Typical Frame Research Articles

Potential utility of using both APOEε4 and Aβ positivity to enrich clinical trials of tau‐targeting therapies

AbstractBackgroundThe use of enrichment strategies is crucial for selecting individuals with the highest probability of Alzheimer’s disease (AD)‐related progression in typical clinical trial time frames. Although both amyloid‐β (Aβ) pathology and the apolipoprotein E ε4 (APOEε4) genotype have been shown to accelerate tau accumulation, it is still not clear whether assessing both APOEε4 genotype and Aβ positivity is useful to enrich tau‐targeting trials using tau positron emission tomography (PET) as outcome. Here, we investigated the implications of considering APOEε4 carriership for population enrichment in trials testing drug effects on tau tangle deposition in cognitively impaired (CI) individuals across the AD continuum.MethodWe studied 29 Aβ positive CI individuals (16 with mild cognitive impairment [MCI] and 13 with AD dementia) from the McGill Translational Biomarkers in Aging and Dementia (TRIAD) cohort. Study participants underwent clinical assessments, APOE genotyping, magnetic resonance imaging, PET for Aβ ([18F]AZD4694) and tau ([18F]MK6240) at baseline, as well as a follow‐up tau‐PET scan (mean follow‐up, 2.2 years). Aβ positivity was determined as global [18F]AZD4694 SUVR ≥ 1.55.ResultNo demographic differences were observed between APOEε4 carriers and noncarriers (Table 1). Regression analysis revealed that APOEε4 carriers had higher tau‐PET SUVR increase in temporal regions compared to APOEε4 noncarriers (Figure 1). The use of Aβ positivity alone for population enrichment of a clinical trial focusing on CI individuals would require a sample size of 436 individuals per study arm to test a 25% drug effect on tau‐PET accumulation (Figure 2). A similar clinical trial with a population enrichment strategy using Aβ positivity plus APOEε4 carriership would require a sample size of as few as 158 individuals per study arm (reduction of 64% in relation to using only Aβ positivity) to test the same drug effect (Figure 2).ConclusionOur results reveal that APOEε4 carriership is associated with increased tau tangle accumulation in CI individuals who are Aβ positive. Clinical trials testing drug effects on tangle deposition may benefit from assessing both APOEε4 carriership and Aβ positivity statuses as enrollment criteria to select individuals at higher risk of fast tau accumulation, resulting in a more cost‐effective trial.

Investigation of Effect of Wind-Induced Vibration on Typical Frame Structures on the Open Decks of Large Cruise Ships Based on the Subdomain Method

Due to the tall and large superstructures of cruise ships, the wind-induced vibration of frame structure on open decks cannot be neglected. This study investigated the wind-induced vibration of a typical frame structure on a cruise ship by using wind tunnel tests and numerical simulations. Wind tunnel tests were conducted to explore the simulation methods of the fluid–structure interaction (FSI). CFD simulations were performed to obtain the wind field data of the entire ship, which was utilized as an input for the open deck through the subdomain method. Subsequently, wind-induced vibration simulations of the guide rail frame structure on the open deck was carried out under various wind conditions. The results revealed that employing the turbulence model SST k-ω had a good agreement with the experimental data. The entire ship’s CFD results have a significant impact on the subdomain’s wind-induced vibration results. The vibration frequency of the guide rail frame structure was mainly concentrated between 0.8–10.1 Hz. The most unfavorable conditions appear at the wind attack angles of 0° and 120°. This study can provide some instructive insights for the prediction of wind-induced vibration and control of typical structures on the open decks of large cruise ships.

Evaluation of a novel biomechanics-informed walking frame, developed through a Knowledge Transfer Partnership between biomechanists and design engineers.

