Active Measures Research Articles

Valvular and myocardial fibroblast activation in aortic stenosis: a prospective positron emission tomography study

Abstract Introduction In patients with aortic stenosis, fibrosis is a common pathophysiological feature of leaflet thickening as well as left ventricular decompensation as it transitions from hypertrophy to heart failure. Valvular fibrosis can be quantified by contrast-enhanced computed tomography, and myocardial fibrosis by late gadolinium enhancement on magnetic resonance imaging, but neither can detect the activity of fibrosis and extracellular matrix remodelling. Gallium-68 Fibroblast Activation Protein Inhibitor (68Ga-FAPI) binds to activated fibroblasts, the key effector cell of fibrogenesis, and provides a measure of fibroblast activation and fibrosis activity. We aimed to measure fibrosis activity in the aortic valve and left ventricular myocardium of patients with aortic stenosis using 68Ga-FAPI uptake. Methods In a prospective observational cohort, patients with aortic stenosis and control subjects with normal aortic valves underwent transthoracic echocardiography, 68Ga-FAPI positron emission tomography, computed tomography, and magnetic resonance imaging. Valvular and myocardial 68Ga-FAPI uptake was quantified using the target-to-background ratio (TBRmax). Valvular non-calcific volume was quantified on computed tomography and replacement myocardial fibrosis was quantified by late gadolinium enhancement on magnetic resonance imaging. Results Fifty patients with aortic valve disease (9 with aortic sclerosis, and 7 with mild, 23 with moderate and 11 with severe aortic stenosis; 72±8 years, 70% male) and 4 control subjects (66±7 years, 50% male) participated. Increased 68Ga-FAPI uptake was observed in the aortic valves of patients with aortic sclerosis and stenosis and peaked in those with moderate disease (Figure 1). TBRmax of 68Ga-FAPI uptake correlated with the aortic valve non-calcific volume (r=0.354, p<0.05) on computed tomography. Thirty-one patients (62%) had myocardial 68Ga-FAPI uptake, of whom half (n=17; 34%) also had late gadolinium enhancement corresponding to the region of 68Ga-FAPI uptake (Figure 2). Myocardial 68Ga-FAPI uptake correlated with increased indexed left ventricular mass (r=0.333, p<0.05) and left ventricular wall thickness (r=0.385, p<0.05). Conclusions For the first time, we have identified both valvular and myocardial fibrosis activity in patients with aortic stenosis. Valvular fibroblast activation is increased in patients with aortic sclerosis and stenosis, peaking in patients with moderate disease and correlating with leaflet thickening. Myocardial fibroblast activation is seen in the majority of patients with aortic stenosis both in areas with and without established fibrosis, and is associated with indices of adverse left ventricular remodelling. Activated fibroblasts are thus an important potential treatment target in the valve and myocardium, with 68Ga-FAPI positron emission tomography holding major promise in better understanding the pathophysiology, progression and consequences of aortic stenosis.

Reduction of screen induced myopia by parental interventions

Abstract Background Excessive use of digital devices, including smartphones and tablets, has been shown to increase the risk of myopia in children. Gaps persist in understanding parental attitudes towards handheld screen use and effective interventions guiding eye health policies. This study examined the associations between parental behavior related to myopia and children’s handheld screen use. Methods Data obtained from 395 parents of pre-adolescents (Mean age 10.63; SD 1.09) were used, collected from an online community panel. Parents reported on various behavioral determinants related to myopia and their child’s screen time: knowledge, attitude, risk perception and self-efficacy. They reported on their child’s frequency and amount of screen use. Logistic regression analysis was used to assess associations between variables, using parental efforts to reduce screens as outcome measure. Results Of the 395 participating 9-12 year-olds, 73.4% of the children spent up to two hours a day on recreational handheld screens, 26% more than two hours. Of the parents surveyed, 28.1% perceived the risk of screen-induced myopia as significant, prompting 62.6% of them to take active measures to minimize screen time. The more knowledge parents had on child myopia the more they attempted to reduce screen time (OR = 2.57; 95% CI [1.57-4.19], p = <.001). Moreover, a more negative attitude towards screens was significantly related to attempting to reduce screen time (OR = 1.26; 95% CI[1.17-1.35],p = <.001). Key messages • These findings emphasize a need to address parental knowledge and attitude towards myopia and screen time reduction. • We recommend increasing knowledge, influencing attitude and searching for alternatives as a part of behavioral change strategies.

