The prognostic significance of the adaptation potential of the cardiovascular system in 10- and 11-year-old children

Experimental physiological studies were made in 10–11-year-old boys and girls, students of a gymnasium and an education-upbringing complex. The functional parameters recorded in children momentarily included: the heart rate, systolic and diastolic arterial pressure, Roufier index, and the adaptation potential (AP) of the cardiovascular system as an integral index of the adaptivity level of human organism on the whole, measured according to special formulas, and the index of the risk of disease development. Apart from it, the height, body mass, vital lung capacity, and strength of hand grip were measured, the puberty stage and deviations in the functioning of organs and systems were revealed. The AP levels used to evaluate adults’ adaptation did not agree with 10–11-year-old children’s physical development degree, puberty stages, and health condition (belonging to different health groups). No agreement was found between the levels of these parameters and the degrees of AP of the cardiovascular system in 10–11-year-old children based on their individual values and sigmal deviations of this index. Therefore, a conclusion on the adaptation capacities of a child’s organism and the risk of disease development in it based on the AP values may be erroneous. The authors suggest an age scale of the AP levels for 10–11-year-old children.     

Imaging protein activity in live embryos using fluorescence resonance energy transfer biosensors

Fluorescence resonance energy transfer (FRET)-based molecular biosensors serve as important tools for studying protein activity in live cells and have been widely used for this purpose over the past decade. However, FRET biosensors are rarely used in the context of the live organism because of the inherent high cellular complexity and imaging challenges associated with the three-dimensional environment. Here we provide a protocol for using single-chain intramolecular FRET-based biosensors in early development. We provide a general protocol for FRET ratio imaging in embryos, including the data-acquisition conditions and the algorithm for ratio image generation. We then use the pRaichu RacFRET biosensor to exemplify the adaptation and optimization of a particular biosensor for use in live zebrafish embryos. Once an optimized biosensor is available, the complete procedure, including introduction of the probes into embryos, imaging and data analysis, requires 2-3 d.     

A Salience Theory of Learning and Behavior: With Perspectives on Neurobiology and Cognition

Traditional behaviorists have described behaviors fundamentally as responses to stimuli or, perhaps more liberally, as behaviors under the control of discriminative stimuli or contexts. They have held responses or behaviors to be established, strengthened, sustained, and inhibited or extinguished by contingent events: notably reinforcers, punishers, or the absence of either. In addition, they believed reinforcement acts on the response, the behavior, not on the organism. Here, and in support of Hebb’s view, we advance a contrarian view. A key principle of our framework is that species’ brains are uniquely designed to perceive and to relate stimulus events that are contiguous, salient, and relevant to adaptation. In accordance with what we here view as the constructive biases of species’ brains, stimuli are differentially organized into amalgams that reflect an exchange of salience and response-eliciting properties of component units, which are then integrated to form a basis of knowledge about the organism and its ecological niche. One can then base adaptation on overarching principles and rules, not just on simple associations. Species may create emergent behaviors with no history of specific training, and even new capacities, to service adaptation to both familiar and novel challenges.     

Organisms of deep sea hydrothermal vents as a source for studying adaptation and evolution

It has been postulated that life originated in a similar environment to those of deep sea hydrothermal vents. These environments are located along volcanic ridges and are characterized by extreme conditions such as unique physical properties (temperature, pressure), chemical toxicity, and absence of photosynthesis. However, numerous living organisms have been discovered in these hostile environments, including a variety of microorganisms and many animal species which live in intimate and complex symbioses with sulfo-oxidizing and methanotrophic bacteria. Recent proteomic analyses of the endosymbiont ofRiftia pachyptila and genome sequences of some free living and symbiotic bacteria have provided complementary information about the potential metabolic and genomic capacities of these organisms. The evolution of these adaptive strategies is connected with different mechanisms of genetic adaptation including horizontal gene transfer and . various structural and functional mutations. Therefore, the organisms in this environment are good models for studying the evolution of prokaryotes and eukaryotes as well as different aspects of the biology of adaptation. This review describes some current research concerning metabolic and plausible genetic adaptations of organisms in a deep sea environment, usingRiftia pachyptila as model.     

