Conventional Set Research Articles

Early and Late Effects of Medium Cutoff Dialyzer on Arterial Stiffness in Maintenance Hemodialysis Patients

ABSTRACTIntroductionRemoving uremic toxins from the body is one of the most critical points in the maintenance hemodialysis (MHD) population. This study aimed to evaluate the effects of medium cutoff (MCO) membranes on pulse wave velocity (PWV) and augmentation index (AIx), early markers of arterial stiffness, in MHD patients over both short‐ and long‐term periods.MethodsTwenty MHD patients were included in this study. Patients were switched from low‐flux to MCO membranes. Hemodynamic parameters and laboratory results were recorded in the low‐flux membrane as baseline and the second week and the sixth month after switching to the MCO membranes. PWV and AIx were measured using the IME Mobil‐O‐Graph.FindingsThe median was 69.5 years old, with 60% female predominance. 35% of the patients were diabetic, 70% had hypertension, and 21.1% were smokers. The median systolic, diastolic blood pressure, mean arterial pressure, and pulse were similar at all study time points. The pulse pressure tended to decrease with a significant reduction in the sixth month (p = 0.73 and p = 0.03). We did not observe any significant differences regarding the PWV measurements (p = 0.71 and p = 0.62) and total vascular resistance (p = 0.23 and p = 0.79). The median AIx decreased during the study time points, with a significant difference between the second‐week MCO and the sixth‐month MCO measurements (p = 0.04).DiscussionOur findings underscore the potential benefits of MCO membranes to provide a favorable cardiovascular profile in conventional HD setting.

Innovative Project-Based Learning Video Tutorial Media: Development and Its Effect on Students Collaborative Skills

Mastery of the 4C skills (Critical Thinking, Communication, Collaboration, Creativity) is essential for success in 21st-century education. However, the persistent challenges in developing collaboration skills highlight a critical gap in current educational practices. This research seeks to develop a Project-Based Learning (PjBL) video tutorial and assess its impact on enhancing students' collaboration skills in high school biology education. Using a Research and Development (R&D) design based on the Alessi & Trollip model, the study involved two media experts, two content specialists, three teachers, and twenty-nine students as participants. Data were gathered through observations, interviews, and questionnaires, and analyzed using the N-Gain technique to evaluate improvements in collaboration skills, alongside descriptive percentage techniques to assess the feasibility of the video media product. The urgency of this research lies in addressing the limitations of traditional teaching methods, which often fail to foster active collaboration among students. Findings from the planning phase, including interviews with biology teachers, revealed a lack of collaborative interaction in conventional classroom settings. In response, a video tutorial was developed to enhance teamwork and collaboration during project assignments. Expert validation yielded a high feasibility score of 85.3%, and user testing showed excellent results with an average score of 83.7%. The video tutorial achieved an N-Gain value of 0.52, categorized as moderate, indicating a significant improvement in students' collaboration skills. This research is significant as it provides a practical, scalable solution to improve collaborative learning through innovative media in biology education. Further studies are recommended to expand the development of PjBL-based videos for other subjects and to investigate their long-term impact on 21st-century skills.

Evaluation of Analytical Performance of Rapid Diagnostic Test Kits for Blood Groupings

Purpose: This study aimed to determine the analytical performance of ABO and Rh D rapid diagnostic test kits as a substitute for the conventional tube method. Design/Methodology/Approach: 161 participants who visited the Koforidua Technical University Clinic Laboratory were recruited from August to September 2022. The rapid diagnostic ABO and Rh D test kits were used to determine the ABO and Rh D blood groups of the study participants. The concordance rate, kappa analysis and Receiver Operating Characteristics (ROC) were performed. Findings: The strength of agreement of the two diagnostic methods in detecting ABO and Rh D blood type using Kappa analyses was excellent (k꞊1.00; standard error꞊0.00; P-value=0.001). All diagnostic performance statistics of the RDT were not different from the tube method being the standard. Research Limitation: This research focused on the analytical performance of the rapid test kits but not on different brands of the test kits for their comparative studies. Practical Implication: This paper could potentially ensure reliable results, facilitate certification, and enable test kits to be accepted in the market. Social Implication: This study will assist policy-makers in increasing access to healthcare to enable testing in resource-limited settings and improving health outcomes as timely diagnosis and management facilitate better patient outcomes. Originality/ Value: This study is based on providing reliable information on portable and point-of-care diagnostic testing outside conventional laboratory settings for timely diagnosis.

