Science.gov

Sample records for reached maximum growth

  1. Lake Levels in Northeastern South Dakota Reach Historical Maximum Elevations in 2011

    NASA Astrophysics Data System (ADS)

    Anderson, M. T.; Driscoll, D. G.

    2011-12-01

    The hydroclimatic conditions in the winter and spring of 2011 in eastern South Dakota combined to raise lake levels to historical maximums in northeastern South Dakota. The high lake levels caused extensive damage to lakeside homes and the transportation grid of rural, county, and State roads. These lake levels are one more manifestation of long-term upward trends of precipitation and streamflow conditions for the area. For example, upward trends are evident in the annual streamflow records for the James and Big Sioux Rivers in eastern South Dakota (Anderson and others, 2008). Levels in Waubay Lake in Day County reached an elevation of 1805.36 feet above the National Geodetic Vertical Datum of 1929 on July 18, 2011, exceeding the previous maximum level that occurred in 1999 by 1.36 feet. Anecdotal evidence and measurements indicate that many other lakes also reached maximum levels in 2011, such as Bitter Lake (1802.98 feet), Blue Dog Lake (1805.80), and Rush Lake (1805.75). These lakes are within a closed basin, with Bitter Lake being the terminal lake. At an estimated elevation of about 1811 feet, water in the Waubay-Bitter Lake system would begin to flow into the Big Sioux River. Some areas of the glaciated terrain of eastern South Dakota have such low topographic relief, that comparatively small increases in lake levels can inundate large land areas. The valuable historical archive of freely available satellite imagery from the U.S. Geological Survey permits analysis of the areal extent of flooding. Landsat and France's SPOT (Système Probatoire d'Observation de la Terre) imagery are coupled with lake-level hydrographs to clearly depict change in land-surface inundation over time. Image analysis will present the change in flooded acreage from minimum lake levels in 1976 to maximum levels in July 2011 for Day County. The hydroclimatic trends are indicating wetter conditions, which leaves open the possibility that lake levels may continue to rise in future years.

  2. Occurrence and Impact of Insects in Maximum Growth Plantations

    SciTech Connect

    Nowak, J.T.; Berisford, C.W.

    2001-01-01

    Investigation of the relationships between intensive management practices and insect infestation using maximum growth potential studies of loblolly pine constructed over five years using a hierarchy of cultural treatments-monitoring differences in growth and insect infestation levels related to the increasing management intensities. This study shows that tree fertilization can increase coneworm infestation and demonstrated that tip moth management tree growth, at least initially.

  3. Growth and Maximum Size of Tiger Sharks (Galeocerdo cuvier) in Hawaii

    PubMed Central

    Meyer, Carl G.; O'Malley, Joseph M.; Papastamatiou, Yannis P.; Dale, Jonathan J.; Hutchinson, Melanie R.; Anderson, James M.; Royer, Mark A.; Holland, Kim N.

    2014-01-01

    Tiger sharks (Galecerdo cuvier) are apex predators characterized by their broad diet, large size and rapid growth. Tiger shark maximum size is typically between 380 & 450 cm Total Length (TL), with a few individuals reaching 550 cm TL, but the maximum size of tiger sharks in Hawaii waters remains uncertain. A previous study suggested tiger sharks grow rather slowly in Hawaii compared to other regions, but this may have been an artifact of the method used to estimate growth (unvalidated vertebral ring counts) compounded by small sample size and narrow size range. Since 1993, the University of Hawaii has conducted a research program aimed at elucidating tiger shark biology, and to date 420 tiger sharks have been tagged and 50 recaptured. All recaptures were from Hawaii except a single shark recaptured off Isla Jacques Cousteau (24°13?17?N 109°52?14?W), in the southern Gulf of California (minimum distance between tag and recapture sites ?=? approximately 5,000 km), after 366 days at liberty (DAL). We used these empirical mark-recapture data to estimate growth rates and maximum size for tiger sharks in Hawaii. We found that tiger sharks in Hawaii grow twice as fast as previously thought, on average reaching 340 cm TL by age 5, and attaining a maximum size of 403 cm TL. Our model indicates the fastest growing individuals attain 400 cm TL by age 5, and the largest reach a maximum size of 444 cm TL. The largest shark captured during our study was 464 cm TL but individuals >450 cm TL were extremely rare (0.005% of sharks captured). We conclude that tiger shark growth rates and maximum sizes in Hawaii are generally consistent with those in other regions, and hypothesize that a broad diet may help them to achieve this rapid growth by maximizing prey consumption rates. PMID:24416287

  4. Have the “mega-journals” reached the limits to growth?

    PubMed Central

    2015-01-01

    A “mega-journal” is a new type of scientific journal that publishes freely accessible articles, which have been peer reviewed for scientific trustworthiness, but leaves it to the readers to decide which articles are of interest and importance to them. In the wake of the phenomenal success of PLOS ONE, several other publishers have recently started mega-journals. This article presents the evolution of mega-journals since 2010 in terms of article publication rates. The fastest growth seems to have ebbed out at around 35,000 annual articles for the 14 journals combined. Acceptance rates are in the range of 50–70%, and speed of publication is around 3–5 months. Common features in mega-journals are alternative impact metrics, easy reusability of figures and data, post-publication discussions and portable reviews from other journals. PMID:26038735

  5. Allometries of Maximum Growth Rate versus Body Mass at Maximum Growth Indicate That Non-Avian Dinosaurs Had Growth Rates Typical of Fast Growing Ectothermic Sauropsids

    PubMed Central

    Werner, Jan; Griebeler, Eva Maria

    2014-01-01

    We tested if growth rates of recent taxa are unequivocally separated between endotherms and ectotherms, and compared these to dinosaurian growth rates. We therefore performed linear regression analyses on the log-transformed maximum growth rate against log-transformed body mass at maximum growth for extant altricial birds, precocial birds, eutherians, marsupials, reptiles, fishes and dinosaurs. Regression models of precocial birds (and fishes) strongly differed from Case’s study (1978), which is often used to compare dinosaurian growth rates to those of extant vertebrates. For all taxonomic groups, the slope of 0.75 expected from the Metabolic Theory of Ecology was statistically supported. To compare growth rates between taxonomic groups we therefore used regressions with this fixed slope and group-specific intercepts. On average, maximum growth rates of ectotherms were about 10 (reptiles) to 20 (fishes) times (in comparison to mammals) or even 45 (reptiles) to 100 (fishes) times (in comparison to birds) lower than in endotherms. While on average all taxa were clearly separated from each other, individual growth rates overlapped between several taxa and even between endotherms and ectotherms. Dinosaurs had growth rates intermediate between similar sized/scaled-up reptiles and mammals, but a much lower rate than scaled-up birds. All dinosaurian growth rates were within the range of extant reptiles and mammals, and were lower than those of birds. Under the assumption that growth rate and metabolic rate are indeed linked, our results suggest two alternative interpretations. Compared to other sauropsids, the growth rates of studied dinosaurs clearly indicate that they had an ectothermic rather than an endothermic metabolic rate. Compared to other vertebrate growth rates, the overall high variability in growth rates of extant groups and the high overlap between individual growth rates of endothermic and ectothermic extant species make it impossible to rule out either of the two thermoregulation strategies for studied dinosaurs. PMID:24586409

  6. The number e^{(1/2)} is the ratio between the time of maximum value and the time of maximum growth rate for restricted growth phenomena?

    E-print Network

    Zi-Niu Wu

    2013-10-02

    For many natural process of growth, with the growth rate independent of size due to Gibrat law and with the growth process following a log-normal distribution, the ratio between the time (D) for maximum value and the time (L) for maximum growth rate (inflexion point) is then equal to the square root of the base of the natural logarithm (e^{1/2}). On the logarithm scale this ratio becomes one half ((1/2)). It remains an open question, due to lack of complete data for various cases with restricted growth, whether this e^{1/2} ratio can be stated as e^{1/2}-Law. Two established examples already published, one for an epidemic spreading and one for droplet production, support however this ratio. Another example appears to be the height of humain body. For boys the maximum height occurs near 23 years old while the maximum growth rate is at the age near 14, and there ratio is close to e^{1/2}. The main theoretical base to obtain this conclusion is problem independent, provided the growth process is restricted, such as public intervention to control the spreading of communicable epidemics, so that an entropy is associated with the process and the role of dissipation, representing the mechanism of intervention, is maximized. Under this formulation the principle of maximum rate of entropy production is used to make the production process problem independent.

  7. Radiative Impacts on the Growth of Drops within Simulated Marine Stratocumulus. Part I: Maximum Solar Heating

    E-print Network

    Harrington, Jerry Y.

    Radiative Impacts on the Growth of Drops within Simulated Marine Stratocumulus. Part I: Maximum Solar Heating CHRISTOPHER M. HARTMAN AND JERRY Y. HARRINGTON Department of Meteorology, The Pennsylvania November 2004) ABSTRACT The effects of solar heating and infrared cooling on the vapor depositional growth

  8. StockRecruitment Dynamics and the Maximum Population Growth Rate of the Barndoor Skate on Georges Bank

    E-print Network

    Kuehl, Steven A.

    Stock­Recruitment Dynamics and the Maximum Population Growth Rate of the Barndoor Skate on Georges population dynamics: the relationship of recruitment to spawner abundance and the maximum population growth of the instantaneous maximum population growth rate of 0.37­0.38 per year. A second analysis was also conducted using

  9. Expanding the reach of youth mentoring: partnering with youth for personal growth and social change.

    PubMed

    Liang, Belle; Spencer, Renée; West, Jennifer; Rappaport, Nancy

    2013-04-01

    The goals of youth mentoring have broadened from redressing youth problems to promoting positive youth development. Yet, many of the principles associated with contemporary conceptualizations of development found in the positive youth development (PYD) and community psychology (CP) literature have yet to be fully integrated into mentoring research and practice. These approaches place greater emphasis on youth as assets to their communities and the promotion of positive development through the cultivation of these assets, often by fostering collaborative partnerships between youth and adults to effect social change. In this paper, we examine how bringing these systemic, asset-oriented approaches more fully to bear on the youth mentoring process creates opportunities that may both extend the reach and deepen the impact of youth mentoring through the promotion of community, social, and individual change. PMID:23267749

  10. Persistent growth of CO2 emissions and implications for reaching climate targets

    NASA Astrophysics Data System (ADS)

    Friedlingstein, P.; Andrew, R. M.; Rogelj, J.; Peters, G. P.; Canadell, J. G.; Knutti, R.; Luderer, G.; Raupach, M. R.; Schaeffer, M.; van Vuuren, D. P.; Le Quéré, C.

    2014-10-01

    Efforts to limit climate change below a given temperature level require that global emissions of CO2 cumulated over time remain below a limited quota. This quota varies depending on the temperature level, the desired probability of staying below this level and the contributions of other gases. In spite of this restriction, global emissions of CO2 from fossil fuel combustion and cement production have continued to grow by 2.5% per year on average over the past decade. Two thirds of the CO2 emission quota consistent with a 2 °C temperature limit has already been used, and the total quota will likely be exhausted in a further 30 years at the 2014 emissions rates. We show that CO2 emissions track the high end of the latest generation of emissions scenarios, due to lower than anticipated carbon intensity improvements of emerging economies and higher global gross domestic product growth. In the absence of more stringent mitigation, these trends are set to continue and further reduce the remaining quota until the onset of a potential new climate agreement in 2020. Breaking current emission trends in the short term is key to retaining credible climate targets within a rapidly diminishing emission quota.

  11. Phylogenetic prediction of the maximum per capita rate of population growth

    PubMed Central

    Fagan, William F.; Pearson, Yanthe E.; Larsen, Elise A.; Lynch, Heather J.; Turner, Jessica B.; Staver, Hilary; Noble, Andrew E.; Bewick, Sharon; Goldberg, Emma E.

    2013-01-01

    The maximum per capita rate of population growth, r, is a central measure of population biology. However, researchers can only directly calculate r when adequate time series, life tables and similar datasets are available. We instead view r as an evolvable, synthetic life-history trait and use comparative phylogenetic approaches to predict r for poorly known species. Combining molecular phylogenies, life-history trait data and stochastic macroevolutionary models, we predicted r for mammals of the Caniformia and Cervidae. Cross-validation analyses demonstrated that, even with sparse life-history data, comparative methods estimated r well and outperformed models based on body mass. Values of r predicted via comparative methods were in strong rank agreement with observed values and reduced mean prediction errors by approximately 68 per cent compared with two null models. We demonstrate the utility of our method by estimating r for 102 extant species in these mammal groups with unknown life-history traits. PMID:23720545

  12. On-line estimation of the maximum specific growth rate of nitrifiers in activated sludge systems

    SciTech Connect

    Yuan, Z.; Bogaert, H.; Devisscher, M.; Vanrolleghem, P.; Verstraete, W.

    1999-11-05

    The on-line estimation of the maximum specific growth rate of autotrophic biomass is addressed in this article. A general nitrification process model, which is valid for any realistic flow pattern, is used to develop the estimation algorithm. Depending on the measurements available, two estimation equations are derived. While both require measuring the nitrification activity of the activated sludge, one requires the additional measurement of the nitrifiable nitrogen concentrations at the two ends of the bioreactor, and the other requires the nitrate nitrogen concentrations at the same location. The algorithm alo requires some stoichlometric and kinetic parameters. However, sensitivity analysis shows that the estimate is insensitive to the parameters other than the autotrophoc decay rate. Compared to the existing algorithms, the algorithm developed in this article does not rely on the assumption of ideal flow pattern in the plant and does not require an error-prone estimate of the autotrophic biomass concentration. Experimental and simulation studies show that the algorithm performs well and is robust to influence variations and accidental sludge losses.

  13. Pigmentation in Drosophila melanogaster reaches its maximum in Ethiopia and correlates most strongly with ultra-violet radiation in sub-Saharan Africa

    PubMed Central

    2014-01-01

    Background Pigmentation has a long history of investigation in evolutionary biology. In Drosophila melanogaster, latitudinal and altitudinal clines have been found but their underlying causes remain unclear. Moreover, most studies were conducted on cosmopolitan populations which have a relatively low level of genetic structure and diversity compared to sub-Saharan African populations. We investigated: 1) the correlation between pigmentation traits within and between the thorax and the fourth abdominal segment, and 2) their associations with different geographical and ecological variables, using 710 lines belonging to 30 sub-Saharan and cosmopolitan populations. Results Pigmentation clines substantially differed between sub-Saharan and cosmopolitan populations. While positive correlations with latitude have previously been described in Europe, India and Australia, in agreement with Bogert's rule or the thermal melanism hypothesis, we found a significant negative correlation in Africa. This correlation persisted even after correction for altitude, which in its turn showed a positive correlation with pigmentation independently from latitude. More importantly, we found that thoracic pigmentation reaches its maximal values in this species in high-altitude populations of Ethiopia (1,600-3,100 m). Ethiopian flies have a diffuse wide thoracic trident making the mesonotum and the head almost black, a phenotype that is absent from all other sub-Saharan or cosmopolitan populations including high-altitude flies from Peru (~3,400 m). Ecological analyses indicated that the variable most predictive of pigmentation in Africa, especially for the thorax, was ultra-violet (UV) intensity, consistent with the so-called Gloger's rule invoking a role of melanin in UV protection. Conclusion Our data suggest that different environmental factors may shape clinal variation in tropical and temperate regions, and may lead to the evolution of different degrees of melanism in different high altitude populations in the tropics. PMID:25115161

  14. Maximum likelihood estimation of population growth rates based on the coalescent.

    PubMed Central

    Kuhner, M K; Yamato, J; Felsenstein, J

    1998-01-01

    We describe a method for co-estimating 4Nemu (four times the product of effective population size and neutral mutation rate) and population growth rate from sequence samples using Metropolis-Hastings sampling. Population growth (or decline) is assumed to be exponential. The estimates of growth rate are biased upwards, especially when 4Nemu is low; there is also a slight upwards bias in the estimate of 4Nemu itself due to correlation between the parameters. This bias cannot be attributed solely to Metropolis-Hastings sampling but appears to be an inherent property of the estimator and is expected to appear in any approach which estimates growth rate from genealogy structure. Sampling additional unlinked loci is much more effective in reducing the bias than increasing the number or length of sequences from the same locus. PMID:9584114

  15. Ecotypic variation in growth responses to simulated herbivory: trade-off between maximum relative growth rate and tolerance to defoliation in an annual plant.

    PubMed

    Camargo, Iván D; Tapia-López, Rosalinda; Núñez-Farfán, Juan

    2015-01-01

    It has been hypothesized that slow-growing plants are more likely to maximize above-ground biomass and fitness when defoliated by herbivores than those with an already high relative growth rate (RGR). Some populations of the annual herb Datura stramonium L. can tolerate foliar damage better than others. The physiological basis of this difference is examined here in a comparative study of two ecotypes that differ in tolerance and maximum growth rate, using a growth analytical approach. One hundred and fifty-four plants of each ecotype grown under controlled conditions were suddenly defoliated (35 % of total leaf area removed) and a similar sample size of plants remained undefoliated (control). Ontogenetic plastic changes in RGR and its growth components [net assimilation rate (NAR), specific leaf area and leaf weight ratio (LWR)] after defoliation were measured to determine whether these plastic changes maximize plant growth and fitness. Different ontogenetic phases of the response were discerned and increased RGR of defoliated plants was detected at the end of the experimental period, but brought about by a different growth component (NAR or LWR) in each ecotype. These changes in RGR are putatively related to increases in fitness in defoliated environments. At the intra-specific scale, data showed a trade-off between the ability to grow under benign environmental conditions and the ability to tolerate resource limitation due to defoliation. PMID:25725085

  16. Ecotypic variation in growth responses to simulated herbivory: trade-off between maximum relative growth rate and tolerance to defoliation in an annual plant

    PubMed Central

    Camargo, Iván D.; Tapia-López, Rosalinda; Núñez-Farfán, Juan

    2015-01-01

    It has been hypothesized that slow-growing plants are more likely to maximize above-ground biomass and fitness when defoliated by herbivores than those with an already high relative growth rate (RGR). Some populations of the annual herb Datura stramonium L. can tolerate foliar damage better than others. The physiological basis of this difference is examined here in a comparative study of two ecotypes that differ in tolerance and maximum growth rate, using a growth analytical approach. One hundred and fifty-four plants of each ecotype grown under controlled conditions were suddenly defoliated (35 % of total leaf area removed) and a similar sample size of plants remained undefoliated (control). Ontogenetic plastic changes in RGR and its growth components [net assimilation rate (NAR), specific leaf area and leaf weight ratio (LWR)] after defoliation were measured to determine whether these plastic changes maximize plant growth and fitness. Different ontogenetic phases of the response were discerned and increased RGR of defoliated plants was detected at the end of the experimental period, but brought about by a different growth component (NAR or LWR) in each ecotype. These changes in RGR are putatively related to increases in fitness in defoliated environments. At the intra-specific scale, data showed a trade-off between the ability to grow under benign environmental conditions and the ability to tolerate resource limitation due to defoliation. PMID:25725085

  17. REACH Presentation.

    ERIC Educational Resources Information Center

    Bucklee, Joanne

    In an effort to provide support for employees and their families, Red Deer College (RDC) developed the Resources, Employees, Assistance, Counselling, and Health (REACH) program. The program is administered by a committee of five people who represent the five major employee groups at the college (i.e., senior administration, middle administration,…

  18. Controls on the Growth and Maximum Size of Fault Arrays and Fault Segments--Insights from Experimental Clay Models

    NASA Astrophysics Data System (ADS)

    Schlische, R. W.; Withjack, M. O.; Ackermann, R. V.; Clifton, A. E.

    2003-12-01

    We have used a series of scaled experimental models with clay to study the nucleation, growth and linkage of fault arrays and their constituent fault segments. We have varied the clay thickness and the magnitude, rate, width, and obliquity of deformation. We have also varied the basal boundary conditions: 1) focussed deformation associated with the edges of moving metal plates or metal blocks, simulating the effects of fault reactivation on a cover sequence, and 2) deformation above a rubber sheet, simulating distributed deformation. For small amounts of strain, the lengths of fault arrays and segments increase with increasing deformation and increase with decreasing deformation rate. Most fault arrays and segments ultimately achieve a `maximum' length. This length depends on mechanical-layer thickness (increasing as thickness increases), deformation-zone width (increasing as width increases), and obliquity (decreasing as obliquity increases). Mechanical-layer thickness and deformation-zone width have an especially strong influence on the 'maximum' length of fault segments. The length of the fault array that develops during fault reactivation is strongly controlled by the length of the underlying reactivated fault, whereas the length of the constituent fault segments is controlled by the factors discussed above. Although a hard-linked fault array ultimately develops from these segments (given enough displacement on the reactivated fault), evidence of the location of former segment boundaries is long-lived. This evidence includes breached relay ramps, fault-displacement folds, and fault strands. The persistence of these features decreases with increasing displacement on the reactivated fault, decreasing thickness of the cover sequence, and decreasing obliquity. As most fault populations have a 'maximum' length, we expect that power-law size distributions will be uncommon. Our experimental models indicate that an exponential size distribution describes most fault populations. An exception is fault populations that form during orthogonal deformation at low strains. At higher strains, these fault populations also exhibit an exponential size distribution, with a power-law to exponential transition occurring at higher strains in thicker mechanical layers. As the maximum length of faults is limited in the experimental models, we expect that the scaling law between length and displacement will change with increasing strain. This may contribute to the large scatter in experimental and natural length-displacement data.

  19. Logistic Growth The logistic equation is a model of limited population growth. The exponential growth model

    E-print Network

    Ikenaga, Bruce

    9­28­1998 Logistic Growth The logistic equation is a model of limited population growth and K grow almost exponentially at first. Growth slows as N nears the limiting population K. As t !1, N, and the carrying capacity of the cabinet is K = 10000. The population reaches its maximum growth rate in 4 days

  20. AEROSOL NUCLEATION AND GROWTH DURING LAMINAR TUBE FLOW: MAXIMUM SATURATIONS AND NUCLEATION RATES. (R827354C008)

    EPA Science Inventory

    An approximate method of estimating the maximum saturation, the nucleation rate, and the total number nucleated per second during the laminar flow of a hot vapour–gas mixture along a tube with cold walls is described. The basis of the approach is that the temperature an...

  1. Variation of Maximum Tree Height and Annual Shoot Growth of Smith Fir at Various Elevations in the Sygera Mountains, Southeastern Tibetan Plateau

    PubMed Central

    Wang, Yafeng; ?ufar, Katarina; Eckstein, Dieter; Liang, Eryuan

    2012-01-01

    Little is known about tree height and height growth (as annual shoot elongation of the apical part of vertical stems) of coniferous trees growing at various altitudes on the Tibetan Plateau, which provides a high-elevation natural platform for assessing tree growth performance in relation to future climate change. We here investigated the variation of maximum tree height and annual height increment of Smith fir (Abies georgei var. smithii) in seven forest plots (30 m×40 m) along two altitudinal transects between 3,800 m and 4,200/4,390 m above sea level (a.s.l.) in the Sygera Mountains, southeastern Tibetan Plateau. Four plots were located on north-facing slopes and three plots on southeast-facing slopes. At each site, annual shoot growth was obtained by measuring the distance between successive terminal bud scars along the main stem of 25 trees that were between 2 and 4 m high. Maximum/mean tree height and mean annual height increment of Smith fir decreased with increasing altitude up to the tree line, indicative of a stress gradient (the dominant temperature gradient) along the altitudinal transect. Above-average mean minimum summer (particularly July) temperatures affected height increment positively, whereas precipitation had no significant effect on shoot growth. The time series of annual height increments of Smith fir can be used for the reconstruction of past climate on the southeastern Tibetan Plateau. In addition, it can be expected that the rising summer temperatures observed in the recent past and anticipated for the future will enhance Smith fir's growth throughout its altitudinal distribution range. PMID:22396738

  2. Treponema pallidum 3-phosphoglycerate mutase is a heat-labile enzyme that may limit the maximum growth temperature for the spirochete.

    PubMed

    Benoit, S; Posey, J E; Chenoweth, M R; Gherardini, F C

    2001-08-01

    In the causative agent of syphilis, Treponema pallidum, the gene encoding 3-phosphoglycerate mutase, gpm, is part of a six-gene operon (tro operon) that is regulated by the Mn-dependent repressor TroR. Since substrate-level phosphorylation via the Embden-Meyerhof pathway is the principal way to generate ATP in T. pallidum and Gpm is a key enzyme in this pathway, Mn could exert a regulatory effect on central metabolism in this bacterium. To study this, T. pallidum gpm was cloned, Gpm was purified from Escherichia coli, and antiserum against the recombinant protein was raised. Immunoblots indicated that Gpm was expressed in freshly extracted infective T. pallidum. Enzyme assays indicated that Gpm did not require Mn(2+) while 2,3-diphosphoglycerate (DPG) was required for maximum activity. Consistent with these observations, Mn did not copurify with Gpm. The purified Gpm was stable for more than 4 h at 25 degrees C, retained only 50% activity after incubation for 20 min at 34 degrees C or 10 min at 37 degrees C, and was completely inactive after 10 min at 42 degrees C. The temperature effect was attenuated when 1 mM DPG was added to the assay mixture. The recombinant Gpm from pSLB2 complemented E. coli strain PL225 (gpm) and restored growth on minimal glucose medium in a temperature-dependent manner. Increasing the temperature of cultures of E. coli PL225 harboring pSLB2 from 34 to 42 degrees C resulted in a 7- to 11-h period in which no growth occurred (compared to wild-type E. coli). These data suggest that biochemical properties of Gpm could be one contributing factor to the heat sensitivity of T. pallidum. PMID:11466272

  3. Clonal Clustering Using 10-Gene Multilocus Sequence Typing Reveals an Association Between Genotype and Listeria monocytogenes Maximum Growth Rate in Defined Medium.

    PubMed

    Tang, Silin; Wiedmann, Martin; Gardner, Alexandra L; Brown, Ana' M; Boor, Kathryn J; Bergholz, Teresa M

    2015-12-01

    We used a 10-gene (10G) multilocus sequence typing scheme to investigate the diversity and phylogenetic distribution of 124 Listeria monocytogenes strains across major lineages, major serotypes, and seven epidemic clones that have been previously associated with outbreaks. The 124 isolates proved to be diverse, with a total of 81 sequence types (10G-STs) belonging to 13 clonal complexes (CCs), where all STs of the same CC differ from one another in up to 3 of the 10 alleles (named as 10G-triple-locus-variant-clonal-complexes [10G-TLV-CCs]). Phenotypic characterization for 105 of the 124 strains showed that L. monocytogenes had variable maximum growth rate (?max) in a defined medium at 16°C, and classification by lineage or serotype was not able to reflect the genetic basis for the difference of this phenotype. Among the six major 10G-TLV-CCs, 10G-TLV-CC4 that included lineage I strains had significantly lower ?max (Tukey honestly significant difference adjusted [adj.] p?growth of these L. monocytogenes isolates under nutrient-limited conditions among some of the CCs. However, the other three (10G-TLV-CC2, 6, and 10) of the six major 10G-TLV-CCs containing either lineage I or lineage II strains did not show significantly different ?max compared to the others (adj. p?

  4. Effects of High-Flow Experiments from Glen Canyon Dam on Abundance, Growth, and Survival Rates of Early Life Stages of Rainbow Trout in the Lees Ferry Reach of the Colorado River

    USGS Publications Warehouse

    Korman, Josh; Kaplinski, Matthew; Melis, Theodore S.

    2010-01-01

    High-flow experiments (HFEs) from Glen Canyon Dam are primarily intended to conserve fine sediment and improve habitat conditions for native fish in the Colorado River as it flows through Grand Canyon National Park, Arizona. These experimental flows also have the potential to affect the rainbow trout (Oncorhynchus mykiss) population in the Lees Ferry tailwater reach immediately below the dam, which supports a highly valued recreational fishery and likely influences the abundance of rainbow trout in Grand Canyon. Understanding how flow regimes affect the survival and growth of juvenile rainbow trout is critical to interpreting trends in adult abundance. This study reports on the effects of HFEs in 2004 and 2008 on early life stages of rainbow trout in the Lees Ferry reach on the basis of monthly sampling of redds (egg nests) and the abundance of the age-0 trout (fertilization to about 1 to 2 months from emergence) and their growth during a 7-year period between 2003 and 2009. Multiple lines of evidence indicate that the March 2008 HFE resulted in a large increase in early survival rates of age-0 trout because of an improvement in habitat conditions. A stock-recruitment analysis demonstrated that age-0 abundance in July 2008 was more than fourfold higher than expected, given the number of viable eggs that produced these fish. A hatch-date analysis showed that early survival rates were much higher for cohorts that hatched about 1 month after the 2008 HFE (about April 15, 2008) relative to those fish that hatched before this date. These cohorts, fertilized after the 2008 HFE, would have emerged into a benthic invertebrate community that had recovered, and was possibly enhanced by, the HFE. Interannual differences in growth of age-0 trout, determined on the basis of otolith microstructure, support this hypothesis. Growth rates in the summer and fall of 2008 (0.44 mm/day) were virtually the same as in 2006 (0.46 mm/day), the highest recorded during 6 years, even though abundance was eightfold greater in 2008. We speculate that the 60-hour-long 2008 HFE (with peak magnitude about twice that of the annual peak flow during the previous 4 years) increased interstitial spaces in the gravel bed substrate and food availability or quality, leading to higher early survival of recently emerged trout and better growth of these fish through summer and fall. Abundance in 2009 was more than twofold higher than expected, given the estimated number of viable eggs deposited in that year, perhaps indicating that the effect of the 2008 HFE on early life stages was somewhat persistent. In a 3-week interval that spanned the November 2004 HFE, abundance of age-0 trout that were approximately 7 months old from hatch experienced about a threefold decline, compared to the approximately twofold decrease observed between November and December 2008. Abundance of age-0 trout that were approximately 10 months old from hatch was very similar across sampling trips that spanned the March 2008 HFE. It is uncertain whether the decline in abundance after the November 2004 HFE was the result of higher flow-induced mortality or higher flow-induced downstream dispersal. A focused monitoring effort in Marble Canyon (the reach immediately downstream of the Lees Ferry tailwater) before and after future HFEs is recommended to resolve this uncertainty. Relatively detailed monitoring of early life stages-such as the program described in this study-is essential to establish linkages between Glen Canyon Dam operations, or possibly other factors, and trends in the abundance of important nonnative and native fish populations living downstream within Grand Canyon National Park.

  5. [Bluetongue disease reaches Switzerland].

    PubMed

    Hofmann, M; Griot, C; Chaignat, V; Perler, L; Thür, B

    2008-02-01

    Since 2006 bluetongue disease is rapidly spreading across Europe and reached Switzerland in October 2007. In the present article a short overview about the disease and the virus is given, and the first three clinical bluetongue disease cases in cattle, and the respective laboratory findings are presented. PMID:18369049

  6. Reaching for the Stars.

    ERIC Educational Resources Information Center

    Roper-Davis, Sharon

    1999-01-01

    Describes "Reaching for the Stars," a program which develops teaming and mentoring skills in senior physics students. Phase 1 requires student pairs to design a rocket; Phase 2 pairs seniors with gifted second graders who build the rocket from written instructions; and in Phase 3, pairs of seniors create a children's storybook explaining one of…

  7. REACH. Refrigeration Units.

    ERIC Educational Resources Information Center

    Snow, Rufus; And Others

    As a part of the REACH (Refrigeration, Electro-Mechanical, Air-Conditioning, Heating) electromechanical cluster, this student manual contains individualized instructional units in the area of refrigeration. The instructional units focus on refrigeration fundamentals, tubing and pipe, refrigerants, troubleshooting, window air conditioning, and…

  8. Reaching for the Stars

    ERIC Educational Resources Information Center

    Terry, Dorothy Givens

    2012-01-01

    Dr. Mae Jemison is the world's first woman astronaut of color who continues to reach for the stars. Jemison was recently successful in leading a team that has secured a $500,000 federal grant to make interstellar space travel a reality. The Dorothy Jemison Foundation for Excellence (named after Jemison's mother) was selected in June by the Defense…

  9. "Brown's" Far Reaching Impact

    ERIC Educational Resources Information Center

    Chinn, Philip C.

    2004-01-01

    Although the 1954 "Brown v. Board of Education" U.S. Supreme Court decision changed the face of American education forever, few individuals at that time could have fully realized its far-reaching implications. Certainly, the National Association for the Advancement of Colored People Legal Director Thurgood Marshall in his arguments was focusing on…

  10. Reaching Black Men. Commentary

    ERIC Educational Resources Information Center

    Gassman, Marybeth

    2010-01-01

    Journalist Elizabeth Redden brings to the surface several salient issues in her article entitled, "Reaching Black Men." First, she illuminates that fact that access is not enough when it comes to educating African American men. Second, she points to the importance of having campus-wide initiatives to support the success of Black men. And lastly,…

  11. REACH. Major Appliance.

    ERIC Educational Resources Information Center

    English, Charles; And Others

    As a part of the REACH (Refrigeration, Electro-Mechanical, Air-Conditioning, Heating) electromechanical cluster, this student manual contains individualized instructional units in the area of major appliances. The instructional units focus on installation of appliances, troubleshooting washing machines, troubleshooting electric dryers,…

  12. Reaching Your Fitness Goals

    MedlinePLUS

    Everyday Fitness Ideas from the National Institute on Aging at NIH www.nia.nih.gov/Go4Life Reaching Your Fitness Goals You’ll begin to see results in ... longer, and more easily. As you increase your fitness level, you also might find that you need ...

  13. Effects of Experimental High Flow Releases and Increased Fluctuations in Flow from Glen Canyon Dam on Abundance, Growth, and Survival Rates of Early Life Stages of Rainbow Trout in the Lee's Ferry Reach of the Colorado River

    NASA Astrophysics Data System (ADS)

    Korman, Josh

    2010-05-01

    The abundance of adult fish populations is controlled by the growth and survival rates of early life stages. Evaluating the effects of flow regimes on early life stages is therefore critical to determine how these regimes affect the abundance of adult populations. Experimental high flow releases from Glen Canyon Dam, primarily intended to conserve fine sediment and improve habitat conditions for native fish in the Colorado River in Grand Canyon, AZ, have been conducted in 1996, 2004, and 2008. These flows potentially affect the Lee's Ferry reach rainbow trout population, located immediately downstream of the dam, which supports a highly valued fishery and likely influences the abundance of rainbow trout in Grand Canyon. Due to concerns about negative effects of high trout abundance on endangered native fish, hourly variation in flow from Glen Canyon Dam was experimentally increased between 2003 and 2005 to reduce trout abundance. This study reports on the effects of experimental high flow releases and fluctuating flows on early life stages of rainbow trout in the Lee's Ferry reach based on monthly sampling of redds (egg nests) and the abundance and growth of age-0 trout between 2003 and 2009. Data on spawn timing, spawning elevations, and intergravel temperatures were integrated in a model to estimate the magnitude and seasonal trend in incubation mortality resulting from redd dewatering due to fluctuations in flow. Experimental fluctuations from January through March promoted spawning at higher elevations where the duration of dewatering was longer and intergravel temperatures exceeded lethal thresholds. Flow-dependent incubation mortality rates were 24% (2003) and 50% (2004) in years with higher flow fluctuations, compared to 5-11% under normal operations (2006-2009). Spatial and temporal predictions of mortality were consistent with direct observations of egg mortality determined from the excavation of 125 redds. The amount of variation in backcalculated hatch date distributions predicted by flow-independent (84-93%) and flow-dependent (82-91%) incubation loss models were similar. Age-0 abundance was generally independent of viable egg deposition, except in one year when egg deposition was 10-fold lower due to reduced spawning activity. There was no evidence from the hatch date or stock-recruitment analysis that flow-dependent incubation losses, although large in experimental years, affected the abundance of the age-0 population. The data indicate that strong compensation in survival rates shortly after emergence mitigated the impact of flow-dependent losses. Multiple lines of evidence demonstrated that the March 2008 high flow experiment (HFE) resulted in a large increase in early survival rates (fertilization to ~1-2 months from emergence) of age-0 trout due an improvement in habitat conditions. A stock-recruitment analysis indicated that age-0 abundance in July 2008 was over four-fold higher than expected given the number of viable redds that produced these fish. A hatch date analysis indicated that early survival rates were much higher for cohorts that emerged about two months after the HFE. These cohorts, which were fertilized after the HFE, were not exposed to high flows and emerged into better quality habitat. Inter annual differences in growth of age-0 trout based on otolith microstructure support this hypothesis. Growth rates in the summer and fall of 2008 (0.44 mm·day-1) were virtually the same as in 2006 (0.46 mm·day-1), the highest recorded over six years, even though abundance was eight-fold greater in 2008. I speculate that high flows in 2008 increased interstitial spaces in the substrate and food availability or quality, leading to higher early survival of recently emerged trout and better growth during summer and fall. Abundance in 2009 was over two-fold higher than expected, possibly indicating that the effect of the HFE on early life stages was somewhat persistent.

  14. Maximum Jailbreak

    NASA Astrophysics Data System (ADS)

    Singleton, B.

    First formulated one hundred and fifty years ago by the heretical scholar Nikolai Federov, the doctrine of cosmism begins with an absolute refusal to treat the most basic factors conditioning life on Earth ­ gravity and death ­ as necessary constraints on action. As manifest through the intoxicated cheers of its early advocates that humans should storm the heavens and conquer death, cosmism's foundational gesture was to conceive of the earth as a trap. Its duty was therefore to understand the duty of philosophy, economics and design to be the creation of means to escape it. This could be regarded as a jailbreak at the maximum possible scale, a heist in which the human species could steal itself from the vault of the Earth. After several decades of relative disinterest new space ventures are inspiring scientific, technological and popular imaginations, this essay explores what kind of cosmism might be constructed today. In this paper cosmism's position as a means of escape is both reviewed and evaluated by reflecting on the potential of technology that actually can help us achieve its aims and also through the lens and state-ofthe-art philosophy of accelerationism, which seeks to outrun modern tropes by intensifying them.

  15. High Performance “Reach” Codes 

    E-print Network

    Edelson, J.

    2011-01-01

    Buildings Institute A Growing Role for Codes and Stretch Codes in Utility Programs Clean Air Through Energy Efficiency November 9, 2011 ESL-KT-11-11-39 CATEE 2011, Dallas, Texas, Nov. 7 ? 9, 2011 New Buildings Institute ESL-KT-11-11-39 CATEE 2011... of Codes ? Building Codes Construction Codes Energy Codes Stretch or Reach Energy Codes Above-code programs Green or Sustainability Codes Model Codes ?Existing Building? Codes Outcome-Based Codes ESL-KT-11-11-39 CATEE 2011, Dallas, Texas, Nov. 7...

  16. Estimation of alga growth stage and lipid content growth rate

    NASA Technical Reports Server (NTRS)

    Embaye, Tsegereda N. (Inventor); Trent, Jonathan D. (Inventor)

    2012-01-01

    Method and system for estimating a growth stage of an alga in an ambient fluid. Measured light beam absorption or reflection values through or from the alga and through an ambient fluid, in each of two or more wavelength sub-ranges, are compared with reference light beam absorption values for corresponding wavelength sub-ranges for in each alga growth stage to determine (1) which alga growth stage, if any, is more likely and (2) whether estimated lipid content of the alga is increasing or has peaked. Alga growth is preferably terminated when lipid content has approximately reached a maximum value.

  17. Variability and Constancy in Cellular Growth of Arabidopsis Sepals.

    PubMed

    Tauriello, Gerardo; Meyer, Heather M; Smith, Richard S; Koumoutsakos, Petros; Roeder, Adrienne H K

    2015-12-01

    Growth of tissues is highly reproducible; yet, growth of individual cells in a tissue is highly variable, and neighboring cells can grow at different rates. We analyzed the growth of epidermal cell lineages in the Arabidopsis (Arabidopsis thaliana) sepal to determine how the growth curves of individual cell lineages relate to one another in a developing tissue. To identify underlying growth trends, we developed a continuous displacement field to predict spatially averaged growth rates. We showed that this displacement field accurately describes the growth of sepal cell lineages and reveals underlying trends within the variability of in vivo cellular growth. We found that the tissue, individual cell lineages, and cell walls all exhibit growth rates that are initially low, accelerate to a maximum, and decrease again. Accordingly, these growth curves can be represented by sigmoid functions. We examined the relationships among the cell lineage growth curves and surprisingly found that all lineages reach the same maximum growth rate relative to their size. However, the cell lineages are not synchronized; each cell lineage reaches this same maximum relative growth rate but at different times. The heterogeneity in observed growth results from shifting the same underlying sigmoid curve in time and scaling by size. Thus, despite the variability in growth observed in our study and others, individual cell lineages in the developing sepal follow similarly shaped growth curves. PMID:26432876

  18. Europe reaches the Moon

    NASA Astrophysics Data System (ADS)

    2004-11-01

    A complex package of tests on new technologies was successfully performed during the cruise to the Moon, while the spacecraft was getting ready for the scientific investigations which will come next. These technologies pave the way for future planetary missions. SMART-1 reached its closest point to the lunar surface so far - its first ‘perilune’ - at an altitude of about 5000 kilometres at 18:48 Central European Time (CET) on 15 November. Just hours before that, at 06:24 CET, SMART-1’s solar-electric propulsion system (or ‘ion engine’) was started up and is now being fired for the delicate manoeuvre that will stabilise the spacecraft in lunar orbit. During this crucial phase, the engine will run almost continuously for the next four days, and then for a series of shorter burns, allowing SMART-1 to reach its final operational orbit by making ever-decreasing loops around the Moon. By about mid-January, SMART-1 will be orbiting the Moon at altitudes between 300 kilometres (over the lunar south pole) and 3000 kilometres (over the lunar north pole), beginning its scientific observations. The main purpose of the first part of the SMART-1 mission, concluding with the arrival at the Moon, was to demonstrate new spacecraft technologies. In particular, the solar-electric propulsion system was tested over a long spiralling trip to the Moon of more than 84 million kilometres. This is a distance comparable to an interplanetary cruise. For the first time ever, gravity-assist manoeuvres, which use the gravitational pull of the approaching Moon, were performed by an electrically-propelled spacecraft. The success of this test is important to the prospects for future interplanetary missions using ion engines. SMART-1 has demonstrated new techniques for eventually achieving autonomous spacecraft navigation. The OBAN experiment tested navigation software on ground computers to determine the exact position and velocity of the spacecraft using images of celestial objects taken by the AMIE camera on SMART-1 as references. Once used on board future spacecraft, the technique demonstrated by OBAN will allow spacecraft to know where they are in space and how fast they are moving, limiting the need for intervention by ground control teams. SMART-1 also carried out deep-space communication tests, with the KaTE and RSIS experiments, consisting of testing radio transmissions at very high frequencies compared to traditional radio frequencies. Such transmissions will allow the transfer of ever-increasing volumes of scientific data from future spacecraft. With the Laser Link experiment, SMART-1 tested the feasibility of pointing a laser beam from Earth at a spacecraft moving at deep-space distances for future communication purposes. During the cruise, to prepare for the lunar science phase, SMART-1 made preliminary tests on four miniaturised instruments, which are being used for the first time in space: the AMIE camera, which has already imaged Earth, the Moon and two total lunar eclipses from space, the D-CIXS and XSM X-ray instruments, and the SIR infrared spectrometer. In all, SMART-1 clocked up 332 orbits around Earth. It fired its engine 289 times during the cruise phase, operating for a total of about 3700 hours. Only 59 kilograms of xenon propellant were used (out of 82 kilograms). Overall, the engine performed extremely well, enabling the spacecraft to reach the Moon two months earlier than expected. The extra fuel available also allowed the mission designers to significantly reduce the altitude of the final orbit around the Moon. This closer approach to the surface will be even more favourable for the science observations that start in January. The extra fuel will also be used to boost the spacecraft back into a stable orbit, after six months of operations around the Moon, in June, if the scientific mission is extended.

  19. Reaching Beyond The Stars

    NASA Astrophysics Data System (ADS)

    Baker, Mariah; Rosenthal, L.; Gaughan, A.; Hopkins, E.

    2014-01-01

    Strawbridge Observatory at Haverford College is home to a undergraduate-led public observing program. Our program holds ~once monthly public events throughout the academic year that take advantage of eyepiece observing on our 16-inch and 12-inch telescopes as well as of the classroom, library, and projection system. These resources allow us to organize a variety of astronomy related activities that are engaging for individuals of all ages: accessible student talks, current film screenings and even arts and crafts for the families who attend with young children. These events aim to spark curiosity in others about scientific discovery and about the remarkable nature of the world in which we live. In addition to exciting local families about astronomy, this program has excited Haverford students from a range of disciplines about both science and education. Being entirely student led means that we are able to take the initiative in planning, coordinating and running all events, fostering an atmosphere of collaboration, experimentation and commitment amongst our volunteers. Additionally, this program is one of the few at Haverford that regularly reaches beyond the campus walls to promote and build relationships with the outside community. In light of this, our program presents a distinctive and enlightening opportunity for student volunteers: we get to use our scientific backgrounds to educate a general audience, while also learning from them about how to communicate and inspire in others the excitement we feel about the subject of astronomy. The work on this project has been supported by NSF AST-1151462.

  20. Tree growth in carbon dioxide enriched air and its implications for global carbon cycling and maximum levels of atmospheric CO2

    NASA Astrophysics Data System (ADS)

    Idso, Sherwood B.; Kimball, Bruce A.

    1993-09-01

    In the longest carbon dioxide enrichment experiment ever conducted, well-watered and adequately fertilized sour orange tree seedlings were planted directly into the ground at Phoenix, Arizona, in July 1987 and continuously exposed, from mid-November of that year, to either ambient air or air enriched with an extra 300 ppmv of CO2 in clear-plastic-wall open-top enclosures. Only 18 months later, the CO2-enriched trees had grown 2.8 times larger than the ambient-treated trees; and they have maintained that productivity differential to the present day. This tremendous growth advantage is due to two major factors: a CO2-induced increase in daytime net photosynthesis and a CO2-induced reduction in nighttime dark respiration. Measurements of these physiological processes in another experiment have shown three Australlian tree species to respond similarly; while an independent study of the atmosphere's seasonal CO2 cycle suggests that all earth's trees, in the mean, probably share this same response. A brief review of the plant science literature outlines how such a large growth response to atmospheric CO2 enrichment might possibly be maintained in light of resource limitations existing in nature. Finally, it is noted that a CO2 "fertilization effect" of this magnitude should substantially slow the rate at which anthropogenic carbon dioxide would otherwise accumulate in the atmosphere, possibly putting an acceptable upper limit on the level to which the CO2 content of the air may ultimately rise.

  1. Variability and Constancy in Cellular Growth of Arabidopsis Sepals1[OPEN

    PubMed Central

    Tauriello, Gerardo; Meyer, Heather M.; Smith, Richard S.

    2015-01-01

    Growth of tissues is highly reproducible; yet, growth of individual cells in a tissue is highly variable, and neighboring cells can grow at different rates. We analyzed the growth of epidermal cell lineages in the Arabidopsis (Arabidopsis thaliana) sepal to determine how the growth curves of individual cell lineages relate to one another in a developing tissue. To identify underlying growth trends, we developed a continuous displacement field to predict spatially averaged growth rates. We showed that this displacement field accurately describes the growth of sepal cell lineages and reveals underlying trends within the variability of in vivo cellular growth. We found that the tissue, individual cell lineages, and cell walls all exhibit growth rates that are initially low, accelerate to a maximum, and decrease again. Accordingly, these growth curves can be represented by sigmoid functions. We examined the relationships among the cell lineage growth curves and surprisingly found that all lineages reach the same maximum growth rate relative to their size. However, the cell lineages are not synchronized; each cell lineage reaches this same maximum relative growth rate but at different times. The heterogeneity in observed growth results from shifting the same underlying sigmoid curve in time and scaling by size. Thus, despite the variability in growth observed in our study and others, individual cell lineages in the developing sepal follow similarly shaped growth curves. PMID:26432876

  2. Maximum Entropy Fundamentals

    NASA Astrophysics Data System (ADS)

    Harremoeës, P.; Topsøe, F.

    2001-09-01

    In its modern formulation, the Maximum Entropy Principle was promoted by E.T. Jaynes, starting in the mid-fifties. The principle dictates that one should look for a distribution, consistent with available information, which maximizes the entropy. However, this principle focuses only on distributions and it appears advantageous to bring information theoretical thinking more prominently into play by also focusing on the "observer" and on coding. This view was brought forward by the second named author in the late seventies and is the view we will follow-up on here. It leads to the consideration of a certain game, the Code Length Game and, via standard game theoretical thinking, to a principle of Game Theoretical Equilibrium. This principle is more basic than the Maximum Entropy Principle in the sense that the search for one type of optimal strategies in the Code Length Game translates directly into the search for distributions with maximum entropy. In the present paper we offer a self-contained and comprehensive treatment of fundamentals of both principles mentioned, based on a study of the Code Length Game. Though new concepts and results are presented, the reading should be instructional and accessible to a rather wide audience, at least if certain mathematical details are left aside at a rst reading. The most frequently studied instance of entropy maximization pertains to the Mean Energy Model which involves a moment constraint related to a given function, here taken to represent "energy". This type of application is very well known from the literature with hundreds of applications pertaining to several different elds and will also here serve as important illustration of the theory. But our approach reaches further, especially regarding the study of continuity properties of the entropy function, and this leads to new results which allow a discussion of models with so-called entropy loss. These results have tempted us to speculate over the development of natural languages. In fact, we are able to relate our theoretical findings to the empirically found Zipf's law which involves statistical aspects of words in a language. The apparent irregularity inherent in models with entropy loss turns out to imply desirable stability properties of languages.

  3. Astronomical reach of fundamental physics.

    PubMed

    Burrows, Adam S; Ostriker, Jeremiah P

    2014-02-18

    Using basic physical arguments, we derive by dimensional and physical analysis the characteristic masses and sizes of important objects in the universe in terms of just a few fundamental constants. This exercise illustrates the unifying power of physics and the profound connections between the small and the large in the cosmos we inhabit. We focus on the minimum and maximum masses of normal stars, the corresponding quantities for neutron stars, the maximum mass of a rocky planet, the maximum mass of a white dwarf, and the mass of a typical galaxy. To zeroth order, we show that all these masses can be expressed in terms of either the Planck mass or the Chandrasekar mass, in combination with various dimensionless quantities. With these examples, we expose the deep interrelationships imposed by nature between disparate realms of the universe and the amazing consequences of the unifying character of physical law. PMID:24477692

  4. Astronomical reach of fundamental physics

    PubMed Central

    Burrows, Adam S.; Ostriker, Jeremiah P.

    2014-01-01

    Using basic physical arguments, we derive by dimensional and physical analysis the characteristic masses and sizes of important objects in the universe in terms of just a few fundamental constants. This exercise illustrates the unifying power of physics and the profound connections between the small and the large in the cosmos we inhabit. We focus on the minimum and maximum masses of normal stars, the corresponding quantities for neutron stars, the maximum mass of a rocky planet, the maximum mass of a white dwarf, and the mass of a typical galaxy. To zeroth order, we show that all these masses can be expressed in terms of either the Planck mass or the Chandrasekar mass, in combination with various dimensionless quantities. With these examples, we expose the deep interrelationships imposed by nature between disparate realms of the universe and the amazing consequences of the unifying character of physical law. PMID:24477692

  5. Approximate maximum parsimony and ancestral maximum likelihood.

    PubMed

    Alon, Noga; Chor, Benny; Pardi, Fabio; Rapoport, Anat

    2010-01-01

    We explore the maximum parsimony (MP) and ancestral maximum likelihood (AML) criteria in phylogenetic tree reconstruction. Both problems are NP-hard, so we seek approximate solutions. We formulate the two problems as Steiner tree problems under appropriate distances. The gist of our approach is the succinct characterization of Steiner trees for a small number of leaves for the two distances. This enables the use of known Steiner tree approximation algorithms. The approach leads to a 16/9 approximation ratio for AML and asymptotically to a 1.55 approximation ratio for MP. PMID:20150680

  6. PNW RIVER REACH FILE DOCUMENTATION

    EPA Science Inventory

    The U.S. Geological Survey (USGS) in cooperation with Federal and state agencies, and NW Indian Tribes has produced a 1:100,000-scale River Reach data layer for the Pacific Northwest that will serve water-resource management applications for the next decade or more. The Pacific N...

  7. Reaching All Students with Mathematics.

    ERIC Educational Resources Information Center

    Cuevas, Gilbert, Ed.; Driscoll, Mark, Ed.

    The National Council of Teachers of Mathematics'"Curriculum and Evaluation Standards for School Mathematics" and "Professional Standards for Teaching Mathematics" reflect the belief that all students can learn a significant core of high-quality mathematics. Recognizing the magnitude of the task of reaching all students, this book was put together…

  8. Project REACH. Final Evaluation Report.

    ERIC Educational Resources Information Center

    Gross, Alan L.; And Others

    This document describes a pilot adult literacy program called Project REACH (Reading, Education, Achievement), which was begun in 1987 in New York by the Governor's Office for Employee Relations (GOER) and the Civil Service Employees' Association (CSEA). Following an executive summary, an introduction sets the stage by explaining the need for the…

  9. Faster Edge-Define Silicon-Ribbon Growth

    NASA Technical Reports Server (NTRS)

    Richter, R.

    1986-01-01

    End-cooling allows faster growth and yields single-crystal ribbons. Improvement in edge-defined film-fed process for growing silicon ribbons increases speed of growth and improves quality of silicon product. Also produces silicon sheets, webs, or boules. Cold shoes cool melt at ends of emerging sheet. Since solidification at ends now occurs before end menisci reach maximum height, ribbon drawn substantially faster.

  10. Environmental Degradation, Disproportionality, and the Double Diversion: Reaching out, Reaching ahead, and Reaching beyond

    ERIC Educational Resources Information Center

    Freudenburg, William R.

    2006-01-01

    Rather than seeking ivory-tower isolation, members of the Rural Sociological Society have always been distinguished by a willingness to work with specialists from a broad range of disciplines, and to work on some of the world's most challenging problems. What is less commonly recognized is that the willingness to reach beyond disciplinary…

  11. Accessible Buildings for People with Walking and Reaching Limitations.

    ERIC Educational Resources Information Center

    Steinfeld, Edward; And Others

    Research was reviewed and conducted regarding the accessibility of buildings for physically disabled persons. Data was produced regarding anthropometrics (eye level and reach limits for ambulant, semiambulant, and wheelchair bound persons); wheelchair maneuvers; speed and distance (maximum travel distances for people with limitations of stamina);…

  12. Maximum a Posteriori Maximum Entropy Signal Denoising

    NASA Astrophysics Data System (ADS)

    Seghouane, Abd-Krim; Knockaert, Luc

    2007-11-01

    When fitting wavelet based models, shrinkage of the empirical wavelet coefficients is an effective tool for signal denoising. Based on different approaches, different shrinkage functions have been proposed in the literature. The shrinkage functions derived using Bayesian estimation theory depend on the prior used on the wavelet coefficients. However, no simple and direct method exists for the choice of the prior. In this paper a new method based on maximum entropy considerations is proposed for the construction of the prior on the wavelet coefficients. The new shrinkage function is obtained by coupling this prior to maximum a posteriori arguments. A comparison with classical shrinkage functions is given in a simulation example of image denoising in order to illustrate the effectiveness of the proposed thresholding method.

