Step Strategy Research Articles

Classification and Definitions of Compensatory Protective Step Strategies in Older Adults: A Scoping Review.

The risk for an unexpected fall can be due to increasing age, health conditions, and loss of cognitive, sensory, or musculoskeletal functions. Falls have personal and economic consequences in many countries. Different disturbances can occur during gait, such as tripping, slipping, or other unexpected circumstances that can generate a loss of balance. The strategies used to recover balance depend on many factors, but selecting a correct response strategy influences the success of balance recovery. (1) To collect and clarify the definitions of compensatory protective step strategies to recover balance in older adults; (2) to identify the most used methods to induce loss of balance; and (3) to identify the most used spatiotemporal variables in analyzing these actions. The present review has followed the PRISMA guideline extension for Scoping Review (PRISMA-ScR) and the phases proposed by Askery and O'Malley. The search was conducted in three databases: PubMed, Web of Science, and Scopus. A total of 525 articles were identified, and 53 studies were included. Forty-five articles were quasi-experimental studies, six articles were randomized controlled trials, and two studies had an observational design. In total, 12 compensatory protective step strategies have been identified. There are 12 compensatory protective step strategies: lowering and elevating strategy, short- and long-step strategy, backward and forward stepping for slip, single step, multiple steps, lateral sidesteps or loaded leg sidestep unloaded leg sidestep, crossover step (behind and front), and medial sidestep. To standardize the terminology applied in future studies, we recommend collecting these strategies under the term of compensatory protective step strategies. The most used methods to induce loss of balance are the tether-release, trip, waist-pull, and slip methods. The variables analyzed by articles are the number of steps, the acceleration phase and deceleration phase, COM displacement, the step initiation or step duration, stance phase time, swing phase time and double-stance duration, stride length, step length, speed step, speed gait and the type of step.

Stair-Fall Risk Parameters in a Controlled Gait Laboratory Environment and Real (Domestic) Houses: A Prospective Study in Faller and Non-Faller Groups.

Falling on stairs is a major health hazard for older people. Risk factors for stair falls have been identified, but these are mostly examined in controlled biomechanics/gait laboratory environments, on experimental stairs with a given set of step dimensions. It remains unknown whether the conclusions drawn from these controlled environments would apply to the negotiation of other domestic staircases with different dimensions in real houses where people live. The aim of this paper is to investigate whether selected biomechanical stepping behavior determined through stair gait parameters such as foot clearance, foot contact length and cadence are maintained when the staircase dimensions are different in real houses. Twenty-five older adults (>65 years) walked on a custom-made seven-step laboratory staircase. Older adults were classified into two groups (fallers and non-fallers) based on recent fall history. Among the 25 participants, 13 people had at least one fall, trip, or slip in the last six months and they were assigned to the fallers group; 12 people did not experience any fall in the last six months, so they were assigned to the non-fallers group. In addition, these participants walked on the stairs in three different real exemplar houses wearing a novel instrumented shoe sensor system that could measure the above stair gait parameters. MATLAB was used to extract fall risk parameters from the collected data. One-way ANOVA was used to compare fall risk parameters on the different staircases. In addition, the laboratory-based fall risk parameters were compared to those derived from the real house stairs. There was a significant difference in selected stair-fall biomechanical risk factors among the house and laboratory staircases. The fall risk group comparisons suggest that high-risk fallers implemented a biomechanically riskier strategy that could increase overall falling risk. The significant differences due to the main effects of the fallers and non-fallers groups were obtained. For example, when ascending, the fallers group had less foot clearance on the entry (p = 0.016) and middle steps (p = 0.003); in addition, they had more foot clearance variability on the entry steps (p = 0.003). This suggests that the fallers group in this present study did not adopt more conservative stepping strategies during stair ascent compared to low-risk older adults. By showing less foot clearance and more variability in foot clearance, the risk for a trip would be increased.

A One Step Strategy Based on Hollow Gold Nanoparticles to Detect C-Reactive Protein with High Sensitivity (Hs-CRP) in Serum for Monitoring Cardiovascular Disease.