Walking aids such as walking frames offer support during walking, yet paradoxically, people who self-report using them remain more likely to fall than people who do not. Lifting of walking frames when crossing door thresholds or when turning has shown to reduce stability, and certain design features drive the need to lift (e.g. small, non-swivelling wheels at the front). To overcome shortfalls in design and provide better stability, biomechanists and industrial engineers engaged in a Knowledge Transfer Partnership to develop a novel walking frame that reduces the need for lifting during everyday tasks. This paper presents the results for the final prototype regarding stability, safety and other aspects of usability. Four studies were conducted that explored the prototype in relation to the current standard frame: a detailed gait lab study of 9 healthy older adults performing repeated trials for a range of everyday tasks provided mechanical measures of stability, a real-world study that involved 9 users of walking frames provided measures of body weight transfer and lifting events, two interview studies (5 healthcare professionals and 7 users of walking frames) elicited stakeholder perceptions regarding stability, safety and usability. Analysis of healthy older adults using a standard walking frame and the prototype frame demonstrated that the prototype increases stability during performance of complex everyday tasks (p < 0.05). Similarly, gait assessments of walking frame users in their home environment showed that the prototype facilitated safer usage patterns and provided greater and more continuous body weight support. Interviews with healthcare professionals and users showed that the prototype was perceived to be safe and effective and hence more usable. The outcomes of the separate studies all support the same conclusion: the prototype is an improvement on the status quo, the typical front-wheeled Zimmer frame for indoor use which has not changed in design for decades. The significance of this work lies in the success of the Knowledge Transfer Partnership and in biomechanics-informed design leading to improvements, which in future may be applied to other walking aids, to benefit walking aid users by promoting safer, more stable use of their aid.

State estimation for distribution power systems by applying an advanced optimization approach

New centralized automation functions in distribution system control centers are needed in order to ensure the control of both distribution network and connected DGs. Consequently, state estimators need to be developed for future distribution systems to assess the network’s state in real time, i.e., minutes typical time frame, based on real, and virtual measurements. This paper proposes a new method based on the particle community optimization algorithm to estimate the state of electricity distribution networks. To increase the efficiency, accuracy, and speed of convergence rate to the answer and prevent the main particle assembly algorithm from fluctuating, the second particle assembly loop is provided in addition to the mutation algorithm and the isolation function. To consider the uncertainty of loads in distribution networks, modeled as active and reactive, virtual measurements with realistic error have been modeled. Results are presented and discussed to prove the efficiency of the proposed method, including sensitivity analysis for parameters used by the algorithm. The simulation results on two 6-bus and 34-bus radial distribution networks of the IEEE test show that the estimation of the distribution state based on the proposed DLM-PSO algorithm has a lower estimation error and standard deviation than the original HBMO, GA, WLS, and PSO algorithms.

Membrane behavior of uni- and bidirectional non-crimp fabrics in off-axis-tension tests

The production of high-performance composite parts with non-crimp fabrics (NCFs) requires a profound understanding of the material’s behavior during draping to prevent forming defects such as wrinkling and gapping. Simulation methods can be used to model the complex material behavior of NCFs and predict their deformation during the draping process. However, NCFs do not intrinsically deform under pure shear like most woven fabrics, but often under superimposed shear, transverse tension and in-plane roving compaction. Therefore, non-standard characterization methods have to be applied besides typical picture frame tests or bias-extension tests. Off-axis-tension tests (OATs) utilize a simple setup to characterize a fabric’s membrane behavior under different ratios of superimposed shear, transverse tension and in-plane compaction. OATs at three different bias angles (30^circ , 45^circ and 60^circ ) are conducted to investigate a unidirectional and a bidirectional NCF. A method is presented to measure the fiber curvatures in addition to the occurring strains. The investigations reveal a relatively symmetrical, shear-dominated behavior with limited roving slippage for the Biax-NCF. The behavior of the UD-NCF strongly depends on the stitching load during tests and is characterized by an asymmetric shear behavior as well as significant roving slippage. The off-axis-tension test results can be used as the basis for the development and validation of new simulation methods to model the complex membrane behavior of NCFs.

High-speed X-ray radiography for experiments in impact dynamics using high-power X-ray tube, cesium iodine scintillator and laboratory optical camera

X-ray radiography and computed tomography have become well-established methods for investigation of internal structure of objects and for defectoscopy. Recently, the methods have even been used for in-situ analysis of materials under mechanical loading. Although the techniques would be very suitable for analysis during dynamic events, their application is constrained by typical achievable frame rates. Therefore, fast imaging is usually limited to facilities providing sufficient flux like particle accelerators. In this paper, we test imaging performance of a laboratory-based setup with a high-power X-ray tube, a scintillation panel, and an optical camera. Fast-rotating object and typical specimens for impact testing are irradiated with different power settings and quality of captured images is evaluated and analyzed. It is found out that the system can be successfully used for imaging at several hundred frames per second allowing for inspection of slow impact dynamics experiments.