  13. Tuning in to Another Person's Action Capabilities: Perceiving Maximal Jumping-Reach Height from Walking Kinematics

    ERIC Educational Resources Information Center

    Ramenzoni, Veronica; Riley, Michael A.; Davis, Tehran; Shockley, Kevin; Armstrong, Rachel

    2008-01-01

    Three experiments investigated the ability to perceive the maximum height to which another actor could jump to reach an object. Experiment 1 determined the accuracy of estimates for another actor's maximal reach-with-jump height and compared these estimates to estimates of the actor's standing maximal reaching height and to estimates of the…

  14. Reaching the Retarded Through Art.

    ERIC Educational Resources Information Center

    Baumgartner, Bernice B.; Shultz, Joyce B.

    Included in the manual on art are suggestions concerning growth through a good classroom climate, orderly arrangements, displays, and a good visual experience; a view of development through art, concept differentiation, motor and sensory skills, self fulfillment and thought processes, and art as therapy; and the art program itself. The program…

  15. Mirror versus parallel bimanual reaching

    PubMed Central

    2013-01-01

    Background In spite of their importance to everyday function, tasks that require both hands to work together such as lifting and carrying large objects have not been well studied and the full potential of how new technology might facilitate recovery remains unknown. Methods To help identify the best modes for self-teleoperated bimanual training, we used an advanced haptic/graphic environment to compare several modes of practice. In a 2-by-2 study, we compared mirror vs. parallel reaching movements, and also compared veridical display to one that transforms the right hand’s cursor to the opposite side, reducing the area that the visual system has to monitor. Twenty healthy, right-handed subjects (5 in each group) practiced 200 movements. We hypothesized that parallel reaching movements would be the best performing, and attending to one visual area would reduce the task difficulty. Results The two-way comparison revealed that mirror movement times took an average 1.24 s longer to complete than parallel. Surprisingly, subjects’ movement times moving to one target (attending to one visual area) also took an average of 1.66 s longer than subjects moving to two targets. For both hands, there was also a significant interaction effect, revealing the lowest errors for parallel movements moving to two targets (p?reaching performance can be observed with parallel movements with a veridical display (moving to two separate targets). These results point to the expected levels of challenge for these bimanual training modes, which could be used to advise therapy choices in self-neurorehabilitation. PMID:23837908

  16. Physics Reach at Future Colliders

    SciTech Connect

    Krawczyk, Maria

    2007-11-27

    The physics reach at future colliders is discussed, with focus on the Higgs sector. First we present the Standard Model and some results obtained at the existing high-energy hadron collider, Tevatron, together with the corresponding expectations for the Large Hadron Collider (LHC), which starts operating in 2008. Then we discuss important low energy measurements: the anomalous magnetic moment for muon and the leptonic B-decay together with b{yields}s{gamma}. Finally the potential of the planned e{sup +}e{sup -} International Linear Collider (ILC) and its possible option Photon Linear Collider (PLC), e{gamma} and {gamma}{gamma}, is shortly presented.

  17. Maximum thrust mode evaluation

    NASA Technical Reports Server (NTRS)

    Orme, John S.; Nobbs, Steven G.

    1995-01-01

    Measured reductions in acceleration times which resulted from the application of the F-15 performance seeking control (PSC) maximum thrust mode during the dual-engine test phase is presented as a function of power setting and flight condition. Data were collected at altitudes of 30,000 and 45,000 feet at military and maximum afterburning power settings. The time savings for the supersonic acceleration is less than at subsonic Mach numbers because of the increased modeling and control complexity. In addition, the propulsion system was designed to be optimized at the mid supersonic Mach number range. Recall that even though the engine is at maximum afterburner, PSC does not trim the afterburner for the maximum thrust mode. Subsonically at military power, time to accelerate from Mach 0.6 to 0.95 was cut by between 6 and 8 percent with a single engine application of PSC, and over 14 percent when both engines were optimized. At maximum afterburner, the level of thrust increases were similar in magnitude to the military power results, but because of higher thrust levels at maximum afterburner and higher aircraft drag at supersonic Mach numbers the percentage thrust increase and time to accelerate was less than for the supersonic accelerations. Savings in time to accelerate supersonically at maximum afterburner ranged from 4 to 7 percent. In general, the maximum thrust mode has performed well, demonstrating significant thrust increases at military and maximum afterburner power. Increases of up to 15 percent at typical combat-type flight conditions were identified. Thrust increases of this magnitude could be useful in a combat situation.

  18. Distribution of the time at which N vicious walkers reach their maximal height

    NASA Astrophysics Data System (ADS)

    Rambeau, Joachim; Schehr, Grégory

    2011-06-01

    We study the extreme statistics of N nonintersecting Brownian motions (vicious walkers) over a unit time interval in one dimension. Using path-integral techniques we compute exactly the joint distribution of the maximum M and of the time ?M at which this maximum is reached. We focus in particular on nonintersecting Brownian bridges (“watermelons without wall”) and nonintersecting Brownian excursions (“watermelons with a wall”). We discuss in detail the relationships between such vicious walkers models in watermelon configurations and stochastic growth models in curved geometry on the one hand and the directed polymer in a disordered medium (DPRM) with one free end point on the other hand. We also check our results using numerical simulations of Dyson’s Brownian motion and confront them with numerical simulations of the polynuclear growth model (PNG) and of a model of DPRM on a discrete lattice. Some of the results presented here were announced in a recent letter [J. Rambeau and G. Schehr, Europhys. Lett.EULEEJ0295-507510.1209/0295-5075/91/60006 91, 60006 (2010)].

  19. Distribution of the time at which N vicious walkers reach their maximal height

    E-print Network

    Rambeau, Joachim

    2011-01-01

    We study the extreme statistics of N non-intersecting Brownian motions (vicious walkers) over a unit time interval in one dimension. Using path-integral techniques we compute exactly the joint distribution of the maximum M and of the time \\tau_M at which this maximum is reached. We focus in particular on non-intersecting Brownian bridges ("watermelons without wall") and non-intersecting Brownian excursions ("watermelons with a wall"). We discuss in detail the relationships between such vicious walkers models in watermelons configurations and stochastic growth models in curved geometry on the one hand and the directed polymer in a disordered medium (DPRM) with one free end-point on the other hand. We also check our results using numerical simulations of Dyson's Brownian motion and confront them with numerical simulations of the Polynuclear Growth Model (PNG) and of a model of DPRM on a discrete lattice. Some of the results presented here were announced in a recent letter [J. Rambeau and G. Schehr, Europhys. Le...

  20. Distribution of the time at which N vicious walkers reach their maximal height

    E-print Network

    Joachim Rambeau; Gregory Schehr

    2011-02-08

    We study the extreme statistics of N non-intersecting Brownian motions (vicious walkers) over a unit time interval in one dimension. Using path-integral techniques we compute exactly the joint distribution of the maximum M and of the time \\tau_M at which this maximum is reached. We focus in particular on non-intersecting Brownian bridges ("watermelons without wall") and non-intersecting Brownian excursions ("watermelons with a wall"). We discuss in detail the relationships between such vicious walkers models in watermelons configurations and stochastic growth models in curved geometry on the one hand and the directed polymer in a disordered medium (DPRM) with one free end-point on the other hand. We also check our results using numerical simulations of Dyson's Brownian motion and confront them with numerical simulations of the Polynuclear Growth Model (PNG) and of a model of DPRM on a discrete lattice. Some of the results presented here were announced in a recent letter [J. Rambeau and G. Schehr, Europhys. Lett. 91, 60006 (2010)].

  1. What causes cooling water temperature gradients in forested stream reaches?

    NASA Astrophysics Data System (ADS)

    Garner, G.; Malcolm, I. A.; Sadler, J. P.; Hannah, D. M.

    2014-06-01

    Previous studies have suggested that shading by riparian vegetation may reduce maximum water temperature and provide refugia for temperature sensitive aquatic organisms. Longitudinal cooling gradients have been observed during the daytime for stream reaches shaded by coniferous trees downstream of clear cuts, or deciduous woodland downstream of open moorland. However, little is known about the energy exchange processes that drive such gradients, especially in semi-natural woodland contexts, and in the absence of potentially confounding cool groundwater inflows. To address this gap, this study quantified and modelled variability in stream temperature and heat fluxes along an upland reach of the Girnock Burn (a tributary of the Aberdeenshire Dee, Scotland) where riparian landuse transitions from open moorland to semi-natural forest. Observations were made along a 1050 m reach using a spatially-distributed network of ten water temperature micro-loggers, three automatic weather stations and >200 hemispherical photographs, which were used to estimate incoming solar radiation. These data parameterised a high-resolution energy flux model, incorporating flow-routing, which predicted spatio-temporal variability in stream temperature. Variability in stream temperature was controlled largely by energy fluxes at the water column-atmosphere interface. Predominantly net energy gains occurred along the reach during daylight hours, and heat exchange across the bed-water column interface accounted for <1% of the net energy budget. For periods when daytime net radiation gains were high (under clear skies), differences between water temperature observations decreased in the streamwise direction; a maximum difference of 2.5 °C was observed between the upstream reach boundary and 1050 m downstream. Furthermore, daily maximum water temperature at 1050 m downstream was ?1°C cooler than at the upstream reach boundary and lagged the occurrence of daily maximum water temperature upstream by >1h. Temperature gradients were not generated by cooling of stream water, but rather by a combination of reduced rates of heating in the woodland reach and advection of cooler (overnight and early morning) water from the upstream moorland catchment. Longitudinal thermal gradients were indistinct at night and on days when net radiation gains were low (under over-cast skies), thus when changes in net energy gains or losses did not vary significantly in space and time, and heat advected into the reach was reasonably consistent. The findings of the study and the modelling approach employed are useful tools for assessing optimal planting strategies for mitigating against ecologically damaging stream temperature maxima.

  2. Infrastructure for Reaching Disadvantaged Consumers

    PubMed Central

    Hovenga, Evelyn J. S.; Hovel, Joe; Klotz, Jeanette; Robins, Patricia

    1998-01-01

    Both consumers and health service providers need access to up-to-date information, including patient and practice guidelines, that allows them to make decisions in partnership about individual and public health in line with the primary health care model of health service delivery. Only then is it possible for patient preferences to be considered while the health of the general population is improved. The Commonwealth Government of Australia has allocated $250 million over five years, starting July 1, 1997, to support activities and projects designed to meet a range of telecommunication needs in regional, rural, and remote Australia. This paper defines rural and remote communities, then reviews rural and remote health services, information, and telecommunication technology infrastructures and their use in Australia to establish the current state of access to information tools by rural and remote communities and rural health workers in Australia today. It is argued that a suitable telecommunication infrastructure is needed to reach disadvantaged persons in extremely remote areas and that intersectoral support is essential to build this infrastructure. In addition, education will make its utilization possible. PMID:9609497

  3. Metasurface holograms reaching 80% efficiency

    NASA Astrophysics Data System (ADS)

    Zheng, Guoxing; Mühlenbernd, Holger; Kenney, Mitchell; Li, Guixin; Zentgraf, Thomas; Zhang, Shuang

    2015-05-01

    Surfaces covered by ultrathin plasmonic structures—so-called metasurfaces—have recently been shown to be capable of completely controlling the phase of light, representing a new paradigm for the design of innovative optical elements such as ultrathin flat lenses, directional couplers for surface plasmon polaritons and wave plate vortex beam generation. Among the various types of metasurfaces, geometric metasurfaces, which consist of an array of plasmonic nanorods with spatially varying orientations, have shown superior phase control due to the geometric nature of their phase profile. Metasurfaces have recently been used to make computer-generated holograms, but the hologram efficiency remained too low at visible wavelengths for practical purposes. Here, we report the design and realization of a geometric metasurface hologram reaching diffraction efficiencies of 80% at 825?nm and a broad bandwidth between 630?nm and 1,050?nm. The 16-level-phase computer-generated hologram demonstrated here combines the advantages of a geometric metasurface for the superior control of the phase profile and of reflectarrays for achieving high polarization conversion efficiency. Specifically, the design of the hologram integrates a ground metal plane with a geometric metasurface that enhances the conversion efficiency between the two circular polarization states, leading to high diffraction efficiency without complicating the fabrication process. Because of these advantages, our strategy could be viable for various practical holographic applications.

  4. Metasurface holograms reaching 80% efficiency.

    PubMed

    Zheng, Guoxing; Mühlenbernd, Holger; Kenney, Mitchell; Li, Guixin; Zentgraf, Thomas; Zhang, Shuang

    2015-04-01

    Surfaces covered by ultrathin plasmonic structures--so-called metasurfaces--have recently been shown to be capable of completely controlling the phase of light, representing a new paradigm for the design of innovative optical elements such as ultrathin flat lenses, directional couplers for surface plasmon polaritons and wave plate vortex beam generation. Among the various types of metasurfaces, geometric metasurfaces, which consist of an array of plasmonic nanorods with spatially varying orientations, have shown superior phase control due to the geometric nature of their phase profile. Metasurfaces have recently been used to make computer-generated holograms, but the hologram efficiency remained too low at visible wavelengths for practical purposes. Here, we report the design and realization of a geometric metasurface hologram reaching diffraction efficiencies of 80% at 825?nm and a broad bandwidth between 630?nm and 1,050?nm. The 16-level-phase computer-generated hologram demonstrated here combines the advantages of a geometric metasurface for the superior control of the phase profile and of reflectarrays for achieving high polarization conversion efficiency. Specifically, the design of the hologram integrates a ground metal plane with a geometric metasurface that enhances the conversion efficiency between the two circular polarization states, leading to high diffraction efficiency without complicating the fabrication process. Because of these advantages, our strategy could be viable for various practical holographic applications. PMID:25705870

  5. The 2011 Northern Hemisphere Solar Maximum

    NASA Astrophysics Data System (ADS)

    Altrock, Richard C.

    2013-01-01

    Altrock (1997, Solar Phys. 170, 411) discusses a process in which Fe XIV 530.3 nm emission features appear at high latitudes and gradually migrate towards the equator, merging with the sunspot "butterfly diagram". In cycles 21 - 23 solar maximum occurred when the number of Fe XIV emission regions per day > 0.19 (averaged over 365 days and both hemispheres) first reached latitudes 18°, 21° and 21°, for an average of 20° ± 1.7°. Another high-latitude process is the "Rush to the Poles" of polar crown prominences and their associated coronal emission, including Fe XIV. The Rush is a harbinger of solar maximum (cf. Altrock, 2003, Solar Phys. 216, 343). Solar maximum in cycles 21 - 23 occurred when the center line of the Rush reached a critical latitude. These latitudes were 76°, 74° and 78°, respectively, for an average of 76° ± 2°. Cycle 24 displays an intermittent Rush that is only well-defined in the northern hemisphere. In 2009 an initial slope of 4.6°/yr was found in the north, compared to an average of 9.4 ± 1.7 °/yr in the previous three cycles. However, in 2010 the slope increased to 7.5°/yr. Extending that rate to 76° ± 2° indicates that the solar maximum smoothed sunspot number in the northern hemisphere already occurred at 2011.6 ± 0.3. In the southern hemisphere the Rush is very poorly defined. A linear fit to several maxima would reach 76° in the south at 2014.2. In 1999, persistent Fe XIV coronal emission connected with the ESC appeared near 70° in the north and began migrating towards the equator at a rate 40% slower than the previous two solar cycles. A fit to the early ESC would not reach 20° until 2019.8. However, in 2009 and 2010 an acceleration occurred. Currently the greatest number of emission regions is at 21° in the north and 24°in the south. This indicates that solar maximum is occurring now in the north but not yet in the south. The latest global smoothed sunspot numbers show an inflection point in late 2011, which could represent solar maximum in the northern hemisphere. Sunspot areas in the northern hemisphere reached a maximum in late 2011. The southern areas are still increasing.

  6. Dynamic push-pull characteristics at three hand-reach envelopes: applications for the workplace.

    PubMed

    Calé-Benzoor, Maya; Dickstein, Ruth; Arnon, Michal; Ayalon, Moshe

    2016-01-01

    Pushing and pulling are common tasks in the workplace. Overexertion injuries related to manual pushing and pulling are often observed, and therefore the understanding of work capacity is important for efficient and safe workstation design. The purpose of the present study was to describe workloads obtained during different reach envelopes during a seated push-pull task. Forty-five women performed an isokinetic push-pull sequence at two velocities. Strength, work and agonist/antagonist muscle ratio were calculated for the full range of motion (ROM). We then divided the ROM into three reach envelopes - neutral, medium, and maximum reach. The work capacity for each direction was determined and the reach envelope work data were compared. Push capability was best at medium reach envelope and pulling was best at maximum reach envelope. Push/pull strength ratio was approximately 1. A recommendation was made to avoid strenuous push-pull tasks at neutral reach envelopes. PMID:26360213

  7. Has the world economy reached its globalization limit?

    E-print Network

    Miskiewicz, Janusz

    2009-01-01

    The economy globalization measure problem is discussed. Four macroeconomic indices of twenty among the "richest" countries are examined. Four types of "distances" are calculated.Two types of networks are next constructed for each distance measure definition. It is shown that the globalization process can be best characterised by an entropy measure, based on entropy Manhattan distance. It is observed that a globalization maximum was reached in the interval 1970-2000. More recently a deglobalization process is observed.

  8. Nucleation and growth in the initial stage of metastable titanium disilicide formation

    E-print Network

    Allen, Leslie H.

    Nucleation and growth in the initial stage of metastable titanium disilicide formation Z. Ma, Y. Xu on temperature, reaching a maximum of 7.2X 10m3/A at around 575 "C. The formation of titanium disilicides through the re- action of titanium with crystalline silicon has been exten- sively studied from different aspects

  9. ALMA telescope reaches new heights

    NASA Astrophysics Data System (ADS)

    2009-09-01

    The ALMA (Atacama Large Millimeter/submillimeter Array) astronomical observatory has taken another step forward - and upwards. One of its state-of-the-art antennas was carried for the first time to the 5000m plateau of Chajnantor, in the Chilean Andes, on the back of a custom-built giant transporter. The antenna, which weighs about 100 tons and has a diameter of 12 metres, was transported up to the high-altitude Array Operations Site, where the extremely dry and rarefied air is ideal for ALMA's observations of the Universe. The conditions at the Array Operations Site on Chajnantor, while excellent for astronomy, are also very harsh. Only half as much oxygen is available as at sea level, making it very difficult to work there. This is why ALMA's antennas are assembled and tested at the lower 2900 m altitude of the ALMA Operations Support Facility. It was from this relatively hospitable base camp that the ALMA antenna began its journey to the high Chajnantor site. "This is an important moment for ALMA. We are very happy that the first transport of an antenna to the high site went flawlessly. This achievement was only possible through contributions from all international ALMA partners: this particular antenna is provided by Japan, the heavy-lift transporter by Europe, and the receiving electronics inside the antenna by North America, Europe, and Asia", said Wolfgang Wild, European ALMA Project Manager. The trip began when one of the two ALMA transporters, named Otto, lifted the antenna onto its back. It then carried its heavy load along the 28 km road from the Operations Support Facility up to the Array Operations Site. While the transporter is capable of speeds of up to 12 km/hour when carrying an antenna, this first journey was made more slowly to ensure that everything worked as expected, taking about seven hours. The ALMA antennas are the most advanced submillimetre-wavelength antennas ever made. They are designed to operate fully exposed in the harsh conditions of the Array Operations Site. This means surviving strong winds and temperatures between +20 and -20 Celsius whilst being able to point precisely enough that they could pick out a golf ball at a distance of 15 km, and to keep their smooth reflecting surfaces accurate to better than 25 micrometres (less than the typical thickness of a human hair). Once the transporter reached the high plateau it carried the antenna to a concrete pad - a docking station with connections for power and fibre optics - and positioned it with an accuracy of a few millimetres. The transporter is guided by a laser steering system and, just like some cars today, also has ultrasonic collision detectors. These sensors ensure the safety of the state-of-the-art antennas as the transporter drives them across what will soon be a rather crowded plateau. Ultimately, ALMA will have at least 66 antennas distributed over about 200 pads, spread over distances of up to 18.5 km and operating as a single, giant telescope. Even when ALMA is fully operational, the transporters will be used to move the antennas between pads to reconfigure the telescope for different kinds of observations. "Transporting our first antenna to the Chajnantor plateau is a epic feat which exemplifies the exciting times in which ALMA is living. Day after day, our global collaboration brings us closer to the birth of the most ambitious ground-based astronomical observatory in the world", said Thijs de Graauw, ALMA Director. This first ALMA antenna at the high site will soon be joined by others and the ALMA team looks forward to making their first observations from the Chajnantor plateau. They plan to link three antennas by early 2010, and to make the first scientific observations with ALMA in the second half of 2011. ALMA will help astronomers answer important questions about our cosmic origins. The telescope will observe the Universe using light with millimetre and submillimetre wavelengths, between infrared light and radio waves in the electromagnetic spectrum. Light at these wavelengths comes from some of th

  10. Interference of Different Types of Seats on Postural Control System during a Forward-Reaching Task in Individuals with Paraplegia

    ERIC Educational Resources Information Center

    de Abreu, Daniela Cristina Carvalho; Takara, Kelly; Metring, Nathalia Lopes; Reis, Julia Guimaraes; Cliquet, Alberto, Jr.

    2012-01-01

    We aimed to evaluate the influence of different types of wheelchair seats on paraplegic individuals' postural control using a maximum anterior reaching test. Balance evaluations during 50, 75, and 90% of each individual's maximum reach in the forward direction using two different cushions on seat (one foam and one gel) and a no-cushion condition…

  11. Maximum Entropy Approximation

    NASA Astrophysics Data System (ADS)

    Sukumar, N.

    2005-11-01

    In this paper, the construction of scattered data approximants is studied using the principle of maximum entropy. For under-determined and ill-posed problems, Jaynes's principle of maximum information-theoretic entropy is a means for least-biased statistical inference when insufficient information is available. Consider a set of distinct nodes {xi}i=1n in Rd, and a point p with coordinate x that is located within the convex hull of the set {xi}. The convex approximation of a function u(x) is written as: uh(x) = ?i=1n ?i(x)ui, where {?i}i=1n ? 0 are known as shape functions, and uh must reproduce affine functions (d = 2): ?i=1n ?i = 1, ?i=1n ?ixi = x, ?i=1n ?iyi = y. We view the shape functions as a discrete probability distribution, and the linear constraints as the expectation of a linear function. For n > 3, the problem is under-determined. To obtain a unique solution, we compute ?i by maximizing the uncertainty H(?) = - ?i=1n ?i log ?i, subject to the above three constraints. In this approach, only the nodal coordinates are used, and neither the nodal connectivity nor any user-defined parameters are required to determine ?i—the defining characteristics of a mesh-free Galerkin approximant. Numerical results for {?i}i=1n are obtained using a convex minimization algorithm, and shape function plots are presented for different nodal configurations.

  12. university-logo Maximum likelihood

    E-print Network

    McCullagh, Peter

    university-logo Maximum likelihood Applications and examples REML and residual likelihood Peter McCullagh REML #12;university-logo Maximum likelihood Applications and examples JAN: Some personal remarks... IC #12;university-logo Maximum likelihood Applications and examples Outline 1 Maximum likelihood REML

  13. From Hard to Reach to How to Reach: A Systematic Review of the Literature on Hard-to-Reach Families

    ERIC Educational Resources Information Center

    Boag-Munroe, Gill; Evangelou, Maria

    2012-01-01

    This paper presents a review of the literature relating to hard-to-reach families which has been published over the last 12 years in the UK, USA, Canada and Australia. The purpose of the review was twofold: to gain insights to understandings of the term "hard-to-reach" within these services--education, health and social--which might be aiming to…

  14. Maximum gravitational recoil.

    PubMed

    Campanelli, Manuela; Lousto, Carlos O; Zlochower, Yosef; Merritt, David

    2007-06-01

    Recent calculations of gravitational radiation recoil generated during black-hole binary mergers have reopened the possibility that a merged binary can be ejected even from the nucleus of a massive host galaxy. Here we report the first systematic study of gravitational recoil of equal-mass binaries with equal, but counteraligned, spins parallel to the orbital plane. Such an orientation of the spins is expected to maximize the recoil. We find that recoil velocity (which is perpendicular to the orbital plane) varies sinusoidally with the angle that the initial spin directions make with the initial linear momenta of each hole and scales up to a maximum of approximately 4000 km s-1 for maximally rotating holes. Our results show that the amplitude of the recoil velocity can depend sensitively on spin orientations of the black holes prior to merger. PMID:17677894

  15. Introduction to maximum entropy

    SciTech Connect

    Sivia, D.S.

    1988-01-01

    The maximum entropy (MaxEnt) principle has been successfully used in image reconstruction in a wide variety of fields. We review the need for such methods in data analysis and show, by use of a very simple example, why MaxEnt is to be preferred over other regularizing functions. This leads to a more general interpretation of the MaxEnt method, and its use is illustrated with several different examples. Practical difficulties with non-linear problems still remain, this being highlighted by the notorious phase problem in crystallography. We conclude with an example from neutron scattering, using data from a filter difference spectrometer to contrast MaxEnt with a conventional deconvolution. 12 refs., 8 figs., 1 tab.

  16. Reaching higher goals by means of a reflecting wall

    NASA Astrophysics Data System (ADS)

    Faella, O.; De Luca, R.

    2015-05-01

    A student realizes that a point particle that is able to rise at a given point P0 at height H when launched vertically from the origin O of a Cartesian plane at a fixed initial speed V0 cannot reach, by means of a direct shot from a small spring cannon, a point P positioned at the same height H and distance d from P0, with 0 < d ? R, where R is the maximum horizontal distance attainable with an optimum throw at an angle of 45°. However, the student realizes that, in the absence of air resistance, conservation of energy does not prevent this possibility. Therefore, in order to reach point P, the student uses a perfectly reflecting surface, opportunely inclined with respect to the horizontal. The full story of how this is done will be narrated in this article.

  17. Calibrating Reach Distance to Visual Targets

    ERIC Educational Resources Information Center

    Mon-Williams, Mark; Bingham, Geoffrey P.

    2007-01-01

    The authors investigated the calibration of reach distance by gradually distorting the haptic feedback obtained when participants grasped visible target objects. The authors found that the modified relationship between visually specified distance and reach distance could be captured by a straight-line mapping function. Thus, the relation could be…

  18. Generalized Maximum Entropy

    NASA Technical Reports Server (NTRS)

    Cheeseman, Peter; Stutz, John

    2005-01-01

    A long standing mystery in using Maximum Entropy (MaxEnt) is how to deal with constraints whose values are uncertain. This situation arises when constraint values are estimated from data, because of finite sample sizes. One approach to this problem, advocated by E.T. Jaynes [1], is to ignore this uncertainty, and treat the empirically observed values as exact. We refer to this as the classic MaxEnt approach. Classic MaxEnt gives point probabilities (subject to the given constraints), rather than probability densities. We develop an alternative approach that assumes that the uncertain constraint values are represented by a probability density {e.g: a Gaussian), and this uncertainty yields a MaxEnt posterior probability density. That is, the classic MaxEnt point probabilities are regarded as a multidimensional function of the given constraint values, and uncertainty on these values is transmitted through the MaxEnt function to give uncertainty over the MaXEnt probabilities. We illustrate this approach by explicitly calculating the generalized MaxEnt density for a simple but common case, then show how this can be extended numerically to the general case. This paper expands the generalized MaxEnt concept introduced in a previous paper [3].

  19. Solar Maximum Mission

    SciTech Connect

    Chipman, E.G.

    1981-03-15

    The Solar Maximum Mission spacecraft, launched on 1980 February 14, carries seven instruments for the study of solar flares and other aspects of solar activity. These instruments observe in spectral ranges from gamma-rays through the visible, using imaging, spectroscopy, and high-time-resolution light curves to study flares phenomena. In addition, one instrument incorporates an Active Cavity Radiometer for accurate measurement of the total solar radiant output. We review some of the most important current observational and theoretical questions of solar flare physics and indicate the ways in which the experiments on SMM will be able to attack these questions. The SMS observing program is described. The observing programs of the instruments for the study of flares are planned together, at a central location, to provide simultaneous observations of solar events by several instruments whenever possible. A Guest Investigator program has been initiated which allows broad use of these instruments by the scientific community and supports ground-based observations in conjunction with SMM observing programs.

  20. Revealing the maximum strength in nanotwinned copper.

    PubMed

    Lu, L; Chen, X; Huang, X; Lu, K

    2009-01-30

    The strength of polycrystalline materials increases with decreasing grain size. Below a critical size, smaller grains might lead to softening, as suggested by atomistic simulations. The strongest size should arise at a transition in deformation mechanism from lattice dislocation activities to grain boundary-related processes. We investigated the maximum strength of nanotwinned copper samples with different twin thicknesses. We found that the strength increases with decreasing twin thickness, reaching a maximum at 15 nanometers, followed by a softening at smaller values that is accompanied by enhanced strain hardening and tensile ductility. The strongest twin thickness originates from a transition in the yielding mechanism from the slip transfer across twin boundaries to the activity of preexisting easy dislocation sources. PMID:19179523

  1. The sun and heliosphere at solar maximum.

    PubMed

    Smith, E J; Marsden, R G; Balogh, A; Gloeckler, G; Geiss, J; McComas, D J; McKibben, R B; MacDowall, R J; Lanzerotti, L J; Krupp, N; Krueger, H; Landgraf, M

    2003-11-14

    Recent Ulysses observations from the Sun's equator to the poles reveal fundamental properties of the three-dimensional heliosphere at the maximum in solar activity. The heliospheric magnetic field originates from a magnetic dipole oriented nearly perpendicular to, instead of nearly parallel to, the Sun's rotation axis. Magnetic fields, solar wind, and energetic charged particles from low-latitude sources reach all latitudes, including the polar caps. The very fast high-latitude wind and polar coronal holes disappear and reappear together. Solar wind speed continues to be inversely correlated with coronal temperature. The cosmic ray flux is reduced symmetrically at all latitudes. PMID:14615526

  2. The database for reaching experiments and models.

    PubMed

    Walker, Ben; Kording, Konrad

    2013-01-01

    Reaching is one of the central experimental paradigms in the field of motor control, and many computational models of reaching have been published. While most of these models try to explain subject data (such as movement kinematics, reaching performance, forces, etc.) from only a single experiment, distinct experiments often share experimental conditions and record similar kinematics. This suggests that reaching models could be applied to (and falsified by) multiple experiments. However, using multiple datasets is difficult because experimental data formats vary widely. Standardizing data formats promises to enable scientists to test model predictions against many experiments and to compare experimental results across labs. Here we report on the development of a new resource available to scientists: a database of reaching called the Database for Reaching Experiments And Models (DREAM). DREAM collects both experimental datasets and models and facilitates their comparison by standardizing formats. The DREAM project promises to be useful for experimentalists who want to understand how their data relates to models, for modelers who want to test their theories, and for educators who want to help students better understand reaching experiments, models, and data analysis. PMID:24244351

  3. Growth kinetics of the Golgi apparatus during the cell cycle in onion root meristems.

    PubMed

    Garcia-Herdugo, G; González-Reyes, J A; Gracia-Navarro, F; Navas, P

    1988-09-01

    In onion root meristems, the number of dictyosomes per cell shows a kinetics of growth strongly related to the cell cycle. During the interphase of steady-state proliferative cells, the volume density and numerical density of the Golgi apparatus decrease to reach minimum values in late-interphase cells, characterized by their greatest length. This pattern is also found in the total volume occupied by Golgi apparatus. Once in mitosis, the above-mentioned parameters begin to increase reaching maximum mean values in telophase. After the experimental uncoupling of chromosome and growth cycles by presynchronization with hydroxyurea, we found a similar behaviour pattern in the Golgi apparatus: decreasing values during interphase and a triggering of Golgi-apparatus growth in prophase independently of the bigger cell sizes reached in mitosis as an effect of pretreatment with hydroxyurea. These results indicate a cyclic kinetics of this subcellular component in higher-plant meristems, coupled with early mitotic events. PMID:24221867

  4. Limitations of extended reach drilling in deepwater 

    E-print Network

    Akinfenwa, Akinwunmi Adebayo

    2000-01-01

    with the high cost of deepwater drilling rigs and development. The technical limitations and risks associated with extended reach drilling (ERD) in deepwater are uncertain. How far can we drill using existing rigs and upgraded rig components? This thesis...

  5. Reaching the Overlooked Student in Physical Education

    ERIC Educational Resources Information Center

    Esslinger, Keri; Esslinger, Travis; Bagshaw, Jarad

    2015-01-01

    This article describes the use of live action role-playing, or "LARPing," as a non-traditional activity that has the potential to reach students who are not interested in traditional physical education.

  6. The Astronomical Reach of Fundamental Physics

    E-print Network

    Burrows, Adam

    2014-01-01

    Using basic physical arguments, we derive by dimensional and physical analysis the characteristic masses and sizes of important objects in the Universe in terms of just a few fundamental constants. This exercise illustrates the unifying power of physics and the profound connections between the small and the large in the Cosmos we inhabit. We focus on the minimum and maximum masses of normal stars, the corresponding quantities for neutron stars, the maximum mass of a rocky planet, the maximum mass of a white dwarf, and the mass of a typical galaxy. To zeroth order, we show that all these masses can be expressed in terms of either the Planck mass or the Chandrasekar mass, in combination with various dimensionless quantities. With these examples we expose the deep interrelationships imposed by Nature between disparate realms of the Universe and the amazing consequences of the unifying character of physical law.

  7. Approximating Human Reaching Volumes Using Inverse Kinematics

    E-print Network

    Rodríguez, Inmaculada

    , Switzerland Abstract This paper presents a system to analyse the reaching capabilities of the human body. Our system for the human body. Our research is motivated due to the necessity of systems which help to manage. Introduction Virtual Humans are a valuable medium for gaining knowledge and understanding about the human body

  8. Project Reach: Final Report--Year 2.

    ERIC Educational Resources Information Center

    McClelland, Samuel D.

    The second year of Project Reach, a Federally funded two-year program, pursued two tactics for increasing the adult basic education (ABE) program relevance and effectiveness in South Bend, Indiana: (1) the training/hiring of ABE students as media paraprofessionals, and (2) a media enrollment campaign of various media promotions (television/radio…

  9. Women Reaching Women. Volunteer Coordinator's Training Program.

    ERIC Educational Resources Information Center

    Pola, Yvonne; Ihlenfeld, Gayle

    Based on the experiences of the Women Reaching Women chapters in Wisconsin, this manual provides information on beginning and implementing a volunteer program to train women to help female drug and alcohol abusers. The materials are designed for volunteer coordinators who may be paid or unpaid persons. The manual, containing four sections, is…

  10. What Determines Limb Selection for Reaching?

    ERIC Educational Resources Information Center

    Helbig, Casi Rabb; Gabbard, Carl

    2004-01-01

    While motor dominance appears to drive limb selection for reaching movements at the midline and ipsilateral (dominant) side, this study examined the possible determinants associated with what drives the programming of movements in response to stimuli presented in contralateral space. Experiment 1 distinguished between object proximity and a…

  11. Reaching Rural Women: Case Studies and Strategies.

    ERIC Educational Resources Information Center

    Colle, Royal D.; Fernandez de Colle, Susana

    Although not often considered in the past by planners because their economic contributions are not performed for money, rural women are contributors to the development of their countries. The urgency of reaching women with important information to break the cycle of poverty is now being recognized by the major development agencies. While there are…

  12. Pumpdown assistance extends coiled tubing reach

    SciTech Connect

    Tailby, R.J. )

    1992-07-01

    One of the most challenging coiled tubing applications to emerge in the last few years is horizontal well maintenance. When wireline cannot be used, techniques that offer some of the same flexibility, availability and relatively low cost must be used. During this same period, however, drilling technology has also made huge strides in horizontal and extended-reach areas. Wells are now being drilled with horizontal lengths in excess of 6,000 ft and measured depths of more than 22,000 ft. This paper reports that although horizontal wells are definitely here to stay, many operators have had to reevaluate their positions after being confronted with the problem of recompleting these wells to eliminate excessive water or gas production. A full workover with workstring using either a drilling rig or snubbing unit can be expensive and may lead to lost production because of limited rig availability. Coiled tubing has successfully been used in most cases thus far, but it has length and horizontal reach limitations that drilling technology will soon overtake. Within the constraints of current technology and tube capabilities, coiled tubing does not have the buckling resistance or reel capacity to service today's longest horizontal and extended reach wells or those planned and foreseen in the future. Even if coiled tubing can reach TD, operations requiring downward force are severely restricted.

  13. The Old Brown Coat Reaching Out

    E-print Network

    Alford, Simon

    " this setting ­ caring fo the farmers, truckers and salt of the earth rural residents - in a low volume ED armedThe Old Brown Coat Reaching Out: Experiencing rural emergency medicine In our unending quest for expansion, innovation, and ­ of course ­ income, the UIC ED department has contracted with rural hospitals

  14. REACH. Teacher's Guide, Volume III. Task Analysis.

    ERIC Educational Resources Information Center

    Morris, James Lee; And Others

    Designed for use with individualized instructional units (CE 026 345-347, CE 026 349-351) in the electromechanical cluster, this third volume of the postsecondary teacher's guide presents the task analysis which was used in the development of the REACH (Refrigeration, Electro-Mechanical, Air Conditioning, Heating) curriculum. The major blocks of…

  15. Project: "Teach 'n' Reach" Teacher's Guide.

    ERIC Educational Resources Information Center

    Kagan, Arleen

    The first of five volumes for Project Teach 'n' Reach, designed to help teachers of grades 1-6 in regular classrooms to teach about various kinds of handicapping conditions, is a teacher's guide. Performance objectives, activities, worksheets, and resources are listed for the use of these teachers in the implementation of their social-science and…

  16. Scaling of Reference Reach for Desired Bankfull Discharge

    E-print Network

    McEnroe, Bruce M.; Young, C. Bryan; Shelley, John

    2014-04-01

    The reference reach method is commonly used for natural stream design. In the reference reach approach, a stable reach is selected to serve as the design template for a design reach. The planform and profile of this reference ...

  17. Virtual arm's reach influences perceived distances but only after experience reaching.

    PubMed

    Linkenauger, Sally A; Bülthoff, Heinrich H; Mohler, Betty J

    2015-04-01

    Considerable empirical evidence has shown influences of the action capabilities of the body on the perception of sizes and distances. Generally, as one's action capabilities increase, the perception of the relevant distance (over which the action is to be performed) decreases and vice versa. As a consequence, it has been proposed that the body's action capabilities act as a perceptual ruler, which is used to measure perceived sizes and distances. In this set of studies, we investigated this hypothesis by assessing the influence of arm's reach on the perception of distance. By providing participant with a self-representing avatar seen in a first-person perspective in virtual reality, we were able to introduce novel and completely unfamiliar alterations in the virtual arm's reach to evaluate their impact on perceived distance. Using both action-based and visual matching measures, we found that virtual arm's reach influenced perceived distance in virtual environments. Due to the participants' inexperience with the reach alterations, we also were able to assess the amount of experience with the new arm's reach required to influence perceived distance. We found that minimal experience reaching with the virtual arm can influence perceived distance. However, some reaching experience is required. Merely having a long or short virtual arm, even one that is synchronized to one's movements, is not enough to influence distance perception if one has no experience reaching. PMID:25446965

  18. Comparison of Robot-Assisted Reaching to Free Reaching in Promoting Recovery

    E-print Network

    Reinkensmeyer, David J.

    , the subjects performed unassisted, unrestrained reaching exercises to the same targets for the same number by the patient are the primary stimulus for recovery, rather than the robot assistance. Indeed, unassisted of unassisted, free reaching exercise performed by another group. This paper presents t

  19. Mobile Experience Sampling: Reaching the Parts of Facebook Other Methods Cannot Reach

    E-print Network

    Henderson, Tristan

    Mobile Experience Sampling: Reaching the Parts of Facebook Other Methods Cannot Reach Fehmi Ben obtained from a 2-week experiment with 40 students sharing their location in real time on Facebook their location on the Facebook SNS with a mobile phone. We recruited stu- dents to participate in an experiment

  20. Distance Reached in the Anteromedial Reach Test as a Function of Learning and Leg Length

    ERIC Educational Resources Information Center

    Bent, Nicholas P.; Rushton, Alison B.; Wright, Chris C.; Batt, Mark E.

    2012-01-01

    The Anteromedial Reach Test (ART) is a new outcome measure for assessing dynamic knee stability in anterior cruciate ligament-injured patients. The effect of learning and leg length on distance reached in the ART was examined. Thirty-two healthy volunteers performed 15 trials of the ART on each leg. There was a moderate correlation (r = 0.44-0.50)…

  1. Olefins and chemical regulation in Europe: REACH.

    PubMed

    Penman, Mike; Banton, Marcy; Erler, Steffen; Moore, Nigel; Semmler, Klaus

    2015-11-01

    REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) is the European Union's chemical regulation for the management of risk to human health and the environment (European Chemicals Agency, 2006). This regulation entered into force in June 2007 and required manufacturers and importers to register substances produced in annual quantities of 1000 tonnes or more by December 2010, with further deadlines for lower tonnages in 2013 and 2018. Depending on the type of registration, required information included the substance's identification, the hazards of the substance, the potential exposure arising from the manufacture or import, the identified uses of the substance, and the operational conditions and risk management measures applied or recommended to downstream users. Among the content developed to support this information were Derived No-Effect Levels or Derived Minimal Effect Levels (DNELs/DMELs) for human health hazard assessment, Predicted No Effect Concentrations (PNECs) for environmental hazard assessment, and exposure scenarios for exposure and risk assessment. Once registered, substances may undergo evaluation by the European Chemicals Agency (ECHA) or Member State authorities and be subject to requests for additional information or testing as well as additional risk reduction measures. To manage the REACH registration and related activities for the European olefins and aromatics industry, the Lower Olefins and Aromatics REACH Consortium was formed in 2008 with administrative and technical support provided by Penman Consulting. A total of 135 substances are managed by this group including 26 individual chemical registrations (e.g. benzene, 1,3-butadiene) and 13 categories consisting of 5-26 substances. This presentation will describe the content of selected registrations prepared for 2010 in addition to the significant post-2010 activities. Beyond REACH, content of the registrations may also be relevant to other European activities, for example consideration of worker DNELs/DMELs for occupational exposure level setting, discussion of this aspect will be presented for 1,3-butadiene. PMID:25861726

  2. Initial conditions for reaching the critical velocity

    E-print Network

    Georges Meynet; Sylvia Ekström; André Maeder; Fabio Barblan

    2006-01-16

    The aim of this paper is to determine the initial rotational velocities required on the ZAMS for single stars to reach the critical velocity, sometimes called the break-up velocity, during the Main-Sequence (MS) phase. Some useful relations between $\\Omega/\\Omega_{\\rm crit}$, $\\upsilon/\\upsilon_{\\rm crit}$ ($\\upsilon$ is the velocity at the equator), the moments of inertia, the angular momenta, the kinetic energy in the rotation and various other basic physical quantities are obtained.

  3. Maximum Entropy Production and the

    E-print Network

    Zeng, Ning

    : You can't break even. (Carnot 1824, Clausius 1850) #12;Thermodynamics 101 (Prigogine 1962) #12;Maximum representation of dynamical constraints (energy, water, carbon etc.) Type I: MEP through parameter optimization

  4. This research focuses on the stress and structure evolution observed in-situ during the earliest stages of thin film growth in Cu/Au(111)-(22x 3) system. For the research, an ultra high vacuum-scanning

    E-print Network

    and in-situ stress evolution monitoring. The design and fabrication processes for the modifications change. The intrinsic stress evolution observed at the onset of Cu growth was tensile in character and reached a maximum of 0.18 N/m at approximately 0.8ML, with an average tensile slope of 1.0GPa. As the film

  5. Well control procedures for extended reach wells 

    E-print Network

    Gjorv, Bjorn

    2004-09-30

    island development concept versus ERD wells.............................. 2 Fig. 2 Industry comparison of ERD wells ...................................................................... 3 Fig. 3 Gas migration in a highly inclined and rugose wellbore.... Fig. 3 ? Gas migration in a highly inclined and rugose wellbore. In ERD and horizontal wells the maximum casing-shoe pressure during a well control procedure is usually smaller and the choke pressures remain lower for a longer period of time...

  6. Characteristics of channel steps and reach morphology in headwater streams, southeast Alaska

    NASA Astrophysics Data System (ADS)

    Gomi, Takashi; Sidle, Roy C.; Woodsmith, Richard D.; Bryant, Mason D.

    2003-03-01

    The effect of timber harvesting and mass movement on channel steps and reach morphology was examined in 16 headwater streams of SE Alaska. Channel steps formed by woody debris and boulders are significant channel units in headwater streams. Numbers, intervals, and heights of steps did not differ among management and disturbance regimes. A negative exponential relationship between channel gradient and mean length of step intervals was observed in the fluvial reaches (<0.25 unit gradient) of recent landslide and old-growth channels. No such relationship was found in upper reaches (?0.25 gradient) where colluvial processes dominated. Woody debris and sediment recruitment from regenerating riparian stands may have obscured any strong relationship between step geometry and channel gradient in young alder, young conifer, and recent clear-cut channels. Channel reaches are described as pool-riffles, step-pools, step-steps, cascades, rapids, and bedrock. Geometry of channel steps principally characterized channel reach types. We infer that fluvial processes dominated in pool-riffle and step-pool reaches, while colluvial processes dominated in bedrock reaches. Step-step, rapids, and cascade reaches occurred in channels dominated by both fluvial processes and colluvial processes. Step-step reaches were transitional from cascades (upstream) to step-pool reaches (downstream). Woody debris recruited from riparian corridors and logging activities formed steps and then sequentially might modify channel reach types from step-pools to step-steps. Scour, runout, and deposition of sediment and woody debris from landslides and debris flows modified the distribution of reach types (bedrock, cascade, and step-pool) and the structure of steps within reaches.

  7. 2015 Antarctic Maximum Sea Ice Extent Breaks Streak of Record Highs - Duration: 49 seconds.

    NASA Video Gallery

    Antarctic sea ice likely reached its annual maximum extent on Oct. 6, barring a late season surge. This video shows the evolution of the sea ice cover of the Southern Ocean from its minimum yearly ...

  8. Information Superhighways: Will They Reach Community Colleges?

    ERIC Educational Resources Information Center

    Bigelow, Douglas

    1993-01-01

    Traces the growth of national information networks from the original network (ARPAnet) to the Internet and the National Research and Education Network (NREN). Reviews the debate on national networking, including issues related to the technology itself and policies that will shape it, and whether community colleges stand to gain or lose after the…

  9. Spallation Neutron Source reaches megawatt power

    SciTech Connect

    Dr. William F. Brinkman

    2009-09-30

    The Department of Energy's Spallation Neutron Source (SNS), already the world's most powerful facility for pulsed neutron scattering science, is now the first pulsed spallation neutron source to break the one-megawatt barrier. "Advances in the materials sciences are fundamental to the development of clean and sustainable energy technologies. In reaching this milestone of operating power, the Spallation Neutron Source is providing scientists with an unmatched resource for unlocking the secrets of materials at the molecular level," said Dr. William F. Brinkman, Director of DOE's Office of Science.

  10. Spallation Neutron Source reaches megawatt power

    ScienceCinema

    Dr. William F. Brinkman

    2010-01-08

    The Department of Energy's Spallation Neutron Source (SNS), already the world's most powerful facility for pulsed neutron scattering science, is now the first pulsed spallation neutron source to break the one-megawatt barrier. "Advances in the materials sciences are fundamental to the development of clean and sustainable energy technologies. In reaching this milestone of operating power, the Spallation Neutron Source is providing scientists with an unmatched resource for unlocking the secrets of materials at the molecular level," said Dr. William F. Brinkman, Director of DOE's Office of Science.

  11. Reach and get capability in a computing environment

    DOEpatents

    Bouchard, Ann M. (Albuquerque, NM); Osbourn, Gordon C. (Albuquerque, NM)

    2012-06-05

    A reach and get technique includes invoking a reach command from a reach location within a computing environment. A user can then navigate to an object within the computing environment and invoke a get command on the object. In response to invoking the get command, the computing environment is automatically navigated back to the reach location and the object copied into the reach location.

  12. [A growth study of Prioria copaifera (Caesalpinaceae) using dendrochronological techniques].

    PubMed

    Giraldo Jiménez, Jorge Andrés; del Valle Arango, Jorge Ignacio

    2011-12-01

    The Cativo (Prioria copaifera) forms very homogeneous forests called cativales in the flooded plains of some rivers from Costa Rica to Colombia. For over 70 years Cativo has been the main base of the timber industry in the Colombian Darien area. Because of high productivity and high-dominance of Cativo trees, they represent one of the most prone tropical forests for sustainable forest management. The objective of this research is to model diameter and timber volume growth and growth rates (absolute, mean and relative) of Cativo as a function of age, using tree ring data derived from dendrochronologycal techniques. We evaluated the annual nature of the tree rings by radiocarbon analysis and crossdating techniques. Besides, the diameter and volume growth was modeled using von Bertalanffy's model. As of our results, we estimated the life span of Cativo in 614 years as the time required to reach 99% of the asymptotic diameter. By the mean value we have found that the mean rate of diameter growth is 0.31cm/y. The species requires 90 years to reach 40cm in diameter, the regulated cut diameter in Colombia. We find that Cativo reaches maximum current annual increment (ICA) in diameter at 40 years and in volume at 90 years with rates of 0.5cm/y and 0.032m3/y per tree, respectively. The maximum diameter mean annual increments (MAI) are achieved at 80 years and for the volume at 140 year, with growth rates of 0.45cm/y and 0.018m3/y per tree, respectively. The generated information is useful for the sustainable management of Cativò forests. PMID:22208095

  13. Mass reach scaling for future hadron colliders

    NASA Astrophysics Data System (ADS)

    Rizzo, Thomas G.

    2015-04-01

    The primary goal of any future hadron collider is to discover new physics (NP) associated with a high mass scale, , beyond the range of the LHC. In order to maintain the same relative mass reach for rate-limited NP, , as increases, Richter recently reminded us that the required integrated luminosity obtainable at future hadron colliders (FHC) must grow rapidly, , in the limit of naive scaling. This would imply, e.g., a 50-fold increase in the required integrated luminosity when going from the 14 TeV LHC to a FHC with TeV, an increase that would prove quite challenging on many different fronts. In this paper we point out, due to the scaling violations associated with the evolution of the parton density functions (PDFs) and the running of the strong coupling, , that the actual luminosity necessary in order to maintain any fixed value of the relative mass reach is somewhat greater than this scaling result indicates. However, the actual values of the required luminosity scaling are found to be dependent upon the detailed nature of the NP being considered. Here we elucidate this point explicitly by employing several specific benchmark examples of possible NP scenarios and briefly discuss the (relatively weak) search impact in each case if these luminosity goals are not met.

  14. Mass Reach Scaling for Future Hadron Colliders

    E-print Network

    Thomas G. Rizzo

    2015-03-09

    The primary goal of any future hadron collider is to discover new physics (NP) associated with a high mass scale, $M$, beyond the range of the LHC. In order to maintain the same {\\it relative} mass reach for NP, $M/{\\sqrt s}$, as $\\sqrt s$ increases, Richter recently reminded us that the required integrated luminosity obtainable at future hadron colliders (FHC) must grow rapidly, $\\sim s$, in the limit of naive scaling. This would imply, eg, a $\\sim 50$-fold increase in the required integrated luminosity when going from the 14 TeV LHC to a FHC with $\\sqrt s=100$ TeV, an increase that would prove quite challenging on many different fronts. In this paper we point out, due to the scaling violations associated with the evolution of the parton density functions (PDFs) and the running of the strong coupling, $\\alpha_s$, that the actual luminosity necessary in order to maintain any fixed value of the relative mass reach is somewhat greater than this scaling result indicates. However, the actual values of the required luminosity scaling are found to be dependent upon the detailed nature of the NP being considered. Here we elucidate this point explicitly by employing several specific benchmark examples of possible NP scenarios and briefly discuss the (relatively weak) search impact in each case if these luminosity goals are not met.

  15. NASA's Astronomy Education Program: Reaching Diverse Audiences

    NASA Astrophysics Data System (ADS)

    Hasan, Hashima; Smith, Denise Anne; Hertz, Paul; Meinke, Bonnie

    2015-08-01

    An overview will be given of the rich programs developed by NASA to inject the science from it's Astrophysics missions into STEM activities targeted to diverse audiences. For example, Astro4Girls was started as a pilot program during IYA2009. This program partners NASA astrophysics education programs with public libraries to provide NASA-themed hands-on education activities for girls and their families, and has been executed across the country. School curricula and NASA websites have been translated in Spanish; Braille books have been developed for the visually impaired; programs have been developed for the hearing impaired. Special effort has been made to reach underrepresented minorities. Audiences include students, teachers, and the general public through formal and informal education settings, social media and other outlets. NASA Astrophysics education providers include teams embedded in its space flight missions; professionals selected though peer reviewed programs; as well as the Science Mission Directorate Astrophysics Education forum. Representative examples will be presented to demonstrate the reach of NASA education programs, as well as an evaluation of the effectiveness of these programs.

  16. Can donated media placements reach intended audiences?

    PubMed

    Cooper, Crystale Purvis; Gelb, Cynthia A; Chu, Jennifer; Polonec, Lindsey

    2013-09-01

    Donated media placements for public service announcements (PSAs) can be difficult to secure, and may not always reach intended audiences. Strategies used by the Centers for Disease Control and Prevention's (CDC) Screen for Life: National Colorectal Cancer Action Campaign (SFL) to obtain donated media placements include producing a diverse mix of high-quality PSAs, co-branding with state and tribal health agencies, securing celebrity involvement, monitoring media trends to identify new distribution opportunities, and strategically timing the release of PSAs. To investigate open-ended recall of PSAs promoting colorectal cancer screening, CDC conducted 12 focus groups in three U.S. cities with men and women either nearing age 50 years, when screening is recommended to begin, or aged 50-75 years who were not in compliance with screening guidelines. In most focus groups, multiple participants recalled exposure to PSAs promoting colorectal cancer screening, and most of these individuals reported having seen SFL PSAs on television, in transit stations, or on the sides of public buses. Some participants reported exposure to SFL PSAs without prompting from the moderator, as they explained how they learned about the disease. Several participants reported learning key campaign messages from PSAs, including that colorectal cancer screening should begin at age 50 years and screening can find polyps so they can be removed before becoming cancerous. Donated media placements can reach and educate mass audiences, including millions of U.S. adults who have not been screened appropriately for colorectal cancer. PMID:23720533

  17. Maximum freeze-out baryon density in nuclear collisions

    SciTech Connect

    Randrup, Jorgen; Cleymans, Jean

    2006-07-11

    Using simple parametrizations of the thermodynamicfreeze-out parameters vextracted from the data over a wide beam-energyrange, we reexpress the hadronic freeze-out line in terms of theunderlying dynamical quantities, the net baryon density rhoB and theenergy density epsilon, which are subject to local conservation laws.This analysis makes it apparent that rhoB exhibits a maximum as thecollision energy is decreased. This maximum freeze-out density hasmu=400-500 MeV, which is above the critical value, and it is reached fora fixed-target bombarding energy of 20-30 A GeV.

