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Nevin Manimala Statistics

Can Satellites Predict Yield? Ensemble Machine Learning and Statistical Analysis of Sentinel-2 Imagery for Processing Tomato Yield Prediction

Sensors (Basel). 2023 Feb 26;23(5):2586. doi: 10.3390/s23052586.

ABSTRACT

In this paper, we propose an innovative approach for robust prediction of processing tomato yield using open-source AutoML techniques and statistical analysis. Sentinel-2 satellite imagery was deployed to obtain values of five (5) selected vegetation indices (VIs) during the growing season of 2021 (April to September) at 5-day intervals. Actual recorded yields were collected across 108 fields, corresponding to a total area of 410.10 ha of processing tomato in central Greece, to assess the performance of Vis at different temporal scales. In addition, VIs were connected with the crop phenology to establish the annual dynamics of the crop. The highest Pearson coefficient (r) values occurred during a period of 80 to 90 days, indicating the strong relationship between the VIs and the yield. Specifically, RVI presented the highest correlation values of the growing season at 80 (r = 0.72) and 90 days (r = 0.75), while NDVI performed better at 85 days (r = 0.72). This output was confirmed by the AutoML technique, which also indicated the highest performance of the VIs during the same period, with the values of the adjusted R2 ranging from 0.60 to 0.72. The most precise results were obtained with the combination of ARD regression and SVR, which was the most successful combination for building an ensemble (adj. R2 = 0.67 ± 0.02).

PMID:36904790 | DOI:10.3390/s23052586

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Nevin Manimala Statistics

Ambient Electromagnetic Radiation as a Predictor of Honey Bee (Apis mellifera) Traffic in Linear and Non-Linear Regression: Numerical Stability, Physical Time and Energy Efficiency

Sensors (Basel). 2023 Feb 26;23(5):2584. doi: 10.3390/s23052584.

ABSTRACT

Since bee traffic is a contributing factor to hive health and electromagnetic radiation has a growing presence in the urban milieu, we investigate ambient electromagnetic radiation as a predictor of bee traffic in the hive’s vicinity in an urban environment. To that end, we built two multi-sensor stations and deployed them for four and a half months at a private apiary in Logan, UT, USA. to record ambient weather and electromagnetic radiation. We placed two non-invasive video loggers on two hives at the apiary to extract omnidirectional bee motion counts from videos. The time-aligned datasets were used to evaluate 200 linear and 3,703,200 non-linear (random forest and support vector machine) regressors to predict bee motion counts from time, weather, and electromagnetic radiation. In all regressors, electromagnetic radiation was as good a predictor of traffic as weather. Both weather and electromagnetic radiation were better predictors than time. On the 13,412 time-aligned weather, electromagnetic radiation, and bee traffic records, random forest regressors had higher maximum R2 scores and resulted in more energy efficient parameterized grid searches. Both types of regressors were numerically stable.

PMID:36904786 | DOI:10.3390/s23052584

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Nevin Manimala Statistics

A Novel Approach for Direction of Arrival Estimation in Co-Located MIMO Radars by Exploiting Extended Array Manifold Vectors

Sensors (Basel). 2023 Feb 24;23(5):2550. doi: 10.3390/s23052550.

ABSTRACT

Multiple-input multiple-output (MIMO) radars enable better estimation accuracy with improved resolution in contrast to traditional radar systems; thus, this field has attracted attention in recent years from researchers, funding agencies, and practitioners. The objective of this work is to estimate the direction of arrival of targets for co-located MIMO radars by proposing a novel approach called flower pollination. This approach is simple in concept, easy to implement and has the capability of solving complex optimization problems. The received data from the far field located targets are initially passed through the matched filter to enhance the signal-to-noise ratio, and then the fitness function is optimized by incorporating the concept of virtual or extended array manifold vectors of the system. The proposed approach outperforms other algorithms mentioned in the literature by utilizing statistical tools for fitness, root mean square error, cumulative distribution function, histograms, and box plots.

PMID:36904753 | DOI:10.3390/s23052550

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Nevin Manimala Statistics

Self-Monitoring Diabetes-Related Foot Ulcers with the MyFootCare App: A Mixed Methods Study

Sensors (Basel). 2023 Feb 24;23(5):2547. doi: 10.3390/s23052547.

