Heliyon

Journal: Heliyon

Publisher

Elsevier

ISSN

2405-8440

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Publications 1 - 10 of 18

Identifying treatment non-responders based on pre-treatment gait characteristics - A machine learning approach
Visscher, Rosa M.S.; Murer, Julia; Fahimi, Fatemeh; et al. (2023)
Heliyon
Background: Paediatric movement disorders such as cerebral palsy often negatively impact walking behaviour. Although clinical gait analysis is usually performed to guide therapy decisions, not all respond positively to their assigned treatment. Identifying these individuals based on their pre-treatment characteristics could guide clinicians towards more appropriate and personalized interventions. Using routinely collected pre-treatment gait and anthropometric features, we aimed to assess whether standard machine learning approaches can be effective in identifying patients at risk of negative treatment outcomes. Methods: Observational data of 119 patients with movement disorders were retrospectively extracted from a local clinical database, comprising sagittal joint angles and spatiotemporal parameters, derived from motion capture data pre- and post-treatment (physiotherapy, orthosis, botulin toxin injections, or surgery). Participants were labelled based on their change in gait profile score (GPS, non-responders with a decline in GPS of <1.6° vs. responders). Their pre-treatment features (sagittal joint angles, spatiotemporal parameters, anthropometrics) were used to train a support vector machine classifier with 5-fold cross-validation and Bayesian optimization within a MATLAB-based Classification Learner App. Results: An average accuracy of 88.2 ± 0.5 % was achieved for identifying participants whose gait will not respond to treatment, with 64 % true negative rate and an area under the curve of 88 %. Conclusion: Overall, a classical machine learning model was able to identify patients at risk of not responding to treatment, based on gait features and anthropometrics collected prior to treatment. The output of such a model could function as a warning signal, notifying clinicians that a certain individual might not respond well to the standard of care and that a more personalized intervention might be needed.
Semi-supervised learning with flexible threshold for non-intrusive load monitoring
Tang, Tao; Li, Keke; Su, Chang; et al. (2024)
Heliyon
Non-intrusive load monitoring (NILM) can obtain fine-grained power consumption information for individual appliances within the user without installing additional hardware sensors. With the rapid development of the deep learning model, many methods have been utilized to address NILM problems and have achieved enhanced appliance identification performance. However, supervised learning models require a substantial volume of annotated data to function effectively, which is time-consuming, laborious, and difficult to implement in real scenarios. In this paper, we propose a novel semi-supervised learning method that combines consistency regularization and pseudo-labels to help identification of appliances with limited labeled data and an abundance of unlabeled data. In addition, given the different learning difficulties of various appliance categories, for example, feature learning is more difficult for multi-state appliances than two-state appliances, the thresholds employed for different appliances are adjusted in a flexible way at each time step so that the informative unlabeled data and their pseudo-labels can be delivered. Experiments have been conducted on publicly available datasets, and the results indicate that the proposed method attains superior appliance identification performance compared to cutting-edge methods.
Growing cocoa in semi-arid climate and the rhythmicity of stem growth and leaf flushing determined by dendrometers
Waldburger, Thainná; Anken, Thomas; Walter, Achim; et al. (2024)
Heliyon
This study investigated the performance of cocoa trees within an irrigated cocoa plantation situated in the semi-arid region of Bahia, Brazil. Two treatments were compared: “full sun,” where cocoa trees were not shaded, and “shade,” where trees were covered with a shading net absorbing 30 % of the radiation. The number of leaves and the leaf area index (LAI) were assessed using destructive method on 8 trees. In addition, new flushing of leaves, categorized into four flushing stages, were assessed visually on a weekly basis during two years. The variation of the stem diameter was measured using dendrometer sensors (n = 12 trees). Yield parameters like dry bean yield and number of fruits (healthy and aborted) were assessed on 40 trees per treatment. Both treatments, performed well in the semi-arid region. Generative parameters, such