Quantitative Measurements Research Articles

The Use of Simulated Participant and Virtual Reality Simulation to Enhance Nursing Students’ Communication Skills in “End of Life Care” - A Single-Arm Repeated Measures Study

BackgroundIncreasing demand for palliative care necessitates effective training for nursing students in end-of-life (EOL) and advanced care planning (ACP). Conventional teaching methods often fall short. MethodsA single-arm pre-post design involved 219 nursing students in VR and SP simulations. Quantitative measures and qualitative feedback were obtained. ResultsStatistical analysis revealed significant improvement post-intervention (p < 0.001). Qualitative feedback highlighted realism, interactivity, and skill development. Challenges included emotional intensity and scenario repetition. ConclusionsCombining virtual reality (VR) and simulated participant (SP) simulation significantly enhances nursing students' confidence and communication for end-of-life (EOL) conversations, offering a realistic educational experience. Further research is recommended in understanding this teaching method.

Development of molecularly imprinted photonic crystal hydrogel based smart sensor for selective uric acid detection

Determination of uric acid (UA) concentration is important in clinical analysis, as its variation is an indication of several health-related conditions. Here, we discuss the development of a Molecularly imprinted photonic crystal hydrogel (MICPH)-based colourimetric sensor for the selective detection of UA. The developed MIPCH-UA sensor displays a bright structural colour, which varies as the sensor swells upon rebinding the UA molecules. The structural colour change is directly related to the concentration of the target molecule and can serve as an easy readout of the sensor response. This colour change can also be recorded spectrally, providing a quantitative measure of the sensor response. With a low limit of detection (LoD) of 1.01×10-9M, the sensor is capable of detecting low concentrations of UA. Moreover, the sensor endows the advantage of fast responsiveness and reusability when employed for UA assays. The sensor performance remains consistently reliable over an extended duration of up to one month, thereby ensuring cost-effectiveness in monitoring UA levels. The specific detection capability of the sensor allows the accurate and reliable measurement of UA in the presence of various interfering molecules and complex sample matrices. The structural colour change of the sensor was used to train a CNN-based deep learning algorithm to quantitatively predict the UA concentration. The integration of the machine learning algorithm with the developed sensor provides an accurate and efficient smart sensor platform well-suited for real-time sensing of uric acid.

Comparison of DNA quantity and quality from fecal samples of mammals transported in ethanol or lysis buffer

Using fecal microbial community profiles through sequencing approaches helps to unravel the intimate interplay between health, wellness, and diet in wild animals with their environment. Ensuring the proper preservation of fecal samples before processing is crucial to ensure reliable results. In this study, we evaluated the efficiency of two different preservation methods, considering the following criteria: DNA yield, quality and integrity, and microbial community structure based on Oxford Nanopore amplicon sequencing of the V3-V4 region of bacterial 16 s rRNA and protozoa 18S rRNA genes. Eighteen matched pairs of mammalian fecal samples were collected and transported in 99.8% ethanol and lysis buffer; processing occurred between 55 and 461 days post-collection. Wilcoxon signed-rank tests were used to analyze quantitative measurements for paired samples. The A260/280 ratio, a measure of nucleic acid purity, was assessed descriptively for each media, and the Bartlett test evaluated dispersion of this ratio. A Fisher test was performed to compare the number of positive reactions for DNA extraction or PCR amplification of the 16S and 18S rRNA genes between both media. The concentration of total DNA and amplicons, as well as the number of reads obtained in sequencing, was significantly higher in the samples preserved with lysis buffer compared to ethanol, with magnitudes up to three times higher. Electrophoretic analysis of total DNA and amplicons further confirmed superior DNA integrity in lysis buffer preserved samples. The A260/280 values obtained using the lysis buffer were of optimal purity (mean: 1.92) and with little dispersion (SD: 0.27); on the other hand, the ethanol samples also presented an excellent average quality (mean: 1.94), but they were dispersed (SD: 1.10). For molecular studies using mammalian feces, the lysis Buffer reagent proved to be a reliable solution for their collection, conservation, and storage.

