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Sample records for activity predict variation

  1. Prediction of solar activity from solar background magnetic field variations in cycles 21-23

    Shepherd, Simon J. [School of Engineering, University of Bradford, Bradford, BD7 1DP (United Kingdom); Zharkov, Sergei I. [Department of Physics and Mathematics, University of Hull, Kingston upon Tyne, HU6 7RS (United Kingdom); Zharkova, Valentina V., E-mail: s.j.shepherd@brad.ac.uk, E-mail: s.zharkov@hull.ac.uk, E-mail: valentina.zharkova@northumbria.ac.uk [Department of Mathematics and Information Systems, University of Northumbria, Newcastle upon Tyne, NE2 8ST (United Kingdom)

    2014-11-01

    A comprehensive spectral analysis of both the solar background magnetic field (SBMF) in cycles 21-23 and the sunspot magnetic field in cycle 23 reported in our recent paper showed the presence of two principal components (PCs) of SBMF having opposite polarity, e.g., originating in the northern and southern hemispheres, respectively. Over a duration of one solar cycle, both waves are found to travel with an increasing phase shift toward the northern hemisphere in odd cycles 21 and 23 and to the southern hemisphere in even cycle 22. These waves were linked to solar dynamo waves assumed to form in different layers of the solar interior. In this paper, for the first time, the PCs of SBMF in cycles 21-23 are analyzed with the symbolic regression technique using Hamiltonian principles, allowing us to uncover the underlying mathematical laws governing these complex waves in the SBMF presented by PCs and to extrapolate these PCs to cycles 24-26. The PCs predicted for cycle 24 very closely fit (with an accuracy better than 98%) the PCs derived from the SBMF observations in this cycle. This approach also predicts a strong reduction of the SBMF in cycles 25 and 26 and, thus, a reduction of the resulting solar activity. This decrease is accompanied by an increasing phase shift between the two predicted PCs (magnetic waves) in cycle 25 leading to their full separation into the opposite hemispheres in cycle 26. The variations of the modulus summary of the two PCs in SBMF reveals a remarkable resemblance to the average number of sunspots in cycles 21-24 and to predictions of reduced sunspot numbers compared to cycle 24: 80% in cycle 25 and 40% in cycle 26.

  2. Genetic variation in the proximal promoter of ABC and SLC superfamilies: liver and kidney specific expression and promoter activity predict variation.

    Stephanie E Hesselson

    Full Text Available Membrane transporters play crucial roles in the cellular uptake and efflux of an array of small molecules including nutrients, environmental toxins, and many clinically used drugs. We hypothesized that common genetic variation in the proximal promoter regions of transporter genes contribute to observed variation in drug response. A total of 579 polymorphisms were identified in the proximal promoters (-250 to +50 bp and flanking 5' sequence of 107 transporters in the ATP Binding Cassette (ABC and Solute Carrier (SLC superfamilies in 272 DNA samples from ethnically diverse populations. Many transporter promoters contained multiple common polymorphisms. Using a sliding window analysis, we observed that, on average, nucleotide diversity (pi was lowest at approximately 300 bp upstream of the transcription start site, suggesting that this region may harbor important functional elements. The proximal promoters of transporters that were highly expressed in the liver had greater nucleotide diversity than those that were highly expressed in the kidney consistent with greater negative selective pressure on the promoters of kidney transporters. Twenty-one promoters were evaluated for activity using reporter assays. Greater nucleotide diversity was observed in promoters with strong activity compared to promoters with weak activity, suggesting that weak promoters are under more negative selective pressure than promoters with high activity. Collectively, these results suggest that the proximal promoter region of membrane transporters is rich in variation and that variants in these regions may play a role in interindividual variation in drug disposition and response.

  3. Prediction of interannual climate variations

    It has been known for some time that the behavior of the short-term fluctuations of the earth's atmosphere resembles that of a chaotic non-linear dynamical system, and that the day-to-day weather cannot be predicted beyond a few weeks. However, it has also been found that the interactions of the atmosphere with the underlying oceans and the land surfaces can produce fluctuations whose time scales are much longer than the limits of deterministic prediction of weather. It is, therefore, natural to ask whether it is possible that the seasonal and longer time averages of climate fluctuations can be predicted with sufficient skill to be beneficial for social and economic applications, even though the details of day-to-day weather cannot be predicted beyond a few weeks. The main objective of the workshop was to address this question by assessing the current state of knowledge on predictability of seasonal and interannual climate variability and to investigate various possibilities for its prediction. (orig./KW)

  4. Predicting geomagnetic activity indices

    Complete text of publication follows. Magnetically active times, e.g., Kp > 5, are notoriously difficult to predict, precisely the times when such predictions are crucial to the space weather users. Taking advantage of the routinely available solar wind measurements at Lagrangian point (L1) and nowcast Kps, Kp and Dst forecast models based on neural networks were developed with the focus on improving the forecast for active times. To satisfy different needs and operational constraints, three models were developed: (1) a model that inputs nowcast Kp and solar wind parameters and predicts Kp 1 hr ahead; (2) a model with the same input as model 1 and predicts Kp 4 hr ahead; and (3) a model that inputs only solar wind parameters and predicts Kp 1 hr ahead (the exact prediction lead time depends on the solar wind speed and the location of the solar wind monitor.) Extensive evaluations of these models and other major operational Kp forecast models show that, while the new models can predict Kps more accurately for all activities, the most dramatic improvements occur for moderate and active times. Similar Dst models were developed. Information dynamics analysis of Kp, suggests that geospace is more dominated by internal dynamics near solar minimum than near solar maximum, when it is more directly driven by external inputs, namely solar wind and interplanetary magnetic field (IMF).

  5. Predicting global variation in infectious disease severity

    Jensen, Per M.; De Fine Licht, Henrik H.

    2016-01-01

    Background and objectives: Understanding the underlying causes for the variation in case-fatality-ratios (CFR) is important for assessing the mechanism governing global disparity in the burden of infectious diseases. Variation in CFR is likely to be driven by factors such as population genetics, demography, transmission patterns and general health status. We present data here that support the hypothsis that changes in CFRs for specific diseases may be the result of serial passage through different hosts. For example passage through adults may lead to lower CFR, whereas passage through children may have the opposite effect. Accordingly changes in CFR may occur in parallel with demographic transitions. Methodology: We explored the predictability of CFR using data obtained from the World Health Organization (WHO) disease databases for four human diseases: mumps, malaria, tuberculosis and leptospirosis and assessed these for association with a range of population characteristics, such as crude birth and death rates, median age of the population, mean body mass index, proportion living in urban areas and tuberculosis vaccine coverage. We then tested this predictive model on Danish historical demographic and population data. Results: Birth rates were the best predictor for mumps and malaria CFR. For tuberculosis CFR death rates were the best predictor and for leptospirosis population density was a significant predictor. Conclusions and implications: CFR predictors differed among diseases according to their biology. We suggest that the overall result reflects an interaction between the forces driving demographic change and the virulence of human-to-human transmitted diseases. PMID:26884415

  6. Predicting global variation in infectious disease severity

    Jensen, Per Moestrup; de Fine Licht, Henrik Hjarvard

    2016-01-01

    Background and objectives: Understanding the underlying causes for the variation in case-fatality-ratios (CFR) is important for assessing the mechanism governing global disparity in the burden of infectious diseases. Variation in CFR is likely to be driven by factors such as population genetics...

  7. Predicting facial characteristics from complex polygenic variations

    Fagertun, Jens; Wolffhechel, Karin Marie Brandt; Pers, Tune;

    2015-01-01

    traits in a linear regression. We show in this proof-of-concept study for facial trait prediction from genome-wide SNP data that some facial characteristics can be modeled by genetic information: facial width, eyebrow width, distance between eyes, and features involving mouth shape are predicted with...

  8. Genotypic richness predicts phenotypic variation in an endangered clonal plant.

    Evans, Suzanna M; Sinclair, Elizabeth A; Poore, Alistair G B; Bain, Keryn F; Vergés, Adriana

    2016-01-01

    Declines in genetic diversity within a species can affect the stability and functioning of populations. The conservation of genetic diversity is thus a priority, especially for threatened or endangered species. The importance of genetic variation, however, is dependent on the degree to which it translates into phenotypic variation for traits that affect individual performance and ecological processes. This is especially important for predominantly clonal species, as no single clone is likely to maximise all aspects of performance. Here we show that intraspecific genotypic diversity as measured using microsatellites is a strong predictor of phenotypic variation in morphological traits and shoot productivity of the threatened, predominantly clonal seagrass Posidonia australis, on the east coast of Australia. Biomass and surface area variation was most strongly predicted by genotypic richness, while variation in leaf chemistry (phenolics and nitrogen) was unrelated to genotypic richness. Genotypic richness did not predict tissue loss to herbivores or epiphyte load, however we did find that increased herbivore damage was positively correlated with allelic richness. Although there was no clear relationship between higher primary productivity and genotypic richness, variation in shoot productivity within a meadow was significantly greater in more genotypically diverse meadows. The proportion of phenotypic variation explained by environmental conditions varied among different genotypes, and there was generally no variation in phenotypic traits among genotypes present in the same meadows. Our results show that genotypic richness as measured through the use of presumably neutral DNA markers does covary with phenotypic variation in functionally relevant traits such as leaf morphology and shoot productivity. The remarkably long lifespan of individual Posidonia plants suggests that plasticity within genotypes has played an important role in the longevity of the species

  9. Genotypic richness predicts phenotypic variation in an endangered clonal plant

    Sinclair, Elizabeth A.; Poore, Alistair G.B.; Bain, Keryn F.; Vergés, Adriana

    2016-01-01

    Declines in genetic diversity within a species can affect the stability and functioning of populations. The conservation of genetic diversity is thus a priority, especially for threatened or endangered species. The importance of genetic variation, however, is dependent on the degree to which it translates into phenotypic variation for traits that affect individual performance and ecological processes. This is especially important for predominantly clonal species, as no single clone is likely to maximise all aspects of performance. Here we show that intraspecific genotypic diversity as measured using microsatellites is a strong predictor of phenotypic variation in morphological traits and shoot productivity of the threatened, predominantly clonal seagrass Posidonia australis, on the east coast of Australia. Biomass and surface area variation was most strongly predicted by genotypic richness, while variation in leaf chemistry (phenolics and nitrogen) was unrelated to genotypic richness. Genotypic richness did not predict tissue loss to herbivores or epiphyte load, however we did find that increased herbivore damage was positively correlated with allelic richness. Although there was no clear relationship between higher primary productivity and genotypic richness, variation in shoot productivity within a meadow was significantly greater in more genotypically diverse meadows. The proportion of phenotypic variation explained by environmental conditions varied among different genotypes, and there was generally no variation in phenotypic traits among genotypes present in the same meadows. Our results show that genotypic richness as measured through the use of presumably neutral DNA markers does covary with phenotypic variation in functionally relevant traits such as leaf morphology and shoot productivity. The remarkably long lifespan of individual Posidonia plants suggests that plasticity within genotypes has played an important role in the longevity of the species

  10. Predicting individual variation in language from infant speech perception measures

    Cristia, A.; Seidl, A; Junge, C.; Soderstrom, M.; Hagoort, P.

    2014-01-01

    There are increasing reports that individual variation in behavioral and neurophysiological measures of infant speech processing predicts later language outcomes, and specifically concurrent or subsequent vocabulary size. If such findings are held up under scrutiny, they could both illuminate theoretical models of language development and contribute to the prediction of communicative disorders. A qualitative, systematic review of this emergent literature illustrated the variety of approaches ...

  11. A simple physical model predicts small exon length variations.

    2006-04-01

    Full Text Available One of the most common splice variations are small exon length variations caused by the use of alternative donor or acceptor splice sites that are in very close proximity on the pre-mRNA. Among these, three-nucleotide variations at so-called NAGNAG tandem acceptor sites have recently attracted considerable attention, and it has been suggested that these variations are regulated and serve to fine-tune protein forms by the addition or removal of a single amino acid. In this paper we first show that in-frame exon length variations are generally overrepresented and that this overrepresentation can be quantitatively explained by the effect of nonsense-mediated decay. Our analysis allows us to estimate that about 50% of frame-shifted coding transcripts are targeted by nonsense-mediated decay. Second, we show that a simple physical model that assumes that the splicing machinery stochastically binds to nearby splice sites in proportion to the affinities of the sites correctly predicts the relative abundances of different small length variations at both boundaries. Finally, using the same simple physical model, we show that for NAGNAG sites, the difference in affinities of the neighboring sites for the splicing machinery accurately predicts whether splicing will occur only at the first site, splicing will occur only at the second site, or three-nucleotide splice variants are likely to occur. Our analysis thus suggests that small exon length variations are the result of stochastic binding of the spliceosome at neighboring splice sites. Small exon length variations occur when there are nearby alternative splice sites that have similar affinity for the splicing machinery.

  12. Thermal Phase Variations of WASP-12b: Defying Predictions

    Cowan, N B; Croll, B; Shekhtman, L M; Burrows, A; Deming, D; Greene, T; Hora, J L

    2011-01-01

    [Abridged] We report Warm Spitzer full-orbit phase observations of WASP-12b at 3.6 and 4.5 micron. We are able to measure the transit depths, eclipse depths, thermal and ellipsoidal phase variations at both wavelengths. The large amplitude phase variations, combined with the planet's previously-measured day-side spectral energy distribution, is indicative of non-zero Bond albedo and very poor day-night heat redistribution. The transit depths in the mid-infrared indicate that the atmospheric opacity is greater at 3.6 than at 4.5 micron, in disagreement with model predictions, irrespective of C/O ratio. The secondary eclipse depths are consistent with previous studies. We do not detect ellipsoidal variations at 3.6 micron, but our parameter uncertainties -estimated via prayer-bead Monte Carlo- keep this non-detection consistent with model predictions. At 4.5 micron, on the other hand, we detect ellipsoidal variations that are much stronger than predicted. If interpreted as a geometric effect due to the planet's...

  13. Seasonal variation in leisure time physical activity.

    Uitenbroek, D G

    1993-06-01

    In this paper seasonal variation in leisure time physical activity for exercise is studied and quantified with regard to several popular exercise activities and taking the respondents gender, occupational status, and age into consideration. The analysis concerns data collected by telephone in Scotland between January 1989 and March 1992. Data from 7,202 male and 9,284 female respondents is used in the analysis; cosinor analysis using GLIM is applied. Considerable seasonal variation was found affecting both outdoor and indoor activities. During the peak phase in July, 32% of the respondents reported exercising for at least 20 min three or more times during the previous week, in the winter period this decreased to 23%. Older respondents were found to exercise more later in the year and also showed seasonal variation to a larger extent than younger respondents. This is particularly so for those respondents who exercise at a relatively high frequency. PMID:8321115

  14. Prediction of geomagnetic secular variation using data assimilation techniques

    Complete text of publication follows. An important part of geopotential research is to develop models of the time-varying geomagnetic field, not only for scientific use but for practical purposes. The IGRF is the most commonly used model of the field; a very important aspect of this model is the secular variation (SV) model, from which predictions of the field are calculated up to 5 years after the initial epoch. This predictive model is currently calculated from observations alone. Here we propose a new approach, assimilating geomagnetic observations to geodynamo models for SV prediction. Assimilation of measurements and numerical models has been widely used in atmospheric and oceanic studies to better estimate the true dynamical states and to predict more accurately the changes of the observables in future. Similar approaches could be very useful for geomagnetic field modeling, in particular prediction of geomagnetic secular variation (SV) on decadal time scales. We have developed a geomagnetic data assimilation system (MoSSTDAS) to combine geomagnetic field model output for the past 7000 years and our numerical core dynamics model to better constrain the (numerical) core state, and to predict geomagnetic field and secular variations up to 20 years. Our forecast is very accurate. For 5-year forecast, the correlation between the field morphologies at the core-mantle boundary is greater than 99.5% over the 20th century, while the correlation between SVs is larger than 95%. To examine the broad applicability, we are modifying the assimilation process to best emulate the standard practice (e.g. IGRF) in the geomagnetic community, and to benchmark our results with those documented and published in the past.

  15. Stress responsiveness predicts individual variation in mate selectivity.

    Vitousek, Maren N; Romero, L Michael

    2013-06-15

    Steroid hormones, including glucocorticoids, mediate a variety of behavioral and physiological processes. Circulating hormone concentrations vary substantially within populations, and although hormone titers predict reproductive success in several species, little is known about how individual variation in circulating hormone concentrations is linked with most reproductive behaviors in free-living organisms. Mate choice is an important and often costly component of reproduction that also varies substantially within populations. We examined whether energetically costly mate selection behavior in female Galápagos marine iguanas (Amblyrhynchus cristatus) was associated with individual variation in the concentrations of hormones previously shown to differ between reproductive and non-reproductive females during the breeding season (corticosterone and testosterone). Stress-induced corticosterone levels - which are suppressed in female marine iguanas during reproduction - were individually repeatable throughout the seven-week breeding period. Mate selectivity was strongly predicted by individual variation in stress-induced corticosterone: reproductive females that secreted less corticosterone in response to a standardized stressor assessed more displaying males. Neither baseline corticosterone nor testosterone predicted variation in mate selectivity. Scaled body mass was not significantly associated with mate selectivity, but females that began the breeding period in lower body condition showed a trend towards being less selective about potential mates. These results provide the first evidence that individual variation in the corticosterone stress response is associated with how selective females are in their choice of a mate, an important contributor to fitness in many species. Future research is needed to determine the functional basis of this association, and whether transient acute increases in circulating corticosterone directly mediate mate choice behaviors. PMID

  16. THERMAL PHASE VARIATIONS OF WASP-12b: DEFYING PREDICTIONS

    Cowan, Nicolas B.; Shekhtman, Louis M. [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and Department of Physics and Astronomy, Northwestern University, 2131 Tech Dr, Evanston, IL 60208 (United States); Machalek, Pavel [SETI Institute, 189 Bernardo Ave., Suite 100, Mountain View, CA 94043 (United States); Croll, Bryce [Department of Astronomy and Astrophysics, University of Toronto, 50 George St., Toronto, ON, M5S 3H4 (Canada); Burrows, Adam [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 05844 (United States); Deming, Drake [Planetary Systems Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Greene, Tom [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Hora, Joseph L., E-mail: n-cowan@northwestern.edu [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

    2012-03-01

    We report Warm Spitzer full-orbit phase observations of WASP-12b at 3.6 and 4.5 {mu}m. This extremely inflated hot Jupiter is thought to be overflowing its Roche lobe, undergoing mass loss and accretion onto its host star, and has been claimed to have a C/O ratio in excess of unity. We are able to measure the transit depths, eclipse depths, thermal and ellipsoidal phase variations at both wavelengths. The large-amplitude phase variations, combined with the planet's previously measured dayside spectral energy distribution, are indicative of non-zero Bond albedo and very poor day-night heat redistribution. The transit depths in the mid-infrared-(R{sub p} /R{sub *}){sup 2} = 0.0123(3) and 0.0111(3) at 3.6 and 4.5 {mu}m, respectively-indicate that the atmospheric opacity is greater at 3.6 than at 4.5 {mu}m, in disagreement with model predictions, irrespective of C/O ratio. The secondary eclipse depths are consistent with previous studies: F{sub day}/F{sub *} = 0.0038(4) and 0.0039(3) at 3.6 and 4.5 {mu}m, respectively. We do not detect ellipsoidal variations at 3.6 {mu}m, but our parameter uncertainties-estimated via prayer-bead Monte Carlo-keep this non-detection consistent with model predictions. At 4.5 {mu}m, on the other hand, we detect ellipsoidal variations that are much stronger than predicted. If interpreted as a geometric effect due to the planet's elongated shape, these variations imply a 3:2 ratio for the planet's longest:shortest axes and a relatively bright day-night terminator. If we instead presume that the 4.5 {mu}m ellipsoidal variations are due to uncorrected systematic noise and we fix the amplitude of the variations to zero, the best-fit 4.5 {mu}m transit depth becomes commensurate with the 3.6 {mu}m depth, within the uncertainties. The relative transit depths are then consistent with a solar composition and short scale height at the terminator. Assuming zero ellipsoidal variations also yields a much deeper 4.5 {mu}m eclipse depth

  17. THERMAL PHASE VARIATIONS OF WASP-12b: DEFYING PREDICTIONS

    We report Warm Spitzer full-orbit phase observations of WASP-12b at 3.6 and 4.5 μm. This extremely inflated hot Jupiter is thought to be overflowing its Roche lobe, undergoing mass loss and accretion onto its host star, and has been claimed to have a C/O ratio in excess of unity. We are able to measure the transit depths, eclipse depths, thermal and ellipsoidal phase variations at both wavelengths. The large-amplitude phase variations, combined with the planet's previously measured dayside spectral energy distribution, are indicative of non-zero Bond albedo and very poor day-night heat redistribution. The transit depths in the mid-infrared—(Rp /R*)2 = 0.0123(3) and 0.0111(3) at 3.6 and 4.5 μm, respectively—indicate that the atmospheric opacity is greater at 3.6 than at 4.5 μm, in disagreement with model predictions, irrespective of C/O ratio. The secondary eclipse depths are consistent with previous studies: Fday/F* = 0.0038(4) and 0.0039(3) at 3.6 and 4.5 μm, respectively. We do not detect ellipsoidal variations at 3.6 μm, but our parameter uncertainties—estimated via prayer-bead Monte Carlo—keep this non-detection consistent with model predictions. At 4.5 μm, on the other hand, we detect ellipsoidal variations that are much stronger than predicted. If interpreted as a geometric effect due to the planet's elongated shape, these variations imply a 3:2 ratio for the planet's longest:shortest axes and a relatively bright day-night terminator. If we instead presume that the 4.5 μm ellipsoidal variations are due to uncorrected systematic noise and we fix the amplitude of the variations to zero, the best-fit 4.5 μm transit depth becomes commensurate with the 3.6 μm depth, within the uncertainties. The relative transit depths are then consistent with a solar composition and short scale height at the terminator. Assuming zero ellipsoidal variations also yields a much deeper 4.5 μm eclipse depth, consistent with a solar composition and modest temperature

  18. VARIATIONS OF SOLAR ROTATION AND SUNSPOT ACTIVITY

    The continuous wavelet transformation is used to study the temporal variations of the rotational cycle length of daily sunspot numbers from 1849 January 1 to 2010 February 28, from a global point of view. The rotational cycle length of the Sun is found to have a secular trend, which statistically shows a linear decrease by about 0.47 days during the time interval considered. The empirical mode decomposition analysis of the temporal variations of the rotational cycle length shows an acceleration trend for the surface rotation rate from cycles 11 to 19, but a deceleration trend from the beginning of cycle 20 onward. We cannot determine whether the rotation rate around the maximum times of the Schwable cycles should be faster or slower than that around the minimum times, implying no Schwable cycle in the long-term variations of rotation. The results obtained are compared to those from the literature. It is inferred that the variation of the rotational cycle length may be related to the variation of sunspot activity in the long run.

  19. Long-term variations of solar activity

    2007-01-01

    Using the Lomb-Scargle periodogram we analyzed two sunspot series: the one over the past 11000 years at the 10-year interval based upon the survey data of 14C concentration in tree-rings, reconstructed by Solanki et al.; and the sunspot number over the past 7000 years, derived from geomagnetic variations by Usoskin et al. We found the periods and quasi-periods in solar activity, such as about 225, 352, 441, 522 and 561 a, and near 1000 and 2000 a. An approach of wavelet transform was applied to check the two sunspot time series, with emphasis on investigating time-varying characteristics in the long-term fluctuations of solar activity. The results show that the lengths and amplitudes of the periods have changed with time, and large variations have taken place during some periods.

  20. Predicting individual variation in language from infant speech perception measures.

    Cristia, Alejandrina; Seidl, Amanda; Junge, Caroline; Soderstrom, Melanie; Hagoort, Peter

    2014-01-01

    There are increasing reports that individual variation in behavioral and neurophysiological measures of infant speech processing predicts later language outcomes, and specifically concurrent or subsequent vocabulary size. If such findings are held up under scrutiny, they could both illuminate theoretical models of language development and contribute to the prediction of communicative disorders. A qualitative, systematic review of this emergent literature illustrated the variety of approaches that have been used and highlighted some conceptual problems regarding the measurements. A quantitative analysis of the same data established that the bivariate relation was significant, with correlations of similar strength to those found for well-established nonlinguistic predictors of language. Further exploration of infant speech perception predictors, particularly from a methodological perspective, is recommended. PMID:24320112

  1. Predicting Variations in Math Performancein Four Countries Using TIMSS

    Daniel Koretz

    2001-09-01

    Full Text Available Although international comparisons of average student performance are a staple of U.S. educational debate, little attention has been paid to cross-national differences in the variability of performance. It is often assumed that the performance of U.S. students is unusually variable or that the distribution of U.S. scores is left-skewed – that is, that it has an unusually long ‘tail' of low-scoring students – but data from international studies are rarely brought to bear on these questions. This study used data from the Third International Mathematics and Science Study (TIMSS to compare the variability of performance in the U.S., Australia, France, Germany, Hong Kong, Korea, and Japan; investigate how this performance variation is distributed within and between classrooms; and explore how well background variables predict performance at both levels. TIMSS shows that the U.S. is not anomalous in terms of the amount, distribution, or prediction of performance variation. Nonetheless, some striking differences appear between countries that are potentially important for both research and policy. In the U.S., Germany, Hong Kong, and Australia, between 42 and 47 percent of score variance was between classrooms. At the other extreme, Japan and Korea both had less than 10 percent of score variance between classrooms. Two-level models (student and classroom were used to explore the prediction of performance by social background variables in four of these countries (the U.S., Hong Kong, France, and Korea. The final models included only a few variables; TIMSS lacked some important background variables, such as income, and other variables were dropped either because of problems revealed by exploratory data analysis or because of a lack of significance in the models. In all four countries, these sparse models predicted most of the between-classroom score variance (from 59 to 94 percent but very little of the within-classroom variance. Korea was the only

  2. ATHENS SEASONAL VARIATION OF GROUND RESISTANCE PREDICTION USING NEURAL NETWORKS

    S. Anbazhagan

    2015-10-01

    Full Text Available The objective in ground resistance is to attain the most minimal ground safety esteem conceivable that bodes well monetarily and physically. An application of artificial neural networks (ANN to presage and relegation has been growing rapidly due to sundry unique characteristics of ANN models. A decent forecast is able to capture the dubiousness associated with those ground resistance. A portion of the key instabilities are soil composition, moisture content, temperature, ground electrodes and spacing of the electrodes. Propelled by this need, this paper endeavors to develop a generalized regression neural network (GRNN to predict the ground resistance. The GRNN has a single design parameter and expeditious learning and efficacious modeling for nonlinear time series. The precision of the forecast is applied to the Athens seasonal variation of ground resistance that shows the efficacy of the proposed approach.

  3. Rare copy number deletions predict individual variation in intelligence.

    Ronald A Yeo

    Full Text Available Phenotypic variation in human intellectual functioning shows substantial heritability, as demonstrated by a long history of behavior genetic studies. Many recent molecular genetic studies have attempted to uncover specific genetic variations responsible for this heritability, but identified effects capture little variance and have proven difficult to replicate. The present study, motivated an interest in "mutation load" emerging from evolutionary perspectives, examined the importance of the number of rare (or infrequent copy number variations (CNVs, and the total number of base pairs included in such deletions, for psychometric intelligence. Genetic data was collected using the Illumina 1MDuoBeadChip Array from a sample of 202 adult individuals with alcohol dependence, and a subset of these (N = 77 had been administered the Wechsler Abbreviated Scale of Intelligence (WASI. After removing CNV outliers, the impact of rare genetic deletions on psychometric intelligence was investigated in 74 individuals. The total length of the rare deletions significantly and negatively predicted intelligence (r = -.30, p = .01. As prior studies have indicated greater heritability in individuals with relatively higher parental socioeconomic status (SES, we also examined the impact of ethnicity (Anglo/White vs. Other, as a proxy measure of SES; these groups did not differ on any genetic variable. This categorical variable significantly moderated the effect of length of deletions on intelligence, with larger effects being noted in the Anglo/White group. Overall, these results suggest that rare deletions (between 5% and 1% population frequency or less adversely affect intellectual functioning, and that pleotropic effects might partly account for the association of intelligence with health and mental health status. Significant limitations of this research, including issues of generalizability and CNV measurement, are discussed.

  4. Predictable patterns in planetary transit timing variations and transit duration variations due to exomoons

    Heller, René; Placek, Ben; Angerhausen, Daniel; Agol, Eric

    2016-01-01

    We present new ways to identify single and multiple moons around extrasolar planets using planetary transit timing variations (TTVs) and transit duration variations (TDVs). For planets with one moon, measurements from successive transits exhibit a hitherto undescribed pattern in the TTV-TDV diagram, originating from the stroboscopic sampling of the planet's orbit around the planet-moon barycenter. This pattern is fully determined and analytically predictable after three consecutive transits. The more measurements become available, the more the TTV-TDV diagram approaches an ellipse. For planets with multiple moons in orbital mean motion resonance (MMR), like the Galilean moons, the pattern is much more complex and addressed numerically in this report. Exomoons in MMR can also form closed, predictable TTV-TDV figures if the drift of the moons' pericenters is sufficiently slow. We find that MMR exomoons produce loops in the TTV-TDV diagram and that the number of these loops is equal to the order of the MMR, or t...

  5. CREATING THE KULTUK POLYGON FOR EARTHQUAKE PREDICTION: VARIATIONS OF (234U/238U AND 87SR/86SR IN GROUNDWATER FROM ACTIVE FAULTS AT THE WESTERN SHORE OF LAKE BAIKAL

    S. V. Rasskazov

    2015-12-01

    direction at 14°, which resulted in the synchronization of (234U/238U at these stations (Fig. 13. At the background of the chaotic state of the monitoring system of the Kultuk polygon, it is possible to distinguish sequential self‐organization phases from а to г as evidenced by the azimuthal synchronization of the stations. The spatial development of the recorded processes was represented the sequential seismogenic activation of the western termination of the Obruchev fault (Fig. 14. From the analyses of temporal variations of U concentrations (Fig. 15, we infer that the dynamics of uranium ingress into water was different at stations 9 and 8. In the initial monitoring stage, the background extremely high values of (234U/238U and concentrations of uranium were inconsistent at stations 9 and 8. Later on, at station 9, episodes of the high mobility of uranium from the deformation zone alternated with episodes of the high mobility of uranium from the oxidation zone. At station 8, in the period from 26 October 2012 to 04 July 2013, uranium impulses took place occasionally in the deformation zone, and a few were combined with earthquakes of class 9 or 10. From 07 August 2013, the above‐mentioned impulses were replaced by uranium impulses from the oxidation zone. At this stage, an anomalous ingress of uranium was recorded.Conclusion. To validate the system of monitoring stations in the Kultuk polygon for earthquake prediction, spatial variations of (234U/238U both in groundwater and surface water were studied. On sites of the tectonically stable areas, it was found that components of the surface runoff had admixtures of ground water components from the nearsurface water sources. On sites located at active faults, surface runoff components had admixtures of groundwater components from the deformation zone and oxidation zone. On sites located at active faults whereat permanent water streams lacked, the components from the deformation zone contained admixture of near

  6. Predictable patterns in planetary transit timing variations and transit duration variations due to exomoons

    Heller, René; Hippke, Michael; Placek, Ben; Angerhausen, Daniel; Agol, Eric

    2016-06-01

    We present new ways to identify single and multiple moons around extrasolar planets using planetary transit timing variations (TTVs) and transit duration variations (TDVs). For planets with one moon, measurements from successive transits exhibit a hitherto undescribed pattern in the TTV-TDV diagram, originating from the stroboscopic sampling of the planet's orbit around the planet-moon barycenter. This pattern is fully determined and analytically predictable after three consecutive transits. The more measurements become available, the more the TTV-TDV diagram approaches an ellipse. For planets with multiple moons in orbital mean motion resonance (MMR), like the Galilean moon system, the pattern is much more complex and addressed numerically in this report. Exomoons in MMR can also form closed, predictable TTV-TDV figures, as long as the drift of the moons' pericenters is sufficiently slow. We find that MMR exomoons produce loops in the TTV-TDV diagram and that the number of these loops is equal to the order of the MMR, or the largest integer in the MMR ratio. We use a Bayesian model and Monte Carlo simulations to test the discoverability of exomoons using TTV-TDV diagrams with current and near-future technology. In a blind test, two of us (BP, DA) successfully retrieved a large moon from simulated TTV-TDV by co-authors MH and RH, which resembled data from a known Kepler planet candidate. Single exomoons with a 10% moon-to-planet mass ratio, like to Pluto-Charon binary, can be detectable in the archival data of the Kepler primary mission. Multi-exomoon systems, however, require either larger telescopes or brighter target stars. Complementary detection methods invoking a moon's own photometric transit or its orbital sampling effect can be used for validation or falsification. A combination of TESS, CHEOPS, and PLATO data would offer a compelling opportunity for an exomoon discovery around a bright star.

  7. Human activity recognition and prediction

    2016-01-01

    This book provides a unique view of human activity recognition, especially fine-grained human activity structure learning, human-interaction recognition, RGB-D data based action recognition, temporal decomposition, and causality learning in unconstrained human activity videos. The techniques discussed give readers tools that provide a significant improvement over existing methodologies of video content understanding by taking advantage of activity recognition. It links multiple popular research fields in computer vision, machine learning, human-centered computing, human-computer interaction, image classification, and pattern recognition. In addition, the book includes several key chapters covering multiple emerging topics in the field. Contributed by top experts and practitioners, the chapters present key topics from different angles and blend both methodology and application, composing a solid overview of the human activity recognition techniques. .

  8. Rare Copy Number Deletions Predict Individual Variation in Intelligence

    Yeo, Ronald A.; Gangestad, Steven W.; Liu, Jingyu; Calhoun, Vince D.; Kent E. Hutchison

    2011-01-01

    Phenotypic variation in human intellectual functioning shows substantial heritability, as demonstrated by a long history of behavior genetic studies. Many recent molecular genetic studies have attempted to uncover specific genetic variations responsible for this heritability, but identified effects capture little variance and have proven difficult to replicate. The present study, motivated an interest in “mutation load” emerging from evolutionary perspectives, examined the importance of the n...