Self-Efficacy, Patient Activation, and the Burden of Inflammatory Bowel Disease on Patients' Daily Lives.

The effective management of inflammatory bowel disease (IBD) requires complex self-management behaviors. Both patient activation (the degree to which patients are willing and able to engage in care) and self-efficacy (one's confidence in performing certain behaviors) are thought to play an important role in chronic disease self-management, but patient activation is a broad concept that can be more difficult to precisely target than self-efficacy. We aimed to describe the relationship between patient activation, self-efficacy, and the burden of IBD on patients' daily lives. Patients with IBD were recruited from a single center to complete a survey including the Patient Activation Measure (PAM-13®), the IBD Self-Efficacy Scale (IBD-SES), and an IBD-specific patient-reported outcome measure. Using multivariable linear regression, we examined the relationship between IBD burden, self-efficacy, and patient activation, adjusting a priori for age, gender, IBD type, IBD medications, active corticosteroid use, anxiety, and depression. We performed a post-hoc mediation analysis to examine self-efficacy as a potential mediator in the relationship between patient activation and the burden of IBD on patient's daily lives. A total of 132 patients with IBD completed the survey (59% Crohn's disease, 41% ulcerative colitis, 52% female). Higher levels of patient activation and higher levels of self-efficacy were each associated with lower IBD burden (patient activation: ß = -1.9, p < 0.001, self-efficacy: ß = -2.6, p < 0.001). Post hoc mediation analysis confirmed that the relationship between patient activation and daily IBD burden was mediated by self-efficacy (Average Causal Mediation Effect = -1.00, p < 0.001, proportion mediated = 0.62, p < 0.001). The relationship between patient activation and IBD burden is highly mediated by self-efficacy, suggesting that self-efficacy could be a more precise target for intervention. Future studies could focus on targeting self-efficacy to build individuals' confidence in IBD self-management and testing of IBD-tailored self-management programs to ultimately improve disease outcomes.

New insights into the prediction for the potential of soil organic carbon accumulation: From the perspective of non-equilibrium statistical mechanics

The accumulation of soil organic carbon (SOC) is significant for soil health and ecosystem services. Numerous studies have assessed the dynamic changes of SOC by considering the microbial system as an equilibrium system. However, they failed to reveal the complexity of the SOC accumulation/loss process, as the microbial system is a non-equilibrium system affected by stochastic fluctuations from the external environment. This study is the first to explore the complex non-equilibrium relationship between microbial carbon use efficiency (CUE) and SOC by using potential landscape and flux in non-equilibrium statistical mechanics. Nitrogen (N) was identified as the most critical environmental factor influencing CUE on a global scale, with the transition between the carbon loss state and the carbon sequestration state observed along N gradients. Random perturbations of other environmental factors could also trigger transition. Non-equilibrium thermodynamic quantities indicated that carbon sequestration had the potential to be achieved when N = 0.5 g/kg, where active soil management measures should be taken. Furthermore, the non-equilibrium relationship between CUE and SOC was clarified through potential energy analysis, where the average deviation between predictions and actual observations of SOC is about 1.9792 g/kg. This study provides an effective framework for predicting SOC accumulation.

High-speed 3D measurement using the kinoform array and light source shift

A new, to the best of our knowledge, fringe projector using the kinoform is proposed in this Letter. The kinoform array makes the hologram easy to manufacture, and the phase shift is realized by light source shift. The fringes can be shifted at a high speed due to the high-speed switch of the light source. An active binocular 3D measurement system using the proposed projector is demonstrated, and a binocular matching algorithm from coarse to fine using a laser speckle and fringe phase is proposed. Three laser diodes are adopted as light sources, and the three-step phase-shifting is achieved. The dimension of the projector is 30 mm × 26 mm × 12 mm and the switching speed is up to 1.5 kHz. The 3D measurement speed reaches 70 fps in the experiment.