as dry bean yield (±2,000 kg/ha), fruit healthy and abortion rate per plot, were unaffected by full sun and shade treatments. The treatments showed high fruit abortion rates of (±60 %), showing that there's still much room for yield optimization. Additionally, stem diameter of the trees showed a significant reduction of the stem growth (daily increase of stem diameter) and maximum daily shrinkage (daily variation of stem diameter) during the flushing of new leaves. This implies that the emergence of new leaves significantly influences stem growth, consequently affecting the fruits which are growing on the stem. This assumption was corroborated by the significantly increased fruit abortion rate during the flushing of new leaves (stages 1 & 2). These findings highlight the potential of dendrometers to quantify this effect what can be used in future to optimize management practices. By doing so, more effective strategies can be developed to enhance cocoa yield and overall productivity in semi-arid regions.
Enhancing the performance of beech-timber concrete hybrids by a wood surface pre-treatment using sol-gel chemistry
Kostić, Sanja; Meier, Sandro; Cabane, Etienne; et al. (2018)
Heliyon
Drought considerably affects physiological and biochemical processes in trees and thus also reproduction. However, little is known about shifts in reproductive strategies in relation to changes in water availability. We investigated cone and seed traits as well as needle and twig growth traits in pine trees along a natural precipitation gradient (290 mm–750 mm) and in a long-term irrigation experiment to understand reproductive responses to water availability. Combining multiple traits, we found that cone trait richness and divergence were positively correlated with water availability. This suggests drought-induced environmental filtering resulting in a reduced set of cone trait combinations. In contrast, seed trait diversity indices were negatively correlated with water availability, suggesting that pine trees tend to maximize seed trait dissimilarity in multiple dimensions to efficiently utilize scarce resources. Trade-offs between reproduction and vegetative growth were observed along the transect but not in the irrigation experiment, which may be a result of different drought severity between the two study regions. Our results highlight the importance of considering a broad aridity gradient and different spatial-temporal scales when studying plant reproductive responses to precipitation change. Furthermore, the present study indicates that quantifying complementary components of trait diversity allows to interpret ecologically complex changes in trait distribution in multiple dimensions.
Effects of endodontic irrigants on blood and blood-stained dentin
Zollinger, Adrian; Attin, Thomas; Mohn, Dirk; et al. (2019)
Heliyon
Objectives This study aimed to investigate bleaching effects of common endodontic irrigants on human whole blood and blood-stained dentin. Specifically, it was assessed whether sodium hypochlorite at a clinically recommended concentration (2.5% NaOCl) would bleach with similar efficacy as a peroxide-based irrigant at higher molarity (5% H2O2). Furthermore, the effects of a NaOCl-compatible chelator with a high affinity to iron (Dual Rinse HEDP) were investigated. Methods Human whole blood was mixed at a 1:20 ratio with either phosphate-buffered saline, 9% HEDP, 2.5% NaOCl, 2.5% NaOCl containing 9% HEDP, or 5% H2O2. Effects were assessed spectrometrically and photographically. Human dentin specimens were prepared with a methacrylate reservoir for liquids and a polished assessment side over 1 mm dentin thickness. Dentin was stained using human whole blood for 3 weeks and subsequently exposed to the irrigants for 60 min. Measurements were performed in the CIELAB color space. Results were compared using parametric tests with the alpha-type error set to 5%. Results When directly exposed, the solutions containing NaOCl completely discolored the blood, while the 5% H2O2 exerted a bleaching effect without complete dissolution of dissolved matter, and the pure 9% HEDP had no effect at all. The NaOCl solutions bleached blood-stained dentin more efficiently than H2O2 (p < 0.05). Conclusions Under the current conditions, the 2.5% NaOCl solution had a stronger bleaching effect on blood and blood-stained dentin than 5% H2O2. HEDP did not have any direct impact on blood color or NaOCl-derived bleaching.
Understanding reminiscence and its negative functions in the everyday conversations of young adults: A machine learning approach
Ferrario, Andrea; Demiray, Burcu (2024)
Heliyon
