Sample records for reached maximum growth

  1. Have We Reached a Maximum Astronomical Research Output?

    NASA Astrophysics Data System (ADS)

    Abt, Helmut A.

    2010-08-01

    The US astronomical research output during the past 50 yr has been growing at 6 times the population increase and we wonder whether that ratio can continue. I counted pages of the AJ and ApJ for the past 50 yr, and corrected them for changes in format, foreign input, online contributions, and population increases. For the combined two journals, the American astronomical output is still increasing at a current 128 pages per million people. The same is true for UK contributions to the MNRAS, except that those lag behind the US by 10 yr. For Europe I did not want to dilute the contributions in A&A from the major producers with those of the countries still developing major astronomical centers. Therefore I counted pages for France, Germany, Italy, and the Netherlands (FGIN) only. However, Europeans still publish many of their articles in MNRAS, in particular, and ApJ. Counting FGIN articles in all four journals showed a steady rise but with a 12 yr lag behind the US. We conclude that the astronomical research rates in all three regions have not yet reached a maximum.

  2. On minimizing maximum transient energy growth

    Microsoft Academic Search

    James F. Whidborne; John McKernan; Anthony J. Steer

    2005-01-01

    Abstract The problem of minimizing the maximum,transient energy growth is considered. This problem has importance in some fluid flow control problems and other classes of non-linear systems. Conditions for the existence of static controllers that restrict the maximum,transient energy growth to unity are established. An explicit parametrization of all linear controllers ensuring monotonic decrease of the transient energy is derived.

  3. Maximum grasping reach of operators possessing functional impairments of the upper extremities

    E-print Network

    Goebel, Lucky Arlan

    1978-01-01

    ARM. HORIZONTAL POSITIOil 0 . 35 37 40 LIST OF FIGURES Figure WHEELCHAIR SUBJECT PERFORMING MAXIMUM GRASPING REACH VIEW OF THE CHAIR BASE BOARD SHOWING HORIZONTAL POSITION MARKINGS REAR VIEW OF ENTIRE MEASURING APPARATUS FRONT VIEW OF BOOM... by the subject, in conjunction with the measuring apparatus, simulates a disabled operator seated in a wheelchair or on a conventional type chair at a workbench. Extensive studies have been completed on the non-disabled seated operator to determine specific...

  4. Analysis of maximum reach in WDM PON architecture based on distributed Raman amplification and pump recycling technique.

    PubMed

    Kim, Chul Han; Lee, Ju Han; Lee, Kwanil

    2007-10-29

    We analyze the performance of bidirectional WDM PON architecture which utilizes distributed Raman amplification and pump recycling technique. The maximum reach at data rates of 622 Mb/s and 1.25 Gb/s in the proposed WDM PON architecture is calculated by taking into account the effects of power budget, chromatic dispersion of transmission fiber, and Raman amplification-induced noises with a given amount of Raman pump power. From the result, the maximum reach for 622 Mb/s and 1.25 Gb/s signal transmission is calculated to be 65 km and 60 km with a Raman pump power of 700 mW, respectively. We also find that the calculated results agree well with the experimental results which were reported previously. PMID:19550773

  5. On the Minimization of Maximum Transient Energy Growth

    Microsoft Academic Search

    James F. Whidborne; John McKernan

    2007-01-01

    The problem of minimizing the maximum transient energy growth is considered. This problem has importance in some fluid flow control problems and other classes of nonlinear systems. Conditions for the existence of static controllers that ensure strict dissipativity of the transient energy are established and an explicit parametrization of all such controllers is provided. It also is shown that by

  6. Have the "mega-journals" reached the limits to growth?

    PubMed

    Björk, Bo-Christer

    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

  7. 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

  8. 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

    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

  9. 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.

  10. Maximum Degree Growth of the Iterated Line Graph

    E-print Network

    Hartke, Stephen

    that is not a path, the inequality k+1 2k - 2 holds. Niepel, Knor, and Solt´es [3] have conjectured above, Niepel, Knor, and Solt´es [3] developed the following bounds for the maximum degree k and minimum (MDGP) if (L(G)) = 2(G) - 2. The conjecture of Niepel, Knor, and Solt´es can now be stated as follows

  11. Impact of seed source power on dispersion-limited maximum reach in WDM-PONs using broadband light source seeded optical sources.

    PubMed

    Kim, Chul Han

    2012-02-13

    The maximum reach in a WDM-PON using a broadband light source (BLS) seeded optical source has been experimentally evaluated by taking into account both effects of dispersion-induced pulse broadening and excess intensity noise (EIN) increase. In order to investigate the impact of BLS seed source power on the dispersion-limited performance, the system's performance has been measured and compared as a function of the spectrum-sliced BLS seed power into a reflective semiconductor optical amplifier (RSOA). From the results, we confirmed that the maximum reach in a RSOA based WDM-PON was mainly degraded by the dispersion-induced EIN increase. Therefore, by mitigating the effect of dispersion-induced EIN increase with a high seed power into a RSOA, the maximum reach in the WDM-PON using a BLS seeded RSOA source could be achieved to be ~60 km of single-mode fiber at the spectrum-sliced BLS seed power of >-10 dBm and a 1.25 Gb/s signal without using any dispersion-compensating techniques. PMID:22418106

  12. Effects of lag and maximum growth in contaminant transport and biodegradation modeling

    SciTech Connect

    Wood, B.D. [Pacific Northwest Lab., Richland, WA (United States); Dawson, C.N. [Rice Univ., Houston, TX (United States). Dept. of Mathematical Sciences

    1992-06-01

    The effects of time lag and maximum microbial growth on biodegradation in contaminant transport are discussed. A mathematical model is formulated that accounts for these effects, and a numerical case study is presented that demonstrates how lag influences biodegradation.

  13. Distribution and maximum growth depth of Fucus vesiculosus along the Gulf of Finland

    Microsoft Academic Search

    S. Bäck; A. Ruuskanen

    2000-01-01

    A survey of the distribution and maximum depth of a continuous Fucus vesiculosus belt was carried out in the Gulf of Finland in 1991. F. vesiculosus is widely distributed throughout the Gulf of Finland, including the vicinity of Vyborg Bay, Russia in the east. The maximum\\u000a growth depth of F. vesiculosus in the Gulf of Finland reflects two different patterns

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

    E-print Network

    Growth and Maximum Size of Tiger Sharks (Galeocerdo cuvier) in Hawaii Carl G. Meyer1 *, Joseph M. O , Mark A. Royer1 , Kim N. Holland1 1 Hawaii Institute of Marine Biology, University of Hawaii at Manoa, Honolulu, Hawai'i, United States of America, 2 National Marine Fisheries Service, Pacific Islands Fisheries

  15. Growth, yield and photosynthesis of Panicum maximum and Stylosanthes hamata under elevated CO2.

    PubMed

    Bhatt, R K; Baig, M J; Tiwari, H S; Roy, Sharmila

    2010-07-01

    Plant height, biomass production, assimilatory functions and chlorophyll accumulation of Panicum maximum and Stylosanthes hamata in intercropping systems was influenced significantly under elevated CO2 (600 +/- 50 ppm) in open top chambers (OTCs). The plant height increased by 32.0 and 49.0% over the control in P. maximum and S. hamata respectively in intercropping system under elevated CO2 over open field grown crops (Ca). P. maximum and S. hamata produced 67 and 85% higher fresh and dry biomass respectively under elevated CO2. Rates of photosynthesis and stomatal conductance increased in both the crop species in intercropping systems under elevated CO2. The canopy photosynthesis (photosynthesis x leaf area index) of these crop species increased significantly under elevated CO2 over the open grown crops. The chlorophyll a and b accumulation were also higher in the leaves of both the crop species as grown in OTC with elevated CO2. The increased chlorophyll content, leaf area index and canopy photosynthesis led to higher growth and biomass production in these crop species under elevated CO2. The total carbon sequestration in crop biomass and soils during the three years was 21.53 Mg C/ha under elevated CO2. The data revealed that P. maximum and S. hamata intercropping system is the potential as a sink for the increasing level of CO2 in the atmosphere in the semi-arid tropics. PMID:21186734

  16. Phytoplankton growth rates in the freshwater tidal reaches of the Schelde estuary (Belgium) estimated using a simple light-limited primary production model

    Microsoft Academic Search

    Koenraad Muylaert; Micky Tackx; Wim Vyverman

    2005-01-01

    During the course of 1996, phytoplankton was monitored in the turbid, freshwater tidal reaches of the Schelde estuary. Using a simple light-limited primary production model, phytoplankton growth rates were estimated to evaluate whether phytoplankton could attain net positive growth rates and whether growth rates were high enough for a bloom to develop. Two phytoplankton blooms were observed in the freshwater

  17. Relationship between the heat resistance of spores and the optimum and maximum growth temperatures of Bacillus species.

    PubMed Central

    Warth, A D

    1978-01-01

    Heat resistance of spores of Bacillus strains was compared with the temperature adaptation of each strain as measured by the optimum and maximum growth temperatures and the heat resistance of vegetative cells. Maximum growth temperatures ranged from 31 to 76 degrees C and were little affected by the nature of the growth medium. The temperature giving maximum growth rate was closely correlated to the maximum temperature for growth, and about 6 degrees C lower. Vetetative-cell heat resistance, determined on exponential-phase cells, was also correlated with maximum growth temperature. The temperature at which spores were inactivated with a decimal reduction time of 10 min was in the range of 75 to 121 degrees C. This temperature was 46 +/- 7 degrees C higher than the maximum growth temperature and correlated with it and the other cell parameters. Spore heat resistance can be considered to have two components, the temperature adaptation characteristic of the species and the stabilization conferred by the spore state. PMID:659368

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

    SciTech Connect

    Yuan, Z. [Univ. of Queensland (Australia). Advanced Wastewater Management Centre] [Univ. of Queensland (Australia). Advanced Wastewater Management Centre; [Univ. Gent (Belgium). Biomath Dept.; Bogaert, H. [R and D, Aartselaar (Belgium)] [R and D, Aartselaar (Belgium); [Univ. Gent (Belgium). Dept. of Microbial Ecology; Devisscher, M.; Vanrolleghem, P.; Verstraete, W. [Univ. Gent (Belgium)] [Univ. Gent (Belgium)

    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.

  19. Significance of river-aquifer interactions for reach-scale thermal patterns and trout growth potential in the Motueka River, New Zealand

    NASA Astrophysics Data System (ADS)

    Olsen, Dean A.; Young, Roger G.

    2009-02-01

    To assess whether reaches of the Motueka River (New Zealand) that gain water from groundwater were likely to represent significant cold-water refugia for brown trout during periods of high water temperatures, water temperature was monitored for more than 18 months in two gaining reaches of the Motueka River and three reaches that were predicted to be losing water to groundwater. These data were used to predict brown trout ( Salmo trutta) growth in gaining and losing reaches. Groundwater inputs had a small effect on water temperature at the reach-scale and modelling suggests that the differences observed were unlikely to result in appreciable differences in trout growth. Several coldwater patches were identified within the study reach that were up to 3.5°C cooler than the mainstem, but these were generally shallow and were unlikely to provide refuge for adult trout. The exception was Hinetai Spring, which had a mean water temperature of close to 16°C during the period January-March, when temperatures in the mainstem regularly exceeded 19°C. Trout were observed within the cold-water plume at the mouth of Hinetai Stream, which would allow them to thermoregulate when mainstem temperatures are unfavourable while still being able to capitalise on food resources available in the mainstem.

  20. Effects of light intensity on growth, anatomy and forage quality of two tropical grasses (Brachiaria brizantha and Panicum maximum var. trichoglume)

    Microsoft Academic Search

    B. Deinum; R. D. Sulastri; M. H. J. Zeinab; A. Maassen

    1996-01-01

    Effects of light intensity on growth, histology and anatomy, and nutritive value were studied in seedlings of two shade tolerant species: Brachiaria brizantha and Panicum maximum var. trichoglume. They were studied under greenhouse conditions in pots with sandy soil and sufficient N and cut after a growth period of 8 weeks. High light intensity stimulated growth, tillering and yield per

  1. 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

  2. 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

  3. Physiological and growth responses of C3 and C4 plants at the Pleistocene glacial maximum

    SciTech Connect

    Strain, B.R. [Duke Univ., Durham, NC (United States)

    1995-06-01

    A C3 plant (Abutilon theophrasti) and a C4 plant (Amaranthus retroflexus) were grown from seed in the Duke University Phytotron under four CO2 concentrations (15 Pa, below the Pleistocene minimum), 27 Pa (pre-industrial), 35 Pa (current), and 70 Pa (future) to examine photosynthetic, growth and reproduction responses of annual plants to historic and future levels of CO2. Net photosynthesis and growth were greatly inhibited at 15 Pa and greatly stimulated at 70 Pa. in the C3 Abutilon but only slightly affected in the C4 Amaranthus. Flower bud initiation was not affected by CO2 treatment in either species but all flower buds in 15 Pa CO2 aborted in the C3 within two days of appearance while no inhibition of reproduction was observed at low CO2 in the C4. Differences in physiology, growth and reproduction to the low levels of atmospheric CO2 of the Pleistocene suggest that competitive interactions of C3 and C4 annuals have changed through geologic time. A major question concerning the survival and evolution of obligate C3 annuals during the CO2 minima of the Pleistocene is raised by the results of this study.

  4. Reaching the hard to reach.

    PubMed

    Bhiwandi, P; Campbell, M; Potts, M

    1994-01-01

    The 1994 International Conference on Population and Development proposed increasing contraceptive couple protection from 550 million in 1995 to 880 million in 2015. The task for family planning (FP) programs is to provide access to services for, sometimes, inaccessible rural populations. FP need based on desire for no more children has ranged from under 20% in Senegal to almost 80% in Peru. Socioeconomic development was found not to be a prerequisite for fertility change. Gender inequalities in education and social autonomy must be changed. FP access is very important among women with a disadvantaged background or among women unsure about FP. Bangladesh is a good example of a country with increased contraceptive prevalence despite low income. The rule of thumb is that contraception increases of 15% contribute to a drop in family size of about one child. Program effectiveness is related to a variety of factors: contraceptive availability at many locations, acceptable price of contraception, delivery of the oral contraceptives without prescriptions, and other strategies. FP is a service not a medical treatment. A range of methods must be promoted and available from a range of facilities. Contraceptive use is dependent on the woman's stage in her lifecycle and is dependent on informed choice. Community-based distribution systems are effective, whereas free distribution by poorly-trained field workers is not always very effective because patient payment of all or part of the cost assures quality and freedom of choice. Effective programs for underprivileged groups involve aggressive, easy to manage programs that can be replicated rapidly. FP serves a useful function in depressing maternal mortality among the poor in Africa, who have no access to quality health services. Social marketing is an effective strategy for reaching remote areas. Political will and robust management are necessary commodities. PMID:12345832

  5. Growth Control of MoS2 Nanosheets on Carbon Cloth for Maximum Active Edges Exposed: An Excellent Hydrogen Evolution 3D Cathode.

    PubMed

    Zhang, Nan; Gan, Shiyu; Wu, Tongshun; Ma, Weiguang; Han, Dongxue; Niu, Li

    2015-06-10

    To greatly improve the hydrogen evolution reaction (HER) performance, it is the key approach to expose as many active edges of MoS2 as possible. This target is the research hotspot and difficulty of MoS2 which is a promising HER catalyst. In this work, we realized the active-edges control of MoS2 nanosheets on carbon cloth (CC) by growth control during the synthesis procedure. Moreover, MoS2 nanosheets vertically grown on carbon cloth (MoS2?CC) was confirmed to be the best morphology with maximum active edges exposed. Multifactors structure control resulted in abundant active-edges exposure and effective electron delivery, thus excellent HER activity. This three-dimensional cathode, MoS2?CC, can reach a great current density of 200 mA/cm(2) at a small overpotential of 205 mV. The preeminent HER performance can rival the best MoS2-based catalyst ever reported. PMID:25980786

  6. Effect of carbon substrate on electron acceptor diauxic lag and anoxic maximum specific growth rate in species with and without periplasmic enzyme

    Microsoft Academic Search

    Anna I. Casasús; Dong-Uk Lee; Ryan K. Hamilton; Spyros A. Svoronos; Ben Koopman

    2007-01-01

    The effect of oxidation state of carbon substrate on the diauxic lag of facultative anaerobic denitrifying bacteria growing aerobically upon switching to anoxic growth was studied. Also studied was the effect on the anoxic maximum specific growth rate. Two pure bacteria cultures were used, Paracoccus pantotrophus, denitrifying bacteria containing a periplasmic nitrate reductase (Nap), and Pseudomonas denitrificans, denitrifying bacteria lacking

  7. Interannual physiological and growth responses of glacial Juniperus to changes in atmospheric [CO2] since the Last Glacial Maximum

    NASA Astrophysics Data System (ADS)

    Gerhart, L. M.; Harris, J. M.; Ward, J. K.

    2011-12-01

    During the Last Glacial Maximum, atmospheric [CO2] was as low as 180 ppm and has currently risen to a modern value of 393 ppm as a result of fossil fuel combustion and deforestation. In order to understand how changing [CO2] influenced trees over the last 50,000 years, we analyzed carbon isotope ratios and width of individual tree rings from glacial Juniperus specimens preserved in the Rancho La Brea tar pits in southern California (aged 14-49 kyr BP). Modern trees were also analyzed to compare effects of changing precipitation, temperature and atmospheric [CO2] on physiology and growth. To assess physiological responses, we calculated ci/ca (intercellular [CO2]/atmospheric [CO2]) for each annual ring of each tree. This ratio incorporates numerous aspects of plant physiology, including stomatal conductance and photosynthetic capacity. In addition, we measured ring widths for each sample, and standardized these measurements into indices in order to compare across individuals. Mean ci/ca values remained constant throughout 50,000 years despite major environmental changes, indicating a long-term physiological set point for ci/ca in this group. Constant ci/ca ratios would be maintained through offsetting changes in stomatal conductance and photosynthetic capacity. Glacial Juniperus never experienced ci values below 90 ppm, suggesting a survival compensation point for Juniperus. In addition, glacial trees showed significantly reduced interannual variation in ci/ca, even though interannual climatic variability was as high during the LGM in this region as it is today. A lack of variability in ci/ca of glacial trees suggests that tree physiology was dominated by low [CO2], which shows low interannual variation. Modern trees showed high interannual variation in ci/ca, since water availability dominates current physiological responses and varies greatly from year to year. Interestingly, interannual variation in ring width index did not show significant differences between glacial and modern trees, suggesting these trees were adapted to maintain growth under low [CO2]. These adaptations may constrain the ability of modern trees to fully utilize increases in atmospheric [CO2]. These results have significant implications for our understanding of the adaptations of trees to changing [CO2] and indicate that the environmental factors that most strongly influence plant physiology may have changed over geologic time scales.

  8. Investigation of the maximum quantum yield of PS II in Haematococcus pluvialis cell cultures during growth: effects of chemical or high-intensity light treatment.

    PubMed

    Wang, Hui-Chih; Cho, Man-Gi; Riznichenko, Galina; Rubin, Andrey B; Lee, Ji-Hyun

    2011-09-01

    In this study, we investigated the increase in photosynthetic quantum yield that occurs in advance of increased microalgal growth. Haematococcus pluvialis was cultivated under normal conditions; the number of cells, the maximum quantum yield of photosystem II (F(v)/F(m)), and optical density were measured. We observed an increase in F(v)/F(m) approximately 72h prior to the cell growth phase. To confirm the relationship between photosynthetic yield and growth, samples were treated with several chemicals under high-intensity light illumination and control conditions to inhibit photosystem II and induce a decrease in the quantum photosynthetic yield. The samples were exposed to high-intensity light at an irradiance of 400?mol photonsm(-2)s(-1) for varied amount of time and were treated with chemicals such as 3-(3,4-dichlorophenyl)-1,1-dimethylurea, nigericin sodium salt and valinomycin. We observed that both the photooxidation of photosystem II reaction centers and the formation of transmembrane electrochemical gradients led to an initial decrease in fluorescence yield after the onset of high-intensity light illumination. We also observed that treatment of high-intensity light illuminated cells with antibiotics after adaptation to moderate light intensities caused a difference in photosynthetic activity. In conclusion, the maximum quantum yield of photosystem II is obtained prior to the cell growth phase and can therefore be used as a prediction parameter for cell growth. PMID:21592814

  9. Paclobutrazol and plant-growth promoting bacterial endophyte Pantoea sp. enhance copper tolerance of guinea grass ( Panicum maximum ) in hydroponic culture

    Microsoft Academic Search

    Wei HuoChun-hua; Chun-hua Zhuang; Ya Cao; Meng Pu; Hui Yao; Lai-qing Lou; Qing-sheng Cai

    As most gramineous plants, guinea grass (Panicum maximum) comprise cellulosic biomass, which may be used as a feedstock for bioenergy. In order to develop such potential energy plants\\u000a on copper-polluted lands, the hydroponic experiments with Cu, Paclobutrazol (PP333, a kind of antigibberellin) and plant growth-promoting\\u000a bacterial endophyte (PGPB) treatments were carried out in a greenhouse. The seedlings of two cultivars

  10. 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...

  11. 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

  12. Diet digestible energy content affects lysine utilization, but not dietary lysine requirements of rainbow trout ( Oncorhynchus mykiss) for maximum growth

    Microsoft Academic Search

    Pedro Encarnação; Cornelis de Lange; Markus Rodehutscord; Dirk Hoehler; Wafa Bureau; Dominique P Bureau

    2004-01-01

    The effect of diet composition on essential amino acid (EAA) utilization and requirements is a topic of some controversy in fish. A growth trial was conducted to examine the effect of diet digestible energy (DE) content on lysine utilization and lysine requirement in rainbow trout (Oncorhynchus mykiss). Twelve isoproteic (40% digestible protein (DP)) practical wheat-gluten-based diets, with two DE levels

  13. On Some Growth Properties of Entire Functions Using Their Maximum Moduli Focusing (p, q)th Relative Order

    PubMed Central

    Sanchez Ruiz, Luis Manuel; Datta, Sanjib Kumar; Biswas, Tanmay; Mondal, Golok Kumar

    2014-01-01

    We discuss some growth rates of composite entire functions on the basis of the definition of relative (p, q)th order (relative (p, q)th lower order) with respect to another entire function which improve some earlier results of Roy (2010) where p and q are any two positive integers. PMID:25530991

  14. Reaching Your Fitness Goals

    MedlinePLUS

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

  15. 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…

  16. REACH. Electricity Units. Secondary.

    ERIC Educational Resources Information Center

    Smith, Gene; Sappe, Hoyt

    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 electricity. The instructional units focus on electricity fundamentals and electric motors. Each unit follows a typical format that includes a unit sheet,…

  17. "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…

  18. 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.

  19. Pretoria Centre Reaches Out

    NASA Astrophysics Data System (ADS)

    Olivier, Bosman

    2014-08-01

    On 5 July 2014 six members of the Pretoria Centre of ASSA braved the light pollution of one of the shopping malls in Centurion to reach out to shoppers a la John Dobson and to show them the moon, Mars and Saturn. Although the centre hosts regular monthly public observing evenings, it was felt that we should take astronomy to the people rather than wait for the people to come to us.

  20. High Performance “Reach” Codes 

    E-print Network

    Edelson, J.

    2011-01-01

    Jim Edelson New 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..., Nov. 7 ? 9, 2011 ?31? Flavors 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...

  1. 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.

  2. Maximum Likelihood

    NSDL National Science Digital Library

    Siegrist, Kyle

    This material introduces the basic theory of maximum likelihood estimation by discussing the likelihood function, the log likelihood function, and maximizing these functions using calculus. Several exercises ask students to derive certain estimators, while others have students compare the behavior of those estimators with other possibilities through the use of various JAVA applets. The applets use the same control features: the sliders set the parameter values, the Â?Stop #Â? drop down menu sets the number of samples taken, the Â?Update #Â? drop down menu sets how often the graph and tables update during the experiment, the single arrow takes one sample, the double arrow runs the full experiment, the square stops the experiment, and the back arrow resets the applet. This page is one lesson from the Virtual Laboratories in Statistics.

  3. Factors Influencing Escherichia coli and Enterococcus durans Growth in Parenteral Nutrition With and Without Lipid Emulsion to Inform Maximum Duration of Infusion Policy Decisions.

    PubMed

    Austin, Peter David; Hand, Kieran Sean; Elia, Marinos

    2014-06-25

    Background: Recommendations effectively restrict the infusion duration of lipid-containing parenteral nutrition (PN) from a single bag, purportedly because it encourages growth of potential microbial contaminants more than lipid-free PN. Since other variables, including osmolarity, may independently affect microbial growth, this study examined variables affecting growth of Escherichia coli and Enterococcus durans in PN infusates. Materials and Methods: Growth of E coli and E durans was assessed in quadruplicate in 12 different PN infusates, with and without lipid, in varying glucose concentrations. Results: Results are presented as mean log10 colony-forming units (cfu)/mL ± SEM at 48 hours. The log10cfu/mL of both E coli and E durans in PN increased considerably after adjustment for baseline log10cfu/mL and pH, from 1.093 to 2.241 (P < .001) and from 0.843 to 3.451 (P < .001) respectively. Growth of each microorganism was independently increased by lipid inclusion, or increasing the proportion of nonnitrogen energy from lipid, and reduced by raising the glucose concentration or energy density. Increasing the osmolarity of lipid-PN with glucose or sodium chloride reduced growth but only significantly for sodium chloride (E coli, P = .025; E durans, P = .045). Induced changes in pH affected the growth of the 2 organisms differently. Conclusion: The presence of lipid and an increasing proportion of energy from lipid in PN favored the growth of E coli and E durans. Osmolarity changes and the nutrient type causing these changes independently affect the growth of these microbes. Each effect needs to be considered when establishing guidelines based on the growth of potential contaminants in different types of PN. PMID:24969406

  4. Reaching for the Unreachable: Reorganization of Reaching with Walking

    PubMed Central

    Grzyb, Beata J.; Smith, Linda B.; del Pobil, Angel P.

    2015-01-01

    Previous research suggests that reaching and walking behaviors may be linked developmentally as reaching changes at the onset of walking. Here we report new evidence on an apparent loss of the distinction between the reachable and nonreachable distances as children start walking. The experiment compared nonwalkers, walkers with help, and independent walkers in a reaching task to targets at varying distances. Reaching attempts, contact, leaning, and communication behaviors were recorded. Most of the children reached for the unreachable objects the first time it was presented. Nonwalkers, however, reached less on the subsequent trials showing clear adjustment of their reaching decisions with the failures. On the contrary, walkers consistently attempted reaches to targets at unreachable distances. We suggest that these reaching errors may result from inappropriate integration of reaching and locomotor actions, attention control and near/far visual space. We propose a reward-mediated model implemented on a NAO humanoid robot that replicates the main results from our study showing an increase in reaching attempts to nonreachable distances after the onset of walking.

  5. The most rapid possible growth of the maximum modulus of a canonical product of noninteger order with a prescribed majorant of the counting function of zeros

    SciTech Connect

    Popov, Anton Yu [M. V. Lomonosov Moscow State University, Faculty of Mechanics and Mathematics, Moscow (Russian Federation)

    2013-05-31

    Asymptotically sharp estimates for the logarithm of the maximum modulus of a canonical product are obtained in the case when the counting function of zeros has a prescribed majorant, while the arguments of the zeros can be arbitrary. Bibliography: 9 titles.

  6. Colony growth and the ontogeny of worker polymorphism in the fire ant, Solenopsis invicta

    Microsoft Academic Search

    Walter R. Tschinkel

    1988-01-01

    Colony size and worker polymorphism (headwidth) were determined for fire ant colonies ranging from incipient to 12 years of age. Colonies grew approximately logistically, reaching half size between 21\\/2 and 31\\/2 yr and reaching their maximum size of about 220000 workers after 4 to 6 yr. Colony size showed strong seasonal variation. There was some evidence that growth rate may

  7. Polyamine concentrations in four Poa species, differing in their maximum relative growth rate, grown with free access to nitrate and at limiting nitrate supply

    Microsoft Academic Search

    Emanuil Karanov; Vera Alexieva; Hans Lambers

    1998-01-01

    Polyamines are thought to play a role in the control of inherent or environmentally-induced growth rates of plants. To test this contention, we grew plants of four grass species, the inherently fast-growing Poa annua L. and Poa trivialis L. and the inherently slow-growing Poa compressa L. and Poa pratensis (L.) Schreb., at three levels of nitrate supply. Firstly, plants were

  8. Reaching ignition in the tokamak

    SciTech Connect

    Furth, H.P.

    1985-06-01

    This review covers the following areas: (1) the physics of burning plasmas, (2) plasma physics requirements for reaching ignition, (3) design studies for ignition devices, and (4) prospects for an ignition project. (MOW)

  9. Seasonal growth in Laminaria longicruris : Relations with dissolved inorganic nutrients and internal reserves of nitrogen

    Microsoft Academic Search

    A. R. O. Chapman; J. S. Craigie

    1977-01-01

    Observations have been made on seasonal fluctuations in dissolved inorganic nutrients, internal reserves of nitrogen and growth rates in Laminaria longicruris. The onset of winter growth in shallow-water stations (6 and 9 m) correlated well with improved dissolved nitrate conditions in the sea. During the winter, reserves of NO3-were accumulated by the plants and reached maximum values of 150 µmoles

  10. Changes in biologically active ultraviolet radiation reaching the Earth's surface

    Microsoft Academic Search

    S. Madronich; R. L. McKenzie; L. O. Björn; M. M. Caldwell; M. Ilyas

    1998-01-01

    Stratospheric ozone levels are near their lowest point since measurements began, so current ultraviolet-B (UV-B ) radiation levels are thought to be close to their maximum. Total stratospheric content of ozone-depleting substances is expected to reach a maximum before the year 2000. All other things eing equal, the current ozone losses and related UV-B increases should be close to their

  11. 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...

  12. Reaching First Year College Students

    Microsoft Academic Search

    Mary Kate Boyd-Byrnes; Dona McDermott

    2007-01-01

    In light of the new emphasis on information literacy, this research updates previous studies and explores current practices in first year library instruction and programming. Academic librarians are reaching out to freshmen seminar programs, first year orientations, Introduction to College courses, and English composition courses to integrate information-literacy instruction into the curriculum of these programs. This study will examine how

  13. 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…

  14. 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);…

  15. Growth characteristics of aquatic macrophytes cultured in nutrient-enriched water: I. Water hyacinth, water lettuce, and pennywort

    Microsoft Academic Search

    K. R. Reddy; W. F. Debusk

    1984-01-01

    Seasonal growth characteristics and biomass yield potential of 3 floating aquatic macrophytes cultured in nutrient nonlimiting\\u000a conditions were evaluated in central Florida’s climatic conditions. Growth cycle (growth curve) of the plants was found to\\u000a be complete when maximum plant density was reached and no additional increase in growth was recorded. Biomass yield per unit\\u000a area and time was found to

  16. 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

  17. Sampling hard to reach populations.

    PubMed

    Faugier, J; Sargeant, M

    1997-10-01

    Studies on 'hidden populations', such as homeless people, prostitutes and drug addicts, raise a number of specific methodological questions usually absent from research involving known populations and less sensitive subjects. This paper examines the advantages and limitations of nonrandom methods of data collection such as snowball sampling. It reviews the currently available literature on sampling hard to reach populations and highlights the dearth of material currently available on this subject. The paper also assesses the potential for using these methods in nursing research. The sampling methodology used by Faugier (1996) in her study of prostitutes, HIV and drugs is used as a current example within this context. PMID:9354993

  18. Feeding a diet contaminated with ochratoxin A for chickens at the maximum level recommended by the EU for poultry feeds (0.1 mg/kg). 1. Effects on growth and slaughter performance, haematological and serum traits.

    PubMed

    Pozzo, L; Salamano, G; Mellia, E; Gennero, M S; Doglione, L; Cavallarin, L; Tarantola, M; Forneris, G; Schiavone, A

    2013-05-01

    The European Commission Recommendation 2006/576/EC, suggests that the maximum level of Ochratoxin A (OTA) in poultry feeds should be set at 0.1 mg OTA/kg. Thirty-six one-day-old male Hubburd broiler chickens were divided into two groups, a Control (basal diet) and an Ochratoxin A (basal diet + 0.1 mg OTA/kg) group. The growth and slaughter performance traits were recorded. The liver, spleen, bursa of Fabricius and thymus weights were measured. The erythrocyte and leukocyte numbers were assayed in blood samples, and the heterophils to lymphocytes (H/L) ratio was determined. Alpha-1-acid glycoprotein (AGP), lysozyme, the total protein and the electrophoretic pattern were evaluated in serum samples. Liver enzymes (alanino aminotransferase, ALT and aspartate aminotransferase, AST) and kidney function parameters (uric acid and creatinine) were quantified. The results revealed that feeding a 0.1 mg OTA/kg contaminated diet to chicks caused a decrease in the absolute thymus weight (p < 0.05) and a lower total protein (p < 0.01), albumin (p < 0.01), alpha (p < 0.05), beta (p = 0.001) and gamma (p = 0.001) globulins serum concentration in the Ochratoxin A group. Moreover, the albumin-to-globulin (A/G) ratio of the OTA-treated animals resulted to be higher (p < 0.05). Feeding broiler chickens, a diet contaminated with the maximum level admitted by the European Commission Recommendation (0.1 mg OTA/kg), did not affect the animal performance, slaughter traits, organ weights, haematological parameters, liver enzyme or renal function parameters concentrations but had an overall immunosuppressant effect, with reduction in the thymus weight and of the total serum protein, albumin, alpha, beta and gamma globulins concentration. PMID:23639013

  19. 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.

  20. Agreement Reached on Fiji Hostages

    NSDL National Science Digital Library

    de Nie, Michael Willem.

    Fiji's military rulers and the group of gunmen holding 31 members of the former government hostage have apparently reached a deal that will end the five-week political crisis and free the hostages "within days." The crisis began when a group led by George Speight raided the parliament building on May 19, demanding more power for indigenous Fijians. Most of the demands made by Speight -- that the 1997 multiracial constitution be thrown out and that Prime Minister Mahendra Chaudhry, Fiji's first prime minister of Indian descent, be fired -- have already been met. In the 36 days since the storming of parliament, Fiji's economy has entered a steep downward spiral. On May 29, the military declared martial law and assumed control of the government. On June 6, Fiji was suspended from the Commonwealth, and Australia, New Zealand, and the United States have threatened economic sanctions if Fiji is not restored to democracy. Meanwhile, Australian trade unions have refused to handle cargo to and from Fiji, freezing much of the country's exports. The garment, sugar, and tourism industries have all reported large losses and layoffs. The military regime has announced that the details of the deal will be made known tomorrow, and the hostages will then be released. Previous announcements regarding their release, however, have come to nothing. Once the immediate crisis is solved, the military has said they will continue to run the country for another three months and would then create an interim government to make preparations for new elections within two years.

  1. REACH Report to the Rockefeller Foundation. Revised.

    ERIC Educational Resources Information Center

    Blodgett, Jack

    This document summarizes the activities of REACH, the Rural Education Alliance for Collaborative Humanities. REACH is an effort to strengthen rural education in South Carolina through writing and the study of local history and culture. Among REACH projects are the REACH School Programs, fostering student created research on the history and…

  2. Effect of physiological age on growth vigour of seed potatoes of two cultivars. 5. Review of literature and integration of some experimental results

    Microsoft Academic Search

    D. E. Van der Zaag; C. D. Van Loon

    1987-01-01

    The most important literature on physiological age is discussed and an attempt is made to describe the relationship between the chronological age and growth vigour of seed of cvs. Jaerla and Désirée produced in three seasons and stored at 4 or 12°C in darkness. The seed of both cultivars reaches maximum growth vigour earlier when stored at 12°C, although this

  3. Maximum grasping reach of operators possessing functional impairments of the upper extremities 

    E-print Network

    Goebel, Lucky Arlan

    1978-01-01

    anthropometric measurements. Judicious application of these measurements led to improved work station designs and greater operator efficiency. The literature provides a wealth of information dealing with the seated operator. However, despite this abundance..., numerous areas of interest remain unexplored. One of the unknown areas relates to anthropometric data applicable specifically to the seated handicapped operator. In some instances, measurements currently available on nondisabled or able operators could...

  4. 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

  5. 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…

  6. The usefulness of the reach angle concept for hazard zoning using statistical approach

    Microsoft Academic Search

    Michel Jaboyedoff; Andrea Pedrazzini

    2010-01-01

    Since Heim (1932) the reach angle or Farböschung or the shadow angle has been widely studied to estimate runout distance of landslides and snow avalanches. The distance used to determine the reach angle is based either on the maximum of runout distance or on a threshold distance. This discrepancy between deterministic and statistical approaches has to be explained. We inspected

  7. REACH: impact on the US cosmetics industry?

    PubMed

    Pouillot, Anne; Polla, Barbara; Polla, Ada

    2009-03-01

    The Registration, Evaluation, Authorization and restriction of Chemicals (REACH) is a recent European regulation on chemical substances meant to protect human health and the environment. REACH imposes the "precautionary principle" where additional data and definitive action are required when uncertainty is identified. The cosmetics industry is only partially concerned by REACH: while the stages of registration and evaluation apply to cosmetics, those of authorization and restriction most likely will not, as cosmetic ingredients are already subject to regulation by various agencies and directives. REACH has potential benefits to the industry including the possibility of reassuring consumers and improving their image of chemicals and cosmetics. However, REACH also has potential disadvantages, mainly with regard to impeding innovation. The American cosmetics industry will be affected by REACH, because all US manufacturers who export substances to Europe will have to fully comply with REACH. PMID:19250158

  8. Benchmarking for maximum value.

    PubMed

    Baldwin, Ed

    2009-03-01

    Speaking at the most recent Healthcare Estates conference, Ed Baldwin, of international built asset consultancy EC Harris LLP, examined the role of benchmarking and market-testing--two of the key methods used to evaluate the quality and cost-effectiveness of hard and soft FM services provided under PFI healthcare schemes to ensure they are offering maximum value for money. PMID:19344004

  9. Last Glacial Maximum

    NSDL National Science Digital Library

    Kristine DeLong

    In this activity for undergraduates, students explore the CLIMAP (Climate: Long-Range Investigation, Mapping and Prediction) model results for differences between the modern and the Last Glacial Maximum (LGM) and discover the how climate and vegetation may have changed in different regions of the Earth based on scientific data.

  10. Biology, not environment, drives major patterns in maximum tetrapod body size through time.

    PubMed

    Sookias, Roland B; Benson, Roger B J; Butler, Richard J

    2012-08-23

    Abiotic and biological factors have been hypothesized as controlling maximum body size of tetrapods and other animals through geological time. We analyse the effects of three abiotic factors--oxygen, temperature and land area--on maximum size of Permian-Jurassic archosauromorphs and therapsids, and Cenozoic mammals, using time series generalized least-squares regression models. We also examine maximum size growth curves for the Permian-Jurassic data by comparing fits of Gompertz and logistic models. When serial correlation is removed, we find no robust correlations, indicating that these environmental factors did not consistently control tetrapod maximum size. Gompertz models--i.e. exponentially decreasing rate of size increase at larger sizes--fit maximum size curves far better than logistic models. This suggests that biological limits such as reduced fecundity and niche space availability become increasingly limiting as larger sizes are reached. Environmental factors analysed may still have imposed an upper limit on tetrapod body size, but any environmentally imposed limit did not vary substantially during the intervals examined despite variation in these environmental factors. PMID:22513278

  11. EXECUTIVE SUMMARY: REACH OUT AND READ ASSESSMENT

    Microsoft Academic Search

    Jacqueline Gramann

    The Reach Out and Read Assessment (RORA) project was a quasi-experimental study designed to evaluate the effectiveness of a Reach Out and Read program. Reach Out and Read (ROR) is a non-profit, national organization that features giving parenting and literacy information to families. Books are given to their children at well-child visits between the ages of six months and five

  12. The effect of fluid flow on coiled tubing reach

    SciTech Connect

    Bhalla, K.; Walton, I.C.