Landscape structure and genetic architecture jointly impact rates of niche evolution

Evolutionary adaptation is a key driver of species' range dynamics. Understanding the factors that affect rates of adaptation at range margins is thus crucial for interpreting and predicting changes in species' ranges. The spatial structure of environmental conditions is one of the determinants of whether and how quickly adaptations occur. However, while landscape structures at range edges are typically complex, most theoretical work has so far focused on relatively simple environmental geometries. Using an individual‐based allelic model, we explore the effects of different landscape structures on the rate of adaptation to novel environments and investigate how these structures interact with the genetic architecture of the trait governing adaptation and the dispersal capacity of the considered species. Generally, we find that rapid adaptation is favored by a good match between the coarseness of the trait's genetic architecture (many loci of small effects versus few loci of large effects) and the coarseness of the landscape (abruptness of transitions in environmental conditions). For example, in rugged landscapes, adaptation is quicker for genetic architectures with few loci of large effects, while for shallow gradients the opposite is true. Moreover, dispersal capacities affect the rate of adaptation by modulating the ‘apparent coarseness’ of the landscape: a gradient perceived as smooth by species with limited dispersal capacities appears rather steep for highly dispersive ones. We also find that the distribution of evolving phenotypes strongly depends on the interplay of landscape structure and dispersal capacities, ranging from two distinct phenotypes for most rugged landscapes, over the co‐occurrence of an additional third phenotype for highly dispersive species, to the whole range of phenotypes on smooth gradients. By identifying basic factors that drive the fixation probability of newly arising beneficial mutations, we hope to further broaden the understanding of evolutionary adaptation at range margins and, hence, species' range dynamics.     

Adaptation to environmental temperature is a major determinant of molecular evolutionary rates in archaea

Methods to infer the ancestral conditions of life are commonly based on geological and paleontological analyses. Recently, several studies used genome sequences to gain information about past ecological conditions taking advantage of the property that the G+C and amino acid contents of bacterial and archaeal ribosomal DNA genes and proteins, respectively, are strongly influenced by the environmental temperature. The adaptation to optimal growth temperature (OGT) since the Last Universal Common Ancestor (LUCA) over the universal tree of life was examined, and it was concluded that LUCA was likely to have been a mesophilic organism and that a parallel adaptation to high temperature occurred independently along the two lineages leading to the ancestors of Bacteria on one side and of Archaea and Eukarya on the other side. Here, we focus on Archaea to gain a precise view of the adaptation to OGT over time in this domain. It has been often proposed on the basis of indirect evidence that the last archaeal common ancestor was a hyperthermophilic organism. Moreover, many results showed the influence of environmental temperature on the evolutionary dynamics of archaeal genomes: Thermophilic organisms generally display lower evolutionary rates than mesophiles. However, to our knowledge, no study tried to explain the differences of evolutionary rates for the entire archaeal domain and to investigate the evolution of substitution rates over time. A comprehensive archaeal phylogeny and a non homogeneous model of the molecular evolutionary process allowed us to estimate ancestral base and amino acid compositions and OGTs at each internal node of the archaeal phylogenetic tree. The last archaeal common ancestor is predicted to have been hyperthermophilic and adaptations to cooler environments can be observed for extant mesophilic species. Furthermore, mesophilic species present both long branches and high variation of nucleotide and amino acid compositions since the last archaeal common ancestor. The increase of substitution rates observed in mesophilic lineages along all their branches can be interpreted as an ongoing adaptation to colder temperatures and to new metabolisms. We conclude that environmental temperature is a major factor that governs evolutionary rates in Archaea.     

Psychosocial modifiers of response to stress

The impact of stress upon an organism is far more complex than the simple design of most stress research implies. We offer an expanded model for studying the relation of stressors to pathological outcomes, which takes into account both the adaptive capacity of the organism before the stressor occurs and the defenses marshalled in response to the stressor. The model also distinguishes among the initial responses of alarm, sustained defensive behaviors, and the relatively irreversible endstates which remain after resistance has ended. Realizing that only a multidiscomplinary approach can begin to capture the wholeness of human experience, this research paradigm anticipates that stressors, adaptive capacities, defenses, alarm reactions, and pathologial end-states will take place at the biological, psychological, interpersonal and sociocultural levels simultaneously and successively. Data on life change stress and psychological health outcomes gathered as part of the Air Traffic Controller Health Change Study are analyzed to illustrate the use of the model in identifying psychosocial and biological modifiers of response to stress.     