Investigation of Camera-Free Eye-Tracking Glasses Compared to a Video-Based System.

Technological advances in eye-tracking have resulted in lightweight, portable solutions that are capable of capturing eye movements beyond laboratory settings. Eye-tracking devices have typically relied on heavier, video-based systems to detect pupil and corneal reflections. Advances in mobile eye-tracking technology could facilitate research and its application in ecological settings; more traditional laboratory research methods are able to be modified and transferred to real-world scenarios. One recent technology, the AdHawk MindLink, introduced a novel camera-free system embedded in typical eyeglass frames. This paper evaluates the AdHawk MindLink by comparing the eye-tracking recordings with a research "gold standard", the EyeLink II. By concurrently capturing data from both eyes, we compare the capability of each eye tracker to quantify metrics from fixation, saccade, and smooth pursuit tasks-typical elements in eye movement research-across a sample of 13 adults. The MindLink system was capable of capturing fixation stability within a radius of less than 0.5∘, estimating horizontal saccade amplitudes with an accuracy of 0.04∘± 2.3∘, vertical saccade amplitudes with an accuracy of 0.32∘± 2.3∘, and smooth pursuit speeds with an accuracy of 0.5 to 3∘s, depending on the pursuit speed. While the performance of the MindLink system in measuring fixation stability, saccade amplitude, and smooth pursuit eye movements were slightly inferior to the video-based system, MindLink provides sufficient gaze-tracking capabilities for dynamic settings and experiments.

Seismic and collapse behavior of existing high-rise steel buildings under long-period earthquakes

This work presented the experimental and numerical evaluation of the seismic and collapse behavior of Japanese existing high-rise steel buildings subjected to long-period ground motions (LPGMs). Initially, the experiment (E-Defense, 2008) was performed by the full-scale shaking table tests on a typical 21-story steel frame substructure. Accordingly, a nonlinear rotational spring model was used in the numerical modeling. In consideration of the stiffness/strength deterioration and fatigue fracture of beam-column connections, the cyclic pushover analysis was utilized to account for such effect using seismic response data from system-level testing. Subsequently, the numerical model parameters were derived and validated with the initial experiment on the high-rise steel frame substructure. Herein, a well agreement on the seismic failure behavior between simulation and experiment was found in this situation. Furthermore, both field-welded and shop-welded connections on the seismic performance were included for comparison. For the 21-story prototype steel building (built before 1970s), a series of numerical collapse analyses were performed. The above revised model using nonlinear static pushover analysis and time history analysis were conducted to simulate and compare the effects of connection details and composite slabs on the 21-story prototype building. Finally, a cyclic loading protocol for simulating LPGMs was proposed, and the related ultimate failure behavior of the high-rise building was analytically discussed. Critically, this work should provide a viable strategy to numerically simulate the seismic and collapse behavior of high-rise steel buildings in this progressing construction field.

A tale of two tool(kit)s: from canonical antonymy to non-canonical opposition in the Qur’anic discourse

