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Algorithmic analysis of a complex reliability system subject to multiple events with a preventive maintenance strategy and a Bernoulli vacation policy through MMAPs
No full textIn this work, a single-unit multi-state system is considered. The system is subject to internal failures, as well as external shocks with multiple consequences. It also incorporates a preventive maintenance strategy and a Bernoulli vacation policy for the repairperson. It is algorithmically modeled in both continuous and discrete time using Marked Markovian Arrival Processes (MMAP). The system’s operation/degradation level is divided into an indeterminate number of levels. Upon returning from a vacation period, the repair technician may initiate corrective repair, perform preventive maintenance, replace the unit, remain idle at the workplace, or begin a new vacation period. The decision in the latter two cases is made probabilistically based on the system’s operational level. This methodology allows the model and its associated measures to be algorithmically derived in both
transient and stationary regimes, presented in a matrix-algorithmic form. Analytical-matrix methods are used to obtain the system’s steady-state behaviour as well as various performance measures. Costs and rewards are introduced to analyze when the system becomes profitable. Measures associated with costs over time and in the stationary regime are defined and considered for optimization studies. A numerical example demonstrates the versatility of the model by solving a probabilistic optimization problem using a multi-objective Pareto analysis approach and performing a comparative evaluation of multiple models. Genetic algorithm is applied to find the optimization results in the reduced solution space. All modeling and associated measures have been computationally implemented in Matlab.The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Juan Eloy Ruiz-Castro reports financial support was provided by Government of Andalusia. Juan Eloy Ruiz-Castro reports financial support was provided by Spain Ministry of Science and Innovation. Juan Eloy Ruiz-Castro reports financial support was provided by IMAG-María de Maeztu. Juan Eloy Ruiz-Castro reports a relationship with Government of Andalusia that includes: funding grants. Juan Eloy Ruiz-Castro reports a relationship with Spain Ministry of Science and Innovation that includes: funding grants. Juan Eloy Ruiz-Castro reports a relationship with IMAG-María de Maeztu that includes: funding grants. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Funding for open access charge: Universidad de Granada / CBU
Hemispheric asymmetry for visual information processing in 3D space
No full textThere is an asymmetry in the ability to process visual information in the left and right visual fields. Extensive
literature has consistently shown that young, healthy human adults exhibit a visuospatial bias towards the left
hemifield (pseudoneglect). This leftward bias has traditionally been demonstrated through horizontal line
bisection tasks in 2D experimental settings. However, as research progressed into 3D space, where lines are
presented far from the observer, the dissipation of the classical leftward bias tended to reverse into a rightward
bias. The precise distances at which the leftward bias, a neutral point, and rightward biases occur remain unclear.
Here, we present a meta-analysis to model how bisection performance changes across 3D space quantitatively.
We identified the boundary conditions where leftward biases reverse into rightward biases and at what distances
this change can be predicted using line bisection. A total of 30 samples (25 studies, 142 bisection-error effects,
n = 720) were included. Overall, the analysis revealed a significant leftward bias within near space, followed by a
rightward bias in far space. Three critical ranges for visuospatial asymmetries across depth were revealed in
young, healthy adults: (1) significant leftward biases up to 48 cm, (2) no reliable leftward/rightward biases from
49 to 87 cm, and (3) significant rightward biases beyond 88 cm. In addition, we revealed significant moderating
effects of participant age (50 + years old), the use of tools to perform bisection, and the control of retinal size
across depth. The findings establish important benchmarks when investigating visuospatial asymmetries and
could inform clinical assessment.European Union’s Horizon 2020 - Marie SkłodowskaCurie Actions (project Nº 101149355
Sex-specific acute effects of postural hammock exercise on autonomic regulation and plantar pressure in individuals with low back pain
