A reliable automatic categorization of respiratory effort is paramount for sleep-disordered breathing characterization from polysomnography. A respiratory effort related arousal (RERA) is a subtle ...breathing obstruction associated with an arousal. For identification of RERAs we focused on: chest and abdomen EMGs, airflow, and EEG; monitoring changes in ECG and SaO2. The quality of signals was assessed to overcome sensor associated problems and sporadic individual signal losses. We evaluated an ensemble learning and a deep learning approach using the engineered feature set trained on the 994 available records. The initial ensemble model was officially scored achieving a 0.081 area under the precision-recall curve (AUPRC) on a test set, whereas for the recurrent neural network model the average AUPRC was 0.295, obtained using 10-fold cross-validation.
In this work, measures of information dynamics are used to describe the dynamics of heart rate and cardiorespiratory interaction associated to sleep breathing disorders. In a large group of patients ...reporting repeated episodes of hypopneas, apneas (central, obstructive, mixed) and respiratory effort related arousals (RERA), we computed information storage of heart period variability and information transfer from heart period to airflow amplitude before, during and after each event. We find a general tendency to decrease of the information storage, suggesting higher complexity of the cardiac dynamics. The information transfer decreased during apneic events, and increased during milder disorders hypopneas and RERA. These findings reflect the impact of different sleep breathing disorders on respiratory sinus arrhythmia, and may have physiological and clinical relevance.
In this work, nonlinear model-free methods for bivariate time series analysis have been applied to study cardiorespiratory interactions. Specifically, entropy-based (i.e. Transfer Entropy and Cross ...Entropy) and Convergent Cross Mapping asymmetric coupling measures have been computed on heart rate and breathing time series extracted from electrocardiographic (ECG) and respiratory signals acquired on 19 young healthy subjects during an experimental protocol including spontaneous and controlled breathing conditions. Results evidence a bidirectional nature of cardiorespiratory interactions, and highlight clear similarities and differences among the three considered measures.
In-depth analysis of viewing behavior is an important factor informing educational video design. Research has largely addressed the support of such analyses for individual learners or has relied on ...aggregating user interactions with video players to derive potential points of interest. Only in recent years, with rising use of commercial video hosting platform, the data necessary to analyze viewing behavior on a larger scale and independently of active user interactions with learning content has become widely available. This article proposes to examine audience retention data to obtain in-depth information about the usage of educational videos and calculate metrics that can serve as a starting point for qualitatively examining the effects of didactic video design decisions. We propose a set of metrics and present a toolchain for extracting the necessary data from YouTube Analytics and calculating these metrics. The usefulness of these metrics is showcased on three different scenarios of use that are backed with real-world analytics data from flipped classroom courses. Our results show that the detailed audience retention data provided by video hosting platforms can provide insights that go beyond the current state-of-the-art in in-video learning analytics.
Chemical and physical transformations by milling are attracting enormous interest for their ability to access new materials and clean reactivity, and are central to a number of core industries, from ...mineral processing to pharmaceutical manufacturing. While continuous mechanical stress during milling is thought to create an environment supporting nonconventional reactivity and exotic intermediates, such speculations have remained without proof. Here we use in situ, real-time powder X-ray diffraction monitoring to discover and capture a metastable, novel-topology intermediate of a mechanochemical transformation. Monitoring the mechanochemical synthesis of an archetypal metal-organic framework ZIF-8 by in situ powder X-ray diffraction reveals unexpected amorphization, and on further milling recrystallization into a non-porous material via a metastable intermediate based on a previously unreported topology, herein named katsenite (kat). The discovery of this phase and topology provides direct evidence that milling transformations can involve short-lived, structurally unusual phases not yet accessed by conventional chemistry.
Honey liqueur is an alcoholic drink derived from honey and strong fruit brandy of suitable type, traditionally made in Serbia and other Balkan countries. Although European Union has regulated the ...levels of neonicotinoid insecticides in honey and pollen, there is an increased risk of the presence of these compounds in traditional products made from honey. The objective of this study was to develop an optimized LC–MS/MS analytical method with dispersive liquid–liquid microextraction (DLLME) and QuEChERS sample preparation procedures for analysis of seven neonicotinoids (dinotefuran, nitenpyram, thiamethoxam, clothianidin, imidacloprid, acetamiprid and thiacloprid) in honey liqueur. The LC–MS/MS conditions were optimized to unequivocally provide good chromatographic separation, selectivity and specificity of developed method. The method was validated to fulfill the requirements of SANCO/12495/2011 for both sample pretreatment procedures providing results for accuracy (R, 69.2–113.4% for DLLME; 71.8–94.9% for QuEChERS), precision (RSD expressed in terms of repeatability (3.21–10.20% for DLLME; 4.19–12.81% for QuEChERS) and within-laboratory reproducibility (9.11–16.63% for DLLME; 11.32–16.40% for QuEChERS)), limits of detection (LOD, 0.5–1.5μgL−1 for DLLME; 1.0–2.5μgL−1 for QuEChERS) and quantification (LOQ, 1.0–5.0μgL−1 for DLLME; 2.5–10.0μgL−1 for QuEChERS). Matrix effects were compensated by the use of matrix-matched calibration. Analysis of real honey liqueur samples obtained from local markets showed the presence of clothianidin or thiacloprid in four of the analyzed samples, therefore implicating the necessity of ongoing control of this type of traditional product.
•A LC–MS/MS method for neonicotinoids determination in honey liqueur is proposed.•Sample preparation with DLLME and QuEChERS was tested.•Good performance was obtained in terms of selectivity, precision and accuracy.•Honey liqueur samples were analyzed using the developed method.
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