  9. Spatial variation in water loss predicts terrestrial salamander distribution and population dynamics.

    Peterman, W E; Semlitsch, R D

    2014-10-01

    Many patterns observed in ecology, such as species richness, life history variation, habitat use, and distribution, have physiological underpinnings. For many ectothermic organisms, temperature relationships shape these patterns, but for terrestrial amphibians, water balance may supersede temperature as the most critical physiologically limiting factor. Many amphibian species have little resistance to water loss, which restricts them to moist microhabitats, and may significantly affect foraging, dispersal, and courtship. Using plaster models as surrogates for terrestrial plethodontid salamanders (Plethodon albagula), we measured water loss under ecologically relevant field conditions to estimate the duration of surface activity time across the landscape. Surface activity time was significantly affected by topography, solar exposure, canopy cover, maximum air temperature, and time since rain. Spatially, surface activity times were highest in ravine habitats and lowest on ridges. Surface activity time was a significant predictor of salamander abundance, as well as a predictor of successful recruitment; the probability of a juvenile salamander occupying an area with high surface activity time was two times greater than an area with limited predicted surface activity. Our results suggest that survival, recruitment, or both are demographic processes that are affected by water loss and the ability of salamanders to be surface-active. Results from our study extend our understanding of plethodontid salamander ecology, emphasize the limitations imposed by their unique physiology, and highlight the importance of water loss to spatial population dynamics. These findings are timely for understanding the effects that fluctuating temperature and moisture conditions predicted for future climates will have on plethodontid salamanders. PMID:25154754

  10. Activity Prediction: A Twitter-based Exploration

    Weerkamp, W.; Rijke, de, M.

    2012-01-01

    Social media platforms allow users to share their messages with everyone else. In microblogs, e.g., Twitter, people mostly report on what they did, they talk about current activities, and mention things they plan to do in the near future. In this paper, we propose the task of activity prediction, that is, trying to establish a set of activities that are likely to become popular at a later time. We perform a small-scale initial experiment, in which we try to predict popular activities for the ...

  11. K Variations and Anisotropy: Microstructure Effect and Numerical Predictions

    李旭东; 李华清

    2003-01-01

    Computer experiments were performed on simulated polycrystalline material samples that possess locally anisotropic microstructures to investigate stress intensity factor ( K ) variations and anisotropy along fronts of microcracks of different sizes. The anisotropic K , arising from inhomogeneous stresses in broken grains, was determined for planar microcracks by using a weight function-based numerical technique. It has been found that the grain-orientation-geometry-induced local anisotropy produces large variations in K along front of microcracks, when the crack size is of the order of few grain diameters. Synergetic effect of grain orientation and geometry of broken grains control K variations and evolution along the microcrack front. The K variations may diminish at large crack sizes, signifying a shift of K calculation to bulk stress dependence from local stress dependence. Local grain geometry and texture may lead to K anisotropy, producing unusually higher/lower K at a segment of the crack front. Either K variation or anisotropy cannot be ignored when assessing a microcrack.

  12. Predicting stretcher carriage: Investigating variations in bilateral carry tests.

    Beck, Ben; Middleton, Kane J; Carstairs, Greg L; Billing, Daniel C; Caldwell, Joanne N

    2016-07-01

    Carrying a casualty on a stretcher is a critical task within military and emergency service occupations. This study evaluated the impact of manipulating carry speed and the object type in bilateral carries on the ability to predict performance and reflect the physical and physiological requirements of a unilateral stretcher carry. We demonstrated that three task-related predictive tests; a jerry can carry performed at 4.5 km h(-1)or 5.0 km h(-1) and a kettle-bell carry performed at 5.0 km h(-1) were strongly predictive of the physical and physiological demands of an individual participating as part of a four-person stretcher carry team. Therefore, bilateral predictive assessments have the utility for predicting the suitability of employees to effectively and safely conduct a four-person unilateral stretcher carry. PMID:26995042

  13. Common polygenic variation enhances risk prediction for Alzheimer's disease.

    Escott-Price, Valentina; Sims, Rebecca; Bannister, Christian; Harold, Denise; Vronskaya, Maria; Majounie, Elisa; Badarinarayan, Nandini; Morgan, Kevin; Passmore, Peter; Holmes, Clive; Powell, John; Brayne, Carol; Gill, Michael; Mead, Simon; Goate, Alison; Cruchaga, Carlos; Lambert, Jean-Charles; van Duijn, Cornelia; Maier, Wolfgang; Ramirez, Alfredo; Holmans, Peter; Jones, Lesley; Hardy, John; Seshadri, Sudha; Schellenberg, Gerard D; Amouyel, Philippe; Williams, Julie

    2015-12-01

    The identification of subjects at high risk for Alzheimer's disease is important for prognosis and early intervention. We investigated the polygenic architecture of Alzheimer's disease and the accuracy of Alzheimer's disease prediction models, including and excluding the polygenic component in the model. This study used genotype data from the powerful dataset comprising 17 008 cases and 37 154 controls obtained from the International Genomics of Alzheimer's Project (IGAP). Polygenic score analysis tested whether the alleles identified to associate with disease in one sample set were significantly enriched in the cases relative to the controls in an independent sample. The disease prediction accuracy was investigated in a subset of the IGAP data, a sample of 3049 cases and 1554 controls (for whom APOE genotype data were available) by means of sensitivity, specificity, area under the receiver operating characteristic curve (AUC) and positive and negative predictive values. We observed significant evidence for a polygenic component enriched in Alzheimer's disease (P = 4.9 × 10(-26)). This enrichment remained significant after APOE and other genome-wide associated regions were excluded (P = 3.4 × 10(-19)). The best prediction accuracy AUC = 78.2% (95% confidence interval 77-80%) was achieved by a logistic regression model with APOE, the polygenic score, sex and age as predictors. In conclusion, Alzheimer's disease has a significant polygenic component, which has predictive utility for Alzheimer's disease risk and could be a valuable research tool complementing experimental designs, including preventative clinical trials, stem cell selection and high/low risk clinical studies. In modelling a range of sample disease prevalences, we found that polygenic scores almost doubles case prediction from chance with increased prediction at polygenic extremes. PMID:26490334

  14. Evolutionary rate variation and RNA secondary structure prediction

    Knudsen, B; Andersen, E S; Damgaard, Christian Kroun;

    2004-01-01

    regions. In addition we obtained an alignment of the 5' HIV-1 region that is more consistent with the structure than that currently in the database. We added randomized noise to the original values of the rates to investigate the stability of predictions to rate matrix deviations. We find that changes...... by applying rates derived from tRNA and rRNA to the prediction of the much more rapidly evolving 5'-region of HIV-1. We find that the HIV-1 prediction is in agreement with experimental data, even though the relative evolutionary rate between A and G is significantly increased, both in stem and loop...... of approach. Determining these rates can be hard to do reliably without a large and accurate initial alignment, which ideally also has structural annotation. Hence, one must often apply rates extracted from other RNA families with trusted alignments and structures. Here, we investigate this problem...

  15. Prediction of Length-of-day Variations Based on Gaussian Processes

    Lei, Yu; Zhao, Dan-Ning; Gao, Yu-Ping; Cai, Hong-Bing

    2015-07-01

    Due to the complicated time-varying characteristics of the length-of-day (LOD) variations, the accuracies of traditional linear models for the prediction of the LOD variations, such as the least squares extrapolation model, the time-series analysis model and so on, cannot satisfy the requirements for the real-time and high-precision applications. In this paper, a new machine learning algorithm - the Gaussian process (GP) model is employed to forecast the LOD variations. Its prediction accuracy is analyzed and compared with those of the back propagation neural networks (BPNN), general regression neural networks (GRNN), and the Earth Orientation Parameters Prediction Comparison Campaign (EOP PCC). The results demonstrate that the application of the GP model to the prediction of the LOD variations is efficient and feasible.

  16. Real-time rapid prediction of variations of Earth's rotational rate

    WANG QiJie; LIAO DeOhun; ZHOU YongHong

    2008-01-01

    Real-time rapid prediction of variations of the Earth's rotational rate is of great scientific and practical importance. However, due to the complicated time-variable characteristics of variations of the Earth's rotational rate (i.e., length of day, LOD), it is usually difficult to obtain satisfactory predictions by con-ventional linear time series analysis methods. This study employs the nonlinear artificial neural net-works (ANN) to predict the LOD variations. The topology of the ANN model is determined by minimizing the root mean square errors (RMSE) of the predictions. Considering the close relationships between the LOD variations and the atmospheric circulation movement, the operational prediction series of axial atmospheric angular momentum (AAM) is incorporated into the ANN model as an additional input in the real-time rapid prediction of LOD variations with 1 -5 days ahead. The results show that the LOD pre-diction is significantly improved after introducing the operational prediction series of AAM into the ANN model.

  17. Prediction of fine-tuned promoter activity from DNA sequence

    Siwo, Geoffrey; Rider, Andrew; Tan, Asako; Pinapati, Richard; Emrich, Scott; Chawla, Nitesh; Ferdig, Michael

    2016-01-01

    The quantitative prediction of transcriptional activity of genes using promoter sequence is fundamental to the engineering of biological systems for industrial purposes and understanding the natural variation in gene expression. To catalyze the development of new algorithms for this purpose, the Dialogue on Reverse Engineering Assessment and Methods (DREAM) organized a community challenge seeking predictive models of promoter activity given normalized promoter activity data for 90 ribosomal protein promoters driving expression of a fluorescent reporter gene. By developing an unbiased modeling approach that performs an iterative search for predictive DNA sequence features using the frequencies of various k-mers, inferred DNA mechanical properties and spatial positions of promoter sequences, we achieved the best performer status in this challenge. The specific predictive features used in the model included the frequency of the nucleotide G, the length of polymeric tracts of T and TA, the frequencies of 6 distinct trinucleotides and 12 tetranucleotides, and the predicted protein deformability of the DNA sequence. Our method accurately predicted the activity of 20 natural variants of ribosomal protein promoters (Spearman correlation r = 0.73) as compared to 33 laboratory-mutated variants of the promoters (r = 0.57) in a test set that was hidden from participants. Notably, our model differed substantially from the rest in 2 main ways: i) it did not explicitly utilize transcription factor binding information implying that subtle DNA sequence features are highly associated with gene expression, and ii) it was entirely based on features extracted exclusively from the 100 bp region upstream from the translational start site demonstrating that this region encodes much of the overall promoter activity. The findings from this study have important implications for the engineering of predictable gene expression systems and the evolution of gene expression in naturally occurring

  18. Global water cycle and solar activity variations

    Al-Tameemi, Muthanna A.; Chukin, Vladimir V.

    2016-05-01

    The water cycle is the most active and most important component in the circulation of global mass and energy in the Earth system. Furthermore, water cycle parameters such as evaporation, precipitation, and precipitable water vapour play a major role in global climate change. In this work, we attempt to determine the impact of solar activity on the global water cycle by analyzing the global monthly values of precipitable water vapour, precipitation, and the Solar Modulation Potential in 1983-2008. The first object of this study was to calculate global evaporation for the period 1983-2008. For this purpose, we determined the water cycle rate from satellite data, and precipitation/evaporation relationship from 10 years of Planet Simulator model data. The second object of our study was to investigate the relationship between the Solar Modulation Potential (solar activity index) and the evaporation for the period 1983-2008. The results showed that there is a relationship between the solar modulation potential and the evaporation values for the period of study. Therefore, we can assume that the solar activity has an impact on the global water cycle.

  19. Global genetic variations predict brain response to faces

    Dickie, Erin W; Tahmasebi, Amir; French, Leon;

    2014-01-01

    Face expressions are a rich source of social signals. Here we estimated the proportion of phenotypic variance in the brain response to facial expressions explained by common genetic variance captured by ∼ 500,000 single nucleotide polymorphisms. Using genomic-relationship-matrix restricted maximu...... of connections with other network nodes, suggesting that the genetic model captures variations across the adolescent brains in co-opting these regions into the face network.......Face expressions are a rich source of social signals. Here we estimated the proportion of phenotypic variance in the brain response to facial expressions explained by common genetic variance captured by ∼ 500,000 single nucleotide polymorphisms. Using genomic-relationship-matrix restricted maximum...... face network, as defined previously. In 9 out of these 25 regions, common genetic variance explained a significant proportion of phenotypic variance (40-50%) in their response to ambiguous facial expressions; this was not the case for angry facial expressions. Across the network, the strength of the...

  20. Nonlinear variational method for predicting fast collisionless magnetic reconnection

    Hirota, M; Ishii, Y; Yagi, M; Aiba, N

    2013-01-01

    A mechanism for fast magnetic reconnection in collisionless plasma is studied for understanding sawtooth collapse in tokamak discharges. Explosive growth of the tearing mode driven by electron inertia is analytically estimated by using an energy principle with a nonlinear displacement map. Decrease of the potential energy in the nonlinear regime (where the island width exceeds the electron skin depth) is found to be steeper than in the linear regime, resulting in accelerated reconnection. Release of free energy by such ideal fluid motion leads to unsteady and strong convective flow, which is not deterred by the small dissipation effects in high-temperature tokamak plasmas. Direct numerical simulation in slab geometry substantiates the theoretical prediction of the nonlinear growth.

  1. Possibilities of anthropogenic variations of thunderstorm activity

    The possibilities of anthropogenic modifications of thunderstorm activity are investigated. Different approaches were used to estimate the number of thunderstorms that could be modified by anthropogenic heat rejection. As a result it was found that about 50 percent of the thunderstorms occurring annually over the Swiss plateau or the area around the city of Basel offer the potential of an anthropogenic modification. On the basis of simplified physical models, the energy-flux to start a medium thunderstorm is estimated to be about 0.01 - 0.1 GW, if the energy is available as kinetic energy, and about 100 GW for thermal energy. Computer simulations with a parcel model confirm these orders of magnitude. The model calculations indicate also, that the power required to start a small thunderstorm under especially critical (unstable) weather situations can be an order of magnitude smaller than the above values. Comparing the required 100 GW thermal starting energy-flux with a single dry or wet 2 GW cooling tower suggests, that for climatic conditions typical for Switzerland, the formation of a thunderstorm due to cooling tower heat rejection is a very unlikely event. Power parks consisting of 30 - 50 dry cooling towers rejecting 2 GW each would be required to severely modify thunderstorm activity in their surroundings. About 5 to 10 cooling towers concentrated at one site would probably be a critical limit. When exceeded, modifications of thunderstorm activity seem to become climatologically significant. (Auth.)

  2. Application of Method of Variation to Analyze and Predict Human Induced Modifications of Water Resource Systems

    Dessu, S. B.; Melesse, A. M.; Mahadev, B.; McClain, M.

    2010-12-01

    Water resource systems have often used gravitational surface and subsurface flows because of their practicality in hydrological modeling and prediction. Activities such as inter/intra-basin water transfer, the use of small pumps and the construction of micro-ponds challenge the tradition of natural rivers as water resource management unit. On the contrary, precipitation is barely affected by topography and plot harvesting in wet regions can be more manageable than diverting from rivers. Therefore, it is indicative to attend to systems where precipitation drives the dynamics while the internal mechanics constitutes spectrum of human activity and decision in a network of plots. The trade-in volume and path of harvested precipitation depends on water balance, energy balance and the kinematics of supply and demand. Method of variation can be used to understand and predict the implication of local excess precipitation harvest and exchange on the natural water system. A system model was developed using the variational form of Euler-Bernoulli’s equation for the Kenyan Mara River basin. Satellite derived digital elevation models, precipitation estimates, and surface properties such as fractional impervious surface area, are used to estimate the available water resource. Four management conditions are imposed in the model: gravitational flow, open water extraction and high water use investment at upstream and downstream respectively. According to the model, the first management maintains the basin status quo while the open source management could induce externality. The high water market at the upstream in the third management offers more than 50% of the basin-wide total revenue to the upper third section of the basin thus may promote more harvesting. The open source and upstream exploitation suggest potential drop of water availability to downstream. The model exposed the latent potential of economic gradient to reconfigure the flow network along the direction where the

  3. Controlling cyclic combustion timing variations using a symbol-statistics predictive approach in an HCCI engine

    Highlights: ► Misfire reduction in a combustion engine based on chaotic theory methods. ► Chaotic theory analysis of cyclic variation of a HCCI engine near misfire. ► Symbol sequence approach is used to predict ignition timing one cycle-ahead. ► Prediction is combined with feedback control to lower HCCI combustion variation. ► Feedback control extends the HCCI operating range into the misfire region. -- Abstract: Cyclic variation of a Homogeneous Charge Compression Ignition (HCCI) engine near misfire is analyzed using chaotic theory methods and feedback control is used to stabilize high cyclic variations. Variation of consecutive cycles of θPmax (the crank angle of maximum cylinder pressure over an engine cycle) for a Primary Reference Fuel engine is analyzed near misfire operation for five test points with similar conditions but different octane numbers. The return map of the time series of θPmax at each combustion cycle reveals the deterministic and random portions of the dynamics near misfire for this HCCI engine. A symbol-statistic approach is used to predict θPmax one cycle-ahead. Predicted θPmax has similar dynamical behavior to the experimental measurements. Based on this cycle ahead prediction, and using fuel octane as the input, feedback control is used to stabilize the instability of θPmax variations at this engine condition near misfire.

  4. On the level of skill in predicting maximum sunspot number - A comparative study of single variate and bivariate precursor techniques

    Wilson, Robert M.

    1990-01-01

    The level of skill in predicting the size of the sunspot cycle is investigated for the two types of precursor techniques, single variate and bivariate fits, both applied to cycle 22. The present level of growth in solar activity is compared to the mean level of growth (cycles 10-21) and to the predictions based on the precursor techniques. It is shown that, for cycle 22, both single variate methods (based on geomagnetic data) and bivariate methods suggest a maximum amplitude smaller than that observed for cycle 19, and possibly for cycle 21. Compared to the mean cycle, cycle 22 is presently behaving as if it were a +2.6 sigma cycle (maximum amplitude of about 225), which means that either it will be the first cycle not to be reliably predicted by the combined precursor techniques or its deviation relative to the mean cycle will substantially decrease over the next 18 months.

  5. Ionospheric Variations in the Region of the Equatorial Ionization Anomaly Crest: Comparison Between Observations and IRI-2012 Model Predictions.

    Oyeyemi, E. O.; Bolaji, S.; Adewale, A. O.; Akala, A. O.; Oladipo, O. A.; Olugbon, B.; Olawepo, O. A.; Adeniyi, J. O.; Adimula, I.

    2015-12-01

    The objective of this work is to study the variations of the F2-layer critical frequency (foF2) in the region of equatorial ionization anomaly crest and check the accuracy of International Reference Ionosphere (IRI-2012) model predictions using ionosonde measurements from a number of stations in this region. We have used data, based on availability, corresponding to different seasonal and solar activity periods from each station considered to carry out our investigations. Details of the statistical analysis using percentage deviation (PD), upper and lower inter-quartile range (IQR) and relative deviation module mean (RDMM) for the evaluation of the IRI model performance are presented. The results show that, generally, the IRI model predictions have agreement with the observed values in terms of the pattern of variations but there are number of cases where IRI model overestimates and underestimates the observed values. Results from this study will be of help to improving prediction ability of the IRI models.

  6. Platelet serotonin transporter function predicts default-mode network activity.

    Christian Scharinger

    Full Text Available The serotonin transporter (5-HTT is abundantly expressed in humans by the serotonin transporter gene SLC6A4 and removes serotonin (5-HT from extracellular space. A blood-brain relationship between platelet and synaptosomal 5-HT reuptake has been suggested, but it is unknown today, if platelet 5-HT uptake can predict neural activation of human brain networks that are known to be under serotonergic influence.A functional magnetic resonance study was performed in 48 healthy subjects and maximal 5-HT uptake velocity (Vmax was assessed in blood platelets. We used a mixed-effects multilevel analysis technique (MEMA to test for linear relationships between whole-brain, blood-oxygen-level dependent (BOLD activity and platelet Vmax.The present study demonstrates that increases in platelet Vmax significantly predict default-mode network (DMN suppression in healthy subjects independent of genetic variation within SLC6A4. Furthermore, functional connectivity analyses indicate that platelet Vmax is related to global DMN activation and not intrinsic DMN connectivity.This study provides evidence that platelet Vmax predicts global DMN activation changes in healthy subjects. Given previous reports on platelet-synaptosomal Vmax coupling, results further suggest an important role of neuronal 5-HT reuptake in DMN regulation.

  7. Prediction control of active power filters

    王莉娜; 罗安

    2003-01-01

    A prediction method to obtain harmonic reference for active power filter is presented. It is a new use ofthe adaptive predictive filter based on FIR. The delay inherent in digital controller is successfully compensated by u-sing the proposed method, and the computing load is not very large compared with the conventional method. Moreo-ver, no additional hardware is needed. Its DSP-based realization is also presented, which is characterized by time-va-riant rate sampling, quasi synchronous sampling, and synchronous operation among the line frequency, PWM gener-ating and sampling in A/D unit. Synchronous operation releases the limitation on PWM modulation ratio and guar-antees that the electrical noises resulting from the switching operation of IGBTs do not interfere with the sampledcurrent. The simulation and experimental results verify the satisfactory performance of the proposed method.

  8. Temporal patterns of saccadic eye movements predict individual variation in alternation rate during binocular rivalry

    Hancock, Sarah; Gareze, Lynn; Findlay, John M; Andrews, Timothy J.

    2012-01-01

    Interindividual variation has been shown in the rates at which subjects alternate in perception during viewing of binocular rivalry and other ambiguous figures. A similar pattern of interindividual variation is evident in the rate of eye movements. The aim of this study was to determine whether individual differences in the rate of binocular rivalry predict individual differences in the rate of eye movements. First, participants reported changes in perception during contour rivalry. We found ...

  9. CERAPP: Collaborative estrogen receptor activity prediction project

    Mansouri, Kamel; Abdelaziz, Ahmed; Rybacka, Aleksandra;

    2016-01-01

    Background: Humans are exposed to thousands of man-made chemicals in the environment. Some chemicals mimic natural endocrine hormones and, thus, have the potential to be endocrine disruptors. Most of these chemicals have never been tested for their ability to interact with the estrogen receptor (ER......). Risk assessors need tools to prioritize chemicals for evaluation in costly in vivo tests, for instance, within the U.S. EPA Endocrine Disruptor Screening Program. oBjectives: We describe a large-scale modeling project called CERAPP (Collaborative Estrogen Receptor Activity Prediction Project) and...

  10. Research in using radon content variation to predict earthquakes in China

    This paper provides an overview of our researches in using anomalous variation of radon content in earthquake prediction in China, including observations and studies on earthquake precursors, researches on mechanism of radon precursors, and their complexity. In March 1966, an Ms7.2 strong earthquake broke out in Xingtai, North China unexpected, causing a great deal of casualty. China started earthquake prediction research ever since, so does the research in using variation of radon content to predict earthquakes. In the past 30 years, we have accumulated numerous precursory observational data, and have greatly advanced the understanding of the mechanism of radon earthquake precursors. Radon, as one of the most important items for precursory observation, has played a key role in the earthquake monitoring and prediction in China. (author)

  11. Seasonal variations in daily rhythms of activity in athletic horses.

    Bertolucci, C; Giannetto, C; Fazio, F; Piccione, G

    2008-07-01

    Circadian rhythms reflect extensive programming of biological activity that meets and exploits the challenges and opportunities offered by the periodic nature of the environment. In the present investigation, we recorded the total activity of athletic horses kept at four different times of the year (vernal equinox, summer solstice, autumn equinox and winter solstice), to evaluate the presence of seasonal variations of daily activity rhythms. Athletic Thoroughbred horses were kept in individual boxes with paddock. Digitally integrated measure of total activity of each mare was continuously recorded by actigraphy-based data loggers. Horse total activities were not evenly distributed over the day, but they were mainly diurnal during the year. Daily activity rhythms showed clear seasonal variations, with the highest daily amount of activity during the vernal equinox and the lowest during the winter solstice. Interestingly, the amount of activity during either photophase or scotophase changed significantly throughout the year. Circadian analysis of horse activities showed that the acrophase, the estimated time at which the peak of the rhythm occurs, did not change during the year, it always occurred in the middle of the photoperiod. Analysing the time structure of long-term and continuously measured activity and feeding could be a useful method to critically evaluate athletic horse management systems in which spontaneous locomotor activity and feeding are severely limited. Circadian rhythms are present in several elements of sensory motor and psychomotor functions and these would be taken into consideration to plan the training schedules and competitions in athletic horses. PMID:22443706

  12. Variation in GYS1 interacts with exercise and gender to predict cardiovascular mortality.

    Jenny Fredriksson

    Full Text Available BACKGROUND: The muscle glycogen synthase gene (GYS1 has been associated with type 2 diabetes (T2D, the metabolic syndrome (MetS, male myocardial infarction and a defective increase in muscle glycogen synthase protein in response to exercise. We addressed the questions whether polymorphism in GYS1 can predict cardiovascular (CV mortality in a high-risk population, if this risk is influenced by gender or physical activity, and if the association is independent of genetic variation in nearby apolipoprotein E gene (APOE. METHODOLOGY/PRINCIPAL FINDINGS: Polymorphisms in GYS1 (XbaIC>T and APOE (-219G>T, epsilon2/epsilon3/epsilon4 were genotyped in 4,654 subjects participating in the Botnia T2D-family study and followed for a median of eight years. Mortality analyses were performed using Cox proportional-hazards regression. During the follow-up period, 749 individuals died, 409 due to CV causes. In males the GYS1 XbaI T-allele (hazard ratio (HR 1.9 [1.2-2.9], T2D (2.5 [1.7-3.8], earlier CV events (1.7 [1.2-2.5], physical inactivity (1.9 [1.2-2.9] and smoking (1.5 [1.0-2.3] predicted CV mortality. The GYS1 XbaI T-allele predicted CV mortality particularly in physically active males (HR 1.7 [1.3-2.0]. Association of GYS1 with CV mortality was independent of APOE (219TT/epsilon4, which by its own exerted an effect on CV mortality risk in females (2.9 [1.9-4.4]. Other independent predictors of CV mortality in females were fasting plasma glucose (1.2 [1.1-1.2], high body mass index (BMI (1.0 [1.0-1.1], hypertension (1.9 [1.2-3.1], earlier CV events (1.9 [1.3-2.8] and physical inactivity (1.9 [1.2-2.8]. CONCLUSIONS/SIGNIFICANCE: Polymorphisms in GYS1 and APOE predict CV mortality in T2D families in a gender-specific fashion and independently of each other. Physical exercise seems to unmask the effect associated with the GYS1 polymorphism, rendering carriers of the variant allele less susceptible to the protective effect of exercise on the risk of CV death

  13. Using an expiratory resistor, arterial pulse pressure variations predict fluid responsiveness during spontaneous breathing: an experimental porcine study

    Dahl, Michael K.; Vistisen, Simon T; Koefoed-Nielsen, Jacob; Larsson, Anders

    2009-01-01

    Introduction Fluid responsiveness prediction is difficult in spontaneously breathing patients. Because the swings in intrathoracic pressure are minor during spontaneous breathing, dynamic parameters like pulse pressure variation (PPV) and systolic pressure variation (SPV) are usually small. We hypothesized that during spontaneous breathing, inspiratory and/or expiratory resistors could induce high arterial pressure variations at hypovolemia and low variations at normovolemia and hypervolemia....

  14. Predictive Distribution of the Dirichlet Mixture Model by the Local Variational Inference Method

    Ma, Zhanyu; Leijon, Arne; Tan, Zheng-Hua;

    2014-01-01

    predictive likelihood of the new upcoming data, especially when the amount of training data is small. The Bayesian estimation of a Dirichlet mixture model (DMM) is, in general, not analytically tractable. In our previous work, we have proposed a global variational inference-based method for approximately...

  15. Genomic Copy Number Variations in the Genomes of Leukocytes Predict Prostate Cancer Clinical Outcomes.

    Yan P Yu

    Full Text Available Accurate prediction of prostate cancer clinical courses remains elusive. In this study, we performed whole genome copy number analysis on leukocytes of 273 prostate cancer patients using Affymetrix SNP6.0 chip. Copy number variations (CNV were found across all chromosomes of the human genome. An average of 152 CNV fragments per genome was identified in the leukocytes from prostate cancer patients. The size distributions of CNV in the genome of leukocytes were highly correlative with prostate cancer aggressiveness. A prostate cancer outcome prediction model was developed based on large size ratio of CNV from the leukocyte genomes. This prediction model generated an average prediction rate of 75.2%, with sensitivity of 77.3% and specificity of 69.0% for prostate cancer recurrence. When combined with Nomogram and the status of fusion transcripts, the average prediction rate was improved to 82.5% with sensitivity of 84.8% and specificity of 78.2%. In addition, the leukocyte prediction model was 62.6% accurate in predicting short prostate specific antigen doubling time. When combined with Gleason's grade, Nomogram and the status of fusion transcripts, the prediction model generated a correct prediction rate of 77.5% with 73.7% sensitivity and 80.1% specificity. To our knowledge, this is the first study showing that CNVs in leukocyte genomes are predictive of clinical outcomes of a human malignancy.

  16. Neutron flux variations near the Earth’s crust. A possible tectonic activity detection

    B. M. Kuzhevskij

    2003-01-01

    Full Text Available The present work contains some results of observations of neutron flux variations near the Earth’s surface. The Earth’s crust is determined to be a significant source of thermal and slow neutrons, originated from the interaction between the nuclei of the elements of the Earth’s crust and the atmosphere and α-particles, produced by decay of radioactive gases (Radon, Thoron and Actinon. In turn, variations of radioactive gases exhalation is connected with geodynamical processes in the Earth’s crust, including tectonic activity. This determined relation between the processes in the Earth’s crust and neutrons’ flux allow to use variations of thermal and slow neutrons’ flux in order to observe increasing tectonic activity and to develop methods for short-term prediction of natural hazards.

  17. Response of global lightning activity to air temperature variation

    MA Ming; TAO Shanchang; ZHU Baoyou; L(U) Weitao; TAN Yongbo

    2005-01-01

    It is an issue of great attention but yet not very clear whether lightning activities increase or decrease on a warmer world. Reeve et al. presented that lightning activities in global land and the Northern Hemisphere land have positive response to the increase of wet bulb temperature at 1000hPa. Is this positive response restricted only to wet bulb temperature or in land? What is the response of global lightning activities (in both land and ocean) to the global surface air temperature variation like? This paper, based on the 5-year or 8-year OTD/LIS satellite-based lightning detecting data and the NCEP reanalysis data, makes a reanalysis of the response of the global and regional lightning activities to temperature variations. The results show that on the interannual time scale the global total flash rate has positive response to the variation in global surface air temperature, with the sensitivity of 17±7% K-1. Also, the seasonal mean flash rate of continents all over the world and that of continents in the Northern Hemisphere have sensitive positive response to increase of global surface air temperature and wet bulb temperature, with the sensitivity of about 13±5% K-1, a bit lower than estimation of 40% K-1 in Reeve et al. However, the Southern Hemisphere and other areas like the tropics show no significant correlation.

  18. Diurnal changes of earthquake activity and geomagnetic Sq-variations

    G. Duma

    2003-01-01

    Full Text Available Statistic analyses demonstrate that the probability of earthquake occurrence in many earthquake regions strongly depends on the time of day, that is on Local Time (e.g. Conrad, 1909, 1932; Shimshoni, 1971; Duma, 1997; Duma and Vilardo, 1998. This also applies to strong earthquake activity. Moreover, recent observations reveal an involvement of the regular diurnal variations of the Earth’s magnetic field, commonly known as Sq-variations, in this geodynamic process of changing earthquake activity with the time of day (Duma, 1996, 1999. In the article it is attempted to quantify the forces which result from the interaction between the induced Sq-variation currents in the Earth’s lithosphere and the regional Earth’s magnetic field, in order to assess the influence on the tectonic stress field and on seismic activity. A reliable model is obtained, which indicates a high energy involved in this process. The effect of Sq-induction is compared with the results of the large scale electromagnetic experiment "Khibiny" (Velikhov, 1989, where a giant artificial current loop was activated in the Barents Sea.

  19. Diurnal changes of earthquake activity and geomagnetic Sq-variations

    Duma, G.; Ruzhin, Y.

    Statistic analyses demonstrate that the probability of earthquake occurrence in many earthquake regions strongly depends on the time of day, that is on Local Time (e.g. Conrad, 1909, 1932; Shimshoni, 1971; Duma, 1997; Duma and Vilardo, 1998). This also applies to strong earthquake activity. Moreover, recent observations reveal an involvement of the regular diurnal variations of the Earth's magnetic field, commonly known as Sq-variations, in this geodynamic process of changing earthquake activity with the time of day (Duma, 1996, 1999). In the article it is attempted to quantify the forces which result from the interaction between the induced Sq-variation currents in the Earth's lithosphere and the regional Earth's magnetic field, in order to assess the influence on the tectonic stress field and on seismic activity. A reliable model is obtained, which indicates a high energy involved in this process. The effect of Sq-induction is compared with the results of the large scale electromagnetic experiment "Khibiny" (Velikhov, 1989), where a giant artificial current loop was activated in the Barents Sea.

  20. Intrapulpal temperature variation during bleaching with various activation mechanisms

    Sílvia Masae de Araujo Michida

    2009-10-01

    Full Text Available OBJECTIVES: The aim of this study was to evaluate the intrapulpal temperature variation after bleaching treatment with 35% hydrogen peroxide using different sources of activation. MATERIAL AND METHODS: Twenty-four human teeth were sectioned in the mesiodistal direction providing 48 specimens, and were divided into 4 groups (n=12: (G1 Control - Bleaching gel without light activation, (G2 Bleaching gel + halogen light, (G3 Bleaching gel + LED, (G4 Bleaching gel + Nd:YAG Laser. The temperatures were recorded using a digital thermometer at 4 time points: before bleaching gel application, 1 min after bleaching gel application, during activation of the bleaching gel, and after the bleaching agent turned from a dark-red into a clear gel. Data were analyzed statistically by the Dunnet's test, ANOVA and Tukey's test (a=0.05. RESULTS: The mean intrapulpal temperature values (ºC in the groups were: G1: 0.617 ± 0.41; G2: 1.800 ± 0.68; G3: 0.975 ± 0.51; and G4: 4.325 ± 1.09. The mean maximum temperature variation (MTV values were: 1.5ºC (G1, 2.9ºC (G2, 1.7ºC (G3 and 6.9ºC (G4. When comparing the experimental groups to the control group, G3 was not statistically different from G1 (p>0.05, but G2 and G4 presented significantly higher (p<0.05 intrapulpal temperatures and MTV. The three experimental groups differed significantly (p<0.05 from each other. CONCLUSIONS: The Nd:YAG laser was the activation method that presented the highest values of intrapulpal temperature variation when compared with LED and halogen light. The group activated by LED light presented the lowest values of temperature variation, which were similar to that of the control group.

  1. Diurnal changes of earthquake activity and geomagnetic Sq-variations

    Duma, G.; Y. Ruzhin

    2003-01-01

    Statistic analyses demonstrate that the probability of earthquake occurrence in many earthquake regions strongly depends on the time of day, that is on Local Time (e.g. Conrad, 1909, 1932; Shimshoni, 1971; Duma, 1997; Duma and Vilardo, 1998). This also applies to strong earthquake activity. Moreover, recent observations reveal an involvement of the regular diurnal variations of the Earth’s magnetic field, commonly known as Sq-vari...

