Short Step Research Articles

How can operational research make a real difference in healthcare? Challenges of implementation

This paper is based on the keynote address given by the paper's first author at EURO 2021. We draw on our experience over more than three decades to define the critical challenges of healthcare implementation. We do not address issues pertaining to technical quality of a solution. Rather, we focus on five general characteristics of the problem that should be carefully considered for any healthcare project that requires implementation. The problem needs an internal Champion; there should be a current Critical Issue; one must understand and adapt to the Cultural dynamics of the organization; appropriate Data exists; and we need to manage Expectations. We illustrate each with examples of our successes, failures, and mixed results. Finally, we summarize what short and long-term steps we believe the operational research community can take that will lead to improvement in each of these areas.

Combined Gait and Grasping in Autistic and Non-Autistic Youths

ABSTRACT This study was designed to extend research on motor skill development in autism spectrum disorder using a dual-task skill. Nine autistic and 18 non-autistic youths walked without grasping or while reaching to grasp a small or large object. Step extremity ratio, percent time in double support, and normalized speed were quantified. We hypothesized that gait would differ between autistic and non-autistic youth and that differences would be moderated by the phase (approach and grasp) and the complexity of the task (walking and grasping versus walking alone). Although gait parameters were similar during the walking-only trials, the combined task resulted in slower speed and shorter steps in autistic youth, particularly during the grasp phase. These findings, while in a small sample, offer preliminary evidence that autistic youth who show typical gait during simple assessments of motor ability may have difficulties in more complex tasks that require the coordination of movements.

Analysis of the Time Step Influence in the Yearly Simulation of Integrated Seawater Multi-Effect Distillation and Parabolic trough Concentrating Solar Thermal Power Plants

The joint demand for power and freshwater is continuously increasing due to population growth, the rise of economic activity, and climate change. Integrated concentrating solar thermal power and desalination (CSP+D) plants may provide a key solution for the pressing freshwater deficit and energy problems in many regions of the world. Simulation tools with an accurate prediction of the yearly electric energy and freshwater production are needed. This paper analyzed the influence of the time step in the annual simulation of a CSP+D plant composed of a seawater multi-effect distillation unit and a parabolic trough concentrating solar thermal power plant, considering the location of Tabernas (Spain). A dynamic simulation tool of this system was developed, implementing the models in Engineering Equation Solver. The annual electricity and water productions obtained for the study case considered were 154 GWh and 3.45 hm3, respectively, using 5 min time steps, and 94 GWh and 2.1 hm3, respectively, with 1 h time steps. The results obtained show that a short time step interval (5 min) is recommended when using the detailed CSP model considered, which is prepared for simulation with short time steps. Step times of 1 h lead to excessive errors (about 30% in summer and 100% in winter), which underestimate the actual production.

Direct Regeneration of Spent Lithium Iron Phosphate via a Low-Temperature Molten Salt Process Coupled with a Reductive Environment

A huge number of spent lithium-ion batteries (LIBs) have caused serious problems such as resource waste and environmental pollution. Lithium iron phosphate (LFP) is one of the major cathode materials in the spent LIBs. It is urgently needed to develop a safe, environmentally friendly, and cost competitive approach to regenerate the LFP cathode collected from the spent LIBs. The nitrate molten salt process has been utilized to regenerate layered cathode materials, which are nevertheless non-compatible with the LFP regeneration process. The LFP crystal lattice will be destroyed during the molten salt process by the oxidative environment, where Fe(II) is oxidized to Fe(III). A new approach is proposed in this work to tackle this issue, where a low-temperature molten salt process is coupled with a reductive environment to suppress oxidation of Fe(II). In detail, lithium nitrate is used as a molten salt medium and lithium source simultaneously. Sucrose is used as a carbon source to provide a reductive environment. Through a short molten-salt relithiation step at 300 °C and further annealing process at 650 °C, LFP particles with a lithium-deficient and damaged structure can be successfully recovered. The rapid lithium replenishment process exposes more (101) crystal planes facilitating lithium-ion transportation. As a result, the regenerated LFP delivers a specific capacity of 145 mAh g–1 at 0.5C, which is more than a 13% increase relative to the spent LFP and has a better rate performance than pristine LFP at 5C. In addition, we also point out that the LFP is converted to Li3PO4 with the increase in lithium source and the extension of treatment time. This work provides a new promising way to regenerate spent LFP cathodes.