Adaptive Vision-Based Gait Environment Classification for Soft Ankle Exoskeleton

Lower limb exoskeletons have been developed to improve functionality and assist with daily activities in various environments. Although these systems utilize sensors for gait phase detection, they lack anticipatory information about environmental changes, which limits their adaptability. This paper presents a vision-based intelligent gait environment detection algorithm for a lightweight ankle exosuit designed to enhance gait stability and safety for stroke patients, particularly during stair negotiation. The proposed system employs YOLOv8 for real-time environment classification, combined with a long short-term memory (LSTM) network for spatio-temporal feature extraction, enabling the precise detection of environmental transitions. An experimental study evaluated the classification algorithm and soft ankle exosuit performance through three conditions using kinematic analysis and muscle activation measurements. The algorithm achieved an overall accuracy of over 95% per class, which significantly enhanced the exosuit’s ability to detect environmental changes, and thereby improved its responsiveness to various conditions. Notably, the exosuit increased the ankle dorsiflexion angles and reduced the muscle activation during the stair ascent, which enhanced the foot clearance. The results of this study indicate that advanced spatio-temporal feature analysis and environment classification improve the exoskeleton’s gait assistance, improving adaptability in complex environments for stroke patients.

Insurance Solution for Climate Change: Legislation Analysis in Türkiye

In the light of changing and evolving parameters throughout the World, risk definitions vary as well, leading to the necessity to make new risk definitions in various fields in addition to those, the effects of which can be easily observed and measured, such as technology and information securiAty. This change also manifests itself in the insurance industry based on climate change. The increase in the number and scale of climate-based natural disasters throughout the World, in conjunction with global warming, made the economic losses caused by natural disasters visible. Climate changeA caused and will continue to cause significant changes in many fields of the insurance industry, such as property insurances, agricultural insurances, and health insurance. The insurance industry attempts to mitigate the negative impacts of climate change through active risk measures such as mapping, risk analysis, funding research, collective data sharing, and active participation in climate protection activities throughout the World. However, it is crucial for the State and affiliated public enterprises to support this process as a regulatory and adequate power, create a suitable legal, financial and regulatory framework for private sector initiatives, and conduct informative activities about the importance of insurance in natural disasters. Emerging financial burden should be divided between individual-public-private enterprises, and this division should be made in a balanced and fair manner in the light of the applicable legislation. This study primarily addresses the devastating impacts of climate change on the World and Turkey, which emerged notably in the recent era and the financial burden brought about by this. Then the issue of responsibility of the public sector, which is responsible for taking necessary and adequate measures against climate change, was explored in the context of both national legislation and international agreements. The adequacy of the applicable legislation for the State and public enterprises to create a suitable consciousness-raising, a preventive and compensatory legal framework specific to the climate change in Turkey was reviewed, and suggestions were made.

Evaluating a digital tool for supporting people affected by breast cancer: a prospective randomized controlled trial—the ADAPT study

PurposeThis study reports the findings from the ADAPT randomized controlled trial (RCT), concerning the impact of a digital tool for supported self-management in people affected by breast cancer on patient activation as the primary outcome, with health-related quality of life (HRQoL), and health status as secondary outcomes.MethodsWomen with early-stage breast cancer were randomly assigned to standard care (control) or standard care in addition to the breast cancer digital tool (intervention). Data were collected using a demographic questionnaire, the Patient Activation Measure (PAM-13), the European Organization for Research and Treatment of Cancer Core Quality of Life Questionnaire (EORTC QLQ-C30), and the EuroQol 5-Dimension 5-Level questionnaire (EQ-5D-5L) at baseline, 6 weeks, 3 months, 6 months, and 1 year from diagnosis. Linear mixed effect model regression was used to assess the effect of the digital tool over the first year from diagnosis while correcting for intra-participant correlation.ResultsA total of 166 participants were included, with 85 being randomized into the intervention. No significant differences (p > 0.05) in the PAM-13 scores, EORTC QLQ-C30 scales (global QoL, physical functioning, emotional functioning, pain, fatigue), and EQ-5D-5L Index between the control and intervention groups were observed. It is important to note that there was significant non-adherence within the intervention group.ConclusionThe breast cancer digital tool had no statistically significant impact on patient activation, HRQoL, and health status over time compared to standard care alone in women with early-stage breast cancer. Future research should focus on identifying and addressing barriers to digital tool engagement to improve efficacy.Clinical trial informationThe study was registered at https://clinicaltrials.gov (NCT03866655) on 7 March 2019 (https://clinicaltrials.gov/study/NCT03866655).

