Initial Studies Research Articles

Integrated environmental education physics project to enhance student creativity

This study aims to describe the results of research on physics education integrated with environmental issues, especially related to climate change, through literature review and its implementation in schools. The aspects observed include the feasibility, effectiveness, and student responses to the implementation of integrated physics learning with environmental education related to climate change to enhance creativity. The research method used was quantitative research with a true experimental design involving pretest and posttest control groups. The subjects of the study were science students in public secondary schools in Jombang, divided into experimental and control groups. The research data were processed using observation sheets for the feasibility of learning, prerequisite tests including tests for data normality and homogeneity, paired t-tests, two-tailed t-tests, one-tailed t-tests, n-gain tests, effect size, and student response questionnaires. Based on the research findings, it can be concluded that (1) there is a significant difference in students' creativity before and after the implementation of integrated physics learning with environmental education related to climate change, with the experimental group experiencing a higher increase compared to the control group, indicating the effectiveness of integrated physics learning with environmental education. (2) Student responses after the implementation of integrated physics learning with environmental education related to climate change were categorized as excellent. Therefore, as an initial study, it can be stated that climate change education can be implemented in the form of project performance and has an impact on student creativity.

Supporting the Management of Rolling Stock Maintenance with an Ontology-Based Virtual Depot

The railway industry forecasts growth in passenger and freight traffic over the next 30 years. This places additional demands on rolling stock depot facilities, many of which were designed and built before the modern age of information technology. This paper explores the potential of improving the efficiency and effectiveness of rolling stock maintenance management to meet the challenges of the near future, by utilising advanced computing techniques. The objective of the work is to create optimised maintenance plans for a fleet of trains, considering optimal use of resources. As a “glue” for joining up functions and operations, a generic Depot and Vehicle ontology (called the Virtual Depot) is introduced. The ontology captures the structures, relationships, and attributes of objects in the Depot (rolling stock, sensors, depot assets, tools, resources, and staff). The ontology is populated with example company and fleet-specific knowledge using an automated knowledge acquisition method. This paper describes the systematic method for the creation of a Virtual Depot. Two particular aspects are discussed in detail—knowledge acquisition of fleet-specific information obtained from a manufacturer’s Vehicle Maintenance Instruction manuals and the construction of a short-term scheduling process within the Virtual Depot. Our evaluation considers the integrative aspects of the method, demonstrating how the ontological structure and its acquired specific information informs and benefits the scheduling process, in particular with respect to schedule optimisation. Results from an initial case study show there is significant potential to optimise short-term maintenance schedules, and the ability to automatically consider resource availability in short-term scheduling is demonstrated.

Towards an industrial perspective for urea-to-hydrogen valorization by electro-oxidation on nickel(III): Real effluents and pilot-scale proof of concept

This paper presents an investigation into urea-to-hydrogen valorization through electro-oxidation on nickel(III). The study has dual objectives: (i) to gain a better understanding of the effects of organic compounds (other than urea) in human urine on UEO and (ii) to upscale the process to pilot-scale. Initial voltammetric studies at lab-scale using real human urine showed that urea adsorption on nickel(III) sites, followed by its electro-oxidation, competes with molecules such as creatinine, histidine, and creatine. Notably, creatinine reduced the nickel(II) oxidation signal by up to 20 %, indicating its reaction precedence over urea. Additionally, the oxidation rate of urea by nickel(III) in urine exhibited a much lower partial order (0.1), as opposed to 0.3 in KOH solution, confirming the impact of competitive adsorption. Subsequently, UEO experiments were upscaled using a specially designed 1 L undivided tubular EC reactor operating in multi-pass mode. Potentiostatic electrolysis of a urea synthetic solution was conducted over 70 h, achieving nitrogen and carbon species mass balances of over 97 %—a milestone previously unreported at this scale. The study further examined the influence of operating parameters such as anode surface area, flow rate and applied potential on the EC process. This investigation underscored the impact of factor like reactor geometry, controlled potential and temperature on process efficiency. Parameters for optimal N2 production, highest urea conversion rate, etc., were also defined. Finally, the electrolysis of human urine at pilot-scale unveiled new challenges distinct from those encountered with urea synthetic solutions.