Biomechanical Correlates of Falls Risk in Gait Impaired Stroke Survivors.

Increased falls risk is prevalent among stroke survivors with gait impairments. Tripping is the leading cause of falls and it is highly associated with mid-swing Minimum Foot Clearance (MFC), when the foot’s vertical margin from the walking surface is minimal. The current study investigated MFC characteristics of post-stroke individuals (n = 40) and healthy senior controls (n = 21) during preferred speed treadmill walking, using an Optotrak 3D motion capture system to record foot-ground clearance. In addition to MFC, bi-lateral spatio-temporal gait parameters, including step length, step width and double support time, were obtained for the post-stroke group’s Unaffected and Affected limb and the control group’s Dominant and Non-dominant limbs. Statistical analysis of MFC included central tendency (mean, median), step-to-step variability (standard deviation and interquartile range) and distribution (skewness and kurtosis). In addition, the first percentile, that is the lowest 1% of MFC values (MFC 1%) were computed to identify very high-risk foot trajectory control. Spatio-temporal parameters were described using the mean and standard deviation with a 2 × 2 (Group × Limb) Multivariate Analysis of Variance applied to determine significant Group and Limb effects. Pearson’s correlations were used to reveal any interdependence between gait variables and MFC control. The main finding of the current research was that post-stroke group’s affected limb demonstrated lower MFC 1% with higher variability and lower kurtosis. Post-stroke gait was also characterised by shorter step length, larger step width and increased double support time. Gait retraining methods, such as using real-time biofeedback, would, therefore, be recommended for post-stroke individuals, allowing them to acquire optimum swing foot control and reduce their tripping risk by elevating the swing foot and improving step-to-step consistency in gait control.

Effects of vision on energy expenditure and kinematics during level walking

PurposeWe have previously observed substantially higher oxygen uptake in soldiers walking on terrain at night than when performing the same walk in bright daylight. The aims of the present study were to investigate the influence of vision on mechanical efficiency during slow, horizontal, constant-speed walking, and to determine whether any vision influence is modified by load carriage.MethodsEach subject (n = 15) walked (3.3 km/h) for 10 min on a treadmill in four different conditions: (1) full vision, no carried load, (2) no vision, no carried load, (3) full vision with a 25.5-kg rucksack, (4) no vision with a 25.5-kg rucksack.ResultsOxygen uptake was 0.94 ± 0.12 l/min in condition (1), 1.15 ± 0.20 l/min in (2), 1.15 ± 0.12 l/min in (3) and 1.35 ± 0.19 l/min in (4). Thus, lack of vision increased oxygen uptake by about 19%. Analyses of movement pattern, by use of optical markers attached to the limbs and torso, revealed considerably shorter step length (12 and 10%) in the no vision (2 and 4) than full vision conditions (1 and 3). No vision conditions (2 and 4) increased step width by 6 and 6%, and increased vertical foot clearance by 20 and 16% compared to full vision conditions (1 and 3).ConclusionThe results suggest that vision has a marked influence on mechanical efficiency even during entrained, repetitive movements performed on an obstacle-free horizontal surface under highly predictable conditions.

EFFECT OF LOAD ON GAIT

Introduction: Material Handling is one of the major activities performed by the workforce in the present scenario in industries. Our study aims to do the experiment with 22 different subjects and to collect the data using MiniSun IDEEA3 Gait Analysis instrument and to analyse the parameters Speed, EE and Stride length and find preventable measures to reduce fall risk. Material and Methods: Gait analysis experiment has been done with the subject with backpack and double pack with load of 5 kg and 10 kg. In the Industrial scenario, from construction site to cement industry, workers are carrying the load from one place to another. For instance, the typical scenario includes the transferring the load in backpack. All experiments were done in the institutegymnastic. Our study methodology deals with the conditions of experimentation, how sensors, recorder and sub recorder attached to subject body and how its working. This includes subject experiment conditions such as subject is walking on even surface and stairs with 5 kg backpack, 10 kg backpack and 5 kg double pack. When subject walks, data gets collected in recorder from sub recorder through wirelessly. Results: When subject walks with 10 kg backpack load gait parameters shows the worst condition i.e. prone to fall. However, if 10 kg backpack load distributed to 5 kg each side front and rear i.e. called double pack result shows a reliable change i.e. a safe limit to prevent the fall risk. So rather than preferring a backpack, double pack would be recommendable to prevent fall risk. The reason behind speed reduction is shorter steps with carrying load as compare to no load, which fails to maintain minimum unimpaired walking speed 55m/min. But greater than 75 m/min suggested to exceptional life expectancy. But not prove to be best in reduced fall risk while carrying. When load increases, speed get decreases, energy expenditure increases, stride length decreases. These all-gait parameters indicate a significant change that is the major cause of fall during manual material handling in industries. Conclusion: So those with high BMI if carry material in manual material handling industries, the Speed and EE will be major and considerable factor to fall. Thus Speed and energy expenditure needs to be investigated with Influence of walking speed, external load, energy expenditure and power on gait characteristics, to find the relationship between the risk of injury to kinematic changes due to external load on speed, energy expenditure and power.