  2. How to evaluate performance of prediction methods? Measures and their interpretation in variation effect analysis

    Vihinen Mauno

    2012-06-01

    Full Text Available Abstract Background Prediction methods are increasingly used in biosciences to forecast diverse features and characteristics. Binary two-state classifiers are the most common applications. They are usually based on machine learning approaches. For the end user it is often problematic to evaluate the true performance and applicability of computational tools as some knowledge about computer science and statistics would be needed. Results Instructions are given on how to interpret and compare method evaluation results. For systematic method performance analysis is needed established benchmark datasets which contain cases with known outcome, and suitable evaluation measures. The criteria for benchmark datasets are discussed along with their implementation in VariBench, benchmark database for variations. There is no single measure that alone could describe all the aspects of method performance. Predictions of genetic variation effects on DNA, RNA and protein level are important as information about variants can be produced much faster than their disease relevance can be experimentally verified. Therefore numerous prediction tools have been developed, however, systematic analyses of their performance and comparison have just started to emerge. Conclusions The end users of prediction tools should be able to understand how evaluation is done and how to interpret the results. Six main performance evaluation measures are introduced. These include sensitivity, specificity, positive predictive value, negative predictive value, accuracy and Matthews correlation coefficient. Together with receiver operating characteristics (ROC analysis they provide a good picture about the performance of methods and allow their objective and quantitative comparison. A checklist of items to look at is provided. Comparisons of methods for missense variant tolerance, protein stability changes due to amino acid substitutions, and effects of variations on mRNA splicing are

  3. Improving prediction accuracy of GPS satellite clocks with periodic variation behaviour

    The broadcast ephemeris and IGS ultra-rapid predicted (IGU-P) products are primarily available for use in real-time GPS applications. The IGU orbit precision has been remarkably improved since late 2007, but its clock products have not shown acceptably high-quality prediction performance. One reason for this fact is that satellite atomic clocks in space can be easily influenced by various factors such as temperature and environment and this leads to complicated aspects like periodic variations, which are not sufficiently described by conventional models. A more reliable prediction model is thus proposed in this paper in order to be utilized particularly in describing the periodic variation behaviour satisfactorily. The proposed prediction model for satellite clocks adds cyclic terms to overcome the periodic effects and adopts delay coordinate embedding, which offers the possibility of accessing linear or nonlinear coupling characteristics like satellite behaviour. The simulation results have shown that the proposed prediction model outperforms the IGU-P solutions at least on a daily basis. (rapid communication)

  4. Explained variation and predictive accuracy in general parametric statistical models: the role of model misspecification

    Rosthøj, Susanne; Keiding, Niels

    2004-01-01

    When studying a regression model measures of explained variation are used to assess the degree to which the covariates determine the outcome of interest. Measures of predictive accuracy are used to assess the accuracy of the predictions based on the covariates and the regression model. We give a ...... detailed and general introduction to the two measures and the estimation procedures. The framework we set up allows for a study of the effect of misspecification on the quantities estimated. We also introduce a generalization to survival analysis....

  5. Deducing ink thickness variations of fluorescent print by a spectral prediction model

    Wang, Qingjuan; Zhang, Yixin; Tian, Dongwen

    2012-01-01

    In the color printing process, the thickness and uniformity of ink have a great affect on the color reproduction. The ink thickness uniformity is an important parameters of measuring the quality of printing. Based on the fluorescent additives may absorb ultraviolet light and exit blue light or visible light and by considering the expansion of the ink, optical properties of paper with fluorescent additives , the internal lateral spread of light in paper with fluorescent additives and the fluorescent Clapper-Yule spectral reflectance prediction model, we introduce two factor parameters which are the initial thickness of the inks and the factor of ink thickness variation. A model for deducing ink thickness variations of printing on the fluorescent substrate is developed by the least square method and the spectrum reflectance of prints which measures the ink thickness variations. The correctness of the conclusions are verified by experiment.

  6. Intraspecific morphological and genetic variation of common species predicts ranges of threatened ones

    Fuller, Trevon L.; Thomassen, Henri A.; Peralvo, Manuel; Buermann, Wolfgang; Milá, Borja; Kieswetter, Charles M.; Jarrín-V, Pablo; Devitt, Susan E. Cameron; Mason, Eliza; Schweizer, Rena M.; Schlunegger, Jasmin; Chan, Janice; Wang, Ophelia; Schneider, Christopher J.; Pollinger, John P.; Saatchi, Sassan; Graham, Catherine H.; Wayne, Robert K.; Smith, Thomas B.

    2013-01-01

    Predicting where threatened species occur is useful for making informed conservation decisions. However, because they are usually rare, surveying threatened species is often expensive and time intensive. Here, we show how regions where common species exhibit high genetic and morphological divergence among populations can be used to predict the occurrence of species of conservation concern. Intraspecific variation of common species of birds, bats and frogs from Ecuador were found to be a significantly better predictor for the occurrence of threatened species than suites of environmental variables or the occurrence of amphibians and birds. Fully 93 per cent of the threatened species analysed had their range adequately represented by the geographical distribution of the morphological and genetic variation found in seven common species. Both higher numbers of threatened species and greater genetic and morphological variation of common species occurred along elevation gradients. Higher levels of intraspecific divergence may be the result of disruptive selection and/or introgression along gradients. We suggest that collecting data on genetic and morphological variation in common species can be a cost effective tool for conservation planning, and that future biodiversity inventories include surveying genetic and morphological data of common species whenever feasible. PMID:23595273

  7. Measured and Predicted Variations in Fast Neutron Spectrum in Massive Shields of Water and Concrete

    The absolute magnitude, and the variations in form, of the fast neutron spectrum during deep penetration (0.8 - 1.1 metre) in massive shields of water, ordinary and magnetite concrete have been studied by using threshold detectors (In (n, h'), S(n,p), Al(n, α)). The results have been compared with predictions by two rigorous (NIOBE, Moments method) and two non-rigorous (multigroup removal-diffusion) shielding codes (NRN, RASH D). The absolute results predicted were in general within 50% of the measured ones, i. e. showed as good or better accuracy than thermal and epithermal flux predictions in the same small-reactor configurations. No difference in accuracy was found between the rigorous and non-rigorous methods. The changes in the relative form of the spectrum (indicated by variations in the (Al/S) and (In/S) reaction rate ratios and amounting to factors up to 3 - 4 during a one metre penetration in water) were rather accurately (within 10 - 30%) predicted by all of the methods. The photonuclear excitation of the 335 keV level used for detecting the In(n, n') reaction was found to distort completely the In results in water at penetrations > 50 cm

  8. Active experiments in the ionosphere and geomagnetic field variations

    Sivokon, V. P.; Cherneva, N. V.; Khomutov, S. Y.; Serovetnikov, A. S.

    2014-11-01

    Variations of ionospheric-magnetospheric relation energy, as one of the possible outer climatology factors, may be traced on the basis of analysis of natural geophysical phenomena such as ionosphere artificial radio radiation and magnetic storms. Experiments on active impact on the ionosphere have been carried out for quite a long time in Russia as well. The most modern heating stand is located in Alaska; it has been used within the HAARP Program. The possibility of this stand to affect geophysical fields, in particular, the geomagnetic field is of interest.

  9. Computational Methodology for the Prediction of Functional Requirement Variations Across the Product Life-Cycle

    Mandil, Guillaume; Rivière, Alain

    2009-01-01

    The great majority of engineered products are subject to thermo-mechanical loads which vary with the product environment during the various phases of its life-cycle (machining, assembly, intended service use...). Those load variations may result in different values of the parts nominal dimensions, which in turn generate corresponding variation of the effective clearance (functional requirement) in the assembly. Usually, and according to the contractual drawings, the parts are measured after the machining stage, whereas the interesting measurement values are the ones taken in service for they allow the prediction of clearance value under operating conditions. Unfortunately, measurement in operating conditions may not be practical to obtain. Hence, the main purpose of this research is to create, through computations and simulations, links between the values of the loads, dimensions and functional requirements during the successive phases of the life cycle of some given product. [...

  10. Surface Temperature Variation Prediction Model Using Real-Time Weather Forecasts

    Karimi, M.; Vant-Hull, B.; Nazari, R.; Khanbilvardi, R.

    2015-12-01

    Combination of climate change and urbanization are heating up cities and putting the lives of millions of people in danger. More than half of the world's total population resides in cities and urban centers. Cities are experiencing urban Heat Island (UHI) effect. Hotter days are associated with serious health impacts, heart attaches and respiratory and cardiovascular diseases. Densely populated cities like Manhattan, New York can be affected by UHI impact much more than less populated cities. Even though many studies have been focused on the impact of UHI and temperature changes between urban and rural air temperature, not many look at the temperature variations within a city. These studies mostly use remote sensing data or typical measurements collected by local meteorological station networks. Local meteorological measurements only have local coverage and cannot be used to study the impact of UHI in a city and remote sensing data such as MODIS, LANDSAT and ASTER have with very low resolution which cannot be used for the purpose of this study. Therefore, predicting surface temperature in urban cities using weather data can be useful.Three months of Field campaign in Manhattan were used to measure spatial and temporal temperature variations within an urban setting by placing 10 fixed sensors deployed to measure temperature, relative humidity and sunlight. Fixed instrument shelters containing relative humidity, temperature and illumination sensors were mounted on lampposts in ten different locations in Manhattan (Vant-Hull et al, 2014). The shelters were fixed 3-4 meters above the ground for the period of three months from June 23 to September 20th of 2013 making measurements with the interval of 3 minutes. These high resolution temperature measurements and three months of weather data were used to predict temperature variability from weather forecasts. This study shows that the amplitude of spatial and temporal variation in temperature for each day can be predicted

  11. The Built Environment Predicts Observed Physical Activity

    Kelly, Cheryl; Wilson, Jeffrey S.; Schootman, Mario; Clennin, Morgan; Baker, Elizabeth A.; Miller, Douglas K.

    2014-01-01

    Background: In order to improve our understanding of the relationship between the built environment and physical activity, it is important to identify associations between specific geographic characteristics and physical activity behaviors. Purpose: Examine relationships between observed physical activity behavior and measures of the built environment collected on 291 street segments in Indianapolis and St. Louis. Methods: Street segments were selected using a stratified geographic samp...

  12. Prediction of seasonal climate-induced variations in global food production

    Iizumi, Toshichika; Sakuma, Hirofumi; Yokozawa, Masayuki; Luo, Jing-Jia; Challinor, Andrew J.; Brown, Molly E.; Sakurai, Gen; Yamagata, Toshio

    2013-10-01

    Consumers, including the poor in many countries, are increasingly dependent on food imports and are thus exposed to variations in yields, production and export prices in the major food-producing regions of the world. National governments and commercial entities are therefore paying increased attention to the cropping forecasts of important food-exporting countries as well as to their own domestic food production. Given the increased volatility of food markets and the rising incidence of climatic extremes affecting food production, food price spikes may increase in prevalence in future years. Here we present a global assessment of the reliability of crop failure hindcasts for major crops at two lead times derived by linking ensemble seasonal climatic forecasts with statistical crop models. We found that moderate-to-marked yield loss over a substantial percentage (26-33%) of the harvested area of these crops is reliably predictable if climatic forecasts are near perfect. However, only rice and wheat production are reliably predictable at three months before the harvest using within-season hindcasts. The reliabilities of estimates varied substantially by crop--rice and wheat yields were the most predictable, followed by soybean and maize. The reasons for variation in the reliability of the estimates included the differences in crop sensitivity to the climate and the technology used by the crop-producing regions. Our findings reveal that the use of seasonal climatic forecasts to predict crop failures will be useful for monitoring global food production and will encourage the adaptation of food systems toclimatic extremes.

  13. Spatial-Temporal Variation and Prediction of Rainfall in Northeastern Nigeria

    Umar M. Bibi

    2014-09-01

    Full Text Available In Northeastern Nigeria seasonal rainfall is critical for the availability of water for domestic use through surface and sub-surface recharge and agricultural production, which is mostly rain fed. Variability in rainfall over the last 60 years is the main cause for crop failure and water scarcity in the region, particularly, due to late onset of rainfall, short dry spells and multi-annual droughts. In this study, we analyze 27 years (1980–2006 of gridded daily rainfall data obtained from a merged dataset by the National Centre for Environmental Prediction and Climate Research Unit reanalysis data (NCEP-CRU for spatial-temporal variability of monthly amounts and frequency in rainfall and rainfall trends. Temporal variability was assessed using the percentage coefficient of variation and temporal trends in rainfall were assessed using maps of linear regression slopes for the months of May through October. These six months cover the period of the onset and cessation of the wet season throughout the region. Monthly rainfall amount and frequency were then predicted over a 24-month period using the Auto Regressive Integrated Moving Average (ARIMA Model. The predictions were evaluated using NCEP-CRU data for the same period. Kolmogorov Smirnov test results suggest that despite there are some months during the wet season (May–October when there is no significant agreement (p < 0.05 between the monthly distribution of the values of the model and the corresponding 24-month NCEP-CRU data, the model did better than simply replicating the long term mean of the data used for the prediction. Overall, the model does well in areas and months with lower temporal rainfall variability. Maps of the coefficient of variation and regression slopes are presented to indicate areas of high rainfall variability and water deficit over the period under study. The implications of these results for future policies on Agriculture and Water Management in the region are

  14. Stock Price Change Rate Prediction by Utilizing Social Network Activities

    Shangkun Deng; Takashi Mitsubuchi; Akito Sakurai

    2014-01-01

    Predicting stock price change rates for providing valuable information to investors is a challenging task. Individual participants may express their opinions in social network service (SNS) before or after their transactions in the market; we hypothesize that stock price change rate is better predicted by a function of social network service activities and technical indicators than by a function of just stock market activities. The hypothesis is tested by accuracy of predictions as well as pe...

  15. Variations in Extratropical Cyclone Activity in Northern East Asia

    WANG Xinmin; ZHAI Panmao; WANG Cuicui

    2009-01-01

    Based on an improved objective cyclone detection and tracking algorithm, decadal variations in extratropical cyclones in northern East Asia are studied by using the ECMWF 40 Year Reanalysis (ERA-40) sea-level pressure data during 1958-2001. The results reveal that extratropical cyclone activity has displayed clear seasonal, interannual, and decadal variability in northern East Asia. Spring is the season when cyclones occur most frequently. The spatial distribution of extratropical cyclones shows that cyclones occur mainly within the 40°-50°N latitudinal band in northern East Asia, and the most frequent region of occurrence is in Mongolia. Furthermore, this study also reveals the fact that the frequency of extratropical cyclones has significantly decreased in the lower latitude region of northern East Asia during 1958-2001, but dccadal variability has dominated in higher latitude bands, with frequent cyclone genesis. The intensity of extratropical cyclones has decreased on an annual and seasonal basis. Variation of the annual number of cyclones in northern East Asia is associated with the mean intensity of the baroclinic frontal zone, which is influenced by climate warming in the higher latitudes. Moreover, the dipole structure of extratopical cyclone change, with increases in the north and decreases in the southern part of northern East Asia, is related to the northward movement of the baroclinic frontal zone on either side of 110°E.

  16. Reconstruction and prediction of variations in the open solar magnetic flux and interplanetary conditions

    Mike Lockwood

    2013-01-01

    Historic geomagnetic activity observations have been used to reveal centennial variations in the open solar flux and the near-Earth heliospheric conditions (the interplanetary magnetic field and the solar wind speed). The various methods are in very good agreement for the past 135 years when there were sufficient reliable magnetic observatories in operation to eliminate problems due to site-specific errors and calibration drifts. This review underlines the physical principles that allow these...

  17. Analysis of substructural variation in families of enzymatic proteins with applications to protein function prediction

    Fofanov Viacheslav Y

    2010-05-01

    Full Text Available Abstract Background Structural variations caused by a wide range of physico-chemical and biological sources directly influence the function of a protein. For enzymatic proteins, the structure and chemistry of the catalytic binding site residues can be loosely defined as a substructure of the protein. Comparative analysis of drug-receptor substructures across and within species has been used for lead evaluation. Substructure-level similarity between the binding sites of functionally similar proteins has also been used to identify instances of convergent evolution among proteins. In functionally homologous protein families, shared chemistry and geometry at catalytic sites provide a common, local point of comparison among proteins that may differ significantly at the sequence, fold, or domain topology levels. Results This paper describes two key results that can be used separately or in combination for protein function analysis. The Family-wise Analysis of SubStructural Templates (FASST method uses all-against-all substructure comparison to determine Substructural Clusters (SCs. SCs characterize the binding site substructural variation within a protein family. In this paper we focus on examples of automatically determined SCs that can be linked to phylogenetic distance between family members, segregation by conformation, and organization by homology among convergent protein lineages. The Motif Ensemble Statistical Hypothesis (MESH framework constructs a representative motif for each protein cluster among the SCs determined by FASST to build motif ensembles that are shown through a series of function prediction experiments to improve the function prediction power of existing motifs. Conclusions FASST contributes a critical feedback and assessment step to existing binding site substructure identification methods and can be used for the thorough investigation of structure-function relationships. The application of MESH allows for an automated

  18. Activity, exposure rate and spectrum prediction with Java programming

    In order to envision the radiation exposure during Neutron Activation Analysis (NAA) experiments, a software called Activity Predictor is developed using JavaTM programming language. The Activity Predictor calculates activities, exposure rates and gamma spectra of activated samples for NAA experiments performed at Radiation Science and Engineering Center (RSEC), Penn State Breazeale Reactor (PSBR). The calculation procedure for predictions involves both analytical and Monte Carlo methods. The Activity Predictor software is validated with a series of activation experiments. It has been found that Activity Predictor software calculates the activities and exposure rates precisely. The software also predicts gamma spectrum for each measurement. The predicted spectra agreed partially with measured spectra. The error in net photo peak areas varied from 4.8 to 51.29%, which is considered to be due to simplistic modeling, statistical fluctuations and unknown contaminants in the samples. (author)

  19. Active Power Filter Using Predicted Current Control

    Xiaojie, Y.; Pivoňka, P.; Valouch, Viktor

    2001-01-01

    Roč. 46, č. 1 (2001), s. 41-50. ISSN 0001-7043 Institutional research plan: CEZ:AV0Z2057903 Keywords : active power filter * control strategy Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  20. Prediction of galactic cosmic ray intensity variation for a few (up to 10-12) years ahead on the basis of convection-diffusion and drift model

    We determine the dimension of the Heliosphere (modulation region) radial diffusion coefficient and other parameters of convection-diffusion and drift mechanisms of cosmic ray (CR) long-term variation, depending on particle energy, the level of solar activity (SA) and general solar magnetic field. This important information we obtain on the basis of CR and SA data in the past, taking into account the theory of convection-diffusion and drift global modulation of galactic CR in the Heliosphere. By using these results and predictions which are regularly published elsewhere of expected SA variation in the near future and prediction of next future SA cycle, we may make a prediction of the expected in the near future long-term cosmic ray intensity variation. We show that by this method we may make a prediction of the expected in the near future (up to 10-12 years, and may be more, in dependence for what period can be made definite prediction of SA) galactic cosmic ray intensity variation in the interplanetary space of different distances from the Sun, in the Earth's magnetosphere, and in the atmosphere at different altitudes and latitudes. (orig.)

  1. Spatial variation and prediction of forest biomass in a heterogeneous landscape

    S.Lamsal; D.M.Rizzo; R.K.Meentemeyer

    2012-01-01

    Large areas assessments of forest biomass distribution are a challenge in heterogeneous landscapes,where variations in tree growth and species composition occur over short distances.In this study,we use statistical and geospatial modeling on densely sampled forest biomass data to analyze the relative importance of ecological and physiographic variables as determinants of spatial variation of forest biomass in the environmentally heterogeneous region of the Big Sur,California.We estimated biomass in 280 forest plots (one plot per 2.85 km2) and measured an array of ecological (vegetation community type,distance to edge,amount of surrounding non-forest vegetation,soil properties,fire history) and physiographic drivers (elevation,potential soil moisture and solar radiation,proximity to the coast) of tree growth at each plot location.Our geostatistical analyses revealed that biomass distribution is spatially structured and autocorrelated up to 3.1 km.Regression tree (RT) models showed that both physiographic and ecological factors influenced biomass distribution.Across randomly selected sample densities (sample size 112 to 280),ecological effects of vegetation community type and distance to forest edge,and physiographic effects of elevation,potentialsoil moisture and solar radiation were the most consistent predictors of biomass.Topographic moisture index and potential solar radiation had a positive effect on biomass,indicating the importance of topographicallymediated energy and moisture on plant growth and biomass accumulation.RT model explained 35% of the variation in biomass and spatially autocorrelated variation were retained in regession residuals.Regression kriging model,developed from RT combined with kriging of regression residuals,was used to map biomass across the Big Sur.This study demonstrates how statistical and geospatial modeling can be used to discriminate the relative importance of physiographic and ecologic effects on forest biomass and develop

  2. Solar activity, geomagnetic perturbations and Vrancea (Romania) earthquake short-term predictability

    The paper presents the main results of applying the electromagnetic method for the short- term prediction of Vrancea earthquakes. The results are based on electromagnetic records made at Muntele Rosu Geophysical Observatory in Romania during the period December 1997 to July 2003. The paper highlights the importance as a precursor factor of the magnetic impedance BZ/BX, where BZ is the vertical component of the geomagnetic flux density and BX its horizontal component. The time variation of BZ/BX is closely examined in correlation with Vrancea seismic activity. The variations are compared to the geomagnetic perturbation of Ak > 20 (magnetic storms) that are generated by solar activity. Relations between these three factors, i.e. the BZ/BX ratio, magnetic storms, and Vrancea seismic activity are seen to combine into five distinct situations. The feasibility and difficulties of using the electromagnetic method for the short-term prediction of Vrancea earthquakes are examined in the final section. (authors)

  3. Length and activation dependent variations in muscle shear wave speed

    Muscle stiffness is known to vary as a result of a variety of disease states, yet current clinical methods for quantifying muscle stiffness have limitations including cost and availability. We investigated the capability of shear wave elastography (SWE) to measure variations in gastrocnemius shear wave speed induced via active contraction and passive stretch. Ten healthy young adults were tested. Shear wave speeds were measured using a SWE transducer positioned over the medial gastrocnemius at ankle angles ranging from maximum dorsiflexion to maximum plantarflexion. Shear wave speeds were also measured during voluntary plantarflexor contractions at a fixed ankle angle. Average shear wave speed increased significantly from 2.6 to 5.6 m s–1 with passive dorsiflexion and the knee in an extended posture, but did not vary with dorsiflexion when the gastrocnemius was shortened in a flexed knee posture. During active contractions, shear wave speed monotonically varied with the net ankle moment generated, reaching 8.3 m s–1 in the maximally contracted condition. There was a linear correlation between shear wave speed and net ankle moment in both the active and passive conditions; however, the slope of this linear relationship was significantly steeper for the data collected during passive loading conditions. The results show that SWE is a promising approach for quantitatively assessing changes in mechanical muscle loading. However, the differential effect of active and passive loading on shear wave speed makes it important to carefully consider the relevant loading conditions in which to use SWE to characterize in vivo muscle properties. (paper)

  4. Spatial and temporal variations of thunderstorm activities over Sri Lanka

    Sonnadara, Upul

    2016-05-01

    Spatial and temporal variation of frequencies of thunderstorms over Sri Lanka using thunder day data is presented. A thunder day is simply a calendar day in which thunder is heard at least once at a given location. Two sets of data were collected and analyzed: annual totals for 10 climatological stations for a period of 50 years and monthly totals for 20 climatological stations for a period of 20 years. The average annual thunder days over Sri Lanka was found to be 76. Among the climatological stations considered, a high number of annual thunder days was recorded in Ratnapura (150 days/year), followed by Colombo (108 days/year) and Bandarawela (106 days/year). It appears that there are no widespread long-term increasing or decreasing trends in thunderstorm frequencies. However, Colombo, the capital of Sri Lanka which has over two million people shows an increasing trend of 0.8 thunder days per year. Although there is a high variability between stations reporting the number of thunder days, the overall pattern within a year is clear. Thunderstorm frequencies are high during two periods: March-May and September-November, which coincide with the first inter-monsoon and second inter-monsoon periods. Compared to the dry zone, the wet zone, especially the southwestern region, has high thunderstorm activity. There is a clear spatial difference in thunderstorm activities during the southwest and northeast monsoon seasons. During both these seasons, enhanced thunderstorm activities are reported on the leeward side of the mountain range. A slight reduction in the thunderstorm activities was found in the high elevation areas of the hill country compared to the surrounding areas. A lightning ground flash density map derived using annual thunder days is also presented.

  5. Predicting mining activity with parallel genetic algorithms

    Talaie, S.; Leigh, R.; Louis, S.J.; Raines, G.L.

    2005-01-01

    We explore several different techniques in our quest to improve the overall model performance of a genetic algorithm calibrated probabilistic cellular automata. We use the Kappa statistic to measure correlation between ground truth data and data predicted by the model. Within the genetic algorithm, we introduce a new evaluation function sensitive to spatial correctness and we explore the idea of evolving different rule parameters for different subregions of the land. We reduce the time required to run a simulation from 6 hours to 10 minutes by parallelizing the code and employing a 10-node cluster. Our empirical results suggest that using the spatially sensitive evaluation function does indeed improve the performance of the model and our preliminary results also show that evolving different rule parameters for different regions tends to improve overall model performance. Copyright 2005 ACM.

  6. Robust Active Suspension Design Subject to Vehicle Inertial Parameter Variations

    Hai-Ping Du; Nong Zhang

    2010-01-01

    This paper presents an approach in designing a robust controller for vehicle suspensions considering changes in vehicle inertial properties. A four-degree-of-freedom half-car model with active suspension is studied in this paper, and three main performance requirements are considered. Among these requirements, the ride comfort performance is optimized by minimizing the H∞ norm of the transfer function from the road disturbance to the sprung mass acceleration, while the road holding performance and the suspension deflection limitation are guaranteed by constraining the generalized H2 (GH2) norms of the transfer functions from the road disturbance to the dynamic tyre load and the suspension deflection to be less than their hard limits, respectively. At the same time, the controller saturation problem is considered by constraining its peak response output to be less than a given limit using the GH2 norm as well. By solving the finite number of linear matrix inequalities (LMIs) with the minimization optimization procedure, the controller gains, which are dependent on the time-varying inertial parameters, can be obtained. Numerical simulations on both frequency and bump responses show that the designed parameter-dependent controller can achieve better active suspension performance compared with the passive suspension in spite of the variations of inertial parameters.

  7. Measured and Predicted Variations in Fast Neutron Spectrum when Penetrating Laminated Fe-D2O

    Variations of the fast neutron spectrum in thin regions of alternating Fe and DO have been studied using threshold detectors (ln(n, n' ), S(n, p), Al(n, α)). The results have been compared to those calculated by two shielding codes (NRN and RASH D) of multigroup removal-diffusion type. The absolute fast spectrum calculated in our rather complicated configurations was found to agree with measurements within the same accuracy (a factor of two) as did the thermal flux. The calculated spectrum is slightly harder than the measured one, but the detailed variations (covering the range 1:5) in the form of the spectrum when penetrating Fe agree with observations to within 15-20 %. In and Al activities were found to be proportional to the integrated flux over 1 MeV throughout the whole configuration, while S showed the least proportionality

  8. From field to region yield predictions in response to pedo-climatic variations in Eastern Canada

    JÉGO, G.; Pattey, E.; Liu, J.

    2013-12-01

    The increase in global population coupled with new pressures to produce energy and bioproducts from agricultural land requires an increase in crop productivity. However, the influence of climate and soil variations on crop production and environmental performance is not fully understood and accounted for to define more sustainable and economical management strategies. Regional crop modeling can be a great tool for understanding the impact of climate variations on crop production, for planning grain handling and for assessing the impact of agriculture on the environment, but it is often limited by the availability of input data. The STICS ("Simulateur mulTIdisciplinaire pour les Cultures Standard") crop model, developed by INRA (France) is a functional crop model which has a built-in module to optimize several input parameters by minimizing the difference between calculated and measured output variables, such as Leaf Area Index (LAI). STICS crop model was adapted to the short growing season of the Mixedwood Plains Ecozone using field experiments results, to predict biomass and yield of soybean, spring wheat and corn. To minimize the numbers of inference required for regional applications, 'generic' cultivars rather than specific ones have been calibrated in STICS. After the calibration of several model parameters, the root mean square error (RMSE) of yield and biomass predictions ranged from 10% to 30% for the three crops. A bit more scattering was obtained for LAI (20%prediction to climate variations. Using RS data to re-initialize input parameters that are not readily available (e.g. seeding date) is considered an effective way

  9. Prediction model for sequence variation in the glycoprotein gene of infectious hematopoietic necrosis virus in California, U.S.A.

    Kelley, Garry O; Garabed, Rebecca; Branscum, Adam; Perez, Andres; Thurmond, Mark

    2007-12-13

    The influence of spatio-temporal factors on genetic variation of infectious hematopoietic necrosis virus (IHNV) is an active area of research. Using host-isolate pairs collected from 1966 to 2004 for 237 IHNV isolates from California and southern Oregon, we examined genetic variation of the mid-G gene of IHNV that could be quantified across times and geographic locations. Information hypothesized to influence genetic variation was environmental and/or fish host demographic factors, viz. location (inland or coastal), year of isolation, habitat (river, lake, or hatchery), the agent factors of subgroup (LI or LII) and serotype (1, 2, or 3), and the host factors of fish age (juvenile or adult), sex (male or female), and season of spawning run (spring, fall, late fall, winter). Inverse distance weighting (IDW) was performed to create isopleth maps of the genetic distances of each subgroup. IDW maps showed that more genetic divergence was predicted for isolates found inland (for both subgroups: LI and LII) than for coastal watershed isolates. A mixed-effect beta regression with a logit link function was used to seek associations between genetic distances and hypothesized explanatory factors. The model that best described genetic distance contained the factors of location, year of isolation, and the interaction between location and year. Our model suggests that genetic distance was greater for isolates collected from 1966 to 2004 at inland locations than for isolates found in coastal watersheds during the same years. The agreement between the IDW and beta regression analyses quantitatively supports our conclusion that, during this time period, more genetic variation existed within subgroup LII in inland watersheds than within coastal LI isolates. PMID:18286806

  10. Regional geomagnetic field variations and seismic activity of the northern Tien Shan

    Complete text of publication follows. At present the problem of short-term earthquake prediction based on 'precursors' (featured variations of various geophysical fields) is far from solving. At the same time an evidence of earthquake triggering by natural and man-made factors is world-wide verified. Based on well-monitored triggering impacts the new concept of earthquake prediction may be developed. One of the possible powerful triggering mechanisms was proposed by G. Duma and Yu. Ruzhin [2003], indicating the generation of mechanical force in the Earth crust due to interaction of telluric currents with geomagnetic field. For verification of this hypothesis a territory of Bishkek geodynamical proving ground was selected where seismic, geomagnetic, magnetotelluric, and GPS observatories are concentrated, and extensive geophysical databases are available. Possible correlations of seismic activity of the Northern Tien Shan region (40.5 deg-44.5 degN, 71.5 deg-78.5 degE) and variations of geomagnetic magnetic field, as well as and lunar-solar tides within the period 1994-2007 are analyzed. Various statistical methods (cross-correlation, spectral analysis) were employed. The earthquake daily frequency distribution shows a common performance with the regular diurnal geomagnetic field variations. Time difference [T(E)-T(Max GMF)] between the earthquake occurrence and time of maximal daily geomagnetic field has normal distribution. 40% of earthquakes occurred in the range of -4 to +4 hour from maximal daily geomagnetic field. The effect is more pronounced for weak earthquakes (M<4), but it is observed for the whole seismic activity as well. There are a number of common long periods (7, 9, 14, 28 days) in the z-component of the earth tide and seismic activity. Nevertheless, no effect of the diurnal tidal cycle on the seismicity has been revealed. The geomagnetic correlations, which have been found, are observed for the entire region under study, and they do not depend on

  11. Nestling activity levels during begging behaviour predicts activity level and body mass in adulthood

    Luke S.C. McCowan

    2014-09-01

    Full Text Available Across a range of species including humans, personality traits, or differences in behaviour between individuals that are consistent over time, have been demonstrated. However, few studies have measured whether these consistent differences are evident in very young animals, and whether they persist over an individual’s entire lifespan. Here we investigated the begging behaviour of very young cross-fostered zebra finch nestlings and the relationship between that and adult activity levels. We found a link between the nestling activity behaviour head movements during begging, measured at just five and seven days after hatching, and adult activity levels, measured when individuals were between three and three and a half years old. Moreover, body mass was found to be negatively correlated with both nestling and adult activity levels, suggesting that individuals which carry less body fat as adults are less active both as adults and during begging as nestlings. Our work suggests that the personality traits identified here in both very young nestlings and adults may be linked to physiological factors such as metabolism or environmental sources of variation. Moreover, our work suggests it may be possible to predict an individual’s future adult personality at a very young age, opening up new avenues for future work to explore the relationship between personality and a number of aspects of individual life history and survival.

  12. Nestling activity levels during begging behaviour predicts activity level and body mass in adulthood.

    McCowan, Luke S C; Griffith, Simon C

    2014-01-01

    Across a range of species including humans, personality traits, or differences in behaviour between individuals that are consistent over time, have been demonstrated. However, few studies have measured whether these consistent differences are evident in very young animals, and whether they persist over an individual's entire lifespan. Here we investigated the begging behaviour of very young cross-fostered zebra finch nestlings and the relationship between that and adult activity levels. We found a link between the nestling activity behaviour head movements during begging, measured at just five and seven days after hatching, and adult activity levels, measured when individuals were between three and three and a half years old. Moreover, body mass was found to be negatively correlated with both nestling and adult activity levels, suggesting that individuals which carry less body fat as adults are less active both as adults and during begging as nestlings. Our work suggests that the personality traits identified here in both very young nestlings and adults may be linked to physiological factors such as metabolism or environmental sources of variation. Moreover, our work suggests it may be possible to predict an individual's future adult personality at a very young age, opening up new avenues for future work to explore the relationship between personality and a number of aspects of individual life history and survival. PMID:25279258

  13. Using Proximity to Predict Activity in Social Networks

    Lerman, Kristina; Intagorn, Suradej; Kang, Jeon-Hyung; Ghosh, Rumi

    2011-01-01

    The structure of a social network contains information useful for predicting its evolution. Nodes that are "close" in some sense are more likely to become linked in the future than more distant nodes. We show that structural information can also help predict node activity. We use proximity to capture the degree to which two nodes are "close" to each other in the network. In addition to standard proximity metrics used in the link prediction task, such as neighborhood overlap, we introduce new ...