Crimean Congo hemorrhagic fever virus exposure among febrile patients, cattle herders, and cattle herds in Cameroon

Problem addressedCrimean Congo hemorrhagic fever (CCHF) is a tick-borne disease with high fatality rates and an expansive geographic distribution, yet disease prevalence data in Cameroon is lacking. ObjectiveThis study aimed to determine CCHF virus (CCHFV) seroprevalence and tick distribution among cattle herders and febrile patients in West and Centre Cameroon. Methods and approachTwo cross-sectional serological studies of human and cattle were conducted from October to December 2021 and from June to July 2022, which included the collection of ticks. Enzyme-linked immunosorbent assay (ELISA) were used to detect anti-CCHFV antibodies, while a knowledge, attitudes, and practice (KAP) survey assessed tick and tickborne disease related knowledge and behaviors among herders. Tick identification used morphological keys. ResultsThe KAP survey showed adequate tick knowledge (94.5 %) among herders but poor understanding of disease transmission, with favorable attitudes towards tick control (24.7 %) but inadequate implementation. Rhipicephalus annulatus (64.1 %) predominated among the 1,296 ticks collected during each rainy season. Among cattle, 27.4 % were seropositive, and seropositivity was associated with specific villages, cattle age (>4 years), and female sex. Herders had a 17.8 % seroprevalence, while febrile patients had 8.3 %, with higher rates in those >20 years old for both groups. Self-reported tick removal by herders after contact and grazing may increase CCHFV exposure. ConclusionsThis study confirms CCHFV circulation in rural West Cameroon and unexpected exposure risk in Yaounde, highlighting the need for active entomological surveillance and preventive measures in transhumance and cattle market activities. Establishing an occupation-based surveillance system can help identify CCHFV hotspots to prevent outbreaks.

External Moderation of Reactor Core Neutrons for Optimized Production of Ultra-Cold Neutrons

The ultra-cold neutron (UCN) source being commissioned at North Carolina State University’s PULSTAR reactor is uniquely optimized for UCN production in the former graphite-filled thermal column outside of the reactor pool. The source utilizes a remote moderation design, which is particularly well suited to the PULSTAR reactor because of its high thermal and epithermal neutron leakage from the core face. This large non-equilibrium flux from the core is efficiently transported to the UCN source through the specially designed beam port in order to optimize UCN production at any given reactor power. The increased distance to the source from the core also greatly limits the heat load on the cryogenic system. A MCNP (Monte Carlo N-Particle) model of this system was developed and is in good agreement with gold foil activation measurements using a test configuration as well as with the real UCN source’s heavy water moderator. These results established a firm baseline for estimates of the cold neutron flux available for UCN production and prove that remote moderation in a thermal column port is a valuable option for future designs of cryogenic UCN sources.

Electrophysiological signature of interoceptive attention: a spectral and source localization analysis.

The ability to attend to and consciously process interoceptive signals is deemed critical for the development of minimal self, adaptive self-regulation and affective experience, and optimal expression of both instrumental and executive cognitive functions. Yet, notwithstanding the richness of theoretical proposals concerning inferential accounts of interoception, empirical evidence is still scarce. Building on such premises, this study was designed to investigate the electrophysiological signature of cognitive processes leading to aware coding of interoceptive signals via EEG source localization. Thirty-six healthy participants completed an interoceptive accuracy task, i.e., the Heartbeat Counting Task (HCT), while we collected task-related and resting state electrophysiological activity. eLORETA modelling and statistical nonparametric mapping were used to estimate intracortical current density and link such estimates to participants' performance at the task. Source analysis highlighted higher current density estimates for alpha frequencies during HCT with respect to rest, with the primary cortical generator in the right parahippocampal gyrus. Also, a set of medial cortical structures-primarily represented by the cingulate gyrus-showed significant relation between task-related changes in current density estimates for beta oscillations and HCT scores. Findings suggest the informativity of EEG task-related measures of neural activation when used to assess interoceptive skills, as well as of the potential of metrics and analysis based on source localization in the quest to improve our understanding of interoceptive accuracy and neurofunctional correlates of related active inferences.

