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1712. Assessing muscular oxygenation during incremental exercise using near-infrared spectroscopy: comparison of three different methods
- Creator:
- Agbangla, N. F., Audiffren, M., and Albinet, C. T.
- Type:
- article, model:article, and TEXT
- Subject:
- NIRS, muscle hemodynamics, linear slope, amplitude, and area under the curve
- Language:
- English
- Description:
- Using continuous-wave near-infrared spectroscopy (NIRS), this study compared three different methods, namely the slope method (SM), the amplitude method (AM), and the area under the curve (AUC) method to determine the variations of intramuscular oxygenation level as a function of workload. Ten right-handed subjects (22±4 years) performed one isometric contraction at each of three different workloads (30 %, 50 % and 90 % of maximal voluntary strength) during a period of twenty seconds. Changes in oxyhemoglobin (Δ[HbO2]) and deoxyhemoglobin (Δ[HHb]) concentrations in the superficial flexor of fingers were recorded using continuous-wave NIRS. The results showed a strong consistency between the three methods, with standardized Cronbach alphas of 0.87 for Δ[HHb] and 0.95 for Δ[HbO2]. No significant differences between the three methods were observed concerning Δ[HHb] as a function of workload. However, only the SM showed sufficient sensitivity to detect a significant decrease in Δ[HbO2] between 30 % and 50 % of workload (p<0.01). Among these three methods, the SM appeared to be the only method that was well adapted and sensitive enough to determine slight changes in Δ[HbO2]. Theoretical and methodological implications of these results are discussed.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1713. Assessing spider community structure in a beech forest: Effects of sampling method
- Creator:
- Hövemeyer, Klaus and Stippich, Gabriele
- Type:
- article, model:article, and TEXT
- Subject:
- Aranae, sampling efficiency, catch compositon, beech forest, emergence traps, pitfall traps, soil samples, arboreal photo-eclectors, and ecological groups
- Language:
- English
- Description:
- The spider community of a beech forest on limestone was studied for one year using four sampling techniques: emergence traps, pitfall traps, soil samples, and arboreal eclectors. 87 spider species were recorded. Emergence traps and arboreal eclectors were particularly efficient in detecting spider species. Dominance identity (percentage similarity) was highest for catches from emergence traps and pitfall traps. Species recorded were assigned to various ecological groups. In terms of proportional abundance, representation of the ecological groups varied and appeared related to the sampling method used. Stratum type and type of prey capture strategy accounted for >60% of the variance in the catch results (canonical correspondence analysis). Proportional abundance of funnel-web spiders was much higher in pitfall trap catches (31.7%) than in any other method (1.0-11.6%).
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1714. Assessing the evolution of learning capabilities and disorders with a graphical exploratory analysis of surveys containing missing and conflicting answers
- Creator:
- Sánchez , Luciano, Couso , Inés, Otero , José , and Palacios , Ana
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Knowledge surveys, graphical exploratory analysis, multidimensional scaling, and fuzzy fitness-based genetic algorithms
- Language:
- English
- Description:
- The analysis of the evolution of learning with graphical maps is based on the placement of the individuals in positions that are computed on the basis of their answers to certain tests. These techniques are useful for detecting similarities between the knowledge profiles of the subjects and can also be used for assessing the acquisition of capabilities after a course. In this paper, we propose to extend some graphical exploratory analysis techniques to the case where there are missing or conflicting answers in the tests. We will also consider that either a missing or unknown answer, or a set of conflictive answers to a survey, is aptly represented by an interval or a fuzzy set. This representation causes that each individual in the map is no longer a point but a figure whose shape and size determine the coherence of the answers and whose position with respect to its neighbors determines the similarities and differences between the individuals.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1715. Assessing the evolution of learning capabilities and disorders with a graphical exploratory analysis of surveys containing missing nd conflicting answers
- Creator:
- Sánchez-Monedero, J., Hervás-Martínez , C., Gutiérrez , P. A., Ruz, Mariano Carbonero , Ramírez Moreno , M. C. , and Cruz-Ramírez , M.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Accuracy, differential evolution, extreme learning machine, multiclass classification, multiobjective, neural networks, and sensitivity
- Language:
- English
- Description:
- Accuracy alone can be deceptive when evaluating the performance of a classifier, especially if the problem involves a high number of classes. This paper proposes an approach used for dealing with multi-class problems, which tries to avoid this issue. The approach is based on the Extreme Learning Machine (ELM) classifier, which is trained by using a Differential Evolution (DE) algorithm. Two error measures (Accuracy, $C$, and Sensitivity, S) are combined and applied as a fitness function for the algorithm. The proposed approach is able to obtain multi-class classifiers with a high classification rate level in the global dataset with an acceptable level of accuracy for each class. This methodology is evaluated over seven benchmark classification problems and one real problem, obtaining promising results.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1716. Assessment of efficacy of treatment for supratentorial brain tumors in children