Digital culture for lean & agile organization

Digital culture in an organization is the relationship between employees and the use of technology. Embracing digital has now become a mandate for any organization to be successful and it is imperative especially for lean organizations to develop a digital & data mindset to remain competitive in the marketplace. Digital tools help organizations save time and money while improving communication, driving productivity, recruiting top talent, giving employees the ability to work from anywhere, providing information that can influence business decisions, and more. The paper identifies four major components that can help make digital transformation a success in lean & agile Organizations. A top down approach, strategy over technology mindset, a culture that encourages innovation, risk taking and optimizing operational processes are the most important elements that can drive digital transformation. Additionally, upskilling employees & encouraging them to take ownership of their growth lies at the core of making a digital culture sustainable. A case study of initiatives by several companies toward digital transformation has been discussed to design the best possible strategy that can drive digital culture in lean & agile organizations. Executive support, removing the concept of silos, breaking the stereotype around failure & risk aversion are a few of the factors that have been identified.

Probiotic and prebiotic interventions in eating disorders: Anarrative review.

The review aimed to summarise and discuss findings focused on therapeutic probiotic and prebiotic interventions in eating disorders (ED). Using PubMed/MEDLINE, Cochrane Library, and Web of Science all published studies were retrieved until February 2023, following PRISMA guidelines. From the 111 initial studies, 5 met the inclusion criteria for this review. All studies included in this narrative review were focused on anorexia nervosa (AN). Three longitudinal, randomised, controlled trials aimed to evaluate interventions with probiotics (Lactobacillus reuteri, yoghurt with Lactobacillus, and Streptococcus) in children and adolescents. These studies primarily emphasised medical outcomes and anthropometric measures following the administration of probiotics. However, the findings yielded mixed results in terms of short-term weight gain or alterations in specific immunological parameters. With a lower level of evidence, supplementation with synbiotics (probiotic+prebiotic) has been associated with improvements in microbiota diversity and attenuation of inflammatory responses. Research on probiotics and prebiotics in ED is limited, primarily focussing on anorexia nervosa (AN). Their use in AN regarding medical and anthropometric outcomes needs further confirmation and future research should be warranted to assess their impact on psychological and ED symptomatology, where there is a notable gap in the existing literature.

Optimal assessment of the glomerular filtration rate in older chinese patients using the equations of the Berlin Initiative Study

AimTo evaluate the performances of the various estimated glomerular filtration rate (eGFR) equations of the Chronic Kidney Disease Epidemiology Collaboration, the Berlin Initiative Study (BIS), and the Full Age Spectrum (FAS) in older Chinese.MethodsThis study enrolled Chinese adults aged ≥ 65 years who underwent GFR measurements (via 99Tcm-DTPA renal dynamic imaging) in our hospital from 2011 to 2022. Using the measured glomerular filtration rate (mGFR) as the reference, we derived the bias, precision, accuracy, and consistency of each equation.ResultsWe enrolled 519 participants, comprising 155 with mGFR ≥ 60 mL/min/1.73 m2 and 364 with mGFR < 60 mL/min/1.73 m2. In the total patients, the BIS equation based on creatinine and cystatin C (BIScr-cys) exhibited the lowest bias [median (95% confidence interval): 1.61 (0.77–2.18)], highest precision [interquartile range 11.82 (10.32–13.70)], highest accuracy (P30: 81.12%), and best consistency (95% limit of agreement: 101.5 mL/min/1.73 m2). In the mGFR ≥ 60 mL/min/1.73 m2 subgroup, the BIScr-cys and FAS equation based on creatinine and cystatin C (FAScr-cys) performed better than the other equations; in the mGFR < 60 mL/min/1.73 m2 subgroup, all equations exhibited relatively large deviations from the mGFR. Of all eight equations, the BIScr-cys performed the best.ConclusionsAlthough no equation was fully accurate in the mGFR < 60 mL/min/1.73 m2 subgroup, the BIScr-cys (of the eight equations) assessed the eGFRs of the entire population best. A new equation is urgently required for older Chinese and even East Asians, especially those with moderate-to-severe renal insufficiency.