Abstract A number of discourse functions of canonical antonyms have been quantified and classified in English and across languages, each of which is associated with typical syntactic frames. Taking such a classification of canonical antonymy as an analytical toolkit, (Davies, Matt. 2012. A new approach to oppositions in discourse: the role of syntactic frames in the triggering of noncanonical oppositions. Journal of English Linguistics 40(1). 41–73) quantified and qualified the role of these frames in triggering non-canonical oppositions in English news discourse. Synergizing the provisional typologies of canonical antonymy (Hassanein, Hamada. 2018. Discourse functions of opposition in Classical Arabic: The case in ḥadīth genre. Lingua 201. 18–44; Jones, Steven. 2002. Antonymy: A corpus-based perspective. London and New York: Routledge.) and non-canonical opposition (Davies, Matt. 2012. A new approach to oppositions in discourse: the role of syntactic frames in the triggering of noncanonical oppositions. Journal of English Linguistics 40(1). 41–73), this study has sought to develop a dynamic toolkit for the quantitative and qualitative analyses of non-canonical opposition across Arabic varieties and potentially other languages. The toolkit was tested quantitatively and qualitatively against a dataset of 2125 non-canonical oppositional pairs collected from the Qur’an with reference to the Qur’anic Arabic Corpus. Results showed that the syntactic frames which house a wide range of co-occurring canonical antonyms also house a wider range of non-canonical oppositions in binary and trinary representations of abstract and concrete entities. The role of syntactic frames in the triggering of non-canonical oppositions is quantitatively and qualitatively significant for locating and explicating the ideological repercussions of oppositions towards Qur’an interpretation. It is concluded that a synergy of typologies results in a replicable pathway for analysis.

Comparative study on failure mechanism of multi-storey planar composite frames with RC beams to CFST columns subjected to compartment fire

This paper presents a theoretical study of the failure mechanism of planar composite frames composed of reinforced concrete (RC) beams to concrete-filled steel tubular (CFST) columns subjected to compartment fire. The numerical analyses on the planar composite frames with multiple stories and spans are meant to reproduce the conditions of framed members in multi-storey composite structures in real buildings. A refined finite element model is established and calibrated against the thermal and mechanical results from physical testing and shows good reliability in general. Using this model, this study proposes comparative analyses on the failure mechanisms of three typical composite frames, and discusses the effects of two significant parameters: the beam-to-column linear stiffness ratio and the fire protection thickness of the composite column. The responses of the heated composite frames, including the rotational deformation and stiffness degradation of framed joints, the internal force redistribution within framed members, and the failure mode of framed structures are investigated and discussed. The results indicate that there are two important parameters should be considered in the design of composite frames in fire.

SMA-braced steel frames influenced by temperature: Practical modelling strategy and probabilistic performance assessment

This study presents a practical and efficient modelling approach for shape memory alloy (SMA)-braced steel frames under various temperatures, and examines their probabilistic performance affected by temperature. A one-dimensional constitutive model is developed in OpenSees to capture the superelasticity (SE), partial SE, shape memory effect (SME), and permanent yielding behaviors of SMA elements subjected to varying temperatures. The proposed modelling approach is partly validated against an experimental study newly conducted in the present work. The material-level investigation is followed by a comprehensive probabilistic performance assessment of a typical steel frame employing SMA-based self-centering braces (SMA-SCBs), where a practical and realistic modelling strategy for the SMA-SCB is developed to capture the degradation behavior, especially at low temperatures. Seismic risk assessment is conducted to evaluate the collapse resistance and resilience performance of the considered structures, with the influence of temperature highlighted. Among other important findings, it is shown that the decrease in environment temperature significantly increases the peak inter-story drift (PID) and residual inter-story drift (RID) responses. Under the maximum considered earthquake (MCE), the probability of collapse increases from 2.7% to 19.7% when the temperature decreases from 30 °C to −15 °C. From a self-centering capability point of view, the probabilistic of exceedance of 0.5% RID threshold soars from negligible to nearly 100%, considering the same temperature variation. The study highlights the fact that temperature plays a significant role in the annual rate of exceedance of all damage states, and warns that the idealized flag-shaped modelling approach for SMA components is extremely unsafe at low temperatures.

Frequent vs. infrequent words shape toddlers' real-time sentence comprehension.

We examined how noun frequency and the typicality of surrounding linguistic context contribute to children's real-time comprehension. Monolingual English-learning toddlers viewed pairs of pictures while hearing sentences with typical or atypical sentence frames (Look at the… vs. Examine the…), followed by nouns that were higher- or lower-frequency labels for a referent (horse vs. pony). Toddlers showed no significant differences in comprehension of nouns in typical and atypical sentence frames. However, they were less accurate in recognizing lower-frequency nouns, particularly among toddlers with smaller vocabularies. We conclude that toddlers can recognize nouns in diverse sentence contexts, but their representations develop gradually.