    1996-12-31

    A critical parameter to the success of many coiled tubing (CT) operations in highly deviated or horizontal wells is the depth penetration that can be attained before the CT buckles and locks up. Achieving a desired depth is always critical in CT operations and attaining an additional reach of a few hundred feet can be crucial. This paper addresses the effect of fluid flow in the CT and in the CT/wellbore annulus on the state of force and stress in the CT, and thereby predicts its effect on the reach attainable by the CT. The flow of fluid through the CT and annulus between the CT and borehole modifies the pressures and the effective force which governs the mechanical stability of the CT. The net force per unit length due to fluid flow in the coiled tubing and annulus between the coiled tubing casing/well is calculated in terms of the shear stress and its effect on the onset of buckling and lockup is determined. The model is then implemented in a full tubing forces calculation and the effect of flowing fluids and producing fluids on reach is analyzed. The new model is utilized in the design of commercial jobs. The exact analytic model shows that fluid flow inside the CT has zero impact on reach, that downward flow in the annulus has a favourable impact, and upward flow in the annulus reduces the maximum attainable reach. Using the full tubing forces model, a coiled tubing job can be designed taking into account the flow of a fluid with a specified rheology, density and flow rate. Thus the feasibility of attaining a given reach can be more accurately determined. Results are presented in the form of the surface weight for commercial wells and compared to field jobs.

  13. Modeling the impact of the indigenous microbial population on the maximum population density of Salmonella on alfalfa.

    PubMed

    Rijgersberg, Hajo; Franz, Eelco; Nierop Groot, Masja; Tromp, Seth-Oscar

    2013-07-01

    Within a microbial risk assessment framework, modeling the maximum population density (MPD) of a pathogenic microorganism is important but often not considered. This paper describes a model predicting the MPD of Salmonella on alfalfa as a function of the initial contamination level, the total count of the indigenous microbial population, the maximum pathogen growth rate and the maximum population density of the indigenous microbial population. The model is parameterized by experimental data describing growth of Salmonella on sprouting alfalfa seeds at inoculum size, native microbial load and Pseudomonas fluorescens 2-79. The obtained model fits well to the experimental data, with standard errors less than ten percent of the fitted average values. The results show that the MPD of Salmonella is not only dictated by performance characteristics of Salmonella but depends on the characteristics of the indigenous microbial population like total number of cells and its growth rate. The model can improve the predictions of microbiological growth in quantitative microbial risk assessments. Using this model, the effects of preventive measures to reduce pathogenic load and a concurrent effect on the background population can be better evaluated. If competing microorganisms are more sensitive to a particular decontamination method, a pathogenic microorganism may grow faster and reach a higher level. More knowledge regarding the effect of the indigenous microbial population (size, diversity, composition) of food products on pathogen dynamics is needed in order to make adequate predictions of pathogen dynamics on various food products. PMID:23456855

  14. Homogeneous Growth of Zinc Oxide Whiskers

    NASA Astrophysics Data System (ADS)

    Saitoh, Hidetoshi; Satoh, Minoru; Tanaka, Norio; Ueda, Yoshikazu; Ohshio, Shigeo

    1999-12-01

    Several common modes of crystal growth provide particularly simple and elegant examples of spontaneous pattern formation not only in nature but also under artificial circumstances. We have already reported that well-organized ZnO whiskers are epitaxially grown using a chemical vapor deposition technique [Satoh et al..: Jpn. J. of Appl. Phys. 38 (1999) L586]. One aim of this study is to determine the optimum growth conditions for obtaining the structure containing homogeneous whiskers grown with a relatively high growth rate. A substrate temperature of 550°C and a vaporizing temperature of 125°C are the most appropriate for obtaining homogeneous whiskers. Whiskers are highly oriented in the a-and c-axes directions of the hexagonal structure. The growth rate reached a maximum value as high as 7.5 nm/s.

  15. Librarians' Role in Reach Out and Read

    Microsoft Academic Search

    Kerri Ann Christopher; David C. Duggar

    2008-01-01

    Librarians serving pediatricians have an opportunity to participate in establishing and\\/or maintaining a Reach Out and Read (ROR) program at their workplace. Reach Out and Read is a pediatric preliteracy program that targets at-risk children living in poverty. It addresses the link between poverty and illiteracy by equipping pediatricians with the tools they need to incorporate literacy counseling information into

  16. School Furniture Dimensions: Standing and Reaching.

    ERIC Educational Resources Information Center

    Department of Education and Science, London (England).

    Performance of school children in regard to their standing and reach postures are described with dimensions given on the limits of their performance only. The facts of task performances are presented for the following tasks--(1) seeing into a shelf, (2) reaching into a shelf, (3) drawing on a vertical surface, (4) sitting or standing while…

  17. Reaching Reluctant Students: Insights from Torey Hayden

    Microsoft Academic Search

    Mike Marlowe

    Abstract Students who fight or avoid adults cannot learn from them. This article illustrates important principles of reaching these challenging youngsters by using examples drawn from the writings of Torey Hayden. Hayden’s series of books are based on her rich experiences as a teacher of troubled children. ,,,,,“Reaching,Reluctant Students: Insights from Torey Hayden” ,,Torey Hayden's books are autobiographical accounts of

  18. 1999-01-1916 Simulating Reach Motions

    E-print Network

    Faraway, Julian

    to the famous "Bernstein's Problem" of how the human body overcomes an excessive number of degrees of freedom normal human reach behavior is dependent on many factors. Anthropometry, age, gender, joint mobility configurations, and tool weights are a few other task factors that can affect dynamic reach postures. This paper

  19. Population Growth

    NSDL National Science Digital Library

    2009-01-01

    These activities explore population growth rates and its consequences with regard to the distribution of natural resources. Population growth is perhaps the most important environmental issue of our time. As population increases and as people seek to raise their standard of living, more stress is put on our earth’s finite resources.One aspect of the population issue is the sheer magnitude of the numbers involved. World population did not reach 1 billion until the year 1800. Since then it has grown exponentially to reach our current 6.7 billion.

  20. 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.

  1. 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

  2. Parietal Reach Region Encodes Reach Depth Using Retinal Disparity and Vergence Angle Signals

    E-print Network

    Andersen, Richard

    the spiking activity of PRR neurons from two rhesus macaques trained to fixate and perform memory reaches to encode the direction of an intended reach movement to eccentric targets on a single frontoparallel plane

  3. Reach for Excellence The University of Leeds Reach for Excellence programme is inspiring bright teenagers from

    E-print Network

    Haase, Markus

    Reach for Excellence The University of Leeds Reach for Excellence programme is inspiring bright for Excellence builds on the success of an innovative pilot project, which over the course of four years has support of the Liz and Terry Bramall Foundation, the Reach for Excellence programme is now fully funded

  4. An Interim Evaluation of Teacher and Principal Experiences during the Pilot Phase of AISD Reach. Policy Evaluation Report

    ERIC Educational Resources Information Center

    Burns, Susan Freeman; Gardner, Catherine D.; Meeuwsen, Joyce

    2009-01-01

    In July 2007, the Austin Independent School District (AISD) began implementation of AISD REACH, a comprehensive and strategic compensation initiative. The initiative addressed three key areas: student growth, professional growth, and recruitment and retention of teachers and principals at highest needs schools. REACH combines an outcome-based pay…

  5. 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

  6. Growth yields and fermentation balance of Bacteroides fragilis cultured in glucose-enriched medium.

    PubMed Central

    Frantz, J C; McCallum, R E

    1979-01-01

    Bacteroides fragilis is an obligate anaerobic bacterium classified with the gram-negative, non-sporeforming bacilli and is the Bacteroides species most frequently isolated from human infections. In the present study, experiments were designed to investigate growth characteristics of B. fragilis in a complex medium. In a minimal defined medium, which was employed for comparison purposes, B. fragilis grew with a generation time of 2 h. Growth of the organism in glucose-enriched medium used in the present study was superior. Maximum generation time was 60 min. Total and viable cells (colony-forming units) were 8.9 x 10(9) and 2.1 x 10(9), respectively, at maximum measurable growth. The molar growth yield (Ym) was 51.5. Growth yields were found to reach a maximum 2 to 3 h before maximum growth and to vary with respect to the phase of growth. Estimates of the fermentation products indicated that glucose was the sole energy substrate. Major products included acetic acid, propionic acid, lactic acid, and succinic acid. Other products included ethyl alcohol, pyruvic acid, and fumaric acid. No attempt was made to recover CO2 or formic acid. The OR balances from two experiments were 0.013 and -0.093 and the respective carbon recoveries were 6.268 and 6.241. The results of the present study show that B. fragilis is capable of rapid rates of growth in vitro by using glucose as the sole energy source. PMID:438119

  7. Manual asymmetries in the kinematics of a reach-to-grasp action.

    PubMed

    Flindall, Jason W; Doan, Jon B; Gonzalez, Claudia L R

    2014-01-01

    In the present study, we manipulated the perceived demand of an ecologically valid task to investigate the possible presence of manual asymmetries in a reach-to-grasp action. Participants reached, grasped and sipped from a water glass under low (nearly empty) and high (nearly full) demand conditions. Participants reached to grasp in closed-loop, open-loop and delay visual conditions. Manual asymmetries were found in movement time, peak velocity and maximum grip aperture variability. Consistent with reach-to-point literature: (1) right-handed actions were completed in less time than left-handed actions in visually and memory-guided conditions; (2) right-handed movements were more accurate (i.e., produced more consistent maximum grip apertures) than left-handed movements in visually guided conditions. The results support a theory of left-hemisphere specialization for visual control of action. PMID:24350797

  8. Minimal Length, Friedmann Equations and Maximum Density

    E-print Network

    Adel Awad; Ahmed Farag Ali

    2014-06-14

    Inspired by Jacobson's thermodynamic approach[gr-qc/9504004], Cai et al [hep-th/0501055,hep-th/0609128] have shown the emergence of Friedmann equations from the first law of thermodynamics. We extend Akbar--Cai derivation [hep-th/0609128] of Friedmann equations to accommodate a general entropy-area law. Studying the resulted Friedmann equations using a specific entropy-area law, which is motivated by the generalized uncertainty principle (GUP), reveals the existence of a maximum energy density closed to Planck density. Allowing for a general continuous pressure $p(\\rho,a)$ leads to bounded curvature invariants and a general nonsingular evolution. In this case, the maximum energy density is reached in a finite time and there is no cosmological evolution beyond this point which leaves the big bang singularity inaccessible from a spacetime prospective. The existence of maximum energy density and a general nonsingular evolution is independent of the equation of state and the spacial curvature $k$. As an example we study the evolution of the equation of state $p=\\omega \\rho$ through its phase-space diagram to show the existence of a maximum energy which is reachable in a finite time.

  9. 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.

  10. Reach classifications of the lower Mississippi River

    Microsoft Academic Search

    L. A. Orlowski; S. A. Schumm; P. W. Mielke

    1995-01-01

    A classification of the lower Mississippi River into geomorphically distinct reaches provides an effective framework within which the influence of numerous morphologic variables can be analyzed. A singular realization of the river, however, requires that a statistical inference be applied to the results which provides a level of assurance to the conclusions. A nonparametric method, Multi-Response Permutation Procedures (MRPP), is

  11. 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…

  12. Intramural Sports Official Reaches All-American

    E-print Network

    Almor, Amit

    Intramural Sports position a student can reach at Carolina. Outdoor Recreation Hosts Exam Week Stress-breaker Outdoor Recreation held its third De- Stress for Success: Exam Breaker for students on Monday, April 23. The four- hour event attracted a variety of students to enjoy fun activities and to break from studying. De-Stress

  13. 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…

  14. REACH. Electricity Units, Post-Secondary.

    ERIC Educational Resources Information Center

    Smith, Gene; And Others

    As a part of the REACH (Refrigeration, Electro-Mechanical, Air-Conditioning, Heating) electromechanical cluster, this postsecondary student manual contains individualized instructional units in the area of electricity. The instructional units focus on electricity fundamentals, electric motors, electrical components, and controls and installation.…

  15. Increasing TLB reach using TCAM cells 

    E-print Network

    Kumar, Anuj

    2005-02-17

    . To support dynamic aggregation, we introduce the use of ternary-CAM (TCAM) cells at the second-level TLB. The modified TLB architecture results in an increase of TLB reach without additional CAM entries. We also adopt bulk prefetching concurrently...

  16. Kinematic analysis of reaching in the cat

    Microsoft Academic Search

    J. H. Martin; S. E. Cooper; C. Ghez

    1995-01-01

    The present study examines the kinematic features of forelimb movements made by cats reaching for food in horizontal target wells located at different heights and distances. Wrist paths consisted of two relatively straight segments joined at a “via-point” in front of the aperture of the food well. In the initial lift phase, the paw was raised to the via-point in

  17. Reaching 6th through 8th

    E-print Network

    Smith, Alice E.

    th and 7th grades), and Cynda Fickert, a math teacher at Auburn Junior High School (8th grade of 6th and 7th graders and a math teacher of 8th graders joined the research team on the projectReaching 6th through 8th Grade Students through the National Science Foundation Research

  18. 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

  19. Dark Matter Reach of the MAJORANA DEMONSTRATOR

    NASA Astrophysics Data System (ADS)

    Vorren, Kristopher; Majorana Collaboration

    2013-10-01

    Neutrinoless double-beta decay experiments are reducing backgrounds to unprecedented levels, allowing them to expand their physics reach. The MAJORANA DEMONSTRATOR is currently being built at the 4850 ft level of the Sanford Underground Research Facility (SURF) in Lead, SD. The experiment will utilize multiple p-type point-contact (PPC) germanium detectors constructed from approximately 40 kg of ultra-pure germanium (30 kg enriched) and radiopure components. Because of the large overburdern, low thresholds, and low background of the experiment, the DEMONSTRATOR will be well positioned to search for light (<10 GeV/c2) WIMPs. To do so, the low energy region (<20 keV) of the DEMONSTRATOR spectrum will need to be well characterized. This talk will discuss backgrounds in this region and the potential dark matter reach of the MAJORANA DEMONSTRATOR. This work is supported by grants from the DOE Office of Nuclear Physics and the NSF Particle Astrophysics program.

  20. Uncalibrated Visual Servoing in Reaching Tasks

    Microsoft Academic Search

    E. Grosso; G. Metta; A. Oddera; G. Sandini

    1995-01-01

    Designing robotic systems aimed to act in unstructured and generally dynamic environments,sensory capabilities become a key for intelligent behaviors. This paperdescribes a calibration-free approach to the problem of reaching an object in spaceunder visual guidance. Servoing is based on binocular vision: a continuous measureof the end-effector motion field, derived from real-time computation of the binocularoptical flow over the stereo images,

  1. Phenomenological model of UV-induced Bragg grating growth in germanosilicate fibers

    NASA Astrophysics Data System (ADS)

    Huebner, Joerg; Svalgaard, Mikael; Gruener-Nielsen, Lars; Kristensen, Martin

    1997-01-01

    Germanium doped glasses show a permanent increase of the refractive index after illumination with UV light. With a UV interference pattern produced by a phasemask, permanent Bragg gratings can be induced in optical fibers and planar waveguides. The growth of these Bragg gratings shows oscillations meaning that the grating reflectivity raises, reaches a maximum, then vanishes slowly and raises again to another maximum. We have recorded the first oscillation in more than ten different non-sensitized germanosilicate fibers. In this paper we present a model of the growth behavior, relating it to the visibility of the interference pattern generated by the phasemask, showing that the coherence of the laser light used to induce the grating has a strong influence on the growth behavior of the Bragg grating. The model is in excellent agreement with the measured grating growth behavior.

  2. Progress Report, June 1974: Reaching Out...

    ERIC Educational Resources Information Center

    Research for Better Schools, Inc., Philadelphia, PA.

    This report reviews programs of individualized instruction in the basic skills of mathematics, language arts, science, and social education as well as in new curriculums which foster the skills needed for social education as well and emotional growth. The development and operation of an experience-based model for career education is described, and…

  3. 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.

  4. Rapid and transitory stimulation of 3-O-methylglucose transport by growth hormone

    Microsoft Academic Search

    C. Carter-Su; F. W. Rozsa; Xueyan Wang; J. R. Stubbart

    1988-01-01

    The regulation of hexose transport by growth hormone (GH) was investigated using isolated rat adipocytes. GH caused a rapid (<3 min) rise in rates of 3-O-methylglucose transport that reached a maximum of two to six times the basal rates in 10-30 min. The stimulation of transport was transitory, and rates of transport started to decline 15-30 min after GH was

  5. 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

  6. 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.

  7. A model for learning human reaching movements.

    PubMed

    Karniel, A; Inbar, G F

    1997-09-01

    Reaching movement is a fast movement towards a given target. The main characteristics of such a movement are straight path and a bell-shaped speed profile. In this work a mathematical model for the control of the human arm during ballistic reaching movements is presented. The model of the arm contains a 2 degrees of freedom planar manipulator, and a Hill-type, non-linear mechanical model of six muscles. The arm model is taken from the literature with minor changes. The nervous system is modeled as an adjustable pattern generator that creates the control signals to the muscles. The control signals in this model are rectangular pulses activated at various amplitudes and timings, that are determined according to the given target. These amplitudes and timings are the parameters that should be related to each target and initial conditions in the work-space. The model of the nervous system consists of an artificial neural net that maps any given target to the parameter space of the pattern generator. In order to train this net, the nervous system model includes a sensitivity model that transforms the error from the arm end-point coordinates to the parameter coordinates. The error is assessed only at the termination of the movement from knowledge of the results. The role of the non-linearity in the muscle model and the performance of the learning scheme are analysed, illustrated in simulations and discussed. The results of the present study demonstrate the central nervous system's (CNS) ability to generate typical reaching movements with a simple feedforward controller that controls only the timing and amplitude of rectangular excitation pulses to the muscles and adjusts these parameters based on knowledge of the results. In this scheme, which is based on the adjustment of only a few parameters instead of the whole trajectory, the dimension of the control problem is reduced significantly. It is shown that the non-linear properties of the muscles are essential to achieve this simple control. This conclusion agrees with the general concept that motor control is the result of an interaction between the nervous system and the musculoskeletal dynamics. PMID:9352631

  8. Limitations of extended reach drilling in deepwater 

    E-print Network

    Akinfenwa, Akinwunmi Adebayo

    2000-01-01

    , 000-ft departure. This is illustrated in Fig. 2. 1. 1. In March 1999, Total drilled a world record extended reach well, horizontal- displacement (HD) 34, 728-ft, measured depth (MD) 36, 693-ft from an onshore location in Tierra del Fuego, Argentina... V V V V V V W V V V XXX XX X X X XX X X X VV VVV VV V WW WW X X 'X X X X X X X X X X 'X X V W V V V V V W V V V X X X X X X X X X X Y X X X V W V V V V V V V V V X? X XX XX X XX XXX X X V VV VV VVV VV V ?+ -i 4 X X X X X X X X X X W V V V V V V...

  9. The Generalization of Prior Uncertainty during Reaching

    PubMed Central

    Stevenson, Ian H.; Vilares, Iris; Kording, Konrad P.

    2014-01-01

    Bayesian statistics defines how new information, given by a likelihood, should be combined with previously acquired information, given by a prior distribution. Many experiments have shown that humans make use of such priors in cognitive, perceptual, and motor tasks, but where do priors come from? As people never experience the same situation twice, they can only construct priors by generalizing from similar past experiences. Here we examine the generalization of priors over stochastic visuomotor perturbations in reaching experiments. In particular, we look into how the first two moments of the prior—the mean and variance (uncertainty)—generalize. We find that uncertainty appears to generalize differently from the mean of the prior, and an interesting asymmetry arises when the mean and the uncertainty are manipulated simultaneously. PMID:25143626

  10. Project Outreach: Organizations Unified to Reach Youth.

    PubMed Central

    Dunnington, B C; Hayes, M L

    1989-01-01

    Youths of today are forced to deal with the external pressures of alcohol and drug abuse on all levels-from the older youngsters across the street pressuring them to be "cool," to the "cute dog" enticing them with the glamour of being the original "party animal." Through today's mass communications, young people are exposed to negative, self-destructive attitudes. It is important, therefore, to expose them to a more positive influence and try to reach them through parental guidance, personal contact, and peer pressure. To achieve this, the University of Missouri's Kansas City Chapter of the American Pharmaceutical Association's Academy of Students of Pharmacy, in conjunction with the Metropolitan Kansas City Area Task Force on Alcohol and Other Drug Abuse, proposed the development of an annual drug abuse prevention program that specifically targets fifth graders in the greater Kansas City metropolitan area. A primary goal of Project Outreach (Organizations Unified to Reach Youth) is to unite drug abuse prevention programs in the greater Kansas City metropolitan area in their outreach efforts to give positive support to Kansas City's youth against alcohol and other drugs. Phase I of Project Outreach consisted of a series of programs for the parents in the community. Phase II entailed college students who spoke to fifth graders in their classrooms. These students also participated in poster and poem contents centered around drug abuse prevention. In Phase III, which featured an outstanding, motivated speaker, the sample group of 600 fifth graders in the area participated in a major event to give positive peer pressure to say no to drugs.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2493666

  11. Principles of maximum entropy and maximum caliber in statistical physics

    NASA Astrophysics Data System (ADS)

    Pressé, Steve; Ghosh, Kingshuk; Lee, Julian; Dill, Ken A.

    2013-07-01

    The variational principles called maximum entropy (MaxEnt) and maximum caliber (MaxCal) are reviewed. MaxEnt originated in the statistical physics of Boltzmann and Gibbs, as a theoretical tool for predicting the equilibrium states of thermal systems. Later, entropy maximization was also applied to matters of information, signal transmission, and image reconstruction. Recently, since the work of Shore and Johnson, MaxEnt has been regarded as a principle that is broader than either physics or information alone. MaxEnt is a procedure that ensures that inferences drawn from stochastic data satisfy basic self-consistency requirements. The different historical justifications for the entropy S=-?ipilog?pi and its corresponding variational principles are reviewed. As an illustration of the broadening purview of maximum entropy principles, maximum caliber, which is path entropy maximization applied to the trajectories of dynamical systems, is also reviewed. Examples are given in which maximum caliber is used to interpret dynamical fluctuations in biology and on the nanoscale, in single-molecule and few-particle systems such as molecular motors, chemical reactions, biological feedback circuits, and diffusion in microfluidics devices.

  12. Reaching site closure for groundwater under multiple regulatory agencies

    SciTech Connect

    Glucksberg, N. [MACTEC, Inc., Portland, ME (United States); Couture, B. [Connecticut Yankee Atomic Power Company, East Ham (United States)

    2007-07-01

    Groundwater at the Connecticut Yankee Atomic Power Company (CYAPCO) Haddam Neck Plant (HNP) has been impacted by both radionuclides and chemical constituents. Furthermore, the cleanup standards and closure requirements for HNP are regulated both by federal and state agencies. The only consistent requirement is the development of a site conceptual model and an understanding of the hydrogeologic conditions that will govern contaminant transport and identify potential receptors. The cleanup criteria to reach site closure for radionuclides is regulated by both the Nuclear Regulatory Commission (NRC) and the Connecticut Department of Environmental Protection (CTDEP) Bureau of Air Management, Radiological Division. For license termination under the NRC, the total effective dose equivalent (TEDE) for all media can not exceed 25 milli-Rem per year (mRem/yr) plus As Low as Reasonably Achievable (ALARA). The CTDEP has a similar requirement with the TEDE not to exceed 19 mRem/yr plus ALARA. To reach these criteria, derived concentration guideline levels (DCGLs) were developed for radiological exposures from three (3) media components; soil, existing groundwater and future groundwater from left-in place foundations or footings. Based on current conditions, the target dose contribution from existing and future groundwater is not to exceed 2 mRem/yr TEDE. After source (soil) remediation is complete, the NRC requires two (2) years of quarterly monitoring to demonstrate that groundwater quality meets the DCGLs and does not show an upward trend. CYAPCO's NRC License Termination Plan (LTP) specifies a minimum 18-month period of groundwater monitoring, as long as samples are collected during two spring/high water seasons, to verify the efficacy of remedial actions at HNP. In addition to the 19 mRem/yr criteria, the CTDEP also requires groundwater to be in compliance with the Remediation Standards Regulation (RSRs). There are no published criteria for radionuclides in the RSRs, however CTDEP has approved the United States Environmental Protection Agency's (USEPA's) Maximum Contaminant Levels (MCLs) as the clean up standards for individual constituents. After remediation of an identified contamination source, the RSRs require that at least one groundwater monitoring well, hydraulically down-gradient of the remediation area, be sampled to confirm that the remediation has not impacted groundwater quality. After four quarters of groundwater monitoring with results below the MCLs, additional groundwater sampling must continue for up to three years to reach site closure in accordance with the RSRs. The cleanup criteria for chemical constituents, including boron, are regulated by the USEPA under the Resource Conservation and Recovery Act (RCRA) and the CTDEP Bureau of Water Protection and Land Reuse. The USEPA, however, has accepted the CTDEP RSRs as the cleanup criteria for RCRA. Therefore attainment of the CTDEP RSRs is the only set of criteria needed to reach closure, but both agencies retain oversight, interpretation, and closure authority. As stated above, under the RSRs, groundwater must be monitored following a source remediation for a minimum of four quarters. After demonstrating that the remediation was successful, then additional groundwater sampling is required for up to three additional years. However, the number of monitoring wells and frequency of sampling are not defined in the RSRs and must be negotiated with CTDEP. To successfully reach closure, the conceptual site model, groundwater transport mechanisms, and potential receptors must be defined. Once the hydrogeology is understood, a long term groundwater monitoring program can then be coordinated to meet each agencies requirement to both terminate the NRC license and reach site closure under RCRA. (authors)

  13. Coral mortality increases wave energy reaching shores protected by reef flats: Examples from the Seychelles

    Microsoft Academic Search

    Charles Sheppard; David J. Dixon; Michael Gourlay; Anne Sheppard; Rolph Payet

    2005-01-01

    In the granitic Seychelles, many shores and beaches are fringed by coral reef flats which provide protection to shores from erosion by waves. The surfaces of these reef flats support a complex ecology. About 10 years ago their seaward zones were extensively covered by a rich coral growth, which reached approximately to mean low water level, but in 1998 this

  14. 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

  15. Cell cycle checkpoint regulators reach a zillion

    PubMed Central

    Yasutis, Kimberly M.; Kozminski, Keith G.

    2013-01-01

    Entry into mitosis is regulated by a checkpoint at the boundary between the G2 and M phases of the cell cycle (G2/M). In many organisms, this checkpoint surveys DNA damage and cell size and is controlled by both the activation of mitotic cyclin-dependent kinases (Cdks) and the inhibition of an opposing phosphatase, protein phosphatase 2A (PP2A). Misregulation of mitotic entry can often lead to oncogenesis or cell death. Recent research has focused on discovering the signaling pathways that feed into the core checkpoint control mechanisms dependent on Cdk and PP2A. Herein, we review the conserved mechanisms of the G2/M transition, including recently discovered upstream signaling pathways that link cell growth and DNA replication to cell cycle progression. Critical consideration of the human, frog and yeast models of mitotic entry frame unresolved and emerging questions in this field, providing a prediction of signaling molecules and pathways yet to be discovered. PMID:23598718

  16. Growth of cranial volume: an anthropometric study.

    PubMed

    Purkait, Ruma

    2011-05-01

    The aim of the study is to follow the growth dynamics of cranial volume from birth to 18 years of age among 1623 central Indian subjects. Anthropometric technique was adopted to estimate the cranial volume using maximum length, width and auricular height of head. The mean cranial volume at birth is 376 cc in male and 308 cc in female i.e. 28% and 26% of the 18 years old volume. Within a year the volume reaches 65% in male and 59% in female of the adult size due to very rapid growth during the first six months after birth. The adult cranial volume at 18 years is 1329 cc in males and 1193 cc in females, approximately 3.5 and 4 times of the birth size respectively. The cranial volume reaches its adult size in females at 16 years of age and a year later in males. The present study has generated metrical norms for all growing ages and also the growth dynamics for cranial volume of Indian subjects which will be useful to physicians as a guideline in correcting cranial deformity. PMID:21315671

  17. Original article Simulation of the maximum yield of sugar cane

    E-print Network

    Paris-Sud XI, Université de

    Original article Simulation of the maximum yield of sugar cane at different altitudes: effect - To minimize the production costs of sugar cane, for the diverse sites of production found in La Réunion. Existing mod- els simulate poorly the temperature-radiation interaction. A model of sugar cane growth has

  18. 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)

  19. Maximum Chemical and Physical Hardness

    Microsoft Academic Search

    Ralph G. Pearson

    1999-01-01

    Density functional theory (DFT) is briefly reviewed, especially concepts such as the electronic chemical potential and the hardness of the electron density function. There is much evidence, and a mathematical proof, that this chemical hardness is a maximum for an equilibrium system. The proof is based on a combination of statistical mechanics, the fluctuation-dissipation theorem, and correlation functions. In MO

  20. 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.

  1. Salinity effect on plant growth and leaf demography of the mangrove, Avicennia germinans L

    Microsoft Academic Search

    N. Suárez; E. Medina

    2005-01-01

    We assessed the effect of salinity on plant growth and leaf expansion rates, as well as the leaf life span and the dynamics\\u000a of leaf production and mortality in seedlings of Avicennia germinans L. grown at 0, 170, 430, 680, and 940 mol m?3 NaCl. The relative growth rates (RGR) after 27 weeks reached a maximum (10.4 mg g?1 d?1) in 170 mol m?3 NaCl and decreased

  2. 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.

  3. Maximum cooling and maximum efficiency of thermoacoustic refrigerators

    NASA Astrophysics Data System (ADS)

    Tartibu, L. K.

    2015-06-01

    This work provides valid experimental evidence on the difference between design for maximum cooling and maximum efficiency for thermoacoustic refrigerators. In addition, the influence of the geometry of the honeycomb ceramic stack on the performance of thermoacoustic refrigerators is presented as it affects the cooling power. Sixteen cordierite honeycomb ceramic stacks with square cross sections having four different lengths of 26, 48, 70 and 100 mm are considered. Measurements are taken at six different locations of the stack hot ends from the pressure antinode, namely 100, 200, 300, 400, 500 and 600 mm respectively. Measurement of temperature difference across the stack ends at steady state for different stack geometries are used to compute the cooling load and the coefficient of performance. The results obtained with atmospheric air showed that there is a distinct optimum depending on the design goal.

  4. Reaching extra-solar-system targets via large post-perihelion lightness-jumping sailcraft

    Microsoft Academic Search

    Giovanni Vulpetti

    2011-01-01

    The fast solar sailing theory has been applied for the first time to a many-target two-spacecraft sailcraft mission concept with maximum lightness number significantly >1. The farthest target is the solar gravitational lens zone. 550AU are reached by the escaping sailcraft 17.5 years after the departure from the Earth–Moon system. Nanotechnology is required for the sail system envisaged for this

  5. Reaching remote areas in Latin America.

    PubMed

    Jaimes, R

    1994-01-01

    Poor communities in remote and inaccessible areas tend to not only be cut off from family planning education and services, but they are also deprived of basic primary health care services. Efforts to bring family planning to such communities and populations should therefore be linked with other services. The author presents three examples of programs to bring effective family planning services to remote communities in Central and South America. Outside of the municipal center in the Tuxtlas region of Mexico, education and health levels are low and people live according to ancient customs. Ten years ago with the help of MEXFAM, the IPPF affiliate in Mexico, two social promoters established themselves in the town of Catemaco to develop a community program of family planning and health care offering education and prevention to improve the quality of people's lives. Through their health brigades taking health services to towns without an established health center, the program has influenced an estimated 100,000 people in 50 villages and towns. The program also has a clinic. In Guatemala, the Family Welfare Association (APROFAM) gave bicycles to 240 volunteer health care workers to facilitate their outreach work in rural areas. APROFAM since 1988 has operated an integrated program to treat intestinal parasites and promote family planning in San Lucas de Toliman, an Indian town close to Lake Atitlan. Providing health care to more than 10,000 people, the volunteer staff has covered the entire department of Solola, reaching each family in the area. Field educators travel on motorcycles through the rural areas of Guatemala coordinating with the health volunteers the distribution of contraceptives at the community level. The Integrated Project's Clinic was founded in 1992 and currently carries out pregnancy and Pap tests, as well as general lab tests. Finally, Puna is an island in the middle of the Gulf of Guayaquil, Ecuador. Women on the island typically have 10-14 pregnancies, families are extremely poor, and the population long had access to neither basic health services nor modern contraceptives and birth control. The Association for Ecuadorian Family Welfare (APROFE) realized the importance of finding some way to provide the residents of Puna with family planning, maternal and child health care, and primary health care. To that end, the organization built a fiberglass boat, installed modern equipment, and hired a doctor, nurse, and sociologist-educator trained in family planning and primary health care who now serve the population. PMID:12345742

  6. XMM classroom competitions : reaching for the stars!

    NASA Astrophysics Data System (ADS)

    1999-09-01

    Partnered by a unique education network 'European Schoolnet'(*), ESA is today launching these three competitions for schools (age range: 8 to final year) in its Member States: draw a telescope, describe the benefits of space-based astronomy or produce an astronomy observation proposal. Details can be found on the special competition website : http://sci.esa.int/xmm/competition "Draw me a telescope!" This competition for 8 to 12 year-olds asks the class to draw a telescope (inside a 20 - 50 cm diameter circle). The 14 winning entries, one per Member State, will be included in a specially-designed official XMM mission logo to go on the Ariane-5 launcher fairing for official unveiling on launch day. A representative of each winning class will be invited to Kourou for the launch. Deadline for entries : 8 October 1999. For full information on how to enter see : http://sci.esa.int/xmm/competition "What's new, Mr Galileo?" The essay competition for 13 to 15 year-olds challenges an English class, writing in the international language of space, to submit a single page (500 words maximum) description of space-based astronomy and its benefits for humanity. The 14 winners, one per Member States, will be invited to Kourou to visit the Guiana Space Centre, Europe's spaceport, and witness final XMM launch preparations. Deadline for entries : 15 October 1999. For full information on how to enter see : http://sci.esa.int/xmm/competition. "Stargazing" In the final-year class competition, ESA is providing a unique opportunity to use the XMM telescope. Here, the physics class, assisted by the scientific community, has to submit an observation project. The 14 winning proposals will be put into practice in 2000 at a summer camp. Further details will be announced once XMM is in orbit. Note to editors: The X-ray Multi-Mirror mission is the second Cornerstone of ESA's Horizon 2000 Plus science programme. The telescope will revolutionise cosmic X-ray astronomy by harvesting far more X-rays per hour than any previous mission. Its large effective collecting area (120 m2 of mirror, 4500 cm2 of X-ray collecting area) and highly eccentric orbit will allow long-duration observation of unprecedented sensitivity. This enormous capability will enable astronomers to analyse many strong sources of cosmic X-rays very quickly and also discover and characterise many faint sources.

  7. Investigation of river eutrophication as part of a low dissolved oxygen total maximum daily load implementation.

    PubMed

    Stringfellow, William; Herr, Joel; Litton, Gary; Brunell, Mark; Borglin, Sharon; Hanlon, Jeremy; Chen, Carl; Graham, Justin; Burks, Remie; Dahlgren, Randy; Kendall, Carol; Brown, Russ; Quinn, Nigel

    2009-01-01

    In the United States, environmentally impaired rivers are subject to regulation under total maximum daily load (TMDL) regulations that specify watershed wide water quality standards. In California, the setting of TMDL standards is accompanied by the development of scientific and management plans directed at achieving specific water quality objectives. The San Joaquin River (SJR) in the Central Valley of California now has a TMDL for dissolved oxygen (DO). Low DO conditions in the SJR are caused in part by excessive phytoplankton growth (eutrophication) in the shallow, upstream portion of the river that create oxygen demand in the deeper estuary. This paper reports on scientific studies that were conducted to develop a mass balance on nutrients and phytoplankton in the SJR. A mass balance model was developed using WARMF, a model specifically designed for use in TMDL management applications. It was demonstrated that phytoplankton biomass accumulates rapidly in a 88 km reach where plankton from small, slow moving tributaries are diluted and combined with fresh nutrient inputs in faster moving water. The SJR-WARMF model was demonstrated to accurately predict phytoplankton growth in the SJR. Model results suggest that modest reductions in nutrients alone will not limit algal biomass accumulation, but that combined strategies of nutrient reduction and algal control in tributaries may have benefit. The SJR-WARMF model provides stakeholders a practical, scientific tool for setting remediation priorities on a watershed scale. PMID:19151480

  8. 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.

  9. Evaluation of Logjam Scour in the Context of Reach-scale River Channel Adjustments

    NASA Astrophysics Data System (ADS)

    Hanrahan, T. P.; Vernon, C. R.

    2012-12-01

    River channel modifications for protection, enhancement and restoration often include flow resistance elements such as large wood and rock structures. Evaluating the effectiveness of these modifications in achieving design objectives can be confounded by river channel adjustments occurring at larger spatial scales throughout the reach of interest. Engineered logjams are one example where the design objectives typically include riverbed scour and the creation of pools. We surveyed riverbed elevations before and after the installation of engineered logjams, and compared those measurements to predictions from empirical scour equations. Riverbed elevations throughout the reach were also surveyed along cross-sections before and after restoration activities. River channel expansion and contraction throughout the reach was measured by mapping the unvegetated channel boundary for a period of years before and after restoration. Maximum riverbed scour immediately adjacent to the engineered logjams was 1.27 m, while maximum riverbed aggradation was 1.88 m. General riverbed scour and aggradation throughout the study reached was much larger, ranging from 2.71 m of scour to 2.96 m of aggradation. Over a period of 4 years, the channel expanded throughout the area of logjam installation, with increases in channel width ranging from 25.2 m to 58.2 m. Results from this study highlight the importance of considering large scale interactions between vegetation and river morphodynamics in the planning and implementation of river channel modifications.

  10. Total Maximum Daily Load Program

    NSDL National Science Digital Library

    The Environmental Protection Agency (EPA) provides this informative resource on Total Maximum Daily Loads (TMDL). A term used to discuss water quality, TMDL refers to "a calculation of the maximum amount of a pollutant that a water body can receive and still meet water quality standards." The TMDL Program Website offers background information on TMDLs (including FAQs), a National Overview of Impaired Waters in the US, and two standard presentations on TMDLs (HTML and Power Point). The heart of the site, however, is the interactive map of the US, which allows users access to each state's TMDL Program. Within each state, watershed names and maps, as well as source information (Water body, Parameter of Concern, Priority for TMDL Development), are provided.

  11. Fungal and bacterial growth in soil with plant materials of different C/N ratios.

    PubMed

    Rousk, Johannes; Bååth, Erland

    2007-12-01

    Fungal (acetate-in-ergosterol incorporation) and bacterial (leucine/thymidine incorporation) growth resulting from alfalfa (C/N=15) and barley straw (C/N=75) addition was studied in soil microcosms for 64 days. Nitrogen amendments were used to compensate for the C/N difference between the substrates. Fungal growth increased to a maximum after 3-7 days, at five to eight times the controls, following the addition of straw, and three to four times the controls following the addition of alfalfa. After 20-30 days, the fungal growth rate converged with the controls, resulting in a cumulative fungal growth two to three times the controls following straw addition and about 20% higher than the controls following alfalfa addition. The bacterial growth rate reached rates five times the controls following alfalfa addition and twice that of the controls following straw addition after 3-7 days. It remained elevated after 64 days. The cumulative bacterial growth was two and four times the controls following straw and alfalfa addition, respectively. A negative correlation was found between N addition and bacterial growth, while N stimulated fungal growth. Thus, the C/N ratio of the additions (substrate and extra N) could not entirely explain the different results regarding fungal and bacterial growths. Respiration was not always related to the combined growth of the microorganisms, emphasizing the requirement for a better understanding of growth efficiencies of fungi and bacteria. PMID:17991019

  12. Solar maximum: solar array degradation

    SciTech Connect

    Miller, T.