Review of Photodetectors for Space Lidars

Photodetectors play a critical role in space lidars designed for scientific investigations from orbit around planetary bodies. The detectors must be highly sensitive due to the long range of measurements and tight constraints on the size, weight, and power of the instrument. The detectors must also be space radiation tolerant over multi-year mission lifetimes with no significant performance degradation. Early space lidars used diode-pumped Nd:YAG lasers with a single beam for range and atmospheric backscattering measurements at 1064 nm or its frequency harmonics. The photodetectors used were single-element photomultiplier tubes and infrared performance-enhanced silicon avalanche photodiodes. Space lidars have advanced to multiple beams for surface topographic mapping and active infrared spectroscopic measurements of atmospheric species and surface composition, which demand increased performance and new capabilities for lidar detectors. Higher sensitivity detectors are required so that multi-beam and multi-wavelength measurements can be performed without increasing the laser and instrument power. Pixelated photodetectors are needed so that a single detector assembly can be used for simultaneous multi-channel measurements. Photon-counting photodetectors are needed for active spectroscopy measurements from short-wave infrared to mid-wave infrared. HgCdTe avalanche photodiode arrays have emerged recently as a promising technology to fill these needs. This paper gives a review of the photodetectors used in past and present lidars and the development and outlook of HgCdTe APD arrays for future space lidars.

Validation of the Patient Activation Measure (PAM-13) among individuals with chronic spinal cord injury in mainland China

Context/objective: The 13-item Patient Activation Measure (PAM-13) is the most widely used generic patient activation measure, but spinal cord injury (SCI) related psychometric evaluation of PAM-13 has not been explored globally. This study aimed to assess the validity of the Chinese version of the PAM-13 (PAM-13-C) for individuals with chronic spinal cord injury (CSCI). Design: Cross-sectional study. Setting: Shanghai Sunshine Rehabilitation Center, and some participants were recruited in a WeChat group (the most commonly used social media platform in China). Participants: 284 individuals with spinal cord injury who had lived with the injury for ≥0.5 year. Interventions: NA. Outcome measures: The PAM-13-C, global QoL, seven-item generalized anxiety disorder scale (GAD-7) and nine-item patient health questionnaire (PHQ-9), and General Self-Efficacy Scale (GSES) were used. Results: The mean (SD) PAM-13-C score was 57.4 (16.5). The highest percentage of NA could be observed in item 9 (12.0%). Floor and ceiling effects of the total scores of PAM-13-C were small (0.7% and 6.7%), but a ceiling effect could be observed among all items. Exploratory Factor Analysis supported a one-factor model of the PAM-13-C (CFI = 0.97; RMSEA = 0.07). Construct validity was established through correlation analysis among the PAM-13-C, GAD-7/PHQ-9, global QoL, and GSES. The PAM-13-C demonstrated excellent internal consistency (Cronbach’s α = 0.95) and acceptable test-retest reliability. Conclusion: The PAM-13-C is a reliable and valid measure of patient activation for individuals with CSCI in China.

Magnetic Railway Sleeper Detector

In an ever expanding railway network all around the world, the need for track maintenance grows steadily. Traditionally, one major part of track maintenance is ramming large vibrating steel picks into the gravel between and under railway sleepers to compress the gravel and generate a safe substructure. Even today, maintenance personnel still have to manually locate the sleepers if they cannot be detected by computer vision systems or visually by the operator. Here we developed a first of its kind magnetic sleeper detector, even able to find sleepers, buried in gravel, undetectable by vision based systems. Our approach of magnetic detection is based on a DC magnetic field excitation and a detector moving with respect to the rail system, including the sleepers and fasteners for mounting the rails. Due to railway application constraints a large air gap between the sensor and the sleeper structure is required, which significantly complicates the magnetic sensing task for robust sleeper detection. The design and optimization of the magnetic circuit was based on extensive 3D simulation studies to ensure highest possible variation in magnetic flux density at the sensor locations for absence and presence of a sleeper. Furthermore, a low noise and high sensitivity electronic circuit has been realized to cope with sensor signal offsets from unknown or changing sensor orientations with respect to the earth’s magnetic field, or magnetic interferences from other trains potentially passing by during active measurements. Since we only want to detect sleepers in close vicinity of the moving sensor system, digital signal processing of the acquired signals can easily compensate for disturbing slowly changing or static field components within real world application scenarios. We demonstrate that magnetic detection of even buried sleepers on railway tracks is possible for distances of up to 172 mm between the sensor and the sleeper. This enables an even higher level of railway maintenance automation previously impossible in certain scenarios.

