Correlation between Drosophila population sizes and solar activity parameters

The relationships between the time series of the changes in the sizes of experimental Drosophila melanogaster populations at the preimaginal stage and three heliogeophysical indices (Wolf numbers, 10.7-cm radio flux intensity, and the K _p index of geomagnetic activity) have been analyzed. The results demonstrate a significant relationship between the population dynamics and heliogeophysical factors and dependence of this relationship on the phase of the 11-year solar activity cycle. Factors related to solar activity may stimulate female fertility and egg survival.     

The dynamics of the motions of Drosophila melanogaster laboratory populations correlates with the parameters of space weather

Analysis of the motions of Drosophila melanogaster laboratory populations and their relationship to the heliogeophysical parameters (the radio-wave flux at the wavelength of 10.7 cm (F10.7), Wolf numbers (W), the planetary K _p-index, an indicator of geomagnetic activity) was carried out. A significant correlation between the changes in the characteristics of solar activity (F10.7, W) and the dynamics of the motions of Drosophila was detected. The association strongly depends on the sexual structure of the Drosophila populations, which follows from the difference in the distributions of this association.

     

Correlation of biophysical parameters of biologically active points and variations of heliogeophysical factors

The correlation between the parameters of biologically active points and the dynamics of solar activity was studied. Statistically significant correlations between electroconductivity of biologically active points and solar activity indices (sunspot number, Ap-index, solar radiowave flux) were revealed. The spectral analysis of the temporal organization of biologically active points revealed a set of periods present in the dynamics of solar activity. It was concluded that bioelectric system of the human organism is a complicated multilevel time-structure, which effectively reacts to changes in heliogeophysical dynamics. The bioelectric system of biologically active points is considered to be one of general information channels of electromagnetic nature, which realize the connection of organism with environment.     

Response of the human body to heliogeophysical disturbanes

A correlation between variations in the medical parameters and the heliogeophysical indices describing physical processes during solar storms was established. It was proposed that one of the reasons for the biotropic effects observed is rheological shifts of human blood during enhancement of solar activity. The influence of heliogeophysical disturbances on the rheological properties of blood was investigated.     

Effects of Long-Term Variations in Cosmic Rhythms upon Human Biochemical Parameters

No studies of human biochemical parameters that were long enough to be comparable with the 11-year solar cycle could be found in the scientific literature. Therefore, we performed an analysis of correlations between fluctuations of blood biochemical parameters detected during a 12-year period and the time courses of some heliogeophysical factors. It was shown that the biochemical system of the blood responds to the influence of these factors. The study was based on 443 results of biochemical tests and 4883 daily records of heliogeophysical parameters. It was shown that the system of biochemical parameters changes synchronously with the impacts studied. This follows from similar spectral harmonics and periods of these physiological and physical processes, including the total correlative estimate (criterion function) of the biochemical parameters, which adequately describes functional changes in the biochemical system of the blood.     

Variations in the intensity of solar neutrinos as a problem for physical chemistry

A comparison of variations in the solar neutrino flux in Brookhaven measurements with solar activity indices clearly shows that the neutrino flux is controlled by surface solar processes. These processes can lead to changes in the efficiency of registrations of the neutrino flux. From this view point, the results of the measurements of the neutrino flux on the Brookhaven detector in 1970-1994 (108 runs) were analyzed. It was found that the neutrino flux depends on the heliogeophysical situation. The well known anticorrelation between the neutrino flux and Wolf numbers is observed only for odd cycle of solar activity. A similar regularity occurs for critical frequencies of E-ionosphere. By contrast, the correlation between the neutrino flux and the Ap-index is observed only for the even activity cycle. The predominance of the sign of radial component of the interplanetary magnetic field in the last 7-14 days of exposure has the greatest effect on the neutrino flux (this sign changes as the sign of the total magnetic field of the Sun changes). In short runs, the neutrino flux changes more than threefold. The conclusion is made that variations of the solar neutrino flux are falcious. These fictitious variations are caused probably by the action of very low-frequency electromagnetic emissions of the magnetosphere upon the substance of the target and the technology of the extraction of 37Ar atoms from perchloretylene.     