    1985-08-01

    The 5-year in-orbit power degradation of the silicon solar array aboard the Solar Maximum Satellite was evaluated. This was the first spacecraft to use Teflon R FEP as a coverglass adhesive, thus avoiding the necessity of an ultraviolet filter. The peak power tracking mode of the power regulator unit was employed to ensure consistent maximum power comparisons. Telemetry was normalized to account for the effects of illumination intensity, charged particle irradiation dosage, and solar array temperature. Reference conditions of 1.0 solar constant at air mass zero and 301 K (28 C) were used as a basis for normalization. Beginning-of-life array power was 2230 watts. Currently, the array output is 1830 watts. This corresponds to a 16 percent loss in array performance over 5 years. Comparison of Solar Maximum Telemetry and predicted power levels indicate that array output is 2 percent less than predictions based on an annual 1.0 MeV equivalent election fluence of 2.34 x ten to the 13th power square centimeters space environment.

  13. Segmental Trunk Control Acquisition and Reaching in Typically Developing Infants

    PubMed Central

    Rachwani, Jaya; Santamaria, Victor; Saavedra, Sandra L.; Wood, Stacy; Porter, Francine; Woollacott, Marjorie H.

    2013-01-01

    This study explored the influence of an external support at the thoracic and pelvic level of the trunk on the success of reaching, postural stability and reaching kinematics while infants reached for a toy. Seventeen infants (4–6 months) were clustered into two groups according to their trunk control assessed with the Segmental Assessment of Trunk Control (SATCo). Major differences were seen between groups with pelvic support, whereas with thoracic support, all infants showed similar quality reaching behaviours. With the external pelvic support, infants who had acquired trunk control in the lumbar region were more accurate in their reaching movements (less movement time, improved straightness of reach, less movement units and path length per movement unit) and were more stable (decreased trunk and head displacement) during a reach than infants that had only acquired trunk control in the thoracic region. These results support the hypothesis that trunk control influences the quality of reaching behaviour. PMID:23681292

  14. Segmental trunk control acquisition and reaching in typically developing infants.

    PubMed

    Rachwani, Jaya; Santamaria, Victor; Saavedra, Sandra L; Wood, Stacy; Porter, Francine; Woollacott, Marjorie H

    2013-07-01

    This study explored the influence of an external support at the thoracic and pelvic level of the trunk on the success of reaching, postural stability and reaching kinematics while infants reached for a toy. Seventeen infants (4-6 months) were clustered into two groups according to their trunk control assessed with the Segmental Assessment of Trunk Control. Major differences were seen between groups with pelvic support, whereas with thoracic support, all infants showed similar quality reaching behaviors. With the external pelvic support, infants who had acquired trunk control in the lumbar region were more accurate in their reaching movements (less movement time, improved straightness of reach, less movement units and increased path length per movement unit) and were more stable (decreased trunk and head displacement) during a reach than infants who had only acquired trunk control in the thoracic region. These results support the hypothesis that trunk control influences the quality of reaching behavior. PMID:23681292

  15. 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.

  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. Local Impact, National Influence, Global Reach UC San Diego

    E-print Network

    Russell, Lynn

    -year diversity postdoc fellowship in conjunction with the UCOP Postdoctoral Fellowship Program · Reaching out Overnight Program and Black Family Get-Together #12;Local Impact, National Influence, Global Reach Diversity, Global Reach Diversity Update To read more about our actions to increase diversity, visit http

  18. Visual servoing for path reaching with nonholonomic robots Journal: Robotica

    E-print Network

    Paris-Sud XI, Université de

    Visual servoing for path reaching with nonholonomic robots Journal: Robotica Manuscript ID: ROB these files (e.g. movies) online. VisionBasedPathReaching-Robotica.tex figure.tar.gz VisionBasedPathReaching.mp4 Proof for review onlyhal-00639659,version1-9Nov2011 Author manuscript, published in "Robotica 29

  19. 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].

  20. 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

  1. Advanced modulation formats for high-performance short-reach optical interconnects.

    PubMed

    Hu, Qian; Che, Di; Wang, Yifei; Shieh, William

    2015-02-01

    The explosive growth of the traffic between data centers has led to an urgent demand for high-performance short-reach optical interconnects with data rate beyond 100G per wavelength and transmission distance over hundreds of kilometers. Since direct detection (DD) provides a cost-efficient solution for short-reach interconnects, various advanced modulation formats have been intensively studied to improve the performance of DD for high-performance short-reach optical interconnects. In this paper, we report the recent progress on the advanced DD modulation formats that provide superior electrical spectral efficiency (SE) and transmission reach beyond that of simple direct modulation (DM) based direct detection (DM/DD). We first provide a review of the current advanced modulation formats for high-performance short-reach optical interconnects. Among these formats, Stokes vector direct detection (SV-DD) achieves the highest electrical spectrum efficiency, presenting itself as a promising candidate for future short-reach networks. We then expound some novel algorithms to achieve high-performance SV-DD systems under severe impairments of either polarization mode dispersion (PMD) or polarization dependent loss (PDL). PMID:25836183

  2. 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

  3. 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.

  4. 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

  5. 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.

  6. Ethylene and the growth of rice seedlings

    SciTech Connect

    Salter, S.O.; Kende, H.

    1985-09-01

    Etiolated whole rice seedlings enclosed in sealed vials produced ethylene at a rate of 0.9 picomole per hour per seedling. When 2-centimeter-long shoots were subdivided into 5-millimeter-long sections, the sections containing the tip of the shoot evolved 37% of the total ethylene with the remaining 63% being produced along a gradient decreasing to the base of the shoot. The tip of coleoptile also had the highest level of the ethylene presursor 1-aminocyclopropane-1-carboxylic acid and of the ethylene-forming enzyme activity. In short-term experiments, the growth rate of decapitated seedlings was restored to almost that of intact seedlings by application of ethylene at a concentration of 10 microliters per liter. Apart from ethylene, O/sub 2/ also participates in the control of coleoptile growth. When rice seedlings were grown in a gas mixture of N/sub 2/ and O/sub 2/, the length of the coleoptiles reached a maximum at a concentration of 2.5% O/sub 2/. Lower and higher concentrations of O/sub 2/ reduced coleoptile growth. The effect of exogenous ethylene on coleoptile growth was also O/sub 2/ dependent. 25 references, 6 figures, 3 tables.

  7. A Tree-Like Model for Brain Growth and Structure

    PubMed Central

    Yan, Benjamin C.; Yan, Johnson F.

    2013-01-01

    The Flory-Stockmayer theory for the polycondensation of branched polymers, modified for finite systems beyond the gel point, is applied to the connection (synapses) of neurons, which can be considered highly branched “monomeric” units. Initially, the process is a linear growth and tree-like branching between dendrites and axons of nonself-neurons. After the gel point and at the maximum “tree” size, the tree-like model prescribes, on average, one pair of twin synapses per neuron. About 13% of neurons, “unconnected” to the maximum tree, migrate to the surface to form cortical layers. The number of synapses in each neuron may reach 10000, indicating a tremendous amount of flexible, redundant, and neuroplastic loop-forming linkages which can be preserved or pruned by experience and learning. PMID:24078809

  8. Postural control during standing reach in children with Down syndrome.

    PubMed

    Chen, Hao-Ling; Yeh, Chun-Fu; Howe, Tsu-Hsin

    2015-03-01

    The purpose of the present study was to investigate the dynamic postural control of children with Down syndrome (DS). Specifically, we compared postural control and goal-directed reaching performance between children with DS and typically developing children during standing reach. Standing reach performance was analyzed in three main phases using the kinematic and kinetic data collected from a force plate and a motion capture system. Fourteen children with DS, age and gender matched with fourteen typically developing children, were recruited for this study. The results showed that the demand of the standing reach task affected both dynamic postural control and reaching performance in children with DS, especially in the condition of beyond arm's length reaching. More postural adjustment strategies were recruited when reaching distance was beyond arm's length. Children with DS tended to use inefficient and conservative strategies for postural stability and reaching. That is, children with DS perform standing reach with increased reaction and execution time and decreased amplitudes of center of pressure displacements. Standing reach resembled functional balance that is required in daily activities. It is suggested to be considered as a part of strength and balance training program with graded task difficulty. PMID:25590172

  9. Environmental changes after ecological water conveyance in the lower reaches of Heihe River, northwest China

    Microsoft Academic Search

    Qiaoling Guo; Qi Feng; Jianlin Li

    2009-01-01

    This paper analyzed the dynamic change of the groundwater level by 6 years’ monitoring in field monitoring and the change\\u000a of vegetation by the field survey and satellite remote sensing after watering in the lower reaches of Heihe River. The findings\\u000a indicated: (1) the groundwater level elevation and the plant growth are closely related to the volume and the duration of

  10. System for Memorizing Maximum Values

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor)

    1996-01-01

    The invention discloses a system capable of memorizing maximum sensed values. The system includes conditioning circuitry which receives the analog output signal from a sensor transducer. The conditioning circuitry rectifies and filters the analog signal and provides an input signal to a digital driver, which may be either liner or logarithmic. The driver converts the analog signal to discrete digital values, which in turn triggers an output signal on one of a plurality of driver output lines n. The particular output lines selected is dependent on the converted digital value. A microfuse memory device connects across the driver output lines, with n segments. Each segment is associated with one driver output line, and includes a microfuse that is blown when a signal appears on the associated driver output line.

  11. System for memorizing maximum values

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (inventor)

    1992-01-01

    The invention discloses a system capable of memorizing maximum sensed values. The system includes conditioning circuitry which receives the analog output signal from a sensor transducer. The conditioning circuitry rectifies and filters the analog signal and provides an input signal to a digital driver, which may be either linear or logarithmic. The driver converts the analog signal to discrete digital values, which in turn triggers an output signal on one of a plurality of driver output lines n. The particular output lines selected is dependent on the converted digital value. A microfuse memory device connects across the driver output lines, with n segments. Each segment is associated with one driver output line, and includes a microfuse that is blown when a signal appears on the associated driver output line.

  12. 40 Gb/s CAP32 short reach transmission over 80 km single mode fiber.

    PubMed

    Gao, Yuliang; Zhuge, Qunbi; Wang, Wei; Xu, Xian; Buset, Jonathan M; Qiu, Meng; Morsy-Osman, Mohamed; Chagnon, Mathieu; Li, Feng; Wang, Liang; Lu, Chao; Lau, Alan Pak Tao; Plant, David V

    2015-05-01

    We present a method to mitigate the chromatic dispersion (CD)-induced power fading effect (PFE) in high-speed and short-reach carrier-less amplitude and phase (CAP) systems using the degenerate four-wave mixing (DFWM) effect and a decision feedback equalizer (DFE). Theoretical and numerical investigations reveal that DFWM components produced by the interaction between the main carrier and the signal sideband help to mitigate PFE in direct detection systems. By optimizing the launch power, a maximum reach of 60 km in single mode fiber (SMF-e + ) at 1530nm is experimentally demonstrated for a 40 Gbit/s CAP32 system. In addition, we study the performance of a decision feedback equalizer (DFE) and a traditional linear equalizer (LE) in a channel with non-flat in-band frequency response. The superior PFE tolerance of DFE is experimentally validated, and thereby, the maximum reach is extended to 80 km. To the best of our knowledge, this is the twice the longest transmission distance reported so far for a single-carrier 40 Gbit/s CAP system around 1550 nm. PMID:25969236

  13. Regulation of expression and function of m2 and m4 muscarinic receptors in cultured embryonic chick heart cells by transforming growth factor-? 1

    Microsoft Academic Search

    Darrell A. Jackson; Neil M. Nathanson

    1997-01-01

    Incubation of cultured embryonic chicken heart cells with transforming growth factor ?1 (TGF-?1) resulted in a concentration- and time-dependent decrease in the number of muscarinic acetylcholine receptors (mAChR), which reached a maximum by 24 hr. Twenty-four hours following TGF-?1 treatment, cm2 and cm4 mAChR protein levels were decreased 59 and 41%, respectively, and cm2 mRNA and cm4 mRNA levels were

  14. The maximum height of grasses is determined by roots.

    PubMed

    Cao, Kun-Fang; Yang, Shi-Jian; Zhang, Yong-Jiang; Brodribb, Tim J

    2012-07-01

    Grasses such as bamboos can produce upright stems more than 30 m tall, yet the processes that constrain plant height in this important group have never been investigated. Air embolisms form commonly in the water transport system of grasses and we hypothesised that root pressure-dependent refilling these embolisms should limit the maximum height of grass species to the magnitude of their root pressure. Confirming this hypothesis, we show that in 59 species of bamboo grown in two common gardens, the maximum heights of culms of 67 clones are closely predicted by the maximum measured root pressure overnight. Furthermore, we demonstrate that water transport in these bamboo species is dependent on root pressure to repair hydraulic dysfunction sustained during normal diurnal gas exchange. Our results established the critical importance of root pressure in the tallest grass species and provide a new basis for understanding the limits for plant growth. PMID:22489611

  15. 4 Maximum Entropy Production and Non-equilibrium Statistical Mechanics

    Microsoft Academic Search

    Roderick C. Dewar

    Over the last 30 years empirical evidence in favour of the Maximum Entropy Production (MEP) principle for non-equilibrium\\u000a systems has been accumulating from studies of phenomena as diverse as planetary climates, crystal growth morphology, bacterial\\u000a metabolism and photosynthesis. And yet MEP is still regarded by many as nothing other than a curiosity, largely because a\\u000a theoretical justification for it has

  16. Simplified calculations involving the maximum load on bridge fatigue details under inspection. Part II: Fatigue

    Microsoft Academic Search

    T. D. Righiniotis

    2004-01-01

    Fatigue crack growth implies that the maximum load that may be sustained by a bridge detail becomes a function of time. Two examples are studied here which demonstrate that, under a set of specified assumptions, the fatigue life under variable amplitude loading is approximately lognormal. Following this treatment, simplified calculations are presented which allow maximum load specification in terms of

  17. 6 Physical Model for the Maximum Fraction of Retained Austenite 2 6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

    E-print Network

    Cambridge, University of

    the bainite transformation. However, this partitioning occurs after the di usionless growth of each bainite plate 1, 2] so that the transformation cannot occur if di usionless growth is thermodynamically not possible. At some stage in the evolution of the microstructure the austenite carbon concentration reaches

  18. Improving predictability of time series using maximum entropy methods

    E-print Network

    Gregor Chliamovitch; Alexandre Dupuis; Bastien Chopard; Anton Golub

    2014-11-28

    We discuss how maximum entropy methods may be applied to the reconstruction of Markov processes underlying empirical time series and compare this approach to usual frequency sampling. It is shown that, at least in low dimension, there exists a subset of the space of stochastic matrices for which the MaxEnt method is more efficient than sampling, in the sense that shorter historical samples have to be considered to reach the same accuracy. Considering short samples is of particular interest when modelling smoothly non-stationary processes, for then it provides, under some conditions, a powerful forecasting tool. The method is illustrated for a discretized empirical series of exchange rates.

  19. Improving predictability of time series using maximum entropy methods

    NASA Astrophysics Data System (ADS)

    Chliamovitch, G.; Dupuis, A.; Golub, A.; Chopard, B.

    2015-04-01

    We discuss how maximum entropy methods may be applied to the reconstruction of Markov processes underlying empirical time series and compare this approach to usual frequency sampling. It is shown that, in low dimension, there exists a subset of the space of stochastic matrices for which the MaxEnt method is more efficient than sampling, in the sense that shorter historical samples have to be considered to reach the same accuracy. Considering short samples is of particular interest when modelling smoothly non-stationary processes, which provides, under some conditions, a powerful forecasting tool. The method is illustrated for a discretized empirical series of exchange rates.

  20. The use of a game to promote arm reach in persons with traumatic brain injury.

    PubMed

    Sietsema, J M; Nelson, D L; Mulder, R M; Mervau-Scheidel, D; White, B E

    1993-01-01

    This study tested a principle of occupational therapy and motor learning theory in the context of neurodevelopmental treatment techniques. Ten trials of occupationally embedded intervention (playing Simon, a computer-controlled game) were compared with 10 trials of rote arm-reach exercise. A counterbalanced design was structured so that each subject experienced each condition one week apart. Subjects were 17 men and 3 women with traumatic brain injury who exhibited mild to moderate spasticity in the upper extremity. Maximum distance from hip to wrist during active reach of the affected extremity was measured by digitization of videotape with the Motion Analysis EV-3D system. Results indicated that the use of the game elicited significantly more range of motion than the rote exercise (t (19) = 5.77, p < .001). These results support the use of an occupationally embedded intervention for persons with traumatic brain injury and add to the theoretical base of occupational therapy. PMID:8418672

  1. REACHING OUT TO A NEW GENERATION OF STUDENTS AND FACULTY

    E-print Network

    Cinabro, David

    REACHING OUT TO A NEW GENERATION OF STUDENTS AND FACULTY WINTER 10 outlookA NEWSLETTER FROM their college careers." During the summer, Befus coordinated the iStart Summer Reading Program, a common reading, and 75% of requests placed in ArticleReach are filled within 24 hours. Considering that some

  2. Corticospinal Control during Reach, Grasp, and Precision Lift in Man

    Microsoft Academic Search

    R. N. Lemon; R. S. Johanss; G. Westling

    1995-01-01

    Transcranial magnetic brain stimulation (TMS) was used to assess the influence of the corticospinal system on motor output in seven human subjects during a task in which they had to reach out, grasp, and lift an object. Stimuli, directed at the hand area of the motor cortex, were delivered at eight defined points during the task: during reach, at grip

  3. 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

  4. Synthesizing TSCA and REACH: Practical Principles for Chemical Regulation Reform

    Microsoft Academic Search

    John S. Applegate

    2008-01-01

    The European Union's newly enacted comprehensive regulation for industrial chemicals, known as REACH, draws heavily on three decades of experience in the United States under the Toxic Substances Control Act. Much of that experience has been negative, inasmuch as TSCA is widely regarded as a disappointment among US environmental laws, and so REACH deliberately reverses many of the legislative choices

  5. 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...

  6. Modifications to the Standard Sit-and-Reach Flexibility Protocol.

    ERIC Educational Resources Information Center

    Holt, Laurence E.; Burke, Darren G.; Pelham, Thomas W.

    1999-01-01

    Describes several modifications of the standard sit-and-reach flexibility protocol using a new device called the multitest flexometer (MTF). Using the MTF, researchers could take six flexibility measures beyond the stand-and-reach test. The modified protocol allowed the indirect assessment of the influence of the four major muscle groups that…

  7. 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.…

  8. [REACH: the guidance documents of the European Chemicals Agency (ECHA)].

    PubMed

    Lulei, Michael

    2008-12-01

    ECHA provides numerous Guidance Documents for the implementation of the REACH Regulation, emphasising that this Regulation is the only authentic legal reference. Furthermore, ECHA states that information in the Guidance Documents does not constitute legal advice and that public authorities do not accept any liability for the contents of these documents. Consequently, the companies themselves are responsible for the correct implementation of REACH. Because of their enormous volume and complexity, full knowledge of the contents of all Guidance Documents is not possible. Guidance Documents provide help with certain questions about REACH implementation. Companies complying with the REACH Regulation must be allowed to deviate from guidance. Furthermore, authorities cannot simply use the Guidance Documents for enforcement. Their decisions must be based on the Regulation. This publication describes the aims, goals and legal status of Guidance Documents. Problems concerning the comprehensibility of guidance and conformity with the REACH Regulation are discussed based on the examples of substance identification and chemical safety assessment. PMID:19137220

  9. Parameterized Algorithms for Directed Maximum Leaf Problems

    E-print Network

    Krivelevich, Michael

    Parameterized Algorithms for Directed Maximum Leaf Problems Noga Alon 1 , Fedor V. Fomin 2 spanning tree, then D contains one with at least (n/2) 1/5 - 1 leaves. 1 Introduction The Maximum Leaf a digraph D, the Directed Maximum Leaf Out­Branching problem is the problem of finding an out­branching in D

  10. Maximum entropy principal for transportation

    SciTech Connect

    Bilich, F. [University of Brasilia (Brazil); Da Silva, R. [National Research Council (Brazil)

    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.

  11. Riparian shading and groundwater enhance growth potential for smallmouth bass in Ozark streams.

    PubMed

    Whitledge, Gregory W; Rabeni, Charles F; Annis, Gust; Sowa, Scott P

    2006-08-01

    Moderation of stream temperatures by riparian shading and groundwater are known to promote growth and survival of salmonid fishes, but effects of riparian shade and groundwater on to be growth of warmwater stream fishes are poorly understood or assumed to be negligible. We used stream temperature models to relate shading from riparian vegetation and groundwater inflow to summer water temperatures in Missouri Ozark streams and evaluated effects of summer water temperatures on smallmouth bass, Micropterus dolomieu, growth using a bioenergetics model. Bioenergetics model simulations revealed that adult smallmouth bass in non-spring-fed streams have lower growth potential during summer than fish in spring-fed streams, are subject to mass loss when stream temperatures exceed 27 degrees C, and will likely exhibit greater interannual variation in growth during summer if all growth-influencing factors, other than temperature, are identical between the two stream types. Temperature models indicated that increased riparian shading will expand the longitudinal extent of thermal habitat capable of supporting adult smallmouth bass growth in spring-fed stream reaches when mean daily air temperatures exceed 27 degrees C. Optimum growth temperature (22 degrees C) will be present only in spring-fed streams under these conditions. Potential for increasing shade through riparian restoration is greatest for streams <5 m wide and along north-south reaches of larger streams. However, temperature models also indicated that restoring riparian shading to maximum levels throughout a watershed would increase the total stream mileage capable of supporting positive growth of adult smallmouth bass by only 1-6% when air temperatures are at or near average summer maxima; increases in suitable thermal habitat would be greatest in watersheds with higher spring densities. Riparian management for maintenance or restoration of the thermal habitat of adult smallmouth bass during summer should be focused in areas strongly influenced by groundwater. Restoring riparian shading along spring-fed warmwater streams will likely benefit adult smallmouth bass growth and may ultimately influence population sizes. PMID:16937811

  12. The impact of REACH on classification for human health hazards.

    PubMed

    Oltmanns, J; Bunke, D; Jenseit, W; Heidorn, C

    2014-11-01

    The REACH Regulation represents a major piece of chemical legislation in the EU and requires manufacturers and importers of chemicals to assess the safety of their substances. The classification of substances for their hazards is one of the crucial elements in this process. We analysed the effect of REACH on classification for human health endpoints by comparing information from REACH registration dossiers with legally binding, harmonised classifications. The analysis included 142 chemicals produced at very high tonnages in the EU, the majority of which have already been assessed in the past. Of 20 substances lacking a harmonised classification, 12 chemicals were classified in REACH registration dossiers. More importantly, 37 substances with harmonised classifications for human health endpoints had stricter classifications in registration dossiers and 29 of these were classified for at least one additional endpoint not covered by the harmonised classification. Substance-specific analyses suggest that one third of these additional endpoints emerged from experimental studies performed to fulfil information requirements under REACH, while two thirds resulted from a new assessment of pre-REACH studies. We conclude that REACH leads to an improved hazard characterisation even for substances with a potentially good data basis. PMID:25128672

  13. Target modality affects visually guided online control of reaching.

    PubMed

    Cameron, Brendan D; López-Moliner, Joan

    2015-05-01

    The integration of vision and proprioception for estimating the hand's starting location prior to a reach has been shown to depend on the modality of the target towards which the reach is planned. Here we investigated whether the processing of online feedback is also influenced by target modality. Participants made reaching movements to a target that was defined by vision, proprioception, or both, and visual feedback about the unfolding movement was either present or absent. To measure online control we used the variability across trials; we examined the course of this variability for the different target modalities and effector conditions. Our results showed that the rate of decrease in variability in the later part of the movements (an indicator of online control) was minimally influenced by effector vision when participants reached towards a proprioceptive target, whereas the rate of decrease was clearly influenced by effector vision when participants reached towards a visual target. In other words, when participants reached towards a proprioceptively defined target they relied less on visual information about the moving hand than when they reached towards a visually defined target. These results suggest that target modality influences visual processing for online control. PMID:24997229

  14. 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

  15. Proprioceptive Body Illusions Modulate the Visual Perception of Reaching Distance

    PubMed Central

    Petroni, Agustin; Carbajal, M. Julia; Sigman, Mariano

    2015-01-01

    The neurobiology of reaching has been extensively studied in human and non-human primates. However, the mechanisms that allow a subject to decide—without engaging in explicit action—whether an object is reachable are not fully understood. Some studies conclude that decisions near the reach limit depend on motor simulations of the reaching movement. Others have shown that the body schema plays a role in explicit and implicit distance estimation, especially after motor practice with a tool. In this study we evaluate the causal role of multisensory body representations in the perception of reachable space. We reasoned that if body schema is used to estimate reach, an illusion of the finger size induced by proprioceptive stimulation should propagate to the perception of reaching distances. To test this hypothesis we induced a proprioceptive illusion of extension or shrinkage of the right index finger while participants judged a series of LEDs as reachable or non-reachable without actual movement. Our results show that reach distance estimation depends on the illusory perceived size of the finger: illusory elongation produced a shift of reaching distance away from the body whereas illusory shrinkage produced the opposite effect. Combining these results with previous findings, we suggest that deciding if a target is reachable requires an integration of body inputs in high order multisensory parietal areas that engage in movement simulations through connections with frontal premotor areas. PMID:26110274

  16. 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.

  17. Impact of maximum sustainable yield on competitive community.

    PubMed

    Ge?ek, Sun?ana; Legovi?, Tarzan

    2012-08-21

    A system of n competing logistical species of the Volterra type under proportional harvesting strategy is analyzed. In case of selective harvesting, when the effort is adjusted to each species, the optimum effort may result in the total maximum sustainable yield (TMSY(1)). When it exists, reaching TMSY(1) does not affect the system stability character, but it does affect the state, and hence some populations may reach too small a value to persist in nature. If competition is strong, species with smaller biotic potential may be driven to extinction. In case the system is harvested with a common harvesting effort, such as in trawler fishery, the total maximum sustainable yield (TMSY(2)) is smaller than TMSY(1), and all the species with lower or equal biotic potential to the optimum harvesting effort will be driven to extinction. In this case a call for implementation of the MSY is equivalent to a call for the extermination of some species and it runs directly against the Convention on Biological Diversity (CBD, 1992). Therefore, all legal documents advocating MSY in ecosystems starting with the Johannesburg Plan of Implementation (JPI, 2002) must be urgently retracted and replaced with adaptive management which will respect CBD. PMID:22575971

  18. Effects of divergent selection for yolk testosterone content on growth characteristics of Japanese quail.

    PubMed

    Okuliarova, Monika; Kostal, Lubor; Zeman, Michal

    2011-09-01

    Effects of yolk androgens on postnatal growth of offspring have been widely studied but their physiological role in the growth control is not fully understood due to an inconsistency in obtained results. We investigated androgen-mediated maternal effects on postnatal growth in relation to endocrine control mechanisms using two lines of Japanese quail divergently selected for high (HET) and low (LET) egg testosterone (T) content. Embryonic growth did not differ between the lines. During the growth period HET quail were heavier and displayed longer tarsi as compared with LET quail, with more pronounced line differences in males than females. HET males were heavier than LET males from the age of 2 weeks, reached the age of maximum growth rate earlier, and displayed higher asymptotic body weight than LET males. Accelerated growth in HET males was not accompanied by increased postembryonic plasma T concentrations. Plasma triiodothyronine levels did not differ between lines while plasma thyroxine levels were decreased in HET as compared with LET female chicks. Line differences in body weight disappeared in adult quail suggesting that yolk androgens, increased in a physiological way, resulted in stimulation of juvenile growth rate in precocial Japanese quail under stable social and environmental conditions. PMID:21627997

  19. 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.

  20. Linear increase in cell volume during the growth cycle of Schizosaccharomyces pombe

    SciTech Connect

    Kubitschek, H.E.; Clay, K.

    1985-01-01

    Classical observations on the growth of cells of the fission yeast Schizosaccharomyces pombe indicate that cell length and volume increase to a maximum value, which is reached about three-quarters of the way through the growth cycle, followed by a constant volume plateau. The authors have reexamined the growth of these cells by phase microscopy. When growth conditions were perturbed by inoculating cells at high density, in the presence of contaminant, or upon agar slips containing the growth medium in 4% agar, all cells grew in the classical pattern. But, at smaller agar concentrations and lower cell densities, many cells grew at a constant rate throughout the entire cell cycle. Also, the frequency of this linear pattern of cell growth increased as growth perturbations were reduced. They interpret these results as evidence for a sensitivity of this microorganism to perturbations of steady-state growth. The constant rate of volume increase throughout the cell cycle in unperturbed cells, when considered along with Mitchison's earlier results for constant dry mass increase, suggests that the buoyant densities of these cells remain constant during the entire cell cycle.

  1. Project Career REACH: Marketing Strategies for Effective Guidance Programs.

    ERIC Educational Resources Information Center

    Bollendorf, Marsha; And Others

    1990-01-01

    Outlines the practical marketing strategies used to implement Project Career REACH, a career development program for high school freshmen. Marketing basics for guidance programs are discussed, including mission analysis, market analysis, resource analysis, strategic planning, and evaluation. (TE)

  2. Helping the Library Reach Out to the Future

    MedlinePLUS

    ... Bar Home Current Issue Past Issues Helping the Library Reach Out to the Future Past Issues / Fall ... On behalf of the Friends of the National Library of Medicine (FNLM), welcome to the Fall 2007 ...

  3. Multimodal perception in the control of infant reaching.

    PubMed

    Clifton, R K; Rochat, P; Robin, D J; Berthier, N E

    1994-08-01

    Six-month-old infants were presented with sounding objects under 3 conditions of illumination: in full vision, in the dark with target location specified by a glowing and sounding object, and in the dark with location specified by sound alone. Reaching behavior was videotaped with an infrared camera, and hand movement was measured by infrared-emitting diodes on the hand that were tracked by a motion analysis system. No differences were found in reaching behavior for objects in the light and glowing objects in the dark. Reaches for sounding objects in the dark had higher speeds, shorter durations, and more errors compared to the other 2 conditions. These findings indicate that vision of the hand did not appear to affect infants' reaching in this situation, whereas vision of the target did. PMID:8083641

  4. Action, perception and postural planning when reaching for tools.

    PubMed

    Sunderland, Alan

    2013-06-01

    The dorsal and ventral streams model of action and perception suggests that reaching to grasp a tool for use involves integrated operation of the two streams. Few attempts have been made to test the limits of this integration in normal subjects. Twenty normal subjects reached for tools or geometric objects which were rotated rapidly during reaching or immediately beforehand. In a first experiment it was shown that reaching for an inverted tool was slower than reaching for objects which required hand inversion due to proximity to a physical barrier. Also, for the right hand, tool rotation during reaching provoked a higher incidence of hand rotation in the wrong direction than did rotation of objects. In a second similar experiment, hand inversion when grasping objects was induced by the need to plan a future action rather than by proximity of a physical barrier. Despite this balancing of complexity of postural planning for tools and objects, hand rotation errors for both hands were more common for tools than objects. This was consistent with the two-stream model in suggesting that there was a process which produced rapid online tracking of stimulus rotation and this had to be overcome by a slower process which dictated grasping in accordance with knowledge of tool use. PMID:23571500

  5. 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

  6. Energy Production, Frictional Dissipation, and Maximum Intensity of a Numerically Simulated Tropical Cyclone*

    E-print Network

    Wang, Yuqing

    Energy Production, Frictional Dissipation, and Maximum Intensity of a Numerically Simulated is eventually dissipated due to surface friction. Since the energy production rate is a linear function while intensifies. When the dissipation rate eventually reaches the production rate, the TC has no excess energy

  7. Energy Production, Frictional Dissipation, and Maximum Intensity of a Numerically Simulated Tropical Cyclone

    E-print Network

    Wang, Yuqing

    0 Energy Production, Frictional Dissipation, and Maximum Intensity of a Numerically Simulated is eventually dissipated due to surface friction. Since the energy production rate is a linear function while intensifies. When the dissipation rate eventually reaches the production rate, the TC has no excess energy

  8. [Spatiotemporal change characteristics of agricultural climate resources in middle and lower reaches of Yangtze River].

    PubMed

    Li, Yong; Yang, Xiao-guang; Dai, Shu-wei; Wang, Wen-feng

    2010-11-01

    The period 1961-2007 was divided into two by the time node of year 1981, and the change characteristics of the agricultural climate resources both in period I (1961-1980) and in period II (1981-2007) were analyzed and compared. The results showed that under the background of global warming, the average climatic trend rate of > or = 10 degrees C accumulated temperature in the middle and lower reaches of Yangtze River in temperature-defined growth season during 1961-2007 was 74 degrees C x d x 10 a(-1), and the > or =10 degrees C accumulated temperature in period II was 124 d higher than that in period I. Comparing with that in period I, the safe planting boundary of double cropping rice in period II moved 0.79 degrees northward. In 1961-2007, the precipitation in temperature-defined growth season had an overall increasing trend. Comparing with those in period I, the precipitation and the area of > or = 767 mm precipitation (water requirement for normal growth of double cropping rice) in period II were increased by 1.6% and 1.13 x 10(4) km2, respectively. The average sunshine hour in temperature-defined growth season in period II was reduced by 8.1%, comparing with that in period I. In recent 47 years, about 91.1% stations in the reaches showed a decreasing trend in sunshine hours. Comparing with that in period I, the reference crop evapotranspiration in temperature-defined growth season in period II showed a slightly decreasing trend, and its low value region expanded while its high value region narrowed. The beginning date of daily temperature over 10 degrees C was averagely 2 days earlier in period II than that in period I, while the ending date was in reverse. The ending date of daily temperature over 22 degrees C was almost the same in periods I and II. PMID:21361018

  9. Optimising the Yield of Energy From Biomass by Analytical Models of the Rate of Growth

    NASA Astrophysics Data System (ADS)

    Abolins, J.; Gravitis, J.; Kosmacha, J.

    2010-01-01

    In the reported study of growth-rates of grey alder (Alnus incana) stands at different quality sites the authors, as a continuation of an earlier study, propose and use analytical models to approximate experimental data of mean annual increments of standing stock. The model equations of growth-rate functions are further used to optimise the cutting age by minimising the total area of stands for sustainable annual supply of biomass. The growth-rate behaviour with the age of natural grey alder stands is described by an exponential function of three parameters defining the initial and the maximum growth-rates, and the age at which the growth-rate maximum is reached. None of the parameters is known from experiment, and they are found by least-square fit of the available experimental mean values appraised at the chosen time intervals into the model. A high correlation between the experimental data and the model function is found. The optimum cutting age of 18 years determined in the earlier study is confirmed. In farmed stands the growth-rate is made to continue increasing at a lower speed, and is well approximated by a linear function, in which case it is shown that the cutting age cannot be optimised with respect to the area minimum existing under the condition of a decreasing growth-rate after passing a maximum. In the case of a constant or slowly growing annual increment the authors suggest considering the ratio between the increment of stock per unit of the total area to the increase in the area. The overall efficiency of using the product of photosynthesis for a 20-year-old grey alder stand is roughly estimated to be 0.3%.

  10. Erich Regener and the ionisation maximum of the atmosphere

    NASA Astrophysics Data System (ADS)

    Carlson, P.; Watson, A. A.

    2014-12-01

    In the 1930s the German physicist Erich Regener (1881-1955) did important work on the measurement of the rate of production of ionisation deep under water and in the atmosphere. Along with one of his students, Georg Pfotzer, he discovered the altitude at which the production of ionisation in the atmosphere reaches a maximum, often, but misleadingly, called the Pfotzer maximum. Regener was one of the first to estimate the energy density of cosmic rays, an estimate that was used by Baade and Zwicky to bolster their postulate that supernovae might be their source. Yet Regener's name is less recognised by present-day cosmic ray physicists than it should be, largely because in 1937 he was forced to take early retirement by the National Socialists as his wife had Jewish ancestors. In this paper we briefly review his work on cosmic rays and recommend an alternative naming of the ionisation maximum. The influence that Regener had on the field through his son, his son-in-law, his grandsons and his students, and through his links with Rutherford's group in Cambridge, is discussed in an appendix. Regener was nominated for the Nobel Prize in Physics by Schrödinger in 1938. He died in 1955 at the age of 73.

  11. Effects of Pictorial Cues on Reaching Depend on the Distinctiveness of Target Objects

    PubMed Central

    Himmelbach, Marc

    2013-01-01

    There is an ongoing debate under what conditions learned object sizes influence visuomotor control under preserved stereovision. Using meaningful objects (matchboxes of locally well-known brands in the UK) a previous study has nicely shown that the recognition of these objects influences action programming by means of reach amplitude and grasp pre-shaping even under binocular vision. Using the same paradigm, we demonstrated that short-term learning of colour-size associations was not sufficient to induce any visuomotor effects under binocular viewing conditions. Now we used the same matchboxes, for which the familiarity effect was shown in the UK, with German participants who have never seen these objects before. We addressed the question whether simply a high degree of distinctness, or whether instead actual prior familiarity of these objects, are required to affect motor computations. We found that under monocular and binocular viewing conditions the learned size and location influenced the amplitude of the reaching component significantly. In contrast, the maximum grip aperture remained unaffected for binocular vision. We conclude that visual distinctness is sufficient to form reliable associations in short-term learning to influence reaching even for preserved stereovision. Grasp pre-shaping instead seems to be less susceptible to such perceptual effects. PMID:23382882

  12. The usefulness of the reach angle concept for hazard zoning using statistical approach

    NASA Astrophysics Data System (ADS)

    Jaboyedoff, Michel; Pedrazzini, Andrea

    2010-05-01

    Since Heim (1932) the reach angle or Farböschung or the shadow angle has been widely studied to estimate runout distance of landslides and snow avalanches. The distance used to determine the reach angle is based either on the maximum of runout distance or on a threshold distance. This discrepancy between deterministic and statistical approaches has to be explained. We inspected the uncertainty on the parameters of the simple model of the energy line. The relevant uncertainty comes essentially from the friction parameters along the travel of the moving mass. As a consequence the friction coefficient can be assumed as a random variable along the landslide path. Passing at the limit the friction coefficient can be assumed as a sum of random variables. Owing to the central limit theorem the friction coefficient must follow a normal distribution. This hypothesis of normal distribution of friction angle is equivalent to the reach angles if the assumed variability is only of a few degrees. The results of this theory can be verified on several gravitational movements' data sets such as rock falls, shallow landslides, snow avalanches, etc. This permits also to unify all the different approaches taking into account the differences between energy line and Farböschung. The Farböschung appears as a limiting case of energy line slope.

  13. Temporal dynamics of non-structural carbohydrates and xylem growth in Pinus sylvestris exposed to drought

    PubMed Central

    Oberhuber, Walter; Swidrak, Irene; Pirkebner, Daniela; Gruber, Andreas

    2011-01-01

    Wood formation requires a continuous supply of carbohydrates for structural growth and metabolism. In the montane belt of the central Austrian Alps we monitored the temporal dynamics of xylem growth and non-structural carbohydrates (NSC) in stem sapwood of Pinus sylvestris L. during the growing season 2009, which was characterized by exceptional soil dryness within the study area. Soil water content dropped below 10 % at the time of maximum xylem growth end of May. Histological analyses have been used to describe cambial activity and xylem growth. Determination of NSC was performed using specific enzymatic assays revealing that total NSC ranged from 0.8 to 1.7 % dry matter throughout the year. Significant variations (P < 0.05) of the size of the NSC pool were observed during the growing season. Starch showed persistent abundance throughout the year reaching a maximum shortly before onset of late wood formation in mid-July. Seasonal dynamics of NSC and xylem growth suggest that (i) high sink activity occurred at start of the growing season in spring and during late wood formation in summer and (ii) there was no particular shortage in NSC, which caused P. sylvestris to draw upon stem reserves more heavily during drought in 2009. PMID:22003262

  14. 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

  15. 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.

  16. Engineering growth Undergraduates enrolled in Engineering reach all-time high

    E-print Network

    Auckland, University of

    of female and Mori and Pacific Island students. Like Caleb, most will have prepared for an engineering, inductive power transfer, yacht and sail design, medical applications and earthquake engineering. One

  17. 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)

  18. Reaching Every Reader: Promotional Strategies for the Elementary School Library Media Specialist. Professional Growth Series.