Straightforward predictive direct power control for grid-connected ANPC inverter with flying capacitor voltage self-balancing

Improving control quality in inverter systems has attracted considerable attention, particularly in multilevel inverters for high-power applications. This study suggests a straightforward predictive direct power control system for a five-level Active Neutral Point Clamped inverter connected to the grid. The proposed method offers the benefit of reducing the heavy computational load by implementing a two-stage optimization process for the objective function. In contrast to the conventional finite control set model predictive control which involves comprehensive searches for all possible switching configurations within the iterative optimization process, the suggested approach focuses only on potential voltage vectors based on the desired inverter voltage’s location at the initial stage. Second, the self-balancing flying capacitor voltages are guaranteed by employing the duplicative switching states. Another advantage of the presented algorithm is an obviation of numerous selecting weighting factors. The effectiveness of the advanced strategy is confirmed through extensive comparative simulation and hardware-in-the-loop studies conducted in both conditions during stable states and transitions. Contrasted to the previous technique, this innovative method demonstrates an improvement in the grid’s power ripple and total harmonic distortion of the current by 14.66% and 19.58%. Furthermore, the computational time required for this method is significantly reduced by 64.58%, and 61.36% correlate to the traditional and other approaches, respectively. These results may facilitate the implementation of an effective control approach for multilevel inverters, employing a cost-effective control platform by a limited sampling interval.

Evaluation of Pedicle Screw Position on Computerized Tomography Using Three-Dimensional Reconstruction Software.

Background and Objectives: Recent advances in intraoperative navigation systems have improved the accuracy of pedicle screw placement in spine surgery. However, many hospitals have limited access to these advanced technologies due to resource constraints. In such settings, postoperative computed tomography (CT) evaluation remains crucial for assessing screw placement and related potential complications. Metal artifacts in CT scans often compromise the diagnostic accuracy. This study aimed to develop and validate three-dimensional (3-D) reconstruction software to enhance screw localization accuracy and facilitate its practical clinical application. Materials and Methods: This study included two phases: 3-D software development utilizing specific threshold values of Hounsfield units for titanium screws followed by internal validation. For validation, fifty pedicle screws were inserted into porcine lumbar vertebrae with random violation (superior, inferior, medial, or lateral). Three fellowship-trained surgeons evaluated screw positions using both conventional CT bone window settings and the developed software. Additional clinical validation involving 386 pedicle screws from cervical to lumbar spine was performed by two surgeons. Results: The software demonstrated significantly higher specificity (83% vs. 63%) and positive predictive value (96% vs. 91%) compared to conventional CT bone window settings, while maintaining 100% sensitivity and negative predictive value. Interobserver reliability was excellent for both methods (0.961 for bone window vs. 0.990 for software). In clinical validation, the software showed superior intraobserver (0.83 vs. 0.74) and interobserver reliability (0.855 vs. 0.513) compared to picture archiving and communication system (PACS) workstation evaluation. Conclusions: The developed software provides improved accuracy and reliability in pedicle screw position evaluation through distinct screw outline visualization and metal artifact reduction. Its equipment-independent nature and cost-effectiveness make it particularly valuable for clinical implementation.

The Use, Profile, Uptake, Characteristics and Attributes of Users of Homeopathy: Initial Findings from a Student Teaching Tele-Healthcare Clinic Based in North America

Research into the uptake profile and usage of Homeopathy has hitherto tended to be buried amongst complementary medicine research. Despite high levels of uptake of homeopathy, and robust numbers of over-the-counter sales of homeopathic products the current evidence evaluating the uptake of homeopathy remains limited on several fronts. The aim of this study is to explore the basic demographic features and characteristics of users of homeopathy services. The setting is a student teaching tele-health facility based in NA. Concurrent intake forms from 303 participants were analyzed. Intake forms were entered into a coding frame instrument designed and developed to explore health care information. A majority of participants (70%) who attend this clinic are female. The average age is 31 years old. Almost half of the participants in this clinic were using other additional complementary therapies in the management of their conditions. Almost the same number of participants (134) were only using homeopathy. The majority had some prior use of homeopathic products (91.6%), but 52.8% of participants had never worked with a professional homeopath. Twenty-four conditions are listed by participants as chief health complaints. Findings are in alignment with what is already known about the uptake in complementary medicine. Findings also reveal that the users of Homeopathy are seeking an ‘alternative’ to conventional medicine rather than only using Homeopathy as ‘complementary’ medicine. A proportion of participants in this clinical setting find homeopathy through over-the-counter sales and are, for a period, self-prescribing in chronic conditions. Further comparative research is needed to compare this to other complementary medicine avenues as well as conventional medicine settings. Conclusion: This in-depth empirical study of the users of homeopathy at one clinical facility represents initial, novel measured preliminary insights into the participants features and characteristics.