No full textThis work was supported by UALtransfierE (ref:TRFE–SI–2022/012) and was approved by the University of Almeria Ethics Committee (UALBIO2023/005). EM-R was supported by the Juan de la Cierva Grant (JDC2023-389 051490-I) funded by MCIN/AEI/10.13039/501100011033 and by “FSE+"Background: Low back pain is a leading cause of disability worldwide, with significant socioeconomic implications. The autonomic nervous system is implicated in the pathophysiology of back pain, with changes in heart rate variability (HRV) and plantar pressure observed in affected individuals. This study aimed to evaluate the effects of a single postural hammock-based exercise session on HRV and plantar pressure in individuals with low back pain. Methods: Forty-three participants (mean age 48.88 ± 11.87, 67 % women) with lower back pain were assessed before and after a 60-min exercise session, which incorporated flexibility, strength training, and deep breathing techniques designed to enhance autonomic regulation in a postural hammock. HRV was measured using a Polar heart monitor, and plantar pressure was analyzed with the Podoprint S4 System. Linear mixed-effects models were used to analyze the effects of the intervention, and subgroup analyses based on sex were performed using R Studio (v. 4.3). Results: The results indicated a significant reduction in heart rate (mean difference: − 5.2 bpm, p ≤ 0.01) and an increase in the HRV parameter very low frequency power (VLF; mean difference: 0.6 ms2, p ≤ 0.01), across all participants. No other HRV parameters showed significant changes. Women showed greater improvements in heart rate (mean difference: − 6.5 bpm, p ≤ 0.01) and VLF (mean difference: 0.6 ms2, p = 0.011) compared to men. However, no significant changes were observed in plantar pressure parameters. Conclusion: These findings suggest that a single session of postural hammock exercise may influence autonomic balance, particularly in women, but does not appear to affect plantar pressure in a static standing position. Further research is needed to explore the long-term benefits and mechanisms underlying these effects.UALtransfierE, TRFE–SI–2022/012University of Almeria Ethics Committee, UALBIO2023/005MCIN/AEI/10.13039/501100011033 and by “FSE+", Juan de la Cierva Grant (JDC2023-389 051490-I
Multianalyte method to simultaneously evaluate occupational exposure to anesthetic gases in urine samples from healthcare professionals
No full textManuscrito sin revisión, subido a revista para su consideración por el editor.This study was carried out in the framework of the European Partnership for the Assessment of Risks from Chemicals (PARC) and received funding from the European Union Horizon Europe research and innovation program under Grant Agreement #101057014. However, views and opinions expressed are those of the author(s) alone and do not necessarily reflect those of the European Union or the Health and Digital Executive Agency. Neither the European Union nor the granting authority can be held responsible for them. The study also received co-funding from the Biomedical Research Networking Center-CIBER de Epidemiología y Salud Pública (CIBERESP) of the Institute of Health Carlos III (ISCIII). The authors are grateful to the ISCIII for the predoctoral contract granted to A Pérez-Cantero (Grant no. FI24/00299), the Sara Borrell Program awarded to A Rodríguez-Carrillo (Grant no. CD24/00116), and the Miguel Servet Program granted to V Mustieles (Grant no. CP25/00111). The authors are also grateful for the Salvador de Madariaga Program del Ministerio de Universidades (PRX23_00541) for a grant to MF Fernández. This article is part of the PhD thesis developed by L Espín-Moreno under the Clinical Medicine and Public Health Program of the University of Granada.Objective: Monitoring occupational exposure in hospital settings requires valid non-invasive exposure assessment methods. We aimed to develop a multianalyte method to characterize and quantify urinary levels of anesthetic gases in healthcare professionals. Methods: Urine samples were collected from 37 recently exposed and 24 non-exposed professionals. A multianalyte method was developed and validated to measure urinary concentrations of desflurane, isoflurane, sevoflurane, and its main metabolite, hexafluoroisopropanol, using headspace gas chromatography coupled to mass spectrometry (HS-GC-MS). Results: The methodology was successfully validated. It demonstrated adequate linearity and sensitivity [correlation coefficients (R²): 99.5–99.9%]. Limits of detection for the anesthetic gases were 0.15 to 0.60 ng/mL, and limits of quantification were 0.5 to 2.0 ng/mL. The recovery percentage ranged from 95.17% to 102.40%, and relative standard deviations were below 15%. Detectable concentrations in exposed participants ranged from 1.0 to 3.80 ng/mL (mean 0.53 ng/mL) for desflurane, 0.5 to 19.59 ng/mL (mean 1.39 ng/mL) for sevoflurane, and 2.0 to 729.35 ng/mL (mean 49.74 ng/mL) for hexafluoroisopropanol (HFIP). No detectable concentrations of isoflurane were found in the exposed volunteers, nor were any of the anesthetics found in the non-exposed volunteers. Conclusions: A multianalyte HS-GC-MS method was successfully developed to simultaneously determine four anesthetic gases in urine samples and was validated in real-world samples from healthcare professionals. Future studies are needed to investigate the safety of exposure to these compounds for anesthesiologists and operating room nurses.European Union Horizon Europe research and innovation, #101057014Institute of Health Carlos III (ISCIII)ISCIII, Grant no. FI24/00299, CD24/00116, CP25/00111Ministerio de Universidades, PRX23_0054