A formative mixed methods evaluation of a new Ross program: why context matters

BackgroundThe Ross procedure is a technically complex operation to address the pathology of the aortic valve. Prior attempts at widespread implementation have been plagued with variations in effectiveness. We report our initial programmatic outcomes using dissemination and implementation (D&I) science frameworks, with an aim to define both programmatic efficacy and effectiveness. The study design was a single center, explanatory sequential mixed methods evaluation of a Ross surgery program from June 2020 to April 2023. Quantitative measures for baseline patient characteristics and postoperative outcomes were summarized. Qualitative measures were obtained using semi-structured interviews and characterized using implementation science frameworks.ResultsA total of 71 patients underwent the Ross procedure at a single academic center. Mean age was 40 years (± 13). There were no perioperative deaths or valve-related reinterventions (0%). During the follow-up period, 2 (2.8%) patients required re-operation and 2 (2.8%) required balloon dilation of the pulmonary homograft. Qualitative measures noted communication and prospective self-audit facilitated measures of effectiveness, as dichotomy within expected vs. observed outcomes led to program modifications. Collaboration across hospital systems promoted adoption and implementation, which led to the incorporation of the Ross procedure into accepted organizational practice.ConclusionsIn this formative evaluation, limited-efficacy outcomes demonstrated similar programmatic success to data from other established centers. With the prerequisite center volume and case selection, the Ross procedure is a safe and efficacious treatment for aortic valvular disease. Implementation science can be used both in real-time and retrospectively to guide organizational efforts to improve outcomes and to improve the translation of results across centers.

Performance of T2 mapping in the staging of Graves' ophthalmopathy based on different region of interest selection methods.

Discriminating the stage of Graves' ophthalmopathy (GO) is crucial for clinical decision. Application of conventional T2-weighted imaging in the staging is still limited. To evaluate the performance of T2 mapping based on two different regions of interest (ROIs) for staging GO. In total, 56 GO patients were retrospectively enrolled and divided into two groups according to the clinical activity score (CAS). T2 relaxation time (T2RT) of extraocular muscle (EOM) on T2 mapping based on two different ROIs (T2RTROI-1: ROIs were drawn separately in the four EOMs; T2RTROI-2: ROI was drawn in the most inflamed EOM) was measured and compared between active and inactive groups. Both T2RTROI-1 and T2RTROI-2 values in the active GO were significantly higher than those of inactive GO (P <0.001). T2RTROI-1 and T2RTROI-2 values were positively correlated with CAS (rs=0.73, 0.69; P <0.001). When the T2RTROI-1 value of 83.3 ms and T2RTROI-2 value of 106.3 ms were used as cutoff values for staging GO, respectively, the best results were obtained with areas under the curve (AUCs) of 0.822 and 0.827. There was no significant difference for AUCs between T2RTROI-1 and T2RTROI-2 (P = 0.751). Excellent and good inter-observer agreements were achieved in quantitative measurements for T2RTROI-1 and T2RTROI-2 values, respectively, with intraclass correlation coefficients of 0.954 and 0.882. The T2RT values derived from two different ROIs were useful for assessment of disease activity. Taking reproducibility and diagnostic performance into consideration, T2RTROI-1 would be an ideal image biomarker for staging GO compared to T2RTROI-2.

Consideration of Age for Quantitative Measurements in Ecological Studies

The physiological age of a plant or its parts is important for quantitative studies in Ecology. It is demonstrated by measurements of leaf size that the number of nodes from the apex in individuals is a good indicator of the physiological age among natural populations. Hence, it is suggested that for measurements of leaf and internode of individuals in a heterogenous population a definite size range for the uppermost or the first visible leaf or internode be fixed for counting downwards. The plastochron index be, however, used for other quantitative estimations in ecological studies.