  14. Total variation regularization for fMRI-based prediction of behaviour

    Michel, Vincent; Varoquaux, Gaël; Eger, Evelyn; Thirion, Bertrand

    2011-01-01

    While medical imaging typically provides massive amounts of data, the extraction of relevant information for predictive diagnosis remains a difficult challenge. Functional MRI (fMRI) data, that provide an indirect measure of task-related or spontaneous neuronal activity, are classically analyzed in a mass-univariate procedure yielding statistical parametric maps. This analysis framework disregards some important principles of brain organization: population coding, distributed and overlapping representations. Multivariate pattern analysis, i.e., the prediction of behavioural variables from brain activation patterns better captures this structure. To cope with the high dimensionality of the data, the learning method has to be regularized. However, the spatial structure of the image is not taken into account in standard regularization methods, so that the extracted features are often hard to interpret. More informative and interpretable results can be obtained with the l_1 norm of the image gradient, a.k.a. its ...

  15. Line Impedance Estimation Using Active and Reactive Power Variations

    Timbus, Adrian Vasile; Rodriguez, Pedro; Teodorescu, Remus;

    2007-01-01

    This paper proposes an estimation method of power system impedance based on power variations caused by a distributed power generation system (DPGS) at the point of common coupling (PCC). The proposed algorithm is computationally simple and uses the voltage variations at the point of common coupling...... (PCC) caused by the variations of the power delivered to utility network to derive the value of grid impedance. Accurate estimation of both resistive and inductive part of the impedance is obtained, as the results presented show....

  16. NAA and NAAG variation in neuronal activation during visual stimulation

    Castellano, G.; Dias, C.S.B. [Grupo de Neurofísica, Departamento de Raios Cósmicos e Cronologia, Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, Campinas, SP (Brazil); Programa de Cooperação Interinstitucional de Apoio à Pesquisa sobre o Cérebro (CInAPCe), SP (Brazil); Foerster, B. [Philips Medical Systems, São Paulo, SP (Brazil); Programa de Cooperação Interinstitucional de Apoio à Pesquisa sobre o Cérebro (CInAPCe), SP (Brazil); Li, L.M. [Departamento de Neurologia, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas, SP (Brazil); Programa de Cooperação Interinstitucional de Apoio à Pesquisa sobre o Cérebro (CInAPCe), SP (Brazil); Covolan, R.J.M. [Grupo de Neurofísica, Departamento de Raios Cósmicos e Cronologia, Instituto de Física Gleb Wataghin, Universidade Estadual de Campinas, Campinas, SP (Brazil); Programa de Cooperação Interinstitucional de Apoio à Pesquisa sobre o Cérebro (CInAPCe), SP (Brazil)

    2012-08-17

    N-acetyl-aspartyl-glutamate (NAAG) and its hydrolysis product N-acetyl-aspartate (NAA) are among the most important brain metabolites. NAA is a marker of neuron integrity and viability, while NAAG modulates glutamate release and may have a role in neuroprotection and synaptic plasticity. Investigating on a quantitative basis the role of these metabolites in brain metabolism in vivo by magnetic resonance spectroscopy (MRS) is a major challenge since the main signals of NAA and NAAG largely overlap. This is a preliminary study in which we evaluated NAA and NAAG changes during a visual stimulation experiment using functional MRS. The paradigm used consisted of a rest period (5 min and 20 s), followed by a stimulation period (10 min and 40 s) and another rest period (10 min and 40 s). MRS from 17 healthy subjects were acquired at 3T with TR/TE = 2000/288 ms. Spectra were averaged over subjects and quantified with LCModel. The main outcomes were that NAA concentration decreased by about 20% with the stimulus, while the concentration of NAAG concomitantly increased by about 200%. Such variations fall into models for the energy metabolism underlying neuronal activation that point to NAAG as being responsible for the hyperemic vascular response that causes the BOLD signal. They also agree with the fact that NAAG and NAA are present in the brain at a ratio of about 1:10, and with the fact that the only known metabolic pathway for NAAG synthesis is from NAA and glutamate.

  17. Variations of the temperature and solar activity in China

    MingQi Li; QuanSheng Ge; ZhiXin Hao; JingYun Zheng

    2014-01-01

    In this paper we analyze daily mean, minimum, and maximum temperature data collected at 119 meteorological stations over five regions of China during the period 1951-2010. The series of minimum, maximum, and mean temperatures from each climatic region have similar signatures, but there are differences among the five regions and the countrywide average. The results indicate that the periods of faster warming were not synchronous across the regions studied: warming in northeast China and Tibet began in 1986, while in central-east, southeast, and northwest China the warming emerged in 1995. Furthermore, central-east and northwest China, and Tibet, have warmed continuously since 2000, but the temper-ature has decreased during this period in southeast China. We evaluated the evolution of these temperature series using a novel nonlinear filtering technique based on the concept of the lifetime of temperature curves. The decadal to secular evolution of solar activity and temperature variation had similar signatures in the northeast, southeast, and northwest re-gions and the average across the whole country, indicating that solar activity is a significant control on climate change over secular time scales in these regions. In comparison with these regions, the signatures were different in central-east China and Tibet because of regional differences (e.g., landforms and elevation) and indirect effects (e.g., cloud cover influencing the radiation balance, thereby inducing climate change). Furthermore, the results of wavelet analysis indicated that the El Niño Southern Oscillation (ENSO) has had a significant impact on climate change, but at different times among the regions, and these changes were most probably induced by differing responses of the atmospheric system to solar forcing.

  18. Climate variation and prediction of rapid intensification in tropical cyclones in the western North Pacific

    Wang, B.; Zhou, X.

    2008-02-01

    One of the greatest challenges in tropical weather forecasting is the rapid intensification (RI) of the tropical cyclone (TC), during which its one-minute maximum sustained wind speed increases at least 30 knots per 24 hours. Here we identify and elucidate the climatic conditions that are critical to the frequency and location of the RI on annual, intraseasonal, and interannual time scales. Whereas RI and formation share common environmental preferences, we found that the percentage of TCs with RI varies annually and from year to year. In August, only 30% of TC actually experiences RI, in contrast to the annual maximum of 47% in November. The proportion of RI in July September is higher during El Niño years (53%) than the corresponding one in the La Niña years (37%). Three climate factors may contribute to the increase in the proportion of RI: the southward shift in the monthly or seasonal mean location of the TC formation, the increase in the low-level westerly meridional shear vorticity, and the decrease in northerly vertical shear. When the mean latitude of TC formation increases, the mixed-layer heat content decreases while TC’s inertial stability increases; both are more detrimental to the RI than to TC formation because the RI requires large amount of latent heat energy being extracted efficiently from the ocean mixed layer and requires accelerated low-level radial inflow that carries latent heat reaching the inner core region. We further demonstrate that the RI frequency in the Philippine Sea and South China Sea can be predicted 10 to 30 days in advance based on the convective anomalies in the equatorial western Pacific (5° S 5° N, 130° 150° E) on intraseasonal time scale. The Niño 3.4 SSTA in June is a potential predictor for the peak TC season (July September) RI activity in the southeast quadrant of the western North Pacific (0 20° N, 140 180° E). The RI is an essential characteristic of category 4 and 5 hurricanes and super typhoons because

  19. Comparison of deterministic and stochastic methods to predict spatial variation of groundwater depth

    Adhikary, Partha Pratim; Dash, Ch. Jyotiprava

    2014-11-01

    Accurate and reliable interpolation of groundwater depth over a region is a pre-requisite for efficient planning and management of water resources. The performance of two deterministic, such as inverse distance weighting (IDW) and radial basis function (RBF) and two stochastic, i.e., ordinary kriging (OK) and universal kriging (UK) interpolation methods was compared to predict spatio-temporal variation of groundwater depth. Pre- and post-monsoon groundwater level data for the year 2006 from 110 different locations over Delhi were used. Analyses revealed that OK and UK methods outperformed the IDW method, and UK performed better than OK. RBF also performed better than IDW and OK. IDW and RBF methods slightly underestimated and both the kriging methods slightly overestimated the prediction of water table depth. OK, RBF and UK yielded 27.52, 27.66 and 51.11 % lower RMSE, 27.49, 35.34 and 51.28 % lower MRE, and 14.21, 16.12 and 21.36 % higher R 2 over IDW. The isodepth-area curves indicated the possibility of exploitation of groundwater up to a depth of 20 m.

  20. Prediction of ppm level electrical failure by using physical variation analysis

    Hou, Hsin-Ming; Kung, Ji-Fu; Hsu, Y.-B.; Yamazaki, Y.; Maruyama, Kotaro; Toyoshima, Yuya; Chen, Chu-en

    2016-03-01

    their spatial correlation distance. For local variations (LV) there is no correlation, whereas for global variations (GV) the correlation distance is very large [7]-[9]. This is the first time to certificate the validation of spatial distribution from the affordable bias contour big data fundamental infrastructures. And then apply statistical techniques to dig out the variation sources. The GV come from systematic issue, which could be compensated by adaptive LT condition or OPC correction. But LV comes from random issue, which being considered as intrinsic problem such as structure, material, tool capability… etc. In this paper studying, we can find out the advanced technology node SRAM contact CD local variation (LV) dominates in total variation, about 70%. It often plays significant in-line real time catching WP-DPMO role of the product yield loss, especially for wafer edge is the worst loss within wafer distribution and causes serious reliability concern. The major root cause of variations comes from the PR material induced burr defect (LV), the second one comes from GV enhanced wafer edge short opportunity, which being attributed to three factors, first one factor is wafer edge CD deliberated enlargement for yield improvement as shown in Fig. 10. Second factor is overlaps/AA shifts due to tool capability dealing with incoming wafer's war page issue and optical periphery layout dependent working pitch issue as shown in Fig. 9 (1)., the last factor comes from wafer edge burr enhanced by wafer edge larger Photo Resistance (PR) spin centrifugal force. After implementing KPIs such as GV related AA/CD indexes as shown in Fig. 9 (1) and 10, respectively, and LV related burr index as shown in Fig. 11., we can construct the parts per million (PPM) level short probability model via multi-variables regression, canonical correlation analysis and logistic transformation. The model provides prediction of PPM level electrical failure by using in-line real time physical

  1. Probabilistic electricity price forecasting with variational heteroscedastic Gaussian process and active learning

    Highlights: • A novel active learning model for the probabilistic electricity price forecasting. • Heteroscedastic Gaussian process that captures the local volatility of the electricity price. • Variational Bayesian learning that avoids over-fitting. • Active learning algorithm that reduces the computational efforts. - Abstract: Electricity price forecasting is essential for the market participants in their decision making. Nevertheless, the accuracy of such forecasting cannot be guaranteed due to the high variability of the price data. For this reason, in many cases, rather than merely point forecasting results, market participants are more interested in the probabilistic price forecasting results, i.e., the prediction intervals of the electricity price. Focusing on this issue, this paper proposes a new model for the probabilistic electricity price forecasting. This model is based on the active learning technique and the variational heteroscedastic Gaussian process (VHGP). It provides the heteroscedastic Gaussian prediction intervals, which effectively quantify the heteroscedastic uncertainties associated with the price data. Because the high computational effort of VHGP hinders its application to the large-scale electricity price forecasting tasks, we design an active learning algorithm to select a most informative training subset from the whole available training set. By constructing the forecasting model on this smaller subset, the computational efforts can be significantly reduced. In this way, the practical applicability of the proposed model is enhanced. The forecasting performance and the computational time of the proposed model are evaluated using the real-world electricity price data, which is obtained from the ANEM, PJM, and New England ISO

  2. Common Variation in the DOPA Decarboxylase (DDC) Gene and Human Striatal DDC Activity In Vivo.

    Eisenberg, Daniel P; Kohn, Philip D; Hegarty, Catherine E; Ianni, Angela M; Kolachana, Bhaskar; Gregory, Michael D; Masdeu, Joseph C; Berman, Karen F

    2016-08-01

    The synthesis of multiple amine neurotransmitters, such as dopamine, norepinephrine, serotonin, and trace amines, relies in part on DOPA decarboxylase (DDC, AADC), an enzyme that is required for normative neural operations. Because rare, loss-of-function mutations in the DDC gene result in severe enzymatic deficiency and devastating autonomic, motor, and cognitive impairment, DDC common genetic polymorphisms have been proposed as a source of more moderate, but clinically important, alterations in DDC function that may contribute to risk, course, or treatment response in complex, heritable neuropsychiatric illnesses. However, a direct link between common genetic variation in DDC and DDC activity in the living human brain has never been established. We therefore tested for this association by conducting extensive genotyping across the DDC gene in a large cohort of 120 healthy individuals, for whom DDC activity was then quantified with [(18)F]-FDOPA positron emission tomography (PET). The specific uptake constant, Ki, a measure of DDC activity, was estimated for striatal regions of interest and found to be predicted by one of five tested haplotypes, particularly in the ventral striatum. These data provide evidence for cis-acting, functional common polymorphisms in the DDC gene and support future work to determine whether such variation might meaningfully contribute to DDC-mediated neural processes relevant to neuropsychiatric illness and treatment. PMID:26924680

  3. A simple method to estimate radial velocity variations due to stellar activity using photometry

    Aigrain, S; Zucker, S

    2011-01-01

    We present a new, simple method to predict activity-induced radial velocity variations using high-precision time-series photometry. It is based on insights from a simple spot model, has only two free parameters (one of which can be estimated from the light curve) and does not require knowledge of the stellar rotation period. We test the method on simulated data and illustrate its performance by applying it to MOST/SOPHIE observations of the planet host-star HD189733, where it gives almost identical results to much more sophisticated, but highly degenerate models, and synthetic data for the Sun, where we demonstrate that it can reproduce variations well below the m/s level. We also apply it to Quarter 1 data for Kepler transit candidate host stars, where it can be used to estimate RV variations down to the 2-3m/s level, and show that RV amplitudes above that level may be expected for approximately two thirds of the candidates we examined.

  4. Predicting Physical Activity in Arab American School Children

    Martin, Jeffrey J.; McCaughtry, Nate; Shen, Bo

    2008-01-01

    Theoretically grounded research on the determinants of Arab American children's physical activity is virtually nonexistent. Thus, the purpose of our investigation was to evaluate the ability of the theory of planned behavior (TPB) and social cognitive theory (SCT) to predict Arab American children's moderate-to-vigorous physical activity (MVPA).…

  5. Predicting spatial variations of tree species richness in tropical forests from high-resolution remote sensing.

    Fricker, Geoffrey A; Wolf, Jeffrey A; Saatchi, Sassan S; Gillespie, Thomas W

    2015-10-01

    There is an increasing interest in identifying theories, empirical data sets, and remote-sensing metrics that can quantify tropical forest alpha diversity at a landscape scale. Quantifying patterns of tree species richness in the field is time consuming, especially in regions with over 100 tree species/ha. We examine species richness in a 50-ha plot in Barro Colorado Island in Panama and test if biophysical measurements of canopy reflectance from high-resolution satellite imagery and detailed vertical forest structure and topography from light detection and ranging (lidar) are associated with species richness across four tree size classes (>1, 1-10, >10, and >20 cm dbh) and three spatial scales (1, 0.25, and 0.04 ha). We use the 2010 tree inventory, including 204,757 individuals belonging to 301 species of freestanding woody plants or 166 ± 1.5 species/ha (mean ± SE), to compare with remote-sensing data. All remote-sensing metrics became less correlated with species richness as spatial resolution decreased from 1.0 ha to 0.04 ha and tree size increased from 1 cm to 20 cm dbh. When all stems with dbh > 1 cm in 1-ha plots were compared to remote-sensing metrics, standard deviation in canopy reflectance explained 13% of the variance in species richness. The standard deviations of canopy height and the topographic wetness index (TWI) derived from lidar were the best metrics to explain the spatial variance in species richness (15% and 24%, respectively). Using multiple regression models, we made predictions of species richness across Barro Colorado Island (BCI) at the 1-ha spatial scale for different tree size classes. We predicted variation in tree species richness among all plants (adjusted r² = 0.35) and trees with dbh > 10 cm (adjusted r² = 0.25). However, the best model results were for understory trees and shrubs (dbh 1-10 cm) (adjusted r² = 0.52) that comprise the majority of species richness in tropical forests. Our results indicate that high

  6. PASS-GP: Predictive active set selection for Gaussian processes

    Henao, Ricardo; Winther, Ole

    We propose a new approximation method for Gaussian process (GP) learning for large data sets that combines inline active set selection with hyperparameter optimization. The predictive probability of the label is used for ranking the data points. We use the leave-one-out predictive probability...... the active set selection strategy and marginal likelihood optimization on the active set. We make extensive tests on the USPS and MNIST digit classification databases with and without incorporating invariances, demonstrating that we can get state-of-the-art results (e.g.0.86% error on MNIST) with...

  7. Statistical Evaluation of Efficiency and Possibility of Earthquake Predictions with Gravity Field Variation and its Analytic Signal in Western China

    Chen, Shi; Jiang, Changsheng; Zhuang, Jiancang

    2016-01-01

    This paper aimed at assessing gravity variations as precursors for earthquake prediction in the Tibet (Xizang)-Qinghai-Xinjiang-Sichuan Region, western China. We here take a statistical approach to evaluate efficiency and possibility of earthquake prediction. We used the most recent spatiotemporal gravity field variation datasets of 2002-2008 for the region that were provided by the Crustal Movement Observation Network of China (CMONC). The datasets were space sparse and time discrete. In 2007-2010, 13 earthquakes (> M s 6.0) occurred in the region. The observed gravity variations have a statistical correlation with the occurrence of these earthquakes through the Molchan error diagram tests that lead to alarms over a good fraction of space-time. The results show that the prediction efficiency of amplitude of analytic signal of gravity variations is better than seismicity rate model and THD and absolute value of gravity variation, implying that gravity variations before earthquake may include precursory information of future large earthquakes.

  8. Predictive Duty Cycle Control of Three-Phase Active-Front-End Rectifiers

    Song, Zhanfeng; Tian, Yanjun; Chen, Wei;

    2016-01-01

    This paper proposed an on-line optimizing duty cycle control approach for three-phase active-front-end rectifiers, aiming to obtain the optimal control actions under different operating conditions. Similar to finite control set model predictive control strategy, a cost function previously...... constructed based on the desired control performance is adopted here, which is essential for the solving process of the optimizing problem. On the other hand, differently, with respect to the proposed strategy, duty cycle signals are optimized, instead of possible switching states. The determination...... of optimal duty cycles is made by predicting the effect of duty cycles on instantaneous current variations and minimizing the cost function. Due to the adoption of behavior prediction, the proposed controller inherits the excellent dynamic characteristics of predictive controllers. Moreover, the application...

  9. Reconstructed Total Solar Irradiance as a precursor for long-term solar activity predictions: a nonlinear dynamics approach

    Sello, S

    2012-01-01

    Total solar irradiance variations, about 0.1% between solar activity maximum and minimum, are available from accurate satellite measurements since 1978 and thus do not provide useful information on longer-term secular trends. Recently, Krivova et al., 2007 reconstructed, using suitable models, the total solar irradiance from the end of the Maunder minimum to the present, based on variations of the surface distribution of the solar magnetic field. The latter is calculated from the long historical record of the sunspot numbers using a simple but consistent physical model. There are many classes of proposed prediction methods for solar cycles behavior, based on different direct solar activity indices or on various valuable proxies. In particular, the precursor based methods, utilize a given proxy index to predict the future evolution of solar activity. Long-term time series of sunspot numbers, allow us to reliably predict the behavior of the next solar cycle, few years in advance. In previous papers we predicted...

  10. Nonlinear Predictive Control of Semi-Active Landing Gear System

    Wu, Dongsu; Gu, Hongbin; Liu, Hui

    2010-01-01

    The application of model predictive control and constructive nonlinear control methodology to semi-active landing gear system is studied in this paper. A unified shock absorber mathematical model incorporates solenoid valve’s electromechanical and magnetic dynamics is built to facilitate simulation and controller design. Then we propose a hierarchical control structure to deal with the high nonlinearity. A dual mode model predictive controller as an outer loop controller is developed to gen...

  11. Predicting Indian Summer Monsoon onset through variations of surface air temperature and relative humidity

    Stolbova, Veronika; Surovyatkina, Elena; Kurths, Jurgen

    2015-04-01

    Indian Summer Monsoon (ISM) rainfall has an enormous effect on Indian agriculture, economy, and, as a consequence, life and prosperity of more than one billion people. Variability of the monsoonal rainfall and its onset have a huge influence on food production, agricultural planning and GDP of the country, which on 22% is determined by agriculture. Consequently, successful forecasting of the ISM onset is a big challenge and large efforts are being put into it. Here, we propose a novel approach for predictability of the ISM onset, based on critical transition theory. The ISM onset is defined as an abrupt transition from sporadious rainfall to spatially organized and temporally sustained rainfall. Taking this into account, we consider the ISM onset as is a critical transition from pre-monsoon to monsoon, which take place in time and also in space. It allows us to suggest that before the onset of ISM on the Indian subcontinent should be areas of critical behavior where indicators of the critical transitions can be detected through an analysis of observational data. First, we identify areas with such critical behavior. Second, we use detected areas as reference points for observation locations for the ISM onset prediction. Third, we derive a precursor for the ISM onset based on the analysis of surface air temperature and relative humidity variations in these reference points. Finally, we demonstrate the performance of this precursor on two observational data sets. The proposed approach allows to determine ISM onset in advance in 67% of all considered years. Our proposed approach is less effective during the anomalous years, which are associated with weak/strong monsoons, e.g. El-Nino, La-Nina or positive Indian Ocean Dipole events. The ISM onset is predicted for 23 out of 27 normal monsoon years (85%) during the past 6 decades. In the anomalous years, we show that time series analysis in both areas during the pre-monsoon period reveals indicators whether the

  12. Variational assimilation of land surface temperature observations for enhanced river flow predictions

    Ercolani, Giulia; Castelli, Fabio

    2016-04-01

    Data assimilation (DA) has the potential of improving hydrologic forecasts. However, many issues arise in case it is employed for spatially distributed hydrologic models that describes processes in various compartments: large dimensionality of the inverse problem, layers governed by different equations, non-linear and discontinuous model structure, complex topology of domains such as surface drainage and river network.On the other hand, integrated models offer the possibility of improving prediction of specific states by exploiting observations of quantities belonging to other compartments. In terms of forecasting river discharges, and hence for their enhancement, soil moisture is a key variable, since it determines the partitioning of rainfall into infiltration and surface runoff. However, soil moisture measurements are affected by issues that could prevent a successful DA and an actual improvement of discharge predictions.In-situ measurements suffer a dramatic spatial scarcity, while observations from satellite are barely accurate and provide spatial information only at a very coarse scale (around 40 km).Hydrologic models that explicitly represent land surface processes of coupled water and energy balance provide a valid alternative to direct DA of soil moisture.They gives the possibility of inferring soil moisture states through DA of remotely sensed Land Surface Temperature (LST), whose measurements are more accurate and with a higher spatial resolution in respect to those of soil moisture. In this work we present the assimilation of LST data in a hydrologic model (Mobidic) that is part of the operational forecasting chain for the Arno river, central Italy, with the aim of improving flood predictions. Mobidic is a raster based, continuous in time and distributed in space hydrologic model, with coupled mass and energy balance at the surface and coupled groundwater and surface hydrology. The variational approach is adopted for DA, since it requires less

  13. Why Does Working Memory Capacity Predict Variation in Reading Comprehension? On the Influence of Mind Wandering and Executive Attention

    McVay, Jennifer C.; Kane, Michael J.

    2011-01-01

    Some people are better readers than others, and this variation in comprehension ability is predicted by measures of working memory capacity (WMC). The primary goal of this study was to investigate the mediating role of mind wandering experiences in the association between WMC and normal individual differences in reading comprehension, as predicted by the executive-attention theory of WMC (e.g., Engle & Kane, 2004). We used a latent-variable, structural-equation-model approach, testing skilled...

  14. Structure based activity prediction of HIV-1 reverse transcriptase inhibitors.

    de Jonge, Marc R; Koymans, Lucien M H; Vinkers, H Maarten; Daeyaert, Frits F D; Heeres, Jan; Lewi, Paul J; Janssen, Paul A J

    2005-03-24

    We have developed a fast and robust computational method for prediction of antiviral activity in automated de novo design of HIV-1 reverse transcriptase inhibitors. This is a structure-based approach that uses a linear relation between activity and interaction energy with discrete orientation sampling and with localized interaction energy terms. The localization allows for the analysis of mutations of the protein target and for the separation of inhibition and a specific binding to the enzyme. We apply the method to the prediction of pIC(50) of HIV-1 reverse transcriptase inhibitors. The model predicts the activity of an arbitrary compound with a q(2) of 0.681 and an average absolute error of 0.66 log value, and it is fast enough to be used in high-throughput computational applications. PMID:15771460

  15. Seasonal variation of CCN concentrations and aerosol activation properties in boreal forest

    S.-L. Sihto

    2011-12-01

    Full Text Available As a part of EUCAARI activities, the annual cycle of cloud condensation nuclei (CCN concentrations and critical diameter for cloud droplet activation as a function of supersaturation were measured using a CCN counter and a HTDMA (hygroscopicity tandem differential mobility analyzer at SMEAR II station, Hyytiälä, Finland. The critical diameters for CCN activation were estimated from (i the measured CCN concentration and particle size distribution data, and (ii the hygroscopic growth factors by applying κ-Köhler theory, in both cases assuming an internally mixed aerosol. The critical diameters derived by these two methods were in good agreement with each other. The effect of new particle formation on the diurnal variation of CCN concentration and critical diameters was studied. New particle formation was observed to increase the CCN concentrations by 70–110%, depending on the supersaturation level. The average value for the κ-parameter determined from hygroscopicity measurements was κ = 0.18 and it predicted well the CCN activation in boreal forest conditions in Hyytiälä. The derived critical diameters and κ-parameter confirm earlier findings with other methods, that aerosol particles at CCN sizes in Hyytiälä are mostly organic, but contain also more hygrosopic, probably inorganic salts like ammonium sulphate, making the particles more CCN active than pure secondary organic aerosol.

  16. Does the ring species concept predict vocal variation in the crimson rosella, Platycercus elegans, complex?

    Ribot, Raoul F. H.; Berg, Mathew L.; Buchanan, Katherine L.; Komdeur, Jan; Joseph, Leo; Bennett, Andrew T. D.

    2009-01-01

    Vocal variation may be important in population divergence. We studied geographical variation in contact calls of parrots of the crimson rosella, Platycercus elegans, complex, which is characterized by striking geographical plumage coloration variation. This complex has long been considered a rare ex

  17. Stroke volume variation does not predict fluid responsiveness in patients with septic shock on pressure support ventilation

    Perner, A; Faber, T

    2006-01-01

    Stroke volume variation (SVV)--as measured by the pulse contour cardiac output (PiCCO) system--predicts the cardiac output response to a fluid challenge in patients on controlled ventilation. Whether this applies to patients on pressure support ventilation is unknown....

  18. Prediction of interindividual variation in drug plasma levels in vivo from individual enzyme kinetic data and physiologically based pharmacokinetic modeling

    Bogaards, J.J.P.; Hissink, E.M.; Briggs, M.; Weaver, R.; Jochemsen, R.; Jackson, P.; Bertrand, M.; Bladeren, P. van

    2000-01-01

    A strategy is presented to predict interindividual variation in drug plasma levels in vivo by the use of physiologically based pharmacokinetic modeling and human in vitro metabolic parameters, obtained through the combined use of microsomes containing single cytochrome P450 enzymes and a human liver

  19. Individual variation in fathers' testosterone reactivity to infant distress predicts parenting behaviors with their 1-year-old infants.

    Kuo, Patty X; Saini, Ekjyot K; Thomason, Elizabeth; Schultheiss, Oliver C; Gonzalez, Richard; Volling, Brenda L

    2016-04-01

    Positive father involvement is associated with positive child outcomes. There is great variation in fathers' involvement and fathering behaviors, and men's testosterone (T) has been proposed as a potential biological contributor to paternal involvement. Previous studies investigating testosterone changes in response to father-infant interactions or exposure to infant cues were unclear as to whether individual variation in T is predictive of fathering behavior. We show that individual variation in fathers' T reactivity to their infants during a challenging laboratory paradigm (Strange Situation) uniquely predicted fathers' positive parenting behaviors during a subsequent father-infant interaction, in addition to other psychosocial determinants of paternal involvement, such as dispositional empathy and marital quality. The findings have implications for understanding fathering behaviors and how fathers can contribute to their children's socioemotional development. © 2015 Wiley Periodicals, Inc. Dev Psychobiol 58: 303-314, 2016. PMID:26497119

  20. TH-A-9A-01: Active Optical Flow Model: Predicting Voxel-Level Dose Prediction in Spine SBRT

    Liu, J; Wu, Q.J.; Yin, F; Kirkpatrick, J; Cabrera, A [Duke University Medical Center, Durham, NC (United States); Ge, Y [University of North Carolina at Charlotte, Charlotte, NC (United States)

    2014-06-15

    Purpose: To predict voxel-level dose distribution and enable effective evaluation of cord dose sparing in spine SBRT. Methods: We present an active optical flow model (AOFM) to statistically describe cord dose variations and train a predictive model to represent correlations between AOFM and PTV contours. Thirty clinically accepted spine SBRT plans are evenly divided into training and testing datasets. The development of predictive model consists of 1) collecting a sequence of dose maps including PTV and OAR (spinal cord) as well as a set of associated PTV contours adjacent to OAR from the training dataset, 2) classifying data into five groups based on PTV's locations relative to OAR, two “Top”s, “Left”, “Right”, and “Bottom”, 3) randomly selecting a dose map as the reference in each group and applying rigid registration and optical flow deformation to match all other maps to the reference, 4) building AOFM by importing optical flow vectors and dose values into the principal component analysis (PCA), 5) applying another PCA to features of PTV and OAR contours to generate an active shape model (ASM), and 6) computing a linear regression model of correlations between AOFM and ASM.When predicting dose distribution of a new case in the testing dataset, the PTV is first assigned to a group based on its contour characteristics. Contour features are then transformed into ASM's principal coordinates of the selected group. Finally, voxel-level dose distribution is determined by mapping from the ASM space to the AOFM space using the predictive model. Results: The DVHs predicted by the AOFM-based model and those in clinical plans are comparable in training and testing datasets. At 2% volume the dose difference between predicted and clinical plans is 4.2±4.4% and 3.3±3.5% in the training and testing datasets, respectively. Conclusion: The AOFM is effective in predicting voxel-level dose distribution for spine SBRT. Partially supported by NIH

  1. Stock price change rate prediction by utilizing social network activities.

    Deng, Shangkun; Mitsubuchi, Takashi; Sakurai, Akito

    2014-01-01

    Predicting stock price change rates for providing valuable information to investors is a challenging task. Individual participants may express their opinions in social network service (SNS) before or after their transactions in the market; we hypothesize that stock price change rate is better predicted by a function of social network service activities and technical indicators than by a function of just stock market activities. The hypothesis is tested by accuracy of predictions as well as performance of simulated trading because success or failure of prediction is better measured by profits or losses the investors gain or suffer. In this paper, we propose a hybrid model that combines multiple kernel learning (MKL) and genetic algorithm (GA). MKL is adopted to optimize the stock price change rate prediction models that are expressed in a multiple kernel linear function of different types of features extracted from different sources. GA is used to optimize the trading rules used in the simulated trading by fusing the return predictions and values of three well-known overbought and oversold technical indicators. Accumulated return and Sharpe ratio were used to test the goodness of performance of the simulated trading. Experimental results show that our proposed model performed better than other models including ones using state of the art techniques. PMID:24790586

  2. The variational nodal method: some history and recent activity

    The variational nodal method combines spherical harmonics expansions in angle with hybrid finite element techniques in space to obtain multigroup transport response matrix algorithms applicable to a wide variety of reactor physics problems. This survey briefly recounts the method's history and reviews its capabilities. Two methods for obtaining discretized equations in the form of response matrices are compared. The first is that contained the widely used VARIANT code, while the second incorporates more recently developed integral transport techniques into the variational nodal framework. The two approaches are combined with a finite sub-element formulation to treat heterogeneous nodes. Results are presented for application to a deep penetration problem and to an OECD benchmark consisting of LWR Mox fuel assemblies. Ongoing work is discussed. (authors)

  3. Predicting Active Users' Personality Based on Micro-Blogging Behaviors

    Lin LI; Li, Ang; Hao, Bibo; Guan, Zengda; Zhu, Tingshao

    2014-01-01

    Because of its richness and availability, micro-blogging has become an ideal platform for conducting psychological research. In this paper, we proposed to predict active users' personality traits through micro-blogging behaviors. 547 Chinese active users of micro-blogging participated in this study. Their personality traits were measured by the Big Five Inventory, and digital records of micro-blogging behaviors were collected via web crawlers. After extracting 845 micro-blogging behavioral fe...

  4. Predicting the Size of Sunspot Cycle 24 on the Basis of Single- and Bi-Variate Geomagnetic Precursor Methods

    Wilson, Robert M.; Hathaway, David H.

    2009-01-01

    Examined are single- and bi-variate geomagnetic precursors for predicting the maximum amplitude (RM) of a sunspot cycle several years in advance. The best single-variate fit is one based on the average of the ap index 36 mo prior to cycle minimum occurrence (E(Rm)), having a coefficient of correlation (r) equal to 0.97 and a standard error of estimate (se) equal to 9.3. Presuming cycle 24 not to be a statistical outlier and its minimum in March 2008, the fit suggests cycle 24 s RM to be about 69 +/- 20 (the 90% prediction interval). The weighted mean prediction of 11 statistically important single-variate fits is 116 +/- 34. The best bi-variate fit is one based on the maximum and minimum values of the 12-mma of the ap index; i.e., APM# and APm*, where # means the value post-E(RM) for the preceding cycle and * means the value in the vicinity of cycle minimum, having r = 0.98 and se = 8.2. It predicts cycle 24 s RM to be about 92 +/- 27. The weighted mean prediction of 22 statistically important bi-variate fits is 112 32. Thus, cycle 24's RM is expected to lie somewhere within the range of about 82 to 144. Also examined are the late-cycle 23 behaviors of geomagnetic indices and solar wind velocity in comparison to the mean behaviors of cycles 2023 and the geomagnetic indices of cycle 14 (RM = 64.2), the weakest sunspot cycle of the modern era.

