Search results for "multivariate statistic"
showing 10 items of 327 documents
Cognitive and neuropsychological profiles of the elderly
1993
Testing the cognitive functions of the elderly is often eclectic and atheoretical. We take a theoretical model, simultaneous and successive processing, and the tests derived from it to describe the cognitive functions of the elderly. Subsequently, the performance of an elderly sample on a battery of neuropsychological tests is examined and also understood in relation to the two processing modes. Subjects were 81 individuals, 75 years old, from a population of nearly 300 persons participating in a Finnish research project on aging. They were administered tests of simultaneous and successive processing as well as an extensive battery of neuropsychological tasks. Multivariate and univariate an…
Frequency Change Patterns across Proficiency Levels in Japanese EFL Learner Speech
2014
This study investigated the overall patterns of variation across seven oral proficiency levels of 1,263 Japanese EFL learners and native English speakers. The methodological approach combined a learner corpus, language processing techniques, and multivariate statistical analyses to identify patterns of language use. The largest spoken learner corpus in Japan, the National Institute of Information and Communications Technology Japanese Learner English (NICT JLE) Corpus was used for the analysis. This corpus consists of transcribed interviews with 1,281 learners and contains over one million running words of spoken English. The transcriptions were compared with data gathered from 20 native En…
CLUSTERING INCOMPLETE SPECTRAL DATA WITH ROBUST METHODS
2018
Abstract. Missing value imputation is a common approach for preprocessing incomplete data sets. In case of data clustering, imputation methods may cause unexpected bias because they may change the underlying structure of the data. In order to avoid prior imputation of missing values the computational operations must be projected on the available data values. In this paper, we apply a robust nan-K-spatmed algorithm to the clustering problem on hyperspectral image data. Robust statistics, such as multivariate medians, are more insensitive to outliers than classical statistics relying on the Gaussian assumptions. They are, however, computationally more intractable due to the lack of closed-for…
Within-student variability in learning experiences, and teachers’ perceptions of students’ task-focus
2016
In order to advance models of educational processes (intraindividual, intensive longitudinal), we propose a model in which we specify state and trait constructs, and an intraindividual variability construct. In our ecological momentary assessment study, we investigated how trait-level and intraindividual variability of students’ learning experiences (intrinsic and extrinsic motivation, task difficulty, effort exertion, help-seeking and competence evaluations) converged with teacher-reported student task-focus. 285 primary school students’ (Years 5 and 6) completed the Learning Experience Questionnaire using handheld computers, on average 13.6 learning episodes during one week (SD = 4.6; Ran…
Preparation, Execution and Experience: A Multivariate Evaluation of ANS-SNS Patterns
1985
Aims to verify with multivariate methods how autonomic-somatic changes (composed by skin conductance, heart rate, pulse amplitude, respiration, blood volume and flexor, frontal and orbicutaris oris EMG-measures) from specific patterns according to event-related demands both during (or after) and before events when contentual and temporal knowledge allowing preparation is varied.
246 Survival of elderly patients with endometrial cancer – predicted by preoperative G-8 geriatric screening tool
2021
Introduction/Background* We evaluated the prognostic impact of various global health assessment tools in accordance to conventional prognostic factors in patients with endometrial cancer (EC) older than 60 years. Methodology G-8 geriatric screening tool (G-8 geriatric score), Lee Schonberg prognostic index (Lee-Index), Charlson Comorbidity Index (CCI) and American Society of Anesthesiologists (ASA-PS) – Physical Status System were retrospectively determined in a consecutive cohort of elderly patients with EC. Univariate and multivariate Cox regression analyses and Kaplan-Meier method were performed to determine the impact of the global health assessment tools on progression free survival (P…
A Multivariate Age-Structured Stochastic Model with Immunization Strategies to Describe Bronchiolitis Dynamics
2021
Bronchiolitis has a high morbidity in children under 2 years old. Respiratory syncytial virus (RSV) is the most common pathogen causing the disease. At present, there is only a costly humanized monoclonal RSV-specific antibody to prevent RSV. However, different immunization strategies are being developed. Hence, evaluation and comparison of their impact is important for policymakers. The analysis of the disease with a Bayesian stochastic compartmental model provided an improved and more natural description of its dynamics. However, the consideration of different age groups is still needed, since disease transmission greatly varies with age. In this work, we propose a multivariate age-struct…
STUDY OF LARGE PELAGIC FISH LIFE-HISTORY TRAITS IN THE CENTRAL MEDITERRANEAN SEA AND PROJECTION UNDER FUTURE CLIMATE CHANGE SCENARIOS
2022
One of the most sensitive life periods for each species is the first life stages (larval and juvenile). The survival rates of pelagic fish larvae in these phases are usually very low and subject to fluctuations, consequently affecting the recruitment of new generations. From historical Tuna landing data, the stock's abundance is fluctuating, especially for Atlantic Bluefin Tuna (ABT) (Thunnus thynnus, Linnaeus, 1758) Eastern stock. It is the largest Mediterranean Tuna and one of the most expensive species in the world. Some studies hypothesized that the fluctuations are dictated by environmental factors, particularly in the early life stages. Therefore, it appears necessary to better unders…
Unveiling the Relationship Between Sea Surface Hydrographic Patterns and Tuna Larval Distribution in the Central Mediterranean Sea
2021
Thunnus thynnus (Atlantic bluefin tuna, ABT) and other tuna species reproduce in the Mediterranean Sea during the summer period. Despite the Central Mediterranean Sea, the Strait of Sicily in particular, being a key spawning site for many tuna species, little is known on the effects of oceanographic variability on their larval distribution in this area. The abundance and presence-absence of larval specimens for three tuna species (ABT, bullet tuna and albacore) were modeled in order to examine their relationships with environmental factors, by analysing historical in situ information collected during seven annual surveys (2010–2016). The results revealed that most tuna larvae for the three …
Tolerance, Adaptation, and Cell Response Elicited by Micromonospora sp. Facing Tellurite Toxicity: A Biological and Physical-Chemical Characterization
2022
The intense use of tellurium (Te) in industrial applications, along with the improper disposal of Te-derivatives, is causing their accumulation in the environment, where oxyanion tellurite (TeO32−) is the most soluble, bioavailable, and toxic Te-species. On the other hand, tellurium is a rare metalloid element whose natural supply will end shortly with possible economic and technological effects. Thus, Te-containing waste represents the source from which Te should be recycled and recovered. Among the explored strategies, the microbial TeO32− biotransformation into less toxic Te-species is the most appropriate concerning the circular economy. Actinomycetes are ideal candidates in…