Deferasirox's Anti-Chemoresistance and Anti-Metastatic Effect on Non-Small Cell Lung Carcinoma.

Clinically approved iron chelators, originally designed to address iron overload disorders, have emerged as potential anticancer agents. Deferasirox (Def), a tridentate iron chelator, has demonstrated antiproliferative effects in cancer. Background/Objectives: This study aims to elucidate the mechanism of action of Def and its impact on non-small cell lung carcinoma (NSCLC). Methods: NSCLC A549 cells were treated with Def to assess cytotoxicity, the effect on nuclear and mitochondrial pathways, and iron-containing proteins and genes to evaluate anti-metastasis and chemoresistance. A lung carcinoma mouse model was used for in vivo studies. Results: Our findings revealed that Def induced cytotoxicity, effectively chelated intracellular iron, and triggered apoptosis through the increase in phosphatidylserine externalization and caspase 3 activity. Additionally, Def caused G0/G1 cell cycle arrest by downregulating the ribonucleotide reductase catalytic subunit. Furthermore, Def perturbed mitochondrial function by promoting the production of reactive oxygen species and the inhibition of glutathione as a measurement of ferroptosis activation. Def demonstrated inhibitory effects on cell migration in scratch assays, which was supported by the upregulation of n-myc downstream-regulated gene 1 and downregulation of the epidermal growth factor receptor protein. Also, Def downregulated one of the main markers of chemoresistance, the ABCB1 gene. In vivo experiments using a lung carcinoma mouse model showed that Def treatment did not affect the animal's body weight and showed a significant decrease in tumor growth. Conclusions: This investigation lays the groundwork for unraveling Def action's molecular targets and mechanisms in lung carcinoma, particularly within iron-related pathways, pointing out its anti-metastasis and anti-chemoresistance effect.

Culturally appropriate options for diabetes self‐management: Results from a patient‐centered comparative effectiveness study

AbstractThis project compared the effectiveness of two evidence‐based models of culturally competent diabetes health promotion: the diabetes self‐management support empowerment model (DSMS) and the chronic care model (CCM). Our primary outcome was improvement in patient capacity for diabetes self‐management as measured by the diabetes knowledge questionnaire (DKQ) and the patient activation measure (PAM). Our secondary outcome was patient success at diabetes self‐management as measured by improvement in A1c, depression scores using the PHQ‐9, and body mass index (BMI). We also gathered data on the cultural competence of the program using the Consumer Assessment of Healthcare Providers and Systems Cultural Competence Set. We compared patient outcomes in two existing sites in Albuquerque, New Mexico that serve a large population of Latinx diabetes patients from low‐income households. Participants were enrolled as dyads—a patient participant (n = 226) and a social support participant (n = 226). Outcomes over time and by program were analyzed using longitudinal linear mixed modeling, adjusted for patient participant demographic characteristics and other potential confounding covariates. Secondary outcomes were also adjusted for potential confounders. Interactions with both time and program helped to assess outcomes. This study did not find a difference between the two sites with respect to the primary outcome measures and only one of the three secondary outcomes showed differential results. The main difference between programs was that depression decreased more for CCM than for DSMS. An exploratory, subgroup analysis revealed that at CCM, patient participants with a very high A1c (&gt;10) demonstrated a clinically meaningful decrease. However, given the higher cultural competence rating for the CCM, statistically significant improvement in depression, and the importance of social support to the patients, results suggest that a culturally and contextually situated diabetes self‐management and education program design may deliver benefit for patients, especially for patients with higher A1c levels.Key Points The team was interdisciplinary. The information presented describes results of both qualitative and quantitative data and involves interpretations that are interdisciplinary in nature. The study design used methods from multiple disciplines.