  18. Maximum freeze-out baryon density in nuclear collisions

    SciTech Connect

    Randrup, J.; Cleymans, J.

    2006-10-15

    Using simple parametrizations of the thermodynamic freeze-out parameters extracted from the data over a wide beam-energy range, we reexpress the hadronic freeze-out line in terms of the underlying dynamic quantities, the net baryon density {rho}{sub B} and the energy density epsiv, which are subject to local conservation laws. This analysis reveals that {rho}{sub B} exhibits a maximum as the collision energy is decreased. This maximum freeze-out density has {mu}=400-500 MeV, which is above the critical value, and it is reached for a fixed-target bombarding energy of 20-30 GeV/nucleon.

  19. Reaching Consensus by Allowing Moments of Indecision

    PubMed Central

    Svenkeson, A.; Swami, A.

    2015-01-01

    Group decision-making processes often turn into a drawn out and costly battle between two opposing subgroups. Using analytical arguments based on a master equation description of the opinion dynamics occurring in a three-state model of cooperatively interacting units, we show how the capability of a social group to reach consensus can be enhanced when there is an intermediate state for indecisive individuals to pass through. The time spent in the intermediate state must be relatively short compared to that of the two polar states in order to create the beneficial effect. Furthermore, the cooperation between individuals must not be too low, as the benefit to consensus is possible only when the cooperation level exceeds a specific threshold. We also discuss how zealots, agents that remain in one state forever, can affect the consensus among the rest of the population by counteracting the benefit of the intermediate state or making it virtually impossible for an opposition to form. PMID:26439503

  20. Reaching Consensus by Allowing Moments of Indecision

    NASA Astrophysics Data System (ADS)

    Svenkeson, A.; Swami, A.

    2015-10-01

    Group decision-making processes often turn into a drawn out and costly battle between two opposing subgroups. Using analytical arguments based on a master equation description of the opinion dynamics occurring in a three-state model of cooperatively interacting units, we show how the capability of a social group to reach consensus can be enhanced when there is an intermediate state for indecisive individuals to pass through. The time spent in the intermediate state must be relatively short compared to that of the two polar states in order to create the beneficial effect. Furthermore, the cooperation between individuals must not be too low, as the benefit to consensus is possible only when the cooperation level exceeds a specific threshold. We also discuss how zealots, agents that remain in one state forever, can affect the consensus among the rest of the population by counteracting the benefit of the intermediate state or making it virtually impossible for an opposition to form.

  1. Speeded reaching movements around invisible obstacles.

    PubMed

    Hudson, Todd E; Wolfe, Uta; Maloney, Laurence T

    2012-01-01

    We analyze the problem of obstacle avoidance from a Bayesian decision-theoretic perspective using an experimental task in which reaches around a virtual obstacle were made toward targets on an upright monitor. Subjects received monetary rewards for touching the target and incurred losses for accidentally touching the intervening obstacle. The locations of target-obstacle pairs within the workspace were varied from trial to trial. We compared human performance to that of a Bayesian ideal movement planner (who chooses motor strategies maximizing expected gain) using the Dominance Test employed in Hudson et al. (2007). The ideal movement planner suffers from the same sources of noise as the human, but selects movement plans that maximize expected gain in the presence of that noise. We find good agreement between the predictions of the model and actual performance in most but not all experimental conditions. PMID:23028276

  2. The Maximum Density of Water.

    ERIC Educational Resources Information Center

    Greenslade, Thomas B., Jr.

    1985-01-01

    Discusses a series of experiments performed by Thomas Hope in 1805 which show the temperature at which water has its maximum density. Early data cast into a modern form as well as guidelines and recent data collected from the author provide background for duplicating Hope's experiments in the classroom. (JN)

  3. DECOMPOSITION USING MAXIMUM AUTOCORRELATION FACTORS

    E-print Network

    the maximum autocorrelation factor (MAF) transform was proposed for multivariate imagery in [18 with variable ordering. This corresponds to a Q-mode analysis of the data matrix. We denote this methods Q-MAF decomposition. It turns out that in many situations the new variables resulting from the MAF and the Q-MAF

  4. Growth physiology and fate of diatoms in the ocean: a review Geraldine Sarthoua,*, Klaas R. Timmermansb

    E-print Network

    rate of photosynthesis, photosynthetic efficiency and light adaptation parameter), nutrient limitation of diatoms (e.g. maximum growth rate, photosynthesis parameters, half- saturation constants, sinking rate and fate of many diatom species, including maximum growth rate, photosynthetic parameters (maximum specific

  5. [Growth modeling of Albizia niopoides (Mimosaceae) using dendrochronological methods].

    PubMed

    Giraldo, Víctor David; del Valle, Jorge Ignacio

    2012-09-01

    The annual growth rings in tropical trees are fairly common, but their study is relatively recent. Growth rings were found in trees of Albizia niopoides from the Porce River Canyon, Central Cordillera of the Colombian Andes. A total of 33 cross-sections were collected from trees distributed throughout the study area from 664-870masl. Cross-dating, spaguetti plot and 14C analyses were used to demonstrate ring annuality, assuming as hypothesis that these are real annual growth rings. A combination of descriptive analysis of time series (smoothing and pre-whitening) to filter climate noise and nonlinear regression with weighted residuals was used to fit the diameter to Korfs growth model, in which the coefficient of determination reaches values close to 100%. The positive residual autocorrelation of order 1, although not significant, is explained by the existence of energy reserves in the stem and by the accumulation of diameter increments required for the construction of the diameter growth model. The current and mean annual maximum increment rates are 1.03 and 0.94cm/year at ages 18 and 46 years old, respectively. These trees are classified within the group of fast growing species which can reach a cut diameter of over 50cm in approximately 52 years. PMID:23025084

  6. Role of nutrient supply on cell growth in bioreactor design for tissue engineering of hematopoietic cells.

    PubMed

    Pathi, Pragyansri; Ma, Teng; Locke, Bruce R

    2005-03-30

    In the present study, a dynamic mathematical model for the growth of granulocyte progenitor cells in the hematopoietic process is developed based on the principles of diffusion and chemical reaction. This model simulates granulocyte progenitor cell growth and oxygen consumption in a three-dimensional (3-D) perfusion bioreactor. Material balances on cells are coupled to the nutrient balances in 3-D matrices to determine the effects of transport limitations on cell growth. The method of volume averaging is used to formulate the material balances for the cells and the nutrients in the porous matrix containing the cells. All model parameters are obtained from the literature. The maximum cell volume fraction reached when oxygen is depleted in the cell layer at 15 days and is nearly 0.63, corresponding to a cell density of 2.25 x 10(8) cells/mL. The substrate inhibition kinetics for cell growth lead to complex effects with respect to the roles of oxygen concentration and supply by convection and diffusion on cell growth. Variation in the height of the liquid layer above the cell matrix where nutrient supply is introduced affected the relative and absolute amounts of oxygen supply by hydrodynamic flow and by diffusion across a gas permeable FEP membrane. Mass transfer restrictions of the FEP membrane are considerable, and the supply of oxygen by convection is essential to achieve higher levels of cell growth. A maximum growth rate occurs at a specific flow rate. For flow rates higher than this optimal, the high oxygen concentration led to growth inhibition and for lower flow rates growth limitations occur due to insufficient oxygen supply. Because of the nonlinear effects of the autocatalytic substrate inhibition growth kinetics coupled to the convective transport, the rate of growth at this optimal flow rate is higher than that in a corresponding well-mixed reactor where oxygen concentration is set at the maximum indicated by the inhibitory kinetics. PMID:15696509

  7. The Southern Glacial Maximum 65,000 years ago and its Unfinished Termination

    NASA Astrophysics Data System (ADS)

    Schaefer, Joerg M.; Putnam, Aaron E.; Denton, George H.; Kaplan, Michael R.; Birkel, Sean; Doughty, Alice M.; Kelley, Sam; Barrell, David J. A.; Finkel, Robert C.; Winckler, Gisela; Anderson, Robert F.; Ninneman, Ulysses S.; Barker, Stephen; Schwartz, Roseanne; Andersen, Bjorn G.; Schluechter, Christian

    2015-04-01

    Glacial maxima and their terminations provide key insights into inter-hemispheric climate dynamics and the coupling of atmosphere, surface and deep ocean, hydrology, and cryosphere, which is fundamental for evaluating the robustness of earth's climate in view of ongoing climate change. The Last Glacial Maximum (LGM, ?26-19 ka ago) is widely seen as the global cold peak during the last glacial cycle, and its transition to the Holocene interglacial, dubbed 'Termination 1 (T1)', as the most dramatic climate reorganization during this interval. Climate records show that over the last 800 ka, ice ages peaked and terminated on average every 100 ka ('100 ka world'). However, the mechanisms pacing glacial-interglacial transitions remain controversial and in particular the hemispheric manifestations and underlying orbital to regional driving forces of glacial maxima and subsequent terminations remain poorly understood. Here we show evidence for a full glacial maximum in the Southern Hemisphere 65.1 ± 2.7 ka ago and its 'Unfinished Termination'. Our 10Be chronology combined with a model simulation demonstrates that New Zealand's glaciers reached their maximum position of the last glacial cycle during Marine Isotope Stage-4 (MIS-4). Southern ocean and greenhouse gas records indicate coeval peak glacial conditions, making the case for the Southern Glacial Maximum about halfway through the last glacial cycle and only 15 ka after the last warm period (MIS-5a). We present the hypothesis that subsequently, driven by boreal summer insolation forcing, a termination began but remained unfinished, possibly because the northern ice sheets were only moderately large and could not supply enough meltwater to the North Atlantic through Heinrich Stadial 6 to drive a full termination. Yet the Unfinished Termination left behind substantial ice on the northern continents (about 50% of the full LGM ice volume) and after another 45 ka of cooling and ice sheet growth the earth was at inter-hemispheric Last Glacial Maximum configuration, when similar orbital forcing hit maximum-size northern ice sheets and ushered in T1 and thus the ongoing interglacial. This argument highlights the critical role of full glacial conditions in both hemispheres for terminations and implies that the Southern Hemisphere climate could transition from interglacial to full glacial conditions in about 15,000 years, while the Northern Hemisphere and its continental ice-sheets required half a glacial cycle.

  8. Cancer costs projected to reach at least $158 billion in 2020

    Cancer.gov

    Based on growth and aging of the U.S. population, medical expenditures for cancer in the year 2020 are projected to reach at least $158 billion (in 2010 dollars) – an increase of 27 percent over 2010. If newly developed tools for cancer diagnosis, treatme

  9. Reaching adolescents: a role for radio.

    PubMed

    1999-12-01

    The radio is a powerful means to reach adolescents and to address their concerns, particularly those that are not being addressed by their families or by the school curriculum. Proving this point is a radio program, "Sandhikhan" (Bengali for adolescence), which aired on national radio covering adolescent health issues, particularly reproductive health. The program's impact was the subject of a WBVHA survey among adolescent radio listeners in West Bengal. About 79% (369 individual listeners) of the respondents rated the radio program very good, with only a negligible 1% describing it as unnecessary. Only 21% of respondents listened to the program alone, with the majority listening in the company of friends, mothers, sisters, brothers, fathers, and other relatives. This suggested a wider group of listeners in addition to the program's primary target audience. Clearly, findings pointed to the effectiveness of teaching adolescent health on the air and the role that was played by WBVHA in developing healthy attitudes and habits among its young audience. The findings of the survey will provide the basis for producing educational materials on reproductive health for students as well as teachers. PMID:12158256

  10. Media perspective - new opportunities for reaching audiences

    NASA Astrophysics Data System (ADS)

    Haswell, Katy

    2007-08-01

    The world of media is experiencing a period of extreme and rapid change with the rise of internet television and the download generation. Many young people no longer watch standard TV. Instead, they go on-line, talking to friends and downloading pictures, videos, music clips to put on their own websites and watch/ listen to on their laptops and mobile phones. Gone are the days when TV controllers determined what you watched and when you watched it. Now the buzzword is IPTV, Internet Protocol Television, with companies such as JOOST offering hundreds of channels on a wide range of subjects, all of which you can choose to watch when and where you wish, on your high-def widescreen with stereo surround sound at home or on your mobile phone on the train. This media revolution is changing the way organisations get their message out. And it is encouraging companies such as advertising agencies to be creative about new ways of accessing audiences. The good news is that we have fresh opportunities to reach young people through internet-based media and material downloaded through tools such as games machines, as well as through the traditional media. And it is important for Europlanet to make the most of these new and exciting developments.

  11. Has Athletic Performance Reached its Peak?

    PubMed

    Berthelot, Geoffroy; Sedeaud, Adrien; Marck, Adrien; Antero-Jacquemin, Juliana; Schipman, Julien; Saulière, Guillaume; Marc, Andy; Desgorces, François-Denis; Toussaint, Jean-François

    2015-09-01

    Limits to athletic performance have long been a topic of myth and debate. However, sport performance appears to have reached a state of stagnation in recent years, suggesting that the physical capabilities of humans and other athletic species, such as greyhounds and thoroughbreds, cannot progress indefinitely. Although the ultimate capabilities may be predictable, the exact path for the absolute maximal performance values remains difficult to assess and relies on technical innovations, sport regulation, and other parameters that depend on current societal and economic conditions. The aim of this literature review was to assess the possible plateau of top physical capabilities in various events and detail the historical backgrounds and sociocultural, anthropometrical, and physiological factors influencing the progress and regression of athletic performance. Time series of performances in Olympic disciplines, such as track and field and swimming events, from 1896 to 2012 reveal a major decrease in performance development. Such a saturation effect is simultaneous in greyhound, thoroughbred, and frog performances. The genetic condition, exhaustion of phenotypic pools, economic context, and the depletion of optimal morphological traits contribute to the observed limitation of physical capabilities. Present conditions prevailing, we approach absolute physical limits and endure a continued period of world record scarcity. Optional scenarios for further improvements will mostly depend on sport technology and modification competition rules. PMID:26094000

  12. Gravitational wave detector with cosmological reach

    NASA Astrophysics Data System (ADS)

    Dwyer, Sheila; Sigg, Daniel; Ballmer, Stefan W.; Barsotti, Lisa; Mavalvala, Nergis; Evans, Matthew

    2015-04-01

    Twenty years ago, construction began on the Laser Interferometer Gravitational-wave Observatory (LIGO). Advanced LIGO, with a factor of 10 better design sensitivity than Initial LIGO, will begin taking data this year, and should soon make detections a monthly occurrence. While Advanced LIGO promises to make first detections of gravitational waves from the nearby universe, an additional factor of 10 increase in sensitivity would put exciting science targets within reach by providing observations of binary black hole inspirals throughout most of the history of star formation, and high signal to noise observations of nearby events. Design studies for future detectors to date rely on significant technological advances that are futuristic and risky. In this paper we propose a different direction. We resurrect the idea of using longer arm lengths coupled with largely proven technologies. Since the major noise sources that limit gravitational wave detectors do not scale trivially with the length of the detector, we study their impact and find that 40 km arm lengths are nearly optimal, and can incorporate currently available technologies to detect gravitational wave sources at cosmological distances (z ?7 ) .

  13. ESO telbib: Linking In and Reaching Out

    NASA Astrophysics Data System (ADS)

    Grothkopf, U.; Meakins, S.

    2015-04-01

    Measuring an observatory's research output is an integral part of its science operations. Like many other observatories, ESO tracks scholarly papers that use observational data from ESO facilities and uses state-of-the-art tools to create, maintain, and further develop the Telescope Bibliography database (telbib). While telbib started out as a stand-alone tool mostly used to compile lists of papers, it has by now developed into a multi-faceted, interlinked system. The core of the telbib database is links between scientific papers and observational data generated by the La Silla Paranal Observatory residing in the ESO archive. This functionality has also been deployed for ALMA data. In addition, telbib reaches out to several other systems, including ESO press releases, the NASA ADS Abstract Service, databases at the CDS Strasbourg, and impact scores at Altmetric.com. We illustrate these features to show how the interconnected telbib system enhances the content of the database as well as the user experience.

  14. San Acacia Reach San Acacia Dam to Escondida Bridge

    E-print Network

    Julien, Pierre Y.

    San Acacia Reach San Acacia Dam to Escondida Bridge Hydraulic Modeling Analysis 1918-2006 Middle, hydraulic modeling analyses have been performed on the San Acacia reach to determine the changes by Reclamation on the San Acacia reach. The 11.6 mile long reach extends from the San Acacia Diversion dam (River

  15. Maximum likelihood estimation for cooperative sequential adsorption

    E-print Network

    Scheichl, Robert

    Maximum likelihood estimation for cooperative sequential adsorption Mathew D. Penrose and Vadim;Maximum likelihood estimation for cooperative sequential adsorption M.D. Penrose, Department of the region. Keywords: cooperative sequential adsorption, space-time point pro- cess, maximum likelihood

  16. Time course of epiphyseal growth plate fusion in rat tibiae

    NASA Technical Reports Server (NTRS)

    Martin, E. A.; Ritman, E. L.; Turner, R. T.

    2003-01-01

    Although the rat is the most common animal model used in studying osteoporosis, it is often used inappropriately. Osteoporosis is a disease that most commonly occurs in humans long after growth plate fusion with the associated cessation of longitudinal bone growth, but there has been a question as to when or to what extent the rat growth plate fuses. To investigate this question, we used microcomputed X-ray tomography, at voxel resolutions ranging from (5.7 micro m)(3) to (11 micro m)(3), to image the proximal epiphyseal growth plates of both male (n = 19) and female (n = 15) rat tibiae, ranging in age from 2 to 25 months. The three-dimensional images were used to evaluate fusion of the epiphyseal growth plate by quantitating the amount of cancellous bone that has bridged across the growth plate. The results suggest that the time course of fusion of the epiphyseal growth plate follows a sigmoidal pattern, with 10% of the maximum number of bridges having formed by 3.9 months in the male tibiae and 5.8 months in the female tibiae, 50% of the maximum number of bridges having formed by 5.6 months in the male tibiae and 5.9 months in the female tibiae, and 90% of the total maximum of bridges have formed by 7.4 months for the males and 6.5 months for the females. The total volume of bridges per tibia at the age at which the maximum number of bridges per tibia has first formed is 0.99 mm(3)/tibia for the males and 0.40 mm(3)/tibia for the females. After the maximum number of bridges (-290 for females, -360 for males) have formed the total volume of bridges per tibia continues to increase for an additional 7.0 months in the males and 17.0 months for the females until they reach maximum values (-1.5 mm(3)/tibia for the males and -2.2 mm(3)/tibia for the females).

  17. Columbia River Estuary Ecosystem Classification Hydrogeomorphic Reach

    USGS Publications Warehouse

    Cannon, Charles M.; Ramirez, Mary F.; Heatwole, Danelle W.; Burke, Jennifer L.; Simenstad, Charles A.; O'Connor, Jim E.; Marcoe, Keith

    2012-01-01

    Estuarine ecosystems are controlled by a variety of processes that operate at multiple spatial and temporal scales. Understanding the hierarchical nature of these processes will aid in prioritization of restoration efforts. This hierarchical Columbia River Estuary Ecosystem Classification (henceforth "Classification") of the Columbia River estuary is a spatial database of the tidally-influenced reaches of the lower Columbia River, the tidally affected parts of its tributaries, and the landforms that make up their floodplains for the 230 kilometers between the Pacific Ocean and Bonneville Dam. This work is a collaborative effort between University of Washington School of Aquatic and Fishery Sciences (henceforth "UW"), U.S. Geological Survey (henceforth "USGS"), and the Lower Columbia Estuary Partnership (henceforth "EP"). Consideration of geomorphologic processes will improve the understanding of controlling physical factors that drive ecosystem evolution along the tidal Columbia River. The Classification is organized around six hierarchical levels, progressing from the coarsest, regional scale to the finest, localized scale: (1) Ecosystem Province; (2) Ecoregion; (3) Hydrogeomorphic Reach; (4) Ecosystem Complex; (5) Geomorphic Catena; and (6) Primary Cover Class. For Levels 4 and 5, we mapped landforms within the Holocene floodplain primarily by visual interpretation of Light Detection and Ranging (LiDAR) topography supplemented with aerial photographs, Natural Resources Conservation Service (NRCS) soils data, and historical maps. Mapped landforms are classified as to their current geomorphic function, the inferred process regime that formed them, and anthropogenic modification. Channels were classified primarily by a set of depth-based rules and geometric relationships. Classification Level 5 floodplain landforms ("geomorphic catenae") were further classified based on multivariate analysis of land-cover within the mapped landform area and attributed as "sub-catena". The extent of detailed mapping is the interpreted Holocene geologic floodplain of the tidal Columbia River and its tributaries to the estimated head of tide. The extent of this dataset also includes tributary valleys that are not mapped in detail. The upstream extents of tributary valleys are an estimation of the limit of Columbia River influence and are for use as containers in future analyses. The geologic floodplain is the geomorphic surface that is actively accumulating sediment through occasional overbank deposition. Most features within the geologic floodplain are considered to be formed during the recent (Holocene-epoch) climatic regime. There are bedrock and pre-Holocene sedimentary deposits included where they are surrounded by Holocene sediment accumulations or have been shaped by Holocene floods. In some places, Holocene landforms such as landslides, tributary fans, and coastal dunes are mapped that extend outside of the modern floodplain. This map is not a floodplain hazard map or delineation of actual flood boundaries. Although wetlands are included in the Classification, they are based on different criteria than jurisdictional wetlands. The extent of mapping may differ from the actual limit of tidal influence.

  18. Flow model for open-channel reach or network

    USGS Publications Warehouse

    Schaffranek, R.W.

    1987-01-01

    Formulation of a one-dimensional model for simulating unsteady flow in a single open-channel reach or in a network of interconnected channels is presented. The model is both general and flexible in that it can be used to simulate a wide range of flow conditions for various channel configurations. It is based on a four-point (box), implicit, finite-difference approximation of the governing nonlinear flow equations with user-definable weighting coefficients to permit varying the solution scheme from box-centered to fully forward. Unique transformation equations are formulated that permit correlation of the unknowns at the extremities of the channels, thereby reducing coefficient matrix and execution time requirements. Discharges and water-surface elevations computed at intermediate locations within a channel are determined following solution of the transformation equations. The matrix of transformation and boundary-condition equations is solved by Gauss elimination using maximum pivot strategy. Two diverse applications of the model are presented to illustrate its broad utility. (USGS)

  19. Determination Of The Maximum Explosion Pressure And The Maximum Rate Of Pressure Rise During Explosion Of Wood Dust Clouds

    NASA Astrophysics Data System (ADS)

    Kuracina, Richard; Szabová, Zuzana; ?ekan, Pavol

    2015-06-01

    The article deals with the measurement of maximum explosion pressure and the maximum rate of exposure pressure rise of wood dust cloud. The measurements were carried out according to STN EN 14034-1+A1:2011 Determination of explosion characteristics of dust clouds. Part 1: Determination of the maximum explosion pressure pmax of dust clouds and the maximum rate of explosion pressure rise according to STN EN 14034-2+A1:2012 Determination of explosion characteristics of dust clouds - Part 2: Determination of the maximum rate of explosion pressure rise (dp/dt)max of dust clouds. The wood dust cloud in the chamber is achieved mechanically. The testing of explosions of wood dust clouds showed that the maximum value of the pressure was reached at the concentrations of 450 g / m3 and its value is 7.95 bar. The fastest increase of pressure was observed at the concentrations of 450 g / m3 and its value was 68 bar / s.

  20. Temporal and spatial evolution of the Antarctic sea ice prior to the September 2012 record maximum extent

    NASA Astrophysics Data System (ADS)

    Turner, John; Hosking, J. Scott; Phillips, Tony; Marshall, Gareth J.

    2013-11-01

    24 September 2012 the Antarctic sea ice extent (SIE) reached a new annual daily maximum (ADM) for the satellite era of 19.72 × 106 km2. The largest positive SIE anomalies compared to the mean of all ADMs were found over the northern Amundsen Sea, off the coast of Wilkes Land, with smaller positive anomalies off the Dronning Maud Land coast (30°W to 30°E). The SIE at the ADM is significantly correlated with the extents for the previous 80 days, but the ice growth during the winter of 2012 was close to the climatological rate, and 1 month before the ADM, the SIE was near the recent mean. Deep depressions in the circumpolar trough since late August 2012 resulted in strong southerly flow and marked northward sea ice advection. The linear trend in SIE suggests that it contributed ~40% to the 2012 anomaly, with depression activity adding ~60%.

  1. Development of microgravity, full body functional reach envelope using 3-D computer graphic models and virtual reality technology

    NASA Technical Reports Server (NTRS)

    Lindsey, Patricia F.

    1994-01-01

    In microgravity conditions mobility is greatly enhanced and body stability is difficult to achieve. Because of these difficulties, optimum placement and accessibility of objects and controls can be critical to required tasks on board shuttle flights or on the proposed space station. Anthropometric measurement of the maximum reach of occupants of a microgravity environment provide knowledge about maximum functional placement for tasking situations. Calculations for a full body, functional reach envelope for microgravity environments are imperative. To this end, three dimensional computer modeled human figures, providing a method of anthropometric measurement, were used to locate the data points that define the full body, functional reach envelope. Virtual reality technology was utilized to enable an occupant of the microgravity environment to experience movement within the reach envelope while immersed in a simulated microgravity environment.

  2. Aging, Maturation and Growth of Sauropodomorph Dinosaurs as Deduced from Growth Curves Using Long Bone Histological Data: An Assessment of Methodological Constraints and Solutions.

    PubMed

    Griebeler, Eva Maria; Klein, Nicole; Sander, P Martin

    2013-01-01

    Information on aging, maturation, and growth is important for understanding life histories of organisms. In extinct dinosaurs, such information can be derived from the histological growth record preserved in the mid-shaft cortex of long bones. Here, we construct growth models to estimate ages at death, ages at sexual maturity, ages at which individuals were fully-grown, and maximum growth rates from the growth record preserved in long bones of six sauropod dinosaur individuals (one indeterminate mamenchisaurid, two Apatosaurus sp., two indeterminate diplodocids, and one Camarasaurus sp.) and one basal sauropodomorph dinosaur individual (Plateosaurus engelhardti). Using these estimates, we establish allometries between body mass and each of these traits and compare these to extant taxa. Growth models considered for each dinosaur individual were the von Bertalanffy model, the Gompertz model, and the logistic model (LGM), all of which have inherently fixed inflection points, and the Chapman-Richards model in which the point is not fixed. We use the arithmetic mean of the age at the inflection point and of the age at which 90% of asymptotic mass is reached to assess respectively the age at sexual maturity or the age at onset of reproduction, because unambiguous indicators of maturity in Sauropodomorpha are lacking. According to an AIC-based model selection process, the LGM was the best model for our sauropodomorph sample. Allometries established are consistent with literature data on other Sauropodomorpha. All Sauropodomorpha reached full size within a time span similar to scaled-up modern mammalian megaherbivores and had similar maximum growth rates to scaled-up modern megaherbivores and ratites, but growth rates of Sauropodomorpha were lower than of an average mammal. Sauropodomorph ages at death probably were lower than that of average scaled-up ratites and megaherbivores. Sauropodomorpha were older at maturation than scaled-up ratites and average mammals, but younger than scaled-up megaherbivores. PMID:23840575

  3. Aging, Maturation and Growth of Sauropodomorph Dinosaurs as Deduced from Growth Curves Using Long Bone Histological Data: An Assessment of Methodological Constraints and Solutions

    PubMed Central

    Griebeler, Eva Maria; Klein, Nicole; Sander, P. Martin

    2013-01-01

    Information on aging, maturation, and growth is important for understanding life histories of organisms. In extinct dinosaurs, such information can be derived from the histological growth record preserved in the mid-shaft cortex of long bones. Here, we construct growth models to estimate ages at death, ages at sexual maturity, ages at which individuals were fully-grown, and maximum growth rates from the growth record preserved in long bones of six sauropod dinosaur individuals (one indeterminate mamenchisaurid, two Apatosaurus sp., two indeterminate diplodocids, and one Camarasaurus sp.) and one basal sauropodomorph dinosaur individual (Plateosaurus engelhardti). Using these estimates, we establish allometries between body mass and each of these traits and compare these to extant taxa. Growth models considered for each dinosaur individual were the von Bertalanffy model, the Gompertz model, and the logistic model (LGM), all of which have inherently fixed inflection points, and the Chapman-Richards model in which the point is not fixed. We use the arithmetic mean of the age at the inflection point and of the age at which 90% of asymptotic mass is reached to assess respectively the age at sexual maturity or the age at onset of reproduction, because unambiguous indicators of maturity in Sauropodomorpha are lacking. According to an AIC-based model selection process, the LGM was the best model for our sauropodomorph sample. Allometries established are consistent with literature data on other Sauropodomorpha. All Sauropodomorpha reached full size within a time span similar to scaled-up modern mammalian megaherbivores and had similar maximum growth rates to scaled-up modern megaherbivores and ratites, but growth rates of Sauropodomorpha were lower than of an average mammal. Sauropodomorph ages at death probably were lower than that of average scaled-up ratites and megaherbivores. Sauropodomorpha were older at maturation than scaled-up ratites and average mammals, but younger than scaled-up megaherbivores. PMID:23840575

  4. Maximum life spur gear design

    NASA Technical Reports Server (NTRS)

    Savage, M.; Mackulin, M. J.; Coe, H. H.; Coy, J. J.

    1991-01-01

    Optimization procedures allow one to design a spur gear reduction for maximum life and other end use criteria. A modified feasible directions search algorithm permits a wide variety of inequality constraints and exact design requirements to be met with low sensitivity to initial guess values. The optimization algorithm is described, and the models for gear life and performance are presented. The algorithm is compact and has been programmed for execution on a desk top computer. Two examples are presented to illustrate the method and its application.

  5. Pontryagin Maximum Principle - a generalization

    E-print Network

    Grabowski, Janusz

    2009-01-01

    The fundamental theorem of the theory of optimal control, the Pontryagin Maximum Principle (PMP), is extended to the setting of almost Lie (AL) algebroids - geometrical objects generalizing Lie algebroids. This formulation of the PMP may be viewed as a scheme comprising reductions of optimal control problems, like the Euler-Poincar'e equations arise as reductions of the Euler-Lagrange equations for the rigid body. The framework is based on a very general concept of homotopy of admissible paths and geometry of AL algebroids and goes back to some ideas of the Lagrangian and Hamiltonian formalisms in this general setting.

  6. What causes cooling water temperature gradients in a forested stream reach?

    NASA Astrophysics Data System (ADS)

    Garner, G.; Malcolm, I. A.; Sadler, J. P.; Hannah, D. M.

    2014-12-01

    Previous studies have suggested that shading by riparian vegetation may reduce maximum water temperatures and provide refugia for temperature-sensitive aquatic organisms. Longitudinal cooling gradients have been observed during the daytime for stream reaches shaded by coniferous trees downstream of clear cuts or deciduous woodland downstream of open moorland. However, little is known about the energy exchange processes that drive such gradients, especially in semi-natural woodland contexts without confounding cool groundwater inflows. To address this gap, this study quantified and modelled variability in stream temperature and heat fluxes along an upland reach of the Girnock Burn (a tributary of the Aberdeenshire Dee, Scotland) where riparian land use transitions from open moorland to semi-natural, predominantly deciduous woodland. Observations were made along a 1050 m reach using a spatially distributed network of 10 water temperature data loggers, 3 automatic weather stations and 211 hemispherical photographs that were used to estimate incoming solar radiation. These data parameterised a high-resolution energy flux model incorporating flow routing, which predicted spatio-temporal variability in stream temperature. Variability in stream temperature was controlled largely by energy fluxes at the water-column-atmosphere interface. Net energy gains occurred along the reach, predominantly during daylight hours, and heat exchange across the bed-water-column interface accounted for <1% of the net energy budget. For periods when daytime net radiation gains were high (under clear skies), differences between water temperature observations increased in the streamwise direction; a maximum instantaneous difference of 2.5 °C was observed between the upstream reach boundary and 1050 m downstream. Furthermore, daily maximum water temperature at 1050 m downstream was ?1 °C cooler than at the upstream reach boundary and lagged by >1 h. Temperature gradients were not generated by cooling of stream water but rather by a combination of reduced rates of heating in the woodland reach and advection of cooler (overnight and early morning) water from the upstream moorland catchment. Longitudinal thermal gradients were indistinct at night and on days when net radiation gains were low (under overcast skies), thus when changes in net energy gains or losses did not vary significantly in space and time, and heat advected into the reach was reasonably consistent. The findings of the study and the modelling approach employed are useful tools for assessing optimal planting strategies for mitigating against ecologically damaging stream temperature maxima.

  7. Maximum-information photoelectron metrology

    NASA Astrophysics Data System (ADS)

    Hockett, P.; Lux, C.; Wollenhaupt, M.; Baumert, T.

    2015-07-01

    Photoelectron interferograms, manifested in photoelectron angular distributions (PADs), are high-information, coherent observables. In order to obtain the maximum information from angle-resolved photoionization experiments it is desirable to record the full, three-dimensional (3D), photoelectron momentum distribution. Here we apply tomographic reconstruction techniques to obtain such 3D distributions from multiphoton ionization of potassium atoms, and fully analyze the energy and angular content of the 3D data. The PADs obtained as a function of energy indicate good agreement with previous 2D data and detailed analysis [Hockett et al., Phys. Rev. Lett. 112, 223001 (2014), 10.1103/PhysRevLett.112.223001] concerning the main spectral features, but also indicate unexpected symmetry breaking in certain regions of momentum space, thus revealing additional continuum interferences which cannot otherwise be observed. These observations reflect the presence of additional ionization pathways and, most generally, illustrate the power of maximum-information measurements of coherent observables for quantum metrology of complex systems.

  8. Development of the southern reaches of Laurentia

    SciTech Connect

    Reed, J.C. Jr. . Federal Center)

    1993-02-01

    Laurentia, the Late Proterozoic continental fragment that now forms the core of North America, has a long and complex history, much of which involves development along its southern margin. The southernmost parts of the Archean continental core are the Wyoming and Superior cratons, both of which contain gneisses that record crust-forming events in the interval 3.8--3.1 Ga as well as greenstone belts that reflect continental growth in the interval 2.8--2.6 Ga. Each of these cratonic elements was assembled and stabilized prior to deposition of passive margin sequences along their southern flanks during the interval [approximately]2.5--1.9 Ga. Between [approximately]1.8 Ga and 1.6 Ga arc-related sedimentary and volcanic rocks were accreted to the southern margin of the Laurentian core during a complex series of tectonic episodes that included events locally referred to as the Penokean, Ivanpah, Yavapai, and Mazatzal orogenies, resulting in the addition of a belt of continental crust at least 1,000 km wide. Voluminous highly evolved granite and rhyolite were emplaced along this southern marginal belt between [approximately] 1.45 and 1.35 Ga under conditions of general tectonic stability, or perhaps dispersed regional extension. This same interval was also marked by onset of deposition of thick Middle Proterozoic sedimentary sequences along the western and southern margins of Laurentia. The eastern margin of Laurentia contains the complexly deformed and metamorphosed rocks of the 1.25 to 1.1 Ga Grenville orogen which, according to recent reconstructions, may record a collision with cratonic elements in western South America. The 2,000 km-long Midcontinent rift system in central Laurentia opened and filled with basalt and sediments at about the same time as the end of Grenville activity.

  9. Maximum vehicle cabin temperatures under different meteorological conditions

    NASA Astrophysics Data System (ADS)

    Grundstein, Andrew; Meentemeyer, Vernon; Dowd, John

    2009-05-01

    A variety of studies have documented the dangerously high temperatures that may occur within the passenger compartment (cabin) of cars under clear sky conditions, even at relatively low ambient air temperatures. Our study, however, is the first to examine cabin temperatures under variable weather conditions. It uses a unique maximum vehicle cabin temperature dataset in conjunction with directly comparable ambient air temperature, solar radiation, and cloud cover data collected from April through August 2007 in Athens, GA. Maximum cabin temperatures, ranging from 41-76°C, varied considerably depending on the weather conditions and the time of year. Clear days had the highest cabin temperatures, with average values of 68°C in the summer and 61°C in the spring. Cloudy days in both the spring and summer were on average approximately 10°C cooler. Our findings indicate that even on cloudy days with lower ambient air temperatures, vehicle cabin temperatures may reach deadly levels. Additionally, two predictive models of maximum daily vehicle cabin temperatures were developed using commonly available meteorological data. One model uses maximum ambient air temperature and average daily solar radiation while the other uses cloud cover percentage as a surrogate for solar radiation. From these models, two maximum vehicle cabin temperature indices were developed to assess the level of danger. The models and indices may be useful for forecasting hazardous conditions, promoting public awareness, and to estimate past cabin temperatures for use in forensic analyses.

  10. Maximum vehicle cabin temperatures under different meteorological conditions.

    PubMed

    Grundstein, Andrew; Meentemeyer, Vernon; Dowd, John

    2009-05-01

    A variety of studies have documented the dangerously high temperatures that may occur within the passenger compartment (cabin) of cars under clear sky conditions, even at relatively low ambient air temperatures. Our study, however, is the first to examine cabin temperatures under variable weather conditions. It uses a unique maximum vehicle cabin temperature dataset in conjunction with directly comparable ambient air temperature, solar radiation, and cloud cover data collected from April through August 2007 in Athens, GA. Maximum cabin temperatures, ranging from 41-76 degrees C, varied considerably depending on the weather conditions and the time of year. Clear days had the highest cabin temperatures, with average values of 68 degrees C in the summer and 61 degrees C in the spring. Cloudy days in both the spring and summer were on average approximately 10 degrees C cooler. Our findings indicate that even on cloudy days with lower ambient air temperatures, vehicle cabin temperatures may reach deadly levels. Additionally, two predictive models of maximum daily vehicle cabin temperatures were developed using commonly available meteorological data. One model uses maximum ambient air temperature and average daily solar radiation while the other uses cloud cover percentage as a surrogate for solar radiation. From these models, two maximum vehicle cabin temperature indices were developed to assess the level of danger. The models and indices may be useful for forecasting hazardous conditions, promoting public awareness, and to estimate past cabin temperatures for use in forensic analyses. PMID:19234721

  11. Dynamical predictability in a simple general circulation model - Average error growth

    NASA Technical Reports Server (NTRS)

    Schubert, Siegfried D.; Suarez, Max

    1989-01-01

    Average predictability and error growth in a simple realistic two-level general circulation model (GCM) were investigated using a series of Monte Carlo experiments for fixed external forcing (perpetual winter in the Northern Hemisphere). It was found that, for realistic initial errors, the dependence of the limit of dynamic predictability on total wavenumber was similar to that found for the ECMWF model for the 1980/1981 winter conditions, with the lowest wavenumbers showing significant skill for forecast ranges of more than 1 month. On the other hand, for very small amplitude errors distributed according to the climate spectrum, the total error growth was superexponential, reaching a maximum growth rate (2-day doubling time) in about 1 week. A simple empirical model of error variance, which involved two broad wavenumber bands and incorporating a 3/2 power saturation term, was found to provide an excellent fit to the GCM error growth behavior.

  12. Information models of software productivity - Limits on productivity growth

    NASA Technical Reports Server (NTRS)

    Tausworthe, Robert C.

    1992-01-01

    Research into generalized information-metric models of software process productivity establishes quantifiable behavior and theoretical bounds. The models establish a fundamental mathematical relationship between software productivity and the human capacity for information traffic, the software product yield (system size), information efficiency, and tool and process efficiencies. An upper bound is derived that quantifies average software productivity and the maximum rate at which it may grow. This bound reveals that ultimately, when tools, methodologies, and automated assistants have reached their maximum effective state, further improvement in productivity can only be achieved through increasing software reuse. The reuse advantage is shown not to increase faster than logarithmically in the number of reusable features available. The reuse bound is further shown to be somewhat dependent on the reuse policy: a general 'reuse everything' policy can lead to a somewhat slower productivity growth than a specialized reuse policy.

  13. Far-Reaching Impacts of African Dust- A Calipso Perspective

    NASA Technical Reports Server (NTRS)

    Yu, Hongbin; Chin, Mian; Yuan, Tianle; Bian, Huisheng; Prospero, Joseph; Omar, Ali; Remer, Lorraine; Winker, David; Yang, Yuekui; Zhang, Yan; Zhang, Zhibo

    2014-01-01

    African dust can transport across the tropical Atlantic and reach the Amazon basin, exerting far-reaching impacts on climate in downwind regions. The transported dust influences the surface-atmosphere interactions and cloud and precipitation processes through perturbing the surface radiative budget and atmospheric radiative heating and acting as cloud condensation nuclei and ice nuclei. Dust also influences biogeochemical cycle and climate through providing nutrients vital to the productivity of ocean biomass and Amazon forests. Assessing these climate impacts relies on an accurate quantification of dust transport and deposition. Currently model simulations show extremely large diversity, which calls for a need of observational constraints. Kaufman et al. (2005) estimated from MODIS aerosol measurements that about 144 Tg of dust is deposited into the tropical Atlantic and 50 Tg of dust into the Amazon in 2001. This estimated dust import to Amazon is a factor of 3-4 higher than other observations and models. However, several studies have argued that the oversimplified characterization of dust vertical profile in the study would have introduced large uncertainty and very likely a high bias. In this study we quantify the trans-Atlantic dust transport and deposition by using 7 years (2007-2013) observations from CALIPSO lidar. CALIPSO acquires high-resolution aerosol extinction and depolarization profiles in both cloud-free and above-cloud conditions. The unique CALIPSO capability of profiling aerosols above clouds offers an unprecedented opportunity of examining uncertainties associated with the use of MODIS clear-sky data. Dust is separated from other types of aerosols using the depolarization measurements. We estimated that on the basis of 7-year average, 118142 Tg of dust is deposited into the tropical Atlantic and 3860 Tg of dust into the Amazon basin. Substantial interannual variations are observed during the period, with the maximum to minimum ratio of about 1.6 and 2.5 for the deposition to the tropical Atlantic and Amazon, respectively. The MODIS-based estimates appear to fall within the range of CALIPSO-based estimates; and the difference between MODIS and CALIPSO estimates can be largely attributed to the interannual variability, which is corroborated by long-term surface dust concentration observations in the tropical Atlantic. Considering that CALIPSO generally tends to underestimate the aerosol loading, our estimate is likely to represent a low bound for the dust transport and deposition estimate. The finding suggests that models have substantial biases and considerable effort is needed to improve model simulations of dust cycle.

  14. Reach and its Impact: NASA and US Aerospace Communities

    NASA Technical Reports Server (NTRS)

    Rothgeb, Matthew J.

    2011-01-01

    REACH is a European law that threatens to impact materials used within the US aerospace communities, including NASA. The presentation briefly covers REACH and generally, its perceived impacts to NASA and the aerospace community within the US.

  15. ERF1 -- Enhanced River Reach File 1.2

    USGS Publications Warehouse

    Alexander, Richard B.; Brakebill, John W.; Brew, Robert E.; Smith, Richard A.

    1999-01-01

    U.S. Environmental Protection Agency's River Reach File 1 (RF1) to ensure the hydrologic integrity of the digital reach traces and to quantify the mean water time of travel in river reaches and reservoirs [see USEPA (1996) for a description of the original RF1].

  16. DRAFT San Acacia Reach San Acacia Dam to Escondida Bridge

    E-print Network

    Julien, Pierre Y.

    DRAFT San Acacia Reach San Acacia Dam to Escondida Bridge Hydraulic Modeling Analysis 1918, hydraulic modeling analyses have been performed on the San Acacia reach to determine the changes by Reclamation on the San Acacia reach. The 11.6 mile long extends from the San Acacia Diversion dam (River Mile

  17. Growth hormone and growth?

    PubMed

    Harvey, Steve

    2013-09-01

    Pituitary GH is obligatory for normal growth in mammals, but the importance of pituitary GH in avian growth is less certain. In birds, pituitary GH is biologically active and has growth promoting actions in the tibia-test bioassay. Its importance in normal growth is indicated by the growth suppression following the surgical removal of the pituitary gland or after the immunoneutralization of endogenous pituitary GH. The partial restoration of growth in some studies with GH-treated hypophysectomized birds also suggests GH dependency in avian growth, as does the dwarfism that occurs in some strains with GHR dysfunctions. Circulating GH concentrations are also correlated with body weight gain, being high in young, rapidly growing birds and low in slower growing older birds. Nevertheless, despite these observations, there is an extensive literature that concludes pituitary GH is not important in avian growth. This is based on numerous studies with hypophysectomized and intact birds that show only slight, transitory or absent growth responses to exogenous GH-treatment. Moreover, while circulating GH levels correlate with weight gain in young birds, this may merely reflect changes in the control of pituitary GH secretion during aging, as numerous studies involving experimental alterations in growth rate fail to show positive correlations between plasma GH concentrations and the alterations in growth rate. Furthermore, growth is known to occur in the absence of pituitary GH, as most embryonic development occurs prior to the ontogenetic appearance of pituitary somatotrophs and the appearance of GH in embryonic circulation. Early embryonic growth is also independent of the endocrine actions of pituitary GH, since removal of the presumptive pituitary gland does not impair early growth. Embryonic growth does, however, occur in the presence of extrapituitary GH, which is produced by most tissues and has autocrine or paracrine roles that locally promote growth and development. The role of GH in avian growth is therefore still unclear. PMID:23376467

  18. Clades reach highest morphological disparity early in their evolution

    PubMed Central

    Hughes, Martin; Gerber, Sylvain; Wills, Matthew Albion

    2013-01-01

    There are few putative macroevolutionary trends or rules that withstand scrutiny. Here, we test and verify the purported tendency for animal clades to reach their maximum morphological variety relatively early in their evolutionary histories (early high disparity). We present a meta-analysis of 98 metazoan clades radiating throughout the Phanerozoic. The disparity profiles of groups through time are summarized in terms of their center of gravity (CG), with values above and below 0.50 indicating top- and bottom-heaviness, respectively. Clades that terminate at one of the “big five” mass extinction events tend to have truncated trajectories, with a significantly top-heavy CG distribution overall. The remaining 63 clades show the opposite tendency, with a significantly bottom-heavy mean CG (relatively early high disparity). Resampling tests are used to identify groups with a CG significantly above or below 0.50; clades not terminating at a mass extinction are three times more likely to be significantly bottom-heavy than top-heavy. Overall, there is no clear temporal trend in disparity profile shapes from the Cambrian to the Recent, and early high disparity is the predominant pattern throughout the Phanerozoic. Our results do not allow us to distinguish between ecological and developmental explanations for this phenomenon. To the extent that ecology has a role, however, the paucity of bottom-heavy clades radiating in the immediate wake of mass extinctions suggests that early high disparity more probably results from the evolution of key apomorphies at the base of clades rather than from physical drivers or catastrophic ecospace clearing. PMID:23884651

  19. Identifying Those Whom Health Promotion Hardly Reaches: A Systematic Review.

    PubMed

    Sokol, Rebeccah; Fisher, Edwin; Hill, Julia

    2015-12-01

    To understand what circumstances lend groups to be recognized as hardly reached by health services and research, we systematically reviewed studies that identified their priority populations as hard to reach. We classified attributes of hardly reached groups into cultural/environmental, individual, and demographic domains. Of the 334 identified studies, 78.74% used attributes that were classified into the cultural/environmental, 74.85% the individual, and 50% the demographic domain to identify those hardly reached. Of all possible combinations of domains, the most common was the use of all three domains (28.74%). Overall, papers were more likely to use attributes to identify their hardly reached population that fell into more than one domain (74.85%) compared to only one domain (25.15%; ?(2), p < .0001). Through this review, we identified the attributes of those who have been identified as hardly reached in published research. No single attribute is used to identify those who are hardly reached. This reflects a socioecological perspective, emphasizing that both intrapersonal and external elements may cause interventions to fail to reach those intended. Moreover, the focus not on populations hardly reached but on the attributes of those hardly reached suggests objectives for interventions to reach them better. PMID:26405265

  20. Maximal lateral reaching distance on the affected side using the multi-directional reach test in persons with stroke

    PubMed Central

    Hwang, Won-Jeong; Kim, Jung-Hyun; Jeon, Seo-Hyun; Chung, Yijung

    2015-01-01

    [Purpose] This study aimed to examine the relationship between maximal lateral reaching distance on the affected side and weight shifting using the Multi-directional Reach Test in persons with stoke. [Subjects] Fifty-one chronic stroke participants were recruited from two rehabilitation hospitals. This study administered the Berg Balance Scale, Timed Up-and-Go, Trunk Impairment Scale, Modified Barthel Index and measured different maximal reaching distances. [Results] The maximal lateral reaching distance on the affected side was correlated with the BBS (r=0.571), TUG (r=?0.478), TIS (r=0.561), and MBI scores (r=0.499), the lateral reaching distance in all directions on the non-affected side (r=0.785), the maximal backward reaching distance (r=0.723), and the maximal forward reaching distance (r=0.673). The maximal reaching distance on the affected side was also affected by that on the non-affected side, in addition to the maximal backward reaching distance and MBI score. The final step model of stepwise multiple regression was explained 69.5%. [Conclusion] Maximal lateral reaching distance on the affected side as determined by the Multi-directional Reach Test is a good method of assessing functional performance in stroke patients. Data regarding maximal reaching distance on the non-affected side can be used to measure functional impairment on the affected side in clinical settings. PMID:26504275

  1. Maximum entropy production in daisyworld

    NASA Astrophysics Data System (ADS)

    Maunu, Haley A.; Knuth, Kevin H.

    2012-05-01

    Daisyworld was first introduced in 1983 by Watson and Lovelock as a model that illustrates how life can influence a planet's climate. These models typically involve modeling a planetary surface on which black and white daisies can grow thus influencing the local surface albedo and therefore also the temperature distribution. Since then, variations of daisyworld have been applied to study problems ranging from ecological systems to global climate. Much of the interest in daisyworld models is due to the fact that they enable one to study self-regulating systems. These models are nonlinear, and as such they exhibit sensitive dependence on initial conditions, and depending on the specifics of the model they can also exhibit feedback loops, oscillations, and chaotic behavior. Many daisyworld models are thermodynamic in nature in that they rely on heat flux and temperature gradients. However, what is not well-known is whether, or even why, a daisyworld model might settle into a maximum entropy production (MEP) state. With the aim to better understand these systems, this paper will discuss what is known about the role of MEP in daisyworld models.

  2. Recovery of three arctic stream reaches from experimental nutrient enrichment

    USGS Publications Warehouse

    Benstead, J.P.; Green, A.C.; Deegan, Linda A.; Peterson, B.J.; Slavik, K.; Bowden, W.B.; Hershey, A.E.

    2007-01-01

    1. Nutrient enrichment and resulting eutrophication is a widespread anthropogenic influence on freshwater ecosystems, but recovery from nutrient enrichment is poorly understood, especially in stream environments. We examined multi-year patterns in community recovery from experimental low-concentration nutrient enrichment (N + P or P only) in three reaches of two Arctic tundra streams (Kuparuk River and Oksrukuyik Creek) on the North Slope of Alaska (U.S.A.). 2. Rates of recovery varied among community components and depended on duration of enrichment (2-13 consecutive growing seasons). Biomass of epilithic algae returned to reference levels rapidly (within 2 years), regardless of nutrients added or enrichment duration. Aquatic bryophyte cover, which increased greatly in the Kuparuk River only after long-term enrichment (8 years), took 8 years of recovery to approach reference levels, after storms had scoured most remnant moss in the recovering reach. 3. Multi-year persistence of bryophytes in the Kuparuk River appeared to prevent recovery of insect populations that had either been positively (e.g. the mayfly Ephemerella, most chironomid midge taxa) or negatively (e.g. the tube-building chironomid Orthocladius rivulorum) affected by this shift in dominant primary producer. These lags in recovery (of >3 years) were probably driven by the persistent effect of bryophytes on physical benthic habitat. 4. Summer growth rates of Arctic grayling (both adults and young-of-year) in Oksrukuyik Creek (fertilised for 6 years with no bryophyte colonisation), which were consistently increased by nutrient addition, returned to reference rates within 1-2 years. 5. Rates of recovery of these virtually pristine Arctic stream ecosystems from low-level nutrient enrichment appeared to be controlled largely by duration of enrichment, mediated through physical habitat shifts caused by eventual bryophyte colonisation, and subsequent physical disturbance that removed bryophytes. Nutrient enrichment of oligotrophic Arctic stream ecosystems caused by climate change or local anthropogenic activity may have dramatic and persistent consequences if it results in the colonisation of long-lived primary producers that alter physical habitat. ?? 2007 The Authors.

  3. SVMs, Generative Kernels & Maximum Margin Statistical Models

    E-print Network

    Gales, Mark

    SVMs, Generative Kernels & Maximum Margin Statistical Models Mark Gales & Martin Layton 16 December 2004 Cambridge University Engineering Department Institute of Statistical Mathematics #12;SVMs, Generative Kernels and Maximum Margin Statistical Models Overview · Dependency Modelling in Speech

  4. Maximum entropy principal for transportation

    SciTech Connect

    Bilich, F.; Da Silva, R.

    2008-11-06

    In this work we deal with modeling of the transportation phenomenon for use in the transportation planning process and policy-impact studies. The model developed is based on the dependence concept, i.e., the notion that the probability of a trip starting at origin i is dependent on the probability of a trip ending at destination j given that the factors (such as travel time, cost, etc.) which affect travel between origin i and destination j assume some specific values. The derivation of the solution of the model employs the maximum entropy principle combining a priori multinomial distribution with a trip utility concept. This model is utilized to forecast trip distributions under a variety of policy changes and scenarios. The dependence coefficients are obtained from a regression equation where the functional form is derived based on conditional probability and perception of factors from experimental psychology. The dependence coefficients encode all the information that was previously encoded in the form of constraints. In addition, the dependence coefficients encode information that cannot be expressed in the form of constraints for practical reasons, namely, computational tractability. The equivalence between the standard formulation (i.e., objective function with constraints) and the dependence formulation (i.e., without constraints) is demonstrated. The parameters of the dependence-based trip-distribution model are estimated, and the model is also validated using commercial air travel data in the U.S. In addition, policy impact analyses (such as allowance of supersonic flights inside the U.S. and user surcharge at noise-impacted airports) on air travel are performed.