    ERIC Educational Resources Information Center

    Miller, Pat

    This book is designed for overextended librarians and for those who are looking for fresh approaches to what they have been doing for years. The intent in the book is to incorporate traditional techniques, such as storytelling and puppetry, with the use of technology, particularly the Internet--many different learning styles are incorporated to…

  19. 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

  20. 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

  1. Growth rates of the infaunal bivalve Soletellina alba (Lamarck, 1818) (Bivalvia: Psammobiidae) in an intermittent estuary of southern Australia

    NASA Astrophysics Data System (ADS)

    Matthews, Ty G.; Fairweather, Peter G.

    2003-12-01

    Caging and a mark-recapture design were used to estimate the growth rate of the brittle, infaunal bivalve Soletellina alba in the Hopkins River estuary. The growth of both caged and uncaged individuals was monitored at three sites near the mouth of the estuary over 180 days. Growth rates did not differ for caged and uncaged bivalves, or for bivalves subject to different amounts of handling, or between sites. Growth did differ between consecutive time intervals, which was attributable to negligible growth occurring during the colder months of autumn/winter. Comparisons of the condition (as indicated by total mass for length 3) of S. alba were inconsistent between sites for caged and uncaged bivalves and for those subject to different amounts of handling. Soletellina alba is a rapidly growing bivalve with mean growth rates for the three time intervals being 0.04±0.002 mm day-1 in summer, 0.02±0.001 mm day-1 in autumn and 0.03±0.001 mm day-1 from summer to winter. Using existing literature, it was shown that a significant relationship exists between maximum shell length and onset of sexual maturity in bivalve molluscs. This relationship predicts that S. alba should reach the onset of sexual maturity at 15.8 mm length. Therefore, it appears that it may be possible for juvenile S. alba (<1 mm) to grow, reach sexual maturity and reproduce in between annual mass-mortality events caused by winter flooding.

  2. Maximum Electrical Stimulation for Urge Incontinence

    Microsoft Academic Search

    Masahiro Nakamura; Tsutomu Sakurai; Hideki Sugao; Takao Sonoda

    1987-01-01

    Urge incontinence was controlled in 13 (62%) of 21 patients by maximum electrical stimulation which was applied to the anus or the perianal skin. The first session of maximum electrical stimulation was able to determine if this treatment would be successful. This method of patient selection for further stimulation was simple and reliable and achieved clinical success in all of

  3. Maximum entropy principle and nonlinear stochastic oscillators

    Microsoft Academic Search

    K. Sobczyk; J. Trebicki

    1993-01-01

    The principle of maximum entropy introduced first in physics and successfully applied in many other fields (e.g. statistics, reliability estimation, simulation) has recently been developed to analyze the systems governed by stochastic differential equations. In this paper we extend the maximum entropy method to the general class of stochastic nonlinear systems and apply it to stochastic nonlinear oscillators. To indicate

  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. MAXIMUM LIKELIHOOD ESTIMATION FOR GENERALISED LOGISTIC DISTRIBUTIONS

    Microsoft Academic Search

    Quanxi Shao

    2002-01-01

    Maximum likelihood estimation for the type I generalised logistic distributions is investigated. We show that the maximum likelihood estimation usually exists, except when the so-called embedded model problem occurs. A full set of embedded distributions is derived, including Gumbel distribution and a two-parameter reciprocal exponential distribution. Properties relating the embedded distributions are given. We also provide criteria to determine when

  6. On bias in maximum likelihood estimators

    Microsoft Academic Search

    K. V. Mardia; H. R. Southworth; C. C. Taylor

    1999-01-01

    It is well known that maximum likelihood estimators are often biased, and it is of use to estimate the expected bias so that we can reduce the mean square errors of our parameter estimates. Expressions for estimating the bias in maximum likelihood estimates have been given by Cox and Hinkley (1974), (Theoretical Statistics, Chapman & Hall, London). In this paper,

  7. Maximum-Likelihood Stereo Correspondence using Field

    E-print Network

    MacLean, W. James

    estimation. 1 Introduction Stereo vision makes use of two images from different view points to construct) motion-compensated stereo estimation. 2 Maximum-Likelihood Stereo Vision Dense stereo correspondence mayMaximum-Likelihood Stereo Correspondence using Field Programmable Gate Arrays Siraj Sabihuddin & W

  8. A new maximum power point tracking system

    Microsoft Academic Search

    W. J. A. Teulings; J. C. Marpinard; A. Capel; D. O'Sullivan

    1993-01-01

    In power systems involving a load, a battery and a solar array, MPPT (maximum power point tracking) is a promising principle to extract the maximum amount of energy from the solar array and distribute it to the battery and loads. A digital hill-climbing control strategy combined with a bidirectional current mode power cell is presented that makes it possible to

  9. Bayesian and Maximum Likelihood Neural Networks

    E-print Network

    Nielsen, Finn Ã?rup

    Bayesian and Maximum Likelihood Neural Networks Finn A ffi rup Nielsen Section for Digital Signal, 1998 OVERVIEW ffl Artificial neural networks ffl Maximum likelihood, MAP, MPL neural networks ffl Bayesian neural networks -- MCMC Bayesian neural networks \\Lambda Hybrid Monte Carlo ffl lyngby matlab

  10. Neural Dynamics of Reaching Following Incorrect or Absent Motor Preparation

    PubMed Central

    Ames, K. Cora; Ryu, Stephen I.; Shenoy, Krishna V.

    2014-01-01

    SUMMARY Moving is thought to take separate preparation and execution steps. While preparing, neural activity in primary motor and dorsal premotor cortices achieves a state specific to an upcoming action, but movements are not performed until the execution phase. We investigated whether this preparatory state (more precisely, prepare-and-hold state) is required for movement execution using two complementary experiments. We compared monkeys’ neural activity during delayed and non-delayed reaches, and in a delayed reaching task in which the target switched locations on a small percentage of trials. Neural population activity bypassed the prepare-and-hold state both in the absence of a delay and if the wrong reach was prepared. However, the initial neural response to the target was similar across behavioral conditions. This suggests that the prepare-and-hold state can be bypassed if needed, but there is a short-latency preparatory step which is performed prior to movement even without a delay. PMID:24462104

  11. Visually Guided Reaching Depends on Motion Area MT+

    PubMed Central

    Whitney, David; Ellison, Amanda; Rice, Nichola J.; Arnold, Derek; Goodale, Melvyn; Walsh, Vincent; Milner, David

    2013-01-01

    Visual information is crucial for goal-directed reaching. A number of studies have recently shown that motion in particular is an important source of information for the visuomotor system. For example, when reaching a stationary object, movement of the background can influence the trajectory of the hand, even when the background motion is irrelevant to the object and task. This manual following response may be a compensatory response to changes in body position, but the underlying mechanism remains unclear. Here we tested whether visual motion area MT+ is necessary to generate the manual following response. We found that stimulation of MT+ with transcranial magnetic stimulation significantly reduced a strong manual following response. MT+ is therefore necessary for generating the manual following response, indicating that it plays a crucial role in guiding goal-directed reaching movements by taking into account background motion in scenes. PMID:17289778

  12. Does aerobic capacity set a limit on fish growth rate?

    Microsoft Academic Search

    P. U. Blier; D. Pelletier

    1997-01-01

    Fish growth is an energetically demanding process. It has been suggested that fish maximum growth rate is limited by the organism's capacity to support energetic demand. We reexamined gill surface area data and found no evidence that maximum growth rate could be limited by the ability to extract oxygen from the environment. We also compared the relationship between aerobic capacity

  13. Soybean Seed Water Relations during in Situ and in Vitro Growth and Maturation.

    PubMed

    Saab, I N; Obendorf, R L

    1989-02-01

    Water, osmotic, and pressure potentials of soybean (Glycine max [L.] Merrill) embryos and related maternal tissues were measured during periods of seed growth and maturation to test the involvement of embryo water relations in seed maturation. Seeds were matured in situ or in an in vitro liquid culture medium in detached pods or as isolated seeds. Changes in water relations of embryo tissues were independent of maternal tissues. During seed maturation in situ, water and osmotic potentials in both embryo and maternal tissues declined sharply near the time of maximum dry weight. During in vitro seed culture with and without pods, water and osmotic potentials in axis and cotyledon tissues declined continuously during growth. Water and osmotic potentials of the seed coat, which was present only during in vitro seed culture with pods, changed little during the culture period. Positive turgor in the embryo was maintained beyond maximum dry weight and the loss of green color during in vitro culture but declined to zero at maturity in situ. The osmotic potential in embryo tissues declined from -1.1 megapascals at early pod fill to between -1.65 and -2.2 megapascals at maximum seed dry weight across all maturation environments. It is suggested that the decreasing osmotic potential in the growing soybean embryo reaches a threshold level that is associated with cessation of growth and onset of seed maturation. PMID:16666590

  14. 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 ...

  15. Overlapping representations for grip type and reach direction.

    PubMed

    Fabbri, Sara; Strnad, Lukas; Caramazza, Alfonso; Lingnau, Angelika

    2014-07-01

    To grasp an object, we need to move the arm toward it and assume the appropriate hand configuration. While previous studies suggested dorsomedial and dorsolateral pathways in the brain specialized respectively for the transport and grip components, more recent studies cast doubt on such a clear-cut distinction. It is unclear, however, to which degree neuronal populations selective for the two components overlap, and if so, to which degree they interact. Here, we used multivoxel pattern analysis (MVPA) of functional magnetic resonance imaging (fMRI) data to investigate the representation of three center-out movements (touch, pincer grip, whole-hand grip) performed in five reach directions. We found selectivity exclusively for reach direction in posterior and rostral superior parietal lobes (SPLp, SPLr), supplementary motor area (SMA), and the superior portion of dorsal premotor cortex (PMDs). Instead, we found selectivity for both grip type and reach direction in the inferior portion of dorsal premotor cortex (PMDi), ventral premotor cortex (PMv), anterior intraparietal sulcus (aIPS), primary motor (M1), somatosensory (S1) cortices and the anterior superior parietal lobe (SPLa). Within these regions, PMv, M1, aIPS and SPLa showed weak interactions between the transport and grip components. Our results suggest that human PMDi and S1 contain both grip- and reach-direction selective neuronal populations that retain their functional independence, whereas this information might be combined at the level of PMv, M1, aIPS, and SPLa. PMID:24650596

  16. 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…

  17. Interconnection of long-reach PON and backbone networks

    Microsoft Academic Search

    Piero Castoldi; Francesco Paolucci; Alessio Giorgetti; Martin Maier

    2009-01-01

    This paper proposes an evolution of the STARGATE long-reach PON architecture to allow the optical interconnection of multiple STARGATEs by means of a GMPLS-based backbone network. The architecture of the optical bypass gateway is proposed and the distributed signalling for establishing inter-STARGATE connection requests is detailed. The optical bypassing capacity of the proposed architecture is evaluated through simulations.

  18. 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)

  19. Japan, EU reach basic agreement over ITER The Yomiuri Shimbun

    E-print Network

    Japan, EU reach basic agreement over ITER The Yomiuri Shimbun The government and the European Union to the unsuccessful candidate country. Japan and France, the EU's candidate, have been bidding to host the facility bidder's country. The ITER project participants--Japan, China, the EU, Russia, South Korea and the United

  20. Characteristics of ocean waters reaching Greenland's glaciers Fiammetta STRANEO,1

    E-print Network

    Johnson, Helen

    Characteristics of ocean waters reaching Greenland's glaciers Fiammetta STRANEO,1 David A of Geography, University of British Columbia, Vancouver, Canada ABSTRACT. Interaction of Greenland's marine the glaciers range from 4.588C in the southeast, to 0.168C in northwest Greenland, consistent with the distance

  1. Extending behavior of hydraulic fracture when reaching formation interface

    Microsoft Academic Search

    Haifeng Zhao; Mian Chen

    2010-01-01

    Stopping extension, extending along formation interface and directly penetrating into bounding layer are three possible reactions of fracture extension when hydraulic fractures reach formation interfaces. The three types of extending behavior are analyzed using rock fracture mechanics and three respective judging criterions are presented. Layered earth stress, layered rock mechanics parameters, formation interface effect, reservoir thickness and operating parameters are

  2. Fall 2010/Spring 2011 Reaching Out to Overseas

    E-print Network

    Suzuki, Masatsugu

    of Visualized Experiments (JoVE), an online publication which he co-founded; and Jes- sica Mezei, CoFall 2010/Spring 2011 Reaching Out to Overseas Colleagues in China, Online Journal of Rural Nursing Program to "help inter- nationalize the library experience." Robyn Anderson, a se- nior majoring

  3. RESEARCH ARTICLE Unconstrained three-dimensional reaching in Rhesus monkeys

    E-print Network

    Jindrich, Devin L.

    after injury, we studied arm movements by non-injured Rhesus monkeys during a food-retrieval task. While. The relation- ships between shoulder and elbow resultant moments were linear during both reach and retrieval recovery after a spinal cord injury and the effectiveness of therapeutic interventions. Keywords Upper limb

  4. Reaching Approximate Agreement in the Presence of Faults

    Microsoft Academic Search

    Danny Dolev; Nancy A. Lynch

    1985-01-01

    This paper considers a variant on the Byzantine Generals problem, in which processes start with arbitrary real values rather than Boolean values or values from some bounded range, and in which approximate, rather than exact, agreement is the desired goal. Algorithms are presented to reach approximate agreement in asynchronous, as well as synchronous systems. The asynchronous agreement algorithm is an

  5. Learning of Visuomotor Transformations for Vectorial Planning of Reaching Trajectories

    Microsoft Academic Search

    John W. Krakauer; Zachary M. Pine; Maria-Felice Ghilardi; Claude Ghez

    2000-01-01

    The planning of visually guided reaches is accomplished by independent specification of extent and direction. We investi- gated whether this separation of extent and direction planning for well practiced movements could be explained by differences in the adaptation to extent and directional errors during motor learning. We compared the time course and generalization of adaptation with two types of screen

  6. Beyond Gazing, Pointing, and Reaching A Survey of Developmental Robotics

    E-print Network

    Sandini, Giulio

    of developmental psychology and robotics that has come to be known as developmen- tal robotics.1 Developmental robots to instantiate and investi- gate models originating from developmental psychology or developmentalBeyond Gazing, Pointing, and Reaching A Survey of Developmental Robotics Max Lungarella

  7. Reaching and Helping Unorganized and Disadvantaged People. Courier No. 33.

    ERIC Educational Resources Information Center

    ASPBAE Courier, 1985

    1985-01-01

    The articles in this issue are mainly concerned with how to reach the poorest and most disadvantaged sections of the population and how best to help once contact has been made. "Nijera Kori in Retrospect: In Search of an Organization of the Rural Poor" (Mohiuddin Ahmad) provides extracts from an evaluation of this grassroots, village-based,…

  8. 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…

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

    Microsoft Academic Search

    Yoram Gutfreund; Tamar Flash; Graziano Fiorito; Binyamin Hochner

    1998-01-01

    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 a basic invariant motor structure: a bend traveling from the base of the arm toward the tip (Gutfreund et al., 1996a). To study the neuronal control of these movements, arm muscle activation (electromyogram (EMG))

  10. Robust visual servoing in 3-D reaching tasks

    Microsoft Academic Search

    Enrico Grosso; Giorgio Metta; Andrea Oddera; Giulio Sandini

    1996-01-01

    This paper describes a novel approach to the problem of reaching an object in space under visual guidance. The approach is characterized by a great robustness to calibration errors, such that virtually no calibration is required. Servoing is based on binocular vision: a continuous measure of the end-effector motion field, derived from real-time computation of the binocular optical flow over

  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. Differential Fault Analysis of AES: Towards Reaching its Limits

    E-print Network

    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

  13. 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

  14. The Argonaute family: tentacles that reach into RNAi, developmental control,

    E-print Network

    The Argonaute family: tentacles that reach into RNAi, developmental control, stem cell maintenance University of New York at Stony Brook, Stony Brook, New York 11794, USA RNA interference (RNAi to enter the RNAi path- way and function to regulate the expression of endog- enous, protein-coding genes

  15. Spatial resolution of spontaneous accelerations in reaching tasks

    Microsoft Academic Search

    Michael Wininger; Nam-Hun Kim; William Craelius

    2009-01-01

    Reaching tasks are considered well-executed if they appear “smooth,” a quality that is typically quantified by its opposite, jerk, the rate of change of acceleration. While jerk is a theoretically sound measure, its application to spastic individuals sometimes yields counter-intuitive results, and does not reveal motor impairment across the workspace. To more generally quantify spontaneous accelerative transients (SATs) within a

  16. Spatial resolution of spontaneous accelerations in reaching tasks

    Microsoft Academic Search

    Michael Wininger; Nam-Hun Kim; William Craelius

    2008-01-01

    Reaching tasks are considered well-executed if they appear ''smooth,'' a quality that is typically quantified by its opposite, jerk, the rate of change of acceleration. While jerk is a theoretically sound measure, its application to spastic individuals sometimes yields counter-intuitive results, and does not reveal motor impairment across the workspace. To more generally quantify spontaneous accelerative transients (SATs) within a

  17. Reaching First Year College Students: Current Practices in Instructional Programs

    ERIC Educational Resources Information Center

    Boyd-Byrnes, Mary Kate; McDermott, Dona

    2006-01-01

    In light of the new emphasis on information literacy, this research updates previous studies and explores current practices in first year library instruction and programming. Academic librarians are reaching out to freshmen seminar programs, first year orientations, Introduction to College courses, and English composition courses to integrate…

  18. 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.…

  19. 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,…

  20. 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,…

  1. Tailoring training to the need: Reaching all the workers

    SciTech Connect

    Jones, E.

    1987-01-01

    By developing a comprehensive concept for radiation protection training at Oak Ridge National Laboratory, we are providing a complete program with easy access for additional radiation protection training upon demand. A framework for implementation of a program tailored to reach differing segments of the workforce quickly and effectively is outlined and illustrated with ORNL program experience. 10 refs.

  2. 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

  3. Discovery mass reach for excited quarks at hadron colliders

    SciTech Connect

    Harris, R.M.

    1996-09-10

    If quarks are composite particles then excited states are expected. We estimate the discovery mass reach as a function of integrated luminosity for excited quarks decaying to dijets at the Tevatron the mass reach is 0.94 TeV for Run 11 (2 fb{sup -1}) and 1. 1 TeV for TeV33 (30 fb{sup -1}). At the LHC the mass reach is 6.3 TeV for 100 fb{sup -1}. At a VLHC with a center of mass energy {radical}s, of 50 TeV (200 TeV) the mass reach is 25 TeV (78 TeV) for an integrated luminosity of 10{sup 4} fb{sup -1}. However, an excited quark with a mass of 25 TeV would be discovered at a hadron collider with {radical}s = 100 TeV and an integrated luminosity of 13 fb{sup -1}, illustrating a physics example where a factor of 2 in machine energy is worth a factor of 1000 in luminosity.

  4. Discovery Mass Reach for Excited Quarks at Hadron Colliders

    E-print Network

    Robert M. Harris

    1996-09-11

    If quarks are composite particles then excited states are expected. We estimate the discovery mass reach as a function of integrated luminosity for excited quarks decaying to dijets at the Tevatron, LHC, and a Very Large Hadron Collider (VLHC). At the Tevatron the mass reach is 0.94 TeV for Run II (2 fb^-1) and 1.1 TeV for TeV33 (30 fb^-1). At the LHC the mass reach is 6.3 TeV for 100 fb^-1. At a VLHC with a center of mass energy, sqrt(s), of 50 TeV (200 TeV) the mass reach is 25 TeV (78 TeV) for an integrated luminosity of 10^4 fb^-1. However, an excited quark with a mass of 25 TeV would be discovered at a hadron collider with sqrt(s)=100 TeV and an integrated luminosity of 13 fb^-1, illustrating a physics example where a factor of 2 in machine energy is worth a factor of 1000 in luminosity.

  5. 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…

  6. 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.

  7. Reaching Out, Reaching In

    ERIC Educational Resources Information Center

    Wren, David J.

    2004-01-01

    In this article, the author describes the intergenerational service-learning program at South Scranton Intermediate School in Scranton, Pennsylvania. Currently in its fifth year of operation, the program was originated by William King, a former principal, as an attempt to develop a working relationship between Oakwood Terrace, an Alzheimer's care…

  8. 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

  9. 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

  10. The REACH perspective: toward a new concept of toxicity testing.

    PubMed

    Schoeters, Greet

    2010-02-01

    A sustainable society and a healthy society are major goals for European policymakers. Although most Europeans live a longer healthy life than ever, there is growing concern and anxiety about unknown health risks and threats of chemicals and a strong demand for more knowledge and more control. European legislation is responding to these demands. An example is the program on Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH), which came into force in 2007. It is a gigantic task for industry and for administrators to evaluate safety files of thousands of chemicals in a period of 12 years and to collect new data for chemicals not yet evaluated. Costs, number of toxicity tests, and number of animals that are needed are already well documented. REACH uses strict guidelines and focuses on apical endpoints that have been covered in the past by animal tests. Animal tests are slow, use unrealistic high doses, and have been shown to not always predict human toxicity correctly. The REACH program has made a clear opening for reduction of in vivo animal tests. Sharing toxicity data is a major improvement. For low tonnage levels, no further in vivo testing is allowed. The combination of scientifically valid information from alternative tests with available animal and human data into a weight-of-evidence approach is part of the integrated test strategy under REACH. Interpretation of this integrated information requires a high degree of expertise, flexibility, and openness toward scientific advances. This will be crucial for the success of the REACH program. It means a shift of attitude and will put a heavy responsibility on scientific experts and regulators, but it is also an opportunity for meeting the safety expectations of our modern society. PMID:20574899

  11. Impact of LSP character on Slepton reach at the LHC

    NASA Astrophysics Data System (ADS)

    Eckel, Jonathan; Ramsey-Musolf, Michael J.; Shepherd, William; Su, Shufang

    2014-11-01

    Searches for supersymmetry at the Large Hadron Collider (LHC) have significantly constrained the parameter space associated with colored superpartners, whereas the constraints on color-singlet superpartners are considerably less severe. In this study, we investigate the dependence of slepton decay branching fractions on the nature of the lightest supersymmetric particle (LSP). In particular, in the Higgsino-like LSP scenarios, both decay branching fractions of and depend strongly on the sign and value of M 1 /M 2, which has strong implications for the reach of dilepton plus [InlineMediaObject not available: see fulltext.] searches for slepton pair production. We extend the experimental results for same flavor, opposite sign dilepton plus [InlineMediaObject not available: see fulltext.] searches at the 8TeV LHC to various LSP scenarios. We find that the LHC bounds on sleptons are strongly enhanced for a non-Bino-like LSP: the 95% C.L. limit for extends from 300 GeV for a Bino-like LSP to about 370 GeV for a Wino-like LSP. The bound for with a Higgsino-like LSP is the strongest (˜ 490 GeV) for M 1 /M 2 ˜ - tan2 ? W and is the weakest (˜ 220 GeV) for M 1 /M 2 ˜ tan2 ? W . We also calculate prospective slepton search reaches at the 14 TeV LHC. With 100 fb-1 integrated luminosity, the projected 95% C.L. mass reach for the left-handed slepton varies from 550 (670) GeV for a Bino-like (Winolike) LSP to 900 (390) GeV for a Higgsino-like LSP under the most optimistic (pessimistic) scenario. The reach for the right-handed slepton is about 440 GeV. The corresponding 5 ? discovery sensitivity is about 100 GeV smaller. For 300 fb-1 integrated luminosity, the reach is about 50 - 100 GeV higher.

  12. 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.

  13. Biochemical changes occurring during growth and storage of two yam species.

    PubMed

    Trèche, S; Agbor-Egbe, T

    1996-03-01

    The biochemical changes occurring during growth and storage of two yam cultivars (Dioscorea rotundata cv. Oshei and Dioscorea dumetorum cv. Jakri) were studied. Tubers were harvested at monthly intervals from the fourth to the tenth month after 50% emergence of the planted yam sets. For storage studies, Oshei and Jakri tubers were harvested 9.5 and 9 months post-emergence, respectively. These were stored under prevailing tropical ambient conditions (18-31 degrees C, 62-100% RH) for 1,2,3 and 4 months. All samples were analysed for dry matter, crude protein, carbohydrate, essential amino acids and mineral contents. The maximum dry matter was reached in both cultivars 9 months post-emergence, being 40.4 and 26.4%, respectively for Oshei and Jakri tubers. This was judged to be the optimum time for harvesting. Starch reached maximum values of 86.7 and 78.3 g/100g, respectively after 6 months. Ethanol-soluble sugars declined from 9.4 to 2.3 g/100g in Oshei but remained constant at over 6.0 g/100g in Jakri tubers during growth. Crude protein values increased slightly to a maximum of 5.4 and 8.0 g/100g, respectively for Oshei and Jakri tubers. During storage, weight losses reached 31% in Oshei tubers and 35% in Jakri after 110 days due to sprouting and dehydration. Starch decreased by approximately 3.5-4.5 g/100g while sugars and fibre values increased slightly in both cultivars. PMID:8833173

  14. 5 CFR 534.203 - Maximum stipends.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...Personnel 1 2014-01-01 2014-01-01 ...OTHER SYSTEMS Student-Employees... First year college undergraduate... Fourth year college undergraduate...maximum money amount in each...agency may pay a student-employee...

  15. 14 CFR 65.47 - Maximum hours.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...CERTIFICATION: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Air Traffic Control Tower Operators § 65.47 Maximum hours. Except in an emergency, a certificated air traffic control tower operator must be relieved of all duties...

  16. 14 CFR 65.47 - Maximum hours.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...CERTIFICATION: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Air Traffic Control Tower Operators § 65.47 Maximum hours. Except in an emergency, a certificated air traffic control tower operator must be relieved of all duties...

  17. 14 CFR 65.47 - Maximum hours.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...CERTIFICATION: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Air Traffic Control Tower Operators § 65.47 Maximum hours. Except in an emergency, a certificated air traffic control tower operator must be relieved of all duties...

  18. 14 CFR 65.47 - Maximum hours.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...CERTIFICATION: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Air Traffic Control Tower Operators § 65.47 Maximum hours. Except in an emergency, a certificated air traffic control tower operator must be relieved of all duties...

  19. 14 CFR 65.47 - Maximum hours.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...CERTIFICATION: AIRMEN OTHER THAN FLIGHT CREWMEMBERS Air Traffic Control Tower Operators § 65.47 Maximum hours. Except in an emergency, a certificated air traffic control tower operator must be relieved of all duties...

  20. On the efficiency at maximum cooling power

    NASA Astrophysics Data System (ADS)

    Apertet, Y.; Ouerdane, H.; Michot, A.; Goupil, C.; Lecoeur, Ph.

    2013-08-01

    The efficiency at maximum power (EMP) of heat engines operating as generators is one corner stone of finite-time thermodynamics, the Curzon-Ahlborn efficiency \\eta_CA being considered as a universal upper bound. Yet, no valid counterpart to \\eta_CA has been derived for the efficiency at maximum cooling power (EMCP) for heat engines operating as refrigerators. In this letter we analyse the reasons of the failure to obtain such a bound and we demonstrate that, despite the introduction of several optimisation criteria, the maximum cooling power condition should be considered as the genuine equivalent of maximum power condition in the finite-time thermodynamics frame. We then propose and discuss an analytic expression for the EMCP in the specific case of exoreversible refrigerators.

  1. Incremental Network Design with Maximum Flows

    E-print Network

    2013-12-21

    Dec 21, 2013 ... Incremental Network Design with Maximum Flows. Thomas ... optimization problems capturing that feature and combining two types of ...... The following computational tools were used to develop and analyze the formulations.

  2. 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…

  3. Modelling floods in hydrologically complex lowland river reaches

    NASA Astrophysics Data System (ADS)

    Stewart, M. D.; Bates, P. D.; Anderson, M. G.; Price, D. A.; Burt, T. P.

    1999-09-01

    This paper considers the modelling of lowland river reaches which contain complex within-reach hydrological interactions. It is clear that river and floodplain flow are the most important processes in terms of flood modelling in lowland systems, although there are often important lateral inflows from catchments and hillslopes bounding the floodplain and from interactions between the river and the floodplain, which can all affect the propagation of the flood wave. Previous models have often either considered a complex representation of the fluvial processes with no representation of the hydrological inflows into the reach (Bates, P.D., Anderson, M.G., Price, D.A., Hardy, R.J., Smith, C.N., 1996. Analysis and development of hydraulic models for floodplain flows. In: Anderson, M.G., Walling, D.E., Bates P.D. (Eds.), Floodplain Processes. Wiley, Chichester, pp. 215-254), or have simulated a range of catchment processes with a poor representation of the river and floodplain (Abbot, M.B., Bathurst, J.C., Cunge, J.A., O'Connell, P.E., Rasmussen, J., 1986. An introduction to the European Hydrological System—Système Hydrologique Européen, SHE, 2. Structure of a physically based, distributed modelling system. Journal of Hydrology, 87, 61-77). Hence, this paper develops a modelling approach based on a two-dimensional finite element hydraulic model of river and floodplain flow, which is linked to a series of simple hydrological models that simulate catchment runoff, surface and subsurface hillslope runoff, and floodplain infiltration. Simulations show that the model is able to predict flood hydrographs for a series of flood events, under a range of different hydrological conditions, down a reach of the River Severn, UK. Furthermore, the comparison of results from simulations using hydrological representations of different degrees of complexity suggest that there are restrictions on the necessary complexity of the hydrological components depending on the application of the model and the available validation data. Simple approaches to the reach scale hydrology may be sufficient if only the bulk outflow hydrograph is required by the user, however more complex spatially and temporally distributed models appear to be required if predictions of the flood inundation extent are desired. The simulations raise the issue of the application of distributed models and attempt to provide a framework for future research. The results suggest that there is a need for the validation of the internal predictions of distributed models of flood flow, and suggests a need for field data of river and floodplain interactions within long lowland river reaches.

  4. 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...

  5. 24 CFR 941.306 - Maximum project cost.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Maximum project cost. 941.306 Section 941.306 Housing...Application and Proposal § 941.306 Maximum project cost. (a) Calculation of maximum project cost. The maximum project cost...

  6. 24 CFR 941.306 - Maximum project cost.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Maximum project cost. 941.306 Section 941.306 Housing...Application and Proposal § 941.306 Maximum project cost. (a) Calculation of maximum project cost. The maximum project cost...

  7. 24 CFR 941.306 - Maximum project cost.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Maximum project cost. 941.306 Section 941.306 Housing...Application and Proposal § 941.306 Maximum project cost. (a) Calculation of maximum project cost. The maximum project cost...

  8. 24 CFR 941.306 - Maximum project cost.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Maximum project cost. 941.306 Section 941.306 Housing...Application and Proposal § 941.306 Maximum project cost. (a) Calculation of maximum project cost. The maximum project cost...

  9. 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.

  10. 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.

  11. Global CO2 rise leads to reduced maximum stomatal conductance in Florida vegetation

    PubMed Central

    Lammertsma, Emmy I.; de Boer, Hugo Jan; Dekker, Stefan C.; Dilcher, David L.; Lotter, André F.; Wagner-Cremer, Friederike

    2011-01-01

    A principle response of C3 plants to increasing concentrations of atmospheric CO2 (CO2) is to reduce transpirational water loss by decreasing stomatal conductance (gs) and simultaneously increase assimilation rates. Via this adaptation, vegetation has the ability to alter hydrology and climate. Therefore, it is important to determine the adaptation of vegetation to the expected anthropogenic rise in CO2. Short-term stomatal opening–closing responses of vegetation to increasing CO2 are described by free-air carbon enrichments growth experiments, and evolutionary adaptations are known from the geological record. However, to date the effects of decadal to centennial CO2 perturbations on stomatal conductance are still largely unknown. Here we reconstruct a 34% (±12%) reduction in maximum stomatal conductance (gsmax) per 100 ppm CO2 increase as a result of the adaptation in stomatal density (D) and pore size at maximal stomatal opening (amax) of nine common species from Florida over the past 150 y. The species-specific gsmax values are determined by different evolutionary development, whereby the angiosperms sampled generally have numerous small stomata and high gsmax, and the conifers and fern have few large stomata and lower gsmax. Although angiosperms and conifers use different D and amax adaptation strategies, our data show a coherent response in gsmax to CO2 rise of the past century. Understanding these adaptations of C3 plants to rising CO2 after decadal to centennial environmental changes is essential for quantification of plant physiological forcing at timescales relevant for global warming, and they are likely to continue until the limits of their phenotypic plasticity are reached. PMID:21330552

  12. 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…

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

    E-print Network

    Natsios, Andrew

    2015-01-01

    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... to Asia and the subcontinent and was used WHAT’S THE TAKEAWAY? The USAID Food for Peace program has been very effective, but it can be made even better. Allowing more local and regional procurement would: ? Make the current food aid program...

  14. On stiffening cables of a long reach manipulator

    SciTech Connect

    Wang, S.L.; Santiago, P. [North Carolina A& T State Univ., Greensboro, NC (United States). Dept. of Mechanical Engineering

    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.

  15. Extended reach and horizontal wells experienced on the Statfjord field

    SciTech Connect

    Kostol, P.; Tjotta, H. (Statoil, Stavanger (Norway))

    1993-09-01

    Statfjord field, the largest producing field in Europe, is located 200 km northwest of Bergen, Norway on the United Kingdom/Norwegian boundary. Statfjord field is being developed with three fully integrated platforms of concrete gravity based on Condeep design. The Statfjord field consists of four reservoirs: Upper Brent, Lower Brent, Dunlin, and Statfjord, which are developed separately. The overall objective for the horizontal and extended reach wells on Statfjord is to maximize the field recovery and accelerate production at a minimal cost. This is done by drilling extended reach wells to the far-away flanks of the field and drilling horizontal wells to drain fault blocks and erosion zones in the Brent reservoir and wedge zones in the Statfjord reservoir. To date, a total of 11 horizontal and extended reach wells have been drilled and completed on Statfjord field. The following have been key factors in drilling the horizontal and extended reach wells: well profile, torque and drag, equipment limitations, hole cleaning, hole stability, mud and cement programs, and surveying. To optimize the well profiles, extensive work has been put into simulating torque, drag, and ECDs. The well profiles are optimized with regards to drilling, completion, and workover, in addition to the reservoir targets. The completion is designed to be able to perform all future work through tubing. Factors like zone isolation requirements, well profile, casing program, logging/testing/perforating requirements, and sand production are considered when planning the completion. A 7 in. monobore completion string together with a 7 in. cemented liner is used to meet the completion objective. Several production logging tool, bridge plug, and perforation jobs have been performed on coiled tubing in horizontal wells on Statfjord field. Problems related to hole cleaning, well killing, fishing, and packer setting have been experienced during drilling and completion of the wells.

  16. Changes in corticospinal excitability during reach adaptation in force fields

    PubMed Central

    Ahmadi-Pajouh, Mohammad Ali; Harran, Michelle D.; Salimpour, Yousef; Shadmehr, Reza

    2013-01-01

    Both abrupt and gradually imposed perturbations produce adaptive changes in motor output, but the neural basis of adaptation may be distinct. Here, we measured the state of the primary motor cortex (M1) and the corticospinal network during adaptation by measuring motor-evoked potentials (MEPs) before reach onset using transcranial magnetic stimulation of M1. Subjects reached in a force field in a schedule in which the field was introduced either abruptly or gradually over many trials. In both groups, by end of the training, muscles that countered the perturbation in a given direction increased their activity during the reach (labeled as the on direction for each muscle). In the abrupt group, in the period before the reach toward the on direction, MEPs in these muscles also increased, suggesting a direction-specific increase in the excitability of the corticospinal network. However, in the gradual group, these MEP changes were missing. After training, there was a period of washout. The MEPs did not return to baseline. Rather, in the abrupt group, off direction MEPs increased to match on direction MEPs. Therefore, we observed changes in corticospinal excitability in the abrupt but not gradual condition. Abrupt training includes the repetition of motor commands, and repetition may be the key factor that produces this plasticity. Furthermore, washout did not return MEPs to baseline, suggesting that washout engaged a new network that masked but did not erase the effects of previous adaptation. Abrupt but not gradual training appears to induce changes in M1 and/or corticospinal networks. PMID:23034365

  17. The Agreement: Agreement Reached in the Multi-party Negotiations

    NSDL National Science Digital Library

    1998-01-01

    CELT, an archive of documents relating to Irish culture and history at University College, Cork, has made available the full text of the historic proposed peace treaty for Northern Ireland. Aimed at ending many years of sectarian violence, the treaty was reached after arduous and intense negotiations. The agreement is to be voted upon by the people of both Northern Ireland and the Irish Republic in late May, 1998.

  18. The challenge of reproductive and developmental toxicology under REACH

    Microsoft Academic Search

    Anthony R. Scialli

    2008-01-01

    The European Union’s REACH regulation has explicit requirements for reproductive and developmental toxicity data on all substances manufactured in or imported into the European Union at ?10metric tons\\/year. Meeting the data requirements with whole-animal testing could result in the use of almost 22 million vertebrate animals for the registration of existing chemicals and cost up to several hundred thousand dollars

  19. Full-Body Hybrid Motor Control for Reaching

    Microsoft Academic Search

    Wenjia Huang; Mubbasir Kapadia; Demetri Terzopoulos

    2010-01-01

    \\u000a In this paper, we present a full-body motor control mechanism that generates coordinated and diverse motion during a reaching\\u000a action. Our framework animates the full human body (stretching arms, flexing of the spine, as well as stepping forward) to\\u000a facilitate the desired end effector behavior. We propose a hierarchical control system for controlling the arms, spine, and\\u000a legs of the

  20. Preliminary findings of a study of the upper reaches of the Tamar Estuary, UK, throughout a complete tidal cycle: Part II: In-situ floc spectra observations

    Microsoft Academic Search

    S. J. Bass; K. R. Dyer

    2007-01-01

    A series of field experiments funded by the Natural Environmental Research Council were conducted in the upper reaches of the Tamar estuary (UK), which placed the measurements within the tidal trajectory of the turbidity maximum. The aim of the study was to examine how the distribution of floc characteristics evolved with respect to changes in the turbulent shear stress, suspended

  1. Application of maximum entropy method for droplet size distribution prediction using instability analysis of liquid sheet

    Microsoft Academic Search

    E. Movahednejad; F. Ommi; S. M. Hosseinalipour; C. P. Chen; S. A. Mahdavi

    This paper describes the implementation of the instability analysis of wave growth on liquid jet surface, and maximum entropy\\u000a principle (MEP) for prediction of droplet diameter distribution in primary breakup region. The early stage of the primary\\u000a breakup, which contains the growth of wave on liquid–gas interface, is deterministic; whereas the droplet formation stage\\u000a at the end of primary breakup

  2. Quantifying loss of independent joint control in acute stroke with a robotic evaluation of reaching workspace.

    PubMed

    Ellis, Michael D; Kottink, Anke I R; Prange, Gerdienke B; Rietman, Johan S; Buurke, Jaap H; Dewald, Julius P A

    2011-01-01

    Early recovery after stroke is significant for slow emergence of volitional movement. Initial movements are constrained by stereotypical co-activation of muscle groups such as shoulder abductors and distal limb flexors resulting in the loss of independent joint control. The objective of this study was to utilize new quantitative methods to evaluate the emergence and progression of the loss of independent joint control in the acute phase of recovery from stroke. Fifteen participants have been followed a maximum range of 2 to 32 weeks post-stroke. Participants underwent weekly and monthly robotic evaluations of horizontal plane reaching workspace as a function of abduction loading (0%-200% of limb weight). The magnitude of loss of independent joint control, indicated by the rate of work area reduction as a function of abduction loading, was evident even as early as 2 weeks post-stroke. Group analysis indicated that individuals with mild stroke show immediate presence of the impairment with an exponential rate of recovery over time while individuals with severe stroke show persistent impairment. Early detection and quantification of reaching impairments, such as the loss of independent joint control, will allow clinicians to more efficiently identify patients who would benefit from impairment-based targeted interventions. For example, patients with severe loss of independent joint control will likely benefit from early administration of an intervention attempting to reduce abnormal shoulder abductor/distal limb flexor co-activations during reaching. The field of rehabilitation robotics has demonstrated such interventions to be promising in the chronic severe stroke population. PMID:22256253

  3. 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,…

  4. 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.

