Background: Identifying patients' knowledge and beliefs about pain is relevant to a patient-centred treatment. The best method of measuring knowledge and beliefs about musculoskeletal conditions is ...unclear. An overview on measurement properties of available questionnaires to assess knowledge and beliefs about musculoskeletal conditions is lacking. Objective: To investigate the measurement properties of available questionnaires that measure knowledge and/or beliefs about musculoskeletal conditions. Methods: A systematic review will be conducted following the COnsensus-based Standards for the selection of health Measurement Instruments (COSMIN) guideline. Electronic databases MEDLINE, EMBASE, CINAHL, and Web of Science will be searched. The search strategy will include three groups of search terms representing (1) construct, (2) population, and (3) instrument, in addition to a search filter on measurement properties. The search strategy will be devised in consultation with a librarian and no restriction on language, publication period or publication status will be applied. Citation tracking (in Scopus) of eligible studies and contact with experts will be conducted in order to minimise the risk of missing relevant articles. We will include primary studies of any study design that developed and/or tested measurement properties of self-reported questionnaires assessing knowledge and/or beliefs about musculoskeletal conditions, targeting people with musculoskeletal conditions or people from the general population. A study will be excluded if the questionnaire was developed and tested exclusively for clinicians or participants with recent trauma history. Search results will be screened by abstract and full text independently by two review authors. Extracted data will include bibliographic details, study characteristics, participants characteristics, questionnaires characteristics, measurement properties results, interpretability, feasibility, and distribution of scores. Authors will be contacted if more information is needed. The methodological quality of included studies will be assessed using the COSMIN Risk of Bias checklist and each item will be scored as "very good", "adequate", reliability (internal consistency, measurement error, and test-retest, inter-rater and intra-rater reliability), validity (content validity including face validity, criterion validity, and construct validity including structural validity, hypotheses testing, and cross-cultural validity), and responsiveness, according to the COSMIN taxonomy definition. The overall assessment of each measurement property of each questionnaire will be classified based on the COSMIN updated criteria. Also, the quality of evidence will be rated using a modified Grading of Recommendations Assessment Development and Evaluation (GRADE) approach. An overall recommendation will be formulated as: (A) Suitable for use: PROMs with evidence for sufficient content validity (any level of evidence) AND at least low-quality evidence for sufficient internal consistency; (B) Potentially suitable for use: PROMs categorised not in A or C; or (C) Not recommended: PROMs with high quality evidence for an insufficient measurement property. Data will be presented descriptively. A pooled result using meta-analysis of the parameters will be conducted if adequate data is available. Significance: The results of this review will contribute to researchers and clinicians making evidence-based decisions on what instrument to use to measure knowledge and/or beliefs about musculoskeletal conditions. Sensitivity analysis of different low-pass filter cut-off frequencies on lumbar spine kinematic data and its impact on the agreement between accelerometers and a motion capture system
Provides extensive and thoroughly exhaustive coverage of precision laser spectroscopy Presents chapters written by recognized experts in their individual fields Topics covered include cold atoms, ...cold molecules, methods and techniques for production of cold molecules, optical frequency standards based on trapped single ions, etc Applicable for researchers and graduate students of optical physics and precision laser spectroscopy
In this work, we provide updated constraints on coupled dark energy (CDE) cosmology with Peebles-Ratra (PR) potential and constant coupling strength β. This modified gravity scenario introduces a ...fifth force between dark matter particles, mediated by a scalar field that plays the role of dark energy. The mass of the dark matter particles does not remain constant, but changes with time as a function of the scalar field. Here we focus on the phenomenological behavior of the model, and assess its ability to describe updated cosmological datasets that include the Planck 2018 cosmic microwave background (CMB) temperature, polarization and lensing, baryon acoustic oscillations, the Pantheon compilation of supernovae of Type Ia, data on H(z) from cosmic chronometers, and redshift-space distortions. We also study the impact of the local measurement of H0 from SH0ES and the strong-lensing time delay data from the H0LICOW Collaboration on the parameter that controls the strength of the interaction in the dark sector. We find a peak corresponding to a coupling β>0 and to a potential parameter α>0, more or less evident depending on the dataset combination. We show separately the impact of each dataset and remark that CMB lensing is especially the one dataset that shifts the peak the most towards ΛCDM. When a model selection criterion based on the full Bayesian evidence is applied, however, ΛCDM is still preferred in all cases, due to the additional parameters introduced in the CDE model.