  5. Seeking the epoch of maximum luminosity for dusty quasars

    SciTech Connect

    Vardanyan, Valeri; Weedman, Daniel; Sargsyan, Lusine E-mail: dweedman@isc.astro.cornell.edu

    2014-08-01

    Infrared luminosities ?L{sub ?}(7.8 ?m) arising from dust reradiation are determined for Sloan Digital Sky Survey (SDSS) quasars with 1.4 maximum at any redshift z < 5, reaching a plateau for z ? 3 with maximum luminosity ?L{sub ?}(7.8 ?m) ? 10{sup 47} erg s{sup –1}; luminosity functions show one quasar Gpc{sup –3} having ?L{sub ?}(7.8 ?m) > 10{sup 46.6} erg s{sup –1} for all 2 reached their maximum luminosity has not yet been identified at any redshift below 5. The most ultraviolet luminous quasars, defined by rest frame ?L{sub ?}(0.25 ?m), have the largest values of the ratio ?L{sub ?}(0.25 ?m)/?L{sub ?}(7.8 ?m) with a maximum ratio at z = 2.9. From these results, we conclude that the quasars most luminous in the ultraviolet have the smallest dust content and appear luminous primarily because of lessened extinction. Observed ultraviolet/infrared luminosity ratios are used to define 'obscured' quasars as those having >5 mag of ultraviolet extinction. We present a new summary of obscured quasars discovered with the Spitzer Infrared Spectrograph and determine the infrared luminosity function of these obscured quasars at z ? 2.1. This is compared with infrared luminosity functions of optically discovered, unobscured quasars in the SDSS and in the AGN and Galaxy Evolution Survey. The comparison indicates comparable numbers of obscured and unobscured quasars at z ? 2.1 with a possible excess of obscured quasars at fainter luminosities.

  6. Action plans can interact to hinder or facilitate reach performance.

    PubMed

    Fournier, Lisa R; Wiediger, Matthew D; Taddese, Ezana F

    2015-11-01

    Executing a reach action can be delayed while retaining another action in working memory (WM) if the two action plans partly overlap rather than do not overlap. This delay (partial repetition cost) occurs when reach responses are under cognitive control. In this study, we investigated whether facilitation (a partial repetition benefit) occurs when reach responses are automatic. We also examined whether the hemisphere controlling the limb or selection of the preferred limb (based on a free-reach task) influences reach performance when the actions partly overlap. Left- and right-handers reached to different stimulus locations to the left and right of body midline with their ipsilateral hand while maintaining an action plan in WM that required the same or the different hand. The results showed a partial repetition benefit for spatially compatible reaches to left and right stimulus locations far from the body midline, but not for those near the body midline. Also, no partial repetition cost was found at any of the stimulus-reach locations. This indicates that automatic reach responses that partly overlap with an action plan maintained in WM are not delayed, but instead can be facilitated (partial repetition benefit). The roles of hemisphere and reach-hand preference in action control and the importance of the degree of feature overlap in obtaining a partial repetition benefit (and cost) are discussed. PMID:26163065

  7. Growth in Employee Unions

    ERIC Educational Resources Information Center

    Grayson, E. C.

    1977-01-01

    A growth in organized school employee groups, particularly teacher groups, may require school boards to develop and maintain an affirmative employee relations program to identify and meet needs before they reach the crisis level and, therefore, prevent the issues from developing around which employee unions must justify their existence.…

  8. Cryosphere: Antarctic ice growth and retreat

    NASA Astrophysics Data System (ADS)

    Evans, Jeffrey

    2015-08-01

    Antarctic Ice Sheet change during the last glacial cycle is unclear. The timing of moraine development in the Ross basin suggests that the ice sheet reached maximum thickness under the warming temperatures of the last termination.

  9. Walking Is Not Like Reaching: Evidence from Periodic Mechanical Perturbations

    E-print Network

    Ahn, Jooeun

    The control architecture underlying human reaching has been established, at least in broad outline. However, despite extensive research, the control architecture underlying human locomotion remains unclear. Some studies ...

  10. Studying reach-scale spatial hydrology in ungauged catchments

    NASA Astrophysics Data System (ADS)

    Callow, J. N.; Boggs, G. S.

    2013-07-01

    Dryland regions are home to some of the most poorly gauged rivers on Earth. Consequently, these regions lack a detailed understanding of the hydrology, are associated with underdevelopment and significant socio-economic disadvantage, though there is increasing pressure to develop the water resources in these areas. However, this is often limited by a lack of data from which to understand regional hydrology and water-dependent processes and make informed water resource management decisions. This paper presents a novel approach to directly map, from remotely sensed imagery, the five flow types and six hydrological metrics defined as the most significant determinants of ecological condition of dryland rivers (Flow (duration of flow), Amplitude (last maximum depth), Pulse Shape (duration of rising limb and falling limb), Duration (present length of inundation), Connection (duration of present downstream connection)). At fourteen "virtual" gauging stations in two rivers (Newcastle Creek and Playford River) on the Barkly Tablelands, northern Australia, daily classified Moderate Resolution Imaging Spectroradiometer (MODIS) imagery was used to map flow types and metrics at 250 m resolution, across 1996 km2. The performance of the "virtual" gauging stations is validated against traditionally gauged data at two locations and confirms that hydrological data significant for ecology can be extracted from daily flood mapping using remotely sensed MODIS imagery. Results found a pronounced downstream trend in flow characteristics from more ephemeral uplands to seasonally-inundated lowlands. Significant between reach variability in the Duration and Connection is also noted, which is related to cross section morphology and river position. It is suggested that this approach could be applied to other poorly or ungauged large, dryland rivers, where the requirements, including limited cloud cover, long (weeks to months) flood pulses, inundation widths of greater than 2 km, and lateral floodplain gradients of less than approximately 0.005 m/m are met. This novel approach for the measurement of ungauged basins offers significant potential to allow research relevant to hydrology and water-dependent processes where traditional approaches to dryland river hydrology are limited by the lack of gauging infrastructure, or by complex multi-channel and low-gradient geomorphology.

  11. Growth hormone and early treatment.

    PubMed

    Antoniazzi, F; Cavarzere, P; Gaudino, R

    2015-06-01

    Growth hormone (GH) treatment is approved by the US Food and Drug Administration (FDA) not only for GH deficiency (GHD) but also for other childhood growth disorders with growth failure and/or short stature. GHD is the most frequent endocrine disorder presenting with short stature in childhood. During neonatal period, metabolic effects due to congenital GHD require a prompt replacement therapy to avoid possible life-threatening complications. In childhood and adolescence, growth impairment is the most evident effect of GHD and early treatment has the aim of restore normal growth and to reach normal adult height. We reassume in this review the conditions causing GHD and the diagnostic challenge to reach an early diagnosis, and an early treatment, necessary to obtain the best results. Finally, we summarize results obtained in clinical studies about pediatric patients with GHD treated at an early age, in which a marked early catch-up growth and a normalization of adult height were obtained. PMID:25734895

  12. Deficits of reaching in subjects with left hemiparesis: a pilot study.

    PubMed

    Trombly, C A

    1992-10-01

    Therapy to restore functional movement of stroke patients is based on assumptions about the deficits that occur in motor control as a result of stroke. Success has been limited, perhaps as a result of insufficient information concerning the characteristics of movement after stroke. In this pilot study, the Waterloo Spatial Motion Analysis Recording Technique (WATSMART), an optoelectric motion analysis system, was used with surface electromyography to measure voluntary reaching in the impaired and unimpaired arms of 5 subjects with left hemiparesis. The ability to reach in a smooth coordinated way was significantly poorer in the impaired arms than in the unimpaired arms, for which scores were essentially normal. The patients were less able to activate the muscles of the impaired arm and, as a result, used a greater percentage of the maximum activity they could generate to complete the unresisted reaching task. The electromyographic differences between arms, however, did not reach significance. The results corroborate previous findings and show that movement deficits of particular patients can be diagnosed precisely with kinematic analysis and electromyography. If greater precision in diagnosis were available clinically, more effective therapy might be developed. PMID:1463060

  13. Unsteady-state transfer of impurities during crystal growth of sucrose in sugarcane solutions

    NASA Astrophysics Data System (ADS)

    Martins, P. M.; Ferreira, A.; Polanco, S.; Rocha, F.; Damas, A. M.; Rein, P.

    2009-07-01

    In this work, we present growth rate data of sucrose crystals in the presence of impurities that can be used by both sugar technologists and crystal growth scientists. Growth rate curves measured in a pilot-scale evaporative crystallizer suggest a period of slow growth that follows the seeding of crystals into supersaturated technical solutions. The observed trend was enhanced by adding typical sugarcane impurities such as starch, fructose or dextran to the industrial syrups. Maximum growth rates of sucrose resulted at intermediate rather than high supersaturation levels in the presence of the additives. The effects of the additives on the sucrose solubility and sucrose mass transfer in solution were taken into account to explain the observed crystal growth kinetics. A novel mechanism was identified of unsteady-state adsorption of impurities at the crystal surface and their gradual replacement by the crystallizing solute towards the equilibrium occupation of the active sites for growth. Specifically designed crystallization experiments at controlled supersaturation confirmed this mechanism by showing increasing crystal growth rates with time until reaching a steady-state value for a given supersaturation level and impurity content.

  14. Habitat and density-dependent growth of the sea urchin Paracentrotus lividus in Galicia (NW Spain)

    NASA Astrophysics Data System (ADS)

    Ouréns, Rosana; Flores, Luis; Fernández, Luis; Freire, Juan

    2013-02-01

    We studied the small-scale spatial variability in the growth of Paracentrotus lividus in two populations in Galicia (NW Spain) by reading growth rings. A tetracycline marking experiment was carried out to verify that the rings form annually. The growth rings were read by two independent readers in order to estimate the uncertainty involved in assigning the age. Of the six growth models evaluated (Tanaka, von Bertalanffy, Gompertz, Richards, logistic and Jolicoeur) the Tanaka function obtained the best fit to the data. This function predicts unlimited growth and a maximum growth rate of 15.00 (± 0.97 SE) mm·year- 1 at 3.09 ± 0.10 years old, which progressively decreases at older ages. However, habitat characteristics lead to intrapopulation variations in this general function. Recruitment seems to occur mainly in shallow waters (? 4 m) and when the sea urchins reach 50 mm (approximately 4 years old) they migrate to deeper areas. Sea urchins larger than 50 mm that stayed in shallow waters grew at a rate between 0.41 and 0.43 mm·year- 1 less than the sea urchins that moved to depths of 8 and 12 m. The population density also influenced the growth, and individuals older than 4 years had higher growth rates in high-density patches than in low-density areas. This could be due to the better environmental conditions in aggregation areas, that is, better protection against waves and predators and/or more abundant food.

  15. Validating CAR - A comparison study of experimentally-derived and computer-generated reach envelopes. [Crewstation Assessment of Reach

    NASA Technical Reports Server (NTRS)

    Harris, R.; Bennett, J.; Stokes, J.

    1982-01-01

    In the present investigation, Crewstation Assessment of Reach (CAR) results in the form of male hand reach envelopes were generated and compared with an anthropometric survey performed by Kennedy (1978) to determine the extent of the validity of the CAR model with respect to experimentally-derived anthropometric data. The CAR-generated reach envelopes extensively matched the Kennedy envelopes. The match was particularly good in the areas to the front and side from which the reach originated. Attention is given to the crewstation model, the operator sample population, the CAR analysis, aspects of validation methodology, and the modeling of experimental parameters.

  16. Patterns of Arm Muscle Activation Involved in Octopus Reaching Movements

    E-print Network

    Hochner, Binyamin

    Patterns of Arm Muscle Activation Involved in Octopus Reaching Movements Yoram Gutfreund,1 Tamar, Stazione Zoologica "A. Dohrn," Naples 80121, Italy The extreme flexibility of the octopus arm allows it to perform many different movements, yet octopuses reach toward a tar- get in a stereotyped manner using

  17. Reaching Year 12 in Victoria, Australia: Student and School Influences

    ERIC Educational Resources Information Center

    Marks, Gary

    2014-01-01

    This paper examines student and school influences on reaching Year 12, the final year of schooling in Victoria, Australia. It analyses data from the population of students who were in Year 9 in 2008. Male, English-speaking background, government school, and especially Indigenous students were less likely to reach Year 12 than comparison groups.…

  18. Reaching a Polygon with Directional Uncertainty Otfried Cheongy

    E-print Network

    Utrecht, Universiteit

    Reaching a Polygon with Directional Uncertainty Otfried Cheongy Ren e van Oostrumz Abstract Assume avoiding polygonal obstacles of complexity n. We show that the complexity of the safe region, from where the robot can reach the goal with a single linear motion with uncertainty , is Om+n, and can be computed

  19. Optic Ataxia: From Balint's Syndrome to the Parietal Reach Region

    E-print Network

    Neuron Review Optic Ataxia: From Balint's Syndrome to the Parietal Reach Region Richard A. Andersen Engineering, California Institute of Technology, Pasadena, CA 91125, USA 2Departments of Neurology@vis.caltech.edu http://dx.doi.org/10.1016/j.neuron.2014.02.025 Optic ataxia is a high-order deficit in reaching

  20. Reach Survival Estimates, 2008 Bill Muir, Steve Smith, Doug Marsh,

    E-print Network

    Reach Survival Estimates, 2008 Bill Muir, Steve Smith, Doug Marsh, John Williams, and Jim FaulknerDalles JohnDay Hells Canyon Oxbow Brownlee Priest Rapids Wanapum Rock Island Rocky Reach Wells Chief Joseph. . Date at McNary Number released McNary to John Day Dam John Day to Bonneville Dam McNary to Bonneville

  1. fMRI Activation during Observation of Others Reach Errors

    E-print Network

    Gribble, Paul

    another person learning to reach in a novel dynamic environ- ment created by a robotic device. Passive observation of reaching movements (whether or not they were perturbed by the robot) was associated of the motor command. Indeed, adaptation may develop in complete absence of vision, solely on the basis

  2. RACIAL AND ETHNIC APPROACHES TO COMMUNITY HEALTH (REACH)

    EPA Science Inventory

    Racial and Ethnic Approaches to Community Health (REACH) 2010 is the cornerstone of CDC's efforts to eliminate racial and ethnic disparities in health. Launched in 1999, REACH 2010 is designed to eliminate disparities in the following six priority areas: cardiovascular disease, i...

  3. Arabidopsis growth curves Antibody effect on fibrinogen to fibrin conversion

    E-print Network

    McCullagh, Peter

    ­40 Typical growth trajectory for one plant zero up to day t0 35 (plant-specific) reaches full height aroundArabidopsis growth curves Antibody effect on fibrinogen to fibrin conversion Growth curve modelsCullagh, Mei Wang Growth curve models #12;Arabidopsis growth curves Antibody effect on fibrinogen to fibrin

  4. 7 CFR 993.602 - Maximum tolerances.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE DRIED PRUNES PRODUCED IN CALIFORNIA Grade Regulations § 993.602 Maximum...

  5. Effects of changing noise in dynamics of reaching on changes in control of reaching: An optimal control perspective

    E-print Network

    Shadmehr, Reza

    Effects of changing noise in dynamics of reaching on changes in control of reaching: An optimal trajectory'. Recently, optimal feedback control framework has been proposed as a model of motor control. This hypothesis in conjunction ii #12;with stochastic optimal feedback control framework has quite interesting

  6. Growth Disorders

    MedlinePLUS

    ... their parents are. But some children have growth disorders. Growth disorders are problems that prevent children from developing normal ... growth can sometimes signal a gland problem or disease. The pituitary gland makes growth hormone, which stimulates ...

  7. Growth Hormone

    MedlinePLUS

    ... limited. Home Visit Global Sites Search Help? Growth Hormone Share this page: Was this page helpful? Also known as: GH; Human Growth Hormone; HGH; Somatotropin; Growth Hormone Stimulation Test; Growth Hormone ...

  8. Environmental stressors afflicting tailwater stream reaches across the United States

    USGS Publications Warehouse

    Miranda, Leandro E.; Krogman, R. M.

    2014-01-01

    The tailwater is the reach of a stream immediately below an impoundment that is hydrologically, physicochemically and biologically altered by the presence and operation of a dam. The overall goal of this study was to gain a nationwide awareness of the issues afflicting tailwater reaches in the United States. Specific objectives included the following: (i) estimate the percentage of reservoirs that support tailwater reaches with environmental conditions suitable for fish assemblages throughout the year, (ii) identify and quantify major sources of environmental stress in those tailwaters that do support fish assemblages and (iii) identify environmental features of tailwater reaches that determine prevalence of key fish taxa. Data were collected through an online survey of fishery managers. Relative to objective 1, 42% of the 1306 reservoirs included in this study had tailwater reaches with sufficient flow to support a fish assemblage throughout the year. The surface area of the reservoir and catchment most strongly delineated reservoirs maintaining tailwater reaches with or without sufficient flow to support a fish assemblage throughout the year. Relative to objective 2, major sources of environmental stress generally reflected flow variables, followed by water quality variables. Relative to objective 3, zoogeography was the primary factor discriminating fish taxa in tailwaters, followed by a wide range of flow and water quality variables. Results for objectives 1–3 varied greatly among nine geographic regions distributed throughout the continental United States. Our results provide a large-scale view of the effects of reservoirs on tailwater reaches and may help guide research and management needs.

  9. Visual information throughout a reach determines endpoint precision.

    PubMed

    Ma-Wyatt, Anna; McKee, Suzanne P

    2007-05-01

    People make rapid, goal-directed movements to interact with their environment. Because these movements have consequences, it is important to be able to control them with a high level of precision and accuracy. Our hypothesis is that vision guides rapid hand movements, thereby enhancing their accuracy and precision. To test this idea, we asked observers to point to a briefly presented target (110 ms). We measured the impact of visual information on endpoint precision by using a shutter to close off view of the hand 50, 110 and 250 ms into the reach. We found that precision was degraded if the view of the hand was restricted at any time during the reach, despite the fact that the target disappeared long before the reach was completed. We therefore conclude that vision keeps the hand on the planned trajectory. We then investigated the effects of a perturbation of target position during the reach. For these experiments, the target remained visible until the reach was completed. The target position was shifted at 110, 180 or 250 ms into the reach. Early shifts in target position were easily compensated for, but late shifts led to a shift in the mean position of the endpoints; observers pointed to the center of the two locations, as a kind of best bet on the position of the target. Visual information is used to guide the hand throughout a reach and has a significant impact on endpoint precision. PMID:17109109

  10. Temporal and temperature effects on the maximum rate of rewarming from hibernation

    PubMed Central

    Utz, Jenifer C.; Velickovska, Vanja; Shmereva, Anastacia; van Breukelen, Frank

    2007-01-01

    During hibernation animals oscillate from near ambient (Ta) to euthermic body temperatures (Tb). As animals arouse, the rate of rewarming (RRW) might be expected to simply increase as a function of time. We monitored the Tb of golden-mantled ground squirrels (Spermophilus lateralis) housed at 4, 8, 12, and 16° C during natural arousals. The maximum RRW, the time required to reach a maximum RRW, and the relative time index all demonstrated negative relationships with Ta. The Tb corresponding to maximal RRW demonstrated a positive relationship with Ta. Squirrels reached maximal RRW when they had generated 30 to 40% of the heat required to reach a euthermic Tb. These data suggest that arousal is more constrained than expected and that both time and temperature influence the RRW. PMID:17948068

  11. Reaching for the Sky: The Growth of Mountain Tourism in Switzerland.

    ERIC Educational Resources Information Center

    Rothwell, Jennifer Truran

    1999-01-01

    Addresses the beginnings of Swiss tourism, its barriers, and the development and role of transportation in mountain tourism. Considers the environmental problems caused by mountain tourism in Switzerland and provides seven teaching ideas. (CMK)

  12. Expanding the Reach of Youth Mentoring: Partnering with Youth for Personal Growth and Social Change

    ERIC Educational Resources Information Center

    Liang, Belle; Spencer, Renee; West, Jennifer; Rappaport, Nancy

    2013-01-01

    The goals of youth mentoring have broadened from redressing youth problems to promoting positive youth development. Yet, many of the principles associated with contemporary conceptualizations of development found in the positive youth development (PYD) and community psychology (CP) literature have yet to be fully integrated into mentoring research…

  13. Effect of Temperature on Growth of Vibrio paraphemolyticus and Vibrio vulnificus in Flounder, Salmon Sashimi and Oyster Meat

    PubMed Central

    Kim, Yoo Won; Lee, Soon Ho; Hwang, In Gun; Yoon, Ki Sun

    2012-01-01

    Vibrio parahaemolyticus and Vibrio vulnificus are the major pathogenic Vibrio species which contaminate ready-to-eat seafood. The purpose of this study was to evaluate the risk of human illness resulting from consumption of ready-to-eat seafood such as sashimi and raw oyster meat due to the presence of V. parahaemolyticus and V. vulnificus. We compared the growth kinetics of V. parahaemolyticus and V. vulnificus strains in broth and ready-to-eat seafood, including flounder and salmon sashimi, as a function of temperature. The growth kinetics of naturally occurring V. vulnificus in raw oyster meat was also evaluated. The minimum growth temperatures of V. parahaemolyticus and V. vulnificus in broth were 13 °C and 11 °C, respectively. Overall, significant differences in lag time (LT) and specific growth rate (SGR) values between flounder and salmon sashimi were observed at temperatures ranging from 13 °C to 30 °C (p < 0.05). The growth of naturally occurring V. vulnificus reached stationary phase at ~4 log CFU/g in oysters, regardless of the storage temperature. This data indicates that the population of V. vulnificus in oysters did not reach the maximum population density as observed in the broth, where growth of V. vulnificus and V. parahaemolyticus isolated from oysters grew up to >8 log CFU/mL. PMID:23330227

  14. 34 CFR 674.12 - Loan maximums.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false Loan maximums. 674.12 Section 674.12 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY EDUCATION, DEPARTMENT OF EDUCATION FEDERAL PERKINS LOAN PROGRAM General Provisions § 674.12 Loan maximums. (a)...

  15. Finding Maximum Length Tours Under Polyhedral Norms

    E-print Network

    Barvinok, Alexander

    Finding Maximum Length Tours Under Polyhedral Norms Alexander Barvinok \\Lambda David S. Johnson y to a polyhedral norm. We show that for any such norm, the problem of finding a tour of maximum length can in time O(n f+1 ), where f is the number of facets of the polyhedron determining the polyhedral norm. Thus

  16. 7 CFR 1778.11 - Maximum grants.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 12 2012-01-01 2012-01-01 false Maximum grants. 1778.11 Section 1778.11 Agriculture... (CONTINUED) EMERGENCY AND IMMINENT COMMUNITY WATER ASSISTANCE GRANTS § 1778.11 Maximum grants. (a) Grants not... the filing of an application. (b) Grants made for repairs, partial replacement, or...

  17. 13 CFR 130.440 - Maximum grant.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 13 Business Credit and Assistance 1 2012-01-01 2012-01-01 false Maximum grant. 130.440 Section 130... § 130.440 Maximum grant. No recipient shall receive an SBDC grant exceeding the greater of the minimum statutory amount, or its pro rata share of all SBDC grants as determined by the statutory formula set...

  18. 7 CFR 1778.11 - Maximum grants.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 12 2013-01-01 2013-01-01 false Maximum grants. 1778.11 Section 1778.11 Agriculture... (CONTINUED) EMERGENCY AND IMMINENT COMMUNITY WATER ASSISTANCE GRANTS § 1778.11 Maximum grants. (a) Grants not... the filing of an application. (b) Grants made for repairs, partial replacement, or...

  19. 13 CFR 130.440 - Maximum grant.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 13 Business Credit and Assistance 1 2013-01-01 2013-01-01 false Maximum grant. 130.440 Section 130... § 130.440 Maximum grant. No recipient shall receive an SBDC grant exceeding the greater of the minimum statutory amount, or its pro rata share of all SBDC grants as determined by the statutory formula set...

  20. 13 CFR 130.440 - Maximum grant.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Maximum grant. 130.440 Section 130... § 130.440 Maximum grant. No recipient shall receive an SBDC grant exceeding the greater of the minimum statutory amount, or its pro rata share of all SBDC grants as determined by the statutory formula set...

  1. 49 CFR 107.329 - Maximum penalties.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...the maximum civil penalty is $110,000 if the violation results in death, serious illness...minimum $495 civil penalty applies to a violation...the maximum civil penalty is $110,000 if the violation results in death, serious...

  2. 49 CFR 107.329 - Maximum penalties.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...the maximum civil penalty is $175,000 if the violation results in death, serious illness...no minimum civil penalty, except for a minimum...the maximum civil penalty is $175,000 if the violation results in death, serious...

  3. 49 CFR 107.329 - Maximum penalties.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...the maximum civil penalty is $110,000 if the violation results in death, serious illness...minimum $495 civil penalty applies to a violation...the maximum civil penalty is $110,000 if the violation results in death, serious...

  4. 49 CFR 107.329 - Maximum penalties.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...the maximum civil penalty is $110,000 if the violation results in death, serious illness...minimum $495 civil penalty applies to a violation...the maximum civil penalty is $110,000 if the violation results in death, serious...

  5. 49 CFR 107.329 - Maximum penalties.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...the maximum civil penalty is $175,000 if the violation results in death, serious illness...no minimum civil penalty, except for a minimum...the maximum civil penalty is $175,000 if the violation results in death, serious...

  6. Reaching Consensus with Imprecise Probabilities over a Network

    E-print Network

    Bertuccelli, Luca F.

    2008-12-20

    This paper discusses the problem of a distributed network of agents attempting to agree on an imprecise probability over a network. Unique from other related work however, the agents must reach agreement while accounting ...

  7. Reachouttopeoplewithdisabilitiesforjobs Reach out to people with disabilities for jobs

    E-print Network

    Firestone, Jeremy

    Reachouttopeoplewithdisabilitiesforjobs f Reach out to people with disabilities for jobs Letter Division of Vocational Rehabilitation. Holding jobs and building careers strengthen a person's sense with disabilities have jobs, it makes for more representative and stronger workplaces. Business, government

  8. New Stream-Reach Hydropower Development (NSD) Fact Sheet

    SciTech Connect

    2014-04-25

    This fact sheet explores the more than 65 gigawatts (GW) of sustainable hydropower potential in U.S. stream-reaches, according to the hydropower resource assessment funded by DOE and executed by Oak Ridge National Laboratory.

  9. Helping the Library Reach Out to the Future

    MedlinePLUS

    ... Issues Helping the Library Reach Out to the Future Past Issues / Fall 2007 Table of Contents For ... of this page please turn Javascript on. Encouraging future medical researchers: (l-r) NLM Director Dr. Donald ...

  10. Low-Cost Tele-assessment System for Home-Based Evaluation of Reaching Ability Following Stroke

    PubMed Central

    Rau, Chi-Lun; Chen, Ya-Ping; Lai, Jin-Shin; Chen, Shih-Ching; Kuo, Te-Son; Jaw, Fu-Shan

    2013-01-01

    Abstract Objective: Tele-assessment techniques can provide healthcare professionals with easily accessible information regarding patients' clinical progress. Recently, kinematic analysis systems have been used to assess rehabilitative outcomes in stroke patients. Kinematic systems, however, are not compatible with tele-assessment. The objective of our study was to develop a tele-assessment system for acquiring kinematic data of forward reaching movements in stroke patients, with an emphasis on cost-effectiveness, portability, and ease of use. Materials and Methods: We selected four healthy control participants and eight hemiplegic stroke patients for our study. The stroke patients were classified as Brunnstrom stage III, stage IV, or stage V. Our tele-assessment system used two three-axes accelerometers, a potentiometer, a multifunctional data acquisition card, and two computers. A standardized kinematic system was applied simultaneously to validate the measurements recorded by our tele-assessment system during five repetitions of forward reaching movements. Results: The correlation coefficients of the reaching displacement, velocity, and acceleration measurements obtained using our tele-assessment system and the standardized kinematic system were 0.956, 0.896, and 0.727, respectively. Differences in the maximum reaching distance and the maximum reaching velocity of forward reaching movements were observed among the study groups. There were no significant differences in the time required to complete the testing session among the study groups. Conclusions: Our tele-assessment system is valid for the evaluation of upper-extremity reaching ability in stroke patients. Further research is needed to investigate the feasibility of the use of the tele-assessment system in patients' homes. PMID:24138613

  11. Project Completion Report on China's Room AC Reach Standard

    SciTech Connect

    Lin, Jiang

    2005-03-10

    After much anticipation and hard work, China's reach standard for room air-conditioners was announced in September 2004, with the first tier going into effect on March 1, 2005 and the reach standard taking effect on January 1, 2009. This is a major milestone in the development of minimum energy efficiency standards in China: finally China has set a minimum standard that is meaningful and stringent. According to our preliminary analysis, the majority of room ACs products on the Chinese market in 2004 would not meet the 2009 reach standard requirement. In addition to setting the minimum requirement, China's new AC standard also include classification requirement for the newly established Energy Information Label, as well as the certification requirement for CECP's Energy Conservation Label. Highlights of the 2009 reach standard include: (1) The Chinese Reach Standard for Room AC in 2009 is tighter than American counterpart, and almost matches the efficiency of American Central Air-Conditioners; and (2) Summer peak demand reduction in 2020 due to the reach standard exceeds the capacity of the Three Gorges Project.

  12. Maximum-Entropy Inference with a Programmable Annealer

    E-print Network

    Nicholas Chancellor; Szilard Szoke; Walter Vinci; Gabriel Aeppli; Paul A. Warburton

    2015-06-26

    Optimisation problems in science and engineering typically involve finding the ground state (i.e. the minimum energy configuration) of a cost function with respect to many variables. If the variables are corrupted by noise then this approach maximises the likelihood that the solution found is correct. An alternative approach is to make use of prior statistical information about the noise in conjunction with Bayes's theorem. The maximum entropy solution to the problem then takes the form of a Boltzmann distribution over the ground and excited states of the cost function. Here we use a programmable Josephson junction array for the information decoding problem which we simulate as a random Ising model in a field. We show experimentally that maximum entropy decoding at finite temperature can in certain cases give competitive and even slightly better bit-error-rates than the maximum likelihood approach at zero temperature, confirming that useful information can be extracted from the excited states of the annealing device. Furthermore we introduce a microscopic bit-by-bit analytical method which is agnostic to the specific application and use it to show that the annealing device samples from a highly Boltzmann-like distribution. Machines of this kind are therefore candidates for use in a wide variety of machine learning applications which exploit maximum entropy inference, including natural language processing and image recognition. We further show that the limiting factor for performance in our experiments is likely to be control errors rather than failure to reach equilibrium. Our work also provides a method for determining if a system is in equilibrium which can be easily generalized. We discuss possible applications of this method to spin glasses and probing the performance of the quantum annealing algorithm.

  13. Flood Frequency Analysis using different flood descriptors - the Warsaw reach of the river Vistula case study

    NASA Astrophysics Data System (ADS)

    Karamuz, Emilia; Kochanek, Krzysztof; Romanowicz, Renata

    2014-05-01

    Flood frequency analysis (FFA) is customarily performed using annual maximum flows. However, there is a number of different flood descriptors that could be used. Among them are water levels, peaks over the threshold, flood-wave duration, flood volume, etc. In this study we compare different approaches to FFA for their suitability for flood risk assessment. The main goal is to obtain the FFA curve with the smallest possible uncertainty limits, in particular for the distribution tail. The extrapolation of FFA curves is crucial in future flood risk assessment in a changing climate. We compare the FFA curves together with their uncertainty limits obtained using flows, water levels, flood inundation area and volumes for the Warsaw reach of the river Vistula. Moreover, we derive the FFA curves obtained using simulated flows. The results are used to derive the error distribution for the maximum simulated and observed values under different modelling techniques and assess its influence on flood risk predictions for ungauged catchments. MIKE11, HEC-RAS and transfer function model are applied in average and extreme conditions to model flow propagation in the Warsaw Vistula reach. The additional questions we want to answer are what is the range of application of different modelling tools under various flow conditions and how can the uncertainty of flood risk assessment be decreased. This work was partly supported by the projects "Stochastic flood forecasting system (The River Vistula reach from Zawichost to Warsaw)" and "Modern statistical models for analysis of flood frequency and features of flood waves", carried by the Institute of Geophysics, Polish Academy of Sciences on the order of the National Science Centre (contracts Nos. 2011/01/B/ST10/06866 and 2012/05/B/ST10/00482, respectively). The water level and flow data were provided by the Institute of Meteorology and Water Management (IMGW), Poland.

  14. A classification of channel-reach morphology in mountain drainage basins synthesizes stream morphologies into seven distinct reach types

    E-print Network

    Montgomery, David R.

    ABSTRACT A classification of channel-reach morphology in mountain drainage basins synthesizes channel condition and response potential in mountain drainage basins. Field investigations demonstrate mountain channels and their lowland counterparts (e.g., Surell, 1841; Dana, 1850; Shaler, 1891

  15. Rapid Plasticity of Motor Corticospinal system with Robotic Reach Training

    PubMed Central

    Kantak, Shailesh S.; Jones-Lush, Lauren M.; Narayanan, Priya; Judkins, Timothy N.; Wittenberg, George F.

    2013-01-01

    Goal-directed reaching is important for activities of daily living. Populations of neurons in the primary motor cortex (M1) that project to spinal motor circuits are known to represent kinematics of reaching movements. We investigated whether repetitive practice of goal-directed reaching movements induces use-dependent plasticity of those kinematic characteristics, in a manner similar to finger movements, as had been shown previously. Transcranial magnetic stimulation (TMS) was used over the scalp to evoke upper extremity movements while the forearm was resting in a robotic cradle. Plasticity was measured by the change in kinematics of these evoked movements following goal-directed reaching practice. Baseline direction of TMS-evoked arm movements was determined for each subject. Subjects then practiced 3 blocks of 160 goal-directed reaching movements in a direction opposite to the baseline direction (14 cm reach 180° from baseline direction) against a 75 N·m spring field. Changes in TMS-evoked whole arm movements were assessed after each practice block and after 5 minutes following the end of practice. Direction and the position of the point of peak velocity of TMS-evoked movements were significantly altered following training and at a 5-minute interval following training, while amplitude did not show significant changes. This was accompanied by changes in the motor evoked potentials (MEPs) of the shoulder and elbow agonist muscles that partly explained the change in direction, mainly by increase in agonist MEP, without significant changes in antagonists. These findings demonstrate that the arm representation accessible by motor cortical stimulation demonstrates rapid plasticity induced by goal-directed robotic reach training in healthy subjects. PMID:23669007

  16. Coordinated turn-and-reach movements. I. Anticipatory compensation for self-generated coriolis and interaction torques

    NASA Technical Reports Server (NTRS)

    Pigeon, Pascale; Bortolami, Simone B.; DiZio, Paul; Lackner, James R.

    2003-01-01

    When reaching movements involve simultaneous trunk rotation, additional interaction torques are generated on the arm that are absent when the trunk is stable. To explore whether the CNS compensates for such self-generated interaction torques, we recorded hand trajectories in reaching tasks involving various amplitudes and velocities of arm extension and trunk rotation. Subjects pointed to three targets on a surface slightly above waist level. Two of the target locations were chosen so that a similar arm configuration relative to the trunk would be required for reaching to them, one of these targets requiring substantial trunk rotation, the other very little. Significant trunk rotation was necessary to reach the third target, but the arm's radial distance to the body remained virtually unchanged. Subjects reached at two speeds-a natural pace (slow) and rapidly (fast)-under normal lighting and in total darkness. Trunk angular velocity and finger velocity relative to the trunk were higher in the fast conditions but were not affected by the presence or absence of vision. Peak trunk velocity increased with increasing trunk rotation up to a maximum of 200 degrees /s. In slow movements, peak finger velocity relative to the trunk was smaller when trunk rotation was necessary to reach the targets. In fast movements, peak finger velocity was approximately 1.7 m/s for all targets. Finger trajectories were more curved when reaching movements involved substantial trunk rotation; however, the terminal errors and the maximal deviation of the trajectory from a straight line were comparable in slow and fast movements. This pattern indicates that the larger Coriolis, centripetal, and inertial interaction torques generated during rapid reaches were compensated by additional joint torques. Trajectory characteristics did not vary with the presence or absence of vision, indicating that visual feedback was unnecessary for anticipatory compensations. In all reaches involving trunk rotation, the finger movement generally occurred entirely during the trunk movement, indicating that the CNS did not minimize Coriolis forces incumbent on trunk rotation by sequencing the arm and trunk motions into a turn followed by a reach. A simplified model of the arm/trunk system revealed that additional interaction torques generated on the arm during voluntary turning and reaching were equivalent to < or =1.8 g (1 g = 9.81 m/s(2)) of external force at the elbow but did not degrade performance. In slow-rotation room studies involving reaching movements during passive rotation, Coriolis forces as small as 0.2 g greatly deflect movement trajectories and endpoints. We conclude that compensatory motor innervations are engaged in a predictive fashion to counteract impending self-generated interaction torques during voluntary reaching movements.

  17. Coordinated turn-and-reach movements. I. Anticipatory compensation for self-generated coriolis and interaction torques.

    PubMed

    Pigeon, Pascale; Bortolami, Simone B; DiZio, Paul; Lackner, James R

    2003-01-01

    When reaching movements involve simultaneous trunk rotation, additional interaction torques are generated on the arm that are absent when the trunk is stable. To explore whether the CNS compensates for such self-generated interaction torques, we recorded hand trajectories in reaching tasks involving various amplitudes and velocities of arm extension and trunk rotation. Subjects pointed to three targets on a surface slightly above waist level. Two of the target locations were chosen so that a similar arm configuration relative to the trunk would be required for reaching to them, one of these targets requiring substantial trunk rotation, the other very little. Significant trunk rotation was necessary to reach the third target, but the arm's radial distance to the body remained virtually unchanged. Subjects reached at two speeds-a natural pace (slow) and rapidly (fast)-under normal lighting and in total darkness. Trunk angular velocity and finger velocity relative to the trunk were higher in the fast conditions but were not affected by the presence or absence of vision. Peak trunk velocity increased with increasing trunk rotation up to a maximum of 200 degrees /s. In slow movements, peak finger velocity relative to the trunk was smaller when trunk rotation was necessary to reach the targets. In fast movements, peak finger velocity was approximately 1.7 m/s for all targets. Finger trajectories were more curved when reaching movements involved substantial trunk rotation; however, the terminal errors and the maximal deviation of the trajectory from a straight line were comparable in slow and fast movements. This pattern indicates that the larger Coriolis, centripetal, and inertial interaction torques generated during rapid reaches were compensated by additional joint torques. Trajectory characteristics did not vary with the presence or absence of vision, indicating that visual feedback was unnecessary for anticipatory compensations. In all reaches involving trunk rotation, the finger movement generally occurred entirely during the trunk movement, indicating that the CNS did not minimize Coriolis forces incumbent on trunk rotation by sequencing the arm and trunk motions into a turn followed by a reach. A simplified model of the arm/trunk system revealed that additional interaction torques generated on the arm during voluntary turning and reaching were equivalent to < or =1.8 g (1 g = 9.81 m/s(2)) of external force at the elbow but did not degrade performance. In slow-rotation room studies involving reaching movements during passive rotation, Coriolis forces as small as 0.2 g greatly deflect movement trajectories and endpoints. We conclude that compensatory motor innervations are engaged in a predictive fashion to counteract impending self-generated interaction torques during voluntary reaching movements. PMID:12522179

  18. Reach-Scale Channel Geometry of a Mountain River

    NASA Astrophysics Data System (ADS)

    Wohl, E.; Kuzma, J.; Brown, N.

    2002-12-01

    N. St. Vrain Creek drains 250 km2 of the Colorado Front Range. The basin is underlain by granitic rocks, and the upper half was glaciated. We used 25 study reaches to examine controls on reach-scale channel geometry. Variables measured included channel geometry (width, depth, gradient, bedforms), grain size, and mean velocity. Drainage area at each study reach ranged from 2.2-245 km2, and gradient from 0.013-0.147 m/m. The increase in discharge with drainage area is strongly linear. Channel types included cascade, step-pool, plane-bed and pool-riffle. We examined correlations among (1) the reach-scale response variables bankfull width (w), hydraulic radius (R), mean velocity (v), Darcy-Weisbach ff, bedform wavelength (bw) and amplitude (a), grain size, relative roughness (R/D84) and shear stress (ss), and (2) potential control variables that change progressively downstream (drainage area, discharge) or that are reach-specific (bed gradient). Specifically, we tested the hypothesis that response variables correlate most strongly with local gradient because of the segmented nature of mountain channels. Results from linear regression analyses indicate that most response variables(R/D84, D50, D84, ff, ss) correlate best with gradient, although w, w/d ratio, and bw correlate best with discharge. Multiple regression analyses using Mallow's Cp selection criterion produced similar results in that most response variables correlate strongly with gradient, although the specific variables differ from those selected with linear regressions: w, a, v, ff and ss correlate with gradient, whereas R, bw and v correlate with discharge. These results suggest that the hypothesis is partially supported: channel bed gradient is likely to be a good predictor for many reach-scale response variables along mountain rivers, but discharge is also a good predictor for some response variables. Thus, although subject to strong constraints imposed by changes in gradient and grain size supplied by processes such as glaciation and rockfall, adjustments in the channel geometry and hydraulics of mountain rivers at the reach-scale produce discernible patterns analogous to those in fully alluvial rivers. Mountain rivers may differ in that imposed reach-scale gradient is an especially important control on reach-scale channel characteristics.

  19. Early local last glacial maximum in the tropical Andes.

    PubMed

    Smith, Jacqueline A; Seltzer, Geoffrey O; Farber, Daniel L; Rodbell, Donald T; Finkel, Robert C

    2005-04-29

    The local last glacial maximum in the tropical Andes was earlier and less extensive than previously thought, based on 106 cosmogenic ages (from beryllium-10 dating) from moraines in Peru and Bolivia. Glaciers reached their greatest extent in the last glacial cycle approximately 34,000 years before the present and were retreating by approximately 21,000 years before the present, implying that tropical controls on ice volumes were asynchronous with those in the Northern Hemisphere. Our estimates of snowline depression reflect about half the temperature change indicated by previous widely cited figures, which helps resolve the discrepancy between estimates of terrestrial and marine temperature depression during the last glacial cycle. PMID:15860623

  20. A Maximum Likelihood Approach to Estimating Correlation Functions

    NASA Astrophysics Data System (ADS)

    Baxter, Eric Jones; Rozo, Eduardo

    2013-12-01

    We define a maximum likelihood (ML for short) estimator for the correlation function, ?, that uses the same pair counting observables (D, R, DD, DR, RR) as the standard Landy & Szalay (LS for short) estimator. The ML estimator outperforms the LS estimator in that it results in smaller measurement errors at any fixed random point density. Put another way, the ML estimator can reach the same precision as the LS estimator with a significantly smaller random point catalog. Moreover, these gains are achieved without significantly increasing the computational requirements for estimating ?. We quantify the relative improvement of the ML estimator over the LS estimator and discuss the regimes under which these improvements are most significant. We present a short guide on how to implement the ML estimator and emphasize that the code alterations required to switch from an LS to an ML estimator are minimal.

  1. A maximum likelihood approach to estimating correlation functions

    SciTech Connect

    Baxter, Eric Jones; Rozo, Eduardo

    2013-12-10

    We define a maximum likelihood (ML for short) estimator for the correlation function, ?, that uses the same pair counting observables (D, R, DD, DR, RR) as the standard Landy and Szalay (LS for short) estimator. The ML estimator outperforms the LS estimator in that it results in smaller measurement errors at any fixed random point density. Put another way, the ML estimator can reach the same precision as the LS estimator with a significantly smaller random point catalog. Moreover, these gains are achieved without significantly increasing the computational requirements for estimating ?. We quantify the relative improvement of the ML estimator over the LS estimator and discuss the regimes under which these improvements are most significant. We present a short guide on how to implement the ML estimator and emphasize that the code alterations required to switch from an LS to an ML estimator are minimal.

  2. Tree growth rates in an Amazonian evergreen forest: seasonal patterns and correlations with leaf phenology

    NASA Astrophysics Data System (ADS)

    Wu, J.; Silva Campos, K.; Prohaska, N.; Ferreira, M. L.; Nelson, B. W.; Saleska, S. R.; da Silva, R.

    2014-12-01

    Metabolism and phenology of tropical forests significantly influence global dynamics of climate, carbon and water. However, there is still lack of mechanistic understanding of the controls on tropical forest metabolism, particularly at individual tree level. In this study, we are interested in investigating (1) what is the seasonal pattern of woody growth for tropical trees and (2) what is the mechanistic controls onwoody growth at individual level?To explore the above questions,we use two data sources from an evergreen tropical forest KM67 site (near Santarem, Brazil). They are: (1) image time series from a tower mounted RGB imaging system, with images recordedin10 minutes interval since October 2013.Images near local noon homogeneous diffuse lighting were selectedfor leaf phenologymonitoring; (2) ground based bi-weekly biometry survey (via dendrometry band technique) for 25 trees from random sampling since September 2013. 12 among 25 trees are within the tower mounted camera image view. Our preliminary resultsdemonstrate that 20 trees among 25 trees surveyed significantly increase woody growth (or "green up") in dry season. Our results also find thatamong those 20 trees, 12 trees reaches the maximum woody increment rate in late dry season with a mean DBH (Diameter at Breast Height) around 30 cm,while 8 trees reaching the maximum in the middle of wet season, with a mean DBH around 90 cm. This study,though limited in the sample size, mightprovide another line of evidence that Amazon rainforests "green up" in dry season. As for mechanistic controls on tropical tree woody control, we hypothesize both climate and leaf phenology control individual woody growth. We would like to link both camera based leaf phenology and climate data in the next to explorethe reason as to the pattern found in this study that bigger trees might have different seasonal growth pattern as smaller trees.

  3. Visually targeted reaching in horse-head grasshoppers

    PubMed Central

    Niven, Jeremy E.; Ott, Swidbert R.; Rogers, Stephen M.

    2012-01-01

    Visually targeted reaching to a specific object is a demanding neuronal task requiring the translation of the location of the object from a two-dimensionsal set of retinotopic coordinates to a motor pattern that guides a limb to that point in three-dimensional space. This sensorimotor transformation has been intensively studied in mammals, but was not previously thought to occur in animals with smaller nervous systems such as insects. We studied horse-head grasshoppers (Orthoptera: Proscopididae) crossing gaps and found that visual inputs are sufficient for them to target their forelimbs to a foothold on the opposite side of the gap. High-speed video analysis showed that these reaches were targeted accurately and directly to footholds at different locations within the visual field through changes in forelimb trajectory and body position, and did not involve stereotyped searching movements. The proscopids estimated distant locations using peering to generate motion parallax, a monocular distance cue, but appeared to use binocular visual cues to estimate the distance of nearby footholds. Following occlusion of regions of binocular overlap, the proscopids resorted to peering to target reaches even to nearby locations. Monocular cues were sufficient for accurate targeting of the ipsilateral but not the contralateral forelimb. Thus, proscopids are capable not only of the sensorimotor transformations necessary for visually targeted reaching with their forelimbs but also of flexibly using different visual cues to target reaches. PMID:22764161

  4. Unconstrained three-dimensional reaching in Rhesus monkeys

    PubMed Central

    Courtine, Gregoire; Liu, James J.; McKay, Heather L.; Moseanko, Rod; Bernot, Timothy J.; Roy, Roland R.; Zhong, Hui; Tuszynski, Mark H.; Reggie Edgerton, V.

    2010-01-01

    To better understand normative behavior for quantitative evaluation of motor recovery after injury, we studied arm movements by non-injured Rhesus monkeys during a food-retrieval task. While seated, monkeys reached, grasped, and retrieved food items. We recorded three-dimensional kinematics and muscle activity, and used inverse dynamics to calculate joint moments due to gravity, segmental interactions, and to the muscles and tissues of the arm. Endpoint paths showed curvature in three dimensions, suggesting that maintaining straight paths was not an important constraint. Joint moments were dominated by gravity. Generalized muscle and interaction moments were less than half of the gravitational moments. The relationships between shoulder and elbow resultant moments were linear during both reach and retrieval. Although both reach and retrieval required elbow flexor moments, an elbow extensor (triceps brachii) was active during both phases. Antagonistic muscles of both the elbow and hand were co-activated during reach and retrieval. Joint behavior could be described by lumped-parameter models analogous to torsional springs at the joints. Minor alterations to joint quasi-stiffness properties, aided by interaction moments, result in reciprocal movements that evolve under the influence of gravity. The strategies identified in monkeys to reach, grasp, and retrieve items will allow the quantification of prehension during recovery after a spinal cord injury and the effectiveness of therapeutic interventions. PMID:21170707

  5. Maximum Likelihood Estimation in Multidimensional Scaling

    ERIC Educational Resources Information Center

    Ramsay, J. O.

    1977-01-01

    A variety of distributional assumptions for dissimilarity judgments in multidimensional scaling are considered, with the lognormal distribution being favored for most situations. Procedures for maximum likelihood estimation in this setting are described and examples are presented. (Author/JKS)

  6. 5 CFR 9701.312 - Maximum rates.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...SECURITY-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM Pay and Pay Administration Overview of Pay System § 9701.312 Maximum rates. (a) DHS may not pay any employee an annual rate of...

  7. 5 CFR 9701.312 - Maximum rates.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...SECURITY-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM Pay and Pay Administration Overview of Pay System § 9701.312 Maximum rates. (a) DHS may not pay any employee an annual rate of...

  8. 5 CFR 9701.312 - Maximum rates.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...SECURITY-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM Pay and Pay Administration Overview of Pay System § 9701.312 Maximum rates. (a) DHS may not pay any employee an annual rate of...

  9. 5 CFR 9701.312 - Maximum rates.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...SECURITY-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM Pay and Pay Administration Overview of Pay System § 9701.312 Maximum rates. (a) DHS may not pay any employee an annual rate of...

  10. Maximum confidence measurements via probabilistic quantum cloning

    NASA Astrophysics Data System (ADS)

    Zhang, Wen-Hai; Yu, Long-Bao; Cao, Zhuo-Liang; Ye, Liu

    2013-03-01

    Probabilistic quantum cloning (PQC) cannot copy a set of linearly dependent quantum states. In this paper, we show that if incorrect copies are allowed to be produced, linearly dependent quantum states may also be cloned by the PQC. By exploiting this kind of PQC to clone a special set of three linearly dependent quantum states, we derive the upper bound of the maximum confidence measure of a set. An explicit transformation of the maximum confidence measure is presented.

  11. Random walk with random resetting to the maximum position

    NASA Astrophysics Data System (ADS)

    Majumdar, Satya N.; Sabhapandit, Sanjib; Schehr, Grégory

    2015-11-01

    We study analytically a simple random walk model on a one-dimensional lattice, where at each time step the walker resets to the maximum of the already visited positions (to the rightmost visited site) with a probability r , and with probability (1 -r ) , it undergoes symmetric random walk, i.e., it hops to one of its neighboring sites, with equal probability (1 -r )/2 . For r =0 , it reduces to a standard random walk whose typical distance grows as ?{n } for large n . In the presence of a nonzero resetting rate 0 maximum and the average position grow ballistically for large n , with a common speed v (r ) . Moreover, the fluctuations around their respective averages grow diffusively, again with the same diffusion coefficient D (r ) . We compute v (r ) and D (r ) explicitly. We also show that the probability distribution of the difference between the maximum and the location of the walker becomes stationary as n ?? . However, the approach to this stationary distribution is accompanied by a dynamical phase transition, characterized by a weakly singular large deviation function. We also show that r =0 is a special "critical" point, for which the growth laws are different from the r ?0 case and we calculate the exact crossover functions that interpolate between the critical (r =0 ) and the off-critical (r ?0 ) behavior for finite but large n .

  12. The measurement of maximum cylinder pressures

    NASA Technical Reports Server (NTRS)

    Hicks, Chester W

    1929-01-01

    The work presented in this report was undertaken at the Langley Memorial Aeronautical Laboratory of the National Advisory Committee for Aeronautics to determine a suitable method for measuring the maximum pressures occurring in aircraft engine cylinders. The study and development of instruments for the measurement of maximum cylinder pressures has been conducted in connection with carburetor and oil engine investigations on a single cylinder aircraft-type engine. Five maximum cylinder-pressure devices have been designed, and tested, in addition to the testing of three commercial indicators. Values of maximum cylinder pressures are given as obtained with various indicators for the same pressures and for various kinds and values of maximum cylinder pressures, produced chiefly by variation of the injection advance angle in high-speed oil engine. The investigations indicate that the greatest accuracy in determining maximum cylinder pressures can be obtained with an electric, balanced-pressure, diaphragm or disk-type indicator so constructed as to have a diaphragm or disk of relatively large area and minimum seat width and mass.

  13. Spatial and Sex-Specific Variation in Growth of Albacore Tuna (Thunnus alalunga) across the South Pacific Ocean

    PubMed Central

    Williams, Ashley J.; Farley, Jessica H.; Hoyle, Simon D.; Davies, Campbell R.; Nicol, Simon J.

    2012-01-01

    Spatial variation in growth is a common feature of demersal fish populations which often exist as discrete adult sub-populations linked by a pelagic larval stage. However, it remains unclear whether variation in growth occurs at similar spatial scales for populations of highly migratory pelagic species, such as tuna. We examined spatial variation in growth of albacore Thunnus alalunga across 90° of longitude in the South Pacific Ocean from the east coast of Australia to the Pitcairn Islands. Using length-at-age data from a validated ageing method we found evidence for significant variation in length-at-age and growth parameters (L? and k) between sexes and across longitudes. Growth trajectories were similar between sexes up until four years of age, after which the length-at-age for males was, on average, greater than that for females. Males reached an average maximum size more than 8 cm larger than females. Length-at-age and growth parameters were consistently greater at more easterly longitudes than at westerly longitudes for both females and males. Our results provide strong evidence that finer spatial structure exists within the South Pacific albacore stock and raises the question of whether the scale of their “highly migratory” nature should be re-assessed. Future stock assessment models for South Pacific albacore should consider sex-specific growth curves and spatial variation in growth within the stock. PMID:22723993

  14. Growth Problems

    MedlinePLUS

    ... function and also play a role in growth. Hypothyroidism can cause slow growth because the thyroid gland ... to support normal growth. A major symptom of hypothyroidism is feeling tired or sluggish. A blood test ...

  15. Discovery Reach of Charged MSSM Higgs Bosons at CMS

    E-print Network

    S. Heinemeyer; A. Nikitenko; G. Weiglein

    2008-09-14

    We review the 5 sigma discovery contours for the charged MSSM Higgs boson at the CMS experiment with 30/fb for the two cases M_H+ m_t. In order to analyze the search reach we combine the latest results for the CMS experimental sensitivities based on full simulation studies with state-of-the-art theoretical predictions of MSSM Higgs-boson production and decay properties. Special emphasis is put on the SUSY parameter dependence of the 5 sigma contours. The variation of $\\mu$ can shift the prospective discovery reach in tan_beta by up to Delta tan_beta = 40.

  16. 24 CFR 886.108 - Maximum annual contract commitment.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 false Maximum annual contract commitment. 886.108 Section 886.108 ...886.108 Maximum annual contract commitment. (a) Number of units assisted...conversion. (b) Maximum annual Contract commitment. The maximum annual housing...

  17. 40 CFR 141.65 - Maximum residual disinfectant levels.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS National Primary Drinking Water Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels § 141.65 Maximum residual disinfectant levels. (a) Maximum...

  18. 44 CFR 208.12 - Maximum Pay Rate Table.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...table that identifies the maximum pay rates for selected System positions that may be used for...as the basis for the maximum pay rate schedule. DHS considers System members' experience and sets maximum pay rates at the maximum...

  19. 44 CFR 208.12 - Maximum Pay Rate Table.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...table that identifies the maximum pay rates for selected System positions that may be used for...as the basis for the maximum pay rate schedule. DHS considers System members' experience and sets maximum pay rates at the maximum...