  5. Effects of intraleaf variations in carbonic anhydrase activity and gas exchange on leaf C18OO isoflux in Zea mays.

    Affek, Hagit P; Krisch, Maria J; Yakir, Dan

    2006-01-01

    Variation in the C18OO content of atmospheric CO2 (delta18Oa) can be used to distinguish photosynthesis from soil respiration, which is based on carbonic anhydrase (CA)-catalyzed 18O exchange between CO2 and 18O-enriched leaf water (delta18Ow). Here we tested the hypothesis that mean leaf delta18Ow and assimilation rates can be used to estimate whole-leaf C18OO flux (isoflux), ignoring intraleaf variations in CA activity and gas exchange parameters. We observed variations in CA activity along the leaf (> 30% decline from the leaf center toward the leaf ends), which were only partially correlated to those in delta18Ow (7 to 21 per thousand), delta18O and delta13C of leaf organic matter (25 to 30 per thousand and -12.8 to -13.2 per thousand, respectively), and substomatal CO2 concentrations (intercellular CO2 concentrations, c(i), at the leaf center were approximately 40% of those at the leaf tip). The combined effect of these variations produced a leaf-integrated isoflux that was different from that predicted based on bulk leaf values. However, because of canceling effects among the influencing parameters, isoflux overestimations were only approximately 10%. Conversely, use of measured parameters from a leaf segment could produce large errors in predicting leaf-integrated C18OO fluxes. PMID:16411935

  6. Short communication: Genetic variation in estrus activity traits

    Løvendahl, P; Chagunda, M G G

    2009-01-01

    with a heritability of 0.18 ± 0.07. The heritability for the period of increased activity was small (0.02 to 0.08) and of similar magnitude as that for the level of activity (0.04 to 0.08). Compared with fertility traits based on artificial insemination field data, activity traits have higher heritability than...

  7. Thermospheric mass density variations during geomagnetic storms and a prediction model based on the merging electric field

    S.-Y. Ma

    2010-09-01

    Full Text Available With the help of four years (2002–2005 of CHAMP accelerometer data we have investigated the dependence of low and mid latitude thermospheric density on the merging electric field, Em, during major magnetic storms. Altogether 30 intensive storm events (Dstmin<−100 nT are chosen for a statistical study. In order to achieve a good correlation Em is preconditioned. Contrary to general opinion, Em has to be applied without saturation effect in order to obtain good results for magnetic storms of all activity levels. The memory effect of the thermosphere is accounted for by a weighted integration of Em over the past 3 h. In addition, a lag time of the mass density response to solar wind input of 0 to 4.5 h depending on latitude and local time is considered. A linear model using the preconditioned Em as main controlling parameter for predicting mass density changes during magnetic storms is developed: ρ=0.5 Em + ρamb, where ρamb is based on the mean density during the quiet day before the storm. We show that this simple relation predicts all storm-induced mass density variations at CHAMP altitude fairly well especially if orbital averages are considered.

  8. Resting alpha activity predicts learning ability in alpha neurofeedback

    Wenya eNan

    2014-07-01

    Full Text Available Individuals differ in their ability to learn how to regulate the alpha activity by neurofeedback. This study aimed to investigate whether the resting alpha activity is related to the learning ability of alpha enhancement in neurofeedback and could be used as a predictor. A total of 25 subjects performed 20 sessions of individualized alpha neurofeedback in order to learn how to enhance activity in the alpha frequency band. The learning ability was assessed by three indices respectively: the training parameter changes between two periods, within a short period and across the whole training time. It was found that the resting alpha amplitude measured before training had significant positive correlations with all learning indices and could be used as a predictor for the learning ability prediction. This finding would help the researchers in not only predicting the training efficacy in individuals but also gaining further insight into the mechanisms of alpha neurofeedback.

  9. Interest rate next-day variation prediction based on hybrid feedforward neural network, particle swarm optimization, and multiresolution techniques

    Lahmiri, Salim

    2016-02-01

    Multiresolution analysis techniques including continuous wavelet transform, empirical mode decomposition, and variational mode decomposition are tested in the context of interest rate next-day variation prediction. In particular, multiresolution analysis techniques are used to decompose interest rate actual variation and feedforward neural network for training and prediction. Particle swarm optimization technique is adopted to optimize its initial weights. For comparison purpose, autoregressive moving average model, random walk process and the naive model are used as main reference models. In order to show the feasibility of the presented hybrid models that combine multiresolution analysis techniques and feedforward neural network optimized by particle swarm optimization, we used a set of six illustrative interest rates; including Moody's seasoned Aaa corporate bond yield, Moody's seasoned Baa corporate bond yield, 3-Month, 6-Month and 1-Year treasury bills, and effective federal fund rate. The forecasting results show that all multiresolution-based prediction systems outperform the conventional reference models on the criteria of mean absolute error, mean absolute deviation, and root mean-squared error. Therefore, it is advantageous to adopt hybrid multiresolution techniques and soft computing models to forecast interest rate daily variations as they provide good forecasting performance.

  10. Individual Variation in Sleep and Motor Activity in Rats

    Tang, Xiangdong; Yang, Linghui; Sanford, Larry D.

    2007-01-01

    We examined individual differences in sleep and motor activity across two consecutive days in rats. EEG and motor activity were recorded via telemetry in Wistar rats (n=29) for 48 h under well-habituated conditions. Rats were grouped based on sleep amounts and stability across days (short [SS, n=7], intermediate [IS, n=15] and long [LS, n=7] sleep) and comparisons were conducted to determine group differences for measures of sleep and motor activity. We found that correlations across recordin...

  11. Predicting active users' personality based on micro-blogging behaviors.

    Lin Li

    Full Text Available Because of its richness and availability, micro-blogging has become an ideal platform for conducting psychological research. In this paper, we proposed to predict active users' personality traits through micro-blogging behaviors. 547 Chinese active users of micro-blogging participated in this study. Their personality traits were measured by the Big Five Inventory, and digital records of micro-blogging behaviors were collected via web crawlers. After extracting 839 micro-blogging behavioral features, we first trained classification models utilizing Support Vector Machine (SVM, differentiating participants with high and low scores on each dimension of the Big Five Inventory [corrected]. The classification accuracy ranged from 84% to 92%. We also built regression models utilizing PaceRegression methods, predicting participants' scores on each dimension of the Big Five Inventory. The Pearson correlation coefficients between predicted scores and actual scores ranged from 0.48 to 0.54. Results indicated that active users' personality traits could be predicted by micro-blogging behaviors.

  12. Prediction of daytime variations of HO2 radical concentrations in the marine boundary layer using BP network

    2010-01-01

    A Back-Propagation Neural Network (BPNN) was established to predict the daytime variations of HO 2 radical concentration observed in the field campaign RISFEX 2003 (RIShiri Fall Experiment 2003) conducted in September 2003 at Rishiri Island (45.07 N,141.12 E,and 35m asl) in the Sea of Japan.The initial weight matrices and bias vectors for the network were optimized by a bee evolutionary genetic algorithm (BEGA).It was found that the input variables sensitive to HO 2 variation were photolysis frequency of O 3 to O(1 D) (J(O 1 D)),a composite parameter defined as the ratio of HC to NO x reactivity towards OH radicals (Φ),and the total aerosol surface area (A).The predicted results are closely correlated with the experimental data with the coefficient of determination (R2) close to 1.In addition,the means and ranges of the predicted HO 2 concentration agree with the observed data with the correlation coefficient (R),the index of agreement (IA) and the fractional bias (FB) in the range of 0.84-0.93,0.88-0.95 and 14%-7%,respectively.This study demonstrates that BPNN is a potential tool to predict the daytime variations of HO 2 radical concentrations in the marine boundary layer (MBL).

  13. Predicting activity approach based on new atoms similarity kernel function.

    Abu El-Atta, Ahmed H; Moussa, M I; Hassanien, Aboul Ella

    2015-07-01

    Drug design is a high cost and long term process. To reduce time and costs for drugs discoveries, new techniques are needed. Chemoinformatics field implements the informational techniques and computer science like machine learning and graph theory to discover the chemical compounds properties, such as toxicity or biological activity. This is done through analyzing their molecular structure (molecular graph). To overcome this problem there is an increasing need for algorithms to analyze and classify graph data to predict the activity of molecules. Kernels methods provide a powerful framework which combines machine learning with graph theory techniques. These kernels methods have led to impressive performance results in many several chemoinformatics problems like biological activity prediction. This paper presents a new approach based on kernel functions to solve activity prediction problem for chemical compounds. First we encode all atoms depending on their neighbors then we use these codes to find a relationship between those atoms each other. Then we use relation between different atoms to find similarity between chemical compounds. The proposed approach was compared with many other classification methods and the results show competitive accuracy with these methods. PMID:26117822

  14. Predictive Active Set Selection Methods for Gaussian Processes

    Henao, Ricardo; Winther, Ole

    2012-01-01

    We propose an active set selection framework for Gaussian process classification for cases when the dataset is large enough to render its inference prohibitive. Our scheme consists of a two step alternating procedure of active set update rules and hyperparameter optimization based upon marginal...... active set parameters that directly control its complexity. We also provide both theoretical and empirical support for our active set selection strategy being a good approximation of a full Gaussian process classifier. Our extensive experiments show that our approach can compete with state...... likelihood maximization. The active set update rules rely on the ability of the predictive distributions of a Gaussian process classifier to estimate the relative contribution of a datapoint when being either included or removed from the model. This means that we can use it to include points with potentially...

  15. Modeling of the diurnal variation of the maximum applicable frequency for radio-communication on short waves considering solar activity

    Method of modeling of the diurnal variation of parameter maximum applicable frequency (MAF) has been developed. The method has been tested by the use of the data of Ionospheric Digital Database of the National Geophysical Data Center (NGDC), Boulder, Colorado, USA, namely, the data of Julruh - (φ=54,5°N). The type of the parameter dependence on solar activity has been studied and a model of diurnal variation of the median values in January has been made. The model is polynomial dependent on F10,7 allowing prediction of MAF. The model is made up according to data of 1958-1986 period. Prognosis was made for the next four years. Error is less than 15% for any hour and it is 10% less in the daytime. The method permits to make models for any point of the Earth (where the measurements are carried out during several cycles of solar activity) for each month. (author)

  16. Platelet Serotonin Transporter Function Predicts Default-Mode Network Activity

    Christian Scharinger; Ulrich Rabl; Christian H. Kasess; Meyer, Bernhard M.; Tina Hofmaier; Kersten Diers; Lucie Bartova; Gerald Pail; Wolfgang Huf; Zeljko Uzelac; Beate Hartinger; Klaudius Kalcher; Thomas Perkmann; Helmuth Haslacher; Andreas Meyer-Lindenberg

    2014-01-01

    Background The serotonin transporter (5-HTT) is abundantly expressed in humans by the serotonin transporter gene SLC6A4 and removes serotonin (5-HT) from extracellular space. A blood-brain relationship between platelet and synaptosomal 5-HT reuptake has been suggested, but it is unknown today, if platelet 5-HT uptake can predict neural activation of human brain networks that are known to be under serotonergic influence. Methods A functional magnetic resonance study was performed in 48 healthy...

  17. Neural activity during encoding predicts false memories created by misinformation

    Okado, Yoko; Stark, Craig E.L.

    2005-01-01

    False memories are often demonstrated using the misinformation paradigm, in which a person's recollection of a witnessed event is altered after exposure to misinformation about the event. The neural basis of this phenomenon, however, remains unknown. We used fMRI to investigate encoding processes during the viewing of an event and misinformation to see whether neural activity during either encoding phase could predict what would be remembered. fMRI data were collected as participants studied ...

  18. Mathematical models for predicting indoor air quality from smoking activity.

    Ott, W R

    1999-01-01

    Much progress has been made over four decades in developing, testing, and evaluating the performance of mathematical models for predicting pollutant concentrations from smoking in indoor settings. Although largely overlooked by the regulatory community, these models provide regulators and risk assessors with practical tools for quantitatively estimating the exposure level that people receive indoors for a given level of smoking activity. This article reviews the development of the mass balanc...

  19. Resource assurance predicts specialist and generalist bee activity in drought

    Minckley, Robert L.; Roulston, T'ai H.; Williams, Neal M.

    2013-01-01

    Many short-lived desert organisms remain in diapause during drought. Theoretically, the cues desert species use to continue diapause through drought should differ depending on the availability of critical resources, but the unpredictability and infrequent occurrence of climate extremes and reduced insect activity during such events make empirical tests of this prediction difficult. An intensive study of a diverse bee–plant community through a drought event found that bee specialists of a drou...

  20. Validation of Predicted Diurnal and Semi-diurnal Tidal Variations in Polar Motion with GPS-based Observations

    Desai, Shailen; Sibois, Aurore

    2016-04-01

    In this paper we reconcile predicted diurnal and semi-diurnal tidal variations in polar motion using observations from the Global Positioning System (GPS) space geodetic technique. We demonstrate closure at the level of less than 4 microarcseconds of the budget between our adopted models for predicted polar motion tidal variations and our GPS-based observations. Our GPS-based observations are composed of a 10-year continuous time series of polar motion estimates with 15-minute temporal resolution. Our adopted models account for the contribution from the relative angular momentum of the ocean tides and so-called libration. We compute predicted ocean tide contributions using a modern hydrodynamic model of tide heights and currents that assimilates satellite altimetry data. We use the model for libration effects provided by the current IERS conventions, as taken from Mathews and Bretagnon [2003]. We also show that the currently recommended models from the International Earth Rotation Service (IERS) conventions do not close the budget with respect to our GPS-based observations. In particular, residual diurnal and semidiurnal tidal variations in polar motion are observed when using the current IERS conventions for ocean tide effects and libration. We infer that the root source for these residual tidal variations is errors in the 20-year old model for ocean tide effects from the IERS conventions, and that predicted ocean tide effects from a modern model mitigates these errors. The noise floor of our high-rate GPS-based times series of polar motion is less than 4 microarcseconds in the diurnal and semidiurnal tidal frequency bands, and is well below the level of the predicted effects of both the ocean tide and libration effects. Diurnal and semidiurnal tidal variations in polar motion are predominantly caused by the ocean tides, which have amplitudes of a few hundred microarcseconds. Libration, namely the effect of external luni-solar torques acting on the triaxial Earth

  1. Model and scenario variations in predicted number of generations of Spodoptera litura Fab. on peanut during future climate change scenario.

    Mathukumalli Srinivasa Rao

    Full Text Available The present study features the estimation of number of generations of tobacco caterpillar, Spodoptera litura. Fab. on peanut crop at six locations in India using MarkSim, which provides General Circulation Model (GCM of future data on daily maximum (T.max, minimum (T.min air temperatures from six models viz., BCCR-BCM2.0, CNRM-CM3, CSIRO-Mk3.5, ECHams5, INCM-CM3.0 and MIROC3.2 along with an ensemble of the six from three emission scenarios (A2, A1B and B1. This data was used to predict the future pest scenarios following the growing degree days approach in four different climate periods viz., Baseline-1975, Near future (NF -2020, Distant future (DF-2050 and Very Distant future (VDF-2080. It is predicted that more generations would occur during the three future climate periods with significant variation among scenarios and models. Among the seven models, 1-2 additional generations were predicted during DF and VDF due to higher future temperatures in CNRM-CM3, ECHams5 & CSIRO-Mk3.5 models. The temperature projections of these models indicated that the generation time would decrease by 18-22% over baseline. Analysis of variance (ANOVA was used to partition the variation in the predicted number of generations and generation time of S. litura on peanut during crop season. Geographical location explained 34% of the total variation in number of generations, followed by time period (26%, model (1.74% and scenario (0.74%. The remaining 14% of the variation was explained by interactions. Increased number of generations and reduction of generation time across the six peanut growing locations of India suggest that the incidence of S. litura may increase due to projected increase in temperatures in future climate change periods.

  2. The health of a nation predicts their mate preferences: cross-cultural variation in women's preferences for masculinized male faces

    DeBruine, Lisa M.; Jones, Benedict C.; Crawford, John R.; Welling, Lisa L. M.; Little, Anthony C.

    2010-01-01

    Recent formulations of sexual selection theory emphasize how mate choice can be affected by environmental factors, such as predation risk and resource quality. Women vary greatly in the extent to which they prefer male masculinity and this variation is hypothesized to reflect differences in how women resolve the trade-off between the costs (e.g. low investment) and benefits (e.g. healthy offspring) associated with choosing a masculine partner. A strong prediction of this trade-off theory is t...

  3. Prefrontal activity predicts monkeys' decisions during an auditory category task

    Jung Hoon Lee

    2009-06-01

    Full Text Available The neural correlates that relate auditory categorization to aspects of goal-directed behavior, such as decision-making, are not well understood. Since the prefrontal cortex plays an important role in executive function and the categorization of auditory objects, we hypothesized that neural activity in the prefrontal cortex (PFC should predict an animal's behavioral reports (decisions during a category task. To test this hypothesis, we tested PFC activity that was recorded while monkeys categorized human spoken words (Russ et al., 2008b. We found that activity in the ventrolateral PFC, on average, correlated best with the monkeys' choices than with the auditory stimuli. This finding demonstrates a direct link between PFC activity and behavioral choices during a non-spatial auditory task.

  4. Variation in activity of pepsin extracted from buffalo stomach mucosa

    Pepsin was extracted from the buffalo's mucosa in an acidic medium by incubating at 40 degree C for 48 h and dried in an air blanket at 50 degree C. Conditions for the maximum yield M pepsin were optimized. Changes in pH, temperature and incubation time affect the yield of pepsin, It has been noted that the time of the year in which extractions were made under optimized conditions was an important factor which affected the yield as well as activity of pepsin. Studies showed that maximum yield 11.5% was in February 2009 and minimum 10.3% in May 2009. It was further studied that the activity of the pepsin extracted in February was higher i.e 110 U/mg as compared to the activity of the enzyme extracted during the month of May which was 102.6 U/mg. The purpose of the study was to consider the conditions of the slaughter houses to attain maximum yield of pepsin with maximum activity. (author)

  5. Variation in Soil Enzyme Activities in a Temperate Agroforestry Watershed

    Integration of agroforestry and grass buffers into row crop watersheds improves overall environmental quality, including soil quality. The objective of this study was to examine management and landscape effects on soil carbon, soil nitrogen, microbial diversity, enzyme activity, and DNA concentrati...

  6. Variation in sexual dimorphism and assortative mating do not predict genetic divergence in the sexually dimorphic Goodeid fish Girardinichthys multiradiatus

    C.MAC(I)AS GARCIA; G SMITH; C.GONZ(A)LEZ ZUARTH; J.A.GRAVES; M.G.RITCHIE

    2012-01-01

    Sexual dimorphism is often used as a proxy for the intensity of sexual selection in comparative studies of sexual selection and diversification.The Mexican Goodeinae are a group of livebearing freshwater fishes with large variation between species in sexual dimorphism in body shape.Previously we found an association between variation in morphological sexual dimorphism between species and the amount of gene flow within populations in the Goodeinae.Here we have examined if morphological differentiation within a single dimorphic species is related to assortative mating or gene flow between populations.In the Amarillo fish Girardinichthys multiradiatus studies have shown that exaggerated male fins are targets of female preferences.We find that populations of the species differ in the level of sexual dimorphism displayed due to faster evolution of differences in male than female morphology.However,this does not predict variation in assortative mating tests in the laboratory; in fact differences in male morphology are negatively correlated with assortative mating.Microsatellite markers reveal significant genetic differences between populations.However,gene flow is not predicted by either morphological differences or assortative mating.Rather,it demonstrates a pattern of isolation by distance with greater differentiation between watersheds.We discuss the caveats of predicting behavioural and genetic divergence from so-called proxies of sexual selection.

  7. Variation in sexual dimorphism and assortative mating do not predict genetic divergence in the sexually dimorphic Goodeid fish Girardinichthys multiradiatus

    C.MACÍAS GARCIA, G.SMITH, C.GONZÁLEZ ZUARTH, J.A. GRAVES,M.G.RITCHIE

    2012-06-01

    Full Text Available Sexual dimorphism is often used as a proxy for the intensity of sexual selection in comparative studies of sexual selection and diversification. The Mexican Goodeinae are a group of livebearing freshwater fishes with large variation between species in sexual dimorphism in body shape. Previously we found an association between variation in morphological sexual dimorphism between species and the amount of gene flow within populations in the Goodeinae. Here we have examined if morphological differentiation within a single dimorphic species is related to assortative mating or gene flow between populations. In the Amarillo fish Girardinichthys multiradiatus studies have shown that exaggerated male fins are targets of female preferences. We find that populations of the species differ in the level of sexual dimorphism displayed due to faster evolution of differences in male than female morphology. However, this does not predict variation in assortative mating tests in the laboratory; in fact differences in male morphology are negatively correlated with assortative mating. Microsatellite markers reveal significant genetic differences between populations. However, gene flow is not predicted by either morphological differences or assortative mating. Rather, it demonstrates a pattern of isolation by distance with greater differentiation between watersheds. We discuss the caveats of predicting behavioural and genetic divergence from so-called proxies of sexual selection [Current Zoology 58 (3: 437-449, 2012].

  8. Daily and seasonal variations of outdoor alpha-activity concentration in Salzburg city/Austria

    Long-term continuous measurements of the atmospheric outdoor alpha-activity concentration have been performed by using a radioaerosol-monitor, roof-mounted 20 m above ground. The alpha-activity concentration was identified to be predominantly attributed to radon progeny. The total alpha-activity covers a range of two orders of magnitude. Three different components of variations could be identified with regard to temporal variations: Short-term diurnal component (daily variation), mid-term component (days to weeks) and long-term component (seasonal variation). Continuous measurements have been recorded since the end of 1993. The results of continuous measurements of the outdoor alpha-activity concentration over a time span from January 1994 to June 1995 are presented. (author)

  9. Assessing effects of variation in global climate data sets on spatial predictions from climate envelope models

    Romanach, Stephanie; Watling, James I.; Fletcher, Robert J., Jr.; Speroterra, Carolina; Bucklin, David N.; Brandt, Laura A.; Pearlstine, Leonard G.; Escribano, Yesenia; Mazzotti, Frank J.

    2014-01-01

    Climate change poses new challenges for natural resource managers. Predictive modeling of species–environment relationships using climate envelope models can enhance our understanding of climate change effects on biodiversity, assist in assessment of invasion risk by exotic organisms, and inform life-history understanding of individual species. While increasing interest has focused on the role of uncertainty in future conditions on model predictions, models also may be sensitive to the initial conditions on which they are trained. Although climate envelope models are usually trained using data on contemporary climate, we lack systematic comparisons of model performance and predictions across alternative climate data sets available for model training. Here, we seek to fill that gap by comparing variability in predictions between two contemporary climate data sets to variability in spatial predictions among three alternative projections of future climate. Overall, correlations between monthly temperature and precipitation variables were very high for both contemporary and future data. Model performance varied across algorithms, but not between two alternative contemporary climate data sets. Spatial predictions varied more among alternative general-circulation models describing future climate conditions than between contemporary climate data sets. However, we did find that climate envelope models with low Cohen's kappa scores made more discrepant spatial predictions between climate data sets for the contemporary period than did models with high Cohen's kappa scores. We suggest conservation planners evaluate multiple performance metrics and be aware of the importance of differences in initial conditions for spatial predictions from climate envelope models.

  10. Generating Novel Allelic Variation Through Activator Insertional Mutagenesis in Maize

    Bai, Ling; Singh, Manjit; Pitt, Lauren; Sweeney, Meredith; Brutnell, Thomas P.

    2007-01-01

    The maize transposable element Activator (Ac) has been exploited as an insertional mutagen to disrupt, clone, and characterize genes in a number of plant species. To develop an Ac-based mutagenesis platform for maize, a large-scale mutagenesis was conducted targeting the pink scutellum1 locus. We selected 1092 Ac transposition events from a closely linked donor Ac, resulting in the recovery of 17 novel ps1 alleles. Multiple phenotypic classes were identified corresponding to Ac insertions in ...

  11. Testing a four-dimensional variational data assimilation method using an improved intermediate coupled model for ENSO analysis and prediction

    Gao, Chuan; Wu, Xinrong; Zhang, Rong-Hua

    2016-07-01

    A four-dimensional variational (4D-Var) data assimilation method is implemented in an improved intermediate coupled model (ICM) of the tropical Pacific. A twin experiment is designed to evaluate the impact of the 4D-Var data assimilation algorithm on ENSO analysis and prediction based on the ICM. The model error is assumed to arise only from the parameter uncertainty. The "observation" of the SST anomaly, which is sampled from a "truth" model simulation that takes default parameter values and has Gaussian noise added, is directly assimilated into the assimilation model with its parameters set erroneously. Results show that 4D-Var effectively reduces the error of ENSO analysis and therefore improves the prediction skill of ENSO events compared with the non-assimilation case. These results provide a promising way for the ICM to achieve better real-time ENSO prediction.

  12. Linear filters as a method of real-time prediction of geomagnetic activity

    Important factors controlling geomagnetic activity include the solar wind velocity, the strength of the interplanetary magnetic field (IMF), and the field orientation. Because these quantities change so much in transit through the solar wind, real-time monitoring immediately upstream of the earth provides the best input for any technique of real-time prediction. One such technique is linear prediction filtering which utilizes past histories of the input and output of a linear system to create a time-invariant filter characterizing the system. Problems of nonlinearity or temporal changes of the system can be handled by appropriate choice of input parameters and piecewise approximation in various ranges of the input. We have created prediction filters for all the standard magnetic indices and tested their efficiency. The filters show that the initial response of the magnetosphere to a southward turning of the IMF peaks in 20 minutes and then again in 55 minutes. After a northward turning, auroral zone indices and the midlatitude ASYM index return to background within 2 hours, while Dst decays exponentially with a time constant of about 8 hours. This paper describes a simple, real-time system utilizing these filters which could predict a substantial fraction of the variation in magnetic activity indices 20 to 50 minutes in advance

  13. Predicting flow at work: investigating the activities and job characteristics that predict flow states at work.

    Nielsen, Karina; Cleal, Bryan

    2010-04-01

    Flow (a state of consciousness where people become totally immersed in an activity and enjoy it intensely) has been identified as a desirable state with positive effects for employee well-being and innovation at work. Flow has been studied using both questionnaires and Experience Sampling Method (ESM). In this study, we used a newly developed 9-item flow scale in an ESM study combined with a questionnaire to examine the predictors of flow at two levels: the activities (brainstorming, planning, problem solving and evaluation) associated with transient flow states and the more stable job characteristics (role clarity, influence and cognitive demands). Participants were 58 line managers from two companies in Denmark; a private accountancy firm and a public elder care organization. We found that line managers in elder care experienced flow more often than accountancy line managers, and activities such as planning, problem solving, and evaluation predicted transient flow states. The more stable job characteristics included in this study were not, however, found to predict flow at work. PMID:20364915

  14. Prediction of Antifungal Activity of Gemini Imidazolium Compounds

    Łukasz Pałkowski

    2015-01-01

    Full Text Available The progress of antimicrobial therapy contributes to the development of strains of fungi resistant to antimicrobial drugs. Since cationic surfactants have been described as good antifungals, we present a SAR study of a novel homologous series of 140 bis-quaternary imidazolium chlorides and analyze them with respect to their biological activity against Candida albicans as one of the major opportunistic pathogens causing a wide spectrum of diseases in human beings. We characterize a set of features of these compounds, concerning their structure, molecular descriptors, and surface active properties. SAR study was conducted with the help of the Dominance-Based Rough Set Approach (DRSA, which involves identification of relevant features and relevant combinations of features being in strong relationship with a high antifungal activity of the compounds. The SAR study shows, moreover, that the antifungal activity is dependent on the type of substituents and their position at the chloride moiety, as well as on the surface active properties of the compounds. We also show that molecular descriptors MlogP, HOMO-LUMO gap, total structure connectivity index, and Wiener index may be useful in prediction of antifungal activity of new chemical compounds.

  15. γ- Irradiation Effect: Variation of Photosynthetic Activity of Euglena

    2002-01-01

    Objective To study the effects of gamma-ray irradiation on carbon fixation (Specific production rate: SPR), CO2 utilization efficiency (CUE) and electron transfer rate (ETR) in the photosynthetic flagellate Euglena gracilis strain Z in a dose-response dependent manner. Methods Euglena cells were cultured in an inorganic nutrient medium containing ammonium chloride or proteose peptone. Cells were exposed to gamma-ray at 5 doses (0, 100, 250, 350, 500 Gy for water). Five days after irradiation, three photosynthetic activities were measured. SPR, which is a carbon uptake rate per unit carbon mass, was determined by 13C tracer methodology. CUE was evaluated using a relation of carbon isotope fractionation in Calvin cycle. ETR in photosystem II (PS II) was measured by a chlorophyll fluorescence analysis. Results Even at a dose of 500 Gy, 80 % of ETR of the non-irradiated control (0 Gy) was sustained, while SPR and CUE were about half the level in the non-irradiated control at 500 Gy. Furthermore, the dose response of ETR was considerably different from the others. Conclusion Our findings suggest that not only PS II but also the Calvin cycle in the photosynthetic system is affected by gamma ray irradiation.

  16. The effects of goal variation on adult physical activity behaviour.

    Moon, Dal-Hyun; Yun, Joonkoo; McNamee, Jeff

    2016-10-01

    The purposes of this study were to examine the effects of varying levels of goals on increasing daily steps and the frequency of goal achievement among middle-aged adults. Ninety-six adults participated in a randomised control study. Participants were randomly assigned to five different step goal groups: (1) Easy (n = 19), (2) Medium (n = 19), (3) Difficult (n = 19), (4) Do-your-best (n = 19), and (5) No goal (n = 20) based on previous research. The participants wore a pedometer and were asked to reach a pre-established goal during the experimental period. In order to examine the effectiveness of the goal difficulty, (a) an average number of steps taken by different goal conditions and (b) the number of days meeting the assigned goal were tested. A one-way ANCOVA revealed significant step count differences among goal groups. Post hoc analyses indicated that the change in step count in both the Medium and Difficult goal groups was significantly greater than the remaining groups. However, there was no significant difference between the medium and difficult goal conditions. In addition, a one-way ANOVA indicated that there were no significant differences in the frequency of goal achievement among the Easy, Medium, and Difficult goal groups. Results suggest that when promoting physical activity through increasing step counts, researchers and clinicians should design goals that are specific and challenging. PMID:26860430

  17. Analysis of Variation Characters and Prediction Model of Soil Temperature in Solar Greenhouse

    2011-01-01

    [Objective] The aim was to study the soil temperature changes and its forecast model in greenhouse by solar heat. [Method] Annual and daily variation characters of soil temperature were analyzed in this paper by using the observation data of air temperature out of solar greenhouse and different layers soil temperature in it. The soil temperature (daily maximum, daily minimum and daily mean) forecasting models were also studied. Simulation and test were conducted to the forecast model of soil temperature in ...

  18. Melanopsin Gene Variations Interact With Season to Predict Sleep Onset and Chronotype

    Roecklein, Kathryn A.; Wong, Patricia M.; Franzen, Peter L.; HASLER, BRANT P.; Wood-Vasey, W. Michael; Nimgaonkar, Vishwajit L.; Miller, Megan A.; Kepreos, Kyle M.; Ferrell, Robert E.; Manuck, Stephen B.

    2012-01-01

    The human melanopsin gene has been reported to mediate risk for seasonal affective disorder (SAD), which is hypothesized to be caused by decreased photic input during winter when light levels fall below threshold, resulting in differences in circadian phase and/or sleep. However, it is unclear if melanopsin increases risk of SAD by causing differences in sleep or circadian phase, or if those differences are symptoms of the mood disorder. To determine if melanopsin sequence variations are asso...

  19. Scarcity of female mates predicts regional variation in men's and women's sociosexual orientation across US states

    Kandrik, Michal; Jones, Benedict C.; DeBruine, Lisa M

    2014-01-01

    Previous studies have linked regional variation in willingness to engage in uncommitted sexual relationships (i.e., sociosexual orientation) to many different socio-ecological measures, such as adult sex ratio, life expectancy, and gross domestic product. However, these studies share a number of potentially serious limitations, including reliance on a single dataset of responses aggregated by country and a failure to properly consider intercorrelations among different socio-ecological measure...

  20. Oxytocin receptor gene variation predicts empathic concern and autonomic arousal while perceiving harm to others

    Karen E. Smith; Porges, Eric C.; Norman, Greg J.; Connelly, Jessica J.; Decety, Jean

    2013-01-01

    Recent research indicates that the neuropeptide oxytocin and the gene for the oxytocin receptor (OXTR) have been implicated in the modulation of various social behaviors, including those related to empathy and sensitivity to others. In this study, we examine the hypothesis that genetic variation in OXTR is associated with autonomic reactions when perceiving others in distress. We also explore the possibility that individual disposition in empathic concern would differ by OXTR genotype. To add...

  1. Variations in solar and geomagnetic activity with periods near to 1.3 year

    Střeštík, Jaroslav

    2009-01-01

    Roč. 1, č. 2 (2009), s. 152-156. ISSN 1896-1517 R&D Projects: GA AV ČR(CZ) IAA300120608 Institutional research plan: CEZ:AV0Z30120515 Keywords : transyear variation * geomagnetic activity * solar activity * wavelet analysis Subject RIV: DE - Earth Magnetism, Geodesy, Geography

  2. The sequential structure of brain activation predicts skill.

    Anderson, John R; Bothell, Daniel; Fincham, Jon M; Moon, Jungaa

    2016-01-29

    In an fMRI study, participants were trained to play a complex video game. They were scanned early and then again after substantial practice. While better players showed greater activation in one region (right dorsal striatum) their relative skill was better diagnosed by considering the sequential structure of whole brain activation. Using a cognitive model that played this game, we extracted a characterization of the mental states that are involved in playing a game and the statistical structure of the transitions among these states. There was a strong correspondence between this measure of sequential structure and the skill of different players. Using multi-voxel pattern analysis, it was possible to recognize, with relatively high accuracy, the cognitive states participants were in during particular scans. We used the sequential structure of these activation-recognized states to predict the skill of individual players. These findings indicate that important features about information-processing strategies can be identified from a model-based analysis of the sequential structure of brain activation. PMID:26707716

  3. Genetic variation and activity of the renin-angiotensin system and severe hypoglycemia in type 1 diabetes

    Pedersen-Bjergaard, U.; Dhamrait, S.S.; Sethi, A.A.;

    2008-01-01

    . lower quartile 2.9, 95% CI, 1.3-6.2), and homo- or hemizygosity for the A-allele of the X chromosome-located AT2R 1675G/A polymorphism (RR vs. noncarriers 2.5, 95% CI, 1.4-5.0). The three risk factors contributed independently to prediction of severe hypoglycemia. A backward multiple regression analysis......BACKGROUND: The deletion-allele of the angiotensin-converting enzyme (ACE) gene and elevated ACE activity are associated with increased risk of severe hypoglycemia in type 1 diabetes. We explored whether genetic and phenotypic variations in other components of the renin-angiotensin system are...... angiotensinogen concentration and serum ACE activity. RESULTS: Three risk factors for severe hypoglycemia were identified: plasma angiotensinogen concentration in the upper quartile (relative rate [RR] vs. lower quartile 3.1, 95% confidence interval [CI,] 1.4-6.8), serum ACE activity in the upper quartile (RR vs...