Key-in-session identity negotiations in a first line treatment for adult anorexia nervosa

BackgroundExploration of client identity negotiations during treatment for Anorexia Nervosa (AN) is a relatively new area of research. Research suggests that difficulties with identity negotiations may present as a barrier to treatment. This study sought to explore individuals’ identity negotiations during therapy sessions using Compulsive Exercise Activity Therapy (LEAP) combined with Cognitive Behaviour Therapy for Anorexia Nervosa (CBT-AN). Analysis focused on moments in therapy where individuals’ identities were dominated or defined by AN and where alternative identities could be generated.Method40 in-session transcripts from sessions at early, mid and end points of the CBT-AN (with LEAP) treatment were qualitatively analysed for nine of the 78 participants in the original randomised control trial. Through a constructivist framework, thematic analysis was used to identify surface and latent meanings and discursive material participants used to negotiate their identities in the context of therapy sessions.ResultsAnalysis of in-therapy transcripts generated two themes pertaining to identity negotiations: (1) troubled identities and (2) rebuilding identities and lives outside of AN. Early therapy sessions explored fragmented and AN dominated identities, including how AN was troubling to participants’ sense of self, contributed to conflicted identities, positioned them outside of normality, and was associated with isolated and othering identities. Within therapy sessions, participants engaged in a recursive process of shifting relationships with AN and themselves and building identities and lives outside of the AN identity. This included generating hopes for recovery and the future more frequently in mid- to late- therapy sessions.ConclusionIdentity negotiations evident in the therapeutic conversations aligned with the key components of the CBT-AN intervention, including addressing (1) the characterisation of oneself as ‘an anorexic’ and (2) the diversification of roles and activities to broaden and enhance self-concepts. Future developments of therapeutic interventions for AN would benefit from greater consideration of ways to assist individuals to more comprehensively address problematic identities, including uncovering identities hidden by the AN identity and generating preferred identities.Trial Registration: Ethics approval was obtained at the time of the initial study and for this embedded research by the HREC at the Western Sydney University (HR777332).

A novel PSMA-targeting tracer with highly negatively charged linker demonstrates decreased salivary gland uptake in mice compared to [68Ga]Ga-PSMA-11

BackgroundThe current generation of radiolabeled PSMA-targeting therapeutic agents is limited by prominent salivary gland binding, which results in dose-limiting xerostomia from radiation exposure. JB-1498 is a urea-based small molecule with a highly negatively charged linker targeting prostate specific membrane antigen (PSMA). Prior work on a similar tracer with the same negatively charged linker demonstrated low normal organ/soft tissue background uptake compared to [68Ga]Ga-PSMA-11. The purpose of this study was to investigate if [68Ga]Ga-JB-1498 had reduced salivary gland uptake in mice compared to [68Ga]Ga-PSMA-11.ResultsJB-1498 demonstrated high affinity for PSMA binding and tumor uptake in a murine tumor model. In an initial biodistribution study with low molar activity, [68Ga]Ga-JB-1498 demonstrated salivary gland uptake of 0.13 ± 0.01%ID/g. In a second biodistribution study in non-tumor-bearing mice with high molar activity, [68Ga]Ga-JB1498 demonstrated salivary gland uptake of 0.39 ± 0.24% ID/g and kidney activity of 10.12 ± 1.73% ID/g at one hour post IV injection. This salivary gland uptake is significantly less than the published uptake of [68Ga]Ga-PSMA-11. Micro-PET visually confirmed the findings of the biodistribution studies. Dynamic micro-PET imaging demonstrated gradually decreasing [68Ga]Ga-JB1498 activity in salivary glands and kidneys, compared to gradually increasing [68Ga]Ga-PSMA-11 activity in these two organs during the first hour.ConclusionBiodistribution and micro-PET imaging of [68Ga]Ga-JB-1498 demonstrate significantly decreased salivary gland uptake and different pharmacokinetic behavior in kidneys and salivary glands in mice compared to [68Ga]Ga-PSMA-11. Our findings suggest that constructing a PSMA-targeting molecule with a highly negatively charged linker is a promising strategy to reduce salivary gland uptake of GCP-II/PSMA ligands in theranostic applications.