Artificial evolution of life history and behavior

We present an individual-based model that uses artificial evolution to predict fit behavior and life-history traits on the basis of environmental data and organism physiology. Our main purpose is to investigate whether artificial evolution is a suitable tool for studying life history and behavior of real biological organisms. The evolutionary adaptation is founded on a genetic algorithm that searches for improved solutions to the traits under scrutiny. From the genetic algorithm's "genetic code," behavior is determined using an artificial neural network. The marine planktivorous fish Müller's pearlside (Maurolicus muelleri) is used as the model organism because of the broad knowledge of its behavior and life history, by which the model's performance is evaluated. The model adapts three traits: habitat choice, energy allocation, and spawning strategy. We present one simulation with, and one without, stochastic juvenile survival. Spawning pattern, longevity, and energy allocation are the life-history traits most affected by stochastic juvenile survival. Predicted behavior is in good agreement with field observations and with previous modeling results, validating the usefulness of the presented model in particular and artificial evolution in ecological modeling in general. The advantages, possibilities, and limitations of this modeling approach are further discussed.     

Pleiotropic Effects of Adaptation to a Single Carbon Source for Growth on Alternative Substrates

It is frequently assumed that populations of genetically modified microorganisms will perform their intended function and then disappear from the environment due to inherent fitness disadvantages resulting from their genetic alteration. However, modified organisms used in bioremediation can be expected to adapt evolutionarily to growth on the anthropogenic substrate that they are intended to degrade. If such adaptation results in improved competitiveness for alternative, naturally occurring substrates, then this will increase the likelihood that the modified organisms will persist in the environment. In this study, bacteria capable of degrading the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) were used to test the effects of evolutionary adaptation to one substrate on fitness during growth on an alternative substrate. Twenty lineages of bacteria were allowed to evolve under abundant resource conditions on either 2,4-D or succinate as their sole carbon source. The competitiveness of each evolved line was then measured relative to that of its ancestor for growth on both substrates. Only three derived lines showed a clear drop in fitness on the alternative substrate after demonstrable adaptation to their selective substrate, while five derived lines showed significant simultaneous increases in fitness on both their selective and alternative substrates. These data demonstrate that adaptation to an anthropogenic substrate can pleiotropically increase competitiveness for an alternative natural substrate and therefore increase the likelihood that a genetically modified organism will persist in the environment.     

Identification of novel microRNA genes in freshwater and marine ecotypes of the three‐spined stickleback (Gasterosteus aculeatus)

The three‐spined stickleback (Gasterosteus aculeatus L.) is an important model organism for studying the molecular mechanisms of speciation and adaptation to salinity. Despite increased interest to microRNA discovery and recent publication on microRNA prediction in the three‐spined stickleback using bioinformatics approaches, there is still a lack of experimental support for these data. In this paper, high‐throughput sequencing technology was applied to identify microRNA genes in gills of the three‐spined stickleback. In total, 595 miRNA genes were discovered; half of them were predicted in previous computational studies and were confirmed here as microRNAs expressed in gill tissue. Moreover, 298 novel microRNA genes were identified. The presence of miRNA genes in selected ‘divergence islands’ was analysed and 10 miRNA genes were identified as not randomly located in ‘divergence islands’. Regulatory regions of miRNA genes were found enriched with selective SNPs that may play a role in freshwater adaptation.     

Long-term effect of irradiance on growth,water relations and epidermal conductance of two cyclamen cultivais

Decrease in leaf irradiance to 50 % due to shading of plants in glasshouse only during clear summer days did not induce significant changes in growth parameters, characteristics of water relations and epidermal conductance of two cyclamen cultivars. Thus the possibility of acclimation of plants to non-stable changes in environmental conditions was not proved. The term acclimation is used here for nonheritable modifications of character caused by exposure of an organism to certain climatic conditions in contradistinction to the term, adaptation, which is used for heritable modifications in the structure and function.     

