Социально-психологические факторы снижения безопасности дорожного движения в системе взаимодействия Человек-Техника-Среда

Predicting the effect of climate change on biodiversity is a multifactorial problem that is complicated by potentially interactive effects with habitat properties and altered species interactions. In a microcosm experiment with communities of microalgae, we analysed whether the effect of rising temperature on diversity depended on the initial or the final temperature of the habitat, on the rate of change, on dispersal and on landscape heterogeneity. We also tested whether the response of species to temperature measured in monoculture allowed prediction of the composition of communities under rising temperature. We found that the final temperature of the habitat was the primary driver of diversity in our experimental communities. Species richness declined faster at higher temperatures. The negative effect of warming was not alleviated by a slower rate of warming or by dispersal among habitats and did not depend on the initial temperature. The response of evenness, however, did depend on the rate of change and on the initial temperature. Community composition was not predictable from monoculture assays, but higher fitness inequality (as seen by larger variance in growth rate among species in monoculture at higher temperatures) explained the faster loss of biodiversity with rising temperature

High predictability of direct competition between marine diatoms under different temperatures and nutrient states

The distribution of marine phytoplankton will shift alongside changes in marine environments, leading to altered species frequencies and community composition. An understanding of the response of mixed populations to abiotic changes is required to adequately predict how environmental change may affect the future composition of phytoplankton communities. This study investigated the growth and competitive ability of two marine diatoms, Phaeodactylum tricornutum and Thalassiosira pseudonana , along a temperature gradient (9–35°C) spanning the thermal niches of both species under both high‐nitrogen nutrient‐replete and low‐nitrogen nutrient‐limited conditions. Across this temperature gradient, the competitive outcome under both nutrient conditions at any assay temperature, and the critical temperature at which competitive advantage shifted from one species to the other, was well predicted by the temperature dependencies of the growth rates of the two species measured in monocultures. The temperature at which the competitive advantage switched from P. tricornutum to T. pseudonana increased from 18.8°C under replete conditions to 25.3°C under nutrient‐limited conditions. Thus, P. tricornutum was a better competitor over a wider temperature range in a low N environment. Being able to determine the competitive outcomes from physiological responses of single species to environmental changes has the potential to significantly improve the predictive power of phytoplankton spatial distribution and community composition models

Communities that thrive in extreme conditions captured from a freshwater lake

Organisms that can grow in extreme conditions would be expected to be confined to extreme environments. However, we were able to capture highly productive communities of algae and bacteria capable of growing in acidic (pH 2), basic (pH 12) and saline (40 ppt) conditions from an ordinary freshwater lake. Microbial communities may thus include taxa that are highly productive in conditions that are far outside the range of conditions experienced in their host ecosystem. The organisms we captured were not obligate extremophiles, but were capable of growing in both extreme and benign conditions. The ability to grow in extreme conditions may thus be a common functional attribute in microbial communities.</jats:p

The essence of psychologic and pedagogical diagnostics

Уточняется понятие «психолого-педагогическая диагностика», рассматриваются функции, принципы, этапы психолого-педагогической диагностикиIn the article the idea of «psychologic and pedagogical diagnostics» is precised, also there are facilities, values, and phases of psychologic and pedagogical diagnostic