Rapid detection and diagnosis of diseases facilitate timely and effective treatment of cardiovascular diseases (CVD). The establishment of a one-step rapid detection method provides a new method for the initial screening and disease risk assessment of patients with cardiovascular diseases in primary medical units. Hollow gold nanoparticles (HGNPs) were synthesized using a cobalt template method followed by use as signal amplification probes for ultra-sensitive quantitative detection of serum C-reactive protein (CRP). To induce the localized surface plasmon resonance (LSPR) and improve protein labeling efficiency, we developed a sensitive detection mode by coating polyvinylpyrrolidone (PVP-K30) on the HGNPs, resulting in a significant improvement in detection performance. Compared to traditional colloidal GNP-based LFTA, PVP-coated HGNPs exhibit a lower visual detection limit of 1 ng/mL, which a 25-fold decrement compare to using GNPs as the antibody-labeled probe, and the detection limit could be reduced to 0.14 ng/mL under the quantitative instrument. The one-step method based on HGNP immunochromatographic strips modified with PVP established in this study can be used for the detection of CRP and hs-CRP in biological samples. The performance of the immunochromatographic technique designed in this study was evaluated from the perspective of synthetic markers, and the application conditions of this strip were screened, verifying its high specificity, indicating that it has high sensitivity and strong detection limit compared to colloidal gold. The sensitivity of the hollow gold immunochromatographic test strip in this article has been increased by about 25 times, providing a new method for rapid detection of CVD in clinical diagnosis.

Large–size porous spherical 3D covalent organic framework for preconcentration of bisphenol F in water samples and orange juice

Large–size spherical sorbents with particle size of 10–50 μm are widely applied in separation fields, however it is still a great challenge to synthesize such large–size spherical covalent organic framework (COF). In this work, a type of large–size porous 3D COF was size–controablly synthesized via a two–step strategy, in which a large–size porous 3D spherical polymer was prepared first through a Pickering emulsion polymerization using nano silica as the stabilizer, and subsequently it was converted into porous spherical 3D COF by a solvothermal method. The as–prepared porous spherical COF (COF–320 as a model) showed size–controllable uniform spherical morphology within 15–45 μm, large specific surface area, fine crystalline structure, and good chemical stability. When used as the sorbent for dispersive solid–phase extraction (d–SPE) of bisphenol F (BPF), the porous spherical COF–320 (15 μm) displayed high adsorption capacity (Qmax = 335.6 mg/g), high enrichment factor (80 folds), and good reusability (at least five cycles). By coupling the d–SPE method to HPLC, a new analytical approach was developed and successfully applied to the determination of trace BPF in two water samples, an orange juice and a standard sample with recoveries of 96.0–102.2 % (RSD = 1.1–1.5 %), 95.7–97.4 % (RSD = 1.4–4.4 %) and 98.7 % (RSD = 2.3 %), respectively. The limit of detection (S/N = 3) and limit of quantification (S/N = 10) were 0.1 and 0.3 ng/mL, respectively. The new synthesis strategy opens a viable way to prepare large–size porous spherical COFs, and the developed analytical method can be potentially applied to sensitively detect the trace BPF in water samples and beverages.

Contemporary Challenges and Censorship in School Libraries in Canada

The purpose of this chapter is to familiarize readers with contemporary challenges and censorship in school libraries and learning commons in Canada. The informal narrative reflects the viewpoints of seasoned advocates for intellectual freedom and social responsibility in the Canadian library sector. Content concentrates on the main sources of challenges, four common types of challenges that can lead to censorship (content, curriculum, genre, and book leveling), an essential two step strategy and related resources for dealing with challenges and combating censorship, and a pointer for educators in library and information programs. The chapter closes with an expression of appreciation and concern for the individuals who take personal and professional risk in managing challenges and combating censorship in school libraries and learning commons in Canada and beyond.

Informed consent process experience in Alzheimer’s Prevention Initiative (API) Autosomal Dominant Alzheimer’s Disease Colombia trial