  20. 44 CFR 208.12 - Maximum Pay Rate Table.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...table that identifies the maximum pay rates for selected System positions that may be used for...as the basis for the maximum pay rate schedule. DHS considers System members' experience and sets maximum pay rates at the maximum...

  1. 44 CFR 208.12 - Maximum Pay Rate Table.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...table that identifies the maximum pay rates for selected System positions that may be used for...as the basis for the maximum pay rate schedule. DHS considers System members' experience and sets maximum pay rates at the maximum...

  2. 44 CFR 208.12 - Maximum Pay Rate Table.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...table that identifies the maximum pay rates for selected System positions that may be used for...as the basis for the maximum pay rate schedule. DHS considers System members' experience and sets maximum pay rates at the maximum...

  3. Possible dynamical explanations for Paltridge's principle of maximum entropy production

    SciTech Connect

    Virgo, Nathaniel Ikegami, Takashi

    2014-12-05

    Throughout the history of non-equilibrium thermodynamics a number of theories have been proposed in which complex, far from equilibrium flow systems are hypothesised to reach a steady state that maximises some quantity. Perhaps the most celebrated is Paltridge's principle of maximum entropy production for the horizontal heat flux in Earth's atmosphere, for which there is some empirical support. There have been a number of attempts to derive such a principle from maximum entropy considerations. However, we currently lack a more mechanistic explanation of how any particular system might self-organise into a state that maximises some quantity. This is in contrast to equilibrium thermodynamics, in which models such as the Ising model have been a great help in understanding the relationship between the predictions of MaxEnt and the dynamics of physical systems. In this paper we show that, unlike in the equilibrium case, Paltridge-type maximisation in non-equilibrium systems cannot be achieved by a simple dynamical feedback mechanism. Nevertheless, we propose several possible mechanisms by which maximisation could occur. Showing that these occur in any real system is a task for future work. The possibilities presented here may not be the only ones. We hope that by presenting them we can provoke further discussion about the possible dynamical mechanisms behind extremum principles for non-equilibrium systems, and their relationship to predictions obtained through MaxEnt.

  4. Possible dynamical explanations for Paltridge's principle of maximum entropy production

    NASA Astrophysics Data System (ADS)

    Virgo, Nathaniel; Ikegami, Takashi

    2014-12-01

    Throughout the history of non-equilibrium thermodynamics a number of theories have been proposed in which complex, far from equilibrium flow systems are hypothesised to reach a steady state that maximises some quantity. Perhaps the most celebrated is Paltridge's principle of maximum entropy production for the horizontal heat flux in Earth's atmosphere, for which there is some empirical support. There have been a number of attempts to derive such a principle from maximum entropy considerations. However, we currently lack a more mechanistic explanation of how any particular system might self-organise into a state that maximises some quantity. This is in contrast to equilibrium thermodynamics, in which models such as the Ising model have been a great help in understanding the relationship between the predictions of MaxEnt and the dynamics of physical systems. In this paper we show that, unlike in the equilibrium case, Paltridge-type maximisation in non-equilibrium systems cannot be achieved by a simple dynamical feedback mechanism. Nevertheless, we propose several possible mechanisms by which maximisation could occur. Showing that these occur in any real system is a task for future work. The possibilities presented here may not be the only ones. We hope that by presenting them we can provoke further discussion about the possible dynamical mechanisms behind extremum principles for non-equilibrium systems, and their relationship to predictions obtained through MaxEnt.

  5. Flower Power: Sunflowers as a Model for Logistic Growth

    ERIC Educational Resources Information Center

    Fernandez, Eileen; Geist, Kristi A.

    2011-01-01

    Logistic growth displays an interesting pattern: It starts fast, exhibiting the rapid growth characteristic of exponential models. As time passes, it slows in response to constraints such as limited resources or reallocation of energy. The growth continues to slow until it reaches a limit, called capacity. When the growth describes a population,…

  6. MIDDLE REACH OF THE SNAKE RIVER: WATER QUALITY MONITORING

    EPA Science Inventory

    The purpose of the project was to collect, analyze, assemble, and assess water quality data and resulting chemical/nutrient loads entering and transported in the Middle Snake River Reach of Idaho, between Milner Dam and King Hill. Studies were conducted during the period of 1990 ...

  7. The Effects of Motivational Graphing on Students Reaching Educational Goals

    ERIC Educational Resources Information Center

    Graves, Loren Adair

    2011-01-01

    The purpose of this research project was to conclude if motivational graphing strategies, when used in Math Response to Intervention (RTI) classes, could increase the students' ability to reach their goals. To complete this investigation the researcher assessed the Math RTI students' ability to count orally within one minute on a biweekly basis.…

  8. Teacher Evaluation in Practice: Implementing Chicago's REACH Students

    ERIC Educational Resources Information Center

    Sporte, Susan E.; Stevens, W. David; Healey, Kaleen; Jiang, Jennie; Hart, Holly

    2013-01-01

    This report focuses on the perceptions and experiences of teachers and administrators during the first year of REACH implementation, which was in many ways a particularly demanding year. These experiences can be helpful to Chicago Public Schools (CPS) and to other districts across the country as they work to restructure and transform teacher…

  9. Reaching diagnostic agreement in Multi-Agent Diagnosis Universiteit Maastricht

    E-print Network

    Langendoen, Koen

    Reaching diagnostic agreement in Multi-Agent Diagnosis Nico Roos IKAT Universiteit Maastricht P specifies the diagnostic setting, which is extended to multi-agent di- agnosis in section 3. Section 4 agreed upon diagnosis for errors observed in a system monitored by a number of different expert agents

  10. Reaching Part-Time Distance Students in Diverse Environments

    ERIC Educational Resources Information Center

    Whitehair, Kristin J.

    2010-01-01

    This article focuses on the model used at the University of Kansas Medical Center to reach graduate students in the School of Nursing. Like many students returning for graduate degrees, distance students are balancing the demands of professional positions, graduate studies, and family life. Topics addressed include: point-of-need assistance,…

  11. NEWNHAM COLLEGE How to reach the college (see map overleaf)

    E-print Network

    Lasenby, Joan

    NEWNHAM COLLEGE CAMBRIDGE How to reach the college (see map overleaf): a) By Bus/Coach: The bus the road. Either take a taxi to Newnham College, or from Drummer Street turn into Emmanuel Street, walk to the junction with St Andrew's Street; turn left, then turn right into Downing Street (opposite Emmanuel College

  12. Reaching Out to the Next Generation of Scientists.

    ERIC Educational Resources Information Center

    Claudio, Luz

    2001-01-01

    Discusses the need for research scientists to come out of their labs and establish links with communities and the need for scientists of color who can better gain access to the communities most often affected by problems such as environmental hazards. Describes ways to encourage this reaching out and breaking of stereotypes about scientists among…

  13. EFNEP Reaches Refugee Youth Using a Mobile Van

    ERIC Educational Resources Information Center

    Gossett, Linda S.

    2012-01-01

    New groups of refugees settled in apartments far from city services. Their children lacked access to organized after-school activities and the opportunity to practice English. The Expanded Food and Nutrition Education Program (EFNEP) wanted to reach and teach the young refugees but lacked the staff and budget to do so. This article discusses how…

  14. Priming of Reach and Grasp Actions by Handled Objects

    ERIC Educational Resources Information Center

    Masson, Michael E. J.; Bub, Daniel N.; Breuer, Andreas T.

    2011-01-01

    Pictures of handled objects such as a beer mug or frying pan are shown to prime speeded reach and grasp actions that are compatible with the object. To determine whether the evocation of motor affordances implied by this result is driven merely by the physical orientation of the object's handle as opposed to higher-level properties of the object,…

  15. Reach for the Stars: Visions for Literacy Coaching Programs

    ERIC Educational Resources Information Center

    DeFord, Diane

    2012-01-01

    This brief by the Literacy Coaching Clearinghouse is about reaching for the stars--stories of vision and commitment from educators in small and large schools. Everyone knows of people who are held up as "visionaries" throughout history: Leonardo Da Vinci, Mahatma Gandhi, Jules Verne, Thomas Edison, Susan Anthony, or John Dewey, to name a few. The…

  16. Can the Hard-to-Reach Adults Become Literate?

    ERIC Educational Resources Information Center

    Fitzgerald, Gisela G.

    1984-01-01

    Addresses the problem of why the millions of hard-core illiterate American adults are not being reached by adult basic education programs. Three factors are cited as frequent reasons for nonparticipation: (1) age, (2) satisfaction with present situation, and (3) poverty. (JOW)

  17. TECH-REACH: A Rehabilitation Technology Information Exchange. Final Report.

    ERIC Educational Resources Information Center

    National Center for Disability Services, Albertson, NY. Research and Training Inst.

    TECH-REACH, a federally funded rehabilitation technology information exchange program, serves New York City and some surrounding areas. Its mission is to improve the delivery of technology information and rehabilitation services for people with disabilities and the professionals who serve them. The information exchange has gathered and maintained…

  18. Estimating reach curves from one data point Georg M. Goerg

    E-print Network

    Cortes, Corinna

    , 2014 Abstract Reach curves arise in advertising and media analysis as they relate the number of content impressions to the number of people who have seen it. This is es- pecially important for measuring the effectiveness of an ad on TV or websites (Nielsen, 2009; Pricewater- houseCoopers, 2010). For a mathematical

  19. Differential Fault Analysis of AES: Towards Reaching its Limits

    E-print Network

    International Association for Cryptologic Research (IACR)

    Differential Fault Analysis of AES: Towards Reaching its Limits Sk Subidh Ali1 , Debdeep. In this paper we present a theoretical analysis of the limits of the Differential Fault Analysis (DFA) of AES. The work has been compared to other works and also the optimal limits of Differential Fault Analysis of AES

  20. Numeric Comparison in a Visually-Guided Manual Reaching Task

    ERIC Educational Resources Information Center

    Song, Joo-Hyun; Nakayama, Ken

    2008-01-01

    Nearly all studies on perception and cognition have used discrete responses to infer internal cognitive processes. In the current study, we demonstrate that visually-guided manual reaching can provide new opportunities to access internal processes over time. In each trial, participants were required to compare a single digit Arabic number…

  1. Reaching a Moveable Visual Target: Dissociations in Brain Tumour Patients

    ERIC Educational Resources Information Center

    Buiatti, Tania; Skrap, Miran; Shallice, Tim

    2013-01-01

    Damage to the posterior parietal cortex (PPC) can lead to Optic Ataxia (OA), in which patients misreach to peripheral targets. Recent research suggested that the PPC might be involved not only in simple reaching tasks toward peripheral targets, but also in changing the hand movement trajectory in real time if the target moves. The present study…

  2. Posterior cortical atrophy: visuomotor deficits in reaching and grasping

    PubMed Central

    Meek, Benjamin P.; Shelton, Paul; Marotta, Jonathan J.

    2013-01-01

    Posterior Cortical Atrophy (PCA) is a rare clinical syndrome characterized by the predominance of higher-order visual disturbances such as optic ataxia, a characteristic of Balint's syndrome. Deficits result from progressive neurodegeneration of occipito-temporal and occipito-parietal cortices. The current study sought to explore the visuomotor functioning of four individuals with PCA by testing their ability to reach out and grasp real objects under various viewing conditions. Experiment 1 had participants reach out and grasp simple, rectangular blocks under visually- and memory-guided conditions. Experiment 2 explored participants' abilities to accurately reach for objects located in their visual periphery. This investigation revealed that PCA patients demonstrate many of the same deficits that have been previously reported in other individuals with optic ataxia, such as “magnetic misreaching”—a pathological reaching bias toward the point of visual fixation when grasping peripheral targets. Unlike many other individuals with optic ataxia, however, the patients in the current study also show symptoms indicative of damage to the more perceptual stream of visual processing, including abolished grip scaling during memory-guided grasping and deficits in face and object identification. These investigations are the first to perform a quantitative analysis of the visuomotor deficits exhibited by patients with PCA. Critically, this study helps characterize common symptoms of PCA, a vital first step for generating effective diagnostic criteria and therapeutic strategies for this understudied neurodegenerative disorder. PMID:23801956

  3. Reaching Out With a New Breed of Worker.

    ERIC Educational Resources Information Center

    Office of Youth Development (DHEW), Washington, DC.

    This publication describes the concept of The National Center for Youth Outreach Workers in reaching out and contacting youth with problems--beyond the confines of an agency, set hours, and limited knowledge of the individual youth. The Center was conceived at a Young Men's Christian Associations' (YMCA) conference in Washington, D. C. in March…

  4. 14. RAILROAD BRIDGE MISSISSIPPI, MONROE CO., ABERDEEN Reach by foot ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. RAILROAD BRIDGE MISSISSIPPI, MONROE CO., ABERDEEN Reach by foot from E end of Vine St. St. Louis and San Francisco RR bridge. Bridge built 1887, replaced, 1969. Credit: Evans Memorial Library, Aberdeen, Ms. No date. Sarcone Photography, Columbus, Ms. Sep 1978. - Bridges of the Upper Tombigbee River Valley, Columbus, Lowndes County, MS

  5. Reaching Consensus with Imprecise Probabilities Over a Network

    E-print Network

    to agreement on a probability vec- tor over a network, such as would be required in a decentralized estimationReaching Consensus with Imprecise Probabilities Over a Network Cameron S. R. Fraser , Luca F Information consensus in sensor networks has received much attention due to its numerous applications

  6. Reaching the Underserved: Complementary Models of Effective Schooling

    ERIC Educational Resources Information Center

    DeStefano, Joseph; Moore, Audrey-Marie Schuh; Balwanz, David; Hartwell, Ash

    2007-01-01

    Many countries that have undergone expansion of access to public education still face significant disparities in school enrollment and attendance rates at sub-national levels, and fail to reach a high proportion of children who are outside of the government system. Completion and student learning have also continued to be system-wide challenges…

  7. Our Global Reach: UNESCO and ICAE as Catalysts

    ERIC Educational Resources Information Center

    Boucouvalas, Marcie

    2012-01-01

    Globalization has become a household word, permeating workplaces and communities, while internationalizing the curriculum has become common practice, not just in higher education, but also reaching into the primary grades and outward into program planning efforts in the non-formal sector. Few fields, however, can claim two international bodies…

  8. Reaching Potentials: Transforming Early Childhood Curriculum and Assessment. Volume 2.

    ERIC Educational Resources Information Center

    Bredekamp, Sue, Ed.; Rosegrant, Teresa, Ed.

    This book builds on Volume 1 of "Reaching Potentials," which attempted to operationalize the "Guidelines for Appropriate Curriculum Content and Assessment" set by the National Association for the Education of Young Children (NAEYC) and the National Association of Early Childhood Specialists in State Departments of Education (NAECS/SDE). Volume 2…

  9. Reaching and Grasping Movements in Infants at Risk: A Review

    ERIC Educational Resources Information Center

    de Campos, Ana Carolina; Rocha, Nelci Adriana Cicuto Ferreira; Savelsbergh, Geert J. P.

    2009-01-01

    Although the influence of intrinsic and extrinsic factors on the development of reaching and grasping skills in typical infants has been extensively described in the literature, the effect of such factors on at-risk infants is still poorly understood. Therefore, the aims of the present study were to analyze the scientific publications, from 1980…

  10. Perceiving Children's Behavior and Reaching Limits in a Risk Environment

    ERIC Educational Resources Information Center

    Cordovil, Rita; Santos, Carlos; Barreiros, Joao

    2012-01-01

    The purpose of this study was to investigate the accuracy of parents' perception of children's reaching limits in a risk scenario. A sample of 68 parents of 1- to 4-year-olds were asked to make a prior estimate of their children's behavior and action limits in a task that involved retrieving a toy out of the water. The action modes used for…

  11. "Terms of Engagement" Not "Hard to Reach Parents"

    ERIC Educational Resources Information Center

    Day, Sara

    2013-01-01

    This article presents findings of qualitative research commissioned by the Achievement for All project in a UK local authority. The research investigated how schools should engage parents, including those considered to be "hard to reach". A focus group methodology was adapted to enable parents to provide answers to the research questions. The…

  12. 12. INTERIOR VIEW WITH JAMES WILLIAMS REACHING FOR THE SAND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. INTERIOR VIEW WITH JAMES WILLIAMS REACHING FOR THE SAND RELEASE LEVER WHICH WILL OPEN THE OVERHEAD STORAGE BIN AND PERMIT A SET AMOUNT OF SAND TO BE DEPOSITED INTO THE FLASK PRIOR TO COMPRESSION BY THE MOLDING MACHINE INSIDE GREY IRON UNIT NO. 1. - Stockham Pipe & Fittings Company, Grey Iron Foundry, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

  13. Brood ecology of Canada geese on the Hanford Reach

    SciTech Connect

    Eberhardt, L.E.

    1983-12-01

    The objective was to examine the ecology of broods of the western Canada goose (Branta canadensis moffitti) on the Hanford Reach of the Columbia River in southcentral Washington. Broods were captured and equipped with radio transmitters and their movements tracked. Major brood rearing areas were identified. 5 references, 2 tables. (ACR)

  14. Promoting early literacy in pediatric practice: twenty years of reach out and read.

    PubMed

    Zuckerman, Barry

    2009-12-01

    Reach Out and Read (ROR) is the first pediatric, evidence-based strategy to prevent problems of early childhood development and learning. With a start in a single clinic in Boston City Hospital in 1989, doctors working in >4000 clinics and practices gave approximately 5.7 million new books to >3.5 million children in all 50 states in 2008. ROR also has become a model for a different way of thinking about parent education during primary care encounters, based less on telling and more on creating real-time learning experiences. ROR flourished because of (1) the growth of pediatric interest in child development, (2) local leadership of pediatric champions as well as nonmedical supporters, coordinators, and volunteers, (3) evidence of effectiveness, and (4) public financial support attributable to strong bipartisan support in Congress, led by Senator Edward Kennedy. Since ROR started, an increasing amount of research confirms the importance of reading aloud for the development of language and other emergent literacy skills, which in turn helps children get ready for school and leads to later success in reading. Future goals include continued growth until all low-income children are reached with pediatric advice and books, a national campaign led by physicians encouraging all parents to read to their children every day, additional evidence-based, parent information to increase the effectiveness of parents reading to children, quality-improvement efforts to achieve the full potential, and global expansion. PMID:19917584

  15. Linking transient storage parameters to exchange mechanisms and reach characteristics

    NASA Astrophysics Data System (ADS)

    Morén, Ida; Wörman, Anders; Riml, Joakim

    2015-04-01

    A traditional way of investigating transient storage zones in streams and rivers comprises the performance of tracer tests. The information gained from the tests however, is in many ways limited by the geomorphological and hydraulic local conditions under which the test was performed. Consequently, there is a need for more general information about how reach characteristics and combined exchange mechanisms affect transient storage retention that can be expressed by scaling factors between physical, measurable parameters and the integrated total retention in a reach. A large number of tracer tests have been performed in a wide variety of reaches around the world and in this project we are taking advantage of already collected data as well as new tracer test performed within the study, to quantitatively evaluate how different geomorphic and hydraulic conditions affect the retention of solutes in rivers. By advancing existing physically based models on the local-scale with the combinations of exchange mechanisms we theoretically describe the relative magnitude of exchange mechanisms, and combinations of these, under specific hydraulic conditions and show how exchange parameters associated with different mechanisms are correlated physically. Both hyporheic transient storage zones (HTS) and surface transient storage zones (STS) are considered. Combined vertical exchange with the HTS can be evaluated by superimposing the velocity fields associated with stream features of different size described mathematically by harmonic functions, while exchange with other zones can be treated as independent and after evaluating the relative importance of the associated exchange parameters it can be added to the vertical exchange to obtain the total integrated retention. Based on the tracer tests, each tested reach is characterised in terms of its geomorphologic and hydraulic features and related statistically to reach-scale parameters evaluated from the tests with a longitudinal transient storage model. Important geomorphologic and hydraulic features used as classification parameters are those that that can be directly linked to specific management measures implemented in streams to increase natural remediation of nutrients and other contaminants. Only field data from reaches where measurements independent of the tracer tests have been done is included in this study in order to correctly analyse dominating mechanisms and combination of mechanisms and to be able to link the retention times to relevant and measurable reach characteristics.

  16. Cell development obeys maximum Fisher information

    E-print Network

    B. R. Frieden; R. A. Gatenby

    2014-04-29

    Eukaryotic cell development has been optimized by natural selection to obey maximal intracellular flux of messenger proteins. This, in turn, implies maximum Fisher information on angular position about a target nuclear pore complex (NPR). The cell is simply modeled as spherical, with cell membrane (CM) diameter 10 micron and concentric nuclear membrane (NM) diameter 6 micron. The NM contains about 3000 nuclear pore complexes (NPCs). Development requires messenger ligands to travel from the CM-NPC-DNA target binding sites. Ligands acquire negative charge by phosphorylation, passing through the cytoplasm over Newtonian trajectories toward positively charged NPCs (utilizing positive nuclear localization sequences). The CM-NPC channel obeys maximized mean protein flux F and Fisher information I at the NPC, with first-order delta I = 0 and approximate 2nd-order delta I = 0 stability to environmental perturbations. Many of its predictions are confirmed, including the dominance of protein pathways of from 1-4 proteins, a 4nm size for the EGFR protein and the approximate flux value F =10^16 proteins/m2-s. After entering the nucleus, each protein ultimately delivers its ligand information to a DNA target site with maximum probability, i.e. maximum Kullback-Liebler entropy HKL. In a smoothness limit HKL approaches IDNA/2, so that the total CM-NPC-DNA channel obeys maximum Fisher I. Thus maximum information approaches non-equilibrium, one condition for life.

  17. Maximum of a Fractional Brownian Motion: Analytic Results from Perturbation Theory.

    PubMed

    Delorme, Mathieu; Wiese, Kay Jörg

    2015-11-20

    Fractional Brownian motion is a non-Markovian Gaussian process X_{t}, indexed by the Hurst exponent H. It generalizes standard Brownian motion (corresponding to H=1/2). We study the probability distribution of the maximum m of the process and the time t_{max} at which the maximum is reached. They are encoded in a path integral, which we evaluate perturbatively around a Brownian, setting H=1/2+?. This allows us to derive analytic results beyond the scaling exponents. Extensive numerical simulations for different values of H test these analytical predictions and show excellent agreement, even for large ?. PMID:26636835

  18. Maximum of a Fractional Brownian Motion: Analytic Results from Perturbation Theory

    NASA Astrophysics Data System (ADS)

    Delorme, Mathieu; Wiese, Kay Jörg

    2015-11-01

    Fractional Brownian motion is a non-Markovian Gaussian process Xt, indexed by the Hurst exponent H . It generalizes standard Brownian motion (corresponding to H =1 /2 ). We study the probability distribution of the maximum m of the process and the time tmax at which the maximum is reached. They are encoded in a path integral, which we evaluate perturbatively around a Brownian, setting H =1 /2 +? . This allows us to derive analytic results beyond the scaling exponents. Extensive numerical simulations for different values of H test these analytical predictions and show excellent agreement, even for large ? .

  19. Postural adjustments and reaching in 4- and 6-month-old infants: an EMG and kinematical study.

    PubMed

    de Graaf-Peters, Victorine B; Bakker, Hanneke; van Eykern, Leo A; Otten, Bert; Hadders-Algra, Mijna

    2007-08-01

    Adequate postural control is a prerequisite for daily activities such as reaching for an object. However, knowledge on the relationship between postural adjustments and the quality of reaching movements during human ontogeny is scarce. Therefore we evaluated the development of the relationship between the kinematic features of reaching movements and the accompanying postural adjustments in young infants. Twelve typically developing (TD) infants were assessed twice, i.e. at 4 and 6 months of age, in supine and supported sitting position. Reaching was elicited by presenting toys in the midline at an arm-length distance while simultaneously surface EMG-activity was recorded from multiple arm-, neck-, trunk- and leg muscles. Concurrently kinematics of reaching were recorded with an ELITE system; kinematic analysis was restricted to the behaviour of so-called movement units, which are sub movements of reaching determined with the help of peaks in the velocity profile of the hand, maximum movement velocity and movement duration. A computer-algorithm determined significant phasic muscle activity. Activity in neck and trunk muscles (postural activity) was related to the onset of the prime mover, which was the arm muscle being activated first. The results indicated that about 50% of reaching movements in lying and sitting infants aged 4 and 6 months were accompanied by direction-specific postural adjustments. At 4 months variation dominated, but at 6 months a preference to recruit muscles in a top-down order (during sitting) and in the configuration of the complete pattern, i.e. the pattern in which all dorsal neck- and trunk muscles are activated in concert, (both conditions) emerged. Interestingly, the postural characteristics such as the presence of direction-specificity, recruitment of the complete pattern and top-down recruitment, were related to how successful the reaching was and the kinematics of reaching. It was concluded that the presence of direction-specific activity is not a prerequisite for the emergence of reaching movements. Nevertheless, already from 4 months onwards a better postural control is associated with a larger success and a better quality of reaching. PMID:17505820

  20. Prediction of the maximum annual mean sunspot number in the coming solar maximum epoch

    NASA Astrophysics Data System (ADS)

    Kane, R. P.

    1987-09-01

    Using an earlier correlation analysis between the annual sunspot numbers at sunspot maximum epochs and the minimum annual aa index in the immediately preceding years (Kane, 1978), the minimum annual aa index during 1985-86 is determined. The value obtained (21.6) implies a maximum annual sunspot number of aobut 190 + or - 40 in the coming solar maximum epoch, in about 1988-89.

  1. Density estimation by maximum quantum entropy

    SciTech Connect

    Silver, R.N.; Wallstrom, T.; Martz, H.F.

    1993-11-01

    A new Bayesian method for non-parametric density estimation is proposed, based on a mathematical analogy to quantum statistical physics. The mathematical procedure is related to maximum entropy methods for inverse problems and image reconstruction. The information divergence enforces global smoothing toward default models, convexity, positivity, extensivity and normalization. The novel feature is the replacement of classical entropy by quantum entropy, so that local smoothing is enforced by constraints on differential operators. The linear response of the estimate is proportional to the covariance. The hyperparameters are estimated by type-II maximum likelihood (evidence). The method is demonstrated on textbook data sets.

  2. Gigantic maximum of nanoscale noncontact friction.

    PubMed

    Saitoh, Kohta; Hayashi, Kenichi; Shibayama, Yoshiyuki; Shirahama, Keiya

    2010-12-01

    We report measurements of noncontact friction between surfaces of NbSe2 and SrTiO3 and a sharp Pt-Ir tip that is oscillated laterally by a quartz tuning fork cantilever. At 4.2 K, the friction coefficients on both the metallic and insulating materials show a giant maximum at the tip-surface distance of several nanometers. The maximum is strongly correlated with an increase in the spring constant of the cantilever. These features can be understood phenomenologically by a distance-dependent relaxation mechanism with distributed time scales. PMID:21231483

  3. Maximum predictive power and the superposition principle

    NASA Technical Reports Server (NTRS)

    Summhammer, Johann

    1994-01-01

    In quantum physics the direct observables are probabilities of events. We ask how observed probabilities must be combined to achieve what we call maximum predictive power. According to this concept the accuracy of a prediction must only depend on the number of runs whose data serve as input for the prediction. We transform each probability to an associated variable whose uncertainty interval depends only on the amount of data and strictly decreases with it. We find that for a probability which is a function of two other probabilities maximum predictive power is achieved when linearly summing their associated variables and transforming back to a probability. This recovers the quantum mechanical superposition principle.

  4. Maximum likelihood clustering with dependent feature trees

    NASA Technical Reports Server (NTRS)

    Chittineni, C. B. (principal investigator)

    1981-01-01

    The decomposition of mixture density of the data into its normal component densities is considered. The densities are approximated with first order dependent feature trees using criteria of mutual information and distance measures. Expressions are presented for the criteria when the densities are Gaussian. By defining different typs of nodes in a general dependent feature tree, maximum likelihood equations are developed for the estimation of parameters using fixed point iterations. The field structure of the data is also taken into account in developing maximum likelihood equations. Experimental results from the processing of remotely sensed multispectral scanner imagery data are included.

  5. A differential method of maximum entropy

    E-print Network

    Bajkova, A T

    1998-01-01

    We consider a differential method of maximum entropy that is based on the linearity of Fourier transform and involves reconstruction of images from the differences of the visibility function. The efficiency of the method is demonstrated with respect to the recovery of source images with bright components against the background of a sufficiently weak extended base. The simulation results are given along with the maps of an extragalactic radio source 0059+581, which were obtained using the standard and differential methods of maximum entropy for three observation dates and show that the principle of differential mapping allows us to increase considerably the dynamic interval of images.

  6. A differential method of maximum entropy

    E-print Network

    Anisa T. Bajkova

    2002-04-19

    We consider a differential method of maximum entropy that is based on the linearity of Fourier transform and involves reconstruction of images from the differences of the visibility function. The efficiency of the method is demonstrated with respect to the recovery of source images with bright components against the background of a sufficiently weak extended base. The simulation results are given along with the maps of an extragalactic radio source 0059+581, which were obtained using the standard and differential methods of maximum entropy for three observation dates and show that the principle of differential mapping allows us to increase considerably the dynamic interval of images.

  7. Efficiency of molecular motors at maximum power

    E-print Network

    Schmiedl, Tim

    2008-01-01

    Molecular motors transduce chemical energy obtained from hydrolizing ATP into mechanical work exerted against an external force. We calculate their efficiency at maximum power output for two simple generic models and show that the qualitative behaviour depends crucially on the position of the transition state. Specifically, we find a transition state near the initial state (sometimes characterized as a "power stroke") to be most favorable with respect to both high power output and high efficiency at maximum power. In this regime, driving the motor further out of equilibrium by applying higher chemical potential differences can even, counter-intuitively, increase the efficiency.

  8. [Human appropriation of net primary production in the middle reach of Heihe River basin].

    PubMed

    Long, Ai-hua; Wang, Hao; Cheng, Guo-dong; Yu, Fu-liang

    2008-04-01

    Based on Miami model, this paper calculated the human appropriation of net primary production (HANPP) in the middle reach of Heihe River basin, discussed the relations between the HANPP and ecosystem diversity, and compared the values of HANPP and ecological footprint (EF) in sustainability assessment. The results showed that the increase of HANPP decreased the ecosystem diversity, and the current average HANPP in study area was 38.61%. The HANPP in Suzhou and Ganzhou districts already exceeded the potential maximum productivity. Considering the climate change and the development of social-economics, the ecosystems in study area would face more stress in the coming 40 years. Comparing with EF, HANPP was more available for the assessment of sustainability in the sight of ecosystem function change. PMID:18593049

  9. Reaching to Throw Compared to Reaching to Place: A Comparison across Individuals with and without Developmental Coordination Disorder

    ERIC Educational Resources Information Center

    Wilmut, Kate; Byrne, Maia; Barnett, Anna L.

    2013-01-01

    When picking up an object, adults show a longer deceleration phase when the onward action has a greater precision requirement. Tailoring action in this way is thought to need forward modelling in order to predict the consequences of movement. Some evidence suggests that young children also tailor reaching in this way; however, how this skill…

  10. Translating the REACH Caregiver Intervention for Use by Area Agency on Aging Personnel: the REACH OUT Program

    ERIC Educational Resources Information Center

    Burgio, Louis D.; Collins, Irene B.; Schmid, Bettina; Wharton, Tracy; McCallum, Debra; DeCoster, Jamie

    2009-01-01

    Purpose: The aim of this study was to translate the evidence-based Resources for Enhancing Alzheimer's Caregiver Health (REACH) II intervention for use in 4 Area Agencies on Aging (AAAs). A secondary aim was to examine possible moderators of treatment outcome. Design and Methods: We used a quasi-experimental pre-post treatment design with no…

  11. Redesigning Schools to Reach Every Student with Excellent Teachers: Change Management--Key Theories to Consider when Extending Reach

    ERIC Educational Resources Information Center

    Barrett, Sharon Kebschull

    2012-01-01

    As schools, their teachers, and outside facilitators redesign jobs and incorporate technology to extend the reach of excellent teachers to more students and develop an Opportunity Culture for all, choosing the right school models is just one part of the task. The human experience--and experience in education--says that even perfect design will not…

  12. Storage changes over the middle reach of the Congo River: comparison between its upper and lower middle reaches

    NASA Astrophysics Data System (ADS)

    Lee, H.; Yuan, T.; Jung, H. C.; Duan, J.; Shum, C. K.; Beighley, E., II

    2014-12-01

    Several studies have been conducted to quantify and characterize terrestrial water storage changes over the Congo's wetlands, especially focusing on the central Congo Basin, or Cuvette Centrale, where vast wetlands can be found. The annual variations of the total storage changes over the Cuvette Centrale wetlands were estimated to range between ~20 km3 to ~30 km3 using PALSAR ScanSAR, Envisat altimetry, and GRACE RL05 data, mostly controlled by surface water. Furthermore, based on precipitation minus evapotranspiration anomalies, and a hydraulic analysis using Envisat altimetry data, the source of the Cuvette Centrale wetland's water is likely to be local upland runoff rather than the fluvial process of river-floodplain exchange as in the Amazon. On the other hand, if we consider the Cuvette Centrale as the lower middle reach of the Congo, little attention has been paid to the upper middle reach of the Congo River, from just downstream of Kisangani to the intersection where the mainstem and the Lulonga River meets. In this study, we will use PALSAR images and Envisat altimetry data to estimate surface water storage changes over the floodplains in the upper middle reaches to make comparison with the lower middle reach. We will also perform the hydraulic analysis using Envisat altimetry height profiles over the river and its adjacent floodplains to examine the source of its water. Finally, the total storage changes, estimated from GRACE regional solutions with higher temporal and spatial resolutions based on the energy conservation principle and the Hillslope River Routing (HRR) model will be investigated to highlight their differences between the upper and lower middle reaches.

  13. Growth, metabolic activity, and productivity of immobilized and freely suspended CHO cells in perfusion culture.

    PubMed

    Hilal-Alnaqbi, Ali; Hu, Alan Y C; Zhang, Zhibing; Al-Rubeai, Mohamed

    2013-01-01

    Chinese hamster ovary (CHO) cells producing ?-galactosidase (?-gal) were successfully cultured on silicone-based porous microcarriers (ImmobaSil FS) in a 1 L stirred-tank perfusion bioreactor. We studied the growth, metabolism, and productivity of free and immobilized cells to understand cellular activity in immobilized conditions. CHO cells attached to ImmobaSil FS significantly better than to other microcarriers. Scanning electron microscope images showed that the CHO cells thoroughly colonized the porous surfaces of the ImmobaSil FS, exhibiting a spherical morphology with microvilli that extended to anchorage cells on the silicone surface. In perfusion culture, the concentration of the attached cells reached 8 × 10(8) cells/mL of carrier, whereas those that remained freely suspended reached 2 × 10(7) cells/mL medium. The ?-gal concentration reached more than 5 unit/mL in perfusion culture, more than fivefold that of batch culture. The maximum concentration per microcarrier was proportional to the initial cell density. The specific growth rate, the specific ?-gal production rate, the percentage of S phase, and the oxygen uptake rate were all relatively lower for immobilized cells than freely suspended cells in the same bioreactor, indicating that not only do cells survive and grow to a greater extent in a free suspension state, but they are also metabolically more active than viable cells inside the pores of the microcarriers. PMID:23701045

  14. Finding balance: Virus populations reach equilibrium during the infection process.

    PubMed

    Harper, S J; Cowell, S J; Dawson, W O

    2015-11-01

    Virus populations, mixtures of viral strains or species, are a common feature of viral infection, and influence many viral processes including infection, transmission, and the induction of disease. Yet, little is known of the rules that define the composition and structure of these populations. In this study, we used three distinct strains of Citrus tristeza virus (CTV) to examine the effect of inoculum composition, titer, and order, on the virus population. We found that CTV populations stabilized at the same equilibrium irrespective of how that population was introduced into a host. In addition, both field and experimental observations showed that these equilibria were relatively uniform between individual hosts of the same species and under the same conditions. We observed that the structure of the equilibria reached is determined primarily by the host, with the same inoculum reaching different equilibria in different species, and by the fitness of individual virus variants. PMID:26291064

  15. Discovery Reach of Charged MSSM Higgs Bosons at CMS

    SciTech Connect

    Heinemeyer, S.; Nikitenko, A.; Weiglein, G.

    2008-11-23

    We review the 5{sigma} discovery contours for the charged MSSM Higgs boson at the CMS experiment with 30 fb{sup -1} for the two cases M{sub H{sup {+-}}}m{sub t}. In order to analyze the search reach we combine the latest results for the CMS experimental sensitivities based on full simulation studies with state-of-the-art theoretical predictions of MSSM Higgs-boson production and decay properties. Special emphasis is put on the SUSY parameter dependence of the 5{sigma} contours. The variation of {mu} can shift the prospective discovery reach in tan{beta} by up to {delta}tan{beta} = 40.

  16. Supermassive Black Hole Growth and Merger Rates from Cosmological N-body Simulations

    SciTech Connect

    Micic, Miroslav; Holley-Bockelmann, Kelly; Sigurdsson, Steinn; Abel, Tom; /SLAC

    2007-10-29

    Understanding how seed black holes grow into intermediate and supermassive black holes (IMBHs and SMBHs, respectively) has important implications for the duty-cycle of active galactic nuclei (AGN), galaxy evolution, and gravitational wave astronomy. Most studies of the cosmological growth and merger history of black holes have used semianalytic models and have concentrated on SMBH growth in luminous galaxies. Using high resolution cosmological N-body simulations, we track the assembly of black holes over a large range of final masses - from seed black holes to SMBHs - over widely varying dynamical histories. We used the dynamics of dark matter halos to track the evolution of seed black holes in three different gas accretion scenarios. We have found that growth of a Sagittarius A* - size SMBH reaches its maximum mass M{sub SMBH}={approx}10{sup 6}M{sub {circle_dot}} at z{approx}6 through early gaseous accretion episodes, after which it stays at near constant mass. At the same redshift, the duty-cycle of the host AGN ends, hence redshift z=6 marks the transition from an AGN to a starburst galaxy which eventually becomes the Milky Way. By tracking black hole growth as a function of time and mass, we estimate that the IMBH merger rate reaches a maximum of R{sub max}=55 yr{sup -1} at z=11. From IMBH merger rates we calculate N{sub ULX}=7 per Milky Way type galaxy per redshift in redshift range 2 {approx}< z {approx}< 6.

  17. Maximum rotation frequency of strange stars

    SciTech Connect

    Zdunik, J.L.; Haensel, P. )

    1990-07-15

    Using the MIT bag model of strange-quark matter, we calculate the maximum angular frequency of the uniform rotation of strange stars. After studying a broad range of the MIT bag-model parameters, we obtain an upper bound of 12.3 kHz.

  18. 49 CFR 107.329 - Maximum penalties.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 2 2014-10-01 2014-10-01 false Maximum penalties. 107.329 Section 107.329 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS AND OIL TRANSPORTATION HAZARDOUS MATERIALS PROGRAM PROCEDURES Enforcement Compliance...

  19. Improved Design Debugging using Maximum Satisfiability

    E-print Network

    Veneris, Andreas

    the performance of current state-of-the-art debugging techniques, thus making them more practical. More and newer debugging techniques must be greatly improved to make debugging practical for industrial problemsImproved Design Debugging using Maximum Satisfiability Sean Safarpour, Hratch Mangassarian, Andreas

  20. Comparing maximum pressures in internal combustion engines

    NASA Technical Reports Server (NTRS)

    Sparrow, Stanwood W; Lee, Stephen M

    1922-01-01

    Thin metal diaphragms form a satisfactory means for comparing maximum pressures in internal combustion engines. The diaphragm is clamped between two metal washers in a spark plug shell and its thickness is chosen such that, when subjected to explosion pressure, the exposed portion will be sheared from the rim in a short time.

  1. Integrating Correlated Bayesian Networks Using Maximum Entropy

    SciTech Connect

    Jarman, Kenneth D.; Whitney, Paul D.

    2011-08-30

    We consider the problem of generating a joint distribution for a pair of Bayesian networks that preserves the multivariate marginal distribution of each network and satisfies prescribed correlation between pairs of nodes taken from both networks. We derive the maximum entropy distribution for any pair of multivariate random vectors and prescribed correlations and demonstrate numerical results for an example integration of Bayesian networks.

  2. Maximum Margin Discriminant Analysis based Face Recognition

    E-print Network

    Szepesvari, Csaba

    Maximum Margin Discriminant Analysis based Face Recognition Korn´el Kov´acs1 , Andr´as Kocsor1 that MMDA is capable of finding good features in face recognition and performs very well provided it is preceded by an appropriate preprocessing phase. 1 Introduction Human face recognition is a special

  3. The maximum output parameters of an amplitron

    NASA Astrophysics Data System (ADS)

    Baiburin, V. B.

    1982-05-01

    Using basic energy concepts, analytic relations are obtained for calculating the maximum value of the output high-frequency power and of the anode current of an amplitron amplifier. The results of the calculations are found to be in agreement with experimental data on the power, efficiency, and anode current. A cylindrical model is used, with the emission limited by a space charge.

  4. 5 CFR 534.203 - Maximum stipends.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...1 L-A Below high school graduation GS-1-1...Third year medical school GS-7-1 (minus...Fourth year medical school GS-9-1 (minus...Medical or dental internship GS-10-1 (minus...determined that a higher maximum...

  5. 5 CFR 534.203 - Maximum stipends.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...1 L-A Below high school graduation GS-1-1...Third year medical school GS-7-1 (minus...Fourth year medical school GS-9-1 (minus...Medical or dental internship GS-10-1 (minus...determined that a higher maximum...

  6. 5 CFR 534.203 - Maximum stipends.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...1 L-A Below high school graduation GS-1-1...Third year medical school GS-7-1 (minus...Fourth year medical school GS-9-1 (minus...Medical or dental internship GS-10-1 (minus...determined that a higher maximum...

  7. 5 CFR 534.203 - Maximum stipends.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...1 L-A Below high school graduation GS-1-1...Third year medical school GS-7-1 (minus...Fourth year medical school GS-9-1 (minus...Medical or dental internship GS-10-1 (minus...determined that a higher maximum...

  8. 5 CFR 534.203 - Maximum stipends.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...1 L-A Below high school graduation GS-1-1...Third year medical school GS-7-1 (minus...Fourth year medical school GS-9-1 (minus...Medical or dental internship GS-10-1 (minus...determined that a higher maximum...

  9. Maximum Possible Transverse Velocity in Special Relativity.

    ERIC Educational Resources Information Center

    Medhekar, Sarang

    1991-01-01

    Using a physical picture, an expression for the maximum possible transverse velocity and orientation required for that by a linear emitter in special theory of relativity has been derived. A differential calculus method is also used to derive the expression. (Author/KR)

  10. Maximum entropy analysis of flow networks

    NASA Astrophysics Data System (ADS)

    Niven, Robert K.; Abel, Markus; Schlegel, Michael; Waldrip, Steven H.

    2014-12-01

    This study examines a generalised maximum entropy (MaxEnt) analysis of a flow network, involving flow rates and potential differences on the network, connected by resistance functions. The analysis gives a generic derivation based on an explicit form of the resistance functions. Accounting for the constraints also leads to an extended form of Gibbs' phase rule, applicable to flow networks.

  11. Maximum entropy analysis of hydraulic pipe networks

    NASA Astrophysics Data System (ADS)

    Waldrip, Steven H.; Niven, Robert K.; Abel, Markus; Schlegel, Michael

    2014-12-01

    A Maximum Entropy (MaxEnt) method is developed to infer mean external and internal flow rates and mean pressure gradients (potential differences) in hydraulic pipe networks, without or with sufficient constraints to render the system deterministic. The proposed method substantially extends existing methods for the analysis of flow networks (e.g. Hardy-Cross), applicable only to deterministic networks.

  12. Playgrounds with Maximum Safety and Minimal Risk.

    ERIC Educational Resources Information Center

    Christoph, Nancy J.

    1999-01-01

    Explores ways of designing playgrounds that afford maximum safety with minimal risk of injury to children, as well as how to conduct a safety audit and the types of playground equipment not recommended for 2- to 5-year olds. Details ways of designing a playground that enhances creative-play experiences. Provides resource information for safety…

  13. 5 CFR 9701.312 - Maximum rates.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Maximum rates. 9701.312 Section 9701.312 Administrative Personnel DEPARTMENT OF HOMELAND SECURITY HUMAN RESOURCES MANAGEMENT SYSTEM (DEPARTMENT OF HOMELAND SECURITY-OFFICE OF PERSONNEL MANAGEMENT) DEPARTMENT OF HOMELAND SECURITY HUMAN...

  14. Weak scale from the maximum entropy principle

    NASA Astrophysics Data System (ADS)

    Hamada, Yuta; Kawai, Hikaru; Kawana, Kiyoharu

    2015-03-01

    The theory of the multiverse and wormholes suggests that the parameters of the Standard Model (SM) are fixed in such a way that the radiation of the S3 universe at the final stage S_rad becomes maximum, which we call the maximum entropy principle. Although it is difficult to confirm this principle generally, for a few parameters of the SM, we can check whether S_rad actually becomes maximum at the observed values. In this paper, we regard S_rad at the final stage as a function of the weak scale (the Higgs expectation value) vh, and show that it becomes maximum around vh = {{O}} (300 GeV) when the dimensionless couplings in the SM, i.e., the Higgs self-coupling, the gauge couplings, and the Yukawa couplings are fixed. Roughly speaking, we find that the weak scale is given by vh ˜ T_{BBN}2 / (M_{pl}ye5), where ye is the Yukawa coupling of electron, T_BBN is the temperature at which the Big Bang nucleosynthesis starts, and M_pl is the Planck mass.

  15. Weak Scale From the Maximum Entropy Principle

    E-print Network

    Yuta Hamada; Hikaru Kawai; Kiyoharu Kawana

    2015-03-28

    The theory of multiverse and wormholes suggests that the parameters of the Standard Model are fixed in such a way that the radiation of the $S^{3}$ universe at the final stage $S_{rad}$ becomes maximum, which we call the maximum entropy principle. Although it is difficult to confirm this principle generally, for a few parameters of the Standard Model, we can check whether $S_{rad}$ actually becomes maximum at the observed values. In this paper, we regard $S_{rad}$ at the final stage as a function of the weak scale ( the Higgs expectation value ) $v_{h}$, and show that it becomes maximum around $v_{h}={\\cal{O}}(300\\text{GeV})$ when the dimensionless couplings in the Standard Model, that is, the Higgs self coupling, the gauge couplings, and the Yukawa couplings are fixed. Roughly speaking, we find that the weak scale is given by \\begin{equation} v_{h}\\sim\\frac{T_{BBN}^{2}}{M_{pl}y_{e}^{5}},\

  16. Reaching Higher Goals by Means of a Reflecting Wall

    ERIC Educational Resources Information Center

    Faella, Orazio; De Luca, Roberto

    2015-01-01

    A student realizes that a point particle that is able to rise at a given point P[subscript 0] at height H when launched vertically from the origin O of a Cartesian plane at a fixed initial speed V[subscript 0] cannot reach, by means of a direct shot from a small spring cannon, a point P positioned at the same height H and distance d from…

  17. On stiffening cables of a long reach manipulator

    SciTech Connect

    Wang, S.L.; Santiago, P.

    1996-02-01

    A long reach manipulator will be used for waste remediation in large underground storage tanks. The manipulator`s slenderness makes it flexible and difficult to control. A low-cost and effective method to enhance the manipulator`s stiffness is proposed in this research by using suspension cables. These cables can also be used to accurately measure the position of the manipulator`s wrist.

  18. Reaching Magnitude +16 with the Modified Video Drift Method

    NASA Astrophysics Data System (ADS)

    Iverson, Ernest; Nugent, Richard

    2015-04-01

    The video drift method of measuring double stars is a quick and efficient way to obtain position angle and separation measurements. With ordinary video cameras magnitude +12 and deeper double star systems often prove difficult or even impossible to measure without using an image intensifier. A simple modification to the video drift method and corresponding VidPro analysis program now makes reaching magnitude +16 a reality for modest amateur equipment.

  19. Hard x-ray Zernike Microscopy Reaches 30 nm Resolution

    SciTech Connect

    Chen, Y.T.; Chu, Y.; Chen, T-Y.; Yi, J.; Lee, W-K.; Wang, C-L.; Kempson, I. M.; Hwu, Y.; Gajdosik, V.; Margaritondo, G.

    2011-03-30

    Since its invention in 1930, Zernike phase contrast has been a pillar in optical microscopy and more recently in x-ray microscopy, in particular for low-absorption-contrast biological specimens. We experimentally demonstrate that hard-x-ray Zernike microscopy now reaches a lateral resolution below 30 nm while strongly enhancing the contrast, thus opening many new research opportunities in biomedicine and materials science.

  20. Hard x-ray Zernike microscopy reaches 30 nm resolution.

    SciTech Connect

    Chen, Y.; Chen, T.; Yi, J.; Chu, Y.; Lee, W.-K.; Wang, C.; Kempson, I.; Hwu, Y.; Gajdosik, V.; Margaritondo, G.

    2011-03-30

    Since its invention in 1930, Zernike phase contrast has been a pillar in optical microscopy and more recently in x-ray microscopy, in particular for low-absorption-contrast biological specimens. We experimentally demonstrate that hard-x-ray Zernike microscopy now reaches a lateral resolution below 30?nm while strongly enhancing the contrast, thus opening many new research opportunities in biomedicine and materials science.

  1. Amplified erosion above waterfalls and oversteepened bedrock reaches

    NASA Astrophysics Data System (ADS)

    Haviv, I.; Enzel, Y.; Whipple, K. X.; Zilberman, E.; Stone, J.; Matmon, A.; Fifield, L. K.

    2006-12-01

    None of the conventional bedrock erosion laws can predict incision immediately upslope of a waterfall lip where the flow is accelerating toward a freefall. Considering the expected increase in flow velocity and shear stress at the lip of a waterfall, we determine erosion amplification at a waterfall lip as ?, where E(?) is the erosion rate at the upstream end of the flow acceleration zone above a waterfall, Fr is the Froude number at this setting, and n ranges between 0.5-1.7. This amplification expression suggests that erosion at the lip could be as much as 2-5 times higher relative to erosion at a normal setting with identical hydraulic geometry. Utilizing this erosion amplification expression in numerical simulations, we demonstrate its impact on reach-scale morphology above waterfalls. Amplified erosion at the lip of a waterfall can trigger the formation of an oversteepened reach whose length is longer than the flow acceleration zone, provided incision wave velocity (Vi) at the upstream edge of the flow acceleration zone is higher than the retreat velocity of the waterfall face. Such an oversteepened reach is expected to be more pronounced when Vi increases with increasing slope. The simulations also suggest that oversteepening can eventually lead to steady state gradients adjacent to a waterfall lip provided Vi decreases with increasing slope. Flow acceleration above waterfalls can thus account, at least partially, for prevalent oversteepened bedrock reaches above waterfalls. Using the cosmogenic isotope Cl-36, we demonstrate that incision wave velocity upstream of a waterfall at the Dead Sea western escarpment is probably high enough for freefall-induced oversteepening to be feasible.

  2. Free dendritic growth

    NASA Technical Reports Server (NTRS)

    Glicksman, M. E.

    1984-01-01

    Free dendritic growth refers to the unconstrained development of crystals within a supercooled melt, which is the classical 'dendrite problem'. Great strides have been taken in recent years in both the theoretical understanding of dendritic growth and its experimental status. The development of this field will be sketched, showing that transport theory and interfacial thermodynamics (capillarity theory) were sufficient ingredients to develop a truly predictive model of dendrite formation. The convenient, but incorrect, notion of 'maximum velocity' was used for many years to estimate the behavior of dendritic transformations until supplanted by modern dynamic stability theory. The proper combinations of transport theory and morphological stability seem to able to predict the salient aspects of dendritic growth, especially in the neighborhood of the tip. The overall development of cast microstructures, such as equiaxed zone formation, rapidly solidified microstructures, etc., also seems to contain additional non-deterministic features which lie outside the current theories discussed here.

  3. Naturalness reach of the large hadron collider in minimal supergravity

    NASA Astrophysics Data System (ADS)

    Allanach, Ben C.; Hetherington, James P. J.; Parker, M. Andrew; Webber, Bryan R.

    2000-08-01

    We re-analyse the prospects of discovering supersymmetry at the LHC, in order to re-express coverage in terms of a fine-tuning parameter and to extend the analysis to scalar masses (m0) above 2 TeV. We use minimal supergravity (mSUGRA) unification assumptions for the SUSY breaking parameters. The discovery reach at high m0 is of renewed interest because this region has recently been found to have a focus point, leading to relatively low fine-tuning, and because it remains uncertain how much of the region can be ruled out due to lack of radiative electroweak symmetry breaking. The best fine tuning reach is found in a mono-leptonic channel, where for ?>0, A0 = 0 and tan ? = 10 (within the focus point region), and a top mass of 174 GeV, all points in mSUGRA with m0 < 4000 GeV, with a fine tuning measure up to 210 (500) are covered by the search, where the definition of fine-tuning excludes (includes) the contribution from the top Yukawa coupling. Even for arbitrarily high m0, mSUGRA can be discovered through gaugino events, provided the gaugino mass parameter M1/2 < 460 GeV. In this region, the mono-leptonic channel still provides the best reach.

  4. Simple PC program plans extended reach, horizontal wells

    SciTech Connect

    Hashem, A.A.

    1995-04-01

    Horizontal drilling is an outgrowth of the latest advances in directional drilling systems. However, horizontal wells require substantial engineering work compared to conventional deviated wells. Because of the difficulties encountered in drilling horizontally, a substantial effort must be expended in properly planning the entire well. Proper planning of the overall operation also ensures the ultimate success of horizontal drilling projects. Very little information is available, however, on how to calculate the horizontal well bore trajectory from limited data. A computer program was developed that will calculate these trajectories quickly and easily. The program can be run on any IBM-compatible computer using MS-DOS version 5 or higher with QBasic, or any basic program that does not require line numbers. Horizontal wells are classified technically as extended reach, near-horizontal and horizontal wells. Extended reach refers to wells between 60{degree} and 70{degree}, final hold angle. Near-horizontal wells are defined as those wells having over 80{degree} final hold angle, and they apply to slightly dipped reservoirs. Horizontal wells, by comparison, are defined as those that reach 90{degree}, final hold angle. Wiggins, et al, published a simple equation for directional and horizontal drilling plans. However, this equation needs to be modified for adaptation to each type of directional and horizontal well.

  5. Non-linear plasma wake growth of electron holes

    SciTech Connect

    Hutchinson, I. H.; Haakonsen, C. B.; Zhou, C.