Consequences of phenotypic plasticity vs. interspecific differences in leaf and root traits for acquisition of aboveground and belowground resources

Trade-offs between acquisition capacities for aboveground and belowground resources were investigated by studying the phenotypic plasticity of leaf and root traits in response to different irradiance levels at low nutrient supply. Two congeneric grasses with contrasting light requirements, Dactylis glomerata and D. polygama, were used. The aim was to analyze phenotypic covariation in components of leaf area and root length in response to above- and belowground resource limitation and the consequences of this variation for resource acquisition and plant growth. At intermediate shading (30 and 20% of full sunlight) the plants were able to maintain their total root length, despite a strongly increased total leaf area and a reduced biomass allocation to roots. This was associated with an unaltered or slightly increased nutrient uptake and growth. At 5.5% relative irradiance, growth was severely reduced, especially in the shade-tolerant D. polygama. The results show that constraints on acquisition capacities for aboveground and belowground resources, caused by biomass allocation, may be alleviated by plasticity in other traits such as tissue-mass density and thickness of roots and leaves. The results also suggest different adaptive constraints for phenotypic plasticity and for genetically determined interspecific variation. Phenotypic plasticity tends to maximize resource acquisition and growth rate in the short term, whereas the higher tissue-mass density and the longer leaf life-span of shade-tolerant species indicate reduced loss rates as a more advantageous species-specific adaptation to shade in the long term.     

Stress, illness, and illness behavior.

This paper examines adaptation as a transactive process involving the skills and capacities of individuals and their supporting groups on the one hand, and the types of challenges they face on the other. Many difficulties in understanding stress processes in illness result from the confusion between illness and illness behavior. It is argued that the medical record is as much a history of the individual's behavior and social selection processes as it is a reflection of levels of physical health. Various examples are discussed, illustrating how medical records can be misleading in research examining the relationship between stress and illness, and how influences attributed to stress may be the result of illness behavior. The paper concludes by examining alternative conceptual models for studying the relationships between life challenges, illness behavior and illness.     

Coupled evolution of digestive,respiratory, circulatory,and excretory systems: A model investigation

A model is developed of evolution of an organism with digestive, respiratory, circulatory, and excretory systems as the single system. The model is realized on the basis of the language STEL-LA 8.0. A balance is found between perfection of each individual physiological system and necessary energy expenditures for survival of the organism as a whole. The model is based on a coupled development of several visceral systems. There is analyzed effect of a change of consumption of substances with food and of oxygen amount on their oxidation, a branching of blood flow to organs, specifically to kidneys, to excrete final products of metabolism from blood. The energy expenditures for circulation are believed to be proportional to blood flow in a given organ. An increase of efficiency of renal excretion from blood of final metabolic products and toxic substances has a favorable effect on inner medium and activity of each cell of an individual, but increases the organism energy expenditures. Interrelation of these factors under conditions of adaptation to changing environmental conditions determines peculiarities of evolution of each physiological system in an individual.     

Morphofunctional parameters and adaptation capabilities of students at the beginning of the third millennium

On the basis of comprehensive anthropometrical observation of 1st and 2nd year students from different faculties of Moscow State University (MSU) carried out in 2002-2003, functional characteristics of the cardiovascular system (systolic and diastolic blood pressure, heart rate) were investigated in 205 young men and 327 young women along with traditional morphological parameters. In comparisons of contemporary young men and women with their peers, whose characteristics were obtained in the course of investigations carried out over the period 1920-1990, secular trends towards an increase of body length and a worsening of strength indices were detected. Evaluation and comparative analysis of adaptation capabilities of students were carried out based on screening and assessment of adaptation potential using the Bayevsky method (1987). It was shown that the parameters of physical development and the level of adaptation of an organism to environmental conditions can be used as additional markers for determination of the health status of contemporary students for early prevention of some diseases, improvement of their physical status and increase of adaptation potentials.     

Efficiency and the role of adaptation in klinokinesis

Klinokinesis is a behavioral mechanism in which an organism moves toward or away from a stimulus source by altering its frequency of change of direction without biasing its turns with respect to the stimulus field. Computer simulation was used to study the efficiency of, and the effect of sensory adaptation on, this behavioral strategy. In modeling an organism with perfect performance (no error in determining the intensity of the stimulus and ability to move in perfectly straight lines) efficiency was about 70% without adaptation, and declined as the rate of adaptation increased. In contrast, models with non-perfect (noisy) performance were frequently able to double or triple their reduced efficiency by adapting to the stimulus intensity. Three types of noise that degraded performance were simulated: (1) intensity noise described random fluctuations in the intensity of the stimulus that were not associated with movement of the organism in the stimulus field; (2) motor noise described random fluctuations in the direction of locomotion as the organism moved along; (3) developmental noise described random differences between individuals in a constant tendency to turn to a certain degree as they moved forward. Adaptation had similar effects with any of the three types of noise. If a particular type of noise was strong enough to degrade performance significantly, then optimal performance occurred with an adaptation rate of about 0.2 per step.     