Purification and characterization of L-asparaginase extracted from local Iraqi green beans (Phaseoulus vulgaris)

The most prevalent metabolite for the storage and transport of nitrogen used in protein production is L-asparagine; in earlier studies, L-asparaginase enzyme derived from microorganisms was utilized to treat cancer cells; therefore, this study aimed to purify and describe this enzyme derived from Iraqi green bean seeds rather than microbial sources. The enzymes were partially purified from green beans by short steps, including centrifugation of crude enzyme, dialysis by Diethylaminoethyl Sepharose Column, and equilibrated using 20 mM Tris-HCl buffer, pH 8.0, and then applied to a sephacryl S-200. Coulometric methods measured the enzymatic activity at 450 nm, and the unit of activity was calculated by comparing it to a standard curve. Purification of L-asparaginase yielded a 5 percent yield, a 2.7 fold increase in activity, and a 43 unit/ml activity. The pH of asparaginase was optimal at 8.0. After a one-day incubation period, this enzyme became more stable at pH levels ranging from 7.5 to 9.5. This enzyme had the same optimal temperature and thermal stability at 40°C, but it was more stable at temperatures ranging from 20 to 40°C, allowing it to retain its maximal activity.

Existing predictive methods applied to gait analysis of patients with diabetes: study protocol for a systematic review

IntroductionType 2 diabetes can lead to gait abnormalities, including a longer stance phase, shorter steps and improper foot pressure distribution. Quantitative data from objective methods for evaluating gait patterns are...

Instantaneous wheat dough relaxation by alternating current electric fields

Wheat dough exhibits poor processibility immediately after a mechanical strain, such as mixing or laminating. For proper dough processing, the relaxation of gluten network must occur during a process interrupting resting time of usually 10–25 min. The ability of electric fields to induce modifications in biological structures within seconds, makes an application of this technique reasonable for accelerating the structural relaxation during dough resting. Applying alternating current electric fields (AC-fields) to wheat dough, causes viscoelastic properties corresponding to those of rested dough: AC-fields (110–260 V, 1–5 s) increased extensibility and softness of dough corresponding to resting times up to 25 or rather 50 min. Based on this significant acceleration of structural relaxation, an almost continuously dough processing after a mechanical stress by a simple and short post-processing step without changing dough's gas release (ΔVtotal ≤ 3.0%) as well as holding capacity (Δgas retention ≤ 1.47%) and the textural properties of the product appears feasible.

Evaluation of Biomechanical Effects and Patient Benefits of a New Orthotic Ankle Joint in Stance Control Orthosis Fittings