    2015-03-15

    An object's wake in a plasma with small Debye length that drifts across the magnetic field is subject to electrostatic electron instabilities. Such situations include, for example, the moon in the solar wind and probes in magnetized laboratory plasmas. The instability drive mechanism can equivalently be considered drift down the potential-energy gradient or drift up the density-gradient. The gradients arise because the plasma wake has a region of depressed density and electrostatic potential into which ions are attracted along the field. The non-linear consequences of the instability are analysed in this paper. At physical ratios of electron to ion mass, neither linear nor quasilinear treatment can explain the observation of large-amplitude perturbations that disrupt the ion streams well before they become ion-ion unstable. We show here, however, that electron holes, once formed, continue to grow, driven by the drift mechanism, and if they remain in the wake may reach a maximum non-linearly stable size, beyond which their uncontrolled growth disrupts the ions. The hole growth calculations provide a quantitative prediction of hole profile and size evolution. Hole growth appears to explain the observations of recent particle-in-cell simulations.

  6. A dynamic growth model of macroalgae: Application in an estuary recovering from treated wastewater and earthquake-driven eutrophication

    NASA Astrophysics Data System (ADS)

    Ren, Jeffrey S.; Barr, Neill G.; Scheuer, Kristin; Schiel, David R.; Zeldis, John

    2014-07-01

    A dynamic growth model of macroalgae was developed to predict growth of the green macroalga Ulva sp. in response to changes in environmental variables. The model is based on common physiological behaviour of macroalgae and hence has general applicability to macroalgae. Three state variables (nitrogen, carbon and phosphorus) were used to describe physiological processes and functional differences between nutrient and carbon uptakes. Carbon uptake is modelled as a function of temperature, light, algal internal state and water current, while nutrient uptake depends on internal state, temperature and environmental nutrient level. Growth can only occur when nutrients in the environment and in the internal storage pools (N-quota and P-quota) reach threshold levels. Physiological rates follow the Arrhenius relationship and increase exponentially with increasing temperature within the temperature tolerance range of a species. When parameterised and applied to Ulva sp. in the eutrophic Avon-Heathcote Estuary, New Zealand, the model generally reproduced field observations of Ulva sp. growth and abundance. Growth followed a clear seasonal cycle with biomass increasing from early-middle summer, reaching peak values in early autumn and then decreasing. Conversely, N-quotient levels were maximal during the winter months, declining during summer peak growth. These seasonal patterns were collectively driven by temperature, light intensity and nutrients. The model captured the N-quota and growth responses of Ulva sp. to the N-reduction arising from diversion of treated wastewater from the Avon-Heathcote Estuary to an offshore outfall in 2010, and of raw sewage N-discharges resulting from wastewater infrastructure damage caused by the Canterbury earthquakes in 2011. Sensitivity analyses revealed that temperature-related parameters and maximum uptake rate of C were among the most sensitive parameters in predicting biomass. In addition, the earthquake-derived changes in reduction of immersion time and decrease in the start biomass prior to summer blooms were shown to drive considerable declines in summer growth and biomass of Ulva sp.

  7. Studies on apple and blueberry fruit constituents: do the polyphenols reach the colon after ingestion?

    PubMed

    Kahle, Kathrin; Kraus, Michael; Scheppach, Wolfgang; Ackermann, Matthias; Ridder, Friederike; Richling, Elke

    2006-04-01

    The aim of our studies was to determine the amount of polyphenols reaching the colon after oral intake of apple juice and blueberries. After a polyphenol-free diet healthy ileostomy volunteers consumed a polyphenol-rich cloudy apple juice while others consumed anthocyanin-rich blueberries. Ileostomy effluent was collected and polyphenols were identified using HPLC-DAD as well as HPLC-ESI-MS/MS; quantification was performed with HPLC-DAD. Most of the orally administered apple polyphenols were absorbed from or metabolized in the small intestine. Between 0 and 33% of the oral dose was recovered in the ileostomy bags with a maximum of excretion after 2 h. A higher amount of the blueberry anthocyanins under study (up to 85%, depending on the sugar moiety) were determined in the ileostomy bags and therefore would reach the colon under physiological circumstances. Such structure-related availability has to be considered when polyphenols are used in model systems to study potential preventive effects in colorectal diseases. PMID:16548015

  8. 75 FR 43840 - Inflation Adjustment of the Ordinary Maximum and Aggravated Maximum Civil Monetary Penalties for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-27

    ... civil monetary penalties per the Inflation Act. See 74 FR 68701 (December 29, 2009). FRA's maximum and... materials violation was $275. 69 FR 30590, May 28, 2004. To implement these SAFETEA-LU amendments to the maximum and minimum penalties, FRA issued a final rule that was published on December 26, 2006, 71...

  9. Theoretical Analysis of Maximum Flow Declination Rate versus Maximum Area Declination Rate in Phonation

    ERIC Educational Resources Information Center

    Titze, Ingo R.

    2006-01-01

    Purpose: Maximum flow declination rate (MFDR) in the glottis is known to correlate strongly with vocal intensity in voicing. This declination, or negative slope on the glottal airflow waveform, is in part attributable to the maximum area declination rate (MADR) and in part to the overall inertia of the air column of the vocal tract (lungs to…

  10. Evaluation of influence of historical changes in land use along the middle Vistula river reach on flood risk

    NASA Astrophysics Data System (ADS)

    Karamuz, Emilia; Romanowicz, Renata; Booij, Martijn

    2014-05-01

    There is a vast literature on the influence of land use changes on rainfall-runoff processes. The problem is difficult as it requires separation of climatic and water management related changes from land use influences. The present paper addresses the problem of the influence of land use changes on maximum flows at cross-sections along the middle River Vistula reach. We adopt a methodology tested at the catchment scale, which consists of an optimisation of a rainfall-runoff model using a moving time horizon and analysis of the variability of model parameters. In the present application, it consists of an analysis of changes of roughness coefficients of a distributed HEC-RAS model, optimised using a moving five-year window. The chosen river reach (between Annopol and Gusin) has a recorded history of land use changes over 50 years (from 1949 to 2001), which included 36% of the study area. The nature of the changes is complex and shows different trends for different plant communities and sections of the valley. Generally, there has been a several percent increase in the area occupied by forests and grassland communities and a slight increase in the proportion of scrub. The first step of the procedure is to define the river reaches that have recorded information on land use changes. The second step is to perform a moving window optimisation of the HEC-RAS model for a chosen river reach. In order to assess the influence of land use changes on maximum flow values, the goodness-of-fit of the simulation of annual maximum water levels is used as an optimisation criterion. In this way the influence of land use changes on maximum inundation extent related to flood risk assessment can be estimated. The final step is to analyse the results and relate the model parameter changes to historical land use changes. We report here the results of the first two steps of the procedure. This work was partly supported from the project "Stochastic flood forecasting system (The River Vistula reach from Zawichost to Warsaw)" carried out by the Institute of Geophysics, Polish Academy of Sciences on the order of the National Science Centre (contract No. 2011/01/B/ST10/06866). The water level and flow data were provided by the Institute of Meteorology and Water Management (IMGW), Poland.

  11. [Growth and mortality parameters of Orthopristis ruber (Perciformes: Haemulidae) from Los Frailes Archipelaeo. Venezuela].

    PubMed

    Atenas, Guerrieri; Eslava, Nora; González, Leo Walter; Guevara, Francisco

    2015-03-01

    Orthopristis ruber is a species in high demand in Eastern Venezuela, but production has been decreasing in recent years. For this reason, our objective was to estimate the growth and mortality parameters of this resource. Monthly samples were collected from June 2011 to May 2012, obtaining 2980 specimens in El Tirano and Puerto Abajo. Data on total length (cm), total weight (g), and sex were recorded for each specimen. No sexual dimorphism was shown with respect to length (t(S)=1.113, p>0.05), so one length-weight ratio was established for both sexes (Wt=0.0612*Lt(2.54)); and they both exhibited minor allometric growth. Growth was estimated by analysis of length frequency distributions using FiSAT software. The estimated growth parameters (L.=39.03cm, W.=679.60g, k=0.48/year and t(O) = -0.32 year) showed moderately rapid growth. Length frequency data were adjusted to the von Bertalaniffy model, and indicated an exponential tendency of accelerated growth during the first years of life, followed by slow growth until the fish reached its maximum length. The coefficient of variation of the growth index (theta) demonstrated no differences in growth pattern. The natural mortality rate (M=0.97/year), from fishing (F=1.57/year), and total mortality (Z=2.54/year), were high, as well as the exploitation rate (E=0.62/year). We concluded that O. ruber has been fully exploited by artisanal fishers, and suggest a continuous study on population dynamics, to recommend optimum management techniques for the fishery. PMID:26299124

  12. Living bacteria rheology: population growth, aggregation patterns and cooperative behaviour under different shear flows

    E-print Network

    P. Patricio; P. L. Almeida; R. Portela; R. G. Sobral; I. R. Grilo; T. Cidade; C. R. Leal

    2014-03-06

    The activity of growing living bacteria was investigated using real-time and in situ rheology -- in stationary and oscillatory shear. Two different strains of the human pathogen Staphylococcus aureus -- strain COL and its isogenic cell wall autolysis mutant -- were considered in this work. For low bacteria density, strain COL forms small clusters, while the mutant, presenting deficient cell separation, forms irregular larger aggregates. In the early stages of growth, when subjected to a stationary shear, the viscosity of both strains increases with the population of cells. As the bacteria reach the exponential phase of growth, the viscosity of the two strains follow different and rich behaviours, with no counterpart in the optical density or in the population's colony forming units measurements. While the viscosity of strain COL keeps increasing during the exponential phase and returns close to its initial value for the late phase of growth, where the population stabilizes, the viscosity of the mutant strain decreases steeply, still in the exponential phase, remains constant for some time and increases again, reaching a constant plateau at a maximum value for the late phase of growth. These complex viscoelastic behaviours, which were observed to be shear stress dependent, are a consequence of two coupled effects: the cell density continuous increase and its changing interacting properties. The viscous and elastic moduli of strain COL, obtained with oscillatory shear, exhibit power-law behaviours whose exponent are dependent on the bacteria growth stage. The viscous and elastic moduli of the mutant have complex behaviours, emerging from the different relaxation times that are associated with the large molecules of the medium and the self-organized structures of bacteria. These behaviours reflect nevertheless the bacteria growth stage.

  13. Living bacteria rheology: Population growth, aggregation patterns, and collective behavior under different shear flows

    NASA Astrophysics Data System (ADS)

    Patrício, P.; Almeida, P. L.; Portela, R.; Sobral, R. G.; Grilo, I. R.; Cidade, T.; Leal, C. R.

    2014-08-01

    The activity of growing living bacteria was investigated using real-time and in situ rheology—in stationary and oscillatory shear. Two different strains of the human pathogen Staphylococcus aureus—strain COL and its isogenic cell wall autolysis mutant, RUSAL9—were considered in this work. For low bacteria density, strain COL forms small clusters, while the mutant, presenting deficient cell separation, forms irregular larger aggregates. In the early stages of growth, when subjected to a stationary shear, the viscosity of the cultures of both strains increases with the population of cells. As the bacteria reach the exponential phase of growth, the viscosity of the cultures of the two strains follows different and rich behaviors, with no counterpart in the optical density or in the population's colony-forming units measurements. While the viscosity of strain COL culture keeps increasing during the exponential phase and returns close to its initial value for the late phase of growth, where the population stabilizes, the viscosity of the mutant strain culture decreases steeply, still in the exponential phase, remains constant for some time, and increases again, reaching a constant plateau at a maximum value for the late phase of growth. These complex viscoelastic behaviors, which were observed to be shear-stress-dependent, are a consequence of two coupled effects: the cell density continuous increase and its changing interacting properties. The viscous and elastic moduli of strain COL culture, obtained with oscillatory shear, exhibit power-law behaviors whose exponents are dependent on the bacteria growth stage. The viscous and elastic moduli of the mutant culture have complex behaviors, emerging from the different relaxation times that are associated with the large molecules of the medium and the self-organized structures of bacteria. Nevertheless, these behaviors reflect the bacteria growth stage.

  14. Interaction Effects of Light, Temperature and Nutrient Limitations (N, P and Si) on Growth, Stoichiometry and Photosynthetic Parameters of the Cold-Water Diatom Chaetoceros wighamii

    PubMed Central

    Spilling, Kristian; Ylöstalo, Pasi; Simis, Stefan; Seppälä, Jukka

    2015-01-01

    Light (20-450 ?mol photons m-2 s-1), temperature (3-11°C) and inorganic nutrient composition (nutrient replete and N, P and Si limitation) were manipulated to study their combined influence on growth, stoichiometry (C:N:P:Chl a) and primary production of the cold water diatom Chaetoceros wighamii. During exponential growth, the maximum growth rate (~0.8 d-1) was observed at high temperture and light; at 3°C the growth rate was ~30% lower under similar light conditions. The interaction effect of light and temperature were clearly visible from growth and cellular stoichiometry. The average C:N:P molar ratio was 80:13:1 during exponential growth, but the range, due to different light acclimation, was widest at the lowest temperature, reaching very low C:P (~50) and N:P ratios (~8) at low light and temperature. The C:Chl a ratio had also a wider range at the lowest temperature during exponential growth, ranging 16-48 (weight ratio) at 3°C compared with 17-33 at 11°C. During exponential growth, there was no clear trend in the Chl a normalized, initial slope (?*) of the photosynthesis-irradiance (PE) curve, but the maximum photosynthetic production (Pm) was highest for cultures acclimated to the highest light and temperature. During the stationary growth phase, the stoichiometric relationship depended on the limiting nutrient, but with generally increasing C:N:P ratio. The average photosynthetic quotient (PQ) during exponential growth was 1.26 but decreased to <1 under nutrient and light limitation, probably due to photorespiration. The results clearly demonstrate that there are interaction effects between light, temperature and nutrient limitation, and the data suggests greater variability of key parameters at low temperature. Understanding these dynamics will be important for improving models of aquatic primary production and biogeochemical cycles in a warming climate. PMID:25993327

  15. Growth and nutrition effects on gilt development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The growth and development of gilts are a component of their lifetime potential for productivity. Growth and development affects not only their ability to reach puberty, they also likely affect their reproductive performance through later parities and their physical soundness as they age. Because of...

  16. Fe XIV Synoptic Observations as a Predictor for the Time of Solar Maximum in Cycle 24

    NASA Astrophysics Data System (ADS)

    Altrock, Ph D., R. C.

    2014-12-01

    In 2012 (Am. Geophys. Union Fall Meeting, Abstract SH12A-05) and 2013 (Solar Phys. Online First, DOI 10.1007/s11207-012-0216-1) Altrock discussed the status of Cycle 24 relative to synoptic observations of Fe XIV from Sacramento Peak (http://nsosp.nso.edu/corona). He found that using earlier cycles, in which solar maximum occurred when Fe XIV emission features associated with the classic "Rush to the Poles" reached latitudes 76° ± 2°, the northern hemisphere Fe XIV features predicted a maximum in the north at 2011.6 ± 0.3. This was confirmed by hemispheric sunspot numbers from SIDC (http://www.sidc.be/silso/) and sunspot areas from NASA MSFC (http://solarscience.msfc.nasa.gov/greenwch.shtml). The earlier papers also noted that southern high-latitude Fe XIV emission indicated the possibility of a southern maximum early in 2014. At low latitudes, earlier cycles reached solar maximum when Fe XIV emission features reached latitudes 20° ± 1.7°. In 2013, these features were at 21° and 15° in the north, again indicating that northern maximum had already occurred. In the south, the Fe XIV features were at 24°. Gopalswamy et al. (2012, Ap. J. Let. 750:L42) came to similar conclusions from a study of microwave brightness and prominence eruptions. This paper will extend the previous studies up to 2014 to include the recent extraordinary surge of activity in the southern hemisphere. In particular we will examine in more detail the relationship between hemispheric Fe XIV emission features and both global and hemispheric sunspot numbers to see (i) if the previous studies correctly predicted the times of hemispheric solar maxima and (ii) what we can learn from the inclusion of two more years of data. The observations used herein are the result of a cooperative program of the Air Force Research Laboratory and the National Solar Observatory.

  17. Fe XIV Synoptic Observations as a Predictor for the Time of Solar Maximum in Cycle 24

    NASA Astrophysics Data System (ADS)

    Altrock, Richard

    2015-04-01

    In 2012 (Am. Geophys. Union Fall Meeting, Abstract SH12A-05) and 2013 (Solar Phys. Online First, DOI 10.1007/s11207-012-0216-1) Altrock discussed the status of Cycle 24 relative to synoptic observations ofFe XIV from Sacramento Peak (http://nsosp.nso.edu/corona). He found that using earlier cycles, in which solar maximum occurred when Fe XIV emission features associated with the classic "Rush to the Poles" reached latitudes 76 ± 2 degrees, the *northern hemisphere* Fe XIV features predicted a maximum in the north at 2011.6 ± 0.3. This was confirmed by hemispheric sunspot numbers from SIDC (http://www.sidc.be/silso/) and sunspot areas from NASA MSFC http://solarscience.msfc.nasa.gov/greenwch.shtml). The earlier papersalso noted that southern high-latitude Fe XIV emission indicated the possibility of a southern maximum early in 2014. At low latitudes, earlier cycles reached solar maximum when Fe XIV emission features reached latitudes 20 ± 1.7 degrees. In 2013, these features were at 21 and 15 degrees in the north, again indicating that northern maximum had already occurred. In the south, the Fe XIV features were at 24 degrees. Gopalswamy et al. (2012, Ap. J. Let. 750:L42) come to similar conclusions from a study of microwave brightness and prominence eruptions. This paper will extend the previous studies up to 2014 to include the recent extraordinary surge of activity in the southern hemisphere. In particular we will examine in more detail the relationship between hemispheric Fe XIV emission features and both global and hemispheric sunspot numbers to see (i) if the previous studies correctly predicted the times of hemispheric solar maxima and (ii) what we can learn from the inclusion of two more years of data. The observations used herein are the result of a cooperative program of the Air Force Research Laboratory and the National Solar Observatory.

  18. Estimating Metabolic Fluxes Using a Maximum Network Flexibility Paradigm

    PubMed Central

    Megchelenbrink, Wout; Rossell, Sergio; Huynen, Martijn A.

    2015-01-01

    Motivation Genome-scale metabolic networks can be modeled in a constraint-based fashion. Reaction stoichiometry combined with flux capacity constraints determine the space of allowable reaction rates. This space is often large and a central challenge in metabolic modeling is finding the biologically most relevant flux distributions. A widely used method is flux balance analysis (FBA), which optimizes a biologically relevant objective such as growth or ATP production. Although FBA has proven to be highly useful for predicting growth and byproduct secretion, it cannot predict the intracellular fluxes under all environmental conditions. Therefore, alternative strategies have been developed to select flux distributions that are in agreement with experimental “omics” data, or by incorporating experimental flux measurements. The latter, unfortunately can only be applied to a limited set of reactions and is currently not feasible at the genome-scale. On the other hand, it has been observed that micro-organisms favor a suboptimal growth rate, possibly in exchange for a more “flexible” metabolic network. Instead of dedicating the internal network state to an optimal growth rate in one condition, a suboptimal growth rate is used, that allows for an easier switch to other nutrient sources. A small decrease in growth rate is exchanged for a relatively large gain in metabolic capability to adapt to changing environmental conditions. Results Here, we propose Maximum Metabolic Flexibility (MMF) a computational method that utilizes this observation to find the most probable intracellular flux distributions. By mapping measured flux data from central metabolism to the genome-scale models of Escherichia coli and Saccharomyces cerevisiae we show that i) indeed, most of the measured fluxes agree with a high adaptability of the network, ii) this result can be used to further reduce the space of feasible solutions iii) this reduced space improves the quantitative predictions made by FBA and contains a significantly larger fraction of the measured fluxes compared to the flux space that was reduced by a uniform sampling approach and iv) MMF can be used to select reactions in the network that contribute most to the steady-state flux space. Constraining the selected reactions improves the quantitative predictions of FBA considerably more than adding an equal amount of flux constraints, selected using a more naïve approach. Our method can be applied to any cell type without requiring prior information. Availability MMF is freely available as a MATLAB plugin at: http://cs.ru.nl/~wmegchel/mmf. PMID:26457579

  19. Vegetation controls on the maximum size of coastal dunes

    PubMed Central

    Durán, Orencio; Moore, Laura J.

    2013-01-01

    Coastal dunes, in particular foredunes, support a resilient ecosystem and reduce coastal vulnerability to storms. In contrast to dry desert dunes, coastal dunes arise from interactions between biological and physical processes. Ecologists have traditionally addressed coastal ecosystems by assuming that they adapt to preexisting dune topography, whereas geomorphologists have studied the properties of foredunes primarily in connection to physical, not biological, factors. Here, we study foredune development using an ecomorphodynamic model that resolves the coevolution of topography and vegetation in response to both physical and ecological factors. We find that foredune growth is eventually limited by a negative feedback between wind flow and topography. As a consequence, steady-state foredunes are scale invariant, which allows us to derive scaling relations for maximum foredune height and formation time. These relations suggest that plant zonation (in particular for strand “dune-building” species) is the primary factor controlling the maximum size of foredunes and therefore the amount of sand stored in a coastal dune system. We also find that aeolian sand supply to the dunes determines the timescale of foredune formation. These results offer a potential explanation for the empirical relation between beach type and foredune size, in which large (small) foredunes are found on dissipative (reflective) beaches. Higher waves associated with dissipative beaches increase the disturbance of strand species, which shifts foredune formation landward and thus leads to larger foredunes. In this scenario, plants play a much more active role in modifying their habitat and altering coastal vulnerability than previously thought. PMID:24101481

  20. Vegetation controls on the maximum size of coastal dunes.

    PubMed

    Durán, Orencio; Moore, Laura J

    2013-10-22

    Coastal dunes, in particular foredunes, support a resilient ecosystem and reduce coastal vulnerability to storms. In contrast to dry desert dunes, coastal dunes arise from interactions between biological and physical processes. Ecologists have traditionally addressed coastal ecosystems by assuming that they adapt to preexisting dune topography, whereas geomorphologists have studied the properties of foredunes primarily in connection to physical, not biological, factors. Here, we study foredune development using an ecomorphodynamic model that resolves the coevolution of topography and vegetation in response to both physical and ecological factors. We find that foredune growth is eventually limited by a negative feedback between wind flow and topography. As a consequence, steady-state foredunes are scale invariant, which allows us to derive scaling relations for maximum foredune height and formation time. These relations suggest that plant zonation (in particular for strand "dune-building" species) is the primary factor controlling the maximum size of foredunes and therefore the amount of sand stored in a coastal dune system. We also find that aeolian sand supply to the dunes determines the timescale of foredune formation. These results offer a potential explanation for the empirical relation between beach type and foredune size, in which large (small) foredunes are found on dissipative (reflective) beaches. Higher waves associated with dissipative beaches increase the disturbance of strand species, which shifts foredune formation landward and thus leads to larger foredunes. In this scenario, plants play a much more active role in modifying their habitat and altering coastal vulnerability than previously thought. PMID:24101481

  1. Population demographics of catostomids in large river ecosystems: effects of discharge and temperature on recruitment dynamics and growth

    USGS Publications Warehouse

    Quist, M.C.; Spiegel, J.R.

    2011-01-01

    Catostomids are among the most widespread and ecologically important groups of fishes in North America, particularly in large river systems. Despite their importance, little information is available on their population demographics and even less is known about factors influencing their population dynamics. The objectives of this study were to describe annual mortality, recruitment variation, and growth of eight catostomid species, and to evaluate the effects of discharge and temperature on year-class strength and growth in Iowa rivers. Catostomids were sampled from 3-km reaches in four nonwadable rivers during June–August 2009. Northern hogsucker, Hypentelium nigricans, golden redhorse, Moxostoma erythrurum, and shorthead redhorse, M. macrolepidotum, typically lived 6–8 years, had very stable recruitment, and had high total annual mortality (i.e., 40–60%). Golden redhorse exhibited the fastest growth of all species. Growth of northern hogsucker and shorthead redhorse was intermediate to the other catostomids. Highfin carpsucker, Carpiodes velifer, quillback, Carpiodes cyprinus, and white sucker, Catostomus commersonii, had high growth rates, low mortality (i.e., 25–30%), and relatively stable recruitment. River carpsucker, Carpiodes carpio, and silver redhorse, M. anisurum, had higher maximum ages (up to age 11), slower growth, lower total annual mortality (20–25%), and higher recruitment variability than the other species. Neither discharge nor temperature was strongly related to recruitment of catostomids. In contrast, several interesting patterns were observed with regard to growth. Species (e.g., carpsuckers, Carpiodes spp.) that typically consume prey items most common in fine substrates (e.g., chironomids) had higher growth rates in reaches dominated by sand and silt substrate. Species (e.g., northern hogsucker) that consume prey associated with large substrates (e.g., plecopterans) had much faster growth in reaches with a high proportion of rocky substrates. Temperature was weakly related to growth of catostomids; however, discharge explained a substantial amount of the variation in growth of nearly all species. Results of this study provide important information on the autecology of catostomids that can be used for comparison among species and systems. These data also suggest that connection of rivers with their floodplain is an important feature for catostomids in temperate river systems.

  2. Mouth Growths

    MedlinePLUS

    ... Multiple bony growths in the mouth may indicate familial adenomatous polyposis, a hereditary disorder of the digestive tract where ... in the colon that often become cancerous (see Familial Adenomatous Polyposis ). Keratoacanthomas (see Keratoacanthomas ) are growths that form on ...

  3. Reaching New Students through New Technologies: A Reader.

    ERIC Educational Resources Information Center

    Purdy, Leslie Noble, Ed.

    Designed to provide a broad picture of the state of instructional television for adults and to identify major issues relating to instructional telecourses, this reader presents 50 articles in seven categories relating to the production and distribution of telecourses. Section I presents six articles on the growth in the use of telecourses, which…

  4. Zipf's law, power laws and maximum entropy

    NASA Astrophysics Data System (ADS)

    Visser, Matt

    2013-04-01

    Zipf's law, and power laws in general, have attracted and continue to attract considerable attention in a wide variety of disciplines—from astronomy to demographics to software structure to economics to linguistics to zoology, and even warfare. A recent model of random group formation (RGF) attempts a general explanation of such phenomena based on Jaynes' notion of maximum entropy applied to a particular choice of cost function. In the present paper I argue that the specific cost function used in the RGF model is in fact unnecessarily complicated, and that power laws can be obtained in a much simpler way by applying maximum entropy ideas directly to the Shannon entropy subject only to a single constraint: that the average of the logarithm of the observable quantity is specified.

  5. A Maximum Radius for Habitable Planets

    NASA Astrophysics Data System (ADS)

    Alibert, Yann

    2015-09-01

    We compute the maximum radius a planet can have in order to fulfill two constraints that are likely necessary conditions for habitability: 1- surface temperature and pressure compatible with the existence of liquid water, and 2- no ice layer at the bottom of a putative global ocean, that would prevent the operation of the geologic carbon cycle to operate. We demonstrate that, above a given radius, these two constraints cannot be met: in the Super-Earth mass range (1-12 Mearth), the overall maximum that a planet can have varies between 1.8 and 2.3 Rearth. This radius is reduced when considering planets with higher Fe/Si ratios, and taking into account irradiation effects on the structure of the gas envelope.

  6. Maximum likelihood estimation of turbulence spectrum parameters

    NASA Technical Reports Server (NTRS)

    Mark, W. D.

    1984-01-01

    Estimation of the integral scale and intensity of a generic turbulence record is treated as a statistical problem of parameter estimation. Properties of parameter estimators and the method of maximum likelihood are reviewed. Likelihood equations are derived for estimation of the integral scale and intensity applicable to a general class of turbulence spectra that includes the von Karman and Dryden transverse and longitudinal spectra as special cases. The method is extended to include the Bullen transverse and longitudinal spectra. Coefficients of variation are given for maximum likelihood estimates of the integral scale and intensity of the von Karman spectra. Application of the method is illustrated by estimating the integral scale and intensity of an atmospheric turbulence vertical velocity record assumed to be governed by the von Karman transverse spectrum.

  7. MAXIMUM LIKELIHOOD ESTIMATION FOR SOCIAL NETWORK DYNAMICS

    PubMed Central

    Snijders, Tom A.B.; Koskinen, Johan; Schweinberger, Michael

    2014-01-01

    A model for network panel data is discussed, based on the assumption that the observed data are discrete observations of a continuous-time Markov process on the space of all directed graphs on a given node set, in which changes in tie variables are independent conditional on the current graph. The model for tie changes is parametric and designed for applications to social network analysis, where the network dynamics can be interpreted as being generated by choices made by the social actors represented by the nodes of the graph. An algorithm for calculating the Maximum Likelihood estimator is presented, based on data augmentation and stochastic approximation. An application to an evolving friendship network is given and a small simulation study is presented which suggests that for small data sets the Maximum Likelihood estimator is more efficient than the earlier proposed Method of Moments estimator. PMID:25419259

  8. A Maximum Radius for Habitable Planets.

    PubMed

    Alibert, Yann

    2015-09-01

    We compute the maximum radius a planet can have in order to fulfill two constraints that are likely necessary conditions for habitability: 1- surface temperature and pressure compatible with the existence of liquid water, and 2- no ice layer at the bottom of a putative global ocean, that would prevent the operation of the geologic carbon cycle to operate. We demonstrate that, above a given radius, these two constraints cannot be met: in the Super-Earth mass range (1-12 Mearth), the overall maximum that a planet can have varies between 1.8 and 2.3 Rearth. This radius is reduced when considering planets with higher Fe/Si ratios, and taking into account irradiation effects on the structure of the gas envelope. PMID:26159097

  9. Nonparametric Maximum Entropy Estimation on Information Diagrams

    E-print Network

    Martin, Elliot A; Meinke, Alexander; D?cht?renko, Filip; Davidsen, Jörn

    2016-01-01

    Maximum entropy estimation is of broad interest for inferring properties of systems across many different disciplines. In this work, we significantly extend a technique we previously introduced for estimating the maximum entropy of a set of random discrete variables when conditioning on bivariate mutual informations and univariate entropies. Specifically, we show how to apply the concept to continuous random variables and vastly expand the types of information-theoretic quantities one can condition on. This allows us to establish a number of significant advantages of our approach over existing ones. Not only does our method perform favorably in the undersampled regime, where existing methods fail, but it also can be dramatically less computationally expensive as the cardinality of the variables increases. In addition, we propose a nonparametric formulation of connected informations and give an illustrative example showing how this agrees with the existing parametric formulation in cases of interest. We furthe...

  10. Tissue Radiation Response with Maximum Tsallis Entropy

    SciTech Connect

    Sotolongo-Grau, O.; Rodriguez-Perez, D.; Antoranz, J. C.; Sotolongo-Costa, Oscar

    2010-10-08

    The expression of survival factors for radiation damaged cells is currently based on probabilistic assumptions and experimentally fitted for each tumor, radiation, and conditions. Here, we show how the simplest of these radiobiological models can be derived from the maximum entropy principle of the classical Boltzmann-Gibbs expression. We extend this derivation using the Tsallis entropy and a cutoff hypothesis, motivated by clinical observations. The obtained expression shows a remarkable agreement with the experimental data found in the literature.

  11. Gravity wave and elevated localized ozone maximum

    SciTech Connect

    Bian, X.; Berkowitz, C.M.; Zhong, S.S.

    1996-12-31

    During the 1992 field study of Northern Atlantic Regional Experiment, relatively localized O{sub 3} maximum were observed by aircraft flight along a horizontal sampling path between Nantucket and Halifax on several occasions. While sampling at a constant altitude between 1500 and 2000 m, the aircraft encountered a plume having O{sub 3} mixing ratio twice as much as the values that had been measured prior to entering the plume. Concurrent with this increase in O{sub 3} mixing ratio was a pronounced drop in the dew point. This feature occurred over a horizontal distance of approximately 200 km. Prior to descending to a lower elevation, a second O{sub 3} maximum/dew point minimum appeared to be encountered. Several hypotheses concerning the origin of this localized O{sub 3} maximum along a horizontal path are rejected, and the periodic nature of the phenomena suggests that they could be explained by propagating internal gravity wave at the top of the boundary layer. Observational support of this hypothesis are soundings from surrounding stations that had temperature profiles resemble those that are typical for gravity wave occurrence. A simple numerical model is used to simulate the variations of ozone concentration, temperature, and dew point caused by perturbation horizontal and vertical wind fields associated with traveling internal gravity waves and to illustrate how the localized O{sub 3} maximum are formed from downward displacement of air parcels from the free troposphere by these waves. The observed ozone oscillation corresponds reasonable well in amplitude and phase with the simple model prediction.

  12. Maximum entropy analysis of cosmic ray composition

    E-print Network

    Nosek, Dalibor; Vícha, Jakub; Trávní?ek, Petr; Nosková, Jana

    2016-01-01

    We focus on the primary composition of cosmic rays with the highest energies that cause extensive air showers in the Earth's atmosphere. A way of examining the two lowest order moments of the sample distribution of the depth of shower maximum is presented. The aim is to show that useful information about the composition of the primary beam can be inferred with limited knowledge we have about processes underlying these observations. In order to describe how the moments of the depth of shower maximum depend on the type of primary particles and their energies, we utilize a superposition model. Using the principle of maximum entropy, we are able to determine what trends in the primary composition are consistent with the input data, while relying on a limited amount of information from shower physics. Some capabilities and limitations of the proposed method are discussed. In order to achieve a realistic description of the primary mass composition, we pay special attention to the choice of the parameters of the sup...

  13. The maximum rate of mammal evolution.

    PubMed

    Evans, Alistair R; Jones, David; Boyer, Alison G; Brown, James H; Costa, Daniel P; Ernest, S K Morgan; Fitzgerald, Erich M G; Fortelius, Mikael; Gittleman, John L; Hamilton, Marcus J; Harding, Larisa E; Lintulaakso, Kari; Lyons, S Kathleen; Okie, Jordan G; Saarinen, Juha J; Sibly, Richard M; Smith, Felisa A; Stephens, Patrick R; Theodor, Jessica M; Uhen, Mark D

    2012-03-13

    How fast can a mammal evolve from the size of a mouse to the size of an elephant? Achieving such a large transformation calls for major biological reorganization. Thus, the speed at which this occurs has important implications for extensive faunal changes, including adaptive radiations and recovery from mass extinctions. To quantify the pace of large-scale evolution we developed a metric, clade maximum rate, which represents the maximum evolutionary rate of a trait within a clade. We applied this metric to body mass evolution in mammals over the last 70 million years, during which multiple large evolutionary transitions occurred in oceans and on continents and islands. Our computations suggest that it took a minimum of 1.6, 5.1, and 10 million generations for terrestrial mammal mass to increase 100-, and 1,000-, and 5,000-fold, respectively. Values for whales were down to half the length (i.e., 1.1, 3, and 5 million generations), perhaps due to the reduced mechanical constraints of living in an aquatic environment. When differences in generation time are considered, we find an exponential increase in maximum mammal body mass during the 35 million years following the Cretaceous-Paleogene (K-Pg) extinction event. Our results also indicate a basic asymmetry in macroevolution: very large decreases (such as extreme insular dwarfism) can happen at more than 10 times the rate of increases. Our findings allow more rigorous comparisons of microevolutionary and macroevolutionary patterns and processes. PMID:22308461

  14. Disappointment Reach, Australia as seen from STS-67 Endeavour

    NASA Technical Reports Server (NTRS)

    1995-01-01

    A nearly vertical view of Disappointment Reach and surroundings. Ripple-like patterns extending at right angles to the tidal flow can be discerned on shoals. Relict sand dune patterns, crests unvegetated, are evident on the western side of the estuary. Red mud brought down the Mooramel River on the east side of the estuary does extend into the shallow water of the inter-tidal lagoons. Most of the light-colored water along the coast, represents shoals of lime sediment. Patterns of sediment distribution by tides, waves, streams, and wind combine to create a complex and colorful scene.

  15. [Kinematic study of reaching-grasping movements in the monkey].

    PubMed

    Fogassi, L; Gallese, V; Gentilucci, M; Chieffi, S; Rizzolatti, G

    1991-07-01

    Kinematics of reaching-grasping movement towards stimuli of three different sizes located at two different distances were studied in one monkey (Macaca nemestrina). Transport and manipulation components were analyzed using the ELITE system. Transport time, peak velocity and deceleration phase of velocity were influenced by stimulus size, whilst acceleration phase remained unmodified. Peak velocity clearly increased with distance, while transport time remained constant (isochrony ). The main parameters of manipulation component were all influenced by stimulus size but they did not vary with distance. A comparison with kinematic data obtained from human subjects was made. PMID:1818597

  16. East Ohio gas 'bridges' service to reach new customers

    SciTech Connect

    Not Available

    1982-12-01

    A lift bridge across the Cuyahoga River at the eastern end of Whiskey Island provided the most feasible route to five new industrial customers for East Ohio Gas Co. in Cleveland. Previously considered ''unpipeable'', the island was reached by building a line along the stationary bridgework 125 ft above the bridge. The 6-in pipe is protected by a heat-fused epoxy coating; welded joints were covered in the field with heat-shrink sleeves. The line is fully electrically insulated and protected from lightning.

  17. Defining a controller architecture for the Long-Reach Manipulator

    SciTech Connect

    Ford, W.E.

    1994-06-01

    To draft a procurement specification for the Long-Reach Manipulator (LRM), the benefits and limitations of the various robotic control system architectures available need to be determined. This report identifies and describes the advantages and potential disadvantages of using an open control system versus a closed (or proprietary) system, focusing on integration of interfaces for sensors, end effectors, tooling, and operator interfaces. In addition, the various controls methodologies of several recent systems are described. Finally, the reasons behind the recommendation to procure an open control system are discussed.

  18. Reaching More for Less: Modernizing US International Food Aid Programs 

    E-print Network

    Natsios, Andrew

    2015-01-01

    stream_source_info V6-1 Food Aid Reform Takeaway.pdf.txt stream_content_type text/plain stream_size 11892 Content-Encoding UTF-8 stream_name V6-1 Food Aid Reform Takeaway.pdf.txt Content-Type text/plain; charset=UTF-8... Reaching More for Less: Modernizing US International Food Aid Programs ANDREW NATSIOS Director, Scowcroft Institute of International Affairs VOLUME 6 | ISSUE 1 | 2015 The Food for Peace program has saved millions of lives around the world...

  19. Factors affecting the age-C resident fish community along shorelines of the Hanford Reach of the Columbia River

    USGS Publications Warehouse

    Gadomski, D.M.; Wagner, P.G.

    2009-01-01

    The Hanford Reach is one of the few remaining unimpounded sections of the Columbia River. However, because of flow management at upstream dams, there are often large fluctuations in water level. To determine how environmental conditions might affect age-0 resident fishes in the Hanford Reach, we evaluated species composition, distribution, abundance, and standard lengths of larval and juvenile fishes along shoreline habitats during July and August 1998, 1999, and 2000. Catches in beach seine hauls during all three years were highly variable. The four most abundant taxa collected were three cyprinids, peamouth (Mylocheilus caurinus), northern pikeminnow (Plychocheilus oregonensis), and redside shiner (Richardson ius balteatus); and suckers (Catostoinus spp.). Highest overall catches were in sloughs of the Hanford Reach in 1999, a year with high flows, lower water level fluctuations, and more vegetation. Mean shoreline summer water temperatures were higher in 1998 than in 1999 and 2000, and mean lengths of the four most abundant taxa in late August were also greater in 1998, due presumably to enhanced growth or an earlier spawning season. In spite of flow fluctuations, overall catches of age-0 resident fishes were greater in the riverine Hanford Reach compared to past catches in a more lentic Columbia River reservoir. High abundances of age-0 resident fishes in the Hanford Reach could be due to more spawning and rearing habitat in this structurally complex area, and may mitigate for negative effects of variable flow regimes.

  20. Delayed growth

    MedlinePLUS

    Growth - slow (child 0 - 5 years); Weight gain - slow (child 0 - 5 years); Slow rate of growth; Retarded growth and development; ... A child should have regular, well-baby check-ups with a health care provider. These checkups are usually scheduled ...

  1. Early maximum extent of paleoglaciers from Mediterranean mountains during the last glaciation.

    PubMed

    Domínguez-Villar, D; Carrasco, R M; Pedraza, J; Cheng, H; Edwards, R L; Willenbring, J K

    2013-01-01

    Mountain glaciers respond directly to changes in precipitation and temperature, thus their margin extent is a high-sensitivity climate proxy. Here, we present a robust (10)Be chronology for the glacier maximum areal extent of central Spain paleoglaciers dated at 26.1 ± 1.3?ka BP. These glaciers reached their maximum extent several thousand years earlier than those from central Europe due to the increased precipitation within a cold period between 25 to 29?ka BP, as confirmed by a local speleothem record. These paleoclimate conditions impacted the maximum extent of mountain glaciers along the western and central Mediterranean region. The cause and timing of the enhanced precipitation implies a southward shift of the North Atlantic Polar Front followed by storm tracks in response to changes in insolation via orbital parameters modulation. Thus, these mountain paleoglaciers from the Mediterranean region record an ocean-continent climate interaction triggered by external forcing. PMID:23783658

  2. Early maximum extent of paleoglaciers from Mediterranean mountains during the last glaciation

    PubMed Central

    Domínguez-Villar, D.; Carrasco, R. M.; Pedraza, J.; Cheng, H.; Edwards, R. L.; Willenbring, J. K.

    2013-01-01

    Mountain glaciers respond directly to changes in precipitation and temperature, thus their margin extent is a high-sensitivity climate proxy. Here, we present a robust 10Be chronology for the glacier maximum areal extent of central Spain paleoglaciers dated at 26.1 ± 1.3?ka BP. These glaciers reached their maximum extent several thousand years earlier than those from central Europe due to the increased precipitation within a cold period between 25 to 29?ka BP, as confirmed by a local speleothem record. These paleoclimate conditions impacted the maximum extent of mountain glaciers along the western and central Mediterranean region. The cause and timing of the enhanced precipitation implies a southward shift of the North Atlantic Polar Front followed by storm tracks in response to changes in insolation via orbital parameters modulation. Thus, these mountain paleoglaciers from the Mediterranean region record an ocean-continent climate interaction triggered by external forcing. PMID:23783658

  3. 30 CFR 56.19062 - Maximum acceleration and deceleration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 2013-07-01 false Maximum acceleration and deceleration. 56.19062 Section...Procedures § 56.19062 Maximum acceleration and deceleration. Maximum normal operating acceleration and deceleration shall not exceed...

  4. 30 CFR 56.19062 - Maximum acceleration and deceleration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 2014-07-01 false Maximum acceleration and deceleration. 56.19062 Section...Procedures § 56.19062 Maximum acceleration and deceleration. Maximum normal operating acceleration and deceleration shall not exceed...

  5. 30 CFR 56.19062 - Maximum acceleration and deceleration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 2010-07-01 false Maximum acceleration and deceleration. 56.19062 Section...Procedures § 56.19062 Maximum acceleration and deceleration. Maximum normal operating acceleration and deceleration shall not exceed...

  6. 30 CFR 56.19062 - Maximum acceleration and deceleration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 2011-07-01 false Maximum acceleration and deceleration. 56.19062 Section...Procedures § 56.19062 Maximum acceleration and deceleration. Maximum normal operating acceleration and deceleration shall not exceed...

  7. 30 CFR 57.19062 - Maximum acceleration and deceleration.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 2014-07-01 false Maximum acceleration and deceleration. 57.19062 Section...Procedures § 57.19062 Maximum acceleration and deceleration. Maximum normal operating acceleration and deceleration shall not exceed...

  8. 30 CFR 57.19062 - Maximum acceleration and deceleration.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 2011-07-01 false Maximum acceleration and deceleration. 57.19062 Section...Procedures § 57.19062 Maximum acceleration and deceleration. Maximum normal operating acceleration and deceleration shall not exceed...

  9. 30 CFR 56.19062 - Maximum acceleration and deceleration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 2012-07-01 false Maximum acceleration and deceleration. 56.19062 Section...Procedures § 56.19062 Maximum acceleration and deceleration. Maximum normal operating acceleration and deceleration shall not exceed...

  10. 30 CFR 57.19062 - Maximum acceleration and deceleration.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 2012-07-01 false Maximum acceleration and deceleration. 57.19062 Section...Procedures § 57.19062 Maximum acceleration and deceleration. Maximum normal operating acceleration and deceleration shall not exceed...

  11. 30 CFR 57.19062 - Maximum acceleration and deceleration.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 2010-07-01 false Maximum acceleration and deceleration. 57.19062 Section...Procedures § 57.19062 Maximum acceleration and deceleration. Maximum normal operating acceleration and deceleration shall not exceed...

  12. 30 CFR 57.19062 - Maximum acceleration and deceleration.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 2013-07-01 false Maximum acceleration and deceleration. 57.19062 Section...Procedures § 57.19062 Maximum acceleration and deceleration. Maximum normal operating acceleration and deceleration shall not exceed...

  13. 24 CFR 886.308 - Maximum total annual contract commitment.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...false Maximum total annual contract commitment. 886.308 Section 886.308 ...308 Maximum total annual contract commitment. (a) Number of units assisted...by which the maximum annual contract commitment per year exceeds amounts paid...

  14. 40 CFR 141.13 - Maximum contaminant levels for turbidity.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...PRIMARY DRINKING WATER REGULATIONS Maximum Contaminant Levels § 141.13 ...maximum contaminant levels for turbidity...both community water systems and non-community...maximum contaminant levels for turbidity in drinking water, measured...

  15. 40 CFR 141.13 - Maximum contaminant levels for turbidity.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...PRIMARY DRINKING WATER REGULATIONS Maximum Contaminant Levels § 141.13 ...maximum contaminant levels for turbidity...both community water systems and non-community...maximum contaminant levels for turbidity in drinking water, measured...

  16. 40 CFR 141.13 - Maximum contaminant levels for turbidity.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...PRIMARY DRINKING WATER REGULATIONS Maximum Contaminant Levels § 141.13 ...maximum contaminant levels for turbidity...both community water systems and non-community...maximum contaminant levels for turbidity in drinking water, measured...

  17. 40 CFR 141.13 - Maximum contaminant levels for turbidity.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...PRIMARY DRINKING WATER REGULATIONS Maximum Contaminant Levels § 141.13 ...maximum contaminant levels for turbidity...both community water systems and non-community...maximum contaminant levels for turbidity in drinking water, measured...

  18. 16 CFR 1505.7 - Maximum acceptable surface temperatures.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... false Maximum acceptable surface temperatures. 1505.7 Section 1505.7 Commercial...1505.7 Maximum acceptable surface temperatures. The maximum acceptable surface temperatures for electrically operated toys...

  19. 16 CFR 1505.7 - Maximum acceptable surface temperatures.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... false Maximum acceptable surface temperatures. 1505.7 Section 1505.7 Commercial...1505.7 Maximum acceptable surface temperatures. The maximum acceptable surface temperatures for electrically operated toys...

  20. 16 CFR 1505.8 - Maximum acceptable material temperatures.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... false Maximum acceptable material temperatures. 1505.8 Section 1505.8 Commercial...1505.8 Maximum acceptable material temperatures. The maximum acceptable material temperatures for electrically operated toys shall...

  1. 16 CFR 1505.7 - Maximum acceptable surface temperatures.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... false Maximum acceptable surface temperatures. 1505.7 Section 1505.7 Commercial...1505.7 Maximum acceptable surface temperatures. The maximum acceptable surface temperatures for electrically operated toys...

  2. 16 CFR 1505.8 - Maximum acceptable material temperatures.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... false Maximum acceptable material temperatures. 1505.8 Section 1505.8 Commercial...1505.8 Maximum acceptable material temperatures. The maximum acceptable material temperatures for electrically operated toys shall...

  3. 16 CFR 1505.8 - Maximum acceptable material temperatures.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... false Maximum acceptable material temperatures. 1505.8 Section 1505.8 Commercial...1505.8 Maximum acceptable material temperatures. The maximum acceptable material temperatures for electrically operated toys shall...

  4. 16 CFR 1505.8 - Maximum acceptable material temperatures.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... false Maximum acceptable material temperatures. 1505.8 Section 1505.8 Commercial...1505.8 Maximum acceptable material temperatures. The maximum acceptable material temperatures for electrically operated toys shall...

  5. 16 CFR 1505.7 - Maximum acceptable surface temperatures.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... false Maximum acceptable surface temperatures. 1505.7 Section 1505.7 Commercial...1505.7 Maximum acceptable surface temperatures. The maximum acceptable surface temperatures for electrically operated toys...

  6. 16 CFR 1505.8 - Maximum acceptable material temperatures.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... false Maximum acceptable material temperatures. 1505.8 Section 1505.8 Commercial...1505.8 Maximum acceptable material temperatures. The maximum acceptable material temperatures for electrically operated toys shall...

  7. 16 CFR 1505.7 - Maximum acceptable surface temperatures.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... false Maximum acceptable surface temperatures. 1505.7 Section 1505.7 Commercial...1505.7 Maximum acceptable surface temperatures. The maximum acceptable surface temperatures for electrically operated toys...

  8. 40 CFR 141.13 - Maximum contaminant levels for turbidity.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Maximum contaminant levels for turbidity. 141.13 Section...PRIMARY DRINKING WATER REGULATIONS Maximum Contaminant Levels § 141.13 Maximum contaminant levels for turbidity. The...

  9. Occurrence of soluble salts and moisture in the unsaturated zone and groundwater hydrochemistry along the middle and lower reaches of the Heihe River in northwest China

    NASA Astrophysics Data System (ADS)

    Zhou, Xun; Fang, Bin; Wan, Li; Cao, Wenbing; Wu, Shengjun; Feng, Weidong

    2006-08-01

    Deforestation, over-development of water resources and population growth have contributed to degeneration of vegetation in the Heihe River Basin in northwest China. Salts and water contents are the most important factors affecting the growth of vegetation in this arid area. This study was conducted to determine soluble salt levels of soils in the unsaturated zone and the hydrochemistry of groundwater at 14 sites in this region. Concentrations of soluble ions in the soils deceased with depth. Soil ion contents increased at depths below the root system of native plants. Sulfate was the dominant anion in both the unsaturated zone and the groundwater. Total dissolved solids (TDS) in groundwater ranged from less than 1 g/L in the middle reaches of the watershed to about 10 g/L in the arid lower reaches. In the middle and upper reaches of the watershed, salinity in soil and groundwater decreased. Groundwater was highly variable in hydrochemistry. The lower reaches was predominated by SO4-Na•Mg and SO4-Mg•Na type water, whereas in the middle reaches groundwater is characterized by lower TDS and HCO3-dominated type water. Evapotranspiration is responsible for occurrence of the soluble salts in the soil profiles. Dissolution is the dominant chemical process in the middle reaches, whereas evapotranspiration prevails in the lower reaches of the Heihe River.

  10. Google Hangouts: Leveraging Social Media to Reach the Education Community

    NASA Astrophysics Data System (ADS)

    Eisenhamer, Bonnie; Summers, Frank; McCallister, Dan; Ryer, Holly

    2015-01-01

    Research shows that educator professional development is most effective when it is sustained and/or when a follow-on component is included to support the learning process. In order to create more comprehensive learning experiences for our workshop participants, the education team at the Space Telescope Science Institute is working collaboratively with scientific staff and other experts to create a follow-on component for our professional development program. The new component utilizes video conferencing platforms, such as Google's Hangouts On Air, to provide educators with content updates and extended learning opportunities in between in-person professional development experiences. The goal is to enhance our professional development program in a cost-effective way while reaching a greater cross-section of educators. Video broadcasts go live on Google+, YouTube, and our website - thus providing access to any user with a web browser. Additionally, the broadcasts are automatically recorded and archived for future viewing on our YouTube channel. This provides educators with anywhere, anytime training that best suits their needs and schedules. This poster will highlight our new Hangouts for educators as well as our cross-departmental efforts to expand the reach of our Hubble Hangouts for the public through a targeted recruitment strategy.

  11. Ricin A chain reaches the endoplasmic reticulum after endocytosis

    SciTech Connect

    Liu Qiong; Zhan Jinbiao . E-mail: jzhan2k@zju.edu.cn; Chen Xinhong; Zheng Shu

    2006-05-12

    Ricin is a potent ribosome inactivating protein and now has been widely used for synthesis of immunotoxins. To target ribosome in the mammalian cytosol, ricin must firstly retrograde transport from the endomembrane system to reach the endoplasmic reticulum (ER) where the ricin A chain (RTA) is recognized by ER components that facilitate its membrane translocation to the cytosol. In the study, the fusion gene of enhanced green fluorescent protein (EGFP)-RTA was expressed with the pET-28a (+) system in Escherichia coli under the control of a T7 promoter. The fusion protein showed a green fluorescence. The recombinant protein can be purified by metal chelated affinity chromatography on a column of NTA. The rabbit anti-GFP antibody can recognize the fusion protein of EGFP-RTA just like the EGFP protein. The cytotoxicity of EGFP-RTA and RTA was evaluated by the MTT assay in HeLa and HEP-G2 cells following fluid-phase endocytosis. The fusion protein had a similar cytotoxicity of RTA. After endocytosis, the subcellular location of the fusion protein can be observed with the laser scanning confocal microscopy and the immuno-gold labeling Electro Microscopy. This study provided important evidence by a visualized way to prove that RTA does reach the endoplasmic reticulum.

  12. Reaching the hip-hop generation: Final (symposium proceedings) report

    SciTech Connect

    Not Available

    1993-05-01

    The goal of this final (closing) report is to capture the flavor of the symposium held March 1 and 2, 1993 in New York City convened by Motivational Educational Entertainment, Inc. (MEE), a black-owned communications research, consulting, and video production company based in Philadelphia, Pennsylvania. The mission of MEE is to understand, reach, and positively affect inner-city youth. Traditional communication approaches from mainstream sources to at-risk youth often don`t account for the unique way youth communicate among themselves and how they relate to the media. This understanding, however, is crucial. To understand youth communication, the people who create and send both entertaining and educational messages to urban youth must be brought into the dialogue. The meeting in New York was intended to provide an important opportunity for senders to meet and evaluate the appropriateness and effectiveness of their messages. In addition, the MEE symposium provided a forum for the continuing public debate about what needs to be done to reach today`s urban teens. Included in this document is a description of symposium goals/objectives, symposium activities, the reaction to and analysis of the symposium, recommendations for future MEE courses of action, and an appendix containing copies of press articles.