Quantitative blood loss measurement methods for early detection of primary postpartum haemorrhage following vaginal birth: A scoping review.

To map the commonly used quantitative blood loss measurement methods in clinical practice and provide a solid foundation for future studies. This study adhered to the JBI methodology for scoping reviews and preferred reporting items for systematic reviews and meta-analyses extension for scoping reviews. We conducted a literature search using five databases to retrieve articles published between January 2012 and September 2022. The search was repeated on 29 February 2024. Data extraction and verification were carried out by two independent researchers using a self-designed data extraction form. Ultimately, 26 studies published between 2012 and 2024 were considered eligible for inclusion. Six categories of methods were identified from the 26 articles. Among the included studies, only two involved randomized controlled trials, with the majority being observational studies. The World Health Organization (2012) version of the postpartum haemorrhage diagnostic criteria was predominantly used in most studies. Gravimetric and volumetric methods emerged as the most commonly used methods for quantifying postpartum haemorrhages. The timing of blood collection was inconsistent among the included studies. Only 12 studies mentioned measures for the management of amniotic fluid. This scoping review supports the replacement of the visual estimation of blood loss with quantitative assessment methods. Supporting a specific assessment approach is not feasible due to the variability of the study. Future research should focus on establishing the best practices for specific quantitative methods to standardize the management of postpartum haemorrhage and reduce the incidence of postpartum haemorrhage-related adverse outcomes. Healthcare professionals need to acknowledge the low accuracy of visual estimation methods and implement quantitative methods to assess postpartum blood loss. Given the limitations inherent in each assessment method, quantification of blood loss should be combined with assessment of maternal vital signs, physiologic indicators and other factors.

Ellipsoid Zone Integrity and Visual Function in Dry Age-Related Macular Degeneration

In this longitudinal retrospective image analysis, conducted on patients diagnosed with dry age-related macular degeneration (AMD) and 5 years of follow-up imaging data, the study aimed to investigate the relationship between ellipsoid zone (EZ) integrity on spectral domain optical coherence tomography (SD-OCT) and visual acuity (VA). Using a machine learning-enabled feature extraction tool, quantitative EZ parameters were derived from SD-OCT images. The analysis revealed significant correlations between EZ integrity metrics and VA. Eyes with excellent VA (≥20/25 Snellen) exhibited higher EZ integrity, including less EZ attenuation, thicker ellipsoid zone-retinal pigment epithelium (EZ-RPE) thickness, and higher EZ intensity, in contrast to eyes with worse VA (≤20/40 Snellen). Additionally, eyes with geographic atrophy (GA) in the foveal region displayed compromised EZ integrity compared to those without GA. Notably, baseline EZ integrity metrics were predictive of future VA loss. These findings suggest that quantitative SD-OCT measurements of EZ integrity could potentially detect early changes in dry AMD and serve as valuable indicators for predicting future functional outcomes. Furthermore, these measurements hold promise for use in clinical trial screenings, offering insights into the progression of the disease and its impact on visual acuity. This study underscores the importance of EZ integrity assessment in understanding and managing dry AMD.

A Quantitative Model to Measure the Level of Culture and Tourism Integration Based on a Spatial Perspective: A Case Study of Beijing from 2000 to 2022

The integration of culture and tourism has become an important factor in the development of the cultural tourism industry, and a quantitative measure of the degree of integration is important for understanding and promoting the high-quality development of the global cultural tourism industry. This study aims to put forward a comprehensive analysis model to show the development trend of cultural and tourism integration, measure the degree of cultural and tourism integration, and analyze the factors affecting the regional heterogeneity of cultural and tourism integration. Using the spatial quantification method of entropy, the spatial coupling coordination degree model, and the geographical weighting model, this paper analyzes the effect and influencing factors of cultural and tourism integration in various districts and counties in Beijing. The results show that the cultural tourism resource endowment of Beijing presents an upward trend and a gradual spillover trend, with obvious spillover to the east and north. The effect of district integration in Beijing has gradually weakened from the city center to the outside, but there is still a serious phenomenon of two levels of differentiation. Factors such as the economic development level, tourism output, cultural output, policy support, and consumption level have spatial heterogeneity on the effect of cultural and tourism integration in each district of Beijing, but the degree of influence is small.