ABSTRACT Introduction A newly introduced generation of orthotic ankle joints with adjustable dorsiflexion and plantarflexion resistances and increased range of motion (ROM) has been well established in orthotic fittings of neurological patients with ankle foot orthoses. The aim of the present study was to investigate whether users of stance control orthoses (SCOs) may also benefit from this orthotic ankle joint principle using a biomechanical test design. Methods Six patients unilaterally fitted with an SCO (E-MAG Active) with the orthotic ankle joint NexGearTango (NGT; Ottobock, Duderstadt, Germany), an ankle joint representing the new principle, were enrolled in the study. The modular principle of the ankle joint allowed testing both the new functionality and the characteristics of a conventional orthotic ankle joint (CAJ; limited uncontrolled ROM). Level walking at slow, medium, and fast speed and with given short steps, ascending and descending a ramp with 10° inclination and standing (level ground as well as 10° incline and decline standing), were assessed while using NGT or CAJ, respectively. Kinematic and kinetic data were captured with an optoelectronic camera system and two force plates. Results The reliability of switching from stance to swing of the orthotic knee joint was clearly enhanced with NGT for short-step level walking and ascending ramps. For ascending ramps, a significantly increased dorsiflexion of 5° during stance and an earlier transition from decelerating to accelerating forces were found with NGT. When standing on slopes, the symmetry of weight distribution between the orthotic and unaffected limb was significantly increased with NGT. Conclusions The increased and resistance-controlled dorsiflexion of the new orthotic ankle joint principle resulted in relevant benefits in gait situations with unlevel conditions and higher demands. Therefore, this orthotic ankle joint principle may represent an additional option to optimize patient fittings with SCOs. Clinical Relevance Statement The use of the new orthotic ankle principle tested in the present study results in relevant benefits, especially in gait situations in unlevel conditions. Therefore, this principle represents an additional option to optimize patient fittings with SCOs.

Synthesis of C3-Cyanomethylated Imidazo[1,2-a]pyridines via Ultrasound-Promoted Three-Component Reaction under Catalyst- and Oxidant-Free Conditions

AbstractAn efficient synthesis of C3-cyanomethylated imidazo[1,2-a]pyridines via ultrasound-promoted three-component reaction under catalyst-free, oxidant-free, and mild conditions has been developed. A series of C3-cyanomethylated imidazo[1,2-a]pyridines were rapidly prepared with satisfactory yields and good functional group compatibility. This strategy cloud also be applied to the synthesis of zolpidem and alpidem in short steps.

Assessment of the degree of lameness in cows

Relevance. The structure of the hoof of cows is a complex biological mechanism consisting of the hoof joint, hoof bone, finger pad, sole, hoof wall, etc. According to V.A. Lukyanovsky (1982), hooves are an additional heart of the animal, since when the hoof hits the ground, the blood actively rises, which allows to create auxiliary pressure in the blood vessels, facilitating the work of the heart muscle. When this system is violated, pathologies of the cardiovascular system often develop. The appearance of foci of the pathological process in different parts of the hoof will not only disrupt the work of the heart, but also cause discomfort, pain, and most importantly — lameness, which will be the driving force in a significant decrease in the productivity of cattle.Methods. Scientists identify three main signs of developing lameness in an animal. The first is the position of the back when walking, normally the back should be smooth and straight, while with the onset of lameness, the animal will carefully rearrange the limb, thereby straining the dorsal muscles, after which a bend in the back will be observed. The second sign is a short step, since with pain syndrome, the animal tries to minimize the load on the diseased limb. The third sign will be the obvious protection of the diseased limb, as a result of which the animal will completely cease to rely on the limb, both when walking and when standing.Results. A systematic approach will allow us to present a mathematical model of a healthy animal and of lame one. Thus, the following pattern can be identified: In order to receive nutrients together with the feed, the cow must reach the feeder, therefore, depending on the degree of lameness, there is a decrease in the consumption of dry matter, up to 15%. Based on this, it can be calculated that with a lack of nutrients and energy, there will be a decrease in milk yield of up to 36%. Which, according to P.I. Nikanorov and I.M. Kasyanov, will lead to a loss of up to 300 kg of milk for the entire lactation period. It was found that in the presence of overgrown and deformed hooves, the daily milk yield of cows is reduced by 5–12%, and with the appearance of cracks in the fragments of the horny capsule — by 19–20%. Also, the birth of a calf is required to obtain milk, and the presence of lameness will negatively affect the production of reproductive hormones, lead to the appearance of “quiet” hunting, which in turn will indirectly lead to a loss of milk productivity.

Optimised Method for Short-Chain Fatty Acid Profiling of Bovine Milk and Serum.