Abstract This paper designs a measuring and detecting device for medical centrifuges. The device integrates the measurement of rotational speed, temperature, and time. The photoelectric tachometer ...was transformed into a laser speed detection module to adapt to the rotational speed measurement of the closed centrifuge and a wireless temperature detection module could be inserted into the slot of the centrifuge tube to measure the temperature of the tube position when the centrifuge rotates at a high speed. This method achieved reliable and accurate measurement of the speed, temperature, and time of various centrifuges with low costs.
Light detection and ranging is widely used in science and industry. Over the past decade, optical frequency combs were shown to offer advantages in optical ranging, enabling fast distance acquisition ...with high accuracy. Driven by emerging high-volume applications such as industrial sensing, drone navigation, or autonomous driving, there is now a growing demand for compact ranging systems. Here, we show that soliton Kerr comb generation in integrated silicon nitride microresonators provides a route to high-performance chip-scale ranging systems. We demonstrate dual-comb distance measurements with Allan deviations down to 12 nanometers at averaging times of 13 microseconds along with ultrafast ranging at acquisition rates of 100 megahertz, allowing for in-flight sampling of gun projectiles moving at 150 meters per second. Combining integrated soliton-comb ranging systems with chip-scale nanophotonic phased arrays could enable compact ultrafast ranging systems for emerging mass applications.
Exceptional points (EPs) are singularities that arise in non-Hermitian physics. Current research efforts focus only on systems supporting isolated EPs characterized by increased sensitivity to ...external perturbations, which makes them potential candidates for building next generation optical sensors. On the downside, this feature is also the Achilles heel of these devices: they are very sensitive to fabrication errors and experimental uncertainties. To overcome this problem, we introduce a new design concept for implementing photonic EPs that combine the robustness required for practical use together with their hallmark sensitivity. Particularly, our proposed structure exhibits a hypersurface of Jordan EPs embedded in a larger space, and having the following peculiar features: (1) A large class of undesired perturbations shift the operating point along the exceptional surface (ES), thus, leaving the system at another EP which explains the robustness; (2) Perturbations due to back reflection or backscattering force the operating point out of the ES, leading to enhanced sensitivity. Importantly, our proposed geometry is relatively easy to implement using standard photonics components and the design concept can be extended to other physical platforms such as microwave or acoustics.
Warming climate, melting ice, rising seas
We know that the sea level will rise as climate warms. Nevertheless, accurate projections of how much sea-level rise will occur are difficult to make based ...solely on modern observations. Determining how ice sheets and sea level have varied in past warm periods can help us better understand how sensitive ice sheets are to higher temperatures. Dutton
et al.
review recent interdisciplinary progress in understanding this issue, based on data from four different warm intervals over the past 3 million years. Their synthesis provides a clear picture of the progress we have made and the hurdles that still exist.
Science
, this issue
10.1126/science.aaa4019
Reconstructing past magnitudes, rates, and sources of sea-level rise can help project what our warmer future may hold.
BACKGROUND
Although thermal expansion of seawater and melting of mountain glaciers have dominated global mean sea level (GMSL) rise over the last century, mass loss from the Greenland and Antarctic ice sheets is expected to exceed other contributions to GMSL rise under future warming. To better constrain polar ice-sheet response to warmer temperatures, we draw on evidence from interglacial periods in the geologic record that experienced warmer polar temperatures and higher GMSLs than present. Coastal records of sea level from these previous warm periods demonstrate geographic variability because of the influence of several geophysical processes that operate across a range of magnitudes and time scales. Inferring GMSL and ice-volume changes from these reconstructions is nontrivial and generally requires the use of geophysical models.
ADVANCES
Interdisciplinary studies of geologic archives have ushered in a new era of deciphering magnitudes, rates, and sources of sea-level rise. Advances in our understanding of polar ice-sheet response to warmer climates have been made through an increase in the number and geographic distribution of sea-level reconstructions, better ice-sheet constraints, and the recognition that several geophysical processes cause spatially complex patterns in sea level. In particular, accounting for glacial isostatic processes helps to decipher spatial variability in coastal sea-level records and has reconciled a number of site-specific sea-level reconstructions for warm periods that have occurred within the past several hundred thousand years. This enables us to infer that during recent interglacial periods, small increases in global mean temperature and just a few degrees of polar warming relative to the preindustrial period resulted in ≥6 m of GMSL rise. Mantle-driven dynamic topography introduces large uncertainties on longer time scales, affecting reconstructions for time periods such as the Pliocene (~3 million years ago), when atmospheric CO
2
was ~400 parts per million (ppm), similar to that of the present. Both modeling and field evidence suggest that polar ice sheets were smaller during this time period, but because dynamic topography can cause tens of meters of vertical displacement at Earth’s surface on million-year time scales and uncertainty in model predictions of this signal are large, it is currently not possible to make a precise estimate of peak GMSL during the Pliocene.