Ecological and evolutionary response of phytoplankton to rising CO2

Atmospheric CO2 concentration has risen to a landmark high of 400 ppm, a level not seen on earth for the past million years, and is expected to continue to increase over the course of this century. Besides its indirect effect on climate, this change will directly affect all photosynthetic organisms, including phytoplankton, through an increased availability of carbon. Through laboratory and field experiments, I investigated the ecological and evolutionary response of phytoplankton communities to rising atmospheric CO2. The rise in atmospheric CO2 is occurring at the same time as increases in the availability of a number of nutrients. In a series of mesocosm experiments in a lake, I found that elevated CO2 can act synergistically with increased nutrient availability to increase phytoplankton growth. Elevated CO2 could thus exacerbate the effect of traditional drivers of eutrophication. Major taxonomic groups of phytoplankton differ in their ability to take up and utilize CO2. In an experiment with six species of phytoplankton belonging to three major taxa (cyanobacteria, diatoms and chlorophytes), I found that these physiological differences lead to predictable changes in community dynamics. Chlorophytes, the type most limited by current CO2 levels, benefit from rising CO2 at the expense of cyanobacteria. The applicability of these findings to natural systems was confirmed in the series of mesocosm experiments. In these experiments, the increase in the frequency of chlorophytes with rising CO2 was observed at both high and low nutrient levels. The increased growth rate with the addition of nutrients and CO2, the physiological differences between major groups of phytoplankton and the associated changes in community compositions may be altered by evolutionary change after sufficiently long exposure of these organisms to elevated CO2. I tested for the probability of evolutionary change in response to elevated CO2 by exposing the previous six species and Chlamydomonas reinhardtii to elevated CO2 for over 750 generations. I found no evidence of evolutionary change, which indicates that predictions of the ecological impact of rising CO2 on phytoplankton based on the current physiology of phytoplankton will remain valid even after hundreds of generations. As phytoplankton are the base of most aquatic food webs and important drivers of the global carbon cycle, this work provides a crucial element for predicting the future state of aquatic systems and global geochemistry undergoing global change.La concentration de CO2 dans l'atmosphère a atteint un niveau record de 400 ppm. Un niveau si élevé n'a pas été atteint lors des derniers millions d'années. Les prédictions actuelles indiquent que la concentration atmosphérique de CO2 va continuer à augmenter tout au long de ce siècle. J'ai utilisé des expériences de laboratoire et des expériences de terrain pour étudier la réponse écologique et évolutive du phytoplancton au changement de concentration de CO2. L'augmentation de la disponibilité de plusieurs autres nutriments se déroule en même temps que l'augmentation de CO2 dans l'atmosphère. Dans une série d'expériences utilisant des mésocosmes en milieu naturel, j'ai constaté que la croissance du phytoplancton augmentait plus avec l'addition simultanée de CO2 et de nutriments qu'avec l'addition uniquement de nutriments. L'augmentation de CO2 atmosphérique pourrait donc exacerber les problèmes d'eutrophisation des milieux aquatiques. Les regroupements taxonomiques importants de phytoplanctons se distinguent par leur capacité d'absorber et d'utiliser le CO2. Dans une expérience de laboratoire, ces différences physiologiques entre six espèces de phytoplancton appartenant à trois (des cyanobactéries, des diatomées et des chlorophytes) ont pour conséquences un changement prévisible des dynamiques écologiques au sein de la communauté de phytoplanctons. La proportion dans la communauté de chlorophytes, le groupe dont la croissance est la plus limitée par les niveaux présents de CO2, augmente avec l'augmentation de CO2, et ce, aux dépens de la proportion de cyanobactéries. Les changements écologiques au niveau de l'augmentation du taux de croissance et les changements des proportions de différents types dans les communautés de phytoplanctons pourraient être altérés par des changements évolutifs lors de l'exposition prolongée du phytoplancton à une concentration de CO2 élevée. J'ai évalué la probabilité d'une réponse évolutive causée par une concentration de CO2 élevée en exposant les six espèces de l'expérience précédente et Chlamydomonas reinhardtii à un niveau de CO2 élevé pour plus de 750 générations. Je n'ai trouvé aucune preuve de changement évolutif, ce qui indique que les prédictions basées sur les caractéristiques physiologiques actuelles des phytoplanctons demeureront valides pour plusieurs centaines de générations. Puisque les phytoplanctons sont à la base de toutes les chaines alimentaires aquatiques importantes et des contributeurs importants aux différents cycles géochimiques planétaires, les recherches présentées dans cette thèse fournissent un élément crucial pour la prédiction de l'état futur des milieux aquatiques et de la géochimie mondiale