  4. Climate variability and change on the Mongolian Plateau: historical variation and future predictions

    Jiang, Liguang; Yao, Zhijun; Huang, He Qing

    2016-01-01

    In this study, variations in temperature and precipitation over the Mongolian Plateau are analyzed using Climatic Research Unit monthly observations from 1911 to 2010. In addition, the climatology regime of future climate projections is presented using 16 state-of-the-art global climate models.......5, respectively, and the increases in mean temperature are 3.5 and 7.1 degrees C. The spatial patterns are more complicated. These results suggest that the Mongolian Plateau will experience significant climate warming and accompanying increased precipitation. Adaptation strategies are needed to improve the...

  5. Uncertainties in modeling, prediction, and actions in response to variations in patient geometric models

    Kashani, Rojano

    External beam radiation therapy is an effective method for treating cancer in many body sites. Highly conformal plans can be created to provide good target coverage while sparing the surrounding normal tissue. A fundamental problem in delivering these conformal plans is the inter- and intra-fractional variations in patient geometry, which result in deviation of the delivered dose from the planned dose, thus reducing the probability of tumor control or increasing the risk of normal tissue toxicity. To address this problem, various motion management strategies have been implemented in the clinic, and several others are under investigation. While the technique employed for management of geometric variation can change depending on the type and source of the variation (set up error, respiratory-induced motion and deformation, or tumor shrinkage or tissue loss in response to treatment) as well as other clinical factors, all these techniques have one thing in common and that is the fact that they are not perfect. This work investigates the uncertainties associated with the measurement and management of motion and deformation, and evaluates the impact of these uncertainties on the accuracy of geometry and dose tracking for treatment adaptation. This research quantified the magnitude and distribution of error in deformable image registration for aligning image volumes acquired at different breathing states. It further explored the potential of reducing the registration error in deforming lung geometry, by applying a method from multivariate statistics (principal component analysis) to identify the significant modes of variation in this geometry. It also demonstrated the potential for tracking respiratory induced deformation in various regions in the lung, using a few surrogates such as implanted markers. In addition to the evaluation of registration error for thoracic geometry affected by respiratory motion, this work also investigates the accuracy of deformable image

  6. Predicting physical activity intentions using a goal perspectives approach: a study of Finnish youth.

    Lintunen, T; Valkonen, A; Leskinen, E; Biddle, S J

    1999-12-01

    Physical activity intentions were studied in 12- to 16-year-old Finnish girls (n= 186) and boys (n=215). Theoretical predictions were used to establish a model that was then tested separately for each sex using path analysis. Firstly, it was hypothesised that malleable conceptions of the nature of sport ability positively influence enjoyment in physical activity and intentions to participate in physical activity, mediated by a task-oriented achievement goal independent of variations in perceptions of competence. Secondly, it was hypothesised that fixed conceptions of the nature of ability decrease enjoyment in physical activity and intentions to participate, mediated by an ego-oriented achievement goal and by perceived competence. The modified models were shown to fit the data. Overall, the results showed that 63% (boys) and 45% (girls) of the variance in intentions was explained by the model. The motivational importance of task orientation and, among the boys, perceived physical competence was confirmed with their direct prediction of intentions. PMID:10606099

  7. Methane production and diurnal variation measured in dairy cows and predicted from fermentation pattern and nutrient or carbon flow

    Brask, Maike; Weisbjerg, Martin Riis; Hellwing, Anne Louise Frydendahl;

    2015-01-01

    . Interactions between feed components, VFA absorption rates and variation between animals seemed to be factors that were complicating the accurate prediction of CH(4). Using a ruminal carbon balance appeared to predict CH(4) production just as well as calculations based on rumen digestion of individual....... In the present study, a data set was compiled from the results of three intensive respiration chamber trials with lactating rumen and intestinal fistulated Holstein cows, including measurements of rumen and intestinal digestion, rumen fermentation parameters and CH(4) production. Two approaches were...... for the deviance. Dietary carbohydrate composition and rumen carbohydrate digestion were the main sources of inaccuracies for both models. Furthermore, differences were related to rumen ammonia concentration with the DOM model and to rumen pH and dietary fat with the DCARB model. Adding these...

  8. Recent and Past Musical Activity Predicts Cognitive Aging Variability: Direct Comparison with Leisure Activities

    Brenda eHanna-Pladdy

    2012-07-01

    Full Text Available Studies evaluating the impact of modifiable lifestyle factors on cognition offer potential insights into sources of cognitive aging variability. Recently, we reported an association between extent of musical instrumental practice throughout the life span (greater than 10 years on preserved cognitive functioning in advanced age . These findings raise the question of whether there are training-induced brain changes in musicians that can transfer to nonmusical cognitive abilities to allow for compensation of age-related cognitive declines. However, because of the relationship between engagement in lifestyle activities and preserved cognition, it remains unclear whether these findings are specifically driven by musical training or the types of individuals likely to engage in greater activities in general. The current study examined the type of leisure activity (musical versus other as well as the timing of engagement (age of acquisition, past versus recent in predictive models of successful cognitive aging. Seventy age and education matched older musicians (> 10 years and nonmusicians (ages 59-80 were evaluated on neuropsychological tests and life-style activities (AAP. Partition analyses were conducted on significant cognitive measures to explain performance variance in musicians. Musicians scored higher on tests of phonemic fluency, verbal immediate recall, judgment of line orientation (JLO, and Letter Number Sequencing (LNS, but not the AAP. The first partition analysis revealed education best predicted JLO in musicians, followed by recent musical engagement which offset low education. In the second partition analysis, early age of musical acquisition (< 9 years predicted enhanced LNS in musicians, while analyses for AAP, verbal recall and fluency were not predictive. Recent and past musical activity, but not leisure activity, predicted variability across verbal and visuospatial domains in aging. Early musical acquisition predicted auditory

  9. Prediction of seasonal climate-induced variations in global food production

    Iizumi, Toshichika; Sakuma, Hirofumi; Yokozawa, Masayuki;

    2013-01-01

    attention to the cropping forecasts of important food-exporting countries as well as to their own domestic food production. Given the increased volatility of food markets and the rising incidence of climatic extremes affecting food production, food price spikes may increase in prevalence in future years(2......-4). Here we present a global assessment of the reliability of crop failure hindcasts for major crops at two lead times derived by linking ensemble seasonal climatic forecasts with statistical crop models. We found that moderate-to-marked yield loss over a substantial percentage (26-33 of the harvested area...... of these crops is reliably predictable if climatic forecasts are near perfect. However, only rice and wheat production are reliably predictable at three months before the harvest using within-season hindcasts. The reliabilities of estimates varied substantially by crop-rice and wheat yields were the most...

  10. Common polygenic variation can predict risk of Alzheimer’s disease

    Escott-Price, Valentina; Sims, Rebecca; Bannister, Christian; Harold, Denise; Vronskaya, Maria; Majounie, Elisa; Badarinarayan, Nandini; Morgan, Kevin; Passmore, Peter; Holmes, Clive; Powell, John; Lovestone, Simon; Brayne, Carol; Gill, Michael; Mead, Simon

    2015-01-01

    Background: The identification of subjects at high risk for Alzheimer’s disease is important for prognosis and early intervention. We investigated the polygenic architecture of Alzheimer’s disease (AD) and the accuracy of AD prediction models, including and excluding the polygenic component in the model. Methods: This study used genotype data from the powerful dataset comprising 17,008 cases and 37,154 controls obtained from the International Genomics of Alzheimer’s Project (IGAP). Polygen...

  11. How to evaluate performance of prediction methods? Measures and their interpretation in variation effect analysis

    Vihinen Mauno

    2012-01-01

    Abstract Background Prediction methods are increasingly used in biosciences to forecast diverse features and characteristics. Binary two-state classifiers are the most common applications. They are usually based on machine learning approaches. For the end user it is often problematic to evaluate the true performance and applicability of computational tools as some knowledge about computer science and statistics would be needed. Results Instructions are given on how to interpret and compare me...

  12. Semiannual and UT variation of geomagnetic activity as history of solar-terrestrial physics

    Complete text of publication follows. There are the classical semiannual variation of geomagnetic activity (GA), first recognized by Sabine (1856) and the Universal Time (UT) variation found by McIntosh (1959). Explanation of the semiannual and UT variation of (GA) presents history of development of the solar-terrestrial physics and is a good test for any modern model of interaction taking into account mutual directions of the solar wind velocity (V), interplanetary magnetic field (IMF) and geomagnetic moment (M). It should be noted that the semiannual and UT variation of GA has not explanation in terms of existing mechanisms for now. In particular, the explanation for the dipole tilt modulation of observed activity is still obscure. Axial hypothesis (Bartels, 1932) must be discarded because of its discordance with observations (Swalgaard, 1977). However, influence of the dipole tilt on GA has theoretical ground in terms of quasi-viscous interaction and Kelvin-Helmholtz instability (Boller and Stolov, 1970). Russell and McPherron (RM), 1973 suggested that the solar magnetic fields lying in the solar equatorial plane have maxima of southward Bz component in the GSM c. s. near maxima of GA. Reconnection as a physical paradigm, as applied to the phenomena of solar-terrestrial physics, and the 'RM' mechanism are criticized simultaneously at present (Akasofu, 1998). The UT variations for different mechanisms must be taken into account as they help discriminate between mechanisms: the 'axial' mechanism has no UT variation, the 'RM' mechanism has the wrong UT variation, and so on. All magnetic indices show clear semiannual variations near equinoxes and distorted UT variation due to uneven station distribution. We present all history of the problem. At last based on our results we suggest a possible explanation of semiannual and UT variation of GA (Kuznetsova et al, 2006). Phase of statistical semiannual variation in our study is determined by semiannual variation of value

  13. Statistical estimations for predicting the detection limit of low activities

    When extremely low activities are measured, the statistics of the observed decay events may be insufficient for a justified application of statistical assessments based on the Gaussian distribution. Student's t-distribution and the theory of the interval estimation are used as the basis for a statistical model for predicting the detection limit and the signal-to-noise ratio which could be reached under the conditions of the measurement. The derived statistical estimations are applicable in cases when a small number of decay events is expected to be recorded. The minimum detectable activity characterizing the detection limit under the conditions of the measurement, is determined at the given confidence limits and assumed permissible relative statistical errors during the measurement of the sample and the background (within the available time limits). The derived statistical estimations can be used for comparing the possibilities offered by the different measuring methods applied for determination of extremely low activities. These evaluations can also be used as a criterion for discussing the reliability of the measurement results. (author). 6 refs

  14. Solubility Prediction of Active Pharmaceutical Compounds with the UNIFAC Model

    Nouar, Abderrahim; Benmessaoud, Ibtissem; Koutchoukali, Ouahiba; Koutchoukali, Mohamed Salah

    2016-03-01

    The crystallization from solution of an active pharmaceutical ingredient requires the knowledge of the solubility in the entire temperature range investigated during the process. However, during the development of a new active ingredient, these data are missing. Its experimental determination is possible, but tedious. UNIFAC Group contribution method Fredenslund et al. (Vapor-liquid equilibria using UNIFAC: a group contribution method, 1977; AIChE J 21:1086, 1975) can be used to predict this physical property. Several modifications on this model have been proposed since its development in 1977, modified UNIFAC of Dortmund Weidlich et al. (Ind Eng Chem Res 26:1372, 1987), Gmehling et al. (Ind Eng Chem Res 32:178, 1993), Pharma-modified UNIFAC Diedrichs et al. (Evaluation und Erweiterung thermodynamischer Modelle zur Vorhersage von Wirkstofflöslichkeiten, PhD Thesis, 2010), KT-UNIFAC Kang et al. (Ind Eng Chem Res 41:3260, 2002), ldots In this study, we used UNIFAC model by considering the linear temperature dependence of interaction parameters as in Pharma-modified UNIFAC and structural groups as defined by KT-UNIFAC first-order model. More than 100 binary datasets were involved in the estimation of interaction parameters. These new parameters were then used to calculate activity coefficient and solubility of some molecules in various solvents at different temperatures. The model gives better results than those from the original UNIFAC and shows good agreement between the experimental solubility and the calculated one.

  15. Decreased dopamine activity predicts relapse in methamphetamine abusers

    Studies in methamphetamine (METH) abusers showed that the decreases in brain dopamine (DA) function might recover with protracted detoxification. However, the extent to which striatal DA function in METH predicts recovery has not been evaluated. Here we assessed whether striatal DA activity in METH abusers is associated with clinical outcomes. Brain DA D2 receptor (D2R) availability was measured with positron emission tomography and (11C)raclopride in 16 METH abusers, both after placebo and after challenge with 60 mg oral methylphenidate (MPH) (to measure DA release) to assess whether it predicted clinical outcomes. For this purpose, METH abusers were tested within 6 months of last METH use and then followed up for 9 months of abstinence. In parallel, 15 healthy controls were tested. METH abusers had lower D2R availability in caudate than in controls. Both METH abusers and controls showed decreased striatal D2R availability after MPH and these decreases were smaller in METH than in controls in left putamen. The six METH abusers who relapsed during the follow-up period had lower D2R availability in dorsal striatum than in controls, and had no D2R changes after MPH challenge. The 10 METH abusers who completed detoxification did not differ from controls neither in striatal D2R availability nor in MPH-induced striatal DA changes. These results provide preliminary evidence that low striatal DA function in METH abusers is associated with a greater likelihood of relapse during treatment. Detection of the extent of DA dysfunction may be helpful in predicting therapeutic outcomes.

  16. Decreased dopamine activity predicts relapse in methamphetamine abusers

    Wang G. J.; Wang, G.-J.; Smith, L.; Volkow, N.D.; Telang, F.; Logan, J.; Tomasi, D.; Wong, C.T.; Hoffman, W.; Jayne, M.; Alia-Klein, N.; Thanos, P.; Fowler, J.S.

    2011-01-20

    Studies in methamphetamine (METH) abusers showed that the decreases in brain dopamine (DA) function might recover with protracted detoxification. However, the extent to which striatal DA function in METH predicts recovery has not been evaluated. Here we assessed whether striatal DA activity in METH abusers is associated with clinical outcomes. Brain DA D2 receptor (D2R) availability was measured with positron emission tomography and [{sup 11}C]raclopride in 16 METH abusers, both after placebo and after challenge with 60 mg oral methylphenidate (MPH) (to measure DA release) to assess whether it predicted clinical outcomes. For this purpose, METH abusers were tested within 6 months of last METH use and then followed up for 9 months of abstinence. In parallel, 15 healthy controls were tested. METH abusers had lower D2R availability in caudate than in controls. Both METH abusers and controls showed decreased striatal D2R availability after MPH and these decreases were smaller in METH than in controls in left putamen. The six METH abusers who relapsed during the follow-up period had lower D2R availability in dorsal striatum than in controls, and had no D2R changes after MPH challenge. The 10 METH abusers who completed detoxification did not differ from controls neither in striatal D2R availability nor in MPH-induced striatal DA changes. These results provide preliminary evidence that low striatal DA function in METH abusers is associated with a greater likelihood of relapse during treatment. Detection of the extent of DA dysfunction may be helpful in predicting therapeutic outcomes.

  17. Geographic variation of surface energy partitioning in the climatic mean predicted from the maximum power limit

    Dhara, Chirag; Kleidon, Axel

    2015-01-01

    Convective and radiative cooling are the two principle mechanisms by which the Earth's surface transfers heat into the atmosphere and that shape surface temperature. However, this partitioning is not sufficiently constrained by energy and mass balances alone. We use a simple energy balance model in which convective fluxes and surface temperatures are determined with the additional thermodynamic limit of maximum convective power. We then show that the broad geographic variation of heat fluxes and surface temperatures in the climatological mean compare very well with the ERA-Interim reanalysis over land and ocean. We also show that the estimates depend considerably on the formulation of longwave radiative transfer and that a spatially uniform offset is related to the assumed cold temperature sink at which the heat engine operates.

  18. Predictable variation of range-sizes across an extreme environmental gradient in a lizard adaptive radiation: evolutionary and ecological inferences.

    Daniel Pincheira-Donoso

    Full Text Available Large-scale patterns of current species geographic range-size variation reflect historical dynamics of dispersal and provide insights into future consequences under changing environments. Evidence suggests that climate warming exerts major damage on high latitude and elevation organisms, where changes are more severe and available space to disperse tracking historical niches is more limited. Species with longer generations (slower adaptive responses, such as vertebrates, and with restricted distributions (lower genetic diversity, higher inbreeding in these environments are expected to be particularly threatened by warming crises. However, a well-known macroecological generalization (Rapoport's rule predicts that species range-sizes increase with increasing latitude-elevation, thus counterbalancing the impact of climate change. Here, I investigate geographic range-size variation across an extreme environmental gradient and as a function of body size, in the prominent Liolaemus lizard adaptive radiation. Conventional and phylogenetic analyses revealed that latitudinal (but not elevational ranges significantly decrease with increasing latitude-elevation, while body size was unrelated to range-size. Evolutionarily, these results are insightful as they suggest a link between spatial environmental gradients and range-size evolution. However, ecologically, these results suggest that Liolaemus might be increasingly threatened if, as predicted by theory, ranges retract and contract continuously under persisting climate warming, potentially increasing extinction risks at high latitudes and elevations.

  19. Effect of source variation on drug release from HPMC tablets: linear regression modeling for prediction of drug release.

    Piriyaprasarth, Suchada; Sriamornsak, Pornsak

    2011-06-15

    The aim of this study was to investigate the effect of source variation of hydroxypropyl methylcellulose (HPMC) raw material on prediction of drug release from HPMC matrix tablets. To achieve this objective, the flow ability (i.e., angle of repose and Carr's compressibility index) and apparent viscosity of HPMC from 3 sources was investigated to differentiate HPMC source variation. The physicochemical properties of drug and manufacturing process were also incorporated to develop the linear regression model for prediction of drug release. Specifically, the in vitro release of 18 formulations was determined according to a 2 × 3 × 3 full factorial design. Further regression analysis provided a quantitative relationship between the response and the studied independent variables. It was found that either apparent viscosity or Carr's compressibility index of HPMC powders combining with solubility and molecular weight of drug had significant impact on the release behavior of drug. The increased drug release was observed when a greater in drug solubility and a decrease in the molecular weight of drug were applied. Most importantly, this study has shown that the HPMC having low viscosity or high compressibility index resulted in an increase of drug release, especially in the case of poorly soluble drugs. PMID:21420475

  20. Macroecology of Sexual Selection: A Predictive Conceptual Framework for Large-Scale Variation in Reproductive Traits.

    Machado, Glauco; Buzatto, Bruno A; García-Hernández, Solimary; Macías-Ordóñez, Rogelio

    2016-09-01

    Abiotic factors exert direct and indirect influences on behavioral, morphological, and life-history traits. Because some of these traits are related to reproduction, there is a causal link between climatic conditions and the expression of reproductive traits. This link allows us to generate predictions on how reproductive traits vary in large geographic scales. Here we formalize this macroecological framework, present some general predictions, and explore empirical examples using harvestmen as study organisms. Our results show that the length of breeding season in harvestmen is primarily influenced by the number of warm months and that precipitation plays a secondary role in modulating the period devoted to reproduction. Moreover, we show that the probability of resource defense polygyny increases with longer breeding seasons and that the presence of this type of mating system positively affects the magnitude of sexual dimorphism in harvestmen. Finally, the presence of postovipositional parental care is also influenced by the length of breeding season but not by actual evapotranspiration, which is our proxy for the intensity of biotic interactions. We argue that the macroecological framework proposed here may be a fruitful field of investigation, with important implications for our understanding of sexual selection and the evolution of reproductive traits in both animals and plants. PMID:27513913

  1. Predicting eruptions from precursory activity using remote sensing data hybridization

    Reath, K. A.; Ramsey, M. S.; Dehn, J.; Webley, P. W.

    2016-07-01

    Many volcanoes produce some level of precursory activity prior to an eruption. This activity may or may not be detected depending on the available monitoring technology. In certain cases, precursors such as thermal output can be interpreted to make forecasts about the time and magnitude of the impending eruption. Kamchatka (Russia) provides an ideal natural laboratory to study a wide variety of eruption styles and precursory activity prior to an eruption. At Bezymianny volcano for example, a clear increase in thermal activity commonly occurs before an eruption, which has allowed predictions to be made months ahead of time. Conversely, the eruption of Tolbachik volcano in 2012 produced no discernable thermal precursors before the large scale effusive eruption. However, most volcanoes fall between the extremes of consistently behaved and completely undetectable, which is the case with neighboring Kliuchevskoi volcano. This study tests the effectiveness of using thermal infrared (TIR) remote sensing to track volcanic thermal precursors using data from both the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and Advanced Very High Resolution Radiometer (AVHRR) sensors. It focuses on three large eruptions that produced different levels and durations of effusive and explosive behavior at Kliuchevskoi. Before each of these eruptions, TIR spaceborne sensors detected thermal anomalies (i.e., pixels with brightness temperatures > 2 °C above the background temperature). High-temporal, low-spatial resolution (i.e., ~ hours and 1 km) AVHRR data are ideal for detecting large thermal events occurring over shorter time scales, such as the hot material ejected following strombolian eruptions. In contrast, high-spatial, low-temporal resolution (i.e., days to weeks and 90 m) ASTER data enables the detection of much lower thermal activity; however, activity with a shorter duration will commonly be missed. ASTER and AVHRR data are combined to track low

  2. Acquisition and Active Navigation of Knowledge Particles throughout Product Variation Design Process

    ZHANG Shuyou; XU Jinghua

    2009-01-01

    The variation design of complex products has such features as multivariate association, weak theory coupling and implicit knowledge iteration. However, present CAD soft wares are still restricted to making decisions only according to current design status in dynamic navigation which leads to the huge drain of the knowledge hidden in design process. In this paper, a method of acquisition and active navigation of knowledge particles throughout product variation design process is put forward. The multi-objective decision information model of the variation design is established via the definition of condition attribute set and decision attribute set in finite universe. The addition and retrieval of the variation semantics is achieved through bidirectional association between the transplantable structures and variation design semantics. The mapping relationships between the topology lapping geometry elements set and constraint relations set family is built by means of geometry feature analysis. The acquisition of knowledge particles is implemented by attribute reduction based on rough set theory to make multi-objective decision of variation design. The topology lapping status of transplantable substructures is known from DOF reduction. The active navigation of knowledge particles is realized through embedded event-condition-action(ECA) rules. The independent prototype system taking Alan, Charles, Ian's system(ACIS) as kernel has been developed to verify the proposed method by applying variation design of complex mechanical products. The test results demonstrate that the navigation decision basis can be successfully extended from static isolated design status to dynamic continuous design process so that it more flexibly adapts to the different designers and various variation design steps. It is of profound significance for enhancing system intelligence as well as improving design quality and efficiency.

  3. Changes in the ecosystem structure of the Black Sea under predicted climatological and anthropogenic variations

    Akoglu, Ekin; Salihoglu, Baris; Fach Salihoglu, Bettina; Libralato, Simone; Cannaby, Heather; Oguz, Temel; Solidoro, Cosimo

    2014-05-01

    A dynamic Ecopath with Ecosim higher-trophic-level (HTL) model representation of the Black Sea ecosystem was coupled to the physical (BIMS-CIR) and biogeochemical (BIMS-ECO) models of the Black Sea in order to investigate historical anthropogenic and climatological interactions and feedbacks in the ecosystem. Further, the coupled models were used to assess the likely consequences of these interactions on the ecosystem's structure and functioning under predicted future climate (IPCC A1B) and fishing variability. Therefore, two model scenarios were used; i) a hindcast scenario (1980-1999) to evaluate and understand the impacts of the short-term climate and physical variability and the introduction of invasive species on the Black Sea ecosystem, and ii) a forecast scenario (2080-2099) to investigate the potential implications of climate change and anthropogenic exploitation on living resources of the Black Sea ecosystem by the end of the 21st century. According to the outcomes of the hindcast simulation, fisheries were found to be the main driver in determining the structure and functioning of the Black Sea ecosystem under changing environmental conditions. The coupled physical-biogeochemical forecast simulations predicted a slight but statistically significant basin-wide increase in the Black Sea's primary productivity by the end of the century due to increased stratification induced by basin-wide temperature increase and reduced Cold Intermediate Layer (CIL) formation which increased the residence time of riverine nutrients within the euphotic zone. Despite this increased primary productivity, the HTL model forecast simulation predicted a significant decrease in the commercial fish stocks primarily due to fisheries exploitation if current catch rates are maintained into the future. Results further suggested that some economically important small pelagic fish species are likely to disappear from the ecosystem making the recovery of the already-collapsed piscivorous

  4. A hybrid land use regression/AERMOD model for predicting intra-urban variation in PM2.5

    Michanowicz, Drew R.; Shmool, Jessie L. C.; Tunno, Brett J.; Tripathy, Sheila; Gillooly, Sara; Kinnee, Ellen; Clougherty, Jane E.

    2016-04-01

    Characterizing near-source spatio-temporal variation is a long -standing challenge in air pollution epidemiology, and common intra-urban modeling approaches [e.g., land use regression (LUR)], do not account for short-term meteorological variation. Atmospheric dispersion modeling approaches, such as AERMOD, can account for near-source pollutant behavior by capturing source-meteorological interactions, but requires external validation and resolved background concentrations. In this study, we integrate AERMOD-based predictions for source-specific fine particle (PM2.5) concentrations into LUR models derived from total ambient PM2.5 measured at 36 unique sites selected to represent different source and elevation profiles, during summer and winter, 2012-2013 in Pittsburgh, Pennsylvania (PA). We modeled PM2.5 emissions from 207 local stationary sources in AERMOD, utilizing the monitoring locations as receptors, and hourly meteorological information matching each sampling period. Finally, we compare results of the integrated LUR/AERMOD hybrid model to those of the AERMOD + background and standard LUR models, at the full domain scale and within a 5 km2 sub-domain surrounding a large industrial facility. The hybrid model improved out-of-sample prediction accuracy by 2-10% over LUR alone, though performance differed by season, in part due to within-season temporal variability. We found differences up to 10 μg/m3 in predicted concentrations, and observed the largest differences within the industrial sub-domain. LUR underestimated concentrations from 500 to 2500 m downwind of major sources. The hybrid modeling approach we developed may help to improve intra-urban exposure estimates, particularly in regions of large industrial sources, sharp elevation gradients, or complex meteorology (e.g., frequent inversion events), such as Pittsburgh, PA. More broadly, the approach may inform the development of spatio-temporal modeling frameworks for air pollution exposure assessment for

  5. Individual variation in baseline and stress-induced corticosterone and prolactin levels predicts parental effort by nesting mourning doves

    Miller, David A.; Vleck, Carol M.; Otis, David L.

    2009-01-01

    Endocrine systems have an important mechanistic role in structuring life-history trade-offs. During breeding, individual variation in prolactin (PRL) and corticosterone (CORT) levels affects behavioral and physiological processes that drive trade-offs between reproduction and self-maintenance. We examined patterns in baseline (BL) and stress induced (SI; level following a standard capture-restraint protocol) levels of PRL and CORT for breeding mourning doves (Zenaida macroura). We determined whether the relationship of adult condition and parental effort to hormone levels in wild birds was consistent with life-history predictions. Both BL PRL and BL CORT level in adults were positively related to nestling weight at early nestling ages, consistent with the prediction of a positive relationship of hormone levels to current parental effort of adults and associated increased energy demand. Results are consistent with the two hormones acting together at baseline levels to limit negative effects of CORT on reproduction while maintaining beneficial effects such as increased foraging for nestling feeding. Our data did not support predictions that SI responses would vary in response to nestling or adult condition. The magnitude of CORT response in the parents to our capture-restraint protocol was negatively correlated with subsequent parental effort. Average nestling weights for adults with the highest SI CORT response were on average 10–15% lighter than expected for their age in follow-up visits after the stress event. Our results demonstrated a relationship between individual hormone levels and within population variation in parental effort and suggested that hormonal control plays an important role in structuring reproductive decisions for mourning doves.

  6. Usage of mitochondrial D-loop variation to predict risk for Huntington disease.

    Mousavizadeh, Kazem; Rajabi, Peyman; Alaee, Mahsa; Dadgar, Sepideh; Houshmand, Massoud

    2015-08-01

    Huntington's disease (HD) is an inherited autosomal neurodegenerative disease caused by the abnormal expansion of the CAG repeats in the Huntingtin (Htt) gene. It has been proven that mitochondrial dysfunction is contributed to the pathogenesis of Huntington's disease. The mitochondrial displacement loop (D-loop) is proven to accumulate mutations at a higher rate than other regions of mtDNA. Thus, we hypothesized that specific SNPs in the D-loop may contribute to the pathogenesis of Huntington's disease. In the present study, 30 patients with Huntington's disease and 463 healthy controls were evaluated for mitochondrial mutation sites within the D-loop region using PCR-sequencing method. Sequence analysis revealed 35 variations in HD group from Cambridge Mitochondrial Sequences. A significant difference (p < 0.05) was seen between patients and control group in eight SNPs. Polymorphisms at C16069T, T16126C, T16189C, T16519C and C16223T were correlated with an increased risk of HD while SNPs at C16150T, T16086C and T16195C were associated with a decreased risk of Huntington's disease. PMID:24471944

  7. Oxytocin receptor gene variation and differential susceptibility to family environment in predicting youth borderline symptoms.

    Hammen, Constance; Bower, Julienne E; Cole, Steven W

    2015-04-01

    Oxytocin appears to be centrally involved in socioemotional functioning, and is hypothesized to be relevant to the severe disruption in close relationships characteristic of borderline personality pathology. We examined whether a polymorphism of the oxytocin receptor gene (OXTR rs53576) interacts with quality of family functioning to predict borderline personality disorder (BPD) symptomatology in a sample of youth at age 20. A total of 385 youth from a longitudinal study of offspring of depressed or nondepressed mothers who were well characterized with respect to their family conditions and BPD symptomatology provided DNA for genotyping. Analyses revealed a significant moderation of the link between early family quality and later BPD symptoms by OXTR rs53576, and the pattern was consistent with differential susceptibility (plasticity). Whereas A-allele carriers had high levels of BPD symptoms under negative family conditions and low levels under positive conditions, GG homozygotes had average levels of BPD symptoms regardless of their family quality. PMID:25102084

  8. Temperament variation in sensitivity to parenting: predicting changes in depression and anxiety.

    Kiff, Cara J; Lengua, Liliana J; Bush, Nicole R

    2011-11-01

    Temperament was examined as a moderator of maternal parenting behaviors, including warmth, negativity, autonomy granting, and guidance. Observations of parenting and questionnaire measures of temperament and adjustment were obtained from a community sample (N = 214; ages 8-12). Trajectories of depression and anxiety were assessed across 3 years. The pattern of parenting as a predictor of internalizing symptoms depended on temperament. Maternal negativity predicted increases in depression for children low in fear. Effortful control moderated sensitivity to maternal negativity, autonomy granting, and guidance. Children low in effortful control reported more symptoms in the presence of negative or poor-fitting parenting. The results support differential responding, but also suggest that temperament may render children vulnerable for the development of problems regardless of parenting. PMID:21800017

  9. Latitudinal Variation in Carbon Storage Can Help Predict Changes in Swamps Affected by Global Warming

    Middleton, Beth A.; McKee, Karen

    2004-01-01

    Plants may offer our best hope of removing greenhouse gases (gases that contribute to global warming) emitted to the atmosphere from the burning of fossil fuels. At the same time, global warming could change environments so that natural plant communities will either need to shift into cooler climate zones, or become extirpated (Prasad and Iverson, 1999; Crumpacker and others, 2001; Davis and Shaw, 2001). It is impossible to know the future, but studies combining field observation of production and modeling can help us make predictions about what may happen to these wetland communities in the future. Widespread wetland types such as baldcypress (Taxodium distichum) swamps in the southeastern portion of the United States could be especially good at carbon sequestration (amount of CO2 stored by forests) from the atmosphere. They have high levels of production and sometimes store undecomposed dead plant material in wet conditions with low oxygen, thus keeping gases stored that would otherwise be released into the atmosphere (fig. 1). To study the ability of baldcypress swamps to store carbon, our project has taken two approaches. The first analysis looked at published data to develop an idea (hypothesis) of how production levels change across a temperature gradient in the baldcypress region (published data study). The second study tested this idea by comparing production levels across a latitudinal range by using swamps in similar field conditions (ongoing carbon storage study). These studies will help us make predictions about the future ability of baldcypress swamps to store carbon in soil and plant biomass, as well as the ability of these forests to shift northward with global warming.

  10. Predicting cell types and genetic variations contributing to disease by combining GWAS and epigenetic data.

    Anna Gerasimova

    Full Text Available Genome-wide association studies (GWASs identify single nucleotide polymorphisms (SNPs that are enriched in individuals suffering from a given disease. Most disease-associated SNPs fall into non-coding regions, so that it is not straightforward to infer phenotype or function; moreover, many SNPs are in tight genetic linkage, so that a SNP identified as associated with a particular disease may not itself be causal, but rather signify the presence of a linked SNP that is functionally relevant to disease pathogenesis. Here, we present an analysis method that takes advantage of the recent rapid accumulation of epigenomics data to address these problems for some SNPs. Using asthma as a prototypic example; we show that non-coding disease-associated SNPs are enriched in genomic regions that function as regulators of transcription, such as enhancers and promoters. Identifying enhancers based on the presence of the histone modification marks such as H3K4me1 in different cell types, we show that the location of enhancers is highly cell-type specific. We use these findings to predict which SNPs are likely to be directly contributing to disease based on their presence in regulatory regions, and in which cell types their effect is expected to be detectable. Moreover, we can also predict which cell types contribute to a disease based on overlap of the disease-associated SNPs with the locations of enhancers present in a given cell type. Finally, we suggest that it will be possible to re-analyze GWAS studies with much higher power by limiting the SNPs considered to those in coding or regulatory regions of cell types relevant to a given disease.

  11. Variation in contents of main active components and antioxidant activity in leaves of different pigeon pea cultivars during growth.