Subtle Syndesmotic Instability.

Latent or subtle syndesmotic instability is defined as an injury to the syndesmosis which is not apparent on static radiographs of the ankle. Syndesmotic injuries have also been referred to as high ankle sprains. Injury to the syndesmosis typically occurs with collision sports and often involves an external rotation force to the ankle. Diagnosis can be delayed because of negative initial imaging studies. Physical examination tests including the external rotation test, proximal squeeze test, and fibular shuck test can assist in the diagnosis. Advanced imaging modalities such as MRI and weight-bearing CT have been studied and can provide prognostic indications for management, although arthroscopic stress evaluation remains the benchmark for diagnosis. Both surgical and nonsurgical management techniques have been described, which can assist patients in returning to their preinjury level of function.

Olfactory and cognitive decrements in 1991 Gulf War veterans with gulf war illness/chronic multisymptom illness

BackgroundGulf War illness (GWI)/Chronic Multisymptom Illness (CMI) is a disorder related to military service in the 1991 Gulf War (GW). Prominent symptoms of GWI/CMI include fatigue, pain, and cognitive dysfunction. Although anosmia is not a typical GWI/CMI symptom, anecdotally some GW veterans have reported losing their sense smell shortly after the war. Because olfactory deficit is a prodromal symptom of neurodegenerative diseases like Parkinson’s and Alzheimer’s disease, and because we previously reported suggestive evidence that deployed GW veterans may be at increased risk for Mild Cognitive Impairment (MCI) and dementia, the current study examined the relationship between olfactory and cognitive function in deployed GW veterans.MethodsEighty deployed GW veterans (mean age: 59.9 ±7.0; 4 female) were tested remotely with the University of Pennsylvania Smell Identification Test (UPSIT) and the Montreal Cognitive Assessment (MoCA). Veterans also completed self-report questionnaires about their health and deployment-related exposures and experiences. UPSIT and MoCA data from healthy control (HC) participants from the Parkinson’s Progression Markers Initiative (PPMI) study were downloaded for comparison.ResultsGW veterans had a mean UPSIT score of 27.8 ± 6.3 (range 9–37) and a mean MoCA score of 25.3 ± 2.8 (range 19–30). According to age- and sex-specific normative data, 31% of GW veterans (vs. 8% PPMI HCs) had UPSIT scores below the 10th percentile. Nearly half (45%) of GW veterans (vs. 8% PPMI HCs) had MoCA scores below the cut-off for identifying MCI. Among GW veterans, but not PPMI HCs, there was a positive correlation between UPSIT and MoCA scores (Spearman’s ρ = 0.39, p < 0.001). There were no significant differences in UPSIT or MoCA scores between GW veterans with and without history of COVID or between those with and without Kansas GWI exclusionary conditions.ConclusionsWe found evidence of olfactory and cognitive deficits and a significant correlation between UPSIT and MoCA scores in a cohort of 80 deployed GW veterans, 99% of whom had CMI. Because impaired olfactory function has been associated with increased risk for MCI and dementia, it may be prudent to screen aging, deployed GW veterans with smell identification tests so that hypo- and anosmic veterans can be followed longitudinally and offered targeted neuroprotective therapies as they become available.

Lysozyme: A Natural Product with Multiple and Useful Antiviral Properties.