AbstractBackgroundRecruiting cognitively‐unimpaired volunteers at high genetic risk of developing dementia into the Alzheimer’s Prevention Initiative (API) Colombia trial, and maintaining study adherence for at least 5 years has been a monumental challenge. Major barriers included inclusion criteria, protocol visit schedule, long informed consent form (ICF), low levels of education of participants, misconceptions about participating in a clinical trial, and blinding to genetic status and treatment arm. We explain how our group went out of the conventional and traditional schemes of informed consent while adhering to good clinical practice and developed a novel approach to the consent process for potential candidates.MethodThe identification, community education, and follow‐up of affected PSEN1 E280A families for the past three decades was the initial fundamental step to initiate a proper ICF process for the study. Then the launch of API Colombia Registry in 2010 was the base for appropriate preparation for the prevention trial. The process for API Colombia trial included step by step strategies, such as: a pre‐screening process developed by the team, pre‐consent informational meeting with the principal investigator in small groups of potential candidates, illustrated materials like a booklet titled “What I should know about informed consent and my decision to participate”, and detailed infographics as a complementary material to main study ICF, use of a voluntary pre‐selection survey. The screening visit was divided in parts: discussion with the sub‐investigator about clinical trial participation, review of participant’s questions, and signatures according to regulatory requirements.ResultFrom 623 potentially eligible registrants for pre‐screening, 319 were consented and underwent full eligibility screening and 252 were randomized. After eight years of study duration, 94% of participants completed the protocol, 90.5% completed the trial on treatment. Most participants who dropped out of the study did it due to incompatibility with work, unexpected pregnancy, or the decision to have children.ConclusionWe attribute successful trial adherence to the consent process that led to a well‐informed, voluntary, and responsible decision, and the participant’s understanding of the unique contribution they can make to change the world by participating in clinical research.

A Global-Local Error-Driven -Adaptive Scheme for Discontinuous Galerkin Time-Domain Method With Local Time-Stepping Strategy

In this paper, a highly efficient <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</i> -adaptive scheme has been developed for discontinuous Galerkin time domain (DGTD) method with local time stepping (LTS) strategy. In the proposed <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</i> -adaptive procedure, the dual-fold error driven scheme has been developed. Compared to the global error range corresponding to the preset base order range, the local maximal error in each discretized element is used to determine the allowable local range of the base order. The local error in each element is compared with the local error range to determine which operation, i.e., the base order increasing or decreasing, is implemented. The resulting two error thresholds are insensitive in the dynamic <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</i> -adaptive procedure. When applying the proposed <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">p</i> -adaptive scheme into the LTS method, a simple grouping approach in terms of the time steps related to the base orders has been developed to rapidly perform the marching-on-in time procedure. Several numerical examples including scattering from a missile, radiation of a ridge gap waveguide (RGW) antenna and transmission of a cylindrical cavity filter are given to demonstrate good accuracy and high efficiency of the proposed method.

Size–controllable synthesis of large–size spherical 3D covalent organic frameworks as efficient on–line solid-phase extraction sorbents coupled to HPLC

BackgroundCovalent organic frameworks (COFs) have found promising applications in separation fields due to their large surface area and high adsorption capacity, but the exiting COFs can not be directly used as the packing materials of on–line solid-phase extraction (SPE) coupled to HPLC and HPLC because their nano/submicron size or irregular shapes might cause ultrahigh column back pressure and low column efficiency. To synthesize the large-size spherical COFs larger than 3 μm as sorbents might be able to address these problems, however it is still a great challenge till now. ResultsIn this work, two large-size spherical 3D COFs (COF–320 and COF–300) were size–controllably synthesized within 10–90 μm via a two–step strategy. These two spherical COFs showed large surface area, fine crystallinity, good chemical/mechanical stability, and good reproducibility. As an application case, when used as the on–line SPE sorbents coupled to HPLC, the large–size spherical COF–320 displayed high binding capacity for bisphenol F (Qmax of 452.49 mg/g), low column back pressure (6–8 psi at flow rate of 1 mL/min), and good reusability (at least 30 cycles). The developed on–line–SPE–HPLC–UV method presented good analytical performance with enrichment factor of 667 folds, linear range of 1.0–400 ng/mL, limit of detection (LOD, S/N = 3) of 0.3 ng/mL, limit of quantification (LOQ, S/N = 10) of 1.0 ng/mL, and recoveries of 100.3–103.2 % (RSDs of 2.0–3.5 %) and 95.2–97.0 % (RSDs of 4.3–5.6 %) for tap water and lake water samples, respectively. SignificanceThis is the first case to synthesize the large–size spherical COFs within 10–90 μm, and this work made it possible to directly use COFs as the filling materials of on–line SPE coupled to HPLC and HPLC. The developed analytical method can be potentially applied to the rapid and sensitive detection of trace bisphenol F in environmental water samples.