    Wei, Zuo-Fu; Jin, Shuang; Luo, Meng; Pan, You-Zhi; Li, Ting-Ting; Qi, Xiao-Lin; Efferth, Thomas; Fu, Yu-Jie; Zu, Yuan-Gang

    2013-10-23

    Pigeon pea is an important and multiuse grain legume crop, and its leaves are a very valuable natural resource. To obtain a high-quality biological resource, it is necessary to choose the excellent cultivar and determine the appropriate harvest time. In this study, the variation in contents of main active components and antioxidant activity in leaves of six pigeon pea cultivars during growth were investigated. The level of each individual active component significantly varied during growth, but with a different pattern, and this variation was different among cultivars. Flavonoid glycosides orientin, vitexin, and apigenin-6,8-di-C-α-L-arabinopyranoside showed two peak values at mid-late and final stages of growth in most cases. Pinostrobin chalcone, longistyline C, and cajaninstilbene acid showed remarkablely higher values at the mid-late stage of growth than at other stages. Pinostrobin had an extremely different variation pattern compared to other active components. Its content was the highest at the earlier stage of growth. Principal component analysis (PCA) revealed that vitexin and apigenin-6,8-di-C-α-L-arabinopyranoside were mainly responsible for distinguishing cultivars analyzed. In a comprehensive consideration, the leaves should preferentially be harvested at the 135th day after sowing when the level of active components and antioxidant activity reached higher values. Cultivars ICP 13092, ICPL 87091, and ICPL 96053 were considered to be excellent cultivars with high antioxidant activity. Our findings can provide valuable information for producing a high-quality pigeon pea resource. PMID:24066714

  12. Brain monoamine oxidase A activity predicts trait aggression.

    Alia-Klein, Nelly; Goldstein, Rita Z; Kriplani, Aarti; Logan, Jean; Tomasi, Dardo; Williams, Benjamin; Telang, Frank; Shumay, Elena; Biegon, Anat; Craig, Ian W; Henn, Fritz; Wang, Gene-Jack; Volkow, Nora D; Fowler, Joanna S

    2008-05-01

    The genetic deletion of monoamine oxidase A (MAO A), an enzyme that breaks down the monoamine neurotransmitters norepinephrine, serotonin, and dopamine, produces aggressive phenotypes across species. Therefore, a common polymorphism in the MAO A gene (MAOA, Mendelian Inheritance in Men database number 309850, referred to as high or low based on transcription in non-neuronal cells) has been investigated in a number of externalizing behavioral and clinical phenotypes. These studies provide evidence linking the low MAOA genotype and violent behavior but only through interaction with severe environmental stressors during childhood. Here, we hypothesized that in healthy adult males the gene product of MAO A in the brain, rather than the gene per se, would be associated with regulating the concentration of brain amines involved in trait aggression. Brain MAO A activity was measured in vivo in healthy nonsmoking men with positron emission tomography using a radioligand specific for MAO A (clorgyline labeled with carbon 11). Trait aggression was measured with the multidimensional personality questionnaire (MPQ). Here we report for the first time that brain MAO A correlates inversely with the MPQ trait measure of aggression (but not with other personality traits) such that the lower the MAO A activity in cortical and subcortical brain regions, the higher the self-reported aggression (in both MAOA genotype groups) contributing to more than one-third of the variability. Because trait aggression is a measure used to predict antisocial behavior, these results underscore the relevance of MAO A as a neurochemical substrate of aberrant aggression. PMID:18463263

  13. Variation in energy expenditure among black-legged kittiwakes : Effects of activity-specific metabolic rates and activity budgets

    Jodice, PGR; Roby, DD; Suryan, RM; Irons, DB; Kaufman, AM; Turco, KR; Visser, GH

    2003-01-01

    We sought to determine the effect of variation in time-activity budgets (TABs) and foraging behavior on energy expenditure rates of parent black-legged kittiwakes (Rissa tridactyla). We quantified TABs using direct observations of radio-tagged adults and simultaneously measured field metabolic rates

  14. Periodic Hα variations in GL 581: Further evidence for an activity origin to GL 581d

    Hatzes, A. P.

    2016-01-01

    Context. Radial velocity measurements initially showed evidence that the M dwarf GL 581 might host up to six planetary companions. Two of these, GL 581g and GL 581d had orbital distances in the so-called "habitable zone" of the star. The existence of both of these planets have been called into question. Additional radial velocity measurements for GL 581g could not confirm its presence. A study of Hα in GL 581 showed that changes in this activity indicator correlated with radial velocity variations attributed to GL 581d. Thus two planets that were important for studies of habitable planets may be artifacts of stellar activity. Aims: Previous investigations analyzing the same activity data have reached different conclusions regarding the existence of GL 581d. We therefore investigated the Hα variations for GL 581 to assess the nature of the radial velocity variations attributed to the possible planet GL 581d. Methods: We performed a Fourier analysis of the published Hα measurements for GL 581. Fourier components were selectively found and removed in a so-called pre-whitening process thus isolating any variations at the orbital frequency of GL 581d. Results: The frequency analysis yields five significant frequencies, one of which is associated with the 66.7 d orbital period of the presumed planet Gl 581d. The Hα variations at this period show sine-like variations that are 180° out-of-phase with the radial velocity variations of GL 581d. This is seen in the full data set that spans almost 7 years, as well as a subset of the data near the end of the time series that had good temporal sampling over 230 days. Furthermore, no significant temporal variations are found in the ratio of the amplitudes of the Hα index and radial velocity variations. This provides additional evidence that the radial velocity signal attributed to GL 581d is in fact due to stellar activity. Conclusions: The analysis confirms the anti-correlation of the radial velocity of GL 581d with the H

  15. The prediction of induced activity levels in and around NIMROD

    Hack, R C

    1973-01-01

    Comparisons are reported between measured and predicted levels of induced radioactivity for a number of irradiation conditions. Good agreement was found between experimental measurements and fairly simple methods of prediction developed at CERN.

  16. Assessing the impact of climate variability and human activities on streamflow variation

    Chang, J.; Zhang, H.; Wang, Y.; Zhu, Y

    2015-01-01

    Water resources in river systems have been changing under the impact of both climate variability and human activities. Assessing the respective impact on decadal streamflow variation is important for water resource management. By using an elasticity-based method and calibrated TOPMODEL and VIC hydrological models, we quantitatively isolated the relative contributions that human activities and climate variability made to decadal streamflow changes in Jinghe basin, located in ...

  17. Assessing the impact of climate variability and human activity to streamflow variation

    Chang, J.; Zhang, H.; Wang, Y.; Zhu, Y

    2015-01-01

    Water resources in river systems have been changing under the impacts of both climate variability and human activities. Assessing the respective impacts on decadal streamflow variation is important for water resources management. By using an elasticity-based method, calibrated TOPMODEL and VIC hydrologic models, we have quantitatively isolated the relative contributions that human activity and climate variability made to decadal streamflow changes in Jinhe b...

  18. Assessing the impact of climate variability and human activities on streamflow variation

    Chang, Jianxia; Zhang, Hongxue; Wang, Yimin; Zhu, Yuelu

    2016-01-01

    Water resources in river systems have been changing under the impact of both climate variability and human activities. Assessing the respective impact on decadal streamflow variation is important for water resource management. By using an elasticity-based method and calibrated TOPMODEL and VIC hydrological models, we quantitatively isolated the relative contributions that human activities and climate variability made to decadal streamflow changes in the Jinghe basin, located...

  19. Accelerometer based Activity Classification with Variational Inference on Sticky HDP-SLDS

    Basbug, Mehmet Emin; Ozcan, Koray; Velipasalar, Senem

    2015-01-01

    As part of daily monitoring of human activities, wearable sensors and devices are becoming increasingly popular sources of data. With the advent of smartphones equipped with acceloremeter, gyroscope and camera; it is now possible to develop activity classification platforms everyone can use conveniently. In this paper, we propose a fast inference method for an unsupervised non-parametric time series model namely variational inference for sticky HDP-SLDS(Hierarchical Dirichlet Process Switchin...

  20. Characterisation of regional variations in a stitched CMOS active pixel sensor

    Stitched, large area, complementary metal-oxide-semiconductor (CMOS), active pixel sensors (APS) show promises for X-ray imaging applications. In this paper we present an investigation of the effects of stitching on uniformity of sensor response for an experimental APS. The sensor, known as LAS (large area sensor), was made by reticular stitching onto a single silicon wafer of a 5x5 array of regions consisting of 270x270 pixels with 40 μm pixel pitch, to yield 1350x1350 pixels and an imaging area of 54x54 mm. Data acquired from two different sensors of the same type were filtered to remove spiking pixels and electromagnetic interference (EMI). The non-linear compensation (NLC) technique for CMOS sensor analysis was used to determine the variation in gain, read noise, full well capacity and dynamic range between stitched regions. Variations across stitched regions were analysed using profiles, analysis of pixel variations at stitch boundaries and using a measurement of non-uniformity within a stitched region. The results showed that non-uniformity variations were present, which increased with signal (1.5-3.5% at dark signal, rising to 3-8%). However, these were found to be smaller than variations caused by differences in readout electronics, particularly at low signal levels. The results suggest these variations should be correctable using standard calibration methods.

  1. Genotypic and Environmental Variations of Arabinoxylan Content and Endoxylanase Activity in Barley Grains

    ZHANG Xiao-qin; XUE Da-wei; WU Fei-bo; ZHANG Guo-ping

    2013-01-01

    Arabinoxylan (AX) content in barley grains is an important quality determinant when barley is used as raw material of malt or beer production. The cultivar and environmental variations of total arabinoxylan (TAX), water extractable arabinoxylan (WEAX) and endoxylanase activity (EA) were investigated using eight barley cultivars growing at seven locations with diverse environmental conditions. The results showed that both barley cultivar and location significantly affected the TAX, WEAX and EA levels, but the variations of TAX content and EA were mainly attributed to cultivar, while the impact of location on WEAX content was greater than that of cultivar. Correlation analysis indicated that TAX was significantly correlated to WUAX.

  2. Periodic Halpha variations in GL 581: Further evidence for an activity origin to GL 581d

    Hatzes, Artie P

    2015-01-01

    Radial velocity measurements showed evidence that the M dwarf GL 581 might host a planet, GL 581d, in the so-called "habitable zone" of the star. A study of Halpha in GL 581 demonstrated that changes in this activity indicator correlated with radial velocity variations attributed to GL 581d. An exopplanet that was important for studies of planet habitability may be an artifact of stellar activity. Previous investigations analyzing the same activity data have reached different conclusions regarding the existence of GL 581d. We therfore investigated the Halpha variations for GL 581 to assess the nature of the radial velocity variations attributed to the possible planet GL 581d. We performed a Fourier analysis of the published Halpha measurements for GL 581d using a so-called pre-whitening process to isolate the variations at the orbital frequency of GL 581d. The frequency analysis yields five significant frequencies, one of which is associated with the 66.7 d orbital period of the presumed planet Gl 581d. The H...

  3. The GEO Water Strategy: Advances in Monitoring, Modeling, and Predicting Groundwater Variations at Regional to Local Scales

    Miller, N. L.; Heinrich, L.; Kukuri, N.; Plag, H.; Famiglietti, J. S.; Rodell, M.

    2012-12-01

    Groundwater remains one of the most important freshwater resources, especially during droughts and as global warming increases. For informed decisions on managing these resources sustainably, it is important to have sound assessments of the current state of groundwater resources as well as future predictions. This requires reliable groundwater quantity and quality data. However global access to this data is limited. As part of the GEOSS Water Strategy, the International Groundwater Assessment Centre (IGRAC) is therefore implementing the Global Groundwater Monitoring Network (GGMN). The GGMN facilitates periodic assessments of changes in groundwater quantity and quality by aggregating data and information from existing groundwater monitoring networks and regional hydrogeological knowledge (Fig. 1). The GGMN is a participatory process that relies upon contributions from regional and national networks of groundwater experts. Such observation data, along with local well data, surface displacements observed by and GPS data and InSAR, and local in situ gravity data, are necessary for evaluation and simulation of groundwater, leading to improved understanding and prediction of groundwater variations. In conjunction with these observations, regional scale groundwater variations are derived as a residual from land surface-groundwater models through extraction of the total mass of water using geo-rectified Gravity Recovery and Climate Experiment (GRACE) data. Such model-based studies have quantified overdraft and regions at risk of groundwater depletion in parts of Asia, US, and Africa (Fig. 2).We provide an overview of these systems, planned missions, and new model-based approaches toward local-scale methods for assimilation of well data for several regions.igure 1. Example of GGMN (Example of Botswana with fictitious data, with local precipitation map) igure 2. GRACE-derived groundwater storage in northwestern India for 2002 - 2008, relative to the mean. Deviations from

  4. Use of systolic pressure variation to predict the cardiovascular response to mini-fluid challenge in anaesthetised dogs.

    Rabozzi, R; Franci, P

    2014-11-01

    Systolic pressure variation (SPV), the maximum variation in systolic pressure values following a single positive pressure breath delivered by controlled mechanical ventilation (CMV), is highly correlated with volaemia in dogs. The aim of this study was to determine an SPV value that would indicate when fluid administration would be beneficial in clinical practice. Twenty-six client-owned dogs were anaesthetised, following which CMV with a peak inspiratory pressure (PIP) of 8 cmH2O was applied. After SPV measurement and recording of heart rate (HR) and blood pressure (BP), 3 mL/kg fluid were administered, then HR and BP were recorded again. Dogs exhibiting a 10% decrease in HR and/or an increase in BP were defined as responders, and their SPV pre-bolus was analysed retrospectively. SPV values > 4 mmHg or >4.5% predicted haemodynamic improvement in dogs with normal cardiovascular function, with a sensitivity of 90% and a specificity of 87%. The area under the curve receiver operating characteristic value for SPV was 0.931 mmHg (95% confidence interval, CI, 0.76-0.99 mmHg) and 0.944% (95% CI 0.78-0.99%). It is proposed that SPV values > 4.5% in dogs with a normal cardiovascular function, anaesthetised with isoflurane in oxygen and air, and on CMV (PIP 8 cmH2O), can be used to predict a cardiovascular response (>10% increase in mean arterial BP and/or >10% decrease in heart rate). PMID:25199508

  5. Predictive active disturbance rejection control for processes with time delay.

    Zheng, Qinling; Gao, Zhiqiang

    2014-07-01

    Active disturbance rejection control (ADRC) has been shown to be an effective tool in dealing with real world problems of dynamic uncertainties, disturbances, nonlinearities, etc. This paper addresses its existing limitations with plants that have a large transport delay. In particular, to overcome the delay, the extended state observer (ESO) in ADRC is modified to form a predictive ADRC, leading to significant improvements in the transient response and stability characteristics, as shown in extensive simulation studies and hardware-in-the-loop tests, as well as in the frequency response analysis. In this research, it is assumed that the amount of delay is approximately known, as is the approximated model of the plant. Even with such uncharacteristic assumptions for ADRC, the proposed method still exhibits significant improvements in both performance and robustness over the existing methods such as the dead-time compensator based on disturbance observer and the Filtered Smith Predictor, in the context of some well-known problems of chemical reactor and boiler control problems. PMID:24182516

  6. An improved model for predicting performance of finned tube heat exchanger under frosting condition, with frost thickness variation along fin

    Tso, C.P. [Multimedia University, Jalan Ayer Keroh Lama, Melaka (Malaysia). Faculty of Engineering and Technology; Cheng, Y.C.; Lai, A.C.K. [Nanyang Technological University, Singapore (Singapore). School of Mechanical and Aerospace Engineering

    2006-01-15

    Frost accumulation on a heat exchanger, a direct result of combined heat and mass transfer between the moist air flowing across a cold surface, causes heat transfer performance degradation due to the insulating effect of frost layer and the coil blockage as the frost grows. The complex geometry of finned tube heat exchangers leads to uneven wall and air temperature distribution inside the coil, and causes variations of frost growth rate and densification along the coil. In this study, a general distributed model with frost formation was developed. The equations for finned tube heat exchanger were derived in non-steady-state manner and quasi-steady state in the frost model. In order to make the model more realistic, the variation of frost along fin due to uneven temperature distribution was included. The presented model is able to predict the dynamic behavior of an air cooler both under non-frost and frost condition. Comparisons were made based on the frost mass accumulation, pressure drop across coil and energy transfer coefficient, and results were found to agree well with reported experimental results. (author)

  7. Pre-mining variation of alpha activity intake in shells of fresh water mussels

    Specific alpha activity distribution in fresh water mussel shells has been studied for mussels collected from several billabongs in the uranium province in the Northern Territory. Track etch detector Kodak LR-115 was exposed to alpha particles emitted from surface areas of shells previously dated by growth-rings counting procedures. The annual average alpha activity was calculated from alpha emission track etch densities corresponding to the dated areas on the shell surfaces. An interesting correlation between the annual rainfall and corresponding annual average shell activity was observed. The results demonstrated that this method could indicate aspects of variations in natural pre-mining radiation background of billabongs which are the source of some of the traditional diet components, suvh as mussels, for local aboriginals. The evaluation of the future influence of uranium mining on the levels of radiation likely to be taken up into diet components must take careful consideration of these observed variations in natural background radiation

  8. Pre-mining variation of alpha activity intake in shells of fresh water mussels

    Kvasnicka, J.; McNally, P.; McKay, T. (Northern Territory Dept. of Mines and Energy, Darwin (Australia)); Allison, H. (Office of the Supervising Scientist for the Alligator Rivers Region, Sydney (Australia)); Bywater, J. (Ranger Uranium Mines Proprietary Ltd., Chatswood (Australia))

    1985-04-01

    Specific alpha activity distribution in fresh water mussel shells has been studied for mussels collected from several billabongs in the uranium province in the Northern Territory. Track etch detector Kodak LR-115 was exposed to alpha particles emitted from surface areas of shells previously dated by growth-rings counting procedures. The annual average alpha activity was calculated from alpha emission track etch densities corresponding to the dated areas on the shell surfaces. An interesting correlation between the annual rainfall and corresponding annual average shell activity was observed. The results demonstrated that this method could indicate aspects of variations in natural pre-mining radiation background of billabongs which are the source of some of the traditional diet components, such as mussels, for local aboriginals. The evaluation of the future influence of uranium mining on the levels of radiation likely to be taken up into diet components must take careful consideration of these observed variations in natural background radiation.

  9. On temporal variation of Ceasium isotopes activities in airborne and fallout

    Monthly variations of Cs-137 and Cs-134 activities in airborne and fallout collected in Dalat from 1986 to 1991 are presented. The variations exhibit distinct maxima in December-January, when dry fallout was predominant. The observed peaks are explained by the intrusion of cold air masses with higher radioactivity from temperate latitudes during the development of large-scale anticyclones frequently observed in the most active winter monsoon period. Very high dry fallout velocity (about 10 cm/s) determined from the airborne and fallout activities clearly demonstrates one of the most relevant characteristics of cold air masses: behind the cold front vertical air motion is descending.(Authors) (1 Fig. 2 Tables)

  10. Seasonal divergence in the interannual responses of Northern Hemisphere vegetation activity to variations in diurnal climate

    Wu, Xiuchen; Liu, Hongyan; Li, Xiaoyan; Liang, Eryuan; Beck, Pieter S. A.; Huang, Yongmei

    2016-01-01

    Seasonal asymmetry in the interannual variations in the daytime and nighttime climate in the Northern Hemisphere (NH) is well documented, but its consequences for vegetation activity remain poorly understood. Here, we investigate the interannual responses of vegetation activity to variations of seasonal mean daytime and nighttime climate in NH (>30 °N) during the past decades using remote sensing retrievals, FLUXNET and tree ring data. Despite a generally significant and positive response of vegetation activity to seasonal mean maximum temperature () in ~22-25% of the boreal (>50 °N) NH between spring and autumn, spring-summer progressive water limitations appear to decouple vegetation activity from the mean summer , particularly in climate zones with dry summers. Drought alleviation during autumn results in vegetation recovery from the marked warming-induced drought limitations observed in spring and summer across 24-26% of the temperate NH. Vegetation activity exhibits a pervasively negative correlation with the autumn mean minimum temperature, which is in contrast to the ambiguous patterns observed in spring and summer. Our findings provide new insights into how seasonal asymmetry in the interannual variations in the mean daytime and nighttime climate interacts with water limitations to produce spatiotemporally variable responses of vegetation growth.

  11. Experimental and analytical study of secondary path variations in active engine mounts

    Hausberg, Fabian; Scheiblegger, Christian; Pfeffer, Peter; Plöchl, Manfred; Hecker, Simon; Rupp, Markus

    2015-03-01

    Active engine mounts (AEMs) provide an effective solution to further improve the acoustic and vibrational comfort of passenger cars. Typically, adaptive feedforward control algorithms, e.g., the filtered-x-least-mean-squares (FxLMS) algorithm, are applied to cancel disturbing engine vibrations. These algorithms require an accurate estimate of the AEM active dynamic characteristics, also known as the secondary path, in order to guarantee control performance and stability. This paper focuses on the experimental and theoretical study of secondary path variations in AEMs. The impact of three major influences, namely nonlinearity, change of preload and component temperature, on the AEM active dynamic characteristics is experimentally analyzed. The obtained test results are theoretically investigated with a linear AEM model which incorporates an appropriate description for elastomeric components. A special experimental set-up extends the model validation of the active dynamic characteristics to higher frequencies up to 400 Hz. The theoretical and experimental results show that significant secondary path variations are merely observed in the frequency range of the AEM actuator's resonance frequency. These variations mainly result from the change of the component temperature. As the stability of the algorithm is primarily affected by the actuator's resonance frequency, the findings of this paper facilitate the design of AEMs with simpler adaptive feedforward algorithms. From a practical point of view it may further be concluded that algorithmic countermeasures against instability are only necessary in the frequency range of the AEM actuator's resonance frequency.

  12. Leisure time physical activity in the Framingham Offspring Study. Description, seasonal variation, and risk factor correlates.

    Dannenberg, A L; Keller, J B; Wilson, P W; Castelli, W P

    1989-01-01

    Self-reported leisure time physical activity was analyzed for 1,598 men and 1,762 women aged 20-69 years in the Framingham Offspring Cycle 2 exam in 1979-1983. Walking for pleasure was generally the most common physical activity for both sexes throughout the year. Substantial seasonal variation was noted for the most common activities: gardening, carpentry, lawn mowing, golf, and running for men; and gardening, swimming, health club exercise, dancing, and bicycling for women. Both sexes expended more kilocalories in physical activities in summer than in winter (p less than 0.001). Frequency of participation in activities sufficient to induce perspiration was associated with frequency of participation in at least one hour of conditioning (greater than or equal to 7.5 kilocal/minute) activities per week (p less than 0.001). Based on age-adjusted mean levels, higher high density lipoprotein cholesterol, lower heart rate, lower body mass index and fewer cigarettes smoked per day were consistently observed across four quartiles of increasing physical activity levels (p less than 0.01). Men who participated in at least one hour of conditioning activities per week had significantly different mean levels for these four risk factors than men who reported less than one hour of such activities per week (p less than 0.001). Results substantiate previous reports of an inverse relation between physical activity levels and cardiovascular risk, and suggest seasonal variation in activity levels should be considered in future studies which explore the relation between physical activity and cardiovascular disease. PMID:2910074

  13. Bet hedging in a warming ocean: predictability of maternal environment shapes offspring size variation in marine sticklebacks.

    Shama, Lisa N S

    2015-12-01

    Bet hedging at reproduction is expected to evolve when mothers are exposed to unpredictable cues for future environmental conditions, whereas transgenerational plasticity (TGP) should be favoured when cues reliably predict the environment offspring will experience. Since climate predictions forecast an increase in both temperature and climate variability, both TGP and bet hedging are likely to become important strategies to mediate climate change effects. Here, the potential to produce variably sized offspring in both warming and unpredictable environments was tested by investigating whether stickleback (Gasterosteus aculeatus) mothers adjusted mean offspring size and within-clutch variation in offspring size in response to experimental manipulation of maternal thermal environment and predictability (alternating between ambient and elevated water temperatures). Reproductive output traits of F1 females were influenced by both temperature and environmental predictability. Mothers that developed at ambient temperature (17 °C) produced larger, but fewer eggs than mothers that developed at elevated temperature (21 °C), implying selection for different-sized offspring in different environments. Mothers in unpredictable environments had smaller mean egg sizes and tended to have greater within-female egg size variability, especially at 21 °C, suggesting that mothers may have dynamically modified the variance in offspring size to spread the risk of incorrectly predicting future environmental conditions. Both TGP and diversification influenced F2 offspring body size. F2 offspring reared at 21 °C had larger mean body sizes if their mother developed at 21 °C, but this TGP benefit was not present for offspring of 17 °C mothers reared at 17 °C, indicating that maternal TGP will be highly relevant for ocean warming scenarios in this system. Offspring of variable environment mothers were smaller but more variable in size than offspring from constant environment

  14. Evaluation of the impact of AIRS profiles on prediction of Indian summer monsoon using WRF variational data assimilation system

    Raju, Attada; Parekh, Anant; Kumar, Prashant; Gnanaseelan, C.

    2015-08-01

    This study investigates the impact of temperature and moisture profiles from Atmospheric Infrared Sounder (AIRS) on the prediction of the Indian summer monsoon, using the variational data assimilation system annexed to the Weather Research and Forecasting model. In this study, three numerical experiments are carried out. The first is the control and includes no assimilation; in the second, named Conv, assimilation of conventional Global Telecommunication System data is performed. The third one, named ConvAIRS, is identical to the Conv except that it also includes assimilation of AIRS profiles. The initial fields of tropospheric temperature and water vapor mixing ratio showed significant improvement over the model domain. Assimilation of AIRS profiles has significant impact on predicting the seasonal mean monsoon characteristics such as tropospheric temperature, low-level moisture distribution, easterly wind shear, and precipitation. The vertical structure of the root-mean-square error is substantially affected by the assimilation of AIRS profiles, with smaller errors in temperature, humidity, and wind magnitude. The consequent improved representation of moisture convergence in the boundary layer (deep convection as well) causes an increase in precipitation forecast skill. The fact that the monsoonal circulation is better captured, thanks to an improved representation of thermal gradients, which in turn leads to more realistic moisture transport, is particularly noteworthy. Several previous data impact studies with AIRS and other sensors have focused on the short or medium range of the forecast. The demonstrated improvement in all the predicted fields associated with the Indian summer monsoon, consequent to the month long assimilation of AIRS profiles, is an innovative finding with large implications to the operational seasonal forecasting capabilities over the Indian subcontinent.

  15. Decadal variation of ocean heat content and tropical cyclone activity over the Bay of Bengal

    Nath, Sankar; Kotal, S. D.; Kundu, P. K.

    2016-02-01

    The upper ocean heat content up to 700 m depth (OHC700) is an important climatic parameter required for atmospheric and oceanographic studies like a cyclone. In this study, therefore, an attempt has been made to examine the inter-decadal variations of tropical cyclone (TC) activity and OHC700 over the Bay of Bengal (BOB) for the post-monsoon season (October-December) during 1955-2013 periods. The sea-surface temperature (SST), geopotential height at 500 hPa, low-level vorticity at 850 hPa, vertical wind shear between 200 and 850 hPa, middle tropospheric humidity at 500 hPa and outgoing long-wave radiation are also being studied using seasonal mean data. The results show a significant inter-decadal variation during 1955-2013, with two distinct decadal periods: active decadal period (ADP) (1955-1988) and inactive decadal period (IDP) (1989-2013). The anomalies of these parameters are opposite in phase for two periods. It is found that the large scale atmospheric features and oceanic parameters have significant inter-decadal variability, but frequency of the tropical cyclone is attributed to the variation in the atmospheric dynamic and thermodynamic conditions rather than the variation of oceanic parameters OHC700 and SSTs during the post-monsoon season.

  16. Decadal variation of ocean heat content and tropical cyclone activity over the Bay of Bengal

    Sankar Nath; S D Kotal; P K Kundu

    2016-02-01

    The upper ocean heat content up to 700 m depth (OHC700) is an important climatic parameter required for atmospheric and oceanographic studies like a cyclone. In this study, therefore, an attempt has been made to examine the inter-decadal variations of tropical cyclone (TC) activity and OHC700 over the Bay of Bengal (BOB) for the post-monsoon season (October–December) during 1955–2013 periods. The sea-surface temperature (SST), geopotential height at 500 hPa, low-level vorticity at 850 hPa, vertical wind shear between 200 and 850 hPa, middle tropospheric humidity at 500 hPa and outgoing long-wave radiation are also being studied using seasonal mean data. The results show a significant inter-decadal variation during 1955–2013, with two distinct decadal periods: active decadal period (ADP) (1955–1988) and inactive decadal period (IDP) (1989–2013). The anomalies of these parameters are opposite in phase for two periods. It is found that the large scale atmospheric features and oceanic parameters have significant inter-decadal variability, but frequency of the tropical cyclone is attributed to the variation in the atmospheric dynamic and thermodynamic conditions rather than the variation of oceanic parameters OHC700 and SSTs during the post-monsoon season.

  17. Prediction of residual metabolic activity after treatment in NSCLC patients

    Rios Velazquez, Emmanuel; Aerts, Hugo J.W.L.; Oberije, Cary; Ruysscher, Dirk De; Lambin, Philippe (Dept. of Radiation Oncology, School for Oncology and Developmental Biology, Maastricht Univ. Medical Center, Maastricht (Netherlands)), E-mail: emmanuel.rios@maastro.nl

    2010-10-15

    Purpose. Metabolic response assessment is often used as a surrogate of local failure and survival. Early identification of patients with residual metabolic activity is essential as this enables selection of patients who could potentially benefit from additional therapy. We report on the development of a pre-treatment prediction model for metabolic response using patient, tumor and treatment factors. Methods. One hundred and one patients with inoperable NSCLC (stage I-IV), treated with 3D conformal radical (chemo)-radiotherapy were retrospectively included in this study. All patients received a pre and post-radiotherapy fluorodeoxyglucose positron emission tomography-computed tomography FDG-PET-CT scan. The electronic medical record system and the medical patient charts were reviewed to obtain demographic, clinical, tumor and treatment data. Primary outcome measure was examined using a metabolic response assessment on a post-radiotherapy FDG-PET-CT scan. Radiotherapy was delivered in fractions of 1.8 Gy, twice a day, with a median prescribed dose of 60 Gy. Results. Overall survival was worse in patients with residual metabolic active areas compared with the patients with a complete metabolic response (p=0.0001). In univariate analysis, three variables were significantly associated with residual disease: larger primary gross tumor volume (GTVprimary, p=0.002), higher pre-treatment maximum standardized uptake value (SUV{sub max}, p=0.0005) in the primary tumor and shorter overall treatment time (OTT, p=0.046). A multivariate model including GTVprimary, SUV{sub max}, equivalent radiation dose at 2 Gy corrected for time (EQD2, T) and OTT yielded an area under the curve assessed by the leave-one-out cross validation of 0.71 (95% CI, 0.65-0.76). Conclusion. Our results confirmed the validity of metabolic response assessment as a surrogate of survival. We developed a multivariate model that is able to identify patients at risk of residual disease. These patients may

  18. A Local Stable Bootstrap for Power Variations of Pure-Jump Semimartingales and Activity Index Estimation

    Hounyo, Ulrich; Varneskov, Rasmus T.

    We provide a new resampling procedure - the local stable bootstrap - that is able to mimic the dependence properties of realized power variations for pure-jump semimartingales observed at different frequencies. This allows us to propose a bootstrap estimator and inference procedure for the activity...... index of the underlying process, β, as well as a bootstrap test for whether it obeys a jump-diffusion or a pure-jump process, that is, of the null hypothesis H₀: β=2 against the alternative H₁: β<2. We establish first-order asymptotic validity of the resulting bootstrap power variations, activity index...... estimator, and diffusion test for H0. Moreover, the finite sample size and power properties of the proposed diffusion test are compared to those of benchmark tests using Monte Carlo simulations. Unlike existing procedures, our bootstrap test is correctly sized in general settings. Finally, we illustrate use...

  19. Variation of Be-7 / Pb-210 activity ratio in aerosol particles

    The main objective of this work was to evaluate the importance of atmospheric transport pathways and air masses origin on the local atmospheric radioactivity levels, by using the variation of Be-7 and Pb-210 activity on aerosol samples. All the samples were collected between May 2000 and July 2001 on the Nuclear and Technological Institute campus in Sacavem. The samples activity was measured gamma spectrometry using an HPGe well-type detector. External influences on local atmospheric radioactivity levels were assessed by using Be-7/Pb-210 activity ratios, together with both nuclides combined activity in the form of a radioactive loading index. It was concluded that the occurrences of low activity ratio values were associated with air masses from continental origin. The occurrence of high relative abundance in Be-7 was associated with descendent vertical movements of the air masses, which promotes the transference to the lower troposphere of Be-7 enriched aerosols. (author)

  20. Activated sewage sludge, a potential animal foodstuff. Part I. Proximate and mineral content; seasonal variation

    Tacon, A.G.J.; Ferns, P.N.

    1979-08-01

    A detailed proximate and mineral analysis of activated sewage sludge is described. Samples were collected at bi-weekly intervals from a rural domestic sewage works for one year. The following annual ranges and mean values were determined for the chemical components within the sludge samples: moisture, total nitrogen, crude protein, Lowry protein, fat, saponification value, available carbohydrate as glucose, fiber, ash, acid insoluble ash, and 26 elements. The seasonal variation patterns observed are discussed. 23 references

  1. Latitudinal variation of the topside electron temperature at different levels of solar activity

    Truhlík, Vladimír; Bilitza, D.; Třísková, Ludmila

    2009-01-01

    Roč. 44, č. 6 (2009), s. 693-700. ISSN 0273-1177 R&D Projects: GA AV ČR IAA300420603 Grant ostatní: NASA (US) NNH06CD17C Institutional research plan: CEZ:AV0Z30420517 Keywords : Electron temperature * Solar activity variation * Latitudinal dependence Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 1.079, year: 2009

  2. Spatial Variations of Soil Microbial Activities in Saline Groundwater-Irrigated Soil Ecosystem

    Chen, Li-Juan; Feng, Qi; Li, Chang-Sheng; Song, You-Xi; Liu, Wei; Si, Jian-Hua; Zhang, Bao-Gui

    2016-05-01

    Spatial variations of soil microbial activities and its relationship with environmental factors are very important for estimating regional soil ecosystem function. Based on field samplings in a typical saline groundwater-irrigated region, spatial variations of soil microbial metabolic activities were investigated. Combined with groundwater quality analysis, the relationship between microbial activities and water salinity was also studied. The results demonstrated that moderate spatial heterogeneity of soil microbial activities presented under the total dissolved solids (TDS) of groundwater ranging from 0.23 to 12.24 g L-1. Groundwater salinity and microbial activities had almost opposite distribution characteristics: slight saline water was mainly distributed in west Baqu and south Quanshan, while severe saline and briny water were dominant in east Baqu and west Huqu; however, total AWCD was higher in the east-center and southwest of Baqu and east Huqu, while it was lower in east Baqu and northwest Huqu. The results of correlation analyses demonstrated that high-salinity groundwater irrigation had significantly adverse effects on soil microbial activities. Major ions Ca2+, Mg2+, Cl_, and SO4 2- in groundwater decisively influenced the results. Three carbon sources, carbohydrates, amines, and phenols, which had minor utilization rates in all irrigation districts, were extremely significantly affected by high-salinity groundwater irrigation. The results presented here offer an approach for diagnosing regional soil ecosystem function changes under saline water irrigation.