  13. An Exploration of the Potential Reach of Smartphones in Diabetes

    PubMed Central

    Blondon, Katherine S; Hebert, Paul L; Ralston, James D

    2014-01-01

    Although smartphones bear potential to improve diabetes self-management, the reach of smartphones in diabetic populations remains uncertain. Using survey data from the Pew Research Center, we compared smartphone use in individuals with and without diabetes, and determined factors associated with smartphone use among those with diabetes. Of the 2989 adults surveyed, 1360 were smartphone users, and 332 individuals had diabetes. Compared to individuals without diabetes, adults with diabetes were less likely to be smartphone users (relative risk of 0.43, 95% CI 0.31 to 0.54) even after adjusting for age, race, ethnicity and socioeconomic status (adjusted RR of 0.78, 95%CI 0.57–0.98). Among individuals with diabetes, high income, younger age and online health information seeking were associated with higher smartphone use. While smartphones can reach subgroups for diabetes care and prevention (racial/ethnic minorities, newly diagnosed individuals), studies are needed to understand this current difference in smartphone use. PMID:25954331

  14. Livestock First Reached Southern Africa in Two Separate Events

    PubMed Central

    Sadr, Karim

    2015-01-01

    After several decades of research on the subject, we now know when the first livestock reached southern Africa but the question of how they got there remains a contentious topic. Debate centres on whether they were brought with a large migration of Khoe-speakers who originated from East Africa; or whether the livestock were traded down-the-line among hunter-gatherer communities; or indeed whether there was a long history of diverse small scale population movements in this part of the world, one or more of which ‘infiltrated’ livestock into southern Africa. A new analysis of the distribution of stone toolkits from a sizeable sample of sub-equatorial African Later Stone Age sites, coupled with existing knowledge of the distribution of the earliest livestock remains and ceramics vessels, has allowed us to isolate two separate infiltration events that brought the first livestock into southern Africa just over 2000 years ago; one infiltration was along the Atlantic seaboard and another entered the middle reaches of the Limpopo River Basin. These findings agree well with the latest results of genetic research which together indicate that multiple, small-scale infiltrations probably were responsible for bringing the first livestock into southern Africa. PMID:26295347

  15. Optically trapped mirror for reaching the standard quantum limit.

    PubMed

    Matsumoto, Nobuyuki; Michimura, Yuta; Aso, Yoichi; Tsubono, Kimio

    2014-06-01

    The preparation of a mechanical oscillator driven by quantum back-action is a fundamental requirement to reach the standard quantum limit (SQL) for force measurement, in optomechanical systems. However, thermal fluctuating force generally dominates a disturbance on the oscillator. In the macroscopic scale, an optical linear cavity including a suspended mirror has been used for the weak force measurement, such as gravitational-wave detectors. This configuration has the advantages of reducing the dissipation of the pendulum (i.e., suspension thermal noise) due to a gravitational dilution by using a thin wire, and of increasing the circulating laser power. However, the use of the thin wire is weak for an optical torsional anti-spring effect in the cavity, due to the low mechanical restoring force of the wire. Thus, there is the trade-off between the stability of the system and the sensitivity. Here, we describe using a triangular optical cavity to overcome this limitation for reaching the SQL. The triangular cavity can provide a sensitive and stable system, because it can optically trap the mirror's motion of the yaw, through an optical positive torsional spring effect. To show this, we demonstrate a measurement of the torsional spring effect caused by radiation pressure forces. PMID:24921489

  16. Livestock First Reached Southern Africa in Two Separate Events.

    PubMed

    Sadr, Karim

    2015-01-01

    After several decades of research on the subject, we now know when the first livestock reached southern Africa but the question of how they got there remains a contentious topic. Debate centres on whether they were brought with a large migration of Khoe-speakers who originated from East Africa; or whether the livestock were traded down-the-line among hunter-gatherer communities; or indeed whether there was a long history of diverse small scale population movements in this part of the world, one or more of which 'infiltrated' livestock into southern Africa. A new analysis of the distribution of stone toolkits from a sizeable sample of sub-equatorial African Later Stone Age sites, coupled with existing knowledge of the distribution of the earliest livestock remains and ceramics vessels, has allowed us to isolate two separate infiltration events that brought the first livestock into southern Africa just over 2000 years ago; one infiltration was along the Atlantic seaboard and another entered the middle reaches of the Limpopo River Basin. These findings agree well with the latest results of genetic research which together indicate that multiple, small-scale infiltrations probably were responsible for bringing the first livestock into southern Africa. PMID:26295347

  17. Tactile gating in a reaching and grasping task

    PubMed Central

    Colino, Francisco L.; Buckingham, Gavin; Cheng, Darian T.; van Donkelaar, Paul; Binsted, Gordon

    2014-01-01

    Abstract A multitude of events bombard our sensory systems at every moment of our lives. Thus, it is important for the sensory cortex to gate unimportant events. Tactile suppression is a well?known phenomenon defined as a reduced ability to detect tactile events on the skin before and during movement. Previous experiments found detection rates decrease just prior to and during finger abduction, and decrease according to the proximity of the moving effector. This study examined how tactile detection changes during a reach to grasp. Fourteen human participants used their right hand to reach and grasp a cylinder. Tactors were attached to the index finger, the fifth digit, and the forearm of both the right and left arm and vibrated at various epochs relative to a “go” tone. Results showed that detection rates at the forearm decreased before movement onset; whereas at the right index finger, right fifth digit and at the left index finger, left fifth digit, and forearm sites did not decrease like in the right forearm. These results indicate that the task affects gating dynamics in a temporally? and contextually dependent manner and implies that feed?forward motor planning processes can modify sensory signals. PMID:24760521

  18. Transient Storage Parameterization of Wetland-dominated Stream Reaches

    NASA Astrophysics Data System (ADS)

    Wilderotter, S. M.; Lightbody, A.; Kalnejais, L. H.; Wollheim, W. M.

    2014-12-01

    Current understanding of the importance of transient storage in fluvial wetlands is limited. Wetlands that have higher connectivity to the main stream channel are important because they have the potential to retain more nitrogen within the river system than wetlands that receive little direct stream discharge. In this study, we investigated how stream water accesses adjacent fluvial wetlands in New England coastal watersheds to improve parameterization in network-scale models. Break through curves of Rhodamine WT were collected for eight wetlands in the Ipswich and Parker (MA) and Lamprey River (NH) watersheds, USA. The curves were inverse modeled using STAMMT-L to optimize the connectivity and size parameters for each reach. Two approaches were tested, a single dominant storage zone and a range of storage zones represented using a power-law distribution of storage zone connectivity. Multiple linear regression analyses were conducted to relate transient storage parameters to stream discharge, area, length-to-width ratio, and reach slope. Resulting regressions will enable more accurate parameterization of surface water transient storage in network-scale models.

  19. Response of hydrological processes to climate change in the middle reaches of the Yellow River, China

    NASA Astrophysics Data System (ADS)

    Yao, X.; Cui, X.; Yu, J.; Sun, W.

    2015-05-01

    According to the IPCC Fourth Assessment, the temperature and evapotranspiration will increase in the future. As a sensitive region to climate change, hydrological process in the middle reaches of the Yellow River will be significantly affected by climate change. In this study, water resources change in the future for a typical basin there: Lushi basin is assessed using the Soil and Water Assessment Tool (SWAT) hydrological model. Downscaled ensemble output from sixteen General Circulation Models (GCMs) for the A1B emission scenario in the 2050s was input to SWAT as the regional climate change scenario. The prediction shows that ET of this basin increases in winter and spring, and decreases in summer and autumn, and the streamflow increases throughout the year. The increased streamflow will probably improve the water demand guarantee and be conducive to crop growth in winter and spring, and may improve the flood risk in summer.

  20. 40 CFR 141.65 - Maximum residual disinfectant levels.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS National Primary Drinking Water Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels §...

  1. 40 CFR 141.65 - Maximum residual disinfectant levels.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS National Primary Drinking Water Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels §...

  2. 40 CFR 141.65 - Maximum residual disinfectant levels.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS National Primary Drinking Water Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels §...

  3. 40 CFR 141.65 - Maximum residual disinfectant levels.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS National Primary Drinking Water Regulations: Maximum Contaminant Levels and Maximum Residual Disinfectant Levels §...

  4. Growth outcome: nutritionist perspective.

    PubMed

    Agostoni, Carlo; Fattore, Giovanni

    2013-01-01

    Increasing evidence points to a fundamental role of early nutrition on rates of growth and development, and later health. We may identify three major fields of scientific interest and clinical application. (1) In developing countries poor growth is associated with greater risk of morbidity and mortality from infectious diseases, mainly lower respiratory infections and diarrhea. In these settings, failure to promote compensatory growth may have negative short-term consequences, and the nutritionist's task is the primary prevention of nutrient deficiencies to promote the full expression of the individual genetic potential, while allowing for recovery of early secondary functional deficiencies. (2) A second challenge for nutritionists is represented by the approach to growth impairments in rare disorders, ranging from congenital disorders to chronic infections. Most disorders are favorably influenced by improved nutritional status and better growth, and patients may satisfactorily reach adolescence, pubertal and reproductive age, up to ageing. Even for the less positive conditions, an improvement in the quality of life for families is in any case a rewarding aim. (3) A third challenge is represented by the definition of the role of nutrition on growth in physiological conditions for all individuals. Concern has been raised about the potential adverse long-term consequences of accelerated child growth rates, possibly resulting in a predisposition to develop non-communicable chronic diseases in the adult age. Accordingly, this hypothesis might explain the benefits of breastfeeding in terms of slower early growth, and the fetal origins hypothesis in terms of adverse postnatal catch-up growth in infants born small. Therefore, growth as viewed by a pediatric nutritionist perspective is a complex matter, ranging from the early stages of intrauterine development up to adult ages and ageing processes. Cost/benefit analyses of interventions on growth such as cost per DALYs (disability-adjusted life years) or QALYs (quality-adjusted life years) should be expanded on population basis and extended also to congenital and invalidating disorders to identify the most effective and economic sustainable strategies of action. PMID:23428675

  5. Effect of spatial target reaching training based on visual biofeedback on the upper extremity function of hemiplegic stroke patients

    PubMed Central

    Kim, Chang-Yong; Lee, Jung-Sun; Lee, Jong-Hun; Kim, Yang-Gu; Shin, A-Reum; Shim, Young-Hun; Ha, Hyun Kun

    2015-01-01

    [Purpose] The aim of this study was to determine the effect of spatial target reaching training (TRT) based on visual biofeedback (VB) on the upper extremity (UE) function of hemiplegic subjects. [Subjects and Methods] Forty subjects between six and eighteen months post-stroke were enrolled in this study. They were randomly allocated to an experimental group (EG, n=20) and a control group (CG, n=20). All subjects received an hour of routine therapy for stroke three times a week for four weeks. Subjects in EG received additional spatial TRT based on VB using a 2-dimensional motion capture analysis system. Both groups were tested at pre and post-intervention. The motor function of each subject’s UE was assessed using the Fugl-Meyer (FM) test of UE and the Wolf Motor Function Test (WMFT). The reaching speed, angle and maximum reach distance were recorded using the motion capture analysis system. The experimental data were analyzed using the paired and independent t-tests. [Results] The mean change scores of the FM Test of UE and WMFT show there was significantly more improvement at post-intervention in EG than in CG. Also, the speed and angle reached showed significantly more increase in the EG compared with the CG. [Conclusions] The findings indicate that UE motor recovery of hemiplegic stroke patients can be enhanced through the use of TRT based on VB. PMID:25995564

  6. Age and Growth of the Round Stingray Urotrygon rogersi, a Particularly Fast-Growing and Short-Lived Elasmobranch

    PubMed Central

    Mejía-Falla, Paola A.; Cortés, Enric; Navia, Andrés F.; Zapata, Fernando A.

    2014-01-01

    We examined the age and growth of Urotrygon rogersi on the Colombian coast of the Eastern Tropical Pacific Ocean by directly estimating age using vertebral centra. We verified annual deposition of growth increments with marginal increment analysis. Eight growth curves were fitted to four data sets defined on the basis of the reproductive cycle (unadjusted or adjusted for age at first band) and size variables (disc width or total length). Model performance was evaluated using Akaike's Information Criterion (AIC), AIC weights and multi-model inference criteria. A two-phase growth function with adjusted age provided the best description of growth for females (based on five parameters, DW? ?=? 20.1 cm, k ?=? 0.22 yr–1) and males (based on four and five parameters, DW? ?=? 15.5 cm, k ?=? 0.65 yr–1). Median maturity of female and male U. rogersi is reached very fast (mean ± SE ?=? 1.0 ± 0.1 year). This is the first age and growth study for a species of the genus Urotrygon and results indicate that U. rogersi attains a smaller maximum size and has a shorter lifespan and lower median age at maturity than species of closely related genera. These life history traits are in contrast with those typically reported for other elasmobranchs. PMID:24776963

  7. Conductivity maximum in a charged colloidal suspension

    SciTech Connect

    Bastea, S

    2009-01-27

    Molecular dynamics simulations of a charged colloidal suspension in the salt-free regime show that the system exhibits an electrical conductivity maximum as a function of colloid charge. We attribute this behavior to two main competing effects: colloid effective charge saturation due to counterion 'condensation' and diffusion slowdown due to the relaxation effect. In agreement with previous observations, we also find that the effective transported charge is larger than the one determined by the Stern layer and suggest that it corresponds to the boundary fluid layer at the surface of the colloidal particles.

  8. Maximum entropy spectral analysis for streamflow forecasting

    NASA Astrophysics Data System (ADS)

    Cui, Huijuan; Singh, Vijay P.

    2016-01-01

    Configurational entropy spectral analysis (CESAS) is developed with spectral power as a random variable for streamflow forecasting. It is found that the CESAS derived by maximizing the configurational entropy yields the same solution as by the Burg entropy spectral analysis (BESA). Comparison of forecasted streamflows by CESAS and BESA shows less than 0.001% difference between the two analyses and thus the two entropy spectral analyses are concluded to be identical. Thus, the Burg entropy spectral analysis and two configurational entropy spectral analyses form the maximum entropy spectral analysis.

  9. Therapeutic Experience of Maximum Feasible Participation

    E-print Network

    Castile, George Pierre

    2006-03-01

    of Maximum Feasible Participation George Pierre Castile In 1965 a number of scholars looked about them at the state of Native Americans, among them was Henry Dobyns, whose contribution to the collec tion, "The American Indian Today," was titled... by the undermining of Indian community organization and the sub- 0026-3079/2005/4603/4-077$2.50/0 American Studies, 46:3/4 (Fall-Winter 2005): 77-87 Indigenous Studies Today, 1 (Fall 2005/Spring 2006) 77 78 George Pierre Castile stitution of government...

  10. Maximum entropy signal restoration with linear programming

    SciTech Connect

    Mastin, G.A.; Hanson, R.J.

    1988-05-01

    Dantzig's bounded-variable method is used to express the maximum entropy restoration problem as a linear programming problem. This is done by approximating the nonlinear objective function with piecewise linear segments, then bounding the variables as a function of the number of segments used. The use of a linear programming approach allows equality constraints found in the traditional Lagrange multiplier method to be relaxed. A robust revised simplex algorithm is used to implement the restoration. Experimental results from 128- and 512-point signal restorations are presented.

  11. Maximum power operation of interacting molecular motors

    NASA Astrophysics Data System (ADS)

    Golubeva, N.; Imparato, A.

    2013-07-01

    We study the mechanical and thermodynamic properties of different traffic models for kinesin which are relevant in biological and experimental contexts. We find that motor-motor interactions play a fundamental role by enhancing the thermodynamic efficiency at maximum power of the motors, as compared to the noninteracting system, in a wide range of biologically compatible scenarios. We furthermore consider the case where the motor-motor interaction directly affects the internal chemical cycle and investigate the effect on the system dynamics and thermodynamics.

  12. Design of toroidal transformers for maximum efficiency

    NASA Technical Reports Server (NTRS)

    Dayton, J. A., Jr.

    1972-01-01

    The design of the most efficient toroidal transformer that can be built given the frequency, volt-ampere rating, magnetic flux density, window fill factor, and materials is described. With the above all held constant and only the dimensions of the magnetic core varied, the most efficient design occurs when the copper losses equal 60 percent of the iron losses. When this criterion is followed, efficiency is only slightly dependent on design frequency and fill factor. The ratios of inside diameter to outside diameter and height to build of the magnetic core that result in transformers of maximum efficiency are computed.

  13. Maximum gravitational-wave energy emissible in magnetar flares

    SciTech Connect

    Corsi, Alessandra; Owen, Benjamin J.

    2011-05-15

    Recent searches of gravitational-wave data raise the question of what maximum gravitational-wave energies could be emitted during gamma-ray flares of highly magnetized neutron stars (magnetars). The highest energies ({approx}10{sup 49} erg) predicted so far come from a model [K. Ioka, Mon. Not. R. Astron. Soc. 327, 639 (2001), http://adsabs.harvard.edu/abs/2001MNRAS.327..639I] in which the internal magnetic field of a magnetar experiences a global reconfiguration, changing the hydromagnetic equilibrium structure of the star and tapping the gravitational potential energy without changing the magnetic potential energy. The largest energies in this model assume very special conditions, including a large change in moment of inertia (which was observed in at most one flare), a very high internal magnetic field, and a very soft equation of state. Here we show that energies of 10{sup 48}-10{sup 49} erg are possible under more generic conditions by tapping the magnetic energy, and we note that similar energies may also be available through cracking of exotic solid cores. Current observational limits on gravitational waves from magnetar fundamental modes are just reaching these energies and will beat them in the era of advanced interferometers.

  14. The maximum contribution to reionization from metal-free stars

    E-print Network

    Jose M. Rozas; Jordi Miralda-Escude; Eduard Salvador-Sole

    2005-11-16

    We estimate the maximum contribution to reionization from the first generation of massive stars, with zero metallicity, under the assumption that one of these stars forms with a fixed mass in every collapsed halo in which metal-free gas is able to cool. We assume that any halo that has already had stars previously formed in one of their halo progenitors will form only stars with metals, which are assigned an emissivity of ionizing radiation equal to that determined at z=4 from the measured intensity of the ionizing background. We examine the impact of molecular hydrogen photodissociation (which tends to reduce cooling when a photodissociating background is produced by the first stars) and X-Ray photoheating (which heats the atomic medium, raising the entropy of the gas before it collapses into halos). We find that in the CDM$\\Lambda$ model supported by present observations, and even assuming no negative feedbacks for the formation of metal-free stars, a reionized mass fraction of 50% is not reached until redshift $z\\sim 12$. The combination of ordinary metal-enriched stars and early metal-free stars can yield a CMB optical depth to electron scattering of at most 0.13. The contribution of metal-free stars to the present Cosmic Infrarred Background is negligibly small.

  15. The contributions of vision and haptics to reaching and grasping

    PubMed Central

    Stone, Kayla D.; Gonzalez, Claudia L. R.

    2015-01-01

    This review aims to provide a comprehensive outlook on the sensory (visual and haptic) contributions to reaching and grasping. The focus is on studies in developing children, normal, and neuropsychological populations, and in sensory-deprived individuals. Studies have suggested a right-hand/left-hemisphere specialization for visually guided grasping and a left-hand/right-hemisphere specialization for haptically guided object recognition. This poses the interesting possibility that when vision is not available and grasping relies heavily on the haptic system, there is an advantage to use the left hand. We review the evidence for this possibility and dissect the unique contributions of the visual and haptic systems to grasping. We ultimately discuss how the integration of these two sensory modalities shape hand preference. PMID:26441777

  16. Outreach Beyond Limits - How CFHT reaches its diverse constituents

    NASA Astrophysics Data System (ADS)

    Laychak, Mary Beth

    2015-08-01

    The Canada-France-Hawaii Telescope serves a diverse audience of astronomers and the general public in six countries: Canada, France, Hawaii (US), Taiwan, Brazil and China. The recent hiring of a full time public outreach manager gives CFHT the opportunity to expand its outreach presence in each of these nations while simultaneously reaching our local Big Island community. These goals are ambitious; unlike other multi-national institutions pursuing a dynamic outreach presence, CFHT is a smaller facility with fewer staff fully devoted to public outreach.CFHT aims to maximize its outreach impact through a combination of online engagement and partnerships with users and stakeholders in its constituent communities. In this talk we will discuss our success, challenges, and lessons learned from our experiences coordinating activities and events in three diverse locations: Hawaii, Canada and France.

  17. Reaching Quantum Supremacy with a Boson Sampling Experiment

    E-print Network

    Latmiral, Ludovico

    2015-01-01

    Boson Sampling represents a promising witness of the supremacy of quantum systems as a resource for the solution of computational problems. The classical hardness of Boson Sampling has been related to the so called Permanent-of-Gaussians Conjecture and has been extended to some generalizations such as scattershot Boson Sampling, approximate and lossy sampling under some reasonable constraints. However, it is still unclear how demanding these bounds are for a quantum experimental sampler. Starting from a state of the art analysis and focusing on the foreseeable practical conditions needed to reach quantum supremacy, we look at different techniques and present a more general and effective solution. We apply our approach to both the experimental suggestions presented to date and we eventually find in both cases a new threshold that is less error sensitive and experimentally more feasible.

  18. QSPR prediction of physico-chemical properties for REACH.

    PubMed

    Dearden, J C; Rotureau, P; Fayet, G

    2013-01-01

    For registration of a chemical, European Union REACH legislation requires information on the relevant physico-chemical properties of the chemical. Predicted property values can be used when the predictions can be shown to be valid and adequate. The relevant physico-chemical properties that are amenable to prediction are: melting/freezing point, boiling point, relative density, vapour pressure, surface tension, water solubility, n-octanol-water partition coefficient, flash point, flammability, explosive properties, self-ignition temperature, adsorption/desorption, dissociation constant, viscosity, and air-water partition coefficient (Henry's law constant). Published quantitative structure-property relationship (QSPR) methods for all of these properties are discussed, together with relevant property prediction software, as an aid for those wishing to use predicted property values in submissions to the European Chemicals Agency (ECHA). PMID:23521394

  19. [Reaching migrants for preventive care: optimization of access and utilization].

    PubMed

    Walter, Ulla; Salman, Ramazan; Krauth, Christian; Machleidt, Wielant

    2007-10-01

    Migrants belong to the hard-to-reach group in health and preventive care. Essential criteria for the sustainable effectiveness of preventive and health promotion consist in the proper selection of target groups and successfully approaching them. The knowledge of possible barriers that make the access to preventive care and health promotion more difficult, e. g. low health literacy, that means the difficulties of linguistic understanding or the low acceptance regarding the provider, is necessary in order to select adequate access possibilities to the defined target groups. Up to now, for this and particularly for the ethno-specific health behaviour of migrants in Germany information hardly exist. So far, there are only a few preventive offers which are target group focussed. The use of native speaking preventive consultants is an attempt to improve the access to preventive care for migrants by low threshold come and access-structures. PMID:17922370

  20. Reaching 10 ms single photon lifetimes for superconducting aluminum cavities

    E-print Network

    M. Reagor; Hanhee Paik; G. Catelani; L. Sun; C. Axline; E. Holland; I. M. Pop; N. A. Masluk; T. Brecht; L. Frunzio; M. H. Devoret; L. I. Glazman; R. J. Schoelkopf

    2013-05-22

    Three-dimensional microwave cavities have recently been combined with superconducting qubits in the circuit quantum electrodynamics (cQED) architecture. These cavities should have less sensitivity to dielectric and conductor losses at surfaces and interfaces, which currently limit the performance of planar resonators. We expect that significantly (>10^3) higher quality factors and longer lifetimes should be achievable for 3D structures. Motivated by this principle, we have reached internal quality factors greater than 0.5x10^9 and intrinsic lifetimes of 0.01 seconds for multiple aluminum superconducting cavity resonators at single photon energies and millikelvin temperatures. These improvements could enable long lived quantum memories with submicrosecond access times when strongly coupled to superconducting qubits.

  1. Reaching the quantum limit of sensitivity in electron spin resonance

    E-print Network

    A. Bienfait; J. J. Pla; Y. Kubo; M. Stern; X. Zhou; C. C. Lo; C. D. Weis; T. Schenkel; M. L. W. Thewalt; D. Vion; D. Esteve; B. Julsgaard; K. Moelmer; J. J. L. Morton; P. Bertet

    2015-07-24

    We report pulsed electron-spin resonance (ESR) measurements on an ensemble of Bismuth donors in Silicon cooled at 10mK in a dilution refrigerator. Using a Josephson parametric microwave amplifier combined with high-quality factor superconducting micro-resonators cooled at millikelvin temperatures, we improve the state-of-the-art sensitivity of inductive ESR detection by nearly 4 orders of magnitude. We demonstrate the detection of 1700 bismuth donor spins in silicon within a single Hahn echo with unit signal-to-noise (SNR) ratio, reduced to just 150 spins by averaging a single Carr-Purcell-Meiboom-Gill sequence. This unprecedented sensitivity reaches the limit set by quantum fluctuations of the electromagnetic field instead of thermal or technical noise, which constitutes a novel regime for magnetic resonance.

  2. Automatic online control of motor adjustments in reaching and grasping.

    PubMed

    Gaveau, Valérie; Pisella, Laure; Priot, Anne-Emmanuelle; Fukui, Takao; Rossetti, Yves; Pélisson, Denis; Prablanc, Claude

    2014-03-01

    Following the princeps investigations of Marc Jeannerod on action-perception, specifically, goal-directed movement, this review article addresses visual and non-visual processes involved in guiding the hand in reaching or grasping tasks. The contributions of different sources of correction of ongoing movements are considered; these include visual feedback of the hand, as well as the often-neglected but important spatial updating and sharpening of goal localization following gaze-saccade orientation. The existence of an automatic online process guiding limb trajectory toward its goal is highlighted by a series of princeps experiments of goal-directed pointing movements. We then review psychophysical, electrophysiological, neuroimaging and clinical studies that have explored the properties of these automatic corrective mechanisms and their neural bases, and established their generality. Finally, the functional significance of automatic corrective mechanisms-referred to as motor flexibility-and their potential use in rehabilitation are discussed. PMID:24334110

  3. Sucrose Synthase Activity in Developing Wheat Endosperms Differing in Maximum Weight 1

    PubMed Central

    Dale, Elizabeth MacDowell; Housley, Thomas Lee

    1986-01-01

    Past research on kernel growth in wheat (Triticum aestivum) has shown that the kernel itself largely regulates the influx of sucrose for consequent starch synthesis in the endosperm of the grain. The first step in the conversion of sucrose to starch is catalyzed by sucrose synthase (EC 2.4.13). Sucrose synthase activity was assayed in developing endosperms from kernels differing in growth rate and in maximum dry weight accumulation. From 10 to 22 days after anthesis, sucrose synthase activity per wheat endosperm remained constant with respect to time in all grains. However, kernels which had higher rates of kernel growth and which achieved greatest maximum weight had consistently and significantly higher sucrose synthase activities at any point in time than did kernels with slower rates of dry matter accumulation and lower maximum weight. In addition, larger kernels had a significantly greater amount of water in which this activity could be expressed. Although the results do not implicate sucrose synthase as the “rate limiting” enzyme in wheat kernel growth, they do emphasize the importance of sucrose synthase activity in larger or more rapidly growing kernels, as compared to smaller slower growing kernels. PMID:16665025

  4. Origin of growth-induced water potential

    SciTech Connect

    Nonami, H.; Boyer, J.S.

    1987-03-01

    The authors developed a new method to measure the solute concentration in the apoplast of stem tissue involving pressurizing the roots of intact seedlings (Glycine max (L.) Merr. or Pisum sativum L.), collecting a small amount of exudate from the surface of the stem under saturating humidities, and determining the osmotic potential of the solution with a micro-osmometer capable of measuring small volumes (0.5 microliter). In the elongating region, the apoplast concentrations were very low (equivalent to osmotic potentials of -0.03 to -0.04 megapascal) and negligible compared to the water potential of the apoplast (-0.15 to -0.30 megapascal) measured directly by isopiestic psychrometry in intact plants. Most of the apoplast water potential consisted of a negative pressure that could be measured with a pressure chamber (-0.15 to -0.28 megapascal). Tests showed that earlier methods involving infiltration of intercellular spaces or pressurizing cut segments caused solute to be released to the apoplast and resulted in spuriously high concentrations. These results indicate that, although a small amount of solute is present in the apoplast, the major component is a tension that is part of a growth-induced gradient in water potential in the enlarging tissue. The gradient originates from the extension of the cell walls, which prevents turgor from reaching its maximum and creates a growth-induced water potential that causes water to move from the xylem at a rate that satisfies the rate of enlargement. The magnitude of the gradient implies that growing tissue contains a large resistance to water movement.

  5. Reaching and grasping behavior in Macaca fascicularis: a kinematic study.

    PubMed

    Sartori, Luisa; Camperio Ciani, Andrea; Bulgheroni, Maria; Castiello, Umberto

    2013-01-01

    The prehensile hand is one of the major traits distinguishing primates from other mammal species. All primates, in fact, are able to grasp an object and hold it in part or entirely using a single hand. Although there is a wealth of behavioral data regarding grasping movements in humans and apes, there is relatively little material on macaques, the animal model often used to investigate neuronal mechanisms responsible for grip control in humans. To date, evidence regarding free-ranging macaques is confined to observational data, while quantitative reports describe studies carried out in laboratory settings or in captivity. The purpose of the present study was to provide the first kinematic descriptions of basic grip behavior with regard to precision and power grips in free-ranging macaque monkeys. Video footage of those animals grasping objects was analyzed frame-by-frame using digitalization techniques. The results revealed that the two types of grips considered are each characterized by specific kinematic signatures. It was also found that hand kinematics was scaled depending on the type of grasp needing to be adopted and the intrinsic properties of the object to be grasped. In accordance with data concerning humans, these findings indicate that the intrinsic features of an object affect the planning and control of reach-to-grasp movements even in free-ranging macaques. The data presented here take research in the field of comparative reach-to-grasp kinematics in human and non-human primates another step forward as they are based on precise measurements of spontaneous grasping movements by animals living/acting in their natural environment. PMID:23064847

  6. Visuo-proprioceptive interactions during adaptation of the human reach

    PubMed Central

    Judkins, Timothy

    2013-01-01

    We examined whether visual and proprioceptive estimates of transient (midreach) target capture errors contribute to motor adaptation according to the probabilistic rules of information integration used for perception. Healthy adult humans grasped and moved a robotic handle between targets in the horizontal plane while the robot generated springlike loads that varied unpredictably from trial to trial. For some trials, a visual cursor faithfully tracked hand motion. In others, the handle's position was locked and subjects viewed motion of a point-mass cursor driven by hand forces. In yet other trials, cursor feedback was dissociated from hand motion or altogether eliminated. We used time- and frequency-domain analyses to characterize how sensorimotor memories influence performance on subsequent reaches. When the senses were used separately, subjects were better at rejecting physical disturbances applied to the hand than virtual disturbances applied to the cursor. In part, this observation reflected differences in how participants used sensorimotor memories to adapt to perturbations when performance feedback was limited to only proprioceptive or visual information channels. When both vision and proprioception were available to guide movement, subjects processed memories in a manner indistinguishable from the vision-only condition, regardless of whether the cursor tracked the hand faithfully or whether we experimentally dissociated motions of the hand and cursor. This was true even though, on average, perceptual uncertainty in the proprioceptive estimation of movement extent exceeded that of visual estimation by just 47%. In contrast to perceptual tasks wherein vision and proprioception both contribute to an optimal estimate of limb state, our findings support a switched-input, multisensory model of predictive load compensation wherein visual feedback of transient performance errors overwhelmingly dominates proprioception in determining adaptive reach performance. PMID:24259549

  7. Efficient heuristics for maximum common substructure search.

    PubMed

    Englert, Péter; Kovács, Péter

    2015-05-26

    Maximum common substructure search is a computationally hard optimization problem with diverse applications in the field of cheminformatics, including similarity search, lead optimization, molecule alignment, and clustering. Most of these applications have strict constraints on running time, so heuristic methods are often preferred. However, the development of an algorithm that is both fast enough and accurate enough for most practical purposes is still a challenge. Moreover, in some applications, the quality of a common substructure depends not only on its size but also on various topological features of the one-to-one atom correspondence it defines. Two state-of-the-art heuristic algorithms for finding maximum common substructures have been implemented at ChemAxon Ltd., and effective heuristics have been developed to improve both their efficiency and the relevance of the atom mappings they provide. The implementations have been thoroughly evaluated and compared with existing solutions (KCOMBU and Indigo). The heuristics have been found to greatly improve the performance and applicability of the algorithms. The purpose of this paper is to introduce the applied methods and present the experimental results. PMID:25865959

  8. Maximum entropy, Nonadditive entropies and Biology

    NASA Astrophysics Data System (ADS)

    Presse, Steve

    2014-03-01

    Gibbs once presciently noted that the elegance and simplicity of the principles of statistical physics were worthy of independent development outside of thermodynamics. Biophysical systems -from the single cell to the single protein level- provide an ideal framework in which to test and apply far-from-equilibrium generalizations of statistical physics. Here we discuss two theoretical topics at the intersection of statistical physics and biology. First, we will describe a recipe for deriving, from first principles, probabilistic equations of motion from limited biophysical single particle tracking data. That is, we will show that maximum entropy principles can be used to determine the most likely statistical weights of trajectories from an ensemble of allowed system trajectories. For instance, using this reasoning, we can show under what circumstances Markov processes and chemical master equations rigorously follow from the data. Second, we will explore the logical implications of using a principle other than maximum entropy to select models (e.g. a model could be a trajectory ensemble in conformational space of a biomolecule) from non-equilibrium biophysical data. In particular, we will show that nonadditive entropy maximization can lead to biophysical models with features that go beyond what is warranted by the data.

  9. Maximum height and minimum time vertical jumping.

    PubMed

    Domire, Zachary J; Challis, John H

    2015-08-20

    The performance criterion in maximum vertical jumping has typically been assumed to simply raise the center of mass as high as possible. In many sporting activities minimizing movement time during the jump is likely also critical to successful performance. The purpose of this study was to examine maximum height jumps performed while minimizing jump time. A direct dynamics model was used to examine squat jump performance, with dual performance criteria: maximize jump height and minimize jump time. The muscle model had activation dynamics, force-length, force-velocity properties, and a series of elastic component representing the tendon. The simulations were run in two modes. In Mode 1 the model was placed in a fixed initial position. In Mode 2 the simulation model selected the initial squat configuration as well as the sequence of muscle activations. The inclusion of time as a factor in Mode 1 simulations resulted in a small decrease in jump height and moderate time savings. The improvement in time was mostly accomplished by taking off from a less extended position. In Mode 2 simulations, more substantial time savings could be achieved by beginning the jump in a more upright posture. However, when time was weighted more heavily in these simulations, there was a more substantial reduction in jump height. Future work is needed to examine the implications for countermovement jumping and to examine the possibility of minimizing movement time as part of the control scheme even when the task is to jump maximally. PMID:25964210

  10. 49 CFR 230.24 - Maximum allowable stress.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Maximum allowable stress. 230.24 Section 230.24... Allowable Stress § 230.24 Maximum allowable stress. (a) Maximum allowable stress value. The maximum allowable stress value on any component of a steam locomotive boiler shall not exceed 1/4 of the...

  11. 49 CFR 230.24 - Maximum allowable stress.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Maximum allowable stress. 230.24 Section 230.24... Allowable Stress § 230.24 Maximum allowable stress. (a) Maximum allowable stress value. The maximum allowable stress value on any component of a steam locomotive boiler shall not exceed 1/4 of the...

  12. 49 CFR 230.24 - Maximum allowable stress.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Maximum allowable stress. 230.24 Section 230.24... Allowable Stress § 230.24 Maximum allowable stress. (a) Maximum allowable stress value. The maximum allowable stress value on any component of a steam locomotive boiler shall not exceed 1/4 of the...

  13. 49 CFR 230.24 - Maximum allowable stress.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Maximum allowable stress. 230.24 Section 230.24... Allowable Stress § 230.24 Maximum allowable stress. (a) Maximum allowable stress value. The maximum allowable stress value on any component of a steam locomotive boiler shall not exceed 1/4 of the...

  14. 40 CFR 141.13 - Maximum contaminant levels for turbidity.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Maximum contaminant levels for... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Maximum Contaminant Levels § 141.13 Maximum contaminant levels for turbidity. The maximum contaminant levels for turbidity are applicable...

  15. 46 CFR 154.556 - Cargo hose: Maximum working pressure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Cargo hose: Maximum working pressure. 154.556 Section... Equipment Cargo Hose § 154.556 Cargo hose: Maximum working pressure. A cargo hose must have a maximum working pressure not less than the maximum pressure to which it may be subjected and at least 1034...

  16. 46 CFR 154.556 - Cargo hose: Maximum working pressure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Cargo hose: Maximum working pressure. 154.556 Section... Equipment Cargo Hose § 154.556 Cargo hose: Maximum working pressure. A cargo hose must have a maximum working pressure not less than the maximum pressure to which it may be subjected and at least 1034...

  17. On the maximum value of the cosmic abundance of oxygen and the oxygen yield

    E-print Network

    L. S. Pilyugin; T. X. Thuan; J. M. Vilchez

    2007-01-11

    We search for the maximum oxygen abundance in spiral galaxies. Because this maximum value is expected to occur in the centers of the most luminous galaxies, we have constructed the luminosity - central metallicity diagram for spiral galaxies, based on a large compilation of existing data on oxygen abundances of HII regions in spiral galaxies. We found that this diagram shows a plateau at high luminosities (-22.3 oxygen abundance 12+log(O/H) ~ 8.87. This provides strong evidence that the oxygen abundance in the centers of the most luminous metal-rich galaxies reaches the maximum attainable value of oxygen abundance. Since some fraction of the oxygen (about 0.08 dex) is expected to be locked into dust grains, the maximum value of the true gas+dust oxygen abundance in spiral galaxies is 12+log(O/H) ~ 8.95. This value is a factor of ~ 2 higher than the recently estimated solar value. Based on the derived maximum oxygen abundance in galaxies, we found the oxygen yield to be about 0.0035, depending on the fraction of oxygen incorporated into dust grains.

  18. Low-level nocturnal wind maximum over the Central Amazon Basin

    NASA Technical Reports Server (NTRS)

    Greco, Steven; Ulanski, Stanley; Garstang, Michael; Houston, Samuel

    1992-01-01

    A low-level nocturnal wind maximum is shown to exist over extensive and nearly undisturbed rainforest near the central Amazon city of Manaus. Meteorological data indicate the presence of this nocturnal wind maximum during both the wet and dry seasons of the Central Amazon Basin. Daytime wind speeds which are characteristically 3-7 m/s between 300 and 1000 m increase to 10-15 m/s shortly after sunset. The wind-speed maximum is reached in the early evening, with wind speeds remaining high until several hours after sunrise. The nocturnal wind maximum is closely linked to a strong low-level inversion formed by radiational cooling of the rainforest canopy. Surface and low-level pressure gradients between the undisturbed forest and the large Amazon river system and the city of Manaus are shown to be responsible for much of the nocturnal wind increase. The pressure gradients are interpreted as a function of the thermal differences between undisturbed forest and the river/city. The importance of both the frictional decoupling and the horizontal pressure gradient suggest that the nocturnal wind maximum does not occur uniformly over all Amazonia. Low-level winds are thought to be pervasive under clear skies and strong surface cooling and that, in many places (i.e., near rivers), local pressure gradients enhance the low-level nocturnal winds.

  19. Automated protein crystal growth facility

    NASA Technical Reports Server (NTRS)

    Donald, Stacey

    1994-01-01

    A customer for the protein crystal growth facility fills the specially designed chamber with the correct solutions, fills the syringes with their quenching solutions, and submits the data needed for the proper growth of their crystal. To make sure that the chambers and syringes are filled correctly, a NASA representative may assist the customer. The data needed is the approximate growth time, the growth temperature, and the desired crystal size, but this data can be changed anytime from the ground, if needed. The chambers are gathered and placed into numbered slots in special drawers. Then, data is entered into a computer for each of the chambers. Technicians map out when each chamber's growth should be activated so that all of the chambers have enough time to grow. All of this data is up-linked to the space station when the previous growth session is over. Anti-vibrational containers need to be constructed for the high forces encountered during the lift off and the landing of the space shuttle, and though our team has not designed these containers, we do not feel that there is any reason why a suitable one could not be made. When the shuttle reaches the space station, an astronaut removes a drawer of quenched chambers from the growth facility and inserts a drawer of new chambers. All twelve of the drawers can be replaced in this fashion. The optical disks can also be removed this way. The old drawers are stored for the trip back to earth. Once inside the growth facility, a chamber is removed by the robot and placed in one of 144 active sites at a time previously picked by a technician. Growth begins when the chamber is inserted into an active site. Then, the sensing system starts to determine the size of the protein crystal. All during the crystal's growth, the customer can view the crystal and read all of the crystal's data, such as growth rate and crystal size. When the sensing system determines that the crystal has reached the predetermined size, the robot is told to pick up a syringe filled with the correct quenchant solution and inject it into the chamber to stop the crystal growth. The chamber is then removed from the active site and placed into its original storage slot. Another chamber is then placed into the active site and the process is repeated in all of the active sites until all of the chambers have complted their growth. After ninety days (the scheduled time between shuttle visits), the crystal growth is completed, and the old drawers are replaced with new ones. Once the customer extracts the crystals, the chambers are retrieved for future customers.

  20. Land Cover Changes and Sediment Connectivity in a Torrential Reach of the Central Spanish Pyrenees

    NASA Astrophysics Data System (ADS)

    San Juan, Yasmina; María García Ruiz, José; Gómez Villar, Amelia; Nadal Romero, Estela; Beguería, Santiago; Álvarez Martínez, Javier; Arnáez Vadillo, Jose; González Sampériz, Penélope; Serrano Muela, María Pilar; Galilea Salvador, Ianire

    2014-05-01

    The Ijuez River drains a sector of the Eocene flysch in the southern Pyrenees, The basin includes natural forests and afforestations in the montane belt, as well as extensive grasslands in the subalpine belt, over 1700 m a.s.l. At the beginning, the streambed develops a narrow canyon with a very steep longitudinal profile that ends in a torrential alluvial plain plenty of cobbles and boulders arranged in a chaotic manner. Several check dams in the middle and lower stretches of the river have contributed to reduce sediment transfer downstream. The upper reach, however, maintains it torrential character. There, the Ijuez River shows the occurrence of various changes in the hydromorphological regime: (i) a terrace level above 3 m of the actual channel, with matrix-supported cobbles indicating a fluvio-torrential regime; (ii) above the terrace level the accumulation of a large number of debris flows occurred; (iii) recently a strong incision of the actual channel occurred, contributing to the dismantlement of fluvial terrace and debris flow deposits. This evolution reflects, most likely, the changes underwent in the subalpine and montane belts due to deforestation and the consequent transformation of the forests into cultivated fields (below 1600 m a.s.l.) and subalpine grasslands to feed the transhumant sheep flocks. Such changes occurred between 2500-2000 years ago and between 1200-900 year ago, according to the deforestation ages obtained from charcoal remnants in soils and lacustrine sediments. Radiocarbon dates obtained for debris flows (from woody remnants located within the debris-flow deposits) in the Ijuez basin indicate an age of approximately 100 years ago, coinciding with the moment of maximum population pressure and the maximum extent of the cultivated area. Along the 20th century, farmland abandonment, afforestations and natural reforestation, as well as the decline of the livestock pressure has reduced sediment yield and connectivity, thus explaining the recent reduction in sediment supply and the consequent channel incision.

  1. REACH: A program for coarse-grained biomolecular simulation

    NASA Astrophysics Data System (ADS)

    Moritsugu, Kei; Smith, Jeremy C.

    2009-07-01

    REACH ( Realistic Extension Algorithm viaCovariance Hessian) is a program package for residue-scale coarse-grained biomolecular simulation. The program calculates the force constants of a residue-scale elastic network model in single-domain proteins using the variance-covariance matrix obtained from atomistic molecular dynamics simulation. Secondary-structure dependence of the force constants is integrated. The method involves self-consistent, direct mapping of atomistic simulation results onto a coarse-grained force field in an efficient automated procedure without requiring iterative fits and avoiding system dependence. Program summaryProgram title: REACH Catalogue identifier: AEDA_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEDA_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 42 244 No. of bytes in distributed program, including test data, etc.: 3 682 118 Distribution format: tar.gz Programming language: FORTRAN 77 Computer: x86 PC Operating system: GNU/Linux, SUSE and Red Hat RAM: Depends on the system size to be calculated Word size: 32 or 64 bits Classification: 3 External routines: LAPACK, BLAS Nature of problem: A direct calculation of force field for residue-scale coarse-grained biomolecular simulation derived from atomistic molecular dynamics trajectory. Solution method: A variance-covariance matrix and the associated Hessian (second-derivative) matrix are calculated from an atomistic molecular dynamics trajectory of single-domain protein internal motion and the off-diagonal Hessian matrix is fitted to that of a residue-scale elastic network model. The resulting force constants for the residue pair interactions are expressed as model functions as a function of pairwise distance. Running time: Depends on the system size and the number of MD trajectory frames used. The test run provided with the distribution takes only a few seconds to execute.

  2. Maximum screening fields of superconducting multilayer structures

    E-print Network

    Gurevich, Alex

    2015-01-01

    It is shown that a multilayer comprised of alternating thin superconducting and insulating layers on a thick substrate can fully screen the applied magnetic field exceeding the superheating fields $H_s$ of both the superconducting layers and the substrate, the maximum Meissner field is achieved at an optimum multilayer thickness. For instance, a dirty layer of thickness $\\sim 0.1\\; \\mu$m at the Nb surface could increase $H_s\\simeq 240$ mT of a clean Nb up to $H_s\\simeq 290$ mT. Optimized multilayers of Nb$_3$Sn, NbN, some of the iron pnictides, or alloyed Nb deposited onto the surface of the Nb resonator cavities could potentially double the rf breakdown field, pushing the peak accelerating electric fields above 100 MV/m while protecting the cavity from dendritic thermomagnetic avalanches caused by local penetration of vortices.

  3. The 1980 solar maximum mission event listing

    NASA Technical Reports Server (NTRS)

    Speich, D. M.; Nelson, J. J.; Licata, J. P.; Tolbert, A. K.

    1991-01-01

    Information is contained on solar burst and transient activity observed by the Solar Maximum Mission (SMM) during 1980 pointed observations. Data from the following SMM experiments are included: (1) Gamma Ray Spectrometer, (2) Hard X-Ray Burst Spectrometer, (3) Hard X-Ray Imaging Spectrometer, (4) Flat Crystal Spectrometer, (5) Bent Crystal Spectrometer, (6) Ultraviolet Spectrometer and Polarimeter, and (7) Coronagraph/Polarimeter. Correlative optical, radio, and Geostationary Operational Environmental Satellite (GOES) x ray data are also presented. Where possible, bursts or transients observed in the various wavelengths were grouped into discrete flare events identified by unique event numbers. Each event carries a qualifier denoting the quality or completeness of the observations. Spacecraft pointing coordinates and flare site angular displacement values from Sun center are also included.

  4. Emitter frequency refinement based on maximum likelihood

    NASA Astrophysics Data System (ADS)

    Xu, Xin; Wang, Huijuan

    2015-07-01

    Frequency estimation via signal sorting is widely recognized as one of the most practical technologies in signal processing. However, the estimated frequencies via signal sorting may be inaccurate and biased due to signal fluctuation under different emitter working modes, problems of transmitter circuit, environmental noises or certain unknown interference sources. Therefore, it has become an important issue to further analyze and refine signal frequencies after signal sorting. To address the above problem, we have brought forward an iterative frequency refinement method based on maximum likelihood. Iteratively, the initial estimated signal frequency values are refined. Experimental results indicate that the refined signal frequencies are more informative than the initial ones. As another advantage of our method, noises and interference sources could be filtered out simultaneously. The efficiency and flexibility enables our method to apply in a wide application area, i.e., communication, electronic reconnaissance and radar intelligence analysis.

  5. Lead in soil: Recommended maximum permissible levels

    SciTech Connect

    Madhavan, S.; Rosenman, K.D.; Shehata, T.

    1989-06-01

    Lead in soil has been recognized as a public health problem, particularly among children. In recent years, attention has been directed to cumulative adverse effects of lead at low levels of intake. Lead-contaminated soil and dust have been identified as important contributors to blood lead levels. Based on available data on blood lead and lead in soil, an approach has been developed to suggest a permissible level of lead in soil, below which there will be reasonable certainty that adverse health effects will not occur. An acceptable level of 600 ppm of lead in soil suggested as a ''safe'' level would contribute no more than 5 micrograms/dl to total blood lead of children under 12 years of age. Maximum permissible levels of lead in soil have been recommended based on the dose-response relationship of lead in soil and blood lead in children.

  6. Approximate maximum likelihood decoding of block codes

    NASA Technical Reports Server (NTRS)

    Greenberger, H. J.

    1979-01-01

    Approximate maximum likelihood decoding algorithms, based upon selecting a small set of candidate code words with the aid of the estimated probability of error of each received symbol, can give performance close to optimum with a reasonable amount of computation. By combining the best features of various algorithms and taking care to perform each step as efficiently as possible, a decoding scheme was developed which can decode codes which have better performance than those presently in use and yet not require an unreasonable amount of computation. The discussion of the details and tradeoffs of presently known efficient optimum and near optimum decoding algorithms leads, naturally, to the one which embodies the best features of all of them.

  7. Diffusivity Maximum in a Reentrant Nematic Phase

    PubMed Central

    Stieger, Tillmann; Mazza, Marco G.; Schoen, Martin

    2012-01-01

    We report molecular dynamics simulations of confined liquid crystals using the Gay–Berne–Kihara model. Upon isobaric cooling, the standard sequence of isotropic–nematic–smectic A phase transitions is found. Upon further cooling a reentrant nematic phase occurs. We investigate the temperature dependence of the self-diffusion coefficient of the fluid in the nematic, smectic and reentrant nematic phases. We find a maximum in diffusivity upon isobaric cooling. Diffusion increases dramatically in the reentrant phase due to the high orientational molecular order. As the temperature is lowered, the diffusion coefficient follows an Arrhenius behavior. The activation energy of the reentrant phase is found in reasonable agreement with the reported experimental data. We discuss how repulsive interactions may be the underlying mechanism that could explain the occurrence of reentrant nematic behavior for polar and non-polar molecules. PMID:22837730

  8. The 1989 Solar Maximum Mission event list

    NASA Technical Reports Server (NTRS)

    Dennis, B. R.; Licata, J. P.; Tolbert, A. K.

    1992-01-01

    This document contains information on solar burst and transient activity observed by the Solar Maximum Mission (SMM) during 1989 pointed observations. Data from the following SMM experiments are included: (1) Gamma Ray Spectrometer, (2) Hard X-Ray Burst Spectrometer, (3) Flat Crystal Spectrometer, (4) Bent Crystal Spectrometer, (5) Ultraviolet Spectrometer Polarimeter, and (6) Coronagraph/Polarimeter. Correlative optical, radio, and Geostationary Operational Satellite (GOES) X-ray data are also presented. Where possible, bursts or transients observed in the various wavelengths were grouped into discrete flare events identified by unique event numbers. Each event carries a qualifier denoting the quality or completeness of the observations. Spacecraft pointing coordinates and flare site angular displacement values from sun center are also included.

  9. Maximum likelihood and the single receptor

    E-print Network

    Robert G. Endres; Ned S. Wingreen

    2009-09-25

    Biological cells are able to accurately sense chemicals with receptors at their surfaces, allowing cells to move towards sources of attractant and away from sources of repellent. The accuracy of sensing chemical concentration is ultimately limited by the random arrival of particles at the receptors by diffusion. This fundamental physical limit is generally considered to be the Berg & Purcell limit [H.C. Berg and E.M. Purcell, Biophys. J. {\\bf 20}, 193 (1977)]. Here we derive a lower limit by applying maximum likelihood to the time series of receptor occupancy. The increased accuracy stems from solely considering the unoccupied time intervals - disregarding the occupied time intervals as these do not contain any information about the external particle concentration, and only decrease the accuracy of the concentration estimate. Receptors which minimize the bound time intervals achieve the highest possible accuracy. We discuss how a cell could implement such an optimal sensing strategy by absorbing or degrading bound particles.

  10. Maximum screening fields of superconducting multilayer structures

    NASA Astrophysics Data System (ADS)

    Gurevich, Alex

    2015-01-01

    It is shown that a multilayer comprised of alternating thin superconducting and insulating layers on a thick substrate can fully screen the applied magnetic field exceeding the superheating fields Hs of both the superconducting layers and the substrate, the maximum Meissner field is achieved at an optimum multilayer thickness. For instance, a dirty layer of thickness ˜0.1 ?m at the Nb surface could increase Hs ? 240 mT of a clean Nb up to Hs ? 290 mT. Optimized multilayers of Nb3Sn, NbN, some of the iron pnictides, or alloyed Nb deposited onto the surface of the Nb resonator cavities could potentially double the rf breakdown field, pushing the peak accelerating electric fields above 100 MV/m while protecting the cavity from dendritic thermomagnetic avalanches caused by local penetration of vortices.

  11. Experimental shock metamorphism of maximum microcline

    NASA Technical Reports Server (NTRS)

    Robertson, P. B.

    1975-01-01

    A series of recovery experiments are conducted to study the behavior of single-crystal perthitic maximum microcline shock-loaded to a peak pressure of 417 kbar. Microcline is found to deform in a manner similar to quartz and other alkali feldspars. It is observed that shock-induced cleavages occur initially at or slightly below the Hugoniot elastic limit (60-85 kbar), that shock-induced rather than thermal disordering begins above the Hugoniot elastic limit, and that all types of planar elements form parallel to crystallographic planes of low Miller indices. When increasing pressure, it is found that bulk density, refractive indices, and birefringence of the recovered material decrease and approach diaplectic glass values, whereas disappearance and weakening of reflections in Debye-Sherrer patterns are due to disordering of the feldspar lattice.

  12. Maximum power flux of auroral kilometric radiation

    NASA Astrophysics Data System (ADS)

    Benson, Robert F.; Fainberg, Joseph

    1991-08-01

    Distant observations of intense auroral kilometric radiation (AKR) are discussed in light of the increased maximum AKR power flux registered by the 3D radio-mapping instrument on ISEE 3. Only AKR events that contain the highest frequency signals are selected, and during spacecraft rotation the spacecraft antenna gain is employed to increase the dynamic range of the instrument. The technique is found to result in the screening of false signals created by instrument overloading as well as the detection of genuine second-harmonic AKR signals while the spacecraft was 17 R(E) from earth. A very strong power flux of fundamental AKR is also reported, exceeding 3 x 10 to the -13th W/sq m/Hz at 360 kHz. The most intense source-region values detected by Isis I and Viking measurements are compared to the strong signal, and the signal is concluded to be the combined signal of a number of sources.

  13. Power Spectrum Estimation II. Linear Maximum Likelihood

    E-print Network

    Andrew J. S. Hamilton

    2005-03-29

    This second paper of two companion papers on the estimation of power spectra specializes to the topic of estimating galaxy power spectra at large, linear scales using maximum likelihood methods. As in the first paper, the aims are pedagogical, and the emphasis is on concepts rather than technical detail. The paper covers most of the salient issues, including selection functions, likelihood functions, Karhunen-Loeve compression, pair-integral bias, Local Group flow, angular or radial systematics (arising for example from extinction), redshift distortions, quadratic compression, decorrelation, and disentanglement. The procedures are illustrated with results from the IRAS PSCz survey. Most of the PSCz graphics included in this paper have not been published elsewhere.

  14. The 1988 Solar Maximum Mission event list

    NASA Technical Reports Server (NTRS)

    Dennis, B. R.; Licata, J. P.; Tolbert, A. K.

    1992-01-01

    Information on solar burst and transient activity observed by the Solar Maximum Mission (SMM) during 1988 pointed observations is presented. Data from the following SMM experiments are included: (1) gamma ray spectrometer; (2) hard x ray burst spectrometer; (3) flat crystal spectrometers; (4) bent crystal spectrometer; (5) ultraviolet spectrometer polarimeter; and (6) coronagraph/polarimeter. Correlative optical, radio, and Geostationary Operational Environmental Satellite (GOES) x ray data are also presented. Where possible, bursts, or transients observed in the various wavelengths were grouped into discrete flare events identified by unique event numbers. Each event carries a qualifier denoting the quality or completeness of the observation. Spacecraft pointing coordinates and flare site angular displacement values from sun center are also included.