Invariant tori of a class of discontinuous systems
No full textBy using suitable canonical transformation and Moser's small twist Theorem, we prove the existence of invariant tori of large amplitude for a periodically forced second-order differential equation with a jump discontinuity.National Natural Science Foundation of China (Grant No. 12271119)Science and Technology Project of Guangxi (Guike AD23023002
Standardized analytical multivariate methods via agnostization of LF-NMR signals – Updating extra virgin olive oil authentication as practical example
No full textExtra virgin olive oil (EVOO) is a high-value commodity traded worldwide; thus, accurate quality control analyses
are essential to ensure its genuineness. In this context, a universal analytical methodology capable of
delivering precise, fast and robust quality assessments would be highly beneficial for stakeholders. This study
extends the instrument-agnostizing methodology from chromatography to low-frequency field nuclear magnetic
resonance spectroscopy (LF-NMR). The proposed approach outlines the required steps to generate instrumentagnostic
fingerprints and demonstrates its application through the development of a global multivariate
model. For this purpose, 93 edible vegetable oils (76 EVOO and 17 non-olive ones) and 9 vegetable oil blends
were analyzed using two different LF-NMR spectrometers operating at 100 MHz and 80 MHz 1H field frequencies.
Each LF-NMR signal was subjected to the instrument-agnostizing methodology to obtain harmonized
LF-NMR fingerprints. To demonstrate the usefulness of this methodology, principal component analysis was
performed to assess the instrument-related variability before and after the instrument-agnostizing methodology.
Finally, partial least squares-discriminant analysis models were developed for each dataset of LF-NMR fingerprints
and evaluated using four main classification performance metrics (sensitivity, specificity, precision and
accuracy). The developed classification model with 100 MHz LF-NMR fingerprints achieved the required values
of quality performance metrics in a conformity scenario, showing for external and cross-instrument validation
sets a sensitivity of 96 % in both cases, and highlighting a precision of 100 % and 96 %, respectively. The
excellent outcome highlights the viability of the instrument-agnostizing methodology, enabling consistent and
accurate quality control across laboratories, regardless of the LF-NMR instrument used
The effectiveness of manual therapy in people with chronic non-specific low back pain: an umbrella review with meta-analysis
No full textBackground:
Chronic nonspecific low back pain (CNLBP) is a widely recognized condition worldwide. Its clinical management must be based on the best current evidence to achieve optimal outcomes, yet there is still a lack of consensus on its clinical approach.
Objective:
To evaluate the effectiveness of manual therapy (MT) on pain intensity, frequency, disability, and quality of life in adults with chronic nonspecific low back pain (CNLBP).
Methods:
A comprehensive search was conducted in 8 databases, covering January 2014 to October 2024. Inclusion criteria included adults with CNLBP, MT interventions provided by healthcare professionals, and systematic reviews (SRs) of randomized controlled trials (RCT). Data on pain intensity, pain frequency, disability, and quality of life measured using validated scales were extracted. The results were shown according to the type of intervention and the period evaluated (short, medium, or long term).
Results:
About 21 SRs with 35,711 participants were included. MT included spinal manipulation, soft-tissue techniques, myofascial techniques, massage, and neuromeningeal techniques. MT outperforms other interventions regarding pain (MD −10.52; 95% CI −13.71 to −7.33) and disability (SMD −0.60; 95% CI−0.80 to −0.40) in the short term, and this effect diminishes over time.
Conclusions:
MT offers significant short-term benefits in reducing pain and disability in individuals with CNLBP. Like most interventions for CNLBP, the effects of MT tend to diminish over time. Nevertheless, MT may serve as a valuable treatment option for short-term pain relief and functional improvement. Limitations in the methodological quality and long-term follow-up of included studies constrain the conclusions that can be drawn about long-term efficacy.Registry of Osteopaths of Spain (ROE
The role of rhythm in learning to read in children with and without reading difficulties: an intervention study
No full textBackground:
Recent research indicates that rhythm can influence the development of phonological awareness and, thus, the learning to read.