A study of the ultrasonic and audible frequency response of commercial loudspeakers for use as parametric acoustic arrays

Parametric acoustic loudspeakers (PAL), also known as parametric acoustic arrays (PAA), are speakers that use ultrasonic waves to generate directive audible sound. They emit an ultrasonic carrier modulated in amplitude by the desired audible signal, and due to non-linear propagation in air, this signal is reproduced in the audible range. Typical applications include audio reproduction for entertainment, but also active noise control and acoustic measurement of material properties. PAA typically consist of an array of piezoelectric transducers set on a surface. However, there are other speakers in the market that, due to their characteristics, could also achieve the PAL effect. This work examines the performance of commercial speakers when reproducing. First, the ultrasonic frequency response of each speaker is examined in free-field conditions using exponential sine sweeps (ESS). This enables searching for potential carrier frequencies to modulate the ESS in the ultrasonic range. The ESS are next modulated in the desired ultrasonic region and emitted through each speaker, obtaining their audible and ultrasonic impulse responses. The results show that some commercial speakers can also operate as PALs, which is interesting from an industrial point of view as it lowers costs and simplifies the assembly process.

Bridge scour monitoring based on active heating and temperature measurement method

Bridge scour monitoring based on active heating and temperature measurement method

Evaluation of Concrete Fatigue Damage with Elastic Wave-based Measurement Techniques

Fatigue damage is a progressive and permanent change in the internal material structure due to cyclic loading. The cyclic loads can be due to wind, waves, temperature variation, and traffic loads. Each cyclic load application introduces micro-damages that accumulate to induce failure. Detecting these micro-damages requires sensitive measuring techniques. Hence this research compares the sensitivity of different measuring techniques applied to fatigue experiments of concrete. The applied NDT are the passive acoustic emission technique (AET) and active ultrasonic measurements. In addition, linear variable differential transformers (LVDTs) are applied as a reference measurement. Accordingly in this research, cylindrical concrete samples are subjected to monotonic and cyclic Brazilian splitting tests. The cylinders are 100 mm in diameter and 150 mm in length. The cyclic load is applied to these samples with a loading frequency of 5 Hz. During the tests, the damage evolution is monitored with AET, ultrasonic measurements and LVDTs. There are eight AE sensors attached to the sample. The two LVDTs are positioned at the center of the sample's front and back side. Besides passively monitoring the acoustic emissions, the AET sensors are also used to do active ultrasonic measurements. The research reports the comparison conducted on the deformations and cracks measured with the LVDTs, the damage growth identified with the AET, and the change in the ultrasonic pulse velocity measurements. In addition, the study also presents the damage analysis capacity of the methods across different types of loading: monotonic, constant amplitude, and stepped fatigue loading. The comparison shows that combination of AET and ultrasonic velocity measurement is a sensitive indicator for damage growth.

Standardized Wound Care: Patchwork Practices?

Standardized care is crucial in health care for ensuring consistent, safe, high-quality, efficient, and evidence-based practices. Care pathways that standardize procedures promote adherence to best practices, reduce variability in treatment, and encourage collaboration among health care teams. This approach ultimately improves patient outcomes, enhances safety, and boosts the overall effectiveness of health care services. However, despite these benefits being widespread across most of the U.S. health care system, wound care stands out as an area where standards can vary significantly. The inconsistency in wound care standards in the United States can be traced to several factors. These include limited structured clinical wound care education, the discretion of health care providers in different business environments, differences in wound care settings, varying access to advanced treatments and technology, patient demographics and socioeconomic status, as well as differences in state laws and regional or institutional practices. Addressing these disparities requires a comprehensive approach that considers the complex interplay of the abovementioned factors. Active measures are needed to improve access, equity, and the quality of wound care services for all patients, regardless of where they live, their socioeconomic status, their health care coverage, or the business interests of providers and their institutions as well as of vendors marketing wound care products inconsistent with evidence-based practice. By understanding and actively addressing these factors, we can work toward achieving more standardized, evidence-based, and patient-centered practices in wound care across the nation.