A Three-Dimensional Hydraulic Stack Model for Redox Flow Batteries Considering Porosity Variations in Porous Felt Electrodes and Bypass Flow in Side Gaps

Redox flow batteries provide high flexibility and scalability for large-scale energy storage systems due to their safety, low cost and decoupling of energy and power. While typical flow frame designs usually assume all parts are standard, the industry can suffer from irregularity and manufacturing tolerances of cell components, such as the shape or dimensions of the flow frame and porous electrode. This paper evaluates the impact of side gaps and porosity differences of the graphite felt due to irregularity and manufacturing tolerances on the electrolyte flow in the active cell areas. A three-dimensional hydraulic model with parameterised multi-cell stack geometry has been developed in COMSOL to compare the cell velocity distributions and pressure losses of a vanadium redox flow battery with flow-through electrodes. The results indicate that the side gaps and porosity segments can result in preferential flow within low-resistance areas, leading to significantly lower flow rates for other cell areas compared with standard flow frames. Proposed countermeasures of adjusting channel locations and applying dimples protruding into the cell cavity from the flow frame show good potential to avoid stagnant zones and maintain theoretical flow rates for the active cell areas.

Identifying a complete genome sequencing of canine parvovirus from red-collared doves in Guangxi, Southern China

Birds are the crucial hosts for viruses since they are able to carry and spread infections that may prove harmful to humans, domestic animals, and other wild animals. Finding a new host can aid in understanding the virus's dynamics of transmission, including how it spreads and potential sources of origin. In this study, 40 fecal samples from birds were collected from various regions of Guangxi province, China. The CPV-2 was found in the sample collected in the group 2019, sample pool 21H with sample ID numbers (BJF-5, BJF-6, BJF-7, BJF-8, BJF-9) by High-throughput sequences. PCR investigation found BJF-6 was positive, and the complete genome, namely, RCD-CPV NA, was found to be 5322 bp in length with typical open reading frames. BLASTn analysis showed that the genome sequence was closely identical to the CPV strain N with 100 % query coverage and 99.04 % identity. After BLAST comparison of NCBI nucleotide, the similarity of BJF6 nucleotide sequence to the first 100 CPVs sequences is 99.60 % - 97.24 %. Genome sequence comparisons and phylogenetic analysis with NS1 and VP2 amino acid sequences suggested that those sequences shared the highest similarity with the Pangolin protoparvovirus strain PPrV, a CPV-2 variant. It's significant to remember that this is a novel instance of CPV being found in an avian species. This study improves knowledge of the variety of avian viruses and provides new light on the factors that contribute to their pathogenicity.

Thermal response of a curtain wall framing system under fire conditions

Curtain walls are the most common façade system for modern office buildings. These facade systems play an important role in containing the fire to the floor of origin, and in the case of failure, the consequences can be severe. The heat from a fire could cause key elements to fail and sections of the facade to detach and fall from the building, facilitating flame spread to upper floors. However, no tools currently exist that can reliably predict the failure of such systems. This study computationally investigates the thermal response of two curtain wall framing systems to fire exposure – the stick system and the unitized system. The model predictions were validated against experimental data and the role of the screw connector is explored. A typical curtain wall aluminium frame system is modelled. The simulation results indicate that when heated from a compartment fire, thermal degradation of the aluminium frame is very rapid, occurring within the first 15 min of fire exposure for ISO-834 standard fire. When heated from the outside, considering the Eurocode external fire, thermal degradation of the pressure plate occurred within 10 min. With the addition of thermal protection or when using steel instead of aluminium profiles, thermal degradation was not predicted within the first 40 min of heating. The findings advance our understanding of curtain wall frame fire behaviour and can help develop more effective fire strategies and more resilient systems.