Correlation of the width of annual tree rings with climatic changes and solar activity

Fluctuations in the width of annual tree rings in the time interval from the eighth century till the present time were analyzed on the basis of dendroclimatic scales. Periods of extremely high and low growth of trees were distinguished, and their correlations with heliogeophysical factors were studied. The major climatic parameters determining the growth of trees are warmth and moisture; a small gain is observed in cold and droughty periods. No correlations between the width of tree rings and the minima and maxima of solar activity cycles were observed with the method used.     

Correlations of life-span variation parameters in 128 successive generations of Drosophila melanogaster with changes in atmospheric pressure and geomagnetic activity

Correlations between the parameters of life-span (LS) distribution of Drosophila melanogaster, including mean LS (MLS) and the time of 10 and 90% population mortality, and some geophysical parameters that are usually beyond the control of researchers dealing with laboratory cultures, including atmospheric pressure, solar activity indices (Wolfs sunspot numbers and 2,800-MHz radio flux), and geomagnetic activity (planetary index, K_p), were studied. Geophysical data were obtained from free-access official web sites of the National Oceanic & Atmospheric Administration of the US Department of Commerce and the Institute of Terrestrial Magnetism and Radiowave Propagation of the Russian Academy of Sciences. The geophysical parameters were calculated only for the period corresponding to 10 days of preimaginal development of the flies from egg to imago. Canonical correlation analysis, calculation of the non-parametric Spearman rank-order correlation coefficients, and graphical data analysis were used. Highly significant correlations between parameters of LS distribution in males and females and environmental factors, such as the atmospheric pressure on the 4th and 5th day of development and geomagnetic activity indices (K_p) on the 6th and 10th day of development were found, with correlation coefficients varying from 0.31 to 0.37 (P<0.02). Assuming a causal relationship between geophysical factors and LS, it may be hypothesized that energetically weak environmental factors determine the formation of LS oscillatory dynamics in laboratory populations. The possible mechanisms underlying the contribution of these environmental factors to the LS variation in successive generations are discussed.     

Clinical cosmobiology: The Lithuanian study 1990–1992

The numbers of deaths from ischaemic heart disease (IHD), stroke (CVA), all accidents except vehicular, vehicular accidents and suicide (overall total, totals for men and women) per month for 36 months (1990–1992) in Lithuania were analysed in relation to: (1) month of the year (1–12); (2) geomagnetic activity; and (3) solar activity. A total of 122227 deaths (64490 men and 57737 women) was studied, and the results compared with those obtained in an earlier study in Israel, differing geographically and climatically from Lithuania. It was shown that the time of year, solar activity, and geomagnetic activity were related to the monthly death distribution, especially regarding death from IHD and suicide. Age and gender differences were apparent in the relationship between death distribution and physical environmental factors. At age >70 years, many of these relationships change. The monthly distribution of deaths from IHD and suicide are adversely correlated with solar activity and with each other. Differences are presumed in serotoninergic effects as caused by environmental influences.     

Ecological dynamics of the toxic bloom-forming cyanobacterium Microcystis aeruginosa and its cyanophages in freshwater

The abundance of potentially Microcystis aeruginosa-infectious cyanophages in freshwater was studied using g91 real-time PCR. A clear increase in cyanophage abundance was observed when M. aeruginosa numbers declined, showing that these factors were significantly negatively correlated. Furthermore, our data suggested that cyanophage dynamics may also affect shifts in microcystin-producing and non-microcystin-producing populations.     

Olive Fruit Fly (Bactrocera oleae) Population Dynamics in the Eastern Mediterranean: Influence of Exogenous Uncertainty on a Monophagous Frugivorous Insect