  5. Connection between maximum-work and maximum-power thermal cycles

    NASA Astrophysics Data System (ADS)

    Gonzalez-Ayala, Julian; Arias-Hernandez, L. A.; Angulo-Brown, F.

    2013-11-01

    A new connection between maximum-power Curzon-Ahlborn thermal cycles and maximum-work reversible cycles is proposed. This linkage is built through a mapping between the exponents of a class of heat transfer laws and the exponents of a family of heat capacities depending on temperature. This connection leads to the recovery of known results and to a wide and interesting set of results for a class of thermal cycles. Among other results it was found that it is possible to use analytically closed expressions for maximum-work efficiencies to calculate good approaches to maximum-power efficiencies. Behind the proposed connection is an interpretation of endoreversibility hypothesis. Additionally, we suggest that certain reversible maximum-work cycles depending on working substance can be used as reversible landmarks for FTT maximum-power cycles, which also depend on working substance properties.

  6. 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.

  7. SD of maximum Stem Diameter (in cm)

    E-print Network

    Schierup, Mikkel Heide

    SD of maximum Stem Diameter (in cm) 1,4 - 13,3 13,4 - 14,8 14,9 - 15,6 15,7 - 16,5 16,6 - 17,3 17,8 12,9 - 14,3 14,4 - 16,1 16,2 - 30,0 Mean of maximum Stem Diameter (in cm) 0,0 - 13,3 13,4 - 14,5 14 look quite similar. Mean of Stem Height, Stem Diameter and Leaf Number seem to show higher values

  8. Open Learning in India: Evolution, Diversification and Reaching Out

    ERIC Educational Resources Information Center

    Sharma, Ramesh C.

    2005-01-01

    Distance education has a history of over four decades in India. There has been a vast growth in the number of learners who need education and thus also the corresponding channels of providing education. Due to the constraints of the traditional educational sector, open and distance learning has been found to be a workable alternative strategy in…

  9. What drives children's limb selection for reaching in hemispace?

    PubMed

    Gabbard, Carl; Helbig, Casi Rabb

    2004-06-01

    Arguably, the act of reaching constitutes one of the most devoted lines of contemporary developmental research. In addition to the underlying dynamical characteristics of motor coordination, a key element in programming is limb selection, a phenomenon (handedness) that has so far resisted any reasonable unified explanation. From a more contemporary view, two factors appear to have the most influence on hand selection for a given task: motor dominance and attentional information related to task demands. This study was designed to determine what factor(s) influence choice of limb for reaching in hemispace in reference to motor dominance, object proximity, and a hemispheric bias favoring use of the hand on the same side as the stimulus. Strong right-handed children were asked to reach and retrieve a small object across right and left hemispace locations beginning with the arms uncrossed and arms-crossed. With the arms-crossed condition, an imagined and actual movement execution was administered. Results from the uncrossed condition supported previous reported findings for adults and children. That is, participants responded ipsilaterally using the hand on the same side as the stimulus, thus supporting the case for object proximity and hemispheric bias. However, in the arms-crossed condition the vast majority of participants preferred keeping the limbs crossed in response to right and left hemispace stimuli, which leads to the suggestion that object proximity rather than hemispheric bias was the driving factor in this context. The behavioral pattern for imagined and actual movement was not significantly different. Overall, the findings add to the growing acceptance that limb selection is task and context dependent, rather than a biologically based invariant feature of motor behavior. PMID:14745465

  10. Maximum union-free subfamilies Choongbum Lee

    E-print Network

    Fox, Jacob

    Maximum union-free subfamilies Jacob Fox Choongbum Lee Benny Sudakov Abstract An old problem of Moser asks: how large of a union-free subfamily does every family of m sets have? A family of sets is called union-free if there are no three distinct sets in the family such that the union of two

  11. Finding Maximum Length Tours Under Polyhedral Norms

    Microsoft Academic Search

    Alexander Barvinok; David S. Johnson; Gerhard J. Woeginger; Russell Woodroofe

    1998-01-01

    We consider the traveling salesman problem when the cities are points in IRdfor some fixed d and distances are computed according to a polyhedral norm. Weshow that for any such norm, the problem of finding a tour of maximum lengthcan be solved in polynomial time. If arithmetic operations are assumed to takeunit time, our algorithms run in time O(nf+1), where

  12. Maximum terminal velocity of relativistic rocket

    Microsoft Academic Search

    G. Vulpetti

    1985-01-01

    The maximum terminal velocity problem of the classical propulsion is extended to a relativistic rocket assumed broken down into active mass, inert mass and gross payload. A fraction of the active mass is converted into energy shared between inert mass and active mass residual. Significant effects are considered. State and co-state equations are carried out to find the exhaust speed

  13. Maximum Homologous Crossover for Linear Genetic Programming

    E-print Network

    Paris-Sud XI, Université de

    Maximum Homologous Crossover for Linear Genetic Programming Michael Defoin Platel1,2 , Manuel Fitness problem, for Linear Genetic Programming. Two variants of the new crossover operator are described of deleterious crossovers. 1 Introduction The role played by crossover in the Genetic Programming (GP

  14. 5 CFR 534.203 - Maximum stipends.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Maximums by grade and step 1 L-A Below high school graduation GS-1-1 (minus 3 steps). L-1 First year college...with persons afflicted with leprosy are increased above the rates prescribed in paragraph (a) of this section to the...

  15. 5 CFR 534.203 - Maximum stipends.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Maximums by grade and step 1 L-A Below high school graduation GS-1-1 (minus 3 steps). L-1 First year college...with persons afflicted with leprosy are increased above the rates prescribed in paragraph (a) of this section to the...

  16. Original article Inequality of maximum a posteriori

    E-print Network

    Boyer, Edmond

    for the genetic evaluation of breeding animals. A logical step would be to use an animal model as well to describeOriginal article Inequality of maximum a posteriori estimators with equivalent sire and animal models for threshold traits M Mayer University of Nairobi, Department of Animal Production, PO Box 29053

  17. 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}},\

  18. Weak Scale From the Maximum Entropy Principle

    E-print Network

    Hamada, Yuta; Kawana, Kiyoharu

    2015-01-01

    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}},\

  19. 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.

  20. ccsd00003341, On nonparametric maximum likelihood

    E-print Network

    Algorithm; Mix- tures of Probability Measures; Repeated Measurements Data; Longitudinal Data. Subject Classi value f(S i ; T i ). This kind of data is known as repeated measurements, or called longitudinal since of Pfanzagl related to mixtures [23, 24]. Keywords: Inverse Problems; Nonlinear Models; Maximum Likelihood; EM

  1. 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.

  2. 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.

  3. Predicting maximum lake depth from surrounding topography.

    PubMed

    Hollister, Jeffrey W; Milstead, W Bryan; Urrutia, M Andrea

    2011-01-01

    Information about lake morphometry (e.g., depth, volume, size, etc.) aids understanding of the physical and ecological dynamics of lakes, yet is often not readily available. The data needed to calculate measures of lake morphometry, particularly lake depth, are usually collected on a lake-by-lake basis and are difficult to obtain across broad regions. To span the gap between studies of individual lakes where detailed data exist and regional studies where access to useful data on lake depth is unavailable, we developed a method to predict maximum lake depth from the slope of the topography surrounding a lake. We use the National Elevation Dataset and the National Hydrography Dataset - Plus to estimate the percent slope of surrounding lakes and use this information to predict maximum lake depth. We also use field measured maximum lake depths from the US EPA's National Lakes Assessment to empirically adjust and cross-validate our predictions. We were able to predict maximum depth for ?28,000 lakes in the Northeastern United States with an average cross-validated RMSE of 5.95 m and 5.09 m and average correlation of 0.82 and 0.69 for Hydrological Unit Code Regions 01 and 02, respectively. The depth predictions and the scripts are openly available as supplements to this manuscript. PMID:21984945

  4. Maximum rotation frequency of strange stars

    SciTech Connect

    Zdunik, J.L.; Haensel, P. (Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences, Bartycka 18, PL-00-716 Warsaw (Poland))

    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.

  5. 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)

  6. Integrated testing strategy (ITS) for bioaccumulation assessment under REACH.

    PubMed

    Lombardo, Anna; Roncaglioni, Alessandra; Benfentati, Emilio; Nendza, Monika; Segner, Helmut; Fernández, Alberto; Kühne, Ralph; Franco, Antonio; Pauné, Eduard; Schüürmann, Gerrit

    2014-08-01

    REACH (registration, evaluation, authorisation and restriction of chemicals) regulation requires that all the chemicals produced or imported in Europe above 1 tonne/year are registered. To register a chemical, physicochemical, toxicological and ecotoxicological information needs to be reported in a dossier. REACH promotes the use of alternative methods to replace, refine and reduce the use of animal (eco)toxicity testing. Within the EU OSIRIS project, integrated testing strategies (ITSs) have been developed for the rational use of non-animal testing approaches in chemical hazard assessment. Here we present an ITS for evaluating the bioaccumulation potential of organic chemicals. The scheme includes the use of all available data (also the non-optimal ones), waiving schemes, analysis of physicochemical properties related to the end point and alternative methods (both in silico and in vitro). In vivo methods are used only as last resort. Using the ITS, in vivo testing could be waived for about 67% of the examined compounds, but bioaccumulation potential could be estimated on the basis of non-animal methods. The presented ITS is freely available through a web tool. PMID:24806447

  7. 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.

  8. Reach-averaged sediment routing model of a canyon river

    USGS Publications Warehouse

    Wiele, S.M.; Wilcock, P.R.; Grams, P.E.

    2007-01-01

    Spatial complexity in channel geometry indicates that accurate prediction of sediment transport requires modeling in at least two dimensions. However, a one-dimensional model may be the only practical or possible alternative, especially for longer river reaches of practical concern in river management or landscape modeling. We have developed a one-dimensional model of the Colorado River through upper Grand Canyon that addresses this problem by reach averaging the channel properties and predicting changes in sand storage using separate source and sink functions coupled to the sand routing model. The model incorporates results from the application of a two-dimensional model of flow, sand transport, and bed evolution, and a new algorithm for setting the near-bed sand boundary condition for sand transported over an exposed bouldery bed. Model predictions were compared to measurements of sand discharge during intermittent tributary inputs and varying discharges controlled by dam releases. The model predictions generally agree well with the timing and magnitude of measured sand discharges but tend to overpredict sand discharge during the early stages of a high release designed to redistribute sand to higher-elevation deposits.

  9. Reaching environmental decisions: Making subjective and objective judgments

    NASA Astrophysics Data System (ADS)

    Ghiselin, Jon

    1982-03-01

    Objective judgments, external to the judge, are compared with subjective, internal judgments. This analysis is made in the context of reaching regulatory decisions affecting the human environment. Examples given include evaluating the potential risk of industrial chemicals and comparing the potential effects of short- and long-term changes in land use. The analysis deals not with the decisions themselves, but rather with the kinds of questions that must be posed in orderto reach such decisions. Decision makers may spuriously distinguish objective from subjective types of judgment, though these are rarely wholly separate. Judges can hardly dispute about objective statements, if truly identical definitions are used. But subjective statements can reasonably be voted upon. Scientists, engineers, and economists represent logical or objective decision makers, tending to work in groups. Subjective thinkers include artists and performers, and others who often work alone. Moral and aesthetic aspects of questions, usually seen as intangible, are treated as if subjective. Financial decisions, usually viewed as tangible, are handled as objective problems. This mechanism for making decisions is well-established in environmental assessment. Though objective questions can be treated well in the monetary terms of cost-benefit analysis, subjective ones cannot. Mathematical and other variants are discussed in relation to the comparison of alternative types of tests.

  10. How do antimalarial drugs reach their intracellular targets?

    PubMed Central

    Basore, Katherine; Cheng, Yang; Kushwaha, Ambuj K.; Nguyen, Son T.; Desai, Sanjay A.

    2015-01-01

    Drugs represent the primary treatment available for human malaria, as caused by Plasmodium spp. Currently approved drugs and antimalarial drug leads generally work against parasite enzymes or activities within infected erythrocytes. To reach their specific targets, these chemicals must cross at least three membranes beginning with the host cell membrane. Uptake at each membrane may involve partitioning and diffusion through the lipid bilayer or facilitated transport through channels or carriers. Here, we review the features of available antimalarials and examine whether transporters may be required for their uptake. Our computational analysis suggests that most antimalarials have high intrinsic membrane permeability, obviating the need for uptake via transporters; a subset of compounds appear to require facilitated uptake. We also review parasite and host transporters that may contribute to drug uptake. Broad permeability channels at the erythrocyte and parasitophorous vacuolar membranes of infected cells relax permeability constraints on antimalarial drug design; however, this uptake mechanism is prone to acquired resistance as the parasite may alter channel activity to reduce drug uptake. A better understanding of how antimalarial drugs reach their intracellular targets is critical to prioritizing drug leads for antimalarial development and may reveal new targets for therapeutic intervention. PMID:25999857

  11. Role of "Reach to Recovery" in breast cancer.

    PubMed

    Willits, M J

    1994-10-01

    Medical personnel should be aware that the Reach to Recovery program has gone from one visit to a radical mastectomy surgery patient to a multifaceted program. Reach to Recovery volunteers have been trained to make lumpectomy, mastectomy, reconstruction, and recurrence visits. They make visits not only in the hospital but at alternative locations (home, physician's office, library, coffee shop). Older women have the same needs as all women--getting back to normal, feeling good about themselves, and their sexuality. Older woman should not be ignored because of their age. Volunteers who visit patients are matched to a patient according to the type of surgery performed and the patient's age; older volunteers visit older patients. Programs continue to evolve as health care changes, with more lumpectomies, more reconstruction, etc. A 2-year evaluation just has been completed, and all the data are in the process of being updated. Medical personnel give medical advice. They offer support and the opportunity to talk to someone who has been there and who understands the concern of the patient with breast cancer. PMID:8087785

  12. 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.

  13. 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.

  14. Long-reach 10-Gb/s RSOA-based WDM PON employing QPSK signal and coherent receiver.

    PubMed

    Cho, K Y; Hong, U H; Jung, S P; Takushima, Y; Agata, A; Sano, T; Horiuchi, Y; Suzuki, M; Chung, Y C

    2012-07-01

    We demonstrate a long-reach wavelength-division-multiplexed passive optical network (WDM PON) operating at the symmetric rate of 10.3 Gb/s. For the cost-effectiveness, we realize the upstream transmission by utilizing directly-modulated TO-can packaged reflective semiconductor optical amplifiers (RSOAs) and digital coherent receivers. In addition, to overcome the limited modulation bandwidth of this TO-can packaged RSOA (~2.2 GHz) and operate it at 10.3 Gb/s, we utilize the quadrature phase shift keying (QPSK) format and the electronic phase equalization technique. The result shows that we can extend the maximum reach of the 10.3-Gb/s RSOA-based WDM PON to ~80 km without using any remote amplifiers. PMID:22772232

  15. From reaching every district to reaching every community: analysis and response to the challenge of equity in immunization in Cambodia

    PubMed Central

    Chan Soeung, Sann; Grundy, John; Duncan, Richard; Thor, Rasoka; Bilous, Julian B

    2013-01-01

    Background An international review of the Cambodian Expanded Programme on Immunization (EPI) in 2010 and other data show that despite immunization coverage increases and vaccine preventable diseases incidence reductions, inequities in access to immunization services exist. Utilizing immunization and health systems literature, analysis of global health databases and the EPI review findings, this paper examines the characteristics of immunization access and outcome inequities, and describes proposed longer-term strategic and operational responses to these problems. Findings The national programme has evolved from earlier central and provincial level planning to strengthening routine immunization coverage through the District level ‘Reaching Every District Strategy’. However, despite remarkable improvements, the review found over 20% of children surveyed were not fully immunized, primarily from communities where inequities of both access and impact persist. These inequities relate mainly to socio-economic exposures including wealth and education level, population mobility and ethnicity. To address these problems, a shift in strategic and operational response is proposed that will include (a) a re-focus of planning on facility level to detect disadvantaged communities, (b) establishment of monitoring systems to provide detailed information on community access and utilization, (c) development of communication strategies and health networks that enable providers to adjust service delivery according to the needs of vulnerable populations, and (d) securing financial, management and political commitment for ‘reaching every community’. Conclusions For Cambodia to achieve its immunization equity objectives and disease reduction goals, a shift of emphasis to health centre and community is needed. This approach will maximize the benefits of new vaccine introduction in the coming ‘Decade of Vaccines’, plus potentially extend the reach of other life-saving maternal and child health interventions to the socially disadvantaged, both in Cambodia and in other countries with a similar level of development. PMID:23048124

  16. 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…

  17. 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

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

    PubMed

    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. PMID:25215771

  19. Early Time Points Perfusion Imaging: Relative Time of Arrival, Maximum Derivatives and Fractional Derivatives

    PubMed Central

    Kwong, Kenneth K.; Wu, Ona; Chan, Suk-Tak; Nelissen, Koen; Kholodov, Mykhaylo; Chesler, David A.

    2011-01-01

    Time of arrival (TOA) of a bolus of contrast agent to the tissue voxel is a reference time point critical for the Early Time Points Perfusion Imaging Method (ET) to make relative cerebral blood flow (rCBF) maps. Due to the low contrast to noise (CNR) condition at TOA, other useful reference time points known as relative time of arrival data points (rTOA) are investigated. Candidate rTOA's include the time to reach the maximum derivative, the maximum second derivative, and the maximum fractional derivative. Each rTOA retains the same relative time distance from TOA for all tissue flow levels provided that ET's basic assumption is met, namely, no contrast agent has a chance to leave the tissue before the time of rTOA. The ET's framework insures that rCBF estimates by different orders of the derivative are theoretically equivalent to each other and monkey perfusion imaging results supported the theory. In rCBF estimation, maximum values of higher order fractional derivatives may be used to replace the maximum derivative which runs a higher risk of violating ET's assumption. Using the maximum values of the derivative of orders ranging from 1 to 1.5 to 2, estimated rCBF results were found to demonstrate a gray-white matter ratio of approximately 3, a number consistent with flow ratio reported in the literature. PMID:21600995

  20. Vegetation controls on the maximum size of coastal dunes

    NASA Astrophysics Data System (ADS)

    Duran Vinent, Orencio; Moore, Laura J.

    2014-05-01

    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 co-evolution 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 time scale 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 landwards and thus leads to larger foredunes.

  1. Need for GLUT4 activation to reach maximum effect of insulin-mediated glucose uptake in brown adipocytes isolated from GLUT4myc-expressing mice.

    PubMed

    Konrad, Daniel; Bilan, Philip J; Nawaz, Zafar; Sweeney, Gary; Niu, Wenyan; Liu, Zhi; Antonescu, Costin N; Rudich, Assaf; Klip, Amira

    2002-09-01

    There is a need to understand whether the amount of GLUT4 at the cell surface determines the extent of glucose uptake in response to insulin. Thus, we created a heterozygous mouse expressing modest levels of myc-tagged GLUT4 (GLUT4myc) in insulin-sensitive tissues under the control of the human GLUT4 promoter. Insulin stimulated 2-deoxyglucose uptake 6.5-fold in isolated brown adipocytes. GLUT1 did not contribute to the insulin response. The stimulation by insulin was completely blocked by wortmannin and partly (55 +/- 2%) by the p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580. Insulin increased surface exposure of GLUT4myc twofold (determined by fluorescent or enzyme-linked myc immunodetection in intact adipocytes). Such increase was completely blocked by wortmannin but insensitive to SB203580. Insulin increased the kinase activity of the p38 MAPK beta-isoform 1.9-fold without affecting p38-alpha. In summary, the GLUT4myc mouse is a promising model for measuring GLUT4 translocation in intact primary cells. It affords direct comparison between GLUT4 translocation and glucose uptake in similar cell preparations, allowing one to study the regulation of GLUT4 activity. Using this animal model, we found that stimulation of glucose uptake into brown adipocytes involves both GLUT4 translocation and activation. PMID:12196464

  2. Reach the Bottom Line of the Sbottom Search

    SciTech Connect

    Alvarez, Ezequiel; Bai, Yang

    2012-05-22

    We propose a new search strategy for directly-produced sbottoms at the LHC with a small mass splitting between the sbottom and its decayed stable neutralino. Our search strategy is based on boosting sbottoms through an energetic initial state radiation jet. In the final state, we require a large missing transverse energy and one or two b-jets besides the initial state radiation jet. We also define a few kinematic variables to further increase the discovery reach. For the case that the sbottom mainly decays into the bottom quark and the stable neutralino, we have found that even for a mass splitting as small as 10 GeV sbottoms with masses up to around 400 GeV can be excluded at the 95% confidence level with 20 inverse femtobarn data at the 8 TeV LHC.

  3. 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.

  4. 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

  5. Bell Atlantic and Communications Workers of America (CWA) Reach Agreement

    NSDL National Science Digital Library

    Waters, Megan.

    This week's In the News examines the recent labor dispute between the Bell Atlantic Corporation and the Communications Workers of America (CWA). The ten resources discussed provide background information on the telecommunications industry and press coverage of the August 9-11, 1998 strike as well as Bell Atlantic's corporate history. Adding a human dimension to typical technological and economic coverage of the telecommunications industry, 73,000 telephone workers paralyzed Bell Atlantic services in thirteen Eastern states on August 9, 1998. Union fear concerning Bell Atlantic's recent acquisition of GTE is cited as a major strike cause as job losses due to new Internet technologies became a reality following the merger. A tentative two-year agreement was reached on August 11, however, ending the conflict with the promise of "high-skill, good paying jobs" that allow workers to reap the benefits of information-age ventures as well as employers.

  6. Modelling stochastic sediment delivery to a channel reach

    NASA Astrophysics Data System (ADS)

    Turowski, Jens

    2010-05-01

    Bedload transport, the sliding, rolling or hopping motion of sediment particles over a river bed, has long been recognised to be a stochastic process. Here, the Birnbaum-Saunders distribution is proposed as a probability distribution function for the transport rates at a given water discharge. This distribution can be derived from simple assumptions without reference to the specific physics of sediment transport and should thus be widely applicable. The function is successfully tested using a high-resolution bedload transport dataset from the Pitzbach stream, Austria. Using other empirical and semi-empirical equations, I develop a system of equations for modelling stochastic sediment delivery to a channel reach that honour the long-term average fluxes. The equations take into account both bedload and suspended load.

  7. 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

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

    PubMed Central

    Ahn, Jooeun; Hogan, Neville

    2012-01-01

    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 show evidence of high-level control focused on lower-limb trajectories; others suggest that nonlinear oscillators such as lower-level rhythmic central pattern generators (CPGs) play a significant role. To resolve this ambiguity, we reasoned that if a nonlinear oscillator contributes to locomotor control, human walking should exhibit dynamic entrainment to periodic mechanical perturbation; entrainment is a distinctive behavior of nonlinear oscillators. Here we present the first behavioral evidence that nonlinear neuro-mechanical oscillators contribute to the production of human walking, albeit weakly. As unimpaired human subjects walked at constant speed, we applied periodic torque pulses to the ankle at periods different from their preferred cadence. The gait period of 18 out of 19 subjects entrained to this mechanical perturbation, converging to match that of the perturbation. Significantly, entrainment occurred only if the perturbation period was close to subjects' preferred walking cadence: it exhibited a narrow basin of entrainment. Further, regardless of the phase within the walking cycle at which perturbation was initiated, subjects' gait synchronized or phase-locked with the mechanical perturbation at a phase of gait where it assisted propulsion. These results were affected neither by auditory feedback nor by a distractor task. However, the convergence to phase-locking was slow. These characteristics indicate that nonlinear neuro-mechanical oscillators make at most a modest contribution to human walking. Our results suggest that human locomotor control is not organized as in reaching to meet a predominantly kinematic specification, but is hierarchically organized with a semi-autonomous peripheral oscillator operating under episodic supervisory control. PMID:22479311

  9. Maximum-entropy description of animal movement.

    PubMed

    Fleming, Chris H; Suba??, Yi?it; Calabrese, Justin M

    2015-03-01

    We introduce a class of maximum-entropy states that naturally includes within it all of the major continuous-time stochastic processes that have been applied to animal movement, including Brownian motion, Ornstein-Uhlenbeck motion, integrated Ornstein-Uhlenbeck motion, a recently discovered hybrid of the previous models, and a new model that describes central-place foraging. We are also able to predict a further hierarchy of new models that will emerge as data quality improves to better resolve the underlying continuity of animal movement. Finally, we also show that Langevin equations must obey a fluctuation-dissipation theorem to generate processes that fall from this class of maximum-entropy distributions when the constraints are purely kinematic. PMID:25871054

  10. Pareto versus lognormal: A maximum entropy test

    NASA Astrophysics Data System (ADS)

    Bee, Marco; Riccaboni, Massimo; Schiavo, Stefano

    2011-08-01

    It is commonly found that distributions that seem to be lognormal over a broad range change to a power-law (Pareto) distribution for the last few percentiles. The distributions of many physical, natural, and social events (earthquake size, species abundance, income and wealth, as well as file, city, and firm sizes) display this structure. We present a test for the occurrence of power-law tails in statistical distributions based on maximum entropy. This methodology allows one to identify the true data-generating processes even in the case when it is neither lognormal nor Pareto. The maximum entropy approach is then compared with other widely used methods and applied to different levels of aggregation of complex systems. Our results provide support for the theory that distributions with lognormal body and Pareto tail can be generated as mixtures of lognormally distributed units.

  11. MAXIMUM LIKELIHOOD ESTIMATION FOR SOCIAL NETWORK DYNAMICS.

    PubMed

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

    2010-06-01

    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

  12. 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

  13. Finding maximum colorful subtrees in practice.

    PubMed

    Rauf, Imran; Rasche, Florian; Nicolas, François; Böcker, Sebastian

    2013-04-01

    In metabolomics and other fields dealing with small compounds, mass spectrometry is applied as a sensitive high-throughput technique. Recently, fragmentation trees have been proposed to automatically analyze the fragmentation mass spectra recorded by such instruments. Computationally, this leads to the problem of finding a maximum weight subtree in an edge-weighted and vertex-colored graph, such that every color appears, at most once in the solution. We introduce new heuristics and an exact algorithm for this Maximum Colorful Subtree problem and evaluate them against existing algorithms on real-world and artificial datasets. Our tree completion heuristic consistently scores better than other heuristics, while the integer programming-based algorithm produces optimal trees with modest running times. Our fast and accurate heuristic can help determine molecular formulas based on fragmentation trees. On the other hand, optimal trees from the integer linear program are useful if structure is relevant, for example for tree alignments. PMID:23509858

  14. UNL Research & Economic Development Growth Initiative Introduction

    E-print Network

    Farritor, Shane

    , metrics, and some mechanisms for reaching them. #12;Office of Research & Economic Development RoleUNL Research & Economic Development Growth Initiative 2012-201 Introduction The University ambitious goals for increasing our growth in research and economic development. The specific challenges

  15. Maximum Entropy Analysis of Queueing Network Models

    Microsoft Academic Search

    Demetres D. Kouvatsos

    1993-01-01

    The principle of Maximum Entropy (ME) provides a consistent method of inference for estimating the form of an unknown discrete-state probability distribution, based on information expressed in terms of true expected values. In this tutorial paper entropy maximisation is used to characterise product-form approximations and resolution algorithms for arbitrary continuous-time and discrete-time Queueing Network Models (QNMs) at equilibrium under Repetitive-Service

  16. Maximum entropy and Bayesian methods. Proceedings.

    NASA Astrophysics Data System (ADS)

    Grandy, W. T., Jr.; Schick, L. H.

    This volume contains a selection of papers presented at the Tenth Annual Workshop on Maximum Entropy and Bayesian Methods. The thirty-six papers included cover a wide range of applications in areas such as economics and econometrics, astronomy and astrophysics, general physics, complex systems, image reconstruction, and probability and mathematics. Together they give an excellent state-of-the-art overview of fundamental methods of data analysis.

  17. Maximum Correntropy Criterion for Robust Face Recognition

    Microsoft Academic Search

    Ran He; Wei-Shi Zheng; Bao-Gang Hu

    2011-01-01

    In this paper, we present a sparse correntropy framework for computing robust sparse representations of face images for recognition. Compared with the state-of-the-art l 1 norm-based sparse representation classifier (SRC), which assumes that noise also has a sparse representation, our sparse algorithm is developed based on the maximum correntropy criterion, which is much more insensitive to outliers. In order to

  18. THEORETICAL ESTIMATE OF MAXIMUM POSSIBLE NUCLEAR EXPLOSION

    Microsoft Academic Search

    Bethe

    1950-01-01

    The maximum nuclear accident which could occur in a Na-cooled, Be moderated, Pu and power producing reactor is estimated theoretically. (T.R.H.) 2O82 Results of nuclear calculations for a variety of compositions of fast, heterogeneous, sodium-cooled, U-235-fueled, plutonium- and power-producing reactors are reported. Core compositions typical of plate-, pin-, or wire-type fuel elements and with uranium as metal, alloy, and oxide

  19. 49 CFR 230.24 - Maximum allowable stress.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 2010-10-01 false Maximum allowable stress. 230.24 Section 230.24 Transportation...STANDARDS Boilers and Appurtenances Allowable Stress § 230.24 Maximum allowable stress. (a) Maximum allowable stress value....

  20. 49 CFR 230.24 - Maximum allowable stress.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 2014-10-01 false Maximum allowable stress. 230.24 Section 230.24 Transportation...STANDARDS Boilers and Appurtenances Allowable Stress § 230.24 Maximum allowable stress. (a) Maximum allowable stress value....

  1. 49 CFR 230.24 - Maximum allowable stress.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 2012-10-01 false Maximum allowable stress. 230.24 Section 230.24 Transportation...STANDARDS Boilers and Appurtenances Allowable Stress § 230.24 Maximum allowable stress. (a) Maximum allowable stress value....

  2. 49 CFR 230.24 - Maximum allowable stress.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 2011-10-01 false Maximum allowable stress. 230.24 Section 230.24 Transportation...STANDARDS Boilers and Appurtenances Allowable Stress § 230.24 Maximum allowable stress. (a) Maximum allowable stress value....

  3. 49 CFR 230.24 - Maximum allowable stress.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 2013-10-01 false Maximum allowable stress. 230.24 Section 230.24 Transportation...STANDARDS Boilers and Appurtenances Allowable Stress § 230.24 Maximum allowable stress. (a) Maximum allowable stress value....

  4. 14 CFR 375.23 - Maximum allowable weights.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... false Maximum allowable weights. 375.23 Section 375...375.23 Maximum allowable weights. Foreign civil aircraft...in the United States on the basis of foreign airworthiness certificates...limitations on maximum certificated weights prescribed or authorized...

  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, 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...

  7. 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...

  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, 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...

  10. 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...

  11. 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...

  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. 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...

  14. 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...

  15. 40 CFR 143.3 - Secondary maximum contaminant levels.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Secondary maximum contaminant levels. 143.3 Section 143.3 ...REGULATIONS § 143.3 Secondary maximum contaminant levels. The secondary maximum contaminant levels for public water systems are...

  16. 40 CFR 35.2205 - Maximum allowable project cost.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Maximum allowable project cost. 35.2205 Section 35.2205...35.2205 Maximum allowable project cost. (a) Grants awarded on or...regulation, the maximum allowable project cost will be the sum of: (1)...

  17. 40 CFR 35.2205 - Maximum allowable project cost.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Maximum allowable project cost. 35.2205 Section 35.2205...35.2205 Maximum allowable project cost. (a) Grants awarded on or...regulation, the maximum allowable project cost will be the sum of: (1)...

  18. 40 CFR 35.2205 - Maximum allowable project cost.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Maximum allowable project cost. 35.2205 Section 35.2205...35.2205 Maximum allowable project cost. (a) Grants awarded on or...regulation, the maximum allowable project cost will be the sum of: (1)...

  19. 40 CFR 35.2205 - Maximum allowable project cost.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Maximum allowable project cost. 35.2205 Section 35.2205...35.2205 Maximum allowable project cost. (a) Grants awarded on or...regulation, the maximum allowable project cost will be the sum of: (1)...

  20. 40 CFR 35.2205 - Maximum allowable project cost.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Maximum allowable project cost. 35.2205 Section 35.2205...35.2205 Maximum allowable project cost. (a) Grants awarded on or...regulation, the maximum allowable project cost will be the sum of: (1)...

  1. 24 CFR 886.108 - Maximum annual contract commitment.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Maximum annual contract commitment. (a) Number of units assisted. Based...in the project. All units currently assisted...to such conversion. Units assisted under section...Maximum annual Contract commitment. The maximum...

  2. 40 CFR 141.13 - Maximum contaminant levels for turbidity.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... false Maximum contaminant levels for turbidity. 141.13 Section 141.13 Protection...141.13 Maximum contaminant levels for turbidity. The maximum contaminant levels for turbidity are applicable to both community...

  3. Coral mortality increases wave energy reaching shores protected by reef flats: Examples from the Seychelles

    NASA Astrophysics Data System (ADS)

    Sheppard, Charles; Dixon, David J.; Gourlay, Michael; Sheppard, Anne; Payet, Rolph

    2005-08-01

    In the granitic Seychelles, many shores and beaches are fringed by coral reef flats which provide protection to shores from erosion by waves. The surfaces of these reef flats support a complex ecology. About 10 years ago their seaward zones were extensively covered by a rich coral growth, which reached approximately to mean low water level, but in 1998 this was largely killed by seawater warming. The resulting large expanses of dead coral skeletons in these locations are now disintegrating, and much of the subsequent modest recovery by new coral recruitment was set back by further mortalities. A mathematical model of wave energy reaching shorelines protected by coral reef flats has been applied to 14 Seychelles reefs. It is derived from equations which predict: (1) the raised water level, or wave set-up, on reef flats resulting from wave breaking, which depends upon offshore wave height and period, depth of still water over the reef flat and the reef crest profile, and (2) the decay of energy from reef edge to shoreline that is affected by width of reef flat, surface roughness, sea level rise and 'pseudo-sea level rise' created by increased depth resulting from disintegration of coral colonies. The model treats each reef as one entity, but because biota and zonation on reef flats are not homogenous, all reefs are divided into four zones. In each, cover by both living and dead biota was estimated for calculation of parameters, and then averaged to obtain input data for the model. All possible biological factors were taken into account, such as the ability of seagrass beds to grow upwards to match expected sea level rise, reduction in height of the reef flat in relation to sea level as zones of dead corals decay, and the observed 'rounding' of reef crests as erosion removes corals from those areas. Estimates were also made of all these factors for a time approximately a decade ago, representing a time before the mass coral mortality, and for approximately a decade in the future when the observed rapid state of dead coral colony disintegration is assumed to have reached an end point. Results of increased energy over the past decade explain observations of erosion in some sites in the Seychelles. Most importantly, it is estimated that the rise in energy reaching shores protected by fringing reefs will now accelerate more rapidly, such that the increase expected over the next decade will be approximately double than that seen over the past decade.

  4. High force reaching task induces widespread inflammation, increased spinal cord neurochemicals and neuropathic pain.

    PubMed

    Elliott, M B; Barr, A E; Clark, B D; Amin, M; Amin, S; Barbe, M F

    2009-01-23

    Repetitive strain injuries (RSI), which include several musculoskeletal disorders and nerve compression injuries, are associated with performance of repetitive and forceful tasks. In this study, we examined in young, adult Sprague-Dawley rats, the effects of performing a voluntary, moderate repetition, high force (MRHF; nine reaches/min; 60% maximum pulling force) task for 12 weeks on motor behavior and nerve function, inflammatory responses in forearm musculoskeletal and nerve tissues and serum, and neurochemical immunoexpression in cervical spinal cord dorsal horns. We observed no change in reach rate, but reduced voluntary participation and grip strength in week 12, and increased cutaneous sensitivity in weeks 6 and 12, the latter indicative of mechanical allodynia. Nerve conduction velocity (NCV) decreased 15% in the median nerve in week 12, indicative of low-grade nerve compression. ED-1 cells increased in distal radius and ulna in week 12, and in the median nerve and forearm muscles and tendons in weeks 6 and 12. Cytokines IL-1alpha, IL-1beta, TNF-alpha, and IL-10 increased in distal forearm bones in week 12, while IL-6 increased in tendon in week 12. However, serum analysis revealed only increased TNF-alpha in week 6 and macrophage inflammatory protein 3a (MIP3a) in weeks 6 and 12. Lastly, Substance P and neurokinin-1 were both increased in weeks 6 and 12 in the dorsal horns of cervical spinal cord segments. These results show that a high force, but moderate repetition task, induced declines in motor and nerve function as well as peripheral and systemic inflammatory responses (albeit the latter was mild). The peripheral inflammatory responses were associated with signs of central sensitization (mechanical allodynia and increased neurochemicals in spinal cord dorsal horns). PMID:19032977

  5. Maximum likelihood and restricted maximum likelihood estimation for a class of Gaussian Markov random fields

    Microsoft Academic Search

    Victor De Oliveira; Marco A. R. Ferreira

    2011-01-01

    This work describes a Gaussian Markov random field model that includes several previously proposed models, and studies properties\\u000a of its maximum likelihood (ML) and restricted maximum likelihood (REML) estimators in a special case. Specifically, for models\\u000a where a particular relation holds between the regression and precision matrices of the model, we provide sufficient conditions\\u000a for existence and uniqueness of ML

  6. Changes in the Species Composition of the Fish Community in a Reach of the Kootenai River, Idaho, after Construction of Libby Dam

    Microsoft Academic Search

    Vaughn L. Paragamian

    2002-01-01

    I evaluated fish community structure and the density and growth of mountain whitefish (Prosopium williamsoni) downstream of Libby Dam in a 1.0-km reach of the Kootenai River, Idaho, in 1994 and compared the results with those of a similar study in 1980, after closure of the dam. In 1980 seven species of fish were collected; mountain whitefish comprised 70% of

  7. [Net ecosystem CO2 exchange and its environmental regulation mechanisms in a reed wetland in the Yellow River Delta of China during the growth season].

    PubMed

    Yang, Li-Qiong; Han, Guang-Xuan; Yu, Jun-Bao; Wu, Li-Xin; Zhu, Min; Xing, Qing-Hui; Wang, Guang-Mei; Mao, Pei-Li

    2013-09-01

    By using eddy covariance technique, this paper measured the net ecosystem CO2 exchange (NEE) in a reed (Phragmites australis) wetland in the Yellow River Delta of China during the growth season of 2011, and investigated the variation patterns of the NEE and related affecting factors. The average diurnal variation of the NEE in different months showed a U-type curve, with the maximum net CO2 uptake rate and release rate being (0.44 +/- 0.03) and (0.16 +/- 0.01) mg CO2 x m(-2) x s(-1), respectively. The NEE, ecosystem respiration (R(eco)), and gross primary productivity (GPP) were all higher in vigorous growth season (from July to September) and lower in early growth season (from May to June) and late growth season (from October to November). Both R(eco) and NEE reached their maximum values in August, while GPP reached its peak value in July. During the growth season, the ecosystem CO2 exchange was mainly dominated by photosynthetic active radiation (PAR), soil temperature (T(s)), and soil water content (SWC). There was a rectangular hyperbolic relationship between the daytime NEE and PAR. The nighttime ecosystem respiration (R(eco,n)) was exponentially correlated with the T(s) at 5 cm depth, and the temperature sensitivity of the ecosystem respiration (Q10) was 2.30. SWC and T(s) were the main factors affecting the R(eco,n). During the entire growth season, the reed wetland ecosystem in the Yellow River delta was an obvious carbon sink, with the total net carbon sequestration being 780.95 g CO2 x m(-2). PMID:24417096

  8. Reach Scale Hydraulic Assessment of Instream Salmonid Habitat Restoration

    NASA Astrophysics Data System (ADS)

    Lacey, R. W. Jay; Millar, Robert G.