Lysozyme, especially the one obtained from hen's egg white, continues to show new pharmacological properties. The fact that only a few of these properties can be translated into therapeutic applications is due to the lack of suitable clinical studies. However, this lack cannot hide the evidence that is emerging from scientific research. This review for the first time examines, from a pharmacological point of view, all the relevant studies on the antiviral properties of lysozyme, analyzing its possible mechanism of action and its ability to block viral infections and, in some cases, inhibit viral replication. Lysozyme can interact with nucleic acids and alter their function, but this effect is uncoupled from the catalytic activity that determines its antibacterial activity; it is present in intact lysozyme but is equally potent in a heat-degraded lysozyme or in a nonapeptide isolated by proteolytic digestion. An analysis of the literature shows that lysozyme can be used both as a disinfectant for raw and processed foods and as a drug to combat viral infections in animals and humans. To summarize, it can be said that lysozyme has important antiviral properties, as already suspected in the initial studies conducted over 50 years ago, and it should be explored in suitable clinical studies on humans.

Berberine alleviates chlorpyrifos-induced nephrotoxicity in rats via modulation of Nrf2/HO-1 axis

Chlorpyrifos (CPS), an organophosphorus insecticide, is widely used for agricultural and non-agricultural purposes with hazardous health effects. Berberine (BBR) is a traditional Chinese medicine and a phytochemical with anti-inflammatory and anti-oxidative properties. The present study evaluated the effects of BBR against kidney damage induced by CPS and the underlying mechanisms. An initial study indicated that BBR 50 mg/kg was optimal under our experimental conditions. Then, 24 rats (6/group) were randomized into: control, BBR (50 mg/kg/day), CPS (10 mg/kg/day), and CPS + BBR. BBR was administration 1 h prior to CPS. Each treatment was delivered daily for a period of 28 consecutive days using a gastric gavage tube. Compared to CPS-alone treated rats, BBR effectively improved renal function by preventing the rise in serum urea, creatinine, and uric levels. The reno-protective effects of BBR were confirmed through a histological examination of kidney tissues. BBR restored oxidant-antioxidant balance in renal tissues mediated by Keap1/Nrf2/HO-1 axis modulation. In addition, BBR decreased nitric oxide (NO) and myeloperoxidase (MPO) activity. This was paralleled with the potent down-regulation of NF-κB. Furthermore, BBR exhibited anti-apoptotic activities supported by the upregulation of Bcl-2 and down-regulation of Bax and caspase-3 expression. In conclusion, our data suggest that BBR attenuates CPS-induced nephrotoxicity in rats by restoring oxidant-antioxidant balance and inhibiting inflammatory response and apoptosis in renal tissue. This is mediated, at least partly, by modulation of the Nrf2/HO-1 axis.

Pathogenic/likely pathogenic mutations identified in Vietnamese children diagnosed with autism spectrum disorder using high-resolution SNP genotyping platform

Among the most prevalent neurodevelopmental disorders, Autism Spectrum Disorder (ASD) is highly diverse showing a broad phenotypic spectrum. ASD also couples with a broad range of mutations, both de novo and inherited. In this study, we used a proprietary SNP genotyping chip to analyze the genomic DNA of 250 Vietnamese children diagnosed with ASD. Our Single Nucleotide Polymorphism (SNP) genotyping chip directly targets more than 800 thousand SNPs in the genome. Our primary focus was to identify pathogenic/likely pathogenic mutations that are potentially linked to more severe symptoms of autism. We identified and validated 23 pathogenic/likely pathogenic mutations in this initial study. The data shows that these mutations were detected in several cases spanning multiple biological pathways. Among the confirmed SNPs, mutations were identified in genes previously known to be strongly associated with ASD such as SLCO1B1, ACADSB, TCF4, HCP5, MOCOS, SRD5A2, MCCC2, DCC, and PRKN while several other mutations are known to associate with autistic traits or other neurodevelopmental disorders. Some mutations were found in multiple patients and some patients carried multiple pathogenic/likely pathogenic mutations. These findings contribute to the identification of potential targets for therapeutic solutions in what is considered a genetically heterogeneous neurodevelopmental disorder.