Luminance Contrast Affects the Binocular Color Fusion Limit

ABSTRACT When the color difference between the images perceived by the left eye and the right eye exceeds a certain threshold, the binocular rivalry could be activated, which is the main cause of visual fatigue. This threshold is referred to as the binocular color fusion limit. Past studies on the quantitative measurement of the binocular color fusion limit were always performed by presenting the stimulus (varying in color, disparity, size, etc.) under a dark background. To investigate how the background luminance and the luminance contrast influence the binocular color fusion limit, a series of forced-choice psychophysical experiments were conducted in a three-dimensional display for three luminance levels of both the stimulus and background. Under each luminance level, the color fusion limit for the D50 chromaticity point was measured on four opposite color directions in the CIE 1976 u F ’v F ’ uniform color space. The results show an increment of color fusion limit as the stimulus-background luminance contrast increases.

Deep learning-based super-resolution of structural brain MRI at 1.5T: application to quantitative volume measurement.

This study investigated the feasibility of using deep learning-based super-resolution (DL-SR) technique on low-resolution (LR) images to generate high-resolution (HR) MR images with the aim of scan time reduction. The efficacy of DL-SR was also assessed through the application of brain volume measurement (BVM). In vivo brain images acquired with 3D-T1W from various MRI scanners were utilized. For model training, LR images were generated by downsampling the original 1mm-2mm isotropic resolution images. Pairs of LR and HR images were used for training 3D residual dense net (RDN). For model testing, actual scanned 2mm isotropic resolution 3D-T1W images with one-minute scan time were used. Normalized root-mean-square error (NRMSE), peak signal-to-noise ratio (PSNR), and structural similarity (SSIM) were used for model evaluation. The evaluation also included brain volume measurement, with assessments of subcortical brain regions. The results showed that DL-SR model improved the quality of LR images compared with cubic interpolation, as indicated by NRMSE (24.22% vs 30.13%), PSNR (26.19 vs 24.65), and SSIM (0.96 vs 0.95). For volumetric assessments, there were no significant differences between DL-SR and actual HR images (p > 0.05, Pearson's correlation > 0.90) at seven subcortical regions. The combination of LR MRI and DL-SR enables addressing prolonged scan time in 3D MRI scans while providing sufficient image quality without affecting brain volume measurement.

On-Site Quantitative Visualization of Singlet Oxygen in Crops via an Organic Small Molecule-Based Ratiometric Fluorescent Probe and a Mobile Fluorescence Analysis Device.

Singlet oxygen (1O2) plays imperative roles in a variety of biotic or abiotic stresses in crops. The change of its concentration within a crop is closely related to the crop growth and development. Accordingly, there is an urgent need to develop an efficient analytical method for on-site quantitative detection of 1O2 in crops. Here, we judiciously constructed a novel ratiometric fluorescent probe, SX-2, for the detection of 1O2 in crops. Upon treating with 1O2, probe SX-2 displayed highly selective ratiometric fluorescence response, which is favorable for the quantitative detection of 1O2. Concurrently, the fluorescence solution color of probe SX-2 was varied, obviously from blue to yellow, indicating that the probe is beneficial for on-site detection by the naked eye. Sensing reaction mechanism studies showed that the 2,3-diphenyl imidazole group in SX-2 could function as a new selective recognition group for 1O2. Probe SX-2 was utilized for the detection of photoirradiation-induced 1O2 and endogenous 1O2 in living cells. The changes in the 1O2 level in zebrafish were also tracked by fluorescence imaging. In addition, the production of 1O2 in crop leaves under a light source of different wavelengths was studied. The results demonstrated more 1O2 were produced under a light source of 365 nm. Furthermore, to achieve on-site quantitative detection, a mobile fluorescence analysis device has been made. Probe SX-2 and mobile fluorescence analysis device were capable of on-site quantitative detecting of 1O2 in crops. The method developed herein will be convenient for the on-site quantitative measurement of 1O2 in distinct crops.

