 1‐year follow‐up. Future research could investigate factors that may predict and optimize outcomes from these types of intervention for people living with chronic pain. Significance: Few previous randomized controlled trials investigating ACT for chronic pain have included long‐term follow‐up. This study found that Exercise combined with ACT was not superior to supervised exercise alone for reducing pain interference at 1‐year follow‐up. Further research is necessary to identify key processes of therapeutic change and to explore how interventions may be modified to enhance clinical outcomes for people with chronic pain. [ABSTRACT FROM AUTHOR]

Isolating seismic instruments from temperature fluctuations is routine practice within the seismological community. However, the necessary degree of thermal stability required in broadband installations to avoid generating noise or compromising the fidelity in the seismic records is largely unknown and likely application dependent. To quantify the temperature sensitivity of seismometers over a broad range of frequencies, we artificially induced local temperature changes on three different models of seismometers to measure the effect of thermal variations on seismometer output. We found that diurnal temperature changes above 0.002°C root mean square (rms) showed significant changes in velocity and acceleration output in comparison to thermally stable reference measurements. We also found that sensor incoherent self-noise increased with temperature variation; these increases in noise can be modeled as 1/f noise (pink noise), and are unlikely to be easily corrected for. These experimental results are compared with the data from Incorporated Research Institutions for Seismology (IRIS) U.S. Geological Survey (USGS) Global Seismographic Network (GSN) station TUC (Tucson, Arizona). This station is well instrumented with temperature sensors and has three different broadband seismometers, each of which uses a different method of thermal isolation. We show that the water bricks and borehole installations give ample temperature attenuation to thermally isolate seismometers from diurnal thermal variability that would compromise seismic data. We find that seismometer installations that provide thermal stability below 0.002°C rms could help to improve long-period vertical seismic data across the GSN by decreasing temperature-driven 1/f noise. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Science Advisory Secretariat Research Document is the property of Her Majesty the Queen in Right of Canada as represented by the Minister of Fisheries & Oceans and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: A number of clinical specialist physiotherapist (CSP)-led musculoskeletal triage clinics have been established in the Republic of Ireland as a means of managing patients referred for an outpatient orthopaedic consultation. Aims: The purpose of this study was to evaluate the outcomes of a recently established 'Musculoskeletal Assessment Clinic' (MAC) in St Vincent's University Hospital (SVUH) Dublin. We identified the (a) number of patients independently managed by the CSPs and (b) conversion rate to orthopaedic intervention as a useful measure of this. Methods: University College Dublin Research Ethics Committee granted ethical exemption and the Clinical Audit Department of SVUH approved the study. A retrospective service evaluation was carried out on all orthopaedic patients who attended the MAC between January and July 2012. Data were analysed using SPSS v20 using descriptive statistics. Results: Seven-hundred and fourteen patients attended the MAC, 54 % of whom were female; mean age 50 years (range 12-89). The majority of patients were diagnosed with low back pain (35 %) and knee osteoarthritis (16 %). The majority of patients who attended the MAC (76 %) were independently managed by the CSPs without need for orthopaedic consultation; from a valid sample ( n = 110), 80 patients required orthopaedic intervention, a conversion rate of 73 %. The most common interventions were arthroplasty (22 %) and arthroscopy (16 %). Conclusions: The findings of this service evaluation indicate that a significant number of patients referred for an orthopaedic consultation may be managed independently by a CSP and that onward referrals for orthopaedic consultation were highly appropriate. [ABSTRACT FROM AUTHOR]

The clinical criteria by which clinicians determine mechanisms-based classifications of pain are not known. The aim of this study was to generate expert consensus-derived lists of clinical criteria suggestive of a clinical dominance of 'nociceptive', 'peripheral neuropathic' and 'central' mechanisms of musculoskeletal pain. A web-based 3 round Delphi survey method was employed as an expert consensus building technique. One hundred and three clinical experts (31 Pain consultants, 72 musculoskeletal physiotherapists) were surveyed. Participants were asked to suggest clinical indicators of three separate categories of pain mechanisms (Round 1), then rate (Round 2) and re-rate their level of agreement/disagreement (Round 3) with those clinical indicators. Consensus was defined by a >or=80% level of agreement. Sixty-two (Response rate, 60%), 60 (58%) and 59 (57%) respondents replied to Rounds 1, 2 and 3 respectively. Twelve 'nociceptive', 14 'peripheral neuropathic' and 17 'central' clinical indicators reached consensus. These expert consensus-derived lists of clinical indicators of 'nociceptive', 'peripheral neuropathic' and 'central' mechanisms of musculoskeletal pain provide some indication of the criteria upon which clinicians may base such mechanistic classifications. Further empirical testing is required in order to evaluate the discriminative validity of these clinical criteria in particular and of mechanisms-based approaches in general. [ABSTRACT FROM AUTHOR]