Development of a complex intervention to prevent delirium in older hospitalized patients by optimizing discharge and transfer processes and involving caregivers: A multi-method study

BackgroundDelirium is a common yet challenging condition in older hospitalized patients, associated with various adverse outcomes. Environmental factors, such as room changes, may contribute to the development or severity of delirium. Most previous research has focused on preventing and reducing this condition by addressing risk factors and facilitating reorientation during hospital stay. ObjectiveWe aimed to systematically develop a complex intervention to prevent delirium in older hospitalized patients by optimizing discharge and transfer processes and involving caregivers during and after these procedures. The intervention combines stakeholder and expert opinions, evidence, and theory. This article provides guidance and inspiration to research groups in developing complex interventions according to the recommendations in the Medical Research Council framework for complex interventions. Design and methodsA stepwise multi-method study was conducted. The preparation phase included analysis of the context and current practice via focus groups. Based on these results, an expert workshop was organized, followed by a Delphi survey. Finally, the intervention was modeled and a program theory was developed, including a logic model. ResultsA complex intervention was developed in an iterative process, involving healthcare professionals, delirium experts, researchers, as well as caregiver and patient representatives. The key intervention component is an 8-point-program, which provides caregivers with recommendations for preventing delirium during the transition phase and in the post-discharge period. Information materials (flyers, handbook, videos, posters, defined “Dos and Don'ts”, discharge checklist), training for healthcare professionals, and status analyses are used as implementation strategies. In addition, roles were established for gatekeepers to act as leaders, and champions to serve as knowledge multipliers and trainers for the multi-professional team in the hospitals. ConclusionsThis study serves as an example of how to develop a complex intervention. In an additional step, the intervention and implementation strategies will be investigated for feasibility and acceptability in a pilot study with an accompanying process evaluation. Tweetable abstractDelirium prevention can benefit from optimizing discharge and transfer processes and involving caregivers of older patients in these procedures. Study registrationDRKS00017828, German Register of Clinical Studies, date of registration 17.09.2019.

Comparison of the Execution Step Strategies on Scheduling Data-intensive Workflows on IaaS Cloud Platforms

The IaaS platforms of the Cloud hold promise for executing parallel applications, particularly data-intensive scientific workflows. An important challenge for users of these platforms executing scientific workflows is to strike the right trade-off between the execution time of the scientific workflow and the cost of using the platform. In a previous article, we proposed an efficient approach that assists the user in finding this compromise. This approach requires an algorithm aimed at minimizing the execution time of the workflow once the platform configuration is set. In this article, we compare two different strategies for executing a workflow after its offline scheduling using an algorithm. The algorithm that we proposed in the previous study has outperform the HEFT algorithm.&#x0D; The first strategy allows some ready tasks to execute earlier than other higher-priority tasks that are ready later due to data transfer times. This strategy is justified by the fact that although our scheduling algorithm attempts to minimize data transfers between tasks running on different virtual machines, this algorithm does not include data transfer times in the planned execution dates for the various tasks of the workflow. The second strategy strictly adheres to the predetermined order among tasks scheduled on the same virtual machine.&#x0D; The results of our evaluations show that the best execution strategy depends on the characteristics of the workflow. For each evaluated workflow, our results demonstrate that our scheduling algorithm combined with the best execution strategy surpasses HEFT. The choice of the best strategy must be determined experimentally following realistic simulations, such as the ones we conduct here using the WRENCH framework, before conducting simulations to find the best compromise between cost and execution time of a workflow on an IaaS platform..

Rate-Dependent Hysteresis Model of a Giant Magnetostrictive Actuator Based on an Improved Cuckoo Algorithm

A rate-dependent asymmetric Prandtl–Ishilinskii (RAPI) model was proposed to tackle the serious rate-dependent hysteresis nonlinearity of the giant magnetostrictive actuator(GMA) output. First, a polynomial function was introduced based on the PI model, and hysteresis factors were introduced to the Play operator, which accurately described the asymmetrical characteristic of the actuator output. On this basis, rate-dependent parameters were added to establish a rate-dependent RAPI model. Second, an improved cuckoo search (ICS) algorithm was proposed to solve the difficulty in the parameter identification of the RAPI model. For the ICS algorithm, the algorithm stability and optimization accuracy were improved using the adaptive step (AS) strategy and bird’s nest disturbance strategy. Then, the effectiveness of the ICS algorithm was tested by comparing it with other parameter identification algorithms. Finally, the rate-dependent RAPI model was verified by combining the output data of the giant magnetostrictive actuator under different frequencies. The results show that the rate-dependent RAPI model exhibits a higher accuracy than the PI model, thus verifying the effectiveness of the rate-dependent RAPI model.