Despite of the economic importance of the olive fly (Bactrocera oleae) and the large amount of biological and ecological studies on the insect, the factors driving its population dynamics (i.e., population persistence and regulation) had not been analytically investigated until the present study. Specifically, our study investigated the autoregressive process of the olive fly populations, and the joint role of intrinsic and extrinsic factors molding the population dynamics of the insect. Accounting for endogenous dynamics and the influences of exogenous factors such as olive grove temperature, the North Atlantic Oscillation and the presence of potential host fruit, we modeled olive fly populations in five locations in the Eastern Mediterranean region. Our models indicate that the rate of population change is mainly shaped by first and higher order non-monotonic, endogenous dynamics (i.e., density-dependent population feedback). The olive grove temperature was the main exogenous driver, while the North Atlantic Oscillation and fruit availability acted as significant exogenous factors in one of the five populations. Seasonal influences were also relevant for three of the populations. In spite of exogenous effects, the rate of population change was fairly stable along time. We propose that a special reproductive mechanism, such as reproductive quiescence, allows populations of monophagous fruit flies such as the olive fly to remain stable. Further, we discuss how weather factors could impinge constraints on the population dynamics at the local level. Particularly, local temperature dynamics could provide forecasting cues for management guidelines. Jointly, our results advocate for establishing monitoring programs and for a major focus of research on the relationship between life history traits and populations dynamics.     

Division synchrony and the dynamics of microbial populations: A size-specific model

A discrete, environmentally coupled, size-specific model of microbial population dynamics in continuous culture is presented. It is mathematically simpler than other models based on similar assumptions and lends itself to numerical and analytic solutions. It displays several phenomena which have been reported in the experimental literature but which are not well understood; specifically, a loose relationship between biomass and numbers (i.e., a time lag between mass growth and cell division) and a critical damping of biomass while numbers continue to oscillate. In addition, the model provides several new predictions: The stable biomass distribution is independent of the environmental factors considered in the model and uniformly distributes the biomass among the size classes. The rate of approach to stability and the frequency of waves through the size distributions are a function of the flow rate and the variance in rate of growth and size at division. The model should provide a useful basis for studying the effects of size specificity on the dynamics of microbial populations cultured in chemostats.     

P-M phenotypes and their correlation with longitude in natural populations of Drosophila melanogaster from Turkey

We analyzed the P-M gonadal dysgenesis characteristics and the molecular patterns of P and KP elements of 35 populations from distinct locations of Turkey and Cyprus to find out P element dynamics in natural populations of Drosophila melanogaster. The results of Gonadal dysgenesis (GD) tests showed a predominat M?? phenotype for this region. Besides Q populations were also found in less numbers. It was also noticed that there is a strong tendency for the presence of a Q type ??buffer zone?? in the Western part of Turkey. The variation in GD percentage (as a index for P element activity and susceptibility) observed among the populations did not show any clear relationship with some geoclimatic variables, but a significant correlation was found between longitude, and P element susceptibility. The P and KP element were also characterized by polymerase chain reaction amplification. The molecular analyses showed that all the populations examined have the entire of 1.15 kb KP element. The molecular patterns of KP elements have been found similar between the populations studied.     

Population dynamics of three songbird species in a nestbox population in Central Europe show effects of density,climate and competitive interactions

Unravelling the contributions of density‐dependent and density‐independent factors in determining species population dynamics is a challenge, especially if the two factors interact. One approach is to apply stochastic population models to long‐term data, yet few studies have included interactions between density‐dependent and density‐independent factors, or explored more than one type of stochastic population model. However, both are important because model choice critically affects inference on population dynamics and stability. Here, we used a multiple models approach and applied log‐linear and non‐linear stochastic population models to time series (spanning 29 years) on the population growth rates of Blue Tits Cyanistes caeruleus, Great Tits Parus major and Pied Flycatchers Ficedula hypoleuca breeding in two nestbox populations in southern Germany. We focused on the roles of climate conditions and intra‐ and interspecific competition in determining population growth rates. Density dependence was evident in all populations. For Blue Tits in one population and for Great Tits in both populations, addition of a density‐independent factor improved model fit. At one location, Blue Tit population growth rate increased following warmer winters, whereas Great Tit population growth rates decreased following warmer springs. Importantly, Great Tit population growth rate also decreased following years of high Blue Tit abundance, but not vice versa. This finding is consistent with asymmetric interspecific competition and implies that competition could carry over to influence population dynamics. At the other location, Great Tit population growth rate decreased following years of high Pied Flycatcher abundance but only when Great Tit population numbers were low, illustrating that the roles of density‐dependent and density‐independent factors are not necessarily mutually exclusive. The dynamics of this Great Tit population, in contrast to the other populations, were unstable and chaotic, raising the question of whether interactions between density‐dependent and density‐independent factors play a role in determining the (in) stability of the dynamics of species populations.     