    2004-12-01

    This study investigates the use of a two-dimensional hydrodynamic model (River2D) for an assessment of the effects of instream large woody debris and rock groyne habitat structures. The bathymetry of a study reach (a side channel of the Chilliwack River located in southwestern British Columbia) was surveyed after the installation of 11 instream restoration structures. A digital elevation model was developed and used with a hydrodynamic model to predict local velocity, depth, scour, and habitat characteristics. The channel was resurveyed after the fall high-flow season during which a bankfull event occurred. Pre-flood and post-flood bathymetry pool distributions were compared. Measured scour was compared to predicted shear and pre-flood and post-flood fish habitat indices for coho salmon (Oncorhynchus kisutch) and steelhead trout (O. mykiss) were compared. Two-dimensional flow model velocity and depth predictions compare favorably to measured field values with mean standard errors of 24 percent and 6 percent, respectively, while areas of predicted high shear coincide with the newly formed pool locations. At high flows, the fish habitat index used (weighted usable area) increased by 150 percent to 210 percent. The application of the hydrodynamic model indicated a net habitat benefit from the restoration activities and provides a means of assessing and optimizing planned works.

  9. 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.

  10. Reaching youth in the Central African Republic. Programme feature.

    PubMed

    Supe, G; Blankhart, D

    1996-01-01

    The Central African Republic's National Program for Sex Education of Youths of School Age has developed programs for students and out-of-school youth aimed at reducing the high incidence of adolescent pregnancy and human immunodeficiency virus (HIV)/sexually transmitted diseases (STDs). One such program, Support to Youth for Responsible Sexuality, has targeted out-of-school youth 10-22 years of age from Bangui. The program operates from the Information Center for Sexual Health, established in 1994. Educational videos are shown at the center, followed by discussion groups. Peer counselors are available for young people who wish to discuss sexual concerns privately. The center also has a small health post staffed by a nurse who performs pregnancy tests and simple STD diagnoses. A troupe of children perform puppet shows (written by program participants) about reproductive health issues throughout the city. Videos on condom use produced by local youth are being shown at movie theaters before the main feature, and condoms are sold at these locations. A newsletter and radio programming are also used to reach out to adolescents with sexual health messages. Plans are underway to establish a mobile information center. Key to the success of this program has been collaboration with the local family planning association, a condom social marketing program, youth clubs, a woman's nongovernmental organization, private video parlors, United Nations agencies, and governmental ministries. PMID:12291988

  11. 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.

  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. How MHC class II molecules reach the endocytic pathway.

    PubMed

    Bénaroch, P; Yilla, M; Raposo, G; Ito, K; Miwa, K; Geuze, H J; Ploegh, H L

    1995-01-01

    We have examined trafficking of major histocompatibility complex (MHC) class II molecules in human B cells exposed to concanamycin B, a highly specific inhibitor of the vacuolar H(+)-ATPases required for acidification of the vacuolar system and for early to late endosomal transport. Neutralization of vacuolar compartments prevents breakdown of the invariant chain (Ii) and blocks conversion of MHC class II molecules to peptide-loaded, SDS-stable alpha beta dimers. Ii remains associated with alpha beta and this complex accumulates internally, as ascertained biochemically and by morphological methods. In concanamycin B-treated cells, a slow increase (> 20-fold) in surface expression of Ii, mostly complexed with alpha beta, is detected. This surface-disposed fraction of alpha beta Ii is nevertheless a minor population that reaches the cell surface directly, or is routed via early endosomes as intermediary stations. In inhibitor-treated cells, the bulk of newly synthesized alpha beta Ii is no longer accessible to fluid phase endocytic markers. It is concluded that the majority of alpha beta Ii is targeted directly from the trans-Golgi network to the compartment for peptide loading, bypassing the cell surface and early endosomes en route to the endocytic pathway. PMID:7530198

  14. Hypothesis: origin of life in deep-reaching tectonic faults.

    PubMed

    Schreiber, Ulrich; Locker-Grütjen, Oliver; Mayer, Christian

    2012-02-01

    The worldwide discussion on the origin of life encounters difficulties when it comes to estimate the conditions of the early earth and to define plausible environments for the development of the first complex organic molecules. Until now, the role of the earth's crust has been more or less ignored. In our opinion, deep-reaching open, interconnected tectonic fault systems may provide possible reaction habitats ranging from nano- to centimetre and even larger dimensions for the formation of prebiotic molecules. In addition to the presence of all necessary raw materials including phosphate, as well as variable pressure and temperature conditions, we suggest that supercritical CO2 as a nonpolar solvent could have played an important role. A hypothetical model for the origin of life is proposed which will be used to design crucial experiments for the model's verification. Because all proposed processes could still occur in tectonic faults at the present time, it may be possible to detect and analyse the formation of prebiotic molecules in order to assess the validity of the proposed hypothesis. PMID:22373604

  15. Hypothesis: Origin of Life in Deep-Reaching Tectonic Faults

    NASA Astrophysics Data System (ADS)

    Schreiber, Ulrich; Locker-Grütjen, Oliver; Mayer, Christian

    2012-02-01

    The worldwide discussion on the origin of life encounters difficulties when it comes to estimate the conditions of the early earth and to define plausible environments for the development of the first complex organic molecules. Until now, the role of the earth's crust has been more or less ignored. In our opinion, deep-reaching open, interconnected tectonic fault systems may provide possible reaction habitats ranging from nano- to centimetre and even larger dimensions for the formation of prebiotic molecules. In addition to the presence of all necessary raw materials including phosphate, as well as variable pressure and temperature conditions, we suggest that supercritical CO2 as a nonpolar solvent could have played an important role. A hypothetical model for the origin of life is proposed which will be used to design crucial experiments for the model's verification. Because all proposed processes could still occur in tectonic faults at the present time, it may be possible to detect and analyse the formation of prebiotic molecules in order to assess the validity of the proposed hypothesis.

  16. Consumer exposure modelling under REACH: Assessing the defaults.

    PubMed

    Oltmanns, J; Neisel, F; Heinemeyer, G; Kaiser, E; Schneider, K

    2015-07-01

    Consumer exposure to chemicals from products and articles is rarely monitored. Since an assessment of consumer exposure has become particularly important under the European REACH Regulation, dedicated modelling approaches with exposure assessment tools are applied. The results of these tools are critically dependent on the default input values embedded in the tools. These inputs were therefore compiled for three lower tier tools (ECETOC TRA (version 3.0), EGRET and REACT)) and benchmarked against a higher tier tool (ConsExpo (version 4.1)). Mostly, conservative input values are used in the lower tier tools. Some cases were identified where the lower tier tools used less conservative values than ConsExpo. However, these deviations only rarely resulted in less conservative exposure estimates compared to ConsExpo, when tested in reference scenarios. This finding is mainly due to the conservatism of (a) the default value for the thickness of the product layer (with complete release of the substance) used for the prediction of dermal exposure and (b) the complete release assumed for volatile substances (i.e. substances with a vapour pressure ?10Pa) for inhalation exposure estimates. The examples demonstrate that care must be taken when changing critical defaults in order to retain conservative estimates of consumer exposure to chemicals. PMID:25908511

  17. 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.

  18. Reach to grasp: the response to a simultaneous perturbation of object position and size.

    PubMed

    Castiello, U; Bennett, K; Chambers, H

    1998-05-01

    This study assessed the reach to grasp movement and its adaptive response to a simultaneous perturbation of object location and size. The aim was to clarify the means by which integration between the neural pathways modulating transport and manipulation is achieved. Participants (n = 11) were required to reach 30 cm to grasp a central illuminated cylinder of either small (0.7 cm) or large (8 cm) diameter. For a small percentage of trials (20/100) a visual perturbation was introduced unexpectedly at the onset of the reaching action. This consisted of a shift of illumination from the central cylinder to a cylinder of differing diameter (large in session A; small in session B) that was positioned 20 degrees to the left (n = 10 trials) or to the right (n = 10) of the central cylinder. The subject was required to grasp the newly illuminated cylinder. Movement duration for these "double" (position and size) perturbed trials was much longer than those of control trials to the central cylinder (session A: by an average of 250 ms; session B: 180 ms), and the increased values were much greater than those reported previously in "single" perturbation studies where either size or location of the object was perturbed. Initial signs of a response to the "double" perturbation were seen almost simultaneously in the transport parameter of peak arm deceleration and in the manipulation parameter of maximum grip aperture, but these changes were not evident until more than 400 ms after movement onset, a response onset much later than that found in "single" perturbation studies. It is proposed that the visual change resultant from the double perturbation activates integration centres that at first gate the flow of information to the parallel channels of transport and manipulation. Following processing of this information, these centres act to instigate a synchronised and coordinated response in both components. These results add support to the existence of neural centres dedicated to the integration of parallel neural pathways, and which exercise flexibility in the degree to which these components are "coupled" functionally. PMID:9628401

  19. An approximate, maximum terminal velocity descent to a point

    SciTech Connect

    Eisler, G.R.; Hull, D.G.

    1987-01-01

    No closed form control solution exists for maximizing the terminal velocity of a hypersonic glider at an arbitrary point. As an alternative, this study uses neighboring extremal theory to provide a sampled data feedback law to guide the vehicle to a constrained ground range and altitude. The guidance algorithm is divided into two parts: 1) computation of a nominal, approximate, maximum terminal velocity trajectory to a constrained final altitude and computation of the resulting unconstrained groundrange, and 2) computation of the neighboring extremal control perturbation at the sample value of flight path angle to compensate for changes in the approximate physical model and enable the vehicle to reach the on-board computed groundrange. The trajectories are characterized by glide and dive flight to the target to minimize the time spent in the denser parts of the atmosphere. The proposed on-line scheme successfully brings the final altitude and range constraints together, as well as compensates for differences in flight model, atmosphere, and aerodynamics at the expense of guidance update computation time. Comparison with an independent, parameter optimization solution for the terminal velocity is excellent. 6 refs., 3 figs.

  20. A Maximum Stellar Surface Density in Dense Stellar Systems

    E-print Network

    Hopkins, Philip F; Quataert, Eliot; Thompson, Todd A

    2009-01-01

    We compile observations of the surface mass density profiles of dense stellar systems, including globular clusters in the Milky Way and nearby galaxies, massive star clusters in nearby starbursts, nuclear star clusters in dwarf spheroidals and late-type disks, ultra-compact dwarfs, and galaxy spheroids spanning the range from low-mass cusp bulges and ellipticals to massive core ellipticals. We show that in all cases the maximum stellar surface density attained in the central regions of these systems is similar, Sigma_max ~ 10^11 M_sun/kpc^2 (~20 g/cm^2), despite the fact that the systems span 7 orders of magnitude in total stellar mass M_star, 5 in effective radius R_e, and have a wide range in effective surface density M_star/R_e^2. The surface density limit is reached on a wide variety of physical scales in different systems and is thus not a limit on three-dimensional stellar density. Given the very different formation mechanisms involved in these different classes of objects, we argue that a single piece ...

  1. Estimating maximum performance: effects of intraindividual variation.

    PubMed

    Adolph, Stephen C; Pickering, Trevor

    2008-04-01

    Researchers often estimate the performance capabilities of animals using a small number of trials per individual. This procedure inevitably underestimates maximum performance, but few studies have examined the magnitude of this effect. In this study we explored the effects of intraindividual variation and individual sample size on the estimation of locomotor performance parameters. We measured sprint speed of the lizard Sceloporus occidentalis at two temperatures (20 degrees C and 35 degrees C), obtaining 20 measurements per individual. Speed did not vary temporally, indicating no training or fatigue effects. About 50% of the overall variation in speed at each temperature was due to intraindividual variation. While speed was repeatable, repeatability decreased slightly with increasing separation between trials. Speeds at 20 degrees C and 35 degrees C were positively correlated, indicating repeatability across temperatures as well. We performed statistical sampling experiments in which we randomly drew a subset of each individual's full set of 20 trials. As expected, the sample's maximum speed increased with the number of trials per individual; for example, five trials yielded an estimate averaging 89% of the true maximum. The number of trials also influenced the sample correlation between mean speeds at 20 degrees C and 35 degrees C; for example, five trials yielded a correlation coefficient averaging 90% of the true correlation. Therefore, intraindividual variation caused underestimation of maximal speed and the correlation between speeds across temperatures. These biases declined as the number of trials per individual increased, and depended on the magnitude of intraindividual variation, as illustrated by running sampling experiments that used modified data sets. PMID:18375858

  2. A comparison of the sit-and-reach test and the back-saver sit-and-reach test in university students

    PubMed Central

    López-Miñarro, Pedro A.; Andújar, Pilar Sáinz de Baranda; RodrÑGuez-GarcÑa, Pedro L.

    2009-01-01

    This study compares the forward reach score, spine and pelvis postures, and hamstring criterion-related validity (concurrent validity) between the sit-and-reach test (SR) and the back-saver sit-and-reach test (BS). Seventy-six men (mean age ± SD: 23.45 ± 3.96 years) and 67 women (mean age ± SD: 23.85 ± 5.36 years) were asked to perform three trials of SR, BS left (BSl), right (BSr), and passive straight leg raise (PSLR) right and left (hamstring criterion measure) in a randomized order. The thoracic, lumbar, and pelvis angles (measured with a Uni-level inclinometer) and forward reach scores were recorded once the subjects reached forward as far as possible without flexing the knees. A repeated measure ANOVA was performed followed by Bonferroni's post hoc test. Pearson correlation coefficients were used to define the relationships between SR and BS scores with respect to PSLR. In both men and women, the thoracic angle in BS was significantly greater than in SR (p<0.016). However, no significant differences were found between the tests in lumbar angle, pelvic angle, and forward reach scores. The concurrent validity of the forward reach score as a measure of hamstring extensibility was moderate in women (0.66 0. 76) and weak to moderate in men (0.51 0.59). The concurrent validity was slightly higher in SR than in BS, although no significant differences between the correlation values were observed. There were significant differences in the thoracic angle between the SR and BS, but not in the forward reach score. There was no difference in concurrent validity between the two tests. However, the traditional SR was preferred because it reached better concurrent validity than the BS. Key points Previous studies have analyzed the validity of sit-and-reach and back-saver sit-and-reach tests as criterion measures of hamstring muscle extensibility. The differences in the position of lower limbs between both the tests could influence the spinal and pelvic angles and forward reach score. Forward reach scores, lumbar and pelvic angles showed no significant differences between the tests, while lower thoracic angle was found in the sit-and-reach. However relatively large changes in thoracic angle were required to be confident true difference had occurred. The sit-and-reach test is the preferred test over the back-saver sit-and-reach as measure of hamstring muscle extensibility. The concurrent validity of sit-and-reach and back-saver sit-and-reach in men is compromised, and hence, other tests should be considered to evaluate the hamstring extensibility. PMID:24150564

  3. 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.

  4. WINNERSS - Reaching a broad audience from an academic institution

    NASA Astrophysics Data System (ADS)

    Limaye, S. S.; Pertzborn, R. A.

    2001-12-01

    "Wisconsin Idea National Network - Education and Research in Space Sciences: Our Home in the Universe" is a Thematic Outreach Program from the University of Wisconsin-Madison. WINNERSS addresses the main current and future research topics in space sciences - origins of the universe, beginning(s) of life in the universe, the abitability of our home planet. These themes have origins in what we have learned in the age of space exploration and bring together the diverse disciplines of physics, astronomy, astrophysics, geology and geophysics, chemistry, atmospheric science, oceanography, astrobiology - or collectively, the space sciences. This has come about through evolution of our knowledge and our understanding of the role of different processes that have shaped our environment. These include the asteroid impacts on the earth and in our solar system, the discovery of possible microbial of life in Martian rocks that came to earth as meteorites, the discovery of planetary systems around other stars. At the same time, there has been a significant evolution in our knowledge and understanding of the universe and the fragility of the environment on our home planet. The sustainability and global environment are highlighted by global change processes such as weather extremes, "ozone hole", and concerns about the global warming illustrated by events such as the break-up of Antarctic icebergs the size of Rhode sland. Following the long tradition of the Wisconsin Idea, WINNERSS will strive to highlight research in these and related topics through Informal Science Education, K-12 programs and teacher development in space sciences. Broad geographic reach is enabled through the alumni clubs and the UW-Madison Speakers Bureau. WINNERSS is funded by the Wisconin Idea Program of the University of Wisconsin and is being implemented in collaboration with the Wisconsin Alumni Association, and the following components of the University of Wisconsin-Madison: the Graduate School, College of Letters and Science and the Office of Education Outreach of the School of Education.

  5. Reach on laser imaging technology to terminal guidance

    NASA Astrophysics Data System (ADS)

    Tan, Xue-chun; Jin, Guang-yong; Wu, Zhi-chao; Ling, Ming; Liang, Zhu

    2009-07-01

    The development of range-imaging devices is motivated by various ground and space applications. Tasks in space missions include docking, rendezvous, manipulating robotic arms, landing and autonomous rover applications, sample identification and surface mapping. The ground applications include the guidance of vehicles, robotic and manipulator arms, and other autonomous or teleoperated machines, as well as surface or construction model generation. Without the scanner devices, scannerless imaging lidars have the characteristic of high frame rate, wide field of view and high reliability,which can be successful used in terminal guidance. Diode pumped laser radar with high repetition rate is studied in this paper. A bistatic system is set up and a high speed signal processor for the system is researched. In a conceptual sense, the imaging lidar has two parts, a transmitter and a receiver. Their field of views overlap throughout the measuring range.The imaging lidar operates as follows. Based on principle of pulsed time-of-flight (TOF) laser range finding, the solid-state laser diode-pumped laser produces short laser pulses, which though the expanded lens, then reach the target. The back reflected light is collected with a receiver lens and fed through optical fibres to discrete avalanche photo diodes (APDs). When a received pulse is detected by the comparator a time to digital converter (TDC) stops counting and a time interval, corresponding to the range, is produced. The precision of a single measurement is about +/-4.0cm, but better precision is achieved by averaging. Information about the reflectivity of the target is gathered by recording the amplitude of the received pulse. Range images with the lidar prototype were taken indoors, the measuring distance was about 14m.

  6. 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.

  7. Better Algorithms and Bounds for Directed Maximum Leaf Problems

    E-print Network

    Krivelevich, Michael

    Better Algorithms and Bounds for Directed Maximum Leaf Problems Noga Alon 1 , Fedor V. Fomin 2 of Mathematical Sciences Chennai, 600 017, India saket@imsc.res.in Abstract. The Directed Maximum Leaf Out Maximum Leaf Out­Branching problem is to find an out­branching in a given digraph with the maximum number

  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 power configuration for multireservoir chemical engines

    NASA Astrophysics Data System (ADS)

    Xia, Shaojun; Chen, Lingen; Sun, Fengrui

    2009-06-01

    A model of a multireservoir isothermal endoreversible chemical engine is put forward in this paper. Optimal control theory is used to determine the optimal configuration of the multireservoir isothermal endoreversible chemical engine for maximum power output. The optimal cycle consists of two constant chemical potential branches and two instantaneous constant mass-flux branches, which is independent of the number of mass reservoirs and the mass transfer law. The results show that, in order to obtain the maximum power output, some mass reservoirs should never connect to the working fluid in the mass transfer processes. A numerical example is provided for a linear mass transfer law three-mass-reservoir chemical engine. The effects of the potential changes of the intermediate mass reservoir on the optimal configuration of the chemical engine and the performance corresponding to the optimal configuration are analyzed. The obtained results are compared with those obtained for a multireservoir endoreversible heat engine. The object studied in this paper is general, and the results could provide some guidelines for optimal design and operation of real chemical engines.

  10. The Maximum Mass of a Neutron Star

    E-print Network

    Vassiliki Kalogera; Gordon Baym

    1996-08-11

    Observational identification of black holes as members of binary systems requires the knowledge of the upper limit on the gravitational mass of a neutron star. We use modern equations of state for neutron star matter, fitted to experimental nucleon-nucleon scattering data and the properties of light nuclei, to calculate, within the framework of Rhoades & Ruffini (1974), the minimum upper limit on a neutron star mass. Regarding the equation of state as valid up to twice nuclear matter saturation density, rho_{nm}, we obtain a secure upper bound on the neutron star mass equal to 2.9 solar masses. We also find that in order to reach the lowest possible upper bound of 2.2 solar masses, we need understand the physical properties of neutron matter up to a density of about 4 times rho_{nm}.

  11. Changes in trunk muscle activation and lumbar-pelvic position associated with abdominal hollowing and reach during a simulated manual material handling task

    Microsoft Academic Search

    Heather L. Butler; Cheryl L. Hubley-Kozey; John W. Kozey

    2007-01-01

    The purpose of this study was to investigate the effect of abdominal hollowing (AH) on trunk muscle activation and lumbar-pelvic motion during a controlled lift and replace task. Surface electromyograms were recorded from five abdominal and two back muscle sites. Sagittal lumbar-pelvic motion was recorded by video. Subjects lifted a 3.8 kg load in normal, maximum and extreme reaches, first while

  12. Eect of load ratio and maximum stress intensity on the fatigue threshold in Ti6Al4V

    E-print Network

    Ritchie, Robert

    Eect of load ratio and maximum stress intensity on the fatigue threshold in Ti±6Al±4V B.L. Boyce, R¯uence of the load ratio, R, and the maximum stress intensity, Kmax, on the threshold for fatigue-crack growth, DKth range of loading frequencies (m 50±1000 Hz) and load ratios (R 0X10±0X95) on fatigue-crack propagation

  13. Growth Hormone Receptor in Growth

    Microsoft Academic Search

    Vivian Hwa

    \\u000a It has been approximately 20 years since the cloning and characterization of the human growth hormone (GH) receptor, GHR, gene. Cell-surface GHR binds circulating GH, which promotes postnatal growth by regulating the expression of insulin-like\\u000a growth factor (IGF)-I. Mutations in the GHR gene cause GH insensitivity (GHI) syndrome, also known as Laron syndrome, a syndrome characterized by severe postnatal growth

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. SubspaceEM: A fast maximum-a-posteriori algorithm for cryo-EM single particle reconstruction.

    PubMed

    Dvornek, Nicha C; Sigworth, Fred J; Tagare, Hemant D

    2015-05-01

    Single particle reconstruction methods based on the maximum-likelihood principle and the expectation-maximization (E-M) algorithm are popular because of their ability to produce high resolution structures. However, these algorithms are computationally very expensive, requiring a network of computational servers. To overcome this computational bottleneck, we propose a new mathematical framework for accelerating maximum-likelihood reconstructions. The speedup is by orders of magnitude and the proposed algorithm produces similar quality reconstructions compared to the standard maximum-likelihood formulation. Our approach uses subspace approximations of the cryo-electron microscopy (cryo-EM) data and projection images, greatly reducing the number of image transformations and comparisons that are computed. Experiments using simulated and actual cryo-EM data show that speedup in overall execution time compared to traditional maximum-likelihood reconstruction reaches factors of over 300. PMID:25839831

  20. Population Growth Curves

    NSDL National Science Digital Library

    2014-09-18

    Using Avida-ED freeware, students control a few factors in an environment populated with digital organisms, and then compare how changing these factors affects population growth. They experiment by altering the environment size (similar to what is called carrying capacity, the maximum population size that an environment can normally sustain), the initial organism gestation rate, and the availability of resources. How systems function often depends on many different factors. By altering these factors one at a time, and observing the results, students are able to clearly see the effect of each one.

  1. 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.

  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. Effect of algal growth phase on Aureococcus anophagefferens susceptibility to hydrogen peroxide.

    PubMed

    Randhawa, Varunpreet; Thakkar, Megha; Wei, Liping

    2013-10-15

    A cell's growth phase could affect its susceptibility to a biocide in microbial control. This study examines the growth phase dependent susceptibility of a brown tide bloom alga Aureococcus anophagefferens to microbial biocide hydrogen peroxide (H2O2). Test cultures of A. anophagefferens cells in exponential and stationary growth phase and similar initial cell density (1.6×10(6) cells mL(-1)) were exposed to 0.4-1.6 mg L(-1) H2O2. Changes in algal growth (in vivo fluorescence, total chlorophyll a, and cell density), cell physiology (maximum quantum yield of photosystem II, and total intracellular non-protein thiols), and H2O2 decomposition were quantified. Results show that the stationary phase cells are more susceptible to H2O2 than the exponential phase cells, and this is attributed to the weaker ROS (reactive oxygen species) scavenging system and consequently greater cell damage in stationary phase cells. The stationary phase cells potentially require 30-40% less H2O2 to reach 90% removal within 12 h of treatment as compared to the exponential phase cells. The results have practical implications in brown tide bloom control with respect to the timing and the dosage of H2O2 application. PMID:24055756

  4. Changes in biologically active ultraviolet radiation reaching the Earth's surface.

    PubMed

    McKenzie, Richard L; Björn, Lars Olof; Bais, Alkiviadis; Ilyasad, Mohammad

    2003-01-01

    Since publication of the 1998 UNEP Assessment, there has been continued rapid expansion of the literature on UV-B radiation. Many measurements have demonstrated the inverse relationship between column ozone amount and UV radiation, and in a few cases long-term increases due to ozone decreases have been identified. The quantity, quality and availability of ground-based UV measurements relevant to assessing the environmental impacts of ozone changes continue to improve. Recent studies have contributed to delineating regional and temporal differences due to aerosols, clouds, and ozone. Improvements in radiative transfer modelling capability now enable more accurate characterization of clouds, snow-cover, and topographical effects. A standardized scale for reporting UV to the public has gained wide acceptance. There has been increased use of satellite data to estimate geographic variability and trends in UV. Progress has been made in assessing the utility of satellite retrievals of UV radiation by comparison with measurements at the Earth's surface. Global climatologies of UV radiation are now available on the Internet. Anthropogenic aerosols play a more important role in attenuating UV irradiances than has been assumed previously, and this will have implications for the accuracy of UV retrievals from satellite data. Progress has been made inferring historical levels of UV radiation using measurements of ozone (from satellites or from ground-based networks) in conjunction with measurements of total solar radiation obtained from extensive meteorological networks. We cannot yet be sure whether global ozone has reached a minimum. Atmospheric chlorine concentrations are beginning to decrease. However, bromine concentrations are still increasing. While these halogen concentrations remain high, the ozone layer remains vulnerable to further depletion from events such as volcanic eruptions that inject material into the stratosphere. Interactions between global warming and ozone depletion could delay ozone recovery by several years, and this topic remains an area of intense research interest. Future changes in greenhouse gases will affect the future evolution of ozone through chemical, radiative, and dynamic processes In this highly coupled system, an evaluation of the relative importance of these processes is difficult: studies are ongoing. A reliable assessment of these effects on total column ozone is limited by uncertainties in lower stratospheric response to these changes. At several sites, changes in UV differ from those expected from ozone changes alone, possibly as a result of long-term changes in aerosols, snow cover, or clouds. This indicates a possible interaction between climate change and UV radiation. Cloud reflectance measured by satellite has shown a long-term increase at some locations, especially in the Antarctic region, but also in Central Europe, which would tend to reduce the UV radiation. Even with the expected decreases in atmospheric chlorine, it will be several years before the beginning of an ozone recovery can be unambiguously identified at individual locations. Because UV-B is more variable than ozone, any identification of its recovery would be further delayed. PMID:12659535

  5. Fatigue crack growth behavior in niobium-hydrogen alloys

    NASA Astrophysics Data System (ADS)

    Lin, Mark Ching-Cheng; Salama, K.

    1997-10-01

    Near-threshold fatigue crack growth behavior has been investigated in niobium-hydrogen alloys. Compact tension specimens (CTS) with three hydrogen conditions are used: hydrogen-free, hydrogen in solid solution, and hydride alloy. The specimens are fatigued at a temperature of 296 K and load ratios of 0.05, 0.4, and 0.75. The results at load ratios of 0.05 and 0.4 show that the threshold stress intensity range (? K th ) decreases as hydrogen is added to niobium. It reaches a minimum at the critical hydrogen concentration ( C cr ), where maximum embrittlement occurs. The critical hydrogen concentration is approximately equal to the solubility limit of hydrogen in niobium. As the hydrogen concentration exceeds C cr , ? K th increases slowly as more hydrogen is added to the specimen. At load ratio 0.75, ? K th decreases continuously as the hydrogen concentration is increased. The results provide evidence that two mechanisms are responsible for fatigue crack growth behavior in niobium-hydrogen alloys. First, embrittlement is retarded by hydride transformation-induced and plasticity-induced crack closures. Second, embrittlement is enhanced by the presence of hydrogen and hydride.

  6. Fatigue crack growth behavior in niobium-hydrogen alloys

    SciTech Connect

    Lin, M.C.C.; Salama, K. [Univ. of Houston, TX (United States). Dept. of Mechanical Engineering

    1997-10-01

    Near-threshold fatigue crack growth behavior has been investigated in niobium-hydrogen alloys. Compact tension specimens (CTS) with three hydrogen conditions are used: hydrogen-free, hydrogen in solid solution, and hydride alloy. The specimens are fatigued at a temperature of 296 K and load ratios of 0.05, 0.4, and 0.75. The results at load ratios of 0.05 and 0.4 show that the threshold stress intensity range ({Delta}K{sub th}) decreases as hydrogen is added to niobium. It reaches a minimum at the critical hydrogen concentration (C{sub cr}), where maximum embrittlement occurs. The critical hydrogen concentration is approximately equal to the solubility limit of hydrogen in niobium. As the hydrogen concentration exceeds C{sub cr}, {Delta}K{sub th} increases slowly as more hydrogen is added to the specimen. At load ratio 0.75, {Delta}K{sub th} decreases continuously as the hydrogen concentration is increased. The results provide evidence that two mechanisms are responsible for fatigue crack growth behavior in niobium-hydrogen alloys. First, embrittlement is retarded by hydride transformation--induced and plasticity-induced crack closures. Second, embrittlement is enhanced by the presence of hydrogen and hydride.

  7. Analysis of scientific productivity using maximum entropy principle and fluctuation-dissipation theorem

    Microsoft Academic Search

    Piotr Fronczak; Agata Fronczak; Janusz A. Holyst

    2007-01-01

    Using data retrieved from the INSPEC database we have quantitatively discussed a few syndromes of the publish-or-perish phenomenon, including the continuous growth of the rate of scientific productivity, and the continuously decreasing percentage of those scientists who stay in science for a long time. Making use of the maximum entropy principle and fluctuation-dissipation theorem, we have shown that the observed

  8. Publish or perish: analysis of scientific productivity using maximum entropy principle and fluctuation-dissipation theorem

    Microsoft Academic Search

    Piotr Fronczak; Agata Fronczak; Janusz A. Ho

    2006-01-01

    Using data retrieved from the INSPEC database we have quantitatively\\u000adiscussed a few syndromes of the publish-or-perish phenomenon, including\\u000acontinuous growth of rate of scientific productivity, and continuously\\u000adecreasing percentage of those scientists who stay in science for a long time.\\u000aMaking use of the maximum entropy principle and fluctuation-dissipation\\u000atheorem, we have shown that the observed fat-tailed distributions of

  9. Temperature Dependence of Maximum Daily Consumption in White Crappie: Implications for Fisheries Management

    Microsoft Academic Search

    R. S. Hayward; E. Arnold

    1996-01-01

    Maximum daily consumption (Cmax) by adult white crappies Pomoxis annularis (164–532 g live weight) provided ad libitum rations of prey fish was determined at 18, 21, 24 and 27°C. Observed increases in Cmax between 18 and 24°C followed by a sharp (two-thirds) decline at 27°C indicated that a low to negative physiological “scope for growth” exists for white crappies at

  10. Handling Temperature Bursts Reaching 464°C: Different Microbial Strategies in the Sisters Peak Hydrothermal Chimney

    PubMed Central

    Kurtz, Stefan; LaRoche, Julie

    2014-01-01

    The active venting Sisters Peak (SP) chimney on the Mid-Atlantic Ridge holds the current temperature record for the hottest ever measured hydrothermal fluids (400°C, accompanied by sudden temperature bursts reaching 464°C). Given the unprecedented temperature regime, we investigated the biome of this chimney with a focus on special microbial adaptations for thermal tolerance. The SP metagenome reveals considerable differences in the taxonomic composition from those of other hydrothermal vent and subsurface samples; these could be better explained by temperature than by other available abiotic parameters. The most common species to which SP genes were assigned were thermophilic Aciduliprofundum sp. strain MAR08-339 (11.8%), Hippea maritima (3.8%), Caldisericum exile (1.5%), and Caminibacter mediatlanticus (1.4%) as well as to the mesophilic Niastella koreensis (2.8%). A statistical analysis of associations between taxonomic and functional gene assignments revealed specific overrepresented functional categories: for Aciduliprofundum, protein biosynthesis, nucleotide metabolism, and energy metabolism genes; for Hippea and Caminibacter, cell motility and/or DNA replication and repair system genes; and for Niastella, cell wall and membrane biogenesis genes. Cultured representatives of these organisms inhabit different thermal niches; i.e., Aciduliprofundum has an optimal growth temperature of 70°C, Hippea and Caminibacter have optimal growth temperatures around 55°C, and Niastella grows between 10 and 37°C. Therefore, we posit that the different enrichment profiles of functional categories reflect distinct microbial strategies to deal with the different impacts of the local sudden temperature bursts in disparate regions of the chimney. PMID:24837379

  11. 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.

  12. Evaluation of a web-based asthma management intervention program for urban teenagers: Reaching the hard to reach

    PubMed Central

    Joseph, Christine LM; Ownby, Dennis R.; Havstad, Suzanne L.; Saltzgaber, Jacqueline; Considine, Shannon; Johnson, Dayna; Peterson, Ed; Alexander, Gwen; Lu, Mei; Gibson-Scipio, Wanda; Johnson, Christine Cole

    2012-01-01

    Purpose Asthma interventions targeting urban adolescents are rare, despite a great need. Motivating adolescents to achieve better self-management of asthma is challenging, and the literature suggests that certain subgroups are more resistant than others. We conducted a school-based, randomized controlled trial to evaluate Puff City, a web-based, tailored asthma intervention, which included a referral coordinator, and incorporated theory-based strategies to target urban teens with characteristics previously found to be associated with lack of behavior change. Methods To identify eligible teens, questionnaires on asthma diagnoses and symptoms were administered to 9–12th graders of participating schools during a scheduled English class. Eligible, consenting students were randomized to Puff City (treatment) or generic asthma education (control). Results 422 students were randomized (98% African-American, mean age=15.6 years). At 12 month follow-up, adjusted Odds Ratios (95% Confidence Intervals) indicated intervention benefit for treatment teens for symptom-days and restricted activity days (analyzed as categorical variables) aOR=0.49 (0.24–0.79), p=0.006 and 0.53 (0.32–0.86), p=0.010, respectively. Among teens meeting baseline criteria for rebelliousness, treatment teens reported fewer symptom-days, symptom-nights, school absences and restricted activity days, aOR=0.30 (0.11–0.80), 0.29 (0.14–0.64), 0.40 (0.20–0.78), and 0.23 (0.10–0.55); all p<0.05. Among teens reporting low perceived emotional support, treatment students reported only fewer symptom-days than controls, aOR=0.23 (0.06 – 0.88), p=0.031. Statistically significant differences in medical care use were not observed. Conclusions Results suggest a theory-based, tailored approach, with a referral coordinator, can improve asthma management in urban teens. Puff City represents a viable strategy for disseminating an effective intervention to high risk and hard-to-reach populations. PMID:23299008

  13. Grazing, respiration, excretion, and growth rates of tintinnids

    Microsoft Academic Search

    Peter G. Verity

    1985-01-01

    Clearance, ingestion, and growth rates of two coastal tintinnid ciliates were measured in batch culture as a function of temperature and phytoplankton concentration. Oxygen consumption and ammonium excretion rates were determined at food concentrations which supported maximum growth rates at each temperature. Clearance, ingestion, respiration, excretion, and growth rates of both species increased with temperature. Clearing rates declined with increasing

  14. 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

  15. Changes in the patterns of inorganic nitrogen and TN\\/TP ratio and the associated mechanism of biological regulation in the shallow lakes of the middle and lower reaches of the Yangtze River

    Microsoft Academic Search

    Shikai Wu; Ping Xie; Songbo Wang; Qiong Zhou

    2006-01-01

    The changes of NH3-N, NO3-N, NO2-N and TN\\/TP were studied during growth and non-growth season in 33 subtropical shallow lakes in the middle and lower reaches\\u000a of the Yangtze River. There were significant positive correlations among all nutrient concentrations, and the correlations\\u000a were better in growth season than in non-growth season. When TP>0.1 mgL?1, NH3-N increased sharply in non-growth season

  16. Target: Alcohol Abuse in the Hard-to-Reach Work Force. Ideas and Resources for Responding to Problems of the Hard-to-Reach Work Force.

    ERIC Educational Resources Information Center

    Informatics, Inc., Rockville, MD.

    This guide is designed as a source of ideas and information for individuals and organizations interested in occupational alcoholism programs for the hard-to-reach work force. Following a brief overview of the problem and a report on progress in occupational alcoholism programming, a working definition of the hard-to-reach work force is offered;…

  17. Maximum Error Modeling for Fault-Tolerant Computation using Maximum a posteriori (MAP) Hypothesis

    E-print Network

    Karthikeyan Lingasubramanian; Syed M. Alam; Sanjukta Bhanja

    2009-10-27

    The application of current generation computing machines in safety-centric applications like implantable biomedical chips and automobile safety has immensely increased the need for reviewing the worst-case error behavior of computing devices for fault-tolerant computation. In this work, we propose an exact probabilistic error model that can compute the maximum error over all possible input space in a circuit specific manner and can handle various types of structural dependencies in the circuit. We also provide the worst-case input vector, which has the highest probability to generate an erroneous output, for any given logic circuit. We also present a study of circuit-specific error bounds for fault-tolerant computation in heterogeneous circuits using the maximum error computed for each circuit. We model the error estimation problem as a maximum a posteriori (MAP) estimate, over the joint error probability function of the entire circuit, calculated efficiently through an intelligent search of the entire input space using probabilistic traversal of a binary join tree using Shenoy-Shafer algorithm. We demonstrate this model using MCNC and ISCAS benchmark circuits and validate it using an equivalent HSpice model. Both results yield the same worst-case input vectors and the highest % difference of our error model over HSpice is just 1.23%. We observe that the maximum error probabilities are significantly larger than the average error probabilities, and provides a much tighter error bounds for fault-tolerant computation. We also find that the error estimates depend on the specific circuit structure and the maximum error probabilities are sensitive to the individual gate failure probabilities.

  18. Implications of a warming North Sea for the growth of haddock Melanogrammus aeglefinus.

    PubMed

    Baudron, A R; Needle, C L; Marshall, C T

    2011-06-01

    The present study aimed firstly, to test for a temperature effect on North Sea haddock Melanogrammus aeglefinus growth and secondly, to develop a model that could be used to assess total length (L(T)) and mass (M)-at-age response to different temperature scenarios. The von Bertalanffy growth model was fitted on a cohort-by-cohort basis from 1970 to 2006. The asymptotic L(T) (L(?)) was negatively correlated with temperature while the rate at which L(?) is reached (K) was positively correlated with temperature. K was negatively correlated with density, whereas no effect on L(?) was observed. These effects were incorporated into a von Bertalanffy model which was extended to include temperature and density as explanatory variables. Only the temperature variable was significant. Fitting the extended von Bertalanffy model revealed that L(?) decreased while K increased with increasing temperature, resulting in up to a 40% loss of individual yield at older ages. The dramatic decline observed in the mean age at which 50% of the population becomes mature suggests that higher temperatures resulted in larger young M. aeglefinus that matured earlier and therefore reached a smaller maximum size. In a global warming context, the loss of individual yield observed at old ages is likely to reduce the fisheries yield for M. aeglefinus in the North Sea. PMID:21651538

  19. Songlines from Direct Collapse Seed Black Holes: Effects of X-Rays on Black Hole Growth and Stellar Populations

    NASA Astrophysics Data System (ADS)

    Aykutalp, Aycin; Wise, John H.; Spaans, Marco; Meijerink, Rowin

    2014-12-01

    In the last decade, the growth of supermassive black holes (SMBHs) has been intricately linked to galaxy formation and evolution and is a key ingredient in the assembly of galaxies. To investigate the origin of SMBHs, we perform cosmological simulations that target the direct collapse black hole seed formation scenario in the presence of two different strong Lyman-Werner (LW) background fields. These simulations include the X-ray irradiation from a central massive black hole (MBH), H2 self-shielding, and stellar feedback from metal-free and metal-enriched stars. We find in both simulations that local X-ray feedback induces metal-free star formation ~0.5 Myr after the MBH forms. The MBH accretion rate reaches a maximum of 10-3 M ? yr-1 in both simulations. However, the duty cycle differs and is derived to be 6% and 50% for the high and low LW cases, respectively. The MBH in the high LW case grows only ~6% in 100 Myr compared to 16% in the low LW case. We find that the maximum accretion rate is determined by the local gas thermodynamics, whereas the duty cycle is determined by the large-scale gas dynamics and gas reservoir. We conclude that radiative feedback from the central MBH plays an important role in star formation in the nuclear regions and stifling initial MBH growth relative to the typical Eddington rate argument, and that initial MBH growth might be affected by the local LW radiation field.