Short-chain fatty acids (SCFA, C2-C5) in milk and serum are derived from rumen bacterial fermentation and, thus, have the potential to be used as biomarkers for the health status of dairy cows. Currently, there is no comprehensive and validated method that can be used to analyse all SCFAs in both bovine serum and milk. This paper reports an optimised protocol, combining 3-nitrophenylhydrazine (3-NPH) derivatisation and liquid chromatography-mass spectrometry (LC-MS) analysis for quantification of SCFA and β-hydroxybutyric acid (BHBA) in both bovine milk and bovine serum. This method is sensitive (limit of detection (LOD) ≤ 0.1 µmol/L of bovine milk and serum), accurate (recovery 84–115% for most analytes) and reproducible (relative standard deviation (RSD) for repeated analyses below 7% for most measurements) with a short sample preparation step. The application of this method to samples collected from a small cohort of animals allowed us to reveal a large variation in SCFA concentration between serum and milk and across different animals as well as the strong correlation of some SCFAs between milk and serum samples.

Azido-type-selective triazole formation by iridium-catalyzed cycloaddition with thioalkynes.

The iridium-catalyzed azide-thioalkyne cycloaddition was found to proceed much faster with benzyl azide than with phenyl azide. The high azido-type selectivity was also observed in other combinations of azides with different steric environments. This finding enabled the efficient assembly of three azidophilic molecules to triazido platforms by three sequential triazole-forming reactions.

Annulation-retro-Claisen cascade of bifunctional peroxides for the synthesis of lactone natural products.

A new and highly efficient annulation-retro-Claisen cascade, which involves the [4 + 1] or [5 + 1] annulation of α-benzoylacetates with bielectrophilic peroxides and a subsequent debenzoylation process under mild basic conditions, has been developed for the rapid construction of valuable tetrahydrofuran- and dihydropyran-2-carboxylates in good yields. By employing the new reaction, the unified total synthesis of γ- and δ-lactone natural products such as (±)-tanikolide, (±)-goniothalamins, (±)-7-epi-goniodiol, and (±)-plakolide A has been accomplished in 4-7 steps.

Concurrent Validity of Zeno Instrumented Walkway and Video-Based Gait Features in Adults With Parkinson's Disease.

Background: Parkinson’s disease (PD) presents with motor symptoms such as bradykinesia, rigidity, and tremor that can affect gait. To monitor changes associated with disease progression or medication use, quantitative gait assessment is often performed during clinical visits. Conversely, vision-based solutions have been proposed for monitoring gait quality in non-clinical settings. Methods: We use three 2D human pose-estimation libraries (AlphaPose, Detectron, OpenPose) and one 3D library (ROMP) to calculate gait features from color video, and correlate them with those extracted by a Zeno instrumented walkway in older adults with PD. We calculate video-based gait features using a manual and automated heel-strike detection algorithm, and compare the correlations when the participants walk towards and away from the camera separately. Results: Based on analysis of 67 bidirectional walking bouts from 25 adults with PD, moderate to strong positive correlations were identified between the number of steps, cadence, as well as the mean and coefficient of variation of step width calculated from Zeno and video using 2D pose-estimation libraries. We noted that our automated heel-strike annotation method struggled to identify short steps. Conclusion: Gait features calculated from 2D joint trajectories are more strongly correlated with the Zeno than analogous gait features calculated from ROMP. Based on our analysis, videos processed with 2D pose-estimation libraries can be used for longitudinal gait monitoring in individuals with PD. Future work will seek to improve the prediction of gait features using a comprehensive machine learning model to predict gait features directly from color video without relying on intermediate extraction of joint trajectories.

Evaluation of the electron transport algorithm in magnetic field in EGS5 Monte Carlo code.

To evaluate the accuracy of electron transport in the magnetic field of Electron Gamma Shower version 5 (EGS5) by using the special Fano cavity test. To simulate electron transport in the magnetic field, the trajectory of the electron was reconstructed with a short step length to restrict fractional energy loss, and the maximum user step length (mxustep) was set at 0.01cm or 0.001cm. For the special Fano cavity test, three-layer slab Fano test geometry was used, and uniform and isotropic per unit mass mono-energetic electrons with 0.01, 0.1, 1.0, and 10MeV were permitted from the central axis of geometry in 0.35T and 1.5T. Furthermore, the magnetic field strength was scaled based on the mass density of the material. The relative difference between the calculated dose to gap and the theoretical value was evaluated. Furthermore, the special Fano cavity test was also performed using EGSnrc with the electron-enhanced electric and magnetic field macros under the same conditions, and the results were compared with those of EGS5. Deviations in 0.35T were within 0.3% regardless of the parameter settings. In 1.5T, stable results within 0.3% were obtained using 0.001cm as the mxustep, except for one at 10MeV. Further, the accuracy of EGSnrc was within 0.2%, except for 10MeV for a 0.2-cm gap in 1.5T. EGS5 with the appropriate parameter settings enable electron transport in magnetic fields similar with the accuracy of EGSnrc.