PROSPECTS FOR INITIAL TRIPLE ANTIHYPERTENSIVE THERAPY

The currently recommended initial dual antihypertensive therapy (AHT) results in poor blood pressure (BP) control, whereas most patients should undergo triple-combination therapy to achieve target levels. We have found only foreign publications concerning initial triple antihypertensive treatment.&#x0D; The aim of the study is to compare the traditional step by step strategy of drug administration and application of three antihypertensive drugs simultaneously.&#x0D; Materials and Methods. Trial subjects were divided into 2 groups: patients who received conventional dual therapy followed by a third drug agent (n=59) and patients who received initial triple AHT (n=57). The frequency of prescribed drugs and their dosage were comparable. The examination was carried at hospital according to the current standards of medical care for hypertensive adults. Values &lt;140/90 mm Hg were taken as BP target level. Office blood pressure was tested 1 and 3 months after the therapy. 24-hour BP control was carried out 12 weeks after treatment.&#x0D; Results. The analysis of cardiovascular risks (CVRs) did not reveal significant intergroup differences (p&gt;0.05). Both treatment regimens demonstrated fewer complaints and a comparable frequency of adverse reactions (p&gt;0.05). Intergroup comparison conducted 1 month after treatment showed lower SBP and DBP levels (p&lt;0.001) and a significant decrease in blood pressure in the 2nd group compared to baseline (p&lt;0.001). The chance of achieving BP target level with the traditional scheme was 0.20, while with the initial triple AHT it was 2.35. The odds ratio was 11.53 (95 % CI 4.76; 27.96).&#x0D; Conclusion. Initial triple antihypertensive therapy has an advantage over the conventional one due to faster achievement of BP target levels. Given the comparable efficacy and frequency of adverse reactions, the strategy may be of interest for further study and implementation in practical medicine.

Analytical method development supported by DoE-DS approach for enantioseparation of (S,S)- and (R,R)-moxifloxacin

In this paper, method for enantiomeric purity testing of fourth-generation fluoroquinolone, moxifloxacin hydrochloride, was developed and validated. Exceptional enantioselectivity for this assay was achieved using cyclodextrin type Chiral Stationary Phase (CSP), phenylcarbamate-β-cyclodextrin CSP, and mobile phase consisted of acetonitrile and triethylammonium acetate (TEAA) buffer. Analytical Quality by Design (AQbD) methodology, comprising Design of Experiments (DoE) - Design Space (DS) approach, was used for method development. In order to select appropriate Critical Method Parameters (CMPs), risk assessment was done using combined three step strategy that involved Ishikawa diagram - CNX (Control, Noise and eXperimental) - FMEA (Failure Mode and Effect Analysis). Three CMPs were further selected and investigated in this study: acetonitrile content in the mobile phase (30–50%, v/v), triethylamine content in the TEAA buffer (0.1–1.5%, v/v) and aqueous phase pH (3.5–4.5). Monte Carlo simulations were performed and 3D-DS was computed. One point situated in the center of 3D-DS was selected as working point for method validation, with the following values of CMPs: acetonitrile content in the mobile phase set to 37% (v/v), triethylamine content in TEAA 0.8% and pH value of the aqueous phase set at 4.0. Also, 2D-DS was created (with fixed one factor – pH value of aqueous phase at 4.0) which also gave us confirmation that the selection of working conditions was suitable. The proposed enantioselective method was further on tested for its quantitative robustness, as well as for its suitability for the intended purpose through validation studies.