Reminiscence is the act of recalling or telling others about relevant personal past experiences. It is an important activity for all individuals, young and old alike. In fact, reminiscence can serve different functions that can support or be detrimental to one's well-being. Although previous studies have extensively investigated older adults' recalling of autobiographical memories, the evidence for young adults remains scarce. Therefore, in this work, we analyze young adults' production of reminiscence and their functions with a naturalistic observation method. Furthermore, we demonstrate that natural language processing and machine learning can automatically detect reminiscence and its negative functions in young adults' everyday conversations. We interpret machine learning model results using Shapley explanations. Our results indicate that young adults reminisce in everyday life mostly to connect with others through conversation, to compensate for a lack of stimulation or to recall difficult past experiences. Moreover, our models improve existing benchmarks from the literature on the automated detection of older adults' reminiscence in everyday life. Finally, our results may support the development of digital health intervention programs that detect reminiscence and its functions in young adults to support their well-being.
Brain vital signs as a quantitative measure of cognition: Methodological implementation in a care home environment
Ighalo, Joshua; Kirby, Eric D.; Song, Xiaowei; et al. (2024)
Heliyon
Introduction: Managing cognitive function in care homes is a significant challenge. Individuals in care have a variety of scores across standard clinical assessments, such as the Mini-Mental Status Exam (MMSE), and many of them have scores that fall within the range associated with dementia. A recent methodological advance, brain vital sign monitoring through auditory event-related potentials, provides an objective and sensitive physiological measurement to track abnormalities, differences, or changes in cognitive function. Taking advantage of point-of-care accessibility, the current study evaluated the methodological feasibility, the assessment of whether a particular research method can be successfully implemented, of quantitatively measuring cognition of care home residents using brain vital signs. Secondarily, the current study examined the relationship between brain vital signs, specifically the cognitive processing associated N400 component, and MMSE scores in care home residents. Materials and methods: Brain vital signs used the established N100 (auditory sensation), P300 (basic attention), and N400 (cognitive processing) event-related potential (ERP) components. A total of 52 residents were enrolled, with all participants evaluated using the MMSE. Participants were assigned into homogeneous groups based on their MMSE scores, and were categorized into low (n = 14), medium (n = 17), and high (n = 13) MMSE groups. Both brain vital sign measures and underlying ERP waveforms were examined. Statistical analyses used partial least squares correlation (PLS) analyses in which both MMSE and age were included as factors, as well as jackknife approaches, to test for significant brain vital sign changes. Results: The current study successfully measured and analyzed standardized, quantifiable brain vital signs in a care home setting. ERP waveform data showed specific N400 changes between MMSE groups as a function of MMSE score. PLS analyses confirmed significant MMSE-related and age-related differences in the N400 amplitude (p < 0.05, corrected). Similarly, the jackknife approach emphasized the N400 latency difference between the low and high MMSE groups. Discussion and conclusion: It was possible to acquire brain vital signs measures in care home residents. Additionally, the current study evaluated brain vital signs relative to MMSE in this group. The comparison revealed significant decreasing in N400 response amplitude (cognitive processing) as a function of both MMSE score and age, as well as a slowing of N400 latency. The findings indicate that objective neurophysiological measures of impairment are detectable in care home residents across the span of MMSE scores. Direct comparison to MMSE- and age-related variables represents a critical initial step ahead of future studies that will investigate relative improvements in sensitivity, validity, reliability and related advantages of brain vital sign monitoring.
Comparison of fetal heart rate variability by symbolic dynamics at the third trimester of pregnancy and low-risk parturition
Montalvo-Jaramillo, Cristian I.; Pliego-Carrillo, Adriana C.; Peña-Castillo, Miguel Á.; et al. (2020)
Heliyon