Aims:
This work aimed to test the relationship between rhythm and reading in Spanish through an intervention study in children with and without reading difficulties.
Methods:
We used a pre-test/post-test design and worked with a sample of 131 children in the first year of primary education (29 with reading difficulties) who were randomly assigned to three groups, depending on whether they received training on phonological awareness, rhythm, or phonological awareness and rhythm. For rhythm training, exercises based on reproducing the sequence of stressed and unstressed syllables of one or more words using the syllable “la” were used. In the phonological awareness-only or rhythm-only groups, mathematical exercises were also used.
Results:
The results indicated that children improved in word reading in all training groups. Mediation analyses with the whole sample suggested that rhythm was related to word reading through phonological awareness. Moreover, children without difficulties improved in phonological awareness, but to a greater extent in the groups where rhythm was trained. Children with difficulties improved in reading pseudowords, but only when phonological awareness or rhythm was trained separately.
Conclusions:
These results suggest that rhythm training can facilitate the development of phonological awareness. For children with reading difficulties, rhythm training may be useful for improving the reading of novel words, but it should be done separately from phonological awareness.AEI/10.13039/501100011033 - (PID2019-110174RB-I00
Forecasting user perceptions of mHealth apps: AI-driven insights from large-scale user-generated content
No full textUser perceptions of mHealth apps are critical for forecasting adoption trends, optimizing app design, and evaluating their broader societal implications for public health and digital inclusion. Understanding how users engage with these applications is essential for their sustained use. This research incorporates AI-driven methodologies to systematically analyze large-scale user-generated content (UGC), providing predictive insights into consumer behavior and digital health engagement. Through three interconnected stages, this paper contributes to technological forecasting, digital health management, and marketing analytics by applying Natural Language Processing (NLP) and Large Language Models (LLMs) to classify brand associations in mHealth app reviews. At the first stage, 849,918 reviews from the most downloaded mHealth apps in the US were analyzed and categorized into tracking, nutrition, step counters, and rest/meditation apps. Using BERT-based topic modeling (BERTopic) and KMeans clustering, we classify key topics under Keller's brand association dimensions. At a second stage, a predictive classification model was developed using fine-tuned DistilBERT. At a third stage, an ANOVA analysis was used to examine differences in user attitudes based on brand associations and app type. Findings highlight the high number of product-related attributes mentioned in user conversations. However, emotional benefits are those driving higher user satisfaction with mHealth apps.Spanish Ministry of Science and Innovation - (TED2021-129513B-C21)Public University of Navarre - (PJUPNA2023-11395)Ministry of Economic Transformation, Industry, Knowledge and Universities of the Regional Government of Andalusia - (PREDOC_00298)NAIR Center and Government of Navarre - grant under "Programa MRR Investigo
Local urban climate zones, environmental pollution, disease prevalence and mortality: Evidence from Barcelona
No full textIn recent decades, environmental pollution has reached alarming levels due to significant population growth and
the increase in transport and industrial activities. Numerous studies indicate that elevated pollutant levels
correlate with heightened mortality rates and an increased risk of disease, leading to substantial health expenditures that many governments and citizens cannot afford. Therefore, it is essential to implement measures that
mitigate these effects and improve the standard of living of the population. This research analyzes the relationship between urban morphological conditions (Urban Index (UI) and Proportion Vegetation (PV), environmental pollutants (Aerosols, Sulfur Dioxide (SO2), Nitrogen Dioxide (NO2) and Carbon Monoxide (CO)) and the
risk of developing diseases (breast, prostate, lung, stomach, colorectal cancer, stroke, chronic obstructive pulmonary disease (COPD), dementia, suicides) in the Local Climate Zones (LCZ) of the city of Barcelona, using
Sentinel 5P and Landsat 8 satellite images. The results reveal that dense LCZs have less cover of vegetation,
greater levels of contaminants, and a higher risk of disease and death. The reduced quantity of green space in
these LCZs inhibits the dispersion of pollutants, associated with increased health issues. This leads to more health
problems. This study provides critical insights into the interconnections among pollutants, vegetation, LCZs, and
health. This information can help come up with city planning ideas that make life better for people who live
there