An Initial Case Study of the Computational Modeling of Cord–Rubber Segments

An Initial Case Study of the Computational Modeling of Cord–Rubber Segments

Aktualisasi Pemberdayaan SDM Pelaku UMKM Kembulsari Melalui Pemberian Motivasi Dan Pendampingan Foto Produk

This activity aims to increase motivation and product photography skills among Kembulsari MSMEs. The Covid-19 pandemic has had a tremendous impact on MSMEs. The physical distance that was implemented at that time caused the sales turnover level of MSMEs to decline to the point that many entrepreneurs stopped production. The pandemic has caused weaknesses in Kembulsari MSMEs and their business continuity. To rebuild the enthusiasm of MSME players in running their businesses, an injection of motivation is needed. Motivation becomes a support system for the basis of self-development intentions. On the other hand, physical distancing means that digital transformation in the marketing sector must be carried out to increase sales volume. These two core problems are the focus of providing solutions for community service activities. Activities carried out offline include initial studies to map problems, coordination with the team and MSME actors, actualization of activities, then regular monitoring. The methods used are lectures, tutorials and discussions. The results of these activities are increased responsibility, work performance and recognition of work performance, MSME players have attractive product photos and increased sales volume. This empowerment succeeded in providing motivation and improving MSME product photography skills

Synthesis of SiO2@Ag Nanocomposite for Investigating Metal-Enhanced Fluorescence and Surface-Enhanced Raman Spectroscopy.

SiO2@Ag nanocomposite (NC) has been synthesized by the chemical reduction and Stӧber method for Metal-enhanced fluorescence (MEF) of Rhodmine 6G (R6G) and Surface-enhanced Raman spectroscopy (SERS) of Malachite green (MG). As-synthesized SiO2@Ag NC indicated SiO2 nanosphere (NS) and Ag nanoparticle (NP) morphologies. The SiO2@Ag NC was high quality with a well-defined crystallite phase with average sizes of 24nm and 132nm for Ag NP and SiO2 NC, respectively. By using SiO2@Ag NC, the photoluminescence (PL) intensity of the R6G (at 59.17ppm) was increased approximately 133 times. The SERS of the MG (at 1.0ppm) with SiO2@Ag NC as substrate clearly observed vibrational modes in MG dye at 798, 916, 1172, 1394, and 1616cm-1. As a result, the SERS enhancement factor (EFSERS) at 1172cm-1 obtained 6.3 × 106. This initial study points to the potential of SiO2@Ag NC as a promising material for MEF and SERS substrates to detect dyes at low concentrations.

The impact of biological sex in peripheral nerve blockade: A prospective pharmacodynamic, pharmacokinetic and morphometric study in volunteers.

The impact of biological sex in peripheral regional anaesthesia is largely unknown. We therefore designed a prospective study in volunteers to investigate the impact of biological sex on pharmacodynamic, pharmacokinetic and morphometric characteristics for peripheral nerve blockade. The initial study plan was powered to include 90 volunteers to find a difference of 35 min in duration of sensory block (primary outcome variable) with 80% power and alpha error at 5%. After discussions in ethical review, a pilot study of 2 x 12 volunteers from each sex were studied. Female and male volunteers received ultrasound guided nerve blockade with 3.0 mL ropivacaine 7.5 mg mL-1. Sensory duration of blockade, as the primary outcome, was evaluated by pinprick testing. Secondary outcomes were sensory onset time of blockade, pharmacokinetic characteristics and the visibility of ulnar nerves using ultrasound. Analyses included Mann-Whitney U-statistics with P<0.05 (two-sided) as significant. After 24 participants, the median (IQR) duration of sensory blockade was 450 (420; 503) min in women and 480 (450; 510) min in men (P = 0.49). Sensory onset time of blockade, and ultrasound visibility of nerves were also similar between the study groups. The total drug exposure across time (AUC0-infinity) was significantly higher in women (P = 0.017). After a the planned power re-analysis after these 24 study paticipants, which suggested that > 400 subjects would be required with 80% power and alpha error of 5% to find significance for the primary outcome parameter for marginal differences, we terminated the study at this point. We did not detect significant differences between female and male study participants in terms of pharmacodynamic and morphometric characteristics after ultrasound guided ulnar nerve blocks. Women did show significantly greater pharmacokinetic ropivacaine exposures. The results of this study indicate that peripheral regional block pharmacodynamic characteristics are independent of the biological sex, whereas pharmacokinetic parameters are sex-dependent.

