Search results for "adaptation"

Intellectual Ability Data Obtaining and Processing for E-Learning System Adaptation

2012

In this article authors describe how an e-learning system can obtain data about learner, so that later it could offer individual content for each learner, based on the obtained data. Authors also describe how the Learning Management System (LMS) Moodle has adapted a standard quiz module interface for testing elementary school students and how students’ individual abilities could be measured more efficiently, for example, by measuring mathematical reaction time. For obtaining necessary testing results and partial processing a new module (TAnalizer) is offered, which is adapted to the Moodle environment. With this module one can gain precise data about each student’s testing process and stude…

The Challenge of Feedback Personalization to Learning Styles in a Web-Based Learning System

2006

Feedback is information that is provided to a user to inform him/her about the result of his/her action and to motivate him/her to further interact with the system. In web-based learning systems (WBLS), feedback is particularly important in test and evaluation tasks. The main objective of the paper is twofold: (1) to encourage WBLS designers and specialists to pay more attention to the problem of feedback adaptation, and (2) to analyze suggestions for feedback personalization to learning styles in a WBLS.

Adaptation of the Presentation in a Multi-tenant Web Information System

2012

We introduced a Web Information System (WIS) adaptation architecture that is based on Software as a Service (SaaS) ideas. It includes adaptation components, which allow adaptation in two levels: the organizations and the users get their own adapted instance of the WIS. The user interface in case of multi-tenancy should be dynamically adapted according to the particular organization and user. The same application component that contains a set of fields, controls and other interface elements should be varied according to the usage context. In this paper we provide a method for adapting the user interface within the proposed adaptation architecture that uses a set of rules describing the seque…

2018

A comprehensive monitoring of fitness, fatigue, and performance is crucial for understanding an athlete's individual responses to training to optimize the scheduling of training and recovery strategies. Resting and exercise-related heart rate measures have received growing interest in recent decades and are considered potentially useful within multivariate response monitoring, as they provide non-invasive and time-efficient insights into the status of the autonomic nervous system (ANS) and aerobic fitness. In team sports, the practical implementation of athlete monitoring systems poses a particular challenge due to the complex and multidimensional structure of game demands and player and te…

Investigation of the roles of AgrA and σB regulators in Listeria monocytogenes adaptation to roots and soil

2020

ABSTRACT Little is known about the regulatory mechanisms that ensure the survival of the food-borne bacterial pathogen Listeria monocytogenes in the telluric environment and on roots. Earlier studies have suggested a regulatory overlap between the Agr cell–cell communication system and the general stress response regulator σB. Here, we investigated the contribution of these two systems to root colonisation and survival in sterilised and biotic soil. The ability to colonise the roots of the grass Festuca arundinacea was significantly compromised in the double mutant (∆agrA∆sigB). In sterile soil at 25°C, a significant defect was observed in the double mutant, suggesting some synergy between …

Diminishing Returns of Population Size in the Rate of RNA Virus Adaptation

2000

ABSTRACT Whenever an asexual viral population evolves by adapting to new environmental conditions, beneficial mutations, the ultimate cause of adaptation, are randomly produced and then fixed in the population. The larger the population size and the higher the mutation rate, the more beneficial mutations can be produced per unit time. With the usually high mutation rate of RNA viruses and in a large enough population, several beneficial mutations could arise at the same time but in different genetic backgrounds, and if the virus is asexual, they will never be brought together through recombination. Thus, the best of these genotypes must outcompete each other on their way to fixation. This c…

Experimental Evolution in Viruses

2011

Experiments in which evolution takes place in real time can help us establish cause–effect relationships that are difficult to infer from the analysis of natural populations. The simplicity, rapid evolution and biomedical relevance of viruses make them a particularly interesting model system for experimental evolution. Bacterial, animal and plant viruses can be passaged under a variety of conditions, either in simple cell culture systems or in vivo to test population biology hypotheses, study the genetic basis of evolution, or predict evolutionary change in nature. Experimental evolution is a conceptually simple and flexible tool which allows us to address issues ranging from the molecular …

The effect of genetic robustness on evolvability in digital organisms

2008

Abstract Background Recent work has revealed that many biological systems keep functioning in the face of mutations and therefore can be considered genetically robust. However, several issues related to robustness remain poorly understood, such as its implications for evolvability (the ability to produce adaptive evolutionary innovations). Results Here, we use the Avida digital evolution platform to explore the effects of genetic robustness on evolvability. First, we obtained digital organisms with varying levels of robustness by evolving them under combinations of mutation rates and population sizes previously shown to select for different levels of robustness. Then, we assessed the abilit…

Delayed lysis confers resistance to the nucleoside analogue 5-fluorouracil and alleviates mutation accumulation in the single-stranded DNA bacterioph…

2014

ABSTRACT Rates of spontaneous mutation determine viral fitness and adaptability. In RNA viruses, treatment with mutagenic nucleoside analogues selects for polymerase variants with increased fidelity, showing that viral mutation rates can be adjusted in response to imposed selective pressures. However, this type of resistance is not possible in viruses that do not encode their own polymerases, such as single-stranded DNA viruses. We previously showed that serial passaging of bacteriophage ϕX174 in the presence of the nucleoside analogue 5-fluorouracil (5-FU) favored substitutions in the lysis protein E (P. Domingo-Calap, M. Pereira-Gomez, and R. Sanjuán, J. Virol. 86: 9640–9646, 2012, doi:10…

Adaptive trends of sequence compositional complexity over pandemic time in the SARS-CoV-2 coronavirus

2021

In the brief time since the outbreak of the COVID 19 pandemic, and despite its proofreading mechanism, the SARS-CoV-2 coronavirus has accumulated a significant amount of genetic variability through recombination and mutation events. To test evolutionary trends that could inform us on the adaptive process of the virus to its human host, we summarize all this variability in the Sequence Compositional Complexity (SCC), a measure of genome heterogeneity that captures the mutational and recombinational changes accumulated by a nucleotide sequence along time. Despite the brief time elapsed, we detected many differences in the number and length of compositional domains, as well as in their nucleot…