A cooperative adaptive genetic algorithm for reentrant hybrid flow shop scheduling with sequence-dependent setup time and limited buffers

This paper deals with a reentrant hybrid flow shop problem with sequence-dependent setup time and limited buffers where there are multiple unrelated parallel machines at each stage. A mathematical model with the minimization of total weighted completion time is constructed for this problem. Considering the complexity of the problem at hand, an effective cooperative adaptive genetic algorithm (CAGA) is proposed. In the algorithm, a dual chain coding scheme and a staged-hierarchical decoding approach are, respectively, designed to encode and decode each solution. Six dispatch heuristics and a dynamic adjustment method are introduced to define initial population. To balance the exploration and exploitation abilities, three effective operations are implemented: (1) two new crossover and mutation operators with collaborative mechanism are imposed on genetic algorithm; (2) an adaptive adjustment strategy is introduced to re-optimize better solutions after mutation operations, where ant colony search algorithm and modified greedy heuristic are intelligently switched; (3) a reset strategy with dynamic variable step strategy is embedded to re-generate some non-improved solutions. A Taguchi method of design of experiment is adopted to calibrate the parameter values in the presented algorithm. Comparison experiments are executed on test instances with different scale problems. Computational results show that the proposed CAGA is more effective and efficient than several well-known algorithms in solving the studied problem.

The fully coupled regionally refined model of E3SM version 2: overview of the atmosphere, land, and river results

Abstract. This paper provides an overview of the United States (US) Department of Energy's (DOE's) Energy Exascale Earth System Model version 2 (E3SMv2) fully coupled regionally refined model (RRM) and documents the overall atmosphere, land, and river results from the Coupled Model Intercomparison Project 6 (CMIP6) DECK (Diagnosis, Evaluation, and Characterization of Klima) and historical simulations – a first-of-its-kind set of climate production simulations using RRM. The North American (NA) RRM (NARRM) is developed as the high-resolution configuration of E3SMv2 with the primary goal of more explicitly addressing DOE's mission needs regarding impacts to the US energy sector facing Earth system changes. The NARRM features finer horizontal resolution grids centered over NA, consisting of 25→100 km atmosphere and land, a 0.125∘ river-routing model, and 14→60 km ocean and sea ice. By design, the computational cost of NARRM is ∼3× of the uniform low-resolution (LR) model at 100 km but only ∼ 10 %–20 % of a globally uniform high-resolution model at 25 km. A novel hybrid time step strategy for the atmosphere is key for NARRM to achieve improved climate simulation fidelity within the high-resolution patch without sacrificing the overall global performance. The global climate, including climatology, time series, sensitivity, and feedback, is confirmed to be largely identical between NARRM and LR as quantified with typical climate metrics. Over the refined NA area, NARRM is generally superior to LR, including for precipitation and clouds over the contiguous US (CONUS), summertime marine stratocumulus clouds off the coast of California, liquid and ice phase clouds near the North Pole region, extratropical cyclones, and spatial variability in land hydrological processes. The improvements over land are related to the better-resolved topography in NARRM, whereas those over ocean are attributable to the improved air–sea interactions with finer grids for both atmosphere and ocean and sea ice. Some features appear insensitive to the resolution change analyzed here, for instance the diurnal propagation of organized mesoscale convective systems over CONUS and the warm-season land–atmosphere coupling at the southern Great Plains. In summary, our study presents a realistically efficient approach to leverage the fully coupled RRM framework for a standard Earth system model release and high-resolution climate production simulations.

Stepping strategies of young adults undergoing sudden external perturbation from different directions

Stepping strategies following external perturbations from different directions is investigated in this work. We analysed the effect of the perturbation angle as well as the level of awareness of individuals and characterised steps out of the sagittal plane between Loaded Side Steps (LSS), Unloaded Medial Steps (UMS) and Unloaded Crossover Steps (UCS). A novel experimental paradigm involving perturbations in different directions was performed on a group of 21 young adults (10 females, 11 males, 20–38 years). Participants underwent 30 randomised perturbations along 5 different angles with different levels of awareness of the upcoming perturbations (with and without wearing a sensory impairment device) for a total of 1260 recorded trials. Results showed that logistic models based on the minimal values of the Margin of Stability (MoS) or on the minimal values of the Time to boundary (Ttb) performed the best in the sagittal plane. However, their accuracy stayed above 79% regardless of the perturbation angle or level of awareness. Regarding the effect of the experimental condition, evidences of different balance recovery behaviours due to the variation of perturbation angles were exposed, but no significant effect of the level of awareness was observed. Finally, we proposed the Distance to Foot boundary (DtFb) as a relevant quantity to characterise the stepping strategies in response to perturbations out of the sagittal plane.