Altered States of Consciousness are Prevalent and Insufficiently Supported Clinically: A Population Survey

Abstract Objectives Adoption of potentially consciousness-altering practices may be leading to a rise in emergent phenomena (EP): sudden unusual mental or somatic experiences often interpreted as spiritual, mystical, energetic, or magical in nature. It is unclear how frequently these altered states of consciousness occur and what the clinical implications may be. Anecdotal accounts and prior literature suggest that EP may be common, under-reported, and followed by either positive or negative changes to well-being. We sought to supplement prior evidence on the prevalence and effects of EP among general populations with large-scale quantitative measurements. Method We measured the prevalence of EP, while not on mind-altering substances, through completion of online surveys by representative samples from three international communities (n = 3135). The communities sampled were UK Qualtrics online panelists, US-based MTurk workers, and the readers of a popular rationalist blog. Samples were broadly representative of underlying populations. Results Forty-five percent of participants reported experiencing non-pharmacologically induced EP at least once in their lives, including derealization (17%), unitive experiences (15%), ecstatic thrills (15%), vivid perceptions (11%), changes in perceived size (10%), bodily heat or electricity (9%), out-of-body experiences (8%), and perception of non-physical lights (5%). Respondents reported a mix of positive and negative well-being outcomes following EP, with 13% claiming moderate or greater suffering and 1.1% claiming life-threatening suffering. Of those who experienced suffering, 63% did not seek help. Conclusions EP are widespread among the studied populations with potential for both positive and negative outcomes, the latter of which do not appear to be adequately addressed through recourse to clinical practice.

From Simple Packaging Materials to Smart Sensors: Sunlight Exposure Sensing in Bubble Wraps Incorporating a Layered Metal Selenide Photocatalyst

AbstractThis work demonstrates that the packaging material commonly called “bubble wraps” (Aeroplast) can be leveraged to serve as a probe to visible sunlight exposure. This probe relies on a newly developed layered metal selenide photocatalyst with the general formula (DMAH)2xMnxSn3–xSe6 (DMSe‐1) (x = 1.3–1.7; DMAH+ = dimethylammonium), featuring a narrow bandgap of 0.76 eV, in addition to an indicator dye and a reducing agent. The photochemically sensitive probe is introduced into the air‐filled compartments of bubble wraps and undergoes photocatalytic degradation, resulting in a chromatic response to sunlight exposure. The probe's sensitivity to variable irradiation doses can be adjusted by varying the amount of the photocatalyst. The color intensity correlates with the absorbed irradiation dose, allowing for qualitative assessment by the naked eye or quantitative measurement using the RGB color system. The results obtained from the new probe agree with those obtained from standard sunlight pyranometers (r = 0.98), with an average error of &lt;15%. This suggests that beyond their use as protective coatings, bubble wraps can be successfully repurposed as visible light sensors. Furthermore, this study describes the initial use of metal chalcogenides as visible light probes, potentially paving the way for the development of innovative light‐sensitive materials.