Application of digital tools and artificial intelligence in the Myasthenia Gravis Core Examination.

Advances in video image analysis and artificial intelligence provide opportunities to transform how patients are evaluated. In this study, we assessed the ability to quantify Zoom video recordings of a standardized neurological examination- the Myasthenia Gravis Core Examination (MG-CE)-designed for telemedicine evaluations. We used Zoom (Zoom Video Communications) videos of patients with myasthenia gravis (MG) who underwent the MG-CE. Computer vision, in combination with artificial intelligence methods, was used to develop algorithms to analyze the videos, with a focus on eye and body motions. To assess the examinations involving vocalization, signal processing methods, such as natural language processing (NLP), were developed. A series of algorithms were developed to automatically compute the metrics of the MG-CE. A total of 51 patients with MG were assessed, with videos recorded twice on separate days, while 15 control subjects were evaluated once. We successfully quantified the positions of the lids, eyes, and arms and developed respiratory metrics based on breath counts. The cheek puff exercise was found to have limited value for quantification. Technical limitations included variations in illumination, bandwidth, and the fact that the recording was conducted from the examiner's side rather than the patient's side. Several aspects of the MG-CE can be quantified to produce continuous measurements using standard Zoom video recordings. Further development of the technology will enable trained non-physician healthcare providers to conduct precise examinations of patients with MG outside of conventional clinical settings, including for the purpose of clinical trials.

Polaron formation in insulators and the key role of hole scattering processes in band insulators, charge density waves, and Mott transitions

A mobile impurity immersed in a noninteracting Fermi sea is dressed by the gapless particle-hole excitations of the fermionic medium. This conventional Fermi-polaron setting is well described by the so-called ladder approximation, which consists of neglecting impurity-hole scattering processes. In this work, we analyze polaron formation in the context of insulating states of matter, considering increasing levels of correlation in the medium: band insulators originating from external periodic potentials, spontaneously formed charge density waves, and a Fermi-Hubbard system undergoing a metal-Mott insulator transition. The polaron spectral function is shown to exhibit striking signatures of the underlying fermionic background, such as the single-particle band gap, particle-hole symmetry and the transition to the Mott state. These signatures are identified within the framework of the Chevy ansatz, i.e., upon restricting the Hilbert space to single particle-hole excitations. Interestingly, we find that the ladder approximation is inaccurate in these band systems, due to the fact that the particle and hole scattering phase spaces are comparable. Our results provide a step forward in the understanding of polaron formation in correlated many-body media, which are relevant to both cold-atom and semiconductor experiments. Published by the American Physical Society 2024

Uncovering Emergent Spacetime Supersymmetry with Rydberg Atom Arrays.

In the zoo of emergent symmetries in quantum many-body physics, the previously unrealized emergent spacetime supersymmetry (SUSY) is particularly intriguing. Although it was known that spacetime SUSY could emerge at the (1+1)d tricritical Ising transition, an experimental realization is still absent. In this Letter, we propose to realize emergent spacetime SUSY using reconfigurable Rydberg atom arrays featuring two distinct sets of Rydberg excitations, tailored for implementation on dual-species platforms. In such systems, the spacetime SUSY manifests itself in the respective correlation functions of a bosonic mode and its fermionic partner. However, the correlation function of the fermionic mode inevitably involves a string operator, making direct measurement challenging in the conventional setting. Here, we leverage the hybrid analog-digital nature of the Rydberg atom arrays, which allows for the simulation of a physical Hamiltonian and the execution of a digital quantum circuit on the same platform. This hybrid protocol offers a new perspective for uncovering the hidden structure of emergent spacetime SUSY.

Multiplexed perturbation of yew reveals cryptic proteins that enable a total biosynthesis of baccatin III and Taxol precursors.