  3. Spatial Variations of Soil Microbial Activities in Saline Groundwater-Irrigated Soil Ecosystem.

    Chen, Li-Juan; Feng, Qi; Li, Chang-Sheng; Song, You-Xi; Liu, Wei; Si, Jian-Hua; Zhang, Bao-Gui

    2016-05-01

    Spatial variations of soil microbial activities and its relationship with environmental factors are very important for estimating regional soil ecosystem function. Based on field samplings in a typical saline groundwater-irrigated region, spatial variations of soil microbial metabolic activities were investigated. Combined with groundwater quality analysis, the relationship between microbial activities and water salinity was also studied. The results demonstrated that moderate spatial heterogeneity of soil microbial activities presented under the total dissolved solids (TDS) of groundwater ranging from 0.23 to 12.24 g L(-1). Groundwater salinity and microbial activities had almost opposite distribution characteristics: slight saline water was mainly distributed in west Baqu and south Quanshan, while severe saline and briny water were dominant in east Baqu and west Huqu; however, total AWCD was higher in the east-center and southwest of Baqu and east Huqu, while it was lower in east Baqu and northwest Huqu. The results of correlation analyses demonstrated that high-salinity groundwater irrigation had significantly adverse effects on soil microbial activities. Major ions Ca(2+), Mg(2+), Cl(_), and SO4 (2-) in groundwater decisively influenced the results. Three carbon sources, carbohydrates, amines, and phenols, which had minor utilization rates in all irrigation districts, were extremely significantly affected by high-salinity groundwater irrigation. The results presented here offer an approach for diagnosing regional soil ecosystem function changes under saline water irrigation. PMID:26872886

  4. Bursty Variations of Jovian 6cm Radio Emissions and Quasi-Periodic Jupiter's Polar Activities

    Lou, Yu-Qing; Song, Huagang; Liu, Yinyu; Meng YANG

    2012-01-01

    In reference to Jupiter south polar quasi-periodic 40-50 min (QP-40) activities and the model scenario for global QP-40 oscillations of the Jovian inner radiation belt (IRB), we validate relevant predictions and confirmations by amassing empirical evidence from Ulysses, Cassini, Chandra, Galileo, XMM-Newton, and Advanced Composition Explorer for Jupiter north polar QP-40 activities. We report ground 6cm radio observations of Jupiter by Urumqi 25m telescope for synchrotron intensity bursty var...

  5. Modeling and prediction of daily gas concentration variation at a mining face based on the elliptic orbit model:A case study

    Yang Zongchang; Zhou Shaowu

    2015-01-01

    Monitoring and analysis of daily gas concentrations at a mining face is a vital task on safety production and security management in the coal-mining industry. This study addresses modeling and prediction of daily gas concentration variations based on the elliptic orbit model. The model describes the hourly variation in daily gas concentration by mapping its time-series into the polar coordinates to create its elliptic orbit trace for further analysis. Experiments show workability of the proposed method that daily gas concentration variation at a mining face of one coal mine in China is well described by the elliptic orbit model. Result analysis and performance comparison of the proposed elliptic orbit model with the classical AR model on the same prediction tasks indicate potentiality of the proposed elliptic orbit model, which presents a vivid approach for modeling and forecasting daily gas concentration variations in an intuitive and concise way.

  6. VFC - Variational Feedback Controller and its application to semi-active suspensions

    Pepe, G.; Carcaterra, A.

    2016-08-01

    Active and semi-active control of oscillating devices and structures is a challenging field and this paper proposes an original investigation based on variational controls that can be successfully applied to mechanical systems. The method produces a general class of new controllers, named VFC - Variational Feedback Controllers, that is the main theoretical contribution of the paper. The value of the theory relies on using a reformulation of the Variational Optimal Control Theory, that has in general the limit of producing control program strategies and not directly feedback control methods. The difficulties are in fact related to the intrinsic nature of the variational optimal control, that must solve initial and final boundary conditions. A special definition of the class of the considered objective functions, permits to skip this difficulty, producing a pure feedback control. The presented theory goes beyond with respect to the most acknowledged LQR variational-based techniques, in that VFC can be applied to more general nonlinear dynamical systems, even with finite time horizon. To test the effectiveness of the novel approach in real engineering problems, a deep investigation on nonlinear suspension systems treated by VFC is proposed in this paper. To this aim, VFC is systematically compared with the most recent methods available in this field and suitable to deal with nonlinear system control of car suspensions. In particular, the comparative analysis is made in terms of both comfort and handling key performance indexes, that permits to easily and significantly compare different control logics, such as the Sky-hook and Ground-hook control families, the Acceleration and Power Driven Dampers. The results of this comparison are collected in a performance plane, having comfort and handling indexes as coordinate axes, showing that VFC controllers completely cover the regions reached by the other mentioned control logics in this plane, but reveal to have access to

  7. Predicting Classroom Achievement from Active Responding on a Computer-Based Groupware System.

    Shin, Jongho; Deno, Stanley L.; Robinson, Steven L.; Marston, Douglas

    2000-01-01

    The predictive validity of active responding on a computer-based groupware system was examined with 48 second graders. Results showed that active responding correlated highly with initial and final performance measures and that active responding contributed significantly to predicting final performance when initial performance was controlled.…

  8. The prediction of seasonal and inter-annual climate variations and their impacts on the water resources in the eastern seaboard of Thailand

    Bejranonda, Werapol

    2014-01-01

    The research of this thesis dissertation covers developments and applications of short-and long-term climate predictions. The short-term prediction emphasizes monthly and seasonal climate, i.e. forecasting from up to the next month over a season to up to a year or so. The long-term predictions pertain to the analysis of inter-annual- and decadal climate variations over the whole 21st century. These two climate prediction methods are validated and applied in the study area, namely, Khlong Yai ...

  9. Individual Variation in the Propensity to Attribute Incentive Salience to an Appetitive Cue Predicts the Propensity to Attribute Motivational Salience to an Aversive Cue

    Morrow, Jonathan D.; Maren, Stephen; ROBINSON, TERRY E.

    2011-01-01

    It has been proposed that animals that attribute high levels of incentive salience to reward-related cues may be especially vulnerable to addiction. Individual variation has also been observed in the motivational value attributed to aversive cues, which may confer vulnerability to anxiety disorders such as post-traumatic stress disorder (PTSD). There may be a core behavioral trait that contributes to individual variation in the motivational value assigned to predictive cues regardless of emot...

  10. Surface tensions of multi-component mixed inorganic/organic aqueous systems of atmospheric significance: measurements, model predictions and importance for cloud activation predictions

    D. O. Topping

    2006-11-01

    Full Text Available In order to predict the physical properties of aerosol particles, it is necessary to adequately capture the behaviour of the ubiquitous complex organic components. One of the key properties which may affect this behaviour is the contribution of the organic components to the surface tension of aqueous particles in the moist atmosphere. Whilst the qualitative effect of organic compounds on solution surface tensions has been widely reported, our quantitative understanding on mixed organic and mixed inorganic/organic systems is limited.  Furthermore, it is unclear whether models that exist in the literature can reproduce the surface tension variability for binary and higher order multi-component organic and mixed inorganic/organic systems of atmospheric significance. The current study aims to resolve both issues to some extent. Surface tensions of single and multiple solute aqueous solutions were measured and compared with predictions from a number of model treatments. On comparison with binary organic systems, two predictive models found in the literature provided a range of values resulting from sensitivity to calculations of pure component surface tensions.  Results indicate that a fitted model can capture the variability of the measured data very well, producing the lowest average percentage deviation for all compounds studied.  The performance of the other models varies with compound and choice of model parameters. The behaviour of ternary mixed inorganic/organic systems was unreliably captured by using a predictive scheme and this was composition dependent. For more "realistic" higher order systems, entirely predictive schemes performed poorly. It was found that use of the binary data in a relatively simple mixing rule, or modification of an existing thermodynamic model with parameters derived from binary data, was able to accurately capture the surface tension variation with concentration. Thus, it would appear that in order to model

  11. Activity Variation of Phanerochaete chrysosporium under Nanosilver Exposure by Controlling of Different Sulfide Sources

    Guo, Zhi; Chen, Guiqiu; Liu, Lingzhi; Zeng, Guangming; Huang, Zhenzhen; Chen, Anwei; Hu, Liang

    2016-02-01

    Due to the particular activation and inhibition behavior of silver nanoparticles (AgNPs) on microbes at various concentrations, it’s crucial to exploit the special concentration effect in environment. Here, we studied the viability variation of Phanerochaete chrysosporium (P. chrysosporium) under exposure to citrate-coated AgNPs (Citrate-AgNPs) in the presence of different sulfide sources (an inorganic sulfide, NaHS and an organic sulfide, thioacetamide (TAA)). The results indicated that both NaHS and TAA can promote activation of P. chrysosporium by Citrate-AgNPs at a higher concentration, which was initial at toxic level. Treatment with various concentrations of Citrate-AgNPs (0-9 mg/L) demonstrated a maximum activation concentration (MAC) at 3 mg/L. With the increase in sulfide concentration, MAC transferred to higher concentration significantly, indicating the obvious “toxicity to activation” transformation at a higher concentration. Ag+ testing exhibited that variations in sulfide-induced Ag+ concentration (3-7 μg/L Ag+) accounted for the “toxicity to activation” transformation. In addition, the similar results were observed on antibacterial application using Escherichia coli as the model species. Based on the research results, the application of this transformation in improving antibacterial activity was proposed. Therefore, the antibacterial activity of AgNPs can be controlled, even at concentration, via adjusting for the sulfide concentration.

  12. Diurnal Variation in Gravity Wave Activity at Low and Middle Latitudes

    Andrioli, V. F.; Fritts, D. C.; Batista, P. P.; Clemesha, B. R.; Janches, Diego

    2013-01-01

    We employ a modified composite day extension of the Hocking (2005) analysis method to study gravity wave (GW) activity in the mesosphere and lower thermosphere using 4 meteor radars spanning latitudes from 7deg S to 53.6deg S. Diurnal and semidiurnal modulations were observed in GW variances over all sites. Semidiurnal modulation with downward phase propagation was observed at lower latitudes mainly near the equinoxes. Diurnal modulations occur mainly near solstice and, except for the zonal component at Cariri (7deg S), do not exhibit downward phase propagation. At a higher latitude (SAAMER, 53.6deg S) these modulations are only observed in the meridional component where we can observe diurnal variation from March to May, and semidiurnal, during January, February, October (above 88 km) and November. Some of these modulations with downward phase progression correlate well with wind shear. When the wind shear is well correlated with the maximum of the variances the diurnal tide has its largest amplitudes, i.e., near equinox. Correlations exhibiting variations with tidal phases suggest significant GW-tidal interactions that have different characters depending on the tidal components and possible mean wind shears. Modulations that do not exhibit phase variations could be indicative of diurnal variations in GW sources.

  13. Origins of the semiannual variation of geomagnetic activity in 1954 and 1996

    L. Svalgaard

    Full Text Available We investigate the cause of the unusually strong semiannual variation of geomagnetic activity observed in the solar minimum years of 1954 and 1996. For 1996 we separate the contributions of the three classical modulation mechanisms (axial, equinoctial, and Russell-McPherron to the six-month wave in the aam index and find that all three contribute about equally. This is in contrast to the longer run of geomagnetic activity (1868-1998 over which the equinoctial effect accounts for ∼70% of the semiannual variation. For both 1954 and 1996, we show that the Russell-McPherron effect was enhanced by the Rosenberg-Coleman effect (an axial polarity effect which increased the amount of the negative (toward Sun [positive (away from Sun] polarity field observed during the first [second] half of the year; such fields yield a southward component in GSM coordinates. Because this favourable condition occurs only for alternate solar cycles, the marked semiannual variation in 1954 and 1996 is a manifestation of the 22-year cycle of geomagnetic activity. The 11-year evolution of the heliospheric current sheet (HCS also contributes to the strong six-month wave during these years. At solar minimum, the streamer belt at the base of the HCS is located near the solar equator, permitting easier access to high speed streams from polar coronal holes when the Earth is at its highest heliographic latitudes in March and September. Such an axial variation in solar wind speed was observed for 1996 and is inferred for 1954. Key words. Magnetosphere (solar wind – magnetosphere interactions; storms and substorms

  14. Long-term stellar activity variations of stars from the HARPS M-dwarf sample: Comparison between activity indices

    da Silva, J Gomes; Bonfils, X

    2010-01-01

    We used four known chromospheric activity indicators to measure long-term activity variations in a sample of 23 M-dwarf stars from the HARPS planet search program. We compared the indices using weighted Pearson correlation coefficients and found that in general (i) the correlation between $S_{CaII}$ and \\ion{Na}{i} is very strong and does not depend on the activity level of the stars, (ii) the correlation between our $S_{CaII}$ and H$\\alpha$ seems to depend on the activity level of the stars, and (iii) there is no strong correlation between $S_{CaII}$ and \\ion{He}{i} for these type of stars.

  15. Interindividual Variation in Functionally Adapted Trait Sets Is Established During Postnatal Growth and Predictable Based on Bone Robustness

    Pandey, Nirnimesh; Bhola, Siddharth; Goldstone, Andrew; Chen, Fred; Chrzanowski, Jessica; Terranova, Carl J.; Ghillani, Richard

    2009-01-01

    Adults acquire unique sets of morphological and tissue-quality bone traits that are predictable based on robustness and deterministic of strength and fragility. How and when individual trait sets arise during growth has not been established. Longitudinal structural changes of the metacarpal diaphysis were measured for boys and girls from 3 mo to 8 yr of age using hand radiographs obtained from the Bolton-Brush collection. Robustness varied ∼2-fold among boys and girls, and individual values were established by 2 yr of age, indicating that genetic and environmental factors controlling the relationship between growth in width and growth in length were established early during postnatal growth. Significant negative correlations between robustness and relative cortical area and a significant positive correlation between robustness and a novel measure capturing the efficiency of growth indicated that coordination of the subperiosteal and endocortical surfaces was responsible for this population acquiring a narrow range of trait sets that was predictable based on robustness. Boys and girls with robust diaphyses had proportionally thinner cortices to minimize mass, whereas children with slender diaphyses had proportionally thicker cortices to maximize stiffness. Girls had more slender metacarpals with proportionally thicker cortices compared with boys at all prepubertal ages. Although postnatal growth patterns varied in fundamentally different ways with sex and robustness, the dependence of trait sets on robustness indicated that children sustained variants affecting subperiosteal growth because they shared a common biological factor regulating functional adaptation. Considering the natural variation in acquired trait sets may help identify determinants of fracture risk, because age-related bone loss and gain will affect slender and robust structures differently. PMID:20001599

  16. Between-school variation in physical activity, aerobic fitness, and organized sports participation

    Kristensen, Peter L; Olesen, Line G; Ried-Larsen, Mathias;

    2013-01-01

    Abstract A large proportion of a child's day is spent at school interacting with certain physical surroundings, teachers, and school friends. Thus, schools could have a marked impact on establishing physical activity habits. The aim of the present study was to assess between-school variation in...... physical activity, aerobic fitness, and organized sports participation. Altogether, we tested 1766 nine- and fifteen-year-old children attending 242 school classes at 35 different schools in Denmark in 1997-2003. The intra-class correlation coefficient (ICC) for objectively assessed physical activity...... ranged between 0.06 and 0.18 depending on the dimension of physical activity and the time considered (i.e. school time vs. leisure time). For aerobic fitness, an ICC of 0.10 was observed, whereas that for organized sports participation ranged between 0.01 and 0.10 depending on the age group. Studying...

  17. CES1 genetic variation affects the activation of angiotensin-converting enzyme inhibitors.

    Wang, X; Wang, G; Shi, J; Aa, J; Comas, R; Liang, Y; Zhu, H-J

    2016-06-01

    The aim of the study was to determine the effect of carboxylesterase 1 (CES1) genetic variation on the activation of angiotensin-converting enzyme inhibitor (ACEI) prodrugs. In vitro incubation study of human liver, intestine and kidney s9 fractions demonstrated that the ACEI prodrugs enalapril, ramipril, perindopril, moexipril and fosinopril are selectively activated by CES1 in the liver. The impact of CES1/CES1VAR and CES1P1/CES1P1VAR genotypes and diplotypes on CES1 expression and activity on enalapril activation was investigated in 102 normal human liver samples. Neither the genotypes nor the diplotypes affected hepatic CES1 expression and activity. Moreover, among several CES1 nonsynonymous variants studied in transfected cell lines, the G143E (rs71647871) was a loss-of-function variant for the activation of all ACEIs tested. The CES1 activity on enalapril activation in human livers with the 143G/E genotype was approximately one-third of that carrying the 143G/G. Thus, some functional CES1 genetic variants (for example, G143E) may impair ACEI activation, and consequently affect therapeutic outcomes of ACEI prodrugs. PMID:26076923

  18. Heartbeat of the Sun from Principal Component Analysis and prediction of solar activity on a millenium timescale.

    Zharkova, V V; Shepherd, S J; Popova, E; Zharkov, S I

    2015-01-01

    We derive two principal components (PCs) of temporal magnetic field variations over the solar cycles 21-24 from full disk magnetograms covering about 39% of data variance, with σ = 0.67. These PCs are attributed to two main magnetic waves travelling from the opposite hemispheres with close frequencies and increasing phase shift. Using symbolic regression analysis we also derive mathematical formulae for these waves and calculate their summary curve which we show is linked to solar activity index. Extrapolation of the PCs backward for 800 years reveals the two 350-year grand cycles superimposed on 22 year-cycles with the features showing a remarkable resemblance to sunspot activity reported in the past including the Maunder and Dalton minimum. The summary curve calculated for the next millennium predicts further three grand cycles with the closest grand minimum occurring in the forthcoming cycles 26-27 with the two magnetic field waves separating into the opposite hemispheres leading to strongly reduced solar activity. These grand cycle variations are probed by α - Ω dynamo model with meridional circulation. Dynamo waves are found generated with close frequencies whose interaction leads to beating effects responsible for the grand cycles (350-400 years) superimposed on a standard 22 year cycle. This approach opens a new era in investigation and confident prediction of solar activity on a millenium timescale. PMID:26511513

  19. Heartbeat of the Sun from Principal Component Analysis and prediction of solar activity on a millenium timescale

    Zharkova, V. V.; Shepherd, S. J.; Popova, E.; Zharkov, S. I.

    2015-10-01

    We derive two principal components (PCs) of temporal magnetic field variations over the solar cycles 21-24 from full disk magnetograms covering about 39% of data variance, with σ = 0.67. These PCs are attributed to two main magnetic waves travelling from the opposite hemispheres with close frequencies and increasing phase shift. Using symbolic regeression analysis we also derive mathematical formulae for these waves and calculate their summary curve which we show is linked to solar activity index. Extrapolation of the PCs backward for 800 years reveals the two 350-year grand cycles superimposed on 22 year-cycles with the features showing a remarkable resemblance to sunspot activity reported in the past including the Maunder and Dalton minimum. The summary curve calculated for the next millennium predicts further three grand cycles with the closest grand minimum occurring in the forthcoming cycles 26-27 with the two magnetic field waves separating into the opposite hemispheres leading to strongly reduced solar activity. These grand cycle variations are probed by α - Ω dynamo model with meridional circulation. Dynamo waves are found generated with close frequencies whose interaction leads to beating effects responsible for the grand cycles (350-400 years) superimposed on a standard 22 year cycle. This approach opens a new era in investigation and confident prediction of solar activity on a millenium timescale.

  20. Variations of 14-C around AD 775 and AD 1795 - due to solar activity

    Neuhaeuser, Ralph

    2015-01-01

    The motivation for our study is the disputed cause for the strong variation of 14-C around AD 775. Our method is to compare the 14-C variation around AD 775 with other periods of strong variability. Our results are: (a) We see three periods, where 14-C varied over 200 yr in a special way showing a certain pattern of strong secular variation: after a Grand Minimum with strongly increasing 14-C, there is a series of strong short-term drop(s), rise(s), and again drop(s) within 60 yr, ending up to 200 yr after the start of the Grand Minimum. These three periods include the strong rises around BC 671, AD 775, and AD 1795. (b) We show with several solar activity proxies (radioisotopes, sunspots, and aurorae) for the AD 770s and 1790s that such intense rapid 14-C increases can be explained by strong rapid decreases in solar activity and, hence, wind, so that the decrease in solar modulation potential leads to an increase in radioisotope production. (c) The strong rises around AD 775 and 1795 are due to three effects...

  1. THE FIRST RESULTS OF STUDIES OF TEMPORARY VARIATIONS IN SOILRADON ACTIVITY OF FAULTS IN WESTERN PRIBAIKALIE

    К. Zh. Seminsky

    2015-09-01

    Full Text Available Radon concentrations in soil air are variable depending on factors that are considered external (planetary and internal (geodynamic relative to the Earth. In active fault zones, variations of gas emanations are most intense. A permanent monitoring station was established near Tyrgan settlement in Western Pribaikalie to study temporal variations of soil radon concentration, Q, in the faults of the Baikal rift, East Siberia. This station is located in the zone of the Primorsky normal fault that is the largest in the region. The station is equipped with radon radiometer PPA01M03 that records Q values every 85 minutes and also monitors a number of meteorological parameters, including atmospheric pressure, humidity, and air temperature.We analysed records of two measurement sessions (148 and 66 days covering a part of the year during which field measurement of Q are possible in the cold climate conditions of the area under study. According to the available monitoring data, variations of radon concentrations in the Primorsky fault zone may vary by more than one order of magnitude through a springsummerautumn period, and such variations are oscillatory. Significant changes of permeability in time occur due to intensive changes in the state of stresses of the rock massives under the impacts of the planetary and geodynamic factors. The influence of the first group of factors, i.e. planetary ones, is manifested by synchronous oscillations of radon concentrations and atmospheric pressure, which phases of occurrence are opposed. Domination of daily and fourday periods gives evidence that the state of stresses of the rock massives is impacted by the lunar tides and cyclonic phenomena associated with the interaction between the Earth and the Sun. The influence of the second group of factors, i.e. geodynamic ones, is suggested by an evident relation between radon emanations and seismic events, including the catastrophic earthquake in Japan (March 11, 2011, M=9

  2. Clinical relevance of pulse pressure variations for predicting fluid responsiveness in mechanically ventilated intensive care unit patients: the grey zone approach

    Biais, Matthieu; Ehrmann, Stephan; Mari, Arnaud; Conte, Benjamin; Mahjoub, Yazine; Desebbe, Olivier; Pottecher, Julien; Lakhal, Karim; Benzekri-Lefevre, Dalila; Molinari, Nicolas; Boulain, Thierry; Lefrant, Jean-Yves; Muller, Laurent; ,

    2014-01-01

    Introduction Pulse pressure variation (PPV) has been shown to predict fluid responsiveness in ventilated intensive care unit (ICU) patients. The present study was aimed at assessing the diagnostic accuracy of PPV for prediction of fluid responsiveness by using the grey zone approach in a large population. Methods The study pooled data of 556 patients from nine French ICUs. Hemodynamic (PPV, central venous pressure (CVP) and cardiac output) and ventilator variables were recorded. Responders we...

  3. Seasonal Variation, Chemical Composition and Antioxidant Activity of Brazilian Propolis Samples

    Érica Weinstein Teixeira

    2010-01-01

    Full Text Available Total phenolic contents, antioxidant activity and chemical composition of propolis samples from three localities of Minas Gerais state (southeast Brazil were determined. Total phenolic contents were determined by the Folin–Ciocalteau method, antioxidant activity was evaluated by DPPH, using BHT as reference, and chemical composition was analyzed by GC/MS. Propolis from Itapecerica and Paula Cândido municipalities were found to have high phenolic contents and pronounced antioxidant activity. From these extracts, 40 substances were identified, among them were simple phenylpropanoids, prenylated phenylpropanoids, sesqui- and diterpenoids. Quantitatively, the main constituent of both samples was allyl-3-prenylcinnamic acid. A sample from Virginópolis municipality had no detectable phenolic substances and contained mainly triterpenoids, the main constituents being α- and β-amyrins. Methanolic extracts from Itapecerica and Paula Cândido exhibited pronounced scavenging activity towards DPPH, indistinguishable from BHT activity. However, extracts from Virginópolis sample exhibited no antioxidant activity. Total phenolic substances, GC/MS analyses and antioxidant activity of samples from Itapecerica collected monthly over a period of 1 year revealed considerable variation. No correlation was observed between antioxidant activity and either total phenolic contents or contents of artepillin C and other phenolic substances, as assayed by CG/MS analysis.

  4. Intraspecific variation of biological activities in venoms from wild and captive Bothrops jararaca.

    Saad, Eduardo; Curtolo Barros, Luciana; Biscola, Natalia; Pimenta, Daniel C; Barraviera, Silvia R C S; Barraviera, Benedito; Seabra Ferreira, Rui

    2012-01-01

    The venom of Bothrops jararaca is composed of complex mixture of molecules, mainly lectins, metalloproteinases, serinoproteinases, desintegrins, phospholipases, and peptides. This composition may vary according to the snake's age, gender, and region of origin. The aim of the was to determine individual variation in Bothrops jararaca venom in the Botucatu region, Sao Paulo State, Brazil, by means of enzymatic, biochemical, and pharmacological characterization, utilizing in vitro tests and biological assays. The activities were compared with those of Brazilian Reference Venom (BRV). Protein concentration varied between adult and juvenile groups. The electrophoretic profiles were similar, with molecular masses ranging between 25 and 50 kD, but with intraspecific variations. Reverse-phase high-performance liquid chromatography (RP-HPLC) revealed protein concentration differences. Coagulant activity did not differ significantly among adult groups, but there was a large variation between juvenile venom and BRV, which coagulated more extensively. Venoms from adults displayed greater hemorrhagic activity, especially in males recently obtained from the wild. In contrast, juveniles kept in captivity and adult males showed higher values. Edematogenic activity displayed an increase in edema in all groups. At the mean lethal dose (LD₅₀), toxicity varied significantly between groups, with venom from captive females being threefold more toxic than juvenile venom. Data illustrate the intra- and interspecific complexity that occurs in snake venoms, which may be attributed to ontogenetic, sexual, and environmental factors that affect variability in Bothrops jararaca venom. Further, it is proposed that Brazilian public health authorities document the constitution of pooled venom employed in the immunization of serum-producing animals due to this variability in venom properties. Given the large Brazilian territory, this variability requires regional monitoring and evaluation of

  5. Sensitivity of predicted scaling and permeability in Enhanced Geothermal Systems to Thermodynamic Data and Activity Models

    Hingerl, Ferdinand F.; Wagner, Thomas; Kulik, Dmitrii A.; Kosakowski, Georg; Driesner, Thomas; Thomsen, Kaj

    2010-05-01

    A consortium of research groups from ETH Zurich, EPF Lausanne, the Paul Scherrer Institut and the University of Bonn collaborates in a comprehensive program of basic research on key aspects of the Enhanced Geothermal Systems (EGSs). As part of this GEOTHERM project (www.geotherm.ethz.ch), we concentrate on the fundamental investigation of thermodynamic models suitable for describing fluid-rock interactions at geothermal conditions. Predictions of the fluid-rock interaction in EGS still face several major challenges. Slight variations in the input thermodynamic and kinetic parameters may result in significant differences in the predicted mineral solubilities and stable assemblage. Realistic modeling of mineral precipitation in turn has implications onto our understanding of the permeability evolution of the geothermal reservoir, as well as the scaling in technical installations. In order to reasonably model an EGS, thermodynamic databases and activity models must be tailored to geothermal conditions. We therefore implemented in GEMS code the Pitzer formalism, which is the standard model used for computing thermodynamic excess properties of brines at elevated temperatures and pressures. This model, however, depends on a vast amount of interaction parameters, which are to a substantial extend unknown. Furthermore, a high order polynomial temperature interpolation makes extrapolation unreliable if not impossible. As an alternative we additionally implemented the EUNIQUAC activity model. EUNIQUAC requires fewer empirical fit parameters (only binary interaction parameters needed) and uses simpler and more stable temperature and pressure extrapolations. This results in an increase in computation speed, which is of crucial importance when performing coupled long term simulations of geothermal reservoirs. To achieve better performance under geothermal conditions, we are currently partly reformulating EUNIQUAC and refitting the existing parameter set. First results of the

  6. Variations of 14C around AD 775 and AD 1795 - due to solar activity

    Neuhäuser, R.; Neuhäuser, D. L.

    2015-12-01

    The motivation for our study is the disputed cause for the strong variation of 14C around AD 775. Our method is to compare the 14C variation around AD 775 with other periods of strong variability. Our results are: (a) We see three periods, where 14C varied over 200 yr in a special way showing a certain pattern of strong secular variation: after a Grand Minimum with strongly increasing 14C, there is a series of strong short-term drop(s), rise(s), and again drop(s) within 60 yr, ending up to 200 yr after the start of the Grand Minimum. These three periods include the strong rises around BC 671, AD 775, and AD 1795. (b) We show with several solar activity proxies (radioisotopes, sunspots, and aurorae) for the AD 770s and 1790s that such intense rapid 14C increases can be explained by strong rapid decreases in solar activity and, hence, wind, so that the decrease in solar modulation potential leads to an increase in radioisotope production. (c) The strong rises around AD 775 and 1795 are due to three effects, (i) very strong activity in the previous cycles (i.e. very low 14C level), (ii) the declining phase of a very strong Schwabe cycle, and (iii) a phase of very weak activity after the strong 14C rise - very short and/or weak cycle(s) like the suddenly starting Dalton minimum. (d) Furthermore, we can show that the strong change at AD 1795 happened after a pair of two packages of four Schwabe cycles with certain hemispheric leadership (each package consists of two Gnevyshev-Ohl pairs, respectively two Hale-Babcock pairs). We show with several additional arguments that the rise around AD 775 was not that special. We conclude that such large, short-term rises in 14C (around BC 671, AD 775, and 1795) do not need to be explained by highly unlikely solar super-flares nor other rare events, but by extra-solar cosmic rays modulated due to solar activity variations.

  7. Factors Predicting Physical Activity Among Children With Special Needs

    Shahram Yazdani, MD

    2013-07-01

    Full Text Available Introduction Obesity is especially prevalent among children with special needs. Both lack of physical activity and unhealthful eating are major contributing factors. The objective of our study was to investigate barriers to physical activity among these children. Methods We surveyed parents of the 171 children attending Vista Del Mar School in Los Angeles, a nonprofit school serving a socioeconomically diverse group of children with special needs from kindergarten through 12th grade. Parents were asked about their child’s and their own physical activity habits, barriers to their child’s exercise, and demographics. The response rate was 67%. Multivariate logistic regression was used to examine predictors of children being physically active at least 3 hours per week. Results Parents reported that 45% of the children were diagnosed with attention deficit hyperactivity disorder, 38% with autism, and 34% with learning disabilities; 47% of children and 56% of parents were physically active less than 3 hours per week. The top barriers to physical activity were reported as child’s lack of interest (43%, lack of developmentally appropriate programs (33%, too many behavioral problems (32%, and parents’ lack of time (29%. However, child’s lack of interest was the only parent-reported barrier independently associated with children’s physical activity. Meanwhile, children whose parents were physically active at least 3 hours per week were 4.2 times as likely to be physically active as children whose parents were less physically active (P = .01. Conclusion In this group of students with special needs, children’s physical activity was strongly associated with parental physical activity; parent-reported barriers may have had less direct effect. Further studies should examine the importance of parental physical activity among children with special needs.

  8. Spring-fall asymmetry of substorm strength, geomagnetic activity and solar wind: Implications for semiannual variation and solar hemispheric asymmetry

    Marsula, K.; Tanskanen, E.; Love, J.J.

    2011-01-01

    We study the seasonal variation of substorms, geomagnetic activity and their solar wind drivers in 1993–2008. The number of substorms and substorm mean duration depict an annual variation with maxima in Winter and Summer, respectively, reflecting the annual change of the local ionosphere. In contradiction, substorm mean amplitude, substorm total efficiency and global geomagnetic activity show a dominant annual variation, with equinoctial maxima alternating between Spring in solar cycle 22 and Fall in cycle 23. The largest annual variations were found in 1994 and 2003, in the declining phase of the two cycles when high-speed streams dominate the solar wind. A similar, large annual variation is found in the solar wind driver of substorms and geomagnetic activity, which implies that the annual variation of substorm strength, substorm efficiency and geomagnetic activity is not due to ionospheric conditions but to a hemispherically asymmetric distribution of solar wind which varies from one cycle to another. Our results imply that the overall semiannual variation in global geomagnetic activity has been seriously overestimated, and is largely an artifact of the dominant annual variation with maxima alternating between Spring and Fall. The results also suggest an intimate connection between the asymmetry of solar magnetic fields and some of the largest geomagnetic disturbances, offering interesting new pathways for forecasting disturbances with a longer lead time to the future.

  9. Resting alpha activity predicts learning ability in alpha neurofeedback

    Wenya eNan; Feng eWan; Mang I eVai; Agostinho eRosa

    2014-01-01

    Individuals differ in their ability to learn how to regulate the alpha activity by neurofeedback. This study aimed to investigate whether the resting alpha activity is related to the learning ability of alpha enhancement in neurofeedback and could be used as a predictor. A total of 25 subjects performed 20 sessions of individualized alpha neurofeedback in order to learn how to enhance activity in the alpha frequency band. The learning ability was assessed by three indices respectively: the tr...

  10. Genetic variation in COMT activity impacts learning and dopamine release capacity in the striatum

    Simpson, Eleanor H.; Morud, Julia; Winiger, Vanessa; Biezonski, Dominik; Zhu, Judy P.; Bach, Mary Elizabeth; Malleret, Gael; Polan, H. Jonathan; Ng-Evans, Scott; Phillips, Paul E.M.; Kellendonk, Christoph; Kandel, Eric R.

    2014-01-01

    A common genetic polymorphism that results in increased activity of the dopamine regulating enzyme COMT (the COMT Val158 allele) has been found to associate with poorer cognitive performance and increased susceptibility to develop psychiatric disorders. It is generally assumed that this increase in COMT activity influences cognitive function and psychiatric disease risk by increasing dopamine turnover in cortical synapses, though this cannot be directly measured in humans. Here we explore a novel transgenic mouse model of increased COMT activity, equivalent to the relative increase in activity observed with the human COMT Val158 allele. By performing an extensive battery of behavioral tests, we found that COMT overexpressing mice (COMT-OE mice) exhibit cognitive deficits selectively in the domains that are affected by the COMT Val158 allele, stimulus–response learning and working memory, functionally validating our model of increased COMT activity. Although we detected no changes in the level of markers for dopamine synthesis and dopamine transport, we found that COMT-OE mice display an increase in dopamine release capacity in the striatum. This result suggests that increased COMT activity may not only affect dopamine signaling by enhancing synaptic clearance in the cortex, but may also cause changes in presynaptic dopamine function in the striatum. These changes may underlie the behavioral deficits observed in the mice and might also play a role in the cognitive deficits and increased psychiatric disease risk associated with genetic variation in COMT activity in humans. PMID:24639487