Advocating for a behavioural science approach to inclusion and diversity

In recent years the benefits of inclusion and diversity have become increasingly clear. Australian and international studies have demonstrated the significant improvements in innovation, productivity and growth that can be achieved when teams are both inclusive and diverse. However, meaningful progress requires moving beyond traditional diversity initiatives. This paper highlights the potential use of behavioural science to design successful implementation strategies to improve diversity and inclusion in the upstream energy industry. This paper will also provide guidance on how scientific methodologies can be applied to measure impact and return on investment (ROI), aligning the business case for diversity and inclusion with individual interventions. Behavioural science involves the observation, hypothesis, experiment and analysis of human behaviour to draw conclusions. It is now a leading school of thought at the world’s top research and learning organisations. This paper argues that by measuring outcomes of diversity and inclusion interventions through a behavioural science approach, organisations can make informed decisions, identify areas of improvement, and refine their strategies to improve ROI. This approach not only ensures that resources are invested effectively but also fosters a culture of continuous learning and adaptation, leading to sustainable and meaningful progress for all employees and stakeholders. Drawing on international research and local case studies, this paper showcases successful applications of behavioural science in transforming organisational cultures, creating safer and more inclusive workplaces. Ideas for quantitative and qualitative measurements are proposed for application in the upstream energy industry, with a particular focus on operational people and performance.

The debris of the ‘last major merger’ is dynamically young

Abstract The Milky Way’s (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the ‘last major merger.’ Hypotheses for the origin of this component include Gaia-Sausage/Enceladus (GSE), where the progenitor collided with the MW proto-disk 8-11 Gyr ago, and the Virgo Radial Merger (VRM), where the progenitor collided with the MW disk within the last 3 Gyr. These two scenarios make different predictions about observable structure in local phase space, because the morphology of debris depends on how long it has had to phase mix. The recently-identified phase-space folds in Gaia DR3 have positive caustic velocities, making them fundamentally different than the phase-mixed chevrons found in simulations at late times. Roughly 20 per cent of the stars in the prograde local stellar halo are associated with the observed caustics. Based on a simple phase-mixing model, the observed number of caustics are consistent with a merger that occurred 1–2 Gyr ago. We also compare the observed phase-space distribution to FIRE-2 Latte simulations of GSE-like mergers, using a quantitative measurement of phase mixing (2D causticality). The observed local phase-space distribution best matches the simulated data 1–2 Gyr after collision, and certainly not later than 3 Gyr. This is further evidence that the progenitor of the ‘last major merger’ did not collide with the MW proto-disk at early times, as is thought for the GSE, but instead collided with the MW disk within the last few Gyr, consistent with the body of work surrounding the VRM.

Motion Correction for Brain MRI Using Deep Learning and a Novel Hybrid Loss Function

Purpose: Motion-induced magnetic resonance imaging (MRI) artifacts can deteriorate image quality and reduce diagnostic accuracy, but motion by human subjects is inevitable and can even be caused by involuntary physiological movements. Deep-learning-based motion correction methods might provide a solution. However, most studies have been based on directly applying existing models, and the trained models are rarely accessible. Therefore, we aim to develop and evaluate a deep-learning-based method (Motion Correction-Net, or MC-Net) for suppressing motion artifacts in brain MRI scans. Methods: A total of 57 subjects, providing 20,889 slices in four datasets, were used. Furthermore, 3T 3D sagittal magnetization-prepared rapid gradient-echo (MP-RAGE) and 2D axial fluid-attenuated inversion-recovery (FLAIR) sequences were acquired. The MC-Net was derived from a UNet combined with a two-stage multi-loss function. T1-weighted axial brain images contaminated with synthetic motions were used to train the network to remove motion artifacts. Evaluation used simulated T1- and T2-weighted axial, coronal, and sagittal images unseen during training, as well as T1-weighted images with motion artifacts from real scans. The performance indices included the peak-signal-to-noise ratio (PSNR), the structural similarity index measure (SSIM), and visual reading scores from three blinded clinical readers. A one-sided Wilcoxon signed-rank test was used to compare reader scores, with p &lt; 0.05 considered significant. Intraclass correlation coefficients (ICCs) were calculated for inter-rater evaluations. Results: The MC-Net outperformed other methods in terms of PSNR and SSIM for the T1 axial test set. The MC-Net significantly improved the quality of all T1-weighted images for all directions (i.e., the mean SSIM of axial, sagittal, and coronal slices improved from 0.77, 0.64, and 0.71 to 0.92, 0.75, and 0.84; the mean PSNR improved from 26.35, 24.03, and 24.55 to 29.72, 24.40, and 25.37, respectively) and for simulated as well as real motion artifacts, both using quantitative measures and visual scores. However, MC-Net performed poorly for images with untrained T2-weighted contrast because the T2 contrast was unseen during training and is different from T1 contrast. Conclusion: The proposed two-stage multi-loss MC-Net can effectively suppress motion artifacts in brain MRI without compromising image quality. Given the efficiency of MC-Net (with a single-image processing time of ~40 ms), it can potentially be used in clinical settings.