Evaluating gene flow using selected markers: a case study.

The extent to which an organism is locally adapted in an environmental pocket depends on the selection intensities inside and outside the pocket, on migration, and on the size of the pocket. When two or more loci are involved in this local adaptation, measuring their frequency gradients and their linkage disequilbria allows one to disentangle the forces-migration and selection-acting on the system. We apply this method to the case of a local adaptation to organophosphate insecticides in the mosquito Culex pipiens pipiens in southern France. The study of two different resistance loci allowed us to estimate with support limits gene flow as well as selection pressure on insecticide resistance and the fitness costs associated with each locus. These estimates permit us to pinpoint the conditions for the maintenance of this pocket of adaptation as well as the effect of the interaction between the two resistance loci.     

Slime mold inspired routing protocols for wireless sensor networks

Many biological systems are composed of unreliable components which self-organize effectively into systems that achieve a balance between efficiency and robustness. One such example is the true slime mold Physarum polycephalum which is an amoeba-like organism that seeks and connects food sources and efficiently distributes nutrients throughout its cell body. The distribution of nutrients is accomplished by a self-assembled resource distribution network of small tubes with varying diameter which can evolve with changing environmental conditions without any global control. In this paper, we exploit two different mechanisms of the slime mold??s tubular network formation process via laboratory experiments and mathematical behavior modeling to design two corresponding localized routing protocols for wireless sensor networks (WSNs) that take both efficiency and robustness into account. In the first mechanism of path growth, slime mold explores its immediate surroundings to discover and connect new food sources during its growth cycle. We adapt this mechanism for a path growth routing protocol by treating data sources and sinks as singular potentials to establish routes from the sinks to all the data sources. The second mechanism of path evolution is the temporal evolution of existing tubes through nonlinear feedback in order to distribute nutrients efficiently throughout the organism. Specifically, the diameters of tubes carrying large fluxes of nutrients grow to expand their capacities, and tubes that are not used decline and disappear entirely. We adapt the tube dynamics of the slime mold for a path evolution routing protocol. In our protocol, we identify one key adaptation parameter to adjust the tradeoff between efficiency and robustness of network routes. Through extensive realistic network simulations and ideal closed form or numerical computations, we validate the effectiveness of both protocols, as well as the efficiency and robustness of the resulting network connectivity.     

Characterization of a highly hop-resistant Lactobacillus brevis strain lacking hop transport

Resistance to hops is a prerequisite for lactic acid bacteria to spoil beer. In this study we analyzed mechanisms of hop resistance of Lactobacillus brevis at the metabolism, membrane physiology, and cell wall composition levels. The beer-spoiling organism L. brevis TMW 1.465 was adapted to high concentrations of hop compounds and compared to a nonadapted strain. Upon adaptation to hops the metabolism changed to minimize ethanol stress. Fructose was used predominantly as a carbon source by the nonadapted strain but served as an electron acceptor upon adaptation to hops, with concomitant formation of acetate instead of ethanol. Furthermore, hop adaptation resulted in higher levels of lipoteichoic acids (LTA) incorporated into the cell wall and altered composition and fluidity of the cytoplasmic membrane. The putative transport protein HitA and enzymes of the arginine deiminase pathway were overexpressed upon hop adaptation. HorA was not expressed, and the transport of hop compounds from the membrane to the extracellular space did not account for increased resistance to hops upon adaptation. Accordingly, hop resistance is a multifactorial dynamic property, which can develop during adaptation. During hop adaptation, arginine catabolism contributes to energy and generation of the proton motive force until a small fraction of the population has established structural improvements. This acquired hop resistance is energy independent and involves an altered cell wall composition. LTA shields the organism from accompanying stresses and provides a reservoir of divalent cations, which are otherwise scarce as a result of their complexation by hop acids. Some of the mechanisms involved in hop resistance overlap with mechanisms of pH resistance and ethanol tolerance and as a result enable beer spoilage by L. brevis.