Słuchanie kerygmatu: Martin Heidegger i Nowa Hermeneutyka. Dwa wstępne rozpoznania

Hearing the Kerygma: Martin Heidegger and the New Hermeneutics. Two Preliminary Findings This paper aims to set a foreground that will further reveal the theological and hermeneutical standpoint of Ernst Fuchs and Gerhard Ebeling. The author argues that some of their basic ideas and concepts, such as human being (Dasein), questionableness (Fraglichkeit), thrownness (Geworfenheit) or language-event (Sprachereignis), owed their origin to Martin Heidegger, but none of them could be considered a mere faded copy of their Heideggerian counterparts. New Hermeneutics were engaged in a theological verification and transposition (rather than accommodation) of Heidegger pursuing his aim of overcoming metaphysics. As a theory of language of faith and verified fundamental ontology, Lutheran hermeneutics deliberately avoided the question of “What does the biblical text actually mean?” or even “What does the text mean to me?” Instead, it took great pains to persist in asking “Why should the biblical text mean anything?” To grasp the supreme importance of this question, the author makes two preliminary observations: on the boredom with language and on radical questionableness or passivity of Dasein. In the section of the article concerning the boredom with language, the author discusses the reasons that prevent man from encountering the Word of God which does not stand for something thus transcending itself, but rather exercises its questioning and transformative power. For it is the Word of God which reveals itself as a biblical skandalon or the obstacle and threshold for Dasein. Instead of reassuring man in his self-understanding, such Word constantly calls human independence and agency into question. For that reason, replacing one language with another is no longer the major challenge. Instead, it is a kerygmatic interpretation of language aimed at restoring man’s intimacy with language as his genuine place of being. It is only a short step from here to disclosing the radical questionableness, that is a state of man becoming a question to himself. As an experience that calls the autonomy of human self into question, radical questionableness involves a divine question to which manmade reality never provides an answer that could be considered definitive, although all the provided answers remain binding. Consequently, such experience reveals a historical and passive path of human being before the divine Word, a path which violates metaphysical constitution of subjectivity and therefore transforms the purpose of proclamation and the meaning of kerygma. As a call and challenge to man, or an answer given by the wholly other God to the question concerning man, kerygma makes Dasein finally capable of entering a relationship with the Word which does not violate divine sovereignty. For it is kerygma that brings the ecstatic nature of man to the fore. Kerygma establishes a speaking-hearing interplay of God and man and makes hearing the basic form of man’s being before God. Such relationship consists therefore in nothing but a responsible acceptance of a gift, that is hearing the divine Word.

Normal pressure hydrocephalus

Normal pressure hydrocephalus – NPH is one of the potentially reversible causes of dementia. In this work, we provide the clinical tools for the management of NPH to the Primary Health Care – PHC physicians. The PubMed and Cochrane databases were reviewed, and 40 articles were chosen, which include randomized clinical trials, metanalysis and systematic reviews. The symptoms of the classic triad are nonspecific and found in the elderly with other diseases. Gait apraxia is the earliest symptom, followed by cognitive impairment and urinary incontinence. The concomitance of the three symptoms occurs in about 60% of the cases in the advanced stages. Apraxia of gait is presented with short steps, without sensorial, vestibulocerebellar or muscle strength changes, which allows it to be distinguished from other pathological marches. Cognitive impairment is subcortical – psychomotor slowliness, inattention, loss of working memory and executive function and preservation of episodic memory – unlike cortical dementias, such as Alzheimer's disease. Urinary incontinence must be distinguished from overflow by prostatism and stress incontinence in women. The PHC physician, when faced with the triad, should request a CT scan or brain MRI and, in the presence of one or two symptoms, rule out other diagnoses. Patients with NPH seek help from the physician in the PHC who must know how to identify and differentiate their symptoms. In the case of suspicion, the study of neuroimaging is mandatory and referral to neurosurgery or neurology is recommended.