Plants make complex and potent therapeutic molecules, but difficulties in sourcing from natural producers or chemical synthesis can challenge their use in the clinic. A prominent example is the anti-cancer therapeutic paclitaxel (Taxol®). Identification of the full paclitaxel biosynthetic pathway would enable heterologous drug production, but it has eluded discovery despite a half century of intensive research. Within the search space of Taxus' large, enzyme-rich genome, we suspected the complex paclitaxel pathway would be difficult to resolve using conventional gene co-expression analysis and small sample sets. To improve the resolution of gene set identification, we developed a multiplexed perturbation strategy to transcriptionally profile cell states spanning tissues, cell types, developmental stages, and elicitation conditions. This approach revealed a set of paclitaxel biosynthetic genes that segregate into expression modules that suggest consecutive biosynthetic sub-pathways. These modules resolved seven new genes that, when combined with previously known enzymes, are sufficient for the de novo biosynthesis and isolation of baccatin III, an industrial precursor for Taxol, in Nicotiana benthamiana leaves at levels comparable to the natural abundance in Taxus needles. Included are taxane 1β-hydroxylase (T1βH), taxane 9α-hydroxylase (T9αH), taxane 7β-O-acyltransferase (T7AT), taxane 7β-O-deacetylase (T7dA), taxane 9α-O-deacetylase (T9dA), and taxane 9-oxidase (T9ox). Importantly, the T9αH we discovered is distinct and independently evolved from those recently reported, which failed to yield baccatin III with downstream enzymes. Unexpectedly, we also found a nuclear transport factor 2 (NTF2)-like protein (FoTO1) crucial for high yields of taxanes; this gene promotes the formation of the desired product during the first taxane oxidation step, resolving a longstanding bottleneck in paclitaxel pathway reconstitution. Together with a new β-phenylalanine-CoA-ligase, the eight genes discovered in this study enables the complete reconstitution of 3'-N-debenzoyl-2'-deoxy-paclitaxel with a 20-enzyme pathway in Nicotiana plants. More broadly, we establish a generalizable approach for pathway discovery that scales the power of co-expression studies to match the complexity of specialized metabolism, enabling discovery of gene sets responsible for high-value biological functions.

Individualised Positive End-Expiratory Pressure Settings Reduce the Incidence of Postoperative Pulmonary Complications: A Systematic Review and Meta-Analysis.

Background: Progressive atelectasis regularly occurs during general anaesthesia; hence, positive end-expiratory pressure (PEEP) is often applied. Individualised PEEP titration may reduce the incidence of postoperative pulmonary complications (PPCs) and improve oxygenation as compared to fixed PEEP settings; however, evidence is lacking. Methods: This systematic review and meta-analysis was registered on PROSPERO (CRD42021282228). A systematic search in four databases (MEDLINE Via PubMed, EMBASE, CENTRAL, and Web of Science) was performed on 14 October 2021 and updated on 26 April 2024. We searched for randomised controlled trials comparing the effects of individually titrated versus fixed PEEP strategies during abdominal surgeries. The primary endpoint was the incidence of PPCs. The secondary endpoints included the PaO2/FiO2 at the end of surgery, individually set PEEP value, vasopressor requirements, and respiratory mechanics. Results: We identified 30 trials (2602 patients). The incidence of PPCs was significantly lower among patients in the individualised group (RR = 0.70, CI: 0.58-0.84). A significantly higher PaO2/FiO2 ratio was found in the individualised group as compared to controls at the end of the surgery (MD = 55.99 mmHg, 95% CI: 31.78-80.21). Individual PEEP was significantly higher as compared to conventional settings (MD = 6.27 cm H2O, CI: 4.30-8.23). Fewer patients in the control group needed vasopressor support; however, this result was non-significant. Lung-function-related outcomes showed better respiratory mechanics in the individualised group (Cstat: MD = 11.92 cm H2O 95% CI: 6.40-17.45). Conclusions: Our results show that individually titrated PEEP results in fewer PPCs and better oxygenation in patients undergoing abdominal surgery.

Examining the customer experience in the metaverse retail revolution

This research examines how the metaverse empowers businesses to craft personalized customer experiences that transcend the limitations of conventional retail settings. Following a review of the literature, we present theory-driven, managerial-oriented research opportunities that advance our understanding of the customer journey and retailing in the metaverse. Opportunities in the prepurchase stage of the customer journey include self-expression and engagement, social influences, and uncertainty avoidance. In the purchase stage, service script disruptions, hyper-personalized experiences, and the disruption of scarcity and NFTs (non-fungible tokens) present potential differentiation strategies. In the postpurchase stage, retailers may gain a competitive advantage by understanding how consumers value the unboxing experience, evaluate products, and deepen customer engagement and advocacy in this new shopping environment. Taken together, we present a three-pronged approach for retail scholars to extend our knowledge of the customer journey within the metaverse and offer practical suggestions for the retailers currently navigating this new paradigm.