One more piece of the family firm debt puzzle: the influence of socioemotional wealth dimensions

AbstractThe literature on debt financing in family firms is still inconclusive. Initial studies have usually focused on the influence of family involvement on firm’s debt levels by using the explanations of traditional economic theories. More recent studies have begun to focus on the role of family goals in family firm debt levels, particularly drawing on socioemotional wealth (SEW), which has helped in the development of financial theories of family business. Nevertheless, existing arguments have usually not considered SEW as a multidimensional construct that covers diverse family goals. In addition, literature has usually drawn on arguments considering SEW as a stock, but have not considered the importance given to SEW (SEWi), which specifically acknowledges SEW as a goal. Our paper responds to recent calls to extend theoretical arguments on the effect of diverse dimensions of SEWi on family firm behavior and to focus on the role of SEWi on the family firms’ debt. Specifically, we test how the CEOs’ assessment of the importance that their family attaches to the continuity, prominence, and enrichment dimensions of SEWi influences the level of debt. To do so, we use a sample of 126 Spanish unlisted family businesses. Our results show that the continuity dimension of SEWi leads family businesses to increase their debt level being a key determinant of this financing decision.

Experimental Investigation to Optimize the Manufacturing Parameters of Ankle–Foot Orthoses Using Composite and Titanium Nanoparticles

The optimum structural characteristics of lamination materials used in the fabrication of prosthetic and orthotic parts were investigated in this work. Optimization was chosen based on high yields, ultimate stresses, and bending stress properties. The ideal materials were determined through the use of an RSM (response surface methodology) which considers three factors: Perlon reinforcement, a layer of glass fiber, and the percentage of titanium nanoparticles combined with the matrix laminating resin. The RSM approach suggests thirteen samples by manipulating two variables: the Ti nano percentage and the number of Perlon layers. Laminating materials, defined by RSM methods and treated with a vacuum system, were submitted to a series of tests. The ideal lamination material was compared with the laminations from the initial study through the use of tensile, flexural, and fatigue testing according to ASTM standards. Tests carried out using version 10.0.2 of Design Expert software showed that, compared with the 12 other laminations, the one with 10 Perlon layers and 0.75 percent Ti nano had the highest overall yield and ultimate and bending loads. Fatigue eventually showed that stamina tension constraints were applied for optimal lamination, compared to ten Perlon lamination layers. We additionally tested the fatigue life of the best material and compared it with the available materials used at prosthetics and orthotics centers.

Comparison of Two Methods for Determining Item Characteristic Functions and Latent Variable Time-Course for Pharmacometric Item Response Models

There are examples in the literature demonstrating different approaches to defining the item characteristic functions (ICF) and characterizing the latent variable time-course within a pharmacometrics item response theory (IRT) framework. One such method estimates both the ICF and latent variable time-course simultaneously, and another method establishes the ICF first then models the latent variable directly. To date, a direct comparison of the “simultaneous” and “sequential” methodologies described in this work has not yet been systematically investigated. Item parameters from a graded response IRT model developed from Parkinson’s Progression Marker Initiative (PPMI) study data were used as simulation parameters. Each method was evaluated under the following conditions: (i) with and without drug effect and (ii) slow progression rate with smaller sample size and rapid progression rate with larger sample size. Overall, the methods performed similarly, with low bias and good precision for key parameters and hypothesis testing for drug effect. The ICF parameters were well determined when the model was correctly specified, with an increase in precision in the scenario with rapid progression. In terms of drug effect, both methods had large estimation bias for the slow progression rate; however, this bias can be considered small relative to overall progression rate. Both methods demonstrated type 1 error control and similar discrimination between model with and without drug effect. The simultaneous method was slightly more precise than the sequential method while the sequential method was more robust towards longitudinal model misspecification and offers practical advantages in model building.