Evaluation and comparison of seismic performance of industrially and traditionally constructed buildings in Iran, a case study of Yasooj

Modern construction methods such as industrial ones have significantly increased the speed of buildings construction. Although these new methods are widely used in some countries, but the fundamental question is about their reliability and efficiency, especially in term of their seismic performance in comparison to the traditional construction methods. In this study, the seismic performance of constructed buildings using industrial construction methods is compared to the typical buildings in Iran. Besides, as main innovation, by defining building industrialization index, the economics of each structure has been also evaluated and the effect of this index on the structural performance has been studied. To this purpose, by conducting statistical studies on existing buildings, their information has been collected and three types of nonlinear finite element models including: eccentric steel braced frame, buckling restrained braced frame and tunnel formwork reinforced concrete shear wall have been prepared and compared. The near field earthquakes records have been used for nonlinear incremental dynamic analysis to obtain the corresponding fragility curves. The results showed that the tunnel formwork RC shear wall and buckling restrained braced frames, in addition to being more economical, also have more reliable collapse fragility curves and present better performance than the typical eccentric braced frames as they have a higher building industrialization index than the third structural system, respectively. Therefore, the modern buildings constructed by industrial methods have a lower casualty and economic risk due to the better seismic behavior compared to typical and traditional buildings.

Corrigendum to Seismic resilience of typical code-conforming RC moment frame buildings in Canada. Earthquake Spectra. Epub ahead of print 13 January 2023. DOI: 10.1177/87552930221145455

Corrigendum to Seismic resilience of typical code-conforming RC moment frame buildings in Canada. Earthquake Spectra. Epub ahead of print 13 January 2023. DOI: 10.1177/87552930221145455

Vertical floor spectra in low- and mid-rise elastic RC moment resisting frame buildings

To examine how floor spectral accelerations affect the design force of flexible Non-Structural Components (NSCs), the present study discusses the estimation of floor response spectra resulting from strong vertical seismic motion. 3-, 6-, 9- and 12-storey reinforced concrete buildings with moderately ductile moment-resisting frame systems, designed in accordance with the National Building Code of Canada [25] were selected for this research. 65 sets of historical records relating to 31 severe earthquakes from across the world were used to analyze the linear behavior of these structures. A constant amplification of the Vertical Floor Spectral Acceleration (FSAV) was observed along the building height. This amplification was noticeably elevated for slab nodes, especially at the center of the interior slab and in shorter buildings. Furthermore, the vertical component of the earthquake had a greater impact at shorter periods, since the maximum vertical acceleration occurred at periods lasting less than 0.35 sec. Finally, equations to estimate FSAV corresponding to the input vertical ground acceleration were proposed for typical code-conforming RC frame buildings.

How Are Tornadic Supercell Soundings Significantly Different From Nearby Baseline Environments?

AbstractThis study explores how tornadic supercell soundings significantly differ from the same‐location and same‐hour baseline environment soundings, sampled from the days prior to or following the event. Permutation testing is used to identify whether sounding‐derived parameters mixed‐layer convective available potential energy and 0–1 km storm‐relative helicity are significantly different between the tornadic and baseline environment. Typically, in an environment with marginal values of certain key environmental parameters, anomalous values of those environmental parameters are more strongly associated with supercell tornadoes. Furthermore, many tornadic events already exhibit environmental conditions favorable for tornadic supercells a day prior to the event itself. Generally, supercell tornadoes that occur during typical peak tornadic activity time frames are easier to distinguish from baseline (non‐tornadic) environments compared to those occurring in other time frames. Spatiotemporal variations of distinguishability between tornadic and baseline environmental parameters add complexity to traditional parameter‐based fixed threshold forecasting.

Thermal Effect on the Design Loads of Multi-Storey RC Buildings on Sloped Terrain in Saudi Arabia

Abstract This research investigates the impact of thermal loads on reinforced concrete (RC) buildings in Saudi Arabia and how they behave on sloped terrain. The study analyzed the effects of different types of support systems (hinged and fixed supports) and strengthening systems (with and without bracings) using the software ETABS-V20. Ground + 9 typical floors frame RC models on sloped terrain subjected to seismic loads were used for the investigation. The dynamic analysis of the ETABS models was performed to evaluate the lateral displacement, storey drift, column shear forces, and base shear forces of the buildings. The study found that using a bracing system and fixed supports under seismic loads increases the model’s displacement and storey drift compared to models with hinged supports and no bracing system. The maximum shear forces values were also higher for models with bracing systems and fixed supports, while the minimum values were for models without bracing systems and with hinged supports.