  20. Human population dynamics in Europe over the Last Glacial Maximum.

    PubMed

    Tallavaara, Miikka; Luoto, Miska; Korhonen, Natalia; Järvinen, Heikki; Seppä, Heikki

    2015-07-01

    The severe cooling and the expansion of the ice sheets during the Last Glacial Maximum (LGM), 27,000-19,000 y ago (27-19 ky ago) had a major impact on plant and animal populations, including humans. Changes in human population size and range have affected our genetic evolution, and recent modeling efforts have reaffirmed the importance of population dynamics in cultural and linguistic evolution, as well. However, in the absence of historical records, estimating past population levels has remained difficult. Here we show that it is possible to model spatially explicit human population dynamics from the pre-LGM at 30 ky ago through the LGM to the Late Glacial in Europe by using climate envelope modeling tools and modern ethnographic datasets to construct a population calibration model. The simulated range and size of the human population correspond significantly with spatiotemporal patterns in the archaeological data, suggesting that climate was a major driver of population dynamics 30-13 ky ago. The simulated population size declined from about 330,000 people at 30 ky ago to a minimum of 130,000 people at 23 ky ago. The Late Glacial population growth was fastest during Greenland interstadial 1, and by 13 ky ago, there were almost 410,000 people in Europe. Even during the coldest part of the LGM, the climatically suitable area for human habitation remained unfragmented and covered 36% of Europe. PMID:26100880

  1. The Maximum Energy of Accelerated Particles in Relativistic Collisionless Shocks

    NASA Astrophysics Data System (ADS)

    Sironi, Lorenzo; Spitkovsky, Anatoly; Arons, Jonathan

    2013-07-01

    The afterglow emission from gamma-ray bursts (GRBs) is usually interpreted as synchrotron radiation from electrons accelerated at the GRB external shock that propagates with relativistic velocities into the magnetized interstellar medium. By means of multi-dimensional particle-in-cell simulations, we investigate the acceleration performance of weakly magnetized relativistic shocks, in the magnetization range 0 <~ ? <~ 10-1. The pre-shock magnetic field is orthogonal to the flow, as generically expected for relativistic shocks. We find that relativistic perpendicular shocks propagating in electron-positron plasmas are efficient particle accelerators if the magnetization is ? <~ 10-3. For electron-ion plasmas, the transition to efficient acceleration occurs for ? <~ 3 × 10-5. Here, the acceleration process proceeds similarly for the two species, since the electrons enter the shock nearly in equipartition with the ions, as a result of strong pre-heating in the self-generated upstream turbulence. In both electron-positron and electron-ion shocks, we find that the maximum energy of the accelerated particles scales in time as ?maxvpropt 1/2. This scaling is shallower than the so-called (and commonly assumed) Bohm limit ?maxvpropt, and it naturally results from the small-scale nature of the Weibel turbulence generated in the shock layer. In magnetized plasmas, the energy of the accelerated particles increases until it reaches a saturation value ?sat/?0 mic 2 ~ ?-1/4, where ?0 mic 2 is the mean energy per particle in the upstream bulk flow. Further energization is prevented by the fact that the self-generated turbulence is confined within a finite region of thickness vprop?-1/2 around the shock. Our results can provide physically grounded inputs for models of non-thermal emission from a variety of astrophysical sources, with particular relevance to GRB afterglows.

  2. Freshwater discharges in a simulation of the Last Glacial Maximum climate using improved river routing

    NASA Astrophysics Data System (ADS)

    Alkama, R.; Kageyama, M.; Ramstein, G.

    2006-11-01

    The large ice-sheets over North America and Europe at the Last Glacial Maximum (LGM) strongly disturbed river pathways. This has never been taken into account in simulations of the LGM climate, even if it could have an impact on the freshwater input to the ocean. Here, we have introduced a more realistic river routing in LGM atmospheric general circulation model simulations. A comparison with classical LGM simulations shows that the discharge into the Arctic Ocean is not drastically different. Even if the Ob and Yenisei rivers could not reach the Arctic Ocean because of the Fennoscandian ice sheet (which results in a lake South of this ice sheet), the discharge of other rivers nearby is increased due to the influence of this lake. The maximum monthly discharge into the North Atlantic Ocean decreases by 34000 m3/s between 54 and 66°N, while it is stronger by 35000 m3/s between 28 and 54°N.

  3. Growth and development of mice and rats conceived and reared at different G-intensities during chronic centrifugation

    NASA Technical Reports Server (NTRS)

    Oyama, J.; Solgaard, L.; Corrales, J.; Monson, C. B.

    1985-01-01

    Prenatal and postnatal growth of rats conceived and reared at different G-intensities from 1.0G (earth gravity) to a maximum of 2.03G were compared. Prenatal growth was not generally impaired but the lung/body mass ratio of 22-day old fetuses at 2.03G was decreased significantly compared to 1.06 controls. Survival of neonatal rats was substantially reduced at 1.71G and 2.03G. Postnatal growth was decreased at the higher G-intensities and showed smaller or no effects at the lower G-intensities. Comparisons of organ/body mass ratios of hyper-G and 1.0G rats at 9 wks of age showed relatively few differences at the lower G-intensities. Postnatal growth of mice at 2.03G was suppressed during the neonatal period but recovered later so that after 9 wks the body mass of females reached and of males approached controls. Results of this preliminary study clearly show the influence of body mass in scaling the effects of hyper-G on the growth and development of and between different animal species.

  4. Human cortical representations for reaching: Mirror neurons for execution, observation, and imagery

    Microsoft Academic Search

    Flavia Filimon; Jonathan D. Nelson; Donald J. Hagler; Martin I. Sereno

    2007-01-01

    We used functional magnetic resonance imaging (fMRI) to map the cortical representations of executed reaching, observed reaching, and imagined reaching in humans. Whereas previous studies have mostly examined hand actions related to grasping, hand–object interactions, or local finger movements, here we were interested in reaching only (i.e. the transport phase of the hand to a particular location in space), without

  5. Conceptual Model of Hydrologic and Thermal Conditions of the Eastbank Aquifer System near Rocky Reach Dam, Douglas County, Washington

    USGS Publications Warehouse

    van Heeswijk, Marijke; Cox, Stephen E.; Huffman, Raegan L.; Curran, Christopher A.

    2008-01-01

    The Lower and Combined Aquifers of the Eastbank Aquifer system, located in a river-terrace deposit along the Columbia River near Rocky Reach Dam, Washington, are primarily recharged by the Columbia River and provide water to the Eastbank Hatchery and the regional water system servicing the cities of Wenatchee, East Wenatchee, and parts of unincorporated Chelan and Douglas Counties. In 2006, mean annual pumpage from the aquifers by the hatchery and regional water system was about 43 and 16 cubic feet per second, respectively. Reportedly, temperatures of ground water pumped by the hatchery have been increasing, thereby making water potentially too warm for salmonid fish production. An evaluation of hourly ground-water and river temperatures from January 1991 through August 2007 indicates increasing interannual trends in temperatures in most of the Lower and Combined Aquifers from 1999 through 2006 that correspond to increasing trends in the annual mean and annual maximum river temperatures during the same period of 0.07 and 0.17?C per year, respectively. There were no trends in the annual minimum river temperatures from 1999 through 2006, and there were no trends in the annual minimum, mean, and maximum river temperatures from 1991 through 1998 and from 1991 through 2007. Increases in river temperatures from 1999 through 2006 are within the natural variability of the river temperatures. Most of the Lower and Combined Aquifers reached thermal equilibrium?defined by constant time lags between changes in river temperatures and subsequent changes in ground-water temperatures?during 1991?98. The only exceptions are the Combined Aquifer north of the well field of the regional water system, which had not reached thermal equilibrium by 2006, and the Lower Aquifer west of the well fields of the hatchery and the regional water system, which reached thermal equilibrium prior to 1991. Because most of the Lower and Combined Aquifers were in thermal equilibrium from 1999 through 2006 and seasonal pumpage patterns were relatively stable, reported trends of increasing temperatures of water pumped by the hatchery well field are most likely explained by increasing trends in river temperatures. Most of the water pumped by the hatchery well field recharges in an area west to southwest of the well field about 2 months prior to the time it is pumped from the aquifer. The northern extent of the hatchery well field may pump some colder water from a bedrock depression to the north and west of the well field. The conceptual model of hydrologic and thermal conditions is supported by analyses of historical water temperatures, water-level data collected on July 18, 2007, and dissolved-constituent and bacterial concentrations in samples collected on August 20?22, 2007.

  6. 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.

  7. Minimum maximum temperature gradient coil design.

    PubMed

    While, Peter T; Poole, Michael S; Forbes, Larry K; Crozier, Stuart

    2013-08-01

    Ohmic heating is a serious problem in gradient coil operation. A method is presented for redesigning cylindrical gradient coils to operate at minimum peak temperature, while maintaining field homogeneity and coil performance. To generate these minimaxT coil windings, an existing analytic method for simulating the spatial temperature distribution of single layer gradient coils is combined with a minimax optimization routine based on sequential quadratic programming. Simulations are provided for symmetric and asymmetric gradient coils that show considerable improvements in reducing maximum temperature over existing methods. The winding patterns of the minimaxT coils were found to be heavily dependent on the assumed thermal material properties and generally display an interesting "fish-eye" spreading of windings in the dense regions of the coil. Small prototype coils were constructed and tested for experimental validation and these demonstrate that with a reasonable estimate of material properties, thermal performance can be improved considerably with negligible change to the field error or standard figures of merit. PMID:23042696

  8. Maximum likelihood inference of reticulate evolutionary histories.

    PubMed

    Yu, Yun; Dong, Jianrong; Liu, Kevin J; Nakhleh, Luay

    2014-11-18

    Hybridization plays an important role in the evolution of certain groups of organisms, adaptation to their environments, and diversification of their genomes. The evolutionary histories of such groups are reticulate, and methods for reconstructing them are still in their infancy and have limited applicability. We present a maximum likelihood method for inferring reticulate evolutionary histories while accounting simultaneously for incomplete lineage sorting. Additionally, we propose methods for assessing confidence in the amount of reticulation and the topology of the inferred evolutionary history. Our method obtains accurate estimates of reticulate evolutionary histories on simulated datasets. Furthermore, our method provides support for a hypothesis of a reticulate evolutionary history inferred from a set of house mouse (Mus musculus) genomes. As evidence of hybridization in eukaryotic groups accumulates, it is essential to have methods that infer reticulate evolutionary histories. The work we present here allows for such inference and provides a significant step toward putting phylogenetic networks on par with phylogenetic trees as a model of capturing evolutionary relationships. PMID:25368173

  9. The Computational Neurobiology of Reaching and Pointing: A Foundation for Motor Learning By Reza

    E-print Network

    Shadmehr, Reza

    The Computational Neurobiology of Reaching and Pointing: A Foundation for Motor Learning By Reza Neurobiology of Reaching and Pointing, a unified and comprehensive synthesis of motor learning and control with the physical world. The Computational Neurobiology of Reaching and Pointing begins with an introduction

  10. Infants Return to Two-Handed Reaching When They Are Learning to Walk

    Microsoft Academic Search

    Daniela Corbetta; Kathryn E. Bojczyk

    2002-01-01

    The authors examined whether infants of about 1 year return to 2-handed reaching when they begin to walk independently. Infants (N = 9) were followed longitudinally before, during, and after their transition to upright locomotion. Every week, the infants' reaching responses and patterns of interlimb coordination were screened in 3 tasks involving different adaptive reaching responses. Before the onset of

  11. Seismic risk analysis for California State Water Project Reach C, 22

    Microsoft Academic Search

    H. C. Shah; M. Movassate; T. C. Zsutty

    1976-01-01

    A seismic hazard map for the region described as Reach C for the California Water Project is developed in this report. Reach C is defined as that portion of the California Water Project from Tehachapi afterbay up to and including the Perris Dam and Lake. The key facilities within this reach include Tehachapi afterbay, Cottonwood power plant site, Pearblossom pumping

  12. Trajectories of reaches to prismatically-displaced targets: evidence for “automatic” visuomotor recalibration

    Microsoft Academic Search

    L. S. Jakobson; M. A. Goodale

    1989-01-01

    The present study examined the kinematics of unrestricted reaches to prismaticallydisplaced targets. The kinematic analysis allowed us (1) to document how and where in the reach adjustments were made to compensate for the prismatic displacement, (2) to detail the changes that occur in the characteristics of reaches during the course of adaptation to the prisms, and (3) to look at

  13. The Reach Out Lab Researching our impact. What are our aspirations?

    E-print Network

    The Reach Out Lab Researching our impact. What are our aspirations? Very few exercises in public participating in the Reach Out Lab activities are being followed over three to five years to assess their career working with in Reach Out Lab and a cohort of non-participating students will be compared as a control

  14. Work output and efficiency at maximum power of linear irreversible heat engines operating with a finite-sized heat source.

    PubMed

    Izumida, Yuki; Okuda, Koji

    2014-05-01

    We formulate the work output and efficiency for linear irreversible heat engines working between a finite-sized hot heat source and an infinite-sized cold heat reservoir until the total system reaches the final thermal equilibrium state with a uniform temperature. We prove that when the heat engines operate at the maximum power under the tight-coupling condition without heat leakage the work output is just half of the exergy, which is known as the maximum available work extracted from a heat source. As a consequence, the corresponding efficiency is also half of its quasistatic counterpart. PMID:24856684

  15. 33 CFR 156.320 - Maximum operating conditions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... POLLUTION OIL AND HAZARDOUS MATERIAL TRANSFER OPERATIONS Lightering Zones and Operational Requirements for the Gulf of Mexico § 156.320 Maximum operating conditions. Unless otherwise specified, the maximum operating conditions...

  16. 33 CFR 156.320 - Maximum operating conditions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... POLLUTION OIL AND HAZARDOUS MATERIAL TRANSFER OPERATIONS Lightering Zones and Operational Requirements for the Gulf of Mexico § 156.320 Maximum operating conditions. Unless otherwise specified, the maximum operating conditions...

  17. 22 CFR 192.44 - Maximum limitation on benefits.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Maximum limitation on benefits. 192.44 Section 192.44 Foreign Relations DEPARTMENT OF STATE HOSTAGE RELIEF VICTIMS OF TERRORISM COMPENSATION Educational Benefits for Captive Situations § 192.44 Maximum limitation on...

  18. 22 CFR 192.44 - Maximum limitation on benefits.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Maximum limitation on benefits. 192.44 Section 192.44 Foreign Relations DEPARTMENT OF STATE HOSTAGE RELIEF VICTIMS OF TERRORISM COMPENSATION Educational Benefits for Captive Situations § 192.44 Maximum limitation on...

  19. 22 CFR 192.44 - Maximum limitation on benefits.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Maximum limitation on benefits. 192.44 Section 192.44 Foreign Relations DEPARTMENT OF STATE HOSTAGE RELIEF VICTIMS OF TERRORISM COMPENSATION Educational Benefits for Captive Situations § 192.44 Maximum limitation on...

  20. 22 CFR 192.44 - Maximum limitation on benefits.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Maximum limitation on benefits. 192.44 Section 192.44 Foreign Relations DEPARTMENT OF STATE HOSTAGE RELIEF VICTIMS OF TERRORISM COMPENSATION Educational Benefits for Captive Situations § 192.44 Maximum limitation on...

  1. 22 CFR 192.44 - Maximum limitation on benefits.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Maximum limitation on benefits. 192.44 Section 192.44 Foreign Relations DEPARTMENT OF STATE HOSTAGE RELIEF VICTIMS OF TERRORISM COMPENSATION Educational Benefits for Captive Situations § 192.44 Maximum limitation on...

  2. 34 CFR 682.204 - Maximum loan amounts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Maximum loan amounts. 682.204 Section 682.204...CONTINUED) FEDERAL FAMILY EDUCATION LOAN (FFEL) PROGRAM General Provisions § 682.204 Maximum loan amounts. (a) Stafford Loan...

  3. 34 CFR 682.204 - Maximum loan amounts.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Maximum loan amounts. 682.204 Section 682.204...CONTINUED) FEDERAL FAMILY EDUCATION LOAN (FFEL) PROGRAM General Provisions § 682.204 Maximum loan amounts. (a) Stafford Loan...

  4. 34 CFR 682.204 - Maximum loan amounts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Maximum loan amounts. 682.204 Section 682.204...CONTINUED) FEDERAL FAMILY EDUCATION LOAN (FFEL) PROGRAM General Provisions § 682.204 Maximum loan amounts. (a) Stafford Loan...

  5. 7 CFR 4290.840 - Maximum term of Financing.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...PROGRAM Financing of Enterprises by RBICs Structuring Rbic Financing of Eligible Enterprises-Types of Financings § 4290.840 Maximum term of Financing. The maximum term of any Debt Security must be no longer than 20...

  6. 33 CFR 155.775 - Maximum cargo level of oil.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Maximum cargo level of oil. 155.775 Section 155.775 Navigation and Navigable Waters COAST GUARD...Personnel, Procedures, Equipment, and Records § 155.775 Maximum cargo level of oil. (a) For...

  7. First year growth in the lithodids Lithodes santolla and Paralomis granulosa reared at different temperatures

    NASA Astrophysics Data System (ADS)

    Calcagno, J. A.; Lovrich, G. A.; Thatje, S.; Nettelmann, U.; Anger, K.

    2005-10-01

    The southern king crab, Lithodes santolla Molina, and stone crab, Paralomis granulosa Jacquinot, inhabit the cold-temperate waters of southernmost South America (southern Chile and Argentina), where stocks of both species are endangered by overfishing. Recent investigations have shown that these crabs show life-cycle adaptations to scarcity of food and low temperatures prevailing in subantarctic regions, including complete lecithotrophy of all larval stages and prolonged periods of brooding and longevity. However, growth and development to maturity are slow under conditions of low temperatures, which may explain the particular vulnerability of subpolar lithodids to fisheries. In the present study, juvenile L. santolla and P. granulosa were individually reared in the laboratory at constant temperatures ranging from 3-15 °C, and rates of survival and development through successive instars were monitored throughout a period of about nine months from hatching. When the experiments were terminated, L. santolla had maximally reached juvenile instar IV (at 6 °C), V (9 °C), or VII (15 °C). In P. granulosa the maximum crab instar reached was II (at 3 °C), V (6 °C), V (9 °C), or VII (15 °C). The intermoult period decreased with increasing temperature, while it increased in successively later instars. In consequence, growth rate showed highly significant differences among temperatures (P<0.001). Growth-at-moult was highest at 9 °C. Rates of survival decreased significantly in juvenile P. granulosa with increasing temperature. Only at 15 °C in L. santolla, was a significantly enhanced mortality found compared with lower temperatures. Our results indicate that juvenile stages of L. santolla and P. granulosa are well adapted to 5-10°C, the range of temperatures typically prevailing in subantarctic marine environments. In spite of causing higher mortality rates, higher rearing temperatures (12-15 °C) should accelerate the rates of growth and maturation, which may be favourable for projects aiming at aquaculture or repopulation of overexploited king crab stocks.

  8. Development of Nitrogen Assimilation Enzymes during Photoautotrophic Growth of Chenopodium rubrum Suspension Cultures.

    PubMed

    Campbell, W H; Ziegler, P; Beck, E

    1984-04-01

    Chenopodium rubrum cells were grown in suspension as a photoautotrophic culture with a 16 hour day. Cell growth had three phases: a 3-day lag, a 3-week logarithmic phase, and a 10-day stationary phase. Chlorophyll content increased steadily during log phase and reached a level of 0.5 to 0.6 mg Chl g(-1) fresh weight. Soluble protein of the cells increased more rapidly from day 4 to day 12 than during midlog phase. Initially, ammonium was taken up in preference to nitrate. However, during the second two weeks of growth, ammonium and nitrate were taken up simultaneously; this period of growth was the time of highest rates of N uptake by the cultured cells. Glutamine synthetase had a high specific activity (17 mumol.hour(-1) mg(-1) protein) in day 1 cells, and this level was sustained until midlog phase when it increased by 20%. Methyl viologen-dependent glutamate synthase specific activity increased rapidly in lag phase cells (day 4 = 10 mumol.hour(-1) mg(-1) protein), but decreased by day 9 to about 50% of the peak and remained constant. NADH:nitrate reductase specific activity increased rapidly in lag phase cells and reached a plateau that lasted from day 4 to 14 (1 mumol.hour(-1) mg(-1) protein). Methyl viologen-dependent nitrite reductase specific activity was high when assayed on day 5 and increased to a maximum on day 15 to 16 (12 mumol.hour(-1) mg(-1) protein). NADPH- and NADH-dependent glutamate dehydrogenase specific activities remained rather constant throughout the growth cycle. The cells appeared to have developed photosynthetic competence and to have leaf-like activities of nitrogen assimilation enzymes. PMID:16663539

  9. Development of Nitrogen Assimilation Enzymes during Photoautotrophic Growth of Chenopodium rubrum Suspension Cultures 1

    PubMed Central

    Campbell, Wilbur H.; Ziegler, Paul; Beck, Erwin

    1984-01-01

    Chenopodium rubrum cells were grown in suspension as a photoautotrophic culture with a 16 hour day. Cell growth had three phases: a 3-day lag, a 3-week logarithmic phase, and a 10-day stationary phase. Chlorophyll content increased steadily during log phase and reached a level of 0.5 to 0.6 mg Chl g?1 fresh weight. Soluble protein of the cells increased more rapidly from day 4 to day 12 than during midlog phase. Initially, ammonium was taken up in preference to nitrate. However, during the second two weeks of growth, ammonium and nitrate were taken up simultaneously; this period of growth was the time of highest rates of N uptake by the cultured cells. Glutamine synthetase had a high specific activity (17 ?mol·hour?1 mg?1 protein) in day 1 cells, and this level was sustained until midlog phase when it increased by 20%. Methyl viologen-dependent glutamate synthase specific activity increased rapidly in lag phase cells (day 4 = 10 ?mol·hour?1 mg?1 protein), but decreased by day 9 to about 50% of the peak and remained constant. NADH:nitrate reductase specific activity increased rapidly in lag phase cells and reached a plateau that lasted from day 4 to 14 (1 ?mol·hour?1 mg?1 protein). Methyl viologen-dependent nitrite reductase specific activity was high when assayed on day 5 and increased to a maximum on day 15 to 16 (12 ?mol·hour?1 mg?1 protein). NADPH- and NADH-dependent glutamate dehydrogenase specific activities remained rather constant throughout the growth cycle. The cells appeared to have developed photosynthetic competence and to have leaf-like activities of nitrogen assimilation enzymes. PMID:16663539

  10. Nitrogen dynamics in the intact grasses Poa trivialis and Panicum maximum receiving contrasting supplies of nitrogen.

    PubMed

    Santos, Patricia M; Thornton, Barry; Corsi, Moacyr

    2002-11-01

    The C(3) grass Poa trivialis and the C(4) grass Panicum maximum were grown in sand culture and received a complete nutrient solution with nitrogen supplied as 1.5 mol m(-3) NH(4)NO(3). (15)N tracer techniques were used to quantify the relative use of root uptake and mobilization in supplying nitrogen to growing leaves in intact plants which either continued to receive nitrogen or which received the complete nutrient solution without nitrogen. The allocation of both (15)N-labelled nitrogen uptake and unlabelled mobilized nitrogen indicated that, under their conditions of growth, the sink strength of growing leaves was relatively greater in P. maximum than P. trivialis. The supply of nitrogen by mobilization to side tillers of P. trivialis was completely stopped as the external nitrogen supply was reduced, whilst in P. maximum some allocation of mobilized nitrogen to side tillers, roots and growing leaves was maintained. In both plant species receiving an uninterrupted supply of nitrogen the allocation pattern of mobilized nitrogen differed from that of nitrogen derived from root uptake. Differences exist in the degree to which P. trivialis and P. maximum utilized uptake and mobilization to supply nitrogen to the growing leaves. In P. trivialis roots were always a net sink of mobilized nitrogen, irrespective of the external nitrogen supply. In P. maximum, roots were a net sink of mobilized nitrogen when external nitrogen was withdrawn, but exhibited both source and sink behaviour when nitrogen supply was continued. PMID:12379783

  11. Heteroepitaxial CVD diamond film growth

    NASA Astrophysics Data System (ADS)

    Dai, Zhongning; Bednarski-Meinke, Connie; Golding, Brage

    2003-03-01

    We have studied the conditions necessary for growth of (001) oriented CVD diamond films on iridium films grown epitaxially on sapphire substrates. Using sequential interrupted growth experiments, we have followed the coalescence of individual crystallites by interface annihilation at an early growth stage. After one-hour growth, an extremely smooth, continuous film of single crystal diamond covers the entire surface of the substrate, an area of 10 mm^2. By growing for extended periods, to a maximum of 48 hr, diamond plates of thickness 35 ?m were produced. XRD, Raman, AFM, EBSD, and SEM analyses were used to characterize the crystallographic and surface quality of the diamond film. Freestanding crystals exhibited (111) cleavage surfaces, the same as natural diamond, and were transparent in visible light. The discovery that (001) Ir on sapphire can be used as a substrate to grow diamond promises to lead to improvements in diamond quality and will enable scale-up to large-area crystals.

  12. In-vivo visualization of melanoma tumor microvessels and blood flow velocity changes accompanying tumor growth

    NASA Astrophysics Data System (ADS)

    Ishida, Hiroki; Hachiga, Tadashi; Andoh, Tsugunobu; Akiguchi, Shunsuke

    2012-11-01

    We demonstrate that using micro multipoint laser Doppler velocimetry (?-MLDV) for noninvasive in-vivo imaging of blood vessels is useful for diagnosing malignant melanomas by comparison with visual diagnosis by dermoscopy. The blood flow velocity in microvessels varied during growth of melanomas transplanted in mouse ears. Mouse ears were observed by ?-MLDV up to 16 days after transplantation. The blood flow velocity in the tumor increased with increasing time and reached maximum of 4.5 mm/s at 9 days, which is more than twice that prior to transplantation. After 12 days, when the lesion had grown to an area of 6.6 mm2, we observed the formation of new blood vessels in the tumor. Finally, when the lesion had an area of 18 mm2 after 16 days, the flow velocity in the tumor decreased to approximately 3.2 mm/s.

  13. 30 CFR 36.44 - Maximum allowable fuel : air ratio.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... false Maximum allowable fuel : air ratio. 36.44 Section 36.44 Mineral...36.44 Maximum allowable fuel : air ratio. (a) When an engine is delivered...shall be accepted. The maximum fuel : air ratio determined from the exhaust-gas...

  14. Maximum Principles at Infinity William H. Meeks III

    E-print Network

    Meeks III, William H.

    Maximum Principles at Infinity William H. Meeks III Harold Rosenberg September 28, 2007 Abstract We prove a general maximum principle at infinity for properly immersed minimal surfaces with boundary in R3 . An important corollary of this maximum principle at infinity is the existence of a fixed sized regular

  15. Maximum Power Training and Plyometrics for Cross-Country Running.

    ERIC Educational Resources Information Center

    Ebben, William P.

    2001-01-01

    Provides a rationale for maximum power training and plyometrics as conditioning strategies for cross-country runners, examining: an evaluation of training methods (strength training and maximum power training and plyometrics); biomechanic and velocity specificity (role in preventing injury); and practical application of maximum power training and…

  16. Density maximum and polarizable models of water

    NASA Astrophysics Data System (ADS)

    Kiss, Péter T.; Baranyai, András

    2012-08-01

    To estimate accurately the density of water over a wide range of temperatures with a density maximum at 4 °C is one of the most stringent tests of molecular models. The shape of the curve influences the ability to describe critical properties and to predict the freezing temperature. While it was demonstrated that with a proper parameter fit nonpolarizable models can approximate this behavior accurately, it is much more difficult to do this for polarizable models. We provide a short overview of ?-T diagrams for existing models, then we give an explanation of this difficulty. We present a version of the BK model [A. Baranyai and P. T. Kiss, J. Chem. Phys. 133, 144109 (2010), 10.1063/1.3490660; A. Baranyai and P. T. Kiss, J. Chem. Phys. 135, 234110 (2011)], 10.1063/1.3670962 which is capable to predict the density of water over a wide range of temperature. The BK model uses the charge-on-spring method with three Gaussian charges. Since the experimental dipole moment and the geometry is fixed, and the quadrupole moment is approximated by a least mean square procedure, parameters of the repulsion and dispersive attraction forces remained as free tools to match experimental properties. Relying on a simplified but plausible justification, the new version of the model uses repulsion and attraction as functions of the induced dipole moment of the molecule. The repulsive force increases, while the attractive force decreases with the size of the molecular dipole moment. At the same time dipole moment dependent dispersion forces are taking part in the polarization of the molecule. This scheme iterates well and, in addition to a reasonable density-temperature function, creates dipole distributions with accurate estimation of the dielectric constant of the liquid.

  17. M3G: Maximum Margin Microarray Gridding

    PubMed Central

    2010-01-01

    Background Complementary DNA (cDNA) microarrays are a well established technology for studying gene expression. A microarray image is obtained by laser scanning a hybridized cDNA microarray, which consists of thousands of spots representing chains of cDNA sequences, arranged in a two-dimensional array. The separation of the spots into distinct cells is widely known as microarray image gridding. Methods In this paper we propose M3G, a novel method for automatic gridding of cDNA microarray images based on the maximization of the margin between the rows and the columns of the spots. Initially the microarray image rotation is estimated and then a pre-processing algorithm is applied for a rough spot detection. In order to diminish the effect of artefacts, only a subset of the detected spots is selected by matching the distribution of the spot sizes to the normal distribution. Then, a set of grid lines is placed on the image in order to separate each pair of consecutive rows and columns of the selected spots. The optimal positioning of the lines is determined by maximizing the margin between these rows and columns by using a maximum margin linear classifier, effectively facilitating the localization of the spots. Results The experimental evaluation was based on a reference set of microarray images containing more than two million spots in total. The results show that M3G outperforms state of the art methods, demonstrating robustness in the presence of noise and artefacts. More than 98% of the spots reside completely inside their respective grid cells, whereas the mean distance between the spot center and the grid cell center is 1.2 pixels. Conclusions The proposed method performs highly accurate gridding in the presence of noise and artefacts, while taking into account the input image rotation. Thus, it provides the potential of achieving perfect gridding for the vast majority of the spots. PMID:20100338

  18. Growth Mindset

    NSDL National Science Digital Library

    2012-01-01

    This page from Character Lab presents information about what a growth mindset is, why it is important and how to develop it. Included is a 3-minute video of Drs. Carol Dweck and Greg Walton of Stanford University discussing how a growth mindset compares to a fixed mindset.

  19. NOTE FROM THE EDITOR: Bayesian and Maximum Entropy Methods Bayesian and Maximum Entropy Methods

    NASA Astrophysics Data System (ADS)

    Dobrzynski, L.

    2008-10-01

    The Bayesian and Maximum Entropy Methods are now standard routines in various data analyses, irrespective of ones own preference to the more conventional approach based on so-called frequentists understanding of the notion of the probability. It is not the purpose of the Editor to show all achievements of these methods in various branches of science, technology and medicine. In the case of condensed matter physics most of the oldest examples of Bayesian analysis can be found in the excellent tutorial textbooks by Sivia and Skilling [1], and Bretthorst [2], while the application of the Maximum Entropy Methods were described in `Maximum Entropy in Action' [3]. On the list of questions addressed one finds such problems as deconvolution and reconstruction of the complicated spectra, e.g. counting the number of lines hidden within the spectrum observed with always finite resolution, reconstruction of charge, spin and momentum density distribution from an incomplete sets of data, etc. On the theoretical side one might find problems like estimation of interatomic potentials [4], application of the MEM to quantum Monte Carlo data [5], Bayesian approach to inverse quantum statistics [6], very general to statistical mechanics [7] etc. Obviously, in spite of the power of the Bayesian and Maximum Entropy Methods, it is not possible for everything to be solved in a unique way by application of these particular methods of analysis, and one of the problems which is often raised is connected not only with a uniqueness of a reconstruction of a given distribution (map) but also with its accuracy (error maps). In this `Comments' section we present a few papers showing more recent advances and views, and highlighting some of the aforementioned problems. References [1] Sivia D S and Skilling J 2006 Data Analysis: A Bayesian Tutorial 2nd edn (Oxford: Oxford University Press) [2] Bretthorst G L 1988 Bayesian Spectruim Analysis and Parameter Estimation (Berlin: Springer) [3] Buck B and Macaulay V A 1991 Maximum Entropy in Action (Oxford: Clarendon) [4] Carlsson A E 1987 Phys. Rev. Lett. 59 1108 [5] von der Linden W, Preuss R and Hanke W 1996 J. Phys.: Condens. Matter 8 3881 [6] Lemm J C, Uhlig J and Weiguny A 2000 Phys. Rev. Lett. 84 2068 [7] Dewar R 2003 J. Phys. A: Math. Gen. 36 631

  20. Scaling of Transient Storage Parameter Estimates with Increasing Reach Length in a Mountain Headwater Stream

    NASA Astrophysics Data System (ADS)

    Briggs, M.; Gooseff, M. N.; McGlynn, B.

    2006-12-01

    . Numerous studies have used the methods of stream tracer experiments and subsequent solute transport modeling to determine transient storage characteristics of streams. Experimental reach length is often determined by site logistics, morphology, specific study goals, etc. Harvey et al. [1996] provided guidance for optimal study reach lengths, based on the Dahmkoler number, as a balance between timescales of advective transport and transient storage. In this study, we investigate the scaling of parameters in a solute transport model (OTIS) with increasing spatial scale of investigation. We conducted 2 6-hour constant rate injections of dissolved NaCl in Spring Park Creek, a headwater stream in the Tenderfoot Creek Experimental Forest, Montana. Below the first injection we sampled 4 reaches ~200m in length, we then moved upstream 640m for the second injection and sampled 3 more ~200 m reaches. Solute transport simulations were conducted for each of these sub-reaches and for combinations of these sub-reaches, from which we assessed estimates of solute velocity, dispersion, transient storage exchange, storage zone size, and Fmed (proportion of median transport time due to storage). Dahmkoler values calculated for each simulation (sub-reaches as well as longer combined reach) were within an order of magnitude of 1, suggesting that our study reach lengths were appropriate. Length-weighted average solute transport and transient storage parameters for the sub-reaches were found to be comparable to their counterparts in the longer reach simulation. In particular the average dispersion found for the sub-reaches (0.43 m2/s) compared very favorably with the value for dispersion calculated for the larger reach (0.40 m2/s). In contrast the weighted average of storage zone size for the sub-reaches was much greater (1.17 m2) than those calculated for the injection reach as a whole (0.09 m2) by a factor of ~13. Weighted average values for transient storage exchange and size for the sub-reaches were both found to be higher than that of the reach as a whole, but only by factors of ~2.5 and 3 respectively. This study indicates that some values of solute transport and transient storage for a particular reach can be reasonably extrapolated from its corresponding component reach values.

  1. To see the effect of sample size on the maximum age more clearly, we can approximate Equation (1) by

    E-print Network

    To see the effect of sample size on the maximum age more clearly, we can approximate Equation (1 of temperature on the rate of growth of juvenile red crabs in the laboratory. Methods Increasing the sample size the sample size from 200 to 1,000 will cause a 27% increase. Ifthe mortality rate is higher for older fish

  2. Reaching Grid Parity Using BP Solar Crystalline Silicon Technology: A Systems Class Application

    SciTech Connect

    Cunningham, Daniel W; Wohlgemuth, John; Carlson, David E; Clark, Roger F; Gleaton, Mark; Posbic, John P; Zahler, James

    2010-12-06

    The primary target market for this program was the residential and commercial PV markets, drawing on BP Solar's premium product and service offerings, brand and marketing strength, and unique routes to market. These two markets were chosen because: (1) in 2005 they represented more than 50% of the overall US PV market; (2) they are the two markets that will likely meet grid parity first; and (3) they are the two market segments in which product development can lead to the added value necessary to generate market growth before reaching grid parity. Federal investment in this program resulted in substantial progress toward the DOE TPP target, providing significant advancements in the following areas: (1) Lower component costs particularly the modules and inverters. (2) Increased availability and lower cost of silicon feedstock. (3) Product specifically developed for residential and commercial applications. (4) Reducing the cost of installation through optimization of the products. (5) Increased value of electricity in mid-term to drive volume increases, via the green grid technology. (6) Large scale manufacture of PV products in the US, generating increased US employment in manufacturing and installation. To achieve these goals BP Solar assembled a team that included suppliers of critical materials, automated equipment developers/manufacturers, inverter and other BOS manufacturers, a utility company, and University research groups. The program addressed all aspects of the crystalline silicon PV business from raw materials (particularly silicon feedstock) through installation of the system on the customers site. By involving the material and equipment vendors, we ensured that supplies of silicon feedstock and other PV specific materials like encapsulation materials (EVA and cover glass) will be available in the quantities required to meet the DOE goals of 5 to 10 GW of installed US PV by 2015 and at the prices necessary for PV systems to reach grid parity in 2015. This final technical report highlights the accomplishments of the BP Solar technical team from 2006 to the end of the project in February 2010. All the main contributors and team members are recognized for this accomplishment and their endeavors are recorded in the twelve main tasks described here.

  3. Multivariate analysis in the maximum strength performance.

    PubMed

    de Souza, E O; Tricoli, V; Paulo, A C; Silva-Batista, C; Cardoso, R K; Brum, P C; Bacurau, A V N; Laurentino, G; Neves-Jr, M; Aihara, A Y; Ugrinowitsch, C

    2012-12-01

    This study performed an exploratory analysis of the anthropometrical and morphological muscle variables related to the one-repetition maximum (1RM) performance. In addition, the capacity of these variables to predict the force production was analyzed. 50 active males were submitted to the experimental procedures: vastus lateralis muscle biopsy, quadriceps magnetic resonance imaging, body mass assessment and 1RM test in the leg-press exercise. K-means cluster analysis was performed after obtaining the body mass, sum of the left and right quadriceps muscle cross-sectional area (?CSA), percentage of the type II fibers and the 1RM performance. The number of clusters was defined a priori and then were labeled as high strength performance (HSP1RM) group and low strength performance (LSP1RM) group. Stepwise multiple regressions were performed by means of body mass, ?CSA, percentage of the type II fibers and clusters as predictors' variables and 1RM performance as response variable. The clusters mean ± SD were: 292.8 ± 52.1 kg, 84.7 ± 17.9 kg, 19249.7 ± 1645.5 mm(2) and 50.8 ± 7.2% for the HSP1RM and 254.0 ± 51.1 kg, 69.2 ± 8.1 kg, 15483.1 ± 1104.8mm(2) and 51.7 ± 6.2%, for the LSP1RM in the 1RM, body mass, ?CSA and muscle fiber type II percentage, respectively. The most important variable in the clusters division was the ?CSA. In addition, the ?CSA and muscle fiber type II percentage explained the variance in the 1RM performance (Adj R2=0.35, p=0.0001) for all participants and for the LSP1RM (Adj R2=0.25, p=0.002). For the HSP1RM, only the ?CSA was entered in the model and showed the highest capacity to explain the variance in the 1RM performance (Adj R2=0.38, p=0.01). As a conclusion, the muscle CSA was the most relevant variable to predict force production in individuals with no strength training background. PMID:22895875

  4. Fluorescence imaging of vascular endothelial growth factor in mice tumors using targeted liposome ICG probe

    NASA Astrophysics Data System (ADS)

    Zanganeh, Saeid; Xu, Yan; Backer, Marina V.; Backer, Joseph M.; Zhu, Quing

    2013-03-01

    Indocyanine Green encapsulating liposomes (Lip/ICG) and scVEGF-Lip/ICG liposomes, decorated with site-specifically lipidated engineered single-chain vascular endothelial growth factor (scVEGF) for targeting VEGF receptors were tested as potential tracers for fluorescent tomography. Two groups of experiments were conducted with tumor-bearing mice (n=4 to 6 per group) with tumors placed in a scattering medium at the imaging depths of 1.5 and 2.0 cm. Lip/ICG and scVEGF-Lip/ICG were injected intravenously in the amounts corresponding to 5 nmol of ICG/mouse. We detected kinetics of increase and decline in fluorescent signals in tumors for both imaging depths and for both targeted and untargeted Lip/ICG. Maximum fluorescent signals were approximately 2-fold higher at 1.5 cm vs. 2.0 cm imaging. A signal from untargeted Lip/ICG reached maximum at 15 min post-injection and then rapidly declined with t1/2 ~15 min. In contrast, a signal from targeted scVEGF-Lip/ICG reached maximum at 30 min post-injection and then slow declined with t1/2 ~60-90 min. Preferential retention of scVEGF-Lip(ICG) vs. Lip(ICG) was confirmed by the analysis of fluorescence in cryosections of corresponding tumors, harvested at 400 min post-injection. Our results suggest that targeted scVEGF-Lip/ICG can provide for significantly better post-injection time window for detection of relatively deeply seated tumors.

