Search results for "Dynamics"

Acid–base properties of functionalised tripodal polyamines and their interaction with nucleotides and nucleic acids

2010

Novel, highly positively charged tripodal polyamines with appended heterocyclic moieties revealed an intriguing panel of protonation species within the biologically relevant range. Studied compounds bind nucleotide monophosphates by mostly electrostatic interactions but only the imidazole analogue showed selectivity toward UMP in respect to other nucleotides. Strong binding of all the studied compounds to both ds-DNA and ds-RNA is to some extent selective toward the latter, showing rather rare RNA over DNA preference.

Ultrafast solvent-assisted level crossing in 1-Naphthol

2013

The nonadiabatic inversion dynamics of the energetic order of the electronic excited states of the photoacid 1-naphthol have been revealed by ultrafast spectroscopy on a femtosecond timescale (see picture; IC=internal conversion). The energetic order of the excited states La and Lb of 1-naphthol is reversed in 60 fs in polar dimethyl sulfoxide solvent.

Studying incidental news : Antecedents, dynamics and implications

2020

In light of concerns about decreasing news use, a decline in interest in political news or even active avoidance or resistance of news in general, the idea of ‘incidental news’ has been seen as a possible remedy. Generally, ‘incidental news’ refers to the ways in which people encounter information about current events through media when they were not actively seeking the news. However, scholars studying incidental news through different theoretical and methodological perspectives have been arriving at differing evaluations of the significance and implications of this phenomenon – to the extent of downright contradictory findings. This introductory piece posits the aim of this special issue…

Dynamic Modeling for Environmental Processes: A Case Study of Lake Engure

2014

Abstract This focus of the study was on system dynamic models that could be useful for modelling environmental processes in Lake Engure. The paper considers the system dynamic model development principles, the most important elements and structure. The aim of the study was to describe possible methods of ecosystem process modelling that allow to represent the actual state of ecosystems and provide opportunities to predict further processes. The methods of ecosystem modelling considered in the paper reveal interactive factors of anthropogenic and environmental processes that influence changes in ecosystems. System dynamic models indicate not only interactions between various factors in the e…

The roles of achievement-related behaviours and parental beliefs in children´s mathematical performance

2003

This study aimed to investigate the developmental dynamics between children's mathematical performance, the task-focused versus task-avoidant behaviours they show in the classroom, and their parents' beliefs concerning their school competence. The mathematical performance of 111 six- to seven-year-old children was tested, and their task-focused versus task-avoidant behaviours were rated by their teachers four times during their first school year. Parents filled in questionnaires measuring their skill-specific and general beliefs about their children's school competencies at the beginning and at the end of the school year. The results showed that parents' beliefs in their children's general …

The Effect of Predator Population Dynamics on Batesian Mimicry Complexes.

2022

Understanding Batesian mimicry is a classic problem in evolutionary biology. In Batesian mimicry, a defended species (the model) is mimicked by an undefended species (the mimic). Prior theories have emphasized the role of predator behavior and learning as well as evolution in model-mimic complexes but have not examined the role of population dynamics in potentially governing the relative abundances and even persistence of model-mimic systems. Here, we examined the effect of the population dynamics of predators and alternative prey on the prevalence of warning-signaling prey composed of models and mimics. Using optimal foraging theory and signal detection theory, we found that the inclusion …

Heterozygote advantage and pleiotropy contribute to intraspecific color trait variability

2022

The persistence of intrapopulation phenotypic variation typically requires some form of balancing selection because drift and directional selection eventually erode genetic variation. Heterozygote advantage remains a classic explanation for the maintenance of genetic variation in the face of selection. However, examples of heterozygote advantage, other than those associated with disease resistance, are rather uncommon. Across most of its distribution, males of the aposematic moth Arctia plantaginis have two hindwing phenotypes determined by a heritable one locus-two allele polymorphism (genotypes: WW/Wy = white morph, yy = yellow morph). Using genotyped moths, we show that the presence of o…

Rational drug discovery : structural studies of protein-ligand complexes

2011

Vegetation Patterns in the Hyperbolic Klausmeier Model with Secondary Seed Dispersal

2023

This work focuses on the dynamics of vegetation stripes in sloped semi-arid environments in the presence of secondary seed dispersal and inertial effects. To this aim, a hyperbolic generalization of the Klausmeier model that encloses the advective downhill transport of plant biomass is taken into account. Analytical investigations were performed to deduce the wave and Turing instability loci at which oscillatory and stationary vegetation patterns arise, respectively. Additional information on the possibility of predicting a null-migrating behavior was extracted with suitable approximations of the dispersion relation. Numerical simulations were also carried out to corroborate theoretical pre…

Numerical Simulations of the Flow Field of a Submerged Hydraulic Jump over Triangular Macroroughnesses

2021

The submerged hydraulic jump is a sudden change from the supercritical to subcritical flow, specified by strong turbulence, air entrainment and energy loss. Despite recent studies, hydraulic jump characteristics in smooth and rough beds, the turbulence, the mean velocity and the flow patterns in the cavity region of a submerged hydraulic jump in the rough beds, especially in the case of triangular macroroughnesses, are not completely understood. The objective of this paper was to numerically investigate via the FLOW-3D model the effects of triangular macroroughnesses on the characteristics of submerged jump, including the longitudinal profile of streamlines, flow patterns in the cavity regi…