Search results for "stages"
showing 10 items of 217 documents
Information dynamics of brain-heart physiological networks during sleep
2014
This study proposes an integrated approach, framed in the emerging fields of network physiology and information dynamics, for the quantitative analysis of brain-heart interaction networks during sleep. With this approach, the time series of cardiac vagal autonomic activity and brain wave activities measured respectively as the normalized high frequency component of heart rate variability and the EEG power in the δ, θ, Ï, and β bands, are considered as realizations of the stochastic processes describing the dynamics of the heart system and of different brain sub-systems. Entropy-based measures are exploited to quantify the predictive information carried by each (sub)system, and to dissec…
Brain and Breathing
2014
Breathing is an essential feature of living organisms, and control of breathing is a very complex topic in human physiology. Breathing is differently modulated under conditions of wakefulness and sleep, and ventilation decreases during sleep in normal subjects. In patients with respiratory diseases, sleep represents a very vulnerable condition, since gas exchange usually worsens, especially in REM sleep. Several types of respiratory events can occur during sleep, and knowledge of control of breathing is essential to understand their pathophysiology. This chapter summarizes the main characteristics of ventilation during both wakefulness and sleep, the differences found between genders, and t…
Unauthorized copying of software and levels of moral development: a literature analysis and its implications for research and practice
2004
. Several approaches for and against the unauthorized copying of software have been proposed. These approaches can be divided into two categories: moral reasoning and solution. These categories of approaches to unauthorized copying of software are scrutinized in the light of Kohlberg's theory of Cognitive Moral Development. The results suggest that most approaches presenting solutions to unauthorized copying of software have focused attention on the lower levels of moral development, while approaches at the highest stage are few and far between. No single approach covers all the stages of moral development. The implications of this analysis for practice and research are discussed.
Nonlinear dynamical aspects of the human sleep EEG.
1994
This article deals with the application of methods from the theory of nonlinear dynamical systems to EEG signals. Theoretical background, mathematical concepts and algorithms for the calculation of "non-linear parameters" are reviewed and influences of the structure of reconstructed data sets on the calculations are pointed out. We present results for the estimation of the correlation dimension D2 and the principal Lyapunov-exponent lambda 1 for sleep EEG data respectively from 10 and 15 healthy subjects corresponding to different sleep stages. Essentially, we found a statistically significant decrease of both D2 and lambda 1 as sleep moves towards slow wave stages. The values for REM sleep…
El mito quinqui. Memoria y represión de las culturas juveniles en la transición postfranquista
2020
Este trabajo parte de una imagen inicial–el cuarto quinqui como habitación histórica–para plantear el estudio del fenómeno quinquillero en una dialéctica compleja entre mitología, historicidad y memoria. Me planteo confrontar el actual regreso de lo quinqui en relación con las emergencias de los supuestos quinquis históricos en el archivo de los años setenta. Se trata, sin duda, de una confrontación problemática. Mi trabajo se organiza en dos tiempos. Primero, se trata de deconstruir “el mito quinqui”, analizando sus características y razones tanto en su construcción actual, como regreso quinqui, como en su emergencia histórica. Y después se trata de pensar qué es lo que ese mito impide ver…
Self and Identity Development during Adolescence across Cultures
2015
The purpose is to show the dynamic of change and stability in the development of identity and self during adolescence. We present some basic differences between the development of self-perceptions and the development of identity according to Erikson's psychosocial formulation. The change and stability dynamics of identity development is subjected to critique from the perspective of the status paradigm as well as more recent theoretical models. The key role of the cultural context's inevitable influence on the development of identity and self-perceptions through the production of relevant cultural variations is also analyzed.
Geographical separation and physiology drive differentiation of microbial communities of two discrete populations of the bat Leptonycteris yerbabuenae
2020
In this paper, we explore how two discrete and geographically separated populations of the lesser long‐nosed bat (Leptonycteris yerbabuenae)—one in central and the other in the Pacific region of Mexico—differ in their fecal microbiota composition. Considering the microbiota–host as a unity, in which extrinsic (as food availability and geography) or intrinsic factors (as physiology) play an important role in the microbiota composition, we would expect differentiation in the microbiota of two geographically separated populations. The Amplicon Sequences Variants (ASVs) of the V4 region of the 16s rRNA gene from 68 individuals were analyzed using alpha and beta diversity metrics. We obtained a …
Ligand-based discovery of novel trypanosomicidal drug-like compounds: In silico identification and experimental support
2010
Abstract Two-dimensional bond-based linear indices and linear discriminant analysis are used in this report to perform a quantitative structure–activity relationship study to identify new trypanosomicidal compounds. A database with 143 anti-trypanosomal and 297 compounds having other clinical uses, are utilized to develop the theoretical models. The best discriminant models computed using bond-based linear indices provides accuracies greater than 90 for both training and test sets. Our models identify as anti-trypanosomals five out of nine compounds of a set of already-synthesized substances. The in vitro anti-trypanosomal activity of this set against epimastigote forms of Trypanosoma cruzi…
Within-host evolution decreases virulence in an opportunistic bacterial pathogen
2015
Abstract Background Pathogens evolve in a close antagonistic relationship with their hosts. The conventional theory proposes that evolution of virulence is highly dependent on the efficiency of direct host-to-host transmission. Many opportunistic pathogens, however, are not strictly dependent on the hosts due to their ability to reproduce in the free-living environment. Therefore it is likely that conflicting selection pressures for growth and survival outside versus within the host, rather than transmission potential, shape the evolution of virulence in opportunists. We tested the role of within-host selection in evolution of virulence by letting a pathogen Serratia marcescens db11 sequent…
Role of protozooplankton in the diet of North Sea autumn spawning herring (Clupea harengus) larvae
2022
AbstractThe role of small prey (< 200 µm) in larval marine fish nutrition is largely understudied. Here, we explore the contribution of protozooplankton (PZP 20–200 µm) to larval fish diets, compared to metazoan microzooplankton (MZP 55–200 µm). More specifically, we tested whether the contribution of PZP increased during the low productivity season and decreased as larvae grow. We used North Sea autumn spawning herring (Clupea harengus) as a case study, as it is a key species with high commercial and ecological importance. In autumn and winter, the potential PZP and MZP prey was dominated by cells < 50 µm (mainly Gymnodiniales, Pronoctiluca pelagica,Tripos spp. and Strombidium spp.),…