ABSTRACT

People with diabetes-related foot ulcers (DFUs) need to perform self-care consistently over many months to promote healing and to mitigate risks of hospitalisation and amputation. However, during that time, improvement in their DFU can be hard to detect. Hence, there is a need for an accessible method to self-monitor DFUs at home. We developed a new mobile phone app, “MyFootCare”, to self-monitor DFU healing progression from photos of the foot. The aim of this study is to evaluate the engagement and perceived value of MyFootCare for people with a plantar DFU over 3 months’ duration. Data are collected through app log data and semi-structured interviews (weeks 0, 3, and 12) and analysed through descriptive statistics and thematic analysis. Ten out of 12 participants perceive MyFootCare as valuable to monitor progress and to reflect on events that affected self-care, and seven participants see it as potentially valuable to enhance consultations. Three app engagement patterns emerge: continuous, temporary, and failed engagement. These patterns highlight enablers for self-monitoring (such as having MyFootCare installed on the participant’s phone) and barriers (such as usability issues and lack of healing progress). We conclude that while many people with DFUs perceive app-based self-monitoring as valuable, actual engagement can be achieved for some but not for all people because of various facilitators and barriers. Further research should target improving usability, accuracy and sharing with healthcare professionals and test clinical outcomes when using the app.

PMID:36904750 | DOI:10.3390/s23052547

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Nevin Manimala Statistics

A New Gain-Phase Error Pre-Calibration Method for Uniform Linear Arrays

Sensors (Basel). 2023 Feb 24;23(5):2544. doi: 10.3390/s23052544.

ABSTRACT

In this paper, we consider the gain-phase error calibration problem for uniform linear arrays (ULAs). Based on the adaptive antenna nulling technique, a new gain-phase error pre-calibration method is proposed, requiring only one calibration source with known direction of arrival (DOA). In the proposed method, a ULA with M array elements is divided into M-1 sub-arrays, and the gain-phase error of each sub-array can be uniquely extracted one by one. Furthermore, in order to obtain the accurate gain-phase error in each sub-array, we formulate an errors-in-variables (EIV) model and present a weighted total least-squares (WTLS) algorithm by exploiting the structure of the received data on sub-arrays. In addition, the solution to the proposed WTLS algorithm is exactly analyzed in the statistical sense, and the spatial location of the calibration source is also discussed. Simulation results demonstrate the efficiency and feasibility of our proposed method in both large-scale and small-scale ULAs and the superiority to some state-of-the-art gain-phase error calibration approaches.

PMID:36904749 | DOI:10.3390/s23052544

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Nevin Manimala Statistics

Microneurography as a minimally invasive method to assess target engagement during neuromodulation

J Neural Eng. 2023 Mar 10. doi: 10.1088/1741-2552/acc35c. Online ahead of print.

ABSTRACT

Peripheral neural signals recorded during neuromodulation therapies provide insights into local neural target engagement and serve as a sensitive biomarker of physiological effect. Although these applications make peripheral recordings important for furthering neuromodulation therapies, the invasive nature of conventional nerve cuffs and longitudinal intrafascicular electrodes (LIFEs) limit their clinical utility. Furthermore, cuff electrodes typically record clear asynchronous neural activity in small animal models but not in large animal models. Microneurography, a minimally invasive technique, is already used routinely in humans to record asynchronous neural activity in the periphery. However, the relative performance of microneurography microelectrodes compared to cuff and LIFE electrodes in measuring neural signals relevant to neuromodulation therapies is not well understood.&#xD;&#xD;Approach. To address this gap, we recorded cervical vagus nerve (cVN) electrically evoked compound action potentials (ECAPs) and spontaneous activity in a human-scaled large animal model – the pig. Additionally, we recorded sensory evoked activity and both invasively and non-invasively evoked CAPs from the great auricular nerve (GAN). In aggregate, this study assesses the potential of microneurography electrodes to measure neural activity during neuromodulation therapies with statistically powered and pre-registered outcomes (https://osf.io/y9k6j).&#xD;&#xD;Main results. The cuff recorded the largest ECAP signal (p<0.01) and had the lowest noise floor amongst the evaluated electrodes. Despite the lower signal to noise ratio, microneurography electrodes were able to detect the threshold for neural activation with similar sensitivity to cuff and LIFE electrodes once a dose-response curve was constructed. Furthermore, the microneurography electrodes recorded distinct sensory evoked neural activity.&#xD;&#xD;Significance. The results show that microneurography electrodes can measure neural signals relevant to neuromodulation therapies. Microneurography could further neuromodulation therapies by providing a real-time biomarker to guide electrode placement and stimulation parameter selection to optimize local neural fiber engagement and study mechanisms of action.

PMID:36898148 | DOI:10.1088/1741-2552/acc35c

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Nevin Manimala Statistics

Clinical and Laboratory Characteristics Predicting the Severity of Carbon Monoxide Poisoning in Children: A Single-Center Retrospective Study

Pediatr Emerg Care. 2023 Mar 13. doi: 10.1097/PEC.0000000000002927. Online ahead of print.

ABSTRACT

OBJECTIVES: Carbon monoxide poisoning (COP) is extremely common throughout the world. The purpose of this study was to assess the demographic, clinical, and laboratory characteristics predicting the severity COP in children.

METHODS: The study included 380 children diagnosed with COP between January 2017 and January 2021 and 380 healthy controls. Carbon monoxide poisoning was diagnosed based on the medical history and a carboxyhemoglobin (COHb) level of more than 5%. The patients were classified as mild (COHb 10%), moderate (COHb 10%-25%), or severely (COHb > 25%) poisoned.