OUTLOOK
Our present climate is warming to a level associated with significant polar ice-sheet loss in the past, but a number of challenges remain to further constrain ice-sheet sensitivity to climate change using paleo–sea level records. Improving our understanding of rates of GMSL rise due to polar ice-mass loss is perhaps the most societally relevant information the paleorecord can provide, yet robust estimates of rates of GMSL rise associated with polar ice-sheet retreat and/or collapse remain a weakness in existing sea-level reconstructions. Improving existing magnitudes, rates, and sources of GMSL rise will require a better (global) distribution of sea-level reconstructions with high temporal resolution and precise elevations and should include sites close to present and former ice sheets. Translating such sea-level data into a robust GMSL signal demands integration with geophysical models, which in turn can be tested through improved spatial and temporal sampling of coastal records.
Further development is needed to refine estimates of past sea level from geochemical proxies. In particular, paired oxygen isotope and Mg/Ca data are currently unable to provide confident, quantitative estimates of peak sea level during these past warm periods. In some GMSL reconstructions, polar ice-sheet retreat is inferred from the total GMSL budget, but identifying the specific ice-sheet sources is currently hindered by limited field evidence at high latitudes. Given the paucity of such data, emerging geochemical and geophysical techniques show promise for identifying the sectors of the ice sheets that were most vulnerable to collapse in the past and perhaps will be again in the future.
Peak global mean temperature, atmospheric CO
2
, maximum global mean sea level (GMSL), and source(s) of meltwater.
Light blue shading indicates uncertainty of GMSL maximum. Red pie charts over Greenland and Antarctica denote fraction (not location) of ice retreat.
Interdisciplinary studies of geologic archives have ushered in a new era of deciphering magnitudes, rates, and sources of sea-level rise from polar ice-sheet loss during past warm periods. Accounting for glacial isostatic processes helps to reconcile spatial variability in peak sea level during marine isotope stages 5e and 11, when the global mean reached 6 to 9 meters and 6 to 13 meters higher than present, respectively. Dynamic topography introduces large uncertainties on longer time scales, precluding robust sea-level estimates for intervals such as the Pliocene. Present climate is warming to a level associated with significant polar ice-sheet loss in the past. Here, we outline advances and challenges involved in constraining ice-sheet sensitivity to climate change with use of paleo–sea level records.
•We critically examine current practice in conducting Exploratory Factor Analysis (EFA) in transportation studies.•A comprehensive overview of the main topics and choices involved in the EFA ...methodology is presented.•A significant gap between current practice and experts' recommendations was observed.•Guidelines for authors and reviewers are provided.
Exploratory factor analysis (EFA) is a widely used statistical method in traffic and transportation research, particularly for the development and validation of measurement instruments. This article critically examines current practices in conducting and reporting EFA in published transportation studies. One hundred and eighty papers published between 2016 and 2018 were examined, of which eighty-two were included in the present study after applying eligibility criteria. The review suggests that the quality of EFA reported in the field is routinely poor: (a) researchers fail to provide sufficient information to be able to adequately assess the appropriateness and quality of both the input data and the reported output; and (b) the decisions underlying the choices of EFA methods are not justified and rely mostly on procedures advised against, particularly the Little-Jiffy approach. In summary, a significant gap between current practice and experts' recommendations exists. We provide some guidelines that may help in conducting, reporting and reviewing EFA in transportation research.
Improving the platinum (Pt) mass activity for the oxygen reduction reaction (ORR) requires optimization of both the specific activity and the electrochemically active surface area (ECSA). We found ...that solution-synthesized Pt/NiO core/shell nanowires can be converted into PtNi alloy nanowires through a thermal annealing process and then transformed into jagged Pt nanowires via electrochemical dealloying. The jagged nanowires exhibit an ECSA of 118 square meters per gram of Pt and a specific activity of 11.5 milliamperes per square centimeter for ORR (at 0.9 volts versus reversible hydrogen electrode), yielding a mass activity of 13.6 amperes per milligram of Pt, nearly double previously reported best values. Reactive molecular dynamics simulations suggest that highly stressed, undercoordinated rhombus-rich surface configurations of the jagged nanowires enhance ORR activity versus more relaxed surfaces.
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