  5. A longitudinal study on growth and growth variables in dogs of four large breeds raised in domestic environments.

    PubMed

    Trangerud, C; Grøndalen, J; Indrebø, A; Tverdal, A; Ropstad, E; Moe, L

    2007-01-01

    The main objective of this study was to describe the growth patterns of 4 large dog breeds [Newfoundland (NF), Labrador retriever (LR), Leonberger (LEO), and Irish wolfhound (IW)] raised in domestic environments and concomitant changes in 2 growth-related clinical variables: total serum alkaline phosphatase (ALP) and the circumference of the distal radius and ulna (CDRU). The second objective was to investigate whether these measurements were affected by a range of independent variables like age, sex, litter number, and birth weight. Seven hundred dogs were included in the study, and BW data, separated by breed and sex, were fitted to the Gompertz function. Birth weight, adjusted for litter number, differed significantly between sexes for 3 breeds (LEO, P = 0.004; NF, P = 0.02; LR, P = 0.009) and approached significance for IW (P = 0.07). Estimated mean BW increased rapidly during the first 100 d after birth in all 4 breeds, then plateaued, with maturity being reached between 351 (female LR) and 413 d (male NF). Estimated mature BW ranged from 30.8 kg for the female LR up to 65.7 kg for the male IW. Weight gain, as expressed by the derivative of the Gompertz function, reached its peak in the smallest breed (LR) at the youngest age, 89 d for the females and 95 d for males. Log-transformed BW was significantly related to age, breed, and sex, and the age x sex and age x breed interactions. Within breeds, age, birth weight, and litter number had a significant effect on log-transformed BW. The estimated average CDRU increased from 90 d of age toward a peak at 180 d. Thereafter, CDRU declined and stabilized at about 1 yr of age. The estimated total ALP concentrations decreased from 90 to 360 d of age, after which they stabilized, at mean concentrations varying among breeds from 98 to 131 IU/L. Maximum least squares mean total ALP concentrations were found at 3 mo of age in all breeds, with the greatest least squares mean concentration in the IW breed (713 IU/L). In a mixed model analysis of the complete data set, total ALP was affected (P < 0.001) by age, breed, and the interaction of age x breed. This study described the main factors influencing growth and provided reference data for other studies, including those related to nutrition and disorders of growth. PMID:17179542

  6. Growth of the facultative anaerobe Shewanella putrefaciens by elemental sulfur reduction

    NASA Technical Reports Server (NTRS)

    Moser, D. P.; Nealson, K. H.

    1996-01-01

    The growth of bacteria by dissimilatory elemental sulfur reduction is generally associated with obligate anaerobes and thermophiles in particular. Here we describe the sulfur-dependent growth of the facultatively anaerobic mesophile Shewanella putrefaciens. Six of nine representative S. putrefaciens isolates from a variety of environments proved able to grow by sulfur reduction, and strain MR-1 was chosen for further study. Growth was monitored in a minimal medium (usually with 0.05% Casamino Acids added as a growth stimulant) containing 30 mM lactate and limiting concentrations of elemental sulfur. When mechanisms were provided for the removal of the metabolic end product, H2S, measurable growth was obtained at sulfur concentrations of from 2 to 30 mM. Initial doubling times were ca. 1.5 h and substrate independent over the range of sulfur concentrations tested. In the cultures with the highest sulfur concentrations, cell numbers increased by greater than 400-fold after 48 h, reaching a maximum density of 6.8 x 10(8) cells ml-1. Yields were determined as total cell carbon and ranged from 1.7 to 5.9 g of C mol of S(0) consumed-1 in the presence of the amino acid supplement and from 0.9 to 3.4 g of C mol of S(0-1) in its absence. Several lines of evidence indicate that cell-to-sulfur contact is not required for growth. Approaches for the culture of sulfur-metabolizing bacteria and potential ecological implications of sulfur reduction in Shewanella-like heterotrophs are discussed.

  7. Slip Accumulation During Normal Fault Growth, Asal Rift

    NASA Astrophysics Data System (ADS)

    Manighetti, I.; Gaudemer, Y.; Perrin, F.; Pinzuti, P.; Feuillet, N.

    2001-12-01

    We investigate the mechanisms of normal fault growth in Asal rift, one of the most recent and active of Afar. The faults offset ~100 ka-old volcanic surfaces, forming long, high (< 10 and 0.2 km) scarps, along which we previously studied the cumulative slip distributions (Manighetti et al., 2001). Some of these faults also cut lacustrine limestones deposited by the Asal lake before its retreat ~6 ka ago, forming smaller scarplets at the base of the cumulative scarps. Combining digital photographs and distance measurements, we measured the heights of such scarplets along five of the faults. Here, we present the results obtained on two of them, one large (A4) and one small (A21) (6 and 1.5 km-long, and 200 and 20 m-high cumulative scarps, respectively). Both faults slipped fast in the last 6 kyr, at a maximum rate higher on the larger fault (7.5+/-0.7 mm/yr versus 1.5+/-0.2 mm/yr on A21). If such maximum rates kept constant in time, we infer that A4 and A21 initiated 27+/-3 and 13+/-3 ka ago, respectively. As A4 slipped by at most 40 cm during the last 1978 seismic sequence, we deduce a recurrence time for similar crisis of 50-120 yr (depending on creep rate), much shorter than previously estimated. Comparing cumulative and 6 ka slip distributions show that, in the last 6 kyr, both faults accumulated vertical displacement without increasing in length. The envelop-shapes of their overall slip distributions remained unchanged, with maximum and minimum slip occurring in the same zones, and overall displacement decreasing almost linearly along the same, long portions of the faults. Growth mainly implied an increase of the maximum displacement (d) over fault length (l) ratio (r=d/l). At a more detailed level, the 6 ka slip profiles show first and second-order irregularities which match those previously detected in the cumulative profiles and interpreted to be connected fault segments. Results suggest that normal faults grow by alternating phases of slip accumulation and lateral propagation. During a first phase, a fault accumulates displacement without increasing in length, from a stage when r is minimum (rmin) to an ultimate stage when r reaches a maximum threshold (rmax; both values previously determined from data). As its length does not increase, the fault may produce characteristic earthquakes. When rmax is reached, the fault starts lengthening, hence propagating, so that r decreases possibly down to rmin. Then, the fault starts again accumulating displacement. The rmin and rmax values determined so far imply that, during its propagation phase, a fault is likely to increase its length by a factor of ~4. They also imply that A4 and A21 are both able to accumulate displacement without propagating for ~25 ka. This makes A21 being currently accumulating slip, whereas A4 is just starting propagating, as previously shown from other evidence. Ref : Manighetti et al., JGR, July 2001

  8. Computational intelligence applied to the growth of quantum dots

    NASA Astrophysics Data System (ADS)

    Singulani, Anderson P.; Vilela Neto, Omar P.; Aurélio Pacheco, Marco C.; Vellasco, Marley B. R.; Pires, Maurício P.; Souza, Patrícia L.

    2008-11-01

    We apply two computational intelligence techniques, namely, artificial neural network and genetic algorithm to the growth of self-assembled quantum dots. The method relies on an existing database of growth parameters with a resulting quantum dot characteristic to be able to later obtain the growth parameters needed to reach a specific value for such a quantum dot characteristic. The computational techniques were used to associate the growth input parameters with the mean height of the deposited quantum dots. Trends of the quantum dot mean height behavior as a function of growth parameters were correctly predicted and the growth parameters required to minimize the quantum dot mean height were provided.

  9. Channel Morphodynamics in Four Reaches of the Lower Missouri River, 2006-07

    USGS Publications Warehouse

    Elliott, Caroline M.; Reuter, Joanna M.; Jacobson, Robert B.

    2009-01-01

    Channel morphodynamics in response to flow modifications from Gavins Point Dam are examined in four reaches of the Lower Missouri River. Measures include changes in channel morphology and indicators of sediment transport in four 6 kilometer long reaches located downstream from Gavins Point Dam, near Yankton, South Dakota, Kenslers Bend, Nebraska, Little Sioux, Iowa, and Miami, Missouri. Each of the four reaches was divided into 300 transects with a 20-meter spacing and surveyed during the summer in 2006 and 2007. A subset of 30 transects was randomly selected and surveyed 7-10 times in 2006-07 over a wide range of discharges including managed and natural flow events. Hydroacoustic mapping used a survey-grade echosounder and a Real Time Kinematic Global Positioning System to evaluate channel change. Acoustic Doppler current profiler measurements were used to evaluate bed-sediment velocity. Results indicate varying amounts of deposition, erosion, net change, and sediment transport in the four Lower Missouri River reaches. The Yankton reach was the most stable over monthly and annual time-frames. The Kenslers Bend and Little Sioux reaches exhibited substantial amounts of deposition and erosion, although net change was generally low in both reaches. Total, or gross geomorphic change was greatest in the Kenslers Bend reach. The Miami reach exhibited varying rates of deposition and erosion, and low net change. The Yankton, Kenslers Bend, and Miami reaches experienced net erosion during the time period that bracketed the managed May 2006 spring rise event from Gavins Point Dam.

  10. Growth chart

    MedlinePLUS

    Height and weight chart ... Growth charts are used to compare your child's height, weight, and head size against children of the ... From these numbers, the national average weight and height for each age and gender were established. The ...

  11. Growth and Yield of Giant Sequoia1 David J. Dulitz 2

    E-print Network

    Standiford, Richard B.

    Growth and Yield of Giant Sequoia1 David J. Dulitz 2 Abstract: Very little information exists concerning growth and yield of giant sequoia (Sequoiadendron giganteum [Lindl.] Buchholz). For old-growth trees, diameter growth is the single factor adding increment since maximum height has been obtained

  12. Setting and Reaching Targets with Computer-Assisted Cochlear Implant Fitting

    PubMed Central

    Szlávik, Zoltán; Buechner, Andreas; Govaerts, Paul J.

    2014-01-01

    Objective. The paper aims to demonstrate the feasibility of defining a substantial set of psychoacoustic outcome measures with preset targets and to adopt a systematic methodology for reaching these targets in a large group of subjects, by more than one clinical centre. Design. Retrospective data analysis. Setting. Multicentre with 14 participating centres. Patients. 255 adults and children using the Advanced Bionics HiRes90k cochlear implant. Intervention. Target driven fitting with the fitting to outcomes expert (FOX) system. Main Outcome Measures. For each patient, 66 measurable psychoacoustical outcomes were recorded several times after cochlear implantation: free field audiometry (6 measures) and speech audiometry (4), spectral discrimination (20), and loudness growth (36), defined from the A§E test battery. These outcomes were reduced to 22 summary variables. The initial results were compared with the latest results. Results. The state of the fitting process could be well monitored by means of the measured variables. The use of the FOX computer assisted CI-programming significantly improved the proportion of the 22 variables on target. When recipients used the automated MAPs provided at switch-on, more than half (57%) of the 22 targets were already achieved before any further optimisation took place. Once the FOX system was applied there was a significant 24% (P < 0.001) increase in the number of targets achieved. Conclusions. This study demonstrates that it is feasible to set targets and to report on the effectiveness of a fitting strategy in terms of these targets. FOX provides an effective tool for achieving a systematic approach to programming, allowing for better optimisation of recipients' MAPs. The setting of well-defined outcome targets allowed a range of different centres to successfully apply a systematic methodology to monitoring the quality of the programming provided. PMID:24757428

  13. Spatial location and pathway memory compared in the reaching vs. walking domains.

    PubMed

    Piccardi, L; Bianchini, F; Nori, R; Marano, A; Iachini, F; Lasala, L; Guariglia, C

    2014-04-30

    Spatial information processing is influenced by the space in which an individual acts and the nature of the stimulus. This distinction is also present in spatial memory, where stimuli are processed differently because of their nature and the space in which they are released. The aim of the present study was to compare college students' performance on spatial location and pathway memory tasks in two different domains (reaching and walking). Reaching space refers to the portion of space within "grasping distance" and walking space to that beyond arm's reach. Research results indicate that it is easier to remember a pathway in the walking than the reaching domain and to remember single spatial locations in the reaching domain. Women are more able to perform the task in the walking domain than the reaching domain and men perform equally well in both domains. PMID:24631564

  14. Does use of a virtual environment change reaching while standing in patients with traumatic brain injury?

    PubMed Central

    2013-01-01

    Background Although numerous virtual reality applications have been developed for sensorimotor retraining in neurologically impaired individuals, it is unclear whether the virtual environment (VE) changes motor performance, especially in patients with brain injuries. To address this question, the movement characteristics of forward arm reaches during standing were compared in physical and virtual environments, presented at different viewing angles. Methods Fifteen patients with traumatic brain injuries (TBI) and 15 sex- and age-matched healthy individuals performed virtual reaches in a computer-generated courtyard with a flower-topped hedge. The hedge was projected on a flat screen and viewed in 3D format in 1 of 3 angles: 10° above horizon (resembling a real-world viewing angle), 50° above horizon, or 90° above horizon (directly overhead). Participants were instructed to reach with their dominant hand avatar and to touch the farthest flower possible without losing their balance or stepping. Virtual reaches were compared with reaches-to-point to a target in an equivalent physical environment. A set of kinematic parameters was used. Results Reaches by patients with TBI were characterized by shorter distances, lower peak velocities, and smaller postural displacements than reaches by control individuals. All participants reached ~9% farther in the VE presented at a 50° angle than they did in the physical environment. Arm displacement in the more natural 10° angle VE was reduced by the same 9-10% compared to physical reaches. Virtual reaches had smaller velocity peaks and took longer than physical reaches. Conclusion The results suggest that visual perception in the VE differs from real-world perception and the performance of functional tasks (e.g., reaching while standing) can be changed in TBI patients, depending on the viewing angle. Accordingly, the viewing angle is a critical parameter that should be adjusted carefully to achieve maximal therapeutic effect during practice in the VE. PMID:23866962

  15. Testing the Growth Rate Hypothesis in Vascular Plants with Above- and Below-Ground Biomass

    PubMed Central

    Yu, Qiang; Wu, Honghui; He, Nianpeng; Lü, Xiaotao; Wang, Zhiping; Elser, James J.; Wu, Jianguo; Han, Xingguo

    2012-01-01

    The growth rate hypothesis (GRH) proposes that higher growth rate (the rate of change in biomass per unit biomass, ?) is associated with higher P concentration and lower C?P and N?P ratios. However, the applicability of the GRH to vascular plants is not well-studied and few studies have been done on belowground biomass. Here we showed that, for aboveground, belowground and total biomass of three study species, ? was positively correlated with N?C under N limitation and positively correlated with P?C under P limitation. However, the N?P ratio was a unimodal function of ?, increasing for small values of ?, reaching a maximum, and then decreasing. The range of variations in ? was positively correlated with variation in C?N?P stoichiometry. Furthermore, ? and C?N?P ranges for aboveground biomass were negatively correlated with those for belowground. Our results confirm the well-known association of growth rate with tissue concentration of the limiting nutrient and provide empirical support for recent theoretical formulations. PMID:22427823

  16. The structure and regulation of expression of the mouse growth hormone receptor and binding protein

    SciTech Connect

    Talamantes, F. [Univ. of California, Santa Cruz, CA (United States)

    1994-12-31

    The mouse growth hormone receptor (mGHR) and the mouse growth hormone-binding protein (mGHBP) are products of a single gene which are generated alternative splicing. The factors that regulate the expression of mGHR and mGHBP mRNA and protein during pregnancy in the mouse are incompletely understood. During pregnancy in the mouse, there are parallel increases in circulating mouse growth hormone (mGH), liver mGHR, and serum mGHBP. The increase in both hepatic mGHR and serum mGHBP begins on Day 9 of gestation and by late gestation the hepatic mGHR content has increased 8-fold and serum mGHBP has increased 30-fold compared with values in nonpregnant controls. A parallel increase occurs in the steady state levels of liver GHR and GHBP encoding mRNAs. The increase in both messages begins on Day 9 of gestation; however, the GHR mRNA reaches maximum levels by Day 13, while the GHBP mRNA continues to increase until the end of pregnancy. The magnitude of the increase in the GHR-encoding message is 15- to 20-fold between nonpregnant and late pregnant mice, and the magnitude of the increase in the GHBP-encoding message is 30- to 50-fold. Both pituitary mGH and the number of conceptuses influence the receptors and binding protein for mGH during pregnancy. 22 refs.

  17. Changes in Polyamine Biosynthesis Associated with Postfertilization Growth and Development in Tobacco Ovary Tissues 1

    PubMed Central

    Slocum, Robert D.; Galston, Arthur W.

    1985-01-01

    Polyamine (PA) titers and the activities of arginine decarboxylase (ADC, EC 4.1.1.19) and ornithine decarboxylase (ODC, EC 4.1.1.17), enzymes which catalyze rate-limiting steps in PA biosynthesis, were monitored during tobacco ovary maturation. In the period between anthesis and fertilization, the protein content of ovary tissues rapidly increased by about 40% and was accompanied by approximately a 3-fold increase in ODC activity, while ADC activity remained nearly constant. PA titers also remained relatively unchanged until fertilization, at which time they increased dramatically and the DNA content of ovary tissues doubled. This increase in PA biosynthesis was correlated with a further 3-fold increase in ODC activity, reaching a maximum 3 to 4 days after fertilization. During this time, ADC activity increased only slightly and accounted for approximately 1% of the total decarboxylase activity when ODC activity peaked. The postfertilization burst of biosynthetic activities slightly preceded a period of rapid ovary enlargement, presumably due to new cell division. During later stages of ovary development, DNA levels fell precipitously, while PA titers and decarboxylase activities decreased to preanthesis levels more slowly. In this period, growth producing a 300% increase in ovary fresh weight appears to be the result of cell enlargement. Synchronous changes in PA titers and in the rates of PA biosynthesis, macromolecular synthesis, and growth in the tobacco ovary suggest that PAs may play a role in the regulation of postfertilization growth and development of this reproductive organ. Images Fig. 1 PMID:11540835

  18. A model based on bootstrapped neural networks for computing the maximum fuel cladding temperature in an Rmbk-1500 nuclear reactor accident

    Microsoft Academic Search

    F. Cadini; E. Zio; V. Kopustinskas; R. Urbonas

    2008-01-01

    The present paper illustrates the use of artificial neural networks for computing the maximum fuel cladding temperature reached during a complete group distribution blockage scenario in an RBMK-1500 nuclear reactor. The uncertainties associated to the neural predictions are quantified by resorting to the bootstrap technique. The trained neural networks are further used to perform a sensitivity analysis aimed at identifying

  19. Reaching Girls

    ERIC Educational Resources Information Center

    Jacobs, Charlotte E.; Kuriloff, Peter J.; Cox, Amanda B.

    2014-01-01

    If educators want to engage girls in learning, they must align teaching practices with girls' specific needs. In a study modeled after Reichert and Hawley's study of boys, the authors learned that lessons with hands-on learning, elements of creativity, multimodal projects, and class discussions all worked to stimulate girls'…

  20. Global Reach

    ERIC Educational Resources Information Center

    Brown, Carol; Halder, John; Woodin, Shawn

    2010-01-01

    One Indonesian student first learned of the program while working as a street vendor selling handicrafts in Jakarta. Today, she works for a television station in her native country as a newsperson and anchor. Another student was so impressed and gratified by his good fortune that he designed, promoted, and raised funds for a peace statue to erect…

  1. Reaching Heather.

    ERIC Educational Resources Information Center

    Deojay, Trisia R.; Pennington, Lynn LeLoup

    2000-01-01

    A three-step framework to help teachers examine and modify teaching practice based on data analysis includes: specify current levels of student performance, create action plans, and evaluate and communicate progress. A case study of a teacher who used the framework to pinpoint one student's writing problems, create change in practice, and assess…

  2. Reach Out

    ERIC Educational Resources Information Center

    Neuringer, Allen

    2011-01-01

    The experimental analysis of behavior (EAB) is in trouble. Financial support for basic operant-conditioning research is difficult to obtain; teaching and research positions in colleges and universities are few; and bright undergraduates join other fields for graduate study. One reason for the difficulty is that EAB basic research does not focus…

  3. Cerebellar inactivation impairs memory of learned prism gaze-reach calibrations

    PubMed Central

    Hathaway, Emily N.; Taylor, Jordan A.; Thach, W. Thomas

    2011-01-01

    Three monkeys performed a visually guided reach-touch task with and without laterally displacing prisms. The prisms offset the normally aligned gaze/reach and subsequent touch. Naive monkeys showed adaptation, such that on repeated prism trials the gaze-reach angle widened and touches hit nearer the target. On the first subsequent no-prism trial the monkeys exhibited an aftereffect, such that the widened gaze-reach angle persisted and touches missed the target in the direction opposite that of initial prism-induced error. After 20–30 days of training, monkeys showed long-term learning and storage of the prism gaze-reach calibration: they switched between prism and no-prism and touched the target on the first trials without adaptation or aftereffect. Injections of lidocaine into posterolateral cerebellar cortex or muscimol or lidocaine into dentate nucleus temporarily inactivated these structures. Immediately after injections into cortex or dentate, reaches were displaced in the direction of prism-displaced gaze, but no-prism reaches were relatively unimpaired. There was little or no adaptation on the day of injection. On days after injection, there was no adaptation and both prism and no-prism reaches were horizontally, and often vertically, displaced. A single permanent lesion (kainic acid) in the lateral dentate nucleus of one monkey immediately impaired only the learned prism gaze-reach calibration and in subsequent days disrupted both learning and performance. This effect persisted for the 18 days of observation, with little or no adaptation. PMID:21389311

  4. The wide reach of enzymology: from bioorganic chemistry to chemical biology and beyond Mechanisms

    E-print Network

    Herschlag, Dan

    The wide reach of enzymology: from bioorganic chemistry to chemical biology and beyond Mechanisms perspectives, opportunities and approaches. How fitting that enzymology, the vital component of bioorganic

  5. Dry Stream Reaches in Carbonate Terranes: Surface Indicators of Ground-Water Reservoirs

    USGS Publications Warehouse

    Brahana, J.V.; Hollyday, E.F.

    1988-01-01

    In areas where dry stream reaches occur, subsurface drainage successfully competes with surface drainage, and sheet-like dissolution openings have developed parallel to bedding creating the ground-water reservoir. Union Hollow in south-central Tennessee is the setting for a case study that illustrates the application of the dry stream reach technique. In this technique, dry stream reach identification is based on two types of readily acquired information: remotely sensed black and white infrared aerial photography; and surface reconnaissance of stream channel characteristics. Test drilling in Union Hollow subsequent to identification of the dry reach proved that a localized ground-water reservoir was present.

  6. Biofilm growth mode promotes maximum carrying capacity and community stability during product inhibition syntrophy.

    PubMed

    Brileya, Kristen A; Camilleri, Laura B; Zane, Grant M; Wall, Judy D; Fields, Matthew W

    2014-01-01

    Sulfate-reducing bacteria (SRB) can interact syntrophically with other community members in the absence of sulfate, and interactions with hydrogen-consuming methanogens are beneficial when these archaea consume potentially inhibitory H2 produced by the SRB. A dual continuous culture approach was used to characterize population structure within a syntrophic biofilm formed by the SRB Desulfovibrio vulgaris Hildenborough and the methanogenic archaeum Methanococcus maripaludis. Under the tested conditions, monocultures of D. vulgaris formed thin, stable biofilms, but monoculture M. maripaludis did not. Microscopy of intact syntrophic biofilm confirmed that D. vulgaris formed a scaffold for the biofilm, while intermediate and steady-state images revealed that M. maripaludis joined the biofilm later, likely in response to H2 produced by the SRB. Close interactions in structured biofilm allowed efficient transfer of H2 to M. maripaludis, and H2 was only detected in cocultures with a mutant SRB that was deficient in biofilm formation (?pilA). M. maripaludis produced more carbohydrate (uronic acid, hexose, and pentose) as a monoculture compared to total coculture biofilm, and this suggested an altered carbon flux during syntrophy. The syntrophic biofilm was structured into ridges (?300 × 50 ?m) and models predicted lactate limitation at ?50 ?m biofilm depth. The biofilm had structure that likely facilitated mass transfer of H2 and lactate, yet maximized biomass with a more even population composition (number of each organism) when compared to the bulk-phase community. Total biomass protein was equivalent in lactate-limited and lactate-excess conditions when a biofilm was present, but in the absence of biofilm, total biomass protein was significantly reduced. The results suggest that multispecies biofilms create an environment conducive to resource sharing, resulting in increased biomass retention, or carrying capacity, for cooperative populations. PMID:25566209

  7. Diversifying Supervision for Maximum Professional Growth: Is a Well-Supervised Teacher a Satisfied Teacher?

    ERIC Educational Resources Information Center

    Robinson, Sylvia G.

    This paper examines the relationship between various characterizations of the clinical supervision model and teacher job satisfaction. The first part of the paper describes teacher job satisfaction and looks at the history and meaning of clinical supervision. The next part of the paper describes Barbara Pavan's (1993) revised clinical supervision…

  8. Sound Off: The Myth of Differentiation in Mathematics--Providing Maximum Growth

    ERIC Educational Resources Information Center

    O'Roark, Jason Lee

    2013-01-01

    After serving as a high school math teacher in Maryland for three years, the author moved to teaching sixth-grade math. His high school background led him to differentiate differently than his colleagues. The article discusses his observations and his conclusions and offers a plan to implement changes in the way mathematics is taught through…

  9. High pressure synthesis gas conversion. Task 2: Determination of maximum operating pressure

    SciTech Connect

    Not Available

    1993-05-01

    The purpose of this research project was to build and test a high pressure fermentation system for the production of ethanol from synthesis gas. The fermenters, pumps, controls, and analytical system were procured or fabricated and assembled in our laboratory. This system was then used to determine the effects of high pressure on growth and ethanol production by C. ljungdahlil. The limits of cell concentration and mass transport relationships were found in CSTR and immobilized cell reactors (ICR). The minimum retention times and reactor volumes were found for ethanol production in these reactors. The purpose of this report was to present the results of high pressure experiments aimed at determining the maximum operating pressure of C. ljungdahlil. Preliminary experiments carried out in approaching the pressure maximum are presented, as well as experimental results at the maximum pressure of 150 psig. This latter pressure was the maximum operating pressure when using the defined medium of Phillips et al., and is expected to change if alternative media are employed.

  10. Self-Assembled Wiggling Nano-Structures and the Principle of Maximum Entropy Production

    PubMed Central

    Belkin, A.; Hubler, A.; Bezryadin, A.

    2015-01-01

    While behavior of equilibrium systems is well understood, evolution of nonequilibrium ones is much less clear. Yet, many researches have suggested that the principle of the maximum entropy production is of key importance in complex systems away from equilibrium. Here, we present a quantitative study of large ensembles of carbon nanotubes suspended in a non-conducting non-polar fluid subject to a strong electric field. Being driven out of equilibrium, the suspension spontaneously organizes into an electrically conducting state under a wide range of parameters. Such self-assembly allows the Joule heating and, therefore, the entropy production in the fluid, to be maximized. Curiously, we find that emerging self-assembled structures can start to wiggle. The wiggling takes place only until the entropy production in the suspension reaches its maximum, at which time the wiggling stops and the structure becomes quasi-stable. Thus, we provide strong evidence that maximum entropy production principle plays an essential role in the evolution of self-organizing systems far from equilibrium. PMID:25662746

  11. States of Maximum Entropy Production In One-dimensional Vertical Climate Models

    NASA Astrophysics Data System (ADS)

    Pujol, T.

    Although the maximum entropy principle (MEP) has been examined by several au- thors in a variety of climate models, only Ozawa and Ohmura (1997) have explicitly analysed the MEP in a one-dimensional (1-D) radiative-convective model (RCM). Here we extend Ozawa and Ohmura's analyses by using two different 1-D RCMs. The first model parameterises the convective fluxes following the mixing length the- ory, from which the eddy thermal diffusion coefficient is chosen to produce the max- imum entropy generation. The value for the eddy thermal diffusion coefficient for a fixed vertical profile of specific humidity (as in Ozawa and Ohmura, 1997) agrees well with that expected for air in stirred conditions. However, the MEP fails when the vertical profile of relative humidity is fixed (i.e., when the water vapor - temperature feedback is included). The second model is much more realistic since we assume that convective processes sustain a critical lapse rate in the troposphere. Thus, the atmo- sphere is divided into a lower convective region with a prescribed lapse rate and an upper radiative-equilibrium region. The surface boundary layer velocity predicted by the MEP appears reasonable. However the discontinuity of temperatures at the surface is too large (10 K). In addition, the convective flux reaches a maximum value for an optical thickness similar to current conditions. This additional result may support the maximum convection hypothesis suggested by Paltridge (1978).

  12. Maximum Likelihood, Profile Likelihood, and Penalized Likelihood: A Primer

    PubMed Central

    Cole, Stephen R.; Chu, Haitao; Greenland, Sander

    2014-01-01

    The method of maximum likelihood is widely used in epidemiology, yet many epidemiologists receive little or no education in the conceptual underpinnings of the approach. Here we provide a primer on maximum likelihood and some important extensions which have proven useful in epidemiologic research, and which reveal connections between maximum likelihood and Bayesian methods. For a given data set and probability model, maximum likelihood finds values of the model parameters that give the observed data the highest probability. As with all inferential statistical methods, maximum likelihood is based on an assumed model and cannot account for bias sources that are not controlled by the model or the study design. Maximum likelihood is nonetheless popular, because it is computationally straightforward and intuitive and because maximum likelihood estimators have desirable large-sample properties in the (largely fictitious) case in which the model has been correctly specified. Here, we work through an example to illustrate the mechanics of maximum likelihood estimation and indicate how improvements can be made easily with commercial software. We then describe recent extensions and generalizations which are better suited to observational health research and which should arguably replace standard maximum likelihood as the default method. PMID:24173548

  13. Maximum range three-dimensional lifting planetary entry

    NASA Technical Reports Server (NTRS)

    Dickmanns, E. D.

    1972-01-01

    Variational equations for maximum range three-dimensional quasisteady glide are given. Nonlinear oscillatory maximum range trajectories obtained with a refined gradient program are approximated by a superposition of quasisteady glide and linearized perturbation equation results. A basic control law is found which is closely followed for maximum cross-range trajectories. The effect of a reradiative heating constraint involving velocity, altitude and angle of attack on a maximum cross-range trajectory for a space shuttle orbiter-type vehicle reentering the earth's atmosphere is investigated numerically.

  14. Individual Module Maximum Power Point Tracking for Thermoelectric Generator Systems

    E-print Network

    Schaltz, Erik

    Individual Module Maximum Power Point Tracking for Thermoelectric Generator Systems Casper Vadstrup of Thermo Electric Generator (TEG) systems a power converter is often inserted between the TEG system

  15. Poisson growth

    NASA Astrophysics Data System (ADS)

    McDonald, Robb; Mineev-Weinstein, Mark

    2015-06-01

    The two-dimensional free boundary problem in which the field is governed by Poisson's equation and for which the velocity of the free boundary is given by the gradient of the field—Poisson growth—is considered. The problem is a generalisation of classic Hele-Shaw free boundary flow or Laplacian growth problem and has many applications. In the case when the right hand side of Poisson's equation is constant, a formulation is obtained in terms of the Schwarz function of the free boundary. From this it is deduced that solutions of the Laplacian growth problem also satisfy the Poisson growth problem, the only difference being in their time evolution. The corresponding moment evolution equations, a Polubarinova-Galin type equation and a Baiocchi-type transformation for Poisson growth are also presented. Some explicit examples are given, one in which cusp formation is inhibited by the addition of the Poisson term, and another for a growing finger in which the Poisson term selects the width of the finger to be half that of the channel. For the more complicated case when the right hand side is linear in one space direction, the Schwarz function method is used to derive an exact solution describing a translating circular blob with changing radius.

  16. A generalization of Pontryagin's maximum principle for dynamic evolutionary games among relatives.

    PubMed

    Day, T; Taylor, P D

    2000-06-01

    We present two theorems that generalize Pontryagin's maximum principle to the setting of dynamic evolutionary games between genetically related individuals. The two theorems correspond to two types of interactions among individuals: patch-structured populations in which individuals locally "play the field" and pairwise interactions. These generalizations can be used in the same way that Pontryagin's maximum principle is used and they are valid for diploid organisms under a single locus, diallelic genetic model. These generalizations involve an interesting, dynamic version of Hamilton's Rule from inclusive fitness theory. We illustrate how these theoretical results can be applied by modeling the evolution of lifetime resource allocation to growth and reproduction in an annual plant when there is competition for resources among related individuals. PMID:10900187

  17. Reaching during virtual rotation: context specific compensations for expected coriolis forces

    NASA Technical Reports Server (NTRS)

    Cohn, J. V.; DiZio, P.; Lackner, J. R.

    2000-01-01

    Subjects who are in an enclosed chamber rotating at constant velocity feel physically stationary but make errors when pointing to targets. Reaching paths and endpoints are deviated in the direction of the transient inertial Coriolis forces generated by their arm movements. By contrast, reaching movements made during natural, voluntary torso rotation seem to be accurate, and subjects are unaware of the Coriolis forces generated by their movements. This pattern suggests that the motor plan for reaching movements uses a representation of body motion to prepare compensations for impending self-generated accelerative loads on the arm. If so, stationary subjects who are experiencing illusory self-rotation should make reaching errors when pointing to a target. These errors should be in the direction opposite the Coriolis accelerations their arm movements would generate if they were actually rotating. To determine whether such compensations exist, we had subjects in four experiments make visually open-loop reaches to targets while they were experiencing compelling illusory self-rotation and displacement induced by rotation of a complex, natural visual scene. The paths and endpoints of their initial reaching movements were significantly displaced leftward during counterclockwise illusory rotary displacement and rightward during clockwise illusory self-displacement. Subjects reached in a curvilinear path to the wrong place. These reaching errors were opposite in direction to the Coriolis forces that would have been generated by their arm movements during actual torso rotation. The magnitude of path curvature and endpoint errors increased as the speed of illusory self-rotation increased. In successive reaches, movement paths became straighter and endpoints more accurate despite the absence of visual error feedback or tactile feedback about target location. When subjects were again presented a stationary scene, their initial reaches were indistinguishable from pre-exposure baseline, indicating a total absence of aftereffects. These experiments demonstrate that the nervous system automatically compensates in a context-specific fashion for the Coriolis forces associated with reaching movements.

  18. Polyhydroxyalkanoate inclusion-body growth and proliferation in Bacillus megaterium

    Microsoft Academic Search

    Gabriel J. McCool; Tania Fernandez; Ning Li; Maura C. Cannon

    1996-01-01

    Polyhydroxyalkanoate (PHA) accumulation and the morphology of PHA inclusion bodies were examined in Bacillus megaterium, strain 11561. Our results show a pattern of PHA degradation and synthesis, and of inclusion body growth and proliferation not previously reported. Degradation of PHA in the lag phase was followed by synthesis of PHA at an accelerating rate during exponential growth. PHA accumulation reached

  19. Modelling and predicting the simultaneous growth of Listeria monocytogenes and psychrotolerant lactic acid bacteria in processed seafood and mayonnaise-based seafood salads.

    PubMed

    Mejlholm, Ole; Dalgaard, Paw

    2015-04-01

    A new combined model for Listeria monocytogenes and psychrotolerant Lactobacillus spp. was constructed and evaluated for processed seafood and mayonnaise-based seafood salads. The new model was constructed by combining existing cardinal parameter models for L. monocytogenes and Lactobacillus spp. using the classical Jameson effect to model microbial interaction. Maximum population density (MPD) values of L. monocytogenes were accurately predicted in processed seafood with a known initial cell concentration of Lactobacillus spp. For these experiments, average MPD values of 4.5 and 4.3 log (cfu/g) were observed and predicted, respectively for L. monocytogenes. In seafood salads, growth of L. monocytogenes continued at a reduced growth rate after Lactobacillus sakei had reached their MPD. This growth pattern was successfully described by an expanded version of the classical Jameson effect model, but only for products with pH of 6.0 or higher. For seafood salads with pH below 6.0 the performance of the new model was unacceptable, primarily due to prediction of no-growth by L. monocytogenes when growth was actually observed. Within its range of applicability the new model can be valuable for risk assessment and risk management of processed seafood as well as for evaluating the compliance of products with the EU regulation for ready-to-eat foods. PMID:25475260

  20. Grazing by meso- and microzooplankton on phytoplankton in the upper reaches of the Schelde estuary (Belgium/The Netherlands)

    NASA Astrophysics Data System (ADS)

    Lionard, M.; Azémar, F.; Boulêtreau, S.; Muylaert, K.; Tackx, M.; Vyverman, W.

    2005-09-01

    In contrast with the marine reaches of estuaries, few studies have dealt with zooplankton grazing on phytoplankton in the upper estuarine reaches, where freshwater zooplankton species tend to dominate the zooplankton community. In spring and early summer 2003, grazing by micro- and mesozooplankton on phytoplankton was investigated at three sites in the upper Schelde estuary. Grazing by mesozooplankton was evaluated by monitoring growth of phytoplankton in 200 ?m filtered water in the presence or absence of mesozooplankton. In different experiments, the grazing impact was tested of the calanoïd copepod Eurytemora affinis, the cyclopoid copepods Acanthocyclops robustus and Cyclops vicinus and the cladocera Chydorus sphaericus, Moina affinis and Daphnia magna/ pulex. No significant grazing impact of mesozooplankton in any experiment was found despite the fact that mesozooplankton densities used in the experiments (20 or 40 ind. l -1) were higher than densities in the field (0.1-6.9 ind. l -1). Grazing by microzooplankton was evaluated by comparing growth of phytoplankton in 30 and 200 ?m filtered water. Microzooplankton in the 30-200 ?m size range included mainly rotifers of the genera Brachionus, Trichocerca and Synchaeta, which were present from 191 to 1777 ind. l -1. Microzooplankton had a significant grazing impact in five out of six experiments. They had a community grazing rate of 0.41-1.83 day -1 and grazed up to 84% of initial phytoplankton standing stock per day. Rotifer clearance rates estimated from microzooplankton community grazing rates and rotifer abundances varied from 8.3 to 41.7 ?l ind. -1 h -1. CHEMTAX analysis of accessory pigment data revealed a similar phytoplankton community composition after incubation with and without microzooplankton, indicating non-selective feeding by rotifers on phytoplankton.