RESULTS: The mean age of the severe group was 8.60 ± 6.30, for the moderate group was 9.50 ± 5.81, for the mild group was 8.79 ± 5.94, and for the control group was 8.95 ± 5.98. The most common place of exposure was at home and all cases were affected accidentally. The coal stove was the most common source of exposure, followed by natural gas. The most common symptoms were nausea/vomiting, vertigo, and headache. Neurologic symptoms such as syncope, confusion, dyspnea, and seizures were more common in the severe group. A total of 91.3% of the children had hyperbaric oxygen therapy, 3.8% were intubated, and 3.8% were transferred to intensive care in the severe group, whereas no death or sequela was observed. Mean platelet volume and red cell distribution width had the highest area under the curve in the receiver operating characteristic analysis (0.659; 0.379). A positive and low statistically significant relationship was found between COHb levels and troponin and lactate levels in the severe group (P < 0.05).

CONCLUSIONS: Carbon monoxide poisoning progressed more severely in children presented with neurological symptoms and have elevated red cell distribution width and mean platelet volume. Even in severe COP cases, satisfactory results have been obtained with early and appropriate treatment.

PMID:36898143 | DOI:10.1097/PEC.0000000000002927

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Nevin Manimala Statistics

Efficient Estimation of the Binaural Masking Level Difference Using a Technique Based on Manual Audiometry

J Speech Lang Hear Res. 2023 Mar 10:1-16. doi: 10.1044/2022_JSLHR-22-00519. Online ahead of print.

ABSTRACT

PURPOSE: The Masking Level Difference (MLD) has been used for decades to evaluate the binaural listening advantage. Although originally measured using Bekesy audiometry, the most common clinical use of the MLD is the CD-based Wilson 500-Hz technique with interleaved N0S0 and N0Sπ components. Here, we propose an alternative technique based on manual audiometry as a faster way of measuring the MLD. The article describes the advantages to this administration technique and evaluates if it is a viable alternative for the Wilson technique.

METHOD: Data were retrospectively analyzed on 264 service members (SMs). All SMs completed both the Wilson and Manual MLDs. Descriptive and correlational statistics were applied to evaluate the comparisons between the two techniques and highlight the differences. Equivalence measures were also completed to compare the tests using a standardized cutoff score. Analyses were also made to compare both techniques to subjective and objective measures of hearing performance.

RESULTS: Moderate to high positive correlations were determined between Wilson and Manual measures of each threshold (N0Sπ and N0S0). Although the Manual and Wilson MLD techniques produced significantly different thresholds, simple linear transformations can be used to obtain approximately equivalent scores on the two tests, and agreement was high for using these transformed scores to identify individuals with substantial MLD deficits. Both techniques had moderate test-retest reliability. The Manual MLD and components had stronger correlations to the subjective and objective hearing measures than the Wilson.

CONCLUSIONS: The Manual technique is a faster method for obtaining MLD scores that is just as reliable as the CD-based Wilson test. With the significant reduction in assessment time and comparable results, the Manual MLD is a viable alternative for direct use in the clinic.

PMID:36898137 | DOI:10.1044/2022_JSLHR-22-00519

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Nevin Manimala Statistics

Evidence for the Cusp Effect in η’ Decays into ηπ^{0}π^{0}

Phys Rev Lett. 2023 Feb 24;130(8):081901. doi: 10.1103/PhysRevLett.130.081901.

ABSTRACT

Using a sample of 4.3×10^{5} η^{‘}→ηπ^{0}π^{0} events selected from the ten billion J/ψ event dataset collected with the BESIII detector, we study the decay η^{‘}→ηπ^{0}π^{0} within the framework of nonrelativistic effective field theory. Evidence for a structure at π^{+}π^{-} mass threshold is observed in the invariant mass spectrum of π^{0}π^{0} with a statistical significance of around 3.5σ, which is consistent with the cusp effect as predicted by the nonrelativistic effective field theory. After introducing the amplitude for describing the cusp effect, the ππ scattering length combination a_{0}-a_{2} is determined to be 0.226±0.060_{stat}±0.013_{syst}, which is in good agreement with theoretical calculation of 0.2644±0.0051.

PMID:36898113 | DOI:10.1103/PhysRevLett.130.081901

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Nevin Manimala Statistics

More Updates to Come of Tisagenlecleucel in Pediatric and Young Adult Patients With Relapsed/Refractory Acute Lymphoblastic Leukemia in the ELIANA Trial: Could the Statistical Methodology Be Further Improved?

J Clin Oncol. 2023 Mar 10:JCO2202839. doi: 10.1200/JCO.22.02839. Online ahead of print.

NO ABSTRACT

PMID:36898080 | DOI:10.1200/JCO.22.02839