Rising complexity and falling explanatory power in ecology

Analyses of published research can provide a realistic perspective on the progress of science. By analyzing more than 18 000 articles published by the preeminent ecological societies, we found that (1) ecological research is becoming increasingly statistically complex, reporting a growing number of P values per article and (2) the value of reported coefficient of determination (R2) has been falling steadily, suggesting a decrease in the marginal explanatory power of ecology. These trends may be due to changes in the way ecology is studied or in the way the findings of investigations are reported. Determining the reason for increasing complexity and declining marginal explanatory power would require a critical review of the scientific process in ecology, from research design to dissemination, and could influence the public interpretation and policy implications of ecological findings

Phenotyping Microarrays for the Characterization of Environmental Microorganisms

Culture-based methods for the characterization of microorganisms remain essential to advances in microbiology. Phenotyping arrays and microplates in which each well represents a different selective growth environment are important tools (1) in the identification of microbial isolates, (2) in the characterization of the phenotypic fingerprint of microbial communities, (3) for linking specific functions with specific organisms or genes, and (4) for the identification of evolutionary trade-offs in the establishment of phenotypes. The use of phenotyping arrays in the study of hydrocarbon and lipid degradation by microbial isolates or communities is an emerging application. The application of phenotyping arrays requires careful selection of substrates, growth medium, and dyes and consideration of the intrinsic limitations of the approach. The use of phenotyping arrays leads to the production of large amounts of data, which require specific approaches for summarization and analysis. Liquid handling automation will increase the feasibility of custom phenotyping arrays that include hydrocarbons and lipids

The effect of elevated CO2 on growth and competition in experimental phytoplankton communities

We report an experiment designed to identify the effect of elevated CO 2 on species of phytoplankton in a simple laboratory system. Major taxa of phytoplankton differ in their ability to take up CO 2, which might lead to predictable changes in the growth rate of species and thereby shifts in the composition of phytoplankton communities in response to rising CO 2. Six species of phytoplankton belonging to three major taxa (cyanobacteria, diatoms and chlorophytes) were cultured in atmospheres whose CO 2 concentration was gradually increased from ambient levels to 1000 parts per million over about 100 generations and then maintained for a further 200 generations at elevated CO 2. The experimental design allowed us to trace a predictive sequence, from physiological features to the growth response of species to elevated CO 2 in pure culture, from the growth response in pure culture to competitive ability in pairwise mixtures and from pairwise competitive ability to shifts in the relative abundance of species in the full community of all six species. CO 2 altered the dynamics of growth in a fashion consistent with known differences among major taxa in their ability to take up and use CO 2. This pure-culture response was partly successful in predicting the outcome of competition in pairwise mixtures, especially the enhanced competitive ability of chlorophytes relative to cyanobacteria, although generally statistical support was weak. The competitive response in pairwise mixtures was a good predictor of changes in competitive ability in the full community. Hence, there is a potential for forging a logical chain of inferences for predicting how phytoplankton communities will respond to elevated CO 2. Clearly further extensive experiments will be required to validate this approach in the greater complexity found in diverse communities and environments of natural systems. © 2011 Blackwell Publishing Ltd

Complete data and R analysis scripts

Laboratory stud

Aquatic primary production in a high-CO2 world

Here, we provide a review of the direct effect of increasing CO2 on aquatic primary producers through its function as a source of carbon, focusing our analysis on the interpretation of this increase as an increase in the availability of a resource. This provides an interesting context to evaluate ecological and evolutionary theories relating to nutrient availability and leads us to: the assessment of theories about limitation of productivity and the integration of CO2 into the co-limitation paradigm; the prediction of community composition and of change in communities from known changes in the environment; and evaluation of the potential for evolutionary adaptation in conditions that increase growth. © 2014 Elsevier Ltd