Contemporary sustainability themes in tourism and hospitality during and post COVID‐19: Critical review and a step strategies forward for post the pandemic

AbstractThe onset of COVID‐19 has challenged economies and industries globally and thwarted their contributions towards the United Nations Sustainable Development Goals (UNSDGs). In coping with the COVID‐19‐related challenges, the global tourism and hospitality industry is also affected to its worst level. Thus, researchers employed bibliometric analysis and a science mapping approach to investigate the structure of the contemporary sustainable issues in tourism and hospitality research during COVID‐19, the most productive and impactful research constituents (journals, organizations, countries, and authors), the most impactful research works, the major emerging research themes, and the agenda for future research. The results of the bibliographic data (Scopus, Jan 2020–Sep 2022) analysis revealed that research in the selected field is still at a very nascent stage. The majority of the research papers focus on ‘responsible consumption and production (UNSDG‐12)’, ‘good health and well‐being (UNSDG‐3)’, and ‘decent work and economic growth (UNSDG‐8)’. The science mapping approach led to the development of eight propositions related to the emerging themes of knowledge. The researchers have discussed each research theme in detail and laid out an agenda for future research.

Numerical Approaches of Block Multistep Method for Propagation of Derivatives Discontinuities in Neutral Delay Differential Equations

It is known that discontinuities may exist in the solution of neutral delay differential equations even though the function is assumed to be continuous along the interval. This problem occurs when the primary discontinuity in the derivatives solution at the initial point propagates to the subsequent points, which results in a secondary discontinuity. As a result, the solution of the neutral delay may no longer be smooth and lead to a larger number of failure steps. This study proposes a block multistep method to deal with the propagation of derivatives discontinuities in neutral delay. The new invention of the numerical approaches by adapting the block multistep method with the Runge–Kutta Fehlberg variable step strategy is developed. The strategies to approximate both retarded and neutral delays and discontinuity tracking equations are performed to maximize the accuracy of the solution. The error analysis is presented by comparing the numerical results with the existing methods to verify the efficiency of the developed approaches. It is demonstrated that the proposed numerical approaches are able to correct the propagation of discontinuities and provide very smooth solutions with accurate results.

Single step strategy to prepare highly microporous carbons derived from melamine and terephthalaldehyde for high-performance material-based hydrogen storage

Future energy sources like hydrogen (H2) have been viewed as a viable substitute for fossil fuels. To develop a sustainable H2 economy, efficient means of storing H2 is an urgent prerequisite. In this regard, materials-based H2 storage is a promising route to achieve United States Department of Energy goals. In the current work, a mixture of “melamine and terephthalaldehyde” undergoes simultaneous polymerization, carbonization, and in-situ activation in the presence of molten salt media (KOH + NaOH) by a single all-in-one approach to create microporous carbons with large specific surface areas (SSA ∼ 2462 m2/g), and total pore volume (∼1.96 cm3/g). As-prepared carbons with excellent textural features activated at 800 °C exhibit remarkable H2 storage capacities (up to 3.62 wt% at −196.15 °C and 1 bar, and 6.41 wt% at 30 bar). The results illustrated that pore size (0.68 nm) plays the dominant role in deciding H2 storage capacity at low pressure in comparison to total SSA and micropore volume. However, greater SSA and larger pores are thought to be the determining parameters for measuring H2 storage capacity at higher pressure (30 bar). Lastly, moderate values of isosteric heat of adsorption (Qst = 5.51–7.99 kJ/mol) demonstrate that H2 storage occur through physisorption.

A unique methanol responsiveness, AIE, acidochromism and mechanofluorochromic features of flexible ethylenediamine bridged rhodamine B-diethylamino hydroxycoumarin conjugate

A new multi-stimulus active ethylenediamine linkage centered Rhodamine B-diethylamino hydroxycoumarin conjugate (RhB-DHC) was designed and successfully fabricated by simple one step strategy. The synthesized compound RhB-DHC displays distinct methanol responsive feature via color transformation from colorless to purple among the various solvents used, aggregation induced emissive (AIE) behavior in EtOH-water mixture and acidochromic property through spirolactum ring opening and closing response of rhodamine B moiety. In solid state, RhB-DHC discloses mechanofluorochromic phenomenon by fluorescence color change upon mechanical grinding. Further, the occurrence of ground state proton transfer reaction in RhB-DHC was recognized by solid state structure, DFT and time dependent DFT calculations.