Abstract 226: Combined Delivery Catheter Systems Aspiration‐First Approach For Stroke Thrombectomy: A Single Center experience

Introduction In acute ischemic stroke management, rapid reperfusion is critical to improving patient outcomes. Previous multicenter studies of the novel Tenzing delivery catheter, designed to simplify stroke thrombectomies, have demonstrated more streamlined procedures, faster delivery times and superior clinical outcomes.[1‐5] Now with three combined delivery catheter systems available—Route 92’s Tenzing‐Freeclimb 70, Penumbra's SENDit‐Red 72 and Q'Apel's Cheetah‐Hippo—there is potential for further advancement. However, data on the Penumbra and Q'Apel systems are currently lacking, and the combined performance of these devices is unknown. Our study aims to evaluate whether these systems improve reperfusion times, outcomes, and complication rates compared to our traditional aspiration thrombectomy approach in our institutional cohort. Methods We retrospectively analyzed prospectively collected data from June 2023 to July 2024, the period when these devices first became available for our use. We compared the outcomes of using the Tenzing, SENDit, and Cheetah combined delivery systems first approach with our typical aspiration‐first approach cases during the same period, commonly a Zoom 71 aspiration catheter, 0.021‐0.027” microcatheter and 0.014‐0.018”” microguidewire. Primary outcomes measured included first on clot time, device deployment, reperfusion times, reperfusion success, and incidence of symptomatic intracranial hemorrhage. Secondary analyses assessed total thrombectomy passes and fluoroscopy times. Results Seventy‐seven patients met the inclusion criteria with a mean age of 68.3 ± 15.7 years; 43% were female. Occlusion sites were M1 (59.7%), ICA terminus (16.8%), basilar or distal vertebral (10.3%), tandem ICA‐M1 (6.5%), and proximal M2 (6.5%). Microwires were not used in 5.2% of cases (n=4). The combined delivery systems (n=20; Penumbra=13, Route 92=4; Q'apel=3) showed significantly faster mean groin‐to‐on clot times (19.95 vs. 23.98 mins, p=0.03) compared to the traditional systems (n=57). The combined systems had faster mean groin‐to‐first device times (25.25 vs. 28.16 mins, p=0.13) and faster mean groin‐to‐reperfusion times (46.16 vs. 49.48 mins, p=0.58). Successful reperfusion (TICI≥2b) was significantly higher with the combined systems (95% vs. 71.9%, p=0.03). Notably, total fluoroscopy times were nominally lower (25.9 mins vs. 29.9 mins, p=0.45), and fewer mean number of passes (1.94 vs 2.48, p=0.14) were nominally seen with the combined systems. The incidence of symptomatic intracranial hemorrhage was significantly lower with the combined systems compared to our conventional set up (0% vs. 8.8%, p=0.01). In addition, the lowest listed price of the combined delivery systems including a microwire was nearly $1,000 greater than our traditional aspiration thrombectomy system ($5,671 vs. $4,674). Eliminating the use of a microwire, which is outside of the Instructions for Use for the SENDit and Cheetah, but acceptable with the Tenzing delivery catheter, results in a marginal cost difference between the combined ($4,900) and traditional systems ($4,674). Conclusions The introduction of the combined delivery catheter systems has the potential to enhance mechanical thrombectomies for acute ischemic stroke. Our cohort's early use data shows promise in reducing reperfusion times and enhancing technical success and safety, allowing for better patient outcomes at a marginally increased financial cost. Further prospective studies are warranted to establish these devices as improved options for stroke intervention.

NOVAsort for error-free droplet microfluidics

High-throughput screening techniques are pivotal to unlocking the mysteries of biology. Yet, the promise of droplet microfluidics in enabling single-cell resolution, ultra-high-throughput screening remains largely unfulfilled. Droplet sorting errors caused by polydisperse droplet sizes that are often inevitable in multi-step assays have severely limited the effectiveness and utility of this technique, especially when screening large libraries. Even a relatively low 1% sorting error results in 10,000 false calls in a 1,000,000 droplet screen, imposing an unreasonably large burden on downstream validation. Here, we present NOVAsort (Next-generation Opto-Volume-based Accurate droplet sorter), a device capable of discerning droplets based on both size and fluorescence intensity. With a 1000- and 10,000-fold reduction in false positives and false negatives, respectively. NOVAsort addresses the challenges of conventional droplet sorting approaches and sets standards for accuracy and throughput in droplet microfluidic assays.