Fetal heart rate variability (fHRV) is an essential source of information to monitor fetal well-being during pregnancy. This study aimed to apply a nonlinear approach, known as symbolic dynamics (SD), for comparing human fHRV in the third trimester of pregnancy during active fetal state (TT) and active labor at term (P). We performed a longitudinal, prospective, descriptive, and comparative study composed of 42 longitudinal recordings of 5-minutes of fetal heartbeat interval series. Recordings were collected from 21 low-risk, healthy, pregnant women attending the Maternal and Child Research Center (CIMIGen), Mexico City. We calculated relevant linear parameters of fHRV between TT and P stages, such as the percentage of differences between adjacent RR intervals >5 ms (PRR5, related to vagal modulations) and other SD parameters such as the percentage of no variations between three successive symbols (%0V, reflects sympathetic modulations) and the probability of low variability with a threshold of 4 ms (POLVAR4, associated with a low variability). We identified statistical differences for PRR5 between TT and P (37.13% [28.47–47.60%] vs. 28.84% [19.36–36.76%], p = 0.03), respectively. Also, for 0V% (65.66% [59.01–71.80%] vs. 71.14% [65.94–75.87%], p = 0.03) and for POLVAR4 values (0.06 [0.04–0.11] vs. 0.15 [0.09–0.24], p = 0.002), respectively. Our results indicate that during parturition, the short-term fetal fHRV is decreased, showing a decreased vagal modulations and higher adrenergic response of the heart. These autonomic modifications may result from the fetal response to the stressful inflammatory challenge of labor. We thus confirmed that the analysis of the SD applied to fHRV time series could be a potential clinical biomarker to differentiate the fetal autonomic cardiac condition at different stages of pregnancy.
Tape-disc-loop-mediated isothermal amplification (TD-LAMP) method as noninvasive approach for diagnosis of cutaneous leishmaniasis caused by L. tropica
Taslimi, Yasaman; Habibzadeh, Sima; Goyonlo, Vahid Mashayekhi; et al. (2023)
Heliyon
Cutaneous leishmaniasis (CL) is a parasitic disease caused by the bite of infectious female sand flies with high socioeconomic burdens. There is currently no non-invasive, point-of-care, diagnostic method with high sensitivity and specificity available for CL. We herein report the development of a non-invasive tape disc (TD) sampling method combined with a loop-mediated isothermal amplification (LAMP) assay using primer sets targeting kinetoplast DNA (kDNA) of Leishmania tropica (L. tropica) with a colorimetric readout for species-specific diagnosis of CL. We tested our Tape-Disc (TD)-LAMP method on a panel of skin samples collected by TD from 35 confirmed L. tropica patients, 35 healthy individuals and 35 patients with non-L. tropica infections. The detection limit of the TD-LAMP assay was determined as 1 fg (fg), and the assay sensitivity and specificity of 97 % and 100 % for L. tropica infection, respectively. This non-invasive, sensitive and rapid diagnostic method warrants further exploration of its use for differential diagnosis of CL in disease endemic settings.
Head-mounted display versus computer monitor for visual attention screening: A comparative study
Baertsch, Tanja; Huang, Ying-Yin; Menozzi, Marino (2023)
Heliyon
Visual attention is crucial to many tasks during working. When it is impaired, the risk of occupational accidents is increased. A potential accident prevention would be the tracking of employees' attentional states to construct break regimes. There is a promising visual attention test administered on a computer monitor (CM) that has several advantages over widely used continuous performance tests in detecting inattentiveness in occupational environments. However, as the setup with a CM is impractical for the use in particular working environments (e.g., lack of space or disturbing exposure to light), the test was implemented into a head-mounted display (HMD). This study aimed to investigate whether the HMD version of the test is a suitable alternative to the CM version. For this purpose, participants (N = 30; 20–29 y) performed both tests. The performance on the HMD was significantly lower than on the CM. Moreover, the performances were compared with normative data recorded with a CM in a previous study. These data significantly differ from the data recorded with the CM in the present study. This emphasizes the importance of a standardized test environment, which could be provided by an HMD. Conclusively, this study revealed that the new VR tool, based on a previous test designed to assess visual skills in a complex visual environment, exhibited good psychometric property regarding the reliability. In additional, no problems were revealed regarding the functionality and usability of the HMD.

Publications 1 - 10 of 18

Journal: Heliyon

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