- Creator:
- Ashrapov, Jamshid
- Format:
- electronic, electronic resource, and remote
- Type:
- model:article, article, Text, and TEXT
- Language:
- English
- Description:
- The analysis of data of 97 children with brain tumors of supratentorial localization was carried out. To estimate treatment efficacy was used a rating scale of quality of life. It was determined that the quality of life of patients with brain gliomas depends on localization of neoplastic process, histological properties of tumor, preoperative neurologic deficit and the patient’s compensated condition., Jamshid Ashrapov, and Literatura
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1717. Assessment of environmental and socio-economic stress
- Creator:
- Helm, Dieter
- Type:
- model:article and TEXT
- Language:
- English
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1718. Assessment of Facial Expressions in Product Appreciation
- Creator:
- Popa, M. C., Rothkrantz, L. J. M., Wiggers, P., and Shan, C.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- product emotions, facial expression analysis, geometric features, appearance features, unsupervised learning, and supervised learning
- Language:
- English
- Description:
- In the marketing area, new trends are emerging, as customers are not only interested in the quality of the products or delivered services, but also in a stimulating shopping experience. Creating and influencing customers' experiences has become a valuable differentiation strategy for retailers. Therefore, understanding and assessing the customers' emotional response in relation to products/services represents an important asset. The purpose of this paper consists of investigating whether the customer's facial expressions shown during product appreciation are positive or negative and also which types of emotions are related to product appreciation. We collected a database of emotional facial expressions, by presenting a set of forty product related pictures to a number of test subjects. Next, we analysed the obtained facial expressions, by extracting both geometric and appearance features. Furthermore, we modeled them both in an unsupervised and supervised manner. Clustering techniques proved to be efficient at differentiating between positive and negative facial expressions in 78\% of the cases. Next, we performed more refined analysis of the different types of emotions, by employing different classification methods and we achieved 84\% accuracy for seven emotional classes and 95\% for the positive vs. negative.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1719. Assessment of HRV after maximal exercise in trained postmenopausal women
- Creator:
- Orri, J. C, Hughes, E. M, Mistry, D. G, and Scala, A
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- menopauza, menopause, training intensity, cardioprotection, 14, and 612
- Language:
- English
- Description:
- Increased parasympathetic tone achieved with endurance training may provide cardioprotection after menopause. To compare heart rate variability (HRV) from rest through maximal exercise and recovery in trained postmenopausal women. Thirtysix postmenopausal women who self-reported training at either moderate (MOD; 3-5.9 METS; 58.9±4.4 year) or vigorous (VIG; >6 METS; 59.7±5.2 year) intensities participated. HRV was measured for 5 min in the supine position, in the last minute of the VO2max test and after 2 min of active recovery. HRV in MOD and VIG was compared using a factorial ANOVA with repeated measures on time. MOD and VIG responded similarly over the three time periods for root mean square of sequential deviations (rMSSD), and high (HF) and low frequency (LF) power (p>0.05). Maximal exercise lowered rMSSD (3.3±0.08 vs. 1.2±0.06) and lnLF (4.1±0.05 vs. 3.3±0.13) and increased lnHF (3.3±0.14 vs. 4.0±0.10; p<0.01) from resting. However, active recovery restored lnHF (3.3±0.11) and lnLF (4.1±0.08) from maximal values (p<0.01). Our findings suggest that moderate and vigorous exercise training may enhance HRV recovery following one bout of maximal exercise in older women., J. C. Orri, E. M. Hughes, D. G. Mistry, A. Scala., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1720. Assessment of models to predict surface subsidence in the Czech part of the upper Silesian coal basin - case study
- Creator:
- Jiránková, Eva, Waclawik, Petr, and Nemcik, Jan
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- longwall mining, surface subsidence, great depth, finite element method, and Knothe method
- Language:
- English
- Description:
- This case study presents the verification of two surface subsidence prediction models for longwall mining at depths greater than 400 m. The surface subsidence points were surveyed and compared for both models. The first model uses empirical calculations to predict the surface subsidence. This method is reliable for predicting surface subsidence at shallower depths. At present, however, coal mining has progressed to great depths. The second model is the 2-dimensional finite element method to predict surface subsidence. In contrast to the first method, this method is based on the regional parameters and uses the rock mass properties to evaluate surface subsidence for multi-seams at any depth. Results show that the finite element method gives a better approximation of the measured surface subsidence than the Knothe method. The maximum surface subsidence, which was determined by the FEM method, was used to adjust the extraction coefficient in the Knothe's method. The predicted value differs from the measured value by 8 %. The slope of the predicted subsidence trough was within the range of 2‒8 % from the surveyed subsidence. This case study proposes a procedure for using both models to successfully predict the surface subsidence.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public