Solar convective velocities: Updated helioseismic constraints

Modeling heat transport by convection is one of the most challenging aspects of solar and stellar physics. The literature currently provides apparently inconsistent observational estimates of the strength of large-scale convective flows in the upper layers of the solar convection zone. In addition, the large-scale convective flows predicted from numerical simulations are substantially stronger than some of the observational inferences in the literature. The current work aims to provide a consistent presentation of some of the main results in the literature both from observations and simulations. To achieve this aim, we carry out an analysis of published estimates of the strength of solar convection at different spatial scales. In particular, we employ a consistent set of conventions to compute the kinetic energy density in the east-west flows. This establishes a clear baseline for future work. The main conclusion is that there are inconsistencies between different observational results and also differences between observations and simulations. This conclusion is important as it demonstrates a need to determine the sources of the inconsistencies between different observational inferences and also to determine the missing ingredients in simulations of solar subsurface convection.

Radiating for Two: Quantifying Radiation Exposure to Pregnant Urologists During Percutaneous Nephrolithotomy.

Current occupational recommendations limit fetal radiation dose to 1 mSv. With increased gender diversity in urology, understanding radiation exposure during pregnancy is crucial. The purpose of this study was to determine surgeon uterine radiation dose during percutaneous nephrolithotomy (PCNL) and compare effectiveness of several radiation reduction strategies in a cadaver model. Two cadavers were used to simulate the surgeon and the patient in a PCNL model. An ion chamber was placed behind the surgeon's anterior uterine wall to measure the radiation dose. Three radiation reduction methods were compared: pulsed fluoroscopy (1, 4, 8, 15, 30 pps), low-dose (LD) fluoroscopy, and surgeon shielding (none, 0.35-, 0.50-, 0.70-mm lead equivalents). The average radiation dose per second was recorded for 20 trials per combination. Assuming 5 minutes of fluoroscopy per PCNL, the number of cases required to exceed the fetal occupational limit was determined. Decreasing pulse frequency from 30 to 1 pps reduced the dose by 96% (P < .001). The LD setting decreased the dose by 56% (P < .001). A 0.35-mm lead apron resulted in a 94% dose reduction (P < .001), and the 0.50- and 0.70-mm lead aprons further reduced the dose by 12% and 47%, respectively. In conventional fluoroscopy settings of automatic exposure control and at 30 pps, a surgeon could perform 12 PCNLs using no lead or 189 PCNLs using a 0.35-mm lead apron before reaching the 1 mSv limit. In addition to shielding, using 1 pps with LD fluoroscopy further decreased radiation exposure, allowing over 6000 cases to be performed with < 1 mSv uterine radiation exposure. Within the limitations of this cadaver study, these data support that high-volume pregnant surgeons using active radiation reduction techniques such as pulsed fluoroscopy, LD fluoroscopy, and appropriate shielding can maintain surgical volume with relatively low risk. Fetal dosimeter use with monthly monitoring is still encouraged to confirm safety throughout pregnancy.

The Underlying Cognitive Processes of Thin Slices Judgments on Teaching Quality

Thin slices ratings (i.e., ratings based on first impressions) have yielded intriguingly accurate results in various domains. Among other, researcher have applied the thin slices technique to assess instructional quality, showing that teacher-student interactions can be reliably inferred by just very short snippets of classroom instruction. The accuracy of thin slices ratings is often explained by dual process theories of social cognition, whereby System 1 refers to an intuitive and fast way of processing, while System 2 denotes a more reflective and analytical way of processing. System 1 is considered the cognitive foundation of thin slices ratings. The central aim of the present study was to understand the underlying cognitive processes shaping the impression formation of thin slices raters of teaching quality. Therefore, an unconventional and innovative research design was required to gain insights into the cognitive “black box” of thin slices raters by examining their verbal data. In an exploratory mixed method research design, we set up Cognitive Laboratories with two different rating situations. In a thin slices rating situation, participants rated instructional quality based on short classroom videos (30 seconds). Participants in a long-video rating situation rated instructional quality based on longer classroom videos (10 minutes). We collected, coded and statistically analyzed participants’ verbal reports regarding their rating processes. The findings suggest that thin slices ratings evolve primarily based on typical processes of System 1 and not on those of System 2. For instance, thin slices ratings are associative and tend to be rather negative than positive. Moreover, an initially formed impression tends to remain stable and is resistant to alteration. Ratings of instructional quality based on longer videos rely on both cognitive systems, with System 2 possibly modifying an initial judgment. Thus, our study does not only explain the cognitive processes under-lying the thin slices ratings, but additionally provides valuable insights into the processes occurring in conventional rating settings.