The aim of this review was to determine the factors that impact on doctors' management of patients with acute low back pain. A methodological assessment of databases (Medline, EMBASE, Psychinfo, BIOSIS, CINAHL, and the Cochrane Central Register of Controlled Trials) identified papers which were screened for inclusion criteria by two independent reviewers. Data were extracted from accepted papers, and the internal validity and strength of the evidence were determined using valid and reliable scales. The search generated a total of 28 papers [quantitative (n=27), qualitative (n=1) methodologies]. Themes were identified from the accepted papers: education (n=18), knowledge of clinical guidelines and impact on management (n=7), and doctors' demographics (n=4). There was consistent evidence that doctors did not adhere to clinical guidelines when performing a spinal assessment. There was inconsistent evidence that education increased adherence with acute LBP guideline recommendations in terms of referral rates to physiotherapy, for investigations, to secondary care and for maintaining patients at work. Strategies to address the factors impacting on doctors' management of acute LBP are required; these would lead to improvement in patient outcomes and reduce healthcare costs. [ABSTRACT FROM AUTHOR]

The purpose of this article is to review the case for the inclusion of a mechanisms-based classification for musculoskeletal pain. In response to perceived limitations of the medical/disease model of pain and illness a mechanisms-based classification system for pain has been advocated. The classification of pain according to the underlying neurophysiological mechanisms responsible for its generation and/or maintenance may better explain the variability and complexities of clinical presentations of musculoskeletal pain and facilitate subsequent decision-making associated with the assessment, treatment and prognosis of patients with musculoskeletal disorders. However, current methods of mechanisms-based classification either lack standardised criteria or propose decision rules whose validity has yet to be substantiated empirically. While the case for a mechanisms-based classification for pain has been well made the onus rests with its advocates to (a) establish its validity for use in clinical practice in defined populations with musculoskeletal disorders, and (b) provide evidence that such a system facilitates improved clinical outcomes. [ABSTRACT FROM AUTHOR]

A small-scale exploratory cross-sectional survey investigated the current use of a range of exercise therapy approaches for low back pain (LBP) by outpatient physiotherapists in the acute hospital setting in the Republic of Ireland, where the majority of publicly funded treatment is delivered.Of the 120 postal questionnaires distributed to 24 physiotherapy departments, 87 were returned (72.5% response rate). The results showed specific spinal stabilization exercises were the most popular exercise therapy for acute (39%; n=35) and chronic (51%; n=48) LBP, followed by the McKenzie approach (acute LBP (ALBP) 35.6%; n=32: chronic LBP (CLBP) 17%; n=16), and abdominal exercise (ALBP 11.1%; n=10: CLBP 9.6%; n=9).The most popular forms of exercise therapy used by outpatient physiotherapists in acute hospital settings in Ireland lack support from evidence-based clinical guidelines, and further large-scale high quality randomized controlled trials of these approaches are warranted. Further research should also establish the use of exercise therapy and attitudes to clinical guidelines of physiotherapists in other countries and healthcare settings. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of this study was to determine the rate and types of injury in competitive dancers of Irish Dance, establish the injury prevention measures used by dancers, and investigate any relationships between prevention measures and incidence of injury. There are no in depth published studies on injury rates or injury prevention strategies for Irish dance.Methods: One hundred and fifty nine Irish dancers who were participants at the North American Irish Dance Championships (July 2-7, 2004) took part in this descriptive epidemiology study. Each participant completed a self administered questionnaire. The subjects were aged from 15 to 24 years (mean: 17.8; SD: 2.9). The number of years dancing ranged from 1 to 20 years (mean: 10.8; SD: 3.8).Results: The results showed 79% (n = 125) of dancers had one or more injuries. The ankle (31%, n = 60) and foot (25%, n = 48) were the most frequently injured. Sixty-three percent (n = 121) of the dancers took over 21 days to recover from their injuries. Use of shock absorbent dance shoes significantly reduced the incidence of ankle injury (p < 0.0001). In addition warm up and cool down were associated with a decreased incidence of ankle injury (p < 0.0001 and p respectively).<0001Conclusions: A variety of lower limb and in particular ankle injuries was reported by the competitive Irish dancers in this study. Injury prevention methods for ankle injury such as warm up, cool down, and use of shock absorbing dance shoes were associated with a decreased incidence of injury and warrant further investigation. [ABSTRACT FROM AUTHOR]