  15. Estimating missing information by maximum likelihood deconvolution.

    PubMed

    Heintzmann, Rainer

    2007-01-01

    The ability of iteratively constrained maximum likelihood (ML) deconvolution to reconstruct out-of-band information is discussed and exemplified by simulations. The frequency dependent relative energy regain, a novel way of quantifying the reconstruction ability, is introduced. The positivity constraint of ML deconvolution allows reconstructing information outside the spatial frequency bandwidth which is set by the optical system. This is demonstrated for noise-free and noisy data. It is also shown that this property depends on the type of object under investigation. An object is constructed where no significant out-of-band reconstruction is possible. It is concluded that in practical situations the amount of possible out-of-band reconstruction depends on the agreement between reality and the model describing "typical objects" incorporated into the algorithm by appropriate penalty functions. PMID:16914319

  16. Maximum entropy model for business cycle synchronization

    NASA Astrophysics Data System (ADS)

    Xi, Ning; Muneepeerakul, Rachata; Azaele, Sandro; Wang, Yougui

    2014-11-01

    The global economy is a complex dynamical system, whose cyclical fluctuations can mainly be characterized by simultaneous recessions or expansions of major economies. Thus, the researches on the synchronization phenomenon are key to understanding and controlling the dynamics of the global economy. Based on a pairwise maximum entropy model, we analyze the business cycle synchronization of the G7 economic system. We obtain a pairwise-interaction network, which exhibits certain clustering structure and accounts for 45% of the entire structure of the interactions within the G7 system. We also find that the pairwise interactions become increasingly inadequate in capturing the synchronization as the size of economic system grows. Thus, higher-order interactions must be taken into account when investigating behaviors of large economic systems.

  17. 40 CFR 1042.140 - Maximum engine power, displacement, power density, and maximum in-use engine speed.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Maximum engine power, displacement, power density, and maximum in-use engine speed...Maximum engine power, displacement, power density, and maximum in-use engine speed...engine power, displacement, and power density of an engine for the purposes of...

  18. 40 CFR 1042.140 - Maximum engine power, displacement, power density, and maximum in-use engine speed.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Maximum engine power, displacement, power density, and maximum in-use engine speed...Maximum engine power, displacement, power density, and maximum in-use engine speed...engine power, displacement, and power density of an engine for the purposes of...

  19. 40 CFR 1042.140 - Maximum engine power, displacement, power density, and maximum in-use engine speed.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Maximum engine power, displacement, power density, and maximum in-use engine speed...Maximum engine power, displacement, power density, and maximum in-use engine speed...engine power, displacement, and power density of an engine for the purposes of...

  20. 40 CFR 1042.140 - Maximum engine power, displacement, power density, and maximum in-use engine speed.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Maximum engine power, displacement, power density, and maximum in-use engine speed...Maximum engine power, displacement, power density, and maximum in-use engine speed...engine power, displacement, and power density of an engine for the purposes of...

  1. Physics of Substorm Growth Phase, Onset, and Dipolarization

    SciTech Connect

    C.Z. Cheng

    2003-10-22

    A new scenario of substorm growth phase, onset, and depolarization during expansion phase and the corresponding physical processes are presented. During the growth phase, as a result of enhanced plasma convection, the plasma pressure and its gradient are continued to be enhanced over the quiet-time values in the plasma sheet. Toward the late growth phase, a strong cross-tail current sheet is formed in the near-Earth plasma sheet region, where a local magnetic well is formed, the plasma beta can reach a local maximum with value larger than 50 and the cross-tail current density can be enhanced to over 10nA/m{sup 2} as obtained from 3D quasi-static magnetospheric equilibrium solutions for the growth phase. The most unstable kinetic ballooning instabilities (KBI) are expected to be located in the tailward side of the strong cross-tail current sheet region. The field lines in the most unstable KBI region map to the transition region between the region-1 and region-2 currents in the ionosphere, which is consistent with the observed initial brightening location of the breakup arc in the intense proton precipitation region. The KBI explains the AMPTE/CCE observations that a low-frequency instability with a wave period of 50-75 seconds is excited about 2-3 minutes prior to substorm onset and grows exponentially to a large amplitude at the onset of current disruption (or current reduction). At the current disruption onset higher frequency instabilities are excited so that the plasma and electromagnetic field fluctuations form a strong turbulent state. Plasma transport takes place due to the strong turbulence to relax the ambient plasma pressure profile so that the plasma pressure and current density are reduced and the ambient magnetic field intensity increases by more than a factor of 2 in the high-beta(sub)eq region and the field line geometry recovers from tail-like to dipole-like dipolarization.

  2. Spacecraft Maximum Allowable Concentrations for Airborne Contaminants

    NASA Technical Reports Server (NTRS)

    James, John T.

    2008-01-01

    The enclosed table lists official spacecraft maximum allowable concentrations (SMACs), which are guideline values set by the NASA/JSC Toxicology Group in cooperation with the National Research Council Committee on Toxicology (NRCCOT). These values should not be used for situations other than human space flight without careful consideration of the criteria used to set each value. The SMACs take into account a number of unique factors such as the effect of space-flight stress on human physiology, the uniform good health of the astronauts, and the absence of pregnant or very young individuals. Documentation of the values is given in a 5 volume series of books entitled "Spacecraft Maximum Allowable Concentrations for Selected Airborne Contaminants" published by the National Academy Press, Washington, D.C. These books can be viewed electronically at http://books.nap.edu/openbook.php?record_id=9786&page=3. Short-term (1 and 24 hour) SMACs are set to manage accidental releases aboard a spacecraft and permit risk of minor, reversible effects such as mild mucosal irritation. In contrast, the long-term SMACs are set to fully protect healthy crewmembers from adverse effects resulting from continuous exposure to specific air pollutants for up to 1000 days. Crewmembers with allergies or unusual sensitivity to trace pollutants may not be afforded complete protection, even when long-term SMACs are not exceeded. Crewmember exposures involve a mixture of contaminants, each at a specific concentration (C(sub n)). These contaminants could interact to elicit symptoms of toxicity even though individual contaminants do not exceed their respective SMACs. The air quality is considered acceptable when the toxicity index (T(sub grp)) for each toxicological group of compounds is less than 1, where T(sub grp), is calculated as follows: T(sub grp) = C(sub 1)/SMAC(sub 1) + C(sub 2/SMAC(sub 2) + ...+C(sub n)/SMAC(sub n).

  3. Computer-based video digitizer analysis of surface extension in maize roots: kinetics of growth rate changes during gravitropism

    NASA Technical Reports Server (NTRS)

    Ishikawa, H.; Hasenstein, K. H.; Evans, M. L.

    1991-01-01

    We used a video digitizer system to measure surface extension and curvature in gravistimulated primary roots of maize (Zea mays L.). Downward curvature began about 25 +/- 7 min after gravistimulation and resulted from a combination of enhanced growth along the upper surface and reduced growth along the lower surface relative to growth in vertically oriented controls. The roots curved at a rate of 1.4 +/- 0.5 degrees min-1 but the pattern of curvature varied somewhat. In about 35% of the samples the roots curved steadily downward and the rate of curvature slowed as the root neared 90 degrees. A final angle of about 90 degrees was reached 110 +/- 35 min after the start of gravistimulation. In about 65% of the samples there was a period of backward curvature (partial reversal of curvature) during the response. In some cases (about 15% of those showing a period of reverse bending) this period of backward curvature occurred before the root reached 90 degrees. Following transient backward curvature, downward curvature resumed and the root approached a final angle of about 90 degrees. In about 65% of the roots showing a period of reverse curvature, the roots curved steadily past the vertical, reaching maximum curvature about 205 +/- 65 min after gravistimulation. The direction of curvature then reversed back toward the vertical. After one or two oscillations about the vertical the roots obtained a vertical orientation and the distribution of growth within the root tip became the same as that prior to gravistimulation. The period of transient backward curvature coincided with and was evidently caused by enhancement of growth along the concave and inhibition of growth along the convex side of the curve, a pattern opposite to that prevailing in the earlier stages of downward curvature. There were periods during the gravitropic response when the normally unimodal growth-rate distribution within the elongation zone became bimodal with two peaks of rapid elongation separated by a region of reduced elongation rate. This occurred at different times on the convex and concave sides of the graviresponding root. During the period of steady downward curvature the elongation zone along the convex side extended farther toward the tip than in the vertical control. During the period of reduced rate of curvature, the zone of elongation extended farther toward the tip along the concave side of the root. The data show that the gravitropic response pattern varies with time and involves changes in localized elongation rates as well as changes in the length and position of the elongation zone. Models of root gravitropic curvature based on simple unimodal inhibition of growth along the lower side cannot account for these complex growth patterns.

  4. A program to help asthmatic students reach their potential.

    PubMed

    Esquibel, K P; Foster, C R; Garnier, V J; Saunders, M L

    1984-01-01

    Asthma is the most common chronic disease of childhood, affecting 15 percent of Americans under the age of 15. It ranks first among the chronic disease in causing school absenteeism, and it has been linked to lowered academic performance. An educational program for elementary school teachers has been developed to assist the asthmatic student in reaching his or her potential. The program addresses needs expressed by members of the Montgomery, Ala., chapter of Parents of Asthmatic Kids (PAK). These parents voiced concern regarding the inadequate preparation of teachers for dealing with the needs of the asthmatic student. Results of a survey of teachers in local elementary schools confirmed their need for asthma education. The program, consisting of an audiovisual presentation, an informative brochure, and an instructional packet to use with first to sixth graders, is designed to be presented in faculty meetings throughout the school system. To evaluate the effectiveness of the module, a simple test is administered before and after the program. The program has been accepted by the American Lung Association of Alabama and is under consideration by the American Lung Association at the national level. PMID:6444200

  5. Breakthrough capability for UVOIR space astronomy: reaching the darkest sky

    NASA Astrophysics Data System (ADS)

    Greenhouse, Matthew A.; Benson, Scott W.; Englander, Jacob; Falck, Robert D.; Fixsen, Dale J.; Gardner, Jonathan P.; Kruk, Jeffrey W.; Oleson, Steven R.; Thronson, Harley A.

    2014-08-01

    We describe how availability of new solar electric propulsion (SEP) technology can substantially increase the science capability of space astronomy missions working within the near-UV to far-infrared (UVOIR) spectrum by making dark sky orbits accessible for the first time. We present two case studies in which SEP is used to enable a 700 kg Explorer-class and 7000 kg flagship-class observatory payload to reach an orbit beyond where the zodiacal dust limits observatory sensitivity. The resulting scientific performance advantage relative to a Sun-Earth L2 point (SEL2) orbit is presented and discussed. We find that making SEP available to astrophysics Explorers can enable this small payload program to rival the science performance of much larger long development-time systems. Similarly, we find that astrophysics utilization of high power SEP being developed for the Asteroid Redirect Robotics Mission (ARRM) can have a substantial impact on the sensitivity performance of heavier flagship-class astrophysics payloads such as the UVOIR successor to the James Webb Space Telescope.

  6. Breakthrough capability for UVOIR space astronomy: Reaching the darkest sky

    NASA Astrophysics Data System (ADS)

    Greenhouse, Matthew A.; Benson, Scott W.; Englander, Jacob; Falck, Robert D.; Fixsen, Dale J.; Gardner, Jonathan P.; Kruk, Jeffrey W.; Oleson, Steven R.; Thronson, Harley A.

    2015-02-01

    We describe how availability of new solar electric propulsion (SEP) technology can substantially increase the science capability of space astronomy missions working within the near-UV to far-infrared (UVOIR) spectrum by making dark sky orbits accessible for the first time. We present a proof of concept case study in which SEP is used to enable a 700 kg Explorer-class observatory payload to reach an orbit beyond where the zodiacal dust limits observatory sensitivity. The resulting scientific performance advantage relative to a Sun-Earth L2 point orbit is presented and discussed. We find that making SEP available to astrophysics Explorers can enable this small payload program to rival the science performance of much larger long development-time systems. We also present flight dynamics analysis which illustrates that this concept can be extended beyond Explorers to substantially improve the sensitivity performance of heavier (7000 kg) flagship-class astrophysics payloads such as the UVOIR successor to the James Webb Space Telescope by using high power SEP that is being developed for the Asteroid Redirect Robotics Mission.

  7. Breakthrough Capability for UVOIR Space Astronomy: Reaching the Darkest Sky

    NASA Technical Reports Server (NTRS)

    Greenhouse, Matthew A.; Benson, Scott W.; Englander, Jacob; Falck, Robert D.; Fixsen, Dale J.; Gardner, Jonathan P.; Kruk, Jeffery W.; Oleson, Steven R.; Thronson, Harley A.

    2015-01-01

    We describe how availability of new solar electric propulsion (SEP) technology can substantially increase the science capability of space astronomy missions working within the near-UV to far-infrared (UVOIR) spectrum by making dark sky orbits accessible for the first time. We present two case studies in which SEP is used to enable a 700 kg Explorer-class and 7000 kg flagship-class observatory payload to reach an orbit beyond where the zodiacal dust limits observatory sensitivity. The resulting scientific performance advantage relative to a Sun-Earth L2 point (SEL2) orbit is presented and discussed. We find that making SEP available to astrophysics Explorers can enable this small payload program to rival the science performance of much larger long development-time systems. Similarly, we find that astrophysics utilization of high power SEP being developed for the Asteroid Redirect Robotics Mission (ARRM) can have a substantial impact on the sensitivity performance of heavier flagship-class astrophysics payloads such as the UVOIR successor to the James Webb Space Telescope.

  8. Breakthrough Capability for UVOIR Space Astronomy: Reaching the Darkest Sky

    NASA Technical Reports Server (NTRS)

    Greenhouse, Matthew A.; Benson, Scott W.; Englander, Jacob; Falck, Robert D.; Fixsen, Dale J.; Gardner, Jonathan P.; Kruk, Jeffrey W.; Oleson, Steven R.; Thronson, Harley A.

    2014-01-01

    We describe how availability of new solar electric propulsion (SEP) technology can substantially increase the science capability of space astronomy missions working within the near-UV to far-infrared (UVOIR) spectrum by making dark sky orbits accessible for the first time. We present a proof of concept case study in which SEP is used to enable a 700 kg Explorer-class observatory payload to reach an orbit beyond where the zodiacal dust limits observatory sensitivity. The resulting scientific performance advantage relative to a Sun-Earth L2 point orbit is presented and discussed. We find that making SEP available to astrophysics Explorers can enable this small payload program to rival the science performance of much larger long development-time systems. We also present flight dynamics analysis which illustrates that this concept can be extended beyond Explorers to substantially improve the sensitivity performance of heavier (7000 kg) flagship-class astrophysics payloads such as the UVOIR successor to the James Webb Space Telescope by using high power SEP that is being developed for the Asteroid Redirect Robotics Mission.

  9. How posture affects macaques' reach-to-grasp movements.

    PubMed

    Sartori, Luisa; Camperio-Ciani, Andrea; Bulgheroni, Maria; Castiello, Umberto

    2014-03-01

    Although there is a wealth of behavioral data regarding grasping movements in non-human primates, how posture influences the kinematics of prehensile behavior is not yet clearly understood. The purpose of this study was to examine and compare kinematic descriptions of grip behaviors while primates (macaque monkeys) were in a sitting posture or when stopping after quadrupedal locomotion (i.e., tripedal stance). Video footage taken while macaques grasped objects was analyzed frame-by-frame using digitalization techniques. Each of the two grip types considered (power and precision grips) was found to be characterized by specific, distinct kinematic signatures for both the reaching and the grasping components when those actions were performed in a sitting position. The grasping component did not differentiate in relation to the type of grip that was needed when, instead, the prehensile action took place in a tripedal stance. Quadrupedal locomotion affected the concomitant organization of prehensile activities determining in fact a similar kinematic patterning for the two grips regardless of the size of the object to be grasped. It is suggested that using a single kinematic grip patterning for all prehensile activities might be both the by-product of planning a grasping action while walking and a way to simplify motor programming during unstable tripedal stance. PMID:24337352

  10. Parametric design studies of long-reach manipulators

    SciTech Connect

    Kwon, D.S.; March-Leuba, S.; Babcock, S.M.; Burks, B.L.; Hamel, W.R.

    1993-11-01

    A number of different approaches have been studied for remediation of waste storage tanks at various sites. One of the most promising approaches is the use of a high-capacity, long-reach manipulation (LRM) system with a variety of end effectors for dislodging the waste. LRMs may have characteristics significantly different from those of industrial robots due to the long links needed to cover the large workspace. Because link lengths are much greater than their diameters, link flexibility, as well as joint or drive train flexibility, is likely to be significant. LRMs will be required for a variety of applications in the Environmental Restoration and Waste Management Program. While each application will present specific functional, kinematic, and performance requirements, a design approach for determining the kinematic applicability and performance characteristics considering link flexibility is presented with a focus on waste storage tank remediation. This paper addresses key design issues for LRM-based waste retrieval systems. It discusses the effects of parameters such as payload capacity, storage tanks size, and access port diameter on manipulator structural design. The estimated weight, fundamental natural frequency, and static deflection of the manipulator have been calculated for various parameter conditions.

  11. On reaching the adiabatic limit in multi-field inflation

    E-print Network

    Sébastien Renaux-Petel; Krzysztof Turzynski

    2014-12-29

    We calculate the scalar spectral index $n_s$ and the tensor-to-scalar ratio $r$ in a class of recently proposed two-field no-scale inflationary models in supergravity. We show that, in order to obtain correct predictions, it is crucial to take into account the coupling between the curvature and the isocurvature perturbations induced by the noncanonical form of the kinetic terms. This coupling enhances the curvature perturbation and suppresses the resulting tensor-to-scalar ratio to the per mille level even for values of the slow-roll parameter $\\epsilon \\sim 0.01$. Beyond these particular models, we emphasise that multifield models of inflation are a priori not predictive, unless one supplies a prescription for the post-inflationary era, or an adiabatic limit is reached before the end of inflation. We examine the conditions that enabled us to actually derive predictions in the models under study, by analysing the various contributions to the effective isocurvature mass in general two-field inflationary models. In particular, we point out a universal geometrical contribution that is important at the end of inflation, and which can be directly extracted from the inflationary Lagrangian, independently of a specific trajectory. Eventually, we point out that spectator fields can lead to oscillatory features in the time-dependent power spectra at the end of inflation. We demonstrate how these features can be model semi-analytically as well as the theoretical uncertainties they can entail.

  12. On reaching the adiabatic limit in multi-field inflation

    NASA Astrophysics Data System (ADS)

    Renaux-Petel, Sébastien; Turzy?ski, Krzysztof

    2015-06-01

    We calculate the scalar spectral index ns and the tensor-to-scalar ratio r in a class of recently proposed two-field no-scale inflationary models in supergravity. We show that, in order to obtain correct predictions, it is crucial to take into account the coupling between the curvature and the isocurvature perturbations induced by the noncanonical form of the kinetic terms. This coupling enhances the curvature perturbation and suppresses the resulting tensor-to-scalar ratio to the per mille level even for values of the slow-roll parameter epsilon ~ 0.01. Beyond these particular models, we emphasise that multifield models of inflation are a priori not predictive, unless one supplies a prescription for the post-inflationary era, or an adiabatic limit is reached before the end of inflation. We examine the conditions that enabled us to actually derive predictions in the models under study, by analysing the various contributions to the effective isocurvature mass in general two-field inflationary models. In particular, we point out a universal geometrical contribution that is important at the end of inflation, and which can be directly extracted from the inflationary Lagrangian, independently of a specific trajectory. Eventually, we point out that spectator fields can lead to oscillatory features in the time-dependent power spectra at the end of inflation. We demonstrate how these features can be model semi-analytically as well as the theoretical uncertainties they can entail.

  13. Recycling in 1998: States moving forward to reach higher goals

    SciTech Connect

    Heumann, J.M.; Egan, K.

    1998-08-01

    As the end of the decade--and century--approaches, the US still is working to push the recycling envelope. The US as a whole has reached its higher recycling rate ever--27%, according to the US EPA, and individual states are striving to meet and surpass their own recycling goals. Yet, it is difficult to compare rates and goals and budgets of individual states to one another, and come up with the nationwide trend in terms of recycling. Comparing recycling programs from state to state is like comparing apples and oranges. Individual states recycle a different amount of material, include a range of materials in their recycling-rate calculations, and have a variety of costs associated with performing these activities. Recycling in New York City is nothing like recycling in Boise, Idaho, for instance. This article presents information from all 50 states and the District of Columbia on their recycling rates, goals, waste generation rates, and the resources they have allocated toward recycling efforts.

  14. Lotic community responses in the Lees Ferry reach

    NASA Astrophysics Data System (ADS)

    McKinney, T.; Rogers, R. S.; Ayers, A. D.; Persons, W. R.

    Responses of periphyton, aquatic macrophytes, benthic macroinvertebrates, and rainbow trout to the 1996 controlled flood were investigated in the Lees Ferry tailwater reach below Glen Canyon Dam on the Colorado River. Lotic biota differed spatially and temporally in abundance and distribution following recession of flood waters, and there was no evidence that the flood benefitted trout or lower trophic levels. The flood was associated with short-term changes in lower trophic levels, but benthic vegetation and macrofauna with low resistance were resilient. Adverse impacts of the flood on lower trophic levels were greater and more prolonged in depositional areas than on cobble bar habitat, but recovery occurred in both habitat types 4-8 months after the flood. The flood likely resulted in some downstream displacement of smaller fish but had no effects on catch rate or condition indices of trout. Percentage of young-of-the-year trout 8 months after the event indicates that the flood did not prevent successful spawning. The flood had little direct influence on diets of trout, but relative gut volume increased in the week after the event, remained high in summer, and composition changed seasonally. Amphipods (Gammarus lacustris), chironomids, and snails were predominant food items, and Gammarus generally were eaten more often and comprised greater relative volume in the diet than other macroinvertebrate taxa.

  15. Reaching Out: The Bachelor of Arts Degree In Physics

    NASA Astrophysics Data System (ADS)

    Hobson, Art

    1996-05-01

    Physics degrees are not only for physicists. Our department believes that it would be healthy if attorneys, physicians, journalists, politicians, businesspeople, and others had undergraduate degrees in physics. Thus, we have begun offering a Bachelor of Arts degree in physics, for students who want to study physics as a background for other fields such as law (patents, environmental law), medical school, business (high-tech firms), journalism (science reporting, environmental reporting), music (accoustics, electronic music), and essentially any other profession. The program reaches outward, outside of physics, rather than pointing toward further work in physics. It begins with the algebra-based introductory course rather than the calculus-based course for future physicists and engineers. Two new courses are being created to provide these pre-professional students with broad science literacy and knowledge of physics-related technologies. The program is more flexible and less technical than the traditional Bachelor of Science program, allowing students time for outside electives and professional requirements in other fields.

  16. Reaching the Students: A New Approach to Enhancing Science Literacy

    NASA Astrophysics Data System (ADS)

    McNamara, B. J.; Burnham, C. C.

    2002-05-01

    Most NSF supported programs directed at improving science literacy among university students who are not majoring in SMET normally target instruction in introductory science or math classes. Unfortunately these efforts seldom reach the vast majority of students at a university because students can fulfil their science requirement by taking several other classes or class sections that are not impacted by the NSF program. Ideally it would be desirable to address the issues of science literacy and science anxiety among non-science majors in a single class that is required of essentially all undergraduates. We describe such a program which is being tested at NMSU. The targeted class is the university's freshman level English class. The idea behind this effort is to provide students with the skills they will need to be successful in their science classes in a less threatening humanities environment. We describe the problems that this approach raises, suggest solutions to these problems, and then discuss the overall status of this effort.

  17. Work Element B: 157. Sampling in Fish-Bearing Reaches [Variation in Productivity in Headwater Reaches of the Wenatchee Subbasin], Final Report for PNW Research Station.

    SciTech Connect

    Polivka, Karl; Bennett, Rita L.

    2009-03-31

    We studied variation in productivity in headwater reaches of the Wenatchee subbasin for multiple field seasons with the objective that we could develop methods for monitoring headwater stream conditions at the subcatchment and stream levels, assign a landscape-scale context via the effects of geoclimatic parameters on biological productivity (macroinvertebrates and fish) and use this information to identify how variability in productivity measured in fishless headwaters is transmitted to fish communities in downstream habitats. In 2008, we addressed this final objective. In collaboration with the University of Alaska Fairbanks we found some broad differences in the production of aquatic macroinvertebrates and in fish abundance across categories that combine the effects of climate and management intensity within the subbasin (ecoregions). From a monitoring standpoint, production of benthic macroinvertebrates was not a good predictor of drifting macroinvertebrates and therefore might be a poor predictor of food resources available to fish. Indeed, there is occasionally a correlation between drifting macroinvertebrate abundance and fish abundance which suggests that headwater-derived resources are important. However, fish in the headwaters appeared to be strongly food-limited and there was no evidence that fishless headwaters provided a consistent subsidy to fish in reaches downstream. Fish abundance and population dynamics in first order headwaters may be linked with similar metrics further down the watershed. The relative strength of local dynamics and inputs into productivity may be constrained or augmented by large-scale biogeoclimatic control. Headwater streams are nested within watersheds, which are in turn nested within ecological subregions; thus, we hypothesized that local effects would not necessarily be mutually exclusive from large-scale influence. To test this we examined the density of primarily salmonid fishes at several spatial and temporal scales within a major sub-basin of the Columbia River and associations of density with ecoregion and individuals drainages within the sub-basin. We further examined habitat metrics that show positive associations with fish abundance to see if these relationships varied at larger spatial scales. We examined the extent to which headwater fish density and temporal variation in density were correlated between the headwaters and the main tributaries of the sub-basin, and the influence of ecoregion influence on density differences, particularly at wider temporal scales. Finally, we examined demographic parameters such as growth and emigration to determine whether density-dependence differs among ecoregions or whether responses were more strongly influenced by the demography of the local fish population.

  18. Bimanual Reaching across the Hemispace: Which Hand Is Yoked to Which?

    ERIC Educational Resources Information Center

    Buckingham, Gavin; Binsted, Gordon; Carey, David P.

    2010-01-01

    When both hands perform concurrent goal-directed reaches, they become yoked to one another. To investigate the direction of this coupling (i.e., which hand is yoked to which), the temporal dynamics of bimanual reaches were compared with equivalent-amplitude unimanual reaches. These reaches were to target pairs located on either the left or right…

  19. Learning to Reach 1 Running head: CONSTRAINING THE MOVEMENT SEARCH SPACE

    E-print Network

    Massachusetts at Amherst, University of

    development during early infancy. However, learning to reach by trial­and­error normally requires a slow properties of the reaching task. We relate these results to the development of reaching during infancy in learning to reach during early infancy (Ashmead, McCarty, Lucas, & Belvedere, 1993; Bushnell, 1985; Clifton

  20. Intraspecific genetic analysis, gamete release performance, and growth of Sargassum muticum (Fucales, Phaeophyta) from China

    NASA Astrophysics Data System (ADS)

    Liu, Feng; Pang, Shaojun; Gao, Suqin; Shan, Tifeng

    2013-11-01

    Sargassum muticum is one of the most abundant and conspicuous native macroalgae species on the northern coasts of China. It often forms large-scale seaweed beds in subtidal zones. This investigation was designed to understand the intraspecific genetic relationships of this alga based on samples collected from four northern coastal sites of China, and to evaluate gamete release and growth capacity in laboratory conditions. The nuclear internal transcribed spacer 2 (ITS2) sequences of 16 samples from four locations were identical. Based on cox3 gene and partial rbcLS operon sequences, intraspecific genetic variability was detected with three and two ribotypes, respectively. Temperature, not irradiance, was shown to significantly affect gamete release and fertilization. Elevated temperature and irradiance enhanced the growth of germlings and vegetative branchlets. Maximum growth rate of germlings was detected at 18-24°C and an irradiance of 60-100 ?mol photons/(m2·s). Under ambient conditions (12-25°C and 60-125 ?mol photons/(m2·s)), relative growth rate of young branchlets could reach 7.5%/d.

  1. Live coral cover may provide resilience to damage from the vermetid gastropod Dendropoma maximum by preventing larval settlement

    NASA Astrophysics Data System (ADS)

    Phillips, N. E.; Shima, J. S.; Osenberg, C. W.

    2014-12-01

    Dendropoma maximum is a vermetid gastropod (a sessile tube-forming snail) commonly associated with living corals throughout shallow-water reefs of the Indo-Pacific. Recent work suggests that, once established, this species can adversely affect growth and survival of corals. Here, we test the hypotheses that disturbances to live coral substrates (e.g., creation of bare patches) facilitate successful larval settlement and subsequent population growth of D. maximum, and conversely, that live coral inhibits D. maximum settlement. In the shallow lagoon of Moorea, French Polynesia, we selected patch reefs where D. maximum was either present or absent (to evaluate potential effects of resident adult conspecifics on recruitment) and established focal quadrats on each reef. In each quadrat, we either experimentally removed 50 % of live coral cover or left the quadrat with 100 % live coral cover. In addition, we deployed units of bare substrate (coral rubble) to each reef. We conducted a census of deployed substrates and quadrats after 6 months and found that D. maximum settled irrespective of resident vermetid populations, and only onto nonliving surfaces (i.e., cleared patches in quadrats, coral rubble, and marine epoxy). In laboratory experiments, we exposed larvae of D. maximum to live coral and found species-specific effects on survival of D. maximum larvae. Porites lobata and Pocillopora sp. killed larvae of D. maximum, Porites rus caused weaker mortality, and Millepora sp. had no effect on larval survival. Collectively, these results suggest that D. maximum requires disturbances that create bare patches to successfully settle onto reefs, and that a high cover of living corals contributes resilience to reefs by limiting settlement opportunities of a species known to reduce coral growth and survival.

  2. Gauging the Nearness and Size of Cycle Maximum

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.; Hathaway, David H.

    2003-01-01

    A simple method for monitoring the nearness and size of conventional cycle maximum for an ongoing sunspot cycle is examined. The method uses the observed maximum daily value and the maximum monthly mean value of international sunspot number and the maximum value of the 2-mo moving average of monthly mean sunspot number to effect the estimation. For cycle 23, a maximum daily value of 246, a maximum monthly mean of 170.1, and a maximum 2-mo moving average of 148.9 were each observed in July 2000. Taken together, these values strongly suggest that conventional maximum amplitude for cycle 23 would be approx. 124.5, occurring near July 2002 +/-5 mo, very close to the now well-established conventional maximum amplitude and occurrence date for cycle 23-120.8 in April 2000.

  3. Synchronised electrical monitoring and high speed video of bubble growth associated with individual discharges during plasma electrolytic oxidation

    NASA Astrophysics Data System (ADS)

    Troughton, S. C.; Nominé, A.; Nominé, A. V.; Henrion, G.; Clyne, T. W.

    2015-12-01

    Synchronised electrical current and high speed video information are presented from individual discharges on Al substrates during PEO processing. Exposure time was 8 ?s and linear spatial resolution 9 ?m. Image sequences were captured for periods of 2 s, during which the sample surface was illuminated with short duration flashes (revealing bubbles formed where the discharge reached the surface of the coating). Correlations were thus established between discharge current, light emission from the discharge channel and (externally-illuminated) dimensions of the bubble as it expanded and contracted. Bubbles reached radii of 500 ?m, within periods of 100 ?s, with peak growth velocity about 10 m/s. It is deduced that bubble growth occurs as a consequence of the progressive volatilisation of water (electrolyte), without substantial increases in either pressure or temperature within the bubble. Current continues to flow through the discharge as the bubble expands, and this growth (and the related increase in electrical resistance) is thought to be responsible for the current being cut off (soon after the point of maximum radius). A semi-quantitative audit is presented of the transformations between different forms of energy that take place during the lifetime of a discharge.

  4. Growth inhibition and altered gene transcript levels in earthworms (Eisenia fetida) exposed to 2,2',4,4'-tetrabromodiphenyl ether.

    PubMed

    Xu, Xiang-Bo; Shi, Ya-Juan; Lu, Yong-Long; Zheng, Xiao-Qi; Ritchie, R J

    2015-07-01

    The toxic effects of the ubiquitous pollutant 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) on the earthworm Eisenia fetida were assessed by determining growth-inhibition and gene transcript levels of superoxide dismutase (SOD), catalase (CAT), glutathione transferase (GST), and transcriptional changes of the stress-response gene (heat-shock protein 70 [Hsp70]). Somatic growth and growth-inhibition rates in all BDE-47-treated groups were significantly different from those of the controls. The SOD gene transcripts were upregulated at all exposure doses and reached the maximum at the concentration of 400 mg/kg dry weight (dw) (3.84-fold, P < 0.01), which protected earthworms from oxidative stresses. However, downregulation of CAT and Hsp70 was present in all exposure doses and reached to the minimum at concentrations of 400 mg/kg dw (0.07-fold, P < 0.01 and 0.06-fold, P < 0.01, respectively). Upregulation of GST gene transcript level presented significant changes at concentrations of 10 (2.69-fold, P < 0.05) and 100 mg/kg dw (2.55-fold, P < 0.05). SOD maintained a dynamic balance to upregulate SOD expression to eliminate superoxide radicals in all dosage treatments, but downregulation of CAT decreased the ability to eliminate hydrogen peroxide. These changes could result in biochemical and physiological disturbances in earthworms. PMID:25600924

  5. Do persistent organic pollutants reach a thermodynamic equilibrium in the global environment?

    PubMed

    Schenker, Sebastian; Scheringer, Martin; Hungerbühler, Konrad

    2014-05-01

    Equilibrium partitioning between different environmental media is one of the main driving forces that govern the environmental fate of organic chemicals. In the global environment, equilibrium partitioning is in competition with long-range transport, advective phase transfer processes such as wet deposition, and degradation. Here we investigate under what conditions equilibrium partitioning is strong enough to control the global distribution of organic chemicals. We use a global multimedia mass-balance model to calculate the Globally Balanced State (GBS) of organic chemicals. The GBS is the state where equilibrium partitioning is in balance with long-range transport; it represents the maximum influence of thermodynamic driving forces on the global distribution of a chemical. Next, we compare the GBS with the Temporal Remote State, which represents the long-term distribution of a chemical in the global environment when the chemical's distribution is influenced by all transport and degradation processes in combination. This comparison allows us to identify the chemical properties required for a substance to reach the GBS as a stable global distribution. We find that thermodynamically controlled distributions are rare and do not occur for most Persistent Organic Pollutants. They are only found for highly volatile and persistent substances, such as chlorofluorocarbons. Furthermore, we find that the thermodynamic cold-trap effect (i.e., accumulation of pollutants at the poles because of reduced vapor pressure at low temperatures) is often strongly attenuated by atmospheric and oceanic long-range transport. PMID:24654605

  6. Estimate of Solar Maximum using the 1-8 \\AA$\\,$Geostationary Operational Environmental Satellites X-ray Measurements

    E-print Network

    Winter, L M

    2014-01-01

    We present an alternate method of determining the progression of the solar cycle through an analysis of the solar X-ray background. Our results are based on the NOAA Geostationary Operational Environmental Satellites (GOES) X-ray data in the 1-8 \\AA$\\,$band from 1986 - present, covering solar cycles 22, 23, and 24. The X-ray background level tracks the progression of the solar cycle through its maximum and minimum. Using the X-ray data, we can therefore make estimates of the solar cycle progression and date of solar maximum. Based upon our analysis, we conclude that the Sun reached its hemisphere-averaged maximum in Solar Cycle 24 in late 2013. This is within six months of the NOAA prediction of a maximum in Spring 2013.

  7. ESTIMATE OF SOLAR MAXIMUM USING THE 1-8 Å GEOSTATIONARY OPERATIONAL ENVIRONMENTAL SATELLITES X-RAY MEASUREMENTS

    SciTech Connect

    Winter, L. M.; Balasubramaniam, K. S.

    2014-10-01

    We present an alternate method of determining the progression of the solar cycle through an analysis of the solar X-ray background. Our results are based on the NOAA Geostationary Operational Environmental Satellites (GOES) X-ray data in the 1-8 Å band from 1986 to the present, covering solar cycles 22, 23, and 24. The X-ray background level tracks the progression of the solar cycle through its maximum and minimum. Using the X-ray data, we can therefore make estimates of the solar cycle progression and the date of solar maximum. Based upon our analysis, we conclude that the Sun reached its hemisphere-averaged maximum in solar cycle 24 in late 2013. This is within six months of the NOAA prediction of a maximum in spring 2013.

  8. Influence of the natural variability on the maximum discharges Q(p%)

    NASA Astrophysics Data System (ADS)

    Drobot, Radu; Florentin Draghia, Aurelian; Trandafir, Romica; Ciuiu, Daniel

    2015-04-01

    The maximum discharges during the flood period are quite variable from one year to another. For the design of the hydraulic structures the maximum discharges Q(p%)corresponding to probabilities of exceedance P% outside the current measured values are of practical interest. The maximum discharge Q(p%) is still not a unique value, but it depends on the data set used for the statistical processing. Thus for the same value of P%, during very wet years the values Q(p%) increase, while after a dry period the same characteristics decrease. In the present paper the influence of the sequence of maximum discharges on the magnitude of the values Q(p%) is put into evidence. First, based on a set of 78 values of maximum annual discharges at Turnu Magurele on the Danube river a set of 1000 values is generated by keeping as close as possible the statistical parameters of the initial set of data. Using a different number of sequence values (from 80 to 1000) the cumulative distribution functions are obtained. Even for medium probabilities of exceedance (meaning 1%) the curves dispersion is significant, the magnitude of the interval between the highest and the lowest values for Q(1%) being approximately 1300 m3/s. This interval is much larger for 0.1% probability of exceedance, reaching 1870 m3/s, which represent almost 10% of the most probable value of the maximum discharge Q(0,1%). The second approach is based only on the registered values. The initial set of 78 maximum discharges was split into an initial set of 30 values; further analysis were carried out by increasing step by step the number of the considered values from 31 to 78 values. The conclusions are the same: the maximum discharges are found in a quite large interval of uncertainty. This large interval could also be the consequence of climate changes. Still, a statistical test did not put into evidence any trend of the maximum discharges. The explanation is due probably to the large size of the Danube river basin, which is able to compensate the regional effects of the climate changes. Generally, one can conclude that the interval of uncertainty of the discharges Q(p%) is influenced not only by the climate changes, but also by the natural variability of the maximum discharges.

  9. Dimensionality of joint torques and muscle patterns for reaching.

    PubMed

    Russo, Marta; D'Andola, Mattia; Portone, Alessandro; Lacquaniti, Francesco; d'Avella, Andrea

    2014-01-01

    Muscle activities underlying many motor behaviors can be generated by a small number of basic activation patterns with specific features shared across movement conditions. Such low-dimensionality suggests that the central nervous system (CNS) relies on a modular organization to simplify control. However, the relationship between the dimensionality of muscle patterns and that of joint torques is not fixed, because of redundancy and non-linearity in mapping the former into the latter, and needs to be investigated. We compared the torques acting at four arm joints during fast reaching movements in different directions in the frontal and sagittal planes and the underlying muscle patterns. The dimensionality of the non-gravitational components of torques and muscle patterns in the spatial, temporal, and spatiotemporal domains was estimated by multidimensional decomposition techniques. The spatial organization of torques was captured by two or three generators, indicating that not all the available coordination patterns are employed by the CNS. A single temporal generator with a biphasic profile was identified, generalizing previous observations on a single plane. The number of spatiotemporal generators was equal to the product of the spatial and temporal dimensionalities and their organization was essentially synchronous. Muscle pattern dimensionalities were higher than torques dimensionalities but also higher than the minimum imposed by the inherent non-negativity of muscle activations. The spatiotemporal dimensionality of the muscle patterns was lower than the product of their spatial and temporal dimensionality, indicating the existence of specific asynchronous coordination patterns. Thus, the larger dimensionalities of the muscle patterns may be required for CNS to overcome the non-linearities of the musculoskeletal system and to flexibly generate endpoint trajectories with simple kinematic features using a limited number of building blocks. PMID:24624078

  10. Robots Explore the Farthest Reaches of Earth and Space

    NASA Technical Reports Server (NTRS)

    2008-01-01

    "We were the first that ever burst/Into that silent sea," the title character recounts in Samuel Taylor Coleridge s opus Rime of the Ancient Mariner. This famous couplet is equally applicable to undersea exploration today as surface voyages then, and has recently been applied to space travel in the title of a chronicle of the early years of human space flight ("Into That Silent Sea: Trailblazers of the Space Era, 1961-1965"), companion to the +n the Shadow of the Moon book and movie. The parallel is certainly fitting, considering both fields explore unknown, harsh, and tantalizingly inhospitable environments. For starters, exploring the Briny Deep and the Final Frontier requires special vehicles, and the most economical and safest means for each employ remotely operated vehicles (ROVs). ROVs have proven the tool of choice for exploring remote locations, allowing scientists to explore the deepest part of the sea and the furthest reaches of the solar system with the least weight penalty, the most flexibility and specialization of design, and without the need to provide for sustaining human life, or the risk of jeopardizing that life. Most NASA probes, including the historic Voyager I and II spacecraft and especially the Mars rovers, Spirit and Opportunity, feature remote operation, but new missions and new planetary environments will demand new capabilities from the robotic explorers of the future. NASA has an acute interest in the development of specialized ROVs, as new lessons learned on Earth can be applied to new environments and increasingly complex missions in the future of space exploration.

  11. An EVA Suit Fatigue, Strength, and Reach Model

    NASA Technical Reports Server (NTRS)

    Maida, James C.

    1999-01-01

    The number of Extra-Vehicular Activities (EVAs) performed will increase dramatically with the upcoming Space Station assembly missions. It is estimated that up to 900 EVA hours may be required to assemble the Space Station with an additional 200 hours per year for maintenance requirements. Efficient modeling tools will be essential to assist in planning these EVAS. Important components include strength and fatigue parameters, multi-body dynamics and kinematics. This project is focused on building a model of the EVA crew member encompassing all these capabilities. Phase 1, which is currently underway, involves collecting EMU suited and unsuited fatigue, strength and range of motion data, for all major joints of the body. Phase 2 involves processing the data for model input, formulating comparisons between the EMU suits and deriving generalized relationships between suited and unsuited data. Phase 3 will be formulation of a multi-body dynamics model of the EMU capable of predicting mass handling properties and integration of empirical data into the model. Phase 4 will be validation of the model with collected EMU data from the Neutral Buoyancy Laboratory at NASA/JSC. Engineers and designers will use tie EVA suit database to better understand the capabilities of the suited individuals. This knowledge will lead to better design of tools and planned operations. Mission planners can use the modeling system and view the animations and the visualizations of the various parameters, such as overall fatigue, motion, timelines, reach, and strength to streamline the timing, duration, task arrangement, personnel and overall efficiency of the EVA tasks. Suit designers can use quantifiable data at common biomechanical structure points to better analyze and compare suit performance.

  12. Dimensionality of joint torques and muscle patterns for reaching

    PubMed Central

    Russo, Marta; D'Andola, Mattia; Portone, Alessandro; Lacquaniti, Francesco; d'Avella, Andrea

    2014-01-01

    Muscle activities underlying many motor behaviors can be generated by a small number of basic activation patterns with specific features shared across movement conditions. Such low-dimensionality suggests that the central nervous system (CNS) relies on a modular organization to simplify control. However, the relationship between the dimensionality of muscle patterns and that of joint torques is not fixed, because of redundancy and non-linearity in mapping the former into the latter, and needs to be investigated. We compared the torques acting at four arm joints during fast reaching movements in different directions in the frontal and sagittal planes and the underlying muscle patterns. The dimensionality of the non-gravitational components of torques and muscle patterns in the spatial, temporal, and spatiotemporal domains was estimated by multidimensional decomposition techniques. The spatial organization of torques was captured by two or three generators, indicating that not all the available coordination patterns are employed by the CNS. A single temporal generator with a biphasic profile was identified, generalizing previous observations on a single plane. The number of spatiotemporal generators was equal to the product of the spatial and temporal dimensionalities and their organization was essentially synchronous. Muscle pattern dimensionalities were higher than torques dimensionalities but also higher than the minimum imposed by the inherent non-negativity of muscle activations. The spatiotemporal dimensionality of the muscle patterns was lower than the product of their spatial and temporal dimensionality, indicating the existence of specific asynchronous coordination patterns. Thus, the larger dimensionalities of the muscle patterns may be required for CNS to overcome the non-linearities of the musculoskeletal system and to flexibly generate endpoint trajectories with simple kinematic features using a limited number of building blocks. PMID:24624078

  13. Technology Transfer, Reaching the Market for Geopressured-Geothermal Resources

    SciTech Connect

    Wys, J. Negus-de

    1992-03-24

    Technology transfer to the industrial sector for geopressured-geothermal technology has included diverse strategies, with successes and obstacles or roadblocks. Numerical data are tabulated in terms of response to the various strategies. Strategy categories include the following: feasibility studies and reports, consortium activities and proceedings, the Geothermal Resource Council, national and international meetings of the American Association of Petroleum Geologists, other societal and organizational meetings, and conferences, Department of Energy solicitation of interest in the Commerce Business Daily, industry peer review panels, and the Secretary's Technology Initiative. Additionally, the potential of a 12-page color brochure on the geopressured-geothermal resource, workshops, and cooperative research and development agreement (CRADA) is discussed. In conclusion, what is the best way to reach the market and what is the winning combination? All of the above strategies contribute to technology transfer and are needed in some combination for the desired success. The most successful strategy activities for bringing in the interest of the largest number of industries and the independents are the consortium meetings, one-on-one telephone calling, and consortium proceedings with information service followup. the most successful strategy activities for bringing in the interest and participation of ''majors'' are national and international peer reviewed papers at internationally recognized industry-related society meetings, and on-call presentations to specific companies. Why? Because quality is insured, major filtering has already taken place, and the integrity of the showcase is established. Thus, the focused strategy is reduced to a target of numbers (general public/minors/independents) versus quality (majors). The numerical results of the activities reflecting four years of technology transfer following the 15 year lead in the early phases of geopressured-geothermal program under the leadership of Dr. Myron Dorfman, reflect a dynamic surveying of what works in technology transfer with industry in the area of geopressured-geothermal resources. The identified obstacles can be removed and future efforts can benefit by this cataloging and discussion of results.

  14. [The silent revolution: child survival has reached a crossroads].

    PubMed

    Bendahmane, D B

    1994-01-01

    Over the past three decades, programs to reduce infant and child mortality have spread to most regions of the globe, and improvements in mortality levels have raised life expectancy in developing countries from 50 years in 1965 to over 60 in 1986. Many of the surviving children, however, are impoverished, poorly educated, and living in inhospitable environments. Conditions have worsened for many in the recent past; the World Bank estimates that the proportion living in extreme poverty has increased from 22.4% in 1985 to 25.5% in 1990 in Latin America and the Caribbean. Extreme poverty, once a largely rural phenomenon, has been brought to the cities by millions of rural migrants. War and civil disturbances in many areas have added to the problems of children. UNICEF estimates that 1.5 million children have been killed and six million incapacitated in armed conflicts in the past decade. Advances in education have not kept pace with advances in child survival. In South America, 99% of children begin primary school, but only 48% finish the fourth grade. An estimated 100 million children worldwide leave school by the fifth grade. The very young age structures in most developing countries increase the difficulty of meeting the needs of children and youth. Means must be found to escape the downward spiral of poverty, excessive population growth, and environmental damage. Population control, infant and general mortality reduction, and education reduce the impact of this vicious cycle. Despite the proven contribution of improved female education to child survival, lower fertility, and improved living standards, many poor countries continue to discriminate against girls in education. The examples of some Asian countries such as Korea and Taiwan suggest that investment in primary and secondary education for all broadens the base for development and leads to longterm political stability. International donors, development agencies, and other organizations should invest in human capital so that poverty, rapid population growth, and environmental degradation acting synergistically do not become the dominant mode of underdevelopment in the next century. PMID:12290208

  15. TRENDS IN ESTIMATED MIXING DEPTH DAILY MAXIMUMS

    SciTech Connect

    Buckley, R; Amy DuPont, A; Robert Kurzeja, R; Matt Parker, M

    2007-11-12

    Mixing depth is an important quantity in the determination of air pollution concentrations. Fireweather forecasts depend strongly on estimates of the mixing depth as a means of determining the altitude and dilution (ventilation rates) of smoke plumes. The Savannah River United States Forest Service (USFS) routinely conducts prescribed fires at the Savannah River Site (SRS), a heavily wooded Department of Energy (DOE) facility located in southwest South Carolina. For many years, the Savannah River National Laboratory (SRNL) has provided forecasts of weather conditions in support of the fire program, including an estimated mixing depth using potential temperature and turbulence change with height at a given location. This paper examines trends in the average estimated mixing depth daily maximum at the SRS over an extended period of time (4.75 years) derived from numerical atmospheric simulations using two versions of the Regional Atmospheric Modeling System (RAMS). This allows for differences to be seen between the model versions, as well as trends on a multi-year time frame. In addition, comparisons of predicted mixing depth for individual days in which special balloon soundings were released are also discussed.

  16. Maximum life spiral bevel reduction design

    NASA Technical Reports Server (NTRS)

    Savage, M.; Prasanna, M. G.; Coe, H. H.

    1992-01-01

    Optimization is applied to the design of a spiral bevel gear reduction for maximum life at a given size. A modified feasible directions search algorithm permits a wide variety of inequality constraints and exact design requirements to be met with low sensitivity to initial values. Gear tooth bending strength and minimum contact ratio under load are included in the active constraints. The optimal design of the spiral bevel gear reduction includes the selection of bearing and shaft proportions in addition to gear mesh parameters. System life is maximized subject to a fixed back-cone distance of the spiral bevel gear set for a specified speed ratio, shaft angle, input torque, and power. Significant parameters in the design are: the spiral angle, the pressure angle, the numbers of teeth on the pinion and gear, and the location and size of the four support bearings. Interpolated polynomials expand the discrete bearing properties and proportions into continuous variables for gradient optimization. After finding the continuous optimum, a designer can analyze near optimal designs for comparison and selection. Design examples show the influence of the bearing lives on the gear parameters in the optimal configurations. For a fixed back-cone distance, optimal designs with larger shaft angles have larger service lives.

  17. Maximum mass of magnetic white dwarfs

    NASA Astrophysics Data System (ADS)

    Manreza Paret, Daryel; Horvath, Jorge Ernesto; Perez Martínez, Aurora

    2015-10-01

    We revisit the problem of the maximum masses of magnetized white dwarfs (WDs). The impact of a strong magnetic field on the structure equations is addressed. The pressures become anisotropic due to the presence of the magnetic field and split into parallel and perpendicular components. We first construct stable solutions of the Tolman-Oppenheimer-Volkoff equations for parallel pressures and find that physical solutions vanish for the perpendicular pressure when B ? 1013 G. This fact establishes an upper bound for a magnetic field and the stability of the configurations in the (quasi) spherical approximation. Our findings also indicate that it is not possible to obtain stable magnetized WDs with super-Chandrasekhar masses because the values of the magnetic field needed for them are higher than this bound. To proceed into the anisotropic regime, we can apply results for structure equations appropriate for a cylindrical metric with anisotropic pressures that were derived in our previous work. From the solutions of the structure equations in cylindrical symmetry we have confirmed the same bound for B ? 1013 G, since beyond this value no physical solutions are possible. Our tentative conclusion is that massive WDs with masses well beyond the Chandrasekhar limit do not constitute stable solutions and should not exist.

  18. Maximum likelihood continuity mapping for fraud detection

    SciTech Connect

    Hogden, J.

    1997-05-01

    The author describes a novel time-series analysis technique called maximum likelihood continuity mapping (MALCOM), and focuses on one application of MALCOM: detecting fraud in medical insurance claims. Given a training data set composed of typical sequences, MALCOM creates a stochastic model of sequence generation, called a continuity map (CM). A CM maximizes the probability of sequences in the training set given the model constraints, CMs can be used to estimate the likelihood of sequences not found in the training set, enabling anomaly detection and sequence prediction--important aspects of data mining. Since MALCOM can be used on sequences of categorical data (e.g., sequences of words) as well as real valued data, MALCOM is also a potential replacement for database search tools such as N-gram analysis. In a recent experiment, MALCOM was used to evaluate the likelihood of patient medical histories, where ``medical history`` is used to mean the sequence of medical procedures performed on a patient. Physicians whose patients had anomalous medical histories (according to MALCOM) were evaluated for fraud by an independent agency. Of the small sample (12 physicians) that has been evaluated, 92% have been determined fraudulent or abusive. Despite the small sample, these results are encouraging.

  19. Maximum windmill efficiency in finite time

    NASA Astrophysics Data System (ADS)

    Huleihil, Mahmoud

    2009-05-01

    The fraction of the kinetic energy of the wind impinging on the rotor-swept area that a wind turbine can convert to useful power has been shown by Betz in an idealized laminar-flow model to have an upper limit of 16/27 or 59% approximately [I. H. Shames, Mechanics of Fluids, 2nd ed. (McGraw-Hill, New York, 1982), pp. A26-A31]. This figure is known as Betz number. Other studies [A. Rauh and W. Seelret, Appl. Energy 17, 15 (1984)] suggested that this figure should be considered as a guideline. In this paper, a new model is introduced and its efficiency at maximum power output is derived. The derived value is shown to be a function of the Betz number B and given by the formula ?mp=1-?1-B . This value is 36.2%, which agrees well with those of actually operating wind turbines. As a guideline, the wind turbine efficiency can be considered to be within the range of the two numbers of merit, the Betz number and ?mp.

  20. Uncertainty analysis for Probable Maximum Precipitation estimates

    NASA Astrophysics Data System (ADS)

    Micovic, Zoran; Schaefer, Melvin G.; Taylor, George H.

    2015-02-01

    An analysis of uncertainty associated with Probable Maximum Precipitation (PMP) estimates is presented. The focus of the study is firmly on PMP estimates derived through meteorological analyses and not on statistically derived PMPs. Theoretical PMP cannot be computed directly and operational PMP estimates are developed through a stepwise procedure using a significant degree of subjective professional judgment. This paper presents a methodology for portraying the uncertain nature of PMP estimation by analyzing individual steps within the PMP derivation procedure whereby for each parameter requiring judgment, a set of possible values is specified and accompanied by expected probabilities. The resulting range of possible PMP values can be compared with the previously derived operational single-value PMP, providing measures of the conservatism and variability of the original estimate. To our knowledge, this is the first uncertainty analysis conducted for a PMP derived through meteorological analyses. The methodology was tested on the La Joie Dam watershed in British Columbia. The results indicate that the commonly used single-value PMP estimate could be more than 40% higher when possible changes in various meteorological variables used to derive the PMP are considered. The findings of this study imply that PMP estimates should always be characterized as a range of values recognizing the significant uncertainties involved in PMP estimation. In fact, we do not know at this time whether precipitation is actually upper-bounded, and if precipitation is upper-bounded, how closely PMP estimates approach the theoretical limit.