Tackling the multitude of uncertainties in energy systems analysis by model coupling and high-performance computing

This paper identifies and addresses three key challenges in energy systems analysis—varying assumptions, computational limitations, and coverage of a few indicators only. First, results depend strongly on assumptions, i.e., varying input data. Hence, comparisons and robust results are hard to achieve. To address this, we use a broad range of possible inputs through an extensive literature review by scenario experts. Second, we overcome computational limitations using high-performance computing (HPC) and an automated workflow. Third, by coupling models and developing 13 indicators to evaluate the overall quality of energy systems in Germany for 2030, we include many aspects of security of supply, market impact, life cycle analysis and cost optimization. A cluster analysis of scenarios by indicators reveals three recognizable clusters, separating systems with a high share of renewables clearly from more conventional sets. Additionally, scenarios can be identified which perform very positive for many of the 13 indicators. We conclude that an automated, coupled workflow on supercomputers based on a broad parameter space is able to produce robust results for many important aspects of future energy systems. Since all models and software components are released as open-source, all components of a multi-perspective model-chain are now available to the energy system modeling community.

The state of e-learning in radiology colleges during the COVID-19 pandemic and its future prospects

This study evaluates the existing electronic learning (e-learning) infrastructure in Sudanese academic institutions that offer radiology education during the COVID-19 pandemic with the aim of understanding the extent and effectiveness of e-learning. By employing a descriptive cross-sectional survey from April to August 2021, data was gathered from undergraduate and postgraduate students enrolled in both public and private radiology educational institutions across Sudan. The questionnaire, created in Google Forms and distributed via email, WhatsApp, and Facebook, captured insights into the students' experiences and challenges with e-learning. The findings revealed that power outages and poor internet access were significant barriers, affecting 50% and 27% of respondents, respectively. While 33% of participants were satisfied with e-learning as a pedagogical strategy, 29% believed it hindered the achievement of educational goals. Furthermore, 78% of the respondents felt that e-learning was not suited to all medical specializations, although 46.6% supported the idea of integrating e-learning with traditional classroom instruction. Despite the adoption of e-learning due to the pandemic, students exhibited a preference for the conventional classroom setting, primarily due to challenges related to internet accessibility and the availability of the necessary technological resources. Significant infrastructure improvements and strategic planning are required to maximize the benefits of e-learning in resource-constrained countries.

Analysis of The Flow-Field Distorsions Induced by Pneumatic Pressure Probes In Test Bench Experiments On Centrifugal Compressors: Are We Testing Right?

Abstract Experimental testing at the test rig still plays a key role in the development of new centrifugal compressor designs for industrial applications. Although a wide set of different probes is used as per common practice, the overall impact of the probes? dimensions on the stage performance and rangeability is often assumed to be negligible. In this study, we aimed at quantifying the intrusiveness effects of pneumatic pressure probes on the flow-field inside a vaned diffuser using a model stage of an industrial centrifugal compressor, for which different experimental setups were tested at the University of Florence test rig. Performance and rangeability were initially assessed using a conventional set of pneumatic probes inserted in the flow path. Then, comparative analyses were realized through dedicated tests by either removing all probes at the diffuser inlet or introducing only a single pressure probe in the upstream section and varying its angular position in the measuring section. Experiments revealed an impact of upstream probes much higher than expected, with a decrease in efficiency and a substantial reduction of stall margin. Moving from this experimental evidence, accurate 3D CFD simulations of the entire stage were carried out including the actual geometry of the probes for two probes configurations and three operating points. Simulations highlighted the effect probes? wakes on downstream vanes and the induced blockage effect, which both appear in line with experimental evidence. As a handout, a recommendation on the optimal probe positioning is suggested.