Impact of an Intergenerational Book Club on Cross-Generational Attitudes: A Mixed-Methods Study

ABSTRACT This mixed-methods study explores the impact of an intergenerational book club, Pages Across Ages, on cross-generational attitudes between older adults and college-aged students. Amidst growing concerns over ageism and demographic shifts, the study investigates how structured dialogue around selected literary works can facilitate understanding and empathy across generations. Pages Across Ages comprised weekly in-person and virtual meetings to discuss Kristin Hannah’s The Four Winds, a novel selected for its potential to foster point-driven conversation about relevant issues across the age continuum. Employing a combination of qualitative and quantitative measures, including the Aging Semantic Differential scale, the study reveals significant shifts in attitudes post-participation. Qualitative data from focus groups corroborate these findings, highlighting themes of mutual learning, changing perspectives, and social justice discussions as a result of intergroup contact. This research underscores the potential of book clubs, which have a rich history in America for their ability to act as vehicles for social change, as platforms for fostering intergenerational engagement and addressing age-related prejudices.

Seeking the most informative design of test specimens for learning constitutive models

Accurate calibration of constitutive models is vital for predicting the mechanical behavior of engineering materials under various loading conditions. Traditionally, the calibration process involves a series of experiments on specimens with simple geometries to capture the complexities in the constitutive models. Each single test conveys a small amount of information that a well-trained human brain can handle, resulting in a large number of experiments needed for a complete calibration. Therefore, traditional calibration approaches are usually costly and time-consuming. With recent advancements in computational techniques, there is an emerging opportunity to leverage geometrically complex specimens in experiments to obtain a larger amount of information for computers to learn and calibrate the model. Despite some initial success, the most important question remains unsettled: How much information does a mechanical test convey? In this work, we answer this question by incorporating information entropy as a quantitative measure in the design of mechanical test specimens. We demonstrate the viability of the proposed approach by comparing the performance of selected test specimens for learning the plasticity model of sheet metal, e.g., the Hill48 anisotropic elastic-plastic model in this case. An optimal entropy criterion is proposed for selecting the appropriate heterogeneous test specimen for inverse calibration, depending on the cardinality of the stress state space considered in the model. Finally, Bayesian optimization is applied to uniaxial and biaxial tension specimens, using the stress state entropy as an objective function, to investigate the general principles of designing specimens with maximum information for learning constitutive models.

A rapid and quantitative absorption-based measurement to study the impact of antibiotics on bacterial growth

Abstract Given the global rise in antimicrobial resistance levels, an urgent need exists to obtain the Minimal Inhibitory Concentration (MIC) of an antibiotic as early as possible. In this paper we present the first test results of a light-based concept where the interaction of a laser beam with the drug-bacterium sample is used for calculating MIC values within 6 hours after cultivation. For this preliminary study, a total of 163 drug-bacterium pairs were tested and benchmarked with broth microdilution (BMD). The pathogen set included Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, Staphylococcus aureus, Staphylococcus capitis, Staphylococcus cohnii, Staphylococcus epidermis, Staphylococcus haemolyticus, Enterococcus and Streptococcus pneumoniae. The selected drugs belonged to 10 different classes. The method under investigation showed a categorical concordance of 86.1% and an essential agreement of 80.3% with BMD. Due to its simplicity, the concept can be easily implemented on existing commercial platforms. This research shows a promise for further studies potentially leading to a novel concept that can be employed to rapidly determine MIC values.&amp;#xD;