Correlation of the solar activity with water electrical conductivity

A correlation between the solar activity (Wolf numbers) and electric conductivity of water was found. It was suggested that changes in the electric conductivity of water are the primary cause of the known correlations between the solar activity and various processes in the biosphere.     

Studies of alphaB crystallin subunit dynamics by surface plasmon resonance

The molecular chaperone activity of alphaB crystallin, an important stress protein in humans, is regulated by physiological factors, including temperature, pH, Ca2+, and ATP. In this study, the role of these factors in regulating the subunit dynamics of human alphaB crystallin was investigated using surface plasmon resonance (SPR). SPR experiments indicate that at temperatures above 37 degrees C, where alphaB crystallin has been reported to have higher chaperone activity, the subunit dynamics of alphaB crystallin were increased with faster association and dissociation rates. SPR experiments also indicate that interactions between alphaB crystallin subunits were enhanced with much faster association and slower dissociation rates at pH values below 7.0, where alphaB crystallin has been reported to have lower chaperone activity. The results suggest that the dynamic and rapid subunit exchange rate may regulate the chaperone activity of alphaB crystallin. The effect of Ca2+ and ATP on the subunit dynamics of alphaB crystallin was minimal, suggesting that Ca2+ and ATP modulate the chaperone activity of alphaB crystallin without altering the subunit dynamics. Based on the SPR results and previously reported biochemical data for the chaperone activity of alphaB crystallin under different conditions of temperature and pH, a model for the relationship between the subunit dynamics and chaperone activity of alphaB crystallin is established. The model is consistent with previous biochemical data for the chaperone activity and subunit dynamics of small heat shock proteins (sHSPs) and establishes a working hypothesis for the relationship between complex assembly and chaperone activity for sHSPs.     

Comparison of Contact Patterns Relevant for Transmission of Respiratory Pathogens in Thailand and the Netherlands Using Respondent-Driven Sampling

Understanding infection dynamics of respiratory diseases requires the identification and quantification of behavioural, social and environmental factors that permit the transmission of these infections between humans. Little empirical information is available about contact patterns within real-world social networks, let alone on differences in these contact networks between populations that differ considerably on a socio-cultural level. Here we compared contact network data that were collected in the Netherlands and Thailand using a similar online respondent-driven method. By asking participants to recruit contact persons we studied network links relevant for the transmission of respiratory infections. We studied correlations between recruiter and recruited contacts to investigate mixing patterns in the observed social network components. In both countries, mixing patterns were assortative by demographic variables and random by total numbers of contacts. However, in Thailand participants reported overall more contacts which resulted in higher effective contact rates. Our findings provide new insights on numbers of contacts and mixing patterns in two different populations. These data could be used to improve parameterisation of mathematical models used to design control strategies. Although the spread of infections through populations depends on more factors, found similarities suggest that spread may be similar in the Netherlands and Thailand.     

Analysis of factors which determine the existence of Yersinia pseudotuberculosis in a saprophytic phase

Data are presented on the effects of a variety of abiotic and biotic environmental factors on the existence and changes in the numbers of Y. pseudotuberculosis. Experiments with sterile soil showed that Y. pseudotuberculosis populations were resistant over a wide range of major abiotic factors: temperature (0-30 degrees C), humidity (15-50%), pH (5.9-9.0). Although exerting some effect on the duration of different growth phases, the above abiotic factors did not influence, within the tested range, the general nature of populational dynamics of the microbe. Comparative experiments carried out in sterile and natural soil specimens using an RNA-polymerase mutant warranted the conclusion that the numbers of Y. pseudotuberculosis in soil (water) are largely controlled by the biotic components of ecosystems, including microflora and microfauna. Y. pseudotuberculosis was shown to exist in the environment (vegetable storehouses and substrate of rodent nests) in association with bacteria belonging to the family Enterobacteriaceae as well as the genera Acinetobacter and Pseudomonas. Endosymbiotic relationships are described between Y. pseudotuberculosis and the free-living infusorian Tetrahymena pyriformis which sustains microbial populations in the soil (water).